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| LOGICAL MAGAZINE oo 

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THE 


GEOLOGICAL MAGAZINE 


Monthly Hournal of Geology. 
Wi!tH WHICH IS INCORPORATED 
THE GHREOLOGIST. 


NOS. DCXLIII) TO DCLIV. 


EDITED BY 
Pe MEW OOM IW GAURDE: iG. ROR SM Guiske Ey vi Ss 


LATE OF THE BRITISH MUSEUM OF NATURAL HISTORY; PRESIDENT OF THE 
PALZEONTOGRAPHICAL SOCIETY 5; ETC. 


Prorressor J. W. GREGORY, D:Sc., F.R.S., F.G.S. 
SRE EE OTANI KC Sule KCK Di Sex ROS nh Gas: 
Prorsssor J. E. MARR, M.A., Sc.D. (Camb.), F.R.S., F.G.S. 
siz JETHRO THALL, M-A., Sc.D. (Camb.), LL.D., F.R.S., V-P.G.S. 
EXGnEssoReW I Wie WALES: ScoDs qi EoD.) Muse: ORS. GS. 
De ARTHUR SMITE WOODWARD, LLD F.R:S.; PL:S., 
F.G.S. 


NEW SHRIHS. DECADE VIL VOL. V_ 


JANUARY—DECEMBER, 1918. 


PNG iol ah 
LONDON: 


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PLATE 


It 
Noe 


I. 
IV. 
v. 


XV. 
XVI. 
XVII. 
XVIII. 
XIX. 


JLMTSHE Ou) Jelbye uals), 


FACING PAGE 


Chalk Polyzoa : : : : : 5 ; t 4 


Interior of Peristome in Conuwlopsis, Hchinocorys, and Echino- 
ence 


Casts of Shells from the Suffolk Boxstones j : 5 ay 20. 


cardvum 


ae » » 30 2 ¢ 6) all 
Hocystis prumeva, Hartt . : : : : ; ; 5 oS 
Chalk Polyzoa é 5 : 6 : c : 9 - 100 
Land-forms, Carnaryonshire . : : : s A ors 
Tertiary Foraminifera, New Guinea . ¢ : : ; 5 Pla 

2 05) sh peed teaean OV Sans ann east a Gn 
George J. Hinde, F.R.S. . ; : 6 ‘ 4 , 5) 33s} 
Leicestershire Dolomites . é : : ; : 9 - 258 
G. W. Lamplugh, F.R.S. : é : : . 5 9) eat, 
Leaves of Noeggerathiopsis ; 3 ; é : : 292, 
Great Erratic of Andesite, New Zealand . ; é : 5 BOT 
1B in Newell Arber, M.A., Sc.D. . He A is Bs aie: PAG) 
British Carboniferous Goniatites ; 6 é : : . 450 


Post-Larval Stages in Irregular Echinoidea ; 5 : . 500 
Basic Intrusions in Radnorshire 3 : . : ; . 502 


Diabase intruded into Llandovery Limestone . 6 : . 504 


LIST OF ILLUSTRATIONS IN THE TEXT. 


PAGE 
Diagrams of perignathie girdle in Plesiechuis, ete. ; : : Ul 
Diagram showing lines of mechanical stress Dan of Hoey ets plan 
of plate . : : f : : ait ieee 
Diagram map of §.W. aneolnenive. saGuine Nation of exposures i O4 
Hydraulic limestones of Owthorpe and Cotgrave Gorse . ; ; BO: 
Transition bed and Middle Lias of Lincoln . : 105 
Middle and Upper Lias of Yorkshire, Lincolnshire, and } Nena tonetne 109 
Diagram of Northampton Sands and Upper Lias_ . : : : 3 TAG 
Sections of Newark District, Nottinghamshire é : : ¢ 2) 22 
Profile of land surface near Tregarth : : > : . a) ALSO) 
“*Pliocene’’ plateau near Bangor . : é : : : : . 154 
Shell-fragments deseribed as Cirripede valves . : : : : 3 
Drawing of deer from cavern of a Pefia : : 5 . : . 173 
George Jennings Hinde, F.R.S. . : \ : : : ; + 236 
Map of Leicestershire dolomites . 5 : é 5 : : . 252 
Bouchardia minvuna, Thomson . 5 : : A : ; . 260 
Phreatoicus australis, Chilton i 3 : : ; p : 278 
Phreatoicus wianamattensis, Chilton . ; : ; i : a Bag) 
Map of part of the London Basin . c : a ASKS: 
Map showing contours of Sub-Hocene and Sie Bien Chalk : ea 02 
Section across part of the London Basin 3 j j : : . 304 
Map of principal ‘dry ’’ lakes, Western Australia . : j } 3 UY 
Locality map of southern portion of Western Australia . é ‘ 4 Bul) 
“Downend Chalk Pit’? on Gallows Hill, Isle of Wight . : F 5) B58} 
William Lower Carter, M.A., F.G.S. |. ; 3 i A ; 5 ase 
Map of Western Ausiralia.. : s ‘ : . 386 
Sketch-section of the Darling Range, eon Mastin ; 3 4) BIS)IL 
Sketch-map of Lenham Bed, Diestien Sands, Louvain . : ‘ . 41L 
Map showing Chalk surface contours, Hast Anglia . ‘ 2 Y . 414 
Calcite cleavage . tl : f i , . 424 
Crustacean tracks in } New vediena Mertianies ‘ : : : . 425 
Anthracomya arenacea, Dawson . : 5 5 : f : - 465 
Huproops Amie, H. Woodw., sp. nov. . ‘ . : 3 : . 466 
Head-shields of Huproops Amie, H. Woodw. 4 : : : . 467 
Bellinurus Trechmanni, H. Woodw., sp. nov. ; ; d t mae Asiale 
Section of nodule showing plant-tissues . : 2 : : 5 . 472 
Yunnan Cystidea . ‘ : : 4 Fi : } 508, 509, 534, 535 
Hyana salonice, n.sp. . 5 A i ; 4 4 Sy Syl 
Map showing mineral resources of iduivalia 545 


» 


- Prornssor J. Wi 
Dr. 


[AS H. HOLLAND, K.C.LE. A.R.OS., D.Sc. 
M.A., Sc.D. 
HALL, M.A. Sc.D. (CAms.), 


‘OF EDWARD M ARR, 
ETHRO JES 


on W. W. WATTS, Sc.D. (CAmB.), 
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“ JANUARY, 1918. 


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EDITED BY 
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LL.D., ABS E.G.S. 
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8 GG IN a eT oS 


1. Oniginan ARTICLES. 

d “imperfectly known Cre- 

eae Byaeines NE: 
ae T Ty 


Saale 
(Plate II.) 
suffolk Boxstones. By ALFRED 
LL. (Plates IL and IV.)....,. 
@, Norite of the Sierra Leone. 


Police 


PG. Si; University. of Stellen 
ch, South Africa 


eh. Novices oF MEMOIRS. 


Geolovieal Structure of the 


‘orest of Dean. By Professor 
; oe Franklin Sibly;D\Se.,F-GsS 


cane REVIEWS. 


‘The dose aan eee of Great 
— Britain: Summary of Progress . 
eological Survey of Scotland: 

S Central Coal-field of Scotland . 
ion of Canada, Ottawa ate 
1eral Production of Canada... 
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SS 37-SOHO' §S ae ARE 


LEVIEWS (continued). Page 


The Coal-fields of Canada 


The Mining of Thin Coal-seams ... 


i. M. Kindle: Recent and Fossil 
Ripple-marks ..... Se aR SM oot 

Mining in South Australia 

North Queensland Tin-fields........, 

Minerals in Crystalline Limestone 

Ove Deposits, Nagato, Japan 

Cretaceous Mollusca, Heypt......... 

Monazite in Travancore 

Geology of Travancore 

Brief Notices: Hommomorphy— 
Varro on Soils—Fossil Inseets— 
Minerals, Glamorgan—77vitylo- 
don—Volkestone Warren 


TY. REPORTS AND PROCEEDINGS. 
The Royal Society 
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Mineralogical Society 
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Geologists’ Association........0..0... 


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No. I—JANUARY, 1918. 


ORIGINAL ARTICLES. 


RCT 
J.—NoTES ON NEW OR IMPERFECTLY KNOWN Cretaceous Potyzoa. 
By R. M. Brypone#, F.G.S. 

(Continued from the November Number, p. 496.) 

(PLATE I.) 


ICARIOUS avicularia, that is to say avicularia ational as 
large as zocecia, have rarely been figured among the Cretaceous 
Cribrilinide, the only good instances I call to mind beine Escharipora 
inerassata, D’Orb.,! Membraniporella ( Cribrilina) Faleoburgensis, Perg.,* 
the illustration ‘of which shows a clear case, although no reference is 
made to it in the text, and Cribrilina ostreicola, Bryd.* They are 
not, however, by any means so rare as this might suggest, and the 
four following species are probably not the only instances which will 
ultimately be added from the English Chalk. 


MeEMBRANIPORELLA ALTONENSIS, sp. nov. (Pl. I, Figs. 1, 2.) 


Zoarium unilaminate, adherent. 

Zoecia small, average length °45 to °5 mm. (exclusive of 
ocecium)) ; side araills prened slightly inwards, front walls arched, 
arising without apparent break from the edges of the side walls and 
pierced by six pairs of radiating slits reaching from the edges nearly 
to the middle line; aperture semicircular, very simple, the posterior 
lip being apparently unthickened. 

Oncia occurring very regularly, helmet-shaped, with apertures 
cut well back. 

Avicularia vicarious, with vaulted blister-like external walls; 
apertures shaped like a thermometer tube, with round bulb and 
straight stem ; there is no raised rim round the bulb, but as it passes 
into the stem rims arise rapidly on either side and enclose the whole 
length of the stem, opening out into a small circle at the anterior 
end to admit a narrow internal front wall; as the surface of the beak 
is horizontal it stands out increasingly as the surface of the external 
wall descends anteriorly. Sometimes the beak is covered by an 
imperforate membrane. This species occurs very rarely in the zone 
of H. planus near Alton, Hants. 


MeMBRANIPORELLA SHawrForpensis, sp. nov. (PI. I, Figs. 6, 7.) 

Zoarium unilaminate, adherent. 

Zowcia of medium size, average length *58 to °62 mm.; the normal 
surface is obviously largely secondary; I have not seen any certain 
Pal. Crét. Franc., v, p. 223, pl. 685, figs. 2, 3 
Bull. Soc. Belge Geol., 1893, p. 176 et seq., text-fig. 7. 

GEOL. MAG., 1909, p. 399, Pl. XXIII, Figs. 1, 2 
DECADE VI.—VOL. V.—NO. I. 1 


pep aie! 
; 


Deets Brydone—New Cretaceous Polyzoa. 


instance of the primary stage, but it is probably represented in 
Fig. 7, and consists of zocecia with distinct bluntly pyriporiform 
side walls, flatly arched front walls, pierced by five pairs of well-_ 
marked slits extending from the edge about a third of the way 
across, and a flatly semicircular aperture with slightly concave and 
upturned posterior lip formed by the broad unthickened margin of 
the front wall; the anterior end of the zocecium rests on the rising 
external wall of the succeeding zocecium, and thins out against it ; 
small distinct avicularia are lodged in the interzocecial depressions ; 
in the secondary and normal stage the posterior lp of the aperture 
thickens and fuses completely with a pair of avicularia at the corners 
of the aperture and extends backwards a little way over the front 
wall in a blunt triangle and forwards on either side of the aperture 
on to the sides of and round the ocwcium so as to form a platform level 
(except for the swelling due to the ocecium) and standing only 
slightly above the front wall in the middle line, but considerably 
above it at the sides, and encroaching on it more or less all round, 
but especially at the posterior end; the result of this encroachment 
is that only three of the pairs of slits usually remain visible and 
then only in reduced length; there is generally more or less of 
a depression in the centre of the anterior lip of the secondary 
aperture. 

Owcia invariably present in the secondary condition and evidently 
highly globose, but without any definite outline; aperture sunk 
below the general surface, so that its free edge is only partially 
visible. 

Avicularia.—(a) Vicarious, average length °55 to *6mm., scoop- 
shaped with approximately parallel side walls and rounded ends; 
the aperture appears to be bounded by the side walls in the posterior 
part, but anteriorly it tapers away and a narrow internal front wall 
appears; there are remains of a transverse bar across the posterior 
end of the aperture; they occur rather freely along the edge of the 
zoarium, and not infrequently in the body of the zoarium, where 
they are deeply sunk. (4) Accessory, in the primary condition 
apparently beak-shaped and distinct; in the secondary - condition 
wholly merged in the general mass, leaving only the broadly arrow- 
head-shaped apertures visible; a pair occur very regularly at the 
posterior corners of the aperture and another pair much less 
regularly at the anterior corners. 

This species is very rare; I have only seen one specimen, from 
the zone (restricted) of 4. guadratus at Shawford, Hants. But for 
its vicarious avicularia it would form a very perfect link between 
Membraniporella subcastrum, Bryd.,' and I. castrum, Bryd.? 

MEMBRANIPORELLA BEDHAMPTONENSIS, sp. nov. (Pl. I, Figs. 3-5.) 

‘Zoarium unilaminate, adherent. 

Zoecia distinct, average length °65 to "7 mm.; side walls strongly 
overarching, front walls arising within the edges of the side walls, 
flatly arched and pierced by five or six pairs of very short, often 


1 Ante, p. 494. 
? GEOL. MAG., 1909, p. 398. 


WES A ae ‘iba 


ORM. Brydone—New Cretaceous Polyzoa. 3 


wide, and even triangular radiating slits; aperture horseshoe-shaped, 
posterior lip formed by the broad unthickened shghtly upturned 
margin of the front wall, and uniting with the anterior lip to form 
a thin subtubular peristome. 

Oecia occurring freely but very erratically, relatively small, with 
rather narrow apertures cut slightly back. 

Avicularia.—(a) Vicarious, average length -6mm., with beaks of 
the hour-glass type, but scoop-shaped, with almost parallel side 
walls hardly folded over or constricted at all in the middle or 
expanded at the ends; the posterior end of the beak is tilted up on 
a strongly inflated external wall; the aperture is long and narrow 
with rounded ends, the posterior end being bluntly rounded and 
enclosed by a very narrow internal front wall, and the anterior end 
tapering somewhat and being enclosed by a wide internal front wall. 
(6) Accessory, small roundish lumps with arrowhead - shaped 
apertures standing up high and possibly sometimes supported on 
slender legs like those of I, Sherbornz, Bryd.’; very abundant, 
grouped thickly round the apertures, sometimes as many as four to 
an aperture, but very rare away from the apertures. ‘The vicarious 
avicularia are very erratic in occurrence, and do not seem to appear 
until the zoarium has reached a fair age, so that they can only be 
expected at the edges, if at all, in small or medium-sized zoaria. 

‘This species seems to be coeval with JZ manonia, Bryd.,? and like 
it very characteristic of and restricted to the lower part of the zone 
of B. mucronata in Hants and the Isle of Wight.* It has been found 
at the very base of that zone at Bedhampton, Hants, but never yet in 
the zone of A. quadratus. It forms avery natural introduction to 


Mempranrporetta Trimensis, sp. nov. (Pl. I, Figs. 8-10.) 

Zoarium unilaminate, adherent or free. 

Zoecia large, average leneth °9 to -95mm., distinct, decidedly 
pyriporiform ; front walls arched, arising at an angle from the edges 
of the side walls, and pierced by about four pairs of short, broad, 
and sometimes triangular slits, with a broad band separating the 
uppermost pair of slits from the aperture and merging at its ends 
imperceptibly into the side walls; aperture typically about five- 
eighths of a circle, with a short, straight, posterior lip, but rather 
variable in shape; posterior lip short and straight with a slightly 
upturned edge, which sometimes develops into a median denticle, 
and combines with the anterior lip produced upwards and slightly 


1 Tbid., 1906, pp. 289-300, Fig. 7 (as Cribrilina Sherborni). 

2 Ante, p. 146. 

3 There is a very similar form in the Weybourne Chalk, in which according 
to my only good specimen the front wall has the slits usually obliterated by 
calcification, the aperture is very irregular in shape and sometimes sharply 
triangular owing to the encroachment of the accessory avicularia, the 
accessory avicularia are only slightly prominent, and the vicarious avicularia 
are longer and wider and expanded at the anterior end, being of the same 
general outline as those of Membranipora invigilata, Bryd. (GEOL. MAG., 
1910, p. 76), and the remains of the transverse bar are much more pronounced. 
I should not care to commit myself to its being a distinct species on practically 
one specimen, but if so it might be named M. Weybournensis. 


4. Herbert L. Hawkins—Studies on the Echinoidea. 


Eorwardé: into a thin subtubular peristome. There is a tendency for 
a roof to arise along the interzocecial furrows and spread over the 
posterior ends of the zocecia. 

Owcia very scarce, large, and very globose; aperture niantow, 
vertical. ay 

Avicularia.—(a) Vicarious, very large, up to 1 mm. in length, of 
hour-glass type, with very round anterior ends and side walls sloping 
outwards in the middle; apertures rounded posteriorly and almost 
pointed anteriorly, with a large area of internal front wall in the 
anterior bulb of the hour-glass and a considerable amount in the 
posterior bulb; there is athick transverse bar just below the area of 
constriction. (6) Accessory, small beak-shaped or rounded masses 
raised above the general surface apparently on slender legs as in 
M. Sherborni, Bryd. (ante), and scattered in great abundance along 
the interzocecial furrows, while sessile specimens encroach very freely 
on the broad posterior lip of the aperture. 

This very fine species occurs sparingly in the Trimingham Chalk. 


EXPLANATION OF PLATE I. 


(All figures x 12 diams.) 
Fic. 1.—Membraniporella Altonensis. Zone of Holaster planus, near Alton, 


Hants. 
nema Die aa 5 Another part of the same specimen 
showing closed ayicularia. 
Meaney ap Bedhamptonensis. Zone of B. mucronata, Bed- 


hampton, Hants. From the 
margin of a large zoarium. 

At ae ae sh Part of the interior of the same 
zoarium. 

er O}s Ke a Part of a zoarium in which no 
avicularia have developed. 

5H Oa dla Be Shawfordensis. Zone of A. quadratus, Shawford, 
Hants. 

», 8-10. ae Trimensis. Zone of B. mucronata, Trimingham. 
Different parts of the same 
zoarium. No. 10 shows an 
oecium slightly confused 
with a perfect avicularium. 


IJ.—Monrenonoeican Sruprrs on THE EcHINOIDEA HoLecrypormDA AND 
THEIR ALLIES. 


By HERBERT L. HAWKINS, M.Sc., F.G.S., Lecturer in Geology, University 
College, Reading. 


VII, Tue PeErienatuic GirpLe or tHE HoLncryporpA AND THE 
CorRESPONDING SrRucTURES OF orHbR IRREGULAR EcHINOIDEA. 
(PLATE II.) 

1. InrRopuction. 

N the three preceding papers of this series descriptions have been 


given of the perignathic girdles of familiar representatives of the 
three families into which the Holectypoida are at present divided. 


Grou. Maae., 1918. Pratt I. 


R. M. Brydone, Photo, Bemrose d: Sons Ltd., Collo. 
Chalk Polyzoa. 


Herbert L. Hawkins—Studies on the Echinoidea. 5 


From the scanty evidence available, it would appear that in respect 
of this structure Plestechinus is typical of the Pygasteridze (even 
including Anorthopygus). The girdle of Holectypus seems essentially 
similar, thereby differing from that of the Discoidiine; but as yet 
the perignathic structures of the Cretaceous Coenholectypus are 
unknown. Large species of Discoides have girdles differing in 
proportions only from those of the smaller forms, typified by 
D. subuculus. In default of further knowledge, the development 
of the girdle in Conulus albogalerus may be considered to be that 
characteristic of the genus and family. It is thus possible to 
summarize the known features of the girdle of the Order with some 
confidence, and to discover the ‘‘ common denominator”’ of its varied 
characters. Stripped of its diverse additions, the girdle is found to 
present a uniform and practically unvaried structure which may be 
regarded, from the systematic standpoint, as being a diagnostic 
feature of the Order. 

The primitive and conservative nature of the Holectypoida among 
Trregular Echinoids has been so often indicated, and indeed is so 
manifest, that it may be taken for granted without further argument. 
It follows from this that there are but two alternative possibilities 
for the lines of descent of all other Orders of the Sub-Class. Hither 
they must have arisen from some ‘‘ Regular’’ stock independently 
of the Holectypoida, in which case they need show no special 
resemblances to that group save under the influence of parallelism of 
development; or else they must have descended directly or indirectly 
from Holectypoid ancestors. In the present paper a brief description 
of the peristomial characters of certain representative Irregular 
Eehinoids is given, and an attempt is made to indicate the presence 
or absence of relationship to the Holectypoida shown by this fragment 
of evidence. The genera whose internal test-structure has been 
examined for this purpose are Clypeaster, Echinocyamus, and Kchin- 
arachnius among the Clypeastroida, Nucleolites and Trematopygus 
amone the ‘‘ Nucleolitoida’’, Conulopsis among the ? Cassiduloida, 
and ELehinocorys, Micraster, and Echinocardium among the Spatangoida. 
In the case of the first and last mentioned Orders, the genera studied 
may be taken as fairly representative of the groups to which they 
belong; but the other two Orders (usually grouped together under 
the name here restricted to the latter) are very imperfectly illustrated. 
This is accounted for by the extreme difficulty of the preparation of 
the Jurassic forms and the virtual impossibility, under existing 
circumstances, of acquiring suitable material of the Cass¢dulus— 
LEchinolampas series, which are almost unrepresented in the British 
fauna, both past and present. 

On stratigraphical evidence it is at least possible to regard the 
Nucleolitoida (including such genera as Wucleolites, Clypeus, and 
Pygurus) as “cousins”? or even ‘‘brothers”’ of the Holectypvida, 
rather than as their lineal descendants. If this should prove to be 
the case an interesting illustration of parallelism would appear. The 
Holectypoida are first found in the Lias, occur in abundance 
throughout the succeeding stages of the Mesozoic, and are represented 
in the Tertiary and Recent faunas only by the apparently degenerate 


6 Herbert L. H awhkins—Studies on the Echinoidea a 


types of Hehinonéus and Micropetalon. The Nucleolitoida similarly 
make their first appearance in the Lias, were extraordinarily abundant 
and varied in the later Mesozoic, and are reduced at the present day 
to a solitary and very simple representative of their least specialized 
family, the Nucleolitide. ‘he time of the first occurrence affords no 
indication of the ancestry of the other three Orders of Irregular 
Kchinoids; and the approximate synchronism of their differentiation, 
while suggestive of a common origin, may well be but another 
expression of the parallelism above indicated. Although evidence 
derived from the study of one series of structures affords no sound 
basis for the erection of a scheme of phylogeny, it is none the less 
profitable to examine it as an index of morphogenetic affinity. If 
the prevalent view of the irreversibility of evolution is correct, such 
indications should at least show which lines of descent are ampossible, 
and so narrow down the limits of probability, which may be further 
restricted by similar arguments founded on the observed characters 
of different sets of structures. It will be in this sense that sugges- 
tions as to the phyletic affinities of the various forms studied will be 
put forward in this paper. 


2. THe Hotectrypor Greve. 
(a) Lhe persistent elements of its structure. 

Although the perignathic girdles of Plestechinus and Conulus appear 
to be essentially dissimilar on a casual inspection, the reverse seems 
to be the truth. Ifthe distinction between the ‘‘ true” and ‘‘false”’ 
ridges of the girdle, which I have argued in the two preceding papers, 
is accepted, the differences between the characters of the “‘ genuine”’ 
girdle in the two genera prove to be of so insignificant an order that 
they would hardly excite surprise if occurring in two species of 
a single genus. The accompanying diagram (Text-fig. 1), in which 
the three best-known girdles of the Holectypoida are associated 
(together with the two chief types of Clypeastroid girdle), shows this 
fundamental identity more clearly than verbal description could 
suggest. In the diagram the buttresses and false ridges (where 
present) are drawn in outline, while the true elements of the girdle, 
both ridges and processes, are blocked in. The undifferentiated parts 
of the corona are indicated by shading. The conservatism of the 
Order could nowhere be expressed more emphatically than by the 
retention of so physiologically important a structure throughout 
the Jurassic and Cretaceous stages with hardly appreciable change. 

The essential characters of the perignathic girdle of the Order 
Holectypoida may be thus described :— 

Ten lath-like processes spring in pairs from the proximal ambulacral 
plates, and are inclined outwards from the vertical axis.. For the 
greater part of their length the pairs diverge slightly (1.e. slope away 
from the perradial line), but at their distal ends they may converge 
to a small extent (i.e. Discordes), never sufficiently to produce even 
the semblance of an arch or ‘‘auricle’”’. ‘he processes are supported 
by variously placed and diversely developed buttresses, but are always 
separated from these by a defined suture, and are composed of more 
compact stereom. 


Elerbert L. Hawkins—Studies on the Behinosden. 


Five very small ridges occupy the inner 
surfaces of the proximal (unpaired) inter- 
ambulacral plates, never extending beyond 
the limits of the latter. They are crescentic 
in plan, have a various sculptured surface, 
and are always separated from the processes 
by a space at least as great as their breadth. 
They may be entirely free (Plesvechinus), or 


‘may become more or less involved in the, 
buttresses when these tend to encircle the’ 


peristome (Discordes and Conulus). 

These two sets of structures, according to 
my belief, are the only ones concerned with 
the attachment of the jaw-muscles, and so 
constitute the true perignathic girdle. All 
other structures entering into the ‘‘ peristomial 
ring” are variously swollen portions of the 
normal plates, adapted for the mechanical 
support of the processes, the jaws, or the 
buccal plates (or in some cases of all three 
sets of ossicles), or for the greater strength 
of the invaginated part of the corona which 
encloses the peristome. The true perignathic 
girdle retains very constant proportions from 
Liassic to Upper Cretaceous times, its only 
noteworthy change consisting of a progressive 
tendency towards increased obliquity in the 
setting of the processes. 

The Holectypoid girdle, as thus restricted, 
is extremely primitive. As regards the pro- 
cesses, it represents a phase reproduced only 
in the early post-larval ontogeny of recent 
Diademoida, and there is some reason to 
believe that the ridges of non-Cidaroid 
Regular Echinoids are first developed on the 
unpaired interambulacral plates. The in- 
ference may be drawn that the Holectypoida 
sprang from a Regular stock at a stage when 
the perignathic girdle had barely progressed 
beyond the early Cidaroid phase, and that, 
unlike most of their Diademoid relatives, 
they failed to improve upon the almost 
phylembryonic structure with which they 
were endowed. 


(b) Zhe perignathic buttresses. 


In all of the Holectypoida whose perignathic 
girdles are known, the processes are supported 
by buttresses which rise from the inner 
surface of the test. These supports are 
demonstrably parts of the actuai coronal 


in outline, and the normal coronal plates shaded. 


) 


y, drawn on ‘‘ Mercator 


B, Discoides; C, Conulus; D, Clypeaster; KE, Echinarachnius. 
arious parts are not accurately shown, all the figures being brought to the same size. 


(in B and C 


‘ures represent the girdle viewed from the peristome laterall 


Oo 
f=) 


. 
‘) 


1.—Diagrams of the perignathic girdle in A, Plesiechinus 
The elements of the true girdle are black, the false ridges 


The fi 


Fie. 


The proportions 


’s Projection ’’. 


of the vy 


8 Herbert L. Hawkins—Studies on the Hehinoidew: =e 


plates, being crossed by transverse sutures, and they can be 
distinguished from the actual elements of the girdle by their less 
polished surfaces and open stereom-mesh in direct continuity 
with that of the plates from which they rise. In Jurassic forms, 
and apparently in their nearest relatives in the Cretaceous period, 
the buttresses are short and steep ridges which radiate for a varying 
distance near to or upon the adradial sutures. In Discoides the same 
series of radiating ridges can be recognized, although they are 
reinforced by others oly similar trend and by a circular region of 
elevation surrounding the peristome. In Conulus, where the whole 
inner adoral surface of the interambulacral area is much thickened, 
no separate buttresses can be distinguished; each area may, however, 
be regarded as being lined by a fused and extended mass of 
buttresses. 

The apparently universal presence of this adambital support for 
the processes is almost peculiar to the Holectypoida. ‘he girdles of 
the Cidaroida and Diademoida are sufficiently strong in themselves 
to stand without additional help; those of the Clypeastroida, though 

often relatively slender, are so encompassed by the ridges and pillars 
which cross the test-cavity that they seem to be equally independent, 
in most cases, of special buttresses. This contrast 1s suggestive of 
some special relation between the perignathic girdle and the jaws in 
the Holectypoida wherein they differ from the other gnathostomatous 
Orders. Perhapsit may be connected with the undoubtedly ‘‘ flaring ” 
character of the lantern. In the Regular Orders the jaws are almost 
vertical, and their weight can best be supported by a ‘‘sling” of 
muscles, on all of which the ‘‘pull”’ would be almost vertically 
downwards. In the Clypeastroida the jaws are practically horizontal 
in typical forms, and they almost articulate with the processes. The 
onus of their support will be shared between the adoral surface of 
the test and the processes, the strain on the latter acting again 
vertically downwards. But with a lantern inclined at, say, 45° from 
the vertical (and a girdle correspondingly splayed), the downward 
weight would tell upon the lath-like processes obliquely, so that they 
would require to be strengthened from below and without to prevent 
fracture. In support of this suggestion it may be recalled that in 
those Clypeastroids in which the lantern is elevated above its normal 
prostrate position, the processes have adambital keels similar in many 
respects to those of Plesiechinus. 

Although the buttresses are obviously, and probably originally, 
connected with the mechanism of the perignathic girdle, they assume 
a more far-reaching function in the Cretaceous Holectypoida and 
their Clypeastroid descendants. The adoral regions of the test in 
both Orders is normally very thin, so that the peristomial invagina- 
tion, as well as the sharply reflexed ambital margin, demand a 
girder-like support. In the Jurassic forms, the latter line of 
weakness is not seriously developed, and the buttresses in conse- 
quence are restricted to the central part of the surface, in the region 
of the invagination of the peristome. In Discoides the ambital 
margin is angular rather than curved, so that the girders are extended 
across that fragile zone. In Conulus, although the ambitus may be 


Herbert L. Hawkins—Studies on the Echinoidea. 9 


as acute as in Drscotdes, the general thickness of the test makes 
unnecessary the prolongation of such carinate buttresses. In the 
Clypeastroida, where the angle between the adoral and adapical 
surfaces of the test is often very acute (e.g. Hchinarachnius), a 
bewildering profusion of essentially buttress-lke structures is 
developed. It is worthy of note that in those Clypeastroids which 
have a moderately rounded ambitus (e.g. Hcehinocyamus) the buttresses 
are for all intents and purposes retained in the relatively simple 
‘« Discordes-phase”’. 

The buttresses may be considered to have been developed primarily 
as supports for the inclined elements of the perignathic girdle, and to 
have acquired a secondary function as joists, girders, or rafters for 
the strengthening of the test-fabric. This secondary function is 
retained, and carried to an almost excessive degree of specialization, 
in the typical Clypeastroids, where the primary purpose of the 
buttresses has disappeared, and their original positions are 
abandoned. 


8. Tue Cryprastroip GIRDLE. 


It is unnecessary to describe in detail the well-known characters 
of the girdle of the Clypeastroida. Students may be referred to the 
exquisite drawings and detailed descriptions in Lovén’s Hehinologica ; 
or, for a general summary, to Jackson’s Phylogeny of the Echan. 

‘It will be sufficient here to indicate the analogies between the various 
types of Clypeastroid girdle with that of the Holectypoida, and to 
indicate the probable relations between them. 

The Clypeastroid girdle seems to consist of processes only. These 
processes are always approximated to one another in pairs near the 
interradial line, and in many groups are fused into a single, though 
often visibly compound, element. Their interradial convergence is 
rendered possible by the reduction in width of the interambulacra 
as they approach the peristome, and by the actual extension of the 
ambulacral plates, whereby they sometimes meet internally across 
the interradius, more or less completely ousting the proximal inter- 
ambulacral plate from participation in the lining of the test-cavity. 
The processes may, however, transgress on to the proximal inter- 
ambulacral plate when this is well represented, this anomaly being 
usual where the processes are fused. 

In Lehinocyamus, a genus usually regarded as showing arrested 
evolution, and approximating to the Discocdes subuculus group of the 
Holectypoida, the perignathic girdle is found to be exceptionally 
specialized. Superficially regarded, it certainly appears like that of 
D. subuculus, especially since it is buttressed up by the thickening 
of the interambulacral plates, and the floor of the test is traversed by 
carine. But each section of the girdle consists of a fused pair of 
processes which are based entirely on the interambulacrum. ‘There 
seems every reason to believe that the girdle does actually consist of 
transposed processes, but there is no proof of the existence of a ridge, 
whether true or false, included between them. It is certainly 
questionable whether such a development can be considered primitive, 
in comparison with that of such a form as Clypeaster. Probably the 


10 Herbert L. Hawkins—Studies on the Echinoidea. 


two types of girdle characterize independent lineages. Echinocyamus . 


(and the Scutellidz) may perhaps claim the small Dzscocdes as their 
ancestors, while the genealogy of Clypeaster leads back through 
Conoclypus to such a type as Duiscoides cylindricus. 

The essential difference between the Holectypoid and Clypeastroid 
girdles lies in the apparent absence of any originally interradial 
element in the latter. This element is, however, so persistently 
minute in the Holectypoida that its suppression would be a slight 
modification when compared with other morphological changes 
introduced in the Tertiary Order. In the Clypeastride, the virtual 
exclusion of the interambulacral plates from the inner rim of the 
peristome renders the change inevitable. In the Achinocyamus series 
the fusion of the two transposed processes would tend to crush the 
ridges out of existence, although it is at least conceivable that some 
trace of them may remain in the middle of each compound ‘‘auricle”’ 
Except in the family of the Fibulariide, the neighbourhood of the 
peristome is practically free from structures due to secondary 
thickening, so as to allow free play for the recumbent lantern. 
There is thus no reason nor opportunity for the development of 
a false ridge. The processes of Clypeaster are upheld by carinze 
recalling those of Plestechinus. 

If the false ridges of Discoides or Conulus were removed (or laid 
parallel with the floor of the test), and the already almost negligible 
true ridges abandoned, the resulting girdle would be, for all intents 
and purposes, that of the Clypeastride. Further knowledge of the 
ontogeny of the girdle of the Fibulariide, Laganidz, and Scutellidee 
is needed before a definite opinion can be formed as to the origin of 
the interradially placed fused ‘‘auricle”. As far as appears at 
present, this could have been produced either by the convergence of 
the isolated processes of a Clypeastrid, or independently by an inter- 
radiad encroachment of the processes of an Holectypoid upon the 
ridges, resulting in the destruction or incorporation of the latter. 
In any case it seems clear that both types of Clypeastroid girdle can 
be regarded as modifications of that of the Holectypoida. 


4. Tue Nocieortrorip PERIstome. 


The following section is based upon an examination of twenty-seven 
specimens of Vucleolites scutatus from the Corallian of Marcham, near 
Abingdon, and of two examples of Zrematopygus from the Faringdon 
Greensand. ‘These are the only forms of this Order in which I have 
as yet succeeded in exposing the interior of the test. Serial sections 
through the adoral regions of a specimen of Galeropygus agarietformis 
and two of Clypeus sinuatus seem to show no serious difference in this 
character from the smaller and more satisfactorily studied genera. 

The greater part of the test of the adoral surface of most 
Nucleolitide is very thin, and the peristome is markedly invaginate. 
(An exception to this rule occurs in those forms which have the 
beginnings of a floscelle developed.) Seen from within the peristome 
it resembles a truncated and obscurely pentagonal hollow cone. The 
interambulacral parts of the margin are quite obviously thicker than 
the ambulacral, and than the rest of the adoral part of the test. 


Sa GA pie ahd } 
bed f 


Herbert L. Hawkins—Studies a he Echanovdea: All 


But this locally thickened region is merely arim, and no trace of any 
structure even remotely suggestive of a perignathic girdle can be 
detected init. Itis not undercut adambitally, but is imperceptibly 
reduced to the average thickness before the invagination is passed. 
The ambulacral part of the peristome border is remarkably thin, and 
shows absolutely no indication of any kind of specialization. It is 
simply the inverted edge of the proximal ambulacral plates. There 
is thus no vestige of a perignathic girdle in the observed genera of 
this Order. 

The complete and sudden disappearance of the jaws and everything 
pertaining to them in the Nucleolitoida is mysterious, but by no 
means surprising. Before the advent of the Oolitic period, while yet 
the Diademoida and Holectypoida had hardly entered upon the paths 
of the evolution of their buccal structures, the Nucleolitoida had 
utterly abandoned all traces of such apparatus. An ontogenetic 
parallel is afforded by the young Hehimonéus, in which a lantern 
and girdle are almost completely developed, both disappearing 
simultaneously at a later stage of growth. In the absence of any 
development capable of correlation with the perignathic girdle, it is 
impossible to make comparisons between the Nucleolitoida and the 
Holectypoida. But the complete diversity of the two Orders in this 
respect, coupled with their contemporaneous and early appearance, 
suggests that they originated independently. Whether they sprang 
from a common stock or are fundamentally distinct, is a problem 
which cannot be attacked on these lines of argument. 


5. Tuer Cassrpunor PERISToME. 


I have examined the interior of the peristomial region in Conulopsis 
(Eechinoconus, Desor) only among the many representatives of this 
Order. The evidence thus obtained, though interesting and 
suggestive, cannot therefore be considered adequate for the formula- 
tion of any definite hypothesis. It seems, however, sufficient to 
indicate the phyletic distinction between this Order and the 
Nucleolitoida, with which it is generally associated. 

Externally, the adoral region in this Order is characterized by the 
expansion of the proximal parts of the ambulacra into variously 
developed phyllodes, separated from one another by more or less 
prominent ‘‘bourrelets”’ on the interambulacra. (Many of the more 
elaborate Nucleolitoida, such as Clypeus and Pygurus, are similar in 
this respect.) Internally, the thickening of the interambulacra is 
almost like a reflection of their external character, so that the 
interradial margins of the peristome are excessively massive. 

In Conulopsis abbreviata, from the Upper Chalk of Norfolk, 
the phyllodes are practically non-existent, although pronounced 
‘‘bourrelets’’ are developed. An internal view of the adoral surface 
shows a remarkable resemblance to that seen in Conulus, and is of 
itself enough to render the generic name morphologically appropriate, 
whatever may be its systematic fate. ‘he ambulacra are terminated 
adorally by an almost unthickened edge, and so appear as five grooves 
radiating from the slightly elliptical aperture of the peristome. ‘The 
interambulacra increase steadily in thickness from the ambitus almost 


w 


iE Herbert L. Hawkins—Studies on the Echinoidea. 


to their proximal termination, and are then steeply bevelled off by 
a pair of concave bays or ‘‘combes’’, between which the areas project 
as rounded spurs almost overhanging the slope of the ‘‘ escarpment ”’. 
The two “‘combes” in each area are most deeply excavated just on 
the interradiad side of the adradial sutures. Here they appear as 
deep slots, differing only in proportion from the hollows in the false 
ridges of Conulus. By analogy, it would seem that these hollows in 
the peristomial margin of Conulopsis must have been destined to 
receive massive buccal plates when the mouth was opened. 

Unless Conulopsis is on a side line of evolution, it would appear to 
be a simple member of the Caratomide, and as such more or less 
ancestrally related to the ZEehinolampas-group. Whatever be its 
other affinities, it must surely be nearly related to Conulus, to judge 
from the nature of most of its test-structures. As far as the 
perignathic girdle is concerned, it may be considered to show the 
retention of the false ridges of Conulus, after the loss of both sets of 
the ‘‘true”’ elements of the girdle. From the scanty evidence at my 
disposal, I believe that Catopygus, a far more ‘‘ advanced” type of 
Cassiduloid, has a similar perignathic structure. Clarke & Twitchell 
(The Mesozoic and Cenozoic Echinodermata of the United States) give 
figures of internal moulds of Cassidulus californicus (pl. xv) and 
Pygorhynchus gould (pl. lxxix) which show a strong interradial 
thickening of the interior of the test at the peristome in these 
typically Cassiduloid species. 


6. Tue Sparancorp PEristomMeE. 


For the present purposes I have examined the interior of the test 
in many examples of Hehinocorys, Micraster, and Echinocardium. 

The predominant feature of the peristome of the Spatangoida is its 
progressive adaptation to the requirements of a burrowing life and 
an ‘‘earthworm”’ mode of feeding. The part of the aperture 
bounded by interambulacrum 5 comes to project below the general 
level of the adoral surface, and its margin develops into a spoon-like 
labrum. All Spatangoids, as far as is known, are entirely destitute 
of jaws. MacBride has recognized as teeth certain spicules produced 
at a very early stage of post-larval ontogeny, but no pyramid or 
auricular vestiges seem to be associated with them, and they disappear 
shortly after their formation. 

Klinghardt has identified as ‘“‘auricles’”’ certain protuberances at 
the side of the peristome in Lehinocorys, but the examination of 
considerable numbers of specimens of #. vulgaris, representative 
of many of the later growth stages, has convinced me that these 
blunt excrescences are not processes (being based upon the inter- 
ambulacra), so that they can hardly be homologous with any part of 
a perignathic girdle in the strict sense of the term. 

Reference has been made in the preceding article of this series to 
the curious ‘‘mode” of excessive stereom-formation prevalent among 
the Kchinoids of the Cretaceous period. The early Spatangoids 
almost universally adopted this character, so that the margins of 
their peristomes are always of considerable thickness. This applies 


Herbert L. Hawkins—Studies on the Echinoidea. 13 


particularly to the anterior and posterior edges of the aperture. 
The thickness is always greater in the interambulacral parts than in 
the ambulacral. Save on the edge of the labrum, there is no 
indication that the thickened margin is adapted to any special 
requirement beyond that of strengthening the free edge of the 
corona. In the case of area 5, the lip is often rolled over away from 
the peristome, and overhangs the ‘‘bowl”’ of the spoon-like labrum 
to a slight extent. In the (presumably) more primitive types, where 
the labrum is hardly worthy of the name (e.g. Hehinocorys) there is 
no trace of such a specialization of the margin, which is merely 
thickened similarly to, but in a less degree than, the other inter- 
ambulacral edges; it must consequently be a secondary development 
suited to the needs of a labrum, and can have no homology with the 
perignathic ridges of less specialized groups. On the thickened 
margins of areas 2 and 8, in Hehinocorys and Mieraster, the line of 
attachment of the buccal membrane is often apparent. Within this 
the secondarily thickened margins rise almost vertically, and seem to 
show no feature inconsistent with the belief that they are simply the 
truncated edges of the coronal plates. They certainly constitute 
“false ridges”, but whether they are to be correlated with those of 
the Holectypoida is very doubtful. 

In most of the Recent Heart-Urchins there is a more or less 
extensive alar projection from interambulacrum 4 near the margin of 
the peristome. In many forms a corresponding, but only just visible, 
projection occurs in area 1, These projections afford support for 
the mesenteries holding the proximal parts of the alimentary canal. 
They have been regarded by some authors as modifications of parts of 
a perignathic girdle. The only fossil in which I have succeeded in 
recognizing even a trace of such a projection is a Schizaster from 
the ? Miocene of Hast Africa. The extreme delicacy of the free part 
of the structure is such that only its foundations could be hoped for 
under the conditions of fossilization. It is possible that the pre- 
sumed ‘‘ auricles’? described by Klinghardt in ehinocorys may 
represent such a structure, though they seem to be somewhat sporadic 
and irregular in their occurrence. But I have never seen a trace of 
these projections in any Cretaceous Spatangoid. As far as my 
experience goes, these cesophageal supports are a recent development 
restricted to fully specialized Heart-Urchins, and so are not likely 
to be homologous with any part of a true perignathic girdle. 

As at present known the peristomial characters of the Spatangoida 
give no satisfactory clue to their morphogenetic relationships, while 
their more elaborate features are purely secondary developments, 
quite unconnected with any ancestral qualities. 


7. SUMMARY. 


The perignathic girdle of the Holectypoida is believed to consist 
of disjunct processes situated almost on the adradial sutures, with 
minute ‘‘ true ridges’’ occupying the inner surfaces of the unpaired 
interambulacral plates. This character is constant throughout the 
group, although it may be partly obscured by the development of 


14 Herbert L. Hawiins- “Studies on the Hohinordeae 


‘‘false ridges”? due to requirements of mechanical strength and to 
the phenomenon of “super-calcification”’. The girdle, apart from 
such modifications, is shown to be essentially primitive—more so 
than that of any modern Diademoids. 

By the default of the proximal interambulacrals, or by an actual 
transgression of the processes, the ridges are wanting in the 
Clypeastroida, and the processes converge towards the interradial 
line, often fusing in pairs. Such a character may readily have been 
derived from the Holectypoid girdle. The presence of so great 
a complexity of internal buttresses in the Clypeastroida points to 
their derivation from some Cretaceous representative of the 
Holectypoida, in which series alone such structures are strongly 
developed. 

The Wucleolites series of Jurassic so-called Cassiduloida (here 
styled Nucleolitoida) seem to possess no trace of a perignathic girdle, 
even in the simpler and early forms. ‘The sudden disappearance of 
the apparatus (there can be hardly any doubt that the ancestors 
of all Euechinoida were gnathostomatous) seems to point to the 
conclusion that the Nucleolitoida arose independently of, but con- 
temporaneously with, the Holectypoida. 

The Cassiduloida, to judge from the characters of one of the least 
specialized forms, Conulopsis (and, I believe, from those imperfectly 
known in Cassidulus itself), have a much thickened peristome in 
which there is a strong resemblance to that of Conulus, although the 
actual ossicles of the girdle are wanting. It is suggested that the 
false ridges are retained in this group, which becomes thereby 
affiliated to the Conulus series of the Holectypoida. 

The Cretaceous Spatangoida have much thickening of the 
peristomial plates, especially in the anterior region, but it has not 
been possible to correlate any of their structures with the girdle, 
true or false, of the Holectvpoida. The cesophageal support 
developed on one or both sides of the peristome in the later Heart- 
Urchins is regarded as an entirely secondary structure, with no 
affinity to any portion of a perignathic girdle. 


EXPLANATION OF PLATE ILI. 


Fie. 1.—Interior of peristome of Conulopsis abbreviata. xX 6. The floor of 
the test is thickened in the same manner as that of Conulus, and deep 

_ slots (? for the reception of retracted buccal plates) are cut in the 
peristomial ‘* escarpment ’’. The actual aperture is very slightly elliptical. 

», 2.—Interior of peristome of Hchinocorys vulgaris. x 5. Except in 
area 5 the floor of the test increases in thickness towards the peristome. 
In the four lateral interambulacra single, crescentic hollows excavate the 
“escarpment’’. The horns of the crescents in areas 2 and 3 are often 
nodular, being the “‘ auricles ’’ noted by Klinghardt. 

,, %.—Plan of interior of peristome in Hchinocardiwm cordatum. In area 1 
there is a small knob which rises partly from the neighbouring ambulacral 
plates. In area 4 a long, twisted mesentery-support rises from foundations 
exactly similar to those in area 1. The edge of the labrum is slightly 
reverted. There is no special modification in areas 2 and 3. 


Grou. Mac., 1918. PrarE Il, 


H.L.H. del. 


INTERIOR OF PERISTOME IN CONULOPSIS, ECHINOCORYS AND 
ECHINOCARDIUM. 


ihe 
es 


x - X ‘hi \ j 


Alfred Bell—Age of the Suffolk Boxstones. 15 


T11.—Tue Surrotxk Boxstonrs AND THEIR PROBABLE AGE. 
By ALFRED BELL. 
(PLATES III AND TV.) 


fJ\HE detrital matter underlying the Suffolk and N.W. Essex 

Crags forms an incongruous mass of disrupted local rocks and 
fossils, supplemented by a few transported boulders of igneous and 
sedimentary rocks of different ages and mostly small. To these have 
to be added organic remains of many classes in various conditions of 
preservation. 

The bulk of this miscellaneous assortment consists of clays and 
sands metamorphosed by phosphatization and other agencies, whose 
fossils indicate two or more distinct horizons ; to place these in their 
proper geological positions it is requisite to see what relations they 
bear to those of the deposits, or strata, above and below, and to 
consider the causes that brought them into their present position. 

The area occupied by this detritus is exceedingly limited, not more 
than sixty square miles in extent, the remains of a much larger 
surface, now lost or destroyed by marine action wearing away the 
coastline. Red Crag, with flints and phosphates, occurs a few miles 
inland as far as Sudbury and Monks Eleigh. 

The fossils belong to two series, the older one rich in fishes and 
crustaceans, usually embedded in a highly phosphatized clay, the 
so-called ‘‘ Coprolites’’. Amongst the fishes, the genera Cymbcum 
and Ha/lecopsis, with the bodies hardly compressed or altered in 
shape, are very common; the pavement-toothed Phyllodus and 
Pycnodus were frequently obtained when the pits were being worked. 
The crustacea have yielded eighteen or twenty species, including 
one Nephrops Reedii, Carter, which has not been recognized elsewhere 
in the London district. These indicate a zone corresponding 
generally to that of the London Clay of Sheppey in Kent. Both 
fishes and crustaceans are often in fine preservation, unlike the 
shells, which seem to have been absorbed or converted into phosphate 
pseudomorphs, and are not pyritized as they are in the Sheppey area. 

Casts of a few of the aragonite mollusca are preserved as a sandy 
or clayey matrix, but slightly phosphatized, the shelly material 
having entirely disappeared. It is difficult in these cases to 
determine to which horizon they belong, as the genera Cytherea, 
Pectunculus, etc., are common to both Eocene and Oligocene, the 
more so as several species, including Cancellara (Bonellitia) evulsa, 
a few Volutes, and Pleurotoma, Rimella and Hippochrenes, pass 
upwards. Professor Prestwich,’ moreover, says: ‘‘The Argile de 
Boom” (to which I shall presently refer) ‘‘ attains around Antwerp 
a thickness of 200 feet, resembling very closely, in its general 
composition and the facies of its fauna, the London Clay, to which 
it was originally referred.” } 

The fauna of these older Eocene clays in England and that of the 
next group tu be considered have very little in common, the 
teleostean fishes and others just mentioned having passed away. 


1 Geology, vol. ii, p. 382, 1888. 


16 Alfred Bell—Age of the Suffolk Boxstones. 


After eliminating the Eocene faunas referred to, there remains 
a miscellaneous series of both marine and terrestrial organisms, the 
former being mostly contained in the boxstones and sandstones, of 
which they form a part (see Gror. Mac., September, 1917, p. 408). 

Professor Boswell, F.G.S., has carefully examined and described 
the petrology of the boxstones, and suggests that some of them may 
have been formed by concretionary segregation of iron oxides, calcium 
phosphate and carbonate around organic nuclei.’ As a rule they are 
irregular in shape, often water-worn, sometimes nearly spherical, 
and of many degrees of hardness, according to the amount of iron 
in their composition; the sand at times being apparently full of small 
tubes (? annelids), loosely cemented, and light in weight and colour. 
‘The excessively hard masses are usually devoid of organic remains of 
any kind. It is impossible to separate these indurated boxstones, 
spherical or otherwise, from the tabular sandstones and loose shells 
found in the body of the Crag, presently to be referred to, as the 
same species of shells occur also in them. These amorphous lumps 
can hardly be termed nodules in the sense usually understood. In 
these as in Cromarty, like the Ichthyolite beds of the Old Red 
Sandstones, in the White Lias, in the Pennystone nodules of the 
Coal-measures with their exquisitely preserved Crustaceans and 
other invertebrata, or those of Coalbrookdale enclosing delicate fern 
fronds and pinnules, the nodules follow the lines of that of the 
organisms enclosed. ‘The cement stones of the Essex London Clay 
at Harwich containing Chelonians may also be regarded as larger 
examples of the same kind. 

On the other hand, the fossils of the boxstones often occur at an 
irregular angle, according to the way in which the sandstone may 
have broken up. Several individuals are frequently present in the 
same block. 

The Mekran nodules described by Mr. R. B. Newton,” fairly 
represent the usual method of inhumation in the best-preserved 
boxstones, so that the same words must apply to both. “ The condition 
of the fossils is nearly always that of a natural cast exhibiting 
internal structure, whilst external features are often preserved in the 
concavity of the shell.” ; 

‘he exterior of these Mekran nodules, ‘‘ many as round as a ball 
with perfectly even surfaces,” has but a superficial analogy to that 
of the boxstones in general. 

Dr. J. J. H. (now Sir Jethro) Teall, F.R.S., in his presidential 
address to the Geologists’ Association® dealing with ‘The Natural 
History of Phosphatic Deposits”, describes the boxstones (p. 383) as 
‘‘nodules of brown phosphatic sandstone which usually contain 
hollow moulds of Pectunculus or other (calcareous) shells”’, and quotes 
Dr. H. Credner, who in treating of the phosphate nodules of the Middle 
Oligocenes of Leipzig where similar nodules occur in place, says, 
‘the phosphate, mainly phosphate of lime, has been concentrated 


1 Grou. MaG., Dec. VI, Vol. ii, p. 250, 1915. 

2 R. B. Newton, F.G.S., ‘‘ Marine Fossils in Limestone Nodules found on 
the Mekran (Baluchistan) Beach ’’: GEOL. MaG., Dec. V, Vol. ii, 1905. 

3 Proce. Geol. Assoc., vol. xvi, p. 369, 1899-1900. 


Alfred Bell —Age of the Suffolk Boxstones. 17 


round calcareous shells and fish remains, but the shells have entirely 
disappeared, and the fish are represented only by the more insoluble 
portions of their skeleton.” Carbonic acid and ammonia are 
formed in connection with the decomposition of animal matter.” 
<¢ Phosphate of lime is soluble in water, charged with carbonic acid, 
and still more so in water containing ammonium carbonate. A solution 
of ammonium phosphate is thus formed at the expense of the fish 
bones, and one of calcium carbonate at the expense of the shells. 
The shells and the fish embedded in the porous sand thus become 
surrounded by water highly charged with calcium carbonate, or 
ammonium phosphate. Where these solutions react there is a 
precipitation of calcium phosphate and some carbonate; in this way 
the loose sand becomes consolidated into a hard nodule.” Dr. W. B. 
Clarke! was the first to give any detailed account of the detritus bed. 
He especially refers to the boxstones as ‘‘ arenaceous clay nodules 
that have been rounded by attrition into forms, more or less spherical, 
upon breaking which a shell, frequently a bivalve, is found in the 
interior. In some cases the shell itself is preserved, in others 
nothing but the cast remains”. He seems to have anticipated 
Dr. Credner by saying, ‘‘It is not unlikely that the presence of the 
shell and its molluscous inhabitant, involving certain chemical 
changes within the mass of clay, may have given rise to the 
consolidation of the surrounding mass.” 

Many phosphatic concretions were dredged by the Challenger off 
the Cape of Good Hope and elsewhere, where sharks’ teeth abounded, 
as many as 1,500 examples of these being taken in one haul of the 
dredge. Sharks’ teeth abound in the loose sand of the older Red 
Crag; nearly all the species are recorded from the Continental 
Oligocene, while a few survive to the present time. 

In working out the relations of the boxstone fauna to that of other 
formations I have utilized the lists given by Dr. Harder,’ Dr. Ravn,* 
M. Vanden Broeck,4 Dr. Nerregaard,® and by Mr. R. B. Newton, 
F.G.S.6 In making these comparisons I have left out the loose 
derivative shells found in the Red Crags, but these are all referred to 
by one or other Continental writers as being of Oligocene age, and 
do not affect the conclusions at which I have arrived. 

Harder quotes 93 species from the Oligocene zones ; 21 of these are 
boxstone species, chiefly Middle Oligocene (23 per cent approx.). 

Ravn 91 species, Middle and Upper Oligocene, of which we have 
36—40 (44 per cent). 

Vanden Broeck 64 species, Middle Oligocene; Argile de Boom 
(Upper Rupélien) 22-24 (38 per cent); Lower Rupélien (Berg) 
62 species, of these I have only found 10 in the boxstones. 


a 


““\ few remarks upon the Crag of Suffolk’? : Ann. Mag. Nat. Hist. (2), 
viii, p. 205. 

Danmarks geologiske Undersegelse, vol. ii, 1913. 

K. Danske Vid. Selsk. Skrift (7), vol. iii, p. 217, 1907. 

Bull. Soc. Belge de Géologie, vol. vii, p. 78, 1893. 

Dansk. Geol. Forening., vol. v, No. 1, 1916. 

Journal of Conchology, vol. xv, 1916-17. 


DECADE VI.—VOL. V.—NO. I. 2 


— 


yol. 


nonirp c WD 


18 Alfred Bell—Age of the Suffolk Boxstones. 


Dr. Norregaard’s list of 64 species, as noted further on, yields 
16, or 25 per cent, boxstone forms. Mr. Newton’s list of 77 species, 
10 or 11, or about 13 per cent. 

Ravn’s list, when closely examined, gives 51 Middle Oligocene 
species, including 15 boxstone forms or about 30 percent, as compared 
with Vanden Broeck’s 38 per cent. 

These analyses show that the ‘‘ boxstone’’ sands are nearer to 
the Oligocene Argile de Boom than to any of the others; they may 
be classed, I suggest, as Upper Rupélien. 

‘De Koninck, in his classic memoir on the fossil shells of Basele, 
Boom, etce., has figured or described many of the shells since found in 
the boxstenes; the above view is strengthened by the presence, both 
here and in Belgium, of similar types of vertebrates, many Elasmo- 
branch fishes and Crustaceans, various species of fossil woods, and 
vegetable debris.’ 

Dr. Clarke noticed the abundance of long thin rolled plaquettes of 
waterworn bones, which caused Sir KE. Ray Lankester to call the 
deposit in which they occur ‘‘the Suffolk bone-bed”. They are 
seldom, if ever, coated with the sandstone matrix, and it is very 
probable that they did not become mineralized till a later period, as 
the bony fragments enclosed in the nodules do not show any signs of 
such action. 

Phosphatization is not confined to age or place, as Sir Jethro Teall * 
has pointed out. Professor Herdman® says also of certain oysters: 
‘‘The shells were worn, many were brown in colour and polished, 
indicating a partial conversion into a phosphatic condition.” 

The presence of fossiliferous boulders in the north-west continental 
area bordering the North Sea is well known. Herr Norregaard * 
states he has collected these blocs from a tudlerve near Esbjerg, and 
although he classes them as Middle Miocene notes that “their fauna 
differs considerably, in certain respects, from that of the Danish 
Miocene”’ (op. cit., p. 46). His list of fossils from these boulders 
runs into sixty-four species. Sixteen of these, including Cardiwm 
ceingulatum, Turritella Geinitzt, Aporrhais speciosa, and Pleurotoma 
Stemmvorthi, are included in our boxstone fauna. 

Mr. Harmer informs me that Mr. van Waterschoot van der Gracht, 
the Director of the Geological Survey of Holland, told him that 
blocks of fossiliferous limestone, believed to be of Oligocene age, 
were not infrequently dredged by the North Sea fishermen. 

The ‘ fossiliferous limestone block from the North Sea” ®, described 
by Mr. R. B. Newton, F.G.S8., seems to have had a similar history. 
It ‘‘has not suffered a sea change’’, nor does it show any signs of 
abrasion or water-action. The stone is, I suggest, older than 
Mr. Newton makes it, and has been, I think, but recently cleared of 
the enveloping clay. Iam sorry to disagree with his interpretation 


1 Mem. Acad. Roy. Bruxelles, vol. xi, 1837. 

2 Proc. Geol. Assoc., vol. xvi, p. 385. 

3 Report on Ceylonese Pearl Fisheries, Roy. Soc., 1903, p. 348. 

4 **Mellem Miocene Blookke fra Esbjerg’’: Dansk. Geol. Foren., vol. v, 
No. 1, 1916. 


Q.J.G.S., vol. Ixxii, 1917. 


Alfred Bell—A ge of the Suffolk Boxstones. 19 


of certain forms, but in place of Ranella gigantea, Aporrhais pes- 
pelicamt, and Yoldia oblongordes, for example, I am inclined to read 
Triton flandricum, Aporrhais speciosus, and Yoldia glaberrima, all 
well-known Oligocene or Miocene species. The Watica figured as 
NV. Alderi isnot the recent form found in British seas; it may possibly 
be a variety of WV. Wystiz, like the one figured by Harder (op. cit., 
pl. v, fig. 27). 

Another question arises in connexion with the ‘‘ boxstones”’, 
1.e. how did the terrestrial mammalia and extra-local rocks become 
associated with them, the vertebrates being of Miocene and Pliocene 
ages, a connecting link appearing in the Mastodon tooth, described 
by Sir E. Ray Lankester as having the valleys or hollows between 
the cusps filled with the boxstone matrix. 

The latter writer described the detritus bed as a great beach or 
littoral accumulation formed immediately before the Coralline Crag 
and derived from many sources. I venture to suggest a different 
solution, viz. that the older phosphatized clays were originally 
deposited as the upper portion of the London Clay, as testified by its 
fossils, the boxstone sands being afterwards laid down upon this, 
both clays and sands having been but little removed from their 
original situation. 

The sands were probabiy deposited in the coralline zone at 
a moderate depth, the presence of so many double bivalves with 
valves closed, and the almost total absence of any of the littoral or 
shore-haunting molluscs, being a conspicuous feature. In due time 
this edge of the Anglo-Belgian basin became raised above the sea- 
level, and remained during that period of elevation as an upraised 
plain on whose surface the animal remains referred to were 
accumulated in local fluviatile deposits from time to time. 

Both clays and sands seem to have been desiccated and dis- 
integrated before the time of the Coralline Crag, but not disturbed, 
as we find it in position beneath the borders of this deposit at 
Sutton and Boyton. Beyond this it disappears, no traces of it 
having been found by Mr. F. W. Harmer when boring into the Crag 
outside these places. 

The detritus did not pass up into the body of the Coralline Crag, 
but in the succeeding zones, the Oakleyan and Newbournian stages, 
the Red Clay is full of the broken-up debris,’ and flints became 
abundant either as isolated blocks of large size and unabraded, with 
the cortex beautifully preserved or as waterworn pieces of smaller size. 

Under the submarine currents of the Coralline Crag sea the floor 
was but little disturbed, but at the close of its earliest portion, 
the Gedgravian of Harmer, a change in the fauna commenced, and the 
Boytonian period ushered in sundry tectonic changes, several species 
of northern or boreal mollusea, such as the Belas, making their 
appearance for the first time in East Anglia. This zone or period 
passed away, and with it a part of the older southern fauna, to be 
replaced by a more northern one. The flints just mentioned were 
due, according to Sir C. Lyell, to ice-action. Many of the smaller 

1 See Bell, ‘‘Sub-Crag Detritus’’: Proc. Prehistoric Soc. East Anglia, 
1915, vol. ii, not vol. xi as on p. 408 (ante). 


20 = Alfred Bell—Age of the Suffolk Bowstones, 


pieces occur in patches, on strings in slight depression of the soil 
beneath, as if an ice-floe, loaded with thes se stones, had grounded, 
leaving its burden intact. One such flint patch is present between 
the Coraline and Red Crag at Pettistree Hall, Sutton, on the 
Coralline Crag Hill of Pr estwich," where I saw it in situ. 

In the Newbournian period of the Red Crag, stormy seas seem to 
have been the normal feature, churning up the disintegrated sea-floor 
with its contents so as to make the fraements an integral part of the 
deposit it was then building. 

The fossils selected in illustration of this paper have been chosen 
as specimens of the various ways in which they occur, or as being 
_ unfigured species. The nomenclature I have used in this and the 
earlier paper will not perhaps commend itself to some scientific 
experts, but may be the better understood by ordinary workers in the 
Crag as being the language they are more familiar with, and will 
enable them to refer to earlier writers with greater facility. These 
continual changes in nomenclature are very bewildering to 
students in general. 

A further revision of material, lately come to hand, enables me 
to add a few species to those already quoted in No, 639 of the 
GrotocicaL Macazinn, September, 1917. : 
2Liomesus Feldhausit (Beyrich), Zeitsch. deutsch. geol. Ges., vol. viii, 

p. 243, pl. i, fig. 9, 1856. Mus. Pract. Geol. London. 

[Except that the boxstone shell is larger than the type there seems to be no 
difference, either in form or sculpture. ] 

Pseudocassis Harmert, n.sp. (see p. 413 ante for reference). Harmer Coll. 
Solariwm Hornesii, Michelotti, Htud. Mioc. inf. Ital., p. 92, pl. x, figs. 11-12, 
1861. Mus. Ipswich. 

[Iwo examples, both showing the underside, may be referred to this species. 
Moulds of the wall of the umbilical opening may be easily mistaken for the 
upper whorls of a small Cancellaria. | 
Cardium fragile, Brocchi, Conch. foss. subap., vol. ii, p. 505, pl. xiii, fig. 4, 

1814. Mus. Pract. Geol. London. 
Mactra ovalis, J. Sowerby, Min. Conch., vol. ii, p. 136, pl. elx, figs. 2-5. 
Mus. Pract. Geol. London. 

[The two last-named occur with Pecten Rwupéliensis, Pectunculus, and 
a number of others—mostly imperfectly exposed bivalves—in an irregular plaque 
of sandstone, see ante, p. 408. | 


EXPLANATION OF PLATES III AND IV. 


PLATE III. 
FIG. 


a 


Fasciolaria erratica (De Koninck), p. 411. la shows details of sculpture, 
16 the internal mould. Mus. Ipswich. 

Sipho Ravni, u.sp., p. 411. Mus. Ipswich. 

? Liomesus Feldhausii (Beyrich). Mus. Pract. Geol. London. 

Ficula acclinis (S. V. Wood), p. 412. Mus. Ipswich. 

Cominella conica, n.sp., p. 412. Mus. Ipswich. 

Semicassis saburon (Bruguiére), p. 412. British Mus. 

Pseudocassis Harmert, n.sp., p. 413. Pseudomorph in a phosphatized 
matrix. Harmer Coll. 

Trigonostoma cf. ampullacea (Brocchi). Mus. York. 

Solarium Hornesvi, Michelotti. Mus. Ipswich. 


1 Q.J.G.S., vol. xxvii, 1870. 


co CO WA OP oo bo 


Guop. Mac., 1918. shed Prate TH. 


G, M Woodward del, Bale, imp. 


CASTS OF SHELLS FROM THE SUFFOLK ‘BOX STONES.” 


Aen ane eer 


} 
‘ 


Gror. Maa., 1918. i > Presi 


Bale, imp. 


G. M. Woodward del. 


CASTS OF SHELLS FROM THE SUFFOLK ‘BOX STONES.” 


RE TOsens he Shand—The Norite of the Sierra Leone. 21 


PLATE IV. 

Fie. 6 

10. Voluta (Pyrgomitra) fusus (Philippi), p. 410. Mus. Ipswich. 

11. Conus antediluvianus, var.,Grateloup, p.410. Mus. Pract.Geol. London. 

12. Plewrotoma Steinvorthi, Semper, p. 410. Mus. York. . 

13. Natica ferruginea, var. (in Sacco), p. 414. Mus. Ipswich. 

14. Calliostoma Xavieri (Costa MS.), p. 415. Mus. Ipswich. 

15. Nucula placentina, Lamarck. Mus. Ipswich. 

16. Astarte Kickxti, Nyst., p. 417. Mus. Pract. Geol. London. 

17. Cardium Woolnoughi, n.sp. 17a shows the sculpture as seen in the 
intaglio or hollow mould. 170, inner mould of organism with the shell 
removed by decalcification. Mus. Pract. Geol. London. 

18. Cyrtodaria vagina (S. V. Wood). Mus. Pract. Geol. London. 

19. Flabellui cuneatum (Goldfuss). Bell Coll. 


Ve: Lia Norire oF tHn Srerra LrEone. 
By Professor 8S. J. SHAND, D.Sc., F.G.S., University of Stellenbosch, Sonth 
Africa. 

NHE Sierra Leone, from which the Colony of Sierra Leone takes 
its name, is a range of palm-covered hills running parallel to 
the coast (N.N.W.-S.8.E.). It is truncated on the north by the 
wide mouth of the Roquelle (Rokell) River, which forms the 
magnificent harbour of Freetown. Towards the south the range 
terminates at Yawry Bay. The length of the Sierra is therefore 
about 25 miles and its width, from Kassa Town to Kissy, 
about 8 miles. On the east side the range descends steeply to the 
Kwaia plain, from which it is separated by Waterloo Creek. The 
detachment of the hills from the interior lowland is sufficiently 
complete to entitle one to speak of the Sierra Leone Peninsula. 
Freetown is built on the north end of the peninsula, overlooking the 
harbour, and it straggles up from sea-level to a height of some 
800 feet on Wilberforce Hill. The greater part of the peninsula is 
covered with thick tropical vegetation right down to sea-level; and 
an additional obstacle to geological study is created by the heavy 
covering of laterite which screens the rocks from observation. In 
places this laterite mantle is 30 feet thick. But along the northern 
shore of the peninsula, from Cape Sierra Leone to the mouth of 
Waterloo Creek, there are nearly continuous exposures of norite, 
and further useful exposures have been made during the construction 
of the Hill Railway and along certain of the roads on the hillside. 
These outcrops make it clear that the whole of the north end of the 
Sierra is formed of norite, and it would not be surprising to learn 

that the entire Sierra has the same composition. 

The norite or gabbro of Freetown was described by G. Giirich in 
1887,1 and I have not been able to trace any subsequent reference to 
it. Rocks from the interior of the colony were examined by G. F. 
Scott Elliot and Miss C. A. Raisin in 18938,?and as far as I am aware 
no further contribution to the geology or petrology of the country 
has been made since that date. I spent a few days in Freetown 
recently, and took advantage of the opportunity to examine the rocks 
and collect a few specimens. I can add little to the account of the 


' Zeit. der Deutschen Geologischen Gesellschaft, vol. xxxix, p. 108. 
2 Colonial Reports, Misc., No. 3 (Sierra Leone), p. 61. 


22 Prof. S. J. Shand—The Norite of the Sierra Leone. 


norite given by Giirich, but where the whole store of observations is 
so meagre any addition to it ought to be useful. It is desirable in 
any case that records relating to British colonies should be accessible 
in the English language. 

The rock, as exposed about Freetown and on Wilberforce Hill, 
shows the following textural facies. 

1. A coarse-grained variety, sometimes forming definite pegmatite 
veins, composed mainly of felspar plates in sub-parallel arrangement. 
Some of the crystals are nearly an inch in diameter, and their colour 
is iron-grey. ‘he coarser the grain of the rock, the smaller the 
proportion of heavy minerals, which may sink to 5 per cent or less. 

2. A medium-grained variety which may be called the average 
rock, in which the felspar crystals have diameters of 2 to 4 mm. 
The arrangement of the crystals is still sub-parallel. Olivine grains ~ 
are prominent, and the heavy (or mafic) minerals constitute about 
25 per cent of the volume of the rock. 

3. A fine-grained variety in which the crystals are equidimensional 
and have an average diameter of less than 0°6mm. ‘The texture is 
similar to that of an aplite, or what is sometimes called a “ trap- 
granulite’’. Heavy minerals make up some 60 per cent of the whole. 
I believe this facies of the rock to bear the same relation to the last 
that an aplite bears to a granite. 

The following minerals are present: plagioclase, olivine, hyper- 
sthene, diallage, titanomagnetite. 

The plagioclase is entirely fresh and glassy, and invariably dark- 
grey in colour. In general it forms pinacoidal tables with Carlsbad 
and albite twinning, but in the aplitic rock it appears in anhedral 
grains. ‘The extinction angles show it to be an acid labradorite, 
approaching Ab, An,. No zonal structure could be detected. 

Olivine is an important constituent of the average rock, but is 
entirely absent from the aplitic facies. It is perfectly fresh, or 
shows only incipient hydration along cracks. The crystals are 
moulded upon the felspars, and are sometimes mere skeletons 
embracing numerous felspar laths. Gtrich has illustrated this 
feature in his paper. Olivine iscommonly intergrown with diallage 
and may be enclosed by hypersthene. Some varieties of the rock 
contain little but felspar and olivine. 

Diallage of asmoky-brown colour is the common pyroxene in the 
coarser varieties of the rock. It is charged with opaque ore- 
inclusions which le along planes of parting. It forms skeleton- 
crystals surrounding felspars, and rounded grains of diallage are 
often completely enclosed in hypersthene. 

Hypersthene is the only ferromagnesian mineral present in the 
aplitic facies of the rock, but in the average rock it is associated 
with, and generally subordinate to, diallage. In the former case the 
hypersthene grains are equidimensional, and they form an even- 
grained aggregate with anhedral felspar grains of the same size. 
Even here, however, the hypersthene has demonstrably been moulded 
on the felspar. In the coarser varieties of the norite the hypersthene 
occurs in anhedral plates which enclose all the other minerals of the 
rock. The pleochroism is strong, indicating a high iron-content. 


Notices of Memoirs—Geology of the Forest of Dean. 23 


Magnetite (titanomagnetite) is present in irregular, often rounded 
grains, but some crystals show isometric sections. A highly refracting 
border (leucoxene ?) surrounds some of the grains, indicating the 
presence of titanium. Scott Elliot noted the occurrence cin the 
hills behind Sierra Leone” of a titaniferous iron-ore yielding 52 per 
cent of metallic iron and 14 per cent of Ti Op. Giirich, too, saw in 
a private collection of minerals in Freetown lumps of magnetite 
as large as the fist. I venture to conclude that this ore-body occurs 
as a segregation within the norite; indeed, the recognition of the 
petrographic character of the rock would lead one to anticipate the 
existence of such segregations. These indications ought to be 
followed up, as they might lead to the discovery of important ore- 
deposits. The matter is one for the attention of the Imperial 
Mineral Resources Bureau. 

Estimates of the percentage composition of these rocks yielded the 
following results in the case of (A), a specimen of what I have called 
the average rock, and (B) the aplitic facies :— 


A. B. 
Vol. %. Weight-%. Vol: %: Weight %.: 
Plagioclase  . : 74 69 41 35 
Olivine . : F 14 16 0 0 
Diallage | 9 10 f 0 0 
HyperstheneJ = \55 59 
Magnetite . é 2°3 4 4 6 


The order in which the minerals crystallized is as follows: 
labradorite, olivine, diallage, hypersthene; magnetite uncertain. In 
brief, the fine-grained rock is a melanocratic norite (mg — micro- 
norite), while the coarser varieties are leucocratic olivine-norites 
(1, —toly- subnorite). I invite attention here to a change which 
ought to be made in the subdivision of the gabbroitic rocks ; namely, 
that in deciding whether a rock is to be attached to gabbro or to 
norite the olivine should be reckoned along with the rhombic pyroxenes, 
since the latter minerals arise by the addition of silica to olivine. 
Thus all troctolites and ‘‘olivine-gabbros’’ (including those above 
described) in which the sum of olivine plus rhombic pyroxenes 
exceeds that of the monoclinic pyroxenes should be regarded as 
norite (subnorite), no a as Gabon: 


NOTICHS OF MEMOTRS.- 


On tHE GrotocicaL SrrucruRE oF THE Forest oF Drawn.’ By 
T. Franxuryn Srsry, D.Sc., F.G.S8., Professor of Geology in the 
University College of South Wales and Monmouthshire, Cardiff. 
(A paper read before the Forest of Dean Branch of the National 
Association of Colliery Managers on October 25, 1917.) 

a 1894 Dr. R. Kidston correlated the Coal Measures of the Forest 
of Dean with the true Upper Coal Measures.* In 1910 Dr. T. T. 

Groom, reasoning from this correlation, pointed out that ‘‘ unless the 

1 Reprinted (by permission), with some emendations by the author, from 


the Colliery Guardian, vol. exiy, No. 2966, November 2, 1917, pp. 839-40. 
2 Proc. Roy. Phys. Soc. Edin., vol. xii, p. 222, 1894. 


24 Notices of Memoirs—Professor T. Franklin Sibly— 


measures that have not been detected [the true Lower and Middle 
Coal Measures] are exceedingly thin, or are represented by the 
upper part of the Millstone Grit, there must be an unconformity at 
the base of the Coal Measures’”’.' \ 

The late Dr. A. Vaughan had proved the Lower Carboniferous age 
of the lowest beds of the Millstone Grit near Mitcheldean.* In 1912 
Dr. E. A. Newell Arber, whose detailed study of the fossil plants in 
the local Coal Measures confirmed Dr. Kidston’s correlation, wrote as 
follows: ‘“‘ Reviewing the present evidence I am inclined to think 
that it will eventually prove that an unconformity exists a short 
distance below the Lower Trenchard Coal perhaps a little above the 
Sandstone vein of Iron Ore. ... True Millstone Grits, Lower, 
Middle, and Transition Coal Measures appear to be absent in the 
Forest of Dean, so that the unconformity in question is of consider- 
able importance.’’ ® 

The present author’s independent investigations led him in 1912 
to the conclusion that an unconformity at the base of the Coal 
Measures is an important structural feature in the Forest of Dean. 
In a short paper on the Carboniferous succession* he described the 
Lower Carboniferous sequence near Mitcheldean, proposed the name 
Drybrook Sandstone for the ‘‘ Millstone Grit” of the district, and 
demonstrated the reality of the intra-Carboniferous unconformity by 
describing the persistent overstep of the Coal Measures across the 
Drybrook Sandstone and Carboniferous Limestone, as well as by 
other evidence. 

The author has been assisted in his later researches in the 
district by a grant from the Government Grant Committee of the 
Royal Society. He is permitted by the Director of the Geological 
Survey of Great Britain to make use of information gained in the 
course of his present investigation, as an officer of the Geological 
Survey, of iron-ores in the Forest of Dean. 


It is well established on paleontological evidence that the 
Carboniferous Limestone of the Forest of Dean represents, approxi- 
mately, the lower half only of the same formation as seen in the 
Avon Gorge at Bristol. The zones of the Carboniferous Limestone 
Series in the Avon Gorge, recognized by the late Dr. Vaughan, are 
denoted, in ascending sequence, by the symbols K, Z, C, 8, D. 
The highest member of the Carboniferous Limestone on the north- 
eastern borders of the Forest of Dean, the Whitehead Limestone, 
represents the topmost part of C (Syringothyris zone) and possibly 
the lowest part of S (Seminula zone). The Whitehead Limestone, 
which rarely exceeds 30 feet in thickness, gives place on the south- 
western border of the Forest to a series of dolomite-mudstones, black 
and grey crystalline dolomites, and clays with dolomite nodules, of 
much greater thickness; but this series does not encroach much on 
the Seminula zone. 

1 Geology in the Field, Jubilee Volume of the Geologists’ Association, 1910, 

. 731. 

y ZO EGaSavOlep bain 2524509 Oar 
3 Phil. Trans. Roy. Soc., vol. ccii, B, pp. 270, 277, 1912. 
4 GEOL. MaG., N.S., Dec. V, Vol. IX, pp. 417-22, 1912. 


Cae 


Geology of the Forest of Dean. 25 


The upper portion of the Carboniferous Limestone of areas to the 
south is represented in the so-called Millstone Grit of the Forest of 
Dean. This Millstone Grit, which succeeds the Carboniferous 
Limestone quite conformably, is mainly, if not entirely, a formation 
of Lower Carboniferous age. The name Drybrook Sandstone was 
applied to it in 1912. 

Thick bands of limestone and dolomite appear in the Drybrook 
Sandstone on the south-western margin of the coai-field. Near 
Milkwall oolitic limestones in the lower part of the formation have 
yielded Semenula ficordes, Cyrtina carbonaria, and other fossils of the 
main Semiula zone (S2). Cyrtina carbonaria has also been observed 
in corresponding beds of dolomite in the Parkhill adit (Fryer’s 
Level). The lower portion of the Drybrook Sandstone may, there- 
fore, be correlated definitely with the main Seminula zone of the 
Carboniferous Limestone. Unquestionably, the Drybrook Sandstone 
passes laterally into limestones as we proceed from the north-eastern 
margin of the Forest of Dean southwards to Chepstow and Bristol. 

Concurrently with the development of limestones the arenaceous 
beds, which compose the bulk of the Drybrook Sandstone even on 
the south-western margin of the coal-field, become finer in grain 
when followed south-westwards. For example, seams of quartz- 
conglomerate are conspicuous in the Drybrook Sandstone of the 
Mitcheldean district, but these have dwindled to insignificance in 
the neighbourhood of Bream. Bands of shale and fine-grained 
sandstone, containing shreds of coal, are found in the upper part of 
the Drybrook Sandstone in the Parkhill adit. 

Owing to overstep by the unconformable Coal Measures the 
Drybrook Sandstone is wholly concealed both on the south-east 
between Lydney Park and Staple Edge Wood, where the Carboni- 
ferous Limestone also is concealed, and on the north between 
Drybrook and Lydbrook Valley. From the same cause the apparent 
thickness of the Drybrook Sandstone varies greatly, and in no 
regular manner, along its outcrop. The thickness is at least 
650 feet in the Soudley Valley between the Shakemantle Pit and 
Staple Edge Halt, where the upper beds are well exposed on the 
railway. 

The Coal Measures of the Forest of Dean lie unconformably, and 
sometimes with great discordance of dip, upon an eroded floor formed 
by the Drybrook Sandstone, the Carboniferous Limestone, and on the 
south-eastern margin of the coal-field, the Old Red Sandstone. 

This important unconformity is due to an intra-Carboniferous 
episode of erust-movement, folding, and denudation which followed 
the deposition of the Drybrook Sandstone, but preceded the formation 
of the existing Coal Measures of the Forest. The latter were 
deposited on the denuded edges of the older strata. An altogether 
later movement involved the Coal Measures, gave them their present 
basin-like arrangement, and served also to accentuate the folding 
previously imposed upon the older rocks. 

The intra-Carboniferous disturbance responsible for the uncon- 
formity necessarily involved the Silurian and the Old Red Sandstone, 
together with the Lower Carboniferous strata. It produced the 


{ y 


26 Notices of Memoirs—Professor T. Franklin Sibly— 


main uplift of the May Hill anticline lying immediately east of the 
Forest of Dean. North-and-south folding predominated, but was 
accompanied by some east-and-west folding. The result was a basin, 
markedly unsymmetrical in structure, on the site of the present 
coal-field. Along what is now the eastern edge of the coal-field the 
Lower Carboniferous strata were involved in the western limb of the 
May Hill anticline, and acquired a steep dip westwards, the larger 
part of the very steep dip that they possess to-day. Westwards 
across the site of the present coal-field, away from the May Hill 
axis, the intensity of folding diminished very rapidly, and on the 
western side of the basin the inward dip of the strata was very 
slight. Consequently, the beds of the Coal Measures are nearly, but 
not exactly, accordant with the underlying strata on the western side 
of the present coal-basin, but markedly discordant with them on the 
eastern side, But, slight though the discordance may be on the 
western side, the behaviour of the outcrops supplies convincing 
evidence of unconformity all around the coal-field. The base of the 
Coal Measures pays no regard to the strike of the Lower Carboniferous 
beds, but everywhere passes to and fro, slowly or rapidly, across 
their outcrops. 

Two interesting and significant features are (1) the development 
of conglomerates at the base of the Coal Measures, and (2) the con- 
cealment of the Trenchard Coal and the measures beneath it by the 
overlap of the overlying measures, on the south-eastern border of the 
coal-field. These may be described in connexion with the uncon- 
formable overstep of the Coal Measures. 

The lowest beds of the Coal Measures, those underlying the 
Trenchard Coal (Upper Trenchard Coal in some parts of the coal- 
field), were termed 'renchard Measures by the late H. D. Hoskold.* 
The Trenchard Measures, although variable in character, usually 
consist largely of yellow grits, in part fine-grained, compact, and 
well-bedded, in part coarse-grained, friable, and imperfectly 
stratified. The intercalated clays are sometimes mottled in purple 
and yellow. A characteristic feature of these grits, particularly in 
the coarse-grained and conglomeratic varieties, is the abundance of 
an indurated, white or yellow clay cementing the grains. Om the 
northern and north-eastern borders of the coal-field these grits of the 
Trenchard Measures often become very coarse-grained and pebbly at 
their base, and bands packed with quartz pebbles or quartzite pebbles 
constitute well-defined basal Coal Measure conglomerates. 

On the northern edge of the coal-field, between Drybrook and the 
Liydbrook Valley, the base of the Coal Measures transgresses the 
older strata rather sharply, the Drybrook Sandstone and the upper 
beds of the Carboniferous Limestone are concealed, and the grits of 
the Trenchard Measures rest directly upon Carboniferous Limestone. 
A quarry 1,100 yards east of Ruardean Church shows masses of 
coarse, pebbly grit resting upon, and in places ‘‘piped”’ down into, 
the dolomites of the Carboniferous limestone. The former extension 
of Coal Measures northwards and westwards across the denuded 

1 “ Geological Notice upon the Forest of Dean’’: Proc. Cotteswold Nat. 
Field Club, vol. x, pp. 123-77, 1892. 


Geology of the Forest of Deun. QE 


edges of the underlying strata is proved by outliers of ‘l'renchard 
Measures. In the large outlier of Howle Hill, represented as 
Millstone Grit on the Geological Survey map (sheets 48 S.W. and 
43 8.K., Old Series), Trenchard Measures rest directly upon the 
Lower Limestone Shales. A smaller outlier on Courtfield Hill, 
Welsh Bicknor, not shown on the Survey map, rests upon the Lower 
Limestone Shales and the base of the Main Limestone. 

The railway-cutting immediately north of Drybrook Halt gives 
a fine section of Trenchard Measures resting upon massive sandstones 
which lhe in the lower part of the Drybrook Sandstone. The basal 
beds of the Coal Measures is here a remarkable pebble-bed with 
large, well-rounded pebbles of grey quartzite. ‘his pebble-bed has 
been traced some distance north of Drybrook, and has been recognized 
in the Howle Hill outlier. 

On the eastern edge of the coal-field from Wigpool Common as far 
south as the Soudley Valley, the 'renchard Measures rest upon 
Drybrook Sandstone. In the Soudley Valley, the railway-cutting 
south of Staple Edge Halt exposes the unconformable contact of the 
two formations. Conglomerates forming the base of the Trenchard 
Measures, and containing fragments of a fine-grained, white sand- 
stone which can be matched in the Drybrook Sandstone of the same 
cutting, rest upon the Drybrook Sandstone with discordance of dip. 
The average dip of the Drybrook Sandstone in the cutting is 
50° W.N.W. The conglomerates dip slightly north of west at 
about 26°. 

South of the Soudley Valley, overstep carries the base of the 
Coal Measures southwards, and then eastwards, across fully 650 feet 
of Drybrook Sandstone and the whole of the Carboniferous Limestone, 
in the distance of barely 2 miles to the southern side of the 
Blackpool Valley. The Lower Carboniferous strata maintain a steep 
north-westerly dip, rising to 65° in places, as their strike swings 
gently from 8.8.W.toS.W. The Coal Measures maintain a moderate 
dip a little north of west. The Drybrook Sandstone and the upper 
beds of the Carboniferous Limestone are transgressed gradually in 
Staple Edge Wood. The bulk of the Carboniferous Limestone is 
transgressed very sharply in the Blackpool Valley. On the south 
side of that valley the base of the Coal Measures continues its rapid 
overstep eastwards until, just north of Danby Lodge, it crosses the 
quartz-conglomerates which lie some 400 feet down in the Old Red 
Sandstone. 

In consequence of this sharp overstep the Carboniferous Limestone 
and the Upper Series of the Old Red Sandstone remain wholly 
concealed from Danby Lodge to the western side of the Cannop 
Valley, above Lydney. In and near Stonebury Wood, north of 
Lydney Park, the quartz-conglomerates of the Old Red and the beds 
of the Carboniferous Limestone, dipping very steeply westward, 
reappear from underneath the cover of unconformable Coal Measures. 
The sharp swing of the Coal Measure base here carries it back 
rapidly from the Old Red Sandstone on to the Drybrook Sandstone 
in Old Park Wood. 


The unconformable overstep of the Coal Measures is attended, on 


28 Reviews—Geological Survey of Great Britavn. 


the south-eastern margin of the coal-field, by conformable overlap. 
The Trenchard Coal and the underlying Trenchard Measures are 
overlapped by the Pennant Sandstone above them. As a result, 
the Pennant comes to rest directly and unconformably upon the 
older, steeply inclined strata, and the Trenchard Measures fail to 
crop over a considerable part of the distance between Staple Edge 
‘Wood and the Cannop Valley. This is abundantly clear at Danby 
Lodge, where the Pennant Sandstone, containing the Coleford High 
- Delf Coal, transgresses the quartz-conglomerates of the Old Red. 
It is confirmed by the section in an old quarry on the northern side 
of the Blackpool Valley, which shows the unconformable junction of 
Pennant Sandstone and Carboniferous Limestone. The sandstones 
in this quarry dip gently westwards. They show lenticles of clay 
and a streak of very coarse grit or quartz-conglomerate at their base, 
and repose upon the worn, hummocky edges of Ge louuile-ets which 
dip north-westwards at about 60°. 

To sum up, an unconformity at the base of the Coal Measures is 
a dominant feature in the geological structure of the Forest of Dean. 
It is evidenced (1) by the overstep of the Coal Measures across the 
Drybrook Sandstone, the Carboniferous Limestone, and the Old Red 
Sandstone, (2) by a great difference between the prevailing dip of 
the older strata and “that of the Coal Measures along the. eastern 
margin of the coal-field, and (3) by visible discordance of dip at 
exposed junctions of the Coal Measures with Drybrook Sandstone and 
Carboniferous Limestone respectively. It is attended by (1) the 
development of basal conglomerates in the Coal Measures, particularly 
well seen on the northern border of the coal- field, and (2) local 
overlap of the Trenchard Measures by the Pennant Sandstone, 
whereby the former are concealed along part of the south-eastern 
edge of the coal-field. 


RAV LHWwWS- 


I.—Gronocican Survey oF Great Briar. 


Summary or Progress oF THE GEoLocicaL SurvVEY oF Great Brirain 
FoR1916. 8yvo; pp. iv +56 and 3figuresintext. London, 1917. 
Price 1s. 6d. 

S was only to be expected, the energies of the Geological Survey 
have been almost entirely diverted into new channels connected 
with the War. Ordinary field work and detailed mapping are 

_ completely suspended, and the remaining staff has devoted itself to 

the investigation of certain pressing problems connected with the 

mineral resources of the country. Almost the only exception to this 
statement is the continuance of the work of examining bore-holes 
now in progress; this information, if not recorded at once, is 
necessarily most difficult to recover at a later date. Five volumes of 

Special Reports have been published dealing with the occurrence of 

certain minerals of economic value, and a further volume is in 

preparation on the subject of refractories; these include sandstones, 
quartzites, ganister, sands, and fireclays (acid refractories), as well as 
the basic rock dolomite. These are used for furnace linings and 


dif 


Reviews—Geological Survey of Scotland. 29 


hearths, moulding sands, silica bricks, fire-bricks, and many other 
purposes. In Scotland the examination of the coal-field has been 
continued, most of the Highland staff being transferred thither, and 
several volumes of special district memoirs have been published or 
are in preparation. The Dalry iron-field has also been investigated 
in detail as a likely source of further supplies of iron-ore of good 
quality. The work of the Chemical Department has Jain chiefly in 
the analyses made in connexion with the report on refractories. 

The Summary of Progress also contains three important appendices 
on deep borings, one in Yorkshire, 7 miles north-west of Doncaster, 
the others in Kent and Sussex. ‘The fourth appendix, by Mr. G. W. 
Lamplugh, F.R.S., contains a summary of the present state of our 
knowledge of the underground range of the Jurassic and Lower 
Cretaceous rocks in Kast Kent, including a good deal of information 
that has only become available since the publication of the memoir on 
the subject in 1911. Some of these results were not accessible till 
after the printing of Mr. Baker’s paper on the same subject in 
the December Number of the Grotoercan Macazrne. The general 
result of Mr. Lamplugh’s work is that the Jurassic and Lower 
Cretaceous rocks together form a great, wedge with a northward 
apex, lntervening between the Paleozoic floor and the Gault, and 
that the northern part of the Wealden anticline is superimposed 
upon a syneline of the deeper rocks. This interesting result has 
become much more clearly apparent from the later borings, although 
it could be demonstrated from the earlier data. 


R. H.R: 


Il.—GrotoctcaL Survey oF ScornanD. 
Tur Economic Grotocy oF THE CrnrRaL CoaL-FIELD OF ScCorLaND. 
Description or ArgEA IT. Mem.Geol. Surv. Scotland. pp.iv+89, 
with folding maps and sections. Kdinburgh, 1917. Price 4s. 6d. 


HE Scottish branch of the Geological Survey is making rapid 
progress with the publication of its excellent series of nine 
memoirs on the coal-fields of Scotland. ‘Those relating to areas V 
and VIII have already been noticed in the Guotoeican Macazine. 
The present volume deals with area II, which lies almost wholly 
within the county of Stirling, and includes the Coal-measures of 
Banknock, Carron, Falkirk, and Slamannan, and the coals and iron- 
stones of the limestone coal group of the Plean and Denny districts. 
The coal-seams are described with the usual amount of detail, and 
from the figures given it is clear that the majority of them come 
within the category of thin coals; these, however, will doubtless 
be profitably worked in the future with improved methods and 
machinery. The Millstone Grit Series of Cumbernauld, Castlecary, 
and Bonnybridge includes important beds of fireclay and ganister, 
which are now of great and increasing importance as refractories. 
Several analyses show that these fireclays are of very good quality 
and are likely to be largely developed within a short time. ‘The 
raised beaches, alluvium, and peat are also briefly described. ‘The 
peat is likely to be of considerable economic value, and indeed was 


30 Reviews— Dominion of Canada, Ottawa. 


already worked before the War for moss-litter; this industry has 
now ceased. 


1. SEE 


T1].—Domrnion or Canapa, Orrawa. 
AnnuaL Report oN THE MineraL Propuction oF CANADA DURING 
THE CaLENDAR YEAR1915. By Joun McLeztsu. pp. 364. Ottawa: 
Government Printing Bureau, 1917. 


O doubt the delay in the publication of this report is due to war 
il conditions. It is not, however, so belated as might at first 
sight appear, since the more important parts saw separate publication 
at a much earlier date, and a preliminary report was issued as early 
as February, 1916; moreover, the preface is dated September 21, 1916. 
The mineral resources of Canada are very considerable, and are as 
yet far from being fully developed. The greater portion of the 
present production is exported for consumption or refining outside 
the Dominion, while on the other hand considerable quantities of the 
products of the mines, after refining or partial treatment, or in the 
shape of manufactured goods ready for consumption, are imported. 
Nearly half the total output, considered from the point of view of 
value, comes from the Province of Ontario, thanks largely to the 
richness of the nickel-cobalt-silver minerals of Cobalt, British 
Columbia, which ranks second, coming a long way behind. The 
whole of the copper, nickel, and silver, and much of the gold is 
exported for treatment. It is interesting to note that of the total 
amount of mine products exported 72 per cent went to the United 
States and 25 per cent to the United Kingdom. Much of the world’s 
supply of asbestos is contributed by Canada, and for the dozen years 
to 1915 the exports of asbestos have averaged over 85 per cent of the 
total shipments; it may be noted that the mineral in question is 
chrysotile (fibrous serpentine) and not the asbestos of mineralogists 
(fibrous amphibole). The report covers the first complete year of 
war, and shows clearly that already the War was having a marked 
effect on mining; the iron and steel industry in particular was very 
active during the year. 
The report is well and neatly arranged, so that reference to it is 
easy, and the salient features are readily gr rasped. 


ITV.—Summanry Reporr or tHe GeoLocicaL SurvEY, DEPARTMENT OF 
Mines, FoR THE YEAR 1916. pp.ix+419. Ottawa, 1917. 


fW\HIS large and closely printed volume gives striking evidence of 

the activity of the Canadian Geological Survey. Owing to the 
War the conditions are necessarily exceptional, and the indoor work 
of the department has been considerably hampered by the taking 
over of its permanent quarters to afford a temporary home for the 
Canadian Parliament after the great fire in February, 1916. The 
outdoor work has naturally been largely concerned with the 
examination of districts likely to yield products of special value at 
the present time. One of the most important of these is tungsten, 
which has been found in considerable quantities in the Yukon 


Reviews—Ooal-fields and Coal Industry of E. Canada. 31 


Territory, as well as in New Brunswick and Nova Scotia. The 
present high price has naturally stimulated the development of even 
small deposits of the ores, which include both wolframite and 
scheelite. In the Lillooet district of British Columbia molybdenite 
ore has been found in streaks and veins in a mass of very quartzose 
granite and is now undergoing development. The molybdenite 
mine of Guyon, Quebec, is also important. Another industry com- 
paratively new to Canada is the mining or quarrying of magnesite, 
for which there is a large demand in America as a refractory to 
replace the magnesite formerly imported from Austria and Greece. 
The magnesite deposits of the Grenville district have already been 
noticed in this Magazine, and the mineral is also being worked in 
British Columbia and other districts. The Californian magnesite 
belt appears to extend into British Columbia. 

One of the most interesting sections of the Report is that dealing 
with investigations for coal, oil, gas, and artesian water in Alberta 
and Saskatchewan. As is well known, Western Canada possesses 
great stores of lignitic coal, forming one of the largest continuous 
coal-fields of the world. This is now undergoing rapid development 
following on the advance of transport facilities. ‘The oil and gas- 
field of Alberta has now reached a stage of important productiveness, 
and the gas is utilized on a very large scale for light, heat, and power 
in the cities of Calgary, Medicine Hat, and others. The strata from 
which the gas is derived are of Cretaceous age, and the structure is 
a broad, low anticline, plunging northwards; the gas-bearing strata 
oceur at two horizons at depths on the average of about 700 and 
1,000 feet from the surface. In the Medicine Hat area there are 
thirty gas-wells, which yield about 88,000,000 cubic feet per day. 
Borings to still greater depths have yielded a strong flow of saline 
water. 

Besides the economic work, the officers of the Survey have carried 
out a very large amount of stratigraphical, paleontological, and 
general geological investigations in all parts of the Dominion, much 
of which is of great interest, but cannot here be mentioned in detail. 


Jigs Dele Dave 


V.—Tue Coat-FIELDS and Coat Inpustry or Easrern CanaDa : 
A GeyneraL Survey anp Description. By Francis W. Gray. 
pp. 67, with 26 plates and 1 map. Ottawa: Government 
Printing Bureau, 1917. 


fYVHIS ably written bulletin contains much of interest both to the 

geologist and the economist. The Carboniferous area is all 
within the maritime provinces, and is nearly a parallelogram in 
shape, the four corners of which are the mouth of Chaleur Bay on 
the west, Fredericton, New Brunswick, on the south, Arichat, Cape 
Breton, on the east, and the head of St. George’s Bay, Newfoundland, 
on the north. The Carboniferous rocks occur on both sides of the 
Cabot Straits, and are possibly continuous under the sea. Unlike the 
common practice which prevails in the United Kingdom, the United 
States, and indeed in other parts of Canada, the mineral rights are 


32 Reviews—Mining of Thin Coal Seams, E. Canada. | 


in the hands of the Government of the Province. This happy result 
came about in a rather curious manner. In 1784, when Cape Breton 
was made a separate province, the Privy Council reserved to the 
Crown all the coal and other valuable minerals, and had earlier 
forbidden the mining of coal, so that the unfortunate colonists had 
the mortification of seeing the coal which fell from the cliffs on to 
the shore washed out to sea. ‘lhe Crown did not make a wise use of 
the Royal prerogative, but leased the mines to the Duke of York, who 
happened to be deeply in debt at the time. The lease was eventually 
broken in 1857 after considerable agitation. The fortunate result 
has been that the mining rights did not fall into private hands. 

The estimated amount of the coal reserve of Nova Scotia is less 
than 1 per cent of the total reserve for Canada, but, because of 
the excellent quality of the deposits, their remoteness from other 
coal-fields, and their accessibility, Mr. Gray considers Nova Scotia 
will remain the chief coal-producing province of the Dominion for a 
long time. At present its output is nearly 60 per cent of that of 
the whole of Canada. One of the great difficulties in working the 
mines is caused by the ever-present gas, and in spite of all the 
precautions taken there have been several bad explosions resulting 
in loss of life. 

Copious statistics of the various mines are given, and the excellent 
index provided renders reference to the report easy. 


VI.—Tue Minine or Turn Coat Szams as appLtep to THE EASTERN 
Coat-FIELps oF Canapa. By J. F. Ketiock Brown. pp. vill 
and 1385, with figures and a coloured map. Department of 
Mines, Ottawa, 1917. 


T is well known that certain parts of the coal-fields of the eastern 
provinces: of Canada contain a large number of thin seams of 
coal in addition to the thick ones which are more generally worked. 
The Government authorities have very wisely undertaken the con- 
sideration of how these may best be turned to-account. The chief 
problem to be solved is to determine whether it is most advisable in 
the public interest to work all seams together, or to preserve either 
the thicker or the thinner seams with a view to keeping up the 
supply as long as possible. In this memoir the line of demarcation 
between a thick and a thin seam is taken at 3 feet: the lower 
limit of possible working under conditions likely to obtain in the 
immediate future is taken as 12 inches, in agreement with the 
views of the British Coal Commission. After a careful survey of 
the whole situation it is recommended that the thin seams should be 
worked concurrently with the thicker ones, in order to extend as far 
as possible the life of the latter, and that measures should also be taken 
to secure co-ordination in colliery- working generally, so as to reduce 
working costs and to prevent wasteful competition. A very complete 
account is given of the position and thicknesses of all known seams, 
together with their depth from the surface. From this it appears 
that by far the richest area is in Pictou County, Nova Scotia, where 
some of the seams run up to nearly 40 feet. Over the rest of the 


Reviews—Recent and Fossil Rupple-marks. 33 


coal districts the seams are much thinner, thougn often still con- 
siderable, and the total reserve is still large. Unfortunately a large 
part of the coal-fields lie under the sea, so that access is rendered 


more difficult: 
Re HR: 


Vil—Recrent anp Fosstzn Rrepre-marks. By E. M. Kryoptz. 
Geological Survey of Canada, Museum Bulletin No. 25. pp. 56, 
with 33 plates. Ottawa: Government Printing Bureau, 1917. 


IPPLE-MARKS are of three distinct types: the first is due to 
current action on a sandy bottom, the second to wave action, 
and the third to the direct action of wind on sand. Mr. Kindle 
discusses very fully the characteristic features of each type, and 
illustrates them by means of photographs and profiles of casts of 
plaster of paris moulds taken directly from ripple-marks. Many of 
the moulds were actually taken under water, at times at not in- 
considerable depths, with the aid of ingenious apparatus which the 
author had specially designed for the purpose. Geologists will be 
grateful to him for his clear exposition of the subject. For the lack 
of some such work geological literature contains many references to 
ripple-marks which are full of mistakes, A common error is to 
suppose that fossil ripple-mark is evidence of shore or shallow-water 
conditions. On the contrary, there is every reason to believe that 
the action of a storm wind will produce ripple-marks to a depth of at 
least fifty fathoms of water. The greatest depth at which the author 
has obtained a plaster of paris mould was 27 feet. Again, many of 
the so-called ‘‘ mud-flows” which have often puzzled geologists are 
really the marks produced by the mutual interference of two or more 
currents. 

It is interesting to note that whereas the amplitude of dune or 
wind ripple-mark shows only slight variation, that of subaqueous 
current ripple-mark may vary enormously, depending on the load of 
sediment carried and the velocity of the current. Ripples of colossal 
size are developed in the Ottawa River during the flood stage over 
the broad sand-bar at Duck Island. In late summer they are laid 
bare at low water, and the crests of the ridges are seen to be 30 to 45 
feet apart and 1 to 2 feet above the troughs. In estuaries subject to 
strong currents terrace-like ripples are formed which though of 
remarkable size closely resemble ordinary ripple-marks. 


VIII.—Sovurn Avsrratra. 

A Review or Mrytne Operations In THE Stare or Sour AUSTRALIA 
DURING THE HALF-YEAR ENDED Drcemper 31, 1916. No. 26. 
Compiled by L. C. Gun, S.M., Chief Registrar and Recorder, 
Department of Mines. pp. 91, with 4 plates and map. Adelaide, 
OT. 


f{\HIS review contains reports on a number of different mining and 

prospecting operations in the State of South Australia. Bores 
have been undertaken with the object of discovering the westerly 
extension of the Wallaroo main lode to the Wallaroo Extended 


2 


DECADE VI.—VOL. V.—NO. I. 2 


34 Reviews—North Queensland Tin-fields. 


Leases, unfortunately without good results, though they were 
continued through the old crystalline rock to a depth of over 
1,000 feet in twocases. Among the special reports, accounts are given 
of the working of precious opal in Stuart’s Range in the centre of 
South Australia, manganese ores at Pernatty Lagoon, boring for oil 
near Robe, and details of various copper-mines, most of which are 
not now working. 

The precious opal occurs in the Desert Sandstone of Upper 
Cretaceous age, as it does in all the other opal-fields of Australia, 
which, like the Stuart’s Range field, are all situated just inside the 
region, which has a rainfallof 15inches perannum. It occurs in veins 
and patches associated with large amounts of common opal, and 
seems to have been formed in a similar manner to that in which 
surface quartzites and limestones are formed in similar dry regions. 
The amount of the precious variety is not large, but good finds are 
made. The Pernatty Lagoon manganese deposits seem to be a 
valuable field of this metal. The ore, which contains from 64 to 81 
per cent of Mn Og, with a certain amount of ferruginous material, 
is associated with a dolomite of uncertain age, and is found generally 
along the master joints. A considerable quantity of ore has been 
raised, and more would be sent away but for difficulties of transport 
in a rainless country. 

Near Robe a bore has been sunk to a depth of 3,950 feet in search 
of oil. The district was the subject of a report in the last review of 
mining operations (No. 24). In this report the Government Geologist 
reported very unfavourably on the oil prospects, and his conclusions 
seem to have been substantiated, since after passing through Tertiary 
limestone, with gravels and lignite, and Jurassic carbonaceous shales 
to the depth above-named no signs of oil have been seen, except 
a little natural gas. Of the copper-mines reviewed, some seem still 
to have good reserves of ore; many were abandoned owing to 
shortage of labour in the days of the gold rush in 1851, and not owing 
to failure of ore supplies. The present time, when the price of 
copper is so high, seems to be a favourable opportunity for restarting 
some of these concerns. 


W.. H- W. 


IX.—Nortu Qurenstann TIN-FIELDS. 


GroLoey anp Minerat Resources oF tHE Cooxrown Disrricr Tin- 
FIELDS (North Queensland, 1914). By E. Crcit Sarnt-Suiru, 
A.S.T.C., Assistant Government Geologist, Queensland Geological 
Survey. pp. 211, with 3 maps, 4 figures, 59 plates, and 3 plans. 
Brisbane, 1916. 

fJYHE Cooktown district tin-fields are situated in a hilly region, 

about 36 miles long, along the east coast of Queensland, running 
south from Cooktown at the mouth of the Annan River. The country 
is composed of slates probably of Gympie (Permo-Carboniferous) age, 
invaded by large masses of granite, with a few flows of post-Tertiary 
basalt and alluvium of two different ages. The tin-ore is found 
in the alluyium, both old and new, and is disseminated through 


Reviews—Minerals nr Crystalline Limestone. 35 


the greisenized granite and associated with small veins of quartz and 
tourmaline in the neighbourhood of its contact with the slates. 
Lodes of any size are very rare, and tin-ore is never found in the 
slates themselves. With the exception of one or two mines, the ore 
is exclusively won in open works by sluicing the loose alluvial 
material or the granite in situ, where it has been deeply weathered 
(sometimes as deep as 100 feet) by the effect of the tropical climate. 
The mining, except in the case of the Wallaby Creek Company at 
Rossville, is on a very small scale, and the water power is provided 
by the local streams, which are led in channels to the site of the 
workings. As there is a very distinct wet and dry season these 
streams do not always contain water, so that the mining in some 
places is confined to the wet season. The Annan River Company, 
however, are working on a much larger scale, and have erected 
powerful pumping plant, so that they can rely on a constant supply 
of water from the lower reaches of the Annan River. This company 
between 1911 and 1914 raised over 146 tons of tinstone, worth over 
£17,000, and is the only large producer in the district with the 
exception of the China Camp group of mines further south, which 
produced in the same time 269 tons of ore. 

The cassiterite is generally black in colour, but ruby and clear 
varieties are found in some localities. he only other mineral 
occurring in quantities which can possibly be regarded as payable is 
wolfram, of which one or two lodes are known, but this is in very 
small quantities. 

The field bids fair to continue to produce tin for some long time to 
come, but will never be a large producer. The content of ore is 
never very great, being as a rule between 13 and 24 lb. to the cubic 
yard, but exists in great quantities, and is for the most part easily 
mined. Two factors interfere to some extent with the development 
of the field, one being the great cost of carriage of materials from 
Cooktown and the other the scrub-covered character of the country, 
which makes prospecting very difficult. 


Wi EE WE: 


X.—MINERALS ASSOCIATED WITH THE CrystaLLINE Limestone AT 
Crestmore, RiverstpE County, Cattrornia. By A. 8. Haxre, 
Bulletin of the Department of Geology, University of California, 
vol. x, pp. 827-60. Berkeley, 1917. Price 40 cents. 


HIS paper is an interesting contribution to the study of the 
thermal metamorphism of limestones of varying composition. 

The limestone forms a mass resting on the upper surface of a mass of 
igneous rocks and penetrated by dykes. The igneous rocks comprise 
granodiorite, quartz-monzonite porphyry, and pegmatite. The total 
number of minerals described is about fifty, and it is clear that these 
may be divided into three categories, those formed by simple 
recrystallization of impurities in the limestone, those formed by 
diffusion into the limestone of material from the igneous magmas, 
and those belonging properly to the magmas. The limestone is for 
the most part fairly pure and has crystallized to a white marble, 

© 


36. Reviews—Ore Deposits of Environs of Hanano- Yama. 


often of very coarse texture, and containing some very remarkable 
masses of sky-blue calcite. The origin of this peculiar colour is 
unknown. ‘he upper part of the limestone was apparently more 
dolomitic, and here. brucite has been largely developed, often in 
association with graphite. In the contact zones, where diffusion of 
silica has taken place from the magma, the commonest minerals are 
wollastonite, vesuvianite, and garnet, with diopside and monticellite. 
Some supposed new minerals are described under the names of 
wilkeite, riversideite, and crestmorite; the analyses and description 
of these are not very convincing, and susest mechanical mixtures of 
silicates and phosphates. In close association with the i igneous rocks 
are also found axinite, scapolite, and datolite, which belong properly 
to pneumatolytic metamorphism. The chief interest of this remark- 
able occurrence lies in the fact that it seems to combine in itself 
nearly all the types of limestone metamorphism hitherto described. 
No indication is given of the age of the limestone or of the 
intrusions. 


Deus Ee hay) 


XI.—Tue Ore Deposits in tHe Environs or Hanano- YAMA, NEAR 
THE Town or Opa, Provinck or Nagato, Japan. By Taxro 
Karo, Journal of the Meiji College of Technology, vol. 1 
pp. 1-95, with 10 plates, 1916. 

ROM an exhaustive study of the mining district of Oda, in the 

Province of Nagato, Japan, a district which has long attracted 
the interest of geologists and mineralogists because of the existence 
of contact-metamorphic ore deposits of diverse character and the 
occurrence of beautiful specimens of copper minerals—cuprite, native 
copper, malachite, and chrysocolla—and of various sulphides, silicates, 
and other contact minerals, Professor Kato draws some important 
conclusions with regard to certain of the problems confronting 
students of contact metamorphism. He considers that ‘‘iron, silica, 
various rarer metals, mineralizers, etc., i.e. the greater part of the 
elements composing the lime-silicate minerals and the entirety of 
ore-minerals of the contact metamorpine: deposits, have been derived 
from the emanations from the magma’ 

Another important point is that the metamorphosing solutions first 
expelled from a consolidating acidic magma are siliceous in character, 
and are afterwards basic, becoming rich in iron, copper, and other 
metals, while still containing some silica; finally, at the end of the 
mineralization the solutions are rich in iron, copper, and sulphur, 
but contain little silica. The lime-silicates are therefore formed 
before the minerals rich in iron, and the sulphides and oxide-ores 
appear about at the same time as the andradite and hedenbergite. 
Although mineralization in contact metamorphic deposits begins with 
the magmatic intrusion and continues up to solidification of ie entire 
mass, the formation of the main deposits is confined to the early—the 
pneumatolytic and pneumato-hydatogenetic—stages, while subse- 
quently occur the hydrothermal alterations of the country rock and 
deposition of sulphide ores associated with quartz and calcite, but no 
lime-silicates. ‘The paper is well illustrated. 


1764 ean 


Reviews—Cretaceous Pelecypoda of Egypt. o7 


XII.—Creracrkous Pretecypopa or Eeypr. 


CATALOGUE DES INVERTEBRES DE L’ H@YPrE REPRESENTES DANS LES 
COLLECTIONS DU MusmE DE GoLoGIE aU Catre. Par R. Fourtav. 
Terrains Cretacts. 2™e Partie: Moxitusqurs LAMELLIBRANCHES. 
4to; pp. vili+109, pls. 7. Cairo: Geological Survey of Egypt, 
Paleontological Series, No. 3. 


fJ\HE rich collections of Egyptian invertebrate fossils contained in 

the Museum of the Geological Survey of Egypt, at Cairo, have 
for some time past been submitted to Monsieur R. Fourtau for 
determination and description, with the result that three important 
monographs have now been published, elaborately illustrated by 
lithographic drawings designed by F. Gauthier, the preparation of 
which reflects the greatest credit on the author, and also on Dr. W. F. 
Hume, the Director of the Survey, under whom the work has been 
accomplished. 

No. 1 of this series, issued in 1913, describing the Eocene 
Echinoidea, was reviewed in the Grotoeitcat Maeazrne for that year, 
and No. 2, pt. 1, devoted to the Cretaceous Echinoderms, was noticed 
in this journal for 1914. The present memoir, No. 3, forms the 
second part of the Cretaceous group of fossils. 

The memoir figures and describes 170 -different forms of 
Pelecypoda, Neumayr’s classification being adopted with modifica- 
tions from the works of Munier-Chalmas, Bernard, H. Douvillé, 
and Pervinquiére, and the genera and families are arranged under 
the groups Taxodonta, Anisomyaria, Schizodonta, Heterodonta, 
Desmodonta, and Pachyodonta. Among the species referred to the 
following are regarded as new: Leda perdita, Conrad, var. sinea, 
Arca egyptiaca, A. coquandi, Ostrea isidis, O. roachensis, Cardita 
roachensis, Lucina dowsoni, Siliqua humer, and Corbula peront. 

Following the various descriptions, the author gives a good 
analysis of the studies of previous observers, and freely criticizes, 
when necessary, their determinations and nomenclature. He is of 
opinion that the name best known for a fossil should be preferred 
even if it be a nomen nudum, in illustration of which Zittel’s Pecten 


Jarafrensis of 1883 may be noted. This fossil, except as a list-name, 


was without history so far as literature was concerned until 1898, 
when Mr. R. Bullen Newton described and figured Peeten mayer- 
eymart, from the Esna Beds of Egypt, which afterwards was 
acknowledged to be the equivalent of P. farafrensis; therefore the 
name of P. mayer-eymari must be adopted for the Zittelian shell, 
although German paleontologists have thought differently, Wanner 
having introduced the old nomen nudum in his memoir of 1902, which 
is now adopted by M. Fourtau. 

In the introduction to his work the author presents us with his 
views on zoological nomenclature, from which the following may be 
quoted: ‘‘En ce qui concerne la nomenclature, j’ai estimé qu’en 
dépit de la loi de priorité, on ne saurait s’en prévaloir contre des 
dénominations peut-étre moins anciennes, mais connues de tous et 
constituant pour le fossile une sorte de possession d’état-civil, que tous 
les codes civilisés reconnaissent aux personnes. Ces exhumations 


38  Reviews—Monazite Sand Deposits, Travancore. 


de noms désuets ou inconnus parfois de tous, ne peuvent que jeter 
le trouble dans la nomenclature, et elles ne sont justifiées que 
lorsque le nom usité a été déja préemployé pour une autre forme.” 
On similar grounds the genus Roudaireva, of Munier-Chalmas, 
1881, is adopted instead of Stoliezka’s Veniella of 1871, which 
undoubtedly has priority. It may be pointed out, likewise, that 
the original orthography of Arca esnaensis has been altered, without 
comment, to A. esnehensis. We consider that the genus Ostrea, of 
which many species are discussed, would have added much to its 
distinctness if it had been divided up into the well-known genera of 
Gryphea, Exogyra, Alectryonia, etc., although it may occasionally be 
difficult to place a species through slight overlapping of its characters. 
The ‘Tableau Synoptique ”’ furnishes a useful conclusion to this 
monograph in which the forms are listed in the order of description, 
together with their stratigraphical and geographical distribution. 
Four stages of the Upper Cretaceous are recognized, viz. Cenomanian, 
Turonian, Emscherian, and Aturian, while the occurrences are 
entered under Egypt, Sinai, and other countries. : 
It is hoped that many more parts of this ‘‘ Paleontological Series” 
may be issued by the Geological Survey of Egypt, although in future 
memoirs we strongly recommend the addition of an alphabetical 
index of all the species and genera, wherever mentioned in the text, 
either as synonyms or otherwise. 
There should be a great demand for this volume and those 
previously published, being indispensable to the student of 
Egyptian paleontology. 


XIII.—Repvorr on tot MonazitE Sanp Deposits in TRAVANCORE. 
By I. C. Cuacko, State Geologist. pp. 138. Trivandrum, 1917. 


IF\HE monazite sand deposits of Southern India have now become of 

considerable commercial importance, and the Government of 
Travancore has carried out a complete survey of all the known 
deposits within its territory. The country rock is mainly composed 
of charnockites and leptynites, overlain in places by the Warkalay 
beds, which are supposed to be Tertiary and equivalent -to the 
Cuddalore sandstones of the east coast. ‘The monazite is found in 
the sands of the seashore, which are black in colour, owing to the 
presence of much magnetite and ilmenite, together with garnet, 
rutile, apatite, and zircon. ‘The total area covered by sands rich 
enough in monazite to be worked is estimated at 1,427 acres, 
calculated to contain about 17,000,000 tons of monazite. However, 
owing to tides, currents, storms, and floods, the total amount of sand 
seems to vary considerably from time to time. Some of the sand- - 
dunes near the shore are also rich in monazite. The monazite is 
undoubtedly derived from the charnockite series: certain pegmatites 
are specially rich in this mineral, but it is probably widely dis- 
seminated in small quantity. It is believed that it has mainly 
passed from the old rocks to the coast deposits by way of the 
Warkalay beds and has been concentrated in the modern sands by 
the action of rivers and the waves of the sea. It is possible that 


Brief Notices. 39 


deposits formed in old lagoons may now be covered up by blown 
sands and silt: such places would probably repay investigation. 


Tee dels 1p 


XIV.—Annvat Report or tHe State Grotogist, TkAVANCORE, FOR 
THE YEAR 1091 mr. pp. 21. Madras, 1917. 


fJVHIS report deals with the re-survey of the southern part of the 

State. The formations here found may be divided into the five 
following groups: (1) crystalline rocks, (2) laterites, (3) limestones, 
(4) the Warkalay formation, (5) the recent deposits. The crystalline 
rocks form part of the great charnockite series: they are on the 
whole intermediate in composition, containing little quartz. These 
typical fresh charnockites are overlain on the higher ground by a 
zone of leptynite, in which the felspar is kaolinized and the 
hypersthene converted into garnet. ‘The massive charnockites are 
cut by numerous dykes of norite. The laterites are chiefly of the 
residual type formed from the crystalline rocks. The Warkalay beds 
are mostly coarse red and yellow sands, and the argillaceous formation 
known as teri probably forms part of this series, which is believed to 
be of Cretaceous age. The occurrence of monazite in the Warkalay 
and recent formations is dealt with in a separate report. The chief 
minerals of economic value, besides monazite, are graphite and 
pyrrhotite. 

DR delle. 


XV.—Brirr Notices. 


1. Homa@omorpuy.—A clear exposition of homceomorphy as applied 
to fossil Corals will be found in a paper by W. D. Lang in the, Proc. 
Geol. Assoc., xxvill (2), 1917. It forms the subject of a demonstra- 
tion given to the members on the occasion of a visit to the British 
Museum (Nat. Hist.). Mr. Lang deals with—(1) Diagnostic characters 
of Corals in general and tests whereby fossil Corals may be known. 
(2) Homeeomorphy in general and its meaning when applied to fossil 
Corals. (3) Cases of homceomorphy in Corals; homceomorphy 
between Corals and Polyzoa; between Corals of different formations, 
and between Corals from the same formation; among Alcyonarian 
Corals. (4) Connexion between homcomorphy and evolutionary 
stages in Corals; ‘‘ Morphic Equivalence” of Buckman; Radicals. 
(5) Relationship of Rugose Corals and Hexacorals; homceomorphy 
in Jurassic Hexacorals. Altogether an admirably useful paper, to 
which the student can refer with advantage. 


2. Varro on Sors.—It may be well to recall to those who work 
on soils the notes made by Varro in the first century B.c. in his 
Rerum rusticarum, of which a new translation was issued in 1912 in 
Bohn’s Classical Library (G. Bell & Sons) by Lloyd Storr-Best. 
Chapter vi deals with the Soil, chapter vii the Site, and chapter ix 
Farm Land. In chapter vii occurs the following passage, so 
interesting to a geologist; Cn. Tremelius Scrofa is speaking: 
‘‘ When I was in command of an army in Transalpine Gaul—in the 


40 Brief Notices. 


interior near the Rhine—I came to several districts where neither 
vine, olive, nor fruit-tree would grow, where they manured the 


fields with ‘marne’ [candida fossicia ereta|, dug from the ground, 


where they could get salt neither by digging nor from the sea, but 
used instead of it salt charcoal made of the burning of certain 
woods.”’ 


8. Fosstr Insects From Ftrorissayr, Conorapo. — This paper, 
by Mr. T. D. A. Cockerell (Proc. United States Nat. Mus., vol. li, 
pp- 889-92, 1917), describes five new species of insects from the 
well-known Miocene shales of Florissant, but being without figures 
they are of little use to the paleontologist. 


4. Muyerats or Gramorcan.—Mr. F. J. North has issued a careful 
paper on the Minerals of Glamorgan in the Trans. Cardiff Nat. Soc., 
xlix, 1916. Some thirty species are recorded and fully described, 
with notes and information of local interest. Special attention is 
paid’ to economics, and the paper concludes with a bibliography. 
Gold in rounded grains is recorded from the Keuper Marl. 


5. Trrrytopon.—A recent examination of the skull of Zritylodon 
longevus, Owen, allows Dr. B. Petronievies to give as mammalian 
characters: divided roots of molar teeth, multituberculate teeth, 
straight and parallel rows of teeth, and no post-frontal bone; as 
reptilian characters: divided nares, pre-frontal bone, and frontal 
bone not bounding the orbit; while those characters both mam- 
malian and reptilian are recorded thus: septomaxillary bones, 
terminal position of anterior nares, backward position of posterior 
nares, divergent parietals, orbito or alisphenoid (or orbitopalatine ?), 
no postorbital bar, and brain-case antero-laterally closed. Some 
further preparation of the type skull by Mr. Barlow has enabled 
Dr. PRetronievics to come to these conclusions, which he considers 
show Ziritylodon to be a direct evidence that the mammals have their 


origin in reptiles, most probably in Theriodont Reptiles (Ann. Mag. © 


Nat. Hist. [8], xx, October, 1917). 


6. Forxesronn Warren.— Despite the long literature on Folkestone 
Warren, it has been left to Mr. C. W. Osman (Proc. Geol. Assoc., 
XXvill (2), 1917) to approach the subject from a mechanical point of 
view and elucidate its structure from the recurring landslips, 
especially that of December, 1896. Studying the effect of com- 
pression on the Gault, the critical slope of Chalk on Gault, types of 
movements in the Warren, and the effect of water on those move- 
ments, he describes the cross sections and accounts for the origin of 
the Warren. Proceeding further, he measures up the Lower Chalk, 
discusses the effect of the Ferques axis on deposition, and gives the 
thickness of the Gault here and at various places in Kent. The paper 
is illustrated by a large-scale section from Folkestone to Dover, and 
sections at numerous points at right angles to the coast. A list of 


fossils collected from the Chalk Marl is provided by Mr. H. A. Allen. 


ni ; \ 


Reports & Proceedings—The Royal Society. 4 


REPORTS AND PROCHHDINGS. 


I.—Tux Roya Socrrry. 


November 22, 1917.—Sir J. J. Thomson, O.M., President, in the 
Chair. 


The following paper was read: ‘‘The Pelmatoporine, a Group of 
Cretaceous Polyzoa.” By W.D. Lang, M.A., F.G.8. (Communicated 
by Dr. F. A. Bather, F:R.8.) 


The evolution of this sub-family is considered in detail. In order 
to present the facts intelligently, they are marshalled according to 
the following theoretical considerations :— 

1. The species le along diverging lineages ; towards the bases or 
proximal ends of these are forms (radicals) with less calcareous 
skeletal matter and less elaboration of structure, and these forms 
appeared earlier in geological time; towards their higher or distal 
ends are forms with more skeletal matter and more elaborate structure, 
appearing later in geological time. 

2. The evolutionary tendency was to deposit the increasing 
superfluity of calcium carbonate where it least interfered with the 
organism’s bionomics; if possible, in such position and shape as 
might even be useful to the organism. Sooner or later the race 
perished through being unable to cope with its constitutional and 
increasing habit of excessive secretion of calcium carbonate. 

3. There is a predisposition in radical forms of different lineages 
to deposit their superfluous calcium carbonate along corresponding 
tracts and with it to build up similar secondary structures.’ They 
differ in comparative rate of building and in amount of elaboration, 
as well as in details in architecture and ornament. Consequently, (a) 
in most cases it is possible to predict the general history of a lineage 
from an examination of one of its early terms; and (b) lineages 
often present series of homceomorphic forms; while characters 
diagnostic of genera, and still more of congeneric lineages, often 
appear trivial and of little importance to the organism. 

4. The ‘‘Law of Recapitulation’’ holds good in post-embryonic 
erowth-stages, not only of the individual but of the colony as 
expressed by the individual constituents at successive distances from 
its starting-point. In fossil Polyzoa, astogeny (as Cumings called 
the development ofthe colony) is more easily observed than ontogeny. 

5. Periodicity is displayed by the Pelmatoporine in their evolution. 

The relations of the various forms are inferred from their adult 
morphology. heir stratigraphical distribution is considered in order 
to confirm these relations, though the evidence of stratigraphy can 
only be negative; it can contradict a supposed relation, but cannot 
affirm it. Finally, astogeny of forms is used to test morphological 
results. 

Incidentally, results obtained by W.'K. Spencer in his investiga- 
tions on evolution of Cretaceous star-fishes are compared and found 
generally to correspond with results described in this paper. 


42 Reports & Proceedings—Edinburgh Geological Society. 


IJ.—Epinsureu Groroeican Socrery. 
1. October 17, 1917.—Professor Jehu, President, in the Chair. 


‘Sketches of South African Geology.”” By Professor 8. J. Shand, 
D.Se., Ph.D. 


The major physiographic divisions of South Africa are the Coastak 
Plain, the Mountain Barrier, and the Interior Plateaux of the Karroo 
and the High Veld.. The Coastal Plain on the west has a width of 
some 80 miles, rising gently from the sea-level to the foot of the 
mountains. Geologically it is formed of rocks of the Nama System 
(Cambrian or Pre-Cambrian), resting upon old metamorphic rocks, 
with numerous great granite intrusions. There is no continuous 
plain on the south coast, but there are many narrow shelves and 
patches of raised beach, testifying to recent movements of elevation. 
On the east side the Coastal Plain again becomes a continuous 
feature, reaching a great width in Portuguese East Africa, where, 
however, little is known of its geological structure. The Mountain 
Barrier of the west and south is the folded margin of the Interior 
Plateau, but on the east it is the fractured edge of the plateau; that 
is to say, the west and south coast ranges are fold mountains, while 
those of the east are fault mountains. ‘The former are largely 
composed of the hard Table Mountain Sandstone, resting with a 
strong unconformity upon the Nama rocks. The age of the able 
Mountain Sandstone is deduced from the fact that the overlying 
Bokkeveld beds yield trilobites, brachiopods, and lamellibranchs of 
Lower Devonian age. On the inner side of the Mountain Barrier the 
rocks: of the Karroo System make their appearance and cover the 
ereater part of the interior of the Sub-Continent. The lowest 
member of this system is the Dwyka Glacial Conglomerate, which 
extends from the South-West African Protectorate to Natal, and 
from the Transvaal to the south-west corner of the Cape Province. 
The higher members of the Karroo System have a more limited 
distribution than this, and the uppermost or Stormberg Series is 
restricted to the eastern districts, where it caps the Drakensberg 
Range. ‘he close of the Karroo period was signalized by great 
igneous activity and diastrophism. The folded ranges were elevated 
at this time; the Karroo sediments were invaded by basic dykes and 
sills, and great outpourings of basaltic lavas took place in the regions 
of the Drakensbergen, the Victoria Falls, the Bushveld, and the 
Kaokoveld. he concluding event seems to have been the drilling 
of the kimberlite pipes, from which diamonds are now obtained. 
The deposition of the rocks of the Karroo System occupied the whole 
period from Carboniferous to early Jurassic time. Rocks younger 
than the Jurassic are only found in restricted areas along the south 
and east coasts, where there are patches of marine Cretaceous and 
Tertiary rocks. 

As regards climate, South Africa shows four fairly distinct natural 
regions—one of summer rains in the east and central districts, one 
of winter rains in the south-west, a semi-arid region in the north and 
north-west, and an entirely desert area extending along the west 
coast roughly from the Orange River to Walvis Bay. This Coastal 


ab 


Reports & Proceedings—Hdinburgh Geological Society. 43 


‘Desert of the South-West African Protectorate has a rainfall of less 
than an inch per annum, and the strong southerly winds cause 
terrible sandstorms. Hvery exposed rock is cut and grooved by the 
sand-blast, and loose pebbles are faceted by the same agency and 
assume the forms known as eimkanter and drevkanter. Wandering 
erescentic sand-dunes or Jbarchans travel ceaselessly northward, 
covering up everything that gets in their way. In this inhospitable 
region diamonds are recovered from the sand by a number of German 
mining companies. 


2. November 21, 1917 (issued December 14, 1917).—Professor Jehu, 
President, in the Chair. 


(1) ‘‘ Descriptions of some new Volcanic Necks near Pittenweem.” 
By D. Balsillie, B.Sc., F.G.S. 


Immediately to the west of Pittenweem Harbour four small 
voleanic necks have been laid bare by the sea. The rocks among 
which these occur consist mainly of sandstones, shales, fireclays, and 
ironstones, along with a thin band of impure limestone yielding 
Entomostraca and Spirorbis that was estimated by Mr. Kirkby to 
be about 1,000 feet above the Encrinite-bed. ‘The strata here dip 
a little to the north of west at high angles, and appear to have 
assumed such a disposition prior to their disruption by active volcanic 
forces. 
he material fillmg the necks is in the main a non-volcanic sedi- 
mentary débris, but includes frequent pieces of a highly vesicular 
white trap. Neither is there discernible assortment of the con- 
stituents in any of these fragmentary accumulations, nor are 
alteration effects conspicuous. It appears probable, therefore, that 
we have here a record of only a transient manifestation of volcanic 
action. 


(2) ‘The Glossopteris Flora.””’ By D. Balsillie, B.Sc., F.G-.S. 

The apparently cosmopolitan floras of Upper Devonian and Lower 
Carboniferous times constitute, as emphasized by Seward, one great, 
phase in the evolution of the plant kingdom. These floras included 
representatives of all the major classes of our present Pteridophyta, 
along with other types now entirely extinct or represented only by 
greatly diminished forms occasionally of the most restricted 
distribution. 

Passing to Upper Carboniferous and Permian times, there is strong 
evidence to show that the earth’s surface was then divisible into two 
great botanical provinces of ecological significance. In the northern 
hemisphere the vegetation might be regarded as merely a continuation 
of the older flora, but enormously amplified and extended. In the 
southern hemisphere, however, a totally new assemblage of types 
appeared, filicinean (pteridospermic?) mainly in the character of 
its foliage, and including as two characteristic genera Glessopteris 
and Gangamopteris. It is this great series of southern forms that has 
been designated the Glossopteris Flora. 

Typical members of this southern flora have been recorded from 


44 Reports & Proceedings — Mineralogical Society. 


Permo-Carboniferous rocks in all the principal land areas of the 
southern hemisphere—India, Australia, South Africa, and South 
America. The obvious method of explaining this remarkable dis- 
continuous distribution is to assume that there were at one time land 
connections between these areas, and, indeed some writers have gone 
so far as to suggest that there formerly existed a great east-and-west 
continent crossing the site of the present Indian Ocean. To this 
last: continent Suess gave the name Gondwanaland. 

Why should the vegetation of Gondwanaland have been peculiar? 
In explanation of this the author made reference to the Talchir rocks 
of India, the Bacchus Marsh conglomerates of Victoria, the Dwyka 
conglomerate of South Africa, aud the Orleans conglomerate at the 
HH of the Santa Catharina rocks in Brazil. All these strata, which 
are in intimate association with the plant-bearing beds, afford 
indisputable evidence of contemporaneous glacial action in late 
Paleozoic times. Geologists, therefore, believe that it was the 
secular climatic change accompanying this Permo-Carboniferous 
glaciation that impressed itself so remarkably upon the vegetation of 
Gondwanaland, extirpating the older lepidophytic types and giving 
birth ultimately to the Glossopteris Flora. 


JIJ.—Mivrratoeicat Socrery. 
Anniversary Meeting, Movember 6.—Dr. J. W. Evans in the Chair. 

The following were elected Officers and Members of Council: 
President, Mr. W. Barlow, F.R.S.; Vice-Presidents, Professor H. L. 
Bowman, Mr. A. Hutchinson; Treasurer, Sir William P. Beale, Bart., 
K.C., M.P.; General Secretary, Dr. G. T. Prior, F.R.S.; Foreign 
Secretary, Professor W. W. Watts, F.R:S.; Editor of the Journal, 
Mr. L. J. Spencer; Ordinary Members of Council, Mr. 1. V. Barker, 
Mr. G. Barrow, Professor C. G. Cullis, Mr. F. P. ee Mr. H. 
Collingridge, Mr. T. Crook, Dr. G. F. Herbert Smith, Bria Bleed ok 
Mhomas, Mr. H. F. Collins, Ma, J.P. De Castro, Professor te ‘Hilton, 
Tientenant Arthur Russell. 


The following papers were read :— 


Miss E. Smith: On Etched Crystals of Gypsum. Baumhauer 
conducted experiments on colemannite and calcite to determine 
whether the phenomenon of etched figures is due to lack of 
homogeneity or irregularity in the incidence of the dissolving liquid 
or to lack of homogeneity in the crystal itself. Further experiments 
now made on cleavage surfaces of gypsum tend on the whole to 
confirm Baumhauer’s conclusion that the second hypothesis is the 
correct one. 

Dr. G. T. Prior: On the Mesosiderite— Grahamite Group of 
Meteorites. Analyses of the mesosiderite Hainholz and _ the 
erahamite Vaca Muerta show that these meteorites do not differ 
materially as regards the amount of felspar, and microscopical 
examination of other mesosiderites supports the idea that there is no 
real distinction between them; the name mesosiderite is therefore 
proposed for the whole group. The groundmass of these meteorites 
consists mainly of anorthite and a pyroxene, poor in lime and having 


Reports & Proceedings—Geological Society of London. 45 


a-ratio of MgO to FeO of about 2. he iron and olivine are very 
unevenly distributed, and have chemical compositions such as they 
have in the pallasites, the iron being poor in nickel (ratio of Fe to 
Ni generally greater than 10), and the olivine poor in ferrous oxide 
(ratio of Mg O to FeO from 6 to 9). In accordance with the author’s 
conception of a genetic relationship of meteorites, it is suggested that 
a eucrite-like magma, i.e. one of higher oxidation, was invaded by 
a pallasite-like magma of lower oxidation. The curiously unequal 
distribution of the nickel-iron and the shattered (cataclastic) 
structure which is generally confined to the parts rich in iron 
support this view. 

Professor H. Hilton: On Changing the Plane of a Gnomonic or 
Stereographic Projection. A method was described by means of 
which the gnomonic or stereographic projection of a crystal on any 
plane may be obtained when the projection on one plane is given. 
The application to the drawing or orthographic projection of the 
erystal. was also discussed. 

Professor H. Hilton: On Cleavage Angle in a Random Section of 
aecrystal. A graphical method was given by means of which it is 
possible to calculate the chance that the angle between the cleavage- 
eracks on a random section of a crystal with two good cleavages may 
lie between specified limits. The method was worked out in detail 
for the cases in which the angle between the cleavage-planes was 
90° or 60°. 


IV.—Gerotoeicat Soctery or Lonpon. 


November 21, 1917.—Dr. Alfred Harker, F.R.S., President, in the 
Chair. 


The following communication was read :— 


**The Shap Minor Intrusions.’”” By James Morrison, B.A., B.Sc. 
(Communicated by Dr. Herbert Lapworth, Sec. G.S., M. Inst. C.E.) 

The paper deals with the minor igneous intrusions occurring in 
the triangular area between Shap, Windermere, and Sedbergh. 

From their field relations and petrographic characters the in- 
trusions are found to belong to one or the other of two well-marked 
groups, a division which is regarded as connoting also an age- 
classification. 

The rocks of the earlier set, characterized by the presence of large 
orthoclase-felspars of the granitic type, are intimately associated 
with the granite, to the immediate neighbourhood of which they are 
practically confined. he rocks range from quartz-felsites to lampro- 
phyres. Of considerable interest in this group is a series of hybrid 
intrusions, consisting essentially of rocks of a more or less basic 
magma enclosing xenocrysts of a more acid (but allied) magma 
obtained by settlement under intratelluric conditions. The constitu- 
tion of any given member of the series is determined by two factors : 
the abundance of xenocrysts and the composition of the matrix, an 
increasing basicity in the latter (due to original magmatic differentia- 
tion) and a decrease in the former marking the successive stages. 
The more acid have affinities with the porphyrites, the more basic 


46. Reports & Proceedings—Geologists’ Association. 


with the lamprophyres, the series ranging from modified biotite- 
porphyrites to modified pilitic lamprophyres. 

The later intrusions are typically free from the large orthoclase-— 
felspars, though quartz-grains may occur even in the basic members. 
Associated centrally with the earlier set they are distributed over a 
much wider area, overlapping the former in every direction. They 
are the result of further differentiation, and are assigned to a later 
period when igneous activity was renewed on a more or less regional 
scale. The rocks include acid felsites and spessartites. . 

The rocks of the earlier set agree in general direction with the 
north-north-west fractures transverse to the strike of the country 
rock, while the later intrusions trend generally east of north. 


V.—Geotoeists’ ASSOCIATION. 


December 1, 1917.—George Barrow, F.G.S., President, in the Chair. 


The following lecture was delivered: ‘‘The Gold Coast.” By 
Albert Ernest Kitson, F.G.S., Director of the Geological Survey of 
the Gold Coast. 


The features to be considered, after a general description of the 
geography and tectonics of the colony, are: the Archean gneisses, 
schists, amphibolites, etc., principally of the Eastern Provinces; the 
folded and zonally contorted pre-Cambrian, or early Paleozoic, 
altered sediments (conglomerates, quartzites, etc.), with interbedded 
voleanic rocks (rhyolite, andesite), flanking the former group and 
extending westward across the colony; deposits of gold and 
manganese. 

Intrusions (into both groups) of granites, syenites, diorites, 
gabbros, etc.; dolerite volcanic necks; gold, tin, ilmenite, and 
molybdenite associated with these rocks. 

The slightly inclined sedimentary rocks of the coast (with 
Devonian fossils) and of the greater part of Ashanti and the Northern 
Provinces with bauxites, oil-shales, and clays; the Tertiary deposits 
of Apollonia with bitumen and oil, the ‘‘laterites”” and associated 
iron-ores. Fluviatile, estuarine, and eolian deposits. 

The evidence of aboriginal occupation, consisting of stone-imple- 
ment factories, camps, and crude forts, was also discussed. 


CORRESPONDENCE. 


ESHA SES 
WORM-BORINGS IN ROCKS. 

Str, —Dr. Bather’s interesting communication on “ Salt-weathering 
and supposed Worm-borings in Australia’? (Grot. Mae., November, 
1917) induces me to direct attention to a paper read by the late 
Duke of Argyll before the Royal Society of Edinburgh in January, 
1889. In this he described similar tubes occurring in some of the 
quartzites of Sutherlandshire, and which he and the late Mr. Etheridge 
attributed to the burrowing of annelids. Some of these tubes were 
horizontal, having been drawn out of the vertical by movements due 
to shearing or slipping of the beds or lamine of the deposit. 


Correspondence—C. Carus- Wilson. AT 


In a communication entitled ‘‘ Pseudo-Scolites” (Research, April 1, 
1889) I pointed out that such tubes or ‘“‘ foralites”? might be seen in 
great numbers on sloping, sandy beaches, especially when the sand 
covers a deposit of shingle, and that they were simply vents formed 
in the wet sand by the escaping air, which was compressed by the 
advancing waves. Ina given slope of shingle, covered with a layer 
of wet sand, there is a certain quantity of air, and this, on being 
compressed by an advancing wave, escapes through the wet sand at 
the surface. The advance of the wave increases the pressure, and 
the confined air escapes from the weakest points at the surface of the 
sand. From the vents thus produced the air issues with considerable 
energy, as bubbles forced through the water of a retreating wave 
often show. The receding tide leaves many of these miniature blow- 
holes intact, and frequently with a crater-like ridge of sand around 
their orifices. In some cases these tubes were 4 or 5 inches in depth, 
and on the more level parts of a beach where firm sand prevailed 
they were filled up with fine mud, Foraminifera, and minute frag- 
ments of shell, ete. Under favourable circumstances these tubes 
might be preserved from future obliteration. 

Such tubes might also be formed in unindurated inland deposits by 
the escape of compressed gases caused by the decomposition of 
organic matter, chemical reactions, and by steam escaping from 
heated areas. 

C. Canus- Witson. 

ALTMORE, WALDEGRAVE Park, 

STRAWBERRY HILL. 
November 18, 1917. 


Nore sy Dr. Baryer. 


I must apologise for having omitted all reference to Dr. Carus- 
Wilson’s previously published obervations, due, I regret to say, to 
pure ignorance of them on my part and presumably also on the part 
of Professor Hogbom, with whose account they entirely agree. The 
pipe-rock of Sutherland is so well known to British geologists that 
it was hardly necessary for me to mention it. Dr. Carus-Wilson’s 
reference to it is apparently intended to suggest that the horizontal 
position of some of the tubes in the Tasmanian rocks may be due to 
subsequent movement. On this point I have no evidence. 

F. A. Batuer. 


BORING FOR COAL AT PRESTEIGN. 

Sir,—The alleged discovery of buried stores of coal at the 
Presteign lime-kilns, suggested by Professor Watts (Grou. Mae., 
1917, p. 552) as the origin of the local delusion that a bed of coal 
crops out there, is a possible explanation ; but it is remarkable and 
lamentable that no tradition of the lime-burning survived among the 
unfortunate subscribers. Some such storing of fuel may account 
also for the local belief in the existence of coal at Cadwell, 3 miles 
E.N.E. of Presteign, where pieces of coal in the soil above a quarry 
in Wenlock mudstones and nodular limestones (containing the usual 
fossils) were visible in 1915. The coal may have been taken there 
to burn lime at some remote period. 


48) Correspondence—T. C. Cantrill—J. Reid: Motr.. . 


Although well aware of the interesting paper on'the Old Radnor ~ 
district by Professor Garwood and Miss Goodyear, I refrained from 
alluding to it, because it bears on a different locality, and (to judge 
by the abstract) deals more particularly with an abnormal facies of 
the Woolhope Limestone—a matter with which I was not concerned. 
My reason for quoting the earlier authorities was to show how com- 
pletely the so-called practical men who ‘promoted the scheme had 
ignored what was already known about their own neighbourhood. 

T. C. Canrritt. 


28 JERMYN STREET, S.W. 1 
December 13, 1917. 


THE KYSON MONKEY. 


Str,—In an important paper published recently by Professor 
Boswell in the Journal of the Ipswich and District Field Club (“‘ The 
Geology of the Woodbridge District, Suffolk’), vol. v, pt. 1, pp. 1-12, 
it is stated (p. 1) in reference to the Eocene sand of Kyson, near 
Woodbridge, that ‘‘ Prestwich found the remains of a monkey 
(Macacus eocenus) in this bed’’. This, however, is incorrect. In 
Owen’s British Fossil Mammals and Birds (1846), on p. 3, he wrote: 
‘‘The fossils manifesting quadrumanous characters were. discovered, 
in 1839, by Mr. William Colchester . . . in the parish of Kingston 
—commonly called Kyson—in Suffolk.” 

A further reference is made to this discovery in the Memoirs of 
the Geological Survey (Lhe Geology of the Country around Ipswich, 
Hadleigh, and Felixstowe). On p. 26, in describing the Kyson beds, 
it is stated: ‘‘ . . . the section was exposed in 1839 at the brick- 
yard at Kingston or Kyson” ; then follow details of the section and 
a list of the Eocene mammals found. Amongst these is mentioned 
“* Hyracotherium cuniculus, Owen (first. called MJacacus eocenus)” 
Lower down on p. 26 it is stated ‘‘ The complete section is given by 
Prof. Prestwich, from whose paper the above details are given’. 
Finally, on p. 143, appears the following: ‘‘145. Owen, (Sir) R. 
‘On the Hyracotherian character of the Lower Molars of the supposed 
Macacus from the Kocene Sand of Kyson, Suffolk’: Ann. Nat. Hist., 
ser. 3, vol. x, p..240.” 

It thus seems clear (1) that the so-called Macacus remains were 
not found by Prestwich, but by Mr. Colchester; (2) that further 
examination of these remains established the fact that they were not 
referable to Macacus at all, but to Hyracotherium cuniculus; and 
(3) that Professor Prestwich made the foregoing facts clear in 
a paper published by him in 1850 (Quart. Journ. Geol. Soc., vol. vi, 
pp. 272, 273). 

As there are apparently some investigators who still believe that 
quadrumanous remains have been found in the Eocene of Suffolk, 
I venture to bring this matter before geologists so that the error may 
be eliminated. 

J. Rem Morr. 

November 26, 1917. 


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I. ORIGINAL ARTICLES. Page Ill. REVIEWS...“ "> “tige 
. Eoeystis, I. Hocystites priunevus James Geikie, the Man and the 
Hartt. By F. A. BATHER, M.A., SUGeolOetStse<ecnuke sept smacse cect 83 
D.Se., F.R.S. (Plate V and Fossil Echini, Panama Canal ....., = 85 | 
Ge PSITOIINES Fab rcare vole seers eerata 49 | Dr. Tempest Anderson’s Voleanic | 
South Staffordshire Fire-clays. By. Studies in Many Lands. By | 
“A. HuBERT Cox, M.Sc., Ph.D., Professor I’. G. Bonney....:....... 86 | 
ENCES cc RU an eeu bs anon erase 56 | Moonta and Wallaroo Mining 
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By A. E. TRuEMAN, M.Sc., 1 il sp ARNC sce an einai Hoppa wea aastae Sou 
F.G.S. (With two Text-figures.) 64 | | 
The New Brachiopod Genus, Lio- IV. REPORTS AND PROCEEDINGS. 
thyrella, of Thomson. By J. j eat f 
WILFRID JACKSON, F.G.S. ...... 73 | Geological Society of London— 
The Kaolin Veins (Singapore). By ee. ty LET se ieaieaen pes ae 
Lieut. J. B. ScrRIVENOR, M.A., Pe ae i ean see re Saree Oy ha 32 
1 (CIS She tha ea fate Oe 79 Edinburgh Geological Society ...... 93 
5 Mineralogical Society.....:.;,.......-. 94 HY 
II. Novices OF MEMOTRS. : 
: Sinters 5 ; VY. OBITUARY. 
Martin Simpson, a Yorkshire es 5 2 
Genlonist er ic otters x hia gg | William Albert Parker, I'.G.S....... 95 
The Mineral Resourcesof the British fie foie 
MUPPET DING. <.2ciyscsncgscuesaneeedugecs eos 82 VI, MISCELLANEOUS. 
Age of the Bolivian Andes............ 83 | Myr: R. Bullen Newton, F.G.S....... 96 
West Australian Foraminifera ...... 83. |: Mr. F..W. Rudler, 1.8S.0., F.G.8.. 96 


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No. II. —FEBRUARY, 1918. 


ORIGINAL ARTICLEHS- 


].—Eoeystis, |. Kocysrires priuazvous Harrr. 
By F. A. BATHER, M.A., D.Sc., F.R:S. 
(PLATE V.) 
(Published by permission of the Trustees oi the British Museum.) 


\HE second edition of J. W. Dawson’s Acadian Geology (1868) 
contains some notes communicated by C. F. Hartt. One of 
these, on p. 643, runs as follows :— 

‘« Hocystites primevus, Billings, Coll. Hartt (Fig. 220). The little 
plate with radiating sculpture, represented somewhat enlarged in 
the figure, is regarded by Mr. Billings, to whom the specimens have 
been submitted, as indicating a new genus of Cystideans.”’ 

In this perfunctory manner, without diagnosis or description, was 
the genus Hocystites founded. Since a named species was mentioned, 
that species, #. primevus, must be taken as genotype, and the generic 
name 1s thereby validated. 

Kocystites primevus again depends solely on the accompanying figure 
220 (our Plate V, Fig. 1). Slight though this may. appear, it does 
represent a plate of peculiar and recognizable shape. The holotype, 
which was said to be in Hartt’s collection, was one of a series of 
specimens from the ‘‘ Primordial Group” of St. John, New Brunswick, 
a group since referred to the Lower Cambrian. ‘The specific name 
therefore may be accepted, and unless the plate can be shown to 
belong to some previously described genus and species, we must 
regard Hocystites primevus as representing an actual independent 
zoological entity. 

It so happens that Dr. G. F. Matthew, of St. John, New Brunswick, 
formed the opinion that the plates known as Hocystites primevus 
were more properly referable to Zrochocystis. He did not publish 
a definite statement to that effect, but he twice suggested or recorded 
the existence of Zrochocystis in Canada, namely, in 1896, ‘‘ Faunas of 
the Paradoxides-Beds in Eastern N. America”? (Trans. New York 
Acad. Sci., xv, p. 207), and in 1899, ‘‘ The Cambrian System in te 
Carmela Valley” (Trans. Roy. Soc. Canada, ser. Ir, vol. 
sect. 4, p. 128). his latter refers to ‘‘a single discoid plate”’ fe 
Division 1 5 of the Cambrian at Long Island, Kennebecasis Bay, 
Nova Scotia. 

DECADE VI.—VOL. V.—NO. II. 4 


50 Dr. F. A. Bather—EHocystis. 


- It was when I asked Dr. Matthew for the evidence on which he 


recorded this Central European genus from the other side of the 
Atlantic that he replied (in litt., February 5, 1900): ‘‘I may say 
that the evidence is not direct. Hocystrtes is founded on single star- 
shaped plates. ‘With these occur a few elongated plates somewhat 
rectangular. The greater abundance of the star-like plates led me to 
infer the probable presence of some such genus as Zrochocystites, as 
the form to which the two kinds of plates belong.” 

The name 77 ochocystites first appeared in print in 1859 (J. Barrande, 
Bull. Soc. Géol. France, ser. 11, vol. xvi, p. 543), but then only as 
a nomen nudum, and without a species. In 1860 De Verneuil & 
Barrande (ser. cit., vol. xvii, p. 537) published a description, and 
took as genotype the Bohemian species 7. bohemicus Barrande, of 
which no other description had till then been published. ‘The fossil 
from north of Sabero, Léon, Spain, which they figured (pl. viii, 
figs. 1, la), was referred to that species ‘‘avec réserve’’; it most 
probably belongs to 7. barrandei Mun.-Chalmas & Bergeron. 

If, then, Dr. Matthew’s opinion is well founded there would follow 
the unfortunate result that Zrochocystis (-ites), as the name of a genus 
with'a clearly understood genotype, would have to yield to Hocystvs 
(-ctes), based on a species that depends in its turn on a single obscure 
plate. It is therefore advisable to subject Hocystites primevus to more 
critical examination than it has yet received. 

There are, of course, more important reasons for undertaking such 
an inquiry. Plates from the Cambrian rocks of widely separated 
parts of the world have been referred to Hocystis, and the name has 
also been doubtfully applied to a fairly well-preserved fossil cystid 
retaining its brachioles—¥Z. (?) longrdactylus Walcott (1886). . 

That I have been able to make this study is due to the kindness of 
Dr. G. F. Matthew, who sent me forty specimens referred by him to 
E. primévus, and considered by him to afford the most complete 
representation of that species. Eleven of these have, through the 
generosity of Dr. Matthew, been retained for the British Museum, 
and registered E 7602- 7612. 

The specimens are labelled ‘‘ Lower Gamitian Division 1, C, 2, 
Paradoxides-beds; St. John, N.B.”’, except three, said to come from 
‘Ratcliff’s Millstream”. 

The matrix of all is a hard irregularly fissile shale, varying in 
colour from dark grey to olive green, and weathering brown. The 
substance of the fossils is either much decayed or entirely dissolved 
away, and the moulds or impressions are often stained with iron 
oxide. The shale has been subjected to some lateral pressure, so 
that in several cases the impressions are distorted. 

The impressions referred by Dr. Matthew to #. primevus are 
divisible into four groups; the numbers of the British Museum 
representatives are quoted, as well as the letters which I attached to 
Dr. Matthew’s specimens. 
‘1. Stellate plates, the typical Hocystites primevus, E 7602-5. 
K 7611-12; G. F. M. a, 6, e, f. 

2. Plates with marginal pores. EK 7608; G. F. M.c. 

8. Columnals. E 7605-7, E 7602; G. F. M. d, g. 


ee ee 


Dr. F. A. Bather—LHocystis. 51 


-4, Undetermined plates. E 7609-10; G. F. M. A. 

There seem no a priore grounds for supposing that all these 
specimens belong to the same species, or even genus. Nor is there 
any external evidence that they donot. They lie close together on 
the same surfaces of shale; at the same time they are never in any 
natural juxtaposition, but always occur as isolated plates or ossicles. 

These four sets will therefore be described separately. 

1. The Stellate Plates are probably to be regarded as thecal plates 
of a Pelmatozoan, and since a parallel is to be found only among 
Cystidea we may regard the Pelmatozoan as a Cystid. 

Each plate has a small, but usually distinct, central umbo, from 

which folds radiate to the periphery. The ridges due to these 
folds on the outer surface of the plate are more marked than the 
corresponding furrows on the inner side of the plate (Figs. 7, 10, 11, 
12). The number of folds varies from five to perhaps as many as 
‘seventeen (Fig. 6). In many instances three folds, arranged in 
Y fashion, are more prominent than the others, and merge into the 
umbo. ‘I'wo folds nearly as pronounced are often seen to approach, 
or perhaps join, the umbo, one on each side of the Y and at about 
right angles to its stem. Thus arise five main folds, which, it will 
be noted, are not of necessity pentamerously symmetrical. The 
remaining folds do not reach the umbo, but while a few come rather 
near to it the rest are mere gofferings of the margin of the plate. 
Thus the total number of folds tends to increase with the size of 
the plate. 

These folds present two points of difference from the folds and 
ridges so common on the thecal plates of many Cystidea and 
Crinoidea.” First, the rare specimens in which the margin of the 
plate is indicated (G. F. M. a, 6) appear to show that the main folds 
were directed towards the angles of the plate, whereas the axial 
folds of Crinoids and the rhomb-folds of Cystids normally pass across 
the sides of the plates, the more prominent among them bisecting 
the sides at right angles. Secondly, whereas the minor ridges of 
Cystidea Rhombifera and of all Crinoidea except Porocrinus are 
parallel to the major axial folds, thus giving rise to the characteristic 
rhomb-structure, the folds of Hocystis primeva radiate from the 
umbo like the spokes of a wheel. It follows from this that in two 
adjacent plates of #. primeva the folds cannot have passed in 
a straight line from one plate to anuther. It also seems probable 
that the plates cannot have fitted very accurately together, and that, 
if in any case two ridges of adjoining stellate plates did lie in the 
same straight line, then there must have been smaller irregular plates 
filling up the interspaces. A similar, though more definite and 
regular arrangement of folds is seen in Amygdalocystis florealis; but 
the plates of Macrocystella marie, which, as they lie in their matrix 
of Shineton Shale, are strongly reminiscent of Hocystis primeva, may 
be distinguished by the axial nature of the folding. 

Since not a single stellate plate in Dr. Matthew’s collection 
preserves a complete outline the exact measurements cannot be 
given. The long diameter varies from 2:5mm. to 6mm., but 
perfect specimens may have exceeded this. In the majority of 


52 Dr. F. A. Bather—EKocystis. 


specimens, as preserved, it is about 5mm. The plates appear to 
have been very thin, but thickened at the umbo and folds. 

Some recent private correspondence suggests the need for an 
explanation that, in using the term folds, I have never meant to 
imply that a plate was subjected to any force which threw it into 
folds. The stereom was, one presumes, deposited in that shape from 
the outset. But it followed the course and structure of the stroma, 
and this was usually affected by mechanical stresses. 

It is quite easy to see how under these conditions there arose the 
hexagonal plating, with folds at right angles to the sutures, common 
in normal many-plated Cystids (e.g. Heliocrinus, Aristocystis, 

ichinosphera); and the modifications produced by the development 
of basal and radial plates, as in Caryocrinus and in normal crincids, 
also present no difficulty. But it is not at once easy to see what 
stresses led to the irregularly pentagonal plates of Hocystis, in which 
pentactiny is superinduced on trisactiny (see. Figs. 2-6). The 
following explanation is therefore offered. 

If a piece of soft woven tissue be lightly stretched over a frame, 
and if a few equal weights be attached to various points in it, then 
the tissue will be dragged into folds leading from each of these 
weighted points to those adjacent. The direction and pattern of the 
folding will depend on the positions of the weight-points. 


ASS Ze] 
vara 
SOK 
Ux Tele Pi 
INNZAS NIZA 
KN KY io 

Diagram showing the lines of mechanical stress 
supposed to have produced the Hocystis plan 
of plate. 

The problem before us, then, is to find the weight-points that 
would produce the fold-pattern of Hocystzs. The three major lines 
of several plates, if plotted on paper, lead to an hexagonal pattern. 
This at first sight does not seem hopeful. But we note that the 
umbones of the plates, instead of lying at the centres of the hexagons, 
lie at the angles, or, in other words, at the nodes where the main 
lines of stress meet. This suggests that a hexagonal folding of the 


Dr. F. A. Bather—Eocystis. 53 


stroma, such as may sometimes be seen in contracting homogeneous 
layers, preceded any extensive calcification, and that consequently 
the stereom was concentrated at the nodes. On this assumption, 
there arises a series of weight-points at the angles of alternating 
hexagonal spaces. Inserting these on our plan (Diagr. p. 52), we 
now proceed to fill in the other lines of stress that would flow 
from such an arrangement. These have been represented in the 
diagram with thicknesses roughly proportional to the distances 
between the weight-points. ‘Thus a triple line connects the nodes 
along the sides of the hexagon; a stout double line connects the 
nodes horizontally; a faint double line connects those at the upper 
and lower angles, this being emphasized because the pull is intensified 
in this direction by gravity ; a stout single line joins the node to the 
nearer pair of the remaining angles, and a faint single line joins it to 
the pair more remote. 

Now take this diagram, worked out on purely a prior? reasoning 
this night (December 5-6, 1917), and compare it with the lines of 
Figs, 2-6, drawn in 1900 before the problem had been formulated. 
Starting from a node there are lines of stress precisely comparable 
with the folds radiating from the umbo; and it will be observed 
that in the diagram no lines occur between the horizontal lines and 
the immediately adjacent main lines, just as the plates are folded 
very faintly or more often not at all in those spaces. 

So much for the folds; now for the outline. If a circle be 
described with the node as a centre, and with radius equal to half 
the side of a hexagon, it will represent the tract that would 
naturally be calcified if calcification spread uniformly outward from 
the node untilit met that spreading from the three adjacent nodes. 
Known facts of growth, however, suggest that the calcification 
would progress more rapidly along the main folds. Let the points 
- where these are cut by the circle be joined by straight lines, and an 
irregular pentagon will result. his is shown in the diagram by 
dotted lines, but these, instead of being quite straight, are bent 
outwards slightly along the minor lines of stress. Thus is produced 
an outline agreeing so closely with the outline of Fig. 7 that the 
correspondence of theory with fact is truly astonishing. 

The plates thus outlined in the diagram do not fill the whole 
space; more particularly is there a large free area round the centre 
of each hexagon. Probably the minor centres of calcification gave 
rise to a number of small intercalary plates. 

If there be any truth in the hypothesis here put forward it follows 
that the Hocystis plan represents an evolutionary stage previous to 
that of the more usual pavement of hexagonal plates. One way in 
which the change might have been effected would be the fusion and 
growth of the plates about the centre of our supposed hexagon ; 
this would produce a series of sub-hexagonal plates each surrounded 
by smaller ones, much as in Deutocystis. Or the original pentagonal 
plates, as they met, might be forced into a hexagonal shape, coupled 
with a strengthening of thefold within the fork of the , ; this would 
produce a plate like that of Amygdalocystis, which is not on the 
norma] plan. 


54 Dr. F. A. Bather—Eocystis. 


2. The two specimens labelled ‘‘ Plates showing Marginal Pores”’ 

are in the form of impressions. One of them (EK 7608) looks strangely 
like one-half of the pectinirhomb of a Glyptocystid; but the 
resemblance disappears when one examines a wax squeeze of it. 
I believe this specimen to be the impression of the sutural margin of 
a plate 3-8 mm. long, about -6 mm. thick at the corners, and 1 mm. 
thick in the middle of the side; the sutural surface is covered with 
slightly irregular vertical ridges, about five to the millimetre, and 
these may have been crenelations fitting into corresponding notches 
in the adjacent plate. These ridges pass right down to the concavely 
curyed margin, which I take to be on the inner side of the plate; 
but on the outer convexly curved, or, rather, gabled, side they 
stop short, so that the suture, if suture it be, was grooved. In the 
middle of the side, however, forming, as it were, the rooftree of the 
gable, is a rather large prominent vertical ridge, probably continuous 
with an axial fold or ridge. Clearly this impression has nothing to 
do with the stellate plates, and there is no adequate reason for 
supposing that the plate which made it belonged to the same 
organism. 
_, The other impression, G. F. M. ¢ (Fig. 8), appears to have been 
formed by the folded edge of a plate which had fallen obliquely into 
the mud. The space formerly occupied by the plate, having been 
subject to less compression, is thicker than usual. The walls of the 
eavity are marked by about seven ridges, varying in distinctness, and 
passing across its thickness. A squeeze of the cavity indicates that 
these ridges correspond to indentations or scollopings in the margin 
of the plate, lying between its folds. If several plates of this shape 
lay next one another in the thecal wall there would be the appearance 
of pores between them. It is quite possible that this is one of the 
stellate plates, and that others of them had a similar margin. 

3. The impressions referred to Columnals are in the main of two 
kinds, long and short. The long ones vary in length from 1 to 3mm., 
with a diameter from 4 to 3 their length. The diameter appears to 
be least about the middle; in other words the ossicles were slightly 
dice-box shaped (Fig. 15). At each end was a conical excavation 
penetrating to a depth about equal to the width of the respective 
columnals. In the impression this appears as a deltoid patch of 
matrix, and is sometimes so pronounced as to give the impression 
a bifurcate appearance, G. F. M. g (Fig.14). In a few cases this may 
be seen at both ends, but more often the matrix has been split 
obliquely to the long axis of the columnal, so that in a single half of 
the impression this cone appears only at one end. ‘The sides of the 
columnals seem to have been marked with irregular vertical strie, 
perhaps due to the original fascicular structure of the stereom 
(Fig. 10, 8). 

The short columnals leave an impression that approaches a square, 
but has the two sides slightly inflected. E 7607 has a length of 
about ‘75 mm. and shows no cone at the ends. One of Dr. Matthew’s 
specimens (d, Fig. 18) is about :25 mm. long, and has a flattened cone 
at each end. rn 

There is no direct evidence that these columnals belonged to the 


Dr. FA. Bather—EHocystis. — so) 


animal that owned the stellate plates. Their association in the rock 
suggests that they did so, but the relatively small size of so many 
suggests that they did not. 

~ On specimen G. F. M. d, a worm-like body, about 11 mm. long and 
1:25 mm. wide, and marked with obscure transverse striz, is labelled 
by Dr. Matthew ‘‘ Hocystites primeva, stem!” One end lies against 
a stellate plate, but there seems no other reason for this ascription. 

4. The Undetermined Plates include many obscure impressions and 
patches of various sizes and shapes—or rather absence of definite 
shape. There seems no reason why some of them should not belong 
to Hocystis, nor any why they should. There are several examples 
of a trihedral sub-pyramidal impression, probably produced by the 
angle of a plate. The wax squeeze drawn (Fig. 19) is taken from 
the largest of these (4). Another type is represented by j, the 
squeeze of which (Fig. 18) shows curved sides meeting in a rounded 
ridge with a wide angle and a rather sharp edge or lip in front. 
Other forms are shown in / and /’ (Figs. 16, 20), but without figuring 
every specimen one cannot convey an idea of the variations in shape 
of these rounded surfaces. Among the fragments is an apparent 
spine, /, possibly the infilling of a columnal (Fig. 17). There are 
also some minute rounded impressions, which may represent the 
intercalary plates of Hocystis. 


From the various plates and ossicles now described it is not easy to 
reconstruct the form of Zocystis. We can recognize the stellate 
plates of the theca and the biconcave columnals, and we are ‘led 
by their numbers and their association to suppose that both belonged 
to the same form. If this be so, then Hocystis possessed a flexibly- 
walled theca borne on a slender flexible stem. One can detect no 
obvious brachiolars, and the undetermined ossicles seem too large to 
be thus interpreted. Possibly they represent proximal columnals 
such as occur in the Heterostelea, to which group Trochocystis 
belongs. Comparison may profitably be made with the stem of 
Cothurnocystis (Bather, 1913, ‘‘Caradocian Cystidea from Girvan,” 
Trans. Roy. Soc. Edinburgh, xlix, pt. ii, No. 6, §§ 200-6, 
text-figs. 19-23). 

If Eocystis be rightly referred to the Heterostelea, it by no means 
follows that it belongs to the Trochocystide. The stellate plates are 
unlike the close-fitting hexagonal plates of Zrochocystis (Barrande, 
1887, Syst. Sil., Cystidées, pls. iii, iv), and there is no trace of the 
characteristic marginals. For similar reasons HKocyst’s cannot be 
referred to the Cothurnocystide or Ceratocystide, and still less to 
the Anomalocystide. It may have resembled Dendrocystis in the 
iregular arrangement of its thecal plates, but it differed in the 
eylindrical or dice-box columnals. 

For the interpretation of Hocystzs it will therefore be necessary to 
consider other forms than Locystis primeva, both such forms as may 
have been referred, with or without hesitation, to Kocyst¢/s, and such 
obscure remains as may have received yet other names. That inquiry 
may form the subject of a future article. 


+ 


56 Dr. A. Hubert Cowa—South Staffordshire Fire-clays. 


EXPLANATION OF PLATE V. 

Fic. HOCYSTIS PRIMAVA. 

1. The Wolotene: reproduced from Dawson’s fig. 220. 

2-6. Diagrams illustrating the direction and strength of the folds in vue 
plates, viz. (2) E 7611, (3) E7604, both being imprints of the inner 
face; (4) G. F.M. f, (5) G.F. M. e, (6) E 7603, these being imprints of 
the outer face. In (2) to (5) there are ten folds to each plate; in all 
there can be distinguished three main folds A, and two folds nearly as 
strong running east and west; subsidiary folds occur in the spaces 
between all of these, except the space in the E.S.E. sector (as seen 
‘in the external imprint), and are rare in the corresponding W.S.W. 
sector. 

7. E7602, showing a plate and a columnal; (a) external, (6) internal 
imprint. x 4 diam. 
8. G.F.M.c. An imprint of a plate supposed to show marginal pores, as 
received. X 8 diam. 
9. The same imprint after removal of more matrix. x 8 diam. 
10. E7602. (a) External imprint of a plate; (b) columnal. x 8 diam. 


11. G.F.M.a. Internalimprint of astellate plate of normalform. x 4 diam. 
12. G.F.M. 6b. External imprint of a plate. x 4 diam. 

13. G.F.M.d. Imprint of columnal(?). x 8 diam. 

14. G.F.M.g. Squeeze from imprint of a columnal. x 4 diam. 

15. Suggested reconstruction of a columnal in solid section. x 4 diam. 

16. F.M. h'. Wax squeeze of an undetermined plate, (a) from above, 


G. 
(6) from the side. x 4 diam. 

17. G.F.M.l. Wax squeeze of an external imprint, possibly the infilling of 
acolumnal. x 4 diam. 

18. G.F.M. 7. Wax squeeze of an external imprint of an undetermined 
plate. x 4 diam. 

19. G.F.M.&. Ditto. 

20. G.F.M. h. Ditto. 

Drawings by G. C. Chubb, from the specimens and from pencil drawings by 
the author. 


Il.—Nores on some Sourn STaFFORDSHIRE FIre-cLaYsS AND THEIR 
Brenaviour on Ienirion. 


By ARTHUR HUBERT Cox, M.Sce., Ph.D., F.G.S. 


LL geologists are familiar with those changes effected in 
argillaceous rocks under the influence of heat from igneous 
intrusions, changes that result in the formation of such roeks as 
ehiastolite-slate, andalusite-hornfels, etc. It is therefore somewhat 
surprising that the changes produced during the artificial heating of 
clays should remain comparatively unknown to the body of geologists, 
although such changes are produced every day on a large scale 
during the baking of clays for the manufacture of pottery of various 
kinds. These changes have, indeed, been very little studied from 
the mineralogical standpoint. It might at first sight be expected 
that any changes brought about artificially by the action of heat on 
a clay would compare somewhat. closely with those resulting in an 
argillaceous rock when subjected to contact-metamorphism—at any 
rate in the normal case of the latter change—when there is no 
transference of material from the igneous to the sedimentary rock. 
Yet such is hardly the case; there are certainly points of resem- 
blance, but there are also very notable differences. It must be made 
clear that the clays used in the experiments to be described were 


Gon. Maa., 1918. Prats V. 


Ws 


IK aces 


S 


y 
nt : 
4m 


EZ i 
ZA 


Wh 
I] 


ee 


q 
Ny 


F. A. Bather and G. C. Chubb del. Bale imp. 


EOCYSTIS PRIMAEVA HARTT. 


er 


Dr: A. Hubert Cox —South Staffordshire Pire-clays. 57 


selected on account of their importance for certain industrial uses, 
and not on account of any special similarity to those argillaceous 
rocks usually affected by contact-metamorphism. They are there- 
fore clays of a special type with certain chemical characteristics that 
distinguish them from the more commonly occurring, and therefore 
more commonly metamorphosed, argillaceous rocks. Nevertheless, 
the lithological correspondence is close enough to institute certain 
comparisons. 

Before proceeding, however, to discuss such comparisons of the 
artificially induced changes with those occurring during contact- 
metamorphism, the characters of the raw material must be briefly 
described. The clays subjected to experiment were mostly fire-clays 
from the Coal-measures of South Staffordshire. The mode of 
occurrence of the origin of the South Staffordshire fire-clays has 
been recently discussed by Professor Boulton.’ Fuire-clays differ, of 
course, from the commonly occurring clays in their very low alkali- 
content, and as a rule also in their lower iron-content. The 
particular clays examined were found to consist essentially of 
a mixture of two types of material, (1) a fine-grained base or clay- 
substance and (2) a larger or smaller amount of arenaceous material. 

1. The clay-substance consists of an extremely fine-grained 
material; its investigation therefore presents many difficulties. It 
is only transparent in the thinnest sections, and is then seen to be 
pale-yellow or almost colourless, the colour gradually increasing 
with the thickness, so that the material soon becomes yellowish- 
brown and almost opaque. It is not quite clear whether the colour 
is a property of the material itself, or arises as the result of iron- 
staining. Wherever it could be tested the material proved to be 
birefringent. In consequence, however, of the very small size of the 
crystals compensation occurs in any but the thinnest sections, so that 
the material appears to be almost isotropic. By use of the gypsum 
plate, however, the double refraction can be made apparent. The 
clay material appears, therefore, to be entirely crystalline. It has 
often been supposed that the ultimate base in many clays is an 
amorphous material, but certainly none of the South Staffordshire 
fire-clays examined by the writer showed any clear signs of the 
presence of such matter. Further, no amorphous material could be 
isolated by means of heavy solutions. When tested in bromoform 
solutions of varying density it was found that no material floated in 
solutions of specific gravity less than 2°50. On gradually increasing 
the density of the solution above that point a slight scum rose to the 
surface, but even this proved to be crystalline. There is, therefore, 
an entire absence from these clays of material with a specific gravity 
less than 2°50. This fact tells strongly against the presence of any 
amorphous material, seeing that, whereas (crystalline) kaolinite has 
the specific gravity 2°65, the amorphous forms of hydrated aluminium 
silicate, such as halloysite, have a density of only about 2:0—-2°2. 
If therefore any such substance occurred in the clay its presence 
should be easy to determine. 


1 Trans. Eng. Ceramic Soc., vol. xvi, p. 287, 1916-17. 


Da. Dr: A. Hubert Cox—South Staffordshire Fire-clays. ‘e 


It: seems clear, then, that: the clays examined consist entirely of 
erystalline material, and that amorphous matter is absent altogether. 
On the other hand, Dr. Mellor has recently adduced evidence from © 
the heating-curves of some South Staffordshire fire-clays for the 
existence in them of ‘‘clayite’’, which he regards as being amorphous.} 
But, as stated above, no amorphous matter could be found De 
mineralogical examination. 

The mere fact that the clay-base is crystalline and not amorphous 
does not, however, prevent the fine material form acting in certain 
respects like a colloid. For example, if suspended in water, it may 
be readily precipitated by the addition of certain electrolytes, 
particularly by acids. 

-It is unnecessary for the purpose in view in this communication to 
enter into the vexed question as to the actual mineralogical 
composition of this clay-base. It certainly seems, however, to act as 
a single substance with definite optical characters, and therefore 
presumably definite chemical composition. Itis, moreover, significant 
_that the more the fine material of a clay can be purified, the more 
nearly does it approach kaolin, Al, Os, 2 Si Os, 2 H, O, in chemical 
composition. It is true that there are certain marked differences of 
appearance between the substance of the clay-base of these South 
Staffordshire clays and the kaolinin a china-clay. These differences 
appear to be intimately connected with the variation in their plasticity, 
the fire-clay being highly plastic, whereas the china- ey 1s. oul 
slightly plastic. 

2. Arenaceous material was present in all the clays eal 
and often in amounts. surprisingly large, considering the typical 
argillaceous appearance of hand-specimens. The arenaceous material 
consists for the most part of quartz-grains exactly comparable with 
those in a normal fine-grained sandstone. Grains other than quartz 
are not abundant, but a certain number of chert-grains were usually 
to be found. Undoubted felspar was only rarely observed, and the 
same was true for clastic micas. Isolated examples of heavy minerals, 
such as tourmaline, zircon, rutile, etc., were usually present, but in 
amounts so small as to be negligible in affecting the properties of 
the clays. 

Besides the larger, more or less rounded, and obviously detrital 
sand-grains, there were also present innumerable minute flakes and 
chips of quartz. These passed downwards into the finest quartz- 
dust, almost comparable in grain with the material of the clay-base 
itself. It is evident that, owing to its very fine grain it would 
prove almost impossible to separate much of this free silica from the 
true clay material by any mere process of washing. In view of the 
occurrence of chert-grains among the sandy material of the clays, 
if seems very possible that some of. this quartz-flour may have 
been derived from the disintegration of cherty rocks. On the other 
hand, it may have had its origin in the small secondary quartzes 
that would result from the alterations undergone by many of the 
minerals of the old land surface then undergoing denudation. In 


! Trans. Eng. Ceramic Soc., vol. xvi, p. 83, 1916-17. 


Dr, A. Hubert Coa—South Staffordshire Fire-clays. 59 


any case it is evident that this fine quartz-flour is of true detrital 
origin, and not an authigenous constituent arising as the result of 
secondary changes in the clay itself. 

Among the minor constituents of the clays, carbonaceous menerel 
can invariably be recognized in the hand-specimen; this probably 
plays an important part in determining the porosity of the burnt 
clay. Pyrites occurs dispersed as a fine flour, and a certain amount 
of oxides of iron may also be recognized. ~ 

The first stage of ignition consisted in heating the clay (made 
plastic with water and then dried) to a temperature of 1000-1080° C. 
for about fifteen minutes. ‘The main changes during this preliminary 
heating were: (1) the burning-off of carbonaceous material, (2) the 
oxidation of ferrous compounds, involving a colour-change from the 
original dark-grey to a paler and more yellowish tint, (3) an almost 
complete loss of the combined water. The originally soft clay is 
thus converted into a ‘ biscuit-clay”’, as it is termed by the pottery 
manufacturers. The biscuit is highly porous, and therefore can 
absorb water, but it cannot be reconverted into a plastic material 
comparable with the original clay. Some important change has 
therefore taken place during the burning, and the biscuited clay has 
lost all power to combine with water. Curiously enough this change, 
presumably chemical, is not accompanied by any corresponding 
change in the physical characters as revealed by the microscope, 
although the macroscopic change is obvious enough. ‘The biscuited 
clay presents in fact, so far as I could observe, very much the same 
appearance under the microscope as the original clay. 

When, however, the ignition is carried out at a higher temperature, 
about 1500° C., various interesting chemical anal mineralogical 
changes begin. The clay now gradually ‘“ vitrifies’’, owing to the 
partial fusion of the Jess refractory constituents, resulting in the 
formation of material that is practically a glass. The amorphous 
nature of the new material is not, however, readily established in the 
early stages of the process. ‘he difficulty arises both from the 
minuteness of the particles, and the extent to which the newly- 
formed vitreous material is crowded with as yet unaltered crystalline 
material. Also the glass, as first formed, is in a state of strain, since 
the vitrification takes place without the material ever becoming 
actually liquid in the popular sense. Accordingly the glass is 
birefringent in the early stages of the process. As the heating is 
continued, more and more of the original crystalline material Joses 
its identity, and the resulting vitreous substance thus has more 
chance to adjust itself. This latter factor is, however, partly 
counterbalanced by the fact that the newly-formed glass occupies 
more room than the crystalline material, as is shown by the respective 
densities. Owing to slight flow-movements, a minute, irregular 
streakiness soon appears. ‘The strain is thereupon somewhat lessened, 
so that the material becomes, over small areas, quite isotropic. 

The vitreous material can then be seen gradually to corrode and 
absorb even the larger sand-grains, so that an almost uniform product 
is finally obtained. As stated above, all these changes take place 
without the material ever becoming really liquid, always provided that 


60 Dr. A. Hubert Cox—South Staffordshire Fire-clays. — 


one is dealing with-a truly refractory clay, and accordingly the ignited 
article retains its original shape. The resulting product, in fact, 
does not present to the naked eye any marked difference to the 
biscuit-clay, save that it appears, perhaps, to be a little more compact. 
A careful examination, however, reveals slight traces of fusion 
having taken place, and the material no longer tends to crumble 
easily as does the biscuit-clay. Actually, however, the specific 
gravity is lowered, as is only to be expected when crystalline material 
passes over into the amorphous condition. 

A high-grade clay will then remain in much the same condition, 
even when subjected to considerably higher temperatures, tempera- 
tures up to 1600° C., or even in certain special cases up to 1700° C. 
Vitrification is naturally progressive, but still the clay does not soften 
appreciably until these temperatures are reached. An inferior clay, 
on the other hand, under the same conditions melts down more or 
less completely, naturally changing its shape completely during the 
process. All stages from readily fusible clays to highly refractory 
ones may be obtained. It was found that the softening-point of 
lower-grade fire-clays was considerably raised if the coarse sand- 
(quartz-) grains were first removed by washing. Conversely these 
coarser portions from the clay, when treated alone, were found to 
have a very low softening-point, becoming quite fluid at the higher 
temperatures. This point will be further referred to below. 

Returning to the more refractory clays, with increase of tempera- 
ture an entirely new change begins, the results of which become 
more and more marked the longer the clay is subjected to the higher 
temperature. The new change consists in a devitrification of the 
glass owing to the separation of tiny needles of some crystalline 
substance. This devitrification may set in before the vitrification is 
quite complete, in that the larger quartz-grains may not have been 
finally absorbed by the fluxing sroundmass. In specimens exposed 
to a very high temperature for many weeks the devitrification has 
proceeded to a very considerable extent, although it still remains 
incomplete. The material so obtained consists of a colourless and 
completely isotropic glass enclosing great numbers of small crystals. 
The crystals, in fact, : are so numerous and so small as to render the 
glass opaque except in very thin section, when the glass appears as 
if it contains a vast number of little globules. Under favourable 
conditions, and with high powers, the apparent globules are seen to 
be really angular, and exceptionally they are seen to be elongated in 
prismatic form. 

The crystals were isolated by means of cold dilute hydrofluoric 
acid, which remained without action on them. ra all’ proved to 
be acicular in form, with a high refractive index—about 1:°66— 
straight extinction, and + character. They ne therefore, of 
a sillimanite. There appear to be no substances present other than 
sillimanite and the clear glass. In one specimen, which had been 
exposed to a high temperature for many weeks, and in which, 
therefore, the crystallization may reasonably be assumed to be 
complete, the amount of sillimanite was found to vary between 29:0 
and 33:3 per cent. 


Dr. A. Hubert Cox—NSouth Staffordshire Fire-clays. 61 


The separation of. the crystalline sillimanite, with a specific 
gravity 3°23, naturally involves a considerable contraction. The 
result is the formation of a drusy material, in which the cavities 
are of comparatively large size and quite irregular in shape. 

The marked tendency to the production of sillimanite when 
substances approximating in composition to kaolin are strongly 
heated, has been observed on various occasions. Wernadsky ‘ 
obtained it from artificial mixture of Al, Os and Si O,, and also from 
kaolin. He further noted its formation in crucibles and fire-bricks 
from various fire-clays. It was also observed by Mellor? in 
porcelains made from mixtures rich in china-clay and felspar fired at 
temperatures over 1300°C.3 It is a remarkable point that the 
sillimanite formed from the fire-clays seems not to have the same 
composition as the naturally-occurring sillimanite of the rocks. 
The natural product is always stated to have the composition 
Ale Si Os, or Al, Os, Si O2, where the Al, O; : Si Og ratio is as 1:1. 
The artificial product, however, seems to have the ratio 11: 8, as 
shown by the following figures :— 


Calculated for 
11 Ale Os, 8 Si Oo | Ale Os, Si O. 
SiO, 30-07 | 28-89 29-96 37-03 
Al, O; 69°93 | 71-11 70°04 62°97 

The analysis was carried out by volatilizing the Si O2 from the 
crystals (obtained as mentioned above, p. 62) as Si Fy, the Als O; being 
left as such on ignition. 

A similar result was obtained by Wernadsky ‘ for sillimanite from 
fire-clays, whereas the sillimanite formed from artificial mixtures of 
Al, O; and $i0 had the normal composition Al, Si Os, whatever the 
proportions of Alz Os and Si Oz in the original mixture.® 

Sillimanite of the composition 11 Als Os, 8 Si Oz was recorded by 
Sainte-Claire, Deville, and Caron ® as formed by the action of Al I's on 
Si Oz, but, so far as I am aware, there is no case recorded of an 
analogous product occurring in the metamorphic rocks. The question 
is, however, deserving of further investigation. 

Sillimanite is a chemically simple substance, and it is well known 
that the fusing-point of a chemically simple substance is lowered by 
the introduction of impurities. Now all the clays examined contained 
sandy (quartzose) material giving an SiO2: AleO,; ratio much greater 
than that in sillimanite. It appeared probable, therefore, that the 
refractoriness of the clays would be increased by removing the excess 
of sand. ‘his was actually found to be the case, as already 
mentioned (p. 60). Since, however, the clays all contain much 


* Bull. Soc. Min. France, vol. xiii, p. 260, 1890. 

* Journ. Soc. Chem. Ind., vol. xxvi, p. 375, 1907. 

* For a summary of the effects of heat on kaolin and kaolinite, see J. A. 
Howe, Handbook to the Collection of Kaolin . . . (Mem. Geol. Surv.), 1914, 
p- 151, with references. 

* Bull. Soe. Min. France, vol. xiii, p. 270, 1890. 

> Op. cit., p. 263. 

® C.R., vol. xlvi, p. 766, 1858. 


62 Dr. A. Hubert Cox—South Staffordshire Fire-clays. 


free silica in the form of a quartz-flour, the Si O, : Al, O, ratio still 
remained in excess of that demanded by eilGnanite. This excess 
of silica could not be readily removed by any simple process of 
elutriation in consequence of the extremely fine-grained character of 
the quartz-dust, the particles of which become comparable in size 
with those of the clay-base itself." In order, therefore, to bring the 
$i 0. : Ale O; ratio down to that demanded by sillimanite, alumina in 
various forms was added to the clays in various amounts. The 
refractoriness of the clays was then again found to be further 


‘increased, or in other words the Sela was very consider- 


ably raised. 

Turning now to a comparison of the changes occurring in 
artificially heated clays with those in contact- altered ar gillaceous 
rocks, there are certain points of resemblance, as is only to be 
expected. But there are also, in most cases, some very interesting 
differences in behaviour. 

In the first place it will be noted that the aluminium-silicate 
formed under artificial heating was the high-temperature form 


_ sillimanite. In no case was the low-temperature form andalusite 


observed, and, so far as I am aware, the artificial production of that 
mineral has never been recorded. 

In contact-altered rocks, on the other hand, both minerals may 
occur, sometimes exclusively the one or the other, sometimes both 
together, whereas in yet other cases hyanite is the characteristic 
mineral. 

Again, the more obviously contact-altered rocks are almost always 
holocrystalline, belonging to, or approximating to, the granular 
rocks classed as hornfels. Cases of vitreous rocks produced by 
contact-action are the exception rather than the rule. We have, 
however, examples of such vitreous rocks in the buchites, or vitrified 
phyllites, British specimens of which have been described from 
Argyllshire by Dr. Flett.? 

In these vitrified phyllites, however, the newly-formed aluminium 
silicate occurs, not in the pure state as andalusite or sillimanite, but 
combined with MgO as cordierite. ‘his, however, is merely the 
result of the high magnesia-content of the original phyllite, in which 
the magnesia was present in the form of chlorite. 

Apart from the buchites certain other examples of contact- 
altered rocks are known that match in all respects the products 
formed by the continued ignition of fire-clays. They are rocks that 
occur as xenoliths in basic intrusive rocks in Mull. A complete 
account of the phenomena there shown is not at present available, 
but some mention of the rocks has been made by the officers of the 
Geological Survey inrecent Summaries of Progress. These xenoliths, 


1 Tt has been shown possible to remove this silica-dust by osmosis, a process 
that has been claimed to yield excellent results in other cases [W. R. Ormandy, 
Trans. Eng. Cer. Soc., vol. xii, p. 36, 1912-13, and vol. xiii, p. 35, 1913-14]. 
When a suspension of clay is electrolized the quartz remains neutral, the clay- 
substance goes to the — pole, while most of the impurities go to the + pole. 

2 Geology of the Country near Oban and Desig) (Mem, “Geol. Surv.), 1908, 
p. 129, with references. 


. 
i) 


Dr, A. Hubert Cox—South Staffordshire Fire-clays. 68 


derived from highly aluminous shales, have been converted into 
sillimanite-hornfels, that is, rocks consisting ‘‘entirely of minute 
slender needles of sillimanite set in a colourless glassy base’’.! One 
such rock has been analysed. 

It is noteworthy that these vitrified rocks occur, as a rule, in 
association with those basic intrusive rocks, such as olivine-dolerites, 
camptonites, monchiquites, etc., that show a tendency to contain 
more or less analcite. The magmas that give rise to such rocks, 
therefore, must have been richer in water-vapour than is normally 
the case in igneous magmas. Accordingly it may well be that the 
vitrifying action which they exerted on the surrounding sediments 
was facilitated by the presence of the hot vapours. his conclusion 
is supported by the analyses quoted by Dr. Flett,? which show an 
accession of water to the vitrified rock as compared with the 
unaltered rock. 

It may well be that the vitrification of the ignited fire-clays was 
hkewise facilitated by the presence of slight traces of water that had 
escaped volatilization during the preliminary heating to the biscuit 
stage. In this connexion it may be noticed that most glassy rocks, 
such as the pitchstones and tachylites, show a high water-content. 
Obsidians, however, form an exception to this rule. 

Summarizing the results we may say that the artificially heated 
clay, originally cryptocrystalline in texture, shows first a vitrifica- 
tion, followed by a partial devitrification, resulting in the formation 
of the high-temperature mineral sillimanite. The texture still 
remains very fine-grained. 

The naturally heated rocks, on the other hand, do not normally 
show signs of any vitrification having taken place. Rather do they 
pass into rocks of the holocrystalline hornfels type with a medium 
to coarse texture, and in which low-temperature minerals may be 
found either alongside, or to the complete exclusion of, high- 
temperature minerals. Such contact-action was therefore brought 
about by a comparatively small rise of temperature, extending, 
however, over a considerable time. 

Exceptionally there do occur vitrified rocks comparing more 
closely with the artificially altered fire-clays, but such vitrified 
rocks are only associated with special types of igneous rocks, and 
water-vapour probably played an important role in determining their 
special features. 

I have to express my indebtedness to Professor Sir Herbert 
Jackson, K.B.E., F.R.S., for his most valuable advice and for 
reading through this paper, and to the Controller of the Optical 
Munitions and Glassware Department of the Ministry of Munitions 
of War for permission to publish these results of an investigation 
primarily undertaken on behalf of that Department, and carried out 
in connexion with Sir Herbert Jackson’s researches on fire-clays for 
the Clay Research Committee of the Institute of Chemistry. 


1 A. E. Radley, Swmmary of Progress for 1914 (Mem. Geol. Surv.), 1915, 
p- 57. 
2 Op. supra cit., p. 132. 


64 A. H. Trueman—The Inas of South Lincolnshire. 


IlI1.—Tar Lras or Sovurm LinconnsHire. 


By A. E. TRUEMAN, M.Sc., F.G.S., formerly Research Scholar, University 
College, Nottingham. 


InrRopucrory. 


HE area to be described is that part of the Lias outcrop extending 
from Lincoln southwards to Barrow-on-Soar and Grantham, 

and includes south-west Lincolnshire and small portions of north- 
east Leicestershire and east Nottinghamshire (see Map, Fig. 1). 


LINCOLN 
Devecenia 
Waddington 


Bassingham | 


Brant Broughto 


NEWARK * Ge ee 
| ce y Leadenhall 


“Cotham Caytho rbe TI 


Gonerby 


sia Bottesford 
a Sedoebrook 
| Cotgrave Gorse . Barnstone an *GRANTHAM| 


o ry 


Woolstho be toga 


barre: (Outhor e 
- P Plun siersfoxd 


CY 


nar 
Stathern 


Normanton Hills 
- ne White lain 
Bett ‘) Old Dalby” 


eBarrow-on-Soar oe Cee 
Fic. 1.—Diagram map of South-West Lincolnshire to show the position of 
exposures. (Adapted from the Index Map of the Geological Survey.) 


The rocks of this district were mapped by the Geological Survey, 


and an account of some of them was published in 1885! and 18887; 


* The Geology of South-West Lincolnshire (Mem. Geol. Sury.), 1885. 
2 Country around Lincoln (Mem. Geol. Surv.), 1888. 


A, KH. Trueman—Tie Lias of South Lincolnshire. 65 


the south-western part of the area has been resurveyed and described 
in more recent memoirs. A summary of the geology of the area 
was prepared in 1910 by A. J. Jukes-Browne,' but except for these 
publications the literature is scattered and consists mainly of short 
papers; details of these are given where they are referred to. 

It will therefore be seen that the Lias as a whole has not been 
studied in this neighbourhood for some thirty years. During this 
time the Lias of other areas has been carefully investigated by 
numerous workers, resulting in great advancement in our knowledge 
of the succession. This work has been undertaken in order to deter- 
mine whether the Lincolnshire succession agrees with that recorded 
elsewhere. 

Since there are no continuous sections available for study, the 
work has been confined to artificial exposures in limestone and 
ironstone quarries and clay pits. Many of the exposures examined 
by previous writers have long been abandoned, owing to the closing 
of the hand-brickyards in the area;* moreover, on account of the 
war, many of the remaining yards have been temporarily closed, 
and consequently it 1s often a matter of some difficulty to collect 
fossils in situ. Thus it may be expected that the faunal lists will 
be considerably increased and much fresh detail obtained by further 
work when the pits are reopened. While only scattered observa- 
tions may be made on the Lower Lias clays, it has been possible to 
make a detailed comparison of the Middle and Upper Lias. In the 
course of the work samples of clay from each exposure have been 
“washed”? and the residue examined for Foraminifera, details of 
which are given in the lists. 

It is necessary to state that the interpretation of ‘‘ zone”’ adopted 
in this paper is that given by Mr. W. D. Lang,* who emphasized the 
fact that once a zone is defined its boundaries ‘‘ theoretically are 
fixed for ever”’. The so-called zones which have been used at 
Lincoln have often been unsatisfactory ; for example, the deposits 
known as commune zone in Lincolnshire and Yorkshire are quite 
different in age. If zonal terms were correctly used, such a contra- 
diction would be impossible. In this paper the hemeral terms 
introduced by Mr. S. 8. Buckman, which have sometimes been 
miscalled zones, have in the Upper Lias been used as sub-zones of 
Oppel’s cumbersome zone of Posedonomya Bronnt. 

In the course of this work much help has been received from 
numerous workers in Lincolnshire, especially Mr. A. Smith, of 
Lincoln Museum, and Mr. H. Preston, of Grantham, who generously 
placed at my disposal their detailed knowledge of the district. For 
permission to examine specimens I am also grateful to Mr. G. W. 
Lamplugh and Mr. H. A. Allen, of the Jermyn Street Museum 
(Geological Survey); and to Mr. KE. E. Lowe, of Leicester Museum. 
Mr. 8. 8. Buckman has kindly named several ammonites and assisted 


! Lincolnshire, Jubilee Vol., Geol. Assoc., 1910. 
SAB. Trueman, ** Lias Brickyards i in South-West Lincolnshire ’ : Trans. 
Lines Nat. Union, 1917. 
* W. D. Lang, ‘*‘ Geology of Charmouth Cliffs, ete.’’?: Proc. Geol. Assoc., 
1914, p. 307. 


DECADE VI.—VOL. V.—NO. II. 5 


66 A. HE. Trueman—The Lias of South Lincolnshire. 


im other ways. Much help in the field has been given by Messrs. 
W.E. Howarth and W. D. Varney, while at all stages of my work 
Professor H. H. Swinnerton has offered advice and encouragement, 
for which I am greatly indebted. I have also to thank Professor 
T. F. Sibly for reading my manuscript and making various suggestions. 


The general succession of Liassic rocks in this area is as follows :— 


Feet. 
UPPER Lias. Shales with concretions . 3 about 100 
Thickness decreasing northwards. 
(No higher beds than the subzone of swbcarimatum 
are present at Lincoln, and the subzone of 
fibulatum at Grantham.) 
MIDDLE Lias. a. Marls and Ironstone (present in South 
Lincolnshire. Only thinly represented around Lincoln). 3-30 
b. Shales. : : : é : 30-70 
Lower Liss. a. Blue, black, and grey shales, with . 
nodules and bands of earthy limestones . about 700 
b. Hydraulic limestones : : : 25 


It will be most convenient to consider the rocks in the following 
order :— 
1. Hydraulic Limestones. 
2. Lower Lias Clays. 
3. Middle and Upper Lias. 
(a) Lincoln, (6) Grantham. 


1. Hypraviic LIMestones. 


The number of Hydraulic Limestone quarries now being worked 
is considerably smaller than it was a few years ago, but Lias 
cement is still made at Barnstone, Owthorpe, and Barrow-on-Soar ; 
a large quarry near the railway at Normanton Hills, East Leake, 
has only recently been abandoned, and a complete section of the 
beds from the Keuper to the Lower Lias is still visible, while the 
junction of Rhetic and Lias is also exposed at- Cotgrave Gorse. 
The limestone quarries east of Newark have not been worked for 
several years, and in only one of these is the succession clear. 
However, the construction of trenches at the Royal Engineers’ Depot 
at Coddington has made it possible to study the sequence in the 
Newark neighbourhood. Colonel H. Jerome kindly gave permission 
to study this section. 

An examination of the available sections and a comparison of the 
diagrams which have been constructed, as suggested by the late 
Dr. Vaughan,’ to show the ranges of the fossils, indicates that there 
are three types of transition from Rhetic to Lower Lias in this 
district, viz. :— 

1. The type seen at Owthorpe, a full account of which was given in 
a previous paper;* it was pointed out that the lowest beds do not 
contain Psiloceras planorbis, the zonal ammonite, which is likewise 
absent in the lowest beds at Cotgrave Gorse, Normanton Hills, 
Barnstone, and Newark. T. Wright noticed that in the South of 

1 A. Vaughan, ‘‘ Lower Beds of the Lower Lias of Sedbury Cliff’: Q.J.G.S., 
vol. lix, p. 396, 1903. 

* A. E. Trueman, ‘‘ Fauna of the Hydraulic Limestones’’: GEOL. MaG., 
Dec. VI, Vol. II, p. 150, 1915. 


A. BH. Trueman—The Lias of South Lincolnshire. 67 


England also the lowest beds of the Lias did not contain any 
ammonites,’ while the numerous sections recorded in the Memoirs of 
the Geological Survey indicate that this condition is of frequent 
occurrence.* Indeed, it has been suggested that these lowest beds 
should be considered as of pre-planorbis age,®> and called ‘‘ Pleuromya 
and Ostrea Beds’’.4 Their age and relationships were discussed in 
the paper referred to. 

2. At Barrow-on-Soar Psiloceras planorbis occurs in beds which 
are the equivalent of the so-called pre-planorbis beds of other 
localities. 

3. The third type, associated with the Sun Bed, seen at Cotgrave 
Gorse, has indications of a slight break in sequence at the top of the 
Rheetic. 

The first type of transition from Rhetic to Lias may be seen 
at Owthorpe, Barnstone, and near Kast Leake, where the sections 
all conform more or less to the following :— 


Feet. 

Angulata { Dark-blue shales with Selenite crystals and with rare 
zone. {limestone nodules, with Schl. angulata . : he) 
Dark-blue shales : ‘about 9 

“*Root Bed,’’ a massive bed of yellow earthy limestone 
with Lima and P. planorbis . 1 

Flagey beds; fissile limestones or shales with abundant 
Planor bis C. Johnstont 5 2 
zone. Earthy limestone and shales with P. ‘planorbis 3 
& without nA 2 
Fine blue limestone with Oyster Beds and Pleur omya : 2 

Hard blue shales with el limestones and Mcdiola 
minima : s é : 5 5) 


The beds with Conon nelle were not seed eeepe: at 
Barnstone, where they may be seen at the south-eastern end of the 
quarry. The sections at Coddington, in the trenches two miles east 
of Newark Church, show about 20 feet of hard limestones and shales 
belonging to the planorbis zone. The upper beds in this district are 
much coarser than those in the south of the county, but the section 
does not. differ in any essential points from that noted by Wilson® in 
the same neighbourhood at Cotham. 

Only one section of Lower Lias can now be examined in the neigh- 
bourhood of Barrow-on-Soar, and this is situated north of the 
railway near Sileby, one and a half miles west-south-west of Barrow 
Church. The details are similar to those given by H. B. Woodward ° 
and M. Brown.7 Comparing these two interpretations, it will be 
noted first that Brown assigned to the Rhetic certain beds, about 


1 T. Wright, ‘‘ Lower Lias and Avicula contorta zone’’: Q.J.G.S., vol. xvi, 
p. 374, 1860. 

2 See, for example, H. B. Woodward, Lias of England and Wales (Mem. 
Geol. Surv.), 1893, pp. 137, 141, 145. 

3 L. Richardson, Geology of Cheltenham, 1904, p. 38. 

Tsetse Buckman, Yorkshire Type Ammonites, vol. i, p. xvi, 1910. 

° E. Wilson, Geology of South-West Lincolnshire (Mem. Geol. Surv.), 1885, 
16 Ale 
6° H. B. Woodward, Lias of England and Wales (Mem. Geol. Surv.), 1893, 
p. 169. 

7 In Geology 0 Country near Leicester (Mem. Geol. Surv.), 1903, pp. 22-3. 


68 <A. HE. Trueman—The Lias of South Lincolnshire. 


4 feet in thickness, which Woodward had considered as Lias. These 
are unfossiliferous earthy limestones and shales, unlike those usually 
found in the Rheetic, and are probably of Liassic age, but the absence 
of a continuous section in this neighbourhood makes it undesirable 
at present to give a definite statement. Even if these beds should 
prove to be the equivalents of the lowest beds elsewhere, the entrance 
of P. planorbis must have been distinctly earlier at Barrow than in 
any of the other localities examined. 

It will be further noticed that in Brown’s table the ‘ Roof Bed oF 
at Barrow is included in the angulata zone, although Woodward, who 
did not attempt to separate the planorbis and angulata zones, had 
previously recorded P. planorbis from the same bed. As a matter of 
fact, the lowest definite occurrence of S. angulata is some. 10 feet 
higher. Brown apparently considered ‘‘ Schlothevmia catenata’’* to 
indicate the lower part of the angulata zone, but this is doubtful; 
Wright inferred that his example. of ‘‘ 8. catenata”’ from Barrow 
was from the planorbis zone,* and Hyatt also showed that 
‘< §. catenata”’ most frequently occurs in the upper part of the 
planorbis zone on the Continent.’ 

Further, it must be noticed that the Roof Bed of Barrow is almost 
identical in lithology and fossil content with the bed at Barnstone 
and elsewhere, to which I have applied the same name, and that in 
these places P. planorbis occurs above this level. There seems little 
doubt, therefore, that these beds with S. catenata (Waehneroceras), 
should be assigned to the planorbis zone; the sudden dominance of 
Waehneroceras in the Barrow-on-Soar district is merely a local 
characteristic comparable with the relatively early appearance of 
P. planorbis in that neighbourhood. Thus the general section at 
Barrow is as follows :— 


ft. in. 
Blue shale 6 0 
angles | Impersistent limestone with 8. angulata 3 
ane Blue shale with S. angulata . 0 
Dark-blue pyritic shale, with great abundance of Waeh- 
neroceras spp. and C. Johnstont. & 10 0 
Roof Bed. Yellow earthy limestone with P. planorbis, 
Planor bis C. Johnstoni, and Lima . 5 : aay eatolag@ 
zone. Hard blue shales with impersistent flaggy limestone : 4 0 
' | Blue shales and pale-blue limestones with P. planorbis, 
insect remains, andalge . : So eel La) 
HKarthy limestone and brown shales, unfossiliferous : 4 0 


-It is apparent that the fossil succession is very different from that 
which. has been observed elsewhere, both in this area and in many 
other parts of the country. 

A third type of transition from Rheetic to Lias is seen in a small 
stone quarry near Cotgrave Gorse, one and a half miles east-north- 
’ east of the section described at Owthorpe. The uppermost bed of 


1 The forms known as Schlotheimia catenata, d’Orb., should be referred to 
several species of the genus Waehneroceras. See Table of Fossils. 

2 T. Wright, ““ Monographs of Lias Ammonites’’: Palwont. Soc., pl. xix, 
figs. 5-7. 

3 A. Hyatt, ‘‘Genesis of the Arietide’’: Smiths. Contrib. Knowl., 1889, 
Tables. 


: A, E. Trweman—The Lias of South Lincolnshire. 


HYDRAULIC LIMESTONE FOSSILS. 


69 


[a = Lower Planorbis zone (‘‘ pre-planorbis’’ beds), b = Upper Planorbis zone, 
ce = Angulatus zone. | 


Barrow- 
on-Soar- 


Normanton 


Hills. 


Owthorpe. 


Cotgrave 
Gorse. 


Barnstone. 


! 


Coddington. 


Saurian remains ; 

Fish teeth and seales . 
Psiloceras planorbis, Sow. . 
Caloceras Johnstoni, Sow. . 
C. ef. Belcheri, Simps. : 
Waehneroceras frigga, Wah. 
W. exechoptychum, Wah. . 
Schlotheimia angulata, Sch. 
Belemnites cf. acutus, Mill. 
Turbo spp. 

Avicula cygnipes, Y. &B. 


Lima (Plagiostoma) gigantea, 


Sow. 
L. hettangiensis, Terq. 
I. pectinoides, Sow. . 
Monotis cf. fallax, Pfliicke . 
Modiola minima, Sow. 
Ostrea liassica, Strick]. 
O. sp 
Pocton pollue, a ‘Orb. . 
P. Thiollieri, Mart. 
Pina sp. 
Plewromya cr divcombeia, 
Moore 2 
P. sp. 
Cidaris Edwar dsi, Wright . 
Pentacrinus psilonoti, Qu. 
Holothurian spines 
(2? Cucwmaria) ‘ 
H. plates (? Synapta) . 
Worm bores 
Cytheridea ellipsoidea, Jones 
C. cf. Moorei, Jones . 
Dentalina pauperata, dv’ Orb. 
D. tecta, Terq. 
Fr ondiculari 1a nodosari 1, 
pRerqe) i". 
F. Terqueni, a’ Orb. 
Involutina liassica, Jones . 
Lagena elongata, Ehrenb. . 
J.. cf. ovata, Terq. 
Marginulina Romeri, Reuss. 
Nodosaria raphanistr um, 
Linn. 
N. raphanus, Linn. 
N. radicula, Linn. 
Algee, Fucoid 
Wood fragments. 


a D 


2a 


ab 


Bs 10) 
a 
b 
b 


b 
a 


-ab 
a b 
b 
be 


b 


Bb io) 


70 A. EB. Trueman—The Lias of South Lincolnshire. 


the Rhetic in this quarry is similar to the one which has been 
described in the South of England as the ‘‘Sun Bed”.’ The section 
was given briefly by the Survey,” but more fully it is as follows:— _ 


ft. in. 
Blue shales with Echinoid spines ; s : 2 0 
EKarthy limestone with Ostrea, Modiola, and Lima 9 Te 2 
Hard blue limestone with Modiola : : ; 5 
Laminated blue shale . : : : 5 Siete: ; i 3 
Sun Bed. Purple limestone : : : : : ig 


As shown in Fig. 2, the lowest beds of the Loge Lias, which are 
well developed at Owthorpe, a mile and a half away, are only 
thinly represented at Cotgrave Gorse. ‘This, together with the 
irregular appearance of the surface of the Sun Bed, suggests that 
a short break in deposition may have occurred in this locality. The 
occurrence of the Sun Bed at the top of the Rhetic on Beacon Hill, 
Newark,’ about half a mile west of the Coddington trench sections, 
is also interesting, but the section is now overgrown and it is 
impossible to compare the succeeding deposits. 


Owthorbe. Cotgrave Gorse. 


Pleuramya Beds Ostrea Beds 


Modiola Beds 


sHAERT IC 


Fic. 2.—Hydraulic Limestones of Owthorpe and Cotgrave Gorse ; 
the lower beds thinning north-westwards. 


2. Lower Lras Crays. 


Apart from their use in brickmaking, these clays have little 
economic value, and exposures in this area are rare. It is therefore 
only possible to give an account of scattered observations, the 
preservation of which may eventually facilitate a more complete 
study of the district. Deep borings have shown the thickness of 


1 A. KH. Trueman, op. cit., 1915, p. 152. 
* Geology of Melton Mowbray (Mem. Geol. Sury.), 1909, p. 19. 
* Geology of South-West Lincolnshire (Mem. Geol. Surv.), 1885, p. 21. 


A. E. Prueman—The Lias of South Lincolnshire. 71 


these clays to be about 700 feet, but yielded insufficient fosetl 
evidence to determine the thickness of the zones. 

Bottesford.—Brickyard 400 yards north-east of the church. 

Although the brickearth used here is of alluvial origin, Professor 
Swinnerton in 1915 found in a small exposure at the eastern end of 
the yard a limestone with Coroniceras Bucklandi, which had not 
previously been found in this area, although it had been recorded in 
North Lincolnshire. In 1916 the section was as follows :— 


ft. in. 
Grey earthy limestone, yellow outside, with C. Bucklandi . 6 
Blue clay . d : ‘ j : ; iL) (3 
Yellow-grey earthy limestone 5 b ‘ i i 4 
Blue clay . é : ; ‘ : : : 1 0 
Blue earthy limestone | i : , : é 5 4 
Clay . : : ‘ , : é : ! d c 2 0 

Fossuls. 

Fish teeth. Pecten sp. 
Coromiceras Bucklandi, Sow. Pleuromya sp. 
Gryphea (?) arcuata, Lam. Echinoid spines. 
Hippopodium ponderosum, Sow. Pentacrinus et. scalaris, Goldf. 
Lima gigantea, Sow. Cytheridea spp. 
Modiola sp. Glandulina paucicosta, Roem. 
Ostrea liassica, Str. Marginulina picta, Terq. 


An interesting feature of the fauna is the presence of numerous 
ostreaform Lamellibranchs, varying in development from the pro- 
dissoconch to adult stages. 

Sedgebrook.—Brickyard 400 yards north of Sedgebrook Station. 

The exposure shows the following : — 


Feet. 
Soil; ete. . : i 2 
Blue clay, w eathering yellow, with impersistent ferruginous 
limestones and shell beds . d é 5 : : : 6 
Fossils. 

Armnioceras cf. semicostatum, Y. & B. Nucula aff. palme, Sow. 
A. cf. ceras, Agass. Ostrea goldfussi, Bronn. 
Belemmtes acutus, Mill. O. sp. 
B. cf. breviformis, Voltz. Pecten cf. equalis, Qu. 
Amberieya elegans, Miinst. P. calvus, Gold. 
Trochus Redcarensis, Tate. P. lunularis, Roem. 
GUS S50, P. ef. priscws, Sch. 
Turbo sp. P. textorius, Sch. 
Arca sp. Pholadomya aft. glabra, Agass. 
Arcomya hispida, T. & B. Pinna Hartmanni, Ziet. 
Astarte aff. striato-sulcata, Roem. Serpula sp. 
Gryphea obliqua, Sow. Rhynchonella calcicosta, Qu. 
G. arcuata, Lam. Kchinoid spines. 
G. arcuata (a wide variety). Cytheridea ellipsoidea, Jones. 
G. cf. cymbrum, Lam. C. Moorei, Jones. 
Hippopodvum ferrz, Cross-Ether. C. aff. elongata, Blake. 
Lima (Plagiostoma) gigantea, Sow. Dentalina cf. funiculosa, Terq. 
I. (P.) punctata, Sow. D. (2) pauperata, d’Orb. 
LL. (P.) aff. succincta, Sch. Frondicularia Terquemi, d’Orb. 
Tnmea acuticosta, Miinst. Lingulina tenera, Borne. 
Macromya sp. Margmulina picta, Terq. 
Modiola bifasciata, Tate. Vaginulina anomala, Blake. 


1 Water-supply of Lincolnshire (Mem. Geol. Sury.), 1904, pp. 63, 101. 
2 By F. M. Burton; see Geology of Lincoln (Mem. Geol. Surv.), 1888, p. 19. 


72 A. BE. Trueman—The Laas of South Lincolnshire. 


The zone is evidently that of Pentacrinus tuberculatus, and the 
horizon near that of the Plungar ironstone. The fauna resembles 
that recorded by the Rev, J. E. Cross in the ironstones of the ‘‘ semz- 
costatus zone”’ (tuberculatus zone of Oppel) at Scunthorpe, in North 
Lincolnshire.’ It is interesting to note the absence at Sedgebrook of 
all species of Cardinia, one of the commonest and most characteristic 
fossils in the north of the county. Cardinia does occur, however, 
within a few miles of Sedgebrook, near Bottesford and Allington, Z 
and this suggests that the horizon seen here is not precisely that of 
the Scunthorpe ironstone. 

The strata between the two horizons just described were penetrated 
in 1916 by an unsuccessful boring for water, which was made at 
Plungar, about a quarter of a mile south- west of the church. The 
section was roughly as follows :— 


Feet. 
Tronstone and clay with Gryphea, Lima, and Avicula about 4 
Dark-grey marl 5 y , : : : Se we 
Dark shale with shelly bands . : ‘ i : : Sipe 4) 
Light-blue shale : : etd (D) 
Several beds of fine blue limestone with C. Bucklandi : : 2 
Blue shale : ‘ : : 6 


It is probable that with tie oie of ie uppenmene few feet, 
all the rocks passed through belong to the Bucklandi zone, which 
apparently has a thickness of more than a hundred feet. 

Higher beds were shown by another boring a few yards east of the 
Stathern Station; it was made in 1916 by Messrs. Le Grand and 
Sutcliffe, who gave permission to examine the core and supplied 
some of the following particulars :— 


od 
cs 
= 


bo ag rt Ctr TT 


Blue-grey clay. : 

Shell beds and shales. Har thy limestone with Ostrea 

Soft dark clay . : c é 

Light-grey clay with thin limestone 

Light-blue, hard limestone ; Ostrea 

Light-blue marl] . : : 

Massive limestone 

Black pyritic marl 

rey sandy marl with iramalhioranenen 

*Grey marl with bands of earthy neeronel Sith Ostr, ed, 
Pecten, Avicula inequivalvis : ; 

Clay with bands of limestone 

(Boring abandoned; no water reached. ) 


for) 


bo 


iso) 


i 
SS Samsecoooos 


i) 
forgive) 


The bed indicated * contains an association of fossils which 
resemble those in the ironstone band at Plungar, and is probably its 
equivalent. The outcrop of the ironstone can only be traced for 
two and a half miles south-west of Plungar,’ and it appears to have 
a similarly restricted extension towards the south-east, for no 
indication of it is shown in the boring, the strata passed through 
consisting almost entirely of clays and shales. 


' J. E. Cross, ‘‘ Geology of North-West Lincolnshire ’’: Q.J.G.S., vol. xxxi, 
p. 123, 1875. 

2 Geology of South-West Lincolnshire (Mem. Geol. Surv.), 1885, p. 30. 

3 W. Gibson, Geology of Melton Mowbray, etc. (Mem. Geol. Surv.), 1909, 
108 G35 


J. W. Jackson—The Brachiopod Liothyrella. 73 


_ Exposures of the clays above the Plungar ironstone are rare, and 
such as still exist are not very helpful. <A brick-pit south of Brant 
Broughton shows 10feet of fine-textured sandy clay, with fossils 
indicating the oxynotum zone; another pit near the canal at. Wools- 
thorpe shows similar clays which were thought by the Survey? to 
represent part of the Jameson zone. A disused brick-pit south-east 
of Bassingham in 1916 showed the following succession :— 


ft. in. 

ys “Marly clay with Pleuromya ; 4 ; 1 
Yellow raggy limestone with Belemnites . : : : é i. @ 
Clay . é 6 : 6 0 


Such fossils as were Pond lonaened the Sanvey? s conclusion that 
these beds should be assigned to the armatum zone.’ 


(To be concluded in the March Number.) 


IV.—On rox New Bracuiorop Genus, Lioruyretia, or. Tuomson, 
By J. WILFRID JACKSON, F.G.S., Assistant Keeper, Manchester Museum. 


HE new genus, Liothyrella, has recently been created by 
Dr. J. Allan Thomson?* for the reception of a series of recent 
and fossil Terebratulids commonly ascribed to the genus Liothyrina. 
The chief characters upon which the genus is founded are the 
presence of fine radial ribbing on the surface of the shells and the 
possession of a short, low, thin, mesial septum in the dorsal valve. 
In the thickness of the shell, Ziothyrella is said to stand between 
LInothyrina (genotype L. vitrea) and Terebratula, sensu str., all three 
genera being finely punctate. Thomson takes the recent Magellanic 
species L. wea (Brod.) as the genotype of Lzothyrella, and includes in 
the same genus L. uva, var. notorcadensis, Jackson,‘ from Scotia Bay, 
South Orkneys, and a new species dredged off Tasmania by the 
Mawson Expedition, as well as two Australian Tertiary ‘species, 
Terebratula tateana, Tenison-Woods, and 7. concentrica (Hutton). 
He remarks that ‘‘ probably also many of the other southern 
species ascribed to JLvothyrina will be included here, but the 
descriptions do not state whether or not a mesial septum is present” 
(op. eit... p. 44). 

The excellent researches made recently by Thomson upon the 
morphology and classification of the Brachiopoda are to be highly 
commended, as they have led to some remarkable discoveries being 
made in connexion with New Zealand Tertiary species. Though 
agreeing in the main with his conclusions regarding some of the 
groups with which he has recently dealt, I feel compelled to dissent 
from him with regard to the proposed division of the ZLzothyrine on 
the lines defined. My own researches, extending over several years 
and embracing numerous recent and fossil species, have led me to 
offer the following observations. 

1 A. J. Jukes-Browne, Geology of South-West Lincolnshire (Mem. Geol. 
Surv.), 1885, p. 32. 

2 W. H. Dalton, Geology of Lincoln (Mem. Geol. Surv.), 1888, p. 21. 

3 Trans. N. Zeal. Inst., vol. xlviii (1915), p. 44, 1916. 


4 Jackson, ‘‘The Brachiopoda of the Scottish National Antarctic Expedition ”’ 
Trans. Roy. Soc. Edin., vol. xlviii, pt. ii (No. 19), p. 375, pl. i, figs. 1-3, 1912. 


74 J. W. Jackson—The Brachiopod Liothyrella. | 


With regard to the mesial dorsal septum, though this appears to 
be occasionally absent in the genotype of Liothyrina, viz. L. vitrea, 
it is present in two of my specimens from the Mediterranean as | 
a slight, but distinct, ridge between the muscle scars. One shell is 
of large size with a thick test, but otherwise agrees with normal 
L. vitrea. Fine radial strie are present on all my specimens. The 
radial strize of Z. vitrea was noted by Fischer and Oehlert in 1891,' 
as well as the thickening of the test and the presence of a mesial 
septum in thick shells. JZ. vitrea thus possesses the three essential 
characters upon which the new genus Liothyrella is founded. 

Liothyrina cubensis (Pourt.), another northern species, often 
regarded as merely a form of Liothyrina sphenordea (Phil.), supplies 
us with contributory evidence. In one of my specimens from the 
coast of Mexico, which agrees exactly with Davidson’s? and 
Blochmann’s® figures, the radial striz are present, but are very 
indistinct; there is also a slight thread-like ridge between the 
muscle scars in the dorsal valve. In two specimens of the same 
species from Porto Rico (100 fathoms) the radial strie and slight 
mesial septum are also present, the latter showing through the shell. 

In 1908 Blochmann (op. cit., pp. 612-25) divided the genus 
Liothyrina in two groups according to the presence or absence of 
certain calcareous spicules at the base of the cirri (Cirrensockeln). 
The first group, that in which the spicules are present, is widely 
distributed, and includes LZ. affinis, Calc. (Mediterranean, Azores, 
ete., and possibly West Indies), Z. arctica, Friele (Iceland and 
Greenland), Z. antarctica, Blochmann (Antarctica), Z. wuinteri, 
Blochmann (St. Paul, Indian Ocean), Z. uva, Brod. (Magellanic 
region and Western American coast to Mexico). With these he 
provisionally included JZ. davidsoni, Adams, Z. elarkeana, Dall, 
L. fulva, Blochmann, and ZL. moseleyz, Davidson. The second group, 
without the basal spicules, comprises ZL. vitrea (Born), L. sphenordea, 
Philippi, Z. cubensis, Pourt., Z. bartletti, Dall, and L. stearnsz, 
Dall & Pilsbry. This group occurs chiefly in the Mediterranean 
Sea and Atlantic Ocean, but one species (LZ. stearns?) is found off the 
east coast of Japan. Another species (Z. cernica, Crosse), found at 
Mauritius, is also referred to this group, though neither spicule nor 
brachidium are known. The figures of Z. bartlett: and L. stearnsi 
given by Blochmann (op. cit., pl. xxxix, figs. 27, 29) distinctly show 
that each possesses a dorsal mesial septum. 

Since Blochmann made this division other forms have been 
described, viz. Z. uva, var. notorcadensis, Jackson (South Orkneys, 
South Georgia, and Western Antarctic), and ZL. blochmanni, Jackson 
(Antarctica). The former appears to belong to the first group, the 
latter -to the second group. Further examples of Z. fulva, from 


1 Haped. Scient. du ‘‘ Travailleur et du Talisman, 1880-3’’: Brachiopodes, 
Paris, 1891, pp. 51, 57. 
2 “A Monograph of Recent Brachiopoda,’’ pt. i: Trans. Linn. Soc., ser. 1, 
Zool., vol. iv, pt. i, pl. ii, figs. 19-196, 1886. 

> “Zur Systematik und geographischen Verbreitung der Brachiopoden”’ : 
Zeit. fiir wissen. Zool., Bd. xe, pl. xxxviii, figs. 21-21c, 1908. 

+ Jackson, op. cit., pp. 375, 378. 


J. W. Juckson—The Brachiopod Lnothyrella. i 


‘Tasmanian waters, show that it is now to be relegated to the second 
sroup, as this species has no cirri bases.’ I had independently 
arrived at a similar conclusion from the construction of its loop and 
hinge-processes, details of which are given on a later page. 

Of the first group I have only been able to study actual specimens 
of Z. uva and its var., and ZL. antarctica, as well as some recent and 
fossil specimens of Z. affints—the recent from off the Algerian coast, 
the fossil from the Pliocene of South Italy and Sicily. 

L. uva and L. antaretica have extremely fine radiating striz on the 
surface of the shells, and both possess a slight mesial dorsal septum ; 
this is at times somewhat more noticeable than in JL. vitrea and 
LI. cubensis, though not to any great degree. L. uva, var. notorca- 
densis, and ZL. blochmanni show similar features (see Jackson, op. 
cit., 1912). 

On ZL. affinis from Algeria the radii are clearly present and 
wide apart; there is also a fine mesial septum in the umbonal 
cavity of the dorsal valve; the shells are rounded in outline. Of the 
fossil examples, two forms are present—elongate-oval (= typical 
affinis) and rounded (ef. arctica)\—from the two localities, viz. Calabria, 
S. Italy, and Messina, Sicily. These two forms are too near each 
other to warrant separate distinction. The radial strize on both forms 
are very indistinct, but they can sometimes be made clearer by 
slightly moistening the surface of the valves. In type of cardinalia 
they agree with the Algerian ZL. affinis, but the presence of a mesial 
septum is a little uncertain. 

The presence or absence of radial striation on Terebratulids should 
form an interesting study. The following area few of the occurrences 
which have come under my notice. Of Jurassic Terebratule, 
T. phillipsi, from the Inferior Oolite of Broadwindsor, has incipient 
radii, especially on the anterior portions of the valves. On 7. inter- 
media, from the Cornbrash of Kidlington, the radii are likewise 
present on the anterior and lateral portions of the shell. Among 
Cretaceous forms, radial striation is fairly strong and wavy all over 
the shell in 7. sella from the Lower Greensand of Hythe and 
Wellingborough. TZ. depressa, var. cyrta, from the Lower Greensand 
of Upware, also shows striz radiating from the beak: the dorsal 
valve of this form has a mesial septum. On several of the Chalk 
species presumed to belong to Liothyrina, e.g. T. carnea, T. semi- 
globosa, etc., the striz can also be detected. They are fairly wide 
apart and appear to be just below the outer layer of the test: they 
are very indistinct and can only be seen on holding the shell in 
a particular position. My observations have been made on 7’. carnea 
from Grayesend, Norwich, Caburn, and Maestricht, and on 7. semz- 
globosa from Lewes and other localities. 7. carnea possesses a distinct 
mesial dorsal septum. A specimen of Z. obesa, from ‘Chalk, 
Sussex (?)”, in my collection, is also radially ribbed, especially on 
the flanks. The radii extend from near the beak to the anterior 
border, and are closer together and more distinct than in 7. carnea, 


1 Blochmann, ‘‘Some Australian Brachiopods’’: Papers and Proc. Roy, Soc. 
Tasm. for 1913 (1914), pp. 112, ete. 


76 J. W. Jackson—The Brachiopod Liothyrella. 


ete. This feature is clearly shown in Davidson’s figures,’ and is — 
referred to in the text (p. 54). It resembles that seen on recent 
Dyscolie, especially D. crosset, Dav. 

Among the Tertiary species, 7. bisinuata, from the London Clay, 
is a good example. On my specimens from near Fareham the 
radii are fairly wide apart and more noticeable on the side areas. 
The dorsal valves show a thin, low, thread-like mesial septum, 
superposed on a flat platform separating large pear-shaped muscular 
impressions. In type of cardinalia this species is similar to the 
well-known Crag Zerebratule, which also show the striation very 
distinctly, especially on the lateral parts of the valves. These, 
however, have no mesial dorsal septum. They are presumed to be 
true TZerebratule. The cardinalia of these Crag forms and of 
T. bisinuata, of the London Clay, have never been properly described. 
The type is a peculiar one: there is a prominent semicireular, or 
semi-ovate, cardinal process standing out from the apex of the valve 
like a shelf; the socket-ridges, bounding the dental sockets, are 
prominent and diverge from the apex, or at least from the corners of 
the cardinal process; their inner sides descend sharply and touch 
the floor of the valve posteriorly ; the plates then curve upwards 
(ventrally) to the well-marked crural bases, the posterior extremities 
of which are often clearly separated from the apex by a small space. 
On the inner sides of the strong ridges forming the crural bases, 
thin, narrow, plates are given off, these plates being free from 
contact with the valve posteriorly and well separated from each 
other mesially.?. In some of the dwarf Crag Terebratule these inner 
hinge-plates are much broader and touch each other in the median 
line at their posterior ends. While dealing with the Crag Zere- 
bratule it may be of interest to refer to an allied form occurring in 
the Pliocene of Calabria, 8. Italy. This form, usually recorded as 
T. grandis or T. scille, has a type of cardinalia similar to the Crag 
form, except that the inner hinge-plates are very rudimentary. Of 
the five examples cleaned out “and examined (these being of equal 
size to the Crag examples dealt with), all exhibit the same features ; 
but in one or two there is a thread-like mesial septum. 

The above-mentioned ridges (crural bases) with their attached 
inner hinge-plates clearly distinguish this type of cardinalia from 
that of Liothyrina. No evidence of these inner plates is present in 
any recent Liothyrine ; nor are the crural bases so well defined. 

The aseription of the Chalk species to the genus Lvothyrina 
(mainly, I believe, on account of the grooves for the attachment of 
the pallial sinuses showing through the test) is open to some 
question. Their general external appearance, small foramen, and 
the massiveness of the cardinalia suggest that they might be 
terminal members of a distinct genetic group. The following 
remarks are based mainly on a study of several valves of 7. carnea 
which have been developed to show interior details. The most 


1 Monog. Brit. Cret. Brach. (Pal. Soc.), 1854, pl. v, figs. 13-16. 
2 For a good figure of the cardinalia, see Davidson, Monog. Brit. Tert. Brach. 
(Pal. Soc.), 1852, planusnhews. 


J. W. Jackson—The Brachiopod Liothyrella, - TT 


notable feature of this species is the excessive thickening of the 
hinge-processes and muscular fulcra generally. ‘This fact renders 
it a somewhat difficult matter to define the type of cardinalia. 
I fortunately possess one specimen in which the calcification has 
not progressed so far as usual: this shows both cardinala and 
brachidium. The crural bases in this are well-defined and consist 
of fairly broad plates set almost vertically to the slight hinge- 
plates uniting them with the high-standing socket-ridges. The 
hinge-plates unite along the middle line of the crural bases, the 
latter having a well-defined ventral and dorsal edge. I have seen 
no junction like this in any recent Lrothyrina; nor is it present in 
the Crag or London Clay TZerebratule. There is a prominent 
cardinal process at the apex of the valve; also a thin hair-like 
mesial septum in the umbonal cavity. Both the cardinal process 
and mesial septum become more definite in the thickened specimens. 
The crura are broad and short; the descending branches and trans- 
verse band of the loop are also broad, and the latter is sharply bent 
ventralwardsin the middle. he junction of the descending branches 
with the transverse band issharply angulated. Figures of the interior 
of 7. carnea are given by both Davidson ' and Quenstedt.? 

Before proceeding it might here be appropriate to point out that 
the brachidium of the Crag Zerebratule differs from that of 7. carnea 
in being relatively wider with a narrow transverse band not sharply 
bent ventrally, and in having much sharper points at the extremities 
of the descending branches. It has also longer crural points.* In 
general characters it resembles that of the recent Z. wva, but not 
that of LZ. vitrea.* 

The cardinalia and brachidium in recent Liothyrine exhibit some 
interesting features. The type seen in Z. wa and closely allied 
forms differs somewhat from that of the genotype, L. vitrea, and 
very materially from that of Z. stearnsi or L. bartletti. The extremes 
are clearly seen in Blochmann’s figures (op. cit., 1908, pl. xxxix). 
In LZ. ua the whole structure is of a short triangular form, and the 
transverse band of the loop is very narrow. The junction of the 
descending branches with the transverse band is sharply pointed. 
The crural points are close in. - Between the socket-ridges and the 
ill-defined crural bases is a narrow curved plate. There is a thin 
mesial septum. In JZ. stearnst, on the other hand, the structure 
consists of long, almost parallel, descending processes, and the 
transverse band is very broad; it is alsosharply bent ventralwards 
in the middle. The characteristics of Z. stearnsi are taken from 
Blochmann’s figure (op. cit., 1908, pl. xxxix, fig. 29). ZL. vitrea 
and some others appear to agree closely with this form. In general 
the crural bases, which are not very marked, are well separated 


1 Monog. Brit. Cret. Brach. (Pal. Soc.), 1854, pl. viii, figs. 2, 2a. 
b 2 Petrefactenkunde Deutsch., II, Brachiopoden, Leipzig, 1871, pl. xlviii, 

g. 42. 

* This is based upon the figure given by Davidson, Suppl. Tert. Brach. 
(Pal. Soc.), 1874, pl. ii, fig 1, and upon imperfect specimens of my own. 

* The ovate outline and broad dorsal uniplication of the Crag shells also 
show greater affinity with LZ. wva. 


78 J. W. Juckson—The Brachiopod Liothyrella. 


from the socket-ridges by flat, or slightly concave, thin plates.! As 
stated previously, a thin mesial septum is present in some of these 
forms. ; ; 

These two types appear to characterize two distinct groups of 
species, the members of which possess certain common features. 
The first group comprises broadly dorsally uniplicate oval shells 
with a rounded front, as, for example, Z. wa, and var. notorcadensis 
and ZL. antarctica, a group which, according to Blochmann, possesses 
basal spicules in the cirri; while the second group comprises shells 
with a somewhat truncated front, and, in some cases, broad dorsal 
uniplication, such as L. witrea, L. sphenoidea, L. cubensis, L. bartletii, 
and Z. stearnst—a group without the basal spicules. The shells of 
this group are, as a rule, much larger than those of the first group. 

By adopting the principle of classification by means of the 
construction of the brachidium and cardinalia I had already arrived 
at the conclusion that two such groups existed. It is interesting, 
therefore, to find that this is borne out with regard to spiculation. 
We have thus a standard which is of some service in the classification 
of fossil forms, the question of spiculation being, of course, im- 
practicable for fossils. It was on these grounds that I placed 
ZL. fulva, which has a broad transverse indented band to its loop,? in 
the second, or LZ. vitrea, group. This hasnow happily been confirmed 
by Blochmann’s researches with regard to spiculation. From his 
figures (op. cit., 1914, pl. x, figs. 1-4) this species appears to be 
non-plicate with a tendency towards a truncated front. 

Other species of recent Lrothyrine still await further examination. 
L. moseleyt, apparently a lenticular species, has a broad indented 
transverse band to its loop.* Its spiculation is, as yet, unknown, 
but from the circumstance that a broad band appears to go with 
weak spiculation, it is not unreasonable to assume that it will be 
found to be of the Z. vitrea type. The interior details of Z. david- 
sont and L. clarkeana are too scanty for diagnostic purposes. The 
Antarctic Z. blochmanni has a type of cardinalia and brachidium 
quite distinct from that of Z. uva or L. antarctica, it being nearer 
that of ZL. sphenoidea.t Its spiculation appears to be of a weak 
character, and, therefore, more like that of the Z. vitrea series, with 
which I have placed it. 

From the above observations it has been seen that the presence or 
absence of radial striation, or of a mesial dorsal septum, does not 
assist materially in the separation of Terebratulids into generic 
groups. On the other hand, the character of the brachidium and 
especially the cardinalia, which owing to their role as supports for 
important elements of the muscular system, and consequently 


' See Blochmann, op. cit., 1908, pl. xxxix; also Fischer & Oehlert, op. cit., 
1891, pl. iii (for LZ. vitrea and L. sphenoidea). 

2 See Blochmann, op. cit., 1908, pl. xxxix, fig. 26; and Blochmann, op. cit., 
1914, pl. x, figs. 5, 6. 

3 See Blochmann, Wissen. Hrgeb. der Schwed. S.-P. Exped., 1901-3, 
Bd. vi, Lief. vii, pl. i, fig. 14, 1912. 

* Compare Jackson, op. cit., 1912, pl. i, fig. 6, with Blochmann, op. cit., 
1908, pl. xxxix, fig. 23a. 


J.B. Scrivenor—Kaolin Veins, Federated Malay States. 79 


subject to more modification, may provide more certain ground for 
distinguishing the various groups of related species. 

On these grounds it has been clearly proved that the Chalk species 
(7. carnea, etc.) are not to be referred to Lvothyrina, but probably 
belong to a separate group entirely; and that the Crag and other 
Tertiary Zerebratule form another distinct series. If we accept the 
evidence as trustworthy in these cases, we seem compelled to 
acknowledge the new genus Liothyrella, recently created by Thomson, 
subject to the emendations dealt with in this paper. 


V.—Tase Kaorrn Verns. 
By Lieutenant J. B. SCRIVENOR, M.A., F.G.S. 
AOLIN occurs abundantly in the Federated Malay States in 


connexion with granite, and is certainly formed on a large 
scale by weathering. The purest kaolin in large quantity, however, 
is found as veins in clay above limestone at Gopeng aid elsewhere in 
Kinta, and in quartzite and shales near Tanjong Malim and Kerling. 
The purity of these veins and the information obtained about those 
in Kinta when traced down to limestone, lead to interesting 
considerations about their origin, and the nature of the material in 
the limestone is a matter of importance in connexion with the 
possibility of establishing a kaolin industry. 

The form of the Gopeng veins has been described elsewhere, and 
in the early edition of the Kinta publication, illustrations were given 
showing the junction of the kaolin and clay. In A Handbook to the 
Collection of Kaolin, China-clay, and China-stone in the Museum of 
Practical Geology, 1914, by Mr. J. A. Howe, some notes were 
contributed and a vein at Kramat Pulai figured (p. 102). In these 
notes I stated, “‘ No fresh felspar or partially decomposed felspar has 
been detected as yet in these veins. This might be taken as evidence 
of the kaolin having been kaolin ad origine and not an alteration 
product, but it is not conclusive evidence against a pneumatolytic 
origin.”’ Since writing this, residues from many samples of kaolins 
treated with acid have been examined, and among them some from 
the Gopeng veins. The minerals unattacked are mica, quartz, 
tourmaline, and small grains, not abundant, that may be partially 
decomposed felspar. From kaolin near Kerling (Selangor) sand 
lighter than 2°8 sp.g. was separated, and in it are a few grains that 
may be partially decomposed felspar. In the field I have not seen 
any felspar in these veins, but in places where quartz is abundant 
I have noticed a trace of graphic structure, as though quartz and 
felspar had once been intergrown. 

A pink mica is present in these veins and has been described as 
lepidolite. A specimen of similar mica from Chanderiang gave 
a strong lithia reaction with the spectroscope, but one specimen from 
Gopeng proves on analysis by Mr. C. Salter, to be muscovite with 
°86 per cent of manganese. It is possible, therefore, that much 
of the pink mica may be a manganese mica. 

Tin-ore is believed to occur in the Gopeng veins, and is known 
to occur in the Kerling veins, in fact they are worked for tin. 


80 J. B. Scrivenor—Kaolin Veins, Federated Malay States. 


Kaolin from the Kerling veins was washed and afforded deep brown 
cassiterite and mica. No toarmaline was found. in the concentrate, 
nor was it seen in the field. 

Lately information has been obtained at Gopeng and Pulai about 
these veins in contact with the limestone. At Kramat Pulai 
a pinnacle of limestone was exposed in January, 1916, close to 
a kaolin vein. In the limestone was a granitic vein about 2 feet 
wide, bordered by a pale-green massive mineral with a slightly 
greasy feel. The granitic rock contains felspar, sometimes in 
porphyritic crystals. Sections show that it consists of quartz, 
orthoclase, and plagioclase, the last being abundant. One specimen 
is finely veined by a serpentinous mineral that is probably the pale- 
green mineral just mentioned. They show a little tourmaline and 
some altered biotite, and also micaceous aggregates suggesting 
pinite pseudomorphs of cordierite. Near by, in the same pinnacle, 
are thin veins of ‘‘mountain-leather”’ or asbestos of the serpentine 
variety (magnesium silicate), together with purple quartz. No vein 
of kaolin was seen in the limestone. 

On the Kinta Tin Mines, Ltd., large quantities of the pale-green 
massive mineral occur in juxtaposition to limestone. It is not as 
greasy to the touch as steatite, but resembles it, and partial analysis 
showed that it consists of magnesium and aluminium silicate. It is 
therefore one of the ill-defined minerals allied to serpentine, and 
differs from the kaolin in having magnesium present in addition. 

The same mineral occurs associated with kaolin in two of the 
open-case mines on the Gopeng Consolidated land. In that on the 
north of and close to the Khota Bahru Road there were found with it 
fairly large crystals of a reddish mica which contained no lithium, 
and one specimen was found consisting of this mica, quartz, and 
andalusite. ‘The kaolin, close to where this specimen was taken, 
contained dendritic markings of manganese oxide, and a small pocket 
was found in the kaolin of black clay consisting of manganese and 
iron oxides. Its presence was puzzling until it was discovered that 
some at least of the. pink mica at Gopeng is a manganese mica. 

In a big mine south of the Khota Bahru Road there was a good 
section in March, 1916, of the magnesium-aluminium silicate in the 
limestone. It formed a distinct vein about 2 feet across. Close by 
was kaolin with quartz and white mica. Near by here pockets 
of the same mineral were found in pure white kaolin. — 

In the above instances there is no evidence of the kaolin 
continuing in the limestone as kaolin. It changes to something 
else, and the green magnesium - aluminium silicate suggests a 
reaction between the magma that supplied the kaolin and magnesium 
in the limestone. The way in which the granitic vein on Kramat 
Pulai is bordered and veined by this mineral favours this view. 
On the North Tambun Mine, however, I have seen a very thin 
kaolin vein in limestone, and many years ago I saw a similar 
thing at Tambun. However, there is now strong evidence that the 
bigger veins do not go down into the limestone as kaolin, and one 
naturally wants to know how they were formed, and the first 
explanation that presents itself is that they are veins that were 


~ 


J.B. Scrivenor—Kaolin Veins, Federated Malay States. 81 


originally chiefly felspar, which has been altered to kaolin’ by 
deep-seated changes during the last stages of the cooling of the 
granitic magma. If that is incorrect, then the kaolin must have 
been kaolin from the moment it consolidated, or it must have been 
formed in recent times by weathering. With regard to this question 
of the origin of kaolin, there is a marked difference of opinion 
between British and American geologists. It is difficult to get one 
of the former who has not visited the Tropics to allow that kaolin 
can be formed by weathering at all. On the other hand, Lindgren, 
in his Jhneral Deposits, p. 305, writes as follows: ‘‘The idea 
that the mineral may form by pneumatolysis, or the action of water 
or gases liberated at high temperature from igneous magmas, is 
assuredly untenable; a strongly hydrous mineral, parting with its 
water at the comparatively low temperatures of 300 to 400°C., could 
not possibly originate in the presence of such minerals as topaz and 
tourmaline.”’ Lindgren favours an opinion that certain china-clay 
deposits in Cornwall, generally regarded as of pneumatolytic origin, 
were formed by the weathering of sericitic granite, the sericite being 
due to previous alteration by thermal waters. It is not necessary, 
however, to postulate that kaolin was formed at the same time as 
topaz and tourmaline. It may have been formed afterwards when 
the temperature was lower; and, as kaolin formed by weathering 
from the granite in the Malay States contains much of recognizable 
felspar, unattacked or only partially attacked, the purity of the 
Gopeng and other kaolin veins might be cited as pointing to a 
different mode of origin. The objections to its having been kaolin 
from the beginning are the same as those brought forward by 
Lindgren to pneumatolysis, and even stronger when applied to this 
idea and more applicable. Moreover, there is some, although not 
good, evidence of felspar being present in small quantities. On 
the other hand, if the kaolin is due to pneumatolytie action, why 
do the large veins stop when the limestone is reached? The 
granitic vein on Kramat Pulai points to pneumatolysis, if it took 
place at all, having been confined to rocks above the limestone, 
and makes weathering seem less impossible as a mode of origin 
than I once thought. It is to be hoped that future excavations 
on the tin-mines will give some decisive information one way or 
the other. 

Specimens of kaolinite formed by weathering from felspar in 
the Main Range granite at the Gap, Pahang, and specimens of 
kaolinite from Gopeng and Kerling, have been compared with 
kaolinite from a kaolinized felspar crystal in the Dartmoor granite. 
The refractive index is about the same in all cases. The double 
refraction is more marked in the Gap kaolin than in the others. 
In the Gopeng specimen fan-shaped and vermicular aggregates of 
plates are common. Vermicular aggregates also occur in the 
Kerling specimen. The Gap kaolinite forms some aggregates of 
parallel plates, and the kaolinite from the Dartmoor specimen 
forms irregular flakes only. 

At the same time specimens of ‘‘ Lenzinite” and ‘‘ Glagerite’’ 
allied hydrous silicates of alumina, were examined. The Lenzinite 

DECADE VI.—VOL. V.—NO. II. 6 


82 Notices of Memoirs—Martin Simpson. 


had a lower refractive index than any of the above; the double 
refraction was hardly noticeable and it consisted of very fine flakes 
and minute vermicular aggregates. The Glagerite had a higher 
refractive index than any of the other specimens. 

The examination of these specimens was undertaken in the hope 
of arriving at some definite conclusion about the origin of the kaolin 
veins in this country, but it cannot be said that one has been 
attained. 


NOTICHS OF MEMOTRS. 


I.—Marrtin Simpson, 4 YorKsHire GxEotoeisr (1800-92). 
T the annual meeting of the Yorkshire Geological Society, held 
at Leeds on December 12, Mr. T. Sheppard, M.Sc., F.G.S., read 
a paper on “‘ Martin Simpson and his Work ’’. 

Martin Simpson was born at Whitby in 1800, and died in 1892. 
He spent most of his life in the Whitby district, and for over half 
a century had charge of the valuable Geological Collection in the 
Museum there, though for a short period he was Curator of the 
Yorkshire Geological Society’s Collection, now in the Museum at 
Leeds. He was one of the pioneer workers among the Yorkshire 
Liassic rocks, and considering the early date of his researches the 
enormous amount of information he accumulated was remarkable, 
and his methods of research had a surprisingly modern air. He was 
the author of a number of geological memoirs, most of which are now 
exceedingly scarce. 

Mr. Sheppard showed a complete series of these works, which he 
had collected, the most important being a memoir on the Ammonites 
of the Yorkshire Lias, which was long since said to be so rare that 
only one copy was known. Another work, published when the 
author was 84 years of age, was The Fossils of the Yorkshire Luas, 
in which no fewer than 743 species were enumerated and more or 
less described. Simpson measured with a foot-rule the thickness of 
the Lias beds north and south of Whitby, taking special note of the 
fossils in each bed, a very early example of zonal collecting. 


IJ.—THe Minerat Resources oF THE British Empire. 


NOR the second year in succession the Swiney lectures were 
given by Dr. J. S. Flett, F.R.S. As already announced in 

the GronoeicaL Magazine, the subject chosen was ‘‘The Mineral 
Resources of the British Empire”. By means of a judicious 
mixture of statistics, engineering, and geology Dr. Flett succeeded 
in giving a remarkably interesting, though necessarily condensed, 
account of a very large subject. It was shown that in the case 
of some minerals, such as tin, nickel, and diamonds, the British 
Empire is still the greatest producer, while in other instances its 
former pre-eminence has passed into foreign hands, especially into 
those of the United States and Germany. It is evident that in the 
immediate future Canada will be an important producer of many 
minerals, besides oil and gas on a large scale. The mines of Sudbury, 
Cobalt, and Porcupine were dealt with by the lecturer in some 


a 
1 ae 
2 


Reviews—Life of James Geikie. — 83 


detail, and a great future was predicted for the metal cobalt, which 
in some ways is.superior to nickel. The production of tungsten ores 
has been greatly stimulated by the War, and many new sources have 
been discovered. Molybdenum is also rapidly increasing in im- 
portance for the same reason. The gold production of South Africa 
has now reached the enormous value of nearly forty million pounds 
sterling per annum. 

The lectures, which were illustrated by a large number of excellent 
lantern slides, were listened to by large and appreciative audiences, 
and must be regarded as highly successful. 


Il1.—THe AcE or trun Bottvian ANDES. 


N 1915 Professors Singewald and Benjamin L. Miller collected 
from rocks of hitherto undetermined age in the copper district 
of Corocoro fossil plants of the same flora as that previously known 
from the silver district of Potosi, whence also they made collections. 
These have been described by Professor E. W. Berry (Proc. U.S. 
Nat. Mus., vol. liv, pp. 103-64, pls. xv—xviii, October, 1917) and 
the types and figured specimens presented to the United States 
National Museum. The age of the flora is determined as Pliocene, 
whence it follows that the major elevation of the Eastern Andes 
of Bolivia and the high plateau took place in the late Plocene and 
throughout the Pleistocene, and that the extensive mineralization 
of the region is of equally late geological age. A Brachiopod, 
Discinisca singewaldi, found at 18,500 feet above sea-level, and 
described by Professor Schuchert in the same. paper, similarly 
proves an elevation of at least that amount since Miocene times. 


TV.—Westr AvsrraLian CHatk ForaMINIFERA. 


fJ\HE fauna of the Gingin Chalk (= Albian to Cenomanian) was 

made known by the researches of Robert Etheridge, jun. 
(Bull. Geol. Surv. W. Australia, No. 55, 1913), and its Foraminiferal 
contents listed by Howchin (Rep. Adelaide Meeting Austr. Assoc., 
September, 1893). Since then Frederick Chapman has been working 
on the deposit, and has now produced a monograph on the Foramini- 
fera and Ostracoda (Bull., No. 72, 1917). A mere glance at 
Chapman’s careful drawings shows the completely Upper Cretaceous 
nature of the deposit and the remarkable agreement of the fauna 
with the English equivalents. Kighty-one pages, of which 14 are 
devoted to illustrations (plates); 134 species of Foraminifera, 16 of 
Ostracoda. 


REVIEWS. 


I.—James Gerrxin, THE Man and THE Gerorocisr. By Marion 
I. Newsiern and J. 8. Frerr. pp. xi + 227, with four portraits. 
Edinburgh: Oliver & Boyd, 1917. Price 7s. 6d. 

fJ\HIS charmingly written book is divided into two distinct parts. 

The first, by Miss Newbigin, deals with James Geikie’s life 
from the biographical standpoint, while in the second part Dr. Flett 


Sao Reviews—Life of James Geikie. 


gives an appreciation of his scientific work. The first part sketches — 
in a somewhat brief but thoroughly interesting way the career of one 
of the best-known British geologists of the second half of the 
nineteenth century, a man who had a great influence on the trend of 
geological thought in this country and who was mainly responsible 
for building up a highly successful school of geology in the University 
of Edinburgh. The authoress deals in a sympathetic way with 
Professor Geikie’s private life, with his career on the Geological 
Survey, and with the part he played in the scientific and social life of 
‘Scotland in his time. Although primarily an investigator and field 
geologist, Professor Geikie ultimately became a great teacher and his 
books are known everywhere for their breadth of view, lucidity, and 
charm of style. Perhaps, however, his success as a teacher and on 
the Survey was still more owing to his personality and to his power 
of communicating some of his own enthusiasm to his fellow-workers 
and pupils. 

As a geologist James Geikie was a specialist in two directions: 
he was always deeply interested in the origin of physical and 
structural features, and in his teaching and writings he endeavoured 
to draw out the connexion between topography and geological 
structure. But his name will always be indissolubly connected with 
the study of glaciation. In the second part of this book Dr. Flett 
has given us an admirable and impartial summary of his work on 
this thorny subject. The glacial controversy has been a long one, 
comprising several distinct phases; even now it seems almost as far 
as ever from an end. The life of James Geikie may in a certain 
sense be regarded as an impersonation of the history of glaciology. 
When his work began the submergence theory was dominant, though 
soon to be replaced by the land-ice conception. In this change of 
view his own work played a great part. ‘he course of evolution in 
this respect may be traced in the successive editions of his book, 
The Great Ice Age. Some twenty years ago land-ice appeared to 
hold almost undisputed possession of the field, although some notable 
geological authorities have always questioned its applicability to 
districts such as central and eastern England, far from any system of 
mountains. However, of late years a certain number of awkward 
facts have cropped up and the still small voice of doubt is again 
making itself heard in the ears of some of the younger generation ; 
at any rate, it is clear that the time has not yet arrived for a definite 
decision, and it would be well to suspend judgment for a while. _ 

Another phase of the glacial controversy relates to the occurrence 
of periods of milder climate between successive glaciations. It is 
with this part of the subject that Professor Geikie was always most 
closely connected. He will ever be remembered as the apostle of 
interglacial periods. In his later writings he maintained a succession 
of six separate glaciations with temperate periods between. In this 
respect his views agree closely with those of many Continental and 
American authorities, and, although he did not at the time receive 
much support in this country, the trend of recent work has 
undoubtedly been unfavourable to the hypothesis of a single advance 
and retreat of the ice, which at one time was the orthodox view. 


Panacuneitaeail Kehini, Panama. 85 


This is impossible to reconcile with the results of the examination of 
peat-mosses and Arctic plant-beds in many parts of the British Isles, 
and still more with the brilliant discoveries of recent years in 
regard to the stages of palewolithic culture and their relation to the 
Pleistocene deposits. It is too early as yet to pronounce any decided 
opinion on this subject, but, as Dr. Flett points out, there are signs 
of a very decided reaction in this respect. If Professor Geikie went 
too far in one direction, it is certain that his opponents went too far 
in the other. The subject is a peculiarly difficult one, and it is 
evident that long and patient investigation is still needed before 
a final settlement can be reached. It will be conceded by all, what- 
ever may be their personal predilections, that the life-work of James 
Geikie played a leading part in the unravelling of this tangled skein, 
and the authors of this book are to be congratulated on having given 
a clear picture of a great man and a great geologist. 
Ings dels des, 


I1.—Fossin Eonrnt or tHE Panama Canat Zone and Costa Rica. 
By Rosert Tracy Jacxson.. Proc. U.S. Nat. Mus,, vol. liu, 
pp. 489-501, pls. ]x1i—lxviii. 

ae short and lavishly illustrated paper provides an account of 

the Echinoids collected from the Oligocene-Miocene rocks 

excavated during the making of the Panama Canal. The fauna thus 
displayed is of asomewhat restricted, but characteristically American, 
type. No Regular Echinoids are recorded, and the species described 
belong to four genera only of Irregular forms. ‘The two species of 
Clypeaster (of which one, C. gatuni, is new) call for no special 
comment. The three species of Hncope (2. annectans, E. platytata, 
and #. megatrema, all new) exhibit features of exceptional interest, 
to which reference will be made below. The solitary Hehinolampas 
is a well-known West Indian form. Of the three species of Schizaster, 
two (S. eristatus and S. panamensis) are new, but their preservation 
is very imperfect. 

The genus Hncope includes an extensive series of Scutelliform 
Clypeastroids, characterized by marginal slits on the ambulacra, and 
a solitary lunule perforating the posterior interambulacrum about 
midway between the apex and the ambitus. This quality may be 
considered as intermediate between that of Scuted/a, in which there 
is no lunule and hardly any development of marginal slits, and that 
of Melita, in which the interradial lunule is present, while the 
marginal slits have become distally enclosed so as to produce 
ambulacral lunules. The ontogeny of the latter genus shows that 
the ambulacral lunules are developed from slits or notches around 
which the test spreads in later growth-stages, but that the interradial 
lunule is formed by resorption of the test, and is thus a real 
perforation. (There is one species of Mellita in which all the lunules 
have the latter character, but this is quite exceptional.) 

In Encope annectans, described in the paper under review, the 
marginal (ambulacral) slits are in the stage of embayment normal for 
species from the horizon (? Burdigalian), but there is no interradial 


86 Beviews—Prof. Bonney— Volcanoes in Many Lands. 


lunule, properly speaking. Instead, there are two short, narrow 
grooves indented into the test, one on the adapical surface and one 
immediately below on the adoral surface by the periproct. The 
appearance is as if the specimens were wax models which had been 
pinched by a hot pair of fine forceps. ‘The lunule is thus in this 
species ‘‘ caught in the act’ of developing by resorption. There is 
no question of this being an ontogenetic stage of some more ordinary 
species, for the type is 86mm. long, and another specimen 93 mm. 
We have here a peculiarly perfect illustration of the interrelation 
between phylogeny and ontogeny. 

But Encope annectans must be a specially retarded or atavistic 
species, for side by side with it, in the same district and at the same 
horizon, lived #. megatrema, in which the interradial lunule is 
gigantic when compared with that usual in the genus. The great 
triangular perforation occupies a large part of what should have been 
the posterior interambulacrum, comparable (when viewed from the 
adapical surface) with the large periproct of such a genus as Prleus. 
E. megatrema represents a high-water mark of lunule-specialization 
that has not been attained since. Thus the period of the Gatun 
formation in Central America marks the childhood of the Hncope- 
. stock, and the two species here discussed represent respectively the 
backward and precocious members of the family. Students of 
phylogeny will welcome this reminder that it is particularly 
characteristic of youth to run to extremes, and it is this faculty 
which makes children so fascinating, be they of Holocene or 


Oligocene date. 
D8 Ge IGai ely 


III.—Votcantc Srupres In Many Lanps (Seconp Sezrtrzs),’ being 
Repropuctions oF PHoTOGRAPHS TAKEN BY THE AvurHoR. By 
Tempest AnpErson, M.D., D.Sc., ete.; Text by Professor T. G. 
BowneEy, Sec.D., F.R.S., ete. London: John Murray, 1917. 
lds. net. 


LL geologists who remember Dr. Tempest Anderson’s first book 

of photographs of volcanic phenomena will welcome the 
publication of a second series which has been undertaken by Professor 
Bonney under the above title. The work entailed in collecting and 
arranging the views here reproduced must have been considerable, 
since many of them deal with little-known districts, and as some in 
addition were taken on Dr. Anderson’s last journey, from which 
unfortunately he never returned, the exact localities of many of 


' The first part of Dr. Tempest Anderson’s Volcanic Studies in Many Lands 
appeared in 1903, and was reviewed in the GEOLOGICAL MAGAZINE for that 
year by Mr. Hudleston, pp. 160-4. Dr. Tempest Anderson, who spent 
many years in visiting and photographing active and extinct volcanoes in 
almost every part of the globe, died on his return voyage from the Philippine 
Islands, August 26, 1913 (see Obituary, GEOL. MaG., Oct. 1913, pp. 478-9). 
By his will he left £50,000 to the Yorkshire Philosophical Society, of which 
he had always been a generous supporter; he also added £25,000 to the 
Percy Sladen Memorial Fund, endowed by his sister in 1904 (see GEOL. MAG., 
Feb. 1914, .p. 96). 


* Reviews—Prof. Bonney—Volcanoes in Many Lands. 87 


them were rather doubtful owing to the fact that the notes which he 
left were often very brief. However, Professor Bonney has done his 
work well and has, from the material which he found, built up very 
interesting accounts of some rather imperfectly known volcanic 
regions. 

The book is prefaced by a short life of the author by his friend 
Mr. G. Yeld, and the chapters immediately following this deal with 
European volcanoes, and illustrations are given of Vesuvius, Etna, 
and Stromboli, the latter in eruption; one illustration shows a 
curious oval-shaped detached smoke cloud floating away from the 
summit of Etna. The following chapters deal with a second visit to 
Martinique and St. Vincent, and photographs are reproduced of the 
returning vegetation on these volcanoes, and also of the surface of 
the ash deposits formed in the eruption of 1902, showing the effect 
of denudation on the loose material. In 1906 Dr. Anderson visited 
Mexico to attend a meeting of the International Geological Congress 
and endeavoured to obtain photographs of the volcanoes of that 
country. Owing to the difficulties of travel, not so much was 
accomplished as was hoped, but photographs were obtained of some 
of the principal peaks, the most striking being those of Iztaccihuatl 
and Colima. 

From here Dr. Anderson went on to Guatemala. The volcanoes 
of this country form a row of cones averaging from 10,000 to 
12,000 feet in height, roughly parallel with the Pacific coast. They 
are situated along ‘the edge of a hilly platform about 5,000 feet high, 
which rises abr uptly from the sea, so that, from a passing ship, they 
may be seen to the full advantage. Their activity is rather inter- 
mittent, but eruptions, when they do occur, are generally violent ; 
the ejected material is chiefly fragmentary, lava being very rare. 

The most important cones are Cerro Quemado, Atitlan, and Santa 
Maria. The first, except for a small eruption in 1891, has been 
quiet since 1785, when it discharged large quantities of lava which 
must have been very viscous, as the flows often terminate with 
vertical walls as much as 100 feet in height. Some very fine ‘‘ bread- 
crust’’ bombs were seen here, one of which is shown in a photo- 
graph. Atitlan, 11,570 feet high, is 35 miles south-east of Cerro 
Quemado. Dr. Anderson ascended the mountain, but found on the 
summit only a very ill-defined crater, with afew fumaroles. The 
mountain looks down on to a lake twenty miles in length, which 
from its shape seems to have been a volcanic crater. ‘he third 
mountain, Santa Maria, which lies a few miles south of Cerro 
Quemado, is a very regularly shaped ash cone. Prior to 1902 it was 
supposed to be extinct, but in that year a great lateral outburst 
occurred which shattered the northern slopes of the cone and 
produced a new subsidiary crater on a small shelf 6,000 feet above 
sea-level. The new crater was oval in shape, about three-quarters 
of a mile long, with its major axis parallel to the Pacific coast. 
Photographs are reproduced showing Atitlan and Santa Maria and 
also a nearer view of the new crater on the latter mountain; the 
distant view of Santa Maria is an exceptionally fine piece of work, 
and shows the great rent in the side of the cone and the new crater. 


88 Reviews—Prof. Bonney—Volcanoes in Many Lands. * 


‘After several chapters dealing with Tarawera, Matavanu, and 
Kilauea, the book goes on to consider Java, Krakatau, and Luzon. 

In Java Dr. Anderson visited, among other peaks, Guntur, 
Papandayang, Telaga Bodas, and the lenger crater, with its enclosed 
cones of Batok, Bromo, and Widodaren. Guntur is a fine pyramidal 
mass rising up out of quite level ground. It is now quiescent, and, 
though a fine photograph of it was obtained from a distance, the 
jungle with which it was covered made it impossible to photograph 
the crater. Papandayang, which is quite close to Guntur, is also 
at present quiescent, but in 1772 there occurred one of the most 
destructive eruptions which have affected the island. It shows 
from a distance the characteristic form of a fragmental cone, its 
crater is large, but is now only occupied by fumaroles and hot 
springs. From here Dr. Anderson went on to the other end of 
the island, where he visited the Tenger crater and its accompanying 
smaller cones. This region shows volcanic phenomena on a very 
large scale. The Tenger crater, which is close to the town of 
Tosari, is 6 miles long by 43 broad, and contains on its floor, 
which is known as the Zandzee, three minor cones, Batok, Bromo, 
and Widodaren. These all present the customary form of such 
minor fragmental cones, and their sides are deeply furrowed by 
small gullies cut out of the loose ash. Of these only Bromo is 
still active. Some very excellent photographs were obtained of this 
crater, one showing very well the smooth-sided depression lke 
a ‘gigantic pudding mould’’ with the steaming vent at the bottom. 
From Java Dr. Anderson went on to Krakatau, and from there to 
Luzon in the Philippine Islands, where he visited the Taal lake and 
voleano, and also sailed round the island, taking photographs of 
several volcanoes on the way. One of these is Mayon, in the south- 
east corner of Luzon; this, as seen from the sea, presents a very fine 
example of an ash cone, being 8,970 feet high, quite symmetrical 
and showing the concave volcanic curve to perfection. This voleano 
was in eruption in 1814, and devastated the neighbouring country, 
killing 12,000 of the natives. At the south-western corner of the 
island is the Taal volcano. This is an island in the centre of 
the Taal or Bombon lake, which is a huge cauldron of water 
17 miles long by 11 wide, and is probably the remains of a great 
caldera. The Taal volcano is about 760 feet high, dotted over with 
small craters, and having one chief crater about three-quarters of 
a mile wide; it contains two hot lakes and also a small internal 
crater with boiling mud on its floor. A few blocks of lava are 
visible, but no flows or dykes can be seen. ‘There have been fairly 
frequent eruptions, the most violent of which took place in 1754. 

The most striking feature of the photographs reproduced in this 
book is the many excellent distant views of the mountains which are 
included; the portraying of details of volcanic craters must always 
be difficult on account of the impossibility of exhibiting properly the 
bowl-like form from any position on the rim even with a lens giving 
a very wide angle of view, and also to the presence of clouds of 
smoke and steam, but the general view of a mountain is generally 
much more satisfactory from a pictorial and also scientific point of 


Reviews— Moonta and Wallaroo, South Australia. 89 


view, and in this collection full advantage has been taken of this 
point by Dr. Anderson. However, the photographs of the craters 
of La Soufriére and Bromo are notable exceptions to the above 
statement and give the general form of these craters to perfection. 

Unfortunately, Dr. Anderson never returned from his last journey 
to the East, as he was taken ill on his way home with enteric fever, 
from which he died and was buried at Suez. However, Professor 
Bonney is to be congratulated on giving to the world this collection 
of his photographs, which will be of the greatest service to all 
geologists and especially to those who are not so fortunate as to be 
able to go out and see the actual voicanoes themselves. 


W. H. Witcocxson. 


1V.—TueE Gerotocy or THE Moonta anp Wattaroo Minine Disrrict, 
Soura Austratia. By R. L. Jack. Geological Survey of South 
Australia. pp. 185, with figures, folding maps, and sections. 
Adelaide, 1917. 


fY\HE mines of the Moonta and Wallaroo area, on Spencer Gulf, are 

responsible for a very large proportion of the copper production 
of South Australia: up to the end of 1916 they had yielded copper 
to the aggregate value of over £19,000,000. This memoir gives 
a remarkably clear and well-written account of the geology of an 
area which is interesting both from its great economic importance 
and from its bearing on general petrological problems, and especially 
on the question of the differentiation of igneous magmas. The 
formations present are Precambrian, Cambrian, and Tertiary, together 
with a thick cover of recent deposits. The Precambrian series 
consists of highly altered sediments of various kinds, basic and acid 
igneous rocks, and a large mass of felspar-porphyry, which is probably 
intrusive in the foregoing: the whole of these are cut by granites 
and pegmatite dykes, also of Precambrian age. The productive lodes 
of the Moonta area are found in pegmatite dykes cutting the felspar- 
porphyry. They do not pass up into the Cambrian strata. The 
Cambrian rocks are not of much interest, and only a few small patches 
now remain. ‘The Tertiary rock is a thin white or buff limestone, 
with fossils; the character of these is not stated in the report. 
A large part of the country is occupied by a so-called travertine of 
recent date: this is obviously similar to the surface limestones of 
South Africa. Along the coast and also in certain inland areas is an 
extensive development of sand-dunes. 

The pegmatites of Moonta consist of quartz, microcline, and biotite, 
with a considerable number of peculiar minerals, especially hematite, 
tourmaline, ferberite, scheelite, molybdenite, galena, smaltite, 
blende, and apatite. By far the most important copper minerals are 
chalcopyrite and bornite. At the surface is an oxidized zone about 
100 to 150 feet in depth, with a variety of oxides, sulphates, 
carbonates, and chlorides of copper and other metals. Below the 
leached caps of the lodes is a zone of native copper: this feature is 
difficult to explain. The lodes of the Wallaroo area are found in the 
ancient sediments, and are less well defined than those of Moonta, 


90 Reports & Proceedings—Geological Society of London. 


being more in the nature of impregnations of the country rock, but 
the mineral assemblage is similar and is obviously derived from the 
same magma, perhaps ata slightly later date, when differentiation had 
proceeded further. At a still later stage there seems to have been 
a good deal of secondary enrichment by sulphides and chlorides. 

This area forms an excellent example of the metasomatic type of 
vein deposit, including both sulphidic and oxidic ores. ‘The 
connexion between the mineral veins and the granitic intrusions is 
particularly clear, and the mineral association is of a distinctive and 
peculiar character. 


deg daly Jt, 


REPORTS AND PROCHHEDINGS. 


————— 


1.—Gronoeicat Socrrry or Lonpon. 


1. December 5, 1917.—Dr. Alfred Harker, F.R.S., President, in the 
Chair. 


A demonstration on the application of X-rays to the determination 
of the interior structure of microscopic fossils, particularly with 
reference to the dimorphism of the Nummulites, was given by 
E. Heron-Allen, F.L.S., F.G.S., Pres.R.M.S., and J. E. Barnard, 
F.R.M.S. 

Mr. Heron-Allen said that in the year 1826 Alcide d’Orbigny 
published among the innumerable, and for many years unidentified, 
nomina nuda that compose his ‘Tableau Méthodique de la Classe 
Céphalopodes”’ the name Rotalia dubia. This species was left 
untouched by Parker & Jones in their remarkable series of articles 
‘¢On the Nomenclature of the Foraminifera”. The French naturalist 
G. Berthelin was the first investigator to unearth and make use of 
the ‘‘Planches inédites” which had been partly completed by 
@’Orbigny for the illustration of his great work upon the Foraminifera, 
a work that was never published. Working with Parker & Jones’s 
paper, Berthelin made for his own use careful tracings of 246 of 
A. d’Orbigny’s unfinished outline sketches. These sketches were 
never elaborated by d’Orbigny upon the ‘‘ Planches”’, which are still 
preserved in the Laboratoire de Paléontologie under the care of 
Professor Marcellin Boule; among them was found the sketch of 
Rotalia dubia. On the death of Berthelin the tracings passed into the 
possession of Professor Carlo Fornasini, of Bologna, who reproduced 
them all in a valuable series of papers published between the years 
1898 and 1908. Fornasini’s opinion was that the organism depicted 
by @’Orbigny was doubtfully of Rhizopodal nature, and that it was 
probably referable to the Ostracoda. The speaker said that he had 
examined the d’Orbigny type-specimens in Paris in 1914, and had 
noted that Rotalia dubia was a worn and unidentified organism, 
resembling an Ostracod. 

There the matter rested until Mr. Arthur Earland and the speaker, 
while examining the material brought by Dr. J. J. Simpson from the 
Kerimba Archipelago (Portuguese East Africa) in 1915, discovered 
one or two undoubted Foraminifera of an unknown type, which 


Reports & Proceedings—Geological Society of London. 91 


resembled Berthelin’s tracing. Professor Boule kindly sent the 
d’Orbigny type-specimen to London, and the Rhizopodal nature of 
Rotalia dubia was established. It is not a Rotalia, and it must 
await determination until more specimens are obtained. It has been 
named provisionally Pegidia papillata. There were two or three 
forms of the organism, but only one perfect specimen of the 
@Orbigny type; and it was undesirable to risk destruction by 
cutting a section of it. In these circumstances Mr. Barnard was 
approached, and he experimented with the object of ascertaining the 
interior structure of the shell by means of the X-rays. His results 
were extraordinarily promising, and led to further experiments. 

The speaker showed on the screen photographs of the common 
and dense Foraminifer Jassilina secans (d’Orb.), followed by a 
skiagraph of the same. A skiagraph of the still denser test of | 
Biloculina bulloides, d’Orb., shows the arrangement of the earlier 
chambers as clearly as it is indicated in Schlumberger’s beautiful 
sections. ‘The application of X-rays to the dense imperforate shells 
Cornuspira foliacea (Philippi) produced skiagraphs showing the 
dimorphism of the shells, both megalo- and microspheric primordial 
chambers being clearly distinguishable. Such results led to the 
extension of the experiments to the agglutinated arenaceous forms, 
of which sections are made with extreme difficulty. ‘The skiagraph 
of Astrorhiza arenarta, Norman, shows the internal cavities that 
contained the protoplasmic body. ‘T'wo arenaceous forms, Sotellina 
labyrinthica, Brady, and Jaculella obtusa, Brady, that are almost 
identical in external appearance, are distinguished at once by their 
respective skiagraphs, the one exhibiting a simple tubular cavity, 
the other appearing labyrinthic. 

Mr. Barnard subsequently experimented on still more difficult 
material. The massive Operculina complanata, Defrance, the 
umbilical portion of which is obscured by a mass of secondary 
shell-substance, furnished a clear skiagraph that showed some 
curious distortions of the internal septa. Similar results were 
obtained in the case of Orbiculina adunca (Fichtel & Moll), another 
species overladen with shell-matter. Cyclammina cancellata, Brady, 
is an arenaceous form, composed of softer mud and sand, studded 
with coarse sand-grains, which make section-cutting almost an 
impossibility. The skiagraphs, however, reveal the primordial 
chamber and establish the character of this form. 

The determination of the Nummulites, depending as it does on 
a knowledge of the internal structure of the test, is greatly facilitated 
by the application of X-rays, which removes the necessity of splitting 
it or cutting sections through it. 

The speaker showed ordinary photographs and skiagraphs, made 
at slightly varying azimuths, of Vwmmulites levigata and JV. vario- 
laria, forms that strew the shores of Selsey Bill. A particularly 
notable result was obtained in the case of WV. gizehensis, an organism 
that forms the dense masses of Nummulitic limestone of which the 
Pyramids of Egypt and the Citadel at Cairo are built. 

Mr. Barnard said that, although the utilization of X-rays to 
determine the internal structure of various bodies was well known, 


92 Reports & Proceedings—Geological Society of London. | 


he was not aware that the method had been successfully applied to 
small objects, such as Foraminifera. After he had begun his 
- experiments he found that M. Pierre Goby had done some work in 
this direction in France, but the method as he described it is 
surrounded with considerable mystery and elaboration of apparatus, 
which appear quite unnecessary. The speaker’s results were arrived 
at independently ; in fact, they are really a side issue. 

His original experiments were directed rather towards the use of 
X-rays in obtaining magnified images, altogether apart from the 
usual skiagraphic methods in which a shadowgraph is, in fact, all 
that can be produced. The primary object has not yet been achieved, 
although there is some reason to hope that it may ultimately come 
to pass. The results shown by Mr. Heron-Allen are obtained by 
quite simple means. A very narrow beam of X-rays, such as would 
be termed ‘‘a parallel beam” when speaking in terms of ordinary 
light, is allowed to impinge on the object, the latter being in contact 
with the photographic plate. The negative produced is, therefore, 
of the same size as the object. Photographie enlargement is then 
resorted to, and the result had been shown on the screen. There are 
two points to which careful attention is required if success is to be 
achieved. 

The quality of the X-rays must be suited to the object. In nearly 
all cases of small objects, what are known as ‘‘ soft’ X-rays must be 
used, and the degree of softness is the crux of the whole matter. 
The photographic plate must be of exceedingly fine grain, otherwise 
the amount of enlargement that can be obtained is very limited. 
Difficulties in this direction have been overcome, and Mr. Heron- 
Allen has stated that the results are of considerable biological value. 


Dr. A. Smith Woodward, F.R.S., V.P.G.S., exhibited a radiogram 
of the original slab of lithographic stone containing the skeleton of 
Archeopteryx, made for the British Museum by Dr. Robert Knox in 
1916. It was evident that the penetrability of the fossil bones to 
the X-rays was the same as that of the surrounding matrix. The 
only portions of the skeleton visible in the radiogram were those 
more or less raised above the general surface of the slab. This result 
accorded with that obtained bv Professor W. Branca when he 
similarly experimented with the Berlin specimen of Archeopteryx. 


2. December 19, 1917.—Dr. Alfred Harker, F.R.S., President, 
in the Chair. 


The following communication was read :— 


‘““The Chellaston Gypsum-Breccia considered in its relation to 
the Gypsum-Anhydrite Deposits of Britain.” By Bernard Smith, 
M.A., F.G.S. 

This communication is designed to clear up some of the ambiguities 
that have arisen with regard to the actual mode of formation of the 
deposits of gypsum in Britain—chiefly from the point of view of 
the field observer. An attempt is made also to show the true 


Reports eZ Proceedings—Hdinburgh Geological Society. 93 


relationship of the gypsum. to the beds of anhydrite with which it is 
sometimes associated. 

A description is given of a remarkable breccia occurring at 
Chellaston in Derbyshire, and its origin is discussed. Important 
occurrences of gypsum in other parts of the country, as well as the 
alternative theories as to their mode of formation, are then reviewed 
in the light thus obtamed. 

The remainder of the paper deals mainly with the possible 
interchanges between anhydrite and gypsum. ‘The place and 
the function of the fibrous form of gypsum are indicated, and 
a nomenclature is suggested for certain isolated masses of the 
mineral, 

The chief conclusions are as follows :— 

1. At Chellaston the gypsum was laid down as such, and has 
suffered no appreciable alteration or addition since the time of its 
original deposition and brecciation. There is no evidence that the 
rock was ever anhydrous. 

2. By comparison with this deposit, and also by independent 
evidence, if seems probable that most of the important beds of 
gypsum in the country were laid down as gy pon, and have behaved 
throughout as stratified deposits. 

3. When anhydrite is present, the evidence favours the view that 
it is original, and was deposited in a stratiform manner in sequence 
with gypsum. 

4. Microscopic evidence shows that there has been, in some cases, 
an alteration of anhydrite into gypsum where the two minerals were 
in original juxtaposition; this alteration, however, is considered to 
have occurred at, or immediately after, the time of deposition, and 
to be confined to the existing plane of contact of the two minerals. 


Il.—Epinpured Grotocican Socrery. 
December 19, 1917.—Professor Jehu, President, in the Chair. 


1. ‘‘Marginal Intrusive Phenomena near Linlithgow and at 
Auchinoon.” By T. Cuthbert Day, F.C.S., F.R.S.E. (Illustrated 
by lantern views and rock specimens. ) 

At Hillhouse Quarry, near Linlithgow, the dyke of white trap 
with its branches has produced considerable contact alteration in the 
limestones and shales, while the thick sheet of columnar olivine 
basalt which overlies the sediments does not appear to have caused 
any change; it, however, transgresses the strata considerably, 
which, it is ‘suggested, may be due to contemporaneous erosion and 
that the basalt may prove to be a lava. 

It was pointed out that the pecular brecciation seen in certain 
bands of dolerite at Cockelrue which have been enclosed in the 
intrusive mass of the hill is probably due, not to crushing or move- 
ment, but to numerous crack joints produced on cooling. 

The dolerites of the district do not readily take the form of white 
trap when found in contact with carbonaceous shales. 

A large exposure of intrusion breccia was described in a quarry of 


94 Reports & Proceedings—Mineralogical Socvety. — : 


dolerite at Kettlestoun, composed of fragments of igneous and sedi- 
mentary rocks cemented together by dolerite, and occupying a large 
part of one face of the quarry. A peculiar spotted shale, due to 
contact alteration, in the same quarry was also described. 

In connexion with the exposure of dolerite and overlying hornfels 
at Auchinoon, it was stated that a quantitative analysis of the 
alkalies in the dolerite showed a considerable falling off as the 
margin was approached, and that while the hornfels in contact 
showed nearly 7 per cent alkalies, no trace of lime was found in the 
specimen analysed. 


2. **On a Section of the Wardie Shales, with Intrusions, exposed 
in the Stank at Corstorphines, and on the Draining of the Old Lochs 
at Gogar and Corstorphine.”” By D. Tait. 

The main purpose of the communication was to eee a hitherto 
unrecorded section of the Wardie Shales in the Stank at the west end 
of Dovecot Road, Corstorphine. The beds there consist of sandstone 
and shales, dipping west at 20°. These are cut by two east and 
west quartz dolerite dykes, which alter the shales in their vicinity. 
The section is on the south side of the Middleton Hall fault, the 
position of which is probably indicated by a spring of water situated 
a few yards north of the locality. It was pointed out that this 
section lies between Gogar Loch and Corstorphine Loch, both now 
drained, and also midway between the buried river channels of the 
Almond at Turnhouse and the Water of Leith at Roseburn. Both of 
these channels are below sea-level at these points. It therefore 
appears probable that the rocks in which this section was excavated 
formed a watershed between them in pre-Glacial times. 

Photographs of a series of old maps, chronologically arranged, 
were thrown on the screen to show the progress of draining of Goear 
Loch and Corstorphine Loch. An Act of Parliament ahome us that 
these draining operations were in progress in 1661. Their final. 
stage is recorded in the New Statistical Account, which says that 
about 1831 the Stank was widened and deepened. 


I1I.—Mineratoeican Socrery. 

January 15, 1918.—W. Barlow, F.R.S., President, in the Chair. 

Dr. J. W. Evans: ‘‘ Diagrams expressing the Composition of 
a Rock.” These diagrams are intended, like “those of Michel Lévy 
and Miigge, to indicate at a glance the significance of the analysis of 
a rock or complex mineral silicate. The molecular proportions of the 
constituents are determined in the usual manner, those of the ferrous 
and magnesium oxides, however, being doubled. The silica is 
represented by two rectangles placed side by side, the length of 
each being half the molecular proportion of silica. In one of these 
rectangles lengths equal to the molecular proportions of potash, soda, 
and lime are measured off in succession, and in the other those of 
alumina, iron oxide, and magnesia. Thus, the same space represents 
both metallic oxide and silica, and so far as felspars, felspathoids, 
or egirine are actually or potentially present, the monoxide and 
sesquioxide they contain are with two molecules of silica represented 


With 


Ouituann SW As Papen 95 


by contiguous portions of the two rectangles. The excess, if any, 
ot lime over available alumina has the silica necessary to form 
wollastonite, and the excess, if any, of iron oxide over available soda 
and the magnesia have the silica required to form orthosilicates. 
The remaining silica space is then divided up to show the additional 
silica required or available for the felspars, felspathoids, and egirine, 
and that available to convert the orthosilicates of iron and magnesium 
into metasilicates. The remainder represents free silica or quartz. 

Dr. G. F. Herbert Smith: ‘‘ On the use of the Gnomonic Projection 
in the calculation of Crystals.’”’ If projected on to a plane at right 
angles to the edge of the zone containing the poles from which 
biangular measurements were made, the diagram takes the form of 
a net, the nodes of which represent the principal poles. » The unit 
lengths of the net are easily calculated from the data, and once the 
rectangular co-ordinates of any node with respect to axes on the 
diagram have been determined those of the remainder follow by 
simple addition or subtraction; the corresponding spherical angles. 
are deduced by a simple calculation. The accuracy of the calcula- 
tions may be checked from the diagram at every step. To keep the 
projection corresponding to any crystal within reasonable dimensions 
it is sometimes convenient to project on to the faces of acube. The 
direction of a zone when crossing from one face to another is very 
simply found from the diagram. 


QySieIo Of NISL Sse 


WILLIAM ALBERT PARKER, F.G.S. 
Born 1855. DIED JANUARY 14, 1918. 


We deeply regret to record the death of Mr. W. A. Parker, of 
Rochdale, which took place on January 14 at the age of 63. For 
many years he was a highly esteemed schoolmaster in Rochdale. 
Here he indulged his taste for scientific research, especially geology, 
and became associated in friendship with a small but enthusiastic 
body of geologists, including, amongst others, Walter Baldwin, the 
late W. H. Sutcliffe, Dr. March, James Horsfall, Robert Law, and 
S. S. Platt. Assisted by other members of this band Mr. Parker 
specially devoted himself to the task of working out the beds of 
shale, with ironstone nodules containing fossils, of Middle Coal- 
measure age at Sparth, Rochdale. This led to the discovery of 
a numerous and rich series of fossils, including rare Orthopterous 
insects, Arachnida, and Crustacea, many of which have been figured 
and described in the Groroeican Macazinr (see volumes for 1907, 
pp. 400-7, 589-49; 1911, pp. 361-6; 1913, pp. 852, 856). A new 
Crustacean, Rochdaleia Parkert, was named after our friend. Many 
of these valuable specimens are now preserved in the Manchester 
Museum and in the British Museum (Natural History). His loss will 
be keenly felt by a large circle of geological friends in the Midlands. 


Eis 


96 Miscellaneous. 


MISCHLLAN HOUS. 


JUBILEE OF A. GovVERNMENYT GEOLOGIST. 

Mr. R. Bullen Newton, F.G.S., of the Geological Department, 
British Museum (Natural History), has just completed fifty years 
active Government service. During the earlier part of his official 
career, which commenced on January 6, 1868, Mr. Newton was one 
of the Assistant Naturalists of the Geological Survey under the late 
Professor Huxley. He was transferred to the British Museum in 
August, 1880, at the time of the removal of the Natural History 
Collections to Cromwell Road, in which he took an active part. His 
numerous published researches on various branches of paleontology, 
especially the Mollusca and Foraminifera, have had a distinct 
bearing on the geology of widely scattered regions. He has been 
Preaden: of the Malacological Society of ibamdion and of the Concho- 
logical Society of Great Britain and ireland. We offer Mr. Newton 
our congratulations on his extended and valuable scientific labours. 


F. W. Roper, 1.8.0., F.G.S. (1840-1915). 


Our readers will remember that in the summer of 1915 the 
University College of Wales, Aberystwyth, became the possessors 
of the library and lifelong collections of the late F. W. Rudler, 
who was Professor and Dean of the College in the years 1876-80, 
and subsequently Curator of the Museum of Practical Geology, 
Jermyn Street, London." 

His library, consisting of some 2,000 volumes and 4,000 pamphlets, 
has been tabulated and cross-indexed, and his extensive collection of 
rocks, fossils, etc., carefully labelled. The Mineralogical Collection 
has been made available for teaching and demonstration purposes, 
while the archeological and other specimens have been added to the 
College Museum. The additions thus made to the College, further 
assisted by the foundation of the ‘“‘ F. W. Rudler Geological Research 
Scholarship”, have greatly increased the facilities for students, 
particularly in the subject ‘of geology. 

Monsieur Jules Bernaerts, the eminent Belen sculptor (of the 
Royal Academy of Brussels), has executed a life-size medallion of 
Professor Rudler, which has been framed in oak and placed in the 
wall of the College Quadrangle, and below it a brass tablet (executed 
by Messrs. G. Maile & Son, of Euston Road, London), bearing the 
inscription, ‘‘In memory of F. W. Rudler, 1.8.0., F.G.S., 1840— 
1915. Professor in this College 1876-80, and Founder of the College 
Museum,” has been affixed to a polished slab of Welsh marble 
specially cut for the purpose from the Narberth Quarries. 

Professor Rudler’s numerous friends and all concerned in the 
welfare of the College will be pleased to know that the collections 
which he formed with so much ability have thus been made available 
for the furtherance ofthose studies in which he was so deeply 
interested and to which he devoted the labours of a lifetime. On 
behalf of the College.—S. G. Ruptmr, one of the Governors. 


THE UNIVERSITY COLLEGE OF WALES, ABERYSTWYTH, 
January 7, 1918. 
1 For obituary and portrait see GEOL. MAG., 1915, pp. 142-4. 


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ASSISTED BY ; 
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| . 
GeO NWSE now aS 
ae I. OniGInaL ARTICLES. Page NOTICES OF MEMOIRS (cont.). Page 
New or imperfectly known Chalk Age. By Marsden Manson, C.E., a 
Polyzoa. By R. M. BRYDONE, 3 BAe se oes ee inden oma EM ops ba ce 1294 4) 
F.G.S. (Plate VI.) .............. 97 | John Michell and Martin Simpson. 131 7~ 
The lias of South Lincolnshire. 2 
Tl. Reviews. 
By A. EH. TRUEMAN, M.Sce., re 5) us 
F.G.S. (With three Text-figures:) British Resources of Sands used 
© Concluded.) /.......s0000.. Ses 101 for Glass, ete. By Professor 
Mountain Building. By KR. M. P. G. H. Boswell ......0.......... 181 
DbELEY, M. Inst. C.H.,V.P.G.8. 111 | Phosphates of Saldanha Bay. By 
Datum-linesin the English Keuper. 4 Bes ! Le du Toit... ams poe 138 
By R. L. SHERLOCK, D.Se., | Building and Ornamental Stones 
A.R.C.Sce. E.G S (With a of Canada. By W: A. Parks 133 
Seation.) ieee ew er ok j99 | Geology of the Transkei, South 
- ANoteon Isostasy. By A. MoRLEY Africa. By A. Ti. du Toit perce, 135 
DAVIES ERE. See oc. Low-temperature Formation of 
kG S. Imperial College of Alkaline Be eval in Limestone. 
Science and Technology ......... 125 By R.A, Daly.. feose ceettaee FBO 
IY, REPORTS AND EA eT 
ai II. Novicks OF MEMOIRS. Geological Society of London— 
_ A Hyena-den in Iveland. Report Sam aye one TOs kar alte aseeoates 136 
} by R. F. Schartf and others ...... 127 TAMU eames anes aes One 
: Fossil Man in South Africa. By MebuuainGetai. sete cn ee seenen eS 
Dr. Broom and others ............ 128 Me butiatiys2 OFM Racca ep 142 
| Factsrevealed by Antarctic Research Edinburgh Geological Society ...... 143 
‘ | bearing upon Problems of the Ice oo SSGGUUULOM sve sate gna: 144 


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THE 


GHOLOGICAL MAGAZINE 


NEW SERIES. DECADE Ni. i VOLE NM. 


No. III.—MARCH, 1918. 


ORIGIINAI ARTICLES. 
— 


I.—NorEs oN NEW OR IMPERFECTLY KNOWN CHaLK Poryzoa. 
By R. M. BRYDONE, F.G.S. 
(Continued from the January Number, p. 4.) 
(PLATE VI.) 
PseuDOSTEGE concursA,’ sp. nov. (Pl. VI, Figs. 1--3.) 


Zoarium incrusting, with a tendency to grow in bands: the 
general surface stands high and shows no trace of zocecial boundaries ; 
it is much rumpled, apparently unsystematically, but is only 
broken by the zocecial peristomes; these are short tubular 
prominences inclined slightly forwards but bent upwards at the 
ends so as to end in a plane parallel with the general surface: the 
apertures are on the whole circular, but very rarely truly so, and 
occasionally very irregular; they vary in internal diameter from 
‘08 in a small specimen such as Fig. 2 up to’l15mm. in a large 
specimen such as Fig. 38; the peristomes are thick and each has 
from one to four pores init; these pores are generally small and 
round, but occasionally among the larger ones are found definite 
instances of arrowhead shape which makes it possible that all are 
avicularian: round the edges of the zoarium there is a fairly 
complete fringe of simple shallow Membraniporiform zoccia, with the 
general surface either ending abruptly above them or sloping gradually 
down to them. 

Oecia small and globose, perched on or sunk slightly into the 
anterior part of the peristome, very erratic in occurrence. 

Avicularia of two kinds—(qa) accessory, as above described, 
(6) vicarious, of hour-glass type with the upper lobe much elongated, 
the lower very short and devoid of internal front wall and indications 
of a transverse bar at the point of maximum constriction; these 
occur at or near the edge of the zoarium. 

This species is referred only provisionally to Pseudostege, as I do 
not feel confident that the fringe of Membraniporiform zoccia 
really represents a primary stage, nor am I clear as to how exactly 
the general zoarial crust is developed. The species is introduced 
here because it occurs at the same horizon in Hants, about the 
junction of the zones of 4. guadratus and B. mucronata, as several of 
the Membraniporelie I have just been describing, and presents so 


1 The term Psewdostega has been used for a division of the Cheilostomata, 
presumably as a neuter plural. This term is not therefore identical with my 
genus Pseudostega (GEOL. MaG., 1910, p. 259), which is a feminine singular, 
but to avoid any risk of confusion it is perhaps as well to amend my term to 
Pseudostege. 


DECADE VI.—VOL. V.—NO. III. 7 


98 R. M. Brydone—New Chalk Polyzoa. 


many points of resemblance (apart from the Cribriline surface) to 
some of them, e.g. I. thoraceformis and If. Shawfordensis that it 
seemed bound to be a member of that group with a complete 
secondary front wall. Ihave not, however, been able to find any 
trace of Cribriline structure about it. It seems to lead almost 
directly to 

CELLEPORA (?) DiasTorpEs, sp. nov. (Pl. VI, Fig. 4.) 

Zoarium incrusting, consisting of a common crust out of which 
arise long tubular, slightly barrel-shaped zocecia, free for the greater 
part of their length, inclined strongly forwards but sometimes 
turning erect at the end; they have slightly thickened peristomes, in 
which there may be from one to three pores, one in the middle of 
the posterior part being fairly regular; these pores can often be seen 
in the larger zocecia to be the apertures of tubuli mainly embedded 
in the zocecial wall; the apertures are more or less circular, but 
sometimes very irregular in shape: the occia are very small, 
globose, perched on the anterior part of the peristome and over- 
hanging the greater part of the aperture: there is a partial fringe 
of shallow Membraniporiform zocecia. 

This species is fairly common at Trimingham, and is probably to 
be found in the Norwich Chalk, as I have specimens from Norwich 
and Weybourne which seem to be inchoate forms of this species. 
It is so clearly in most respects a development from Pseudostege 
concursa (ante) that it is rather surprising that there should be 
no trace of vicarious avicularia. Apart from the ocecia and the 
peristomial pores it might easily pass for a sturdy Dvuastopora. 

% % * 

There is a large group of Membranipore in which a pair of pores 
or tubes at the anterior end are repeated with great regularity and 
another group in which a single tubular prominence occurs very 
persistently at the posterior end of the aperture. Both are well 
represented in the English Chalk, and they might be expected to be 
always easily distinguishable, but this is not the case. I propose to 
_deal with some of the English species of these groups in order of 
seniority. 

MemBRANIPORA SEAFORDENSIS, sp. nov. (Pl. VI, Figs. 5, 6.) 

Zoarium unilaminate, normally incrusting, occasionally free. 

Zoecia of medium size, average length ‘5 to-6 mm., breadth -4mm., 
with thin common side-walls; apertures naturally widely oval, but 
rendered irregularly polygonal by intrusion of the edges of the more 
or less rounded protuberances, with small round or elliptical apertures, 
of which a pair is set with extreme regularity on the front wall of 
every zocecium anteriorly to the ocecium; these protuberances 
appear to be accessory avicularia of the small beak-shaped type in 
a primitive stage; sometimes they become confluent. 

Oecia occur with very great regularity: they are set on a shelf so 
deep within the aperture at the anterior end that their tops are little 
more than flush with, or may even be below, the general surface ; 
their apertures appear to be very strongly cut back, so that the 
visible top is very much shorter than the basal shelf: the latter is 


kh. M. Brydone—New Chalk Polyzoa. 99 


indicated in a few zocecia at the top of Fig. 5, from which the 
ocecia have been broken away. 

The species is fairly regular in occurrence in the zone of 
I. cor-testudinarium at Seaford. It is fairly intermediate between 
the published figures of Flustrina constrieta, D’Orb.,1 and F. ovalis, 
D’Orb.,? but Canu i in his “ Revision ” throws doubt upon the validity 
of either of these species. 

MEMBRANIPORA MULTIFISSA, sp. nov. (Pl. VI, Figs. 7, 8.) 

Zoarvum unilaminate, incrusting. 

Zoecia of medium age. average length 5 to°6mm., breadth '4mm., 
without any definitely visible interzowcial sutures; apertures 
broadly oval, flattened at the anterior end, enclosed by rather rounded 
margins which approach one another rather closely laterally but are 
quite distant longitudinally; a pair of rather large sub-tubular pores 
occur very regularly on the outer edges of the margins just beside 
the anterior end of the aperture, while between the margins there 
are numerous irregularly scattered and less pronounced openings, 
some of which are tubular, while others are mere fissures possibly 
along zocecial boundaries. 

Oecra fairly abundant, always broken, semicircular in ground plan. 

Avicularia probably of two kinds—(a) accessory, represented by 
the paired marginal pores, (4) vicarious, scarce, of hour-glass type, 
with a long area of constriction, traces of a cross-bar at its lower end, 
a narrow internal front wall in the short round anterior lobe, and no 
internal front wall in the small posterior lobe, which has a very 
slender rim marked off by a little furrow, a feature not brought out 
by the photographs. 

This species occurs in the zone of IL. cor-anguinum at Gravesend. 
The relative size of its paired pores, no Jess than its possession of 
vicarious avicularia, distinguish it from any figured species, except 
I, dolium, Bryd. 

MEMBRANIPORA SEVINGTONENSIS, sp. nov. (Pl. VI, Fig. 9.) 

Zoarium unilaminate, free. 

Zoecia large, average length:7 mm., with oval apertures narrowing 
considerably to the anterior end, which is flattened by the edge of an 
inward sloping shelf, and surrounded by raised margins almost in 
contact with one another and bearing from seven to nine pairs of blunt 
imperforate denticles, of which those round the anterior end are very 
slender: at the foot of nearly every zocecium there is a large, more 
or less semicircular, hollow thin-walled protuberance, which is 
probably avicularian; between this and the aperture the raised 
margin dies away and the tubercles disappear; there are no other 
indications of avicularia. 

Owcia occurring erratically, shortly and widely conical with 
rounded ends and a free edge apparently almost straight; when they 
are present that part of the apertural margin which they embrace 
does not undergo any depression, but is bare of tubercles; they may 
push to one side the protuberances of the succeeding zocecia or cause 
them to be absent. 


1 Pal. Crét. Franc., vol. v, p. 304, pl. 702, figs. 5-7. 
2 Loe. cit., p. 304, pl. 702, figs. 8-10. 


100 R. M. Brydone—New Chalk Polyzoa. 


This species was found in the zone of U. cor-anguinum at Sevington, 
in Hants. It has obvious relationship with the figure of Flustrellaria 
granulosa, D’Orb.,' but that figure must be quite unreliable, as Canu, 
in his ‘ Revision” , unites the ty pe with Plustrellarta dentata, a widely 
different form. waco Sree 


MEMBRANIPORA SANDALINA, sp. nov. (Pl. VI, Fig. 10.) 

Zoarium unilaminate, incrusting. 

Zoecia of medium size, average length ‘6mm. with small oval 
apertures from ‘3 to °35 mm. in length, tapering considerably to the 
flattened anterior end and surrounded by broad, rather indefinite 
inward-sloping margins, which arise out of a common crust rather 
sharply in the anterior part, but die away posteriorly: at the anterior 
end there is a pair of small pores high up on the inner side of the 
margin just behind the end of the aperture, and a pair of tiny pores 
on the outer edge of the margin at its corners just outside the points 
from which the occium starts: the pair of small pores occurs with 
very great regularity, and as the pair of tiny pores can almost always 
be detected when the presence of an ocecium assists the search, 
it also is probably always present: at the posterior end of the 
aperture there is, or rather there should typically be, a central 
hollow protuberance rather like the front half of a email laid with 
the toe pointing away from the aperture; this is actually the case 
with zowcia which do not have to accommodate the occium of 
another zoceclum, and sometimes even when. this accommodation 
has to be provided ; but in the latter case, as a rule, the protuberance 
is displaced by the ocecium and splits into two rather emallcy 
lateral ones. 

Owcia very regular in occurrence, long and helmet-shaped, with 
apertures cut a long way back. | 

Avicularia probably of two kinds: (a) accessory, the protuberances 
above described; (0) vicarious, rather scarce, of the hour-glass type, 
elongated and narrow, with very little infold in the centre, no 
internal front wall in the lower lobe, and an inflated external front 
wall at the posterior end. — 

This species, too, occurs in the zone of WU. cor-anguinum at 
Gravesend. The two preceding species can obviously be referred to 
one of the two groups mentioned above. This species not only 
combines the characters of the two groups, but exhibits an actual 
passage of the character of the second group into a very plausible 
imitation of the character of the first group. 


EXPLANATION OF PLATE VI. 


Fic, (All figures x 12 diams.) 

1, 2.. Pseudostege concursa. Zone of A. quadratus. Shawford, Hants. 
ROR - Si Zone of B. mucronata. Portsdown, Hants. 

4. Cellepora diastoides. Trimingham. 

6. Membranipora Seafordensis. Seaford, Sussex. 

8. es multifissa. Gravesend, Kent. 

9. pan Sevingtonensis... Sevington, Hants. 
10. A sandalina. Gravesend, Kent. 


5, 
7; 


+ Pal. Crét. Franc., vol. v, p. 525, pl. 725, figs. 1-4. 


Grou. Mae., 1918. Prats VI. 


R. M, Brydone, Photo. Bemrose d&: Sons Ltd., Collo. 
Chalk Polyzoa. 


A, EB. Trueman—The Lias of South Lincolnshire. 101 


Il.—Tue Lirias or Sourm LincotnsHire. 


By A. EH. TRuEMAN, M.Sc., F.G.S., formerly Research Scholar, University 
College, Nottingham, 


(Concluded from page 73.) 


UT while it is difficult to collect fossils in situ in the upper part 
of the Lower Lias, a very good knowledge of the fauna is 
obtained from the material which may be collected on the tunnel 
heaps between Old Dalby and Saxelby. I have been permitted to 
study the large collection of specimens from these heaps which are 
preserved at University College, Nottingham, and the Engineer of 
the Midland Railway Company gave me leave to make small 
excavations. ‘lhe following lists give some idea of the fauna, which 
contains abundant Ammonites, especially of the genera Zragophyllo- 
ceras, Polymorphites, and Platypleuroceras. The Foraminifera like- 
wise are unusually interesting ; a list of genera identified by Wilson 
has already been given by Quilter’; according to the list given by 
H. B. Woodward? no Zextularia-like form is known from the Lias 
of any other British locality. 


Fossils. 


Cf. Asteroceras sagittarvum. 
Acanthopleuroceras cf. valdani, 
d’Orb. (rare). 


Cf. Cymbites levigatum, Hyatt (rare). 


Deroceras aft. armatwm, Sow. 
Oxynoticeras flavum, Simps. 
O. cf. polyophyllum, Simps. 
O. oxynotum, Qu. (rare). 


Platypleuroceras cf. brevispina, Sow. 


P. aureum, Qu. (abundant). 

P. sp. noy. (with knotted venter). 
P. rotundum, Qu. (abundant). 

P. Birchioides, Qu. 

Polymorphites jupiter, d’Orb. (rare). 
P. cf. jupiter, d’Orb. (common). 

P. caprarws, Qu. 

P. mixtus, Qu. (abundant). 

P. trwialis, Bean-Simps. 

P. costatus, Qu. 

Tragophylloceras ambiguum, Simps. 
T. aff. numismale, Qu. 

T, loscombi, Sow. (abundant). 

T. cf. 1bex, Qu. 

Nautilus intermedius, Sow. (rare). 


Belemnites cf. charmouthensis, Mayer. 


B. acutus, Mill. 
Acteonima sp. 
Amberleya conspersa, Tate. 


Cerithium liassicum, Moore (abun- 


dant). 
Chemmitzia (?) semitecta, Tate. 
C. citharella, Tate. 
Cryptenia (?) consobrina, Tate. 


Hucyclus sp. 

Pleurotomaria anglica, Sow. 
Trochus dalbiense, Wils. 

Turbo sp. 

Turritella trigemmata, Wils. 
Arcomya elongata, Roem. 

Astarte ef. striato-sulcata, Roem. 
Cardinia cf. levis. 

Ceromya sp. 

Gryphea cymbiwm, Lam. (abundant). 
G. (?) incurva, Sow. 
Hippopodium ponderosum, Sow. 

(abundant). 

Macrodon intermediwm, Simps. 
Modiola scalprum, Sow. 

M. cf. hillanoides, Chap. & Dew. 
M. sp. 

Nucula sp. 

Nuculana (Leda) subovalis, Goldf. 
N. (L.) minor, Simps. 

N. (L.) complanata, Goldf. 

N. (L.) galathea, d’Orb. 

Pecten priscus, Sch. 

P. sp. nov. 

Pholadomya glabra, Agass. 

(= ambigua, Sow.). 
Plewromya aff. costata, Y. & B. 
Plicatula spinosa, Sow. 
Rhynchonella fodinalis, Tate. 

R. lineata, Y. & B. 
Spiriferina cf. Walcotti, Sow. 
Waldheimia lagenalis, Qu. 
Cincta numismalis, Qu. 


1. E. Quilter, ‘‘ Lower Lias of Leicester’’?: GEOL. MAG., 1886, p. 64. 
2H. B. Woodward, Lias of England and Wales, 1893, p. 377. 


102 A.B. Trueman—The Inas of South Lincolnshire. 


Montlivaltia mucronata, Dune. 
_M. Haimei, Chap. & Dew. 

Hatracrinus Britannicus, Sch. 

Serpula sp. ; 

Ditrypa etalensis, Piette. 

Cytheridea sp. 

Holothuroid plates. 


Cristellaria cf. convpressa, d’Orb. 


D. sp. 

Frondicularia intumescens, Born. 
fF. cf. Terquemt, d’Orb. 

Ff. sp. 

Glandulina sp. 

G. (?) paucicosta, Roem. 
Lingulina tenera, Born. 
Marginulina reversa, T. & B. 


C. crepidula, F. & M. Miliolina (Spirillina) sp. 
C. recta, d’Orb. Nodosaria radicula, Linn. 
C. rotulata, Lam. N. sp. 

C. varians, Born. ef. Nonionina sp. 
Dentalina convmunis, d’Orb. Orbulina universa, d’Orb. 
D. glandulosa, Terq. Textularia sp. 

Judging from a less complete list of fossils Mr. B. Smith? was 
able to infer the presence of representatives of the zones from 
oxynotus to jamesont. From the above it is now possible to assert 
that the beds from Oppel’s zone of A. oxynotus to that of A. cbex are 
represented. The record of Deroceras davei, Sow., from Old Dalby ? 
suggests that still higher beds are present, but the specimen bearing 
that name in the Leicester Museum, to which the record presumably 
refers, is wrongly identified, being simply a species of Lytoceras. 

The association of fossils from such diverse horizons on a single 
heap, or series of heaps, is rather confusing, but it must be remembered 
that the material composing the heaps has been accumulated from 
some two hundred feet of clay, which is approximately the thickness 
of the zones named in Yorkshire. It was pointed out by Quilter,’ 
however, that species are to some extent confined to definite parts of - 
the spoil heaps. ‘Thus, on the lower spoil heap may be found fossils 
from the oxynotus zone, with numerous Gryphee, Pholadomya, and 
Corals, while the upper heap is rich in Platypleuroceras, Poly- 
morphites, Tragophylloceras, and crinoid stems from the zbex zone 
(valdani zone of Buckman). ‘he clays on the heaps at the Saxelby 
end of the tunnel doubtless represent the upper part of the dex 
zone, but they are less fossiliferous. 

The upper part of the Lower Lias ( O/stoceras sub-zone) 1s exposed 
at Waddington Brick Pit, a few yards east of the railway station. 
About twenty feet of blue shales are here seen, weathered yellow at 
the top. The nodules are very fossiliferous, each containing one or 
more capricorn ammonites, chiefly Ovstoceras figulinum, O. omissum, 
and O. curvicornum. ‘‘ Androgynoceras”’ cf. capricornum, Wt., and 
Amblycoceras crescens, Hyatt, are also common. A single specimen 
of the zone fossil, Deroceras dave’, was also found here; apparently — 
this is the most northerly English record for this fossil, which is 
fairly common in beds of this age in the South of England. 


Fossils. 


Deroceras davei, Sow. (very scarce). O. figulinum, Simps. (abundant). 
Oistoceras omissum, Simps. (abun- Amblycoceras crescens, Hyatt (not 
dant). uncommon). 


1 B. Smith, Geology of Melton Mowbray (Mem. Geol. Surv.), 1909, p. 37. 

2 C. Fox-Strangways, Geology of Leicester (Mem. Geol. Surv.), 1903, p. 108. 

3-H. E. Quilter, ‘‘ Lower Lias of Leicestershire ’’?: GEOL. MAG., Dec. III, 
Vol. III, p. 59, 1886. 


A. H. Trueman—The Inas of Sowth Lincolnshire. 103 


A. sp. C. sp. 
** Androgynoceras’’ aft. maculatum, Dentalina brevis, d’Orb. 

Y. & B. D. communis, d’Orb. 
A. cf. capricornum, Wt. (abundant). _D. ef. nodosa, d’Orb. 
Belemnites clavatus, Blainv. D. glandulosa, Terq. 
B. milleri, Phill. D. spp. 
Avicula inequivalvis, Sow. Frondicularia Terquemt, d’ Orb. 
Leda sp. F’. intumescens, Born. 
Lima eucharis, d’Orb. (rare). Lingulina tenera, Born. 
Pecten equivalvis, Sow. (common). Marginulina Rimeri, Reuss. 
Protocardium truncatum, Sow. Nodosaria raphanistrum, Linn. 
Ehynchonella cf. rvmosa, Qu. N. sp. 
Cristellaria crepidula, F. & M. Trochamina sp. (?). 


A similar fauna characterizes the lower beds exposed at Brace- 
bridge, a mile north of Waddington, but this section is more 
conveniently considered later. 


3. MippLE anp Upper Lias. 


A. Lincoln District. 


The best exposure of Middle Lias and contiguous deposits in this 
area is seen at Bracebridge Brick Pit, about three miles south of the 
Cathedral, Lincoln, where the following section is exposed :— 


ft. in. 

tenuicostatum Grey paper shales, weathering orange, with layers 

sub-zone. of flat, green nodules containing Inoceramus. 

15ft. 3in. + Dactylioceras cf. tenwicostatum, D. senicelatum, 
Posidonomya bron . . 15 0 

Impersistent band of dark earthy nodular limestone, 

f with well-preserved ee bronni. ‘‘ Cone- 
in-cone ’’ structure : 3 

acutum sub- Greenish shale with Tiltoniceras sacutum, T. costatum. 5 

zone. 3ft. Dactylioceras athleticum. D. ct. tenuicostatum, 
Leptena sp. ; : 6 4 

Light-grey shale with Dactyloids (D. athleticun., 

D. cf. hollandrei), Protocardium sp., ne 
hybrida : 2 8 

spinatum Light-grey shale with scattered phosphatic nodules ; ; 
zone. ‘Paltopleur oceras spp. . 1 @ 

19ft. 10in. Layer of ferruginous nodules with many phosphatic 
nodules 6 


Light-grey shales with scattered phosphatic nodules ; 
Paltoplewroceras spp.; some beds full of Pr oto- 
cardium truncatum, Dentalium giganteum, and 
Gomomya hybrida : . 14 0 

Main Nodule Bed; variable, but usually ‘consists of 
two beds of brown ironstone separated by green 
shales with phosphatic nodules. Pecten equivalvis, 

P. lunularis, Avicula cygnipes, Leda (Nuculana) 


graphica, Belemnites sp., Rhynchonella sp. . . 2 4 
Grey shales with Paltopleur oceras spp. Many 

Lamellibranchs 2 0 
margaritatus Dark-grey micaceous shales with levers of ironstone 
zone. 30 ft. nodules. Amaltheus margaritatus, A. gibbosa, 


A. levis, Sequenziceras spp., Modiola scalprum, 
Nuculana Quenstedti, Ostrea sp., Gresslya spp., 
Plicatula spinosa, P. calvus, Hucyclus imbricatus, 
Cryptenia consobrina . : 5 : ; plone 


104 A. E. Trueman—The Lias of South Lincolnshire. 


ft. in. 
Dark-grey micaceous shales with ferruginous con- 
cretions in beds and scattered. Amaltheus spp. 
(common). Oistoceras spp. and ‘‘ Androgynoceras’? 
spp. (decreasing towards the upper part). Modiola 
subcancellata, Goniomya hybrida, Cucullea 


miinstert, Gresslya spp., Pecten spp. . .15 0 

Oistoceras Dark-grey shales with reddish pyzitic nodules, con- 
sub-zone, taining Oistoceras figulinwm, O. omissum, O. 
Lvparoceras curvicornum, ‘* Androgynoceras’? capricornum 
sub-zone, (Wright), Amblycoceras crescens, Beaniceras aff. 
and luridum, Liytoceras sp., Gresslya spp., Leda 

latecosta (Nuculana) spp. . 15 0 
sub-zone. Dark-grey clunchy clay with nodules and two. shell 


beds, with capricorn ammonites, Gresslya lunulata, 

Pecten spp., Plewromya granata, Cucullea sp., 

Plicatula spinosa : . 10 0 
Dark-grey shales with scattered nodules. " Capricorn 

ammonites less common, Androgynoceras cf. 

‘striatum’, Lytoceras ct. lineatus, Wt. (non Schl.), 

very abundant. Goniomya hybrida, Pecten equi- 

valvis, P. calvus . : ‘ : 3 . 10 O 


(The bottom 20 feet was examined during the construction of 
a reservoir at the northern end of the pit in 1917 and is not now 
_ visible.) 

The most remarkable feature of the fauna is the abundance and 
variety in the Ovstoceras sub-zone of the capricorn ammonites, which 
with the ‘‘spherocones”’ or ‘‘ strvatum”’-like forms evolved. from 
them pass into the lower part of the margaritatus zone. Thus species 
of Amaltheus and Oistoceras may be collected in the same bed up to 
within fifteen feet of the base of the spinatum zone. This feature 
does not seem to occur except around Lincoln, and possibly in North 
Lincolnshire, where Ussher! found capricorn ammonites only ten feet 
below the Marlstone rock bed (spymatum zone). ‘‘ Amm. striatum” 
was recorded at Bracebridge by the Survey, but the ammonite 
usually known by this name occurs much lower in the sequence; 
the forms found at Lincoln previously included under that name are 
the spheerocone stages of Amblycoceras, Oistoceras, and Androgyno- 
ceras. It is hoped that these will be described shortly. 

The section to be examined at the Albion Brickworks (formerly 
Handley’s Pit) one mile north of the Lincoln Cathedral, shows 
a faunal succession which does not differ from that seen at Brace- 
bridge, but there are some interesting differences in the lithology of 
the spunatum zone and the overlying Transition Bed. 


SECTION AT THE ALBION BRICKWORKS. 


ft. in. 
tenuicostatwm Paper shales, weathered red and orange . : . 15 0 
sub-zone. 
acutum sub- Greenish shale with Tiltoniceras and Dactylioceras 
zone, 2ft. 6in. athleticum . eG 


Ferruginous sandstone with Dactyloids (D. athieticum, 
D. cf. tenuicostatum, D. semicelatum, Coeloceras 
ef. fonticulum) . : : : A eatin (0) 


1 A. E. Ussher, Geology of North Lincolnshire, ete. (Mem. Geol. Surv.), 
1890, p. 49. 


A. E. Trueman—The Lias of South Lincolnshire. 105 


ft. in. 
spinatum Ironstone with phosphatic nodules. Belemmnites, 
zone, 22ft.8in. Rhynchonella tetrahedra, Terebratula punctata, 
Cincta numismalis, Plewromya costata, Pecten 
equwalvis, P. lunularis 10 
Light-grey shales with several thin phosphatic nodule 
beds. : about 19 0O 
Light-grey shales with Amaltheus sp. 4 ‘ 5 abe 
Ferruginous limestone with Pecten equivalvis . : 10 
Several phosepasie nodule beds 4 5 6 10 
margaritatus ~ Shale : : : ‘ » to base 30 0 
zone. 
Randleys Pir, Lineatn, Brovebridge ac lineata 


Toe Margantatum. 


Fic. 8.—The Transition Bed and Middle Lias of Lincoln. 
(P, level of phosphatic nodule beds.) 


Comparing the spinatum zone in the above section with that at 
Bracebridge it is seen that the phosphatic nodule beds are not 
contemporaneous (Fig. 3), and cannot be used for correlation. 
J. H. Cooke,! after examining the section just described, concluded 
that the Konmieene limestone which is taken to be near the upper 
limit of the margaritatus zone was the Lincoln representative of the 
Marlstone of other localities. This was shown to be erroneous by 
the Rev. E. Nelson and Mr. H. Preston, who considered that the 
upper rock bed was the Marlstone equivalent. It must be noted, 
however, that only the lower part of this bed contains spinatum zone 
fossils ; the upper part has numerous Dactyloids, a fact which was 
apparently overlooked by previous writers. Thus the Lincoln 
equivalent of the Marlstone ironstone of the south of the county is 
a light-grey shale with abundant phosphatic nodules at varying 
levels, 


1 J. H. Cooke, GEOL. MaG., Dec. IV, Vol. IV, p. 253, 1897. 


106 A. L. Trueman—The Lias of South Lincolnshire. 


The Transition Bed (acutwm sub-zone), which has not previously 
been definitely proved except in Leicestershire, Northamptonshire, 
and Warwickshire, is well developed in the Lincoln district. The 
lithology of the lower part varies remarkably, consisting of clay at 
Bracebridge and of sand a few miles away, at the Albion works. 
‘The upper part, however, in both sections, consists of green shale. 
Dactyloids are common throughout (Dactylioceras athleticum, D. cf. 
semicelatum, D. cf. tenuicostatum), but the zonal fossil 7. acutum 
appears to be confined to the green shale at the top. The Transition 
Bed of this district is thus different from that of the Midlands, where 
Dactyloids and Ziltoniceras acutum appear together in the lowest bed. 
Thus we must either conclude that only the upper portion of the 
Transition Bed of Lincoln is homotaxial with the Transition Bed of 
the Midlands, or else that 7. acutum did not arrive in the Lincoln 
area until later. No indications of a break in sequence are to be 
found either at the top or bottom of the Transition Bed. Ifa break 
occurred, however, it would possibly be at the base of the green 
shale. 

Immediately overlying the green shales of the Transition Bed at 
Bracebridge is an impersistent dark-grey limestone containing 
Posidonomya bronni, succeeded by paper shales with impressions of 
compressed ammonites. In places where the limestone is not present 
there is a more gradual transition between the shales and the 
junction is less easy to define. 

In the cliff above the Albion Brick Pit the Upper Lias clays were 
formerly worked in Swan’s Pit. This pit is now disused and the 
section cannot be fully studied, but is probably as follows :— 


CLIFF ABOVE THE ALBION BRICK PIT. 


ft. in 
Oolitic limestone (Lincolnshire Limestone) : 8x80 
Northampton Sands (ferruginous) 4 6 
[Yeovilian and part of Whitbian deposits missing—non- sequence. 7] 
subcarinatum  Well-laminated shales, blue and black, with ferru- 


sub-zone. ginous nodules. Fossils rare. Hildoceras bifrons. 40 0 
50 ft. Shell bed. Trigonia pulchella, Nucula hanmeri, 
Hildoceras, Dactylioceras . 1 4 
Shales and shell beds with Dactylioeeras. Frechiella 
subcarimata : 8 8 
pseudovatum- Shell bed with Lucina 1 6 
falevferwm Shale with shell beds and septaria " containing 
sub-zones. Harpoceras aft. mnuilgraviwm, Phylloceras cf. 
20 ft. 6in. heterophyllum, Nucula, Belemnites subtenwis about 19 0 
exaratum Shales, not now exposed . : : ; about 15 0 
sub-zone. 
tenuicostatum Paper shales . : : ; é : about 15 0 
sub-zone. 


In constructing the above section use has been made of those given 
by Messrs. W. D. Carr! and W. H. Dalton.’ 

The upper part of the Lias here is not very fossiliferous, but as no 
fossils of a higher horizon than Hvldoceras bifrons have been found, it 
is probable that there is a non-sequence between the Lias and Oolites, 


1 W.D. Carr, Gkou. MaG., Dec. II, Vol. X, p. 164, 1883. 
2 W.H. Dalton, Lincoln (Mem. Geol. Sury.), 1881, p. 33. 


A. BE. Trueman—The Lias of South Lincolnshire. 


the sub-zones from fibulatum upwards being absent. 


the conclusion of W. H. Dalton.! 


B. Grantham. 


107 


This supports 


It is useful to compare the sections described above with those in 


the neighbourhood of Grantham. 


The junction with the overlying 


ironstone is exposed at the waterworks at Saltersford about one 
mile south of Grantham, where an extensive collection of fossils 


from the excavations was made by Mr. H. Preston, F.G.S., 
generously placed his notes and specimens at my disposal. 
the remainder of the Upper Lias is exposed in Rudd’s 


who 


Much of 
Brick Yard, 


several hundred yards west of the railway station, while the Middle 
Lias may be seen in the brick-pits at Gonerby. The general section 
may thus be taken as follows :— 


fibulatum 
sub-zone. 
223 ft. 


subcarinatum 
sub-zone. 
51 ft. 


pseudovatum- 
falciferum. 
sub-zone. 
9 ft. 6 in. 


exaratum 
sub-zone. 
15 ft. 


tenuicostatum 
sub-zone. 
15 ft. 
acutum 
sub-zone. 
spinatum 
zone. 35 ft. 


Micaceous shale, grey, iron-stained, unfossiliferous 
Grey shales with Psewdolioceras cf. lythense, 
Porpoceras vortex, P. aff. verticosum, Hildoceras 
bifrons, H. hildense, Phylloceras cf. heterophyliwm, 
Peronoceras cf. attenuatum. Leda ovum very 
abundant in pockets. (=Lower Leda ovum Beds 
of Northamptonshire) : ‘ 
Grey shales with scattered “nodules. "Hildoceras 
bifrons, Dactylioceras commune, D. cf. equi- 
striatum, D. hollandrei, Celoceras crassum . ; 
Dark earthy limestone. Hildoceras bifrons, Dactylio- 
ceras commune, Frechiella subcarinata i 5 
Grey shale with scattered nodules. Dactyloids 
abundantin nodules. In the lower part, Harpoceras 
aff. mulgraviunr occurs 6 
Oolite Bed. Rubbly ferruginous limestone and clay 
with scattered Oolite grains. Many fossils. 
Harpoceratoides ovatum, Y. & B., in upper part. 
Harpoceras aff. falcifer, H. mulgraviwm, H. 
? strangwayst, Dactylioceras gracile, D. acanthus, 
Celoceras aff. fonticulwm, Onustus sp., Nucula 
hammert 
Grey shale with nodules, Harpoceras aff. falcifer, 
Dactylioceras spp., Celoceras aff. fonticulum 
Grey shales with blue limestone nodules, containing 
well-preserved ammonites at all stages of growth. 
Al. aff. exaratuin, Hlegantuliceras elegantulum, 
Dactylioceras vermis, Inoceramus 
Paper shales with flattened nodules ; 
insect remains 


fish “smile amd 


Unknown. 
exposed 

Marlstone ironstone, with Rhynchonella tetrahedra 
and Terebratula punctata j about 

Micaceous clay with beds of rubbly ferruginous stone, 
yellow sandy layers containing many bivalves, and 
large ironstone septaria, Pholadomya ee Cucullea 
sp., Paltoplewroceras spp. c 


Junction of Middle and Upper Lias not 


1 Loe. cit. 


ft. in 


lei OF 


. 20 0 


108 A. #. Trueman—The Lias of South Lincolnshire. 


ft. in. 

margaritatum Grey micaceous shale with ferruginous limestone and 
zone. thin bands of septaria. Amaltheus margaritatus, 

55 ft. 6 in. Amaltheus levis, Cucullea miinsteri, Pecten calvus 25 0 
“Nodule Bed,’’ a bed of ferruginous stone with small 

phosphatic nodules é 3 ‘ 6 
Dark-blue shale, with scattered septaria. A. mar- 

garitatus, Seguenzicer asalgovianum . 2 Aes a0) 


The margaritatus zone at Grantham is much thicker than it is near 
Lincoln and the ammonites of the Ovstoceras sub-zone do not pass — 
into it. A curious feature of the margaritatus zone of Grantham is 
the presence of a bed of phosphatic nodules. It has been suggested 
that this bed is the equivalent of that seen near Lincoln,’ but 
evidently its horizon is very different. Noexposure of the Transition 
Bed has been examined in the Grantham neighbourhood, but it may 
be seen in the Caythorpe district, about eight miles to the north, 
where the following section was measured near the railway bridge, 
about a mile south of Caythorpe Church. 


ft. in. 

tenuicostatum Paper shales with fish scales. ane gee é S20 
sub-zone. 

2? acutum Ferruginous sand. ¢ : : . : : 4 
sub-zone. 

spynatum Oolitic ironstone : oe 2 U 

zone. Blue-green ironstone weathering to reddish- -yellow, 
fossils rare. : F gd oy 30) 


South of Grantham the junction of the Middle at Upper Lias may 
again be seen near Harby, four hundred yards north-east of White 
Lodge. 


ft. in. 
tenwicostatun. Blue paper shales, Dactylioceras tenwicostatwm, D. cf. 
sub-zone. semicelatum, Pseudolioceras sp. Fish scales. balls}. 
Cream-coloured limestone with fish teeth and scales . 1 
2acutum White limestone with many broken sheils 2 
sub-zone. 
spunatum Red ironstone, with abundant Rhynchonella and 
zone. Terebratula . : é : ; : 5 lOO) 


At neither of these places, however, have any ammonites been 
found in the beds which are taken to represent the acutwm sub-zone. 
It will also be noticed that the Transition Bed thins out as it is 
followed southwards through the county; thus it is not in direct 
continuation with that of the Midlands. Probably there was 
a slight uplift over the greater part of the country after the hemera 
of spinatum, several shallow basins being formed, and during the 
hemera of acutum sediments only accumulated in these restricted areas, 
one of which was around Lincoln but only extended for a few miles 
to the south. 

One of the most interesting fossils found in the Upper Lias of 
Grantham is one which Mr. 8. 8. Buckman has identified as 
Harpoceratoides ovatum, Y. & B., indicating the pseudovatum sub- 
zone, which had not previously been proved to exist outside 


1 H. B. Woodward, Lias of England and Wales (Mem. Geol. Surv.), 1893, 
p. 241. 


A, E. Trueman—The Lias of South Lincolnshire. 109 


Yorkshire.’ The Oolite Bed, in the upper part of which this fossil 
was found, probably represents a period of slow deposition.? This 
period is similarly represented in Northamptonshire, where it lasted 
longer, during the deposition of the subearinatum sub-zone, which is 
consequently much thinner than in Lincolnshire.® 


Ve 


A 


TRAMP TCH 


RANTHAM| 


Lincolnshire, and Northamptonshire 


quals 150 feet.) 
“ After B. Thompson, Jubilee Vol., Geol. Assoc., 1910. 


9 


Lincoin 
— 
ss 


(Vertical scale, 1 inch e 


Fic. 4.—Middle and Upper Lias of Yorkshire, 


AfterS. 8. Buckman, Whitby Memoir, 1915, p. 69. 


iH i y WHIT] 

2 HH nH H H i TM 

rap es ibe] | Ht HH 

=) < h ti AH 

11) 1 | H Ui il Hh 
21) 3 i HH 
s|| Hut Hh 

palit ee PRY MTT a 

E 5 Bee, ee 

Siete shes sys Bnei tie ante ate 

a Rigi erstin 3 Ea 3 Tah oe at 

= os 2 = Fee (aa = Satie 

= free = & ee Fel ey RR on Giese 

oO = 4 = OD = £ a ea) 

<a ose 8 & 2 AS si se Soe Mw 

Se Ea tesisl NOP PVPS hous eh Ee ee 


1 


1S. 8S. Buckman, Geology of Whitby, etc. (Mem. Geol. Surv.), 1915, 
pp. 75, 102. 

* H. Preston & A. E. Trueman, ‘‘Oolite Grains in the Upper Lias of 
Grantham ’’: Naturalist, 1917, 1s Pal 

> B. Thompson, Northamptonshire (Jub. Vol. Geol. Assoc.), 1910, p. 462. 


110 A. #. Trueman—The LInas of South Lincolnshire. 


GENERAL CONSIDERATION oF THE Upprr Lias. (Figs. 4 and 5.) 

The variation in the thickness of the Upper Lias in Lincolnshire 
has resulted from two movements, viz. : 

(1) A series of uplifts along an axis in South Yorkshire at 

intervals during the deposition of Lias and later rocks. 

(2) The migration of the area of maximum deposition of the 

Upper Lias from north to south. 

This latter movement was traced by Mr. 8. 8. Buckman,’ who 
showed that the zones which are represented by thick deposits in 
Yorkshire, are only present as thin layers further south, while later 
zones not well developed in Yorkshire are very thick in the south. 
This migration of the area of maximum deposition may now be traced 
across Lincolnshire; thus the tenwicostatum subcarinatum sub-zones 
attain their maximum thickness in Yorkshire, and are fairly thick in 
Lincolnshire, but rapidly decrease in thickness towards Northampton- 
shire and the south. On the other hand, the fibulatum zone, which 
is only thinly represented in Yorkshire, shows increasing thicknesses 
at Grantham and Northampton. In this area it is interesting to 
notice that the places of minimum deposition in any zone are 
characterized by Oolitic beds. It is probable that during the 
deposition of the Upper Lias a shallow down fold passed gradually 
from Yorkshire southwards, its position determining the area of 
maximum deposit at any time. 


Lincoln Grantham : ‘Northampton Ste 


——s = Pusass 
S$uo-zone 
= Subearinarum 
: Sub- zone. 
Fic. 5.—Diagram showing the relationship of the Northampton Sands and 
Upper Lias. (Not to scale.) : 

Accompanying this movement was one which probably commenced 
earlier, that is, an uplift or rather a series of uplifts along an axis 
in South Yorkshire. Asa result of this the thickness of the Lias as 
a whole decreases as it is traced southwards across Yorkshire or 
northwards across Lincolnshire. The Upper Lias also decreases in 
thickness in the same way; in Northamptonshire it is about two 
hundred feet thick, at Grantham 115 feet, and at Lincoln only one 
hundred feet, diminishing still more rapidly further north until at 
Appleby? it is usually little more than fifty feet thick. The 
thinning, however, is probably not so regular as appears from these 
figures, for at Caythorpe, between Grantham and Lincoln, a boring 
showed the Upper Lias to be nearly two hundred feet thick,® 

1 §. S. Buckman, ‘‘ Certain Jurassic (Lias—Oolite) Strata of South Dorset’’: 
Quart. Journ. Geol. Soc., vol. lxvi, p. 88, 1910. 

2 Water-Supply of Lincolnshire (Mem. Geol. Sury.), 1904, pp. 33-5. 
nee Preston, ‘‘ On a New Boring at Caythorpe’’: Q.J.G.S., vol. lix, p. 29, 


R. M. Deeley—Mountain Burlding. 111 


although judging from the fossils obtained, no higher sub-zones 
were present than usually occur in Lincolnshire. The change in 
thickness of the Upper Lias from Lincoln southwards, moreover, is 
not due to an increase in the thickness of the component zones, which 
vary in thickness as pointed out above, but is due to the greater 
extent of the non-sequence at the top of the Lias when traced 
northwards across Lincolnshire; thus, while the fibulatum, braunianum, 
and Jillc sub-zones are present in Northamptonshire, of these only 
the fibulatum sub-zone is definitely represented at Grantham, and 
none of them are found at Lincoln. It appears, therefore, that 
uplift in South Yorkshire occurred at intervals, namely, during the 
deposition of Lower and Middle Lias, and towards the close of 
deposition of Upper Lias. 


I1I.—Moonvain Boixvine. 
By R. M. DEELEY, M.Inst.C.H., V.P.G.S. 

(JX\HE structure of mountain ranges has always been difficult to 
understand. They often show that peculiarly complicated 
disturbances of strata have occurred in the process of their formation. 
Mountain ranges in many stages of dissection are to be seen in 
various parts of the world; but the better knowledge which their 
study has furnished us with has not, at the moment, always assisted 
us in the better understanding of the problem of mountain building. 

At the present time the compression theory may be said to be the 
one most generally accepted. It is thus described by James Geikie: ? 
‘‘ Little progress could be made towards a satisfactory theory until 
the geoiogical structure or architecture of individual mountain chains 
had been studied with precision. Many observations and descriptions 
of the folded rocks of the Alps and other regions had been recorded 
... but... geology could still present no clear conception of 
a mountain range as an organic unity ... it was not until the 
appearance in 1848 of the well known essay by Professors W. B. 
and H. D. Rogers on the physical structure of the Appalacians, that 
geologists generally began to realize what is meant by the architecture 
of mountains of elevation. Thanks to the labours of these brilliant 
observers and their many successors, we are no longer in doubt as to 
the part played by compression in the formation of mountain ranges.” 
That compression is the cause of the upheaval of mountain ranges, 
and the folded structure they present, James Geikie had no doubt, 
and he enforces his argument by pointing to the phenomena of 
cleavage, schistosity, etc., as the result of the same action. 

To some, however, the amount of compression required to form 
a mountain range, not to mention the sharply marked anticlines and 
synclines of less elevated regions, seems greater than can be allowed. 
To again quote James Geikie,? ‘‘ While overfolding and wholesale 
horizontal displacements are the most characteristic features of 
Alpine architecture, it must not be forgotten that compression 


' Mountains, their Origin, Growth, and Decay, 1913, p. 66. 
2 Thid., p. 130. 


112 R. M, Deeley—Mowntain Building. 


resulted only in the bulging up or general elevation of the great 
central massifs, and in diminishing the width of the entire Alpine 
area. Many years ago Professor Heim was of opinion that if all the 
Alpine folds were smoothed out and the strata regained their original 
position, they would necessarily extend over a much wider area; 
the two points Ztirich and Como, for example, would be further 
apart than they are at present by some 120 to 150 kilometres. But 
this estimate he thinks is now much under the mark; according to 
him, the Alpine area before compression took place was a flat land 
measuring probably 600 to 1,200 kilometres across. Instead of this 
broad low-lying tract, we have now a lofty mountain chain averaging 
no more than 150 kilometres in width.” He accounts for the com- 
pression by adopting the theory that ‘‘The movements referred to 
are doubtless due to the wrinkling of the earth’s crust over the 
slowly cooling and contracting material ’’. 

The above quotations have been made for the purpose of showing 
what may be considered to be the attitude of very many geologists 
at the present day. However, the theories he advocates he did not 
originate, but they certainly appeared to him to be sufficiently well 
established to admit of their being placed before the public as sound. 

Many physicists who have carefully studied this theory of com- 
pression by cooling are quite satisfied that it is not capable of 
accounting for the amount of compression required. O. Fisher, for 
example, maintains that secular contraction of a solid globe through 
mere cooling will not account for the observed phenomena. he idea 
is that the already cooled surface of the earth was thrown into folds 
as the hotter interior cooled. We must assume, for instance, that 
* during the formation of the Alps the compression may have amounted 
to 1,200 —150 kilometres, or 1,050 kilometres. To effect this, even 
if the whole of the crumpling were concentrated in the Swiss Alpine 
region, the earth must have decreased in diameter by about 334 
kilometres. Indeed, the contraction that is required in the diameter. 
of the earth is very much greater than can possibly be allowed. 

Thrust planes have also been regarded as proof of compression.’ 
J. Geikie remarks: ‘‘ But notable as these rock-movements are, 
they cannot compare in extent to the similar translations which have 
been recognized in Scandinavia, where in one particular case a massive 
sheet, many thousand feet thick, is believed by, some geologists to 
have been driven from west to east, for a distance apparently of 
80 miles or thereabouts.’’ It is unfortunate that these faults should 
have been called ‘“‘ thrust planes’’. It would be impossible to thrust 
a sheet of rock over the surface beneath if the proportions of thickness 
to distance were anything like those mentioned. A force applied to 
one end of such a rock sheet would merely buckle it up for a short 
distance. ‘‘Gliding plane’ would be better than ‘‘ thrust plane” 
as a name for such phenomena. 

In view of the considerations that have been mentioned, it would 
be well to consider whether the folding, etc., that is so often exhibited 
in mountain chains may not be the result of other agencies. 


1 Tbid., p. 173. 


R. M. Deeley—Mountain Building. 113 


Some experiments recently made by the author of this paper,! 
showed that when a heavy viscous layer of sealing-wax loaded with 
‘sand rested upon a layer of pitch, the heavy wax sank into the lighter 
layer below, in such a manner as to simulate the effects of com- 
pression. This point was noticed by Mr. G. W. Lamplugh, who 
called my attention to it, and he inquired whether the same con- 
ditions could be applied to the folding of mountain chains. If such 
were the case the folding would result in local tension, not general 
compression. 

The experiment above referred to was made for the purpose of 
showing that when a heavy bed of sandy gravel, or clay with stones, 
rests upon a soft clay or brickearth, if the two deposits were brought 
into a viscous condition after frost, then the heavy overlying bed 
would settle into the lighter bed below in a manner which would 
produce a structure very closely resembling the ‘‘ trail and underplight”’ 
of Spurrell. 

That the crust of the earth is flexible, and that it, therefore, can 
sink and rise, as denudation and deposition take place, is now 
generally conceded. In the case of the Gangetic trough Oldham,? 
though not considering that the trough owes its origin to the weight 
of the alluvium, remarks: ‘‘ But though the weight of the sediment 
cannot have been the originating cause of the depression of the 
Gangetic trough, it may have had considerable influence in deter- 
mining the magnitude of its dimensions, for if there had been some 
other cause capable of forcing down the level of the crust to a given 
depth before the resistance to further movement became equal to the 
force, then the addition of a load of alluvium would enable the same 
force to lower the level to,a greater extent than if the hollow had 
been left empty or only filled with water. The amount of this extra 
depression would depend on the balance between the force and the 
resistance ; if both remained appreciably constant, within the limits 
of the movement involved, the weight of the alluyium would enable 
this to be carried about five times further than would otherwise be 
the case, so that the Gangetic trough, taken as 15,000 feet deep, 
would only have a depth of about 3,000 feet had it not been filled 
with alluvium as fast as it was formed.” 

The above reasoning is based upon the fact that wherever mountains 
occur it has been found that the crust beneath them is of low density 
and that the mountains float upon this lighter material. Simwarly, 
beneath the deep seas the crust is of high density and the land level 
is caused to sink to great depths. As changes in the level of the land 
have been numerous, and of great magnitude during geological time, 
it is clear that changes in the density of the lower portions of the 
earth’s crust are continually but slowly taking place. As long as 
such areas of high or low density persist there will continue to be 
mountains or deep seas. Denudation alone cannot reduce a mountain 


1 R. M. Deeley, ‘‘ Trail and Underplight’’: Grou. MaG., Dec. VI, Vol. III, 
pp- 2-5, 1916. 
2 “The Structure of the Himalayas’’: Geol. Survey of India, vol. xlii, 
pt. ii, p. 122 
DECADE VI.—VOL. V.—NO. II. 8 


114 R. M. Deeley—Mowntain Burlding. 


range; for as long as the rocks below are of low density the mountain 
mass will rise as fast as material is removed by denuding influences. 

_ The cause of the variations in the density of the deep-seated 

portions of the earth’s crust is as yet uncertain; but we are entitled 

to regard the crust as floating upon a liquid : stratum of great viscosity, 

or a very plastic solid stratum, 

It may not be out of place to explain what is here meant by 
plasticity and viscosity. 

Although it is certain that our present knowledge of the properties 
of fluids and solids, from the physical point of view, is by no means 
complete, it will not be out of place to consider some of the very 
complex phenomena they exhibit, and which have a bearing upon 
geological problems. The subject is, indeed, one of, very great 
importance to the engineer and physicist, for to the former the 
physical properties of solids have to be considered as far as they affect 
the stability of all kinds of structures, whilst in the case of the 
latter they have to be borne in mind when dealing with the question 
of the stability of mountain ranges, etc. 

One very frequently hears semifluids spoken of, and there are 
many who are of opinion that there is a regular transition of the 
solid into the liquid state, or that there are a large number of 
substances which can be arranged in such an order that they show 
a transition from the solid to the liquid state. The idea that 
liquidity is only a matter of degree was well expressed by Tyndall,’ 
who writes: ‘‘ What was the physical condition of the rock when 
it was thus bent and folded like a pliant mass? Was it necessarily 
sotter than it is at present? I do not think so. The shock which 
would crush a railway carriage, if communicated at once, is harmless 
when distributed over the interval necessary for the pushing in of the 
buffer. By suddenly stopping a cock from which water flows you 
may burst the conveyance pipe, while a slow turning on of the cock 
keeps all safe.”’ All this is more plausible than sound. He then 
goes on: ‘‘ Might not a solid rock by ages of pressure be folded as 
above? It isa physical axiom that no body is perfectly hard,*none 
perfectly soft, none perfectly elastic. The hardest body subjected to 
pressure yields, however little, and the same body when the pressure 
is removed cannot return to its original form. If it did not yield in 
the slightest degree it would be perfectly hard; if it could completely 
return to its original shape it would be perfectly elastic.”’ 

‘Tet a pound weight be placed upon a cube of granite; the cube 
is flattened, though in an infinitesimal degree. Let the weight be 
removed, the cube remains a little flattened ; it cannot quite return 
to its primitive condition. Let us call the cube thus flattened No. 1. 
Starting with No. 1 as a new mass, let the pound weight be laid 
upon it; the mass yields, and on removing the weight it cannot 
return to the dimensions of No. 1; we have “¢ more flattened mass, 
No. 2. Proceeding in this manner, it is manifest that by a repetition 
of the process we should produce a series of masses, each succeeding 
one more flattened than the former. This appears to be a necessary 
consequence of the physical axiom referred to above. 

1 Glaciers of the Alps, 1860, p. 9. 


R. M. Deeley—Mountain Building. 115 


** Now, if instead of removing and replacing the weight in the 
manner supposed, we cause it to rest continuously on the cube, the 
flattening, which above was intermittent, will be continuous; no 
matter how hard the cube may be, there will be a gradual yielding 
of its mass under pressure.’ 

Since the above was written a great deal of additional information 
has been obtained experimentally ; but very few attempts have been 
made to put this in a form which would be useful to the geologist, 
or eyen to the engineer who has not made a special study of the 
subject; and one may say with truth that although Tyndall’s state- 
ment now seems very far from being a complete or even correct one, 
many modern writers seem to base their geological theories upon 
some such theory of the solid and liquid states. 

From the scientific point of view there is every reason to believe 
that the solid and liquid conditions of matter must be regarded as 
quite distinct physically, and that when the one state passes into the 
other the change is abrupt. 

In the case of a liquid, if it be placed in a hollow cup-shaped 
vessel it will be found that the upper surface is a perfectly level one. 
Water, for example, after a few oscillations, settles down quickly. 
A thick lubricating oil does so more slowly; but pitch may take 
weeks or even years to reach the perfectly horizontal position. 
There is no question but that all liquids, under such conditions, flow 
until their upper surfaces are quite horizontal, and in this respect 
they are all true liquids but differ in viscosity. In every portion of 
the mass the stresses eventually become equal and opposite. 

If small boats be placed on these liquids, in the case of oil and ~ 
water they will quickly sink until they have displaced their weight 
of oil or water. In the case of the pitch, a similar boat, when first 
placed on the surface, will rest there, but it will slowly sink into the 
pitch until it also floats and displaces exactly its own weight of pitch. 
Oil, water, and pitch are all perfect liquids, but pitch is more 
viscous than oil, and oil is more viscous than water. At the same 
temperature and pressure the fluidity (viscosity) is always the same 
in the case of liquids possessing definite chemical compositions, and 
may be expressed in terms of some particular unit such as Poise, 
which is a C.G.S. scale. 

A solid may be either hard or soft, but however soft it may be it is 
not aliquid. Thus, if we had a very large vessel partly full of soft 
clay (a material much softer than pitch), its upper surface would 
never become quite flat. Ifa heavy boat were placed upon the soft 
clay the boat would sink some distance into it, but it would never 
sink until it displaced an equal weight of clay. Indeed, it would 
sink to a certain distance into the clay quite rapidly, and would then 
come practically to a standstill. However, it might go on con- 
tinuously sinking slowly and yet never displace its weight of clay. 
This may be illustrated in the following way: Imagine that the rate 
at which it sinks gets slower andslower. Take it that in the first hour 
it sinks half a yard. In the next hour it sinks one-quarter of a yard, 
in the next one-eighth of a yard, and so on. At this rate it will 
always be sinking, but will never sink more than one yard. Tyndall’s 


116 R. M. Deeley—Mountarin Burlding. 


cube would déform in some such way as this, and the deformation 
would never become appreciable. 

However, if a soft solid have too great a weight placed upon it, it 
will yield continuously much as will a liquid. In extruding lead 
through a hole in a cylinder no movement takes place until a certain 
pressure is reached; the lead then flows out through the hole and 
flows faster as the pressure 1s increased. 

Now the upper portion of the earth’s surface is composed of rocks 
varying in hardness. Buildings may be erected upon it which will 
be permanently stable, provided the load on their foundations is not 
too great. ‘The load per square foot that may with safety be placed 
upon each kind of rock varies considerably, and it is the engineer’s 
endeavour to find out what is the smallest area and depth of founda- 
tion that will ensure stability in each case, so as to keep the cost of 
the building as low as possible. 

The load-carrying capacity of any kind of rock varies much 
according to surrounding conditions. Dry clay will carry more than 
wet clay. On this account the water escaping from a burst water- 
pipe may so soften the clay or marl upon which a building rests 
that the foundations give way. Vibrations caused by heavy vehicles 
have the same effect. Railway bridges and retaining walls have 
to be made much stronger, for the same loads, than have road bridges. 
and walls. No doubt the foundations of St. Paul’s Cathedral were, 
in most instances, amply sufficient under the conditions existing 
when Wren built it, but the vibrations resulting from the heavy 
road and rail traffic of our times, and the effects upon the local 
drainage produced by sewers, etc., have much interfered with their 
stability. 

The nature of the resistance to stress offered by the materials. 
forming the earth’s crust is in some cases of a liquid and in others of 
a plastic description. The liquids, whether water or molten rock, 
settle down with their upper surface layers practically horizontal ; 
but owing to their varying density and the plastic resistance they 
offer to flow, the solid rocks stand at various levels. We thus have 
large raised areas floating upon ‘‘roots” of light material and 
depressed areas over roots of heavy material, the whole floating upon 
a plastic or liquid substratum. It has been suggested that this. 
substratum rests upon harder material, and it has been called the 
asthenosphere. But the raised areas are not necessarily quite stable. 
The materials of which they are built up are being denuded and 
carried to lower levels, with the result that the area rises to restore 
the balance, and the areas over which deposition takes place sink for 
the same reason. 

The flexing of the earth’s crust by the moon results in ‘‘ earth 
tides”, and these, together with earthquake shocks, have the same 
effect upon the stability of mountain masses as have the vibrations. 
produced by heavy traffic upon the foundations of St. Paul’s 
Cathedral. Elevated areas consequently tend to flow and spread 
outwards over the surrounding lower lands, or to slide under the 
action of gravity bodily into depressions. Such sheets of rock are not. 
pushed along by pressure applied at one end; they slide bodily down 


R. M. Deeley—Mountarin Building. TAL 


a slope under the action of gravity, every yard of the mass furnishing © 
its own propulsive force. 

How the dense ‘‘roots’’? of depressed areas and the lighter 
‘roots’? of elevated areas arise, it 1s not my intention to discuss. 
That such roots exist a perusal of the paper by R. D. Oldham 
already referred to will demonstrate. 

Rain, rivers, etc., attack the elevated areas, cutting out river 
valleys of varying width. The character of the resulting scenery 
depends upon the nature and hardness of the rocks. The depth and 
width of the valleys resulting from denudation must bear a close 
relationship. to the forces required to make the rocks flow. When 
the rocks are soft and erosion results in the production of deep 
valleys, then the valley bottoms rise, the sides close in, and various 
irregularities in the bedding planes result. In this way anticlines 
and synclines are very frequently formed zzthout lateral pressure. 
Such movements are greatly assisted by temperatures. 

The crust of the earth grows warmer and warmer as the depth 
increases. This gradient of temperature in the crust is about 1° F. 
for every 70 feet of descent. At great depths the rocks are con- 
sequently very hot. Now a solid almost always becomes softer and 
softer as the temperature is raised, and the force which will cause 
it to flow becomes smaller and smaller. If the temperature were 
raised so high that the force which would produce continuous flow 
fell to almost zero, then the solid would have been abruptly turned 
into a liquid, and flow would result however small the force might be. 

When a plastic substance is distorted microscopic examination 
shows that it has resulted from the formation of many distinct shear 
planes. On the other hand, the distortion of a viscous substance is 
caused by shear between planes whose thicknesses are of molecular 
dimensions. 

A piece of granite overloaded would break into small fragments. 
It would not flow like soft clay. However, if the granite were 
surrounded by some substance under very great pressure, then the 
particles of rock would be so firmly held together that it would not 
fracture if deformed; but would change its shape without breaking. 
It thus comes about that although hard rocks are fractured by earth 
movements near the earth’s surface, they remain massive at great 
depths although they suffer distortion. This ability of rocks at great 
depths to suffer distortion without fracture is, of course, much 
assisted by the high temperature prevailing there. 

The idea that the surface rocks are floating in very many places 
upon a fluid stratum can be shown to be probable by many 
phenomena. During Tertiary times, over an area of some 200,000 
square miles of what is now Idaho, Oregon, and Washington, fluid 
basic lavas welled up more or less steadily through great fissures, 
and covered the whole country with sheets of lava aggregating in 
places 2,000 feet or more in thickness. In India a like area was 
covered to a depth of from 4,000 to 6,000 feet, while over the Lake 
Superior basin and some of the surrounding areas the thickness 
reached by more ancient lava floods was from 15,000 to 25,000 feet. 
There are amongst these lavas very few beds of ash or cinders, so 


118 R. M. Deeley—Mountarin Building. 


that the eruption or welling up of these enormous volumes of lava 
was not of a violent character. There are many cases also where 
~ huge blocks of country, bounded by faults, have subsided, and the 
liquid magma below has issued along the fault lines. 

We must, therefore, take it that large areas of the earth’s surface 
have been, and probably now are, really resting upon a substratum 
of liquid or nearly liquid rock, and that in many cases the cooler and 
heavier surface rocks have subsided bodily, the liquid rising through 
great fissures and spreading over them as they sink. Here there are 
no signs of compression ; rather has the crust been stretched to form 
the fissures through which the lava welled up. 

No ordinary amount of compression could give rise to a mountain 
range; for as the rocks thickened locally under the compressive 
forces, their weight would cause them to sink, and depression might 
result rather than elevation. It has been suggested that the heating 
up is caused by compression. However, in the case of North 
America, where the vast quantities of basic lava welled up, the rocks 
are generally horizontal and show no signs of compression. All that 
can be made out is that mountain chains seem to have risen in areas 
which have been ones of active recent deposition, and do not appear 
to have formed in areas covered by rocks of great age. All our great 
modern mountain ranges were raised in Tertiary times over areas of 
recent deposition. — 

It is probable that our anticlines and synclines are generally the 
result of the irregular sinking of the earth’s surface where it rests 
upon fluid or very plastic magmas. The syncline of the Thames 
Valley, for example, would seem to have varied from time to time, 
sometimes becoming more pronounced and then flattening out again. 

The view that rocks of varying density resting upon a liquid 
substratum may produce synclines and anticlines has already been 
suggested by Coleman.1 He says: ‘‘Some years ago I ventured 
another explanation. Granite is specifically lighter than most of the 
greenstones and schists of the Kewatin; and molten granite, even if 
not at avery high temperature, is lighter than the relatively cold 
rocks above it. If the rocks above were unequally struck, so that 
some areas were less burdened than others, it is conceivable that 
these differences in gravity might cause the granite to creep slowly 
up beneath the parts with lightest loads, whilst overlying rocks 
sagged into synclines in the heavily loaded parts.” 

‘‘ Whatever the cause, these batholiths enclosed by meshes of 
schist are the most constant feature of the Canadian Archean, 
though in many places erosion has cut so deeply that the meshes 
have all but disappeared, leaving only straight or curving bands of 
hornblende schists enclosed in Laurentian gneiss.’’ 

Here we appear to have a mountain mass so deeply dissected by 
denudation that the cause of the existence of the anticlines and 
synclines which no doubt characterized the ranges is disclosed. The 
folds were not formed by lateral pressure, but by the stretching of 
the beds of rock as some portions settled down and others rose. 


1 Presidential Address, Brit. Ass. Rep., 1910, p. 54. 


R. M. Deeley—Mountarin Building. 119 


However, the bending of the rock stratum, although resulting in 
a general stretching, would also produce local compression. That 
a mountain range may be resting upon a liquid or very plastic base, 
as would appear to have been the case with the old mountain range 
the ‘‘roots” of which are now the Canadian shield, leads to some 
important consequences. 

My chief endeavour has been to show that there are other ways 
of accounting for anticlines and synclines than by compression. 
To further illustrate the suggestion some remarks will be made 
concerning the history of the Swiss Alps. 

The structure of the Swiss Alps was for many years an enigma ; 
but there seems every reason to believe that the broad outlines of 
their architecture are now known. 

At the base we have crystalline gneisses, schists, and granites. 
They form the lofty massifs of Mont Blanc, the Aiguilles Ronglies, 
the Bernese and Gothard Alps, etc. They once formed a highly 
worn or much denuded surface, upon which the newer rocks were 
deposited. The older rocks are chiefly crystalline masses and some 
Carboniferous strata, while the overlying bedded series range in age 
from Permian and Triassic down to early Cainozoic. These sediments 
filled up the valleys and submerged the mountains of the old land. 
The area over which they were deposited was a subsiding one. We 
are told that after the deposition of these sediments the sea bottom 
was raised and a low flat undulating land area was formed ; and that 
great rock-sheets from the north and south were then thrust up 
gentle inclines over this land. The chief of these sheets are the 
Helvetian, Lepontine, East-Alpine, and South-Alpine. That these 
sheets could have been thrust up and over each other and over a 
rising land seems quite impossible. That they are there, and have 
travelled great distances, is certain; but the conditions under which 
they have travelled require further elucidation. 

It may be that the sea in which these early sediments were 
deposited became very deep, and that the rock-sheets slowly slid into 
this deep sea one after the other; for in most instances the upper 
sheets are formed of older rocks than the lower ones. The covering 
of the sea bed by cold rock-sheets instead of water would deepen the 
sea, whilst the removal from the shallow water or land of the cold 
rock-sheets would be replaced by rising warmer rock. This would 
increase the gradient and result in further slides. 

The whole mass was then raised and folded. It is very doubtful 
if this folding was the result of pressure: rather may it have been 
due to the differential vertical earth movements resulting from 
denudation. During the rising of the Alps great deposits were 
formed along the margins of the mountains. It is a peculiar fact 
that some of the rock folds have moved outwards and been thrown 
over these deposits. Indeed, it may be that overfolds are not due to 
thrust; but are due to the flow of the elevated rocks near the margins 
of the mountains towards or even over the surrounding low lands. 

It is rather a rash thing perhaps to suggest that compression has 
not been a prime factor in earth movements; but the difficulties that 
can be urged against the idea are so very great, that it cannot be 


120 Dr. BR. L. Sherlock—Datwm-lines in English Kewper. 


considered more than a working hypothesis until the physical 
difficulties are met. If it can be shown that compression is not 
required, and that the phenomena of folded mountain chains can be 
otherwise explained, a distinct advance would be made in dynamical 
geology. 


TV.—Darum-tines In THE EnciisH KEvrrr. 
By R. L. SHeRLocK, D.Sc., A.R.C.Sc., F.G.S. 


N the almost complete absence of fossils in the British Keuper 
there has been a lack of datum-lines in that formation by which 
we may compare the horizons of different sections. Yet in such 
a thick and widely spread deposit it 1s very desirable to have sub- 
divisions enabling us to give the particular part of the Keuper to 
which a section belongs. In deposits such as the New Red 
formations too great stress has been laid on lithology, inevitable 
perhaps in the scarcity of fossils, but a source of grave errors in 
correlation. For example, Mr. L. J. Wills! thinks that fossils found 
in the Keuper of Warwick have affinity, not with the Keuper, but 
with the Muschelkalk of Germany. Again, there are strata in the 
Permo-Bunter of Nottinghamshire* which might be mistaken for 
Keuper Waterstones, if only lithology was considered. Over small 
areas a band of sandstone with some peculiarities may be used as 
a datum-line, as in the Arden district of Warwickshire* and in 
Nottinghamshire,* but these are of local value only. 

Recently Mr. Bernard Smith and myself have had occasion to visit 
all places where gypsum is worked, or likely to be workable, 
throughout England, and it appears that the workable deposits of 
gypsum within the Keuper occur at definite horizons. The economic 
results have been published in a recent memoir,® but I wish here to 
show that they give us two definite horizons, the upper one found at 
intervals between North Yorkshire and Somerset and the other over 
parts of three Midland counties. “Using these datum-lines, I propose 
to show that they help us to state the nature of the Keuper- Rheetic 
junction and to determine whether or not the Tea-green Marls oceur 
at a definite horizon. 

1. Lhe Upper Horizon.—Four beds of gypsum occur in a definite 
order in the quarries and mines situated between Beacon Hill 
(Newark) and Orston, to the south-west, a distance of 95 miles. In 
the figure sections are given of the strata found at Newark, Hawton, 
Bowbridge, and Orston. Those at Newark, Bowbridge, and Orston 


1 “On the Fossiliferous Lower Keuper Rocks of Worcestershire’’: Proce. 
Geol. Assoc., vol. xxi, p. 268, 1910. 

2, R. L. Sherlock, ‘‘ The Relationship of the Permian to the Triag in 
Nottinghamshire ”’ : Quart. Journ. Geol. Soc., vol. Ixvii, p. 82, 1911. 

3. A. Matley, ‘‘The Upper Keuper (or Arden) Sandstone Group and 
Associated Rocks of Warwickshire’’: Quart. Journ. Geol. Soc., vol. lxviil, 
pp. 252-80, 1912. 

11835 Smith, ‘“The Upper Keuper Sandstones of Hast Nottinghamshire ”’ : 
GEOL. MaAG., 1910, pp. 302-11. 

> R. L. Sherlock & B. Smith, Special Reports on the Mineral Resources of 
Great Britain (Mem. Geol. Sury.), vol. iii, ‘‘ Gypsum and Anhydrite,’’ 1915. 


Dr. R. L. Sherlock—Datum-lines in English Keuper. 121 


have already been published.’ The two latter mines and quarries 
belong to The Vale of Belvoir and Newark Plaster Company, the 
others to Messrs. Cofferata & Co., and my thanks are due to these 
two firms for the kindness with which they have allowed me to visit 
the sections, and for information. The distance from Beacon Hill, 
Newark, to Hawton is about 2 miles; Hawton and Bowbridge are 
only separated by some 350 yards, Bowbridge lies slightly to the 
east of Hawton, and in consequence of the easterly dip higher beds 
are visible at Bowbridge than at Hawton. From Bowbridge to 
Orston is about 7 miles. The Orston mine was at the time (1915) 
disused and the details of the section were given by the proprietor. 
Except at Orston the seams of gypsum are visible throughout the 
extensive sections (the Hawton quarry is about 700 yards long), and 
occur in the same order and at approximately the same distance 
apart, and there.is no doubt that they are definitely bedded deposits. 
Additional evidence of this is furnished by the fact that some of the 
accompanying beds can be correlated in different sections. Thus, the 
‘Riders’ (see Sections, p. 122), a nodular band of gypsum resembling 
a line of flints in chalk, occurs between the Top and Middle White 
Rocks, at Newark, at Hawton, and at Bowbridge; while the 
‘‘Bastard”’, a 3 ft. band of mixed green marl and gypsum, occurs 
7 feet above the Top White Rock at the same three localities. 

At Beacon Hill, Newark, some 664 feet of strata intervene 
between the Top White Rock and the base of the Rhetic beds.’ At 
Bowbridge there are 45 feet of strata exposed above the rock, and, in 
addition, a certain amount crops out under alluvium between the 
section and the Rheetic escarpment. At the constant dip prevalent 
over the district there is room for about 20 feet of strata in this gap, 
giving approximately 65 feet of strata up to the Rhetic base, or 
practically the same as at Newark, 2 miles away. At Orston there 
is recorded 39 feet of strata above the Top White Rock. Un- 
fortunately the section cannot now be seen, and the exact thickness 
of strata cropping out between it and the Rhetic base, cut through 
in the railway about 20 yards away, cannot be measured exactly. 
It would appear that the total thickness of strata between the Top 
White Rock and the Rhetic is a few feet less at Orston than at 
Newark. 

This evidence shows that between Newark and Orston the Rhetic 
is separated from the Top White Rock by a belt of strata of 
practically constant thickness. In the absence of complete sections 
it cannot be said that the thickness of the intervening strata is 
absolutely constant, but it can be said that throughout the distance 
of 93 miles the variation is not more than a few feet and may be 
quite absent, and that over a distance of 2 miles there is no variation 
whatever. Hxact correspondence in thickness of the marl beds in 
any two sections is not to be expected, as we may see from the 
sections figured, and any small differences in the thicknesses of the 
intermediate strata are more likely to be due to variation (and cancel 
themselves out) than to an unconformity, however slight, of the 

1 A. J. Jukes-Browne, Geology of the South-West part of Lincolnshire 
(Mem. Geol. Surv.), 1885, p. 18. 


& 


122 Dr. R. L. Sherlock—Datum-lines in English Keuper. 


Rhetic. Hence we may conclude that in this district the Rhetic is 
strictly conformable to the Keuper. 

Away from the Newark-—Orston district we cannot trace the 
individual beds of gypsum. We do find, however, that a belt of 
strata containing beds of gypsum occurs at approximately a constant 
distance below the Rheetic beds at numerous places between Middles- 
brough and Somerset. The gypsiferous belt is of varying thickness, 
being better developed in some places than in others, and we cannot 


NEWARK HAWTON, BOWBRIDGE ORSTON 
Aliuvrtum 


wilh Fed 
GYPSUM 


Marl wil L 
earse 
Alluvum few cakes GYPSUM PRE | 
Marl with of GYPSUM Marwith\o ; 
GyPSUM Balls of | 2 
Grey eRe __--— -— Grey GYPSUM |S 5 
-=5520_ Fock : rock 
astard? ~~ cee ere ipo Sarl wilh 2 
imuxedgreen marlkgyp _ bastard _ Balk of 
ae 5 Titec Marl with Ked GYR 
GYPSUM «ee GYPSUM Marl with 
fe e ‘cakes’ Balk of GYPSY 
Sopwtite rn = = SSSSllit SRW Fock 
ee eee Ballsof GIP 
TMUGION EN AP STi a eo all of GYPSY 
TMI TOOCEEESY. ~~ a “tego white Fock 
2D O>| Btue tock ~~ - ely 
Ae we toch 
Bottant while rock Bue 
Marl with Bottom while ro 
GYPSUM ao 
Blue rock 
Marl 


Sections in the Newark District of Nottinghamshire. 
Scale : 1 inch represents 18 feet. 


pick out a particular seam as a datum-line over a large area. But 
the belt as a whole may be so treated, if its approximate middle be 
taken. North of Newark the belt becomes more poorly developed,’ 
but it has been worked in the past at Laughterton, near Gainsborough ; 
at Winton, Stank Grange, Hallikeld, and Little Sessay, near 
Northallerton; and at Eston, near Middlesbrough. Proceeding in 
the opposite direction, it is worked at Cropweli Bishop, Notts. In 


Dr. B. L. Sherlock—Datum-lines in English Keuper. 128 


Leicestershire the gypsiferous belt is seen at Thurmaston Brickyard 
and at Gipsy Lane Brickyard,’ Leicester; but between Cropwell 
Bishop and ‘Tutbury in Staffordshire the lower horizon of gypsum (to 
be mentioned later on) is economically the more important one. 
Near Penarth, in Glamorgan, near Yate, in Gloucestershire, and 
near Watchet, in Somerset, the upper horizon is being, or has been, 
worked. 

It is remarkable that although on the west side of Watchet 
gypsum is abundant enough to be quarried, at St. Audries,” on the 
east side of Watchet, it is quite absent. Buta band of indurated marl, 
4 to 6 inches thick, occurs containing celestine, at a depth of 69 feet 
below the base of the Rhetic, i.e. at the horizon of the gypsum. 
At Yate, in Gloucestershire, the celestine deposits occur at the same 
horizon as the gypsum, but only in one place have the two minerals 
been found together. We may therefore infer that at St. Audries 
the absence of gypsum is due to the presence of celestine at the same 
horizon. : 

2. The lower horizon of gypsum is worked extensively in the 
Gotham district of Nottinghamshire and in East Staffordshire. 
A bed of gypsum, usually from 7 to 11 feet in thickness, is worked at 
Gotham, Hast Leake, Barton, Thrumpton, and Kingston-upon-Soar, 
all in Nottinghamshire, and the gypsum of Chellaston, Derbyshire, 
probably belongs to this horizon. In Staffordshire the bed is from 
8 to 15 feet in thickness, and is worked in the parishes of Hanbury 
and Draycott. The bed is characterized by a ball-like structure on 
a large scale, the thicker parts of the seam representing more or less 
distinctly the sphzeroids, and the thinner parts the intervals between 
them. ‘In thickness and spheroidal structure the bed is fairly well 
marked off from other beds of gypsum in the Keuper. 

At Kast Leake the gypsum is said to occur about 150 feet below the 
Tea-green Marls. This is but a rough estimate, and the thickness of 
Tea-green Marls is not stated. The Tea-green Marls vary a good 
deal in thickness, but at Newark, where they are best seen, there is 
about 18 feet of them. This would give roughly 168 feet of strata 
between the gypsum and the Rhetic beds. At Glebe Mine, Gotham, 
the details of a ventilating shaft have been preserved,*® and show 
a thickness of 160 feet between the gypsum and the Rheetic beds. 
At a depth of 86 feet below the Rheetic a thick bed of gypsum was 
found, and this is probably part of the upper belt. At Fauld, near 
Tutbury, Staffordshire, the gypsum is thought to be about 145 feet 
below the top of the Keuper Marl. The discrepancy between the 
depth here and at Gotham may be due to various causes, but a likely 
one is that, as Rheetic beds were not separated from Lias when the 
district was mapped, about 1852, it is probable that the Tea-green 
Marls have been put with them in the Lias, in accordance with the 
then current idea that the green marls were part of the Rhetic. If 


1 For full section see T. O. Bosworth, The Keuper Marls around Charnwood, 
Leicester, 1913, p. 117. 

2 Vertical sections, Geol. Surv., Sheet 47, No. 6. 

* Special Reports on the Mineral Sources of Great Britain (Mem. Geol. 
Sury.), vol. iii, p. 26, 1915. 


124 Dr. R. L. Sherlock—Datum-lines in English Kewper. 


so, the depth of the gypsum below the Rhetic might be much the 
same as at Gotham. In Warwickshire gypsum occurs at Spernall 
Park, 75 miles north-west of Stratford-upon-Avon, at about 150 to 
160 feet below the Rhetic beds, but not in workable quantities. 
Owing te the scarcity of measured sections we cannot be certain that 
this second horizon occurs at a constant depth below the top of the 
Keuper—it is only probable. 

The question of the mode of origin of gypsum is a he one and 
cannot be gone into here. It suffices that the gypsiferous deposits 
we are dealing with are clearly, in the main, primary strata, although 
secondary gypsum is also present, and the deposits represent some 
special condition, occurring at a definite period over a wide area and 
therefore of chronological value. 

The occurrence of these two belts of gypsiferous strata at 
approximately constant depths below the Rhetic beds points 
strongly to the conformability of the Rheetic to the Keuper. The 
sharp line of demarcation between them is therefore no more than 
the result of the waves of the open sea entering the Caspian-like 
sea in which the Keuper was deposited and washing up the 
Keuper mud. 

The highest beds of the Keuper are the Tea-green Marls, at one 
time considered to be part of the Rhetic beds. If the Rhetic were 
unconformable to the Keuper it would follow that the Tea-green Marls 
occurred at varying positions in the Keuper Series, and it would be 
highly probable that the green colour is the result of alteration of 
red beds by secondary changes. But if, as the evidence given above 
seems to show, the Rhetic is conformable to the Keuper, then the 
Tea-green Marls everywhere occur at about the same horizon, so far 
as the upper boundary is concerned, and there is a probability that 
their colour is original. The green.strata, however, vary greatly in 
thickness, for instance at Colston Bassett, Nottinghamshire,’ they 
are only about 15 feet thick, whereas near Watchet * they are 115 feet 
in thickness. Also the base is often indefinite, sometimes dying out 
downwards raggedly, sometimes ending in alternate beds of green 
and red marl. Hence, the top being fixed, the base must occur at 
somewhat different horizons in different places. 

One result of the wide variations in thickness of the Tea-green 
Marls is that the higher gypsum horizon is sometimes below it, in 
red strata, as in Nottinghamshire, and sometimes well within the 
green beds, as at Watchet. It appears that the conditions of 
formation of green marl were neither inimical nor helpful to the 
formation of gypsum. 

The green strata seem to indicate the coming of the open-sea 
conditions. The occasional presence of fossilssuch as Ostrea bristovt, 
tichardson, recorded by Mr. L. Richardson,® indicates a change in 


‘ B. Smith in Geology of the Melton Mowbray District and South-East 
Nottinghamshire (Mem. Geol. Surv.), 1909, p. 16. 

“ L. Richardson, ‘‘ The Rhetic and Contiguous Deposits of West, Mid, and 
part of Hast Somerset”: Quart. Journ. Geol. Soc., vol. lxvii, pp. 19-20, 1911. 
* L. Richardson, ‘‘ The Rheetic and Contiguous Deposits of Glamorganshire’’ 

Quart. Journ. Geol. Soc., vol. lxi, p. 399, 1905. 


Dr, A. Morley Davies—On Isostasy. 125 


the water, perhaps due to the washing in at spring-tides of waves 
from the open sea, now almost ready to break into the landlocked 
area in which the Keuper Marl was formed. It is interesting to 
note that, north of Nottingham, Tea-green strata also occur, at the 
bottom of the Keuper, unconformable to the Bunter below, and 
perhaps representing the Jast traces of brackish water before the area 
was finally cut off from the open sea. 


V.—A. Nore ow Isosrasy. 
By A. Morey Davies, A.R.C.S., D.Sc., F.G.S., Imperial College of Science 
and Technology. 

f{\HERE is a regrettable tendency to looseness of thought among 

geologists on the subject of isostasy. I give no quotations in 
support of this assertion, firstly because, being always in the form of 
casual allusions to the principle, they would require long hunting 
down; and secondly because, if given, they would fasten upon a few 
individual geologists a criticism which: should be more general. 
The usual form in which the looseness of thought shows itself is in 
explanations of shallow-water deposits of thickness greater than 
their depth of accumulation. We are frequently told that such 
thick deposits result from local subsidence due to the loading of the 
sea-floor by the great weight of sediment, and reference is made to 
the principle of isostasy as justifying this explanation. 

The principle of isostasy is that the distribution of mass in 
a heterogeneous earth tends to be so adjusted that variations of the 
surface from the theoretical ellipsoid of rotation are compensated by 
differences of density in the deeper parts of the underlying crust. 
The continents are supported on a mass of less density, the oceans on 
a mass of greater density; and similarly for the mountain-chains and 
ocean-troughs in relation to the average of the continents and oceans 
respectively. 

This compensation of excess of matter at the surface by defect of 
density below and of defect at the surface by excess of density 
below is termed isostatic compensation, and the adjustment of the 
earth’s crust towards a condition of isostatic equilibrium caused by 
gravitative stress is termed isostatic adjustment. Compensation is 
supposed to be complete within a comparatively shallow depth 
(122 kilometres according to the later calculations of the United 
States Coast and Geodetic Survey), and the mass of matter under 
any protuberant or depressed area from sea-level down to this depth 
is termed the supporting column of that area. 

Now imagine the adjacent parts of an ocean and continent, in 
perfect isostatic equilibrium. Denudation removes material from 
the continent, which is deposited on the ocean bottom. Isostasy is 
disturbed, and if isostatic adjustment takes place the tendency will 
be for the continent to rise, the sea-floor to sink, and material in the 
depths to ‘‘ flow ”’ from the supporting column of the ocean into that 
of the continent. But how far can these movements go? ‘The 
oceanic supporting column is composed, ex hypothes?, of material of 
more than average density; the material deposited, being uncon- 
solidated sediment, is of less than average density. The former we 


126 Dr. A. Morley Davies—On Tsostasy. 


may estimate to have a density of 3. As to the latter, the average 
density of sedimentary material (making no allowance for porosity) 
is 2°7. Porosity to the extent of 20 per cent brings the density of 
unconsolidated dry sediment to about 2°16 (Indian geologists give 
2°2 as the average for the Siwalik rocks, so 2°16 is not too low for 
quite unconsolidated material). But we have to deal with sediment 
saturated with sea-water to the extent of the 20 per cent of its 
volume allowed for porosity; this brings the density up to 2°36. 
The sediment, however, displaces sea-water as it accumulates, and 
though it thereby raises the sea-level, that rise, being distributed 
over the whole ocean, is negligible. The effective density for the 
calculation of isostatic overloading is therefore 1°36. 

A mass of sediment on the sea-bottom, then, would depress the 
latter to the extent of 1, or about nine-twentieths of its own 
thickness, ¢f the isostatic adjustment 1s perfect and immediate. Thus 
at whatever depth deposition begins a thickness equal to ar 
or about 1:83 times that depth, could accumulate before the sea was 
completely silted up. Taking the 100-fathom line as the limit 
between deep and shallow water, shallow-water deposits could 
accumulate, under conditions of the most delicate isostatic adjust- 
ment, to a thickness of only about 1,100 feet before accumulation 
became inter-tidal or subaérial in character, and in that thickness 
there would be a gradual transition from deposits of 100-fathom type 
at the bottom to littoral deposits at the top. If we suppose the 
isostatic adjustment to be spasmodic instead of continuous, there will 
be an alternating character in the sediments instead of a gradual 
transition, but the total thickness will be, if anything, diminished, 
since the adjustment will be less perfect. 

It may be objected that 8 is too high a figure for the density of 
the supporting column. If we take it at so improbably low a figure 
as 2°7, the maximum possible thickness is only increased from 1,100 
to just over 1,200 feet. 

But what right have we to assume such delicate isostatic adjustment 
as these calculations imply? The theory of isostasy originated in 
America, where the careful investigations of Hayford and the United 
States Coast and Geodetic Survey showed that there is an approxima- 
tion to isostatic equilibrium—or, at least, that there is such on a 
certain assumption as to the depth of compensation. When Crosfield 
investigated India on the same assumption he found that country to 
diverge considerably from isostatic equilibrium. ‘This was naturally 
explained by the immense crustal disturbances in that region, which, 
reaching a maximum in the Miocene period, have not yet entirely 
died out. If these great disturbances have not been capable of full 
isostatic adjustment in the long period of time that has elapsed 
since the Miocene period, can we justifiably assume that the gentle 
accumulation of sediment is continually and immediately adjusted ? 

Without venturing into any discussion of the complicated subject 
of the rigidity of the earth’s crust, I may call.attention to the view 
of Professor Barrell that the strength of the crust is ‘‘twenty, fifty, 


Notices of Memoirs—A Hycena-den in Ireland. 127 


or even a hundred times greater than that advanced in recent years 
by the champions of high isostasy”’.' If this opinion, the result of 
very careful mathematical studies, be put aside as a pendulum- 
swing in the opposite direction to that of the isostasy enthusiasts, 
the adoption of a mean position would still diminish our belief in 
the possibility of explaining great thicknesses of shallow-water 
deposits by the sole process of isostatic adjustment. 


NOTICHS OF MEMOTRS. 


Se 
1.—A Hyawa-pen in [RELAND. 


Tue Expnoration oF Casrnepook Cave, Counry Cork: BEING THE 
Turrp Report FROM THE COMMITTEE APPOINTED TO EXPLORE 
Trish Caves. By R. F. Scuarrr, H. J. Srymour, and KH. TY. 
Newton. Proc. Roy. Irish Acad., vol. xxxiv, sect. B, No. 3, 
pp. 33-72, pls. v—vii, January, 1918. 


HE last work of the accomplished and enthusiastic Irish cave- 
explorer, the late Mr. R. J. Ussher, was the careful examination 
of the Castlepook cave, co. Cork, which is of much interest as being 
further south than any cave previously dealt with in Ireland. It is 
formed as usual by the widening of joints in the Carboniferous 
Limestone, and the deposits on the floor consist not only of the 
ordinary cave-earth and stalagmite but also of sand and gravel 
introduced by water. The cave, in fact, must have been subjected 
to numerous inundations, and it can never have been suitable for 
habitation by man. As described by Professor H. J. Seymour, all 
the pebbles in the introduced gravel are of local origin, whereas 
many of those in the boulder-clay of the surrounding country are 
granites from a considerable distance. Some of the deposits 
containing bones may therefore be of pre-Glacial date. The lowest 
layer yields especially remains of a brown bear (Ursus arctos) as 
large as the American Grizzly—certainly not the familar cave-bear. 
The next layer in some places is crowded with the bones, teeth, and 
coprolites of the cave-hyzna, with remains of the reindeer and the 
young mammoth which it dragged into the cave for food. The 
discovery of a hyzna-den in Ireland is especially interesting; and 
the proof that the hyena and reindeer were contemporaneous is 
important. As might be expected, all the remains of the reindeer 
are very fragmentary; but Dr. R. F. Scharff, who reports on the 
mammals, has studied all the known Irish specimens of reindeer, 
including a fine skull from a bog near Ashbourne, co. Meath, and 
concludes that they represent a peculiar race which he names 
Rangifer tarandus hibernicus. Among truly Pleistocene mammals 
there are also the Arctic fox, wolf, hare, Scandinavian lemming, 
a new form of Arctic lemming, and the Irishdeer. Numerous bones 
of birds, determined by Mr. EK. T. Newton, also occur, but do not 
include any extinct or noteworthy species. Asi S eos 
1 “* The Strength of the Harth’s Crust’’: Jowrn. Geol. (Chicago), vol. xxii, 
p. 313, 1914. ‘lhe whole investigation is in eleven sections, scattered through 


128 Notices of Memoirs—Fossil Man vn South Africa. 


Il.—Fossiz Man in Sourn Arnica. 


1. Pretiminary Nore on tae Ancient Homan Sxkui-remarns 
FROM THE ‘l'ransvaat. By S. H. Haveuron. With notes 
appended on Fragments of Limb-bones, by R. B. THomson, and 
Fragments of Stone, by L. Périnevry. Trans. Roy. Soe. 
S. Africa, vol. vi, py 1-14, pls. i-x, 1917. 

2. Fossizr Man in Soura Arrica. By Roserr Broom. American 
Museum Journal, vol. xvu, pp. 141-2, 1917. 


ELL-FOSSILIZED portions of a human skeleton were 
discovered in 1913-14 in a cultivated field on the farm of 
Kolonies Plaats, Boskop, in the Potchefstroom district of the 
Transvaal. The greater part of a skull-cap, a temporal bone, the 
horizontal portion of the left mandibular ramus, and some fragments 
of limb-bones were recovered; but it is uncertain whether the 
remains represent a burial, and there are no associated fossils or 
implements to indicate their age. A preliminary description of these 
interesting specimens is now published and helps to dispel some 
of the sensational illusions which were derived from newspaper 
reports at the time of the discovery. 

The skull is rather thick, its thickness at the parietal boss being 
13 to 14mm. _ Its brain-capacity is also remarkably large, probably 
not less than 1830c.c. he cephalic index is about 75, so that the 
specimen is almost dolichocephalic. The forehead is steep, without 
prominent brow-ridges; but the temporal bone is primitive in the 
shallowness of the glenoid fossa for the mandibular articulation and 
the prominence of the supramastoid ridge. The mandible seems to 
have had a prominent bony chin, and the total length of the molar- 
series must have been as short as that of the modern European, less 
than that of the Australian. The second molar, typically modern 
human, is the only tooth preserved; and the alveoli of the other 
teeth are too imperfect to determine much of their proportions. On 
the whole, Mr. Haughton thinks it ‘‘ possible that the Boskop man 

was a mem ber of a race which ultimately developed into the 
Bantu type”’ 

The limb-bones found with the skull are too imperfect for 
discussion, especially in their present encrusted state, and the three 
plates of photographs devoted to them are not illuminating. 
According to Dr. Péringuey, no stone unplemenes have yet been 
met with at the same spot. 

Dr. Broom expresses the opinion that the Boskop man is 
intermediate between Hoanthropus and the early African type of 
man. In fact, he considers there is ‘‘ no doubt that the canine was 
about as large as in the jaw which he still believes belongs to the 
Piltdown skull’. He also thinks the incisors were much larger 
than in modern man. Mr. Haughton’s description and figures, 
however, lend no support to these views. 

J itSho NA 


Notices of Memoirs—Ice Age and Antarctic Research. 129 


II].—Tuer Bearrne oF THE Facts REVEALED By Anrarctic ResEaRce 
UPON THE ProBiEMS oF THE Ice AcE.' By Marspen Manson, 
C.E., Ph.D., Mem. Amer. Soc.C.E., San Francisco, California. 
From Science, n.s., vol. xlvi, No. 1200, pp. 639-40. 


ECENT Antarctic explorations and researches have yielded 

significant evidence regarding the problems of the Ice Age, and 

of the similarity of the succession of geological climates in polar 
with those in other latitudes.’ 

These researches have been prosecuted to the ultimate limit of 
courage, devotion to duty, and endurance—the noble sacrifice of life 
—as in the cases of Captain Scott, R.N., and his devoted companions 
and members of the expedition of Sir Ernest Shackleton. 

The data secured by these expeditions are alone sufficient to 
establish the following premises :— 

1. That Antarctic ice, although covering areas several times larger 
than all other ice-covered areas, is slowly decreasing in extent and 
depth. 

2. That the same succession of geological climates have prevailed 
in Antarctic as in other latitudes.’ 

So vital are these evidences of the retreat of Antarctic ice that it 
may be well to briefly quote or refer to the most prominent instances : 
‘¢ All these evidences and many others which space will not allow 
me to mention lead up to one great fact—namely, that the glaciation 
of the Antarctic regions is receding.* The ice is everywhere 
retreating.» The high level moraines decrease in height above the 
present surface of the ice, the débris being two thousand feet up 
near the coast and only two hundred feet above near the plateau. 
(Scott’s lecture on the great ice barrier.*)”’ 

This observation applies to an ice-covered area of over 116,000 
square miles. 

Mr. Griffith Taylor notes the recession of Dry Valley Glacier 
twenty miles from the sea below Taylor Glacier.’ 

Mr. Taylor also notes and speaks with confidence of the passage of 
the Ice Age from Antarctica.* 

In speaking of the evidence of ice retreat over Antarctic areas 


1 This term as used by the writer refers to the Great Ice Age of Pleistocene 
time. He holds that the occurrences of ice as a geologic agent of magnitude 
during eras preceding the Pleistocene were not ‘‘worldwide’’ nor as 
“* phenomenal’’, nor were they preceded, accompanied, nor followed by 
conditions as significant as corresponding phenomena of the Ice Age. Compte 
Rendu du XIéme Congrés Géologique International, Stockholm, 1910, 

. 1105. 
Ps Scott’s Last Expedition, vol. ii, p. 206. 

> This part of the evidence is not considered in this paper except inferentially 
as bearing upon the general subject. 

4 Scott, The Voyage of the‘‘ Discovery’’, vol. ii, p. 416. See also pp. 423-5, 
and sketch-map of ice distribution, p. 448. 

> Scott, Nateonal Antarctic Expedition, 1900-1904, vol. i, p. 94. 

8 Scott’s Last Expedition, vol. ii, p. 294. 

7 Thid., p. 286. 

8 Ibid., p. 288. See also photograph following pp. 286, 292. 


DECADE VI.—VOL. V.—NO. III. 9 


130 Notices of Memoirs—Ice Age and Antarctic Research. 


explored by him, Sir Ernest Shackleton said: ‘‘Some time in the 
future these lands will be of use to humanity.” ? 

This impressive and conclusive evidence is corroborated by the 
greater and still more impressive evidences of the comparatively 
recent uncovering of temperate land areas,* and the progressive 
retreat of the snow-line to higher elevations in temperate and 
tropical latitudes and towards the poles at sea-level, being far greater 
in Arctic than in Antarctic regions. We are therefore confronted 
with the conclusions— 

1. That the disappearance of the Ice Age is an active present 
process and must be accounted for by activities and energies now at 
work, and that the use of assumptions and hypotheses is not 
permissible. 

2. That the rates and lines of retreat are and have been determined 
by exposure to solar energy and the temperatures established 
thereby ; and by the difference in the specific heat of the land and 
water hemispheres. 

3. That the lines of the disappearance of ice are not conformable 
with those of its deposition, and mark a distinctly different exposure 
and climatic control from that which prevailed prior to the 
culmination of the Ice Age. 

4. This retreat also marks a rise in mean surface temperature 
along these new lines, manifestly due to recently inaugurated 
exposure to solar radiation and also the inauguration of the trapping 
of heat derived from such exposure; which process is cumulative 
and has a maximum not yet reached. 

The researches under the direction of Captain Scott and Sir Ernest 
Shackleton have therefore very rigidly conditioned any inquiry as to 
the causes of glacial accumulation and retreat. These conditions 
are CORRECTIVE and DIRECTIVE—corrective, in that they have entirely 
removed any doubts as to the alternate glaciation of the poles under 
the alternate occurrence of aphelion and perihelion polar winters by 
the precession of the equinoxes, as advanced by Croll; directive, in 
that they have imposed an appeal to energies now active as causes of 
retreat, and divested the problem of resorts to the fascinating but 
dangerous uses of suppositions and hypotheses. a 

They have, moreover, pointed out with unerring accuracy the 
vital conclusion that the same energies which have but recently 
converted the glacial lake beds of Canada into the most productive 
grain fields of the world will in time convert the tundras of to-day 
into the grain fields of to-morrow. * = 


1 Address to the Commonwealth Club, San Francisco, Calif., November 7,. 
1916. 

> Slight fluctuations in the retreat of the small residual glaciers in temperate 
latitudes are noted in the reports of the Commission on Glaciers of the 
International Geological Congress by Professor Harry Fielding Reid. But 
the great measures of the progressiveness of glacial retreat are in the past 
disappearance of the Pleistocene ice-fields of temperate latitudes and the 
present retreat in the Antarctic and Arctic regions. 

3 See also Compte Rendu du XIéme Congrés Géologique International, 
Stockholm, 1910, p. 1102. 


Notices of Memoirs—Yorkshire Naturalists’ Union. 1381 


The bearing of this conclusion upon the ultimate development of 
the human race is so far-reaching in its consequences that the great 
sacrifice of life attendant upon the prosecution of these researches 
stands forever as a memorial in the correction of the erroneous and 
widespread conception that the earth is in a period of refrigeration, 
desiccation, and decay; and establishes the conclusion that it is in 
the springtime of a new climatic control during which the areas 
fitted for man’s uses are being extended and that the moss of polar 
wastes will be replaced by rye and wheat. 


1V.—Joun Micuett anp Martin Simpson. 


IR ARCHIBALD GEIKIE read as his Presidential Address to 
the Yorkshire Union of Naturalists, 1917,,a memoir on John 
Michell (1724-93), one of the pioneer geologists of this country. 
The memoir, written in Sir Archibald’s delightful style, appears in 
full in the Yorkshire Naturalist for January, 1918. 

Mr. Thomas Sheppard, remembered recently for his able memoir 
on William Smith, read to the Yorkshire Geological Society a paper 
on Martin Simpson (1800-92) (see Gror. Mac., February, 1918, 
p. 82). 


RHEVIEWwS- 


I.—Sanps usEep In MANUFACTURES. 


1. A Memorr on British Resources oF SANDS SUITABLE FoR Gtass- 
makING, witH Nores on cerrain Crusuep Rocks anp REFRACTORY 
Mareriats. By P. G. H. Boswetzt. pp. 92. London: Longmans, 
Green & Co. 1916, 

2. A Supprementary Mrmorr on British Resources oF SanDs AND 
Rocks vUsep IN GULAss-MANUFACTURE, WiIrtH NorEs ON CERTAIN 
Rerracrory Materrarts. By P.G.H. Boswrert. pp. 92. London: 
Longmans, Green & Co. 1917. 

3. Brrrish Guass-sanps; THEIR Locarton anp CHaracreristics. By 
P. G. H. Boswert. From the Transactions of the Society of 
Glass Technology, vol. i, 1917. 

4. Norges on American Hica-crapr Guass-sanps. By P. G. H. 
Boswrtt. From the Transactions of the Society of Glass Tech- 
nology, vol. i, 1917. 

5. Some Gxotoatcat Caaracrers or Mourpine-sanps. By P.G. H. 
Boswett. Reprinted from the Foundry Trade Journal, August, 
ON c 

6. Sanps vusep IN MeratturercaL Practice, with CoMPARATIVE 
Nores oN THOSE USED IN GLASs-MANUFACTURE. By P. G. H. 
Boswett. Reprinted from the Journal of the Society of Chemical 
Industry, 1917. 


\HE petrology of the sedimentary rocks is a subject that has been 
unduly neglected until recent times. Considerable attention 

was devoted to the matter by Professor Bonney, mainly in connexion 
with cemented types which could be studied in their slices. ‘he 
early investigations of Retgers, Dick, Thoulet, Bréon, and others may 


132 Revriews—Prof. Boswell—EHconomic Uses of Sands. 


also be mentioned, but the study on modern lines of the unconsolidated 
sediments may be said to date from the classical work of Dr. Thomas 
on the Trias sands of the West of England. Since then much work 
of high scientific value has been carried out by Mr. Crook, 
Mr. Bosworth, and other. Asis well known, Professor Boswell has 
made an extensive study of the mineral constitution of sediments, 
and when the investigation of sands became a matter of urgent 
practical importance his knowledge of methods and technique 
rendered most valuable service. The six publications above cited 
contain the results of work carried out by him at the instance of the 
Ministry of Munitions. The first on the list has already been 
reviewed in these pages and is only included here for the sake of 
completeness. 

On the outbreak of war a large part of the imported supplies of 
sand and other similar materials failed, and manufacturers were 
driven by sheer necessity to inquire into the British resources that 
might be available to replace them. Sand is used on a large scale 
for many industrial purposes: in metallurgy it is employed for 
moulding and as a refractory material ; it is the fundamental necessity 
of glass-making, and it is also used for building, for filtration, as an 
abrasive, and for many other purposes. The author describes very 
fully the characters essential for each particular purpose. For glass- 
making the criterion is purity: a sand adapted for high quality glass 
should consist as nearly as possible of pure quartz, while what are 
commonly known as ‘‘heavy minerals’ should be in the smallest 
possible quantity. Iron compounds spoil the colour, while such 
infusible substances as zircon and rutile produce flaws. Recent 
research has shown that the presence of a small amount of alumina is 
not really deleterious, hence felspar up to a certain proportion is not 
objectionable. Hvenness of grain is also important, since it leads to 
uniform and regular fusion. The requisites for a moulding sand are 
that it should consist mainly of fairly large grains with a sufficient 
amount of very fine binding material, thus having a large water- 
holding capacity. The sands of the Trias best fulfil these require- 
ments. Other sands are now often employed with an artificial 
binding material. 

No British glass sands are quite equal in quality to the very best 
imported kinds, such as those of Fontainebleau and Lippe, but we 
possess material suitable for even the best kinds of optical glass, 
while our reserves of sand available for common glass are practically 
inexhaustible. 

The properties of a sand depend on several factors, of which the 
most important are chemical and mineralogical composition and 
texture. The first two are obviously interdependent, and in their 
investigation the methods devised for geological purposes are of the 
utmost value. The texture, which is equivalent to size of grain, is 
determined by mechanical analysis, using the methods devised for the 
study of agricultural soils. It is clearly shown that the state of 
division is a matter of the greatest practical importance, since it 
controls to a very large extent the physical properties on which so 
much of the value of the sand for metallurgical purposes depends. 


Reviews—A. L.du Toit—Phosphates of Saldanha Bay. 133 


Very large quantities of sands, crushed rocks, clays, and other similar 
materials are also employed as what may be called for convenience 
‘‘refractories’’ in many industrial processes carried on at high tem- 
peratures. This subject is dealt with briefly by Professor Boswell. 
It is known, however, that an investigation on a large scale of British 
resources of refractories has been carried out by the Geological Survey, 
and the publication of their results will be awaited with much 
interest. 

It is apparent that the detailed study of sands, undertaken 
originally for purely geological purposes, has proved of great practical 
and economic use, thus affording one more instance, if one were 
needed, of the ultimate value of pure science for industrial ends, a 
fact which has long been recognized and acted on in Germany, but 
which the people of this country are only just beginning to realize. 

R. H.R. 


I].—Rerorr on THE PuospHates or SatpanHa Bay. By A. L. 
pu Torr. Memoir 10, Geological Survey of the Union of South 
Africa. pp. 34, witha map. Pretoria, 1917. Price 2s. 6d. 


(J\HE region described in this report lies on the west coast of Cape 

Colony: the country consists of granite, quartz-porphyry, 
surface limestones, and blown sand. Along the coast are raised 
beaches. In connexion with these a small quantity of good quality 
phosphorite has been located, while in addition there are great 
masses of phosphate of alumina and iron of much less agricultural 
value. It is hoped that a special method of treatment that has been 
devised will enable this phosphate to be used as a fertilizer. The 
origin of the phosphate is interesting. It is due to the percolation 
of solutions from guano into limestones, shell-beds of the raised 
beaches, and other detrital deposits. Even boulders and chips of 
granite and porphyry are more or less phosphatized. The whole 
phenomenon is compared by the author with Sir J. J. H. Teall’s 
classical description of Clipperton Atoll, where a trachyte has been 


phosphatized by a similar process. 
R. H. R. 


IlI.—Reporr on tHE Burtpine and ORNAMENTAL Srones oF Canada. 
Vol. IV: Provinces of Manitoba, Saskatchewan, and Alberta. By 
Wittiam A. Parks. pp. xiv+3338, with 56 plates and 7 drawings 
and maps. Ottawa: Government Printing Bureau, 1916. 


IYVHIS, the fourth, volume of the excellent series of reports on the 

building and ornamental stones of Canada which is issued under 
the auspices of the Canadian Department of Mines, deals with the 
products of the three provinces of Manitoba, Saskatchewan, and 
Alberta, and is from the pen of Dr. W. A. Parks. As he states in 
the letter of transmittal to the Director of the Mines Branch, in the 
earlier volumes attention was paid only to actual quarries, whereas 
in the present one the scope has been enlarged so as to include 
possible sources of supply which have not yet been exploited, and 
‘in consequence of this change of plan the report has reached 


134 | Reviews—Canadian Building Stones. 


a length, compared with the earlier volumes, which is somewhat out 
of proportion to the relative importance of the building stone 
industry in the three Provinces under consideration ’’. 

In the opening chapter the author gives a general account of the 
building stones of the three provinces, and briefly explains the 
nature of the physical tests to which the several samples have been 
subjected in order to ascertain their suitability for the purpose and 
their capacity to withstand weathering. The determinations made 
included the specific gravity, weight per cubic foot, porosity, ratio of 
absorption, coefficient of saturation, crushing tests (dry, wet, and 
frozen), transverse and shearing strength tests, and corrosion, 
drilling, and chiselling tests. In the corrosion test cubes of the 
stone under investigation were suspended in water through which 
carbonic acid gas and oxygen were passed, and the whole operation 
took four weeks, the water being changed twice weekly. Mr. MacLean, 
who was in charge of this part of the investigation, discovered that 
the rate of solution of limestone was materially affected by the 
pressure maintained in the containing bottle, and he devised special 
apparatus for keeping the pressure constant. The provinces in 
question do not as yet yield much diversity of building stone, the 
present supply being confined to the mottled limestones of Tyndall in 
Manitoba and the Paskapoo Sandstones of Alberta, but there are 
possibilities of other occurrences of these stones being worked as 
soon as the demand justifies it. ‘The eastern ranges of the Rocky 
Mountains, which come within the scope of the book, cannot be 
drawn upon for building stone to any great extent, because the 
limestone of which they chiefly consist is so hard and shattered as to 
be unsuitable for the purpose. 

A concise discussion of the geology of the region is the subject of 
the following chapter. As is well known, its most conspicuous 
physical character is found in the great prairie plains which stretch 
from the rocky district of the Manitoba lakes and Lake Winnipeg on 
the east to the foothills of the Rocky Mountains on the west, and 
building stone can only be looked for on the margin of the plains 
owing to the thickness of the soil over the whole of them. In the 
remaining eight chapters the various rocks furnishing building stones 
are considered in detail, commencing with the limestones and sand- 
stones, and passing on to the miscellaneous rocks and ornamental 
stones; while the physical characters of the stones and statistical 
data are tabulated in appendices. 

The Tyndall Limestone has been used for such important buildings 
as the Parliament buildings at Regina and the Post Office at Moose 
Jaw in Saskatchewan, and the Post Office at Lethbridge in Alberta ; 
while the Paskapoo Sandstone has been selected for the Court House 
at Lethbridge, the Royal Bank at Medicine Hat, the Court House and 
Parliament buildings at Edmonton, Knox Church, the Land Titles 
building, City Hall, and the Carnegie Public Library at Calgary, in 
the province of Alberta. Photographs of all these buildings are 
included among the numerous illustrations. There are also six 
plates in colour showing sections of limestone, granite, and sand- 
stone. 


Reviews—Geology of Transkei, South Afroca. 1385 


IV.—Tue Gerotogy or Parr or tHE Transxer. EXpLanaTION oF 
Suerr 27, (Carn) Mactear—Umrata. By A. L. pu Toir; with 
an introduction by A. W. RogezErs, Geological Survey. pp. 32. 
Pretoria, 1917. Price 2s. 6d. 

fF\HIS memoir is to accompany the map on the scale of 3°75 miles 

to an inch, prepared by Dr.du Toit. The map contains a very 
large amount of detail, considering the character of the country, 
which includes part of the great Drakensberg escarpment and rises 
to a height of some 9,000 feet. The area surveyed is entirely com- 
posed of the rocks of the Karroo system and their accompanying lavas, 
ashes, and intrusions. The whole of the Karroo system is repre- 
sented and reaches the great thickness of 14,000 feet, exclusive of 
the Stormberg lavas, which are about 3,000 feet more. The strata 
are normal in character and contain plants and reptiles, hence 
horizons can now be fixed with fair accuracy, since it has been found 
possible to establish reptile zones in this formation. Some coal- 
seams of workable thickness are found in the Molteno beds. A con- 
siderable number of volcanic necks have been located, and the Karroo 
dolerites have been intruded on an enormous scale, chiefly in the 

Keea and Beaufort series. 

Perhaps the most interesting part of the memoir is the description 
of the copper-nickel bearing area of Insizwa and Tabankulu. The 
ores occur at the lower contact of great cakes of gabbro-norite, a 
special phase of the Karroo dolerites, intruded into the lower division 
of the Beaufort beds. These masses, which are about 3,000 feet 
thick, have undergone magmatic differentiation by gravity, the 
lower part being a picrite, followed by olivine-norite and norite; at 
the top there is even a little quartz as micropegmatite. The Insizwa 
mass is some ten miles in diameter. ‘lhe ores occur at the base of 
the intrusion and also to a certain extent in the country rock close to 
the contact. ‘he principal minerals are pyrrhotite, chalcopyrite, 
and pentlandite, with smaller amounts of niccolite and bornite and 
some oxidized copper and nickel minerals. Platinum has been found 
by assay up to 1 oz. per ton, but it is not yet known in what form it 
occurs. There is also a little gold. The ores were undoubtedly 
formed by differentiation from the norite magma, and the whole 
occurrence is very similar to the famous nickel deposits of Sudbury, 
in Ontario. From the geological relations it appears highly probable 
that the amount of ore will increase in depth when followed below the 
intrusion. The deposits are now being actively developed, and it 
seems probable that they will eventually prove to be of great com- 
mercial value. 


ebay. 


V.—Low-tTemPrrature Formation oF ALKALINE Freispar 1N LiMe- 
stonn. By R.A. Dany. Proceedings of the National Academy 

of Sciences, vol. ili, pp. 659-65, 1917. 
UTHIGENIC Peale of felenee including orthoclase, albite, and 
perhaps microcline, have been described by various authors in 
the Jurassic limestones of the Alps and in the Chalk of the Paris 
Basin. The crystals are well-shaped, but very minute, and are 


186 Reports & Proceedings—Geological Society of London. 


supposed to have been formed on the sea-floor during the deposition 
of the sediment: in the case of the Paris Basin, at any rate, thermal 
metamorphism is excluded. With these observations Mr. Daly com- 
pares a remarkable dolomite in Alberta, probably of Pre-Cambrian 
age. It consists chiefly of grains of carbonate of rhombohedral form, 
but certain layers are heavily charged with clumps and interlocking 
grains of glass-clear orthoclase, from 0°01 to 0:05 mm. in diameter, 
and without good crystal form. The total amount of felspar is 
estimated at 37 per cent of the rock. It is suggested that these 
crystals were also developed during the deposition of the sediment at 
the ordinary temperature. 


R. H. R. 


REHEPORTS AND PROCHEDINGS. 


I.—Geonoeicat Socrery or Lonpon. 
1. January 9, 1918.—Dr. Alfred Harker, F.R.S., President, in the 
watt Chair. 

The following communication was read :— 

“The Highest Silurian Rocks of the Clun Forest District 
(Shropshire). ” By Laurence Dudley Stamp, B.Sc., A.K.C.L. 
(Communicated by Dr. A. H. Cox, F.G.S.) 

Clun Forest is a large district—extending on both sides of the 
Welsh Border—in which Upper Silurian rocks crop out over a wide 
area, interrupted by outliers of Old Red Sandstone. The district is 
separated from the typical Silurian area of Ludlow, which lies some 
15 miles away to the east, by the great line of disturbance that 
passes through Church Stretton and Old Radnor. 

The classification adopted for the highest Silurian strata is as 
follows :— 


Thickness 
in feet. 
OLD RED SANDSTONE 3 : : Purplish-red sandstones. 
Temeside Shales. . 350 Olive-green shales with bands 


of micaceous green grit; a 
fragment-bed, with Huryp- 


TEMESIDE terid and plant remains, 
GROUP. forms the upper limit. 
Downton Castle Sandstone 110 Yellowsandstones and tilestones, 
Series. with shales and Platyschisma 
Limestones. 
Upper . 50 Green laminated flags and blue 
flagstones. 
Cae ious beds Lower . 300 een bedded calcareous 
OW 
Ceonn | flagstones. ‘ 
Rhynchonella Beds . . 300 Grey calcareous flags with 
massive blue flagstones. 
AYMESTRY f Dayia Shales . : ?300 Striped laminated shales and 
GRouP. \ mudstones. 
Lower Ludlow Shales é Dark-grey shales and indurated 
el mudstones. 
Total . : 1410 


The distribution and characters of the beds are described. The 
succession compares very closely with that in the Ludlow district 


Reports & Proceedings—Geological Society of London. 137 


itself. The main differences are: (1) that the Aymestry Limestone 
is represented by mudstones west of the great fault-line, and (2) that 
all other divisions show greatly increased thicknesses. 

There is no evidence of any stratigraphical break. On the contrary, 
the sequence is complete from the Lower Ludlow rocks up into the 
Old Red Sandstone, and the changes in lithology are usually quite 
gradual. The oncoming of the Old Red Sandstone conditions is 
discussed, with regard to their effect on the lithological and 
paleontological characters of the strata. 

The extent of Old Red Sandstone, as indicated on present maps, 
must be greatly restricted, since most of the supposed Old Red 
Sandstone has been found to belong to the Temeside Group, which 
in this district attains a great development. The Silurian age of the 
beds in question is shown by the occurrence in them of Lingula 
minima, and of characteristic Lamellibranchs, etc., also by comparison 
with similar strata in the Ludlow area. 

A comparison with other districts in which Upper Silurian rocks 
are developed shows that deposition attained its maximum along the 
Welsh Border, the thickness of the formations decreasing rapidly 
southwards and eastwards. 

On the east of the district, in the neighbourhood of the great 
fault-line, the strata are considerably folded along axes ranging 
north-north-eastwards, parallel to the main fault, with minor faults 
following the same direction. Away from the major faults the 
folding is gentler in character, and a series of folds ranging nearly 
due east and west make their appearance. Farther west the north- 
north-eastward folding and fracturing reappear. 


2. January 23, 1918.—Dr. Alfred Harker, F.R.S., President, in the 
Chair. 

The following communication was read :— 

‘On a Flaked Flint from the Red Crag.” By Professor William 
Johnson Sollas, M.A., Sc.D., LL.D., F.R.S., V.P.G.S. 

The remarkable specimen forming the subject of the paper was 
obtained by Mr. Reid Moir from the base of the Red Crag exposed in 
the brick-pit worked by Messrs. Bolton & Company near Ipswich. 

It is a fragment of a nodule of chalk-flint, irregularly rhombic in 
outline, with a nearly flat base and a rounded upper surface ‘which 
retains the whitish weathered crust of the original nodule. 

The base was formed by a natural fracture which exposes the fresh 
flint bordered by its weathered crust. 

Both upper and under surfaces of the specimen are scored with 
scratches which are mainly straight, but in some cases curvilinear. 

Two adjacent sides have been flaked by a force acting from below 
upwards, in a manner that recalls Aurignacian or Neolithic workman- 
ship. The two edges in which the flaked faces meet the base are 
marked by irregular minute and secondary chipping, such as might 
be produced by use. On the hypothesis that the flint has been flaked 
by design, these edges will correspond to the ‘‘ surface d@’utilisation ”’ 
of M. Rutot, and we should expect to find on the opposite edges of 
the flint the ‘‘ surface d’accommodation ”’, as in fact we do. 


g 
2 


138 Reports & Proceedings—Ceological Society of London. 


A singular feature, which seems difficult to reconcile with its use 
as an implement, is the restriction of the flaking on one edge to the 
_ weathered crust. 

The origin of the flaking is discussed, and the author, while 
admitting that the fashioning of the flint is not inconsistent with 
intelligent design, concludes that the evidence is not sufficient to 
establish this beyond dispute. Itiseminentlya case of ‘‘not proven”’ 


The Secretary read a letter from Mr. J. Reid Moir, in which he 
stated that the flint in question was found by him in the detritus- 
bed below the decalcified Crag in the brickfield of Messrs. Bolton 
and Co., Henley Road, Ipswich, and that the author at first accepted 
the specimen as being of undeniable human origin. Mr. Reid Moir 
further expressed the opinion that the flaking to be seen upon the 
specimen was ‘‘human’”’ in its characteristics, and referred to his 
printed papers in support of that opinion. 


3. February 6, 1918.—Dr. Alfred Harker, F.R.S., President, in the 
Chair. 

The following communication was read :— 

“Some Considerations arising from the Frequency of Earthquakes.” 
By Richard Dixon Oldhan, F. i See Gas: 

The publication ‘of an abstract of twenty years record of earthquakes 
in Italy gives an opportunity for studying the effect of the 
gravitational attraction of the sun; the period is so nearly coincident 
with the lunar cycles of 19 and 18°6 years that the effect of the 
moon may be regarded as eliminated, the record is of exceptional 
continuity and completeness, and the number of observations is large . 
enough to allow of the extraction of groups sufficiently numerous to 
give good averages. 

The distribution of the stresses is dealt with in textbooks; there 
is a maximum upward stress, in diminution of the earth’s attraction 
at its surface, at the two points where the sun is in the zenith or 
nadir, and a maximum downward stress along the great circle where 
it is on the horizon; but as, for the purpose of this investigation, 
a decrease of downward pressure is equivalent to an increase of 
upward, I shall take the line along which the downward stress is 
greatest as the zero-line, and express the amount of stress at any 
other time or place as a fraction of the difference between the net 
force of gravity along this line and at the point where the sun is in 
the zenith. The fraction, at any given time and place, depends 
solely on the zenith distance of the sun, which is continually varying 
with the revolution of the earth. At the equinox, when the sun is 
on the equator, the curve of variation between 6 a.m. and 6 p.m. is 
the same as in the other half of the day; at any other part of the 
year it is not symmetrical in the two halves of the day, but is the 
same during the day in the summer half of the year as during 
the night in the corresponding part of the winter half, when the 
declination of the sun is equal in amount, though opposite in 
direction. 


} Boll. Soc. Sismol. Italiana, vol. xx, p. 30, 1916. 


Reports & Proceedings—Geological Society of London. 139 


This gave the first suggestion for grouping the records. The year 
was divided into two halves by the equinoxes, and the day into two 
halves, at six hours before or after noon, called day and night for 
convenience, irrespective of the time of sunrise or sunset. The 
result is given in the tabular statement below, the frequency being 
expressed as a ratio to the mean, of each group, taken as 100 :— 


DISTRIBUTION OF SHOCKS BY DAY AND NIGHT. 


Italy, 1891-1910. Day. Night. 
June—July : : * : a) SOW ALO! 
Summer half . 5 : : Aid rctown muse] Lt 
Whole year . : : : . 84 : 116 
Winter half . : : : Sun ted eases ug LLG) 
December—January . ‘ : Aan Ae) tbe) 

Japan, 1885-1892. 

Summer half . : : j 5 Me 8 Os 
Whole year . Ba POs 4 ea O FL cnr sua Oss 
Winter half . : : : MO Sian taiellOzs 

Assam Aftershocks. 

Summer half . : ; : a NB Be By 
Whole year . : ‘ 6 5 NOY Sy OB 
Winter half . : 3 oe OIE 384 BH) 


From this statement it will be seen that the mean ratio of day to 
night shocks over the whole period is represented by the figures 
84:116; for the summer half of the year they become 88: 112, and 
for the winter half 81: 119, showing that during the day the shocks 
are somewhat less frequent in the winter, with an opposite variation 
during the night. Taken by itself this difference might be merely 
fortuitous, and further confirmation is required: this can be got 
in two ways. In the first place by comparison with other records, 
two of which, Milne’s catalogue of Japanese earthquakes from 1885 
to 1892’ and the aftershocks of the Indian earthquake of 1897, 
stood ready for use. ‘They show a variation identical in character 
with that of the Italian record. A second test depends on the 
argument that, if the variation is in any way seasonal, the divergence 
should be increased at the height of each season; the figures for the 
months of January—February and of June-July were taken out, as 
representing midwinter and midsummer respectively, and found to 
show a divergence in each case greater than, and in the same 
direction as, the respective half-years. 

Taken by itself the variation, as between any pair of ratios, is as 
likely to be in one direction as in the other, but the odds against 
a complete concordance throughout the whole series is 31 to 1; 
there is, therefore, a strong presumption that the variations are not 
fortuitous, but due to some common cause which tends to increase 
the frequency during the day and decrease it during the night in 
summer, with the opposite in winter. 

The variation in the frequency of earthquakes may, or may not, 
be connected with the variation in the gravitational stresses due to 
the sun; but there is another line of investigation by which 
a connexion may be better traced, dependent on the fact that the 
prevailing effect of the vertical stress is in the direction of lightening 

1 Seismol. Journ. Japan, vol. iv, 1895. 
2 Mem. Geol. Surv. India, vol. xxxv, pt. ii, 1903. 


140 Reports & Proceedings—Geological Society of Lonaon. 


the load, and the prevailing direction of the horizontal stress 
between east and south, during the six hours before the meridian 
passages at noon and midnight, and of an increase in the downward 
pressure and a horizontal stress between south and west during the 
next six hours. The record was accordingly grouped by the 
successive two-hour periods from XII to XII o’clock, and the mean 
amount of variation in the stresses was calculated for the same 
periods. The result is set forth in the appended tabular statement :— 


DISTRIBUTION OF STRESSES AND SHOCKS 1N Two-HouR PERIODS, 
BEFORE AND AFTER MIDDAY AND MIDNIGHT. 


Hours . : . XII II Til VI VIII xX XII | 


STRESSES. 
Mean range of stress in each 
two-hours, in Italy. 


Total stress . j : . | —710| —-27| —-23| +-23 | +-27 | +-10 
Horizontal component . . | +:07 | —-11}) —-20} +-20] +-11 | —-07 
Vertical component . . | —:14] —-27| —-13 | +-13 | +-27] 4-14 
SHOCKS. 


Ratio of actual to mean fre- 
quency of each two-hour 
period. 

ITauy, 1891-1910 : . | 1-06) 1:17] 1-01) «-90 88 99 


JAPAN, Aftershocks of Mino- 
Owari, October 28, 1891 .| 1-01 95 °96 -97 | 1:08) 1-03 
JAPAN, 1885-90 . : . | 1:00} 1-11 “89 -98 | 1-C3 -99 


From these figures it is seen that, while there is no apparent 
relation between the frequency and the total, or the horizontal, 
stress, there is a close one with the variation of the vertical stress ; 
the greatest number of earthquakes being in the period in which 
there is the greatest increase of downward pressure; as the rate of 
increase diminishes the number of shocks is less, suffering a further 
diminution as the pressure begins to decrease, and reaching its 
minimum in the period where the decrease in pressure is greatest, 
increasing again in the same way to the maximum. 

An attempt to apply the same method to the Japan record gave 
a result which was, at first sight, contradictory and also inconsistent 
in itself, for it gave an absolute maximum at the time when the 
Italhan gave a minimum, with another maximum, almost as great, 
in coincidence with the Italian; but, in any comparison, it is 
necessary to allow for the contrast in the character of the two 
records. The Italian does not contain more than two, or at most 
three, great earthquakes of the type that gives rise to long-distance 
records (bathyseisms), and the aftershocks account for no more than 
a quarter of the whole record; the Japanese record, on the other 
hand, is dominated by bathyseisms and aftershocks. Not only does 
the region give origin to an unusually large number of teleseisms, or 


Reports & Proceedings—Geological Society of London. 141 


bathyseisms, but aftershocks form fully three-quarters of the record, 
and nearly a half consists of aftershocks of the Muino-Owari 
earthquake of October 28, 1891. Taking these separately, we get 
a curve of frequency similar to the Italian, except that the maximum 
and minimum are reversed, the greatest number of shocks corresponding 
to the period when the load is being lightened most rapidly, 
indicating that these shocks are due to a general movement of 
elevation rather than depression, a conclusion in accord with field 
observations of other great earthquakes. In addition, the shocks 
which occurred during the period 1885-90 were taken out, as 
representing a more normal activity, though still one in which 
aftershocks form fully half of the record, and the curve was found, 
as might have been expected from the character of the record, to 
combine the features of the Mino-Owari aftershocks with those of 
the Italian curve of frequency, of earthquakes prevailingly of the 
so-called ‘‘ tectonic ’’ type. 

These results are of twofold geological interest. In the first 
place they confirm the conclusion drawn from a study of the 
Californian earthquake of 1906,’ that the great earthquakes differ 
from the ordinary, not merely in degree but in kind. ‘They indicate 
that in the latter the main stress is compressive, probably due to 
settlement, and in the former to elevation or tension, a conclusion 
which is in accord with the fact that, in those cases in which it has 
been possible to compare accurate measurements made before and 
after the earthquake, the comparison has indicated an expansion, 
elevation, or both, of the area affected by the disturbance. 

The second point of interest is that the figures give a means of 
estimating the rate of growth of the strain which produces earth- 
quakes. If we accept the hypothesis that earthquakes, in the 
limited sense of their orchesis, are due to the relief by fracture of 
a growing strain when this has reached the breaking point, it can be 
easily shown that a variable strain, acting in alternate periods in 
increase or decrease of the general growth of strain, while leaving 
the average rate unaltered, will give rise to a corresponding variation 
in the frequency of shocks in each period; and, besides that, there is 
a simple relation between the magnitudes of the two stresses, to 
which the strains are due, and the variations from the mean 
frequency of earthquakes. A calculation on these lines shows that 
the growth of strain, for Italy, is such that, accepting the published 
estimates that an area of the earth’s crust of the magnitude of Italy 
would crush under its own weight if left unsupported to the extent of 
zoo of the force of gravity, the breaking strain would be reached 
in about 33 years, starting from a condition of no strain. The 
aftershocks of the Mino-Owari earthquake give a little less than half 
this figure, which is again reduced to from five to six months if 
account is taken of the difference between the resistance of rock to 
tension and to compression. ‘hese figures are given for what they 
are worth; at the least, they are of interest as being the first 
authentic estimate which it has been possible to make of the time 
required to prepare for, and, thence, of the rate of growth of the 
particular tectonic process involved in the production of earthquakes. 

1 Q.J.G.S., vol. lxv, p. 14, 1909. 


142 Reports & Proceedings—Geological Society of London, 


4. February 20, 1918.—George William Lamplugh, F.R.S. eer 
in the Chair. 


The following communication was read :— 

‘“The Geological Aspects of the Coral Reef Problem.” By 
Professor William Morris Davis, For. Corr.G.S. 

The communication is a critical review of the various theories 
that have been put forward up to the present time to explain the 
origin of coral reefs. A voyage in the Pacific, made in the year 
1914, enabled the author to collect new evidence bearing upon the 
question, and to make observations that have influenced him in his 
support of Darwin’s theory. 

After laying stress upon the embayment of shore-lines as a a proof 
of subsidence, the author expresses the opinion that all theories that 
postulate a fixed relation between reef formation and ocean level are 
disproved, and are probably inapplicable to the case of atolls. It 
appears certain that reef upgrowth is intimately associated with 
submergence wherever the matter can be tested. The solution of 
the coral reef problem turns at present upon some means of dis- 
criminating between a submergence caused by subsidence and a sub- 
mergence caused either by a general rise of the ocean level due to 
the uplift of the ocean floor beyond the coral reef region or to the 
melting of the Pleistocene ice-sheets. Although no means of such 
discrimination are known, the author presents reasons that lead him 
to regard changes in ocean level as of secondary importance, and that 
have caused him to attribute the submergence demanded by self- 
encircled islands to local subsidence, in accordance with the views of 
Darwin and Dana. He regards the theory that presupposes the 
raising of the ocean level by uplift as extravagant in its demands, 
and he finds the theory of ‘‘Glacial Control’? inadequate when 
applhed to barrier reefs and encircled islands. 

Stress is laid on the highly significant unconformable relationship 
that exists between reef and lagoon limestones and their foundations 
a feature that presents the strongest testimony for subsidence. 
In such a case the foundations must have suffered erosion for a con- 
siderable period before they were submerged, in preparation for the 
unconformable deposition of reef limestones upon them. From 
a consideration of such unconformable relations it is concluded that 
fringing reefs do not mark stationary or rising islands as generally 
as Darwin supposed. 

With regard to elevated reefs, the author demonstrates the 
impossibility of explaining their features by regarding them as 
having been stationary while the ocean surface was lowered, and 
holds that they must be due to local and diverse uplift affecting the 
islands themselves, following on epochs of subsidence which were 
the epochs of reef formation. The theory that such reefs were 
formed during pauses in the elevation and emergence is considered 
to be seriously defective, and is contrary to Darwin’s views. 

The author discusses the studies of Semper on the reefs of the 
Pelew Islands, the origin of atolls as propounded by Rein, the views 
of Murray on barrier reefs and atolls, and of Wharton on the 
truncation of atoll foundations; but forms the opinion that the 


Reports & Proceedings—Hdinburgh Geological Society. 143 


geological evidence for subsidence has been overlooked by these 
investigators, who paid no attention to the evidence afforded by 
unconformable contacts or embayed shore-lines. 

The author feels that scientific opinion in regard to the origin of 
coral reefs has been guided rather by subjective preference than by 
objective logic. He considers that Darwin’s theory of intermittent 
subsidence is the most competent to explain the facts, and while he 
holds that other theories than Darwin’s deserve cordial consideration, 
he feels that the burden of proof should be laid upon those who 
assume that reef foundations have not subsided. 


II.—EpinsureH Grotogican Soctery. 
January 16, 1918.—Professor Jehu, President, in the Chair. 

‘The Supplies in Scotland of Felspars suitable for Industrial 
Purposes.” By Dr. Campbell. 

Recent investigations of Scottish sources of alkali felspars had 
been necessitated by (1) the difficulty of obtaining shipment of the 
Scandinavian ‘‘spar’’, which is used extensively in the enamel, 
glass, and pottery industries, and (2) the possibility of utilizing 
potash felspars as a source of soluble potash salts, hitherto imported 
from Germany. 

Dr. Campbell gave an account of the results so far obtained of an 
inquiry carried out by Mr. Dinham and himself on behalf of the 
Geological Survey of Scotland. Pegmatites, the chief source of 
alkali felspars, were described from Beinn Ceannabeinne, the district 
between Lochs Laxford and Inchard, Rhiconich, and Overscaig in 
Sutherlandshire, from the Strontian district of Argyllshire, from 
Portsoy, Banffshire, and from Monymusk, Aberdeenshire. It was 
shown that, from their high content of silica and iron oxides, many 
of the Scottish pegmatites would be classed as spar of Grade 38. 
There were, however, abundant supplies of spar of Grade 2, and at 
a few localities, particularly at Rhiconich, Strontian, and Mony- 
musk, spar of Grade 1 (equal to the best Scandinavian spar) could 
be made available by hand-picking. Analyses of the average material 
of the best pegmatites gave potash content ranging from 7°42 to 
9°35 per cent. The red potash spar at Rhiconich was found to be 
associated with a buff-coloured spar containing 7:13 per cent of soda, 
which might be separated by hand-picking and utilized in the glass 
industry. Estimates were given of the quantity of spar available at 
each locality. The most extensive deposits are those at Beinn 
Ceannabeinne, where at least 12,000,000 tons could be obtained by 
open-cast working. 

Certain highly felspathic granites and felsites were regarded also 
as likely to be of economic value. Of the granites examined, the 
well-known Corrennie granite of Aberdeenshire was most promising. 
An average sample of the rock yielded 8-02 per cent of potash, and 
the only ferro-magnesian mineral present, biotite, occurs very 
sparingly. The spoil heaps in the quarries would furnish an 
immediate supply of many thousands of tons, and for practical 
purposes the available supplies might be regarded as ‘‘unlimited”’. 


144 Reports & Proceedings—Geologists’ Association. 


The best of the felsites so far investigated was a sill on the 
Kincardineshire coast near Cove Bay Railway Station. The rock 
consists essentially of felspar, quartz, and muscovite, and is entirely 
free from ferro-magnesian minerals. In chemical composition it 
resembles closely a spar of Grade 3 from Kingle’s Quarry, Bedford, 
N.Y., which is much used in the enamel and glass industries in 
America. It contains 4°67 per cent of potash and 3°53 per cent 
of soda. 

Attention was directed to various methods by which potash might 
be extracted from felspar—in particular to the processes devised by 
Rodin and Ashcroft—and to the possibility of utilizing felspar as raw 
material in the Portland cement industry, the potash being recovered 
as a by-product. 

Promising results had been obtained in recent trials made to test 
the suitability of Scottish spars for the enamel and pottery industries. 
There was thus a possibility of reviving what was an old Scottish 
industry since the Monymusk spar was quarried, ground locally, and 
shipped to the English potteries in the latter half of the eighteenth 
and the beginning of the nineteenth century. 


ITI.—Grotoetsts’ AssociaTIon. 


The annual general meeting of the Association was held at 
University College, Gower Street, W.C.1, on February 2, 1918, 
when the annual report of the Council and the accounts for the year 
ending December 81, 1917, were presented, and the officers and 
Council for the year 1918 elected. The President (George Barrow, 
F.G.S., M.I.M.M.) delivered his address entitled ‘“‘Some Future 
Work for the Geologists’ Association’’. The President showed that 
while the main features of the formations from the Lower Greensand 
- to the Upper Bagshot Beds are fairly well known within the London 
area there is need for far more accurate knowledge of the occurrence 
and pebbly constituents of the Drifts, especially those north of the 
River Thames. Even in the Geological Survey maps the colouring 
and tiomenclature are much confused. The Drifts may be divided 
into two groups—(1) Eastern, (2) Western. Much work remains to 
be done in tabulating the distribution and origins of the far-travelled 
materials almost always present in the former group. The Western 
Drifts, largely of local origin, contain far-travelled materials only in 
their lower and smaller portions. An account was given of these 
two groups indicating their extension and lines of junction, the 
evidence they afford of post-Glacial denudation, and of the pre- 
Glacial form of the district. In considering the significance of the 
small white quartz pebbles abundantly present in the Western local 
drifts, emphasis was laid on their common occurrence at heights 
slightly above 400 O.D. and their derivation from the Lower 
Greensand, through one or more gaps in the Chalk escarpment, 
during a period at least late Pliocene in age, when an estuary 
probably occupied the line of the present lower Thames valley. 
Brief reference was made to the River Terraces and the associated 
Brick-earths, and to localities that require special examination. The 
address was illustrated by lantern slides. 


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GEORGE JENNINGS HINDE, 
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BorN MARCH 24, 1839. DIED MARcH 18, 1918. 


Wirn deep regret we record the loss of our old and valued 
friend George J. Hinde, who for thirty-two years (1886-1918) 
was an Assistant Editor of the Grotogican Magazine, to which 
he has contributed over thirty articles. Dr. Hinde served on 
the Council of the Geological Society for nineteen years, and 
was a Vice-President in 1893. He was elected a Fellow of the 
Royal Society in 1896, held the office of Treasurer to the 
Palzeontographical Society for ten years, and became a Vice- 
President in 1916. He was awarded the Lyell Medal by the 
Council of the Geological Society in 1897. 

He passed peacefully away at “ Ivythorn’’, Avondale Road, 
Croydon, March 18, 1918. Dr. Hinde’s portrait, his life and 
scientific work, together with a list of his memoirs, will appear 
in May.—H. W. 


ORIGINAL ARTICLES. 
—__@——_—_ 


I.—On tHE OriIGIN oF soME LAND-FORMS IN CAERNARVONSHIRE, 
Norta WaAtEs. 


By HENRY DEWEY, F.G.S., of the Geological Survey of England and Wales. 
(PLATE VII.) 


fJ\HE present paper deals with some 30 square miles of land 

situated in Caernarvonshire and embracing the drainage area 
of the River Ogwen and parts of adjacent river-basins.! It is 
doubtful if any part of Great Britain presents in such a small area 
so many interesting topographical features and such beautiful and 
diversified scenery as this part of North Wales. It is in part 
a thoroughly mountainous region accompanied by characteristics that 
belong to mountains, and it is a glaciated. mountain region with 
typical glacial topography. But adjoining the mountains is an area 
of entirely different characteristics, and the change from the one to 
the other is sudden and complete. An upland plain abruptly 
terminates against a range of mountains without the interposition of 


1 See One-inch New Series Ordnance Map, Sheet 106. 
DECADE VI.—VOL. V.—NO. IV. 10 


146 Henry Dewey—Land-forms in Caernarvonshire. 


foot-hills, the crags and pinnacles rising precipitously from the level 
_land; or, in other words, the plain cuts as it were a shelf in the 
mountainous masses. 

Two years ago I communicated to the Geological Society of 
London a paper on the ‘‘ Origin of River Gorges in Cornwall and 
Devon”’,? and therein described an upland plateau that attains 
a maximum altitude of 430 feet above sea-level. In discussing that 
paper Mr. E. Greenly and Professor Fearnsides called attention to 
the existence in North Wales of similar coastal plateaux, but at 
different heights above sea-level from the one I had described. At 
the time those comments were made I was under an impression, 
gained during a short visit to North Wales in the spring of 1915, 
that a precisely similar feature terminating at the same height above 
sea-level occurred in both Cornwall and Caernarvonshire. But I was 
not sufficiently versed in the land-forms of the latter county to feel 
justified in asserting their practical identity. I therefore resolved 
to revisit the district to inquire more particularly into these land- 
forms, and in consequence spent some weeks during the summers of 
1916 and 1917 in making a close investigation of the points to be 
solved. Asa natural consequence other problems arose, and one in 
particular that cannot be settled in Cornwall or Devon, namely, the 
effects of glacial conditions upon this upland plain and the amount of 
denudation which has taken place since those conditions terminated. 
Restricted railway facilities more or less confined work to the district 
around Bethesda, and in consequence I chose for detailed investiga- 
tion the valley of the Ogwen and the country lying between 
Bethesda and Llanberis, and extending westward to Caernarvon and 
Bangor. 

Previous LITERATURE. 


This district is classic ground. Darwin? recognized the glacial 
features of parts of it and described in detail the valley of Llyn 
Idwal. Many years afterwards Sir Andrew Ramsay ® (in spite of 
great difficulties, especially with regard to inadequate topographical 
maps) fully and accurately described the mountainous tract. His 
work will be referred to frequently, but it may here be said that its 
accuracy is such that it needs but little revision, except where 
additions and refinements made possible by more precise methods 
and the general advance in geological science have necessitated 
modifications of nomenclature. His inferences, however, are open 
to question, and have already drawn into controversy many 
observers, including Watts, Marr and Adie,® Dakyns,® Jehu,’ and 
W. M. Davis.® 


Quart. Journ. Geol. Soc., vol. xxii, for 1916, pp. 63-76, published 1917. 
Phil. Mag., ser. II, vol. xxi. 


1 
2 


3 The Old Glaciers of Switzerland and North Wales, London, 1860. 

4 **Notes on some Tarns near Snowdon ’’: GEOL. MAG., 1895, p. 565. 

° ‘The Lakes of Snowdon’’: GEOL. MAG., 1898, p. 51. 

6 ** Some Snowdon Tarns’’: GEOL. MaG., 1900, p. 58. 

“ “The Lakes of Snowdonia and Eastern Carnaryonshire’’: Trans. Roy. 
Soc. Edinburgh, vol. xl, pt. ii, pp. 419-67, 1902. 

8 “* Glacial Erosion in North Wales’’?: Quart. Journ. Geol. Soc., vol. Ixy, 


pp. 281-350, 1909. 


Henry Dewey—Land-forms vm Caernarvonshire. 147 


North Wales was perhaps the first district where the former 
presence of glaciers was inferred from the characters of its land- 
forms. Darwin and Ramsay both described examples of such forms 
near Nant Ffrancon as were then acknowledged to be due to glacial 
action, namely the moraines, perched blocks, roches moutonnées, lakes, 
and the general U-shaped sections of the valleys. Since then other 
land-forms have been recognized as equally significant of glacial 
agencies, such as arétes, cirques, gendarmes, valley steps, and 
hanging valleys. Professor Garwood’ has described typical instances 
in the Ticino Valley. Now all these features are preserved in North 
Wales, but perhaps nowhere in so characteristic a manner as in the 
Nant Ffrancon district. Further, their relationship to earlier land- 
forms is equally well revealed in this neighbourhood, and for these 
reasons the district is one of particular interest to all students of 
geomorphology. 

In the following account each feature is described as it is met with 
in following the valley from the water-divide downwards to its 
confluence with the sea. 


Tur Ogwen VALLEY. 


The Afon Ogwen rises on the southern slopes of Carnedd Dafydd 
as a turbulent mountain torrent, the Afon Dena, and dashes down- 
hill among rocks and boulders in a series of rapids and cascades, 
pursuing a course roughly parallel with a neighbouring stream that 
afterwards flows in a diametrically opposite direction. Near Pont 
T'y-coch the two streams reach flat land partly covered with glacial 
drift and peat, but beneath these superficial deposits lie solid rock 
scored deeply with strie and worn into roches moutonnées. This 
low ground, although apparently flat, is the water-divide between the 
Rivers Ogwen and Llugwy, and from whatever point it is viewed 
appears to be a valley occupied by a sluggish river, which might. be 
flowing in either direction. 


Tur Lakes. 


The Ogwer next flows through marshy ground for a distance of 
three-quarters of a mile, and then swells out into a lake, Llyn Ogwen 
(Pl. VII, Fig. 1). This sheet of water, nearly a mile in length, is 
broadest at its eastern end and narrows towards the west, where its 
waters,escape through a gorge. The total area covered by it is 
approximately 456,400 square yards, but in spite of its size the lake 
is remarkable for its extreme shallowness, the water nowhere. 
attaining a greater depth than 10 feet. It is also noteworthy that 
it is deeper at the eastern end than at the west, the gradient of the 
lake-bottom sloping towards the east.2 It is a picturesque lake,, 
surrounded as it is by noble mountains (Pl. VII, Fig. 1) that form the 
highest group in North Wales, and is apparently landlocked. On its. 
northern banks rise the crags of Carnedd Dafydd, with a perfect cwm 
facing east near its summit, and in which les the small lake 


1 “ Features of Alpine Scenery due to Glacial Protection’’: Geographical 
Journal, 1910, pp. 310-39. 
2 Jehu, op. cit., p. 440. 


148 Henry Dewey—Land-forms in Caernarvonshire. 


Ffynnon Lloer, from which a small stream, the Afon Lloer, flows 
down to Llyn Ogwen. To the south it is flanked by a series of 
magnificent precipices terminated by the serrated edges of Tryfaen 
and Glyder Fach. There are many fine cwms along this ridge, all 
facing north-east, and in one lies Llyn Bochlwyd. 

The lower slopes of T'ryfaen and Carnedd Dafydd both bear record 
of the thickness of the former ice-sheet in their roches moutonnées 
and strie which extend far up their slopes, and also to the action of 
frost and ice in their cwms, llyns, and moraines, but all these 
features are still more perfectly preserved at the western end of 
Llyn Ogwen. 

The Holyhead road follows the side of the lake for a distance of 
over a mile and at approximately the same level the whole way, 
namely, a thousand feet above the level of the sea. A spur of 
Carnedd Dafydd bounds the western end of the lake and is rounded 
into smooth mammillations and roches moutonnées. It is seen in 
Pl. VII, Fig. 1. The waters of the lake, however, flow across this 
smooth rock-barrier in a low gorge and then suddenly plunge down 
into a deep chasm. This feature will be described later in relation 
to a similar one connected with it. 

Llyn Ogwen lies on an upland plain; arising steeply from this 
plain is a rock-step, deeply scored with glacial strize, through which 
a mountain torrent, the Afon Idwal, has ripped a gorge; if this 
torrent be followed, a second plateau is soon reached. It spreads 
out in front of a ring of magnificent precipices that form the base of 
Glyder Fawr and Y Garn and embrace the gloomy Llyn Idwal. 
This plateau rests at a height of about 1,250 feet above sea-level and 
is largely covered with strewn blocks derived from the almost 
vertical walls of the precipices, and in part arranged as moraines. 
Ramsay notes that moraines now skirt Llyn Idwal, the progressive 
retreat of the glacier being marked on the western side of the lake 
by four moraines arranged concentrically one within another. On 
the south and on the east of the lake there are patches of moraine 
matter, and other moraines dam back the waters at its northern end. 
Other glacial features, such as blocs perchés, roches moutonnées, and 
glacial striz, are conspicuous, the striz all being directed towards 
Nant Ffrancon. 

Professor Jehu! investigated the lake and its surroundings, and 
notes that it is broadest at its lower end, whence the River Idwal 
issues. The length of the lake is 846 yards, maximum width 
340 yards, area of water 159,300 square yards, mean breadth 
188 yards or 22 per cent of its length. He took eighty-one 
soundings, which prove the bottom to be very irregular, in places 
rauddy; but over a large part boulders of all sizes seemed to be 
scattered about and interfered with the soundings. The greatest 
depth registered was 36 feet in two places, the mean depth was 
11 feet, while the greater part of the lake was found to be extremely 
shallow, 57 per cent of the total area corresponding to depths under 
10 feet. The deepest part of the lake lies close to its western shore. 
Professor Jehu considers that Llyn Idwal was probably at one time 

1 Op. cit. 


Henry Dewey—Land-forms in Caernarvonshire. 149 


much deeper, but is gradually filling up by rock-falls from the 
neighbouring heights. A mass of drift crosses the valley at the foot 
of the lake, and seems to be of sufficient depth to account for its 
formation and disposes of the necessity for supposing it to be a rock- 
basin. The configuration of the lake-bottom supports this view, for 
there is no deep cup-shaped depression such as is found in other 
lakes of North Wales, but an irregular floor with rocky knobs jutting 
up here and there. Professor Jehu therefore concludes that the lake 
is a barrier-basin with a floor that may have been modified by 
glacial action. 


Tur Vatuey-Sreps at RwarapR OagweEn. 


Llyn Ogwen lies on a plain at 1,000 feet above sea-level. Llyn 
Idwal les on a plain at 1,250 feet above sea-level, while Nant 
Ffrancon extends as a long wide flat for a distance of 3 miles at a 
nearly uniform height of 700 feet above the level of the sea. There 
are thus three plains, rising one above another in tiers; the rise, 
however, between each is not gradual, but abrupt. These features 
are shown on the profile section, p. 150 (Fig. 1a), drawn to natural 
_ scale, and in the view of Nant Ffrancon (Pl. VII, Fig. 2), where the 
lower valley-step is seen across the top of the valley. 

Between Llyn Idwal and Llyn Ogwen the step is steep, and the 
river rushes down its face as a series of torrents, in places in shallow 
gorges until it unites with the River Ogwen at Pont Pen-y-Benglog 
to form the cascade known as Rhaiadr Ogwen. A fine view of the 
chasm is obtained from near the bridge. After heavy rain the gorge 
is choked with spray and the “ monotonous roar that fills the ravine’’. 

Various hypotheses have been advanced to account for the origin 
of such ‘‘ valley-steps”’ in glaciated countries. The two steps at 
Rhaiadr Ogwen are certainly, in part at least, due to the harder 
interbedded and intrusive igneous rocks that lie among the sediments, 
and the absence of similar steps in Nant Ffrancon may be due to the 
absence of igneous rocks in the rest of the valley. 

The gorges cut by the Rivers Idwal and Ogwen at Rhaiadr Ogwen 
have carried the drainage of the two upland plains into Nant 
Ffrancon ; but the study of the topography of the locality indicates 
an earlier drainage into the River Llugwy. This was suggested by 
Brend, and the bathymetrieal survey of Professor Jehu at Llyn Ogwen 
lends support to the hypothesis in that it proved the floor of the 
lake to fall from west to east, i.e. in a direction opposite to the 
flow of the water of the lake. This diversion of drainage was 
brought about in glacial times when glaciers filled Cwm Idwal and 
the plain at Llyn Ogwen. Sub-glacial streams then cut shallow 
gorges in the valley, and these streams persisted when the ice 
melted and carried off the drainage of the two upland plains into. 
Nant Ffrancon. 

Post-Guracrat Erosion. 


The gorges thus initiated have since been deepened by the cascades 
at Rhaiadr Ogwen. Similarly, on the west of the valley a small 
mountain torrent has ripped out a beautiful gorge near Blaen-y-nant 
Farm ; it is cut in bedded ash and is upwards of 40 feet deep. At 


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‘Ld ogal 


Henry Dewey—Land-forms in Caernarvonshire. 151 


Rhaiadr Ogwen the gorge is not much deeper, and the amount of 
post-Glacial cutting appears to be about 50 feet. Elsewhere in the 
valley there is no evidence of a greater amount of post-Glacial 
fluviatile incision, but another significant instance of a similar 
nature is the gorge by the Salmon Pool near Pont-y-garreg. Here 
the thick-bedded grits of the Lingula Flags are carried across the 
valley as a barrier through which the Ogwen has cut a gorge with 
vertical walls not 25 feet apart. At the same locality there are 
three prominent terraces preserved, each about 30 feet above the 
other and all smoothed andstriated byice. These were overwhelmed - 
by the great glacier; but as this retreated up-valley the barrier 
must have held back the waters that formerly spread out as a lake 
and filled Nant Ffrancon (Pl. VII, Fig. 2). Subsequent erosion has 
brought the base-level below that of the wide level tract of Nant 
Ffranecon, and the Ogwen now rushes in a series of picturesque 
cascades and torrents through this belt of country where the grits 
occur. These grits strike straight across the valley and sweep 
upwards to the west to form the precipices rising above Cwm 
Graianog. They are intensely hard and coarse-grained rocks, and 
under the microscope are seen to consist of rounded grains of quartz 
with a subordinate amount of fresh plagioclase felspar and some 
scales of white mica. The rock might be termed an arkose. 

A similar amount of post-Glacial erosion is indicated at many 
localities over a wider area, especially in that little visited and 
desolate tract of moorland that les between the ridge forming 
Carnedd Dafydd and Carnedd Llewellyn and the mountains near 
Aber. - In this tract the rivers have here and there removed the 
glacial detritus from their valleys, but the depth of the post-Glacial 
valleys is seldom more than 45-50 feet. But the Afon Anafon 
near Aber has cut a deep trough in debris and has led to a local 
collapse of a huge scree below the mountain, while the great cliff 
that remains appears to be.a contradiction to the other evidence. 

Here, however, the effect of recent local denudation may be 
noticed. In Cwm Coch near Blaen-y-nant Farm an enormous gash 
has been rent through scree material by a cloud-burst. It is 
upwards of 20 feet deep. Greenly! describes the effect of a similar 
cloud-burst on the scree beneath the lower slopes of Carnedd 
Dafydd where the road was swept away by the torrential waters. 

The mode of occurrence of the glacial drift leaves little room for 
doubt that the principal topographical features had been formed 
before the coming of the ice. All the valleys examined indicate that 
they are essentially pre-Glacial and that very little modification of 
them has taken place in post-Glacial times. This subject will be 
reverted to later and some evidence given in support of the views 
expressed. In the meanwhile the glacial characteristics of the 
Ogwen valley will be further considered. 


Tue Cwms anv tHE Hanoine VALLEYS. 


On the western side of Nant Ffrancon there are many typical 
ewms, and it is significant that all of them face either to the east 


1 GEOL. MAG., 1901, pp. 68, 69. 


152 Henry Dewey—Land-forms vn Caernarvonshire. 


or to the north-east (Pl. VII, Fig. 2). First is Cwm Bochlwyd, 
lying between spurs thrown out from Glyder Fach and Glyder | 
Fawr, and in which lie the sombre waters of Llyn Bochlwyd; this 
forms a characteristic hanging valley with a mountain torrent ripping 
its course down to Llyn Ogwen. Next comes Llyn Idwal in Cwm 
Idwal, flanked by the grand precipices of Glyder Fawr and Y Garn. 
Then from south to north follow Cwm-clyd, Cwm Cywion, Cwm- 
goch, Cwm-Bual, Cwm Perfedd, Cwm-graianog, and Cwm Ceunant. 
In most of these cwms there are relics of their own small glaciers, 
- especially well seen in Cwm-graianog, and it is significant that the 
change of slope marking the truncation of the spurs is practically 
always at a height above sea-level of 1,250 feet; and further, this 
altitude marks the limit of glacial strie incised by the great glacier. 
Of Cwm-graianog Ramsay remarks: ‘‘ But in none of the tributary 
valleys north of Llyn Idwal are the signs of a small glacier so 
distinct as in Cwm-graianog below the steep slopes of Moel Perfedd. 
It is a small craggy valley over half a mile in length looking across 
Nant Ffrancon. On the east the felspathic porphyry of Moel 
Perfedd rises in a rough peak, and on the west the great bare ripple- 
marked strata of the Lingula grits dip towards the hollow at an 
angle of 48° or 50°. 

‘At the mouth of the valley above the steeper descent to Nant 
Ffrancon, a small but beautifully symmetrical terminal moraine 
erosses the valley in a crescent-shaped curve, that once passed from 
200 to 800 yards up the eastern side of the glacier. On this side 
almost every stone of the moraine is a fragment of the felspathic 
rock of Moel Perfedd, havimg been shed from the edge of the glacier 
by a part of the ice that had that mountain as its source. Further 
west along the moraine, the material becomes mixed with fragments 
of grit and slaty sandstone, and, by degrees, passing to the western 
side of the valley, the moraine matter consists entirely of pieces of 
the Lingula beds that form the crags of Carnedd-y-filiast. . . . In 
Cwm-graianog the whole is formed of large angular loose stones 
mixed with smaller debris. The largest of these lies on the top of 
the moraine, from 450 to 500 feet above Nant Ffrancon. It. was 
originally 11 yards long, 9 broad, and about 13 high, and when 
entire must have weighed nearly 300 tons. . . . Inside the moraine 
the bottom of the valley is covered with glacial rubbish and heaps of 
loose blocks.”’ ' 

In marked contrast with these cwms is the even unbroken slope 
that bounds the eastern side of Nant Ffrancon and forms the ridge 
known as Pen-yr-Oleu-wen. But striz can be seen on the rocks 
below Braich-du at a similar height to those on the opposite side of 
the valley. These facts afford evidence of the maximum thickness 
of the glacier that filled Nant Ffrancon. The present level of the 
alluvial tract is 700 feet above sea-level, but the valley is partly 
filled up with boulder-clay and peat, possibly together 40 feet thick. 
The ice was therefore certainly not less than 700 feet thick. It 
enveloped all the land lying at altitudes lower than 1,250 feet, for no 


1 Op. cit., pp. 83, 84. 


Henry Dewey—Land-forms in Caernarvonshire. 158 


arétes or cribs occur below that level, althongh they commence 
immediately above. 

These cwms are shown in PI. VII, Fig. 2, and their bases are all very 
closely at the same altitude. This also corresponds with a plateau 
feature above Bethesda and lying between Nant Ffrancon and 
Clegyr. It is marked on the old map as a Turbary plain, but a lake 
used as a reservoir now occupies most of the area formerly filled with 
peat. ‘This broad moor is covered with drift and extends into the 
valley of Marchlyn-mawr, while remnants of it are seen on the 
opposite side of the Ogwen Valley near Afon Berthan, the Llafar, and 
Afon Caseg Valleys. The feature is conspicuous at Moel Rhiwen 
and near Douglas Hill. 

In Nant Ffrancon the foothills of the mountains are deeply 
striated, the strie pointing down stream; but these do not extend 
above the level of the lips of the cwms. 

Now all these features are attributed by the two schools of 
glacialists respectively to the protective or the erosive function of 
glaciers. The views, however, held by the one school are not 
entirely contradictory to those of the other, but rather are supple- 
mentary, i.e. those who ascribe to glaciers a protective function do 
not exclude thereby erosive action of ice nor the backward stoping 
of Bergschrund. 

Thus Garwood admits the power of ice to erode, but also insists 
on its efficacy under certain circumstances to act much as a bed of 
clay would in protecting underlying rock from disintegration due to 
the expansion and contraction of freezing water. In cwms the 
gently -sloping valley heads are thus protected, while the higher 
slopes are exposed to sun-heat and frost, especially in such cases 
where the main glacier has retreated up its valley leaving tributaries 
above the ice-line, in cwms receiving only small amounts of sun-heat 
‘ on account of their north-easterly or easterly prospect. The almost 
invariable rule of the cwms facing these and the absence of cwms 
facing other directions strongly supports Garwood’s contention. 


Tart Lower VaLiry oF THE OGWEN. 


Between Bethesda and Bangor the Ogwen flows rapidly through 
a deep and well-defined valley, which everywhere bears record of 
glacial activity. The strongly moutonnéed rocks and deeply incised 
striz are well preserved on the Bethesda slates near the village and 
at the mouth of Nant Ffrancon, and at first the wide valley appears 
to be free from drift deposits. Closer examination, however, proves 
that this supposition is incorrect. To take two or three instances 
only among many others, there is first the pit near Felin hen Station, 
where upwards of 20 feet of boulder beds are exposed in a low hill- 
side rising gently from a plain; while near the Halfway House the 
lower slopes of a hill have been cut into, and the open pit exposes 
more than 30 feet of similar boulder material. Elsewhere in the 
area described low hills rising above the general plain level are seen 
to consist of boulder-clay or sand, and these occur at various heights 
above sea-level and down to and below low-tide mark, as near Penrhyn 
Castle and at Beaumaris on Anglesey. Old valleys are partially 


154 Henry Dewey—Land-forms vm Cauernarvonshire. 


infilled with glacial deposits, and the plain and even the tops of hills 
carry boulder beds. This evidence clearly indicates that the wide 
general topography as it at present exists was for the most part 
produced in pre-Glacial times, or at least when the spreads of glacial 
detritus were laid down. 


- 


Tur 480 Foot Prain. 


By keeping to the Ogwen Valley, however, a wrong impression of 
the topography of Caernarvonshire is gained, and it comes as 
a surprise to find, after climbing the hills, not a mountain region, 
but a widespread area of gently undulating ground, p. 150 (Fig. 10), 
where the hills are truncated into flat-topped ridges. On turning 
towards the mountains it is further seen that this plain abuts against 
their masses at an even level for many miles, while they rise from it 
like islands from the sea. 


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Tia. 2.—The ‘‘ Pliocene’’ plateau near Bangor. The plain terminates at 
a height of 430 feet above sea-level, the mountains near Snowdon rising 
abruptly from it. Its wide expanse is clearly seen in this sketch. 


The above picture (Fig. 2) shows a view of these features takén 
from the Bangor Golf Links and looking towards Nant Ffrancon, 
where the wall-like mass of Glyder Fawr is seen bounding the valley 
at right angles to it. 

Another sketch (Pl. VII, Fig. 3), made near the Anglesey 
Monument, shows similar features of a country diversified into 
a series of parallel ridges with flat tops, terminating against the 
mountain mass. In the area bounded by the Ogwen Valley, the 

Padarn Valley, and the mountains there is scarcely a hill that rises 
above this plain, although much of the ground is lower and there are 
several deep river- valleys. The amount of erosion that has taken 
place since the uplift of the plateau is marked by the Menai Straits, 
which attain a depth of 70 feet below sea- level, while the Afon 


Henry Dewey—Land-forms in Caernarvonshire. 155. 


Cegin, the Afon Seiont, and the Afon Cadnant have each cut valleys 
several hundreds of feet deep in the plateau. 

Some agency has truncated all the land at a common level, and 
inspection of the Ordnance map shows that level to be 430 feet above 
that of the sea. There are, however, a few hills that rise above this 
plain, and on almost every one of them a hill-fort consisting of 
circular earthworks is preserved. To mention some examples, there 
are the two camps situated respectively on the west and the east of 
the Padarn Valley near Cwm-y-glo;. the fine hill-fort at Pen-y- 
ddinas by Llanddeiniolen, the Castell near RKhiwlas, the Camp by 
Tregarth, and another at Rhiw Goch. Similarly on Anglesey? the 
earthworks are placed on the few hills that rise above 400 feet and 
are there described as various Mynydds. 

But this plain does not extend far to the east of the River Ogwen, 
as the mountains run out to the coastline near Aber. Its margin is 
rendered obvious on the map by the crowding together of the 
contour-lines above 400 feet, but it is still more conspicuous in 
Nature. Fig. 1d, p. 150, is drawn to the natural scale, and shows 
the abrupt change of slope at the base of the mountains. 

It is difficult to follow the edge of the plain across country, because 
there is no road running parallel with it, but the feature is distinctly 
seen even from a distance. Nevertheless, when the margin is 
reached the ground is usually boggy and often covered with saturated 
‘peat, with small streams soaking through it. Tregarth village is 
built in part on the plain, and here the rise to the adjacent 
mountain is marked by several boggy meadows. But perhaps the 
feature is best seen in the country lying between Llanddeiniolen and 
Moel Rhiwen, especially near Waen, where hillocks composed of 
boulder beds rise above the general plain to form dry patches of 
arable land in a region generally wet. 

The feature cuts straight across the mouth of the Llanberis Valley 
and does not run up into that valley, a fact that implies the formation 
of the valley subsequently to that of the plain. It then extends in 
a general south-westerly direction near Llanrug, where Garth is 
situated on an isolated hill rising out of the plain. Thence by 
Groeslon and Pen-y-groes it spreads toward the Lleyn Peninsula, 
but I have not traced it in detail much beyond the valley of the 
Seiont. 

Such a sudden change of topography suggests a different degree of 
hardness of the rocks underlying the two areas, but reference to the 
geological map (Sheet 78) shows that in both areas similar rocks 
occur. These consist of slates, grits, limestones, and shales with 
bedded and intrusive igneous rocks. In the one area all of them 
have been planed down to a common level; in the other differential 
hardness has led to variety of sculpture. 

Of late it has been the fashion to adopt American terminology in 
describing upland plateaux and also to reject the sea as the agent 
which has produced these features. In some cases the term 
‘‘peneplain”’ may be applicable, but it is difficult to imagine why 
subaerial agencies should cease operating along a purely arbitrary 

1 See Mr. Greenly’s forthcoming Memoir on Anglesey (Mem. Geol. Sury.). 


156 Henry Dewey—Land-forms in Caernarvonshire. 


line, leaving parts of a district immune from attack and reducing at 
the same time adjacent areas of similar geological formation and 
structure to a featureless plain. In the ‘present instance I reject 
the hypothesis of subaerial erosion. Marine erosion proves its 
capability of levelling rocks of all degrees of hardness, as anyone 
familiar with coasts bounding the Atlantic must acknowledge. The 
Cornish coast is a convincing instance of the sea’s power to produce 
level tracts, and moreover lands of all degrees of hardness ultimately 
yield and become reduced to the limit of erosion. Such a marine 
plain is seen at low-water spring tides near Bude, where a quarter of 
a mile of bevelled rocks are exposed. They consist of alternate beds 
of hard sandstone and slate, but all have been planed down to 
a uniform level, or rather a long gentle slope towards the deeper 
waters. The tide in rising suddenly covers this plain, and is apt to 
cut the unwary off from retreat. On this coast it is always well to 
remember that— 
Far back through creeks and inlets making 
Comes silent, flooding in the main. 

There can therefore be no valid reason to offer why the sea did not 
similarly operate on this plain in North Wales. 

It is more difficult to determine the period when this reduction 
occurred; the fact that the feature terminates in both Cornwall and 
in North Wales at precisely the same height above sea-level suggests 
that the two plains are contemporary, whatever their geological age 
may be. That in North Wales the plain is pre-Glacial is proved; in 
Cornwall there are strong reasons for supposing it to be of Pliocene 
age. We are then perhaps justified in accepting as of the same age 
the North Welsh plain at this level. 

In both districts, however, there are wide tracts at lower levels,’ 
notably that at 200-300 feet above Ordnance Datum, but in both 
these do not occur above 480 feet, with the exception of those. 
already mentioned at 700, 1,000, and 1,250 feet respectively. The 
lower plains may also represent other marine plains or peneplains, 
but with these I am not concerned. The point to be emphasized is 
the occurrence in both districts of a plain which does not rise higher 
than 430 feet above sea-level. 

Before concluding I wish to express my thanks to Mr. Greenly for his 
kindly advice and suggestions made during the writing of this paper. 

ConcLusions. 

1. Glacial phenomena as expressed in land-forms have long been 
known in North Wales. In the valley of the Ogwen the whole series 
of land-forms characteristic of glacial topography are represented, 
namely, the lakes, cwms, hanging valleys, valley-steps, and arétes ; 
and in addition the evidence of former glaciers as represented by 
moraines, roches moutonnées, and blocs perchées. 

2. There is sufficient evidence to show that the major land-forms 
are pre-Glacial and that post-Glacial erosion is comparatively slight. 

3. Pre-Glacial erosion had sculptured a former upland plain into 

1 See Ramsay, Geology of North Wales (Mem. Geol. Surv.), p. 269; also 


Quart. Journ. Geol. Soc., 1876, p. 116; also Greenly, Rep. Brit. Assoc. 
Bradford, 1900, p. 737. 


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LAND-FORMS CARNARVONSHIRE. 


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Lieut. Serivenor—Origin of Clays and Boulder-clays. 157 


a region diversified with ridges and valleys, with its own drainage 
system independent of a mountain drainage system adjoining it. 

4. This upland plain terminates at a height of 430 feet above 
sea-level and is of widespread occurrence. 

5. A similar plain forms conspicuous features in Cornwall and in 
Devon, and terminates in those two counties at precisely the same 
height as that of North Wales. This plain is not more recent than 
Pliocene, but may be older. 

6. There is evidence that these upland plains of North Wales and 
Cornwall and Devon were formed contemporaneously and by marine 
erosion. 

EXPLANATION OF PLATE VII. 


Fie. 1.—Llyn Ogwen. The view shows the landlocked waters of the lake 
with the amphitheatre of great mountains encircling it. In the middle 
distance is the low barrier through which the waters escape in a gorge. 
It is deeply grooved by glacial striz, which also extend up the lower spurs 
of Carnedd Dafydd to the right. On the left of the barrier rises a valley- 
step that separates Llyn Idwal and its plain from Llyn Ogwen. ‘The 
mountains in tbe background are Y Garn and Foel Géch. On both of 
these mountains are characteristic cwms, all facing to the north-east. 

Fie. 2.—Nant Ffrancon, looking south. The valley-step igs seen across the 
head of the valley, over which the waters of Rhaiadr Ogwen fall. In the 
middle distance is a “‘roche moutonnée’’; on the right are cwms and 
arétes, while the lower slopes of the mountain show truncated spurs. 
The foreground consists of glacial detritus and peat which has accumulated 
on the floor of the valley. The mountains in the distance are Y Glyder 
Fach and Y Glyder Fawr; on the right are Y Garn and Foel Goch. 

Fie. 3.—The ‘‘ Pliocene ’’ plain of North Caernarvonshire. This view is taken 
from Anglesey and shows the extensive upland plain diversified with deep 
valleys and flat-topped hills. Im the foreground lies the Menai Straits, 
here about 70 feet deep. The Snowdon range of mountains forming the 
background rise abruptly from the plain. 


Jl.—Tue Orem or roe Crays ann Bourper-ciays, FrpErarrp 
Matay Srarrs.! 
By Lieutenant J. B. SCRIVENOR, M.A., F.G.S. 
INCE the earlier edition on the geology of Kinta was written 
k-) much fresh evidence has been brought to light on the subject of 
the origin of the clays and boulder-clays and the tin-bearing deposits 
showing bedding at Gopeng. ‘The effect of this evidence has not 


1 The subjoined note which accompanied this article from the author to the 
Editor of the GEOLOGICAL MAGAZINE was received on January 8, 1918, when 
Mr. Scrivenor was leaving for France :— 

Sir,—With reference to Mr. W. R. Jones’s paper in No. 287 of the 
Quarterly Journal of the Geological Society, pp. 165-94 (isswed November 23, 
1917), on the ‘‘ Secondary Stanniferous Deposits of the Kinta District’’, 
I shall be grateful if you will publish the following article on the “‘ Origin of 
the Clays and Boulder-clays’’. This was written before I left the Malay 
States and before I had seen Mr. Jones’s paper. I note that on p. 176 of his 
paper the latter says that at Kacha, Tambun, Lahat, and Papan, clays and 
boulder-clays can be traced into partly decomposed phyllites exhibiting distinct 
foliation. Ido not remember Mr. Jones offering to show me these occurrences. 
The section at Siputeh mentioned in the fourth paragraph of p. 177 is that 
described by myself, and I took Mr. Jones to the mine to see it. 

J. B, SCRIVENOR. 

R.E. DEPpoT, BALDOCK, HERTS. January 7, 1918. 


158 Lieut. J. B. Scrivenor—Origin of Clays and 


been to lessen the objections to the glacial hypothesis put forward 
by myself, but at the same time it still remains the only explanation 
that meets the facts in a way that can be called at all satisfactory. 
It may be that long acquaintance with the subject has made me see 
difficulties in the way of other explanations where in fact no 
difficulties exist, and my position regarding the question is some- 
what akin to that of a doctor versed in tropical medicine who once 
informed me that the result of many years study of the etiology of 
bert-berv was that he felt he could raise fatal objections to any theory 
that had been proposed. I have not seen sufficient reason as yet, 
however, to change my views on the subject of these clays and 
boulder-clays. Certain sections to be noted later militate against 
a glacial origin, but the evidence of these deposits, including those 
showing bedding at Gopeng, being older than the granite of the Main 
Range is stronger than it was before. In the following paragraphs 
I will attempt to give briefly a statement of the points for and 
against all possible explanations of the peculiarities observed in 
these important sources of tin-ore. 

It will be convenient to consider first the deposits that show no 
bedding. These occur both on the west and on the east of the 
Kinta River, and are especially well developed in the vicinity of 
Siputeh and Pusing. The problem regarding them may be stated 
thus: Are they the result of bedded rocks being broken up and 
completely disorganized owing to the limestone underneath them 
being dissolved away and so producing a general sinking movement 
in the overlying material; or were they originally laid down as 
unbedded clays with irregularly distributed boulders? 

When work was commenced in Kinta the former of these two 
explanations commended itself, and I think that anyone examining 
the evidence cursorily would come to the same conclusion. In 
a paper on the tourmaline-corundum rocks of Kinta (Quart. Journ. 
Geol. Soc., Ixxvi, p. 448, 1910) I gave as my opinion that they were 
derived from rocks associated with schists over limestone, probably 
chert and silicified ihmestone, and I may also remark in passing that 
on p. 488 I referred to the corundum found in the “ alluvium”’ at 
Pulai and elsewhere. 

At that time, however, it was thought that there were two 
occurrences of these rocks known to be in situ, i.e. in the position 
where they were originally deposited before alteration, but in one 
case mining operations proved this not to be the case, while in the 
other the mass of rock, close to the Siputeh bridle-path from Batu 
Gajah, might have been a huge boulder. It is now completely 
hidden by mining silt. 

Bedding that is a division of a mass of rock into clearly defined 
strata of more or less different composition has never been seen in 
these clavs, but in a few cases a faint trace of lamination has been 
seen. ‘This, however, might be the effect of pressure on unstratified 
clay. The tourmaline-corundum rocks are hard, the clays are soft. 
What is required to prove that the former are derived from a con- 
tinuous bed or beds intercalated among softer beds is a section 
showing some sign of it, and as yet no such section has been found. 


Boulder-clays, Federated Malay States. 159 


Another possible suggestion regarding these boulders is that they 
are analogous to ‘‘core-boulders’”’ of granite; that they are portions 
of beds rich in corundum and tourmaline that have resisted 
weathering. It is known that the containing clay is sometimes 
very rich in soluble alumina, derived, it is believed, from minute 
pieces of tourmaline-corundum rock by the alteration of the 
corundum, but where clearly bedded rocks are exposed, as at 
Kacha, Redhills, and near Batu Gajah, there is, with one exception, 
no trace of the pecular structure of these rocks. That exception is 
a rock found near Redhills, containing traces of Radiolaria which 
may have been the foundation of some of the bodies in the 
tourmaline-corundum rocks. 

It is felt now that the previously held views regarding the origin 
- of these rocks will not meet all the facts, and the objections are well 
exemplified at Redhills and Kacha. On the Redhills and Pusing 
Lama mines large boulders of tourmaline-corundum rock are found 
in tin-bearing clay. 

At Redhills hmestone was found underneath the clay. On both 
mines, but on higher ground, soft, weathered, bedded rocks are 
found. On Pusing Lama a section was once uncovered, showing 
small tin-veins in tourmalinized shales. If the clay with boulders 
of tourmaline-corundum rock is simply the shale disorganized over 
sinking limestone, then the shales should contain the tourmaline- 
corundum rock too, but, as far as I am aware, they do not. Over 
the clay these boulders are numerous, but over the shales they are 
replaced by masses of ironstone formed at and near the surface 
(Malayan ‘‘laterite’’). Here, then, is what seems to be a fatal 
objection to the clay being disorganized shale. 

At Kacha the evidence on the old mine worked formerly by 
Towkay Ong Siew is somewhat different. On the lower part of the 
mine there are clearly bedded and somewhat sandy rocks with 
intrusions of aplite. Some of the hardest material has been 
examined, and nothing was found of the structure of the tourmaline- 
corundum rocks. On the other hand, on the high ground that has 
been extensively worked by ground-sluicing, there are abundant 
tourmaline-corundum boulders, some of which can be seen in situ, 
- andno bedding is to be seen now. If the bedded rocks on the lower 
level retain their bedding, and if the rocks on the higher level were 
once bedded, surely the conditions there are more favourable for the 
preservation of that bedding, seeing that the strata on the top of the 
hill are less likely to be disorganized by sinking over limestone as it 
dissolves away than those at the base. 

Once on Pusing Lama a thin bed of clay with boulders was seen 
under shales, and at Kacha evidence was seen of alternation of shale 
and clay with boulders, but as these sections cannot be seen now 
they can hardly be cited as evidence. 

Another strong objection to the theory of the clay being dis- 
organized shale is its condition at the junction with granitic rocks. 

On the Pusing Lama mine a lode was discovered that became well 
known. It was at the contact of a soft granitic rock and soft clay 
with boulders of tourmaline rock and powdery tourmaline evidently 


160 Ineut. J. B. Scrivenor—Origin of Clays and 


of a secondary nature. Tourmaline-corundum rock occurred near 
by. The earlier work on this lode was underground, but now there 
is an open-cast mine on the junction. On the one hand is a granitic 
mass rich in kaolin and traversed by tourmaline veins, one 
sufficiently well preserved to show a small fault; on the other, deep- 
red clay in which an apophysis of granitic vein-material was once 
seen, itself traversed by tourmaline veins. One may argue that 
away from the junction bedded shales and harder rocks might be 
disorganized over limestone so as to simulate boulder-clay, but at 
the granite junction, where the granitic rock is equally soft and 
contains clearly defined tourmaline veins, the bedding of soft and 
hard rocks ought to be preserved. But it is not preserved, and the 
inference is that it never existed. 

But away from the junction also there has been evidence against ° 
the clay being disorganized shale. At least one vein of ore has 
been worked open-cast with a course that could be easily followed. 
How could this be preserved if the clay and boulders are broken-up 
hard and soft strata ? 

Even more striking is the evidence at Tekka and Gopeng, where 
there are good exposures of the junetion between granitic rocks on 
the edge of the Main Range mass and clay at Tekka, while on the 
Ulu Gopeng portion of Gopeng Consolidated is a junction with 
schists. 

These schists are exposed on old workings at the top of 
a steep hill overlooking the town of Gopeng. They are clearly 
bedded and dip at a very high angle to the west. Sandy phyllites 
are common; tourmaline-schist and actinolite-schist occur. Both 

rown and white mica occur. The soil above them contains 
ferruginous masses showing the structure of the schists they have 
replaced on weathering. Quartz veins are abundant. 

The clay at the junction with the granite on the Tekka Ltd. mine 
and on mines further to the south should, if it is the result of the 
extreme weathering of schists, still show some resemblance to the Ulu 
Gopeng sections. The clay cannot be schist that has become a dis- 
organized mass through movement because at the junction tourmaline 
veins have been traced into it; and moreover there are other veins 
found sometimes parallel among themselves, but sometimes brecciated 
by movement, which are the effect of alteration by the granite. 
Under the microscope these veins are found to consist chiefly of 
white mica and fluorite in minute particles. In some veins 
corundum, spinel, and blue tourmaline occur also; and it is 
significant that whereas the tourmaline in the Ulu Gopeng schists 
is brown, that in the clay is blue, and of a shade pale enough to be 
distinctly recognizable in a hand specimen. Only a few grains of 
brown tourmaline have been obtained by washing a quantity of clay. 
Moreover, the clay at the junction shows lamination with bright 
colours, described elsewhere in this Magazine, which has no counter- 
part in the Ulu Gopeng section. If therefore we assume the clay to 
be schists like those at Ulu Gopeng weathered so as to lose all trace 
of bedding we have to explain why alteration by the granite 
produced such different results on the same material. The granite 


Boulder-clays, Federated Malay States. 161 


must have been intruded when the bedded rocks were fresh and 
unweathered deep below the surface, and the only solution seems to 
be that the clay now exposed on the surface never resembled the Ulu 
Gopeng schists. 

In the earlier publication a section was described on the Kramat 
Pulai mine. ‘This was one of those rare cases where I had another 
observer (Mr. W. Rh. Jones) to check the accuracy of my sketch 
before the section was destroyed. Reference to it will show that if 
the boulders are portions of a continuous hard bed broken up the 
kaolin vein must have been broken up too, which is not the case.! 

‘“‘Laterite’’ was mentioned above. This has an interesting bearing 
on the question under discussion. When shales and schists are 
weathered at the surface, generally, but not always, these masses 
of ironstone are formed, and as the iron is gradually deposited 
along bedding-planes and joints the masses exposed at the surface 
frequently preserve the structure of the rock they replace and are 
themselves a guide to.the nature of the country rock. In mining 
operations these ironstone growths often give much trouble, as for 
instance at Bruseh, and if the Kinta clays and boulder-clays were 
weathered shales or schists one might reasonably expect to see 
numbers of them in the soil or in mines where the soil has been 
worked away. But such masses do not occur, as far as I know. 
The clays are sometimes hardened by the deposition of iron, but 
there is no shaley or schistose structure preserved. On the other 
hand, where clearly bedded rocks occur, as at Redhills and near 
Batu Gajah, ironstone replacements do occur, and in ditches near the 
latter locality one can see how the ironstone is gradually deposited 
as the shale weathers away. 

Another point to be considered is this. If we conclude that the 
clays are formed by shale, etc., sinking over limestone as it dissolves 
away, we should first be sure that there has been sufficient alteration 
in the level of the limestone to produce the result. It is impossible 
to obtain precise information, but although there are doubtless places 
where deep cavities have been hollowed out, there is some evidence 
pointing to the general lowering of the limestone surface having 
been slight. 

Usually the limestone surface is a mass of pinnacles, but for some 
time there was exposed, in the bottom of a mine at Tekka, Sungei 
Raia, a large and almost flat platform of limestone that seemed to be 
the original surface. Where the platform ended there were pinnacles 
as in other localities. Again, at Gopeng, under the Gopeng Beds, 
which show stratification, there is a limestone floor. This shows as 
much irregularity as the limestone floor elsewhere, but the beds 
above have retained their stratification, except immediately above 
the soluble rock, where, however, a disorganized pebble-bed, if that 


1 Mr. Jones now seeks to explain this vein as an effect of different colora- 
tion in the clays, but if the Kramat Pulai vein can be thus explained the same 
holds good for all the kaolin veins. I am quoted as describing a case at Pusing 
Bahui which Mr. Jones says is similar, although he did not see it. It was, as 
a matter of fact, different from the Kramat Pulai vein in that it had no sharp 
boundaries and did not consist of kaolin. 


DECADE VI.—VOL. V.—NO. IV. 11 


162 Lieut. J. B. Scrivenor—Origin of Clays and 


be the correct interpretation of its peculiarities, can be traced into 
clearly marked strata. If these deposits at Gopeng retain their 
bedding, why do not the others do so also if they are only weathered 
shale and schist ? 

Some mines have afforded exceptional facilities for studying deep 
tin-bearing deposits, namely the Tronoh and Tambun mines. 
The Tronoh mines contain shales and rich tin-bearing clay, and the 
question is whether the latter are the shales weathered and broken 
up over dissolving limestone or a distinct formation. It might be 
argued with reason that taking this mine alone the former is the 
better explanation and that the tin-ore was introduced by granitic 
intrusions along the fault. I find it hard, however, to adopt this 
view in its entirety. On the west are good sections of bedded shale 
and quartzite, and I am informed that they carry only a little tin, 
although granitic intrusions occur and also quartz veins, in one of 
which wolfram has been found. Going eastward one comes suddenly 
on clays without bedding, but with pebbles in some quantity and 
very rich tin-contents. If the pebbles are derived from the harder 
bedded rocks on the west and the quartz veins one would expect 
them to be of greater size and more angular; and, moreover, seeing 
that granitic intrusions occur in the bedded rocks it is difficult to 
explain the comparatively large amount of tin-ore in the clay if it 
all comes from granitic intrusions also. It might, however, be 
suggested that the rich ore is derived from a long lode in shales, 
now broken down to clay. I once saw a section in a small mine to 
the south of the Tronoh Ltd. mine that might have been thus 
interpreted, but nothing could be proved, and at the present time 
there is nothing visible supporting the view. Nevertheless it may 
be that some such interpretation as this is the correct one, and weak 
points in the theory that the clay is a distinct formation overlying 
the limestone are that nothing is known of it to the east underneath 
the sand and masses of vegetation where the limestone rises nearer the 
surface, nor has anything been proved concerning the presence of 
tin-bearing clay under the bedded rocks on the west. 

In Towkay Chung Thye Phin’s mine the distribution of the ore 
is suggestive of a lode. On one side is the crystalline iimestone, 
coming near the surface of the ground. On the other side is a steep 
bank cut in the shale and quartzite showing innumerable little 
stringers of kaolin and veins with tourmalinized shale on either side. 
The ore-bearing clay occurs along the junction of the limestone and 
shale and quartzite. In the portion of the mine nearer the Tronoh 
Ltd. mine it is a narrow band of a few feet in width only. In the 
gut in the centre of the photograph it is said to die out altogether. 
Beyond it opens out again. 

In the Tronoh South mine again the run of the ore suggests 
a lode rather than a detrital deposit; but in all these Tronoh mines 
there are objections hard to dispose of if we are to regard the 
‘‘Tronoh lead”? as a weathered lode. In the first place, on the 
west wall of the mines the effect of emanations from the granite is 
seen in the tourmalinization of the shales bordering the small veins. 
The shale is hardened and charged with minute crystals and grains 


Boulder-clays, Federated Malay States. 163 


of brown tourmaline. I have not seen anything like it in the rich 
tin-bearing ground. 

Again, in the Pusing neighbourhood veins have been found and 
worked in clay just as soft as the Tronoh pay-dirt. They were 
probably connected with the granite by fissures through the lme- 
stone. In one case the vein was at a contact of granitic rock and 
clay. But these veins preserved their identity as veins. There was 
no mistaking them for anything else. At Tronoh, on the other 
hand, the tin-bearing ground strongly resembles, if it is not, 
a detrital deposit. Ifit were a broken-down lode we would expect 
to find at least some trace of an ‘‘iron-hat”’ containing tin-ore, 
lumps of hardened shale, with tourmaline, and large masses of tin- 
ore. I have already mentioned the only section that I can remember 
as even suggesting a lode. A hard mass with quartz seen lately in 
the Tronoh Ltd. main lumbong also looked as though it might be 
evidence of a lode, but the tin-ore was stated to be all to the east of 
it, and it was only a weathered quartz-vein at the edge of the shales. 

At the North Tambun mine one could see, early in 1916, soft ~ 
shales showing distinct bedding lying on the limestone and unbedded 
clay rich in tin-ore hard by. 

In Towkay Leong Fee’s mine at Tambun highly inclined bedded 
rocks lie side by side with clay very rich in tin-ore. The latter 
sometimes shows a trace of lamination, but I have not seen any 
section where bedded can be traced into unbedded rocks. They. 
appear to be distinct, but one of the Perak mining community who 
has had a long experience of the mine holds the view that the clays 
are the-bedded rocks very much weathered, and tells me that in the 
latter good tin-values have been found. In the North Tambun 
mines the-shales retain their bedding immediately above the lime- 
stone, and it is difficult to understand why in this and in Towkay 
Jeong Fee’s mine the bedded rocks have retained their bedding if 
the others have lost it, seeing that both are equally soft and the 
position of the limestone is such that one cannot help expecting it to 
extend under the bedded rocks. 

At New Tambun also the bedded rocks occurred in qiixtaposition 
to the clays. The former were traversed by numerous small kaolin 
veins. They yielded a little tin-ore throughout, whereas the clay 
was comparatively rich. No lmestone was met with below the 
bedded rocks. 

In the Tronoh and Tambun mines, and also elsewhere, it might be 
argued that in addition to the disturbing effect of the limestone 
surface being lowered, the bedding of shales and schists has been 
destroyed by the media that brought the tin-ore; in fact, this view 
was put forward during a discussion on a paper read in Ipoh some 
years ago. This would account for the greater quantity of tin-ore 
in the ‘clays, but it is difficult to reconcile the theory with observa- 
tions elsewhere. 

In Intan, in Upper Perak; at the Ulu Gopeng mine; at Bruseh, 
in Batang Padang; at Jeher, and near Tanjong Malim; and at 
Pantai, near Kuala Lumpur, bedded shale and quartzite have been 
invaded by tin-bearing media on a large scale, but I do not remember 


164 Ineut. J. B. Scrivenor—Origin of Clays and 


anything that supports the explanation put forward above. In 
every case the bedding is clearly preserved, although the rocks 
are soft. 

Another possibility might be put forward. When some limestone 
dissolves away a residual mass of insoluble impurities is left behind. 
Are the clays and boulder-clays simply the residue left behind as the 
limestone surface was lowered by solution? If the Kinta limestone 
were impure this would account for much, but it would not account 
for the beds with boulders of granite at Gopeng, and I think that 
a fatal objection to it is that analysis shows the lmestone to be an 
exceptionally pure carbonate rock. Analyses by Mr. C. Salter of 
two typical specimens of limestone from near Menglembu gave the 
following results :— 


No. 1. No. 2. 
per cent per ceut 
Si O2 ; 3 ; ; +27 +26 
AloO3  . ; ; é -26 +26 
Feo 03 O O 5 4 -13 -09 
MeO bs etek hen nie 0 3-75 
Ca O : : ; . 64-50 51-80 
C Oz . : : . 44-25 44-892 
100-71 100-98 


At the Tekka granite-junction the veins containing fluorite and 
.the blue tourmaline veins suggest association with limestone; the 
fluorite because it is calcium fluoride, the tourmaline because similar 
tourmaline has been found in limestone on the Tekka Ltd. mine and 
at Siputeh. But I do not think that anyone who has examined the 
crystalline limestone and the clay at ‘'ekka could conclude that the 
latter is the residual impurity of the former. If it were, and if 
the veins were originally encased in limestone, the latter could not 
possibly retain their course as veins now, because the diminution of 
bulk of the containing rock would be enormous. 

Finally, it may be said in favour of the clays and boulder-clays 
having been deposited as clays and boulder-clays that in Sarawak 
there have been exposed, in the gold-mines of Bau and Bidi, many 
sections of shale over limestone, and generally, as far as I can 
recollect, the bedding in the latter was distinctly preserved, although 
the limestone had been attacked by water and carved into irregular 
pinnacles just as much as in Kinta. 

If the clays and boulder-clays were laid down as such the only 
explanation of their peculiarities that can be adduced is that they 
are of glacial origin. The evidence against this and against the 
deposits being in their original condition must now be given. 

The first objection to the glacial theory is that on the west side of 
the valley boulders of different rocks are not mixed up as they 
usually are in boulder-clay. The tourmaline-corundum rocks are 
not mixed with boulders of granitic rocks. On the Siputeh Ltd. 
property I have not seen any tourmaline-corundum rocks, although 
in the Pusing Bharu mine they were very abundant, and have also 
been seen at Siak. On the other hand, in the Siputeh mine are 
abundant boulders of tourmalinized quartzite with tin-ore and 


Boulder-clays, Federated Malay States. 165 


boulders of quartz. Some years ago one or two granitic boulders 
were found in this mine, but the great majority are those just 
described, and in 1914 a section was laid bare in the tributor’s mine 
that affords the strongest evidence against a glacial origin that has 
been found. The section is in a big open-cast mine. On the near 
side of the mine there is a high limestone wall and lignite. The 
limestone extends to the bottom of the mine, which is about 
120 feet deep, and above it, on the far side, is a section showing 
boulder-clay on the left, and in the centre and on the right shale 
and quartzite very much disturbed. About the same time that this 
section was first seen a quartz-vein was exposed in the limestone at 
the bottom of the mine, and, as the boulders in the clay are all quartz 
or tourmalinized quartzite, the’facts point to the boulder-clay being 
much disturbed quartzite and shale beds, together with a quartz- 
vein, completely disorganized in a deep cavity in the limestone. 

This section is the only instance of a boulder-clay being exposed 
in close proximity to bedded rocks from which the boulders could be 
derived, but the same section showed a further point that is difficult 
to understand. On the left of the section and some yards away from 
the bedded rocks were two elongated patches of clay rich in 
tourmaline. These might possibly represent portions of the bedded 
rocks rich in tourmaline, but their form suggested that they were 
the result of the production of secondary tourmaline in the clay, 
in which case the formation of the boulder-clay must have been 
pre-granitic. This, however, is by no means certain, and the 
patches cannot be taken as an objection to the clay and boulders 
having been derived from the shale, quartzite, and quartz-vein at 
some time. In this mine one must conclude that the boulders are 
not of glacial origin, but are the remains of a tin-lode in shale and 
quartzite overlying limestone. 

Another piece of evidence obtained since the earlier edition was 
published concerns the huge boulders of quartz in the Kinta 
Association mine at Tanjong Rambutan. I have been informed that 
at one period during the work a section of a big quartz-vein was 
exposed from which the boulders could have been derived. I did 
not see this section myself. 

On the Tekka Ltd. mine, and in the sections to the south, where 
the clay is in contact with the granite, there is another point that 
must be mentioned. There are no boulders of any size to be seen 
near the granite. For conclusive evidence of the clays being glacial 
one requires boulders at the junction with the granite. They were 
found in the Kramat Puali section, however. 

The doubt concerning the origin of the tin-bearing clay at Tronoh 
and Tambun can be cited against the glacial theory. 

The absence of striz on boulders is also against this explanation, 
but with rocks so weathered as these are, striae cannot be expected, 
if they ever existed, except in the case of boulders of corundum or 
tourmaline-corundum rocks. Nothing has been found that I can 
regard unreservedly as glacial striae. A glaciated pavement of 
limestone would be destroyed by solution. 

Lastly, a powerful argument against the glacial theory is that with 


166 =—s newt. J.B. Serivenor—Origin of Clays and 


the exception of one section at Kacha mentioned earlier in this 
chapter, but which cannot be seen now, the clays and boulder-clays 
have only been seen resting on limestone. An exposure of them above 
argillaceous or arenaceous rocks, or above any rock not soluble to the 
extent that limestone is soluble, would remove all doubt of their 
having been deposited as clays and boulder- clays, but no such section 
can be pointed to. 

The deposits that were described first as the ‘“Gopeng Beds” differ 
from the foregoing in being in part stratified. Sections in the deep 
excavations now being worked and other sections show that this 
stratification is more distinet than was formerly thought to be the case, 
but there are associated clayey beds with isolated boulders such as those 
figured in the earlier edition (pl. v, fig. 8; pl. vii, fig. 3; pl. xvi, fig. 1), 
and when that edition was prepared a glacial origin for them was the 
only satisfactory explanation. Nothing further has been learned 
about the first two cases illustrated by the figures, but other sections 
have been seen where the boulder-beds are immediately above lime- 
stone and could be interpreted as stratified beds disorganized by 
sinking over limestone. This includes deposits invaded by kaolin- 
veins. LTamstill uncertain that this view of pebble-beds being broken . 
up and mingled with clay to simulate boulder-beds is the best. It is 
insufficient to explain the section in which the big boulder figured in 
pl. v, fig. 3, of the earlier edition occurred ; and the boulder figured 
in pl. xvi, fic. 1, and other isolated boulders occurred on some of the 
highest land. 

Iti is difficult to believe that the corundum boulders found at Pulai 
and on the Tekka Ltd. mine were deposited in their present position 
by water-action. An alternative view to their being dropped from ice 
into fine silt is suggested, however, by an exposure on Tekka which 
has only recently been laid bare. In stiff clay overlying the lime- 
stone corundum boulders were found in great numbers, many being 
over 100 lb. in weight. When the limestone floor was exposed, it 
seemed possible from the distribution of the boulders and the position 
of some of them that they had formed a vein in the limestone. No 
corundum could be found embedded in the limestone, but that, of 
course, is not a fatal objection to there having been a vein, the walls 
of which were dissolved away. Some of the corundum boulders are 
angular, some well rounded. Like other specimens found at Pulai 
and Tekka, the surface of the boulders is often pitted as though some 
mineral intergrown with it had been dissolved away. I have not 
obtained any evidence that it was calcite from the form of the cavities, 
but that is possible. 

In Selangor evidence has been found by Mr. Jones of faulting in 
recent alluvium. Figures in the older edition show complicated 
faulting in the deposits under discussion, and we have to consider the 
possibility of the latter being recent alluvium faulted and in part 
disorganized owing to the solution of the underlying limestone. It 
is, I suppose, possible that faulting such as this could be produced by 
such a cause, but it is unlikely ; and the evidence of the kaolin-veins 
is directly opposed to the beds being recent. Accumulated observa- 
tions of the form of the kaolin-yeins and their junction with the clay 


Boulder-clays, Federated Malay States. 167 


and pebble-beds point to their being intrusive The first vein I saw 
was on Kinta Tin Mines Ltd. In 1908 the top of this vein was visible 
and was sketched. In section it could be seen terminating in a thin 
stringer of kaolin in the red clay. Later on the top was cut away by 
a monitor and the vein exposed near the limestone. The junction 
with the clay is shown in plate x of the old edition, as also another 
junction between a kaolin-vein and the clay. In vol. Ixvii, 1912, of 
the Quarterly Journal of the Geological Society, p. 149, fig. 4, a figure 
is given of a kaolin-vein and a tourmaline-vein on Tekka Ltd. 

The evidence of the form of the veins is strengthened by a case 
where a kaolin-vein was found to be bordered at its junction with the 
clay by a mica-tourmaline rock resembling a rock found at the junction 
of granite and clay on Tekka Ltd. This rock is markedly different 
from the body of the vein itself and can only be interpreted as the 
result of metamorphism of the clay. The tourmaline is blue, as on 
Tekka Ltd. 

Sections of kaolin-veins have been exposed in beds high above the 
limestone and also in excavations where they can be seen close to 
limestone. In the latter one may see what I believe to be the effect 
of the settling-down of the clay, pebble-beds, and kaolin-veins, as the 
limestone dissolves. It shows itself sometimes as a brecciation at 
the junction, an excellent example of which was photographed some 
years ago. In other cases the junction of kaolin-vein and clay is very 
confused, and pieces of the kaolin are separated from the parent vein. 

Against the evidence of the kaolin-veins must be set the buried 
trees that are occasionally found. I have explained these as being trees 
that have fallen into old and forgotten excavations. The sandy 
casing found round some of them supports this view (vide Q.J.G.S., 
Ixvili, pp. 150-1, fig. 5, 1912), but a section has lately been photo- 
graphed, unfortunately too late for illustration ; that is a puzzle I am 
unable to solve. It occurs on the Gopeng Consolidated property. 
On the right is a very clearly-marked fault with grey pebble-beds 
and clay on the right of the fault, and the same beds, stained 
red and disturbed, on the left. ‘To the left of the fault is part of 
a big kaolin-vein. It looks as though it had been slightly bent by 
movement of the clay, but can only be regarded as intrusive, since it 
is the same vein as that mentioned above as being bordered by mica- 
tourmaline rock. There are masses of kaolin, isolated in section, 
which may be joined to the parent vein further in, or may be portions 
sheared off by settling over the limestone. The fault does not touch 
the main mass of kaolin. Only six feet, or thereabouts, above the 
kaolin is a mass of wood around which I could find no casing when 
I saw it some days after it was first uncovered. Here, then, we have 
a kaolin-vein that has effected alteration of the rock it is intruded 
into, well-preserved wood 6 feet from it in the same clay, and a fault 
that does not help matters one way or the other. 

In an earlier chapter the possibility was touched on of there being 
in the Kinta Valley detrital deposits belonging to the era when the 
Peninsula was united to the Archipelago or to that when the former 
was a group ofislands. This must be considered briefly in connection 
with the Gopeng deposits. 


168 T. H. Withers—Shell-fragments 


One reason against regarding these bedded deposits as recent - 
alluvium is their position. They form part of a watershed. They 
rise to a considerable height above sea-level; they are as high as 
much of the land formed of shale and quartzite’ in the centre of the 
Kinta Valley ; and they differ from the recent alluvium in containing 
much less vegetable matter, the few buried trees being the only 
material of this nature. Their position, however, does not preclude 
their being the remnant of deep alluvial deposits that filled a valley 
when the Peninsula and the Archipelago were united, but the 
difficulty is to reconcile with this possibility the evidence of the 
kaolin-veins, which must in that case have been intruded into surface 
deposits. 

The same objection applies to their being formed in the sea when 
the Peninsula was a group of islands, and there is the further objection 
that the deposits at Gopeng do not resemble the familiar coast deposits 
of to-day. If they are considered to be of marine origin we have to 
face the absence of marine organization and mangrove mud. 

Both in the case of unbedded and bedded deposits there is still the 
question of the origin of the tin-ore to be noticed. Its most striking 
feature is its angularity, which was shown in plate iv of the earlier 
edition. On the west of the Kinta River there is no doubt that some 
of the ore was brought by media that came through the limestone 
from the granite of the Kledang Range or direct from granitic intru- 
sions such asthat at Pusing Lama. But thisis not sufficient to account 
for all the ore, and I think the only satisfactory solution is that 
detrital ore derived from an older granite was added to by a younger 
granite. It must be remembered that large areas of limestone bed- 
rock have been exposed showing no veins by which tin might have 
come to the rocks above. 

At Tekka and Gopeng the angularity of the detrital ore is against 
its being alluvial, and on the Kinta Tin Mines Ltd. property and 
elsewhere evidence has been found of enrichment from the kaolin-veins 
and the granite of the Main Range. The detrital ore must be older 
than the kaolin-veins, and therefore, we must conclude, older than 
the granite of the Main Range, and it should be kept in mind that 
the granite fragments in the altered volcanic ash of Pulau Nanas, 
near Singapore, show that a granite mass older than the granite of 
the Main Range once existed (Q.J.G.8., Ixvi, p. 428, 1910). 

On pp. 89 and 40 of the 1913 publication I gave some objections 
to these Kinta tin-deposits being held to be of glacial origin. The 
Siputeh section is certainly a further objection, but, seeing that 
extensive glaciation is known to have existed on Gondwanaland about 
the time when these beds were laid down, a glacial origin appears to 
meet more of the facts than any other explanation. 


IIiI.—Some Prrecypop SHELL-FRAGMENTS DESCRIBED AS CIRRIPEDES. 
By THOMAS H. WITHERS, F.G.S. 

MONG a number of Cirripede plates from the Chalk Marl and 

Cambridge Greensand of Cambridge submitted to me some time 

ago, were certain fossils which at first puzzled me considerably. 


described as Orrrupede Valves. 169 


Although there were more than twenty examples, all came apparently 
from the same side of the animal, that is, they were not left and 
right, and this led me to suspect that they were not Cirripede valves, 
and to examine them more closely. One edge close to the narrow 
end of the shell was then seen to be broken quite clean and straight, 
and on comparing these fossils with some Pelecypod shells from the 
same horizon it was quite clear that they were the anterior ears of 
right valves of Aucellina grypheoides (Sow.) (Text-fig. 7, p.170), a shell 
belonging to the family Pteriide (see H. Woods, Pal. Soc. Monogr. 

(etaceane Mollusca, 1905, vol. ii, p. 72, pl. x, figs. 6-13). Other 
specimens submitted at various times from Jurassic and Cretaceous 
rocks, turned out on examination to be the anterior ears of the right 
valves of Pelecypod shells like Pecten, anda number of such specimens 
were included among some Cirripede plates from the Chalk of Rigen 
obtained for the British Museum by Frau Agnes Laur. 

Since the superficial resemblance to Cirripedes of the anterior ears 
of the right valves of Pecten-like shells and other shell-fragments, 
has resulted in their mistaken identification by collectors, even those 
of experience, it is not surprising that some authors should have 
described and figured such fossils as species of Cirripedia. 

Thus, Darwin has figured as a carinal-latus of the Cirripede 
Scalpellum solidulum, the anterior ear of a Pecten from the Cretaceous, 
and a recent examination of the holotype of the supposed Liassic 
Cirripede Pollicipes alatus, shows that this is another case of the 
anterior ear of a Pelecypod being mistaken for a Cirripede valve. 
One or two other instances have been noticed while going through 
the Cirripede literature, and it was thought advisable to include them 
in the present note, for this will serve not only to call attention to 
these remains, but will be a further step towards ridding the 
Cirripedia of all such non-Cirripede material. 


Zoocarsa DoLIcHoRHAMPHIA H. G. Seeley. (Text-fig. 1, p. 170.) 
1870. Zoocapsa dolichorhamphia, H. G. Seeley, Ann. Mag. Nat. Hist., ser. Iv, 


vol. v, p. 283. : 

1877. ns i n (=Avicula or Pecten): H. 
Woodward, Brit. Mus. Cat. 
Brit. Foss. Crustacea, 
p. 146. 

1891. a 4 at (=Avicula or Pecten): H. 


Woods, Cat. Type Foss. 
Woodwardian Mus. Cam- 
bridge, p. 132. 
Since this fossil from the Lias of Lyme Regis was described as 
a sessile Cirripede by Professor Seeley, an examination of the type 
was made by Dr. H. Woodward, who stated in his Catalogue (1877, 
p. 146), ‘‘I am inclined to consider the ‘ tergum’ to be the wing of 
an Avicula or Pecten, and the underlying ‘scutum’ to be another 
portion of the same shell.” H. Woods (1891, p. 132) subsequently 
recorded the fossil as ‘‘ Avicula or Pecten”’. 
No figure has yet been given of this fossil, and only a very 
inadequate idea of it can be deduced from the description. The 
specimen really consists of seven or eight fragments of Pelecypod 


170 T. H. Withers—Shell-fragmenis 


shell embedded closely together, and only one fragment shows the 
outer surface. From their colour and appearance they evidently 
belong to more than one form of shell, but it is impossible to discover 
much from the inner surface of mere shell-fragments. 

The most conspicuous fragment is the irregularly triangular shell- 
fragment marked II in Fig. 1, and this was Seeley’s ‘‘tergum”. It 
is really the anterior ear of a right valve of a Pecten with a part of 
the remaining shell, and shows the inner surface. The sub- 
cylindrical shell-fragment regarded by Seeley as continuous with it 
and as the ‘‘ beak” of the ‘‘tergum”’, does not appear to me to 
belong to it. Above the ‘‘ tergum”’ isa four-sided shell-fragment (I) 
called by Seeley the ‘‘scutum’’, but this is an indeterminable shell- 
fragment quite unlike the inner surface of the scutum of a Cirripede. 


4) ns. 
Y) 
yy 


7: 


1. Zoocapsa dolichorhamphia Seeley. 

2. Pollicipes alatus Tate. (After Tate.) 

3. Scalpellwm solidulum Steenstrup sp. ( 

ad He oe a (After Marsson.) 
5 ( 
7 


After Darwin.) 


6 After Karakasch.) 


Aucellina gryphcoides Sowerby sp. (After Woods.) 
(Figures drawn by Miss G. M. Woodward.) 

Projecting from under the ‘“‘tergum” is another fragment (III) 
with slightly elevated wavy ribs, crossed at right angles by growth- 
lines. ‘This is the only fragment showing the outer surface, and the 
ornament of it agrees very closely with that of the Pelecypod Lima 
gigantea, Sowerby. It represents Seeley’s ‘‘upper latus”. On the 
opposite side of the ‘‘tergum’’, is another fragment (IV) regarded 
by Seeley as one of the compartments, but though Molluscan it is 
impossible to say to what shell it belongs. Professor Seeley stated, 
“‘ Altogether the plates preserved would incline one to suspect that 
there were no more.”’ Itis apparently to be understood from this 


described as Cirripede Valves. Lid 


that he did not include as belonging to his supposed Cirripede, the 
three shell-fragments unnumbered in the figure. 

Not only did Professor Seeley found a new genus for these shell- 
fragments, which obviously belong to different Pelecypods, but he 
regarded them as belonging to a Cirripede which was the type of 
a new iamily intermediate between the Balanide and Verrucide, 
with peculiar affinities towards the Lepadide. A Cirripede valve is 
a well-formed structure, and in no way resembles the fragmentary 
portions of shell in this fossil. 


Ponticirrs anatus R.. Tate. (Text-fig. 2, p. 170.) 


1864. Pollicipes liassicus, R. Htheridge, Quart. Journ. Geol. Soc., vol. xx, 

p. 114 (nomen nudum). 

TSTON e- ee ne Tate, Appendix I to Ann. Rep. Belfast Nat. F. C., p. 23, 
Dla es 6: 

This shell-fragment, which came from the Lower Lias ‘‘4. angu- 
Jatus’’ zone of Island Magee, Antrim, was originally noticed by 
R. Etheridge as a scutum of Podlicipes, and although he gave neither 
description nor figure, he proposed for it the name Pollicipes liassicus. 

R. Tate subsequently described and figured it as a scutum of 
Pollicipes under the new name P. alatus. He remarked—‘‘ The 
single scutal plate here figured is the one to which Mr. Etheridge 
applied: the MS. name of P. lassicus; but, as another species was 
described by Dunker with a similar denomination, P. diasinus,' it 
appears to be advisable not to adopt Mr. Etheridge’s provisional 
name. I, therefore, have selected that of P. alatus.” 

The holotype of P. al/atus is now in the Geological Survey Museum, 
Jermyn Street, registered 28849. Examination has shown that it is 
not a Cirripede valve, but merely the anterior ear of a right valve of 
a Pecten. Dr. F. L. Kitchin, who kindly examined the specimen to 
see if the species could be determined, made the following 
confirmatory report: ‘‘The type of Tate’s Pollicipes alatus is 
undoubtedly the anterior ear of a right valve of a Pecten. I can 
only say that it belongs to one of the smooth Pectens that have been 
commonly ascribed to P. calvus, Goldfuss. Goldfuss only figured left 
valves, and I am not absolutely sure that any of the specimens in 
this museum ascribed to his species are truly identical with it. But 
Tate and others have referred certain smooth forms from the 
angulatus and overlying zones to this species, and in the absence of 
an exhaustive enquiry based on much material it is usual to adopt 
this provisional naming. It is not unlikely that more than one 
species has been thus determined among our British material, but it 
is to one of these that the supposed Pollicipes belongs. The specimen 
is such a fragment that a precise determination of species is scarcely 
to be hoped for.”’ 

In a paper ‘On a New Species of Pollicipes from the Inferior 
Oolite of the Cotteswold Hills”, Gron. Mac., 1908, p. 341, 


1 The name Pollicipes liasinus was given by Dunker (1848, Palgontographica, 
Bd. i, p. 180, pl. xxv, fig. 14) to a supposed tergum from the Lias of Halberstadt, 
and although the figure is not at all like that of a tergum of a Cirripede, an 
examination of the specimen would be necessary before one could give an 
Opinion as to its nature. 


172 T.H. Withers—Shell-fragments described as Curripedes. 


Mr. Linsdall Richardson states, ‘‘I have found several examples of 
plates belonging to a species inseparable from this one [P. alatus, 
Tate | in the Lias of oxynoti-armati hemere that was exposed when 
excavations were being made for a new gas-holder at the Gloucester 
Gas Works.” Mr. Richardson most kindly sent me examples of the 
supposed Cirripede plates from that locality, and these confirm the 
conclusion already arrived at that they, like P. alatus, merely 
represent the right anterior ears of some form of Pecten-like shell. 


ScALPELLUM soLIDULUM Steenstrup sp. (Text-figs. 3-6, p. 170.) 


Steenstrup (1839, Kreyer’s Naturhist. Tidsskrift, Bd. 1, p. 412, 
pl. v, figs. 14, 14*) founded this species on an. undoubted carina of 
a Cirripede from the Chalk of Scania. Darwin, however, when 
redescribing the species in his monograph (Pal. Soc. Monogr. Foss. 
Lepadide, 1851, p. 42, pl. i, figs. 8a—f), included with a carina and 
tergum, a Pelecypod fragment (figs. 8e-f) from Kopinge, Scania, but 
this in no way affects the nomenclature of Scalpellum solidulum. 
This shell-fragment (Text-fig. 3), which was considered by Darwin 
to be a carinal-latus! of S. solidulum, really represents the anterior 
ear of a right valve of a species of Pecten. 

A shell-fragment (Text-fig. 4) of the same nature from the Chalk 
of Riigen, was figured by Marsson (1880, Mitth. naturw. Vereine 
Neu-Vorpommern und Riigen, Jahrg. xii, p. 15, pl. i, fig. 15), and the 
figure given of that fossil is so good, and shows its fractured inner 
edge so well, that one can only wonder that it should have been 
described as a Cirripede valve. 

Subsequently, N. I. Karakasch (‘‘Les Cirrhipédes du terrain 
erétacé de la Crimée,” Trud. St. Petersb. Obsch. Estest., vol. xxx1, 
livr. 5, p. 14, pl. i, figs. 17, 18), no doubt following Darwin and 
Marsson, figured two similar shell-fragments (Text-figs. 5, 6) from 
the Chalk (Upper Senonian) of Bakla, Crimea, as carinal lateral valves 
of Scalpellum solidulum. These may not, however, belong to the 
same species of Pecten to which the shell-fragments figured by 
Darwin and Marsson belong. 

Similar shell-fragments, which are undoubtedly the anterior- ears 
of right valves of Pectens, were included with a large number of 
Cirripede valves in a collection of fossils sent to the Geological 
Department of the British Museum from the Chalk of Riigen, but, as 
in the case of those figured by Darwin, Marsson, and Karakasch, it 
would be a very difficult and unprofitable task to attempt to determine 
the species. 

ConcLusiIon. 

While the present communication may be taken as showing that 
certain so-called Cirripedes from the Jurassic and Cretaceous Rocks 
are really the remains of Pelecypod shells, it must not be regarded as 
exhaustive. It deals only with those of which the originals can be 
examined, or as to the nature of which no doubt is possible. Some 


‘In his other memoir (1851, Ray Soc. Monogr. Lepadide, p. 245) Darwin 
thought that he was wrong in considering this to be a carinal-latus, and that it 
was probably an upper latus. 


Notices of Memoirs—Drawings in Spanish Caves. 173 


other Jurassic fossils figured as Cirripedes are very doubtful, and an 
examination of the originals will probably show that they do not 
belong to the Cirripedia, but from the descriptions and figures it is 
impossible to say what they really are. 


NOTICES OF MEMOTRS. 


a0 aa. 
Drawines iv Spanisn Caves. 

Los Grasapos dz ta Curva DE Prncues. By Epvarpo Hrrndnpez- 
Pacurco. Comisidn de Investigaciones Paleontologicas y Pre- 
historicas, Mem. No. 17, Madrid, 1917. 

HE Spanish Government is to be congratulated on the valuable 
memoirs on Geology, Prehistoric Archeology, Zoology, and 

Botany which are being issued in rapid succession from the National 


—— 


So 


Drawing of a hunted deer, pierced with arrows, on the wall of the cavern of 
La Pena, San Romdén de Candamo, Asturias, Spain. Original about 
4 feet in depth. 


Museum of Natural Sciences in Madrid. They are making known 
the scientific treasures of Spain in a manner which has not hitherto 
been possible; while their attractive style and their profusion of 
admirable illustrations render them all the more welcome. The 
memoirs on the prehistoric drawings in the Spanish caves are 
especially interesting, and the latest, by Dr. Hernandez-Pacheco, 
maintains the standard we have now been led to expect. 


LA Reviews—The South Wales Coalfield. 


The new memoir deals with incised drawings, chiefly of deer, in 
a remote cave in the province of Burgos. Like many of the other 
caves ornamented by Magdalenian man, it consists of little more 
than irregular crevices in the Cretaceous limestone and could 
scarcely have been used as a habitation. Dr. Pacheco thinks that 
the drawings were made there by the hunters merely under the 
impression that they would have some mystic influence on their 
success in the chase. Some of the deer seem to be represented as 
pierced by arrows, and Dr. Pacheco publishes for comparison with 
them a most remarkable incised drawing of a hunted deer lately 
found in the cave of La Pefa, in San Romén de Candamo, in 
Asturias. This drawing is so extraordinary that: we venture to 
reproduce it here. It shows the deer pierced by several arrows, 
standing at bay, in evident distress, with protruded tongue. Of all 
the drawings of game hitherto found in the Spanish and French 
caves this is probably the most animated. The effect is even 
enhanced by the skilful use of lines of shading, and we cannot but 
admire the artistic powers of the old hunters who were able to 
produce such work on irregular surfaces in dark recesses underground. 


AL Sa We 


RHVINWS- 


Memorrs oF THE GroLocicaAL SURVEY. 


I.—Tue Geotoey or tak Sourm Wates Coarririp. Part 1V: Tue 
Country arounD Ponrypripp and Mazsrée. . By A. Srrawan, 
F.R.S., R. H. lrppeman, and W. Grsson. Second edition, revised 
by W. Grsson and T. G. Canrritz. Memoirs of the Geological 
Survey, 1917. pp.ix +160. Price 38s. 6d. 


f¥\HIS memoir deals chiefly with the occurrence of the coal-seams 

in this area and their correlation, both at their outcrops and 
in the shafts of the mines, the character of the coals being described 
in a separate memoir dealing with the whole of the coalfield. The 
coal occurs mainly in the Lower Coal Series, but also to some extent 
in the Pennant Series; the Upper Coal Series is only present in one 
or two places in the area. The higher coals are more bituminous 
than the lower, and all the coals lose bituminous matter in a westerly 
and north-westerly direction, as is common in South Wales. Since 
the issue of the first edition numerous changes in the mines and 
mining have taken place; for example, steam coals are now no longer 
worked west of the Ogwr, while these coals are now being won from 
deep shafts sunk through the Pennant Series north and north-west 
of Llantrisant. Also the mining in the Ogwr and Avan valleys has 
been considerably developed as a consequence of the building of 
docks at Port Talbot, while the mining conditions of the Rhondda 
valleys have altered but little. The memoir contains chapters 
on the geological structure, the Mesozoic rocks, and the glacial 
deposits. It is illustrated by figures and vertical sections showing 
the correlation of the coal-seams, and is accompanied by a colour- 
printed map (Sheet 248) on the scale of one mile to the inch, which 
is a very good example of colour-printing. Wi. We 


Reviews—Geology of North-Eastern Rajputana. 175 


Indian Grotoey. 


I1.—Tue Grotoey or Norta-Kastrrn Raspurana anp ADJACENT 
Disrricrs. By A. M. Hrron, B.Sc., F.G.S., Assoc. Inst.C.E., 
Assistant Superintendent, Geological Survey of India. Memoirs 
of the Geological Survey of India, vol. xlv, pt. i. Calcutta, 
1917. Price 4s. 


NHIS memoir deals with the re-survey of the above district, which 
is roughly contained in a triangle, with the cities of Agra, Jaipur, 
and Delhi at its apices; the original survey was carried out by C. T. 
Hackett in 1881 and is now out ofdate. ‘The region is one of old folded 
rocks; these had been denuded to a peneplain, uplifted a second 
time, and now are in an advanced stage of the second cycle of 
denudation. The greater part of the district is covered with | 
alluvium, but in the south-west part the old rocks come to the 
surface over a considerable area; the dips here are always high, and 
the hard bands stand up as ridges with broad valleys between: this 
close connexion between geological structure and topography is not. 
common in this part of India. 

Two distinct geological systems can be separated—an older, the 
Aravalli system of Archsean age, which may be correlated with 
the Dharwar system of Cental and Southern India, and a newer, the 
Delhi system, which is placed among the Lower Purana rocks. The 
interval separating the two systems corresponds to the Ep-archean 
interval of North America. 

The Aravalli rocks are exposed along the anticlines of the post- 
Delhi folding and consist of highly metamorphosed sediments with 
some intrusive granites, amphibolites, and quartz veins. The Delhi 
system begins with an inconstant quartzite which is overlain by the 
Rialo limestone. This limestone is a pure dolomite and usually 
forms low-lying country, with the exception of a few residual knolls. 
of ironstone formed by metasomatic alteration. The succeeding 
Alwar series consists of quartzites, grits, and associated volcanic 
rocks, invaded by granites, pegmatites, and basic sills, now altered 
to amphibolites. ‘These rocks are succeeded by a banded siliceous 
limestone, the Kushalgarh limestone, with which is associated a 
peculiar rock known as the ‘‘hornstone breccia’. Finally, the 
Delhi system is completed by the Ajabgarh series, which is composed 
chiefly of clays with impure quartzites and limestones, and shows 
deeper-water conditions than the Alwar series. 

The hornstone breccia which is found sometimes below and some- 
times above the Kushalgarh limestone is a very remarkable rock. It 
consists of angular fragments of quartzites, identical with the 
Alwar and Ajabgarh quartzites, some pieces of slate similar to the 
Ajabgarh slates, and brecciated white vein quartz in a very finely 
granular matrix, the grains of which are coated with limonite, and 
which is occasionally sufficiently ferruginous to be used as an iron 
ore. It is suggested that the rock was formed by the crumpling of 
alternating beds of quartzite and slate under the stress of the post- 
Delhi folding; the quartzites, being brittle, would break and be 
pushed into the more yielding slates. Into this shattered rock, 


176 Reviews—Iron-ores of Canada. 


veins of quartz were intruded, and some iron and copper were intro- 
duced into the matrix. Finally the whole mass was again brecciated 
by further folding. 

The post-Tertiary formations which cover the old rocks over a 
great part of the area are partly the old alluvium of the Ganges and 
partly blown sand; a considerable amount of Kankar is found near 
the outcrop of lime-bearing rocks. 

The district contains a fair number of minerals of economic 
importance, but unfortunately only in small quantity. 

The irregular patches of Rialo limestone altered to hematite, 
which contain seams up to 7 feet in thickness, appear to be a 
workable proposition. A fairly large amount of iron has been 
smelted in this region in past times, but all the mines are now closed. 
Copper was mined on a considerable scale in ancient times, but none 
is now extracted. 

The ore was chalcopyrite with pyrrhotite occurring along the 
junction between quartzite and slate at a horizon low down in the 
Alwars. Some kaolin is dug from the pegmatites, and steatite and 
a variety of building stones and marbles are also quarried in the 
district. 

The memoir is illustrated by many excellent drawings and 
photographs of the scenery and structures in the field, photographs 
of specimens, and photo-micrographs of thin sections, and also by 
a geological map and a number of horizontal sections. 


Wi Hep 


CANADIAN [RON-ORE. 


TII.—Inon-ornr Occurrences in Canapa. Vol. I. By E. Linpeman 
and L. L. Botron. Department of Mines, Canada. pp. 71, with 
23 plates and 1 map. Ottawa, 1917. 

{THE literature of the Canadian iron-ore deposits has till now been 
very scattered and difficult of access, and the Department of 
Mines has rendered a useful service by collecting all the available 
data in this convenient form. Jron-mining was not seriously 
developed in Canada till 1896, but since that date it has made rapid 
progress. Nevertheless, even now the proportion of ore mined in the 
Dominion is only about 15 per cent of that smelted in Canadian 
furnaces. The greater part comes from Newfoundland and the 
United States. Among the provinces Ontario is the largest producer: 
the most important source is the Helen Mine in the Michipicoten 
district. The ore is hematite, probably derived from siderite and 
pyrite by oxidation. Prospecting of large areas of banded jaspers 
and magnetite schists correlated with those of the Vermilion and 
Mesabi ranges in Minnesota has led only to disappointing results. 
The only promising occurrence of this kind is the Akitokan iron- 
range in Western Ontario, a magnetite ore with rather high sulphur 
content. In British Columbia there are some promising contact- 
deposits of magnetite which lie near coal and limestone, suitable for 
use as fuel and flux. The great furnaces of Nova Scotia chiefly use 
Newfoundland ore, but they were once supplied by local deposits of 
hematite, limonite, and ankerite in strata of Devonian age. These 


Reviews—Great Australian Artesian Basin. 177 


seem to be contact-deposits, and they are rather rich in sulphur and 
phosphorus. 

This report contains detailed descriptions of a great number of 
small occurrences of iron ores of almost every possible kind in all 
parts of the Dominion, but most of these do not seem likely to be of 
much importance, at any rate in the immediate future. 

An interesting and useful appendix contains a detailed description 
of the Wabana mine in Newfoundland, now one of the largest iron- 
mines in the world, which supplies much of the ore for the Canadian 
furnaces. ‘here are five beds of ironstone, from 5 to 30 feet thick, 
intercalated in Ordovician sandstones and shales. The ore is chiefly 
hematite, with some siderite and chamosite. Theiron content is on 
the average 53 per cent, with silica up to 10 per cent and about 0°85 
per cent of phosphorus. The ore-reserves are very large; a con- 
servative estimate is 2,000,000,000 tons, and this figure may 
eventually be much exceeded. The mines are very conveniently 
situated for shipment of the ore, being close to the coast, where the 
water is sufficiently deep for large ships close in shore. The loading 
_ facilities are so extensive as to permit the loading of 5,000 tons of 
ore per hour. Part of the workings extend under the sea. 

It is interesting to note that a large use has been made of 
magnetic surveys in investigating the iron-ore deposits of Canada, as 
this method was found to give useful results in Sweden. 


Jie Mel ate 


ArrEstaN WaTERS oF AUSTRALIA. 


1VY.—Tur Prosiem or trae Great AusrraLian Arrestan Basin. By 
A] i, pu Vor. Journ. Proc. Roy. Soc: N. 8. Wales, vol. li, 
De Loo lO iT. @ 
N the light of his extensive experience of South African geology 
Dr. du Toit has re-examined the whole problem of the origin of 
the great artesian basin of Australia. Professor Gregory concluded, 
in opposition to the views of many Australian authorities, that the 
water was partly of magmatic origin and partly water included in 
ancient sediments during their deposition, only a small part being of 
modern meteoric origin; Mr. Symmonds considered that most of the 
water was juvenile in the sense of Suess. Dr. du Toit’s views agree 
in the main with those of Professor Gregory in that he regards the 
waters as originating from three sources: (1) residual (Mesozoic), 
(2) plutonic, (3) Tertiary. The bulk of the Mesozoic water is 
believed to have been replaced by alkaline water derived from 
igneous intrusions: these waters are rich in sodium carbonate. On 
the eastern side of the basin early Pleistocene surface water drove out 
much of the still earlier accumulation and carried salts downwards. 
However, Dr. du Toit believes that at the present time the meteoric 
source is of most importance in keeping up the supply, though much 
of the older water may still remain. The notable and alarming 
falling-off in the yield of the wells observed of late years suggests 
the urgent need for efficient Government control of borings in the 
artesian area. Re He Re 
DECADE VI.—VOL. V.—NO. IV. 12 


178 = = Reviews—Mining in South Australia. 


V.—A Review oF Mrinine Operations IN THE STATE OF Sovute 
AUSTRALIA DURING THE HALF-YEAR ENDED JuNE 80, 1917. No. 26. 
Compiled by Lionen C. E. Grz, S.M. Adelaide, 1917. | 


N addition to the mineral statistics for the half-year this review 
contains an account of the Government diamond drilling opera- 
tions, with logs of the bores, an account of several districts where 
there are mineral deposits which seem worth further prospecting, and 
an account of several mines which are either closed down or doing 
little work, with suggestions for their improvement. Among the 
deposits not yet fully prospected are deposits of apatite and graphite 
and also a large pyritic quartz lode which is regarded as a possible 
source of sulphur. 

The apatite deposit is situated at Boolcoomatta Spring and consists 
of pegmatites occurring in Pre-Cambrian gneisses and schists. The 
pegmatites are very coarse-grained, containing felspar crystals up to 
6 inches in length and plates of muscovite up to 1 inch in width. 
There are considerable numbers of veins, of which a fair proportion 
contain apatite in amounts varying from 5 to 60 per cent. The 
graphite deposits are situated chiefly in the southern part of Hyre’s 
peninsula and consist of graphite schists in a series of gneisses, 
schists, and quartzites of Pre-Cambrian age. The outcrops are much 
weathered and decomposed, so that a fair determination of the flake 
graphite present cannot be made, but it is suggested that the quality 
will improve in depth when the oxidized ferruginous zone is pene- 
trated. This deposit is regarded as an important one owing to the 
present large demand for flake graphite for the manufacture of 
graphite crucibles. The review shows great enterprise on the part 
of the Government geologists in seeking out new deposits and in 
trying to revive those mines which for various reasons have ceased 
work or are likely to be closed. WH We 


VI.—A New Test or tHe Sussipence ‘'Heory oF Corat Reers. 
By R. A. Daty. Proceedings of the National Academy of 
Sciences, vol. 11, p. 664, 1916. 

fZ\HE author points out that during the formation of atolls according 

to Darwin’s theory a concavity or ‘‘moat’’ must have been 
formed between the up-growing reef and the subsiding island. The 
filling of this moat, which has never been properly discussed, affords 
another test of the applicability of the theory. The moats have 
always been completely obliterated and the lagoons are very shallow. 
he possible source and means of transport of the material required 
for this filling are discussed in detail by the author. The lagoon 
floor is generally sandy and not covered by growing coral and other 
organisms, while the transport of sand by waves and currents can 
only be small and local. The levelness of the floor is inconsistent 
with filling by this means. ‘The general conclusion is drawn that 
the processes mentioned are not adequate to explain the facts; and 
that existing coral-reefs are new upgrowths from platforms formed 
previously to and independent of reef-growth. The final preparation 
of the platform is supposed to have taken place during the Glacial 
period. Ree SER Re 


Reviews—New Fossil Corals, Pacific Coast. 179 


VII.—New Foss Corts rrom tHE Paciric Coast. By Jorcrn O. 
Nomuanp. University of California publications in Geology, 
vol. x, No. 13, pp. 185-90, pl. v, 1917. 

‘IVE new Tertiary Corals are described and figured, namely, 
k Astrangia boreas, u.sp., Pleistocene (?), Douglas I., South- 
Eastern Alaska; 4. grandis, n.sp., Pliocene, Middle Fernando series, 
Guadalupe, Santa Barbara County, California; Astreopora occidentalis, 
n.sp., Tertiary (?), near Newport, Oregon; Caryophyllia oregonensis, 
n.sp., Oligocene, Astoria series, near Smith’s Point, North-Western 
Oregon; Dendrophyllia californiana, nu.sp., Oligocene, Agasoma 
gravidum beds, near Walnut Creek, Contra Costa County, California. 
An undetermined species of Balanophyllia also is recorded from the 
Pliocene, Middle Fernando series, Fugler Point, S.E. of Santa Maria, 
Santa Barbara County, California, which is of interest as the ‘‘ genus | 
has heretofore been unknown in the Tertiary deposits of the Pacific 
Coast later than the Oligocene”’’. 

Finally, an Oligocene Coral-fauna is mentioned, consisting of 
Balanophyllia sp., Flabellum sp., Paracyathus sp., Pocillopora (?) sp., 
Sphenotrochus (?) sp., and two species of Zrochocyathus ‘‘ associated 
with Dendrophyllia hannibali, Nomland, or in the same series of beds as 
that species’’, in the Astoria group of South-Western Washington. 


Wiebe la: 


REPORTS AND PROCHHDINGS. 


I.—GerotocicaL Socirry or Lonpon. 


1. Annuat GrenerRaL Meerine. 


February 15, 1918.—Dr. Alfred Harker, F.R.S., President, in the 
Chair. 

The Reports of the Council and the Library Committee were read. 
It was stated that there had been a total accession of 29 Fellows in 
the course of 1917. During the same period the losses by death 
and resignation amounted to 43. The total number of Fellows on 
December 3l, 1917, was 1,220. 

The Balance-sheet for that year showed receipts to the angen of 
£2,966 10s. 8d. (excluding the balance of £676 12s. 5d. brought 
forward from 1916) and an expenditure of £3,581 1s. 6d. (including 
the purchase for £475 of £500 5 per cent War Loan). 

The Reports having been received, after a brief discussion, the 
President handed the Wollaston Medal, awarded to Dr. Charles 
Doolittle Walcott, F.M.G.S., to Mr. William H. Buckler, Attaché 
to the Embassy of the United States of America in London, for 
transmission to the recipient, addressing him as follows :— 

Mr. BuckiEr,—The Wollaston Medal, the highest honour at the 
disposal of this Society, is conferred upon Dr. Charles Doolittle Walcott 
in recognition of his eminent services to Geology and Paleontology, more 
particularly among the older fossiliferous rocks of North America. 
While his administrative work, both on the United States Geological 
Survey and at the Smithsonian Institution, has done much for science in 


his own country, his personal researches have excited interest and admira- 
tion wherever Geology is cultivated. 


180 Reports & Proceedings—Geological Society of London. 


He has made important contributions to the history of the Algonkian 
formations, and his discoveries lead us to hope that the less altered of those 
ancient sediments may ultimately yield more abundant and definite relics 
of pre-Cambrian life. His detection of fish-remains in the Ordovician rocks 
of Colorado, again, carried back by a stage the earliest appearance of 
vertebrates in the succession of life-forms. But it is in the Cambrian 
strata that Dr. Walcott has found chief scope for his labours, which, 
pursued principally upon the American continent, have often had a world- 
wide importance. Realizing the dual part which the exponent of 
Paleontology is called upon to sustain, he has illuminated that science 
alike in its geological and in its biological aspect. Under the former head 
should be mentioned the determination and collation of the stratigraphical 
sequence in numerous districts, and the light thrown thereby upon the 
problems of Paleophysiography. In particular, Dr. Walcott’s study of 
the geographical distribution of the Cambrian faunas, establishing the 
existence of two distinct provinces, marked a signal advance in this field. 
On the biological side his work has been no less fruitful in results. It is 
sufficient to recall the series of memoirs dealing with the Trilobites, in 
which he greatly elucidated the organization of that important group, and 
again his two handsome volumes on the Cambrian Brachiopoda. 

In recent years, with energy which a younger man might envy, he has 
pushed his researches into the Rocky Mountains of Canada, amidst scenery 
which his beautiful photographs have made known to many. There he has 
been rewarded by the bringing to light of two richly fossiliferous horizons 
in the Middle Cambrian succession, including in one an assemblage of 
fossils marvellous for the perfect preservation of their detailed structure. 
The preliminary account of the discovery has aroused keen interest, and 
paleontologists eagerly await the full description by a master hand of this 
unique collection. 

If by his official status, joined with his personal record, Dr. Walcott is 
in some sense representative of American geology, with its large oppor- 
tunities so ardently embraced, the occasion may remind us that community 
of scientific interests is perhaps not least among the links which unite your 
country to ours. I have much pleasure, Sir, in placing this Medal in your 
hands for transmission to its recipient, and trust that his future career may 
include achievements no less brilliant than those which we commemorate 
to-day. 


Mr. Buckler replied in the following words:— 


Mr. PrestpENt,—Mr. Page greatly regrets that a long-standing engage- 
ment prevents him from receiving this Medal in person. He has asked me 
to convey to you Dr. Walcott’s deep appreciation of the honour awarded 
by your Society and to assure you that this feeling is shared by our fellow- 
countrymen. Let me thank you, not only for this high distinction con- 
ferred upon American Geology in the person of one of its leading 
representatives, but also for the wishes which you have expressed, and in 
which all Americans will heartily join, for Dr. Walcott’s future labours. 

As a former President of the Baltimore Society of the Archeological 
Institute of America, I may mention that Dr. Walcott presides over the 
Washington Society of that Institute, a fact reminding us that his wide 
interests include Archeology, the younger sister of Paleontology. 

In these times and on such an occasion one cannot but recall-—-as you, 
Sir, have said--the community in scientific, as in literary and political, 
activity which exists between the English-speaking peoples on both sides 
of the Atlantic. It is significant that of the two American Institutions in 
which Dr. Walcott has served as Secretary, the Smithsonian was founded 
by. an Englishman, the Carnegie bya Scotsman. The partnership in arms, 
which now as never before unites our peoples, cannot fail in the coming 
years to strengthen and to extend that scientific comradeship of which your 
tribute to Dr. Walcott is a signal recognition. 


Reports & Proceedings—Greological Society of London. 181 


In handing the Murchison Medal, awarded to Joseph B. Tyrrell, 
M.A., to the Hon. Sir George Halsey Perley, K.C.M.G., High 
Commissioner for the Dominion of Canada, for transmission to the 
recipient, the President addressed him as follows :— 


Sir Grorcr PrriEY,--The Murchison Medal has been awarded to 
Mr. Joseph B, Tyrrell in recognition of the value of his many services to 
geological science. In the breadth of their scope, in the pioneer element 
which has so largely entered, in the practical benefits which have often 
followed, those services may stand as typical of Canada’s contribution to 
Geology. 

During more than thirty years Mr. Tyrrell has been frequently engaged 
in exploring wide tracts of the little-known Barren Lands of Northern 
Canada, making prolonged journeys of a kind which demands no ordinary 
resolution and endurance. Besides thus adding largely to geographical 
knowledge by his own efforts, he has done much to make known the results 
of earlier explorers in the North. While helping very materially to 
develop the mineral resources of the Dominion, he has at the same time 
gathered much valuable information touching the older rocks of the region ; 
and, uniting in his own person the geologist and the prospector, he has 
often shown by example how science and enterprise may go hand in hand, 
to the great advantage of both. 

On the side of pure science, however, his most notable researches have 
been in the domain of Glacial Geology, where his extensive acquaintance 
with the country has enabled him to arrive at conclusions of a large order. 
Prior to 1894 it was generally held that the ice which once overspread 
Canada, east of the Cordillera with its mountain glaciers, emanated from 
a single centre of dispersal.” Mr. Tyrrell first demonstrated the existence 
and approximate limits of a great ice-sheet, which he named the Keewatin, 
centreing in the country west of Hudson Bay and distinct in origin from 
the Labradorean ice-sheet on the east. To these two he subsequently 
added-a third, under the name of the Patrician Glacier, which had its 
gathering-ground to the south of Hudson Bay. His development of this 
thesis, involving a discussion of the relations in time and space of the ice- 
sheets radiating from different centres, must rank among the most im- 
portant contributions to the Glacial history of North America. 

In forwarding to Mr. Tyrrell this token of recognition from the Council 
of the Geological Society, I beg, Sir, that you will add to our congratula- 
tions upon what he has already accomplished our hope that many years of 
activity still remain to him; and this wish will, I am sure, be echoed by 
his numerous friends on both sides of the Atlantic, 


Sir George Perley replied in the following words :— 


Mr. PresipeNtT,—I am very happy to come here to-day and receive this 
Medal on behalf of Mr. Tyrrell, and I only regret that he is not here him- 
self for that purpose. He was in London for some time last year, but 
unfortunately had to return to Canada last month, so that he has missed 
the pleasure of being with you to-day. As I live in Ottawa, I have known 
Mr. Tyrrell for a long time. He is a native-born Canadian, and was for 
many years connected with the Canadian Geological Survey. He showed 
much resource and energy in his work, and it is very fitting that he should 
be recognized by your Society in this way. 

I may say that, in our Dominion, we are proud of our Geological Survey 
and of what it hasdone. We have a large country with great undeveloped 
mineral resources, which the Geological Survey has done a great deal to 
help discover and utilize. Fortunately, Canada has been able to assist 
more than could have been expected in providing minerals and metals 
during the War. Many supplies from enemy countries have been cut off, 
and higher prices have encouraged enterprise. In consequence, we have 
not only provided large quantities of nickel, but we have developed our 


182 Reports & Proceedings—Ceological Society of London. 


copper, lead, and zinc industries to a very considerable extent. Even so, 
I feel sure that our mineral and metal products will be greatly increased in 
the future, and we believe that our resources in that direction have been 
hardly scratched. To exemplify this, I would remind you that the 
wonderful silver deposits at Cobalt, in Ontario, we only discovered by 
chance, although lumbering had been carried on over that district for a 
great many years. The Ontario Government built a line of railway from 
the Canadian Pacific into the North country, and in so doing crossed this 
great silver deposit, which is still producing heavily. 

As representing Canada, I am proud to receive this Medal on account of 
our Dominion, as well as on account of Mr. Tyrrell personally. It seems 
peculiarly appropriate at this time that this honour should be given by 
this old and important Society to a Canadian, and we appreciate the same 
greatly. 

I accept the Medal on behalf of Mr. Tyrrell with grateful thanks, and it 
will give me much pleasure to forward it to him and communicate the 
very kind words with which you, Mr. President, have accompanied it. 


The President then handed the Prestwich Medal, awarded to 
Professor William Boyd Dawkins, F.R.S., to Dr. A. Smith Wood- 


ward, for transmission to the recipient, addressing him as follows :— 


Dr. SmitH Woopwarp,—The Prestwich Medal has this year heen 
awarded to Professor W. Boyd Dawkins, and there will appear, I think, a 
peculiar fitness in the choice which links together these two names. 
Much of the geological work which here receives recognition is such as 
would especially appeal to the Founder of this Medal, and did in his life- 
time engage his lively interest. 

During fifty-six years Prof. Dawkins has contributed nearly thirty papers 
to the Quarterly Journal of this Society, in addition to numerous works 
published elsewhere. His researches in British cave-deposits and in 
mammalian paleontology have long been well known and highly valued. 
He has shown that mammalian remains can be used in the classification of 
the Tertiary strata, and in many ways has cast light upon some interesting 
chapters in the later geological history of Europe. In another direction he 
has made important additions to our knowledge of the geology of the Isle 
of Man. His long connexion with the Victoria University and the support 
which he has given to the Manchester Geological Society have done much 
to promote the study of geology in Lancashire, and his well-known 
publications Cave Hunting and Harly Man in Britain met the needs of a 
wide circle of readers. 

Even more, perhaps, will the name of Prof. Dawkins be always associated 
with the discovery of the Kentish Coalfield, in which he guided to a 
successful issue an enterprise that had already exercised the mind of 
Prestwich himself. The site of the boring at Dover was selected after a 
careful survey of the district, and much patient labour was expended on 
the examination of the cores and the identification by their fossils of the 
several geological horizons pierced. Apart from the material success 
realized, there was in this way accumulated a body of information which 
has important applications to the stratigraphy and tectonics of South- 
Eastern England. 

On behalf of the Council, I ask you to transmit this Medal to Prof. Boyd 
Dawkins in token that he has indeed, in the words of the Founder, ‘‘ done 
well for the advancement of the science of Geology.” 


Dr. Smith Woodward replied in the following words :— 


Mr. PresipENT,—I have much pleasure in receiving this Medal on 
behalf of Prof. Boyd Dawkins, on whom it has been so worthily bestowed. 
He desires me to express his regret that an unavoidable engagement in 
Manchester prevents him from being present to-day to return his thanks 
in person. 


Reports & Proceedings—Geological Society of London. 183 


He writes :— 

*“T feel deeply the honour that the Council have conferred upon me. It 
is specially valuable to me from my long friendship with Prestwich, and 
because my scientific life has been mainly spent in following up the lines of 
inquiry which he made his own—the range of the Coal-measures under the 
Secondary and Tertiary strata of South-Eastern England, the classification 
of the European Tertiaries, and the problem of the antiquity of man in 
Britain. With regard to the first, it may be noted that the South-Eastern 
Coalfield is now clearly defined, and now ranks among the assets of the 
nation. With regard to the second, the classification by the evolution of 
the higher mammalia originally intended for Europe is found to apply to 
the whole of the world. It is now being used by the American geologists 
(Prof. Osborn and others) to define the complicated subdivisions of the 
Tertiaries of the New World. With regard to the third, the problem 
remains now very much as it was in the days of Prestwich, and the zeal 
of the antiquarians and anthropologists to discover the presence of man in 
deposits older than the Pleistocene Period has been met by the caution of 
the geologists, with the net result that the Piltdown remains stand as the 
oldest in the geological record of Great Britain, and that the alleged 
occurrence of traces of man in the Pliocene and older strata is put to 
a suspense account. 

‘**T value, however, the Medal more particularly, as a mark of regard on 
the part of the Society, to which I have been able to contribute but little 
for many years, owing to my duties in other directions.” 


In presenting the Lyell Medal to Henry Woods, M.A., F.R.S., 
the President addressed him as follows:— 


Mr. Woops,—The Council of the Geological Society has selected you for 
distinction as one who ‘‘has deserved well of the Science”, and I think 
that none who has watched your career and is acquainted with your work 
will dissent from that verdict. Your communication to the Society, in 
1896, on the Mollusca of the Chalk Rock, set a standard of skilful and 
accurate diagnosis and description, which has been maintained in all your 
subsequent work, including the important monograph on the Cretaceous 
Lamellibranchia, published by the Paleontoyraphical Society. That the 
philosophical side of Paleontology has also engaged your study is 
sufficiently proved by such papers as that on the evolution of the genus 
Inoceramus ; while that dealing with the igneous rocks of Builth shows 
that your interests are not wholly comprised within one branch of our 
science. Your text-book of Paleontology, based upon practical experience 
at Cambridge, is valued by other teachers, and your knowledge has always 
been, as I am well able to testify, generously placed at the disposal of 
fellow-workers. 

It will be, I trust, an encouragement to you, as it is certainly a source of 
gratification to your friends, that so long a record of good work, faithfully 
pursued for no private end, does not go unrecognized; and, as an old 
colleague, I am pleased that it falls to my lot to place the Lyell Medal in 
your hands as a tangible mark of appreciation. 


Mr. Woods replied in the following words :— 


Mr. PrestpENT,—Twenty years ago the Council gave me great encourage- 
ment by awarding to me the Lyell Fund. The present award also comes 
at a time when encouragement is welcome; not that I feel any loss of 
interest in my work—far from it. But in these times one cannot help 
regretting, amongst other things, that one’s special work in the past has 
little, if any, bearing on matters which are now of practical importance. It 
is, therefore, encouraging to find that the Council have taken a longer 
view, and have continued their traditional policy of giving recognition to 
any and every branch of Geology, whether it has any obvious practical use 
or not. 


184 Reports & Proceedings—Geological Society of London. 


One of the things that struck me most at the beginning of my palonto- 
logical work was the generosity and good-nature of those with whom that 
work brought me into contact, and that pleasant experience has continued 
all through ; whether I have had to do with officials in charge of museums, 
with professional or amateur geologists, or with that useful person some- 
times spoken of disparagingly as the mere collector, all have most freely 
given me the benefit of their experience and the use of their collections ; 
much as I should like on such an occasion as this to mention their names I 
must refrain from doing so—the list is far too long, and I regret that it 
now includes the names of not a few who are no longer living. 

Whilst it gives me great pleasure to receive this mark of the Council’s 
approval of my work, it gives me a further pleasure to regard it as a dis- 
tinction for the Cambridge School of Geology. To those with whom 
I have been associated in that school I owe much—to some of them I am 
deeply indebted. 

I thank the Council most sincerely for this Medal, and you, Sir, for 
your kind words. 

The President then handed the Balance of the Proceeds of the 
Wollaston Donation Fund, awarded to Albert Ernest Kitson, to 
Dr. H. Lapworth, Sec.G.S8., for transmission to the recipient, 
addressing him as follows :— 


Dr. LapwortH,—The Balance of the Proceeds of the Wollaston Donation 
Fund has been awarded to Mr. Albert Ernest Kitson, in recognition of his 
valuable contributions to Geology in Australia and West Africa. 

Beginning in a clerical capacity on the staff of the Department of Mines 
of Victoria, he qualified himself for scientific investigation, and became 
ultimately Senior Field Geologist on the Survey of that State. Besides 
taking an active part in the geological mapping, he wrote numerous papers 
on the geology of Victoria, and seized opportunities to extend his researches 
to New South Wales, Tasmania, and New Zealand. In 1906, on the 
recommendation of his former chief, Prof. J. W. Gregory, Mr. Kitson was 
placed in charge of the Mineral Survey of Southern Nigeria. With 
characteristic energy, in a tropical climate, he traversed the Protectorate 
in every direction, and, in addition to other services, was chiefly responsible 
for the discovery and investigation of the Udi-Okana Coalfield, containing 
vast supplies of coal, the more valuable for its geographical situation. 
This Survey was suspended in 1911, and in 1913 Mr. Kitson received the 
appointment, which he now holds, of Director of the Geological Survey of 
the Gold Coast. His reports on that country have not yet been published ; 
but it is perhaps permissible to mention the discovery of fossiliferous 
Paleozoic rocks of considerable geological interest, and of deposits of 
manganese-ore and of bauxite which have great economic importance. 

That so notable a record of good work should receive recognition from 
this Society must gratify all who are interested either in the advancement 
of geological knowledge or in the mineral resources of the British Empire. 


In presenting the Balance of the Proceeds of the Murchison 
Geological Fund to Thomas Crook, Assoc.R.Coll.Sci., the President 
addressed him as follows :— 


Mr. Croox,—In awarding to you the Balance of the Proceeds of the 
Murchison Geological Fund the Council wishes to recognize the value of 
your contributions to Petrology and Mineralogy, more particularly with 
reference to the mechanical analysis of rocks and also to the mineralogy of 
the British Colonies. The former of these subjects engaged your attention 
while you were at the Royal College of Science in Dublin, and you have 
since pursued it with success, especially in perfecting the use of the 
electro-magnet for the separation of minerals. As a member of the staff of 
the Imperial Institute you have during recent years made many additions 


Reports & Proceedings—Geological Society of London. 185 


to our knowledge of the minerals of the more remote parts of the British 
Empire, the results of your work appearing partly in papers published in 
your own name, but largely in the pages of the Bulletin of the Institute. 
Your petrological publications include some interesting observations on 
** Dedolomitization ” and a suggestive paper on ‘‘ The Genetic Classification 
of Rocks and Ore-Deposits”. In addition, you have collaborated with 
Prof. Cole in an important memoir on a collection of rock-specimens 
dredged off the coast of Ireland, showing how these may be made to yield 
information concerning the submarine geology of the British seas. This 
award, so well deserved, will, I hope, be an encouragement to you in your 
future work, whether official or extra-official. 


The President then presented a moiety of the Balance of the 
Proceeds of the Lyell Geological Fund to Vincent Charles Llling, 
M.A., addressing him as follows :— 


Mr. Inninc,—The Council has awarded to you one moiety of the Balance 
of the Proceeds of the Lyell Geological Fund to mark its appreciation of 
your admirable work among the Lower Paleozoic rocks of Warwickshire. 
Since its discovery by Prof. Charles Lapworth in 1882, the Cambrian inlier 
of Nuneaton has claimed the attention of numerous geologists ; but it was 
reserved for you to show how complete a development of the whole 
Cambrian succession is there exhibited. Ina paper communicated to this 
Society in 1914 you mapped out the various subdivisions which you had 
recognized, and correlated them with the parallel sequence in other areas. 
Of the Abbey Shales, representing in small compass a large portion of the 
Middle Cambrian, you made a full palzontological study, describing 
critically the rich trilobitic fauna and making known a number of new 
species. That this important memoir was professedly only a first instal- 
ment, warrants us in hoping that you will find in the present award 
stimulus to the completion of your projected work. 


In presenting the other moiety of the Balance of the Proceeds of 
the Lyell Geological Fund to William Kingdon Spencer, M.A., the 
President addressed him in the following words :— 


Mr. Spencer,—A moiety of the Balance of the Proceeds of the Lyell 
Geological Fund has been awarded to you by the Council as an acknow- 
ledgment of the value of your paleontological work. : 

Starting with the advantage of a zoological training at Oxford, you have 
devoted the intervals of a busy official life to researches in the paleontology 
of the Echinoderms. You began by applying Prof. Sollas’s method of 
serial sections to elucidate the structure of the Paleozoic forms 
Paleodiscus and Agelacrinus. You then devoted some years to the study 
of the Cretaceous star-fishes, the results of which appeared in a monograph 
upon the British examples and a paper, contributed to the Royal Society, 
upon ‘‘The Evolution of the Cretaceous Asteroidea”. Therein you 
showed, among other conclusions, that the star-fishes are of zonal impor- 
tance, and that different lineages were evolved along parallel lines. More 
recently you have been investigating with great skill that difficult group of 
fossils, the Paleozoic Asterozoa, and your monograph, not yet completed, 
has already brought to light many new facts relative to the morphology 
and phylogeny of those early Echinoderms. It is our hope that this 
recognition may encourage you to persevere in the same path. 

The President then delivered his Anniversary Address, giving 
first obituary notices of If, Emile Sauvage (elected Foreign Corre- 
spondent 1879), W. Bullock Clark (For. Corr. 1904), T. McKenny 
Hughes (el. 1862), Edward Hull (1855), R. H. Tiddeman (1869), 
G. A. Lebour (1870), Arnold Hague (1880), Robert Bell (1865), 
G. F. Franks (1890), G. C. Crick (1881), H. P. Woodward (1883), 


186 Reports & Proceedings—Geological Society of London. — 


Upfield Green (1889), C. O. Trechmann (1882), A. N. Leeds (1898), 
R. Boyle (1911), A. M. Finlayson (1909), and others. 

The President went on to discuss the present position and outlook 
of the study of metamorphism. The rapid development of physical 
chemistry and the successful application of experimental methods 
to petrological questions have greatly changed the situation during 
recent years, and for the first time it seems possible to approach the 
subject of metamorphism systematically from the genetic standpoint. 
For the geologist this implies the critical study, not only of the 
great tracts of crystalline schists and gneisses, but equally of meta- 
morphic aureoles, of pneumatolysis and other contact-effects, and of 
the phenomena, mechanical and mineralogical, related to faults and 
overthrusts. It implies, moreover, the recognition that these are 
all parts of one general problem, that of the reconstruction of rocks 
under varying conditions of temperature and stress. In practice, 
this problem is complicated by the fact that perfect adjustment of 
chemical equilibrium cannot be assumed, either in the rocks prior to 
metamorphism, or during the process of metamorphism itself. 

Some consideration was devoted to the solvents which play an 
essential part in metamorphism and to the limits of migration of 
dissolved material within a rock-mass. The Address proceeded to 
the discussion of what is the most fundamental characteristic of 
metamorphism: namely, that recrystallization takes place in a solid 
environment, and so may be profoundly affected by the existence of 
shearing stress. Stress of this type, on the one hand, arises from 
the crystal growth itself, and on the other hand is called into play 
by external forces. The automatic adjustment of the internally 
created stress to neutralize that provoked from without affords the 
key to all structures of the nature of foliation. The mineralogical 
peculiarities characteristic of the crystalline schists must find their 
explanation in kindred considerations; for it can be shown that the 
chemistry of bodies under shearing stress differs in important respects 
from the chemistry of unstressed bodies. ‘The result is seen in 
the appearance of a certain class of ‘‘ stress-minerals’’ where the 
dynamic element has figured largely in metamorphism, while in the 
same circumstances the formation of minerals of another class seems 
to have been inhibited. But, while some of the general principles 
governing the effects can be formulated, the explanation of these 
lines of the observed associations of minerals is a task for the future. 
It may be that many of the particular problems involved will in 
time be brought within the scope of laboratory experiment. 

The conditions governing metamorphism are temperature and 
shearing stress, with uniform pressure as a factor of less general 
importance. If the orogenic forces are sufficient to maintain shearing 
stress everywhere at its maximum, the stress itself becomes a 
function of temperature, since this determines the elastic limit, and 
the principal conditions of metamorphism come to depend upon a 
single variable. This degree of simplification, however, is not to be 
expected universally. One disturbing factor is the local rise of tem- 
perature sometimes caused by the mechanical generation of heat in 
the crushing of rock-masses. 


Reports & Proceedings—Geological Society of London. 187 


In resigning the chair, the President expressed his thanks to the 
Fellows of the Society, and especially to the Officers, who, as well 
as the permanent officials, had contributed much to the smooth 
working of the Society’s business. 

The ballot for the Officers and Council was taken, and the following were 
declared duly elected for the ensuing year :— 

OFFICERS (who are also ex-officio members of the Council): President - 
George William Lamplugh, F.R.S.  Vice-Presidents: KR. Mountford 
Deeley, M.Inst.C.H.; Alfred Harker, M.A., LL.D., F.R.S.; Professor 
William Johnson Sollas, M.A., LL.D., Se.D., F.R.S.; and Sir Jethro 
J. H. Veall, M.A., LL.D., D.Sce., F.R.S. Secretaries: Herbert Henry 
Thomas, M.A., Se.D.; and Herbert Lapworth, D.Sec., M.Inst.C.H. 
Foreign Secretary: Sir Archibald Geikie, O.M., K.C.B., D.C.L., LL.D., 
Se.D., F.R.S. Treasurer; James Vincent Hlsden, D.Se. 

Counciiu: Charles William Andrews, D.Se., F.R.S.; Francis Arthur 
Bather, M.A., D.Se., F.R.S.; Professor John Cadman, C.M.G., D.Se., 
M.Inst.C.E. ; Arthur Morley Davies, D.Sc., A.R.C.Se.; Professor Edmund 
Johnston Garwood, M.A., Se.D., F.R.S.; John Frederick Norman Green, 
B.A.; Finlay Lorimer Kitchen, M.A., Ph.D. ; Major Henry George Lyons, 
D.Se., F.R.S.; Professor John Edward Marr, M.A., Sce.D., F.B.S. ; 
Richard Dixon Oldham, F.R.S.; Robert Heron Rastall, M.A. ; Professor 
Henry Hurd Swinnerton, D.Se. ; Samuel Hazzledine Warren; Professor 
William Whitehead Watts, M.A., Se.D., LL.D., F.R.S. 


2. March 6, 1918.—Mr. G. W. Lamplugh, F.R.S., President, in the 
Chair. 

Mr. J. F. N. Green delivered a lecture on the Igneous Rocks of the 
Lake District. He first drew attention to some of the manuscript 
6 in. maps of the Lake District, prepared nearly fifty years ago, by 
the Geological Survey, and pointed out that, although undoubtedly 
most accurate, they differed greatly in the volcanic area from his 
own. He suggested that the reason was that there was a funda- 
mental difference in the classification of tuffs and lavas. A large 
proportion of the Lake District rocks were brecciated, and had been 
supposed to be altered tuffs. With the unbrecciated rocks into 
which they passed they had been mapped as ashes. A number of 
specimens and photographs were shown, indicating that the breccia- 
tion and apparent bedding were due to flow. Specimens were also 
shown of explosion breccias, of the normal tuffs (which the Lecturer 
believed to be mainly the result of erosion between eruptions), and 
of rocks simulating true tuffs, but actually sandstones and con- 
glomerates, composed of detrital igneous material. Attention was 
drawn to.the criteria for distinguishing the various types. Recently 
manuscripts had been found in the possession of the Geological 
Survey proving that Aveline, whose maps were extraordinarily 
accurate and detailed, had anticipated by thirty years the Lecturer’s 
separation from the volcanic rocks of the basal beds of the Coniston 
Limestone Series. 

When re-mapped on this basis, the Borrowdale Series appeared as 
asimple and regular sequence, strongly folded and cropping out in 
long bands. An interesting history of vulcanicity was revealed, 
beginning in many places with explosion tuffs followed by a great 
series of pyroxene-andesites over the whole district. Then there 


188 Reports & Proceedings—Edinburgh Geological Society. 


was a pause during which fine-grained andesite tuffs, with a tendency 
to produce true slates, accumulated. This was succeeded by a vast 
outpouring of andesites, of great thickness in the central mountain 
region, but dying out southwards and eastwards. Next a series of 
peculiar mixed tuffs, of special value in mapping, was covered by 
another mass of andesites dying out south-westwards. After this, 
soda-rhyolites covered the whole district, nothing later being 
preserved—with one possible known exception. These volcanic 
rocks were intersected by a varied series of intrusions. 

The solfataric phenomena were of interest, including the pro- 
duction of garnet and graphite, and a remarkable ‘‘streaky’”’ 
structure in the rhyolites. 

An important question related to the age of the large acid 
intrusions associated with the volcanic ee Were they of the 
same age as, or later than, the Devonian folding? A sketch was given 
of the evidence on which the Lecturer assigned the Eskdale and 
Skiddaw granites to the Ordovician volcanic episode, and it was 
suggested that the great Skiddaw anticline was not due to regional 
folding, but a local structure connected with the vulcanicity. 

Lantern-slides of Lake District country were shown, and the 
manner in which the volcanic rocks entered into the scenery was 
pointed out. 


IJ.—Epinsuren GronocicaL Socrery. 


February 20, 1918.—Professor Jehu, President, in the Chair. 
(Issued March 16, 1918.) 


1. ‘Coal Apples.” By J. Masterton, H.M.I.M. 

At the Lochend Pit of Longrigg Colliery, Longriggend, in the 
Upper Drumgray Seam, which is there anthracitic, Mr. Masterton 
found in 1910 rounded balls of coal from 1% inches to 5 inches 
diameter, and occasionally up to 8 inches diameter. ‘The balls were 
slickensided, and, when seen in situ, the surrounding coal matter 
was sometimes slightly displaced. The larger balls, when broken, 
had a strong likeness to cone-in-cone coal. The late Dr. Clough was 
shown the balls, and he drew attention to a note in the Transactions 
of the Glasgow Geological Society recording the discovery of similar 
balls in North Ayrshire by Mr. John Smith. Mr. Smith found. the 
balls near a whin float. 

The apples in Lochend Pit occur in an anthracitic coal, and 
Mr. Masterton found similar balls in most of the pits near Lochend, 
both in the Upper and Lower Drumgray Seams. The whin float 
which underlies the Slamannan District has been proved by bores, 
and is seen at the surface near Forrestfield, to the south of the 
Lochend Pit; it has almost certainly both anthracitized the coal and 
formed the apples, and Mr. Masterton cannot accept Mr. Carruthers’ 
assertions in the Geological Survey’s publications as to the formation 
of the anthracites in the area in question by agencies similar to those 
to which the anthracitization of the coals of South Wales has been 
ascribed. 


Obituary—Captain Lewis Moysey. 189 


Specimens were exhibited from Lochend Pit (Upper Drumgray 
Seam), Drumbon Pit (Upper and Lower Drumgray Seams), and from 
Eastfield Pit (Upper and Lower Drumgray Seams). 

Coal apples were found by Mr. Masterton during the years 1911 
to 1918, and he exhibited specimens from the following localities : 
(1) Moncur Colliery, Kilwinning—in the Ell Seam in a reversed fault, 
and where a line of face was slightly baked and approaching a whin 
dyke; (2) Littlemill Colliery, Rankinston—Main Seam, where the 
working face was approaching a whin dyke; (8) Harallan Colliery, 
Old Cumnock—Maid Splint Seam, ina place going parallel to a whin 
dyke, and 25 yards distant from it; (4) Ponfeigh Colliery, Douglas, 
Lanarkshire—apples described by the manager as occurring near 
a whin dyke, the coal becoming coke close to the dyke. 

Mr. Masterton advanced the opinion that the coal apples were 
pieces of coal matter either of harder nature or of less volatile content 
than the surrounding parts of the seam, and that these parts resisted 
the compression and ‘‘ flux’’, if the term can be used, better than the 
rest of the seam. 


2. ‘*The Raw Materials of the Glass Industry.” (With lantern 
illustrations.) By G. V. Wilson, B.Sc., F.G.S. 


A brief description was given of the materials needed for the 
manufacture of glass, with special reference to the quality of sand 
used. The essentials of an ideal sand were pointed out, namely, 
high percentage of silica, freedom from ferruginous materials, and 
absence of refractory minerals, such as rutile and zircon. Attention 
was drawn also to the importance of the size and shape of the grains. 
Analyses of Fontainebleau and Dutch sands were compared with 
those from the best Scottish localities. None of the latter are quite 
equal to Fontainebleau, but several are as good as, if not better than, 
Dutch. The essential qualities of the clay for making glass pots 
were also noted, such as high plasticity, high refractory quality, and 
freedom from iron in any form. The paper was illustrated by 
lantern slides, many of which were photomicrographs showing the 
minerals formed by the devitrification of a large body of glass. 


OS eae Asm 


CAPTAIN LEWIS MOYSEY, 
hae VE Ce DAs. Mabe HG: 


Born 1869. DIED FEBRUARY 26, 1918. 


We much regret to learn of the death of Dr. Moysey, who was 
lost on the hospital ship Glenart Castle, which was torpedoed on 
February 26. Dr. Moysey had only just joined this ship, as one of 
the medical officers, and he was not among those subsequently 
rescued. 

Dr. Moysey was a graduate of Caius College, Cambridge, and a 
medical man who had long been in practice at Nottingham. He 
was mobilized in the early days of the War, and until quite recently 
he had been occupied with regimental work in this country. 


190 Obitwary—Captain Lewis Moysey. 


He had devoted, over a period of many years, the scanty leisure of 
a busy professional life to the collection of the fossil remains of the 
Coal-measures around his home at Nottingham. He was an 
exceptionally ardent paleontologist, with a keen eye for a good 
specimen, aud he was possessed of great skill and perseverance as 
a collector. 

He rediscovered a half-forgotten method of developing fossils 
contained in clay-ironstone nodules, by freezing them in cold 
storage. This he described in a paper in the Gronocican Maeazine 
for 1908. 

He also contributed several memoirs on some of the rarer specimens 
in his collection. Among these may be mentioned his writings on 
Paleoxyris and allied genera, published by the Geological Society in 
1910 and the British Association in 1913 (1914), which did much to 
clear up the obscurities which then surrounded these fossils. But, 
as a rule, he was content, with great generosity, to place the 
results of his labours in the field in the hands of specialists for | 
description. 

His collection covered a wide range both of Coal-measure animals 
and plants, not a few being unique or exceptionally perfect examples. 
Some of the former have been described in the pages of the 
Grorocicat Macaziye, by Dr. Henry Woodward in 1907 and 1908 
and) Dir Weak: Calman in 1914, and in the publications of the 
Paleontographical Society by Mr. ’R. I. Pocock in 1911. 

Dr. Arber some years ago (1910) also figured some of the best of 
the plant remains in his collection, but many further examples 
which Dr. Moysey had since acquired remain undescribed. It is not 
too much to say that our exceptionally good knowledge of the fauna 
and flora of the Notts and Derby Coalfield is due almost entirely to 
his single-handed efforts, as his list of records contained in the recent 
Survey memoir dealing with this field testifies. 

A few weeks before his death, as if conscious of his impending 
fate, Dr. Moysey made over as gifts his entire collections, the animal 
remains to the Museum of Practical Geology in London and the 
plant specimens to the University of Cambridge. The latter are 
now in the Sedgwick Museum. 

Dr. Moysey possessed many friends among those interested in Coal- 
measure fossils, and his delightful personality, generous nature, and 
enthusiasm for research had ‘endeared him to all of them. 


[Nore sy roe Eprror.—Of the Arthropods discovered by Dr. L. 
Moysey the first specimens were sent in May, 1907, to his friend 
Mr. Henry A. Allen, F.G.8., of the Geological Survey, Jermyn 
Street, and described by Dr. Henry Woodward in the Grorocrcar 
Macazine for June, 1907 (pp. 277-82, Plate XIII). They consisted 
of examples of Lurypterus (#. Moyseyi and EL. Derbiensis) from the 
clay-ironstone nodules of the Coal-measures, Ilkeston, Derbyshire. 

As the result of his experiments in splitting by a freezing and 
thawing process the ironstone nodules obtained on the Shipley Hall 
Estate clay-pit, near Ilkeston, Dr. Moysey records the fortunate 
discovery of a greater proportion of rare fossils in these harder 


Obituary—Captain Lewis Moysey. 191 


nodules than from those found naturally inclined to split in the 
clay-pit. Out of some ninety nodules cracked by freezing he had 
obtained three specimens of Belinurus, one of Palgoxyris, two of 
a ‘‘*new shrimp-like animal”, and one complete but diminutive 
example possibly akin to <Arthropleura armata of Jordan from 
Saarbrucken—he enumerated fifty-seven different fossil organisms 
obtained (see Grou. Mae., 1908, pp. 220-2). 

The new shrimp-like animal (Preanaspides precursor, H. Woodw.) 
referred to by Dr. Moysey, and discovered by him, proved to be of 
the very highest interest, being a Coal-measure representative, or 
ancestral form, of the rare modern Schizopod Anasprdes tasmanie 
from Mt. Wellington, Tasmania (see H. Woodward, Grou. Maa., 1908, 
pp. 885-96). 

On March 28, 1910, Dr. Moysey read a paper before the Geological 
Society of London on Pal@oxyris and other allied fossils from the 
Derby and Nottingham Coal-field (see Quart. Journ. Geol. Soc., 
vol. lxvi, pp. 329-44, pls. xxiv—vii, 1910). 

- Dr. Moysey contributed a note on some undescribed Coal-measure 
fossils from the Nottinghamshire coal-field (British Association, 
Sheffield, 1910, Sect. C, see also Geox. Mac., 1910, p. 474). 

In 1911 Mr. R. I. Pocock, F.R.S., contributed a ‘‘ Monograph of the 
Terrestrial Carboniferous Arachnida of Great Britain” to the annual 
volume of the Paleontographical Society for 1910,in which two 
species obtained by Dr. L. Moysey are figured and described, namely: 
Eobuthus holti, sp. nov. (see p. 15, pl. 1, fig. 2a) and Geralinura 
britanniea, sp. nov. (p. 30, pl. ii, fig. 3). 

In the Gronoetcat Magazine for 1911, pp. 497-507, twelve Text- 
figures, Dr. Moysey described a further series of fossils from the 
Notts and Derbyshire Coal-field, including a new _ bivalved 
Entomostracan, Leava trigonioides, sp. nov. (Fig. 1, p. 498), parts of an 
undescribed Arthropod, and remains of Prestwichia(?), of a Scorpion, 
of Hurypterus, carapace of Anthracosiro sp., of A. Hritschiz, Pocock 
(Figs. 7, 8, p. 508, and Fig. 9, p. 504), of A. Woodwardi, Pocock 
(Fig. 10, p. 504), an opisthoma of Anthracomartus (Figs. 11, 12, 
p. 505); he appends a list of sixteen Arthropods and six other 
fossil remains. 

At the Meeting of the British Association, Birmingham, 1913, 
Dr. Moysey read a paper on Pal@oxyris and other allied fossils and 
on Vetacapsula (see Grou. Mae., 1913, pp. 458-5). The author 
compares these problematical bodies from the Coal-measures with 
the egg-cases of Chimera collei, Rhinochimera, and other Chimeroid 
sharks. 

In 1914 (Guor. Mae., pp. 541-4, Pl. XXXVIII) Dr. W. T. 
Calman figures and briefly describes a remarkable new form of 
‘* Myriopod-like”’ Arthropod probably related to Arthropleura armata 
of Jordan, from the Coal-measures of Saarbrucken, of which similar 
fragmentary remains have been obtained from other coal-fields of 
France and in this country. Dr. Calman considers it to be a new 
species of Arthropod (incert@ sedis), and names it Arthropleura 
Moyseyt after the discoverer, Dr. L. Moysey. 

The Council of the Geological Society of London so lately as 


192 Correspondence—R. L. Sherlock—E. M. Anderson. 


February 19, 1915, awarded him the Lyell Geological Fund in 
recognition of his valuable work on the fossils of the Derby and 
Nottinghamshire Coal-field, including his contribution to the 
recently published Geological Survey memoir on that district. 

That so valuable a life as that of our friend Dr. Lewis Moysey 
should have been sacrificed in so sad and tragic a manner, though in 
the service of his country, only increases our sorrow for his 
premature loss to science and to his personal friends, by whom he 
was greatly valued. | 


K. A. IN. A. 


CORRESPONDENCE. 


SEW icig ceed 
“RLINT-MEAL” FROM THE BRITISH CHALK. 


Srr,—I should be greatly obliged if any of your readers would 
send me properly localized samples of flint-meal from the British 
Chalk, other than the 6. mucronata zone of Norfolk, of which I have 
plenty. Failing flint-meal, weathered chalk containing foraminifera 
is useful provided its horizon is known. 

R. L. SHeRzock. 


GEOLOGICAL SURVEY, 
JERMYN STREET, 8.W. 1. 
February 25, 1918. 


A NOTH ON ISOSTASY. 


Sir,—A rather important consideration has, I think, been over- 
looked by Dr. A. Morley Davies (see Gror. Mae. for March, p. 125). 
In estimating the amount of subsidence that must ensue ‘‘if the 
isostatic adjustment is perfect and immediate” after a sea of 
depth d has been filled to the surface with sediment, we must take 
into account not only the weight of sediment but also the weight of 
water which flows in over the sediment during the process of sinking. 
Allowing for this on the basis of Dr. Davies’ figures, the downward 
movement becomes eee To secure equilibrium, with sedimenta- 
tion up to sea-level, we have the following equation, where @ is the 
total subsidence :— 

1:36d + 2°364 = 382. 


or the total thickness of sediment = 3:12d, instead of 1:83d as 
calculated by Dr. Davies. If we assume for the density of the 
substratum what we may agree is the rather unlikely figure of 2°7, 
the last result is altered to 4 d. 

K. M. AnprERson. 


EDINBURGH. 
March 11, 1918. 


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NEWOOSE RIES. DECADE MIb i VOL. Vi 


No. V.—MAY, 1918. 


ORG amen ASts Asean Sie eS 
REDE Se 


J].—TuHe Genesis or Tungsten OR:s. 
By R..H. RASTALL, M.A., F.G.S. 


HE exploitation of tungsten ores on a large scale is of com- 
paratively recent development. Till lately the industrial 
applications of this metal and its compounds were very limited, and 
they were regarded rather in the light of chemical and mineralogical 
curiosities. In fact, the tungsten minerals were considered a 
nuisance by miners, owing to the difficulty of separating them from 
other valuable and equally heavy ores occurring in close association 
with them. Sodium tungstate was manufactured to a certain 
extent and used as a mordant in dyeing and for rendering textile 
fabrics fireproof, and tungstic oxide was sometimes employed in the 
making of yellow glass. About the year 1905 a demand arose for 
the metal for electric lamp filaments, but at the present time by far 
the most important application is in the metallurgy of steel. The 
addition of a small quantity of tungsten, not more than 7 or 8 per 
cent, together with about 5 per cent of chromium, has a remarkable 
effect on steel, rendering it both hard and tough and suitable for 
high-speed cutting tools. Since the beginning of the War the 
demand for the ores for this purpose has enormously increased, as 
also has the price; new sources are being sought for and opened up 
in many localities; in Colorado and California there was a few 
months ago a tungsten boom recalling the gold rushes of the early 
days. The resources of various parts of the British Empire are also 
being exploited on a large scale, and on its metallurgical side the 
tungsten industry is now very largely in British hands, whereas 
before the War Germany. absorbed the greater part of the world’s 
output of ore. Under present conditions it is naturally very 
difficult to obtain complete and reliable figures, but the following 
table (p. 194) shows approximately the output of tungsten ores 
throughout the world for the last few vears. The figures (in tons) 
are taken from Zhe Mineral Industry, vol. xxv, p. 741, 1916. 
Although the following notes do not claim to contain the results 
of any original work, it is thought that a brief summary of our 
present knowledge of the genesis, mode of oecurrence, and mineral 
associations of the tungsten ores may be of interest to geologists and 
mineralogists. The literature of the subject is widely scattered, 
largely in foreign publications, and the descriptions in most of the 


DECADE VI.—VOL. V.—NO. V. 13 


194 R&R. H. Rastall—The Genesis of Tungsten Ores. 


standard textbooks are not very satisfactory. Mr. A. M. Finlayson’ 
has briefly discussed the genesis of the ores from a theoretical point 
of view in the Grotocicat Macazine for 1910, giving a large number 
of references, and in 1909 the Imperial Institute published a small 
monograph on the subject from the practical standpoint,? but no 
general account of recent date seems to be available. 


1906. 1912. 1913. 1914. 1915. 1916. 

United States . ; 844 1,210 1,397 900 2,120 6,780 
Argentina : : 300 638 © 539 394 171 700 
Bolivia . ‘ : 70 497 564 276 793 920 
Peru : : : = 214 300 196 371 400 
England. . é 276 193 182 205 360 350 
France . : ; 20 230 245 200 200 200 
Germany and Austria 60 167 150 220 250 300 
Portugal . : b 570 1,330 800 967 1,400 1,600 
Spain . : : 200 169 150 84 511 600 
Burma . 5 ; oo 1,905 1,732 | 1,868 2,883 4,123 
Siam  . : : — 108 281 30 297 468 
Japan. : ; 40 205 297. 195 439 1,150 
Queensland . : 800 860 543 435 640 800 
New South Wales . 271 271 209 220 100 146 
New Zealand . : 165 165 270 250 249 300 
World .- . | 4,000 8,780 |10,000 | 8,000 | 12,000 | 19,000 


The element tungsten does not enter into many compounds of 
natural occurrence. It belongs to the group of metallic elements 
that give rise to acid-forming oxides; tungstic acid forms salts with 
several divalent metals, especially iron, manganese, calcium, and lead. 
The tungstates of these metals fall into two well-defined groups; 
the iron and manganese minerals crystallize in the monoclinic 
system, while the others are tetragonal. So far as is known tungsten 
does not occur in nature as sulphides or anhydrous oxides; even the 
oxidation products of the tungstates are few in number, the only one 
that is at all common is tungstic ochre, a yellow powdery substance 
sometimes found as a crust on tungstate minerals. It appears to be 
a hydrated oxide or hydroxide of a not very definite composition. 
The tungstates are remarkably stable minerals, being little affected 
by any weathering agents, and in consequence the ores do not 
undergo secondary enrichment; on the other hand, they show 
a strong tendency to accumulate as shoad and alluvial deposits. 

The iron and manganese tungstates, commonly known collectively 
to the miner as wolfram, form an excellent example of an isomorphous 
series. The two theoretical end-products are ferberite, Fe WO,, and 


1 Finlayson, ‘‘ The Ore-bearing Pegmatites of Carrock Fell’’: GEOL. MAG., 
1910, p. 19. 

2 “The Occurrence and Utilization of Tungsten Ores’’: Bull. Imp. Inst., 
vol. vii, pp. 170, 285, 1909. 


hk. H. Rastall—The Genesis of Tungsten Ores. 195 


hiibnerite, MnWO,. These two molecules may mix in any pro- 
portion. The varieties rich in manganese are perhaps the more 
common, Since every possible gradation of composition is known, 
it has been proposed by Messrs. Hess and Schaller? that arbitrary 
divisions shall be made as follows: all varieties with not more than 
20 per cent of the manganese molecule are called ferberite and those 
with not more than 20 per cent of the iron molecule hiibnerite, 
while intermediate varieties are called wolframite. In the following 
pages, however, the names wolfram or wolframite are used in the 
miner’s sense to include all varieties of iron and manganese 
tungstates. 

The tetragonal tungstates include scheelite, CaWO,, and stolzite, 
PbWO,. Of these the former is by far the more common and 
important. A new mineral from Northern Queensland, chillagite, is 
of interest, since it is an isomorphous mixture of the stolzite 
molecule, PbWO,, and the wulfenite molecule, PbMoO,, thus 
emphasizing the paragenetic connexion which undoubtedly exists 
between tungsten and molybdenum. The close mineralogical 
association between these two elements will appear later. Some 
varieties of both wolframite and scheelite contain a little copper, but 
this does not seem to be of much significance. 

At this point it becomes necessary as a matter of convenience to 
anticipate somewhat and to state that the tungsten deposits can be 
most satisfactorily described under four headings, as follows :— 

(a) Primary wolframite ores with cassiterite. 

(6) Primary wolframite ores without cassiterite. 

(ce) Primary scheelite ores. 

(d) Secondary (detrital) tungsten deposits. 

The justification for this classification will appear in later sections of 
this paper. 


Part I: Wotrramite Ores with CassItERITvE. 


The tungsten ore deposits of the British Isles have lately been 
described very fully in a special memoir of the Geological Survey,’ 
hence it is unnecessary to enter into a large amount of detail 
concerning them. In Cornwall the principal ore is wolframite, in 
Cumberland scheelite. The primary wolframite ores of Cornwall are 
of great interest from the theoretical point of view, since they afford 
an admirable example of the wolframite-cassiterite association. The 
primary ores of Cornwall are clearly of what is generally known as 
pneumatolytic origin, being associated with other minerals and rock- 
types characteristic of this phase of igneous action. It will, 
however, be pointed out in the general discussion of the genesis of 
these ores in a later section that the term pneumatolysis has been 
somewhat overworked in this connexion, and as commonly employed 
it really comprises two quite distinct classes of phenomena, or rather 
phases of igneous activity. 


1 ** Colorado Ferberite and the Wolframite Series’’?: Bull. 583, U.S. Geol. 
Surv., 1914, p. 37. 9 

2 Special Reports on the Mineral Resources of Great Britain, vol. i: 
Tungsten and Manganese Ores (Mem. Geol. Surv.), 1915. 


196 =. H. Rastall—The Genesis of Tungsten Ores. 


The wolframite ores of Cornwall are always in association with 
eranite intrusions; they occur in the granite itself, in pegmatite 
dykes, in lodes, and disseminated in a more or less irregular way in 
certain rocks in the immediate neighbourhood of the granite; the ~ 
association with greisen is particularly close, and is of much genetic 
significance with regard to the mode of distribution of the ores. 

It is quite clear that the pegmatite veins carrying wolfram are 
earlier than either the lodes in the country rock or the greisens. 
The list of minerals found in connexion with the wolfram ores is 
long, but the following are the most characteristic and significant : 
cassiterite, mispickel, chalcopyrite, tourmaline, topaz, and fluorspar. 
In the greisens of St. Michael’s Mount and elsewhere uranium 
minerals also occur in association with wolfram.' The importance of 
this fact will be referred to again later. ‘’o sum up, the whole 
mineral association forms an excellent example of the tin-tungsten- 
fluorine paragenesis, which, as will be seen in the sequel, is so widely 
spread in many parts of the world. 

In connexion with the tourmaline granites of Brittany wolframite 
is found along with cassiterite, molybdenite, mispickel, chalcopyrite, 
blende, and fluorspar. The ores occur in a network of veins (stock- 
work) in the granites, near their contact with mica-schists. The 
resemblance of this mineral assemblage to that found in Cornwall is 
obvious, and both evidently form part of one petrographical province 
from the point of view of the metallic contents of the magma, and 
both are characterized by the presence of fluorine and boron among 
the non-metallic constituents. 

Although so far as is known the German resources of tungsten 
ores are but small, the occurrences are of considerable interest, and 
vood descriptions, have been published. The principal output is 
from the well-known mining district of the Erzgebirge in Saxony 
and Bohemia. The ancient crystalline rocks of the fractured district 
between Dippoldiswalde and Tenlitz are penetrated by great masses 
of quartz-porphyry of Permian age (Teplitz quartz-porphyry); into 
this are intruded domes and bosses of granite of somewhat later date. 
The rocks surrounding the granite are highly mineralized, and in 
particular the quartz-porphyry, above the granite intrusions, is more 
or less converted into greisen and penetrated by innumerable veins 
and stringers carrying a great variety of ores. The districts richest 
in mineral veins are those of Altenberg, Zinnwald, Graupen, Khren- 
friedersdorf, Geyer, Eibenstock, and Johanngeorgenstadt. At 
Altenberg the ores occur in the form of a stockwork in the quartz- 
porphyry above the granite dome to the depth of about 750 feet. 
The mines of Zinnwald are said to be very rich in wolfram, and are 
also worked for lepidolite. Here the veins are in the quartz- 
porphyry and run parallel to the upper surface of the granite dome. 
The principal minerals are wolfram, scheelite, tinstone, arsenopyrite, 
galena, blende, chalcopyrite, tourmaline, topaz, and apatite. The 
impregnation with tin and other ores occurred before the last aplitic 
phase of the granite intrusion. At Ehrenfriedersdorf many tin- 
wolfram lodes of a similar type occur in mica-schist. The whole 

1 The Geology of the Land’s End District (Mem. Geol. Surv.), 1907, p. 53. 


kh. H. Rastall—The Genesis of Tungsten Ores. 197 


mineralization here, as in Cornwall, is closely connected with the 
pneumatolytic phase of the Hercynian granite intrusions, and shows 
very clearly the genetic association of tungsten with tin and the 
highly volatile elements, fluorine, boron, and lithium. 

Although the mines of the Erzgebirge in Saxony and Bohemia 
figure very largely in German mining literature and in textbooks, 
their yield of tungsten ores does not appear to be large, so far as is 
known. In 1912, the last year for which official statistics are 
available, the output for the kingdom of Saxony is stated to be 
101 tons, while no other German state appears to have produced any. 
In the same year the Austrian Empire is said to have produced only 
66 tons. It is believed that most of the wolfram ores were obtained 
by working over the old tin dumps. Nothing definite is known as 
to the extent of the supplies still available, but they are probably 
not very large. It is of course impossible to place great faith in the 
reliability of German statistics in connexion with any product 
connected with war preparations, but in this instance the figures 
may be correct, since in the years before the War Germany imported 
at least half of the world’s total output of tungsten ores. Hence the 
reserves at hand were probably considerable. 

Besides Great Britain the only other European producer of much 
importance is Portugal, although Spain also supplies a certain amount. 
In both these countries the ores are associated with cassiterite, 
belonging therefore to the group now under consideration. According 
to Granell* wolfram ores, usually accompanied by cassiterite, occur 
in a zone consisting of granite intruded into crystalline schists and 
Cambrian sediments, beginning in Galicia and extending through 
Northern Portugal, Zamora, Salamanca, and Caceres, and ending 
where it is cut off abruptly by the great Guadalquivir fault. There 
is also a similar mineral association in the mountain chains of Central 
Spain, in the province of Toledo, at Mijas near Malaga, and in the 
Almagrera Mountains; the latter was the locality of the original 
manganese-free ferberite, first described by Breithaupt. Little 
information is available as to the details of the wolframite ore- 
deposits of Spain and Portugal, but they do not seem to present any 
special features of interest, and a large part of the output is 
apparently alluvial. In the Sierra de Estrellain Portugal wolframite 
occurs in rich lodes up to 4 inches wide, associated with cassiterite 
and arsenopyrite. 

In the Black Hills of Dakota wolframite oceurs in two distinct 
genetic types: 

1. With tinstone, as at Etta Knob and Nigger Hill. 

2. With siliceous gold-ores. 

The ore-deposit of Etta Knob is very remarkable, and in some ways 
unique. It consists of a vertical pipe of pegmatite some 60 yards 
in diameter, containing in addition to quartz, felspar, and mica also 
eassiterite, wolframite,molybdenite, arsenopyrite, tantalite, columbite, 
apatite, beryl, and spodumene, the latter in crystals over 30 feet 
long. The characteristic elements here are evidently tin, tungsten, 


’ Granell, Boll. Soc. Esp. Hist. Nat., vol. ix, p. 81, 1909, and Zeits. fiir 
Kryst., vol. 1, p. 472, 1911. 


198 R&. H. Rastall—The Genesis of Tungsten Ores. 


tantalum, niobium, and lithium.!' There are besides a great number 
of minerals of metamorphic origin, and pneumatolytic action seems 
here to have been very intense. 

Somewhat similar to the foregoing is the well-known occurrence 
of eryolite at Ivigtut in Greenland, which also contains cassiterite 
and wolframite. The cryolite-bearing mass is about 500 feet long 
and from 100 to 180 feet wide, lying in granite, granite-porphyry, 
and gneiss. In the central portion of the mass cryolite predominates, 
with blende, galena, and chalcopyrite. The marginal portions, which 
are of pegmatitic character, consist of quartz, felspar, wolframite, 
cassiterite, molybdenite, and columbite. Fluorite is found in small 
quantity, but boron minerals are absent. This mass must be 
regarded as a special facies of the tin-wolframite pegmatite, 
characterized by tantalum, niobium, and an enormous excess of 
fluorine. 

Wolframite deposits occur on a large scale in a zone of country 
stretching from Tenasserim (Lower Burma) along the western side 
of the Malay Peninsula through Perak and Selangor. The Tavoy 
district of Burma and the Federated Malay States are now important 
producers; according to the latest statistics available Burma has 
now the second largest output of any country in the world. 

In the Tavoy district ® numerous granite masses are intruded into 
the sedimentary rocks of the Mergui Series. These, which are of 
unknown age, consist of quartzites, quartzitic conglomerates, and 
schists, the last being often graphitic. The igneous rocks, for the 
most part biotite granites, contain tourmaline and cassiterite as 
accessories, The wolfram lodes are quartz veins running out from 
the granites into the country rock; the chief minerals are quartz and 
wolframite, which alone occur in any large quantity. ‘The other 
minerals present are cassiterite, molybdenite, arsenopyrite, chalco- 
pyrite, bismuthite, galena, and tourmaline. A very characteristic 
feature is the almost universal occurrence of columbite. According 
to their mineral composition the lodes can be classified into three 
groups— 

1. Wolframite-quartz lodes. 

2. Cassiterite-quartz lodes. 

3. Wolframite greisen. 
Of these the first is by far the most important, the second and third 
groups being apparently rare, but the country is still very im- 
perfectly explored. 

From a generalization of the published descriptions of the Tavoy 
area if may be inferred that the mineral assemblage is specially 
characterized by wolframite, cassiterite, molybdenite, arsenopyrite, 
and columbite. 

Little is apparently known of the intervening Siamese territory 
to the south of Tenasserim, although some ore is now exported, but 
the Federated Malay States are large producers of wolframite as well 


1 Hess, Bull. 380, U.S. Geol. Surv., 1909, p. 149. 

2 Ussing, Danmark Geol. Unterség., ser. 1, No. 12, p. 97; Baldauf, Zeits. 
fiir prakt. Geol., vol. xviii, p. 432, 1910. 

3 Bleeck, Rec. Geol. Surv. India, vol. xliii, p. 48, 1913. 


R. H. Rastall—The Genesis of Twngsten Ores. 199 


as of tin-ore, especially Perak and Selangor. The mining in these 
States, as in Burma, is very largely alluvial, but the minerals are 
also worked in situ in the granites. ‘he tungsten occurrences have 
been well described by Mr. Scrivenor.' The prevailing rock is 
a biotite-hornblende granite, locally rich in tourmaline and cassiterite. 
‘he other minerals associated in the lodes are arsenopyrite, chalco- 
pyrite, fluorspar, and topaz, with occasionally sapphire and thorium- 
cerium minerals. In Selangor the richest shoots of wolfram ore are 
generally found at the contact of granite and schist; where the lodes 
traverse the schists they contain fairly pure wolfram, on the contact 
they contain mixed ore, while within the granite they become richer 
in tin and poorer in wolfram. In this area scheelite deposits are also 
abundant, as will be described in a later section ; the scheelite appears 
to be genetically connected with the wolfram lodes, and is probably 
derived also from the granitic magma under somewhat differing 
conditions. 

The Seward Peninsula of Alaska affords an interesting example 
of a highly mineralized region of the type now being considered.’ 
The country rock consists of quartzite, slate, and especially limestone 
of Paleozoic age, probably Carboniferous. These sediments are 
intruded by granite bosses and by quartz-porphyry dykes; the 
metamorphism thus produced is very intense, especially in the lime- 
stones, which contain many newly-formed minerals rich in boron and 
fluorine, such as tourmaline, axinite, danburite, vesuvianite containing 
boron, and other peculiar ty pes. 

Wolframite occurs in association with cassiterite in two different 

ways. On Cassiterite Creek the quartz-porphyry dykes intruded 
into the limestone are tin-bearing in depth. The tin-ore and 
wolframite occur as veins and stringers in the dykes, associated with 
arsenopyrite and pyrite. Blende and galena are less common, while 
molybdenite is local. The gangue minerals, besides quartz, are 
fluorite, topaz, and zinnwaldite. ‘There are also cassiterite-wolfram 
lodes in the limestone; these lodes appear to be pegmatitic in origin, 
as they contain quartz, felspar and mica, fluorite and topaz; the 
other metallic minerals are chalcopyrite, pyrrhotite, blende, and 
galena. 

Another remarkable occurrence is a wolframite-topaz lode, with 
galena and stannite, on Lost River. The gangue consists of purple 
fluorite and radial topaz. The presence of some silver is shown 
by assays. 

From the chemical point of view the most striking feature of this 
region is the abundance of boron, which has led to the formation of 
many minerals containing that element, of which the most interesting 
are paigeite and hulsite, two new iron-magnesia-tin-boron minerals. 
In this region boron seems to be in excess of fluorine, an unusual 
occurrence. 

The wolframite output of Queensland comes from the northern 


' Paper on Tungsten Ores, read before the F.M.S. Chamber of Mines at 
Ipoh, March 25, 1916 (no place of publication or date). 

2 “*The Geology of the Seward Peninsula Tin Deposits,’’ by A. Knopf, 
Bull. 358, U.S. Geol. Sury., 1908. 


200 R. H. Rastall—The Genesis of Tungsten Ores. 


part of the colony, from the Herberton tin-field, from the Etheridge 
mineral field, from Mount Carbine, Bamford, and other areas. In the 
Herberton district the country rock consists ‘of highly metamorphosed 
sediments, including quartzite, greywacke, and shales, intruded by 
biotite and hornblende granite, quartz porphyry, and felsite. Lodes 
occur in all of these, containing a considerable variety of minerals, 
including cassiterite, wolframite, bismuthine, antimonite, chalco- 
pyrite, galena, magnetite, tourmaline, topaz, and fluorspar. In the 
Hodgkinson field wolframite and molybdenite occur in quartz veins 
in a grey biotite granite. At Mount Carbine slates and schists are 
penetrated by batholiths of porphyritic biotite-granite. In connexion 
with this are pegmatite dykes and interlacing veins forming lodes up 
to 6 feet wide. The pegmatites consist of quartz-felspar rock with 
tourmaline, some muscovite, and a little bery]. The metallic minerals 


are cassiterite, wolframite, arsenopyrite, and molybdenite. The 


wolframite appears to be more closely connected with the felspar 
than with the quartz. One block of wolframite was found weighing 
6 tons. There is also some scheelite. 

In the Bamford district the rocks are mainly igneous, both volcanic 
and intrusive. Wolframite occurs as an original constituent in 
biotite-granite, and also in pegmatites and greisens in connexion 
with the granite. A large number of minerals has been observed 
here; the chief are: wolframite, bismuth (both native and as sulphides, 
carbonates, and oxides), molybdenite, pyrite, chalcopyrite, blende, 
and galena; cassiterite has been found, but it is not very common. 
Of much interest also are ilsemannite, stolzite, and the new mineral 
chillagite, previously mentioned as an isomorphous mixture of lead 
tungstate and lead molybdate. The ore-deposits are mainly in the 
form of pipes of white quartz, with wolframite and molybdenite ; 
vugs are seen up to 20 feet in diameter, containing bismuth, fluorite, 
and some sulphides; the smaller vugs are rich in wolfram, while the 
larger ones are poor. These vugs are possibly due to stoping along 
fissures. Although the form of the wolfram pipes is somewhat 
unusual, they do not differ in any essential feature from the common 
type of wolfram-molybdenite pegmatites formed by solidification of 
the last residues of a granitic magma in which these elements have 
been segregated by differentiation or concentration, whichever word 
is preferred in this connexion. 

From the published descriptions of the Queensland mines it appears 
that a large proportion of the present output comes from shoad 
deposits, which are locally described as alluvial: This material does 
not appear, however, as a rule to have been transported for any 
distance, but rather to be a true residual deposit. 

Wolframite is also found in the tin area of Mount Bischoff in 
Tasmania. Here quartz-porphyry dykes, intruded into Paleozoic 
sediments, have undergone intense pneumatolytic metamorphism, 
being largely replaced by secondary minerals, including cassiterite, 
wolframite, arsenopyrite, pyrrhotite, tourmaline, topaz, and fluorite. 
Perhaps the most striking feature here is the great. development of 
topaz in the altered dykes. 

The extraordinarily rich lodes of the provinces of Oruro and Potosi 


kh. H. Rastall—The Genesis of Tungsten Ores. 201 


in Bolivia have long been worked on a very large scale for tin and 
silver, but lately there has been a great development of wolfram 
mining in this area. In 1916 a very active tungsten boom began in 

Bolivia, as elsewhere, and the output is now very large. ‘The lodes 
are connected with masses of rhyolite and dacite, these being of the 
nature of laccolithic intrusions rather than flows. The gangue 
minerals are quartz, barytes, and carbonates ; the ores in depth are 
mainly sulphides, together with cassiterite and wolframite. The 
metals present in the form of sulphides are iron, lead, zinc, copper, 
antimony, bismuth, and silver; tin sulphide (stannite) i is also found, 
and in the gossan it has been converted into wood-tin. Original 
eassiterite and wolframite represent the primary oxidic ores, but in 
the gossan there are many oxidized minerals, as well as native silver 
and silver chloride in great quantities. Of special interest are three 
minerals, argyrodite, franckeite, and canfieldite, containing the 
exceedingly rare element germanium. It is evident, therefore, that 
the tin-wolfram lodes of Bolivia form an aberrant and in some 
respects transitional type; fluorite and tourmaline certainly do occur, 
but they are quite rare, and pneumatolytic minerals are for the most 
part absent. The whole mineral association shows a much closer 
approach to the sulphide type than is usual in tin-bearing deposits. 

The tin-wolfram-veins of Mexico (Durango, Guanajuato, and San 
Luis Potosi) show some affinity to those of Bolivia; they are 
associated with rhyolites, and the principal minerals in addition to 
cassiterite and wolframite are native bismuth, specular iron-ore, and 
durangite (a sodium-aluminium arsenate with fluorine). ‘Topaz is 
found, but no tourmaline. These veins appear to be of very recent 
date. In this case there are no sulphides, and it is perhaps per- 
missible to regard them as an ultra-oxidic type, specially characterized 
by fluorine. “The relationship to other types of tin-wolfram ores is 
not clear. 

Summary oF Parr I. 

’ A careful consideration of the facts set forth in the foregoing pages 
shows that the ore-deposits of the wolframite-cassiterite type result 
directly from the cooling of granitic magmas, and the metals, tin and 
tungsten, are integral and characteristic constituents of those magmas. 
In many instances cassiterite is -known to occur as a_ primary 
constituent of the granite; less commonly wolframite is found in 
a similar way. As a rule, however, these minerals become con- 
centrated in that fraction which- is highly volatile and escapes from 
the central portions of the intrusion, forming pegmatites and greisens 
in the granite itself and in the surrounding rocks. This tendency is 
doubtless accounted for by the fact that both tin and tungsten form 
highly volatile compounds with fluorine. The formation of cassiterite 
by the action of water on tin fluoride was long ago experimentally 
verified by Daubrée. According to Roscoe and Schorlemmer, tungsten 
hexafluoride is a gas at temperatures above 19°C. under normal 
pressure. All the evidence from the relative distribution of 
eassiterite and wolframite in lodes, goes to show that the latter 
is more volatile than the former, since it usually travels further 
from the margin of the granite; tin-wolfram lodes pass laterally 


202 kh. H. Rastall—The Genesis of Tungsten Ores. 


and continuously into wolfram lodes and these again into pure 
quartz veins. 

When the distribution of these minerals is studied in detail if is 
seen that the original metallic minerals of the granites and the ore- 
minerals of the pegmatites, greisens, and quartz lodes are of common 
genesis. They all arise as products of the crystallization of the 
differentiated magma. There is, therefore, in this case, no real 
distinction between magmatic segregations and vein - deposits. 
Consequently, the classification so prevalent in German textbooks 
into syngenetic and epigenetic deposits here breaks down. The 
difference is mainly one of time, or as it may be otherwise expressed, 
a difference of phase. 

The formation of these deposits, then, may be summarized as 
follows :— 

Ist phase: Concentration within the magma of the metallic 
constituents in combination with the volatile elements, 
especially fluorine and boron. 

2nd phase: Separation from the crystallizing granite of the com- 
pounds thus formed, and escape of the same through fissures. 

3rd phase: Chemical reactions between the compounds in the 
escaping gases or solutions, leading to the formation of 
crystallized ore and gangue minerals. 

It is, of course, impossible to draw any hard and fast line between 
these different phases; they are all parts of one continuous process, 
and in many instances doubtless proceed concurrently. 

Turning now to the mineralogical and chemical side of the question, 
we find a marked similarity of composition in all parts of the world. 
Although there are local differences in detail, yet it is possible to 
enumerate certain minerals of almost universal occurrence in 
association with wolframite and cassiterite. Of these the most 
characteristic among the sulphides are arsenopyrite and molybdenite. 
Chalcopyrite again is common, while blende and galena are more 
sporadic. Of the non-metallic minerals, tourmaline, topaz, and 
fluorite are characteristic, showing the presence of the highly 
volatile and chemically active elements fluorine and boron. 

Special interest attaches to the presence in certain localities only 
of notable amounts of some of the rarer elements, such as niobium, 
tantalum, and uranium. ‘The last, for example, is found in Cornwall, 
while columbite is abundant in Burma and in the extraordinary 
pegmatitic masses of Etta Knob and Ivigtut. At Etta Knob it is 
accompanied by a striking development of lithium minerals. In 
Bolivia silver is the most characteristic element. From these and 
similar considerations it appears possible to subdivide the tin- 
tungsten occurrences into paragenetic sub-types, as follows :— 

uranium . . Cornwall. 


tantalum and Burma, Etta Knob, 
molybdenum, arsenic niobium Tvigtut. 


Tungsten, tin bismuth . . Queensland. 


SUlVery wey aii) | cha CLIN ara UMMM Olinvilale 


R. Bullen Newton—Foraminifera from New Guinea. 203 


Furthermore, with respect to the non-metallic elements, some 
regions are characterized by excess of fluorine, others by excess of 
boron, each giving rise to characteristic groups of minerals, which 
indicate the chemical composition of the original magma. The 
further significance of these facts will be discussed more fully at 
a later stage. 

The following table shows the chief minerals found in ten of the 
more important wolfram-tin ore-deposits in different parts of the 
world :-— 


. d (<b) so 

as . | & aS) = Sh Wines 

— B = A fo] ~ 3 q 

3 = 3 2 rie 5. | ce S 

S rQ a a a 3 n a 

= sy o = fs! q Ba ka i=] a 

| = ao | © co) =I Grol aA oy =| 

s oa N “4 o o = eS o n 

iS) zi 4 & a) = s ay Ss x 

Sf ey | eat ee et eS Sl Se ls 

Wolframite PAR UN 5:88 Weep 2:0 >So. alles \ Al pcuall ore 
Cassiterite x x xe x x x 5 xX x x 
Molybdenite a oe | ee Se Se bre Pe a be Il oe 
Arsenopyrite Scr vibrate lesen pe Ne abceM o:eh lta be i(liulsce) Allo: 
Chalcopyrite me oN Se oe ail ROR oR NSS Tboe ) ae 
Galena x |—|x xe x xe x x | — 
Blende x x | x {|—]x{/—il—| «x x | — 
Pyrite x }/—/—}]—{]x}—|]—}]x;—] x 
Bismuth minerals i ee ee 
Uranium a : SO oe IS oe ee 
Columbite 3 : Spee Wea le) oe X x }|—}]—}]—]}] — 
Tourmaline ; ; Flex Sc x x |—|x x X OK ae 
Fluorite . ; : Sn eX De es Se eal bc Xs x x 
Topaz ‘ : : ae |p Se ae eh oP ioe A ioe Lh Dx) Iie oe 


(To be continued.) 


I[l.—Foramintrerat ann Nutiiore Scrucrures In soMe TERTIARY 
Limestones From New GuInra. 
By R. BULLEN NEWTON, F.G.S., Geological Department, British: Museum." 
(PLATES VIII AND IX.) 


Inrropocrion. 

T the request of Professor J. W. Gregory, F.R.S., of Glasgow 
University, the following report has been prepared dealing with 
some microscopical organisms entering into the composition of certain 
limestones from Central New Guinea. The material studied, com- 
prising Foraminifera and Nullipore (Lithothamnium) remains, has 
been obtained from some rolled limestone pebbles which were 
collected in river-beds of the upper reaches of the Fly River by 
the Right Hon. Sir William Macgregor, G.C.M.G., during an 
expedition carried out in the years 1889 and 1890. Being desirous 
that these limestones should be scientifically examined, Sir William 

submitted them to the Geological Department of the University 


1 Published by permission of the Trustees of the British Museum. 


204 R. Bullen Newton— Foraminifera, etc., 


Glasgow in the hope that Professor Gregory and his staff might issue 
a statement as to their structural and geological value. In accordance 
with this request, therefore, the corals were first examined and 
described in a joint paper by Professor Gregory and Miss J. B. Trench,’ 
while some remarks on the Foraminifera and associated structures 
have been postponed for the present occasion. At the time when the 
corals were in course of description, the writer was appealed to for 
an opinion as to the geological age of one of the pebbles (No. 1), 
exhibiting corals and some smaller organisms, although to give aid 
in this direction it was necessary to prepare microscopical sections of 
the limestone for examination by transmitted ght. It was then 
ascertained that the genus Alveolina was of frequent occurrence, as 
well as other Foraminifera, chiefly of the Milioline group. According 
to Orbigny,? Alveolina originated in Cretaceous times, having been 
recorded from the Cenomanian rocks of France; it is, however, much 
more typical of the Eocene period, being well ‘known in deposits of 
that age as developed in England (Bracklesham Beds particularly), 
Europe, Egypt, Madagascar, India, Java, Celebes, New Guinea, etc. 
The genus is less abundant in the younger Tertiary formations, while 
according to H. B. Brady * two species alone survive in tropical seas 
at the present day. ‘The distribution of this genus, therefore, and 
its association in the limestone pebble with the Miliolines, so 
characteristic of the Bracklesham Beds and corresponding deposits 
of the Paris Basin, suggested that the pebble might be attributed to 
the Lutetian or Middle division of the Eocene series, a result since 
accepted and published in the Gregory and Trench paper previously 
referred to (p. 532). 


BrsiioGRaPHy. 


Several memoirs have been issued on the organic structures of 
New Guinea Tertiary rocks, most of which have been recently 
reviewed in a paper by the writer,* and although it is unnecessary to 
repeat such information it seems desirable to refer again to that part 
of the literature which more particularly concerns the occurrence of 
Alveolina in that country. The first mention of Alveolina in the 
limestones of New Guinea was made by Dr. K. Martin® in 1881, from 
material obtained in north-west regions, the generic determination 
having been confirmed by Schwager, who, moreover, considered that 
the specimens were related to A. spherica (Fortis), the equivalent of 
A. melo (Fichtel & Moll), a characteristic Miocene species, besides 
being known from older Tertiaries as well as from recent seas. The 


1 ** Hocene Corals from the Fly River, Central New Guinea’’: GEOL. MAG., 
1916, pp. 481-8, 529-36, Pls. XIX-XXII. 

2 Prodrome Pal. Strat., 1850, vol. ii, p. 185. 

> Rep. Voy. H. M.S. ‘‘ Challenger’? : Zoology—Foraminifera, vol. ix, pl. xvii, 
figs. 7-15, pp. 221-4, 1884. 

+ R. B. Newton, ‘‘ Notes on some Organic Limestones, etc., collected by the 
Wollaston Expedition in Dutch New Guinea, from Reports on the Collections 
made by the British Ornithologists’ Union Expedition and the Wollaston 
Expedition in Dutch New Guinea (1910-13)’’ : Report No. 20, vol. ii, 1916. 

* ““Bine Tertiaerformation von Neu-Guinea und benachbarten Insel’’: 
Samml. Geol. Reichs.-Mus. Leiden, vol. i, pl. iii, figs. 9-10, p. 70, 1881. 


un Terivary Rocks of New Guinea. 205 


organism was briefly described and figured as Alveolina sp., and was 
said to be associated with Orbitoides, Cycloclypeus, etc., and the 
Nullipore Lethothamnium ( Cumulipora) rosenbergr, Martin, now better 
known as ZL. ramosissimum of Reuss, which is typical of Miocene 
rocks.! The Orbitoides were stated to possess rectangular chamberlets 
(rechteckige mediankammern), as seen on the median plane, thus implying 
the presence of the Kocene genus Orthophragmina. It is evident 
that some confusion must have arisen with the material determined 
by Martin to account for such an assemblage of forms, and it seems 
fair to suggest that the Alveolina and the Orbitoides belonged to an 
Kocene limestone, while the remaining organisms, Cycloclypeus, 
Lithothamnium, ete., indicative of a Miocene origin, were, in all 
probability, observed in another rovk. Martin first of all determined 
this limestone as Tertiary, although a year later? definitely placed 
it in the older Miocene and in correlation with similar deposits of 
Indo-Pacific countries. 

In his 1881 memoir, Martin likewise referred to certain limestones 
he had examined from Geelvink Bay localities and from islands off 
the south-western end of New Guinea, mostly containing Orbitoides, 
a small Mummulina sp., and Lithothamnium rosenbergr. They were 
regarded as of Tertiary age, with a resemblance to the older Miocene 
rocks of Timor, Java, and Sumatra. The Orbitoides were stated to 
belong to the Lepidocycline group of the type of O. gigantea of 
Martin, from the Miocene of Java. 

Schlumberger subsequently studied the same material as described 
by Martin containing the so-called Alreolina sp., which had been 
submitted to him by Dr. Wichmann.* He was unable to recognize 
the accuracy of Martin’s Alveolina, but regarded the organism as 
presenting structures belonging to the genus Lacazina ot Munier- 
Chalmas; he therefore described and figured it under the new 
specific designation of Z. wichmannt. The author also remarked on 
the interest of the discovery since Zacazina had hitherto been 
restricted to the younger Cretaceous rocks of Kurope and Palestine, 
and now, according to Martin’s interpretation as to the age of the 
New Guinea deposits, this genus could be recognized as occurring in 
the Tertiaries of that region. Schlumberger also mentioned that the 
associated Foraminifera included Rotaline, Miliolide, and a true 
Alveolina of the sub-genus Flosculina. Moreover, he had not seen 
the assemblage of forms referred to by Schwager (in Martin), the 
determinations of which he considered as of doubtful value. 

Martin * next identified the presence of Lacazina wichmanni in some 
detrital limestones from south-west New Guinea (Setakwa River, etc.) 


1 R. B. Newton & R. Holland, ‘‘On some Fossils from the Island of 
Formosa, etc.’?: Journ. Coll. Sci. Imp. Univ. Tokyo, Japan, vol. xvii, art. 6, 
pl. i, fig. 8, pp. 17-19, 1902. 

2 “Neue Fundpunkte von Tertiaergesteinen im Indischen Archipel ”’ : 
Samml. Geol. Reichs.-Mus. Leiden. vol. i, p. 178, 1882. 

3“ Note sur Lacazina wichmanni, Schlumberger, n.sp.’?: Bull. Soe. Géol. 
France, ser. II, vol. xxii, pl. xii, pp. 295-8, 1894. 

4 “*Paliozoische, Mesozoische, und Kinozoische Sedimente aus dem siid- 
westlichen Neu-Guinea’’: Samml. Geol. Reichs.-Mus. Leiden, vol. ix, 
pp. 84-107, iey tite 


206 R. Bullen Newton—Foraminifera, etc., 


associated with Alveolina and Nummulina, and on account of its 
frequent occurrence he named the limestones ‘‘ Lacazinenkalk” and 
considered them as of Eocene age. On the same occasion Martin 
also referred to the discovery of Alveolina by Dr. H. A. Lorentz in 
the limestones of Mt. Wilhelmina, situated in south-central Dutch 
territory at an altitude of more than 13,000 feet or 4,461 metres. 
The genus was found accompanying Nummulites, and in consequence 
ascribed to the Eocene period.' A still further reference occurs in 
Martin’s memoir regarding Alveolina, mention being made of its 
identification in the limestones of Digoel River (S.W. New Guinea) 
associated with Lepidocyclina and Lithothamnium and stated to belong 
to the older Miocene. 

The latest notice of importance respecting the occurrence of 
Alveolina in New Guinea is to be found in a report by Dr. L. Rutten,’ 
published in 1914, containing figures and description of a new species, 
A. wichmanni, from the Eocene limestones of Dramai Island, Triton 
Bay, south-west New Guinea, which is stated to have been associated 
with Lacazina wichmanni, Schlumberger. The paleontology of the 
older Miocene limestones of New Guinea has rather recently been 
studied, and quite independently, by Mr. F. Chapman,* of the 
National Museum, Melbourne, and the present writer,* with very 
similar results. The principal organisms recognized were various 
species of Lepidocyclina, Cycloclypeus, Carpenterra, Lithothamnium 
ramosissimum, etc., an assemblage indicative of the Upper Aquitanian, 
which represents the oldest stage of the Miocene formation. 


Tue LivestonE PEBBLES. 


The pebbles submitted for examination are numbered 1, 2, 11, 12, 
and 28, the largest being Nos. 1 (90 X 50mm.) and 2 (105 Xx 
60mm.), whereas the others are, roughly, about a third of their 
size. They consist of slightly different-coloured limestones, which 
in connexion with their organic contents are considered to belong to 
two different Tertiary horizons: the Eocene and the Miocene. 
Being rounded and of water-worn character, they may be termed 
rolled-limestone pebbles; and further, having been collected from 
river-beds in the upper reaches of the Fly River, their origin 
undoubtedly points to the great limestone development which, as 
high mountain ranges, runs east and west through the wide central 
region of New Guinea. 


1 For some unexplained reason this limestone from Mt. Wilhelmina with 
Alveolina has been rather recently determined as of Cretaceous age in an 
article on ‘‘Papua’’ contained in the Federal Handbook, prepared for the 
84th Meeting of the British Association for the Advancement of Science, held 
in Australia, 1914, pp. 256, 321. 

2 “* Woraminiferen-Fuhrende Gesteine von Niederlandisch Neu-Guinea ”’: 
A. Wichmann’s Nova Guinea, vol. vi, ‘‘ Géologie,’’ livr. ii, pl. ix, figs. 1, 2, 
p. 45, 1914. 

3 “Description of a Limestone of Lower Miocene age from Bootless Inlet, 
Papua ’’: Journ. Proc. Roy. Soc. New South Wales, vol. xlviii, pt. ti, pls. vii-i1x, 
pp. 281-301, 1914. 

4 R. B. Newton, the Wollaston Expedition Report, 1916, previously 
alluded to. 


in Tertiary Rocks of New Guinea. 207 


No. 1. This consists of a cream-coloured limestone of one uniform 
tint throughout, and is that previously determined by the writer for 
Professor Gregory as exhibiting <Alveolina, Miliolines, and coral 
structures, and which was referred to the Middle and Lutetian stage 
of the Eocene period. A further examination of this pebble has now 
furnished evidence of the presence of Lacazina and Orthophragmina, 
so that its geological age seems to be beyond question and, moreover, 
it fairly closely corresponds with the ‘‘ Mixen” and “Clibs”’ rocks 
of Bracklesham Bay, England, and the ‘‘ Miliolite’’? Limestone of 
the Paris Basin, all of which contain Alveolina associated with 
Miliolines, and which belong as well to this stage of the Eocene 
Series. 

No. 2. A cream-coloured limestone, but with deep reddish-brown 
veins extending to the centre of the pebble. It contains occasional 
Alveolina, Corals, and an abundance of the Nullipore, Lithothamnium 
ramosissimum, whilst the absence of Miliolines and Lepidocyclines 
may also be noted. Chiefly from the occurrence of the Nullipore, so 
peculiarly characteristic of the Miocene limestones of Europe and 
Far Eastern countries, this pebble is regarded as belonging to that 
division of the Tertiary system. 

No. 11. Is cream-coloured, but intersected by thin dark veinings. 
It resembles No. 1 in possessing similar coral structures, of which it 
is mainly composed. Miliolines are also present, the polished surface 
exhibiting a transverse section of Pentellina like saxorum. No 
Alveolines are discernible, but the assemblage denotes an HKocene 
origin for this pebble. 

No.12. A yellowish cream-coloured limestone containing Miliolines, 
Textularia, Carpenteria conordea, etc., and Lithothamnium ramosissimum, 
the latter suggestive of its Miocene age. 

No. 28. This is mainly composed of a stellate coral structure, 
although its narrower end reveals some minute Foraminifera, 
especially an Alveoliniform-looking organism, occurring as transverse 
and longitudinal sections on the polished surface, which represents 
Lacazina wichmanni, a New Guinea fossil of known Eocene age. 


Organisms contained in the Pebbles. 
FORAMINIFERA. 
ALVEOLINA WICHMANNI, Rutten. (PI. VIII, Figs. 1a, 2a, 3, 4a, 5, 6.) 


Alveolina wichmanni, Rutten, Wichmann’s Nova Gwinea, vol. vi, ‘‘ Géologie,’’ 
pt. ii, pl. ix, figs. 1, 2, p. 45, 1914; Samml. Geol. Reichs.-Mus. Leiden, 

ser. I, vol. ix, pl. xxvi, figs. 3, 4, and pl. xxvii, fig. 2, pp. 315-18, 1914. 
This is an Kocene species having been originally described from 
the limestones of south-west New Guinea (Triton Bay) and after- 
wards from the Island of Celebes. It presents a narrow, tapering, 
and spindle-shaped axis composed of few and often irregularly formed 
layers which vary in number from nine to fourteen. hose forms 
with more regularly disposed layers are represented by Figs. 3 and 
4a, whereas Figs. la and 2a show a greater irregularity and thus 
more closely approach the type. A transverse section displayed on 
the polished surface of the pebble, Fig. 6, exhibits a series of 


\ 


208 kh. Bullen Newton—Foraninifera, etc., 


apertures which represent the longitudinal channels that perforate 
the organism throughout its longer axis. A good longitudinal view 
of a weuthered specimen exposing a partial interior is illustrated by 
Fig. 5, in which the margins of the layers are to be observed together 
with the closely set, external, transverse striations. Miliolines of 
the Quinqueloculine type and other Foraminifera accompany this 
species, see Figs. 16, 2, and 40 of Plate VIII. 

Dimensions.—Length 38-8, width 1-2} mm. 

Occurrence.—Pebble No. 1. 

Distribution.—Kocene deposits of New Guinea and the Island of 
Celebes. ; 
ALvEotIna sp. (PI. IX, Fig. 6a.) 

A longitudinal section of this genus occurs in No. 2 pebble 
associated with Lithothamnium ramosissimum. It is rounded at the 
poles and not fusiform as is the case in A. wichmanni, being most 
nearly related to A. melo (Fichtel & Moll), which, according to Brady,’ 
ranges from Hocene to Recent seas. The presence of the Nullipore 
in this pebble strongly supports its Miocene origin. 

Dimensions.—1 by 4mm. 

Occurrence.—Pebble No. 2. 


Lacazina wichMannt, Schlumberger. (Pl. IX, Figs.-1, 2, 3a.} 

Alveolina sp., cf. A. spherica (Fortis), Martin & Schwager: Samm]. Geol. 
Reichs.-Mus. Leiden, vol. i, pp. 70-83, pl. iii, figs. 9-10, 1881. 

Lacazina wichmanni, Schlumberger, Bull. Soc. Géol. France, ser. III, 
vol. xxii, pl. xii, pp. 295-8, 1894; Rutten, Wichmann’s Nova Guinea, 
vol. vi, ‘‘ Géologie,’’ pt.-ii, pl. vili, figs. 8, 9, p. 44, 1914. 

The form here referred to is of frequent occurrence in No. 1 pebble, 
and is also found in No. 28 pebble accompanying a stellate coral 
structure. Specimens showing both longitudinal and transverse 
sections are well exposed on the polished surfaces of the limestones, 
and they resemble Martin’s figures of <Alveolina sp. found in the 
north-west coastal regions of New Guinea, which was determined by 
Schwager as being related to A. spherica (Fortis), the equivalent of 
A. melo (Fichtel & Moll), a characteristic Miocene species. At 
a later date, however, Schlumberger studied Martin’s material -and 
recognized the supposed Alveolina sp. as a new species of Lacazina, 
Munier-Chalmas (Bull. Soc. Géol. France, ser. m1, vol. x, p. 472, 
1882, type= Alveolina compressa, Orbigny), a genus hitherto restricted 
to the younger Cretaceous rocks of Europe and Palestine. 

The chief features of interest respecting ZL. wichmanni are its 
possession of a spherical initial chamber succeeded by chambers the 
walls of which are alternately open below and above the poles 
throughout its growth. The chambers are also divided internally 
by numerous longitudinal ribs radiating from the external wall of 
each chamber and often appearing to reach the inner surface of the 
succeeding layer. These characters are more or less expressed in the 
present examples, although the delicate openings of the chamber 
walls are most difficult to trace, and their existence is only obscurely 
indicated. The radio-longitudinal ribbing appears also to be finer 


1 Challenger Report: Foraminifera, 1884, pl. xvii, figs. 13-15, p. 223. 


in Tertiary Rocks of New Guinea. 209 


than in Schlumberger’s illustrations, but if our figures are subjected 
to a higher magnification a coarser effect is produced which yields 
a considerable resemblance to the type. First regarded as Tertiary, 
then Miocene, Martin’ finally admitted this organism as of Eocene age, 
more particularly as it was now known to have been found with 
Nummulites in the rocks of south-western New Guinea (Setakwa 
River). On account of its great frequency in the limestones of 
New Guinea, Martin established the name Lacazinenkalk. Miliolines 
are in close association with this genus, forms being clearly depicted 
in Fig. 3 of Plate IX. 

Dimensions.—From 1 to 4 mm. in diameter. 

Occurrence.—In pebbles Nos. 1 and 28. 

Distribution.—Species found only in New Guinea rocks. 


OrrHopHRacmiINA sp. (Pl. IX, Fig. 4.) 


A fragmentary example of this genus is to be observed on the 
polished surface of No. 1 pebble. It is merely a portion of a 
horizontal section measuring about 8 mm. across the disc, exhibiting 
remains of eight or nine of the later annulations which enclose 
numerous rectangular chamberlets characteristic of Orthophragmina, 
an Kocene genus founded by Munier-Chalmas* in 1891, on the type 
of Michelin’s Orbitolites pratt, from the Eocene of Biarritz, France. 

From this single imperfect specimen and with no knowledge of its 
embryonic characters, it is not possible to venture on a specific 
determination. Nevertheless, so far as the evidence goes, it may be 
stated to show resemblances to the published figures of O. pratti,$ 
which includes Giimbel’s Orbitoides (Discocyclina) papyracea, non 
Boubée,* an Kocene form of Kurope and other countries. 

Oceurrence.—VPebble No.1; associated with Alveolina, Lacazina, 
Miliolines, etc. 


CARPENTERIA CoNOIDEA, Rutten. (Pl. IX, Fig. 5.) 
Carpenteria conoidea, Rutten, Wichmann’s Nova Guinea, vol. vi, ‘‘ Géologie,’’ 
pt. ii, pl. vii, figs. 6-9, p. 47, 1914. 

Dr. Rutten has described an erect form of Carpenteria from the 
older Miocene deposits of northern New Guinea to which the present 
specimen may be referred. ‘The fossil in question is the large 
central organism represented in Fig. 5, in which is displayed a 
longitudinal view of the interior showing a segmental structure 
composed of thick and porous walls, and a well-marked conoid-apical 
region, from which succeeds its later development widening 
appreciably to the base. The chambers, especially those observed 
near the base, are of crescentic form resembling Glodigerina. 


1 ** Paldozoische, Mesozoische, und Kanozoische Sedimente siidwestlichen 
Neu-Guinea’’: Samml. Geol. Reichs.-Mus. Leiden, vol. ix, p. 104, 1911. 

2 Htude du Tithonique, du Crétacé, et du Tertiaire du Vicentin, 1891, 
Thése de doctorat, p. 18. 

3 Schlumberger, Bull. Soc. Géol. France, ser. IV, vol. iii, pls. viii, ix, p. 274, 
1903. 

4 Gimbel, Beitrage zur Foraminiferen der Nordalpinen Hocdngebilde, 1868, 
ples sleep wll 

DECADE VI.—VOL. V.—NO. V. 14 


210 R. Bullen N ewton—Foraminifera, etc., 


This organism is associated with Zeartularia, Quinqueloculine, ete., 
and Lithothamnium ramosissimum, the presence of the latter more 
particularly suggesting a Miocene origin. 

Dimensions.—Length 2, width 1mm. 

Occurrence.—Found in No. 12 pebble. 

Distribution.—Known only in the Miocene rocks of New Guitea. 


’ Mintorines. (Pl. VIII, Figs. 1b, 26, 46; Pl. 1X, Fig. 30.) 


Milioline Foraminifera associated with Alveolina, Lacazina, etc., 
are abundant in No. 1 Pebble. The more striking form, as seen in 
the sections and represented by our photographic figures, exhibits 
transversely plicated chamber walls, thus suggesting a relationship 
to Pentellina saxorum (Orbigny), a fossil of frequent occurrence in 
the Miliolitic Limestone of Paris and the ‘‘Clibs” and ‘‘ Mixen” 
rocks of the Bracklesham Beds of England, all of which belong to the 
Lutetian or Middle Eocene horizon. 

It is interesting to note that Miliolines with similarly associated 
forms have been reported from the Eocene limestones of the Island 
of Celebes by Dr. Rutten.’ 

Dimensions.—14 mm. in diameter. 


Occurrence.—In No. 1 pebble. 


PLANTH (NULLIPORE). 
LirHorHaMNIUM RAMosIssIMUM, Reuss. (Pl. IX, Figs. 64, 7.) 


Nullipora ramosissima, Reuss, Nat. Abhand]. Haidinger, vol. ii, pt. i, pl. iii, 
figs. 10, 11, p. 29, 1848. 

Lithothammum ramosissimum, Giimbel, Abhandl. k. bayerischen Akad. 
Wiss. Miinchen, vol. xi, pt. i, pl. i, fig. 1, p. 34, 1871. 

Cumulipora rosenbergi, Martin, Samml. Geol. Reichs.-Mus. Leiden, vol. i, 
pp. 12 14, 64, pl. iii, fig. 7, 1881. 

Lithothamnim ramosissimum, Nishiwada, Journ. Coll. Sci. Imp. Univ. 
Tokyo, vol. vii, pt. iii, p. 236, pl. xxix, figs. 1-4, 1894. 

L. (Cumutlipora) rosenbergi, Newton & Holland, Journ, Geol. Soc. Tokyo, 
vol. vii, No. 81, p. 22, 1900. 

LL. ramosissumum, Néwton & Holland, Journ. Coll. Sci. Imp. Univ. Tokyo, 
vol. xviii, pt. vi, p. 17, pl. i, fig. 8, 1902; Chapman, Journ. Proc. Roy. 
Soc. New South Wales, vol. xlviii, p. 286, 1914; R. B. Newton, Reports 
Coll. Brit. Ornith. Union Wollaston Exped. Dutch New Guinea, vol. ii, 
Rep. No. 20, pl. i, p. 17, 1916. 


This well-known calcareous alga, first recorded from the European 
Miocene and so abundantly represented in the same formation as 
developed in Far Eastern countries, is of prolific occurrence in No. 2 
pebble. Its elegant structure, well seen in Fig. 7, includes the 
arrangement of ‘the rectangular tissue cells within the regularly 
disposed annulations of growth forming the branches. More massive 
forms of the genus are also present in the limestone, one being 
_ observed at the base of the section illustrated by Fig. 60 in close 
proximity to the branches that have been further enlarged in Fig. 7. 

The specimen is associated with an Alveolina (Pl. IX, _ 6a) 
having a probable relationship to the Miocene A. melo. 


1 «* Studien iiber Foraminiferen aus Ost-Asien’’: Samm]. Geol. Reichs.-Mus. 
Leiden, vol. ix, pp. 308-10, 1914. 


Lose 
soe 


Nee 
Se 


aS: 


x 
set 
By, 


Grou. Maa., 1918. 


P. Dellman, photo. 


TERTIARY FORAMINIFERA, 


NEW 


Prate VIII. 


R. B. Newton, direvit. 


GUINEA. 


a 


in Tertiary Rocks of New Guinea. 21. 


Dimensions.—Rather more than 2 mm. in length. 

Occurrence.—In pebble No. 2. 

Distribution. — Europe and Indo-Pacific regions — Formosa, 
Philippines, Japan, Christmas Island, Borneo, Sumatra, Celebes, 
New Guinea, Australia, etc.; and of Miocene age. 

Resvits. 

The more important facts connected with the examination of the 
limestone pebbles prove that they may be referred to two geological 
horizons, viz. the Eocene and Miocene. The Kocene fossils, found 
in pebbles Nos. 1, 11, and 28, comprise: <Alveolina wichmanni, Laca- 
zina wichmanni, Orthophragmina sp, and cf. Pentellina saxorum. 
The Miocene fossils, restricted to Nos. 2 and 12 pebbles, include: 
Carpenteria conoidea, Alveolina sp., and Lithothamnium ramosissimum. — 

Referring to the Eocene assemblage, it may again be pointed out 
that the association of Alveolina and cf. Pentellina saxorum resembles 
the fossiliferous contents of the ‘‘Clibs” and ‘‘Mixen” rocks of 
England as well as the Miliolitic limestone of Paris, which belong to 
the Lutetian or Middle Eocene group of the Tertiaries; hence, it is 
suggested that a nearly similar age may be determined for the New 
Guinea limestones in question. 

On account of the absence of Lepidocyclina among the Miocene 
organisms, it is somewhat difficult to estimate their true geological 
position in that great formation. The limestones of Papua (British 
New Guinea) and Mt. Carstensz (Dutch New Guinea), described 
respectively by Mr. Chapman and the present writer, have yielded 
various forms of Lepidocyclines, which, studied on the basis of 
researches propounded by Professor H. Douvillé! in connexion with 
similar fossils from some Tertiary limestones of Borneo and the 
Philippine Islands, prove them to be of Aquitanian or older Miocene 
age. In all probability the fossils now described belong to the same 
stage of the Miocene, although the Nullipore Lithothamnium ramo- 
sussimum, it should be remembered, is particularly abundant in the 
‘‘ Leithakalk ’? of Europe (Vienna Basin), which is included in the 
Tortonian or youngest marine stage of the Miocene system. 


EXPLANATION OF PLATES VIII AND IX. 


PLATE VIII. 
ALVEOLINA WICHMANNI, Rutten. 


Fic. la. Longitudinal section of interior. x 10. 

.) 2a. oe) ”) Te) x 20. 

,, 3, 4a. Internal longitudinal sections showing more regularly disposed 
layers than are represented in Figs. laand 2a. x 10. 

,, 5. Longitudinal view of a weathered specimen showing the margins of 
successive layers and external transverse striations. X 10. 

,, 6. Transverse section of specimen preserved on the polished surface 
of the pebble, in which the more or less equidistant apertures 
represent the longitudinal channels that perforate the organism. 


x PDS 
1 ‘Tes Foraminiféres dans le Tertiaire de Borneo’’: Bull. Soc. Géol. 
France, ser. IV, vol. v, p. 454, 1905. ‘‘ Les Foraminiféres dans le Tertiaire des 


Philippines’’: Philippine Journ. Sci., vol. vi, No. 2, pp. 53-80, pls. A-D, 1911. 


212 Dr. FE. A. Newell Arber—Coal-measure Calamites. 


Cf. PENTELLINA SAXORUM (Orbigny). 


Fie. 1b. Internal section. x 10. 

99 2b. oe) oe) x 20. 

eos AA ae x 10. 
The specimens figured on this Plate are from No. 1 pebble. 


Puate IX. 


LACAZINA WICHMANNI, Schlumberger. 
Fic. 1. Longitudinal section. x 12. 
,», 2. Transverse “8 6 1D 
,, 3d. Longitudinal section of a compressed example. «x 10. 
Cf. PENTELLINA SAXORUM (Orbigny). 
,, 380. Internal sections. x 10. 
ORTHOPHRAGMINA sp. 
,, 4. Horizontal section of a fragmentary disc showing the internal 
characteristic rectangular chamberlets and annulations of growth. 
x 8. 
Specimens represented by Figs. 1-4 are from No. 1 pebble. 
CARPENTERIA CONOIDEA, Rutten. 
,, 50. Longitudinal section of interior exhibiting the early conoidal growth, 
a widened base, and chambers of crescentic form. From No. 12 
pebble. x 10. 
ALVEOLINA cf. MELO (Fichtel & Moll). 
,, 6a. Longitudinal view of interior. x 10. 
LITHOTHAMNIUM RAMOSISSIMUM (Reuss). 


,, 6b. Parts of branches seen in longitudinal section. x 10. 
» 7. The same, more highly magnified, displaying the rectangular cell 
structure of the tissue. x 25. 


Specimens represented by Figs. 6a—-7 are from No. 2 pebble. 


II1I.—A Nore on Susmepuntary Casts or CoalL-MEASURE CALAMITES. 
By EH. A. NEWELL ARBER, M.A., Sc.D., F.G.S. 


fF\HE pith-casts of Calamites are common Coal-measure fossils, 

sometimes of use in helping to fix the horizon of certain coals. 
They are, however, notoriously difficult taxonomically, and in 
several cases there is difference of opinion among authorities both 
as to the essential characters of a particular type of pith-cast, 
and also as to what is the most nearly correct name to apply to it. 
Immense space is still taken up by arguments as to what, exactly, 
some ancient and often manifestly rough drawing, supposed to 
represent a type, really depicts—with a view to maintaining a strict 
priority as regards nomenclature. If the original specimen is now 
lost, as is not infrequently the case, the guessing still continues. 
Some workers are not content to start their synonymies chronologically 
with the next oldest figure, the original of which still survives and 
the nature of which is agreed to on all hands. 

But apart from such cases, there are not a few specific names in 
vogue in regard to Calamite pith-casts, and also some other genera, 
which are purely indefinable. ‘They are applied to certain fossils 
because there exists some, usually ancient, figure which they some- 
what resemble, but if we are asked to define these species in relation 


Grou. Maa., 1918. PrAtE DX: 


P. Dollman, photo. R. B. Newton, direvit. 


TERTIARY FORAMINIFERA AND NULLIPORE, NEW GUINEA. 


Dr. E. A. Newell Arber—Coal-measure Calamites. 213 


to other types of Calamite pith-casts we have to confess our inability 
to do so in strict terms. 

There are a certain set of Calamite form-species which have given 
me much trouble in this respect, but until recently I have not 
understood why. Itis a common observation that such specimens as 
I refer to here more particularly, never show the prints of the 
infranodal canals below the nodes. These scars in my experience 
offer one of the best, if not the most satisfactory, means we have of 
discriminating between form-species among pith-casts, considered, of 
course, in conjunction with other morphological features. I have, 
however, now realized that these specimens are not, strictly speaking, 
pith-casts at all. They represent incrustations of surfaces which 
lay external to the pith, and I propose to distinguish them as 
submedullary casts. In such cases the tissues appear to have under- 
gone more or less considerable decay before the cast was formed, no 
doubt to an extent which varied greatly in different cases. The 
result has been that a cast has been formed of the medullary rays and 
bundles at a level which lay external to the true pith-cavity and the 
openings of the infranodal canals into that region. 

I first realized this fact from a study of a slightly tangential 
section! of the wood of a petrified stem of a Calamite, passing through 
anode, in my friend Dr. Scott’s collection. Part of this section is 
figured by Dr. Scott? in his Studies in Fossil Botany, so I need 
only refer to it briefly here. At this level the so-called ‘‘ infranodal 
canals’’ consist of solid masses of tissue, which would leave no print, 
on the cast. It is only the somewhat expanded terminations of the 
canals projecting into the pith-cavity which gives rise to the well- 
known scars. 

This section of Dr. Scott’s appears to me to throw a flood of 
light on such frequently quoted and figured species as Calamites 
canneformis, Schlotheim, 1820; C. pachyderma, Brongn., 1828; 
C. approximatus, Brongn., 1828 (non Schlotheim); C. varvans, Stern- 
berg, 1838; C. Schiitzer, Stur, 1881; and C. Schatzslarensis, Stur, 
1887. 

These specimens are often characterized by the coarseness of the 
ribbing of the internodes. There are, for instance, in the Sedgwick 
Museum, Cambridge,? several examples of large Calamite casts 
from the Dogtooth Rake Ironstone, Chesterfield, with ribs 5-6 mm. 
broad, without any trace of infranodal canals. ‘These appear to 
correspond very closely to the C. pachyderma of Brongniart, and they 
are clearly submedullary in origin. CC. Schatzlarensis of Stur 
appears to be a name founded on several different types of pith- cast, 
and the same is true of that author’s C. Schiitzer. 

C. varians, Sternb., is also indefinable, and nothing is gained 
by transferring C. approximatus, Brongn. (non Schlotheim) to Stur’s 
species .C. Waldenburgensis (as has recently been suggested by Kidston) 
or to an entirely new species, C. Schiitzerformis, forma Waldenburgensis, 


1 No. 897. 
2 Qnd ed. (1908), p. 27, fig. 8; see also pp. 47-8. 
> Nos. 439-41, 478. 


214 H.L. Hawkins—The A. quadratus Zone near Inkpen. 


as recently adopted by Kidston and Jongmans.' All of these sub- 
medullary types I now regard as, strictly speaking, indeterminable 
specifically. If any one of them has any claim to be recognized, 
despite the absence of infranodal scars, it is C. approximatus, Brongn. 


1V.—Note on tHe Occurrence oF THE Zonrn OF A. QUADRATUS 
(Sus-zone oF OrrasTER PILULA) NEAR INKPEN, BERKS. 


By HERBERT L. HAWKINS, M.Sc., F.G.S8., Lecturer in Geology, University 
College, Reading. 


LONG the narrow belt of Upper Chalk that forms the northern 
margin of the Vale of Ham (or Shalbourne), a sunken and 
picturesque lane passes from the village of Inkpen in a direct line to 
Shalbourne. At a distance of about a quarter of a mile west of the 
cross-roads in the village (and about the same north-west of the 
church), the 500 ft. contour crosses thisrcad. On the new series Survey 
map (Sheet 267) a quarry is marked on the northern side of the road 
near this point, and a northerly dip of 25° isrecorded. The quarry is 
now almost completely grassed over, but about 100 yards to the east 
of it (practically on the line of the shaft of the arrow on the map) 
there is an open road-cutting, giving access to the Chalk, on both 
sides of the road. . 

The Chalk is much crushed, and full of small dislocations, but the 
northerly dip is still quite clear. A few scattered flints occur in it, 
but no continuous layers. Fossils are exceedingly scarce—indeed, 
I have paid several visits to the exposure and hitherto failed to find 
anything zonally distinctive. All organic remains are either already 
in fragments, or collapse at any attempt to extract them. 

A recent visit fo this unpromising section has, however, yielded 
evidence of considerable interest. In a block of the Chalk that had, 
for some local reason, escaped the worst degree of compression, three 
fossils oceurred, which, though fragmentary and friable, are unmis- 
takable. Thy are Offaster pilula (a small form, just like those from 
Kantbury, 23 miles to the north-east); a very small, pyramidal, flat- 

based Hehinocorys, whose proportions, so far as they can be determined, 
are exactly those of forms from the O. pilu/asub-zone; anda primary 
interradial of Stawranderaster bulbiferus, which is fully as large as 
the Offaster. Spencer has shown that this species attainsits maximum 
size in the sub-zone of O. pilula. Such an assemblage admits of but. 
one interpretation. ‘The sub-zone of O. piluda is here present. The 
fossils came from the section on the south side of the road, and, 
though absolutely no traces of fossils have as yet appeared on the 
northern side, there can be no doubt that the whole cutting is made 
in this sub-zone. 

According to the geological map, the section occurs about midway 
between the Chalk Rock and the Tertiary border, so that, unless 
a strike-fault occurs to the north of the road (which is quite possible), 
there must be a very considerable thickness of the guadratus-zone 
developed. 


1 Kidston & Jongmans, Mededeel. Rijksopspor. Delfstoff, No. 7, vol. i, pt. i, 
p. 101, 1915-17. 


Dr. Harold Jeffreys—Causes of Mowntarn-Building. 215 


Treacher and White (Proc. Geol. Assoc., xix, p. 385, 1906) identified 
the Uintacrinus sub-zone south-west of Kirby House (to the east of 
our section), and again at Prosperous Farm (about the same distance 
to the west). In both of these instances the exposures were, if 
anything, nearer to the Tertiary boundary than the roadside section. 
Thus it seems probable that the outcrop of guadratus-chalk here is 
of the nature of an outlier, precisely similar to the one that the 
above-named authors record at Laylands Green, Kintbury. ; 

There are now three patches of this zone known to occur at the 
western end of the London Basin, namely, Boxford, Kintbury, and 
Inkpen. It can hardly be an accident that all three occur in an 
almost perfectly straight line, which has a north-east to south-west 
trend. It is true that the Boxford outlier is associated with peculiar 
lithological conditions and great attenuation of the zones, but in the 

-case of the two more southerly outcrops there is no such peculiarity. 
On the present evidence it seems reasonable to postulate the existence 
of a pre-Tertiary syncline along this line, with, perhaps, a parallel 
complementary anticline on the eastern side which is. responsible for 
the Hampstead Marshall inlier. 


V.—Tse Causes or Mounrarn-BoiLpinG. 
By HAROLD JEFFREYS, M.A., D.Sc. 


N article by Mr. R. M. Deeley in the Grorocican Magazine for 
A March, pp. 111-120, is mainly devoted to an attempt to find 
a cause of mountain-building more potent than the compression due to 
cooling, of which he says that ‘‘many physicists . . . are quite 
satisfied that it is not capable of accounting for the amount of 
compression required’’. ‘he only physical argument he quotes in 
support of this statement is that of Osmond Fisher, which he may 
therefore be presumed to consider the most conclusive; yet it is 
certain that no physicist would now admit that Fisher’s reasoning 
has any validity. It rests entirely on Kelvin’s theory of the cooling 
-of the earth, which has had to be completely revised on account of 
the discovery of the extensive distribution of radio-active matter in’ 
the earth’s crust. ‘The time available has been found to be about 
twenty times greater than on Kelvin’s theory, and the cooling has 
therefore had time to extend to a much greater depth and to produce 
accordingly a very much greater compression. Our present knowledge 
indicates that the compression has been enough to shorten the 
circumference of the earth by from 133 to 227 kilometres, according 
to the precise distribution of radio-active matter assumed. The 
level of no strain is at the same time found to be at a depth of about 
80 kilometres, so that the crust-movements due to compression would 
extend to a considerable depth. 

Mr. Deeley next states that the compression required to make the 
Alps would be 1,050 kilometres, and deduces, apparently by a simple 
division by 7, that the diameter must have decreased by about 
334 kilometres, which he says is greater than can possibly be 


216 Dr. Harold Jeffreys—Causes of Mowntain-Building. 


allowed. Now it is obvious that such a contraction, if it occurred, — 
would shorten every diameter of the earth by this amount, and 
-eould therefore raise a mountain chain as high, as broad, and as 
complicated as the Alps, and extending most of the way round the 
earth, whereas the estimate in question refers only to a chain some 
1,000 kilometres in length. This simple method of evaluating 
the contraction needed to produce a single range is evidently 
unsatisfactory ; what we really need to determine is the reduction, 
not in breadth, but in area, if the aggregate contraction needed to 
raise all the mountains of the earth is to be found. Taking the 
Rockies and the Coast Range in California as standards, according to 
the breadth of the particular range considered, and assuming the 
lateral compression to be proportional to the mean height above the 
surroundings (which would be exactly true if the contortion in all 
ranges was geometrically similar and on a scale proportional to the 
height), I have indicated elsewhere that all the known mountain 
ranges could probably be produced by a contraction in circumference 
of some 70 km., only about half of that shown to be available. 
This will, of course, have to be reviséd continually as direct geological 
information about the larger ranges, especially those in Asia, becomes 
available; it will further have to be increased to allow for suboceanic 
mountains and old ranges now almost denuded away. At the same 
time the estimate of the compression that could be produced by 
cooling may need to be increased, as the coefficient of expansion 
may increase more rapidly near the melting-point than I assumed ; 
in any case the available compression and that needed to account 
for mountain-building are of the same order of magnitude, and 
a categorical statement that the theory is inadequate is clearly 
unjustified. 

The theory of compression is complicated by the effects of 
denudation. Whena mass of radio-active matter is removed from the 
surface of a continent, matter at a considerable depth is enabled to 
cool more rapidly in comparison with the average over the whole 
earth. In consequence it tends to contract more, and thereby 
increases the curvature of the outside, just as a bow becomes more 
curved when the string is tightened; the effect of this would be to 
raise the continents considerably. Similarly, the ocean beds would 
be depressed on account of the radio-active sediments acting as 
a blanket. A definite limit must of course be imposed on these 
effects by the weakness of the crust; thus the elevation and lowering 
could never become much greater than was necessary to give isostatic 
compensation, and afterwards more mountains would be raised within 
the continents and fewer on the ocean bed. : 

The alternative hypothesis offered is that crust movements have 
occurred owing to heavy matter sinking into lighter matter below it 
and causing it to spread out horizontally. This is physically quite 
possible, but it is difficult to see how the heavy matter could have 
got to the top in the first place except by compression. Isostatic 
readjustment, subsequent to denudation, might easily produce gentle 
anticlines and synclines, but the violent contortion implied by the 
structure of the great mountain ranges seems difficult to account for 


Dr. Harold Jeffreys—Causes of Mowntain-Building. 217 


by means of the widespread movements that one associates with 
such readjustment. ‘This hypothesis, while doubtless an important 
secondary agency, can therefore scarcely be regarded as giving the 
primary cause of the formation of the great mountain chains. 

A digression in the meanings of the terms rigidity, plasticity, 
viscosity, and fluidity may not be out of place here. When a body is 
exposed to a tangential or shearing stress (such a stress, for instance, 
as would exist if a rectangular block of wood had one face rigidly 
fixed and a tension were applied in the plane of the opposite one) it 
ordinarily changes its shape to some extent. The ideal type of sub- 
stance described as perfectly elastic will spring back completely and 
immediately to its original shape when the stress is removed (the 
complication due to inertia being ignored). In ordinary substances, 
however, the recovery may be incomplete, gradual, or absent. If it 
occurs at all, the substance possesses elasticity, and the coefficient of 
rigidity is measured by the ratio of the stress to the reduction of strain 
when the stress is released. If it is absent, so that the body retains 
the shape it had just before the release, the substance is a flurd. 
Thus a fluid is a substance with no elasticity. One of its properties 
is that when a constant tangential stress is applied for some time it 
goes on changing its shape or flowing ata constant rate ; the viscosity 
is measured by the shearing stress needed to cause flow at a certain 
definite rate. When the viscosity is zero, the substance yields 
completely and instantly to any shearing stress, however small; such 
a substance is a perfect fluid. 

Substances possessing any elasticity are called solids. Imperfection 
of elasticity in a solid may be shown by the recovery after stress 
being partial or gradual. If it is partial, we see that the body has 
undergone a permanent change of shape, called permanent set; such 
a substance is called plastic. Suppose now that a certain stress /’ 
applied for a certain time 7’ causes a permanent set of amount s, 
where s may be small. If the body is then stressed again by the 
same amount and for the same time and released, it will have 
acquired a further permanent set s, making 2s in all. Repeating 
the process » times will give a set ns. Now a constant stress /’ 
would naturally be expected to produce at least as great an effect in 
the same time as an intermittent one; hence a stress / applied 
for a time equal to the sum of n7Z, and the times when there was no 
stress would produce a permanent set not less than ns. This can be 
made as great as we like by making » great enough; hence a plastic 
solid can be made to change its shape as much as we like by applying 
a constant stress for a long enough time. In this respect it therefore 
resembles a viscous fluid.! 


1 Mr. Deeley suggests that the repetition of the stress would not give the 
same set each time, but a smaller one, leading to a convergent series which 
could never exceed a certain small amount. This implies that when a body 
has been strained beyond the limits of recovery it is stronger and more difficult 
so to strain again. The contrary seems more probable, and agrees with 
the phenomena of malleability and ductility, which are inconsistent with 
Mr. Deeley’s hypothesis. Clay can undergo an indefinite amount of 
permanent set, and if the stress needed to give it a definite increase of set 


218 Dr. Harold Jeffreys—Causes of Mowntain-Building. : 


On the other hand, the recovery after stress may be slow, though 
after a long enough time it may become complete. This phenomenon 
is the elastic after-working. It does not lead to permanent set or to 
indefinite flow when a constant stress is applied, and must therefore 
be distinguished from plasticity, even though the same substance 
may possess both properties. There are then two distinct kinds of 
imperfection of elasticity, and the question is further complicated by 
the fact that both are functions of the stress and of the previous 
history of the body, some substances behaving as if perfectly elastic 
for small stresses and very imperfectly so for large ones. For 
instance, suppose a weight laid on a flat surface of wet clay, which 
may be regarded as plastic. It will proceed to sink in, the clay 
acquiring permanent set, but after a time the stresses will become 
too small to cause set, and the weight will cease to sink, though 
appreciable shears still exist. 

The distinctions between these various properties are of funda- 
mental importance in all questions dealing with the behaviour of 
rocks under stress. The idea of plasticity, in particular, must 
always be carefully distinguished from smallness of rigidity. If two 
similar pieces of quartz and copper, for instance, are exposed to the 
same stress, the quartz will yield more; but when the stress is 
released the quartz springs back all the way, while the copper does 
so only partially. Thus copper is more plastic than quartz; on the 
other hand, the change of strain caused instantaneously by the same 
change of stress is less in the copper, which is therefore more rigid. 
In geophysical investigations the fact that a very rigid substance 
may also be a plastic one is continually coming into notice. 

In geological upheavals and readjustments elastic after-working 
is probably of small importance, as the times involved are much 
longer than those needed for the relaxation of the strain. The 
importance of plasticity on the other hand is very great, for solid 
substances may easily flow to a great extent when a lapse of time 
of the order of a geological period is available, without the flow 
producing any noticeable effect when earthquake waves or tides are 
considered, so that for these movements the earth may behave as if 
perfectly elastic. Elastic after-working acts in the opposite direction, 
for if a stress is varying rapidly there will never be time for the 
strain appropriate to it to be produced, and consequently short 
period transverse waves cannot be transmitted for any considerable 
distance. It would thus produce a greater effect on earthquake 
waves than on vibrations of longer period, and we may therefore 
infer from their transmission that it is not appreciable in the crust 
of the earth. The remarkable effects of high pressure and tempera- 
ture on the elastic properties of solids indicate, however, that it 
would be dangerous to deny on this ground its possible importance 
in the centre of the earth. It is certain. that no great part of the 
earth is fluid, for it has been shown by Love that the yielding of the 


increased beyond all limit, as Mr. Deeley supposes, it would obviously be 
impossible to model it by hand. Non-ductile substances break when the set 
becomes great enough, and after this occurs the series will diverge rapidly 
instead of converging. 


Dr. Harold Jeffreys—Causes of Mowntarn Building. 219 


crust would then prevent oceanic tides from reaching any noticeable 
size; earthquake waves could not be transmitted through the fluid 
portions; further, isostasy would be perfect, which is not the case. 
Below the layer of compensation, at a depth of probably some 
300 kilometres, there is a layer of weakness known as the 
‘‘asthenosphere”’, where flow appears to be produced much more 
easily than in the outer portions and most of the isostatic adjustment 
takes place. The properties of earthquake waves nevertheless show 
that it is very rigid. 

The laws of elastico-viscosity and firmo-viscosity that I have used in 
previous papers are precise mathematical expressions of particular 
types of plasticity and elastic after-working respectively. 

In the above discussion nothing has been said about the mechanism 
that causes imperfection of elasticity, and the argument is independent 
of this. Barrell believes that adjustment in the asthenosphere takes 
place by progressive local melting or solution under shear; the 
melted parts immediately flow till the shear is reduced to zero, and 
thus the shears are always kept small. In crystals it may take 
place by sliding on the cleavage planes; such bodies as pitch may be 
deformed by molecular displacement without anything resembling 
fracture ; brittle substances may be crushed to powder and then 
spread out by the stress; but in any of these cases the recovery after 
the stress is removed is incomplete and the general description of 
plasticity applies. Hlastic after-working is to be attributed to 
intermolecular friction. 

Mr. Deeley discusses at much length the question whether the 
liquid and solid states pass into each other continuously or discon- 
tinuously. The sudden change from one to the other at a definite 
temperature is a characteristic property of pure substances; the 
impure aggregates with which geologists have for the most part to 
deal may be expected to pass through a pasty state when heated, in 
which flow becomes steadily more easily produced. The question is 
not, however, a vital one; there is little liquid within the earth, and 
when it does occur it is probably produced, not by heating, but by 
local release of pressure. Most of the interior is probably at a 
higher temperature than the melting-point of ordinary rocks at 
ordinary pressures, and is only kept solid by the high pressures there 
existing. A local fracture would release this and render melting 
possible. 


REFERENCES. 
BARRELL (Joseph). Journal of Geology, vol. xxii, 1914; vol. xxiii, 1915. 
Houmes (Arthur). ‘‘ Radio-activity and the Earth’s Thermal History ’’: 
GEOL. MaG., February-March, 1915; June, 1916. ‘‘ Radio-activity and 
the Measurement of Geological Time’’: Proc. Geol. Assoc., vol. xxvi, 
1915. 
JEFFREYS (Harold). ‘‘ The Compression of the Earth’s Crust in Cooling’’ : 


Phil. Mag., vol. xxxii, pp. 575-91, 1916. ‘‘ The Viscosity of the Harth ”’ 
(Third Paper): Monthly Notices of R.A.S., vol. Ixxvii, pp. 449-56, 1917. 
Love (A. E. H.). Proc. Roy. Soc., vol. lxxxiiA, pp. 73-88, 1909. 


220) Reviews—Geology of Bowrnemouth. 


RAV LHwWwSsS-. 


Sees 

J.—T'sn Grotocy or roe Counrry arounp Bournemouru. Exprana- 
vion oF SHEET 329 (New Series). Memoirs Geological Survey 
England and Wales. Second edition. By H.J. Ospornn-Wuure, 
F.G.S. pp. vi+ 79. London, 1917. Price 2s. net. 


Lee memoir, which is published as a second edition, is really 

anew book. The first edition, written by Mr. Clement Reid, 
was very brief, as it was intended at the time to publish a general 
memoir on the Hampshire Basin. ‘This not being possible, a second 
edition of the sheet memoir has been issued in which the geology of | 
the district is fully described. The book is written in an interesting 
manner; a chapter is devoted to each series of rocks, and is made up 
of a general section followed by more detailed description of the 
particular exposures. In the general sections the geological history 
of the district is clearly brought out. The oldest rock in the area 
covered by the map is the Upper Chalk. At the close of Cretaceous 
times the district was uplifted and denuded, and the Reading Beds 
rest on a surface which shows well-marked evidence of erosion. 
These beds are of freshwater origin. The London Clay, which 
follows them, is of the sandy type showing shallow-water conditions, 
and is becoming thinner to the west. The Bagshot and Bracklesham 
Beds are classified according to the old plan and not according to that 
proposed by Mr. Gardner, owing to the difficulty of separating the 
pipeclays and sands of Corfe and Poole from the Bournemouth fresh- 
water series in the inland exposures. These show a shoaling of the 
water culminating in the Bournemouth freshwater series. 

Throughout Bracklesham time the water became gradually deeper, 
and the Barton Clay shows true marine conditions. This was followed 
by another shallowing of the water as shown by the Barton Sands, 
and the highest Tertiary rocks in the area, the Lower Headon Beds, are 
deltaic in character. From evidence obtained elsewhere the Oligocene 
sea must have spread over this region, but the deposits have all been 
removed. The only record of Miocene or Pliocene times in the 
district is the slight flexuring of the strata, which must correspond to 
the more violent movements observed in the Isle of Purbeck and the 
Isle of Wight. 

The Pleistocene deposits are well represented. Gravels are found 
at many different levels, and have been divided as follows: high 
plateau, 300 ft.; highest terrace, 200 ft.; Holithic terrace, 150 ft. ; 
Paleolithic terrace, 100 ft.; Bransgrove terrace, 60-80 ft.; Valley 
gravels on the valley floors from 30 to 40 ft. above O.D. These all 
consist of subangular flints and quartz sand, and have been laid 
down in running water. No organic remains have been found, but 
implements of Chellean and Acheulian types have been found in the 
Paleeolithic terrace. The rivers which deposited the older of these 
gravels probably drained into the ‘‘Solent River”, which was 
a continuation of the Frome, and whose valley was not breached by 
the sea till after the deposition of the Bournemouth plateau gravel. 
The character of these plateau gravels, when compared with that of 
the modern alluvium, shows that the volume of water in the ancient 


Reviews—Coal Flora of the Netherlands. 221 


rivers must have been very much greater then than itisnow. The 
Paleolithic terrace of the Avon Valley is contemporaneous with the 
Goodwood raised beach, and bears the same relation to it as 
the modern alluvium does to the present beaches. 

The recent alluvium contains beds of peat and submerged forests 
which point to a small submergence in recent times; this is also 
borne out by the form of the coast in Poole and Christchurch 
harbours. The district is not rich in economic deposits. A little 
iron has been worked and alum manufactured from alum shales, but 
the only deposits now being worked to any extent are clays in the 
Reading Beds, the London Clay and the Bagshot Beds which are 
used for pottery. 

Mis EW 


JJ.—Frora oF tHE CaRBONIFEROUS oF THE NETHERLANDS AND 
Apgsacent Reatons. Vol. 1: A MonograpH oF THE CALAMITES 
or Western Evrope. By Dr. R. Kipston and Dr. W. J. 
Jonemans. ‘Text, Part I, 1917; Atlas of 158 plates in 4to, with 
Provisional Explanation of Figures, 1915. Mededeelingen v. d. 
tijksopsporing v. Delfstoffen, No.7. Gravenhage. 


Y undertaking the publication of this large and exhaustive 
monograph, of which only the first part lies before us as yet, 
the Dutch Government has performed a signal service to Palzo- 
botany. Itisin every way entitled to take rank beside the classic 
memoirs of Zeiller and Renault on the fossil floras of the French 
coalfields, which are likewise Government publications. Most 
unfortunately, although Britain is the richest country in Europe as 
regards Coal-measures, no such publications have as yet been under- 
taken by our Government, and in this respect we are far behind 
other nations. 

The present volume relates to the genus Calamites alone. 
Dr. Kadston and Dr. Jongmans, who are together responsible for it, 
have had quite an exceptional experience of these fossils, and either 
the one or the other has, we believe, actually studied practically every 
example of these plants which has been figured by previous authors, 
except in a few cases where the types appear to have been lost. 
They have also refigured here many of these specimens, and thus 
cleared up many points which remained uncertain when we had to 
rely on the original figures, which were often imperfect or indeed 
inaccurate representations of the fossils in question. Both the text 
and plates are thus exceptionally authoritative. The latter consist 
of 158 large quarto sheets in collotype, and there are eighty text- 
figures in addition. Some of the plates are, however, identical with 
those of a smaller atlas published by Jongmans and Kukuk in 1918. 
The illustrations are particularly clear and well chosen. 

At present the atlas covers a somewhat wider field than the text, 
for owing to the War only the first part of the latter has so far 
been published. 

The outlook here is systematic rather than morphological. The 
strength of the treatment adopted lies in the perfection of pure 


222 Reviews—Radioactivity of Canadian Springs. 


synonymies, and in the description of particular specimens. In this 
respect the revision of the genus is exceptionally thorough. ‘The 
_ 207 quarto pages are devoted to 47 species (neglecting varieties) of 
Calamite stems, of which 41 are of Upper, and 6 of Lower 
Carboniferous age. Nine of these are new names, and the number of 
species here first recorded from Britain is a remarkable feature of 
the work. 

Certain names well known and in constant use are changed on 
what appear to be slight grounds. Thus C. ramosus, Art., becomes 
C. carinatus, Sternb.; while it is proposed to replace C. approximatus, 
Brongn. (non Schloth.), by the cumbersome term C. Schiitzetformis, 
K. & J., forma Waldenburgensis, K. One cannot help feeling that 
but little is gained while not a little is lost by such modifications, 
however defensible they may be made by an appeal to the laws of 
strict priority of nomenclature. 

We also find an omission of even a bare mention of all petrified 
material of Calamite stems, in which the anatomical structure is 
preserved, which strikes us as unfortunate in the case of a work 
professing to be a monograph of a genus. 

In conclusion, we hope that our authors may soon be able to 
resume the publication of this valuable systematic work. If in 
future parts they could give us, in addition to the purely systematic 
side, a fuller morphological account on a comparative basis of the 
members of each genus, our indebtedness to them would be still 
further increased. 

KE. A. N. A, 


I11.—Tue Raproacriviry or somE Canapran Minerat Sprines. By 
J. Sarrerry and R. 'T. Exworrny. Canada, Dept. of Mines, 
Bull. No. 16, 1917. 


fF\HE discovery of the radioactivity of mineral waters—in the case, 
for example, of the springs of Bath—confirmed the belief, long 
held, that the specific virtues of many spring waters were due to 
some factor other than the dissolved salts they were known to 
contain. ‘The therapeutic value of radioactive waters lies in the 
increased activity of all the processes of nutrition and metabolism 
which they bring about, in the stimulated growth of red blood-cells, 
and in the elimination of toxins. Radioactive waters (or gases 
escaping from such waters) have thus a high economic value, and the 
Canadian Department of Mines has therefore caused to be carried out 
a systematic examination of a large number of springs in Ontario and 
Quebec and of a group of hot springs at Banff, Alberta. The results — 
are contained in this memoir, together with a general account of 
radioactivity, its measurement, and its medicinal value. 

None of the Canadian springs contain as much. radium as those of 
Bath. The amount found by Sir William Ramsay in the Bath 
Springs was 1388-7 x 10-12 grams per litre, whereas the highest 
amount found in Canada is 46 in the same units. ‘Two other springs 
have 25 and 23-5 units respectively, while the others average less than 
3 units (the value for sea-water is 1 unit). These figures refer to 


Reviews—Professor Daly on Metamorphism. 223 


waters that are permanently radioactive, since they contain radium 
salts in solution. In addition to this, however, there is a temporary 
radioactivity, due to the presence in solution of the short-lived gas 
radium-emanation picked up from the formations through which the 
water has passed. In this respect the Alberta springs are by far the 
most valuable, though the actual figures still fall below those for 
Bath and Buxton. ‘The report is illustrated with a map showing the 
situation of the springs investigated and with twenty-one photographs 
of the springs themselves. 
AntHur Homes. 


IV.—MeramorPHism anp its PHases. By R. A. Daty. Bull. 
Geol. Soc. Am., vol. xxviii, pp. 375-418, 1917. 


ROFESSOR DALY has written a paper on the use and meaning 
of the term metamorphism, and on the classification of the 
various processes which give rise to metamorphic rocks, for which all 
students of geology may well be grateful. The definition advocated 
by the author is as follows: Metamorphism is the sum of the processes 
which, working below the shell of weathering, cause the recrystallization 
of the original crystalline materials in rocks (with or without chemical 
reactions) or the crystallization of original amorphous materials in rocks, 
the change in each case not being accompanied by a general melting of the 
rock or by general simultaneous solution of its constituents. 

All weathering processes are thus cut out, for their inclusion (an 
attempt at which has been made by Van Hise and more recently by 
Leith and Mead) leads to a gigantic subject of unmanageable 
proportions, and one for which the term metamorphism ceases to have 
its restricted, and therefore most useful, traditional significance. 
Volatilization is also excluded, examples of this type of transformation 
being the change from mud to shale, or lignite to coal, and coal to 
anthracite. Daly’s definition, however, does not clearly distinguish 
between alteration processes of exogenetic origin and those of 
endogenetic origin, for some cases of cementation, of recrystallization 
of limestones by phreatic waters, and of metasomatism by descending 
solutions, are clearly included as examples of metamorphism according 
to Daly, although they may be indubitably the result of exogenetic 
processes. Itseems tothe present writer, following the lead of Mr. T. 
Crook, whose paper on the genetic classification of rocks (Ihin. May., 
vol. xvli, p. 55, 1914) is one of the most illuminating recent 
contributions to petrology, that the term metamorphism should be 
still further restricted so as to exclude ali alterations due to 
exogenetic processes. 

The classification of metamorphic processes suggested by Daly is 
as follows :— 


A. Recronat Mrramorpuism (not caused by eruptive bodies). 
I. Sraric Mreramorpuism (organic movement not a causal 
condition). 
1. (Temperature low) Stato-hydral or hydro metamorphism. 
2. (Temperature high) Stato-thermal or load metamorphism. 


224 Reviews —Prof. Daly—Underground Volatile Agents. 


II. Dynamic Meramorpuism (orogenic movement a causal 


condition). 

1. (Temperature low) Dynamo-hydral or slaty (?) meta- 
morphism. 

2. (Temperature high) Dynamo-thermal or friction meta- 
morphism. 


III. Dynamo-static Mertamorputsm (/oad metamorphism in 
rocks lying beneath overthrust masses). 
B. lLocat Meramorpuism (caused by eruptive bodies). 
I. Contract Meramorpuism (magmatic influence in control). 
II. Loap-Conract Mrramorenism (combination of load and 
magmatic influences). 


To discuss the merits of these subdivisions would demand more 
space than it is permissible here to take up, and those who are 
interested will find a vigorous stimulation to thought in the paper 
itself. Whether or not one agrees with all of Professor Daly’s 
proposals, one may at least congratulate him on an earnest and 
valuable attempt to reduce a subject of extreme difficulty from 
a state of comparative chaos to one of at least theoretical order and 
system. 

Arruur Hormss. © 


V.—Genetic CuassiricaTion oF UnpbEercRounpD VoLaTILE AGENTS. 
By R. A. Daty. eon. Geol., xii, p. 487, 1917. 


ee author proposes and discusses the following classification :— 


A. Maemartic or Hypocens (includes volcanic and plutonic). 
J. Juvenite (primitive, virgin, original-magmatic). 

(a) In liquid magma. 

(6) In crystallized igneous rocks and minerals, as 
occlusions, solid solutions, and chemical compounds. 

(c) Hxpelled, from magma or igneous rock by crystall- 
zation or heat; may remain free or go into solid 
solution or new chemical compounds. 

II. Rusvreenr (secondary-magmatic). 
(a), (6), and (c) as above. 


B. Epicene or Epreuat (includes underground atmospheric and 
marine water and associated gases). 
I. Sereace (fresh or marine waters of infiltration). 

1. Vadose (above the water-table). 

2. Phreatic (below the water-table). 

(a) Arrested (free, occluded, in solid solution, or in 
chemical combination). 

(6) Migrating, because of gravity, the earth’s general 
heat, the heat of orogenic crushing, or the heat of 
igneous intrusion. 

II. Connare (fresh or marine waters buried with sediments 
or surface volcanics). 

(a) Stagnant (free, occluded, in solid solution, or in 
chemical combination). 


Reviews—Kalgoorlie, W. Australia. 225 


(b) Expelled, by diagenetic settling, crystallization during 
metamorphism, orogenic stress, the earth’s general 
heat, the heat of orogenic crushing or metamorphic 
changes, or the heat of igneous intrusion. 

C. Mrxep Tyrss. 


V1I.—Own tur Grotogy or THE ALKaLt Rocks IN THE TRANSVAAL. 
By H. A. Brouwer. Journ. Geol., xxv, p. 741, 1917. 


FTER giving a general summary of what is known of the igneous 
complex of the Bushveld, the author deals with the special 
types of alkali rocks that occur in the Pilandsberg and Leeufontein, 
and west of Lydenberg. He suggests that the nepheline syenites and 
allied rocks were derived from a residual magma left after the . 
differentiation from the parent magma of ultra-acid rocks containing 
as much as 97 per cent of SiOz. Not only was the residual magma 
enriched in alkalies and alumina relative to silica, but it also 
contained a concentration of fluorine and other volatile fluxes. Much 
more work, however, is needed in this region before either the age of 
the complex or the genetic relations of its multitude of rock types 
can be accurately determined. 


V1II.—Tue Gerotoaicat Features oF tHE ‘‘NortH Enp’’, Katcoortir. 
By F. R. Ferprmany. Bull. Geol. Surv. Western Australia, 
No. 69. pp. 152, with 43 figures and an atlas of 14 plates. 
Perth, 1916. 


f¥\HE area dealt with in this memoir comprises about 2} square 

miles. It is composed almost entirely of old and highly altered 
igneous rocks, which can be divided into two main groups, 
the older and younger greenstones. ‘The older greenstones were 
originally a large series of basaltic flows, and cover the greater part 
of the surrounding region. Along a line of weakness striking 
N.N.E.-S.S.W. in these older rocks a series of dykes, the younger 
ereenstones, were intruded. ‘These show a gradation from basic to 
more acid composition, and include types ranging from dolerites to 
albite porphyrites, the latter being the last of the succession. At 
different times during the intrusion of these dykes the district was 
subjected to intense pressure in an east and west direction, which 
resulted in the amphibolitization of the igneous rocks and the 
production of shear zones and thrust faults. The period of most 
violent pressure took place after the intrusion of the aibite 
porphyrites. 

Very shortly after this siliceous solutions with vapours of boron, 
sulphur, and hydrocarbons, or oxides of carbon, were forced along the 
shear zones, with the formation of jaspers and graphitic schists. 
These were followed by the gold-bearing solutions. They formed 
several different mineral deposits; quartzose and schistose lodes 
along the strike of the dykes and cross quartz veins striking more 
or less at right angles to the dykes. The auriferous lodes seem to be 
genetically connected with the albite porphyrites, and occur most 
frequently in the neighbourhood of these rocks along the major 

DECADE VI.—VOL. V.—NO. V. 15 


226 Reviews—Cretaceous Fawna, New Zealand. 


shear zones. They are, however, found all through the younger 
 greenstones and even in the older greenstones. In these rocks they 
~ are accompanied by bleaching of the walls of the lode, owing to the 
breaking down of the ferro-magnesian minerals with the formation of 
pyrites. 

Both lodes and cross veins carry gold in payable quantities, and 
both are worked in the mines. ‘The workings have, up till now, 
been confined chiefly to the oxidized zone, and have not anywhere 
been carried far below it owing to the increased difficulty and 
expense of working; they are, however, now being pushed further 
down. 

The memoir gives a short description of the individual mines and 
is illustrated by many figures and photographs, and is accompanied 
by an atlas of large-scale geological maps on which all the details of 
the structure are shown. 


Wi We 


VIII.—Tue Creraceous Faunas oF tHE Norru-Kastern Parr oF THE 
Soura Istanp or New Zeatanp. By Henry Woops, M.A., 
F.R.S. New Zealand Geological Survey, Paleontological 
Bulletin No. 4. pp. i-vill, 1-42, pls. i-xx, text-figs. 1 (map) and 
2 (section). . 
HE fossils described in this work have been collected from two 

series of beds. ‘The one, occurring in the neighbourhood of the 

Clarence River, south of Blenheim, yields a fauna characteristic of 

the Lower Utatur Group of Southern India. This fauna, which has 

been recognized also in Zululand, Madagascar, Australia, Japan, 

Queen Charlotte Island, Peru, and California, is approximately 

Albian in age; and it is of interest that Jnoceramus concentricus, 

so characteristic of the English Albian, is found in the corresponding 

New Zealand deposits. The other series of beds, occurring in the 

neighbourhood of Amuri Bluff, north of Christchurch as well as around 

Christchurch itself, and south of the localities for the Utattr fauna, is 

of Upper Senonian age and passes upwards into the Eocene. The lower 

portions of these beds produces an Upper Senonian fauna comparable 
with that occurring in the Arivalir Beds of Southern India, in 

Madagascar, in the Umzamba Beds of South Africa, in Japan, 

Vancouver, Chile, Southern Patagonia and Graham Land. 

The forms described from the lower fauna include two new species 
of Zrigonia, one of ‘‘ Modiola’’, one of Lima, one of Aucellina, one of 
Panopea, and a new variety of Jnoceramus concentricus. From the 
higher fauna one new species of Muculana is described, one of 
Malletia (Neilo), one of Barbatia, one of ‘* Arca”, one of Cucullea, 
one of Pectunculus, one of Trigonia, one of Pecten ( Camptonectes), one 
of Pecten (Aiquipecten), one of Lima (Limatula), two of Inoceramus, 
one of Astarte (Hriphyla), one of Anthonya, one of Lucina, one of 
Cultellus, two of Callista (Callistina), one of Panopea and one of 
Thracia. 

The figures contained in the twenty plates are collotyped from 
brush-drawings by T. A. Brock, and maintain the level of excellence 
that one has come to expect in his work since the publication of his 


Brief Notices. 227 


drawings in Mr. Woods’ Monograph on Cretaceous Lamellibranchs. 
The plates, moreover, have already had a history; for the original 
issue, we are told in the introduction, was lost in the wreck of 
“Tongariro” off the New Zealand coast in August, 1916. They 
were reprinted from the original blocks, and the Bulletin finally — 
appeared in 1917. 


1X.—Brizr Norices. 
1. Tae Acrive Vorcanors or New Zrartanp. By KE. S. Moonr. 
Journ. Geol., xxv, p. 693, 1917. 

HE author describes the five active voleanoes of New Zealand 
lying along the Whakatane fault, and discusses their relation to 
the later volcanic history and petrographical provinces of the islands. 
Mt. Tarawera and its rocks, varying from rhyolite to basalt and 

including pyroclasts, are dealt with in special detail. 


2. Homocitinr anp Monoctinr. By R. A. Daty. Bull. Geol. 
Soci Aun: yoluxeavil-) pe 89, 1916. 

IW\HE term homocline is suggested as a general name for a mass of 

bedded rocks all of which dip in the same direction. The term 

monocline is thereby restricted in accordance with the definition 

first formulated by Sir A. Geikie. 


REPORTS AND PROCHHDIN GS. 


aa) 
I.—Geronocicat Society or Lonpon. 


March 20, 1918.—G. W. Lamplugh, F.R.S., President, in the 
Chair. 


The President referred with sorrow to the death, on 
March 18, of Dr. George Jennings Hinde, F.R.S., who had 
served the Society for many years as a Member of the 
Council. The President also recorded the loss of Captain 
Lewis Moysey, M.B., R.A.M.C., who was on H.M. Hospital 
Ship Glenart Castle, torpedoed in the Bristol Channel on 
February 26. It was stated that the Council had sent 
resolutions of condolence to the relatives of both these Fellows. 


The President announced that the Council had awarded the 
Proceeds of the Daniel-Pidgeon Fund for the present year to James 
Arthur Butterfield, M.Sc., F.G.S8., who proposes to conduct 
researches in connexion with the Conglomerates and Sandstones 
underlying the Carboniferous Limestone Series in the North-West of 
England. 

Dr. W. F. Smeeth delivered a lecture on the Geology of Southern 
India, with particular reference to the Archean Rocks of the 
Mysore State. With the aid of a map, prepared by the Geological 
Survey of India, the Lecturer pointed out the general character of 


228 Reports & Proceedings—Geological Society of London. 


the geological formations of Southern India, which consist very 
lar gely of a highly folded and foliated complex of Archean gneisses 
and schists, followed by some considerable patches of pre-Cambrian 
slates, limestones, and quartzites; with these are associated basic 
lava-flows and ferruginous jaspers. The remaining formations 
consist of remnants of the Gondwana Beds (Coal-measures of Permo- 
Carboniferous age), a few patches of Cretaceous rocks, some Tertiary 
and Pleistocene deposits, and recent sands and alluvium, all situated 
along the coastal margins of the Peninsula. He contrasted the 
scanty post-Archean record of Southern India, the apparent non- 
submergence of the greater portion of the area, and its freedom from 
great earth-movements since Archean times, with the widely 
extended formations of Northern India, which .recorded oft-repeated 
movements of depression and elevation, culminating in the rise of 
the Himalaya in Tertiary times and accompanied by igneous activity 
on a gigantic scale, as proved by the outpourings of the Deccan Trap. 
In discussing the Archean complex, the Lecturer traced the. 
history of the various views which have been held. Newbold (1850) 
regarded the complex as formed of Protogene schists and gneisses 
intruded into by granites. Bruce Foote (1880) separated the schists 
(to which he gave the name ‘“‘ Dharwar System’’) from the gneisses, 
and regarded them as laid down unconformably upon the gneisses 
and granites which, for many years thereafter, were embraced in the 
term ‘‘ Fundamental Gneissic Complex”’. He regarded the Dharwar 
System as transition-rocks between the old gneisses and the older 
Paleozoic rocks (Cuddapa, ete.). Holland (1898) differentiated the 
Charnockites, showing that they formed a distinct petrographical 
province with intrusive relations to the main members of the 
gneissic complex, and in 1906 he proposed to regard the Cuddapa 
System as pre-Cambrian, and separated by a great Eparcheean 
Interval from the Dharwar System, which, together with the gneissic 
eomplex, he classed as Archean. In 1913 Holland added a group 
of post-Dharwar eruptive rocks, and produced a classification of the 
pre-Cambrian rocks of India which exhibits a remarkable parallelism 
with that given by Lawson (1918) for the pre-Cambrian of Canada. 
The work of the Mysore Geological Survey from 1899 to 1914 had 
gradually eliminated the Fundamental Gneissic Complex, and shown 
that within the area of the Mysore State—representing some 29,000 
square miles of the Archean complex—the oldest rocks were the 
Dharwar System, which had been intruded into by at least four 
successive granite-gneisses, namely: the Champion Gneiss, the 
Peninsular Gneiss (forming the greater part of the area), the 
Charnockites, and the Closepet Granite Series. If we compared 
this succession with Holland’s 1918 classification, without assuming 
any real correlation with the Canadian rocks, but viewing the 
Dharwar rocks as Huronian, as suggested by Holland, then his 
post-Dharwar eruptive series (Algoman) included the whole of the 
gneisses of Mysore, while equivalents of the Laurentian and Ontarian 
formations were wanting. On the other hand, if the Dharwar rocks 
were regarded as Keewatin, then the gneisses of Mysore might 
represent Laurentian and, possibly, Algoman formations, while 


Reports & Proceedings—Geological Society of London. 229 


representatives of the Huronian would be non-existent. Obviously, 
therefore, the Mysore Archzean succession was either very incomplete 
or it did not fit in with the classifications of Holland and Lawson. 
It was to be remembered that Holland’s classification dealt with 
a much wider area than Southern India, and the essential problem 
appeared to be whether his Bundelkhand gneiss (Laurentian) and the 
Bengal gneisses (Keewatin) were really older than, and unconformable 
to, the Dharwar System—as represented by him—or whether they 
were post-Dharwar eruptives corresponding to portions of the Mysore 
gneissic complex. In favour of the latter view it was noted that 
observers acquainted with both have appeared to recognize the 
Bundelkhand and Bengal types of gneisses in and around Mysore, 
and that all of these gneisses have, until recently, been regarded 
as forming part of the great Fundamental Gneissic Complex of Anidiar 

The Lecturer then described the map of Mysore, which, on a scale 
of eight miles to the inch (1 : 506,880), presented a simplified 
summary of the work of the Mysore Geological Survey. On 
lithological grounds the Dharwar System was divided into an Upper 
and a Lower Division. The former was composed largely of basic 
flows and sills with their schistose representatives. Whether some 
of the chloritic schists, slates, phyllites, and argillites were of 
sedimentary origin was still doubtful. In the series as a whole, 
chlorite predominated and hornblende was subordinate. The 
presence of carbonate of lime, magnesia, and iron was a strikingly 
prevalent feature. The Lower Division was composed of dark 
hornblendic epidiorites and schists, which were distinguishable from 
the greenstones of the Upper Division by their dark colour and 
practical absence of chlorite. Many of the greenstones and schists 
of the Upper Division appeared to resemble Keewatin rocks of Lake 
Superior, such as the Ely Greenstone series (save that augite is 
conspicuously absent in the Mysore rocks), and it had been suggested 
that the dark epidiorites, which naturally crop out between the 
rocks of the Upper Division and the intruding gneisses, might be 
merely metamorphosed portions of the greenstones and chlorite- 
schists. This might be true in some cases, but the independent 
existence of the dark hornblendic rocks of the Lower Division was 
supported by the fact that they do not exist in many places where 
the gneisses come into contact with the greenstones; that many of 
the former retain original igneous structures, which would be 
unhkely to survive the chloritization and the subsequent change to 
epidiorite ; and, finally, that the amphibolitization of the rocks of 
the Lower Division appears to have been complete before the 
intrusion of the earliest of the gneisses which, with its associated 
pegmatites and quartz-veins, has developed secondary augite in the 
hornblendic rocks along intrusive contacts. 

The Lecturer referred briefly to the autoclastic conglomerates 
which were usually associated with intrusions of the Champion 
Gneiss, to the intrusive character of some of the quartzites or quartz- 
schists, and to the evidence that the limestones were, partly, if not 
wholly, due to metasomatic replacement of other rocks by carbonates 
of lime and magnesia. 


230 Reports & Proceedings—Mineralogical Socrety. 


The Dharwar schists of Mysore contain a widely extended series 
of banded quartz iron-ore rocks, very similar to those of the Lake 
Superior district, the origin of which has been the subject of much 
discussion and is still very perplexing. Some of the earlier 
American geologists considered them to be directly igneous in origin, 
but these views are now discredited, and replaced by an interesting 
and ingenious theory of chemical precipitation from liquids associated 
with subaqueous lavas. The Lecturer suggested that some of these 
rocks might be pegmatitic intrusions of quartz and magnetite, and 
that some might be the metamorphosed relics of igneous rocks 
composed largely of highly ferruginous amphiboles (such as 
cummingtonite) or other chemically allied minerals. 


ole —MIneraroeicar Socrery. 


March 19, 1918.—W. Barlow, F.R. St President, in the Chair. 


Professor KE. S. Federov: ciGtapiieal Operations _ with four 
Independent Variables.’”? Apropos of Bocke’s suggestion of the use 
of multi-dimensional geometry for such operations, with special 
reference to the case of the chemical constitution of tourmaline, the 
author remarks that he had already put forward a similarsug ovestion, 
without, however, making use of imaginary dimensions. <A system of 
points is replaced by a sy stem of vectors, and in this way, since each 
end of a vector has two co-ordinates, a relation between four inde- 
pendent variables may be expressed graphically. Different series of 
vectors of the first order give rise to vectors of the second order, and 
they in their turn to vectors of the third order. Certain special 
cases were discussed. 

Professor R. P. D. Graham: ‘‘ Lattice-like Inclusions in Calcite, 
from North Burgess, Ontario.’ he calcite, which is almost 
invariably twinned about e (0112), contains numerous fine needles, 
arranged parallel to the edges of the rhombohedron ¢, of a hydrous 
magnesium silicate, which chemical analysis showed to correspond to 
the formula 6 Mg O.6 8102.4 H,O, which is usually assigned to the 
mineral spadaite. Since the needles are only slightly acted on by 
cold dilute acid, they remain behind in the form of a lattice on 
dissolution of the calcite. Other included minerals are pyroxene, 
quartz, titanite, and pyrites. he source of the solutions which 
supplied the magnesium silicate was discussed. 

Dr. J. W. Evans: ‘‘On Linear Rock-Diagrams.” The different 
types of linear or variation diagrams, in which the chemical con- 
stituents of different rocks are represented by vertical distances, 
were reviewed, and the use of modifications to indicate the probable 
mineral compositions was proposed. Lach rock is represented by 
two diagrams. In the first, or alumina diagram, distances repre- 
senting the molecular proportions of (1) the potash, (2) the potash 
and soda, and (3) the potash, soda, and lime in each rock are measured 
vertically upwards in succession one above the other from the base- 
line, and corresponding points for different rocks are connected by 
continuous lines. At the same times distances representing (4) 
the alumina, (5) the iron oxide, and (6) the magnesia are measured 


Reports & Proceedings— Liverpool Geological Society. 231 


on the same lines in the same manner, and are connected by 
continuous lines. Not only will this diagram indicate the pro- 
portions of the constituents, but also the position of the points 
on line (4) relative to those on lines (2) and (8) will indicate 
the probability of the occurrence of minerals dependent on 
the amount of alumina. If (4) is higher than (38), andalusite, 
cordierite, or mica may be expected as well as hypersthene, all the 
lime being converted into anorthite. If (4) is less than (3), diopside, 
augite, or the corresponding amphiboles will probably be present; 
and if it is less than (2), minerals of the egirine type may be found. 
In the second or silica diagrams the lowest series of points show the 
amount of silica required by the bases of a rock for the formation of 
leucite, nepheline, anorthite, wollastonite, and olivine, the second 
series the additional silica necessary to form orthoclase and albite, 
and the third series the amount required to convert the olivine into 
hypersthene, while the fourth line represents the amount of silica 
actually present. The position of the last relative to the others will 
throw valuable light on the silicates that may be expected, though 
allowance must be made for the influence of the bases on one 
another. For instance, the presence of the constituents of 
wollastonite will call for a higher silicification of part of the olivine 
to form a monoclinic pyroxene or amphibole at the expense of the 
felspars. 


III.—Liverpoot GrotocicaL Socrery. 


March 12, 1918.—J. C. M. Goveir, M.D., M.R.C.P., F.G.S., 
u President, in the Chair. 

The following papers were read :-— 

1. ‘On the Distribution and Significance of Barium Compounds in 
Sedimentary Rocks, with special reference to the Trias.” By H. W. 
Greenwood. 

The author had collected a large amount of statistical information 
as to the presence of barium compounds in the lithosphere, the 
oceans, and underground waters, which revealed their widespread 
occurrence, especially in Triassic sandstones in the form of barytes. 
In the latter it was noted that the barytes is apparently invariably 
secondary, and has found its way into the rocks by percolation and 
infiltration, that it occurs in both the Keuper and Bunter divisions, 
is richest at the surface, the quantity falling rapidly with the depth, 
and is commonly most abundant in the highest exposures in any one 
district. These facts, among others, led the author to suggest. that 
the barium had been derived from superincumbent strata, most 
probably Jurassic, a suggestion which, if upheld, would make the 
presence of barytes a valuable index to the original distribution of 
the Jurassic seas. 

2. ‘‘ Notes on the Parallel Roads of Glen Roy.” ByC. B. Travis. 

In this paper the author gave an extremely lucid description of 
these well-known natural features, based upon personal observations 
made during visits within the last few years. 


232 Correspondence—C. J. Gilbert. 


CORRESPONDENCE. 


THE PERMIAN IN THE MIDLANDS. 


Srr,—Some thirty years ago when I was working in the new Red 
Rocks of the Birmingham district, I found that the Bunter 
_ Conglomerate invariably rested upon a Breccia with a slight 
unconformity. I pointed this out to the late Mr. Joseph Landon, 
who also found the same succession at Barr Beacon. Associated 
' with the Breccia were deposits of sandy grit, the formation being of 
varying thickness. I also found—what was of much greater 
importance—that there was a very pronounced unconformity between 
them and the red clays and sandstones upon which they rested. 

On April 12, 1890, I read a paper to the Vesey Club at Sutton 
Coldfield giving full particulars of this formation, which had never 
been separately marked on the Survey map, nor mentioned in the 
Survey memoirs, although its outcrop covered a very considerable 
area. At that time the red clays which cap the Carboniferous 
system in this district were mapped as Permian, which accounts for 
my reference to the breccia beds as a deposit between the ‘‘ Permian ” 
and the Bunter pebble beds. It is now, I believe, pretty generally 
recognized that these red clays belong to the Carboniferous system. 
If this be so, it gives a greatly added interest to these intermediate 
beds, and it comes to be a question whether they are not really the 
representatives of the Permian system in this district. 

I was called away from the Midlands shortly after reading my 
paper, and have since been unable to follow up my investigations. 
Fortunately, however, this district has been recently re-mapped by 
the Geological Survey, and I had the pleasure of hearing a paper 
read by Mr. Cunnington at the Vesey Club in 1914, in which he 
confirmed my work and stated that he had found the beds in some 
places to reach 100 feet in thickness. 

I believe the Survey are proposing to extend their researches, but 
my chief reason in writing this is to point out that much can be done 
by local geologists in carrying out a more detailed investigation in 
regard to these beds. 

A few points I would suggest are :— : 

(1) Through how wide an area are they found beneath the Pebble beds ? 

(2) What is their thickness and constitution in different districts ? 

(3) Is the breccia constant in its composition ? 


(4) Are these beds the equivalent of the typical Permian breccias in other 
places, and are they on the same horizon ? 


(5) The upper part of the deposit in the Sutton Coldfield district is pure 
breccia, the grits being beneath the breccia, and the unconformity with the 
Pebble beds is slight. Is this the rule elsewhere ? 

(6) Can any light be thrown upon the source of the breccia ? 

And more important than all :— 

(7) Do the grits contain any fossils, and what is their age ? 

In this way much may be done to supplement the work of the 
Survey, which is naturally of a more general character. 

A splendid section, showing the junction of the Breccia and the 
Bunter pebble beds can be seen at the Black Pool Quarry at Sutton 
Coldfield, at the base of which at least a quarter of an acre of the 


Yee z tee th ‘ Geyer tet ‘ : a ie 
a 5 ol > 
; _ . : 
g i 
r 


Grou, Maa., 1918. Prats X. — 


Obituary—George Jennings Hinde. 233 


rolling surface of the Breccia, from which the Pebble beds have been 
saqacmedl for road metalling, can be seen. 
My personal belief is that the red clays are Carboniferous, and the 
breccia bed Permian. 
C. J.. Ginperr. 
‘“ STAGHURST,’’ BERKHAMSTED. 
March 21, 1918. 


A NOTE ON ISOSTASY. 

Str,—I am much indebted to Mr. Anderson for calling attention 
to the oversight in my calculation. His re-calculation is perfectly 
right. Consequently, instead of 1,100 feet as the possible thickness 
of. sediment accumulated in a sea of 100 fathom depth, we have 
1,872 feet; or in the improbable case of a density as low as 2-7 for 
the supporting column, as much as 3,000 feet. These figures are 
still far removed from those great thicknesses of shallow-water 
deposit for which isostasy has been claimed as an adequate 
explanation. 


A. Morztery Davies. 
IMPERIAL COLLEGE, S.W. 7. 
April 13, 1918. 


(QyS\issenosrNiSoNai4 Sa 


GEORGE JENNINGS HINDE, 
Pu.D. (Municu), F.R.S., F.G.S., V.P. Pat. Soc. 


BORN MARCH 24, 1839. DiED MarcH 18, 1918. 
i (WITH A PORTRAIT, PLATE X.) 


As a worker gleans in a cornfield after the crop has been harvested, 
I have endeavoured to collect some records of my friend George 
Hinde, whose life’s work terminated in March last. He was 
a Norwich boy, like myself, and went to the Grammar School there, 
but being my junior by seven years we never met until many years 
later, our paths in early life lying wide apart. 

George Hinde was the third son of Ephraim Hinde and grandson 
of the founder of the firm of Ephraim Hinde & Son, Paramatta 
manufacturers in that city. His father lived near his Norwich 
factory, but in 1847 bought a farm at Catton, where he and his 
family resided. George’s mother died when he was 138 years 
old, and at 16 his father sent him to learn farming in Suffolk 
with a Mr. Spelman, where, being a studious lad, he spent his 
leisure hours in acquiring Latin, French, algebra, physics, and 
chemistry. About this time he heard a lecture by the Rev. Mr. 
Blowers on ‘‘Hugh Miller”, which greatly interested him, and he 
bought and read Hugh Miller’s books, and thus his mind was first 
dir ected to the study ‘of geology. 

When 18 years of age he commenced to farm his own land at 
Bawburgh, near Costessy, Norwich. Early in 1862 he attended 
a series of lectures i in Norwich by William Pengelly, F.R.S.; these 
further stimulated his desire to take up geology, which inten on 
became the leading ambition of his life. In the same year he paid 


234 Obituary—George Jennings Hinde. 


a visit to the British Museum, and from my wife’s relationship to 
his family he claimed me as a ‘‘ cousin’’, and so we continued to the 
end. This visit to the ‘‘Geological Department’’ seems to have acted 
as a loadstone which attracted him to the Museum in later years. 
He particularly mentions in his diary the impression made upon 
him by our geological talk. 

In the autumn of that year he gave up his farm and sailed for 
Buenos Aires, and took up sheep farming; but save for a note in his 
diary of a geological walking tour, he does not appear to have had 
much spare time for scientific pursuits in South America. After 
some years ranching in Argentina Hinde returned home, but very 
soon after set out for North America, where he devoted seven years 
entirely to geological research, during which time his travels 
extended from Nova Scotia on the east to Nebraska on the west, 
and from Lake Superior to the Gulf of Mexico. 

For a time he settled in Canada, entering himself as a student in 
geology under Professor H. Alleyne Nicholson, F.R.S., in Toronto 
University, with whom he published his first paper in 1875, ‘‘ On 
the Fossils of the Clinton, Niagara, and Guelph Formations of 
Ontario” (Canadsan Journal, xiv). He also wrote papers on ‘‘ The 
Glacial and Interglacial Strata of Scarboro’ Heights, Ontario” and 
“On the Occurrence of Boulders of the Calciferous Formation 
near Toronto”. Later on he made the interesting discovery of 
‘‘Conodonts’”’ and Annelid jaws in the Cambro-Silurian of Canada 
and the United States. 

teturning to England in 1874, he was elected a Fellow of the 
Geological Society of London. 

He also pursued his search for Conodonts and Annelid jaws in the 
Silurian strata of the West of England and the Sub-Carboniferous rocks 
of Scotland; he found these in many localities identical with those 
he had obtained in North America, which he subsequently figured 
and described in the Quarterly Journal for 1879, 1880, and 1882. 

This work and the renewal of his early study of the Chalk Sponges 
occupied him until 1878, when he visited Sweden, Gotland, and 
Denmark and travelled across Europe to Palestine. 

During 1879-80 he studied. under Professor Kari von Zittel in the 
University of Munich, and upon receiving the degree of ‘‘ Doctor of 
Philosophy”’ he presented for his inaugural dissertation a paper on 
the ‘‘ Fossil Sponge-spicules found in a flint from the Upper Chalk 
at Horstead in Norfolk” (Munich, 1880). 

Dr. George Hinde was married in 1881 to Edith Octavia, daughter 
of James Clark, of Street, Somerset, of the Society of Friends. 

In February, 1882, he was awarded the Wollaston Fund for his 
researches in fossil Invertebrata of North America and the Glacial 
phenomena of Canada. He was also elected a Member of Council of 
the Geological Society, on which he served for nearly twenty years, 
being made a Vice-President in 1893. 

After the removal of the Geological Collections from the British 
Museum at Bloomsbury to the new Natural History Museum in 
Cromwell Road, the Trustees authorized Dr. Hinde to prepare a 
Catalogue of the Fossil Sponges in the Geological Department. This 


Obituary—George Jennings Hinde. 235 
was completed between 1881 and 18838, and forms an important work 
of reference, admirably illustrated by Miss Suft and Mrs. Herschell 
(4to; pp. vill + 248, with 88 plates). 

After the death of my colleague Professor John Morris, in 1885, 
Dr. Hinde became an Assistant Editor of the GrotocrcaL MacaziIne, 
an office he held for thirty-two years to the great advantage of this 
journal, to which he also contributed numerous articles. 

He joined the Palzontographical Society in 1886 and commenced 
a monograph on the British Fossil Sponges, completed in 1912. 
He also contributed with Professor T. Rupert Jones, F.R.S., 
- a monograph on Cretaceous Entomostraca (1889-90). Dr. Hinde 
was elected on the Council in 1897, and Treasurer in 1904, an 
office he held for ten years. On retiring from it he was made 
a. Vice-President in succession to Sir A. Geikie (1916). 

During the meeting of the International Geological Congress in 
London in 1887, Dr. Hinde rendered important services on the 
Committee by preparing a temporary museum in the Library of the 
London University, and also by his knowledge of languages in 
acting as geological guide and interpreter to the numerous dis- 
tinguished foreigners present, to many of whom he was already 
personally known during his extensive travels. 

When the bye-laws of the Geological Society underwent revision 
in 1889, the question of the admission of women as ‘‘ Fellows”’ came 
up for discussion. Dr. Hinde took a very active part in its support ; 
but although Sir Joseph Prestwich and many others maintained that 
the time had come when, women having proved by their work their 
eligibility for Fellowship, the privileges of the Society should be 
extended to them, the proposal was defeated by a majority of four 
out of sixty-two Fellows voting.! 

Dr. Hinde spent many years in active field-work, followed by 
strenuous work in the laboratory in the preparation of rock-sections 
for the microscope, and then, after much study of existing literature, 
came a steady flow of scientific papers, continued for nearly forty 
years. 

In addition to the two important monographs on Fossil Sponges 
already referred to, the subjoined list shows some twenty additional 
separate papers on that class of organisms. 

That on the Receptaculitide (including Ischadites, Spherospongia, 
Acanthoconia, and Receptaculites) from the Silurian and Devonian 
strata of England, Belgium, Silesia, Bohemia, Gotland, Canada, and 
the United States, is an admirable piece of patient investigation 
in solving the nature of an obscure group of fossil organisms long in 
dispute. Hinde proved them to belong to a genus of siliceous 
Hexactinellid sponges, of which he defined their relations and figured 
their structures with elaborate detail (see Q.J.G.S., 1884). 

Another example of careful and laborious work is his memoir 
on the Porosphera, a group of small but very abundant globular 


1 The author of this memoir, when President in 1895, discussed the same 
subject ; but although strongly advocated by many of the Fellows it still 
remains in abeyance. 


236 _ Obituary—George Jennings Hinde. 


bead-like (often perforated) organisms from the Chalk, of which (aided 
by Dr. Arthur Rowe) he collected no fewer than 2,900 specimens. 
_ After examination of their minute structure under the microscope he 
showed them to belong to a group of Lithonine Calcisponges, of 
which he described and figured six species (see Journ. Roy. Micr. 
Soc., 1903). 

By the investigation of chert rocks of Lower Paleozoic age from 
every part of the world Hinde demonstrated their geological impor- 
tance and truly organic origin, built up of millions of microscopic 
siliceous skeletons, often of exquisite forms, of Radiolaria. He 
devoted twenty papers to their description: those from the Cherts of 
the Dutch East Indies he collaborated with Dr. G. A. F. Molengraaff, 
and those of Devon, Cornwall, and Somerset, with Mr. Howard Fox, 
F.G.S., of Falmouth. 


Of the class Annelida, the naked wandering marine worms, 
without hard parts (save very minute toothed jaws and spines), 
were formerly known only by their ¢racks upon the Paleozoic rocks ; 
but jaws of Annelids were found by Hinde in Cambro-Silurian 
formations in America, Britain, Sweden, etc., often mixed, as in-the 
Ludlow ‘‘Bone-bed”, with parts of various other microscopic 
organisms, such as the teeth of cartilaginous fishes, Dyzxine, etc.), 
Crustacean remains, ete. He separated many of these and figured 
them, and also the Annelid jaws,’ for the first time since their 
discovery by Dr. Pander in Russia in 1854.? 

In connexion with the Royal Society he communicated a paper 
on ‘Beds of Sponge-remains in the Lower and Upper Greensand 
Formation of the South of England”, published in the Phil, Trans., 
1886 (pp. 403-53). He also reported to the Royal Society’s 
Committee on Coral Reefs the result of his investigation of the 
organisms obtained by him from the cores extracted from the 


1 The author determined seven genera of Annelids, and enumerated fifty-five 
different forms. 

? Professor Owen, Dr. Harley, and H. Woodward also drew attention to 
them ; see ‘‘Conodonts’’, Murchison’s Siluria, 5th ed., 1872, pp. 134, 356, 
542, 544. 


Obituary—George Jennings Hinde. 237 


borings in a coral-reef on the Funafuti Atoll (see Phil. Trans. for 
1904). 

ae Hinde was elected a Fellow of the Royal Society in 1896. 
In the year following the Council of the Geological Society awarded 
him the Lyell Medal. In presenting it the President, Dr. Henry 
Hicks, referred to the large experience gained by Dr. Hinde with 
Professor Nicholson in Toronto, and continued later under Professor 
K. von Zittel in Munich, which had resulted in the valuable work he 
had since performed that had placed him in the foremost rank of 
those devoted to the study of minute structures of fossil organisms. 

In 1910 the Royal Geological Society of Cornwall conferred upon 
Dr. Hinde the William Bolitho Gold Medal ‘‘for his valuable 
contributions to the Geology and Paleontology of Cornwall” (partly 
in conjunction with Mr. Howard Fox, F.G.8., of Falmouth. 

Such are the gleanings I have gathered from the scientific work of 
my friend George Hinde. He was essentially a keen investigator of 
Nature, an accurate observer, and a strenuous, untiring worker who 
never lost interest in his researches. He was naturally of a silent 
and retiring disposition— having lived much alone in his early life— 
a man who formed few intimacies, but had the gift of ardent 
loyalty to those he made his friends. 

He spent much of his time latterly in his quiet home at Croydon, 
with his books, microscope, and specimens. After some months of 
ill-health, carefully tended by his devoted wife, George Hinde 
passed peacefully away on March 18, 1918. He leaves a family of 
three sons and two daughters. 

Henry Woopwarp. 


LIst OF DR. HINDE’S PAPERS AND MEMOIRS. 


1877. ‘‘ The Glacial and Interglacial Strata of Scarboro’ Heights, Ontario ’’ : 
Canadian Journal, xy, pp. 388-413. 

‘“*The @ccurrence, near ‘Toronto, of boulders of the Calciferous 
Formation ’’: ibid., p. 644. 

1879. ‘‘A new genus of Favosite Coral (Syringolites huronensis), from the 
Niagara Formation, Manitoulin Island’’: Grou. MAG., Dec. IH, 
Vol. VI, pp. 244-6. 

‘*On Conodonts from the Chazy and Cincinnati Group of the Cambro- 
Silurian, ete., in Canada and the United States’’: Quart. Journ. 
Geol. Soc., xxxv, pp. 351-69. 

** Annelid Jaws from the Cambro-Silurian, Silurian, and Devonian 
Formations im Canada ’’: ibid., pp. 370-89. 

1880. ‘‘ Fossil Sponge-spicules from the Upper Chalk, found in the Interior 
of a single Flint-stone, from Horstead in Norfolk ’’ (Inaugural 
Dissertation) : Munich. 

‘* Annelid Jaws from the Wenlock and Ludlow Formations of the West 
of England’’: Quart. Journ. Geol. Soc., xxxvi, pp. 368-78. 

1882. ‘‘ Annelid Remains from the Silurian Strata of the Isle of Gotland ’’: 
Bih. k. Vet. Akad. Handl., Stockholm, vii. 

** Notes on Fossil Calcispongia’’: Ann. Mag. Nat. Hist., x, pp. 185-205. 

1883. Catalogue of the Fossil Sponges in the British Museum (Natural 
History). 4to; pp. viii + 248, with 38 plates. 

1884. ‘‘Structure and Affinities of the Family of the Receptaculitide ’’ : 
Quart. Journ. Geol. Soc., xl, pp. 795-849. 

**Some Fossil Calcisponges from the Well-boring at Richmond, Surrey’’: 
ibid., pp. 778-83. 


238 


1885. 
1886. 


Obituary—George Jennings Hinde. 


‘A new species of Crinoids with Articulate Spines’’?: Ann. Mag. Nat. 
Hist., xv, pp. 157-73. ' 

‘“Beds of Sponge-remains in the Lower and Upper Greensand of the 
South of England’: Phil. Trans. Roy. Soc., clxxvi, pp. 403-53. 

“* Sponge-spicules from the Deposits of St. Hrth’’: Quart. Journ. Geol. 

Soc., xlii, p. 214. 

‘* Hystricrinus, Hinde, versus Arthroacantha, Williams; a question of 
Nomenclature ’’: Ann. Mag. Nat. Hist., xvii, pp. 271-5. 

‘Note on Hophyton (?) explanatum, Hicks, and on Hyalostelia fascicu- 
latus, M’Coy, sp.’’: GEOL. MAG., Dee. III, Vol. III, pp. 337-40. 


1886-1912. The Fossil Sponges. Paleont. Soc. Mon., pp. 264. 


1887. 


1888. 


1889. 


1890. 


1891. 


1892. 


1893. 


“On the genus Hindia, Duncan, and the name of its typical species ”’ 
Ann. Mag. Nat. Hist., xix, pp. 67-79. 

“The Organic Origin of the Chert in the Carboniferous Limestone 
Series of Ireland’’: Grou. MaG., Dec. III, Vol. IV, pp. 435-46. 

““ Character of the Beds of Chert in the Carboniferous Limestone of 
Yorkshire’’: Nature, xxxv, p. 582. 

‘‘New Species of Uruguaya, Carter, with remarks on the Genus’’: 
Ann. Mag. Nat. Hist., xx, pp. 1-12. 

““Note on the Spicules described by Billings in connection with the 
Structure of Archeocyathus minganensis’’: GEOL. MAG., Dec. II, 
Vol. V, pp. 226-8. 

‘*The Chert and Siliceous Schists of the Permo-Carboniferous Strata of 
Spitzbergen ’’: ibid., pp. 241-61. 

““The History and Characters of the genus Septastrea, D’Orbigny 
(1849) ’?: Quart. Journ. Geol. Soc., xliv, pp. 200-27. 

“Notes on Sponges from the Quebec Group at Métis and ne the 
Utica Shale’’?: Canad. Rec. Sci., iii, pp. 59-68. 

‘On Archeocyathus, Billings, and on other genera allied to or 
associated with it, from the Cambrian Strata of North America, 
etc. ’?: Quart. Journ. Geol. Soc., xlv, pp. 125-48. 

‘“On some Fossil Siliceous Sponges from the Quebec Group of Little 
Métis, Canada’’: ibid., Proc. p. 24. 

‘On a true Leuconid Calcisponge from the Middle Lias of Northampton- 
shire’? : Ann. Mag. Nat. Hist., iv, pp. 352-8. 

‘* Fragments of Siliceous Rock from the Boulder Clay of the “Roode 
Klif’ (Friesland)’’: Bull. Soc. Belge Géol., Bruxelles (Mém.), 
pp. 254-8. 

“A new genus of Siliceous Sponges from the Trenton Formation of 
Ottawa’’: Canad. Rec. Sci., ili, pp. 395-8. 

“Ona new genus of Siliceous Sponges from the Lower Calcareous Grit 
of Yorkshire ’’: Quart. Journ. Geol. Soc., xlvi, pp. 54-61. 

‘‘Radiolaria from the Lower Paleozoic Rocks of the South of 
Scotland’’: Ann. Mag. Nat. Hist., vi, pp. 40-59. 

“* Some Ordovician Radiolarian Chert from the Southern Uplands of 
Scotland ’’: Quart. Journ. Geol. Soc., xlvi, Proc. p. 111. 

‘‘Radiolarian Chert in the Ballantrae Series of the South of Scotland’’: 
GEOL. MAG., Dec. III, Vol. VII, p. 144. 

‘Paleontology of Western Australia.” 2. Corals and Polyzoa: 
ibid., pp. 194-204. 

“A new Fossil Sponge from the Utica Shale Formation at Ottawa, 
Canada’’: ibid., VIII, pp. 22-4. 

‘“ Microscopic Structure of the so- called Malm or Firestone Rock of 
Merstham and Godstone, Surrey’’: Proc. Croydon Micr. Club, 
ili, pp. 124-31, 133. 

‘Discovery of Chert containing Radiolaria, ete., in the Paleozoic 
Rocks’’: ibid., p. 253. 

** Palg@osaccus Dawsoni, Hinde, a new genus and species of Hexacti- 
nellid sponge from the Quebec Group, Little Métis, Quebec ”’ : 
GEOL. MaG., Dec. III, Vol. X, pp. 56-9. 


1893. 


1894. 
1896. 


1897. 


1899. 


1900. 


1904. 


1905. 
1908. 
1910. 
1913. 
1875. 


1892. 


Obituary—George Jennings Hinde. 239 


“* Radiolaria in the Mullion Island Chert’’: Quart. Journ. Geol. Soc., 
xlix, pp. 215-18. 

‘* Radiolarian Rock from Fanny Bay, Port Darwin, Australia ’’: ibid., 
pp. 221-6. 

‘* Microscopie Structure of some of the Organic Rocks from the New 
Hebrides ’’: ibid., pp. 230-1. 

‘On Specimens of Archeocyathine from South Australia’’: Proc. 
Geol. Soe. in vol. xlix, p. 8. 

‘“A new Fossil Sponge from the Eocene of the Hast Slope of the 
Ural’? : Bull. Com. Géol. St. Pétersb., xii, pp. 253-7. 

“ Radiolarian Chert from Angel Island, etc., California’’: Bull. Dept. 
Geol. Univ. California, i, pp. 235-40. 

‘Descriptions of new Fossils from the Carboniferous Limestone’? : 
Quart. Journ. Geol. Soc., lii, pp. 438-51. 

“* Additional Notes on the Radiolarian Rocks in the Lower Culm- 
Measures of Dartmoor’’: Trans. Devon Assoc., xxix, pp. 518-23. 

“*Radiolarian Chert from the Island of Billiton’’: Jaarb. Mijnw. 
Nederl. Ind., xxvi, pp. 223-7. 

‘* Eminent Living Geologists: Dr. G. M. Dawson’’: GkoL. Mac., 
Dec. IV, Vol. IV, pp. 193-5. 

‘“‘Radiolaria in the Devonian Rocks of New South Wales’’: Quart. 
Journ. Geol. Soc., lv, pp. 38-63. 

““Radiolaria in Chert from Chypons Farm, Mullion, Cornwall ’’: 
ibid., pp. 214-19. 

Fossil Radiolaria from the Rocks of Central Borneo, obtained by 
G. A. Molengraaff in the Dutch Exploring Expedition of 1893-4. 
8vo; pp. 56. Leyden. 

““Henry Alleyne Nicholson’’ (Obituary): Gron. Maa., Dec. IV, 
Vol. VI, pp. 138-44. 

‘““Gravels of Croydon and its Neighbourhood ’”’: Proc. Croydon Micr. 
Club, iv, pp. 219-33. 

““ Remarkable Calcisponges from the Kocene of Victoria, Australia ’’ : 

~ Quart. Journ. Geol. Soc., lvi, pp. 50-65. 

‘‘Hans Bruno Geinitz ’’ (Obituary): Grou. MaG., Dec. IV, Vol. VII, 
pp. 143-4. 

“Zone of Marsupites in the Chalk at Beddington, near Croydon, 
Surrey ’’: ibid., Dec. V,, Vol. I, pp. 482-7. 


“Structure and Affinities of the genus Porosphera, Steinmann”? : 


Journ. Roy. Mier. Soc., pp. 1-25. 

‘* The Bone-bed in the Upper Ludlow Formation ’’: Proc. Geol. Assoc., 
XVill, pp. 443-6. 

“Note on Fragments of Chert from North China’’: Grou. MaG., 
Dec. V, Vol. II, pp. 255-6. 

‘* Radiolaria from Triassic and other Rocks of the Dutch East Indian 
Archipelago’’: Jaarb. Mijnw. Nederl. Ind., xxxvii, pp. 694-736. 

‘* A new Sponge from the Chalk at Goring-on-Thames’’: Proc. Geol. 
Assoc., xx, pp. 420-1. 

‘* Fossil Sponge-spicules in a Rock from the Deep Lead (?) at Princess 
Royal Township, Norseman District’’: Bull. Geol. Surv. Western 
Australia, No. 36, pp. 7-24. 

“On Solenopora garwoodi, sp. nov., from the Lower Carboniferous in 
the North-West of England’’: Gnron. Maa., Dec. V, Vol. X, 
pp. 289-92. 

GEORGE JENNINGS HINDE & HENRY ALLEYNE NICHOLSON. ‘‘ Notes 
on the Fossils of the Clinton, Niagara, and Guelph Formations 
of Ontario ’’: Canad. Journ., xiv, pp. 137-44. 

—— & Horack B. Woodward. ‘‘ Excursion to Faringdon and 
Abingdon ’’: Proc. Geol. Assoc., xii, pp. 827-33. 

— & W. Murtron Houmes. ‘On the Sponge-remains in the 
Lower Tertiary Strata near Oamaru, Otago, New Zealand”’: 
Journ. Linn. Soc. (Zool.), xxiv, pp. 177-262. 


\ 


240 Miscellaneous. 


1895. GEORGE JENNINGS HINDE & HOWARD Fox. ‘‘On a well-marked 
Horizon of Radiolarian Rocks in the Lower Culm Measures of 
Devon, Cornwall, and West Somerset’’: Quart. Journ. Geol. Soc.,” 
li, pp. 609-67. 

USS. === ‘* Supplementary Notes on the Radiolarian Rocks in the 


Lower Culm Measures to the West of Dartmoor’’: Trans. Devon 
Assoc., xxviii, pp. 774-89. ; 

1897. —— “* Additional Notes on the Radiolarian Rocks in the Lower 
Culm Measures to the Kast and North-East of Dartmoor ’’: ibid., 

Xxix, pp. 518-23. 
—— & W. WHITAKER. ‘“‘ Excursion to Redhill and Merstham (New 

Railway) ’’: Proc. Geol. Assoc., xv, pp. 113-15. 

1909. —— & F. GossiiInG. ‘“‘ Fossils from the Chalk exposed in a Road- 
trench near Croham Hurst, South Croydon ’’: Proc. Croydon Nat. 
Hist. Soc., 1907-8, pp. 183-4. 

1890. T. RUPERT JONES & GEORGE JENNINGS HINDE. A Supplementary 
Monograph of the Cretaceous Hntomostraca of England and 
Ireland. Paleont. Soc. Mon., pp. 70. 


1898. A. H. SALTER & GEORGE JENNINGS HINDE. ‘‘ Excursion to Upper 
Warlingham and Worms Heath’’: Proc. Geol. Assoc., xy, 
pp. 458-9. H. W 


MISCHA N HOUS. 


British Museum (Naturat Huisrory).—At the end of March 
Mr. Richard Hall retired after thirty-eight years of service as 
preparer of fossils in the Geological Department of the British 
Museum. In early life he became a highly skilled mason, and was 
engaged on many and varied important works, including the Prince 
Consort’s tomb at Frogmore, some parts of the House of Commons, 
and buildings on the estate of the Duke of Wellington between 
Grenada and Malaga in Spain. Among his close associates for a 
time was the late Henry Broadhurst, afterwards M.P. Entering 
the British Museum in 1880 his abilities enabled him soon to adapt 
himself to the new special work, and he acquired remarkable 
proficiency in the art of preparing vertebrate skeletons. Under the 
direction of the late Mr. William Davies, his first great success was 
the chiselling of the skeleton of Hyperodapedon gordoni from the 
Triassic sandstone of Elgin, which was described by Professor 
Huxley in 1887. Afterwards, especially under the direction of the 
late Professor H. G. Seeley, he began to extricate the skeletons of 
Pariasaurus and Cynognathus from an almost intractable matrix, and 
his work on these and other reptiles from the Karoo Formation of 
South Africa led to great progress in the more exact study of the 
Triassic reptilian fauna. Dicynodon halli was named after him to 
commemorate his services. Mr. Hall also prepared many other 
important specimens which are now conspicuous in the public 
galleries of the Museum, and among them may be mentioned the 
skeleton of Jehthyosaurus platyodon from Stockton, Warwickshire, 
Pteranodon and Portheus from the Chalk of Kansas, Dinichthys and 
similar fishes from the Devonian of Ohio, and the great collection of 
Mammalian bones from the Pliocene of Pikermi, Greece. He has 
won the appreciation and esteem both of students and colleagues, 
and retires with the best wishes of all who have been associated 
with him. 


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I. OnIGINAL ARLICLES. 

The Genesis of Tungsten Ores. By 
R. H. RASTALL, M.A., F.G.S8. 
(Continued. ) 
Dolomitization and Leicestershire 
Dolomites. By L. M. PARSONS, 

| MESe. (Liond.), D.1.C., E.G.S. 
(Plate XI and Map.) 
The genus Bouchardia and Age of 
Seymour Island Beds. By Dr. 
J.ALLAN THOMSON,M.A.,F.G.S. 
(With a Text-figure:).......0i.:..- 
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By Dr. I. R. CowrPeR REED, 
IVA ARR Gri Satan. sec: wieroeas sees 
Mountain Building. By R. M. 
DEELEY, M.Inst.C.E., F.G.S.... 


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I.—Tae Genesis oF Tunesrek$Ques. 

By R. H. Rasvatn, M.A., F.G.9924 
(Continued from the May Number, p. 203.) 

Parr Il: Worrram Lopes wrrHour CaAssITERITE. 


S already stated in the first part of this paper, a regular 
A gradation may be traced from the cassiterite-wolframite lodes 
to wolframite-quartz veins without cassiterite, a type which appears 
on the whole to be more common in America than elsewhere. In 
many cases this difference is clearly due to a more complete 
differentiation of the magma, but in other instances a purely igneous 
origin is less conclusively established. In Cornwall and other 
granitic areas a tin-wolfram lode can sometimes be traced con- 
tinuously into a welfram lode, and this again into a pure quartz vein. 
Here the pegmatitic origin of the lodes is demonstrated, and as a rule 
the wolfram is accompanied by fluorite and other recognized pneu- 
matolytic minerals, as well as by sulphides similar to those found in 
the tin lodes. Thus the genetic connexion with the tin-bearing 
types is beyond doubt. In a few instances only wolfram is found in 
association with gold ores; the significance of this will be discussed 
in a later section. 

One of the most interesting cases of quartz-wolfram veins without 
tinstone is seen in the Sierra de Cordoba in Argentina.1. Here the 
veins occur in gneiss, and are actually traceable into a large granite 
mass of unknown age which is intruded into the gneiss. They are 
clearly pegmatitic differentiates of the granite. The wolfram occurs 
in large crystals in the quartz and in nests up to half a cubic metre 
in size. he chief minerals found in association with the wolfram 
are mica, apatite, fluorite, molybdenite, and chalcopyrite, and in the 
oxidation zone there are various oxidized copper minerals derived 
‘ from the chalcopyrite. The abundance of apatite is notable and 
somewhat unusual in wolfram lodes. This is an instance of 
differentiation from a magma rich in volatile constituents, especially 
fluorine, but apparently without tin and boron. 

Somewhat similar to the foregoing are some wolfram lodes found 
near Lircay in the province of Angaraes in Peru.” Two dykes or 


1 Bodenbender, ‘‘ Die Wolfram-Minen der Sierra yon Cordoba in der 
Argentinischen Republik’: Zeits. fiir prakt. Geol., 1894, p. 409. 

2 De Habich, ‘‘ Informe sobre los Jacimientos de Tungsteno de la Provincia 
de Angaraes’’: Boll. Cuerpo Ingen. de Minas del Peru, No. 11, p. 31, 1904. 


DECADE VI.—VOL. V.—NO. VI. 16 


942 Rk. H. Rastall—The Genesis of Tungsten Ores. 


veins, some 1°5 metres thick, and mainly consisting of quartz, carry 
wolframite, pyrite, and some gold. The wolframite occurs in 
thickenings of the veins, something like a chain of beads. Here 
there is little evidence of any kind of pneumatolytic action. 

In the United States tungsten ores are very abundant in some 
localities, and the total output is now the largest of any country in 
the world. ‘The tungsten boom of 1916 in the Western States has 
already been referred to. The chief producers are the states of 
Colorado, Arizona, and Nevada, while some important deposits of 
scheelite are now being largely worked in California. The most 
important area of all is undoubtedly Boulder County, Colorado, 
north-west of the city of Denver. The occurrences of wolfram ores 
here have been exhaustively described by Messrs. Hess and 
Schaller.! The ferberite area of Boulder County, of which the town 
of Nederland is the centre, lieson an elevated plateau some 8,000 feet 
above the sea, forming the eastern margin of the Rocky Mountain 
system. The country rock consists of biotite-hornblende granite, 
gneiss, and quartz-mica schist, all of pre-Cambrian age. The ferberite 
occurs in a group of veins striking south-west to north-east and 
accompanied by gold and silver veins of the same general trend. 
The gold veins are of two types, characterized by sulphides and 
tellurides respectively, and the ferberite veins are more closely 
connected with the telluride type of gold vein. The only gangue 
mineral of any importance is quartz; occasionally a little felspar is 
found, together with chalcedony and calcite. The sulphides 
actually found in the ferberite veins include only chalcopyrite, 
galena, and blende, and these only in small quantity. Some 
molybdenite has been recorded from one locality only. These 
veins are extraordinarily rich in ferberite, which sometimes 
comprises the greater part of the veins, being accompanied only by 
a little quartz. It is believed by Lindgren that these deposits are 
a product of comparatively recent thermal activity, and the associa- 
tion with tellurides is noteworthy. 

At Leadville, Colorado, wolframite and scheelite are associated 
with quartz in pyrite-gold veins; the scheelite seems, as usual, to be 
somewhat later than the wolframite. These veins appear to be 
connected with a monzonite porphyry.” 

In the Snake Range, White Pine County, Nevada, wolframite is 
found with scheelite, pyrite, fluorite, and a little gold and silver in 
veins connected with a granite-porphyry and cutting quartzites and 
slates. Here the presence of fluorite indicates pneumatolytic 
tendencies.® 

In the Black Hills of Dakota tungsten ores occur in two very 
different forms: the first, seen at Etta Knob and Nigger Hill, has 
already been mentioned; the second type is quite unlike anything 
hitherto described. According to Irving,‘ the ore shoots of this area 

1 “* Colorado Ferberite and the Wolframite Series ’’?: Bull. 583, U.S. Geol. 
Suryv., 1914. 

2 Witch and Loughlin, Hconomic Geology, vol. xi, p. 30, 1916. 

3? Weeks, Bull. 340, U.S. Geol. Surv., 1908, p. 263. ji 

* Irving, Trans. Amer. Inst. Min. Eng., 1901, and Professional Paper 
No. 36, U.S. Geol. Surv., 1904, p. 363. 


LSS 


R. H. Rastall—The Genesis of Tungsten Ores. 243 


are mineralized patches in a dolomitic limestone of Cambrian age. 
They form flat horizontal masses, highly siliceous in composition, 
and containing pyrite, fluorite, barytes, and occasionally gypsum. 
The wolframite is specially associated with the barytes. There is 
also a small amount of vanadium minerals. This deposit appears to 
have been formed by gradual replacement of the calcareous country 
rock by highly siliceous solutions ascending from below, and the 
concentration at this particular horizon may have been determined 
by the presence of impervious strata above. The tungsten may be 
derived from the underlying Algonkian Series, where wolframite 
occurs in pegmatites with cassiterite. If this is so, this must be 
regarded as a case of secondary metasomatism, but the resemblance 
to the wolfram-gold ores of Colorado and Nevada must also be taken 
‘into account, and the tungsten-bearing solutions may really be of 
direct magmatic origin, of post-Cambrian date, and independent of 
the Algonkian tin-wolfram deposits below. 

A very interesting and remarkable occurrence of wolframite at 
Trumbull, in Connecticut, is described by Hobbs.! An oval hill, 
some 1,000 feet long and 200 feet high, is composed of coarsely 
crystalline marble, with sills of epidiorite above and below. The 
ore-bodies occur along the plane of contact between the lower 
epidiorite sill and the marble, and are concentrated in the epidiorite 
just below the contact. The ore consists of both wolframite and 
scheelite intimately mixed, with a little pyrite. The marble near 
the contact contains many metamorphic minerals, especially scapolite 
and garnet. The contact deposit seems to have been fed by veins in 
the underlying rock, which contain quartz, felspar, fluorite, and 
topaz. There are also some pure quartz veins. All of these are 
evidently of the usual granite-pegmatite type, and their relation to 
the basic sills is not clear. It seems probable that the ore-bodies are 
really due to derivation from a granitic magma and that their 
association with the basic intrusions is purely fortuitous. The latter 
are evidently of the normal chlorine-bearing type, as shown by the 
development of scapolite in the metamorphosed lmestone. The 
presence of much scheelite is easily accounted for by derivation of 
lime from the calcareous rock. ‘his, then, is not a contact ‘deposit 
in the ordinary sense of the word, since the metallic constituents, 
and especially the tungsten, do not seem to have been derived from 
the rock in which they actually occur. It seems much more likely 
to be an example of granitic metamorphism which has happened to 
act on a basic rock and a limestone, and has segregated some con- 
stituents from each, depositing them in combination at or near their 
plane of junction. 

The tungsten ores of Canada have been exhaustively described by 
Walker? in a special report. They do not seem, so far as yet known, 
to be of much economic importance, though some of the lodes are or 


1 Hobbs, Bull. 213, U.S. Geol. Surv., 1903, p.. 98; and Twenty-second 
Ann. Rep. U.S. Geol. Surv., 1901, p. 7. 

2 Walker, Report on the Tungsten Ores of Canada, Department of Mines, 
Ottawa, 1909. Also frequent references in the Annual Reports of the same 
department. 


244 Rk. H. Rastall—The Genesis of Tungsten Ores. 


have been worked. In the Dominion deposits of wolframite and 
scheelite seem to be of almost equally common occurrence, but they 
do not show many features of theoretical interest. The only point 
needing to be mentioned is that in several instances wolframite has 
been found in quartz veins with scarcely any other metallic minerals ; 
occasionally a little pyrite or chalcopyrite is found. In Inverness 
County, Cape Breton, for example, htibnerite is found in quartz veins | 
with a little chalcopyrite. In York County, New Brunswick, 
wolframite occurs in quartz veins with molybdenite, pyrrhotite, 
arsenopyrite, and a little cassiterite; topaz and fluorite are found in 
the gangue; this is evidently a transitional type. In the Kootenay 
district of British Columbia wolframite is found in some quantity 
along with gold in quartz veins cutting granite and various Paleozoic 
rocks. Here little or no sulphide ore is to be found. In the 
Cariboo district wolframite occurs in veins with galena and pyrite, 
while in the Yukon it is found associated with native gold and 
bismuth. All these occurrences should be considered in connexion 
with the gold-tungsten ores of Colorado and Dakota; the general 
question of the relations of this type will be discussed later. 

In most of the wolfram mines of Queensland, as before described, 
the ores are associated with large quantities of tinstone, the latter 
being in most cases the more valuable of the two, but at Mount 
Carbine tinstone is so small in amount as to be negligible. This 
may therefore be regarded as an occurrence belonging to the present 
section of the subject, although tinstone does occur in quantity in 
other parts of the same district. The ores occur in pegmatite dykes 
in connexion with granites intrusive into schists and slates, which 
are highly metamorphosed and are often intensely silicified. The 
plans of the workings show a network of interlacing veins, varying 
in size up to 6 feet wide, but usually about 2 feet. The gangue is 
variable in composition, sometimes it is wholly quartz, while other 
veins consist chiefly of felspar; in the mixed veins quartz usually 
predominates; muscovite is rare, while tourmaline and beryl also 
occur in small quantity. The only other metallic mineral found is 
a small quantity of molybdenite. Wolframite has been found -in 
very large blocks, one weighing 6 tons, but it is more common in 
bladed and acicular forms. So far as the genesis of these deposits 
are concerned, it is quite evident that they were derived from 
a granitic magma, like the tinstone-wolframite ores of other parts of 
Northern Queensland; their occasional association with tinstone in 
the immediate neighbourhood is clear proof of a common origin, and 
it appears that the portion of the granitic magma which gave rise to 
the pegmatitic lodes of Mount Carbine itself had undergone a more 
than usually advanced degree of differentiation, so that the tin- 
wolfram-bearing fraction had been almost completely separated from 
the fraction carrying wolfram alone. The mechanism of this 
separation is uncertain, but it may be connected with differences 
in the freezing-point of compounds of tin and of tungsten respec- 
tively with the volatile elements of the magma, possibly the 
fluorides. From a consideration of the facts observed in other areas, 
such as Cornwall, it seems probable that tungsten is more volatile 


R. H. Rastall—The Genesis of Tungsten Ores. 245 


than tin, or, what amounts to the same thing, has a lower freezing- 
point in certain compounds. If this be so, it would naturally be 
expected that tungsten minerals would tend to travel further from 
their original source than tin minerals, and in some instances it 
seems to be established that this is actually the case. 

An unusual type of tungsten lode containing a considerable amount 
of titanium minerals is found in the Eastern Alps.’ The other 
associates are molybdenite, beryl, quartz, felspar, and apatite. This 
is an unusual combination, since titanium minerals seem to be 
decidedly rare in tin-tungsten lodes. 

Wolfram sometimes occurs in lead-silver lodes, as, for example, at 
Neudorf in the Harz, where it is accompanied by fluorite, but this 
association seems to be decidedly uncommon. 

In concluding the descriptive portion of this section attention may 
be drawn to the remarkable fluorite veins of San Roque in Brazil 
described by Valentin. Although not containing any tungsten ores, 
nevertheless there are affinities to the tungsten type, and these may 
be considered as the extreme case of this kind of differentiation. 
The veins consist almost exclusively of quartz and fluorite, the 
latter showing a great variety of colours. There is occasionally 
a little pyrite, but no other metallic minerals. These veins appear 
to be in close connexion with the intrusion of the granite of Achala, 
and represent the consolidation product of the last residue of the 
magma after the metallic constituents, if present, had been strained 
off and erystallized at higher temperatures. 


Summary or Parr II. 


To sum up this part of the subject, it appears that the wolframite 
deposits without tinstone include a considerable number of types of 
very varying character. Some of them are clearly of direct 
magmatic origin, and formed in a manner exactly similar to the 
wolframite-cassiterite lodes of granite areas. That is to say, they 
are produced from the granitic magma by differentiation carried 
a stage further than in the case of the tin-bearing lodes, leading to 
a complete separation of tin and tungsten. This process may, in 
fact, be regarded as an example of fractional distillation on a large 
scale. The extreme case of this kind of differentidtion is afforded 
by the quartz -fluorite veins of San Roque, which are analogous to 
the topaz veins of some tin-bearing areas. 

But in addition to the foregoing comparatively simple case it will 
be seen that this class also includes several varieties of widely 
different origin; some of these may be due to peculiar forms of 
differentiation, whereas others are certainly metasomatic; for 
example, the replaced dolomite in the Black Hills. It is doubtful 
whether any true contact deposits occur; those hitherto assigned to 
this origin may be capable of explanation in some other way. 
Finally, in some areas our knowledge of the geological conditions is | 


' Weinschenk, ‘‘ Die Minerallagerstitten des Gross-Venediger Stockes’’ 
Zeits. fiir Krist., vol. xxvi, 1896. ) 
* Valentin, ‘‘ Uber das Flussspathvorkommen von San Roque’’: Zeits. fiir 


prakt. Geol., 1896, p. 104. 


246 L. M. Parsons—Dolomitization 


at present too incomplete to allow any conclusions to be formed as to 
the genesis of the ores. 

Theoretical discussion of the facts set forth in this section will be 
postponed until after the scheelite deposits have been described, 
since in many instances the problems involved are very similar. 

(To be continued.) 


IJ].—Dotomirization:-anp THE LurIcESTERSHIRE DoLomIvEs. 
By L. M. Parsons, M.Sc. (Lond.), D.1I.C., F.G.S. 
(PLATE XI.) 

Part 1: Evipences oF THE Prriop or DoLomrrization. 


CONTENTS. 

Classification of Types. 
Field Evidences. 
Inherent Structural Evidences. 
Selective Dolomitization. 
The Absence or Presence of Fossils. 
Classification of Petrological Types. 
The Dense Yellow Dolomites of Breedon, ete. 
The Red Ferruginous Dolomites of Breedon and Breedon Cloud. 
The Barren Grey and Yellow Dolomites of Ticknall and Calke. 

10. Fossiliferous Dolomitic Limestones of Ticknall and Calke. 

N the district north of Ashby-de-la-Zouch dolomitized Carboniferous 

Limestone crops out where the Leicestershire border adjoins that 
of South Derbyshire. The dolomites, which attain a thickness of 
nearly 900 feet in this area, have hitherto received very little attention. 
I therefore propose to give a short description of them with a view 
to ascertaining how far their mode of occurrence and structure afford 
additional examples of, or exceptions to, the usual conclusions adopted 
‘concerning the origin of dolomite. With this object in view I propos 
to give a brief resumé of the evidences generally relied upon to 
explain the origin of dolomite, before proceeding to describe the 
Leicestershire rocks. 


CHAIR AR wD 


1. CrassiFication or TypEs. 

If dolomites are classified .as simply as possible according to the 
period at which the dolomitization! took place, well-defined classes, 
as enumerated below, may be recognized :— 

( 1. Those deposited as elastie rocks derived from 
Primary pre-existing dolomite. 
dolomites. 2. Those chemically precipitated as dolomite, with 
or without the agency of organisms. 

1. Contemporaneous dolomites, or those deposited 
as ordinary limestones which have been altered, soon 
after deposition, by the influence of magnesian salts in 

Secondary } the sea in which the rocks were originally deposited. 

dolomites. 2. Subsequent dolomites deposited as _ ordinary 
limestones which have been altered by the influence 
of waters belonging to some period later than that 
during which the rocks were originally deposited. 


' Throughout this article the term doiomitization signifies the production of 
dolomite, either primary or secondary. 


and Leicestershire Dolomites. 24.7 


With regard to this classification it must be ndéted that as some 
confusion has existed concerning the significance of the term 
‘‘contemporaneous”, that name is used here strictly to denote 
dolomites of secondary origin. 

The term ‘‘ subsequent”? has a wider significance than that of 
‘‘vein” dolomitization, as certain leached dolomites and some other 
dolomitized rocks of undoubted subsequent origin cannot be described 
adequately as vein dolomites, since some of them do not occur in 
association with veins and channels. Evidently vein dolomites 
constitute a subdivision of subsequent dolomites. It is now generally 
admitted that the majority of dolomites are of secondary origin, the 
contemporaneous class probably being more numerous than the 
subsequent, but certain cases of dolomitization appear to be explained 
most satisfactorily by the theory of primary deposition. Many 
chemical experiments have been performed in the endeavour to 
produce dolomite at different pressures and temperatures, but with » 
limited success! In spite of the comparative failure of these 
experimental attempts to produce dolomite artificially, the fact that 
it does occur in nature as a chemical precipitate is shown by its 
occurrence in mineral veins. It is very doubtful whether any 
reliable evidence can be obtained from experiments performed under 
conditions which may be quite unlike the natural conditions which 
existed in the seas of remote geological periods. 

In determining the class to which a dolomite belongs, one must 
rely upon the collective evidence afforded by :— 


Field relations, 

Inherent structural features, 
Selective dolomitization, and 

The absence or presence of fossils. 


Space permits only an incomplete survey of the phenomena 
connected with dolomitization, and a short discussion of the more 
reliable sources of evidence is all that is attempted. 


e 
2. Fretp EVIDENCES. 


(a) The occurrence of truly bedded dolomites associated with beds 
of such deposits as gypsum or rock salt is considered to support the 
view that the dolomite was primarily precipitated.’ 

(6) The theory of primary deposition is also supported by the 
occurrence of genuine beds of dolomite alternating with beds of 
limestone. In this case it is inferred that the dolomite was either 
chemically precipitated,’ or laid down as a clastic deposit derived 
from a source different from that of the non-dolomitic limestone. 
Pseudo-interbedding, characterized by the failure of the dolomitization 
to conform accurately to bedding planes, the lateral transition of 
dolomite into limestone, and sometimes by a streaky development of 


1 See F. W. Clarke, ‘‘ Data of Geo-chemistry’’: Bull. Geol. Sury. U.S.A., 
No. 616, p. 559, 1916. 

2 See Weigelin, Newes Jahrb., Beil. Bd. xxxv, p. 628, 1913. 

5 Suess, The Face of the Earth, English translation, vol. ii, p. 262, 1906. 


248 L. M. Parsons—Dolomitization 


dolomite in the intervening limestone, is in fayour of subsequent 
dolomitization.* 

(c) The presence of interbedded conglomerates containing fragments 
of dolomite derived from older dolomites below would suggest that 
the dolomitization of the older beds was not of subsequent origin, 
and that the dolomitic material of the conglomerate was a primary 
clastic deposit.” 

(d) The persistence of uniform bedded dolomites over a wide area 
without lateral transition into unaltered or poorly magnesian lime- 
stones is considered to be one of the strongest evidences in favour of 
contemporaneous dolomitization.* This conclusion receives further 
support if such dolomites occur at the same stratigraphical horizons 
in different areas, but the presence of dolomite at a certain horizon in _ 
one area and its absence at the same horizon in another area, does 
not necessarily indicate dolomitization of subsequent origin. Dolomite 
may have been formed in shallow water, while poorly dolomitic 
or unaltered limestones were being deposited further from the 
shore-line.* 

(¢) Should beds of dolomite be found, when traced laterally, to 
pass into unaltered or poorly magnesian limestones, the inference is 
in favour of subsequent dolomitization,® provided that other more 
conclusive evidence of a different origin is not forthcoming. 

(f) A patchy development of dolomite and limestone due to rapid 
lateral transition from one into the other is a modification of (e), and 
lends support to a similar conclusion.6 A patchy development of 
dolomite and iimestone on a small scale, known as pseudo-brecciation, 
is discussed later. 

(g) The evidence in favour of subsequent dolomitization is much 
stronger when an irregular or patchy development of dolomite is 
associated with faulting or jointing. In such cases it is obvious 
that the fault planes and joints have probably served as channels for 
percolating magnesian waters of a period subsequent to that during 
which the rock was originally deposited.’ Dolomites of this class 
are properly described as vein dolomites. 

(A) Faulting associated with extensive and non-patchy dolomites 
(d) appear to indicate that the faulting occurred after dolomitization. 

While discussing field relations we may observe that great thickness 
of bedded dolomite has been considered to support the view that the 
dolomite was of primary origin, but since a thick mass of limestone 
may be dolomitized during a long period of subsidence,® as in the 
case of certain coral reefs, it is questionable whether mere thickness 


' Calvin, Iowa Geol. Sury., vol. vii, p. 151, 1896. 
* See Swansea (Mem. Geol. Surv.), 1907, p. 13. 
: Dixon, Swansea (Mem. Geol. Surv.), 1907, p. 13. 


Td ee peadlae 
Hardman, Proc. Roy. Irish Acad., ser. 11, vol. ii, p. 728, 1875-7. 
° F. M. Van Tuyl, ‘‘ The Origin of Dolomite’’: Iowa Geol. Surv., vol. xxv, 
p. 364, 1916. 


’ The Geology of the South Wales Coal Fields (Mem.Geol. Surv.), pt. ii, p-33. 
8 Skeats, ‘‘ On the Dolomites of the Southern Myrol2: OpdnG 3S. volelsa, 
p: 97, 1905. 


and Leicestershire Dolomites. 249 


can be considered to yield any reliable evidence concerning dolomitiza- 
tion in general. 


3. InueERENT StrrucruraL EviIpENCES. 


(c) The degree of idiomorphism of dolomite crystals may afford 
subsidiary evidence concerning the class to which the dolomite 
may be assigned.!. In many cases where subsequent dolomitization 
is amply proved by other evidences, it is found that the rhombohedra 
are considerably more idiomorphic than those of most dolomites of 
undoubted contemporaneous or primary origin. In the latter cases 
there is a marked tendency of the crystals to interfere with one 
another, the resulting structure being amore or less granular mosaic. 

(7) The size of the rhombohedra is usually larger in subsequent 
dolomites where the growth of crystals is less impeded than it is in 
contemporaneous and primary dolomites.’ 

(4) As in the case of idiomorphism and size, the degree of purity 
of a dolomite is suggestive, but by no means conclusive.® 

Crystals of a primarily precipitated dolomite should, in general, be 
less contaminated with impurities than those of a dolomite of 
secondary origin, though a contemporaneous dolomite may attain 
a fair degree of purity. It is, perhaps, safer to place no reliance 
upon the degree of purity. 

(2) The relation of iron oxides, particularly hematite, to the 
dolomite rhombohedra, affords one of the most reliable evidences 
concerning subsequent dolomitization.£ When hematite is included 
either centrally or zonally in the rhombohedra the only possible 
conclusion is that the hematite was introduced at the time when the 
dolomitization took place. For instance, in a district where Trias 
comes above Carboniferous dolomites having zonal inclusions of 
hematite, the obvious inference is that the dolomitization was 
subsequent and associated with waters percolating through the Trias 
(see micro-photograph, Pl. XI, Fig. 1). On the other hand, should 
the hematite be only interstitial, the inference is that dolomitization 
took place before the introduction of iron oxide. Ina case where 
Trias rests upon Carboniferous dolomites, the presence of only 
interstitial hematite in the dolomite would indicate that the 
dolomitization was certainly Pre-Triassic, perhaps contemporaneous. 
Inferences similar to those made from the presence of included 
hematite appear to be justified in cases where dolomitization is 
intimately associated with other ores such as galena and zinc blende.? 

(m) The relation of rhombohedra to chert in cherty dolomites 
affords definite evidence with regard to the relative periods at which 
the dolomite and chert were respectively formed.® If rhombohedra 
oceur enclosed by chert, the inference is that the dolomite was 
formed either before or simultaneously with the chert. On the 


1 See F. M. Van Tuyl, Iowa Geol. Surv., vol. xxv, p. 390 et seq., 1916. 
2 Swansea (Mem. Geol. Surv.), 1907, p. 16. 

5 F. M. Van Tuyl, Iowa Geol. Surv., vol. xxv, p. 319. 

+ Swansea (Mem. Geol. Sury.), 1907, pp. 15, 16. 

5 Schmidt, Trans. St. Louis Acad. Sci., vol. iii, No. 2, 1875, p. 246. 

6 H. H. Thomas, Ammanford (Mem. Geol. Surv.), 1907, p. 76. 


250 LL. M. Parsons—Dolomitization 


other hand, should chert contain no included rhombohedra, the 
formation of chert must have preceded that of dolomite, though this 
does not necessarily prove subsequent dolomitization, since there is 
no indication of any great period of time having elapsed between the 
formation of chert and that of dolomite. 


4. Serxrcrive Dotomrrization. 


The term ‘selective dolomitization’’ has been applied to certain 
phenomena in which the formation of dolomite occurs more in certain 
portions of rock, presumably the less coarsely crystalline and more 
unstable parts, than in other more resistant portions. One result of 
this differentiation is a rock of mottled appearance at times not unlike 
a breccia. The relations between the dolomitic and non-dolomitic 
portions of such rocks may afford evidence concerning the origin of 
the dolomite. 

(nm) Pseudo-brecciation, in which a limestone assumes a mottled 
appearance on account of a patchy development of dolomite on 
a small scale, can scarcely be considered to yield evidence analagous 
to that of patchy dolomitization on a larger scale (f). That 
a pseudo-breccia is unlikely to be due to the formation of primary 
dolomite appears to be a legitimate inference, but the question as 
to whether the dolomitization of any particular pseudo-breccia is 
contemporaneous or subsequent must be decided by inherent evidence 
other than that of mere mottling. Thus a rock of this kind in which 
hematite is aaah y interstitial may be referable to contemporaneous 
dolomitization.' 

Any particular pseudo-breccia may sapoly evidence of its own 
origin, but cannot form the basis for a definite generalization 
concerning the mottling of dolomitic limestones. Each case must 
be considered on its own merits. 

(0) A mottled appearance in which the dolomitic material is 
worm-like or fucoid suggests dolomitization facilitated by the 
presence of the remains of alge or other organisms.? 

Of particular interest are cases of fossiliferous dolomitic limestones 
in which selective dolomitization has differentiated between the 
matrix and organic structures. It frequently happens that in 
dolomitic rocks. proved by general evidence to be of subsequent 
origin, the matrix, whether calcite or aragonite originally, has been 
lar sely converted into recrystallized calcite prior to dolomitization.? 
The recrystallized matrix, presumably on account of its relatively 
coarse texture, is appar ently more stable than the original calcareous 
material of organic remains, consequently dolomite crystals have 
developed more in fossil structures than in the recrystallized matrix. 

(p) Hence it is inferred that differential dolomitization of this 
kind may be an indication of subsequent alteration.. That such 
an inference may not always be legitimate is evident from the 
occasional occurrence of dolomite crystals enclosed by recrystallized 


' For instance, see Swansea (Mem. Geol. Surv.), 1907, pp. 14, 15. 

2 Peach & Horne, North-West Highlands of Scotland (Mem. Geol. Surv.), 
1907, p. 366. 

* Swansea (Mem. Geol. Surv.), 1907, p. 16. 


and Leicestershire Dolomites. Dini 


calcite, suggesting that the dolomitization may have been con- 
temporaneous. 

It has been shown that in certain contemporaneous dolomites, 
fossil structures, including corals, have resisted dolomitization to 
a greater extent than the matrix has done owing to the non- 
recrystallized material of the matrix being more unstable than the 
more coarsely crystalline material of organic remains. 

(q) From this it may be inferred that the greater development of 
dolomite in the matrix than in fossil structures, including corals, is 
in favour of the theory of contemporaneous dolomitization.' But 
while this may be true in many cases, it is by no means certain that 
selective phenomena of this kind should always be relied upon to 
furnish conclusive evidence of the period of dolomitization. In 
connexion with the question of the relative stability of matrix and 
fossil structures, it must be remembered that the calcareous contents 
_ of dolomitic limestones may have consisted originally of any or all 
of the following forms of calcium carbonate: aragonite mud, more 
coarsely crystalline aragonite, calcite mud, and more coarsely 
crystalline calcite. Of hose, ‘aragonite mud is certainly the most 
easily converted into dolomite, and coarsely crystalline calcite is the 
most stable, but whether the more coarsely crystalline aragonite of 
coral tissues is more unstable than calcite mud appears to be an 
open question. It is just this point which weakens evidence afforded 
by selective dolomitization. In the contemporaneous alteration of 
a coral limestone containing few other organic remains, the matrix 
consisting mostly of aragonite mud would certainly be more easily 
dolomitized than the coarser coral structures. 

Most organic limestones, however, consist largely of calcitic 
remains as well as coral structures, so that calcite mud must have 
been present originally in the matrix, and may even have been in 
excess of aragonite mud. If calcite mud is more susceptible to 
alteration than coarser aragonite, in contemporaneous dolomitization 
the matrix would still be dolomitized in preference to coral structures. 
On the other hand, should calcite mud be more stable than coarser 
aragonite, contemporaneous alteration of a mixed organic limestone 
would result in the development of dolomite more in coral structures 
than in the matrix. Again, there appears to be no means by which 
the proportions of aragonite and calcite muds in the original matrix 
may be ascertained. Considerations of this kind suggest that the 
phenomena of the selective dolomitization of organic rocks can 
scarcely be relied upon to supply sound evidence, particularly in 
cases where such phenomena appear to contradict the evidence 
afforded by field relations or other reliable features. 

Selective alteration of oolitic limestones may be more reliable, 
since the differentiation in such cases is between coarser calcite and 
finer calcite. If dolomitization has attacked odliths in preference 
to a recrystallized matrix, the alteration is probably subsequent ; 
on the other hand, the development of dolomite more in a non- 
recrystallized matrix than in ooliths may indicate contemporaneous 
dolomitization, 


? Swansea (Mem, Geol. Sury.), p. 15. 


252 L. M. Parsons—Dolomitization 


REFERENCE. | |e 


TRIAS. 
PERMIAN. 


COAL MEASURES. 


FUILLSTONWE CRIT. 


SHALES. 


CARB. Ls. 


CHARN/I AN. 


TICKNALL & 


@ SREEDON 


E oi 
§ BREEDON CLOUD’ 


® BARROW HILL 
®0OSGATHORPE 


SCALE in NILES. 


le ae i position of the Tees Dee ee a with those 
of the Carboniferous Limestone of Derbyshire and of the Charnwood 
Pre-Cambrian. 


o. Tur Axpsence or Presencr or Fossrtts 1n DOoLoMITEs. 


It is doubtful whether any reliable evidence of the period of 
dolomitization can be obtained from the absence of or ganic remains. 
A primarily precipitated dolomite would probably be deposited under 
conditions unfavourable to life, but it is also conceivable that either 
contemporaneous or subsequent dolomitization could be so complete 
as to obliterate all traces of organic structures that may have been 


and Leicestershire Dolomites. 253 
present originally. In other words, the final stage of secondary 
dolomitization might produce the complete alteration of a rock 
which may have exhibited selective phenomena in its early stages of 
alteration. 

(r) The presence of fossils ina dolomite is a little more significant, 
particularly if they are at all numerous. The argument is then 
against the theory of primary precipitation. In a rock showing no 
selective features the condition of fossil structures as casts or as 
replacements in dolomite, appears to yield very little evidence of 
contemporaneous or subsequent alteration since both casts and 
replacements of the same class of organisms may occur in the same 
bed of dolomite. 

The perfect replacement by dolomite of coral structures is certainly 
suggestive of contemporaneous alteration, since such replacements have 
been found to occur in modern reefs before calcitic recrystallization 
of coral tissues took place." 


Part Il: Tae LercestersHire DoLomIites. 


A series of faulted inliers of Carboniferous dolomites extends in 
a north-westerly direction from the edge of Charnwood, commencing 
with small patches of dolomite at the village of Osgathorpe, 
and ending to the north in the mass forming Breedon Hill, 
a landmark for many miles. Between these limits of the series 
are situated the dolomite hill known as Breedon Cloud and the 
much smaller though petrologically similar inlier called Barrow 
Hill. In each of these cases the Carboniferous Limestone is 
surrounded by unconformable Keuper. A few miles to the west of 
Breedon there are small valley inliers of Lower Carboniferous rocks 
containing bedded dolomites and dolomitic limestones at Ticknall and 
Calke Park. At these localities the Lower Carboniferous is succeeded 
conformably by Millstone Grit, which is overstepped at one or two 
places by Trias. 


6. CLASSIFICATION oF PETROLOGICAL TYPES. 


Disregarding details of stratigraphy and paleontology which I have 
described in another paper,’ and considering the formations purely 
from a petrological point of view without assuming the mode of 
origin of the dolomite, we may distinguish in the area different 
types of dolomitic rocks as follows :— 

Dense yellow dolomites of Breedon and Breedon 
Dolomites proper, containing | Cloud (1).° 

a proportion of magnesium Red ferruginous dolomites of Breedon and 

carbonate approaching 40% Breedon Cloud (2). 

Barren grey and yellow dolomites of Ticknall (4). 
Dolomitic limestones Perth 

taining a relatively small] Fossiliferous dolomitic limestones of Ticknall 

percentage of waaanane| and Calke (3). 

carbonate 


1 See Cullis, ‘‘ The Atoll of Funafuti’’: Report of Coral Reef Committee, 
Royal Society, 1904, section xiv, p. 407. 

2 See Abstracts of the Proc. Geol. Soc. of London, No. 1004, March 14, 
lsat gy 

> The numbers in parentheses indicate relative stratigraphical positions in 
ascending order. 


254 LM. Pareone= “Delonitieanion 


In this table the types predominating in the district are placed 
higher in the list. 


7. Tur Densz YetLow Dotomites oF BreEepon, BreEepon Croup, Ere. 


The bulk of the dolomites of the two Breedons, Barrow Hill, and 
Osgathorpe consists of dense yellow material having a specific gravity 
and chemical composition approaching those of a pure dolomite. 
The proportion of Magnesium Carbonate varies slightly in different 
beds, but averages nearly 40 per cent, while iron compounds and 
insoluble residues are present in small amounts. 

The field relations of these rocks are studied best at Breedon-on- 
the-Hill, where quarries are being worked in a direction at right 
angles to the strike. At this locality more than 800 feet of fairly 
thick-bedded dolomites succeed one another without any marked 
variation in petrological characters and without any apparent com- 
plications due to faulting. Though the chemical composition and 
texture of the material forming one stratum may be slightly different 
from that of another, the inherent characters of any particular bed 
appear to be uniform. The dolomitization is in no case patchy (/).} 
Laterally the beds do not pass into unaltered or poorly dolomitic 
limestones (d), though this fact would have greater significance if the 
Carboniferous Limestone of the area had a larger outcrop. The 
absence of faulting at Breedon suggests the improbability of 
subsequent vein dolomitization associated with dislocation (g). At 
Breedon Cloud strike faulting does occur, but is there associated 
with non-patchy yellow dolomites which do not pass laterally into 
unaltered limestone (A). 

Conglomerates and pseudo-breccias are not present. Microscopic 
sections of the yellow dolomite of Breedon, Breedon Cloud, and 
Barrow Hill show a fine-grained crystalline structure composed 
mainly of small grains more or less allotriomorphic, though some 
rhombohedral outlines may be seen (jy andz). ‘The degree of purity 
is not high since minute dusky inclusions of insoluble matter are 
very numerous (/). There are no zonal or central inclusions of 
hematite, and what little iron oxide does occur, mainly limonite, is 
interstitial (7). Chert is absent from the material exposed in the 
workings of Breedon-on-the-Hill, though it occurs in the yellow 
dolomites of a higher horizon at Breedon Cloud. Sections do not 
show any dolomite rhombohedra in the chert (m). Fossils are not 
numerous at Breedon, Barrow Hill, and Osgathorpe; those that do 
occur at these localities consist chiefly of dolomite casts of Brachiopoda 
and a few corals. At Breedon Cloud, however, higher beds are 
exposed and fossils are more plentiful. Corals are preserved as 
dolomite replacements and as casts (7). Syringopora is usually 
found as casts, but Michelinia, Campophyllum, and other genera exhibit 
septa, tabule, and other structures beautifully preserved in minutely 
erystalline dolomite. Goniatites ( Glyphioceras) also occur as dolomite 
replacements, but Brachiopoda are present as casts. 

The conclusion to be drawn from the collective evidence concerning 


' Italic letters in parentheses refer to corresponding evidences mentioned in 
the earlier part of the article. 


and Leicestershire Dolomites. 255 


the yellow dolomite of Breedon, ete., is undoubtedly in favour of 
contemporaneous dolomitization. 


8. Tue Rep Ferruermous Dotomitrs oF BREEDON AND 
Breepon Curovp. 


The uppermost portion of the Carboniferous Limestone sequence 
seen at Breedon and Breedon Cloud is composed of several feet otf 
thinly bedded red dolomites quite distinct from the more massive 
yellow dolomites below. ‘These red dolomites cannot be seen to pass 
laterally into unaltered limestone (d), but it must be remembered 
that the outcrop is not very extensive. The rock is patchy in the 
sense that the proportion of magnesium carbonate varies in any 
particular stratum, but there are no external appearances analogous 
to those of pseudo-brecciation (n). Faulting occurs at Breedon 
Cloud, though I infer that dislocation has not been a factor of the 
dolomitization for the following reasons: (1) no faulting occurs at 
Breedon-on-the-Hill where these red dolomites are otherwise 
precisely similar to the corresponding rocks at Breedon Cloud, (2) 
the faulting at Breedon Cloud is also associated with the yellow 
dolomites yielding very strong evidence of contemporaneous 
dolomitization (fh). 

Microscopic sections exhibit a structure ‘characterized by idio- 
morphic, fairly large, and very impure rhombohedra (7, 7, and 4). 
Well-marked central and zonal inclusions of hematite occur in the 
erystals of dolomite forming these beds (/) (micro-photo, Pl. XI, 
Fig. 1). The outer zones of the crystals are free from hematite, 
but contain other inclusions similar to those in the rhombohedra of 
the yellow dolomites. A few streaks and patches of recrystallized 
calcite are present, and it is probable that this recrystallization 
took place prior to dolomitization. 

It has yet to be proved whether coarsely erystalline calcite, either 
original or recrystallized, is under any particular conditions immune 
from alteration to dolomite. In connexion with this question, the 
condition of crinoid stems and ossicles in these red dolomites is 
interesting. Micro-photo, Pl. XI, Fig. 2, taken from a specimen 
of the Breedon rock, shows a crinoid ossicle invaded by hematite- 
bearing dolomite near the central passage and around the external ° 
margin, which is badly corroded by the alteration. 

Other organic structures are obscure. That other fossils were 
present in these rocks originally, is shown by the occasional 
occurrence of coral and Brachiopod casts. It appears that we have 
here an instance of undoubted subsequent dolomitization in whick 
both the matrix and organic structures, with the exception of 
encrinites, have been completely altered. Even crinoid remains, a 
most stable form of calcite, have been altered to some extent. With 
regard to the matrix, there is no way of ascertaining its original 
condition. It may have been calcite or aragonite, or a mixture of 
the two; or it may have been calcite recrystallized prior to 
dolomitization. Evidently this rock affords an illustration of the 
fact that conclusions are not easily made from phenomena connected 
with selective dolomitization. 


256 L. M. Parsons—Dolomitization 


The evidences concerning the origin of the Breedon and Breedon 
Cloud red dolomites indicate quite definitely that the dolomitization 
“was subsequent and associated with waters percolating through the 
Trias, which formation rests upon the upturned edges of the red 
dolomites at these localities. It seems fairly evident that this 
subsequent dolomitization has attacked previously unaltered lime- 
stones (2)' lying between apparently contemporaneous dolomites 
stratigraphically lower (1) at the Breedons and higher (4) at 
Ticknall. 


9. Tur Barren Grey anp YeEttow Dotomires or TicknaLL AND 
CALKE. 


About ten feet of bedded dolomites, yellow below but grey above, 
occur at the very top of the Carboniferous Limestone at Ticknall and 
Calke. They are succeeded by dark shales which pass up conformably 
into Millstone Grit. The chemical composition of these dolomites is 
similar to that of certain rocks described by Professor Skeats as 
“Dolomites of theoretical composition’. A comparison of the 
results of analysis makes this evident. 


Dolomite of theoretical Ticknall grey 

composition (Skeats). dolomite. 
Calcium carbonates Q : . 54-7 57-1 
Magnesium carbonate . < . 45:3 38-3 
Iron compounds . : : SSS 2:7 
Insoluble residue . 5 2 : -033 1-5 


In the Ticknall dolomite a small amount of free calcite is present, 
as shown by slides stained with Lemberg’s solution. 

These rocks are seen best in the old lime works of Ticknall, but 
the exposures are very limited in extent, so that the bedded nature 
of these dolomites and their apparent non-passage into unaltered 
limestone cannot be used as reliable evidence of their origin (d). 
There is, on the other hand, not the slightest visible development of 
patchy dolomitization (/). 

A small fault occurs, but this shows no definite connexion with 
the origin of the dolomite. The yellow and grey varieties of the 
rock are very similar in their microscopic characters. Sections show 
a crystalline mass'in which a large number of crystals have been 
rounded off, presumably by simultaneous development (7), but some 
rhombohedral outlines are retained, particularly in the case of some 
of the larger crystals (micro-photo, Pl. XI, Fig. 3). There are very 
numerous inclusions, consisting mainly of minute particles of insoluble 
matter incorporated during crystallization (/), but there are no 
central nor zonal inclusions of hematite (2), iron oxide in the form 
of limonite being interstitial. ‘This feature has special significance 
in view of the fact that reddish rocks of Permian and Triassic ages 
rest upon the limestone in the north-west corner of the Ticknall 
exposures. Chert is absent, and organic remains, if present 
originally, have been completely obliterated (7). According to the 


1 Numbers refer to stratigraphical positions given in the classification of 
petrological types. 
2 Q.J.G.S., 1905, p. 105. 


and Leicestershire Dolomites. 257 


evidence it seems reasonable to infer that the Ticknall dolomites are 
of contemporaneous origin. 


10. Fossrzirerovus Dotomitic Limesrones or TIcKNALL AND CALKE. 


Certain limestones occurring at a slightly lower horizon than that 
of the barren dolomites of ‘icknall, are interesting mainly on 
account of their representing an incomplete stage in the process of 
dolomitization. ‘These limestones are best studied at Ticknall, but 
some of the Calke specimens yield very fine slides showing 
‘‘selective’’ phenomena. The amount of magnesium carbonate 
does not exceed 16 per cent. As in the case of the barren dolomites 
above, these rocks occur apparently in definite beds and are not 
associated with faulting of any importance. Chert is absent. 
Microscopic sections show idiomorphic crystals of dolomite having 
a fair degree of purity (4), and devoid of zonal hematite in- 
clusions (/). ‘The rhombohedra show a decided preference for organic 
structures (p), both coralline and brachiopod, though dolomitization 
occurs to sume extent in the matrix. Micro-photo, Pl. XI, Fig. 4, 
shows rhombohedra developed in organic structures, the matrix 
consisting of recrystallized calcite in places. Though the features 
shown by this photograph are typical, some individual crystals are 
developed partly in an organism and partly in the matrix. The 
rock being of a mixed organic nature, there is no knowledge of the 
relative proportions of aragonite and calcite muds in the original 
matrix, and even if this point could be decided there would still be 
the question of the comparative stability of coarser aragonite and of 
calcite mud to be determined. In one or two cases dolomite crystals 
are entirely surrounded by recrystallized calcite, from which it 
appears that either the recrystallization took place after the 
formation of dolomite or recrystallized calcite has been converted 
into dolomite. The inference that dolomitization was prior to re- 
crystallization would tend to support the theory of contemporaneous 
origin. The selective phenomena exhibited by the Ticknall 
and Calke dolomitic limestones do not, in my opinion, yield any 
conclusive evidence concerning the period of dolomitization, and 
though the balance of evidence derived from other sources may be 
slightly in favour of contemporaneous alteration, it may be wiser to 
consider the matter ‘‘not proven”’ since some of the evidence is of 
a conflicting nature. 

Having arrived at the general conclusion that most of the 
dolomites of the Leicestershire area are of contemporaneous origin, 
may I suggest that they appear to have been formed in shallow 
portions of the Carboniferous sea situated in the Charnwood region. 
The dolomitic nature of these rocks compared with that of the more 
normal limestones occurring at the same horizons (D, and D,) in 
Derbyshire may thus be explained. The case may be somewhat 
similar to that of the Jaminosa dolomites of the Bristol area, which 
are situated about twenty-five miles distant from the more normal 
limestones of the Mendips. ‘The presence of a rich Lamellibranch 
fauna in the D, subzone in Leicestershire, and the presence of only 

DECADE VI.—VOL. V.—NO. VI. 17 


258 Dr. J. Allan Thomson—The genus Bouchardia, 


a few feet of Carboniferous Limestone at places south of Osgathorpe 
as shown by a boring at Desford where the Carboniferous Limestone 
- was found to rest on Pre-Cambrian, supply evidence that shallow- 
water conditions existed in the area during Carboniferous times. 


EXPLANATION OF PLATE XI. 
MICROPHOTOGRAPHS OF THE LEICESTERSHIRE DOLOMITES. 
Fic. 1.—Red dolomite, Breedon, Leicestershire. Idiomorphic rhombohedra, 
having central zonal inclusions of hematite and fairly clear outer 
zones. X 25. 

,, 2.—Red dolomite, Breedon. Calcite of crinoid ossicle invaded by fine- 
grained hematite-bearing dolomite. Matrix completely dolomitized. 
x 25. 

,, 3.—Grey dolomite, Ticknall, south - eastern border of Derbyshire. 
A mosaic of rather allotriomorphic grains devoid of zonal hematite 
but having many dusky inclusions. A few rhombohedral outlines 
are shown. A little limonite is interstitial. x 25. 

», 4,—Fossiliferous dolomitic limestone, Calke Park, Derbyshire. Typical 
section showing preference of dolomite for organic structures. The 
matrix is partly composed of recrystallized calcite. x 25. 


IIl.—Tue cenus Boucnarpié (Bracwiopopa) AND THE AGE OF THE 
YouneEeR Brps oF Seymour Istanp, West ANTARCTIC. 


By J. ALLAN THOMSON, M.A., D.Se., F.G.S., Director of the Dominion 
Museum, Wellington, N.Z. 


Tue AGE oF THE YouNGER Breps oF Seymour ISLAND. 


HELLS with the external aspect of Bouchardia have been known 
for some time from the New Zealand Tertiary (Oamaruian), 
and were first described by Hutton in 19051 under the names 
of Bouchardia rhizoida and B. tapirina.2, The correctness of this 
generic ascription was doubted by von Ihering, who stated that 
the shells lacked the characteristic external form of Bouchardia.* 
In this, however, von Ihering was mistaken, probably owing to the 
unsatisfactory nature of Hutton’s figures, for these species agree 
externally with Bouchardia in the very characters which he supposes 
they lack, viz., the very sharp beak ridges, the more or less straight 
sides, and the presence of a longitudinal cord over the suture of the 
deltidial plates. The most characteristic external feature of the. 
shell of Bouchardia is that the sharp beak ridges unite in an apex 
dorsally of the foramen, i.e. the foramen is epithyrid. In Hutton’s 
supposed Bouchardie the foramen is permesothyrid, but almost 
epithyrid. . 
Buckman‘ has described a number of species of Bouchardia from 
the younger beds of Seymour Island, West Antarctic, and having to 
rely practically on these alone for a determination of the age of the 
beds, and finding no help in the way of direct zoological comparison, 
he has been forced to fall back on a biological argument. 


1 Trans. N.Z. Inst., vol. xxxvii, p. 480. 

” Not Waldheimia tapirina, Hutton, 1873. 

3 Ann. Mus. Nac. Buenos Aires, t. xiv, p. 473, 1907. 

* Wissensch. Ergebn. Schwed. Siidpolar-Exped., Bd. iii, Lief. vii, pp. 14-17, 
32, 1910. 


Grou. Maa., 1918. IPM SCI. 


G. S. Sweeting, photo. 


Bale, tip 


LEICESTERSHIRE DOLOMITES. 


Seymour Island, West Antarctic. 259 


“The Bouchardie, however, may be looked at from another aspect 
—the biological: their stage of development may be considered. 
In this respect they are intermediate between Bouchardie found in 
the Patagonian and in the Oligocene of New Zealand on the one hand, 
and the living Bouchardia rosea on the other; in fact they are, so far 
as biological development is concerned, much more advanced than 
the Patagonian Oligocene species, and much nearer in development 
to the present-day form. 

‘©The character of the Bouchardie is wholly against their being 
earlier than the Bouchardie of the Patagonian. Biologically speaking, 
the Bouchardie of the Patagonian are earlier than the Antarctic 
Bouchardia, for they agree with the young stage and differ from the 
adult stages of these shells. Then the Bouchardie of the New 
Zealand Oligocene are certainly further removed from the Antarctic 
forms; they appear to be biologically earlier than the Patagonian 
species.” 

Recently I have been able to show’ that the New Zealand supposed 
Bouchardieé possess Magellaniform loops and septa, and further that 
in a series of shells with similar beak characters there are repre- 
sentatives with all stages of loop development between those of 
Bouchardia and Magellania. Arguing that the constancy of beak 
characters shows that we are dealing with a stock which has attained 
the Magellaniform loop in its highest member by a different line of 
ancestry from Veothyris and Magellania, I proposed new generic 
names for representatives of each loop stage as follows :— 

Magadina: Genotype Magadina browni, Thomson. Loop Magadini- 

form, i.e. so-called Magadiform of Beecher. 

Magadinella: Genotype Wagasella woodsiana, Tate. Loop Tere- 

bratelliform. 

Rhizothyris: Genotype Bouchardia rhizoida, Hutton. Loop 

Magellaniform. 

Buckman? has since shown that in’the position of the foramen 
there is development from the hypothyrid, through submesothyrid, 
mesothyrid, and permesothyrid to the epithyrid ‘position. In this 
respect, therefore, Rhizothyris is less advanced than Bouchardia, and 
does not necessarily belong to the same stock. The similarity 
between them in beak characters is simply that in each the foramen 
is very advanced in position, and this may be and is the case in 
widely different stocks. Zaqueus, for instance, also possesses a 
permesothyrid foramen, and is certainly no close relation of 
Rhizothyris. 

Buckman’s biological argument, therefore, is weakened by the 
inclusion of the New Zealand species of Rhizothyris, but it still stands 
if confined to species which there is no reason to suspect are not true 
Bouchardia. The most primitive in shape is B. patagonica, von 
Ihering, from the Salamancan (Upper Cretaceous) of Patagonia; then 


1 “*Brachiopod Genera: The Position of Shells with Magaselliform Loops 
and of Shells with Bouchardiform Shape’’: Trans. N.Z. Inst., vol. xlvii, 
pp. 392-4038, 1915. 

ZEA ISE Buckman, ** Terminology for Foraminal Development in Terebratu- 
loids (Brachiopoda)’’: Trans. N.Z. Inst., vol. xlviii, pp. 130-2, 1916. 


260 Dr. J. Allan Thomson—The genus Bouchardia, 


follow in order B. gttteli, von Ihering, from the lower Patagonian, 
B. transplatina, von Lhering, from the Entrerian of Patagonia, along 
with Buckman’s Antarctic species, next the New Zealand Upper 

Oamaruian species described below, and finally B. rosea. 

- Asa matter of fact, however, no such biological argument for the 
age of the Seymour Island beds was necessary, since a direct zoological 
comparison could have been made between B. transplatina, von 
Thering,! and B. angusta, Buckman, which are hardly distinguishable 
from the published figures. In the absence of other evidence, this 
would justify the age of the younger beds of Seymour Isiand being 
placed as Entrerian, i.e. distinctly younger than the Patagonian and 
probably Upper Miocene, which is practically where Buckman 
placed them. 

A New Spectres or BoucwArpra From NEw ZeEaranp. 
Bouchardia minima, sp. nov. (Fig. 1.) 
Shell elongate oval or elliptical, generally much longer than wide, 
greatest width about the middle, sides rounded in the broader forms, 


a b c 


Tlie. 1.—Bouchardia minima, Thomson. Mt. Brown Beds, Waipara District, 
North Canterbury, New Zealand. (a) Holotype, dorsal view; (b) holotype, 
lateral view ; (c) paratype, interior of dorsal valve, ventral view. Enlarged 
6 diameters. 


nearly straight in the narrower forms, front rounded, commissures 
with a low broad anterior sinuation. Valves rather depressed, the 
ventral slightly more convex than the dorsal and obscurely carinated. 
Hinge-line short and curved, beak short, acute, not incurved, beak 
ridges rather blunt, foramen minute, epithyrid, deltidial plates 
obscure, a groove running between the umbones of the two valves. 
Surface of valves smooth with a few moderate lines of growth, 
indicating development from a subcircular through an oval to an 
elliptical shape. 

Interior of ventral valve :—Hinge teeth prominent, bifid, consisting 
of upper and lower processes separated by a well-marked groove ; 

1 H. von Ihering, ‘‘Les mollusques fossiles du Tertiaire et du Crétacé 
supérieure de |’Argentine’’?: Ann. Mus. Nac. Buenos Aires, t. xiv, pp. 480-1, 
1907. Buckman unfortunately overlooked this reference in drawing up his 
bibliography. 


Seymour Island, West Antarctic. 261 


there is a slightly raised ridge along the median line of the anterior 
part of the valve, probably separating the muscular impressions, 
which are not clear. 

Interior of dorsal valve:—Posterior part much thickened with 
elevated solid cardinalia bounded on each side by deep hinge sockets 
which converge posteriorly. As in other species of Bouchardia, 
distinct socket ridges, hinge plates, cardinal process, etc., cannot be 
certainly distinguished. It would perhaps be more correct to term 
the socket walls in this case hinge teeth of the dorsal valve, for there 
is on each side a rounded projecting ridge which fits into the groove 
in the bifid teeth of the ventral valve. The space between the socket 
ridges is filled with shell matter, forming a solid platform, above 
which rises a median boss or cardinal process, rounded anteriorly, 
but with a small posterior tongue. From the sides of this boss two 
narrow ridges converge to meet near the umbo. In the anterior end 
of the solid hinge platform there are three caves entering from the 
floor of the shell, a larger and deeper median one and two smaller 
lateral ones, separated by two small projections. The high median 
septum is situated anteriorly and touches the median projection from 
the floor of the ventral valve. Itrapidly lessens in height posteriorly 
and projects into the median cave of the hinge platform without 
uniting with the latter. On the anterior end of its elevated portion 
it bears a small swollen boss. No sign of the descending brachial 
arms has been observed in any of the numerous specimens examined. 

Dimensions in millimetres :— 

Length. Breadth. Thickness. | 


Holotype . : c : 4-5 3 1:5 

Paratypes . : Boer ane 4-5 3 2 
We ‘ E : : 5 4 1-8 
of a ; 5 é 4 3 1-5 


Type locality.—Base of main limestone, cuesta between Mt. Brown 
aud the Waipara River, North Canterbury. 

Material.—A large series (several hundreds) from the type locality, 
all from one small cave in the limestone; a few specimens from the 
same horizon in the Weka Pass end of the district; a small series 
from Flat Top Hill, Oamaru District, Otago. 

Horizon.—The main Mt. Brown limestone is near the top of the 
sequence of Oamaruian beds of the Weka Pass and Waipara district, 
and probably correlates with the Hutchinson Quarry beds of Oamaru. 
It may therefore be called Upper Oamaruian. The limestone of Flat 
Top Hill is Ototaran, i.e. Middle Oamaruian. The Middle and Upper 
Oamaruian are by general consent Miocene. 

Zoological comparison.—Bouchardia minima is to be compared with 
the other elongate species of the genus, from which it differs by the 
narrowness and curvature of the hinge-line. B. antarctica, Buckman, 
is an elongate form with a broad, nearly straight hinge, then follow 
with narrower and more curved hinges &. attenuata, Buckman, 
B. rosea (Maine), and finally B. minima, in the order named. If the 
development of elongation as revealed by the growth-lines is con- 
sidered B. minima must be placed before #. rosea, since the youthful 
growth-lines are broader in the former. 


262 Dr. J. Allan. Thomson—The genus Bowchardia. 


REMARKS ON THE GENUS BOUCHARDIA. 


Since an external form similar to that of Bouchardia may be 
combined with a more advanced loop, it is necessary before a given 
species can be certainly referred to the genus to have some knowledge 
of the interior arrangements. The loop is known only in the recent 
species B. rosea, and consists of two “anchor-shaped disconnected 
curved lamelle’’ fixed to the posterior end of a high septum. These 
lamelle resemble those of the ascending portion of the loop of Dagas, 
and in both genera they are disconnected, and not united to form 
a ring as in Dagadina and in the Magadiniform and pre-Magadiniform 
stages of Terebratella.' The descending branches of the loop, which 
are complete in Magas and Magadina, are totally absent in B. rosea. 
Beecher has compared the early pre-Magadiniform stages of Tere- 
bratella with the adult loop of Bouchardia, but there is this important 
difference, that in the young of TZeredratella the growth of the 
descending branches commences before that of the ascending 
branches, and there is never a stage in which the ascending branches 
do not form a complete ring or hood on the septum. 

If Bouchardia is correctly placed in the Magellanine, B. rosea must 
be looked upon as a retrograde species, descended from a form 
possessing a complete ring on the septum and incomplete descending 
branches, and now attaining a less instead of a greater caleifieation 
of the loop than its forerunners. If this view is correct, the loops 
of the fossil species of Bouchardia may be expected to show a greater 
calcification than exists in B. rosea. This expectation is not realized 

‘in B. minima, for numerous interiors of this species are available, 
but show no trace at all of a loop except a slight swelling on the 
posterior end of the septum which closely resembles the first stage of 
the hood in the young of TZerebratella rubicunda. If this is a correct 
homology, then Bouchardia minima represents a still earlier loop stage 
than B. rosea, but is apparently also degenerate in that the descending 
branches are not calcified, since these appear first in the Terebratelli- 
form development. The septum does not unite with the cardinalia ~ 
in B. minima, which supports the view that its brachidium is in 
a less advanced stage than that of B. rosea. 

Buckman states that many of the Antarctic Bouchardie examined 
by him were in such condition as to show the internal characters, 
but, unfortunately for the purposes of this discussion, he has given 
no further information than may be gleaned from an enlarged view 
of the interior of B. angusta. The characters of the cardinalia seem 
essentially similar to those of B. minima in the smaller of the two 
figures given, but little can be made of the nature of the loop if any 
exists. The case is still worse for B. sitteli, von Ihering, for von 
Ikering’s figure is far from satisfactory. The interiors of the other 
species ascribed to Bouchardia have not been described or figured. 

Von Ihering in 1907 argued from the then known distribution of 
Bouchardia only in the Salamancan and Patagonian of Patagonia and 

' Cf. P. Fischer & D. P. Oehlert, ‘‘ Mission scientifique du Cap Horn 
(1882-3): Brachiopodes’’: Bull. Soc. Hist. Nat. d’Autun, t. v, pp. 254-334, 


1892. J. A. Thomson, “ Additions to the knowledge of the Recent Brachiopoda 
of New Zealand’’s Trans. N.Z. Inst., vol. xlvii, pp. 404-9, 1915. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 268 


the Recent seas of Brazil that the genus originated in Patagonia. 
Since that date fossil representatives have been found in the West 
Antarctic and in New Zealand, but in younger beds than the 
Patagonian. Towards the end of the Miocene, then, the genus must 
have had a wide distribution in the Southern Ocean, which there is 
considerable reason to believe was much warmer than at present. 
Whether it attained this distribution by dispersion from Patagonia 
or not is hardly a matter for profitable discussion at present, since 
little or nothing is known of the Upper Cretaceous Brachiopods of 
New Zealand and the Antarctic. 


IV.—Nores on THE GENUS HOMALONOTUS. 
By F. R. COWPER REED, Sc.D., F.G.S. 


INCE Salter,’ in 1865, published his classification of the specics 
of the genus Homalonotus, no detailed attempt has been made to 
re-arrange the increased number of species now known into natural 
groups. Salter was not convinced that his scheme was satisfactory, 
and appears to have regarded it as largely artificial, though con- 
venient. The divisions instituted or recognized by him bore the 
names Brongniartia, Salter, 1865 (divided into two sections) ; 
Trimerus, Green, 1832; Kenigia, Salter, 1865; Dipleura, Green, 
1832; and Burmersteriva, Salter, 1865. 

Koch & Kayser,? in 1883, after describing the Lower Devonian 
species of the genus from the KRhenish area and other regions, 
criticized Salter’s system. The separation of Homalonotus and 
Trimerus was not considered sound, but Dipleura was acknowledged 
to mark a distinct group. The Lower Devonian species were 
grouped into two divisions, the first one containing two sub- 
divisions, Homalonotus (which was regarded as equivalent to 
Burmeisteria) and Trimerus; the second division was formed by 
Dipleura. Primary importance was attached to the position of the 
point of section of the lateral margin or genal angle by the facial 
sutures, and secondary importance to the degree of furrowing of 
the py vidium. In the first division the facial sutures cut the 
margin in front of the genal angle, the thoracic axis is broader 
than the pleural lobes, the pyg gidium is parabolic with a blunt or 
pointed extremity, and has its axis and pleural lobes deeply 
furrowed. The presence or absence of spines distinguished the two 
subdivisions of this group. In the second division the facial sutures 
cut the middle of the genal angles, the pleural lobes are as wide as 
the axis, and the pygidium is bluntly rounded and either smooth 
or only weakly furrowed. 

Bigot,’ in 1888, recognized three sections of the genus, for which 
he employed Salter’s group-names Brongniartia, Homalonotus sens. 
str. (= Kenigia), and Trimerus, but he revived Corda’s name 


1 Salter, Mon. Brit. Trilob., 1865, pp. 104, 105. 

2 Koch & Kayser, Abh. geol. specialk. Preuss., Bd. iv, Heft ii, 
pp. 73-157, 1883. 

3 Bigot, Bull. Soc. Géol. France, ser. 11, vol. xvi, pp. 419-35, 1888. 


264 Dr. F. R. Cowper Reed—The genus Homalonotus. 


Plesiacomia for a species H. brevicaudatus (Desl.), which he regarded 
as of independent generic rank. 

Hall,*in the same year, acknowledged only one genus Homalonotus, 
and in his list of references quoted as synonyms Dipleura, Trimerus, 
Plesiacomia, Brongniar tia, and Kenigia. 

Pompecki,? in 1898, put Calymenella, Bergeron, 1890, as a sub- 
genus of Homalonotus, but did not refer to other previously 
established subgeneric groups. 

Woodward,* in 19038, repeated Salter’s definition of the genus 
(with a few alterations) in connexion with his remarks on British 
Devonian species, and recognized Salter’s group, Burmeisteria, 
as valid. 

Giirich,* in 1908, allowed only one genus, Homalonotus, but took 
Brongniartia, Trimerus, and Kenigia as denoting subgenera of the 
Ordovician and Silurian periods. 

Moberg & Gronwall,®> in 1909, discussed Salter’s system of - 
classification of Homalonotus in connexion with their description 
of H. Knight. 

In 1909 Giirich ® introduced a new subgeneric name Digonus for 
a Devonian group of species, and he considered the subgenera 
Dipleura and Burmetsteria as worthy of retention. 

Woods,’ in the same year, regarded Homalonotus, Synhomalonotus 
(Pompecki, 1898), and Calymene as of equal rank and placed them in 
the family Calymenide, but did not mention any subgeneric divisions. 

Raymond,® in 1913, gave as three separate genera the groups 
Homatlonotus, Trimerus, and Dipleura; but Beecher, in the earlier © 
edition (1900) of the same textbook, mentioned only one genus, 
Homalonotus, with Trimerus as a pubpentis: 

A new Brazilian and Turkish subgenus of Lower Devonian age 
was established by Clarke,® in 1913, under the name Schizopyge, and 
the same author employed the name Homalonotus to include the 
type-species of Salter’s Burmeisteria. 


ae SUBGENERIC, OR GROUP-NAMES IN USE. 
. Homalonotus, Konig, 1825. 


The type of the genus Homalonotus chosen by Konig is H. Knighté 
Konig,” of the Upper Ludlow beds of England and Sweden. But 


the generic name has been used for many years in a comprehensive 


* Hall, Paleont. New York, vol. vii, p. xxiii, 1888. 
2 Pompecki, Neues Jahrb. f. Miner. Geol., Bd. i, pp. 235-43, 1898. 
* Woodward, Grou. MAG., Dec. IV, Vol. x, p. 28, 1903. 

* Giirich, Leitfossilien, Lief. i, Camb. Silur., p. 70, pl. xxvi, figs. 1-3, 1908. 

2 Moberg & Gronwall, Om Fyled. Gotlands, Lunds Univ. Arssk., N.F. 
Af. ii, Bd. vy, No. 1, pp. 72- 7, 1909. 

& Giirich, Leitfossilien, Lief. ii, Devon, pp. 155-7, 1909. 

7 Woods, Orustacea and Arachnids, vol. iv, Camb. Nat. Hist., section 
Trilobita, p- 249, 1909. 

: ® Raymond, in Kastman-Zittel’s Textbook of Paleontology, vol. i, p. 724, 
19138. 

® Clarke, Foss. Dev. Parana (Mon. Serv. Geol. Miner. Brasil, vol. i), 
pp. 89-101, 1913. 

10 Konig, Icones Sectiles, 1825, pl. vii, fig. 85. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 265 


manner, including many species which differ widely from the type. 
For this reason Salter,’ in 1865, was led to suggest a new name, 
Kenigia, for the section characterized by H. Knighti, and its 
characters are discussed below under that heading. Other authors 
have not been so precise, and Hall’s? definition of Homalonotus strove 
to be wide enough to embrace the various divergent sections or 
groups, and has, therefore, a more extended application: ‘‘ Body 
usually large, produced, depressed above, with abruptly sloping sides. 
Axial furrows indistinct or obsolete. Surface smooth or spinose. 
Cephalon depressed-convex, wider than long; genal angles rounded ; 
anterior margin somewhat produced; glabella subrectangular, smooth, 
or with faint lateral furrows; eyes small, situated somewhat back 
of the middle of the shield; the facial sutures run from the genal 
angles over the eyes, converging towards the frontal margin, where 
they are connected by the transverse frontal suture, thence they 
continue to the edge of the doublure where they meet, thus inclosing 
a small, free, subtriangular plate. Thorax composed of thirteen 
deeply suleate segments. Pygidium smaller than the cephalon, 
elongate triangular, posteriorly rounded or slightly produced. The 
axis bears usually from ten to fourteen annulations. Pleurz smooth 
or with posteriorly sloping ribs.” This definition, however, is not 
entirely satisfactory, for it is not applicable to the early Ordovician 
species, in which the axial furrows are distinct, and the number of 
segments in the pygidium fewer than stated. Hall also seems to 
regard the commissure uniting the facial sutures in front as not 
a part of them but as a new and separate structure, and he fails to 
remark that the epistomal sutures are distinct. His ‘‘subtriangular 
plate”? is the epistome or rostral shield. It should, moreover, be 
added that the thoracic pleure always have rounded ends, and that 
the pygidium exhibits two main and separate types, one semicircular 
or semi-elliptical and simply rounded, the other triangular and 
acuminate behind. 

The point of section of the margin by the posterior branch of the 
facial suture is also of some importance; Hall shows it in his 
diagrammatic woodcut as bisecting the rounded genal angle; but this 
is not always the case, as Koch (op. cit.) noticed and used as a basis 
of classification. 

Salter’s* earlier definition in 1865 makes no reference to the 
pygidial characters nor to the facial sutures, but it says that the 
genus is distinguished from Calymene, ‘‘its near ally,” by its want of 
distinct trilobation, and goes on to state that ‘‘ Homalonotus is elongate, 
convex, with steep sides and a very broad axis, scarcely distinguished 
from the pleure. There are thirteen body-rings deeply grooved, and 
the fulerum is close to the axis in most of the species. The head 
with an obscure quadrate glabella, slightly lobed; a rostral shield; 
and a quadrate labrum (= hypostome) tuberculate and gibbous in 
the middle and with a bilobed tip. Surface of the body scabrous, 


1 Salter, Mon. Brit. Trilob., p. 106. 
2 Hall, Palesont. New York, vol. vii, p. xxiv, 1888. 
3 Salter, Mon. Brit. Trilob., p. 104. 


266 Dr. F. R. Cowper Reed—The genus Homalonotus. 


occasionally spinous. Internally the cheeks have at their base 
a broad flat space next the glabella”’. 

Raymond (op. cit., 1918, p. 724) defines Homalonotus as follows: 
*“ Axial lobe wide, cephalon short and trilobate in front, cheeks 
forming high mounds crowned by the eyes.” Apparently he had in 
his mind H. Knight, and at any rate this definition would not include 
any of the Ordovician species, and none of them can be put in 
Trimerus or Dipleura, which are the only other Homalonotid genera 
which he quotes. 

Woodward,' in 1903, practically repeated Salter’s definition in 
slightly different phraseology, saying: ‘‘ The peculiar trilobation of 
the body-rings, so conspicuous in most genera, is very indistinct 
in Homalonotus, especially in the thoracic segments, although in 
some species it is better marked in the pygidium. The shape of the 
body is elongate, convex, with steep sides and a very broad axis, 
scarcely distinguished from the pleure. There are thirteen body- 
rings, deeply grooved, and the fulcrum is close to the axis in most of 
the species. ‘he head is triangular, with an obscure quadrate 
glabella slightly lobed and a quadrate labrum; the surface of the 
body is scabrous, occasionally spinous. The pygidium is generally 
narrow and pointed, except in a few species which have a more 
rounded contour.” He goes on to say that ‘‘of the twenty species 
recorded, by far the larger number are from the Silurian”. It will 
be shown in this paper that the climax of the development of the 
genus is in the Devonian period, where the number of species and 
the diversity of types are greatest. 


2. Trimerus, Green, 1832. 


The type of this section or subgenus is the well-known ZZ. delphino- 
cephalus, Green,* first described from the Niagara Limestone of New 
York and subsequently recognized in the Wenlock Limestone of 
Dudley (according to Salter? it is the Woolhope Limestone). Salter 
(op. cit.) defined this section as follows: ‘‘ Elongate, convex, with 
triangular head; eyes not remote; a defined but obscurely lobed 
broad glabella. Thorax slightly lobed; tail many ribbed, pointed, 
often acuminate.” Raymond (op. cit., p. 724) merely states that the 
‘“‘cephalon is longer than in the preceding [i.e. Homalonotus |, not 
trilobate in front, free eheeks narrow’’. There seems to be some 
difference in the British and American specimens as regards the 
glabella, for Hall‘ does not mention or figure any glabellar lobes or 
furrows in his description of the Niagaran types, while in most of the 
Dudley specimens two pairs of more or less faint subcircular lateral 
swellings, not touching the axial furrows, are present on the 
posterior half of the glabella and seem to represent the two posterior 
pairs of lateral lobes, and there is also a weak trace of the first. 
lateral furrows. 

The peculiar subcircular areas on each side of the base of the 


Woodward, GEOL. MAG., Dec. IV, Vol. X, p. 28, 1903. 

Green, Monthly Amer. Journ. Geol., vol. i, p. 559, pl. O, fig. 1, 1832. 
Salter, op. cit., p. 115. 

Hall, Paleont. N.Y., vol. ii, p. 309, pl. Ixviii, figs. 1-14. 


1 
2 
3 
4 


Dr. F. R. Cowper Reed—The genus Homalonotus. 267 


glabella, such as Salter! specially noticed in the South African species 
H. Herscheli, are also present in HH. delphinocephalus; these areas may 
be marked off by a faint curved furrow or have a slight independent 
convexity, but are also distinguished from the rest of the cheeks by 
their smoothness and absence of pitting. They may be termed the 
paraglabellar areas (for further remarks see Aenigia and Burmeisteria). 

The epistomal sutures are very short on the upper surface of the 
head-shield and usually difficult to distinguish, but they are at right 
angles to the conjoint facial sutures and arise in front at a distance 
apart rather less than the anterior width of the glabella. 

The course of the facial sutures themselves on the head-shield is 
usually well seen; Hall (op. cit.) describes them as “ parallel and 
coincident with or slightly within the flexure of the margin, passing 
then obliquely through the eyes and turning [to] come to the margin 
a little above the posterior angle of the head-shield’’. They meet in 
front on the upper surface at an angle forming a more or less pointed 
Gothic arch close to the anterior margin and leaving a wide area 
before the glabella. 

In one specimen in the Sedgwick Museum (Tablet No. 114) from 
the Wenlock Shale of Dudley, the inferior surface of the front part of 
the head-shield is shown; the doublure, which is broad, flattened 
and subcrescentic in shape with the posterior margin forming a 
double sigmoidal curve, reaches back to the front end of the glabella; 
the epistomal sutures are straight and converge posteriorly, thus 
defining a flat elongated triangular epistome which does not appear 
to have been described or figured in the case of British examples of 
the species. 

In the case of the thorax of the type-species it should be mentioned 
that each segment of the axis has an anterior articulating band 
which is separated off by afurrow which bends back gradually before 
reaching the axial furrows and crosses the pleura obliquely. The 
axial furrows of the thorax are not in the same longitudinal line as 
those defining the glabella, for the axial furrows of the head-shield 
on crossing the occipital ring diverge obliquely outwards. There 
are, however, no well-defined axial furrows at all on the thorax, 
faint longitudinal depressions only being present in conjunction with 
a slight constriction of the pleura. At this point also, on each 
segment, there is situated the inner angle of the large triangular 
articulating facet extending to the end of the pleura and forming 
a bevelled flattened surface with a sharp, angulated posterior edge 
which crosses the pleural furrow obliquely without diverting its 
course. Barrande’s* figure of a body-ring of HH. delphinocephalus 
gives an erroneous idea of its characters, for it fails to show that the 
furrow which marks off the articulating band on the anterior of the 
axial ring, is continued across the pleuraand articulating facet as 
the pleural furrow. Hall (op. cit.) describes it more clearly than 
Salter, who does not make it plain that this furrow is continuous. 

Of other species referable to this section Salter mentions two, 
H. Johannis, Salt., and H. cylindricus, Salt., both from the Silurian. 

1 Salter, Trans. Geol. Soc., ser. I, vol. vii, p. 216, pl. xxiv, fig. 1c, 1856. 

° Barrande, Syst. Silur. Bohéme, vol. i, pl. v, fig. 10. 


268 Dr. F. R. Cowper Reed—The genus Homalonotus. 


The former, however, should be placed in the section Kenigia 
according to the structure of the front margin of the head-shield, 
which Salter failed to observe from want of well-preserved specimens. 
But H. eylindricus is undoubtedly a member of Zrimerus so far as its 
pygidium is concerned, and it was on this part that the species was 
based. Salter’s' outline-sketch of a middle-shield (of which the 
specimen cannot be traced), which he thought might belong to this 
species, shows the facial sutures uniting in front in a much flattened 
curve, but there is nothing in other respects to prevent its reference 
to the same section as H. delphinocephalus. 


3. Dipleura, Green, 1832. 


This section or subgenus was founded on the well-known American 
species H. Dekayi, Green,? from the Hamilton Group (Middle 
Devonian). 

Salter (op. cit., p. 105) defines the section as follows: ‘‘ Convex, 
head wide, semi-oval or subtriangular, with somewhat pointed front. 
Glabella narrow, well defined. Eyes rather remote, on gibbous 
cheeks. ‘Thorax slightly lobed. ‘Tail obtuse, hardly ribbed.”’ No 
British representatives are recorded, but Salter refers to it the 
Continental species H. obtusus, Sandb., and probably Z. crassicauda, — 
Sandb., and H. Ahrendi, Roem. 

Raymond (op. cit.) briefly defines Diplewra as follows: ‘‘ Axial 
lobe wide, pygidium smooth.” 

Hall* has given a full description of the species, and we may 
quote his description of the course of the facial sutures: ‘‘ The facial 
sutures take their origin on the lateral margins of the doublure in 
front of the genal angles and pass inward, parallel to the posterior 
margin of the cephalon, to the eye, thence forward with a broad 
curve inward to the anterior margin at the base of the prora, bending 
thence on to the epistomal doublure, meeting at its inferior margin. 
The branches of the facial suture are united on the upper surface of 
the prora by a straight transverse frontal suture, thus leaving a free 
median plate upon the epistoma, which is elongate-subtriangular in 
outline, attenuate at the apex, and recurved at the base, which 
forms the anterior portion of the prora.” The connecting ‘frontal 
suture”? here described, judging from the manner in which the 
facial sutures bend inwards and are connected in front of the 
glabella in H. noticus, Clarke, and other species, must be regarded as 
merely the anterior deflected part of the facial sutures, while the 
so-called continuations of the facial sutures over the anterior edge 
which bound the epistomal plate laterally on the inferior surface of 
the head-shield must correspond with the epistomal sutures of other 
species. 

Here, as in //. ornatus, H. rhenanus, and other Devonian species, 
the flattening of the anterior curve of the anterior conjoint portion 
of the facial sutures gives a spurious appearance of an abnormal 


’ Salter, op. cit., p. 117, fig. 28. 

2 Green, Mon. Trilob. N. Amer., 1832, p. 79, pl. i, figs. 8, 9. 

3 Hall, Paleont. New York, vol. vii, p. 7, pl. ii, figs. 1-11; pl. iii, figs. 1-5; 
pl. iv, figs. 1-6; pl. v, figs. 1-10, 1888. 


Dr, F. R. Cowper Reed—The genus Homalonotus. 269 


transverse and nearly straight special suture on the upper surface of 
the head-shield. It is not clear if Hall regarded this ‘‘ frontal 
suture” as a new independent commissure originating by itself, but 
he apparently believed the facial sutures did not meet on the upper 
surface of the head-shield, but that they were directly continued by 
the epistomal sutures extending on to the inferior surface. 

With regard to the existence of any distinctive features of this 
section, the structure of the epistomal doublure resembles 7. delphino- 
cephalus, and the thorax seems almost identical; but, as Hall (op. cit., 
p- 10) remarks, Dipleura differs from the Homalonoti of the earlier 
Devonian and Silurian of America and Europe in the obsolescence 
of the annulations of the pygidium at maturity. The hypostome is 
subquadrate, with the posterior margin broadly excavated, and is 
much like that of Zr. delphinocephalus. The glabella has three pairs 
of lateral furrows, which become obsolete at an early stage of growth. 
As regards the structure of the head-shield and the flattened anterior 
junction of the facial sutures, we may compare H. rhenanus, Koch,' 
and H. ornatus, Koch,? but as regards the obsolescence of the pygidial 
axis we see an approach to H. levicauda, Quenst.,* though the head- 
shield and outline of the pygidium are distinct in that species. 

Kayser, in a footnote to Koch’s paper (op. cit., p. 10), rightly 
points out that the Rhenish Devonian species H. crassicauda, Sandb., 
and H. Ahrendi, Roem., mentioned by Salter under Dipleura, do not 
strictly belong to this group on account of their strongly ribbed 
and acuminate pygidia, but that A. Schustert, Roem.,* may be 
referred to it. 


4, Brongniartia, Salter, 1865. 


The definition of Brongniartia given by Salter® is as follows: 
‘‘ Depressed, with broad rounded head, remote eyes, well-defined 
lobeless urceolate glabella, and many-ribbed rounded tail.” 

Two divisions were established by Salter with the following brief 
summary of characters: ‘‘(1) Body scarcely trilobed; the axis 
broad (ZH. bisulcatus is the type of the subgenus and of this section) ; 
(2) body strongly trilobed; the axis narrow (type, H. rudis; this 
leads off directly towards Calymene).” 

Before discussing the characters and value of this subgenus proposed 
by Salter we must remark that it is unfortunate that he chose the 
preoccupied name Brongniartia. For J.each in 1824 used it for a genus 
of Coleoptera, and Katon* in March, 1832, proposed it for a new genus 
of Trilobites, of which his Brongniartia carcinodea’ was chosen as 
the type. The latter species, however, is now considered as identical 
with Green’s Zriarthrus becki. Katon in June of the same year 


Koch, op. cit., p. 32, pl. iii, figs. 1-3. 

Ibid., p. 23, pl. ii, figs. 1, 2. 

Koch, op. cit., p. 55, pl. viii, fig. 4. 

Roemer, Beitr. z. Kennt. Nordwest Harz., iii, t. iii, fig. 20, 1855. 
Salter, op. cit., p. 104. 

Eaton, Amer. Journ. Sci., ser. I, vol. xxii, p. 165, 1832. 

Eaton, Geol. Text-book, 2nd ed., June, 1832, p. 33, pl. i, fig. 3. 


NJ aoe Wwnm 


270 Dr. F. R. Cowper Reed—The genus Homalonotus. 


figured as further examples of the genus the Trilobites B. platy- 
cephala’ (= H. Dekayi, Green) and B. ‘sotelea? (= Asaphus 
platycephalus, Stokes). Vogdes* puts B. platycephala, Eaton, as 
a synonym of H. delphinocephalus, Green. It is obvious from these 
facts that the name Brongniartia cannot be retained for Salter’s 
group of Homalonotus. 

The type of the group must now be considered. This species, 
Hf, bisuleatus, was founded by Salter * on specimens in the Geological 
Society’s Collection and in the Woodwardian [Sedgwick] Museum, 
Cambridge. The first figured specimen, a middle-shield (op. cit., 
fig. 24), is stated in the text of McCoy’s Synopsis to be from the 
‘‘Caradoe Sandstone, Wittingslow, near Acton Scott, Shropshire’’, 
but in the explanation of the plate is stated (in error) to be from 
‘‘S.W. of Pwllheli”. The imperfect thorax and pygidium depicted 
in his fig. 26 and the separate pygidium (fig. 27) are from the same 
locality in Shropshire, and all these three specimens are in the 
Geological Society’s Collection, now in the British Museum (Natural 
History), South Kensington. The specimens from which figs. 25 and 
28 were drawn are in the Sedgwick Museum, and came from the 
Welsh locality south-west of Pwllheli. Three other specimens 
(figs. 29-31) are referred by Salter to a variety B minor, and are 
also at Cambridge. But the chief point to be emphasized is that 
the species is undoubtedly founded on the Shropshire specimens, and 
it is by them that its characters are fixed. © 

Salter ® in his monograph in 1865 figured several examples from 
other Welsh localities, but stretched the limits of the species in 
including some of them; the first figures on his plate (pl. x, 
figs. 3, 4) are of those specimens from Wittingslow which he had 
used in his previous description in 1852 and had there figured. 

In his first subsection of Brongniartia Salter put also his species 
Hf, Sedgwicki and H. Edgelli ; the former was founded on two broken 
middle-shields in the Woodwardian Museum and calls for no special 
mention in this place, except with regard to the much flattened and 
wide curvature of the union of the facial sutures, which makes the 
head-shield (as Salter says) truncate in front and unusually broad. 
The second species was founded on a pygidium, but a doubtful 
middle-shield from Horderly was also ascribed to it. 

We must, however, return to a consideration of the characters of 
the typical H. bisulcatus, for Salter’s first description in 1852 is too 
brief, and his second description in 1865 is inaccurate, for it includes 
the ambiguous Welsh specimens, some of which at any rate ought 
probably to be separated off. Confusion is introduced by Salter’s 
conflicting statements that the ‘‘ body is scarcely trilobed ”’ (p. 104) 


1 Eaton, op. cit., pl. ii, fig. 20. 

2 Tbid., pl. ii, fig. 22. 

° Vogdes, Bibliogr. Paleoz. Crust. (Occas. Papers Calif. Acad. Sci., iv, 
p. 311, 1898); Weller, Bull. iv, pt. ii, Nat. Hist. Surv., Chicago Acad. Sci., 
1907, p. 200. 

4 Salter, Appendix to M‘Coy’s Syn. Brit. Paleoz. Foss. Woodw. Mus., 1852, 
p. v, pl. iG, figs. 24-8. 

> Id., Mon. Brit. Trilob., 1865, p. 105, pl. x, figs. 3-10. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 271 


and that the ‘‘trilobation is conspicuous but not deep” (p. 105). 
The latter statement is made for the type species and is incorrect, 
the axial furrows being very shallow and the pleural portions of the 
thorax scarcely marked off from the axis in the general convexity of 
the body. Inthe pygidium, however, the axis is well defined, has an 
independent convexity and well-marked though not deeply impressed 
axial furrows. In the thorax the axial furrows form continuous 
depressions, but each axial ring is independently marked off from its 
pleura by a short oblique transverse furrow corresponding to the one 
crossing the neck ring from the base of the glabella, which Salter 
mentions and shows in his figure (woodcut 24 on p. 106). The base 
of each pleura is somewhat swollen in the angle between this 
transverse furrow and the pleural furrow which is a lateral continua- 
tion of the furrow separating off the articulating band on the axial 
ring. There is a peg-like interior projection situated on the posterior 
margin of the thoracic ring just inside the posterior end of the short 
transverse furrow, and this peg or knob fits into a small corresponding 
notch on the anterior margin of the succeeding ring. Salter shows 
this structure (op. cit., pl. x, fig. 16) in his figure of a segment of 
HH. Brongniarti, Des]., but does not describe it in connexion with 
H. bisulcatus. 

In the case of the pygidium the shape is semi-oval or parabolic in 
all the typical Shropshire specimens; the so-called ‘‘ young one” 
from North Wales, figured by Salter (op. cit., pl. x, fig. 8), is certainly 
different. Salter’s description of the typical form, however, is correct, 
and it is important to notice that the axis is composed of 11-12 rings 
and is continued to the margin by a ‘‘ conical appendage” or post- 
axial angulated triangular piece. There is also a distinct (though 
very narrow) flattened or gently concave border, not sharply defined 
from the rest of the pleural lobes, but the pleure do not cross it. 
The first sulcus crossing the lateral lobes is a direct continuation of 
the one on the axis which separates off the articulating band at its 
front end; we may therefore suspect that the second similar strong 
one is of the same nature, and therefore not a true interpleural furrow 
but homologous with the pleural furrows of the thorax. This opens 
up a curious question as to the nature of the so-called pleurs on the 
pygidium. It was from the presence of these two strong furrows 
that Salter termed the species bisulcatus. 

The original Welsh specimens from the Bala beds south-west of 
Pwllheli which Salter referred to Hf. dbisuleatus and figured as such in 
1852' are undoubtedly distinct from the Shropshire types; the 
middle-shield (fig. 25), by its breadth, shortness, and flattened anterior 
edge, suggests a reference to 7. Sedgwick, and ‘perhaps the pygidium 
(fig. 28), may belong to the same species. But both specimens are 
poor, crushed, and distorted. 

The other Welsh specimen figured as H. bisulcatus in his mono- 
graph in 1865 (pl. x, fig. 6) is likewise much distorted; it is from 
Moel y Garnedd, Bala, and together with some similar fragments in 
the Jermyn Street Museum (;5;, 3%, 3%-) from the same locality may 
belong to a new species. 

1 Salter, op. cit., pl. iG, figs. 25, 28. 


272 Dr. F. R. Cowper Reed—The genus Homalonotus. 


The so-called ‘‘ young specimens’’ from Wales which Salter figured 
in 1865 (pl. x, figs. 7, 8) must certainly be separated from the 
typical H. bisulcatus and are the same as Salter figured in 1852! as 
his var. 8 minor from Maes Meillion. The poor specimen in the 
Sedgwick Museum from the Arenig beds of Ty Obry, figured? as 
H. bisulcatus with a query, is of very doubtful specific and even 
generic reference. 

In the head-shield of the typical Shropshire examples of H. bzsui- 
catus the facial sutures unite very close to the margin, or actually 
along its edge in a broad flattened curve leaving a wide pre-glabellar 
area at least one-third the length of the glabella. There is therefore 
no distinct, much less large, pre-sutural area, the free-cheeks and the 
front end of the epistome apparently forming only a very narrow 
band on the edge of the head-shield in front. Bailey* shows this 
band in a figure of a specimen from the Bala beds of the Onny River. 
But the inferior doublure, the epistome and epistomal sutures have 
not been observed or described in any specimen, and in the majority 
of specimens of the head only the middle-shield is preserved. ‘The 
elabella, which is urceolate, does not show any lobation, and ‘para- 
glabellar areas”? are absent or practically obsolete, but I have seen 
faint indications of them in a head-shield (No. 5) from Marshbrook 
in the Ludlow Museum. 

A species referable to the same group as ZH. bisulcatus is 
H. ascriptus, Reed,* from the Dufton Shales of Melmerby, but it is 
only founded on head-shields somewhat resembling Salter’s var. 
B minor of H. bisuleatus to which reference has above been made. 

The middle-shield doubtfully referred by Salter to H. Hdgelli 
(Salter, op. cit., pl. x, fig. 10, p. 108) and obtained from the Bala 
beds of Horderly, must also be placed here. 

—A new species allied to H. Sedgwicki, from the Bala beds of the 
Vyrnwy Dam, near Rhayader, has been recognized in the Sedgwick 
Museum, and the description of it under the name H. Tawney? is now 
awaiting publication. 

The second section of Brongnartia has as its type H. rudis, Salter,” 
which was founded on two extremely imperfect and distorted casts of 
pygidia from Capel Garmon, Denbighshire, in the Sedgwick Museum. 
The Welsh specimens in the Jermyn Street Museum, which Salter 
mentions (op. cit.) as belonging to this species and some of which he 
subsequently figured in his monograph in 1866 (op. cit., pl. x, fig. 12, 
Nantyr, Llanarmon ;%;; pl. x, figs. 14a, 6, Cader Dinmael 3%), are 
likewise very poor; the second figured one is, however, better than 
the original types. The strongly and well-defined axis to the thorax, 
and the shorter pygidium with fewer axial rings and fewer pleural 
ribs are features separating it from the species H. bisulcatus. But 


1 Tbid., pl. i, figs. 29, 30. 

2 Salter, Mem. Geol. Surv., vol. iii (2nd ed., 1881), p. 526, pl. 11a, fig. 8. 

> Bailey, Fig. Char. Brit. Foss., i, pl. xiii, fig. 9a, 1875. 

+ Reed, Gkou. MAG., Dec. V, Vol. VII, p. 216, Pl. XVII, Figs. 4-8, 1910. 

° Appendix to M‘Coy’s Syn. Pal. Foss. Woodw. Mus., p. y, pl. if, 
figs. 20, 20a. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 278 


H. rudis is an unsatisfactory species owing to the impossibility of 
drawing up a proper diagnosis from the original material. 

The pygidium (No. =; Mus. Pract. Geol.) figured by Salter in 1865 
(op. cit., pl. x, fig. 14) from the ‘‘Caradoc Grits of Cressage, 
Shropshire”’, as probably referable to H. rudis, must certainly be 
separated, and may belong to the new species H. diserratus Reed MS. 
(the description of which awaits publication), but its edges are broken 
and imperfect. 

The other British species referred by Salter to the second section 
of Brongniartia are the two from Budleigh Salterton pebbles 
described as H. Brongniarti, Deslong.,’ and H. Vicaryi, Salter.’ 
A third? unnamed species is described by Salter from the same 
locality, and a fourth from Gorranhaven,* both the latter being 
represented only by pygidia. According to Bigot,> Salter’s 
H. Brongniarti, Desl., is not the same as Deslongchamps’ type, 
but is referable to H/. serratus, de Trom. The figures and description 
of H. vulcani (Murchison), promised by Salter (op. cit., p. 113) have 
never been published ; it is stated® ‘‘to occur in the voleanic grit on 
the west flank of Corndon Mountain in a ravine east of Middleton ” 
but I have not been able to trace the specimen. 

The species of Homalonotus from the Grés de May, Normandy, 
including those from the British pebbles in the Budleigh Salterton 
Triassic conglomerate, and also those from Gorranhaven, belong to 
a group somewhat distinct from the typical Brongniartia, though 
(as stated above) Salter put them in his second section. They seem 
to be the earliest representatives of the genus, apart from any of the 
questionable genus Wesewretus. The characteristics of the group are 
the strong trilobation of the thorax and pygidium, and the short 
transverse or semicircular shape of the pygidium, together with its 
composition of few segments, and its vertical or steeply inclined but 
not completely infolded doublure. It may also be mentioned that 
the pleure on the pygidium are occasionally separated by furrows 
right up to the edge of the doublure, and sometimes show traces 
of division at their ends, and that the furrow which marks off the 
articulating band at the front end of the axis is continued laterally 
as a strong furrow across the large bevelled articulating facet at the 
anterior lateral angles of the pleural lobes. In the case of the head- 
shield it appears that the facial sutures cut the lateral margins 
slightly in front of the genal angles, which are well rounded; the 
glabella is parabolic, semioval, or rounded-trapezoidal, and the axial 
furrows are not sinuated as in //. bisulcatus. The facial sutures 
unite in front marginally or just inside the margin in a regular 
uninterrupted curve, which may or may not be flattened. Most, if 


1 Salter, Quart. Journ. Geol. Soc., vol. xx, p. 290, pl. xv, figs. la, b, 1864 ; 
Mon. Brit. Trilob., p. 110, pl. x, figs. 15-17 ; pl. xiii, fig. 9. 

eet bide pa klale pl. xiii, fig. 10. 

3 Tbid., p. 112, pl. x, fig. ‘18. 

4 Ibid., p- 112, woodcut, fig. 26. 

> Bigot, Bull. Soc. Géol. France, ser. 111, vol. xvi, p. 427, 1888. 

5 Murchison, Silur. Syst., 1839, p. 663; id., Siluria, 2nd ed., 1859, pl. ii, 
figs. 3, 4. 


DECADE VI.—VOL. V.—NO. VI. 18 


274 Dr. F. R. Cowper Reed—The genus Homalonotus. 


not all, of the species seem toshow no glabellar lobes, though Salter ! 
describes furrows and lobes in his H. Brongniartz, Des. 

In H. Deslongchampsi, de Trom., Moriére? describes the thoracic 

pleure as having a little angular projection at the point where they 

begin to bend back, which fits into a notch in the preceding pleure, 

but it is not clear from Bigot’s descriptions and figures (op. cit.) 

if this structure is present in other species. 

The Gorranhayven specimens,* which are most probably referable to 
this group, are too poor for precise determination. 

Barrande* in his supplement figures and describes a perfect. 
individual of the Ordovician species H. bohemicus, Barr.,’ from Stage 
Dd 2, which Salter referred to the second subdivision of Brongniartia, 
and this specimen is particularly interesting because it shows the 
epistomal sutures starting at right angles from the points at which 
the facial sutures bend inwards near the anterior margin and crossing ~ 
the pre-sutural band to pass to the inferior surface of the doublure. 
We may, with much probability, assume that the closely allied other 
species of this group have the structure of the front of the head- 
shield and the behaviour of the sutures on a very similar plan. 

A considerable number of species seem to belong to this group, 
and all those marked* come from the Grés de May or its undoubted 
equivalents :— : 

*H. serratus, de Trom. 2H. Viellardi, De Trom. 


*H. Bonnisenti, Moriére. ?H. draboviensis, Novak” (Bohemia). 

*H. incertus, Bigot. ?H. bohemicus, Barr. (Bohemia). 

*H. Brongniarti, Desl. HA. Brongniarti, De Vern. non Desl.® 

*H. Vicaryt, Salt. (from Sierra Morena). 

*H. Deslongchampsi, de Trom. H. buserratus, Reed, sp. nov., 

*H. Morierei, Bigot. Shropshire. 

*#H. besnevillensis, Bigot. H. {| Neseuretus| quadratus (Hicks), 
HT. Barroisi, Lebesc.® Ramsey Is. 


5. Kenigia, Salter, 1865. 


The type of Salter's section Kenigia is H. Knighti, Konig, of the 
Upper Ludlow Beds of England and Sweden, which Konig chose as 
the type of his genus Homalonotus. The latter name is now generally 
employed in a more comprehensive manner, the characters of 
HH. Knighti being extremely uncommon and scarcely representative 
of the whole assemblage of species. The name Kenigia therefore 
seems desirably applicable in this restricted sense to the group of forms 
resembling H. Anighti. Salter included his H. ludensis in Kenigia, 


1 Salter, Quart. Journ. Geol. Soc., vol. xx, p. 290, pl. xv, fig. 1, 1864. 

2 Moriére, Bull. Soc. Linn. Normandie, ser. III, vol. viii, p. 383, pls. i, 11, 
1884. 

* Collins, Trans. Roy. Geol. Soc. Cornwall, ee p. 53 (reprint). 

* Barrande, Syst. Silur. Bohéme, Suppl. 1, p. 37, pl. i, fig. 6. 

° Barrande, Syst. Silur. Bohéme, vol. i, p. 380, pl. xxxiv, figs. 40-2. 

S menescontal Bull. Soc. Géol. France, ‘ser. III, vol. xiv, p. 801, pl. xxxvi, 
figs. 12, 13, 1857. 

i Novak, Bohm. Trilob., i (Beitr. Paleont. Oest. Ung., Bd. iii, 1881), p. 27, 
t. vill, figs. 9a-c. 

8 De Verneuil, Bull. Soc. Géol. France, ser. Tit, vol. xii, p. 971, pl. xxiii, 
fig. la, 1855. 

° Konig, Icones Sectiles, 1825, pl. vii, fig. 85. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 275 


but this reference seems unwarranted, the head-shield so far as we 
know it not possessing any of the typical characters. The definition 
of Kenigia given by Salter’ was as follows: ‘‘ Convex; head wide, 
transverse, with concave and tricuspidate front, glabella subquadrate, 
well-defined; eyes rather approximate, on gibbous -cheeks; tail 
pointed, many ribbed.’ Salter? described the species H. Knighti 
at some length, but he did not give a clear description or figure 
of the peculiarly characteristic structure of the anterior part of 
the head-shield, which is well seen in some British specimens. 
Moberg & Gronwall*® published some better illustrations of this 
trilobite, and showed distinctly the peculiarities of the anterior 
margin and the course of the facial sutures. It is seen that the 
remarkable tricuspid front is due to the median projection of the 
anterior end of the epistome (= rostral shield) which is bounded on 
each side on the inferior surface by the epistomal sutures. The 
triangular lateral projections are formed by the anterior ends of the 
free-cheeks being angulated forwards, and also bent up and down in 
a zigzag manner. ‘The marginal doublure thus has an unusual 
angulated appearance in a frontal as well as in a superior view. The 
facial sutures unite by a transverse commissure before a very narrow 
pre-glabellar area, and this transverse suture (which must be regarded 
as the direct continuation of the true facial sutures bent rather 
suddenly inwards) consists of two gently sigmoidal halves meeting in 
the middle at an angle so as to form a small median point. The 
sudden change in the direction of the facial sutures may be due to the 
more rapid forward growth of the lateral portions of the head-shield 
as compared with the median portion, and may be directly connected 
with the anterior projection of the front ends of the free cheeks on 
the margin. 

A similar tricuspid front and projecting epistome is found to exist 
in the species H. Johannis, Salter,* as an examination of the types 
and other specimens from the original locality in the Jermyn Street 
Museum proves; Salter did not show this tricuspidation in his figures, 
the anterior end of the epistome of his specimens being imperfect, 
and the lateral projections of the anterior margin of the head-shield 
being blunter and less prominent than in H. Knightt. But he 
figured the inferior doublure and epistomal sutures clearly in his 
figures 2 and 7. 

A character of some importance which is present in H. Knighti 
and less distinctly in WZ. Johannis, is the more or less circumscribed 
subquadrate or rounded area on each side of the base of the glabella. 
These areas are differently ornamented to the rest of the head-shield, 
and resemble in position and shape the “‘alar’’ areas of Harpes. 
But to avoid prejudging their homology they are here termed the 
paraglabellar areas. We shall have occasion to remark on their 
presence in other subgenera. 


1 Salter, Mon. Brit. Trilob., p. 106. 

2 Tbid., p. 119, pl. xii, figs. 2-10, pl. xiii, fig. 8. 

3 Moberg & Grénwall, Om Fyled. Gotl., Lunds Univ. Arssk., N.F., Af. ii, 
Bd. v, No. 1, pp. 72-7, pl. v, figs. 1-4, 1909. 

* Salter, op. cit., p. 117, pl. xiii, figs. 1-7. 


276 R. M. Deeley—Mountain Building. 


The trilobation of the thorax is nearly lost in H. Anightc (which 
is paralleled by H. planus, Sandb., otherwise quite distinct), and the 
axis of the pygidium is scarcely marked off from the lateral lobes, 
the axial furrows in both cases being almost obsolete. The elongated 
triangular shape of the pygidium, its numerous annulations, and its 
produced and pointed extremity are features which are common also 
to Trimerus, Digonus, and Burmeisteria, sens. str., as noticed below. 

H. Johannis differs from H. Hnighti in possessing a broad pre- 
glabellar area, which results in the head-shield haying a triangular 
appearance instead of being transverse and so much shortened as to 
be broader than long. In consequence of the length of the head 
being not thus abnormally reduced, the convergent facial sutures 
approach each other in front more closely before bending abruptly 
inwards to form the transverse commissure. We shall observe a 
similar modification in members of Digonus and Burmeisterva.. 

The hypostome of H. Anightc has been figured by Lindstrom,’ and 
is of the same type as that of H. (Zrimerus) delphinocephalus. 


(To be continued.) 


YV.—Moounrain Boripine. 
By R. M. DEELEY, M.Inst.C.H., F.G.S. 


N an article by Dr. H. Jeffreys in the Gronoercan Maeazine for 
April, pp. 215-19, an attempt is made to show that the discovery 
of radio-active materials in the earth’s crust favours the ‘‘ contraction 
and puckering” theory of mountain building. With regard to 
O. Fisher’s view he writes, ‘‘It rests entirely on Kelvin’s theory of 
the cooling of the earth, which has had to be completely revised on 
account of the discovery of the extensive distribution of radio-active 
matter in the earth’s crust. The time available has been found to 
be about twenty times greater than on Kelvin’s theory, and the 
cooling has therefore had time to extend to a much greater depth 
and to produce a very much greater compression.” We are also 
told what the reduction in the earth’s diameter has probably been, 
and the actual depth of Fisher’s level of no strain. 

Reference is also made to the three very valuable and interesting 
papers by Arthur Holmes published in the Geonoeican Macazine. 
But Holmes is by no means as dogmatic as Dr. Jeffreys. Holmes 
writes: ‘‘If each grain of the earth’s substance were as rich in radio- 
elements as are the rocks which have been examined, the earth’s 
total output of heat from this source alone would, in any given 
period, be about 300 times as great as the amount actually lost by 
conduction to the surface and radiation into space.” 

‘This astonishing result pulls us up sharply, for it is manifestly 
absurd to believe that our planet is becoming hotter at the appalling 
rate implied in these figures, or, indeed, that it is becoming hotter at 
all.’ To get over the difficulty it is suggested that the radio-active 
elements only exist in the outer portion of the crust of the earth, and 
in quantities insufficient to cause the earth to become hotter, and 

' Lindstrém, Handl. k. Svensk. vet. Akad., Bd. xxxiv, No. 8, p. 57, t. iv, 
figs. 20, 21, 1901. 


Notices of Memoirs—A Triassic Isopod Crustacean. 277 


Dr. Jeffreys takes this suggestion to be a fact, and would have us 
believe that the thickness of this radio-active layer has been fairly 
accurately measured and that consequently it is possible to calculate 
the depth of the level of no strain. 

The discovery of radio-active elements in the rocks of the earth 
has not rendered the compression theory any more probable. In its 
naked simplicity it appears to show that the earth is getting hotter 
and increasing in diameter at an ‘“‘appalling rate”. Iam inclined 
to agree with Holmes that the radio-active elements are mainly 
concentrated near the earth’s surface; but think that the exact 
amount of concentration is uncertain. An expanding earth would 
account for the formation of ‘‘ rift valleys’’, normal faults and lines 
of volcanic activity or crustal weakness. 

The theory I have supported to the effect that the folding and 
contortion of the rocks of the earth’s crust have been largely due to 
vertical flow resulting from denudation and horizontal flow by the 
spreading of elevated areas, would account for the peculiarities our 
rocks present even if the earth were slowly expanding. 

Dr. Jeffreys states that “substances possessing any elasticity are 
called solids’. ‘If it is absent . .. the substance is a fluid.” 
Contrast this statement with the following from Maxwell’s Theory | 
of Heat, edited by Lord Rayleigh, p. 802: ‘‘Gases and liquids, and 
perhaps most solids, are perfectly elastic, as regards stress uniform 
in all directions, but no substance which has yet been tried is 
perfectly elastic as regards shearing stress, except perhaps for 
exceeding small values of the stress.” Dr. Jeffreys will find that the 
difference between a solid and a liquid is clearly stated on p. 303 of 
the above quoted work. Both solids and liquids are brittle and 
elastic. This can, in the case of a liquid, be clearly seen as regards 
pitch, but not in the case of water; but all liquids are elastic even 
under tangential stress. 

In my article on ‘‘ Mountain Building” which Dr. Jeffreys 
criticizes, I did not venture to introduce any new theories concerning 
the properties of matter, and I think that my critic should have 
pointed out that his views are not those of our textbooks. To my 
mind his theories concerning the solid and liquid states are quite 
inadmissible. 


NOTICHS OF MEMOTRS. 


i 


A Trrasstc Isopop CrusrackAN FRoM AUSTRALIA. 


A Fossit Isopop BELONGING TO THE FRESHWATER GENUS PHREATOICUS. 
By Cuas. Cuinron. Journ. Proc. Roy. Soc. N.S. Wales, li, 
pp. 865-88, 13 text-figs., 1918. 

F the six (or perhaps seven) sub-orders composing the order 
Isopoda, only the Flabellifera and Valvifera have been definitely 
recognized in a fossil state. ‘The Flabellifera are represented by 
several genera as early as the Jurassic, while the Valvifera are known 
only by a single species from the Oligocene. Professor C. Chilton 
now announces the discovery, in the supposed Rhetic rocks of New 


278 Notices of Memoirs—A Triassic Isopod 


South Wales, of a representative of the remarkable little sub-order, 
the Phreatoicidea. ‘To make clear the importance of this discovery 
itis necessary to give a brief account of the existing members of the 
group. 

The genus Phreatotcus was established thirty-five years ago, by 
Professor Chilton himself, for a blind species which he found 
inhabiting subterranean waters in New Zealand. Other species, 
some of them blind and some with functional eyes, were subsequently 
discovered in streams and lakes of New Zealand, New South Wales, 
Victoria, and Tasmania, and two species of terrestrial habitat were 
also found. Three of the species were referred to as many genera 
distinct from Phreatoicus and forming with it the family Phreatoicide, 
for which Mr. Stebbing in 1893 established the Tribe (now ranked 
as a sub-order) Phreatoicidea. In 1914 Mr. K. H. Barnard greatly 
extended the known range of the group by discovering a species of 
Phreatoicus living in streams on Table Mountain at Cape*Town. 


Fie. 1.—Phreatoicus australis, Chilton. Recent. Mt. Kosciusko, New 
South Wales. x 4. (After Chilton.) 


The Phreatoicidea are distinguished from all other Iscpods by 
having the body more or less compressed from side to side, and 
resembling in general appearance that of an Amphipod. This 
resemblance, however, is no more than superficial, and the structure 
of the animals shows that they are in no way closely related to the 
Amphipoda. 

As in nearly all Isopods, seven somites are distinct in the thoracic 
region, and the telson is not separated from the last abdominal 
somite. In the Phreatoicidea, however, the first five abdominal 
somites are not only distinct and movable but they are of con- 
siderable size. ‘This is of some importance as a primitive character, 
since the abbreviation of the abdominal region is one of the most 
characteristic features distinguishing the Isopoda from the other 
orders of Malacostraca.. Even when, as in many Flabellifera, the 
abdominal somites are distinct from one another, they are crowded 
together, and the greater part of the length of the abdomen is 
formed by the enlarged terminal segment. ‘The great development 
of the side-plates (pleura) of these abdominal somites in the 
Phreatoicidea, and the fact that they are directed downwards 
instead of laterally, are characters of less morphological significance, 
but they contribute to the Amphipod-like aspect. Another character 


Crustacean from Australia. Le) 


that may be regarded as primitive is found in the first or coxal 
segments of the thoracic legs. ‘These are all of small size and, on 
the last six segments at any rate, are movably articulated with the 
body. In this character the Asellota resemble the Phreatoicidea, 
but in other Isopods these segments are expanded into broad ‘‘ coxal 
plates’? and more or less completely fused with the somites that 
carry them. Finally, the last pair of abdominal appendages (uropods) 
' project from near the end of the body as bifurcate styles, like the 
uropods of certain Asellota, and still more like those of Amphipods. 

In nearly all other respects—in the structure of antennules, 
antenne, mouth-parts, thoracic legs, branchial abdominal limbs, and 
even sexual appendages—the Phreatoicidea are commonplace Isopoda, 
not differing essentially from many representatives of the central 
and typical sub-order, the Flabellifera. That they retain certain 
features which we believe to be primitive, or which point the way 
to groups outside the order itself, has already been stated, but this 
is true also of the Asellota and of the Flabellifera, and it is perhaps 
impossible to rank any one of these three sub-orders as, on the 
whole, more primitive than the others. 


Fic. 2.—Phreatoicus wianamattensis, Chilton. Rhmtic(?). St. Peter’s 
Brickworks, Sydney. x 34. (After Chilton.) 


The habitat and the geographical distribution of the Phreatoicidea 
are also noteworthy. Isopods of truly freshwater habitat are few, 
and in no other case are they conspicuously different in structure 
from marine representatives of the group. With the possible 
exception of the single family Asellide, they are scattered, and no 
doubt recent, immigrants from the sea. The Phreatoicidea, on the 
other hand, are not known to have any near relatives among the 
marine Isopoda, and it is this that gives special significance to their 
remarkable distribution in New Zealand, South-Eastern Australia, 
Tasmania, and South Africa. 

In describing the first known species of Phreatotcus, Professor 
Chilton stated that the group ‘‘must be of very considerable 
antiquity”. This prediction he has now had the good fortune to 
verify in a striking manner. The specimens which he describes 
were detected by Mr. R. J. Tillyard while investigating the fossil 
insect fauna of Queensland and New South Wales, and were found 
in the Wianamatta Shale of St. Peter’s Brickworks, Newtown, 
Sydney. The strata in which they occur were at first referred to 


280 Notices of Memowrs—A Triassic Isopod Crustacean. 


the Trias-Jura, and Professor Chilton quotes Mr. Tillyard’s opinion 
that ‘‘evidence is accumulating that will probably place them in 
the Upper Trias, probably as the nearest Australian equivalent of the 
Rhetic ’. Dr. Smith Woodward, who has reported on the fossil 
fishes from the same beds, agrees that the fish fauna, if it had been 
found in the Northern Hemisphere, could not possibly have been 
regarded as of later than Rhetic age. 

The largest specimen obtained must have measured about 30 mm. 
in length when complete. After examining a long series of 
specimens, Professor Chilton shows that, in the general form and 
segmentation of the body, the large size cf the abdominal somites 
with their downwardly directed side-plates, the size and shape of the 
terminal segment and the uropods, the short antenne (or antennules), 
and the form and proportions of the chief segments of the legs, the 
fossils closely resemble the living Phreatoicidea. There is indeed 
nothing to forbid their inclusion in the type-genus, to which he assigns 
them under the name Phreatowcus wianamattensis. 

It seems probable from the presence of insects, of such Mollusca 
as Unio, and of numerous plant remains, that the beds in which the 
fossils are found are of freshwater or estuarine origin, so that even as 
early as the Triassic period the Phreatoicidea had adopted, or were 
on the way to adopt, the freshwater habitat to which they are at the 
present day confined. 

While Phreatotcus is thus one of the oldest, if not the very oldest, 
of fossil Isopods yet discovered, and while it undoubtedly presents 
certain primitive structural characters, it should be noted that it 
throws no light on the phylogeny of the order. It is, indeed, very 
far from being an ancestral type, and it only emphasizes the fact that 
the evolution of the group goes a very long way back in geological 
times. No doubt among these early Isopods, as among those now 
living, a vast number of forms were two small and too delicate in 
structure to be readily preserved as fossils, and, except for some 
lucky chance, it is likely that we may never be able to trace, with 
any clearness, the lines of evolution followed by the various 
sub-orders. 

In reporting the discovery of a species of Phreatoicus living at the 
Cape, Mr. K. H. Barnard called attention to its probable bearing on 
the antiquity of the group and referred to the former extension of 
‘‘Gondwana land” over the areas where species of the genus now 
occur. We-now learn that they existed, probably as freshwater 
animals, within the same area at a time when that extension may 
have been still unbroken. Whether at that remote epoch their 
geographical range was still wider, we cannot tell. If it was, then 
it becomes a most extraordinary coincidence that their fossil remains 
should first be found in a district where the living animals exist 
to-day. 


Reviews—Petrography of the Pacific Islands. 281 


RAV LTHWS- 


-].—PerrrograpyHy oF THE Paciric Istanps. By R. A. Daty. 
Bull. Geol. Soc. America, vol. xxvii, p. 825, 1916. 


iB this paper the author puts forward a proposal for a complete 
scientific exploration, geological, botanical, zoological, and 
anthropological, of the islands composing the regions of Polynesia, 
Melanesia, and Micronesia. ‘These are scattered over an area 
composing nearly one-sixth of the earth’s surface, and the information 
at our disposal concerning them is still very incomplete. The greater 
part of the paper is taken up by a discussion of the petrography of 
this vast region, so far as itis known. It is pointed out that what 
may be called “ continental” rocks, namely, plutonic, metamorphic, 
and sedimentary types apart from coral-rock, are only found in islands 
lying to the west of a line joining the easternmost of the Fiji group 
to the Mariana Islands: all of these are fragments of an ancient 
continent that broke up in Tertiary times. 

In several hundred other islands volcanic rocks have been recorded : 
all the known occurrences are tabulated, and it appears that the 
dominant types are olivine-basalt and pyroxene-andesite. Many 
other varieties related to these, mostly of basic composition, have 
also been recorded, and it is suggested that the andesites and the 
ultrabasic lavas are differentiates of a primary basaltic magma under- 
lying the whole Pacific basin. The scarcity of acid lavas is 
noteworthy: it suggests that in this region the ordinary crust of 
quartzose sediments found in continental areas is absent. This is 
‘In accordance with the high density of the Pacific area as shown by 
geodetic observations. From the evidence adduced it is clear that 
this is a pre-eminently subalkaline province, and the author’s 
well-known theory of syntectic differentiation brought about by 
absorption of limestone is applied to explain the genesis of a certain 
number of occurrences of typically alkaline rocks, such as basanite, 
nepheline-basalt, and varieties containing hatiyne. 


IJ.—Tuser Minerat Inpusrrizs or tHE Unirep Starrs. Sunpsur: 
AN ExampitE or Inpusrrian INDEPENDENCE. By JosrepH LE. 
Poeur. Bulletin 102, pt. i, United States National Museum 
(Smithsonian Institution). pp. 10 and 3 plates. Washington, 
1947. 

f|VHE falling off in the imports of sulphur from Sicily and of 
pyrites from Spain consequent on the War has led to a great 

development of the home supplies of sulphur in the United States, 

and particularly of the native sulphur deposits of the Gulf Coast 
region in Louisiana and Texas. Here the sulphur occurs in dome- 
shaped masses in association with petroleum, rock-salt, and gypsum. 

Many of the domes consist of a core of rock-salt with lenses of 

gypsum and masses of limestone containing petroleum. In two 

instances, at Sulphur, La., and Bryan Heights, Texas, bores showed 
the presence of great masses of pure sulphur beneath several hundred 
feet of quicksand. These masses are supposed to be essentially of 


282 Reviews—The Geology of Pigeon Point, Minnesota. 


igneous origin, and the doming of the rocks is attributed to the force 
of crystallization of minerals from supersaturated solutions. ‘he 
petroleum, however, is probably of later date. Since for various 
reasons ordinary mining is impossible, the sulphur is extracted by 
the Frasch process, which consists essentially in forcing superheated 
water through a pipe to the sulphur horizon and lifting the sulphur 
by means of compressed air, when it is pumped into large bins to 
cool and then loaded straight into trucks. Under the present 
abnormal conditions it is possible that much of this exceptionally 
pure sulphur will have to be used for the manufacture of sulphuric 
acid, an uneconomic proceeding which would be quite unjustifiable 
in normal times. kw 


IlI.—Tue Grotoey or Pickon Pornr, Minnusora. By R. A. Daty. 
American Journal of Scrence, vol. xliii, p. 428, 1917. 
fI\HIS paper gives the results of a further investigation of the 

well- imown intrusion of Pigeon Point, originally described by 
Bayley (Bulletin 109, U.S. Geol. Survey). The main problem is as 
to the nature of the “red rock”’, a granitoid type with much 
micropegmatite. The igneous mass is concluded to be a sill, not 
a dyke as supposed by Bayley; its upper and lower surfaces are 
found to be concordant with the bedding of the Animikie rocks, into 
which it is intruded. The most striking feature is the regular 
variation in the character of the rock from below upwards ; the base 
is olivine-gabbro, followed by gabbro, intermediate rock, and finally 
the highly acid red rock. This variation in composition is due to 
gravitative differentiation, acting on a gabbroid magma which had 
been modified by assimilation of sedimentary material derived from 
the roof of the sill by stoping. The differentiation.is probably 
largely due to gas-action: the presence of much gas is shown by 
the abundance of drusy cavities, and peculiar ‘‘ribbon’’ injections, 
a few centimetres wide, also indicate great pressure in the magma. 
In all the rock-types are found xenoliths of Animikie quartzite 
coated with a shell of red rock. This suggests a diffusion of silica 
from the xenolith into the basic magma. The red rock appears to 
have remained liquid longer than the more basic types, owing to 
concentration in it of gas, which lowered its freezing-point. 
Consequently dykes and veins of red rock are found cutting the 
gabbro as well as the sediments. The red rock is not merely fused 
sediment as supposed by Bayley. Neither differentiation nor fusion 
alone is sufficient to explain all the facts, and the whole phenomenon 
is an example of syntexis, that is assimilation followed by differentia- 
tion of the mixed magma thus formed. RoR 


ITV.—Own a possistE Causa Mrcuanism For HEAVE-FAULT SLIPPING 
IN THE CaLIFORNIA Coast-rance Rereaion. By H. O. Woon. 
Bull. Seismol. Soc. America, vol. v, p. 214, 1914. 


(F\HIS paper has special reference to the origin of the fault-slip 
that caused the disastrous San Francisco earthquake of 1906. 
The theory is based on the principle of isostatic readjustment 


Reports & Proceedings—The Royal Society. 283 


following redistribution of mass by erosionand deposit. It is pointed 
out that in the Sierra Nevada and in the Coast Ranges denudation is 
very active, while most of the material thus set free is deposited 
either in the Great Valley of California or in the sea close to the 
coast. The overloading must be specially conspicuous in and near 
San Francisco Bay. Owing to this overweighting the areas of 
deposition undergo down-warping, while the denuded areas tend to 
rise, thus involving a compensating creep in the plastic depths. It 
is concluded from various lines of evidence that this creep or 
undertow must be greater in a direction parallel to the axes of the 
ranges than perpendicular to these; accordingly a state of tension is 
produced highly favourable to the formation of slip-faults with 
lateral displacement, such as the one that formed so conspicuous 
a feature of the San Francisco earthquake. A considerable amount 
of subsidiary evidence is put forward in support of the main idea, 
partly physiographic, derived from a study of Californian topography, 
and partly geodetic, depending on the results of many elaborate 
investigations of anomalous distribution of gravity and allied 
phenomena in this part of the United States. 
Ts ube ale 


REPORTS AND PROCHEDINGS.- 


I.—Tue Royat Socirry. 
April 25, 1918.—Sir J. J. Thomson, O.M., President, in the Chair. 


The Bakerian Lecture was delivered by the Hon. Sir Charles 
Parsons, K.C.B., F.R.S., on ‘‘ Experiments on the Production of 
Diamond”’. 

In his lecture the author alluded to some of the results of 
experiments described in papers by him to the Royal Society in 1888 
and 1907, more particularly to those on the decomposition by heat of 
carbon compounds under high pressure, and on the effect of applying 
pressure to iron during rapid cooling. 

A description is given of experiments designed to melt carbon 
under pressures up to 15,000 atmospheres by resistance heating and 
by the sudden compression of acetylene oxygen flame, also by the 
firing of high velocity steel bullets through incandescent carbon into 
a cavity in a block of steel. 

Allusion is made to experiments on chemical reactions under high 
pressure and their results. The pressures occurring in rapidly cooled 
ingots of iron and experiments bearing upon this question are dis- 
cussed. Experiments at atmospheric pressure and experiments 7n 
vacuo are described. 

The main conclusions arrived at are: that graphite cannot be 
converted into diamond by heat and pressure alone within the limits 
reached in the experiments; that there is no distinct evidence that 
any of the chemical reactions under pressure have yielded diamond ; 
that the only undoubted source of diamond is from iron previously 
heated to high temperature and then cooled; and that diamond is 
not produced by bulk pressure as previously supposed, but by the 


284 Reports & Proceedings—Geological Society of London. 


action of the gases occluded in the metal and condensed into the 
centre on quick cooling. 

A list of about one-half of the experiments is given in the 
Appendix. 


I1.—Grotoeicat Society oF Lonpon. 


April 17, 1918.—G. W. Lamplugh, F.R.S., President, in the 
Chair. 


The following communication was read :— 

‘‘The Evolution of the Liparoceratide.”’ By Arthur Elijah 
Trueman, M.Sc., F.G.S. 

The Ammonites considered include several sub-parallel series, of 
which four genera were indicated by Mr. 8. S. Buckman in Yorkshire 
Type Ammonites. The details of ontogeny and the sutures, which | 
had not hitherto been compared, have been employed in constructing 
tables showing both the biological and the stratigraphical relations 
of the various species; a revision of the existing classification is 
proposed. 

The early members of each series are similar ‘‘ capricorn” forms 
with slender whorls and stout ribs (for instance, A. capricornus, 
A. latecosta, A. maculatus). In somewhat later examples the 
outer whorl is swollen, and has paired tubercles (for instance, 
A. heterogenes). From this stage the tendency is to shorten the 
period with slender capricorn whorls by accelerating the development 
of bituberculation and prolonging the period of pre-costate globose 
whorls; thus the most advanced members of each series are stout 
bituberculate forms (for instance, A. striatus, A. becher), which do 
not pass in development through a capricorn stage. 

The following genera may be recognized; each includes ammonites 
of the three types mentioned above :— 

1. An earlier group, with tubercles paired in the involute stages ; 
Radstock (Somerset) is the only British locality where these 
ammonites have been found. 


Parinodiceras, gen. nov. Elevated whorl, paired tubercles, the inner and 
outer rows widely separated. Genoholotype. Ammonites striatus 
parinodus, Quenstedt (1884, pl. xxviii, fig. 6). 

Gen. noy. Round whorl, with the rows of tubercles placed close together. 
Genoholotype, a specimen to be figured as a new species. 


2. A later group, with unpaired tubercles in the involute stage. 
These genera are most readily distinguished by sutural characters, 
namely, the relative depths of the external lobe (EL) and the first 
lateral lobe (IL), and by the width of the external saddle (ES). 

(a) With narrow ES (not reaching to the outer tubercles). 


Liparoceras, Hyatt. TL and EL about equal in depth. Genolectotype, 
Ammonites striatus, Bronn. 

Becheiceras, gen. nov. Ib deeper than EL. Genoholotype, Ammonites 
bechei, Wright. (Lias Ammonites, pl. xli, fig. 1.) 

Anisoloboceras, gen. nov. Il much deeper than EL, the ventral lobules 
of IL almost meeting under EL. Genoholotype, Anvmonites nautili- 
formis, J. Buckman. 


_ Reports & Proceedings—Zoological Society of London. 285 


(6) With wide KS, reaching to the outer tubercles. 


Aigoceras, Waagen. EL and IL about equal in depth, IL symmetrical. 
Genolectotype, Ammonites planicosta, d’Orbigny. 

Androgynoceras, Hyatt. ILand EL about equalin depth, ILasymmetrical. 
Genolectotype, Ammonites hybrida, d’Orbigny. 

Oistoceras, S. 8S. Buckman. Ribs with sharp peripheral curve. Suture 
similar to Androgynoceras. Genoholotype, Ammonites figulinus, 


Simpson. 


Amblycoceras, Hyatt. Ribs with slight peripheral curve. IL shallower 
than EL. Genoholotype, 4. capricornus, Hyatt, 1900. 

These ammonites generally occur in the upper part of the Lower 
Lias, where it has been usual to recognize a capricornus zone over- 
lying a strvatus zone. Careful collecting has shown, however, that 
there are several horizons with capricorn ammonites of different 
series and several with the involute forms evolved from them, as 


shown below :— 


margaritatus zone i\ 


be) rNh 
Capricorn Be 
[ Bituberculate ae 
davéizone . . “ia ue 
9 9 
| capicrn ie 
99 9 
( b rh) 1 99 
; Bituberculate 
“abee zone . 2.x : ke 
Vans we 
Bituberculate He 


f Bituberculate ammonites of the A. nawtiliformis series. 


Ovstoceras. 

Oustoceras. 

the A. bechei series. 

Ajgocerasand Androgynoceras. 

Amblycoceras. 

Amblycoceras. 

Aigoceras, Androgynoceras. 

Beaniceras. 

Lvparoceras. 

Luparoceras. 

the first group (with paired 
tubercles). 


In no locality that has been examined is the complete sequence 
shown. The absence of some groups is due to the original distri- 
bution of the ammonites; in other cases it is due to non-sequences 
(for example, the upper part of the dav@i zone is not represented in 


Gloucestershire). 


Two groups of Lias Ammonites are recognized, namely: (i) those 
‘which were evolved directly from a globose ancestor; this includes 
the Liparoceratide, Echioceratide, Hildoceratide, Polymorphide, 
Deroceratide ; and (11) those which passed through an intermediate 
broad-ventered (cadicone) stage; these include the Amaltheide and 


Dactyloidee (with Beaniceras). 


IIl1.—Zooroeicat Socrery or Lonpon. 
April 9, 1918.—Dr. A. Smith Woodward, F.R.S., Vice- President, 


in the Chair. 


Dr. A. Smith Woodward, F.R.S., V.P.Z.S., exhibited fossil rostral 
teeth of the sawfishes Mopristis and Pristis, and referred to the 
progressive changes in the rostral teeth of the Pristide during 


geological time. 


Mr. G. A. Boulenger, F.R.S., exhibited the head of an example of 
Hydrocyon goliath, Blgr., from the Congo, a fish attaining the length 
of 4 feet. The object of the exhibition was to show the enormous 


286 Correspondence—Ernest Gibson. 


shark-like teeth, to which special interest attaches, owing to 
a similarity, recently pointed out by Dr. Eastman, to fossil teeth 
occurring in the Upper Cretaceous, which would appear to indicate 
the existence of Characinide in that geological epoch, a range in 
time which Mr. Boulenger had predicted as probable thirteen 


years ago. 


CORRESPONDENCE. 


DEPOSIT OF GRANULAR IRON-ORE ON THE COAST OF 
BUENOS AYRES. 

Srr,—The newspapers of Buenos Ayres have recently announced 
the discovery of a deposit of granulous iron-ore on the Atlantic sea- 
board of the province of that name. As the whole Argentine 
Republic has hitherto only been able to boast of one genuine occur- 
rence of that valuable mineral, in the shape of the famous meteorite 
hurled into the Gran Chaco in the north (see section of same in 
the Geological Department of the British Museum (Natural History), 
South Kensington), popular curiosity was much aroused and excited. 

As possibly the subject may contain some points of interest, 
I herewith furnish the more important details. 

The locality is the sea-coast and both sides of the mouth of the 
River Quequen Grande, in (roughly) lat. 38° and long. 58°. And 
it is somewhat to the south of the recently named Chapadmalalense 
formation, the site of the Ameghino paleontographical controversy. 

The total area of the deposits is estimated at some 5,000 hectareas. 
It is stated that the magnetic iron-ore is found distributed 
through the sand from the surface to an average depth of 
10 metres (otherwise to where it rests on the ‘‘tosca” or loéss of 
the Pampean formation), and in a proportion of 380 per cent of 
mineral. The result, in accordance with these figures, would 
represent the colossal amount of 750 millions of tons. “As, however, 
the preceding is the commercial phase, or view taken by the parties 
who have obtained the concession for exploiting the situation, it Tey 
be open to very considerable discount. 

I have before me the analysis and reports furnished by various 
Government specialists and departments. On account of the length, 
etc., of these, I have selected in preference one emanating from 
London itself, and which is as follows :— 

ANALYSIS OF Two SAMPLES OF MINERAL. 
Marked 18. Marked 21. 


% % 
Silica . : 3 : a : 1-36 1-10 
Titanium oxide 5 4 : . 17-66 18-14 
Ferrous oxide : 4 ‘ : 74-27 74-11 
Manganous oxide . : é ‘ 0:56 0:62 
Alumina : i : 4 i: 0-22 0-16 
Lime . : i j ‘ 0-38 0-34 
Magnesia _ 0-42 0-33 
Combined water, aillkalies, and lol 5-13 5-20 


100-00 100-00 


Obituary—Professor George Alexander Lowis Lebour. 287 


A special search was made for sulphur and phosphorus, giving the 
figures :— 
Marked 18. Marked 21. 


% % 
Sulphur : : : c : 0-055 0-074 
Phosphorus : . : 0-109 0-115 


Both samples are titanifero ous iron-ore of moderate quality. 
Ernest Gisson. 


25 CADOGAN PLACE, LONDON, S.W.1. 
May 5, 1918. 


ys ICI oryNAS Sa 


PROFESSOR GEORGE ALEXANDER LOUIS LEBOUR, 


M.A., D.Sc., F.G.S., Vicz-PrincipaL or tHe Armstrong CoLurce, 
" Nuweasrun- UPON-TYNE. 


BorRN 1847. DIED FEBRUARY 7, 1918. 


Y the death of Professor Lebour in his 71st year, on February 7, 
1918, the scientific world loses a prominent and interesting 
figure. Born in 1847 and educated at the Royal School of Mines, 
he served from 1867 to 1873 on the Geological Survey of England 
and Wales. He was lecturer in geological surveying at the 
University of Durham College of Science (later, Armstrong College) 
in Newcastle from 1873 to 1879, and succeeded Dr. David Page as 
Professor of Geology in the University. This position he occupied 
until his death, so that for forty-five years he was connected with 
the College, and for thirty-nine years occupied the chair of Geology. 
In 1904 he was awarded the Murchison Medal by the Council of the 
Geological Society, and in the same year was elected Vice-Principal 
of Armstrong College. 

The transference of heat through the crust of the earth occupied 
Lebour’s attention early and led to measurements of underground 
temperature in northern coal-pits, and also in conjunction with 
Herschel, to the determination of the thermal conductivities of 
a great number of rocks. This important work, issued in a series - 
of British Association reports from 1873 to 1881, is well known, and 
many of the data obtained are accepted as standard. 

Lebour’s name will always be associated with the geology of 
Northumberland and Durham. Besides his official maps, he brought 
out in 1877 an excellent geological map of the county of Northumber- 
land, which is the embodiment of much strenuous, clear-sighted 
labour. He was joint author with William Topley of a widely 
quoted paper on the Great Whin Sill, which may be said to have 
definitely established its intrusive character. The stratigraphical 
relations of the Carboniferous rocks form the subject of many papers, 
in which the divisions of the system and the description and 
correlation of the important limestones, etc., are set forth with 
admirable lucidity. The economic aspects of the subject find 
expression in papers on the Redesdale Ironstones and the coals of 
the Bernician series, especially those associated with the Little 
Limestone. The future importance of these coals, which occur in 


eS) Obituary—Robert Mackenzie Johnston. 


rocks below the Coal-measures proper, is strongly insisted upon, and 
the lapse of forty years has but added strength to the views then 
brought forward. Of many papers relating to the Geology of 
Durham may be noted those dealing with the classification of the 
Salt-measures, the breccia-filled fissures in the Magnesian Limestone 
(aptly termed by him breccia-gastes), and the Marl Slate and Yellow 
Sands. 

As many as nineteen papers are recorded under Lebour’s name in 
the GrotogicaL Magazine Index from 1869 to 1887, but he has 
contributed over one hundred papers on geological subjects to 
various journals. One of these of special interest, published as long 
ago as in July, 1876, on ‘“‘ The Carrara Marbles”, gives a most 
instructive history of the geological vicissitudes undergone by these 
highly metamorphosed Limestone Rocks from their reference to 
Eruptive and Cretaceous Oolitic, Jurassic, Liassic, Rheetic, and 
finally being assigned to the Lower Carboniferous age by Coquand 
on the evidence of fossils. he similar saccharoidal limestones of 
St. Béat in the Pyrenees have also been, on the evidence of fossils, 
proved to be equivalent to the statuary marbles of Carrara and of 
like Carboniferous Limestone age. (Gurox. Mac., 1876, pp. 289-92 
and p. 382.) 

Lebour wrote ‘‘ The Geology of Durham” in the Vectoria History 
and the Handbook to the Geology and Natural History of Northumber- 
land and Durham, of which three editions have appeared (1878-89). 
It is a very effective monument to his life-work in the two counties, 
and has the remarkable merit of increasing in value the more it 
is used. 

This brief narrative of work accomplished gives, however,. no true 
estimate of Lebour’s scientific activity and influence. He was 
a many-sided man, of wonderful fluency, both in the written and 
spoken word, and a born teacher. His papers are models of clearness 
and skilful arrangement of material; they are written in flawless 
English, and they often display that sense of humour which was one 
of his notable characteristics. These same qualities were, if possible, 
accentuated in his lectures. He inspired a great band of workers, 
who have carried his methods and enthusiasm to the four quarters of 
the globe, and he was ever ready to help, by his sage advice, those 
whose steps he had directed towards scientific paths.—From Nature, 
February 21, 1918. 

He leaves a widow and two daughters with a wide circle of 
personal and scientific friends to cherish his memory. 


ROBERT MACKENZIE JOHNSTON. 


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Geology of Tasmania, 1888. He received the I.8.0. in 1908, and 
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The Leaves of Noeggerathiopsis, 
Australia. By ROBERT ETHER- 
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M.A., F.R.S., ete. (Plate XIII.) 


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ORIGINAL ARTICLES. 


— 


IT.—ARrRaNGEMENT OF THE LEAVES IN THE AUSTRALIAN SpEcres oF 
NV 0EGGERATHIOPSIS.| 


By R. ETHERIDGE, jun., Director and Curator of the Australian Museum, 
Sydney. 
With a Postscript by Professor A. C. SEwAaRD, M.A., F.R.S., Professor of 
Botany in the University of Cambridge. 
(PLATE XIII.) 


N 1849 Professor J. D. Dana described certain leaves from the 
Illawarra District and Neweastle, New South Wales, occurring 
in the Upper Coal-measures. To these he gave the name of 
Noeggerathia spathulata and WV. media.? Long after, in 1879 to be 
exact, Dr. O. Feistmantel established his genus Noeggerathiopsis for 
the reception of similar leaves from the Talchir—Kararbari Beds of 
the Lower Gondwana System,’ and from his remarks it may, by 
inference, be concluded that Dana’s were included in the new genus 
also. This inference is justified by Feistmantel’s later definite 
reference of these leaves to Moeggerathiopsis;* at the same time he 
added another species, VV. prisca, from the Lower Coal-measures at 
Greta. He believed them to be closely ailied with Cycadeacee. 

It is not my intention to follow step by step the various suggestions 
advanced on the systematic position of Noeggerathiopsis, nor express 
an opinion on the vexed question of specific identity of the leaves; 
suffice it to quote Dr. E, A. N. Arber’s summing up: ‘‘ Considerable 
difference of opinion has existed both with regard to the affinities of 
this genus and also in respect to the identity of some of its members. 
The first Indian specimens were described by Bunbury in 1861, who 
referred them provisionally to the Gymnospermous genus Woeggerathia. 
This generic name was also at one time adopted by Feistmantel . . 
The same author, in 1881, pointed out the close similarity presented 
by the leaves described as RAiptozamites, by Schmalhausen, with the 

1 Noeggerathiopsis = Rhiptozamites, Schmalhausen (Mém. Acad. Imp. Sci. 
St. Petersb., xxvii (7), No. 4, 1879). This identity is admitted by Schenk 
(Zittel’s Handbook Pal., ii, Paleoph., p. 330, f.n.); Kurtz (Revista Museo la 
Plata, v, p. 130, 1894); Arber (Quart. Journ. Geol. Soc., lviii, p. 19, 1902) ; 
Kurtz (Quart. Journ. Geol. Soce., lix, p. 25, 1903). 

* Dana, Wilkes U.S. Explor. Exped., Geol. x, p. 715, pl. xii, figs. 9, 10, 
1849. 

> Feistmantel, ‘‘ Foss. Flora Gondwana Syst.’’? (Pal. Indica), iii, pt. i, 
p. 23, 1879. 

+ Feistmantel, Paleontograplica, Supp. Bd. iii, Lief. iii, Heft ii, pp. 158, 
162, 1879. 

DECADE VI.—VOL. V.—NO. VII. 19 


¥ 


x, 
A 


ry 


290 R. Htheridge—Leaves of the Australian 


Indian and Australian species of Moeggerathiopsis, and the probable. 
affinity of both these genera to the Mesozoic Cycads of the family 
— Zamiee. 

‘In more recent times, ZeiJler, Seward, Solms- Laubach, and others 
have regarded this genus as in all probability a member of the 
Cordaitales, closely allied to Cordaites .. . 

‘‘Zeiller has made a careful study of the leaves described by 
Schmalhausen as Rhiptuzamites. He regards them as belonging to 
a true Cordaites, and as distinct from the members of the Glossopteris 
flora described here, which, however, they closely resemble in several 
TESWE CUS) ce. 

‘‘Zeiller has pointed out that the constant occurrence of Cordaitean 
seeds of the genera Cardiocarpus or Cardaicarpus in association 
with WV. Hislopi, is an additional argument in favour of referring 
Noeggerathiopsis to the Cordaitales.” * 

One of Dana’s figures exhibits a number of leaves ‘‘ proceeding 
from a common base, as if the cluster of leaves growing together, 
and perhaps at the extremity of a branch . . . In this cluster, which 
is evidently a natural group, the leaves are of different ages .. . 
The centre from which the leaves radiate has a shining coaly aspect, 
_as if a soft bud or vegetable base of some thickness had been pressed 
down and carbonized”’.* On the piece of shale figured there are two 
such groups.® 

These illustrations of Dana’s do not seem to have attracted the 
attention of paleobotanists to the extent one would have expected. 
As a matter of fact, I do not remember any direct reference to them 
other than that of Tenison Woods,‘ although I think it may be 
accepted that Arber’s interesting figure® of a specimen in the Clarke 
Collection at Cambridge, and named by McCoy Zeugophyllites elongatus, 
but not of Morris, ‘‘a group of three leaves which appear to radiate 
from some axis unfortunately missing,” is of the same nature. I am 
pleased, therefore, to be now able to supplement Dana’s illustrations 
by an account of four clusters, more or less complete. 

In Dana’s fig. 9 there are portions of nine or ten leaves (it is 
difficult to say how many exactly on the lower side of the figure) 
varying from obtusely spathulate to lanceolate-spathulate, but all 
narrowed at the base. At the right-hand side of the hand-specimen 
is the other fragmentary cluster, but in this instance there is one 
entire leaf and traces of three or four others. Unfortunately, these 
figures do not afford any evidence of the phyllotaxis, whether these 
leaves were in their order spiral, fascicled, or verticillate, or of 
their method of attachment, amplexicaul, articulate, or even sub- 
amplexicaul. Dana’s suggestion of a cluster of leaves growing at the 
end of a branch to some extent suggests a fascicular arrangement, 
a suggestion I return to later. 


1 Arber, Cat. Foss. Plants Glossopteris Flora Brit. Mus., pp. 178-9, 1905. 
2 Dana, Wilkes, U.S. Explor. Exped., Geol. x, p. 715, 1849. 

® Dana, ibid., pl. xii, fig. 9. 

* Ten. Woods, Proc. Linn. Soc. N.S. Wales, ili, pt. i, p. 117, 1883. 

° Arber, Quart. Journ. Geol. Soc., lviii, p. 18, pl. i, fig. 1, 1902. 


Species of Noeggerathiopsis. 291 


We may now turn to the further examples of Woeggerathiopsis 
“leaves. On the specimen illustrated in Plate XIII are two clusters 
more or less imperfect, but in both instances the leaves, such as they 
are, radiate from a centre, the latter representing Dana’s ‘‘ soft bud, 
or vegetable base”. In Fig. 1 of this Plate there are seven leaves, 
or portions thereof, lanceolate-spathulate, the terminations of four 
in which the apices are preserved, acute, and pointed. ‘The second 
example on this same block of stone is smaller and much less perfect, 
with portions of six or seven leaves, of which the two most complete 
have rounded apices. 

The most complete specimen (Pl. XIII, Fig. 2) is on a separate 
piece of matrix and displays no less than at least nine leaves or 
portions. Here there are certainly two in which the apices are 
obtusely rounded, giving to the leaves a more or less elongately 
pyriform or club-shaped outline. On a continuation of this same 
piece of matrix is a small third cluster in which five leaves are 
preserved, all with angular apices, but the apical portions are shorter 
than in Pl. XIII, Fig. 1. On the reverse of this specimen of shale 
occurs the fourth cluster, which consists of the remains of four, or 
perhaps five leaves, also radiate. 

The substance of these leaves is thick, coriaceous, and black in 
colour, in both examples on the large hand-specimen, whilst the 
three on the smaller are matrix impressions with the venation 
apparent. ‘These leaves are petiolate, as described by Arber, and in 
one of the smaller and less complete examples this petiolate attach- 
ment is fairly apparent. 

There are now six instances of this radiate arrangement of leaves 
in Woeggerathiopsis known, and if Arber’s illustration is of the same 
nature (and I have very little doubt it is so), there is then a seventh, 
viz. two by Dana, and the four here described in which the leaves 
are spread out in a circle, radiate from a common centre, and in each 
instance present what, I believe, is the deceptive appearance of being 
on the same plane with one another. It is remarkable that, in the 
six instances, the mode of preservation is precisely the same. 

It is at first difficuit to obliterate from one’s mind the idea of 
a verticillate arrangement of these leaves, but if we devote a little 
consideration to the phyllotaxis of Cordaites, an explanation of this 
radiate arrangement will, I think, be forthcoming, for we must not 
lose sight of the strong consensus of opinion that Cordaites and 
Noeggerathiopsis, if not identical, are most nearly related, Professor 
Seward even saying, in 1907: ‘I prefer to adopt the generic name 
Cordaites in preference to that of Moeggerathiopsis on the ground 
that Noeggerathiopsis is probably not distinct from the widely 
distributed northern type.” ? 

1 Seward, Rec. Geol. Surv. India, xxvi, pt. i, p. 60, 1907. The close 
affinity of the two genera in question is supported by Zeiller, 1882 (Ann. 
Mines, Livr. Sept.-Oct. 1882) ; Schenk, 1890 (Zittel’s Handb. Pal., Abth. ii, 
p. 330, footnote) ; Kurtz, 1894 (Revista Museo de la Plata, v, pp. 130-1, 1894) ; 
White, 1908 (Com. Hstudos Minas Brazil, Relatorio final, 1908, pt. iii, 
p. 546); Krasser, 1909 (Jahrb. Geol. Reichst. Wien, lix, Heft i, p. 121, 1909) ; 
Seward, 1907 (Rec. Geol. Surv. India, xxxvi, pt. i, p. 60, 1907); Seward, 
1907 (Trans. Geol. Soc. S. Africa, x, p. 707, 1907). 


292 R. Htherrdge—Leaves of Noeggerathiopsis. 

One of F. C. Grand-Eury’s figures! of Cordaites lingulatus displays 

the terminal leaves of a branch bunched together or clustered, and 

more or less subimbricate. By exerting downwards an expanding 
pressure upon such a clump, when in the fresh state, a star-like 
disposition, such as we have presented to us in WVoeggerathiopsis, 
would, in all probability, be the result. What appears to be an 
improved copy of Grand-Kury’s figure is given by Renault.” A similar 
terminal clustering is also visible in the former author’s figure of 
Dory- Cordaites.* 

If this cluster method of leaf arrangement be admitted in- 
Noeggerathiopsis it at once lends support to the accuracy of Zeiller’s 
reference to it of certain leaf-bearing branch portions, with leaf-scars 
found in the Coal-measures of Tong-Kin. He remarked as follows: 
‘‘’empreintes correspondant a de petits fragments de rameaux, et 
portant des cicatrices foliaires trés analogues a celles des Cordaicladus, 
marquées chacune de plusieurs cicatricules ponctiformes, disposées 
les unes a la suite des autres sur un arc paralléle au bord supérieur 
de la cicatrice.’’® 

No other example of Woeggerathiopsis leaves preserved in this 
condition, other than those now recorded, has been found in the 
Upper Coal-measures of New South Wales so far as | am aware. 
Referring to an occurrence of stems similar to that recorded by Zeiller, 
Mr. L. Lesquereux* said ‘‘fragments of ribbon-like leaves rarely 
found in connexion with the stems ’’. 

The leaves of Cordaites are said by authorities to be spirally 

arranged on a branch, but a very strange and remarkable form is 
figured by Lesquereux as Cordaites radiatus.° He wrote: ‘‘ Leaves 
short, narrow, linear, obtuse, placed in right-angle and star-like 
around the stems.” His fig. 5 is ‘‘part of a stem covered by 
leaves horizontally diverging, so that each section of the stem shows 
them placed exactly like the rays of a star’. Lesquereux’s 
expressions are not too clear; does he wish it to be inferred that 
the phyllotaxis is verticillate? The figures certainly have such an 
appearance. Or, is it an instance of a clump pressed down from 
above, as I have suggested to account for the radiate arrangement of 
the leaves in Moeggerathiopsis ? 

Locality.—¥ig. 1. Mount Kembla, Illawarra. Collected by W. A. 
Cuneo. Fig. 2. Mount Kembla. Collected by C. Cullen. 

Horizon.—Upper Coal-measures (Permo-Carboniferous). 


EXPLANATION OF PLATE XIII. 
Leaves of Noeggerathiopsis. 
Fic. 1.—Seven leaves radiating from a common centre, lanceolate-spathulate, 
four of the more complete with acute apices. 
,, 2.—Another example, with at least nine leaves radiate and more 
symmetrically arranged than in Fig. 1; two appear to have obtusely 
rounded apices. 


Renault, Cours Bot. Foss., i, pl. xii, fig. 1, 1881. 
Grand-Eury, loc. cit., pl. xviii, fig. 8. 
Zeiller, Ann. des Mines, 1882, Sept.—Oct., p. 26 (separate copy). 
Lesquereux, Descrip. Coal Flora Carb. Form. Pennsylvania (Second Geol. 
Surv. Penn., Report Progress, P), i, p. 525, 1880. 

® Lesquereux, loc. cit., p. 540, pl. Ixxxvii, figs. 5, 6. 


- o DO 


Grou. Mac., 1918. IPAs} UNL, 


P. T, Haminond, Sydney, N.S.IW., del. Bale, virnp. 
LEAVES OF N@GGEHERATHIOPSIS. 


Coat MEASURES. New SourH WALES. 


kh. H. Rastall—The Genesis of Tungsten Ores. 293 


[ Postseript.—The Australian leaf-clusters figured by Mr. Etheridge 
bear a very close resemblance to an Indian specimen reproduced in 
vol. i (p. 242, fig. 472) of my Yossil Plants, which shows leaves 
attached in a close spiral to a supporting axis. 

The late Miss Ruth Holden detected certain differences similar to 
those pointed out by Professor Zeiller in the stomatal arrangement 
on Noeggerathiopsis leaves from India as compared with that on 
English leaves of Cordaites, but the results were not published 
(Fossil Plants, vol. iv, pp. 248-4). Mr.Sahni, of Emmanuel College, 
Cambridge, who has made a further examination of cuticular 
preparations, hopes in the near future to make a contribution to 
this subject.—A. C. Sewarp. ] 


Il.—Tue Genrsis or Tunesten Orgs. 
By R. H. Rastau, M.A., F.G.S. 
(Continued from the June Number, p. 246.) 


Parr Ill: Scuerrrire Depostrs. 


{ROM the descriptions already given, and from a general survey of 
|: the literature of the subject, it is apparent that scheelite is 
a frequent associate of wolframite in the lodes of magmatic origin. 
In fact, a certain number of the occurrences already cited, especially in 
the second part of this paper, might almost as well have been described 
as scheelite deposits, since the two minerals are found in something 
like equal quantities. This applies, for example, to a large number 
of the American and Canadian occurrences, to those of the Malay 
States, and others. This is only to be expected from general 
cousiderations, since gases or solutions containing chemically active 
tungsten compounds coming in contact with calcareous material 
would naturally tend to form calcium tungstate. The same applies 
to lead-bearing minerals; hence in a few instances lead tungstate, 
stolzite, has been found in association with scheelite. It is of 
interest to note that scheelite often contains from 1 to 3 per cent of 
molybdenum. Wolframite and scheelite are often found in lodes and 
other masses very closely intergrown, and in many cases there is 
evidence of much pseudomorphism. In some cases scheelite has 
clearly replaced wolframite, while in other cases the reverse holds. 
The law governing the paramorphism of these minerals is somewhat 
obscure, and it is not easy to say anything definite on the subject. 
In this direction further investigation is required, although the point 
is not perhaps of much practical importance. 

With regard to the predominance of wolframite or scheelite in any 
particular district, the general rule seems to be that wherever the 
country rock is more or less calcareous scheelite tends to form; that 
this would naturally be so is of course obvious, and the subject 
hardly seems to need much further elaboration. ‘The general aspect 
of the problem can be more satisfactorily discussed after consideration 
of certain deposits in which scheelite is the dominant or even the 
only tungsten ore present, since such do occur in various parts of the 
world. 


294 kh. H. Rastall—The Genesis of Tungsten Ores. 


Although scheelite occurs along with wolframite in Cornwall it is 
only in small quantity and of no practical importance. The only 
workable scheelite deposit known in the British Isles is at Grainsgill 
in Cumberland, on the north-eastern side of the Skiddaw area. 
Here the lodes are highly mineralized quartz veins connected with 
the pneumatolytic phase of the Skiddaw granite; they are in close 
association with the greisen of Grainsgill, which is certainly a 
differentiation product of the granite magma. Unfortunately a good 
deal of uncertainty still exists as to the relation of the lodes to the 
surrounding rocks, and especially to the gabbro and granophyre of 
- Carrock Fell. ‘This is a very important point in relation to the age 

of the latter, which is a matter of dispute. ‘The minerals found in 
association with the scheelite ores are molybdenite, arsenopyrite, 
pyromorphite, galena, blende, native bismuth, bismuth telluride 
(with a little gold), and tourmaline, while crystals of fluorite 
have been observed in joint planes in the greisen; it is notable 
also that arsenopyrite occurs in considerable quantity in the same 
rock. It is not known whether the lead-zinc-bismuth minera!s 
are contemporaneous with the quartz and wolfram minerals or 
whether they belong to a later phase of mineralization related to the 
post-Carboniferous lead-zine deposits of the North of England. The 
presence of tourmaline and fluorite indicates pneumatolytic influences, 
and in any case the genetic connexion with the Grainsgill greisen 
seems clear.’ 

In Spain and Portugal scheelite is found together with wolframite 
in many of the deposits. At the La Sorpresa mine in the province 
of Cordoba it occurs in this way in quartz veins, running from 
granite into slate, and the ores tend to occur especially at the 
junction of the two rocks. his fact appears to bring them into the 
category of contact deposits. In a somewhat similar way scheelite 
is found in Haute Vienne, France,? in veins with wolframite, 
cassiterite, molybdenite, arsenopyrite, and pyrite in a gangue of 
quartz. This is an example of its occurrence in the normal tin- 
wolfram lode type. 

An interesting occurrence of scheelite with cassiterite is found -at 
Pitkaranta in Finland, to the north of Lake Ladoga.* Here gneisses 
and schists containing beds of limestone are intruded by Rapakiwi 
granite, and it is in the limestones that the ores principally occur. 
The ores include three principal types: (1) magnetite, (2) copper 
ore, and (3) tin-scheelite ore. All the ores are intergrown with 
a remarkable variety of contact-metamorphic calcareous minerals, 
including diopside, garnet, vesuvianite, chondrodite, and calcite. 
Topaz and fluorite have also been observed in small quantity. This 
-is a particularly instructive case, since here, where the ores are so 
closely associated with limestone, scheelite is found without 


' Finlayson, GEoL. Mac., 1910, p. 19. The Mineral Resources of Great 


Britain, vol.i: ‘Tungsten and Manganese Ores’’ (Mem. Geol. Surv.), 
1916, p. 3. 

” Huré, Bull. Soc. Industrie Minérale, vol. ix, p. 99. 

* Triistedt, ‘‘Die Erzlagerstatten von Pitkiranta am Ladogasee’’: Bull. 


Comm. Geol. Finlande, 1907, No. 19. 


kh. H, Rastall—The Genesis of Tungsten Ores. 295 


wolframite. The mineralization is clearly pneumatolytic, as shown 
by the occurrence of greisen and fluorine-bearing minerals. It is 
evident that caleium carbonate was abundant in the country rock and 
the tungsten compounds of the intrusive magma combined with the 
ealcium rather than withiron; that iron was abundantly present is 
proved by the fact that the iron ores are demonstrably older than the 
tin ores. ‘This case shows certain affinities with the occurrence at 
Trumbull, Connecticut, already referred to at some length. The 
ore-deposits at Pitkaranta are certainly of metamorphic origin, 
being referable to the intrusion of the Rapakiwi granite, and the 
metamorphism is equally clearly of pneumatolytic character; the 
action was selective, and the tungsten-bearing vapours or solutions 
combined by preference with lime rather than iron. 

As before stated, scheelite occurs in many parts of Canada; a good 
example is afforded by the scheelite mine near the Moose River gold- 
mines in Halifax County, Nova Scotia.! The country rock consists 
of highly folded and cleaved quartzites and slates. The veins con- 
taining the scheelite are similar to the gold-bearing veins in the 
adjoining gold-mines. They contain quartz, felspar, mica, tourmaline, 
arsenopyrite, and carbonates (calcite and ankerite). The scheelite is 
concentrated mainly at the top of anticlines or in the troughs of 
synelines. ‘These mineralized veins are accompanied by -veins of 
pure quartz of apparently later date. The mineral veins appear to 
be essentially pegmatitic in their nature, as shown by the presence of 
felspar and mica. .he non-mineralized quartz veins probably repre- 
sent a later differentiate from the same source. 

In the Yukon Territory scheelite has been known for some time as 
a heavy concentrate obtained in gold-washing, and the mineral has 
lately been located in lodes in the neighbourhood of Dublin Gulch. 
It occurs in small quartz veins, which themselves intersect zones of 
pegmatite within the granite. Wolfram and tinstone also oceur in 
small quantities. 

At the present time the world’s greatest producer of scheelite is 
California. The Atolia mining district, in the Mohave Desert, on 
the borders of San Bernardino and Kern Counties, in 1916 shipped 
1,831 tons of scheelite concentrates, carrying on an average 60 per 
cent of tungsten trioxide. A large part of this ore is obtained from 
alluvial deposits, where it is found in lumps up to 100 Ib. in weight, 
but it is also worked to a considerable extent in lodes. These lodes 
are as a rule more or less continuous fissures in granite, but in some 
places they appear to be associated with small basic dykes cutting 
the granite, while in other places the scheelite is found in meta- 
morphosed limestones at or near the granite contact, associated with 
garnet, epidote, and other metamorphic minerals. The lodes proper 
consist of scheelite with a gangue of quartz; they run up to 3 feet 
in width, and have been followed to a depth of 700 feet. In other 
parts of Kern County scheelite occurs in bunches in gold veins, and 
as nearly pure stringers cutting through slate; also in veins in 
granite with amphibole, pyroxene, garnet, sphene, and oxidized 


Report of the Geological Survey of Canada, Department of Mines, for the 
year 1916, Ottawa, 1917, p. 249. 


296 H. A. Baker—The Pre-Thanetian Erosion 


copper minerals, as well as in pegmatites with quartz, oligoclase, 
and muscovite.’ The general association of the scheelite deposits of 
‘California is with siliceous gold veins in connexion with granites. 
This shows a distinct resemblance to the wolfram-gold association of 
Boulder County, Colorado, but in California more lime is present in 
the rocks, and therefore scheelite has been formed instead of 
wolfram. 

In the Federated Malay States scheelite occurs in considerable 
quantity in addition to wolframite. A particularly interesting case 
has been noticed at Salak.? It is a lode about 12 feet wide, con- 
sisting of scheelite, quartz, and light-yellow tourmaline, with traces 
of arsenic and copper. Another scheelite vein also contained fluorite 
and axinite with a little quartz. There are several other instances 
of scheelite lodes all apparently more or less closely associated with 
granite-limestone contacts, ‘The mineral is also found to a small 
extent in the gold veins of the Raub mines, where the country rock 
is distinctly calcareous in character. 


Summary oF Parr III. 


It would be easy to give many more examples of the occurrence of 
scheelite in situ in lodes, veins, and contact deposits, but it is 
doubtful if any good purpose would be served by so doing. Enough 
has been said to show that in very many cases scheelite is found as 
a lode mineral either with or without wolframite. It is also 
a frequent product of contact metamorphism of granites intruded 
into or near limestones. This metamorphism is of the type commonly, 
though perhaps unnecessarily, called pneumatolytic. A regular 
gradation can be traced from the tin-wolfram deposits, through the 
wolfram deposits without tin to the scheelite lodes. This transition 
is on the whole accompanied by a falling-off in the amount of the 
paragenetic molybdenum and arsenic sulphides and the minerals of 
the fluorine-boron group, but in certain instances tourmaline and 
fluorite are found to survive into the scheelite lodes. The genetic 
connexion between scheelite and siliceous gold veins is also of 
significance. 

(To be concluded in the next Number.) 


TI].—On tee Pre-Tuanetian Erosion oF THE CHALK IN PARTS OF 
THE Lonpon Basin. 


By HERBERT ARTHUR BAKER, B.Sc., F.G.S. 


T has long been recogn'zed that, in early Eocene times, while the 
‘‘Caleaire de Mons”’ was being deposited in the Belgian area, 
large tracts of the Upper Chalk were removed by denudation from 
the south-east of England. The true extent of the unconformity 
between the Chalk and our oldest Eocene strata is now to be seen 
only where the Eocene cover yet remains. Even where the Chalk is 


' The Mineral Industry, vol. xxiv, p. 687, 1916, and vol. xxv, p. 724, 1917; 
Mining and Scientific Press, May 27, 1916. 
? Scrivenor, loc. cit., p. 7. 


of the Chalk in the London Basin. 297 


so covered, the unconformity must have been accentuated to some 
extent in consequence of the solvent action of percolating carbonated 
waters, the evidence of which is familiar to us as ‘‘ pipes”’ in the 
Chalk filled with Eocene strata, and the persistent bed of unworn, 
green-coated flints (‘‘ Bull-head” Bed) which everywhere occurs 
between our lowest Eocenes and the Chalk; but such secondary 
action is likely to have been more or less uniform throughout the 
whole area beneath the Tertiary cover. 

Thanks to the steady accumulation of data concerning well-borings 
and the energies of various workers who have given cartographical 
expression to the information thus made available, we have now 
a good working knowledge of the present contours of the Chalk 
surface within the London Basin beneath the Tertiary cover. ‘The 
present configuration of this Chalk surface is, of course, widely 
different from that which it presented at the time of the deposition 
of our oldest Eocenes, in consequence of the tilting and warping 
effects of later movements. Nevertheless, in regard to the area 
within the immediate vicinity of London, we have some knowledge 
of the effects of these post-Cretaceous movements upon the Chalk 
formation, since here a number of deep borings have completely 
pierced the Chalk, thus affording us information as to the present 
level of its base. We are therefore in a position to apply a 
‘correction’, so as to reduce the base of the Chalk to a horizontal 
plane, and, having done this, to observe the form which the ccntours 
of the Chalk surface then take. If the correction be applied so as to 
cause the base of the Chalk to occupy a horizontal plane at present sea- 
level, the resulting surface-contours are then also the ‘‘isopachytes”’ 
or lines of equal thickness of the formation. 

‘The movement of elevation which set in towards the end of 
Cretaceous times and ushered in the Tertiary era appears to haye 
been a widespread and regional one, and it is reasonable to assume 
that in the area under present consideration the base of the Chalk, 
at the beginning of Tertiary times, did not deviate widely from 
horizontality. Consequently the contours of the Chalk surface 
beneath the Eocene cover, when the base of the formation has been 
corrected to horizontality, may fairly be regarded as giving an 
approximately true representation of the configuration of the surface 
upon which our oldest Eocenes were deposited. 

In order to obtain these pre-Thanetian contours of the Chalk 
surface we proceed as follows: We first plot upon the map the sites 
of the deep borings (seventeen in number) which have completely 
pierced the Chalk formation in the area under consideration, inserting 
in each case the depth below Ordnance Datum at which the base of 
the Chalk occurs. We then draw in the present contours in the 
base of the Chalk at intervals of 100 feet, working upon the available 
data, and assuming an even gradient between any boring and its 
neighbours. ‘he total number of borings not being large, the trend 
of the lines is doubtless influenced somewhat unduly by the accidents 
of boring sites, but fortunately the sites are fairly evenly distributed 
throughout the area, and the error involved is not serious. Having 
prepared this map, we superimpose upon it the map of the same area 


298 H. A. Baker—The Pre-Thanetran Hrosion 


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showing the present contours in the sub-EKocene Chalk surface.? 
The first map indicates the amount of correction to be applied to the 
base of the Chalk at any point in order to bring it to horizontality at 
present sea-level, and the superimposed map is corrected corre- 
spondingly. For example, the points at which the O.D. contour 
of the superimposed map intersects the —600 contour of the base of 


1 In this investigation the writer has used the map of the Pre-Tertiary Chalk 
surface prepared by Mr. L. J. Wills (Records of London Wells, Mem. Geol. 
Sury., 1913) and also that by Professor P. G. H. Boswell (Q.J.G.S., 
vol. Ixxi, pl. x): 


of the Chalk vn the London Basin. 299 


the Chalk are points on the 600 contour of the corrected Chalk 
surface. Similarly, points at which the —200 contour of the present 
Chalk surface intersects the —700 contour of the base of the Chalk 
are points on the 500 contour of the corrected surface, and so on. By 
joining up the similarly numbered points so obtained, the contour 
system of the corrected pre-Tertiary Chalk surface is arrived at 
(see Map 1). The numbers appended to the contours possess only 
a relative significance. The base of the Chalk might have been 
corrected so as to cause it to occupy any horizontal plane, but by 
selecting present sea-level as the datum-plane we have the additional 
advantage that the lines serve equally well as the isopachytes of the 
Chalk formation. _ 

A glance at the map reveals at once that the information afforded 
by it well repays the labour-involved in its preparation. It appears 
that the age of the Streatham—Beckton fault is pre-Tertiary, and 
from the form of the lines in the neighbourhood of Loughton we 
may suspect faulting here also. 

The first significant fact which the map brings out with great 
clearness is that in pre-Tertiary times the Chalk of this area was 
denuded in such a way as to produce escarpments facing inwards 
towards the centre of the present London Basin, thus indicating 
plainly that the central area experienced a somewhat greater uplift 
and suffered greater denudation than the district farther west. 
With the exception of a small area between Kentish Town and Mile 
End, where the Chalk has probably been protected by faulting, it 
is a noteworthy fact that the Chalk is thinnest over the area where 
the Gauit beneath it rests directly upon the Paleozoic floor, and the 
general character of the pre-Tertiary denudation of the Chalk surface 
is in very close sympathy with the contours of the Paleozoic floor 
when the latter is corrected for post-Cretaceous movements. 

The writer has elsewhere put forward the view that the area under 
present consideration lies on the south-easterly prolongation of the 
well-known Charnian Axis of Professor P. F. Kendall, and he 
inclines to the belief that the character of the pre-Tertiary 
denudation of the Chalk here points to the operation of Charnian 
posthumous movement in pre-Tertiary times. When we proceed to 
investigate the question of the zonal composition of the denuded 
Upper Chalk surface further suggestive evidence is forthcoming. 
At any rate, additional support is given to the statement made above 
that the general character of the pre-Tertiary denudation of the 
Chalk surface is closely associated with the pre-Cretaceous form of 
the Paleozoic floor. 

In endeavouring to insert upon the map the positions of the 
boundaries of the zonal outcrops beneath the Eocene cover we are at 
once confronted with the difficulty that we have as yet little 
knowledge of the thicknesses of the various zones of the Upper 
Chalk in and near this area. It has been possible, in the case of 
some of the borings, from the details given in the journal, to effect 
the division between Lower, Middle, and Upper Chalk, and some- 
times horizons easily recognizable lithologically, such as the Melbourn 
Rock and the Chalk Rock, can be identified. Apart from this we 


300 H, A. Baker—The Pre-Thanetran Erosion 


are dependent upon the information forthcoming from workers who 

have studied the Chalk of neighbouring districts. It is fairly 
certain, however, that except in the west the whole of the sub- 
Kocene surface of the area under present consideration is occupied by 
_ the outcrop of the thick zone of Dicraster coranguinum. At Crossness 
the Chalk proved to be 684 feet thick, but the Chalk exposed to 
view in the Woolwich district, not far away, is, to the writer’s 
personal knowledge, clearly referable to the Jf. coranguinum zone. 
Of the 654 feet of Chalk occurring at Mile End, 259 feet were 
assigned to the Upper Chalk, and, since allowance must be made for 
the Chalk Rock and the J. cortestudinarium zone, it is not likely 
that any higher horizon than that of JL coranguinum occurs here. 
Even in the case of the 700 feet of Chalk which occurs between 
Kentish Town and Mile End the statement still holds good. If we 
take the thicknesses of the Lower and Middle Chalk as recorded at 
Mile End, allow only 10 feet for the Chalk Rock and 50 feet for the 
zone of I. cortestudinarium, we are left with 225 feet of Chalk, and 
it is hardly likely that the I. coranguinum zone is much less than 
this in thickness. 

Where the Chalk decreases to 500 feet in thickness, as it does 
between Loughton and Turnford, the question arises as to whether 
the W. cortestudinarium zone there composes the sub-Kocene surface. 
At Turnford 406 feet were assigned to the Lower and Middle Chalk 
and 15 feet to the Chalk Rock. Allowing 50 feet for the JL cor- 
testudinartum zone, we are still left with about 380 feet of 
M. coranguinum Chalk. Hence, as already remarked, it is fairly 
certain that except in the west the whole of the sub-Eocene Chalk 
surface of our area is occupied by the outcrop of IL coranguinum 
Chalk. 

But in the west a different state of affairs obtains. Here the 
Chalk reaches a thickness of as much as 950 feet in the neighbour- 
hood of Beaconsfield, and 900 feet a little further south at Taplow. 
In this neighbourhood two deep wells have completely pierced the 
Chalk, one at Slough and the other at Winkfield. With regard to 
the first, beyond the fact that the Chalk was found to have a thick- 
ness of 778 ft. 10 in., no further particulars concerning the formation 
appear to be available. But in the case of the Winkfield well we 
are more fortunately situated. A full account of this has been 
published,’ and we are in possession of the information that the 
Lower Chalk was 219 feet thick, the Middle Chalk 169 feet, the 
Chalk Rock 8 feet, and the Upper Chalk 829 feet. Turning now to 
other authorities for information, we find that Mr. H. J. Osborne 
White ? suggests 50 feet as the thickness of the JZ. cortestudinarium 
zone and 220 feet as that of the JZ. coranguinum zone in this area. 
Adopting these figures, we find that at Winkfield we get 666 feet as 
the thickness of the Chalk from the base of the formation to the base 
of the Marsupites zone, thus leaving 59 feet of Chalk for the latter 


1 Water Supply of Berkshire (Mem. Geol. Sury.), 1902, pp. 95-6. 


* “Berkshire and Part of the Thames Valley’’: Jub. Vol. Geol. Assoc., 
pt. 1i, 1910. 


of the Chalk vm the London Basin. 301 


zone here. Again, fortunately we find two other conveniently 
situated borings supplying information which can be combined with 
these figures. In the well-known deep boring at Richmond Water- 
works the Lower Chalk was 220 feet thick, the Middle Chalk 
145 feet, the Chalk Rock 5 feet, and the Upper Chalk 300 feet. 
Adopting the figure of 50 feet for the thickness of the J. cor- 
testudinarium zone, it is further necessary to take a figure for the 
thickness of the IL coranguinum zone at Richmond. Bearing in 
mind the recorded thickness of 280 feet for this zone further east in 
Kent, the writer adopted as a working figure 250 feet for the 
thickness of JL. coranguinum Chalk at Richmond. Hence, at the 
latter site, the level of 670 feet above the base of the formation, for 
the base of the Alarsupites zone, was arrived at. The third boring 
site affording information is that at Bushey (Colne Valley Water- 
works), where the Lower Chalk was 255 feet thick, the Middle Chalk 
267 feet, the Chalk Rock 8 feet, and the Upper Chalk 156 feet. In 
the absence of any evidence to the contrary the thicknesses of 50 feet 
for the IL cortestudinariwm zone and 220 feet for the AL. coranguinum 
zone may be taken, and the level of 800 feet above the base of the 
formation for the base of the J/arsupites zone is supplied. Having 
now three suitably situated working levels for the base of the 
Marsupites zone, and the present map, the plotting of the concealed 
boundary between I coranguinum and MMarsupites Chalk becomes 
a simple problem in geometry. ‘The result is indicated on the map. 
In view of the possibility that the figure taken for the thickness of 
M. coranguinum Chalk at Richmond (250 feet) may be a little 
excessive, the boundary perhaps lies a httle further south between 
Winkfield and Richmond than is represented. 

Mr. Osborne White gives 70 feet as the superior limit of thickness 
of the Marsupites zone in Berks and Bucks, and the position of the 
upper limiting boundary of the zone is inserted on the map in 
accordance with this figure. On the assumption of an average 
thickness of 25 feet for the Uintacrinus subzone the line of division 
of the latter from the Marsupites band can also be inserted. 

Field-workers, in referring to the interesting development of 
phosphatic Chalk of the Marsupites zone, seen at Taplow, have stated 
that it is not improbable that the poorly exposed upper part of the 
section belongs to the succeeding zone of Actinocamax quadratus, 
although the latter has so far been identified in only two places, 
namely, Borough Hill, west of Winterbourne, and Kintbury, both 
these places being well to the west of the Taplow-—Beaconsfield 
district. Our present map strongly suggests the existence of the 
A. quadratus zone in the latter area, and is an interesting incentive 
to field-workers in that district. From the figures already adopted 
it will be seen that a thickness of 736 feet accounts for the whole of 
the Chalk in this area from the base of the formation to the top of 
the Marsupites zone, and this after giving to the latter its maximum 
thickness of 70 feet. Consequently it follows that in the neighbour- 
hood of Beaconsfield there is still a thickness of rather more than 
200 feet of Chalk to be accounted for, and hence it appears practically 
certain that there the A. guadratus zone possesses a good thickness. 


302 H. A. Baker—The Pre-Thanetian Erosion 


Future quarrying operations in the neighbourhood should prove 
interesting. 

To the writer the point of greatest interest was the discovery that, 
as the concealed zonal outcrops approach within the sphere of 
influence of the ancient Charnian ridge, they suffer an abrupt change 
of strike and take on a northerly as well as a westerly trend. The 
evidence seems convincing that in this area the belt of maximum 
denudation of the Chalk in pre-Thanetian times possessed a 
N.W.-S.E. alignment, and this fact must be ascribed either to 


Miles. 
9 5 10 20 


‘Map showing confours in ! 
the Sub--Fotene and Sub-— 
Pliocene Chaik surface when «— 
the base cf the chalk is cor- 
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sea-level . 
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isopachyles oj of theChalk \ \\ iw A oh \ \ \ oi] ces 
Resa e Challe eT \ 
—o—o-Boundaries of Tertiarie> eae oa 


—+—+Boundary of Ga / \ 
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\ N ° jo52 & | 
A a2 
No 5 / 
x a e 


| 
| 
| 


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ee Actinocamax 
| Marsubiles den e 
{ arwich 
quadratys 659 
B SUPFCLK 


yy AREA 
: Weeley 
Fig 2. G25. H 


the influence exerted by the form of the Paleozoic floor at that time 
or else to the operation of Charnian posthumous movement during 
the erosion of the Chalk. The area furnishing this evidence of 
a tendency on the part of the Chalk zonal outcrops to assume a 
N.W.-S.E. alignment is very small, but considering the great extent 
to which the erosion of the Chalk has been carried during later 
times, the fact that even some evidence of this tendency has been 
preserved to us can only be regarded as a fortunate accident. 

We are, perhaps, hardly in a position to consider the question of 


of the Chalk wn the London Basin. 303 


the precise manner in which this pre-Thanetian denudation of the 
Chalk was effected, but it appears likely that land existed here in 
Montian times and that strike streams ran at the foot of the escarp- 
ment, their direction being influenced by the presence of the ridge 
which proceeded from west to east by way of Southall and Chiswick. 
It is perhaps more than coincidence that the course of the present 
Thames shows a tendency to adhere to the same direction. 

Interesting light is thrown on the question of the source of the 
material composing the Lower Eocenes of the London area. It 
seems clear that the material must have come from the east; it can 
hardly have been carried from the west over the escarpment. We 
have good reason to believe, too, that at this time, to the south of 
the present area, the Wealden uplift had already been initiated, and 
the interesting question is raised as to whether the denudation 
of the Chalk had been carried, by Thanetian times, to an extent 
sufficient to expose to eroding influences an adequately large area of 
the Lower Greensand to furnish the arenaceous material of the 
Lower London Tertiaries. 

A simple movement of submergence appears all that is necessary 
to explain the overlapping of the Thanet Sand by the Reading Beds 
in our area, and with regard to the development of the Lower 
London Tertiary Pebble-beds (Blackheath Pebble-beds) in the 
Woolwich, Blackheath, and Bromley districts, it appears feasible to 
suppose that these accumulated as banks against the easterly 
prolongation of the Southall—Chiswick ridge. 

In view of the notable scarcity of borings which have completely 
pierced the Chalk in Essex, we are very ignorant concerning the 
present level of its base in this county and are, in consequence, 
unable to adopt the present method of investigation here. In 
Suffolk we have more data to work upon, but the area of Chalk yet 
remaining beneath the Eocene cover is very limited for our present 
purpose. Nevertheless, when the base of the Chalk is corrected to 
horizontality, several interesting points are brought out. The Chalk 
surface in this county is then seen to slope away east, west, and 
south from an area of maximum elevation (over 1,200 feet) situated 
between Beccles and Bungay. This area of maximum elevation 
extends north-westward to a spot a little east of Norwich, and is 
evidently the sole relic of an elevated Chalk area which once 
extended much further to the west. In fact, the downward westerly 
slope from this district, beneath the Crag deposits, is clearly the 
result of post-Eocene and pre-Crag denudation of the Chalk. The 
southerly and easterly slopes are, however, facts of deeper significance, 
since these are found beneath the area where the Eocene cover yet 
remains. There is a drop of 200 feet between Beccles and Aldeburgh 
(which is only another way of saying that the Chalk is 200 feet 
thicker in the former place than in the latter), and hence we haye in 
this area the last remaining evidence of the escarpment (now become 
very gently sloping although more elevated) which faced south- 
eastward and stretched away many miles to the west and south. 
The easterly slope of the corrected Chalk surface from Beccles to 
Lowestoft (or thinning of the Chalk formation in that direction) is 


| 


304 H. A. Baker—Pre-Thanetian Erosion, London Basin. 


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J.T. Jutson—Interpretation of Dry Lakes. 305 


a fact that might have been somewhat surprising if we had not been 
partially prepared for it. The Chalkis about 150 feet thicker at 
Beccles than at Lowestoft. The present writer has endeavoured to 
show elsewhere that this area has been affected by posthumous 
movements of an ancient axis which he considers to run parallel 
with Kendall’s Charnian Axis, eastward of Kent, into North France. 
We notice here what we are also apparently able to detect in the 
London area (see section), that during the deposition of the Chalk 
(and possibly to some extent during the deposition of the Gault) 
there was a definite movement of depression along the line of the old . 
axis whereby a somewhat greater thickness of sediment accumulated 
vertically above them than elsewhere. Lowestoft lies somewhat to 
the east of the line of the easterly axis and hence the decrease in 
thickness of the Chalk is accounted for. On this view it follows that 
a great thickness of Chalk must have been removed by denudation 
from the district to the north-west of Norwich, since over 1,350 feet 
of the formation yet remains beneath the Eocene in the neighbour- 
hood of Mundesley and Happisburgh. 

With regard to the zonal outcrops of the Chalk beneath the 
Eocene cover in Suffolk and Essex, the Ostrea lunata zone evidently 
does not occur here, but the line of separation of the Belemnitella 
mucronata and Actinocamax quadratus zones probably runs from 
south-east to north-west beneath the Suffolk Kocenes, meeting the 
coast somewhere in the neighbourhood of Harwich. After emerging 
from beneath the Eocenes westward of Bramford the boundary turns 
sharply to the north as the result of later denudation. The boundary 
between the A. guadratus and Marsupites zones occurs a little to the 
west of Hadleigh, and, beneath the Eocenes, probably sweeps off 
to the south-west. The same may be said of the boundary between 
the Marsupites and ML. coranguinum zones, which occurs a little to 
the west of Sudbury. 

In conclusion, it may be remarked that when the Chalk of Essex 
comes to be better known it will probably be found to be affected by 
a great fault stretching across the whole county from the neighbour- 
hood of Cliffe, in Kent, to near Dunmow and Thaxted, as a result 
of which Chalk of the J/arsupites zone, on the eastern side, is placed 
in juxtaposition with the MZ. coranguinum zone on the western side. 

The section accompanying the present paper is drawn from the 
data suppled by maps showing contours on the Paleozoic floor, in 
the base of the Gault, and the base of the Chalk, prepared by the 


writer at various times. 


ITV.—On rue Occurrence AND INreRPRETATION OF Rock-CLiFFs AND 
Rock-F1Loors on THE WesteRN SuHores oF THE ‘‘ Dry” Lakes IN 
Soura-CrntrRAL WersTERN AUSTRALIA. 

By J. T. JuTSoNn, Geological Survey of Western Australia, Perth. 
Inrropucrion. 
N South-Central Western Australia, in the physiographic division 
which the writer! has termed the Central or Salt Lake Division, 
in a large portion of which the average annual rainfall is about 
1 “An Outline of the Physiographical Geology (Physiography) of Western 
Australia ’’: Bull. 61, Geol. Surv. W. Australia, Perth, 1914, p. 52. 
DECADE VI.—VOL. V.—NO. VII. 20 


306 J. T. Jutson—Interpretation of the Dry Lakes 
10 inches per annum, numerous ‘‘dry” lakes or playas occur.’ 
These have been described and the question of their origin has been 
‘discussed by various authors.2 They have been differently regarded 
as due to glacial, marine, and wind action; also as the remains of 
old Tertiary rivers now largely obliterated by drifting sands; and 
also (in part) as deformation basins. Most writers agree that they 
have been formed under subaerial conditions, and probably most 
will ultimately agree that deformation is responsible for some at 
least of the lakes, or has aided in their formation. 

The theory of a migration of the lakes has also been advanced by 
the present writer. 

Like most other land forms the lake will probably, by further 
research, be shown to be due to no single cause, but to a combination 
of agents of different relative importance. 


SUMMARY. 


This paper describes certain features of the ‘‘ dry” lakes in South- 
Central Western Australia. These features, which repeatedly occur 
over a wide area, indicate, in the writer’s opinion, that the lakes are 
migrating westward; and that wind erosion is playing the dominant 
part in such migration, and consequently in the present forms and 
position of the lakes. Such features are the presence of rock-clifis 
and rock-floors on the western, north-western, south-western, and, 
to a less extent, on the northern sides of the lakes; and the absence 
of such cliffs and floors on the eastern, south-eastern, north-eastern, 
and southern sides of the lakes, the place of such cliffs and floors 
being taken by sand dunes, sand plains, and silts. The facts set forth 
are regarded as confirming, to some extent, the idea of the late 
H. P. Woodward that the ‘‘dry”’ lakes are due to wind action.® 


1 Salts are precipitated on the lake floors on the evaporation of the transient 
thin sheets of water, but so far as the writer is aware there is no thickness of 
salt on any of the lakes. The terms ‘‘salt lakes’’ and ‘‘salt lake division ”’ 
are therefore misnomers. ‘‘ Dry lakes’’ or ‘‘ playas’’ more suitably indicate 
the character of the lakes, but as the latter are frequently connected with one 
another by defined or ill-defined channels, and as many undoubtedly lie along 
the main drainage lines of the country, the writer has suggested the term 
‘‘stream-lake system’’ for this dual capacity of portions of the drainage 
system. The terms ‘“‘salt lakes’’ and ‘‘dry lakes’’ have become so firmly 
rooted in local usage that they will probably remain. It is difficult to suggest 
a suitable name for the physiographic division instead of “‘ salt lake division’’. 
‘“Dry lake or central division’’ would perhaps be the least objectionable 
of any. 

2 As to various theories, see J. W. Gregory, “‘The Lake System of 
Westralia,’? Geog. Journ., June, 1914, pp. 656-64, map. See also C. G. 
Gibson, Bull. 37, Geol. Surv. W. Austral., 1909, p. 12, and Bull. 42, Geol. 
Surv. W. Austral., 1912, pp. 11, 12; J. T. Jutson, op. cit., pp. 138-58, 
and also Geog. Journ., December, 1917, pp. 418-37, map, figures; A. 
Montgomery, Journ. Roy. Soc. W. Austral., vol. ii, pp. 59-96, map, 1915-16; 
J. W. Gregory, Geog. Journ., October, 1916, pp. 826-31; and C. 8S. Honman, 
Bull. 71, Geol. Surv. W. Austral., 1917, p. 144, and Bull. 73, Geol. Surv. 
W. Austral., 1917, p. 17. 

° GEOL. MAG., August, 1897, pp. 363-6. 


an South-Central Western Australia. . 307 


Move or Occurrence or THe Rock-Cuirrs anp Froors, anp 
AssociateD Frarures. (Map I.) 
The lakes are generally long in proportion to their width, so that 
when their trend is referred to it is intended to indicate the direction 
of the lake along its ‘‘length”. The trend of different lakes may be 


a s f ue Tak s 
é 6 L_EQNCRA 

e 
Xe 

20° ComerVatse( PilGoongan Le W\< 
QCYCARRIE® Z 1 
i L. Gordon 

a By j 


eKanowna 


i fi 
boca sa le , Me ee ie 
ot VeSea Gree ert ces ; AG L.Yindar lgenda 
of Coo. garde e S5) caer te i 
Vv é a 


0 “ve 
a Sourseen (‘oss yw or [2 Lefroy. 


4 
Aan i \ 
eds 


Sournern Ocean 


Seale of Mifes 


Q 


Map I.—Showing the principal ‘‘ dry’ lakes in South-Central 
Western Australia. 


308 J.T. Jutson—Interpretation of the Dry Lakes 


in almost any direction. Many vary from approximately north and 
south, through north-north-west, north-west, to west-north-west. 
Some trend north-easterly, and others are approximately east and 
west. Probably, however, in the main there is an approximation to 
north and south with variations to the east and to the west of north 
respectively. When the term ‘“‘ western shore’’ or ‘‘ western side” 
is used in this paper, it is meant to include not only the true 
western shore when the lake trends approximately north and south, 
but also the south-western or north-western shore when the lake 
trends north-west or north-east respectively, because the remarks 
below as to rock-floors and cliffs apply to the westerly shores as a 
whole, despite the defiection of the trend of the lakes from north 
and south. 

Along the western shores of many, and along the northern shores 
of some, of the lakes, rock-cliffs and rock-floors occur. The eastern 
and southern shores are usually destitute of these features, which 
are replaced by silt floors, sand dunes, and sand plains. 

The cliffs are rocky, generally steep, and frequently form very 
prominent features in the landscape, when they project as a series of 
bold headlands into the lake. So far as known, the commonest 
rocks forming the cliffs are what may be called ‘‘greenstones’’, 
a field term which includes many kinds of basic igneous rocks, 
which, however, need not be enumerated here. Cliffs are also 
formed of ‘‘jaspers’’ (quartz hematite schists) and granites. At the 
base of the cliffs rock floors of similar or associated rocks frequently 
occur. These floors are of such smoothness that the writer has 
termed them ‘‘billiard-table rock-floors’”. They may be visible 
outward from the base of the cliffs only for a chain or two or they 
may extend for hundreds of yards up to a mile or more. Such 
floors tend to be covered by the fine silts of the lake, and as these 
silts vary in thickness and superficial area (although little is yet 
known as regards their thickness), the extent of the floors exposed 
also varies. 

The rocky cliffs are being worn away by various agents of erosion, 
the nature of which is described when discussing the meaning of the 
rock-cliffs and floors. 

Some lakes may have no rock-cliffs on any side, but the writer is 
not aware of any with cliffs on the eastern side. It is possible that 
such last-mentioned cliffs nevertheless do occur, but if so they must 
be rare. 

Small valleys may enter lakes, and the lower portions of such 
valleys may, by lateral erosion, become arms of the lakes. 


EXAMPLES OF LAKES WITH THE FEATURES DESCRIBED IN SourH- 
CentraL Western AvsrraLia. (Map I.) 


Kurrawang Lakes, south of the railway line between Kalgoorlie 
and Coolgardie. According to C.S. Honman’s maps and descriptions ' 
the lakes are bounded on the west and north by rock-cliffs, and on 


1 Bull. 56, Geol. Surv. W. Austral., 1914, pls. i, ii, fig. 1, pp. 10-12, 34. 


in South-Central Western Australia. 309 


the south and east by sand plains and sand dunes. The prevailing 
wind is stated to be north-westerly.? 

Hannan's Lake, south-east of Kalgoorlie. Honman’s maps and 
descriptions” show that rock-cliffs and rock-floors occur on the 
western shore of the lake, and sand dunes and sand plains on the 
southern and south-eastern shores, the material forming the dunes 
and plains being blown from the north-west. Honman also refers 
(p. 36) to the migration of the lake to the north-west owing to this 
removal of material. 

Lakes Carey, Raeside, Rebecca, and Goongarrie.—These lakes form 
a remarkable group. ‘hey all lie to the east of the railway line 
running north from Kalgoorlie to Leonora, Lake Carey being the 
most easterly and Lake Goongarrie the most westerly. Lakes Carey, 
Raeside, and Rebecca have been mapped and described by Honman, 
who states* that they all run north-west and south-east; that all 
have escarpments and rock-floors on the western sides and sand dunes 
on the eastern; that the rock flooring on the western side is probably 
due to migration; and that the fact that the rock-flooring is on the 
western side in the case of every lake in the district is probably due 
to the prevailing direction of the wind being from the south-west.‘ 
The writer can confirm from personal observation the occurrence of 
rock-cliffs and floors on the western side of Lake Raeside and their 
absence, in the areas seen by him, on the eastern. The writer's 
observations in regard to Lake Goongarrie, which trends north and 
south, show that rock-cliffs and rock-floors occur on the western 
side, and sand plains and sand dunes on the eastern. The dominant 
winds appear to be westerly. Another moderately large lake, west 
of Lake Goongarrie and of the railway line, has not been examined 
by the writer. 

Lakes north of Southern Cross.—T. Blatchford® points out that 
wind-blown deposits occur on the southern or south-eastern edges of 
the lakes, the northern and western shores being usually more or less 
precipitous with bare rock-floors or covered with very thin deposits. 
He concludes that the lakes are migrating westward, and from his 
remarks the prevailing winds are probably north-westerly. 

The Johnson Lakes, Bremer Range. Honman‘® in referring to these 
lakes states that on the north-western side are found hard rock 
outerops and cliffs, and on the south-eastern blown sand and gypsum, 
forming wide sandy slopes and dunes, due to wind action. 


Oya, Chins 10s AL saver, Ale 
2 Bull. 66, Geol. Surv. W. Austral., 1916, pl. i, pp. 11, 36. 
3 Bull. 73, Geol. Surv. W. Austral., 1917, pp. 17-19. 
It might here be noted that Honman accepts J. W. Gregory’s theory on the 
lakes asa whole as dismembered river systems. See Bull. 71, 1917, p. 144, 
and Bull. 73, 1917, p. 17, Geol. Surv. W. Australia. He also notes (Bull. 71, 
p. 15) that Lakes Carey, Raeside, and Rebecca cross the strike of the rocks, 
and suggests that these lakes may belong to a different cycle of erosion un- 
influenced by geological structure. On the ancient river theory, it could be 
contended in explanation of this feature that the old streams were superposed. 
The question cannot be discussed here. It will be dealt with elsewhere. 

° Bull. 71, Geol. Surv. W. Austral., 1917, pp. 23, 24. 

§ Bull. 59, Geol. Surv. W. Austral., 1914, p. 195. 


4 


310 J.T. Jutson—Interpretation of the Dry Lakes 


WeEsTEAN 
AUSTRALIA 


NORTHERN 
| JERRITORY, 


o LEONORA 


eAALGOORLIE 


Sours Ausrraual 


FC OM or One 


( . * Rocky country, 
Sat in places high 
. and rermnaled 


by steep clhiths. 
os Sand ridges} 


and sand plains 


ABCD tne 
of Section 


Fig.3 ak 
Hf Bedrock == Silts 33: Sands. 


Map II.—Iig. 1: Locality map of the southern portion of Western 
Australia. Fig. 2: Generalized plan of a ‘‘ dry’? lake with rock- 
cliffs and rock-floor. Fig. 3: Diagrammatic section across a 
“dry ’’ lake from west to east, showing (A) the rock-cliffs and 
rock-floor (B) on the western side, fine silts (c) towards the eastern 
side, and blown sands (D) encroaching on the eastern margin of 
the lake. 


an South-Central Western Australia. all 


Lake Cowan, Norseman. W. D, Campbell’s maps and descriptions ' 
of this lake clearly show that rock-cliffs exist on the western shore 
and blown sands on the eastern. 

Lake Barlee—H. W. B. Talbot’s maps*® show this lake to be star- 
shaped; but where north and south trending portions of the lake 
abut rock ridges, the latter are on the western shore of the lake. 

Lake Gordon, near Kanowna. This lake has rocky cliffs on the 
western shore and sands on the eastern, as personally observed by 
the writer. 


Mranine oF THE PHENOMENA DESCRIBED. 


The facts stated above appear to decisively indicate that the 
occurrence of rock-cliffs and rock-floors on the western sides of 
“dry” lakes, and their absence on the eastern sides (with replace- 
ment on such eastern sides by sand and silt), are not merely 
coincidences. There must be some agent now or formerly operating 
with dominant power over wide areas in order to produce such 
remarkable uniformity of conditions. Such power seems to be 
restricted either to marine erosion, or to erosion by terrestrial waters, 
or to wind erosion. These possibilities are now considered. 

Marine erosion does not seem to apply, for reasons that will be 
briefly stated. (1) No evidence has been adduced that the country 
has been recently submerged beneath the ocean farther north than 
Norseman,’ which is about 129 miles north from the southern coast 
of Australia. This distance, however, is short in comparison with 
the north and south length of the belt occupied by the ‘‘ dry”’ lakes. 
(2) The marine theory claims that the forms of the cliffs are due to 
marine erosion. It therefore assumes that these cliffs have practically 
sustained no erosion since their supposed emergence from the sea; 
an assumption the validity of which is at once questioned owing to, 
the fact that normal subaerial erosion—apparently to a considerable 
extent—has taken place near the coast since the last undoubted 
emergence from the sea of the coastal lands, and consequently 
subaerial erosion farther inland must have also occurred. (3) The 
effect of present erosional processes is ignored. (4) As there are 
long sub-parallel lines of cliffs forming the western shores of lakes, 
such cliffs, on the theory of marine erosion, could only be produced 
by many distinct uplifts, with pauses long enough to allow the lines 
of cliffs to be successfully eroded. This means that the country 
should rise by a series of marine-cut very wide benches one above 
another, a state that, so far as all knowledge of the country goes, 
does not exist. Moreover, as the cliffs face the east, the emergence, 
on such theory, must have been from west to east, that is, away 
from the present western coastline, the last land to emerge being 


Bull. 21, Geol. Surv. W. Austral., 1906, p. 21, and plate. 

Bull. 45, Geol. Surv. W. Austral., 1912, pls. i, il. 

Well to the east of Norseman the sea in probably Miocene times was much 
farther north, but this formerly sea-coyered land is outside the area discussed 
in this paper. 


1 
2 
2 
3 


312 J.T. Jutson—Interpretation of the Dry Lakes 


towards the South Australian border. Again, no evidence of this 
has been adduced. 

Krosion by terrestrial waters, either by river or lake, seems also- 
inadequate to explain the facts. Fluviatile action cannot be con- 
ceived to produce such forms in their present positions. Former 
deep permanent lakes could produce cliffs, but such cliffs would not. 
be restricted to practically one side only, nor, stating the matter in 
another way, would the high belts of country be bounded by lakes, 
and the rock-cliffs of such lakes, on mostly one side only. Further- 
more, there is at present no evidence available that such deep 
permanent Jakes ever existed. Lacustrine deposits, with abundant 
fossils, should occur, but so far they have not been discovered, apart 
from the leaves in a deep alluvial deposit at Coolgardie. Rock 
benches are characteristic marks of former deep permanent lakes, but 
none has ever been found.! With regard to the action of the present 
lake waters, as they remain for such a short period and, so far as 
observed by the writer, are only a few inches deep at the margin, 
abrasion by such waters seem out of the question, although there is 
probably some removal of fine detritus from the base of the cliffs by 
the lapping of the transient waters. Moreover, the objection as to 
abrasion on practically one side only, also applies to the present lake 
waters. 

There remains, then, but wind erosion, and this most satisfactorily 
explains the facts as at present known. It is not claimed that wind 
erosion alone is competent to produce the cliffs and rock-floors, and 
to cause the lakes to migrate. The subaerial agents of erosion, 
comprising insolation, ‘‘exsudation,”’ the beating action of rain, and 
general atmospheric weathering, are wearing down the cliffs and 
rock-floors, and the gentle lapping of the lake waters may remove 
some of the detritus. The wind, however, seems to be the 
dominating agent, partly by corrasion, but chiefly by deflation. 
The debris is swept away from the cliffs, thus allowing their further 
destruction, and the billiard-table floors are produced. Sand is 
carried around or across the lake by the wind and deposited on the 
eastern and other sides. This, aided by the deposition of fine silt 
on the lake floor, forces the water westward, thus assisting to bring 
about its migration. In the course of such migration higher rock 
belts are met, cliffs formed, and then gradually worn back. Hence 
rock-cliffs and rock-floors occur on the western sides, and sands on 
the eastern. 

If migration has occurred to any extent, and if such migration is 
chiefly due to wind erosion, then, without regard to other consider- 
ations, the lakes are undoubtedly, in part at least, deflation lakes. 


' It is not contended that larger lakes never existed. They have possibly 
done so, but there is no available evidence that they formed deep permanent 
lakes. What evidence there is points, in some instances, to wider areas of 
shallow ephemeral lakes or playas practically similar to those now in existence, 
and to the probability that such greater lakes have, owing to local conditions, 
shrunk. In other instances the migration of a lake may account for an 
apparently greater former lake of the playa type. 


in South-Central Western Australia. Ss 


This conclusion thus bears out, to some extent at least, Woodward’s 
original idea that such lakes are due to wind action. 

In their general trend, the lakes lie along drainage lines—more or 
less dismembered and probably in part deformed—which have been 
formed under existing conditions or have belonged to an old river 
system when the climate was moister and perhaps the country lower 
than at present, as suggested by Gibson and J. W. Gregory. That 
they are the remains of an ancient river system formed under 
different climatic conditions than those of to-day has not yet been 
demonstrated ; but if it were, such demonstration would not, in the 
writer’s opinion, invalidate the conclusion that portions at least 
of the lakes and the striking characteristics, the subject of this paper, 
are dominantly due to wind erosion. 

_Few observations have as yet been recorded as to the dominant 
direction of the wind, but from the writer’s personal, although 
limited, observations in the Comet Vale—Goongarrie district, made 
since writing his physiography of Western Australia, and the paper 
referred to above in the Geographical Journal, it may be said that 
although there is perhaps no prevailing wind, yet the dominant wind 
appears to be from the west (north-west, west, or south-west). As 
shown above, Honman and Blatchford also hold that the dominant 
wind is from the same quarter. 

Woodward! has noted the retarding effect of the ground-water 
table on wind erosion on lake-floors, and this feature may help to 
explain the very even surfaces of the billiard-table rock- floors, the 
wind receiving at least a temporary check on reaching the more or 
less saturated zone. Honman? also believes that during lake 
migration the rock-floor is kept level by moisture. The silts of the 
lakes are always moist, except perhaps, at times, the actual surface 
film. A moist surface, in addition to preventing the removal of 
material, may also, as pointed out by A. W. Grabau, with regard to 
the American playas,’ catch dust particles carried across the surface 
by the winds, and by this means the thickness of the deposits may be 
increased. Hence the silts of the eastern portions of the ‘‘dry” 
lakes may be partly wind-blown, and not entirely due to deposition 
under water, this wind-blown material being probably derived from 
the western areas.‘ If such wind transportation does take place it 
shows that, despite its retarding effect, the hygroscopic character of 
the silt is not an absolute bar to wind transportation, probably 
because the actual surface may (at various times at least) be 
sufficiently dry to allow such transportation. In any event, however, 
from the facts set out in this paper, it seems clear that the wind can 
and does remove material from the western sides of the ‘‘dry”’ lakes. 


1 Op. cit., p. 365. 

* Bull. 66, Geol. Surv. W. Austral., 1916, p. 36. 

* Principles of Stratigraphy, New York, 1913, p. 603. 

* Dust is no doubt also caught by the lake waters when they are in 
existence, and this is then deposited as an aqueous sediment. 


314 Dr. F; R. Cowper Reed—The genus Homalonotus. 


V.—Nores on THE GENUS HOMALONOTUS. 
By F. R. CowPEr REED, Sc.D., F.G.S.. 
(Concluded from the June Number, p. 276.) 


6. Burmeisteria, Salter, 1865. 


(J\HE type of this section is the Lower Devonian species Homalonotus 
Herschelt (Murchison)! from South Africa and the Falkland 
Isles.? The characters of the section were stated by Salter to be as 
follows: ‘‘ Elongate, convex; head triangular, eyes approximate on 
gibbous cheeks. Glabella distinct, lobeless, spinous. Thorax slightly 
lobed and spinous, as is also the many-ribbed pointed tail.” It 
should at once be stated that the type-species has neither a lobeless 
nor a spinous glabella, and Salter apparently added in these characters 
from the Rhenish H. armatus, Burm., which he included in the 
section. The only British form quoted by Salter is one from Devon- 
shire based on a pygidium which does not conform to the above 
definition and was described under the name WZ. elongatus.* 
Woodward,t in reviewing the Devonian species of Womalonotus, 
follows Salter in including the latter species in Burmeisteria. . 

The course of the facial sutures in H. Herschel: is important; they 
bend in rather suddenly in front, so as to form a transverse, gently 
arched or sinuated commissure and meet in the middle at a very 
obtuse angle. The pre-glabellar area is large, but the pre-sutural 
area is very narrow, as in H. Knightiv. The parallel epistomal 
sutures arise nearly at right angles to the transverse commissure, 
and cross over the margin to the inferior surface. The epistome itself 
has a median apiculus projecting in front of the margin of the head- 
shield, which is otherwise subtruncate. Lake’s species H. colossus,° 
also from the Bokkeveld Beds of South Africa, is represented as 
possessing a similar epistomal projection, and in the Brazilian 
species /7Z. noticus, Clarke,® it is also developed. 

It can hardly be doubted that Salter included more than one 
species of Homalonotus under the one specific name H. Herscheli, 
though Clarke (op. cit.) seems inclined to question it. Lake (op. 
cit.) and Schwarz’ have established several new closely allied species 
from the same South African beds, and an examination of Salter’s 
original types, now in the British Museum, has convinced me that 
H, Herscheli admits of division. The typical form is shown by the 
head-shield (No. 11276) illustrated in his figure la, 6, ¢; this 
specimen comes from the locality Leo Hoek and has a transverse 
shape, a distinctly lobed glabella, and no coarse tubercles or spines on 
the surface, except two or three small ones on the pleuro-occipital 
ring, the general surface of the head-shield being merely ornamented 
with almost equidistant, widely spaced, coarse granules. The facial 
Salter, Trans. Geol. Soc., ser. 11, vol. vii, p. 215, pl. xxiv, figs. 1-7, 1856. 
Clarke, Hoss. Dev. Parana, 1913, p. 93, pl. iii, figs. 1-4. 

Salter, Mon. Brit. Trilob., p. 122, pl. x, figs. 1-2. 

Woodward, GEOL. MAG., Dec. IV, Vol. X, p. 29, 1903. 

Lake, Ann. S. African Mus., vol. iv, pt. iv, p. 216, pl. xxvi, fig. 1, 1904. 
Clarke, op. cit., p. 89, pl. i; pl. ii, figs. 1-13. 

Schwarz, Rec. Albany Mus. S. Africa, vol. i, No. vi, pp. 382-91, 1906. 


a &- © bo 


a 


~1 


Dr. F. R. Cowper Reed—The genus Homalonotus. 315 


sutures cut the lateral borders in front of the genal angles; the 
paraglabellar areas are sunken and circumscribed. The pygidium 
having the same ornamentation is No. 11282, figs. 7a—d, from the 
same locality; this has an interrupted median row of tubercles on 
the axial rings, with a lateral row of rather larger ones on each side ; 
there are only about half a dozen small tubercles, rather irregularly 
disposed, on the lateral lobes. The head-shield represented in Salter’s 
figure 2 (No. 11277) has the shape of Schwarz’s H. hippocampus,} 
but is rather poorly preserved on the upper surface; it is certainly 
more elongated and triangular than No. 11276, though from the 
same locality. The large head-shield (No. 11278) from Warm 
Bokkeveld outlined by Salter in his fig. 3 is crushed and imperfect, 
but the presence of a distinct large tubercle on each side of the 
glabella on the faint basal lobes is sufficient to separate it. Perhaps 
it belongs to Lake’s H, quernus.? 

With regard to Salter’s figured specimens, illustrated by his 
figures 4, 5, 6, 8, we can merely say here that none of them agree 
with the types of H. Herscheli in ornamentation or characters, but 
they suggest a comparison with Schwarz’s species H. horridus?* 
and H. agrestis.4 

Salter included the European Devonian species H. armatus, 
Burm.,° in his section Burmersterva, but the anterior end of the head- 
shield has never been fully described or figured, and so far as we 
know the truncate edge of the middle-shield corresponds with the 
ulmost straight course of the transverse commissure of the facial 
sutures. In the allied Z. rhenanus, Koch,® the anterior edge is 
slightly- concave and the lateral angles project in front, so that 
Giirich has chosen the name Digonus for this group (see below). 

The thorax in all the South African forms ascribed to H. Herschel 
is obscurely trilobed, and the axis is very wide. The pygidium is 
always triangular and produced behind into a point; the segmenta- 
tion is more or less distinct and the joints are numerous. The 
presence of spines on various parts of the body cannot be regarded as 
of primary importance, in spite of Salter’s opinion, and in the type- 
specimens of 7. Herscheli they are either inconspicuous or absent. 

Apparently it was mainly because of the presence of spines that 
Salter included the species H. elongatus, Salt., and H. pradoanus, 
De Vern.,’ in his list of members of Burmeisteria. But in both of 
these the pygidium is rounded behind and not acuminate. The first 
species, H. elongatus, belongs to the same group as H. Champernownet, 
Woodw.,® from Devonshire, and a new species, H. bifurcatus, Reed 
MS., from the same locality, of which the description awaits 


1 Schwarz, op. cit., p. 388, pl. ix, figs. 5a, b. 
? Lake, op. cit., p. 216, pl. xxvii, fig. 1. 
* Schwarz, op. cit., p. 385, pl. ix, figs. la-c. 
+ Ibid., p. 386, pl. ix, figs. 2a, b. 
> Koch, op. cit., p. 12, pl. i, figs. 1-6. 
6 Thid., p. 32, pl. iii, figs. 1-6. 
“ De Verneuil, Bull. Soc. Géol. France, ser. WU, vol. vii, p. 168, pl. iii, 
figs. 4a, b, 1850. 
8 Woodward, GEoL. MaG., Dec. II, Vol. VIII, p. 489, Pl. XIII, 1881. 


‘ 


316 Dr. F. R. Cowper Reed—The genus Homalonotus. 


publication, must also be ascribed to it. The well-marked triloba- 
tion of the body, the narrow and distinctly defined axis, and certain 
_ features of the head-shield (see below under Burmeisterella), as well 
as the oval or semicircular pygidium, mark off this group from the 
true H. Herscheli. ‘The pointed pygidium referred by Woodward ! 
to H. Champernownet on a subsequent occasion seems to belong to 
Giirich’s group Digonus and is certainly in no way related to 
LH. elongatus. 

With #. pradoanus we must associate H. Gervillet, De Vern.,? and 
HT, Barratti, Woodw., the latter from Cornwall. The pygidium has 
a rounded semi-oval shape, a more or less distinct border, but no 
acuminate extremity. The axis in both the thorax and pygidium is 
only faintly marked. The head-shield as seen in H. Gervillet, which 
is the best-known member of the group, has distinctive features (see 
below under Parahomalonotus). ‘The surface is ornamented with 
coarse granules and tubercles, but not spines. H. Gervilled was first 
described from the Devonian of the Bosphorus, but was more fully 
described and figured by Bayle (op. cit.) from the Caleaire de Néhou, 
Manche, France. Another allied French species, H. Hausmanni, 
Rouault,* must be included in this group of species. 

Thus, in addition to the H. Herscheli group (which is the true type 
of Burmeisteria), we find three other groups, i.e. (1) the A. rhenanus 
(=Digonus, Giirich) group, and also the more distinctly marked 
groups of (2) H. elongatus and (8) of H. Gervillei, all developed in 
Devonian times and sometimes all included by paleontologists in 
Burmeisteria. 

7. Calymenella, Bergeron, 1890. 

Bergeron® established this genus in 1890 with a new species, 
C. Boisseli, Bergeron, from the Ordovician of Hérault, as its type, 
and he also included in it the species Calymene Bayani, De Trom. et 
Lebese.® The characteristics of the genus were given as follows: 
““Glabelle peu bombée, arrondie en avant, portant trois sillons, dont 
les deux derniers sont bien visibles; le postérieur s’infléchit en 
arriére. Lobes peu accusés. Joues fixes larges. Limbe trés 
développé en avant de la glabelle et pouvant se terminer. en 
pointe. Pygidium de Calymene.”’ .The facial sutures are believed 
to cut the lateral margin behind, but it is not clear if they unite in 
front on the upper surface of the head at the base of the rostrum. 
It seems, however, that such may possibly have been the case, 
judging from some of Bergeron’s figures, and this would explain the 
absence of the rostrum from some of the specimens of the middle 
shield. The free cheeks are unknown. 

As Pompecki’ has remarked, we may probably regard Calymenella 

alibi. Wolk DX ip. 157, Pie live Hig.3, 18e2. 

2 Bayle, Explic. Carte Géol. France, iv, pl. ii, figs. 1, 3, 6, 1878. 

* Woodward, Grou. MaG., Dec. IV, Vol. X, p. 28, woodeut, 1903. 

* Rouault, Bull. Soc. Géol. France, ser. II, vol. viii, p. 379, woodcut, 1851. 

Pe ae Bull. Soc. Géol. France, ser. III, vol. xviii, p. 365, pl. v, figs. 1-7, 
18 

° De Tromelin & Lebesconte, Bull. Soc. Géol. France, ser. II, vol. iv, 
p. 599, 1875 ; Bergeron, op. cit., pl. v, figs. 8-13. 

q Pompecki, Neues Jahrb. f. Min. Geol., Bd. i, p. 241, 1898. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 317 


as a subgenus of Homalonotus, but it is at any rate an early and 
aberrant form. Apart from the presence of the rostrum, it seems 
allied to the Grés de May species of this genus, rather than to any 
species of Calymene. A rostrum is developed in more than one genus, 
and Ampyxz and Probolium are instances. Vogdes' would apparently 
refer his species Calymene rostrata, from the Clinton Formation, to 
this group or genus Calymenella, but it has a typically lobed glabella 
like Calymene, and the facial sutures cut the anterior margin on each 
side of the base of the rostrum, which is a triangular projection of 
the border, and therefore is structurally distinct. 


8. Digonus, Giirich, 1909. 


The type-species chosen by Gtirich is Hl. gigas, Roemer,’ and 
Giirich’s*® definition of the subgenus may be rendered as follows: 
Middle-shield truncate or concave anteriorly, so that the front 
margin is biangulated; glabella subquadrate; pygidium with 
pointed extremity. The section is characteristic of the Lower 
Devonian, and includes a large number of Continental species, of 
which Gurich mentions H. scabrosus, Koch,* and H. rhenanus, Koch.® 
We may add to Giirich’s definition the fact of the distinct segmenta- 
tion of the pygidium, which separates these European Lower 
Devonian species from Dipleura, as Kayser pointed out in a footnote 
to Koch’s memoir (op. cit., p. 10). Perhaps the British species 
Hf. goniopygeus, Woodw.,° belongs to this group, as the pygidium, 
which alone is known, agrees with Giirich’s type in general 
characters. 

The truncate straight or concave anterior end of the middle- 
shield in the type-forms corresponds to the course of the transverse 
commissure of the facial sutures, and the peculiar course of this 
commissure seems to mark off this group of species from the 
H. Herscheli group, which they resemble as far as the pygidium is 
concerned. In none of them is the true anterior margin of the head- 
shield known, so that we are ignorant if the epistome projects in 
front or if there is a wide pre-sutural area. For these reasons they 
may be regarded as distinct from the typical Burmeisterva group, and 
they seem worthy of complete separation from it. 


9. Schizopyge, Clarke, 1918. 


Clarke’ suggested this name for the aberrant species H. longi- 
caudatus, d’Archiac, Fischer, and de Verneuil,’ of the Lower 
Devonian of Constantinople, and the two Brazilian species, 


1 Vogdes, Amer. Journ. Sci., ser. UI, vol. xxiii, p. 475, 1879; id., Proc. 
Acad. Nat. Sci. Philad., 1880, p. 176, figs. 1, 2; id., Bibliogr. Palsesoz: Crust. 
{Occas. Papers Calif. Acad. Sci., iv, 1893, p. 223). 

* Roemer, Verstein. Harzgeb., t. xi, p. 39, fig. 10, 1843. 

’ Giirich, Leitfossilien, Lief. ii, Devon, pp. 156, 157, fig. 42, 1909. 
Koch, op. cit., p. 115, pl. iii, figs. 8-10; pl. iv. 
Koch, op. cit., p. 32, pl. iii, figs. 1-6. 

5 Woodward, GEOL. MAG., Dec. II, Vol. IX, p. 157, Pl. IV; Fig. 1, 1882. 

7 Clarke, Foss. Dev. Parana, 1913, pp. 97-101. 

8 Tchichatcheff, Asie Mineure, pt. iv, Paléont., 1866, p. 2, pl. i, fig. 8 (figure 
not published). 


2 
4 
5 


318 Dr. F. Rk. Cowper Reed—The genus Homalonotus. 


HT. acanthurus, Clarke,’ and H. parana, Clarke,’ also from the Lower 
Devonian. The characteristic feature of these forms, of which only 
the pygidium and some doubtful fragments of the thorax are known, 
is that the pleure project over the margin of the pygidium as short. 
broad lappets in direct continuation and not as separate spines as in 
Crypheus. Thischaracter is, however, so unlike that of other groups 
of Homalonotus that the reference of these species to this genus seems 
extremely doubtful. No figure of the species H. longicaudatus was 
given in the original work referred to, but Clarke? figures a specimen 
from the Bosphorus under this name. : 


Dovustrrut Mrempers or HoOMALONOTUS. 


Of species doubtfully referred to the genus Homalonotus we may 
mention HH. ? punctillosus, Tornquist,* from the Lepteena Limestone 
of Sweden, which has been recorded from the Keisley Limestone ® in 
England. This trilobite, by the course of the facial sutures, seems 
undoubtedly to belong to another genus. 

There is also one described and figured by McCoy from the Kildare 
Limestone, Ireland, as H. ophiocephalus,® which seems to be a hypostome 
of some other genus, but I have only seen the figured example, and 
it is somewhat poor and problematical. 

The species Asaphus brevicaudatus (Desl.)," which Bigot® has 
removed to Corda’s genus Plesiacomia,? may apparently be regarded 
as of independent generic rank, judging from the published descrip- - 
tions and figures; but I have not been able to examine any 
specimens of it. 


Postrion anp AFFINITIES OF HOMALONOTUS. 


There has been considerable diversity of opinion with regard to the 
position of Homadonotus sens. extenso in any general scheme of 
classification of the Trilobita. The genus has usually been put in 
the family Calymenide, and Pompecki’’ has pointed out its close 
connexion with the genus Calymene and their probable common 
descent from Hicks’! genus JVeseuretws, and he was so much impressed 
with the evidence of their close affinity as to bring together under 
one new generic name Synhomalonotus the combined groups of 
those species of Calymene which are comprised in the C. Tristan, 
C. Arago, and Ptychometopus Series. But he recognized the existence 


! Clarke, ‘‘ Trilob. Grez de Erere e Maecuru, Brazil’’?: Arch. Mus. Nac. Rio 
de Janeiro, vol. ix, p. 10, pl. i, figs. 9, 10, 1890. 

Z Clarke, Foss. Dev. Parana, p. 97, pl. iii, figs. 5, 6. 

> Clarke, ‘‘ Trilob. Grez de Erere e Maecuru, Brazil,  p. 14, pl. i, fig. 8 

: Crees Undersokn. Siljans. Trilobitf., t. i, p. 44, figs. 46, 57; t. ii 
hase 12 

2 Reed, Quart. Journ. Geol. Soc., vol. lii, p. 411, 1896. 

® McCoy, Syn. Silur. Foss. Irel., 1846, p. 53, pl. iv, fig. 4. 

7 Deslongchamps, Mém. Soc. Linn. Calv., ii, pl. ii, figs. 3, 4, 1825. 

° Bigot, Bull. Soc. Géol. France, xvi, p. 433, pl. v, fig. 1c, 1888. 

° Corda, Prodrome, 1847, p. 55, pl. iii, fig. 30. 

10 Pompecki, Neues Jahrb. f. Miner. Geol., Bd. i, pp. 187-248, 1898. 

' Hicks, Quart. Journ. Geol. Soc., vol. xxix, pp. 44, 45, 1873. 


Dr. fF. R. Cowper Reed—The genus Homalonotus. 319 


of two families, the Calymenide and the Homalonotide, and Giirich ! 
in 1908 adopted this classification. Swinnerton? in 1915 followed 
Giirich, but put the two families in a section Calymmenina of a sub- 
order Conocoryphida, which he ascribed to Beecher’s group Opistho- 
parva because of their supposed derivation from the Olenide. 

The family Calymenide (in its wide sense, including Homadonotus) 
was put by Beecher in 1900 and by Raymond in 1913 in the group 
Proparia on account of the course of the facial sutures. But Giirich 
(op. cit.), finding a difficulty in placing it in either of these groups, 
instituted a new group, which he called Gonatoparia, for those genera 
in which the facial sutures cut the genal angles, and he placed the 
Calymenide and Homalonotide in it. Koch, however, had seen that 
some of the Devonian species had the point of section in front of the 
genal angles, and it is-not improbable that some of those from the 
urés de May possessed the same character. If, therefore, we are of 
opinion that Beecher’s scheme and principles of classification of 
the Trilobita are natural and generally applicable, it seems as if 
Homalonotus should be associated with the Proparta rather than 
with the Opisthoparia. The idea of the derivation of Homalonotus 
from the Olenide, and therefore of its place in the Opisthoparia, 
has arisen from its supposed relation to Hicks’ unfortunate genus 
Neseuretus, which Pompecki referred to the Olenide, having failed 
to see that it was of a composite character. So much confusion and 
misunderstanding appears to have arisen about the genus Weseuretus 
that a few remarks upon it may here be made. The type-specimens 
(all of which are poor) are mostly in the Sedgwick Museum and have 
been studied by myself. The first-described species, WV. ramseyensts, 
Hicks,? is apparently identical with Calymene Tristani, Brongn., 
which was chosen by Pompecki as the type of his genus Synhomalo- 
notus. The second described species, JV. guadratus, Hicks,* is an 
indisputable Homalonotus belonging to Salter’s group Brongniartia. 
The third species, WV. recurvatus,® is probably referable to Calymene 
and seems to resemble H. Hebert:, Barrois,® from the Grés armoricain. 
The fourth species, WV. ? elongatus, Hicks,’ may also belong to 
Calymene, but the type is in a poor state of preservation, so that 
the characters are difficult to distinguish. It is now ascertained 
that the beds from which these specimens came are of Arenig and 
not Tremadoc age. From the above remarks it appears that 
Neseuretus must be regarded as a composite and heterogeneous 
assemblage of species and it has no right to be retained as a separate 
generic designation. 

Apart from all other distinctions the fundamental difference 
between Homalonotus and Calymene seems to be that in the former 


? Giirich, Leitfossilien, Lief. i, Camb. Silur., 1908, p. 70. 

2 Swinnerton, GEOL. MAG., Dec. VI, Vol. II, pp. 494, 540-3, 1915. 

° Hicks, op. cit., p. 44, pl. iii, figs. 7-10, 16-22. 

* Ibid., p. 45, pl. iii, figs. 11-13, 23-6. 

> Tbid., p. 45, pl. iii, figs. 5, 6. 

° Barrois, Bull. Soc. Géol. France, ser. 111, vol. xiv, p. 802, pl. xxxvi, fig. 14, 
1886. 

* Hicks, op. cit., p. 45, pl. iii, figs. 1-3. 


320 Dr. F. R. Cowper Reed—The genus Homalonotus. 


the facial sutures unite in front on the upper surface of the head- 
shield, although frequently very close to the margin, whereas in 
Calymene they cut the anterior edge of the head-shield at some 
distance apart and are connected together on the lower surface. 
In Homalonotus, therefore, the median portion of the front margin 
of the head-shield is formed by the epistome, sometimes expanded 
and recurved so as to form a broad pre-sutural prora, whereas in 
Calymene the same part of the head-shield is composed of the pre- 
glabellar post-sutural area, and the epistome is wholly confined to 
the lower surface of the head-shield, not appearing at all on the 
upper surface. The obsolescence, more or less complete, of the 
elabellar lobes and the frequent loss of trilobation in the thorax and 
pygidium of Homalonotus are secondary characters of degeneracy, 
and can hardly be regarded of primary morphological importance 
in comparing the two genera. he correspondence in the number 
of segments in the thorax should not have too much stress laid upon 
it, for in the fairly homogeneous genus of Jl/enus, which shows 
modifications in many respects parallel to Homalonotus, the number 
of segments varies from eight to ten. 

The earlier species of Homalonotus, such as those from the Grés de 
May, show a remarkable resemblance in the characters of the 
pygidium to Calymene, and in some species (e.g. H. biserratus) even 
the bifurcation of the tips of the pleure near the margin is indicated. 
We must, however, remember that even in these early representa- 
tives of Homalonotus all the special characters of the head-shield and 
elabella are fully developed. The more distinct trilobation of the 
body and pygidium is an additional feature in these Grés de May 
species, and they undoubtedly come nearest to Cane 

It is worthy of remark that the genus Calymene itself did not tend 
to differentiate into subgenera, us general character remaining 
extraordinarily constant during its whole stratigraphical range, 
whereas Homalonotus is not nearly so homogeneous an assemblage 
of species, considerable variation having taken place along more or 
less distinct lines of development. 

We may note a somewhat remarkable parallelism in the generic 
life-history of Homalonotus sens. ext. and Asaphus sens. ext., though 
in the latter case the development took place more rapidly and 
simultaneously, being practically within the confines of the 
Ordovician, but in more or less distinct biogeographical areas. 
A rounded semicircular or transverse head-shield goes with a 
rounded semicircular or transverse pygidium with an entire margin. 
A pointed and elongated head-shield accompanies a pointed and 
elongated pygidium, and the number of segments in the latter 
similarly i increases. A somewhat parallel case exists in the genera 
Phacops and Dalmanites. 

In Asaphus we may also remark that the facial sutures, which, as 
in Homalonotus,. unite on the upper surface, may form a regular 
curve or mect in a pointed arch or ogive; they may also lie close to 
the margin or well inside it, or may even cut the front edge and be 
connected below it. But there is no pair of epistomal sutures 
in Asaphus, and the facial sutures cut the hind margin of the 


Dr. F. R. Cowper Reed—The genus Homalonotus. 321 


head-shield well within the genal angles; so that there can be no 
question of direct genetic affinities, but only of homcomorphic 
development. 

CLASSIFICATION. 


The species of Homalonotus may be grouped together into several 
sections or subgenera on the strength of the character and course of 
the facial sutures, the development of the epistome and doublure, 
the degree of trilobation of the thorax, and the shape, trilobation, 
and segmentation of the pygidium. ‘These characters are variously 
combined, but on the whole two large divisions may be recognized 
so far as pygidial characters alone are concerned, one of which is 
marked by rounded and the other by pointed pygidia. In the 
earliest members of ‘the genus the pygidia are short, rounded, and 
composed of few segments, and the trilobation is well marked; in 
some of the Devonian species the rounded form again prevails, but 
there is a larger number of segments, and the trilobation is more or 
less lost. In the Silurian and most of the Devonian species the 
pointed elongated pygidium, composed of many segments, with or 
without distinct trilobation, is found conspicuously developed. 

Many of the groups or sections have already received names from 
various authors, but some of these groups are not homogeneous and 
require subdivision, as the foregoing remarks have indicated. 
Whether these groups are of subgeneric or only lesser rank may be 
a matter of opinion; but in the following list the groups appear to 
possess combinations of characters of morphological importance, and 
it will be observed that the groups also have a stratigraphical relation 
or limitation, and therefore suggest phylogenetic significance. We 
may therefore maintain that they are not artificial assemblages of 
species, but correspond to certain natural divisions of the genus. 
In some cases it is unfortunate that the species are only imperfectly 
known, or that specific names have been attached to mere fragments 
of individuals, or that disconnected portions of doubtful association 
have been brought together under the same specific designation. 
But these are minor defects which are unavoidable, and subsequent 
work may remedy them. 


Subgenera. 


1. Hohomalonotus, nom. prop. (= Brongniartia (pars), Salter, non 
Leach, nee Eaton). 

Head-shield transverse, rounded, more or less semicircular. Facial 
sutures uniting close to anterior margin or on margin in regular 
wide curve, and posteriorly cutting lateral margins slightly in front 
of genal angles. Pre-glabellar area wide; pre-sutural band very 
narrow or wanting. ‘Thorax with well-marked trilobation; axis 
not wider than pleural portions. Pygidium short, broad, expanded, 
composed of few segments (six to eight); axis distinct; pleurx 
continued to edge or nearly to it; doublure vertical or steeply inclined 
at sides, simple, of nearly uniform width all round or narrowing 
slightly posteriorly. 

DECADE VI.—VOL. V.—NO. VII. 21 


322 Dr. F. R. Cowper Reed—The genus Homalonotus 


TypeE.—Homalonotus Brongniarti (Desl.). 
RANGE.—Lower Ordovician. 
DISTRIBUTION.—N. France, Cornwall, Shropshire, Bohemia ? 


EXAMPLES. 
HA. Deslongchampsi, de Trom. H. Barroisi, de Trom. 
HT. Bonissentt, Mor. HI. biserratus, sp. nov. 
H. serratus, de Trom. A. quadratus (Hicks). 
HA. Vicaryi, Salt. ? H. bohemicus, Barr. 
HI. besnevillensis, Bigot. ? H. draboviensis, Novak. 
H. wncertus, Bigot. ? H. medius, Barr. 
H, Morierei, Bigot. 


Remarks.—This section comprises the earliest representatives of 
the genus Homalonotus. There is a close connexion between it and 
Pompecki’s Synhomalonotus, through which the genus is related to 
Calymene. 

2. Calymenella, Bergeron. 


Head-shield triangular, produced in front into a rostrum. Facial 
sutures uniting in front in regular continuous curve at base of 
rostrum and inside margin. Pygidium semicircular, transverse, 
composed of few segments, distinctly trilobed; axis and pleure well 
marked. 

TypE.—H. (Calymenella) Boisseli (Bergeron). 

RANGE.— Ordovician. 

DISTRIBUTION.—France. 

EXAMPLE.—H. (C.) Bayani (De Trom. & Lebesc.). 

Remarxs.—The peculhar distinguishing feature of this subgenus 
is the possession of the rostrum, the precise nature of which has not . 
been thoroughly investigated; but it seems to be merely a much 
elongated narrow prora, as in Dipleura, and to be wholly pre-sutural 
in origin and perhaps epistomal in nature. ‘The head-shield and 
glabella in other respects seem to resemble Hohomalonotus, and the 
pygidium is unmistakably of the same type. Bergeron regarded the 
two species mentioned above as constituting a distinct genus, but 
Pompecki considered that it was only a subgenus of Homalonotus. 


3. Brongniartella, nom. prop. (= Brongniartia (pars), Salter, 
section 1, xon Leach, nec Eaton). 

Head-shield rounded, semi-elliptical or semicircular, wider than 
long. Facial sutures uniting close to anterior margin or on margin 
in regular wide curve, and posteriorly cutting lateral margins nearly 
at genal angles. Glabella urceolate, rhomboidal, or subconical, 
generally lobeless. Pre-glabellar area of moderate width; pre- 
sutural band very narrow or wanting. Thorax with trilobation more 
or less indistinct; axis wider than pleural portions. Pygidium 
rounded, semi-oval or parabolic, composed of nine to twelve segments ; 
axis distinct; pleure continued nearly to margin; border usually 
developed but not defined; doublure flat, horizontal, closely in- 
folded, of nearly uniform width. 

Typr.—H. biswleatus, Salter. 

RANGE.—Middle and Upper Ordovician. 

DISTRIBUTION.—England. 


1 Novak, ‘‘ Zur Kennt. bohm. Trilob.’’?: Beitr. Paleeont. (ist. Ungarns, 
p. 27, pl. viii, figs. 9a—-c, 1884. : 


Dr. F. R. Cowper Reed—The genus Homalonotus. 323 


EXAMPLES. 
H. Sedgwicki, Salter. HI. ascriptus, Reed. 
H. Edgelli, Salter. - ? A. rudis, Salter. 
H. Tawney, sp. nov. 

Rramarks.—It was to this group that Salter first applied the name 
Brongniartia, choosing H. bisulceatus as the type-species. The 
differentiation in structural characters from Synhomalonotus is much 
more marked than in Hohomalonotus, particularly in the pygidium, 
and all the members of this third subgenus occur on higher horizons 
than those of the first subgenus, to which it is, however, closely 
related. 

4. Trimerus, Green. 

Head-shield more or less triangular and elongated. Facial sutures 
uniting anteriorly close to but inside margin in a more or less 
pointed arch, not forming a continuous regular curve, and posteriorly 
cutting genal angles. Pre-glabellar area well developed. Glabella 
subconical, occasionally lobed. Thorax with very broad axis and 
indistinct trilobation. Pygidium composed of many segments, 
triangular, elongated, subcylindrical, ending in a produced acumina- 
tion; trilobation faint; doublure very narrow at sides, widening 
at tip. 

Typr.—H. delphinocephalus (Green). 

RANGE.—Silurian (Wenlock). 

DISTRIBUTION. —Northern Europe, North America, Australia. 

EXAMPLES. 
HA. cylindricus, Salt. H. vomer, Chapman.! 
H. Harrisoni, McCoy. 

Remarks.—VThough in point of stratigraphical succession this sub- 
genus follows immediately on that of the H. bisulcatus type, yet the 
pygidium represents an almost entirely new and independent form, 
and the facial sutures show by their angular junction in front the 
nature and origin of the continuous curved commissure in the earlier 
sections. There is no direct derivation from the Ordovician forms, 
but perhaps links, though at present undiscovered, existed in 
Llandovery times. 


5. Kenigia, Salter. 

Head-shield transverse, broad, short. Epistome projecting in 
front as median process; anterior lateral angles of head-shield 
angulated forwards, the three together making the margin tricuspid. 
Facial sutures bending suddenly inwards near anterior margin and 
uniting in a straight or concave transverse commissure with small 
median point; posterior branches of facial sutures bent back suddenly 
to cut lateral margins nearly at genal angles. Paraglabellar areas 
distinctly marked. Pre-glabellar area very narrow. Thorax with 
trilobation almost obsolete; axis very broad, scarcely defined. 
Pygidium composed of many segments, elongated, acuminate, 
triangular, with smooth pointed posterior process; axis nearly 


1 Chapman, Proc. Roy. Soc. Victoria, vol. xxiv, N.S., pt. ii, p. 298, pl. lxii, 
s. 2,3; pl. lxiii, figs. 1, 2, 1912; Etheridge & Mitchell, Proc. Linn. Soc. 


fig 
N.S.W., vol. xlii, pt. iii, p. 506, 1917. 


324 Dr. F. R. Cowper Reed—The genus Homalonotus. 


obsolete, but segmentation of axis and pleure distinct. Doublure 
widening posteriorly. 

Typr.—H. Knightt, Konig. 

RANGE.—Silurian (Ludlow). 

DISTRIBUTION.—Northern Hurope. 

EXAMPLE.—? H. Johannis, Salt. 

Remarks.—This is undoubtedly a highly specialized group in the 
genus. A similar sudden bend in the anterior course of the facial 
sutures is found in Digonus (q.v.), and the tendency to a projection of 
the epistome is seen less developed in Burmeisteria (q.v.). The whole 
head-shield of the type-species is, however, marked by very unusual 
modifications. It is doubtful if H. Johannis can be closely associated 
with it, in spite of its tricuspid front, as the pre-glabellar portion is 
different; but the pygidia of the two species are very similar. As 
regards the thoracic and pygidial characters of Kenigia it is easy to 
see their general resemblance to Zrimerus. The specimens of the 
type-species in the Ludlow Museum which I have been privileged to 
examine by the kindness of the Curator exhibit the characteristic 
features with great clearness, being unusually well preserved. 


6. Burmetsteria, Salter (sens. restr.). 


Head-shield more or less triangular. Facial sutures convergent 
anteriorly and uniting by a double sigmoidal commissure close to 
front margin, and posteriorly cutting lateral margins in front of 
genal angles. -Pre-glabellar area well developed. Paraglatellar 
areas distinct. Glabella occasionally lobed. Epistome projecting 
in front of anterior margin of head-shield as median pointed process. 
Pre-sutural area very narrow. Thorax with wide, ill-defined axis; 
trilobation indistinct. Pygidium triangular, acuminate, strongly 
convex from side to side, composed of many segments; axis and 
pleurse more or less distinct. Surface of head-shield, thorax, and 
pygidium frequently ornamented with more or less regularly disposed 
large tubercles or spines. 

TypE.—H. Herscheli (Murchison). 

RANGE.—Lower Devonian. 

DISTRIBUTION.—South Africa, South America (including Falkland Islands). 


EXAMPLES. 
A. quernus, Lake. H. agrestis, Schwarz. 
HZ. colossus, Lake. HI. horridus, Schwarz. 
H. perarmatus, Frech. A. lex, Schwarz. 
H. hippocampus, Schwarz. H, noticus, Clarke. 


Remarxs.—This subgenus appears to be limited to the Southern 
Hemisphere. As far as the thorax and pygidium are concerned, its 
relations are with Zrimerus, but the anterior course of the facial 
sutures seems intermediate between Zrimerus and Kenigia. The 
spinosity, which is very irregularly developed in the species, cannot 
have as much importance attached to it as some authors have 
maintained. 

7. Digonus, Giirich. 

Head-shield transverse or subtriangular. Middle-shield with 
anterior lateral angles rectangular, obtuse, or projecting, and with 
anterior margin truncate, straight, or slightly concave. Facial sutures 


Dr. F. R. Cowper Reed—The genus Homalonotus. 325 


bent in suddenly near front margin and uniting in continuous transverse 
commissure. Pre-glabellar area well developed. Glabella short, 
subquadrate, or oblong. Thorax with trilobation usually distinct 
and well marked. Pygidium triangular, elongated, acuminate, more 
or less pointed behind, composed of many segments; trilobation 
generally well marked. Surface of thorax and pygidium occasionally 
scabrous or tuberculated, but not spinose. 
TyprE.—H. gigas, Roemer. 


RANGE.—Lower Devonian. 
DISTRIBUTION.—Rhenish area, France, ? England, ? Argentina. 


! EXAMPLES. 
HT. rhenanus, Koch. H. Le Hiri, Barrois.1 
HZ, scabrosus, Koch. 2? H. goniopygeus, Woodw. 
H. ornatus, Koch. ? H. Kayseri, Thomas.” 


Remarxs.—The strange course of the facial sutures in their 
transverse union is somewhat like that of Kenzgia and Dipleura, but 
the pygidium is closely similar to that of Burmeisteria. The triloba- 
tion of the thorax is, however, more distinct than in the latter. 
The shape of the glabella is unusual. We are not acquainted with 
the true anterior margin of the head-shield, and know nothing about 
the epistome. It is very uncertain if the common but imperfectly 
known species 7. armatus, Burm., belongs to this subgenus (see below). 


8. Burmeisterella, nom. prop. 


Head-shield subtriangular, produced anteriorly into upturned 
prora formed by epistome and bounded by epistomal sutures. Pre- 
sutural area large. Facial sutures bend in suddenly in front and 
unite by transverse commissure close to anterior end of glabella. 
Pre-glabellar area narrow. Thorax with well-defined cylindrical 
axis, of less width than pleural portions; trilobation distinct. 
Pygidium semi-oval, rounded, with regular entire margin (in one 
species provided with pair of short terminal spines); axis narrow, 
elongated, distinct ; composed of many segments; pleure distinct. 
Surface of glabella and of thoracic and pygidial axes ornamented 
with regularly disposed pairs of large tubercles or spines. 

Typr.—H. elongatus, Salt. 

RANGE.—Lower Devonian. 

DISTRIBUTION.— Devonshire, ? Rhenish area. 


EXAMPLES. 
H. Champernownei, Woodw. ? H. aculeatus, Koch.? 
HY, bifurcatus, sp. nov. ? H. armatus, Burm. (head only). 


REMARKS.—Of the type-species we only know the pygidium, but 
the very closely allied species H. Champernownei and H. bifurcatus 
from the same locality and horizon help us to complete the above 
definition. The regular rounded contour, semi-oval shape, well- 
defined narrow axis, and regularly paired tubercles of the pygidium 


1 Barrois, Bull. Soc. Géol. France, ser. III, vol. xiv, p. 687, pl. xxxiii, fig. 5, 
1886. 

* Thomas, Zeitschr, deut. geol. Gesell., Bd. lvii, p. 145, pl. ix, figs. 5, 6, 
1905. 

2 Kochi op. cit.) ps 2ly plea, fie. t 


326 Dr. F. R. Cowper Reed—The genus Homatonotus. 


sufficiently distinguish this subgenus from the typical H. Herschelv 
group. The large pre-sutural area and upturned prora, only known 
from the specimen of H. bifurcatus, sp. nov., in the Sedgwick Museum, 
are likewise peculiar. But they recall the structure of the head- 
shield of Dipleura Dekayt. With regard to the shape and characters 
of the pygidium and general well-marked trilobation, we see affinities 
with the Ordovician Brongniartella. The paired tubercles on the 
glabella and other features of the head-shield of H. armatus suggest 
that this species when completely known may have to be placed in 
this section. The Rhenish HW. aculeatus has a pygidium apparently 
much like that of the new British species H. bzfurcatus. The only 
well-known forms are from Devonshire. 


9. Parahomalonotus, nom. prop. 


Head-shield semicircular, transverse; facial sutures uniting in 
regular wide-arched commissure close to anterior margin. Thorax 
with axis obsolete and trilobation quite lost. Pygidium rounded, 
semicircular, or semi-oval, with entire margin; trilobation more or 
less indistinct, but segmentation well marked; border not crossed by 
pleure. Surface ornamented with coarse tubercles and granules (or 
smooth). 

Typr.—H. Gervillei, De Verneuil.! 

RANGE.—Lower Devonian. 

DISTRIBUTION.—-Europe. 


EXAMPLES. 
H. pradoanus, De Vern. 2? H. levicauda, Quenst. 
H. Barratti, Woodw. ? H. obtusus, Sandb.? 
H. Hausmanni, Rouault. ? H. multicostatus, Koch.* 


? H. planus, Sandb. 

Remarxs.—This subgenus is characterized by the regular curved 
union of the facial sutures close to the anterior margin (reminding 
us of the conditions in Hohomalonotus and Brongniartella), by the 
disappearance of the trilobation in the thorax (as in the Bumastus 
group of Jilenus), and by the regular rounded outline, obsolescent 
trilobation but distinct segmentation of the pygidium. It looks as if 
these characters must be due to reversion, as no Silurian forms are 
known to connect the Ordovician species with this Devonian group. 
The four last-mentioned examples in the above list differ from the 
typical members of this subgenus in several mninor respects, especially 
in being smooth, but for the present may be best referred to this 
subgenus. 

10. Dipleura, Green. 


Head-shield subtriangular, with large pre-sutural prora. Facial 
sutures uniting in front of glabellaby straight transverse commissure, 
but continued directly forwards without deviation into the epistomal 
sutures bounding the prora. ‘Thorax with faint trilobation. 


1 Tchichatcheff, Asie Mineure, Paléont., p. 448, pl. xx, fig. 1, 1866; Bayle, 
Explic. Carte Géol. France, iv, atlas, pl. ii, figs. 1, 8, 6, 1878. 

2 Sandberger, Verstein. rhein. Schicht. Nassau, t. ii, p. 26, figs. 6-6d, 1856 
Koch, op. cit., p. 49, pl. vi, figs. 1-4. 

> Koch, op. cit., p. 52, pl. vi, figs. 5-9. 


Dr. F. R. Cowper Reed—The genus Homalonotus. 327 
Pygidium triangular, subconical, obtusely pointed behind, with 
trilobation obsolete or obsolescent and segmentation very faintly 
marked. 

Typr.—H. Dekayi, Green. 

RANGE.—Middle Devonian (Hamilton Formation). 

DISTRIBUTION.—North America. 

Remarxks.—This subgenus seems confined to North America and 
to be the latest representative of the genus Homalonotus. It is 
extremely doubtful if the Harz species H. Schusteri, Roem.,! is 
rightly referred to Dipleura by Kayser.? The characteristic features 
of Dipleura are the large pre-sutural prora (recalling that of 
Burmeisterella), the straight transverse commissure of the facial 
sutures (somewhat as in Digonus), the direct continuation of the 
facial into the epistomal sutures, and the obsolete trilobation and 
nearly obsolete segmentation of the pygidium. The last-mentioned 
character is, however, also found in H. levicauda, Quenst., attributed 
provisionally to the preceding subgenus, Parahomalonotus. 


ConcLusion. 


With regard to the stratigraphical distribution of the above- 
described ten subgenera of the genus Homalonotus, we note that the 
first three, Hohomalonotus, Calymenella, and Brongniartella, are 
restricted to the Ordovician, the first one being the earliest; Zrimerus 
and Aenigia occur only in the Silurian, and all the rest, Burmetsteria, 
Digonus, Burmeisterella, Parahomalonotus, and Dipleura, are found in 
the Devonian. It is clear, therefore, that the climax of development 
was reached in the Devonian, and it is remarkable that the genus did 
not survive this period. 

The phylogeny of the genus is imperfectly known. We have seen 
that it may be linked with Calymene by means of Synhomalonotus, 
though it must have diverged at an early period, or more probably 
have originated from a common stock. Within the limits of the 
genus the relationships of the different subgenera are difficult to 
trace. There is a considerable morphological gap between the 
Ordovician and Silurian groups, and transitional forms are at present 
unknown. The Devonian subgenera fall into two main groups, one 
of which, comprising Burmeisteria and Digonus, suggests a connexion 
with the Silurian subgenera, but on the other hand Parahomalonotus 
suggests reversion to the earlier types. Burmetsterella in some 
respects also points back to Ordovician forms, but it is undoubtedly 
highly specialized. Diplewra may be a modification of the Digonus 
type, and is the latest representative of the genus in any part of 
the world. 

I am much indebted to the authorities of the Sedgwick Museum, 
Cambridge, the British Museum, the Jermyn Street Museum, the 
Shrewsbury Museum, and the Ludlow Museum for the opportunities 
afforded me of examining specimens in their collections. 


* Roemer, Beitr. z. geol. Kennt. nordw. Harzgeb., iii, t. iii, fig. 20, 1855. 
? Kayser in appendix to Koch, op. cit., p. 76. 


328 : Notices of Memovrs—Dr. H. _ J. Johnston-Lavis— 


NOTICES OF MEMOIRS. 


——._—_ 


_ Brsrioc¢kRaPHy oF THE GroLtocy anv Hruptive PHENOMENA OF THE 
MOBE IMPORTANT VOLCANOES OF SouTHEEN Iraty. Compiled by 
Henry James Jonnston-Lavis, M.D., D.Ch., M.R.C.S8., F.G.S., 
etc., late Professor of Vulcanology in the Royal University of 
Naples, assisted by Madame Awnronza Jonnsron-Lavis. 2nd 
edition, completed, after the author’s death, by Miss M. B. 
Sranron, and edited, with a preface and a short life of the author, 
by B. B. Woopwarp, F.L.S., F.G.S., of the British Museum 
(Nat. Hist.). 4to; pp. xxiv + 374, with a frontispiece and a 
photograph of the author in 1905. London: The University of 
London Press, Ltd., St. Paul’s House, Warwick Square, EC. 4. 
1918. 


(W\HE history and razson a’étre of this important work are set forth 
by the editor, Mr. B. B. Woodward, in his preface, and thence 
we extract the following salient facts : — 


The ‘‘ Congrés Géologique International”’ having arranged to hold 
its second session at Bologna in 1881, the ‘‘Comité d’Organisation”’ 
in that town decided, in their Séance of March 17th, 1879, to 
undertake the compilation of a ‘‘Bibliographie géologique et 
paléontologique de l’Italie”’ as a contribution towards the success of 
the meeting. For many unavoidable reasons that list was an 
imperfect one. Still, a very considerable number of works and 
papers were recorded, the total number of entries amounting to 
6,566. 

Dr. Johnston-Lavis naturally availed himself of those sections 
that concerned his special pursuits and set to work to supply 
deficiencies and to add the titles of further publications as issued. 
In this he was cordially aided by Mme. Lavis, who, working under 
her husband’s directions, industriously transcribed the fresh titles 
and incorporated them with the entries from the older bibliography. 

By the time that the Geologists’ Association paid its visit to 
Southern Italy in the months of September and October, 1889, the 
bibliography had grown to almost twice the size, and Lavis happily 
seized upon the occasion to publish it in 1891 as an appendix to the 
account of the excursion, which was reprinted from the Proceedings 
of the Association, the whole thus forming a valuable manual of 
information on the volcanoes of Southern Italy. 

From that time onwards no opportunity was lost for working at 
this bibliography and endeavouring to render it as complete as such 
a work can ever be. 

When the War broke out, depriving him at once of his practice, he 
had determined to employ his enforced leisure from professional 
duties till happier times should return in systematically revising and 
augmenting the whole bibliography and in ransacking every available 
source with this object in view. 

His tragic death’ cut this project short, and all the loving labour 


1 GEOL. MaG., 1914, p. 480. 


Bibliography of Volcanoes of Southern Italy. 329 


of years of patient research seemed likely to be thrown away had 
not his family most felicitously conceived the idea of completing the 
work so far as might be possible and publishing it as a worthy 
offering to his memory. 

Fortunately, this has been rendered practicable through the cordial 
co-operation of his secretary, who, during recent years, had been 
closely associated with Dr. Johnston-Lavis in the work and was 
thoroughly acquainted with his scheme and method. Miss Stanton 
accordingly continued the researches that had been begun in the 
Library of the Geological Society of London, where the index 
catalogue prepared by Mr. C. Davies Sherborn proved invaluable, 
the Reading Room of the British Museum, and the Libraries in the 
Natural History Museum, extending them to the Library of the 
Société Géologique de France, where she met with cordial assistance, 
especially from the President, M. Maurice Cossmann, and the former 
President, M. Emmanuel de Margerie, and the Bibliothéque 
Nationale de France, where, as unhappily customary in that 
establishment, all spirit of practical help was conspicuous by its 
absence. 

In this way the present bibliography was completed, so far as at 
present practicable, as regards all the more important volcanoes. ‘To 
have extended its scope and to have embraced all volcanic records | 
for the region would have entailed many more years of labour, whilst 
the value of the bibliography would not have been materially 
increased thereby. Nor has it been possible in all cases to incorporate 
in their entirety the individual contents of previous bibliographies in 
the body of the present one. The existence of such sources of 
reference is, however, duly recorded, and the inquirer will, therefore, 
be furnished with the necessary clue towards the object of his 
research. 

On account of the War, all access to Dr. Johnston-Lavis’ own 
library was cut off, and hence many entries that might have been 
completed have perforce had to be included in a less perfect state 
than could have been wished. ‘The whole bibliography must, there- 
fore, under the circumstances of its production, be leniently judged 
and regarded as a stage only towards that ideal work one would like 
to see. 

The Editor has to acknowledge much kindly assistance and advice 
given during the progress of the work by Sir Lazarus Fletcher, 
LEDs ERS: 

The subject-matter has been subdivided, as in the previous 
edition, according to the different volcanic groups, but some 
modifications in these have been introduced that approximately 
follow the author’s known intentions in that respect. 

Altogether there are in this present edition some 7,350 entries, 
and since these include references to the fauna, flora, and 
paleontology of the several districts, in addition to their mineralogy, 
petrology, vulcanology, etc., the work is obviously one of general 
interest and utility to all workers in natural science, and should 
therefore find a place on the shelves of every library of any 
importance. 


330 Reviews—Ordovician and Silwrian Fossils, Yuwn-nan. 


RHEVLEWS.- 


-I.—Orpovicran anD Sinurran Fossrrs From Yun-nan. By F. R. 
Cowper Reep, M.A., Se.D., F.G.S. Paleontologia Indica, n.s., 
vol. vi, Memoir 8, pp. iv + 69, 8 pls., 1917. 

INCE 1913 we have known that Mr. Coggin Brown, during his 

exploration of South-western Yun-nan a few years previously, had 
collected some Lower Ordovician and Silurian fossils. Dr. Cowper 

Reed’s complete description of these is at last published, with 

excellent illustrations by Mr. T. A. Brock, and with determinations 

of the graptolites by Dr. Gertrude Elles. 

The Ordovician fossils are from three localities: Pu-piao, La-méng, 
and Shih-tien. It was from Pu-piao that Loczy on the Szechenyi 
expedition obtained cystid plates referred by him to Hemicosmites. 
The rocks here are mudstones with a calcareous band; all are 
probably of Llandeilo age, and the mudstones, at any rate, contain 
Didymograptus murchisont and its normal associates. The rock at 
La-méng resembles that of the Hwe Mawng Beds in the Northern 
Shan States of Burma, and the few poorly preserved fossils are 
consistent with that horizon. Five types of rock from Shih-tien 
probably represent as many beds. The contained fossils show 
general agreement with the fauna of the Sedaw Beds in the 
Naungkangyi series of the Northern Shan States, and Dr. Reed 
inclines to correlate the beds with Schmidt’s stages B and C 
(Orthoceras, Echinosphara, and Chasmops Limestones) of the Baltic 
region. 

The Silurian beds of Shih-tien consist of two kinds of shale, with 
two different assemblages of graptolites of Llandovery age. ‘The 
higher horizon belongs to the base of the zone of Monograptus 
sedgwicki, and its most abundant fossil is JL. lobiferus. he lower 
horizon abounds in Climacograpti, not specifically determinable, with 
other specimens suggesting the zone of Orthograptus vesiculosus or 
the base of the Monograptus gregarius zone. These two horizons 
yield no fossils other than graptolites. 

Of the Ordovician fossils the most important are the Cystids, in 
respect to number both of specimens and of species and in respect to 
novelty, there being described two new genera and ten new species. 
The genera are Svnocystis and Cvocystis (n.gg.), Pyrocystis, 
Hucystis,  Spheronis, Echinosphera, Heliocrinus,  Caryocystes, 
Echinoencrinus, and Caryoerinus. Crinoids are represented only 
by one specimen of the fossil which Dr. Reed calls Camarocrinus 
asiaticus. Of Brachiopods there are the genera: Philhedra (1 n.sp.), 
Orthis (1 n.sp.), Hemipronites (1 u.var.), Rafinesquina(?), Plectam- 
bonites, Streptis, and Porambonites. Lamellibranchs are represented 
by undetermined species of Ctenodonta and Conocardium ; and Gastro- 
pods by doubtfully determined species of Holopea, Raphistoma, 
Bellerophon, Cyrtolitina, and Hyolithes. Cephalopods are numerous, 
especially at Shih-tien, and belong to Hndoceras, Orthoceras (1 n.sp.), 
Jovellania, Cameroceras(?), Actinoceras, Spyroceras(?), Trocholites 
(1 n.sp.), Letuctes, and Tarphyceras(?). The few and often fragmentary 
remains of 'rilobites are referred to Harpes, Remopleurides, Asaphus, 


Reviews—F. W. Harmer—Glacial Geology. 351 


Ogygites (1 n.sp.), Lllenus (6 spp., of which 1 is new), WVileus, 
Bathyurus (1 n.sp.), Lichas, Calymene (1 u.sp.), and Pliomera 
1 n.sp.). 

ie aaa of the faunas from all three localities, apart from 
obvious similarity to those of the Shan States, are in Dr. Reed’s 
opinion closest with those of North-West Europe. This is perhaps 
more noticeable in the cephalopods than in the cystids. The 
Echinosphera Limestone of the Baltic Provinces and Scandinavia 
certainly has an ‘‘abundance of cystideans”, but the general 
composition of its cystid fauna is not much like that of Shih-tien. 
On the contrary, connection with North America is closely indicated 
by some of the new cystids, possibly by the so-called Camarocrinus, 
and certainly by such cephalopods as Actinoceras cf. brgsbyi and the 
Jovellania. 

The descriptions give sufficient detail, and Dr. Reed seems to have 
extracted a good deal of information from material sometimes 
unpromising. Dr. Reed’s knowledge of these Ordovician faunas is 
undoubtedly ‘‘extensive’’, but he might realize that it is also 
“peculiar”, and might sometimes make matters easier for his less 
learned colleagues by stricter attention to the technical presentation 
of his results. ‘Thus, he gives a full description, with five figures, of 
Hemipronites giraldi var. nov. yunnanensis; but he entirely fails to 
indicate in what it differs from the original species-form. Similarly, 
in addition to the page-and-half description of Ogygites yunnanensis, 
n.sp., 1t would have been well to furnish a brief specific diagnosis ; 
a few other species of the genus are mentioned, but the differences 
are indicated for only two of them. A little more attention to 
matters of this kind would be a great help to the weaker brethren, 
and would add to the gratitude they feel for these interesting 
accessions to our knowledge from the outermost fringes of empire. 


IJ.—Tue Gracian Grotoey or Norrork anp Surrorx. By F. W. 
Hanmer, F.G.S. pp. 26, with 7 figures and a contoured map. 
London: Jarrold & Sons; Dulau & Co., Ltd., 37 Soho Square, W.1. 


N this small book, reprinted from the Transactions of the Norfolk 
and Norwich Naturalists’ Society, vol. ix, Mr. Harmer gives 
a summary, written in a somewhat popular style, of his well-known 
work on the glacial deposits of East Anglia, and of the important 
conclusions that he has been able to draw as to the sequence of 
events in that area during the Pleistocene period. For more than 
fifty years Mr. Harmer has devoted most of the leisure of a busy life 
to this subject, and his conclusions are naturally deserving of the 
most careful consideration. 

‘he lower part of the glacial series is classed under the collective 
name of the North Sea Drift, including the Cromer Till and Con- 
torted Drift of other authors. This contains numerous far-travelled 
erratics from Scotland and Scandinavia, of quite unmistakable 
types, and the source of this material is not a matter of controversy. 
The brickearths of the interior of Norfolk may be taken to represent 
the moraine profonde of the North Sea ice-sheet, while the Cromer 


332 Reviews—J. F. Kemp—The Outlook for Iron. 


ridge isits terminal moraine at some stage of the retreat. But when 
we come to consider the higher members of the glacial series the 
question is not quite so simple. It is quite clear that in Kast Anglia 
there are two boulder-clays, divided by sands and gravels; the most 
notable feature of the upper one, which is equivalent to the Chalky 
Boulder-clay of the Midlands, is the presence of enormous quantities 
of Kimeridgian material, which can only have come from the north- 
west, that is in a direction more or less at right angles to the flow of 
the North Sea Glacier. Mr. Harmer considers that this ice, his 
Great Eastern Glacier, originated in the mountains of the North of 
England and flowed down the Vale of York, across Lincolnshire, and 
over the Fenland, being reinforced by lateral glaciers descending 
from the Pennine valleys and by ice coming up the Humber gap 
from the North Sea. Hence it contains a great variety of Jurassic 
and Cretaceous erratics, especially Kimeridge Clay, Neocomian sand- 
stones, hard Chalk, and characteristic tabular flints from Lincoln- 
shire, the latter being very abundant and easy to recognize. This 
second glacier ploughed up and incorporated in its own deposits 
much of the North Sea Drift, so that the westward extension of the 
latter is ill-defined. This hypothesis explains in a satisfactory 
manner the abundance of Kimeridgian material in Norfolk and 
Suffolk, which is difficult or impossible to account for in any other 
way. Granting the fundamental assumption that land ice can move 
in any direction for any distance over a more or less flat surface, the 
rest is easy. It is also shown by a study of the relation of the drifts 
to the valleys of Norfolk that great denudation took place between 
the deposition of the two boulder-clays, and this fact is of much 
interest in connexion with the question of the occurrence of inter- - 
glacial periods, since a long interval of time is indicated, which may 
correspond to one of the warm periods of Penck and Briickner. The 
origin of the plateau gravels and valley gravels of the area may also 
be ascribed to the torrential waters set free during the later stages 
of the melting and retreat of the ice. 

It will thus be seen that this book contains in a very condensed 
form a summary of an enormous amount of work and presents 
problems of absorbing interest, which will probably continue to 
occupy the attention of geologists for a long time to come. 


Jee dals 1a, 


IIJ.—Tue Ovrtook ror Iron. By J. F. Kemp. From the Smith- 
sonian Report for 1916, pp. 289-809. Washington, 1917. 


ie these few pages the author gives a resumé of our present 

knowledge of the reserves of iron-ore still available, with special 
reference to the United States. The general conclusion is that while 
the supplies of high-grade ore are distinctly limited, the reserves 
of low-grade ore are practically inexhaustible. The output of ore 
from the Lake Superior region, for example, cannot be kept up to the 
present production with a minimum of 50 per cent of iron for more 
than fifty years, while ona similar basis the Clinton ores of Alabama, 
Tennessee, and Georgia can be considered as assured for a little over 
100 years. Hence for a successful continuance of iron-smelting in 


Reviews—A. P. Coleman—Dry Land in Geology. 3338 


the United States one of three things must occur: either a great 
improvement in metallurgical processes, rendering the employment 
of low-grade ores remunerative, or some change of economic con- 
ditions leading to a similar result, or the great development of foreign 
sources of supply accompanied by cheap transport. In conclusion, 
some attention is paid to the amount of coke likely to be available in 
the future for iron-smelting; no apprehension is felt of any failure 
in this quarter, since apparently the fuel will last longer than the 
iron-ore. 


day salnel ie 


IV.—Dry Lanp 1n Geotocy. By A. P. Coneman. Smithsonian 
Report for 1916, pp. 255-72. 


fP\HIS is a reprint from the Bulletin of the Geological Society of 

America of the Presidential Address for 1915. It is pointed 
out that all the earlier geologists confined their attention almost 
exclusively to marine deposits, because these contain abundant 
fossils, whereas in terrestrial deposits they are scarce or wanting. 
It is only of recent years that the importance of the latter group has 
been recognized. ‘The chief types are arid and glacial respectively ; 
arid deposits have now been found or imagined in all systems except 
the Ordovician and Jurassic, and it is possible that the idea has been 
overdone, since it is not proved that all red sandstones were 
necessarily formed in deserts. A careful study also shows a remark- 
ably close association between arid and glacial deposits; at first sight 
this seems improbable, but it is actually occurring in the world 
to-day: The primary question of the origin of the land remains 
unanswered; we can only suppose it to be due on isostatic principles 
to an accidentally uneven distribution of density in the globe, and 
unless we are prepared to admit flow of rock-material below the 
crust on a gigantic scale it seems to follow that continents and ocean 
basins must be on the whole permanent features, and adjustments of 
the boundaries of sea and land have been confined to the margins of 
continental masses. 


Re ES Re 


REPORTS AND PROCHEDINGS. 


GroLoeicaL Socirty or Lonnpon. 


May 1, 1918.—G. W. Lamplugh, F.R.S., President, in the Chair. 

Dr. A. Hubert Cox, M.Sc., F.G.S., delivered a lecture on the 
Relationship between Geological Structure and Magnetic Dis- 
turbance, with especial reference to Leicestershire and the Con- 
cealed Coalfield of Nottinghamshire. 

Before the lecture, at the request of the President, Dr. A. Strahan, 
F.R.S., Director of the Geological Survey, briefly outlined the 
circumstances that had led to an investigation into a possible 
connexion between geological structure and magnetic disturbances. 
The magnetic surveys conducted by Riicker and Thorpe in 1886 and 


334 Reports & Proceedings—Geological Society of London. 


1891 had proved the existence of certain lines and centres of 
disturbance, but those authors observed that ‘‘ the magnetic indica- 
tions appear to be quite independent of the disposition of the newer 
strata”, and he (the speaker) had not been able to detect any 
obvious connexion with the form and structure of the Palsozoic 
rocks below. In 1914-15 a new magnetic survey was made by - 
Mr. G. W. Walker, who confirmed the existence of certain areas of 
disturbance. It was suggested that the effects might be due to 
concealed masses of iron-ore, and the matter was referred to the 
Conjoint Board of Scientific Societies, who appointed an Iron-Ores 
Committee to consider what further steps should be taken. The 
Committee recommended that attention should be concentrated on 
certain areas of marked magnetic disturbance, and that a more 
detailed magnetic survey of these areas, accompanied by a petro- 
logical survey and an examination of the magnetic properties of the 
rocks of the neighbourhood, should be made. He (the speaker) had 
been approached with a view to the petrological work being under- 
taken by the Geological Survey, and it had been arranged by the 
Board of Education, with the consent of H.M. Treasury, that a 
geologist should be temporarily appointed as a member of the staff 
for the purposes of the investigation. Dr. Cox had received the 
appointment, and the lecture which he was about to deliver would 
show that results of great significance had been obtained by him. 
The new magnetic observations had been made by Mr. Walker, and 
the examination of the specimens collected, in regard to their 
magnetic susceptibility, had been conducted by Prof. Ernest Wilson. 

Dr. Cox then described the selected areas, which lay on Lias and 
Keuper Marl between Melton Mowbray and Nottingham, and in 
the neighbourhood of Irthlingborough, where the Northampton 
Sands are being worked as iron-ores. The Middle Lias iron-ores, 
consisting essentially of limonite, which crop out near Melton 
Mowbray, have been proved incapable, by reason of their low 
magnetic susceptibility, of causing disturbances of the magnitudes 
observed, while the distribution of the disturbances showed no 
correspondence with the outcrop of the iron-ores. Nor was any 
other formation among the Secondary rocks found capable of exerting 
any appreciable influence. It appeared, therefore, that the origin 
of the magnetic disturbances must be deep-seated. 

Investigation showed that the disturbances were arranged along 
the lines of a system of faults ranging in direction from north-west 
to nearly west. The faults near Melton Mowbray have not been 
proved in the Paleeozoic rocks, and, so far as their effects on the 
Secondary rocks are concerned, they would appear to be only minor 
dislocations. But farther north, near Nottingham, faults which 
take a parallel course, and probably belong to the same system 
of faulting as those near Melton Mowbray, are known from evidence 
obtained in underground workings to have a much greater throw in 
the Coal-measures than in the Permian and Triassic rocks at the 
surface. It appears, therefore, that movement took place along the 
same lines at more than one period, the earlier and more powerful 
movement being of post-Carboniferous but pre-Permian age, the 


Reports & Proceedings—Geological Society of London. 335 


later movement being post-Triassic. Accordingly, it is probable 
that the small dislocations in the Mesozoic rocks indicate the 
presence of important faults in the underlying Paleozoic. 

The faults can only give rise to magnetic disturbances if they are 
associated with rocks of high magnetic susceptibility. It is known 
from deep borings that the concealed coalfield of Nottinghamshire 
extends into Leicestershire, but how far is not known. Deep 
borings have proved that intrusions of dolerite occur in the Coal- 
measures at several localities in the south-eastern portion of the 
concealed coalfield and always, so far as observed, in the immediate 
vicinity of faults. It has been established that dolerites may exert 
a considerable magnetic effect; and the susceptibility of those that 
occur in the Coal-measures is above the general average. Further, 
no other rocks that are known to occur, or are likely to oceur under 
the area, have susceptibilities as high as the dolerites found in the 
Coal-measures. These facts suggest the possibility of the occurrence 
of dolerites intrusive into Coal-measures beneath the Mesozoic rocks 
of the Melton Mowbray district. 

The distribution of the dolerites actually proved, and of those the 
presence of which is suspected by reason of the magnetic dis- 
turbances, appears to be controlled by the faulting. Moreover, 
whereas the character of the magnetic disturbances is such that it 
would not be explained by a sill or laccolite faulted down to the 
north, in the manner demanded by the observed throw of the 
principal fault, it would be explained by an intrusion that had arisen 
along the fault-plane. The faulting itself is connected with a 
change of strike in the concealed Coal-measures, and the incoming of 
doleritic intrusions in the concealed coalfield, in contrast with their 
absence from the exposed coalfield, appears to depend upon the 
changed tectonic features. ‘Vhe change of strike is apparent, but to 
a less degree, in the Mesozoic rocks which, in the neighbourhood of 
Melton Mowbray, have suffered a local twist due to the development 
of an east-and-west anticlinal structure. 

In view of the evidence that later movements have, in this district, 
followed the lines of earlher and more powerful movements, it 
appears possible and even probable that this post-Jurassic (probably 
post-Cretaceous) anticline is situated along the line of a more pro- 
nounced post-Carboniferous but pre-Permian anticline. In this 
connexion the isolated position of Charnwood Forest has a consider- 
able significance. The Forest is situated on the prolongation of the 
east-and-west line of uplift, and just at the point where this uplift 
crosses the line of the more powerful north-westerly and south- 
easterly (Charnian) uplift. Where the two lines of uplift cross the 
elevation attains its maximum, and the oldest rocks appear. 

The main line of faulting and of magnetic disturbance is parallel 
with and on the northern side of the east-and-west anticline, and 
the faulting is of such a nature that it serves to relieve the folding 
while accentuating the anticlinal structure. It 1s possible that this 
belt of magnetic and geological disturbance marks the southern limit 
of the concealed coalfield. The results obtained by joint magnetic 
and geological work have thus served to emphasize the real 


336 Correspondence—R. Bullen Newton. 


importance of a structure which, when judged merely from its effects 
on the surface rocks, appears to be of only minor importance. 

A further series of observations was carried out on the Jurassic 
iron-ores of the Irthlingborough district of Northamptonshire. The 
ores occur in the form of a nearly horizontal sheet of weakly 
susceptible ferrous carbonate partly oxidized to hydrated oxides. 
They give rise to small magnetic disturbances which are quite 
capable of detection, and these may be of use in determining the 
boundaries of the sheets in areas not affected by larger disturbances 
of deep-seated origin. 

The results obtained by the joint magnetic and geological work in 
the two areas show that this method of investigation may be used to 
extend our knowledge of the underground structure. It appears also 
that an extension of the method to other parts of the country would 
yield information of considerable scientific and economic importance. 

Geological maps were exhibited by Dr. A. Hubert Cox, M.Sc.,F.G.S., 
in illustration of his lecture. 


CORRESPONDENCE. 


RICHARD HALL. 

Srr,—Excellent notices have appeared recently in Mature and in 
the Gronogicat Magazine calling attention to the important work 
accomplished by Mr. Richard Hall, now retired, during his thirty- 
eight years of service in the Geological Department of the British 
Museum as a ‘‘ preparer of fossils ’’. 

Sufficient stress has not been laid on Mr. Hall’s skill in the 
development of invertebrate fossils, also in the preparation of 
delicate microscopic objects and the cutting and polishing of rock- 
surfaces exhibiting organic structures. Special attention might be 
called to the large series of sections of Monticuliporoid corals figured 
and described by Dr. Foord, Mr. Robert Etheridge, jun., and the late 
Professor H. A. Nicholson. 

He also made the large sections on glass of the Paleozoic corals 
now in the Geological Department, which enable the student to 
study with ease the internal characters of the Cyathophylloid and 
other groups. Later he prepared microscopic sections of Foraminiferal 
rocks which proved of material assistance in researches in the geology 
of Africa, Madagascar, New Guinea, Borneo, etc. It is a surprising 
fact that an operator who could so successfully disentomb from its 
matrix a great reptile like the Pariasaurus should have been equally 
proficient in the preparation of delicate sections of microscopic 
objects. R. Butren Newron. 


MISCHIILUAN HOUVUS. 


Luptow Musrum.—We are glad to learn that the Ludlow Natural 
History Society has received a bequest of £200 from the late 
Mrs. Agnes Mary White, daughter of the well-known geologist, the 
late Mr. Humphry Salwey, of The Cliff, Ludlow. It is a welcome 
contribution to the funds of an important institution which has 
suffered much from lack of means during recent years.—A. S. W. 


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Decade VI.—Vol. V.—No. VIII. 


CEOLOGICAL MAGAZINE 


OR 


Monthly Journal of Geologn. 


BEssSCIeh Geni @iii\OG Sse. 


EDITED BY 


HENRY WOODWARD, 


lke Was 


FelReSoq PoG@isaSeq aCe 


ASSISTED BY 
PROFESSOR J. W. GREGORY, D.Sc., F.R.S., F.G.S. 
Sir THOMAS H. HOLLAND, K.C.1.H., A.R.C.S., D.Sc., P.R.S., Vicr-Pres. G.S. 
Dr. JOHN EDWARD MARR, M.A., Sc.D. (Cams.), F.R.S., F.G.S. 
Sir VE MMROM. i. MAI. MAC ScD: (CAnrs.)) DRESS Gest 
PROFESSOR W. W. WATTS, Sc.D. (CamsB.), M.Sc., F.R.S., F.G.S. 


Dr. ARTHUR SMITH WOODWARD, F.R.S., F.L.S., 


Gre Soc. 


AUGUST, 1918, 


CONTE 


I. ORIGINAL ARYICLES. Page 
Eminent Living Geologists: George 
W. Lamiplugh, F.R.S., President 
Geological Society. (With a 

IPoreinmnin, Ie SUL) Pocendcsconanse 337 
On a Hypersthene Andesite from 
Pitcullo, Fife. By D. BALSILLIE, 


IN GooSieenbacend onal ce arch coun ann Geene Hen 346 | 


The Zone of Belemnitella mucro- 
nata in the Isle of Wight. By 
R. M. BRYDONE, F.G.S. (With 
a Text-figure.) 

Recent Geological History of the 
Baltic and Scandinavia. By Sir 
HENRY HowortH, K.C.1.E., 
TEI MotSian di aSia/Nan lta Crals\aapoocoean sor B54 

The Genesis of Tungsten Ores. By 
Ree RASMAT, MOA. SHE Gss: 
(Concluded. ) 

II. REVIEWS. 

The Barberton Gold-mining District, 
South Africa. By A. L. Hall.. 371 

Department of Mines, Canada...... 371 

Geology and Ore-deposits of Burma. 

By J. Coggin Brown, F.G.S...... 372 

Minerals used in Arts and In- 
dustries: Corundum. By P. A. 


IWHiaOI GIR Mameiseiatcasiice <eoetesnanecn 373 
Flint Implements in Suffolk. By 
JPMRCTURNG sc sasdhecc se scent 373 


LONDON: DULAU & 


aSEP 3 


AEVIEWS (continued). Page 
Geolosyof OpdighameDistrict ... 374 
S. W. Whiston: “Phylogeny of 

JEU) O) HIKE NSh are N an GeGsuRU Ain aa 374 
G. A. Boulenger: Eocene Lizards 
ial 1 MeehaKAesenbanetmesbosonon dos wocenees GUD) 


Prof. Cl. Gaillard : On Heterosorex 376 
Dr. A. Windhausen: Patagonian 
Geology 376 
Dr. L.L.Fermor: On ‘‘ Hollandite’’ 376 
E. Lindeman: Iron-ore in Canada 377 
Dr. R. L. Sherlock & B. Smith: 
Mineral Resources of Great Britain 377 


III. REPORTS AND PROCEEDINGS. 
Geological Society of London— 


IN Meng alts)5, ISIS ae casos consedsocueadds 377 
JAE! OVO eas eRe aE eM Naratin ag: 377 
dohaverdlG)  Baaaserouwae euen sua moan ace Gene 373 
Mineralogical Society.................. 380 


IV. CORRESPONDENCE. 


eMmOldrenimevcypceeasecc coc oscen cones 380 
Crane BvomeWendiecca-cssccc: (se ceeee 381 
V. OBITUARY. 

William Lower Carter, M.A., 
EVG.S:  ((Wath’a Portrait.)| ...... 382 

John Watson, M.A., F.G.S......... 383 

Professor V. Amalitsky............... 384 


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PLATE XII. 


Grou. Maa., 1918. 


THE 


GHOLOGICAL MAGAZINE 


NEW SERIES HDECA DIE Nil) i: VOL Mi. 


No. VIII.—AUGUST, 1918. 


OREG TINA T,)) Aura r Geass)! 


1.—Eminent Livine GEoLoeists. 


Grorce Witiiam Lamptuen, F.R.S., President Geol. Soc., Assistant 
Director of the Geological Survey of England and Wales. 


(WITH A PORTRAIT, PLATE XII.) 


T has frequently been asserted that the “born geologist’’—as 
distinguished from the geologist made by education and training 
—owes his conception chiefly to the formation on which he happens 
to be born. Nor is it the beauty of the scenery and the attractive- 
ness of firth and fell, mountain and glen, that usually give the 
impulse in the making of the geologist. It comes in most cases from 
the fossils he sees strewn around him in quarry or hillside—things 
that can be collected and fascinate the youthful mind even more 
than the rocks themselves. But whether the strata or the fossils are 
the stimulus required, it is beyond dispute that Yorkshire—in which 
both are .conspicuous — takes a leading place in England as the 
birthplace of so many eminent geologists in the past century, and 
amongst them the subject of our present sketch worthily deserves to 
find a place. 

George William Lamplugh was born at Driffield, Kast Yorkshire, 
on April 8, 1859, and here he spent his early years until he removed 
with his widowed mother to the coast at Bridlington when he was at 
the impressionable age of 13. It is scarcely possible that anyone 
haying any sympathy with Nature should spend his youthful days 
upon the Yorkshire coast without becoming more or less of 
a geologist. Young Lamplugh soon began to collect the fossils from 
the Chalk and Drift, the latter deposit being a veritable open-air 
museum from the variety of its transported rocks and fossils. From 
the desire to know more about his collections he was led to the 
serious study of geology and to seek association with Yorkshire 
geologists, always a numerous and kindly folk. Amongst these he 
met with members of the Geological Survey working at the time 
in the district. Thus began a lasting friendship with the late 
J. R. Dakyns, with whom he spent some holidays in the field in 
various parts of the country. Circumstances compelled Lamplugh to 
enter early into business, but he resolutely determined to make 
science the serious object of his life, even if it did not procure for 
him the necessary means of livelihood. 

Among the geological deposits on the Yorkshire coast that soon 
attracted Lamplugh’s attention was the Boulder-clay series, to the 

DECADE VI.—VOL. V.—NO. VIII. 22 


338 Eminent Living Geologists—G. W. Lamplugh. 


divisions of which, and in particular that known as the Bridlington 
_ Crag,! he devoted very careful work, and published the results in 
a series of papers, commencing in the Grotoercan Magazine for 
November, 1878 (pp. 509-17), in which the position of the shell- 
bearing beds in relation to the Boulder-clay, sands, and gravels is 
shown. 

Besides the additions to the marine fauna made by Mr. Lamplugh 
(and identified by Dr. H. Woodward, F.R.S.), he records the 
discovery (in 1879, op. cit., p. 393) of a freshwater deposit rich in 
shells of Limnea peregra, suggesting envelopment and transportation 
by the land-ice of both freshwater and marine deposits with the shells 
peculiar to each. He also read a paper in 1879 to the Yorkshire 
Geological and Polytechnic Society ‘‘On the Glacial Beds in Filey 
Bay” (the first of a series on kindred subjects communicated to this 
Society extending over many years). 

It happened that the year 1881 was not only famous as the Jubilee 
of the British Association for the Advancement of Science, but the 
meeting was held in York, the city in which the Association was 
founded in 1831. The rally made by geologists, under the presidency 
of Professor (afterwards Sir A. C.) Ramsay, was truly remarkable, 
and the geologists of Yorkshire, amongst whom was G. W. 
Lamplugh (then 22), attended in force and gave it their whole- 
hearted support. Lamplugh’s contribution to the splendid lst of 
papers read in Section C was ‘‘ On the Bridlington and Dimlington 
Glacial Shell-beds” (Grot. Mae., 1881, pp. 5385-46), with an 
excellent section of the cliff and lists of the Mollusca by Dr. J. Gwyn 
Jeffreys, of the Foraminifera by T. Rupert Jones, W. K. Parker, and 
Dr. H. C. Sorby. The recurrence of many papers on the Bridlington 
shell-beds is not merely due to their great importance, but to the 
fact that these beds are only occasionally seen, being almost con- 
stantly ‘‘masked” by masses of shingle and sand piled above them 
by the wind and tides, and moreover they are being gradually but 
permanently lost to sight by the construction of additional sea-walls 
to prevent the encroachment of the sea upon the cliffs. But for 
Lamplugh’s long resedence on gthe spot, their latest history woubd 
probably never have been written. 

Lamplugh’s first paper read before the Geological Society of 
London, in February, 1884, was on a recent exposure by storms of 
the shelly patches in the Boulder-clay at Bridlington in the winter 
of 1882-3. The mollusca, examined and determined by Dr. J. Gwyn 
Jeffreys, had been increased from 67 to 101, five of the additions 
being new to science; the Cirripedia were also determined by 
Mr. E. T. Newton and Foraminifera by Dr. Crosskey. 

This year marked a determinative step in Lamplugh’s life (he 
calls it his ‘‘ wander-year”’), for in it he started on a year’s tour in 
North America for the purpose of increasing and enlarging his 


1 The history of the Bridlington Crag is given in a paper by the late 
Dr. S. P. Woodward in this journal, Vol. I, p. 49, 1864, which records details 
of the various early investigators and a list of the shells in this deposit com- 
pared with the Coralline Red and Norwich Crag, the Glacial deposits, and 
living species. 


Eminent Living Geologists—G.W. Lamplugh. 339 


geological and general knowledge. The philosopher says ‘‘ know 
thyself’’; geologists say ‘‘ know the world”’, and to do this a man 
must travel, travel, travel. He must possess also the trained eye 
and the retentive memory of the intelligent observer. After some 
study of drifts in the Eastern and North Central States, Lamplugh 
drifted gradually westward to the Pacific Coast, Vancouver Island, 
and Alaska. In winter he journeyed south to the Mexican border 
and as far as New Orleans. Afterwards he described a visit to the 
Muir Glacier in Vature and some features of glaciation observed in 
Vancouver Island in the Proceedings of the Yorkshire Geological and 
Polytechnic Society and in the Quarterly Journal for 1886. 

On returning home Mr. Lamplugh took up with his accustomed 
activity his old geological exploration of the Yorkshire coast,’ and 
especially devoted his attention to the subdivisions of the Speeton 
Clay. His notes on this formation in the Excursion Guide pre- 
pared for the London meeting of the International Geological 
Congress in 1888 brought him into personal association with several 
distinguished Continental geologists, who visited Speeton under his 
guidance, and led him to communicate an important paper on the 
subject to the Geological Society in March, 1889. This paper gave 
the results of a long series of observations made by him, during 
favourable opportunities, at the cliff foot and on the beach at 
Speeton from 1880 to 1889. As the result of his exhaustive labours 
he was able to show, on stratigraphical and paleontological evidence, 
that there is probably at Speeton a continuous series of clays from 
the Jurassic to the Upper Cretaceous, and that the deposition of 
these beds had gone on contemporaneously with the erosion of the 
beds inland. 

This exploration of the Speeton Clay attracted the particular 
attention of the Russian geologist Professor Dr. Alexis P. Pavlow, 
of the University of Moscow. A critical study of the fossils by 
Professor Pavlow gave rise to a joint paper on the Speeton Clay 
and its Equivalents by A. Pavlow and G. W. Lamplugh.? In 
it the authors showed by comparative stratigraphy, and on the 
evidence of the Mesozoic Cephalopods from Russia, this, and other 
countries, the different ‘‘zones’’? into which the Speeton and 
Russian beds have been divided, and the actual sequence from the 
Kammeridgian to the Aptian. 

In the award to Mr. Lamplugh of the ‘‘ Lyell Geological Fund” 
by the Council of the Geological Society in February, 1891, the 
President, Sir A. Geikie, referred to his valuable researches among 
the Glacial deposits of Yorkshire, and particularly to his “investiga- 
tion of the Speeton Clay, as a striking example of the results 
obtained by long and patient labours of an observer resident on the 
spot with unusual facilities to examine and study the beds. 

In 1892 the opportunity so long awaited was afforded Lamplugh 
to join the Geological Survey as an Assistant Geologist, and, as 


oe 


1 He once described himself as 
science. 

? Published in the Bull. Soc. Imp. Nat. Moscou with 11 plates (Moscow, 
1892); see also GEOL. MAG., 1892, pp. 422-6. 


a coastguard ’’ in the service of geological 


340 Eminent Living Geologists—G. W. Lamplugh. 


evidence of the high opinion held by the Director of his qualifica- 
tions, he was sent to survey the Isle of Man, a task in which he was 
occupied for the greater part of the succeeding five years. The 
results of this period are embodied in his papers to the volumes of 
the Quarterly Journal and the Survey Memoir on the Isle of Man. 

It is not often that one geological surveyor has the pleasure and 
satisfaction of seeing his name recorded as having written a memoir 
entirely by himself. The late Professor J. W. Judd when on the 
Survey many years ago claimed to have completed a whole English 
county, that of Rutland, but Mr. Lamplugh surveyed a whole 
island; nay, more, for was not Man a kingdom in itself up to 1765, 
when the Duke of Athol ceded his rights as Lord of Man to the 
Crown; but it still has its own Parliament (the House of Keys). 
Three-fourths of its whole area of 227 square miles (145,325 acres) 
is probably of Upper Cambrian age, whilst borings through Glacial 
drift have revealed a rock-floor of Triassic, Permian, and Lower 
Carboniferous strata below sea-level. Besides its valuable mines of 
silver-lead ore, its shell-marl and peat deposits have yielded many 
remains of the ‘‘ Gigantic Irish Deer”’ (including an entire skeleton 
now set up in the Castle Rushen Museum, Isle of Man), which 
animal Mr. Lamplugh suggested may have crossed over to Man upon 
the ice towards the close of the Glacial period !! 

A brief leave of absence having been granted him, early in 1893 
Mr. Lamplugh paid a flying visit to Arizona and the Pacific Coast of 
America and had a glimpse of the Grand Canon of the Colorado. 

Four years later, having been appointed Secretary of Section C 
(Geology), he attended the meeting of the British Association held 
in Toronto, Canada, and he joined an excursion across the Dominion 
to Vancouver Island under the guidance of Dr. G. M. Dawson, F.R.S., 
an account of which he published in Nature for November, 1897. 
In 1898 Mr. Lamplugh removed to Tonbridge to take part in the 
mapping of the Weald in conjunction with the examination of the 
borings and sinkings for coal then in progress in Kent (see memoir 
with Dr. Kitchin on Kent Mesozoic Rocks, 1911). 

In 1901 the Council of the Geological Society awarded to him 
the Bigsby Medal (the ‘‘young man’s medal’’). In handing it to 
Mr. Lamplugh the President, Mr. Teall, said: ‘‘The Council feel 
that they are placing it in safe hands. You have done much, and 
they confidently expect that you will do more’’:—a trust which has 
since been honourably fulfilled by the recipient. 

Having been appointed ‘‘ District Geologist” in 1901, Mr. Lamplugh 
was sent to Dublin in charge of the Irish branch of the Geological 
Survey, in which post he remained until the Survey was transferred 
to an Irish department and placed under the supervision of 
Professor Grenville A. J. Cole, F.R.S., in 1905. During the period 
~ of his residence in Dublin Lamplugh superintended and took part in 
the mapping of the country around Dublin, Belfast, Cork, and 
Limerick, and issued four memoirs dealing with these areas. 

' Another skeleton of Cervus megaceros, discovered in the Isle of Man in 
1819, was presented to the Edinburgh Museum by the Duke of Athol. Many 


other remains of the same deer haye been met with from 1798 onwards (see 
Geol. Surv. Mem., 1903,spp. 377-88). 


Eminent Living Geologists—G. W. Lamplugh. 341 


In 1905 Mr. G. W. Lamplugh was elected a Fellow of the Royal 
Society, and in the same year he undertook, under the auspices of 
the British Association, the examination of the almost unexplored 
gorge of the Zambesi below the Victoria Falls, one of the grandest 
features of natural scenery to be met with on the African Continent. 
‘“‘Tt is difficult,” says Mr. Lamplugh, ‘‘for anyone standing on the 
brink of the chasm, after having seen the placid flow of the Zambesi 
above the Falls, to believe that the fissure into which the river is so 
suddenly precipitated had been formed gradually by the action of 
the river itself, and not by some great convulsion during which the 
very crust of the earth was rent. The narrowness of the abyss, the 
strange zigzags along which the tumultuous waters rush, after their 
first great plunge, the mystery which has long surrounded the 
further course of the river after it swings away out of sight among 
its forbidding precipices, and the knowledge that the rocks across 
which it plunges are of volcanic origin are all factors that have 
aided the illusion.” The conclusion arrived at by Mr. Lamplugh 
after examining the river carefully was quite in agreement with that 
already advanced by Mr. A. J. C. Molyneux that the prevalent idea 
of a sudden rent of the earth’s crust was inadequate to explain the 
phenomena observed around the Falls, but was compatible with the 
view that the river has slowly sunk its channel into the hard rocks 
which have barred its passage seawards, while evidence afforded in 
other parts of the world sufficiently proves that canyons of even more 
impressive dimensions than the Zambesi have been carved out by the 
erosive agency of water acting through very long periods of time.! 

In the following year Mr. Lamplugh was elected President of the 
Geological Section of the British Association in York and delivered 
an address on ‘‘ Interglacial Problems”’. 

Upon his return from Ireland he took charge of the survey of the 
Midland District (Nottinghamshire, etc.), and shared as writer and 
editor in the publication of several memoirs (see list). Subsequently 
he superintended the field-work in the North Wales district, the 
full results of which are not yet published. 

In 1910 Mr. Lamplugh attended the meeting of the International 
Geological Congress at Stockholm; and previously to the meeting he 
joined with other noted geologists in an expedition to Spitsbergen, 
of which some account was contributed to Nature (December 1, 1910) 
and a description of a striking shelly moraine seen there to the 
Proceedings of the Yorkshire Geological Society for 1911. 

After the retirement of Mr. Horace B. Woodward, F.R.S., in 1908 
the administrative work of Assistant Director of the Survey was 
tuken up by Dr. A. Strahan, F.R.S., until his promotion to the 
Directorship in 1914, when Mr. Lamplugh became Assistant Director. 

In the latter year he made one of the distinguished band 
of geologists who represented our science on the occasion of the 
holding of the British Association in Australia (in August, 1914) 


1 A paper read before the British Association for the Advancement of 
- Science, meeting in South Africa at Johannesburg, August 30, 1905. See also 
the Official Guide to the Falls, 1905, and the GEOLOGICAL MAGAZINE for 
December, 1905, pp. 529-32. 


342  Hminent Living Geologists—G. W. Lamplugh. 


under exceptional facilities arranged by the Australian Governments. 
Not long after their arrival in the Commonwealth came the serious 
intelligence that war had been declared with Germany, a misfortune 
which overshadowed the programme and marred the closing stage of 
the meeting. Mr. Lamplugh was fortunately able, owing to the 
kindness of officials everywhere, to see much of the country, 
particularly in Western Australia, before the outbreak of war, under 
the guidance of Mr. Harry P. Woodward and Professor Woolnough. 

Mr. Lamplugh is “‘ no stranger in our midst”’, but is well known 
and highly esteemed in the scientific world, having been a Geological 
Surveyor for twenty-six years, and served upon the Councils of the 
Royal Society (1914-16), the Royal Geographical Society, and the 
Geological Society (1906-10, a Vice-President 1909-10, 1917), 
and is now its President (1918). As a Yorkshireman he keeps up 
his interest in all the amateur geological activities in the county. 
He is a past-President of the Yorkshire Naturalists’ Union, the Hull 
Geological Society, and the Hertfordshire Natural History Society ; 
and is an Honorary Member of the Rhodesian Scientific Association, 
the Yorkshire Philosophical Society, the Natural History and 
Antiquarian Society of the Isle of Man, and the Nottingham 
Naturalists’ Society. 

One who has worked with G. W. Lamplugh in the field and on the 
Survey and known him for some years writes :— 

“Tf I were compelled to compress into three words my impression 
of Lamplugh’s character, the ones I should choose would be courage, 
determination, and consistency—the courage which spurred him to 
break the current of his life and divert it to the work he loved and 
knew he could do best; the determination with which he has 
mapped out his career, passing through each objective to the next 
and never allowing an opportunity or experience to pass by unused ; 
and the consistent high purpose which has guided the quality of his 
work, whether in the drifts, the Speeton clays, the Trias, or, that 
fool’s paradise for geologists, the Isle of Man. 

“These are the qualities which one sees in the field. A keen and 
accomplished observer as any glacial geologist must be or become, he has 
the elasticity of mind which enables him to turn to the discrimination 
of obscure igneous or metamorphic rocks, to the determination of 
ammonites or belemnites, or to the registering of those minute 
features of landscape which tell the history of physiography. Only 
here we must add the physical fitness for hard and steady work, and 
the disciplined imagination which have made the story of the Zam- 
besi, or the glacial history of the Isle of Man, read like a fairy tale. 

“But it is when the day’s work is done and there ‘creep out the 
little arts that please’ that we discover the man of wide reading 
and liberal culture, of broad knowledge of places, men, and things, 
of deep convictions and serious thought. Then, if not before, we 
find the merciless critical faculty which takes nothing for granted, 
the insight which looks down into the heart of things, and the 
intolerance of sham and shoddy, which, seeking good in all, cannot 
shut its eyes to the evidence that all is not always for the best. 

‘« Although he has undoubtedly read the hundred best books he has 


f 
Eminent Inving Geologists—G. W. Lamplugh. 348 


by no means neglected the others, and, bringing to bear upon his 
great knowledge of literature, on its humane as well as its scientific 
side, a delicate perception and a nice and balanced judgment, he has 
become no mean judge of style and method. But the style that he 
appreciates must be the embroidery that accentuates worth and 
beauty and not that which is intended to hide deficiencies in both. 
It was no small triumph to have detected a new de Rougemont who 
had for the second or third time thrown dust into the eyes of those 
whose business 1t was to see clearly in matters of style. 

‘« Keen as is his evaluation of books, his knowledge of men is not less 
well founded nor his judgment less sound. Having travelled far he 
has made a wide circle of acquaintances of varied sympathies and 
interests, and has met them under circumstances which favour close 
intimacy. ‘To discuss men with him is as entertaining as to discuss 
books, for he has studied the man as well as his work, has seen the 
weak spots as well as the strength, and has the faculty of expressing 
his opinions with a slightly malicious but always good-natured 
humour which gives them a delightful if subacid flavour. 

‘Tf one might be allowed three more epithets they would be—as 
a geologist, sound; as a man, human; as a friend, lovable.”’ 

Mr. Lamplugh’s large knowledge and wide experience in our 
science is always at the service of geologists who seek his kindly 
help. He is without pretence and rather too retiring, but—as he is 
only 59—that may be remedied as he grows older and has longer 
intercourse with his fellow-hammerers. We offer him our sincerest 
good wishes for his Presidency of the Geological Society, and he will 
also carry our warm regard with him for the term of his natural life. 


H. W. 


GEOLOGICAL PAPERS OTHER THAN GEOLOGICAL SURVEY MEMOIRS. 


1878. ‘‘ On the Occurrence of Marine Shells in the Boulder Clay at Bridlington 
and elsewhere on the Yorkshire Coast’’: GEOL. MaG., Dee. II, 
Vol. V, pp. 509-17. 
1879. ‘‘On the Occurrence of Freshwater Remains in the Boulder Clay at 
Bridlington’: ibid., Vol. VI, pp. 393-9. 
1880. ‘‘On the Divisions of the Glacial Beds in Filey Bay’’: Proc. Yorks 
Geol. & Polytech. Soc., vol. vii, pp. 107-17, 1879. 
1881. ‘‘Ona Fault in the Chalk of Flambro’ Head, with some Notes on the 
Drift’’: ibid., pp. 242-6, 1880. 
**On a Shell-bed at the base of the Drift at Speeton, near Filey, on the 
Yorkshire Coast’’?: GEOL. MaG., Dec. II, Vol. VIII, pp. 174-80. 
“On the Bridlington and Dimlington Glacial Shell-beds’’: ibid., 
pp. 535-46. 
1882-90. ‘* Glacial Sections near Bridlington,’’ pt.i: Proc. Yorks Geol. & 
Polytech. Soc., vol. vii, pp. 383-97, 1881; pt. ii, ibid., vol. viii, 
pp. 27-38, 1882; pt. iii, ibid., pp. 240-54; pt. iv, ibid., vol. xi, 
pp. 275-300, 1889. 
1883. ‘* Thornwick Bay, Flamborough’’: ibid., vol. viii, pp. 103-7, 1882. 
1884. ‘Ona Recent Exposure of the Shelly Patches in the Boulder Clay at 
Bridlington Quay ’’: Quart. Journ. Geol. Soc., vol. xl, pp. 312-18. 
(Abstract in GEoL. MAG., Dec. III, Vol. I, p. 185.) 
1886. ‘‘On Glacial Shell-beds in British Columbia’’: ibid., vol. xlii, 
pp. 276-86 (ibid., Vol. III, pp. 233-4). 
“* On Ice-grooved Rock Surfaces near Victoria, Vancouver Island, with 
Notes on the Glacial Phenomena of the Neighbouring Region, and 


344 


1888. 


\ 
Eminent Inving Geologists—G. W. Lamplugh. 


on the Muir Glacier of Alaska’’: Proc. Yorks Geol. & Polytech. 
Soc., vol. ix, pp. 57-70, 1885. 

‘“Report on the Buried Cliff at Sewerby, near Bridlington’’: ibid., 
pp. 381-92, 1887. 

“* Cliff Section at Hilderthorpe ’’ : -ibid., pp. 433-4, 1887. 

‘*On a Mammaliferous Gravel at Hlloughton in the Humber Valley’? : 
ibid., pp. 407-11, 1887. 


1888-91. ‘‘On the Larger Boulders of Flambro’ Head,’’ pt.i: ibid., 


pp. 339-43, 1887; pts. ii and iii, ibid:, vol. xi, pp. 231-9, 1889; 
pt. iv, ibid., pp. 397-408, 1890. 


1888 (1891). ‘“Notes sur la géologie de Flamborough Head ’’: Explications 


1889. 


des Excursions, Internat.. Geol. Congr., 4th Session, Compte 
Rendu, pp..389-407. 

“On the Subdivisions of the Speeton Clay’’: Quart. Journ. Geol. 
Soc., vol. xlv, pp. 575-618. (Abstract in GHoL. MaG., Dec. III, 
Vol. VI, pp. 233-4.) 


1889-91. ‘‘Reports of the Committee . . . investigating an Ancient Sea- 


1890. 


1891. 


1892. 


1891-2. 


1894. 
1895. 


1896. 


1896-7. 


1898. 


1900. 


1901. 


beach near Bridlington Quay’’: Rep. Brit. Assoc., 1888, pp. 328-38; 
ibid., 1890, pp. 375-7. 

‘On a New Locality for the Arctic Fauna of the ‘ Basement’ Boulder 
Clay in Yorkshire’’: GEOL. MAG., Dec. III, Vol. VII, pp. 61-70. 

‘“The Neocomian Clay at Knapton’’: Natwralist, 1890, pp. 336-8. 

‘“ On the Boulders and Glaciated Rock-surfaces of the Yorkshire Coast ’’ : 
Rep. Brit. Assoc., 1890, pp. 797-8. 

“Hast Yorkshire during the Glacial Period’’: ibid., pp. 798-9. 

‘“On the Drifts of Flamborough Head’’: Quart. Journ. Geol. Soce., 
vol. xlvii, pp. 384-431. (Abstract in GEOL. MaG., Dec. III, 
Vol. VIII, p. 239.) 

“The Flamborough Drainage Sections’’: Proc. Yorks Geol. & Polytech. 
Soc., vol. xii, pp. 145-8, 1891. 

(With Professor A. P. PavLow.) ‘‘Argiles de Speeton et leur 
Equivalents’’: Bull. Soc. Imp. Nat. Moseou, N.s., vol. v, 
pp. 181-213, 455-570 (also published separately, Moscow, 1892). 
(Abstract in GEoL. MaG., Dec. III, Vol. IX, pp. 422-6.) 

“Notes on the Snowfall of the Glacial Period’’: Glacialists’ Mag., 
vol. i, pp. 231-3. 

“‘Notes on the Coast between Bridlington and Filey’’: Proc. Yorks 
Geol. & Polytech. Soc., vol. xii, pp. 424-31, 1894. 

(With W. W. Watts.) ‘‘The Crush Conglomerates of the Isle of 
Man ’’: Quart. Journ. Geol. Soc., vol. li, pp. 563-97. (Abstract in 
GEOL. MaG., Dec. IV, Vol. II, pp. 372-3.) 

‘On the Speeton Series in Yorkshire and Lincolnshire ’’: ibid., 
vol. lii, pp. 179-218. (Abstract in GEoL. MaG., Dec. IV, Vol. TI, 
pp. 87-8.) 

““An Outline of the Geology of the Isle of Man’’: Handbook for 
Lwerpool Meeting of British Association, pp. 165-81. 

“Notes on the White Chalk of Yorkshire,’’ pts. i, ii: Proc. 
Yorks Geol. & Polytech. Soc., vol. xiii, pp. 65-87, 1895; pt. iii, 
ibid., pp. 171-91, 1896. 

““Some Open Questions in East Yorkshire Geology’’: Trans. Hull 
Geol. Soc., vol. iv, pp. 24-36. 

‘‘ The Glacial Period and the Irish Fauna’’: Nature, vol. lvii, p. 245. 

‘*On some Effects of Harth-movement on the Carboniferous Volcanic 
Rocks of the Isle of Man’’: Quart. Journ. Geol. Soc., vol. lvi, 
pp. 11-25. (Abstract in GEOL. MaG., Dee. IV, Vol. VII, p. 89.) 

“Note on the Age of the English Wealden Series’’: GEOL. MAG., 
Dec. IV, Vol. VII, pp. 448-5. (Also in Rep. Brit. Assoc., 1900, 
pp. 766-7.) 

‘* Names for British Ice-sheets of the Glacial Period’’: ibid., Vol. VIII, 
p. 142. 


1903. 


1904. 


1905. 


1905-6. 


1906. 


1907. 


1910. 


1911. 
1912. 


1913. 


1886. 
1897. 


1902. 
1906. 


1908. 


Eminent Living Geologists—G. W. Lamplugh. 345 


‘“Belemnites of the Faringdon ‘Sponge-gravels’’’: ibid., Vol. X, 
pp. 32-4. 

(With J. F. WALKER.) ‘‘On a Fossiliferous Band at the top of the 
Lower Greensand near Leighton Buzzard (Beds)’’: Quart. Journ. 
Geol. Soe., vol. lix, pp. 234-65. (Abstract in GEOL. MAG., Dec. IV, 
Vol. X, p. 137.) 

‘‘Land-shells in the Infra-glacial Chalk-rubble at Sewerby, near 
Bridlington Quay ’’: Proc. Yorks Geol. & Polytech. Soc., vol. xv, 
pp. 91-5, 1903. (Abstract in GEOL. MaG., Dec. IV, Vol. X, p.513, 
and Rep. Brit. Assoc., 1903, p. 659.) 

‘On the Disturbance of Junction Beds from Differential Shrinkage and 
similar local causes during Consolidation’’: Rep. Brit. Assoc., 
ayn 666. (Also GEoL. MAG., Dec. IV, Vol. X, pp. 516-17, 
1903. 

**Note on the Conditions of Accumulation of the Yorkshire Chalk, 
as shown by the State of Preservation of the Fossils’’ (Appendix 
C to Paper by A. W. Rows): Proc. Geol. Assoc., vol. xviii, 
pp. 287-9. 

‘“ Note on Lower Cretaceous Phosphatic Beds and their Fauna’’: Rep. 
Brit. Assoc., 1904, p. 548. (Also GEoL. MaG., Dec. V, Vol. I, 
pp. 551-2, 1904.) 

““Notes on the Geological History of the Victoria Falls’’: GEOL. 
MaG., Dee. V, Vol. II, pp. 529-32. (Reprinted from ‘‘ The 
Official Guide to the Victoria Falls’’, by F. W. SYKEs.) 

‘“Report on an Investigation of the Batoka Gorge and adjacent 
portions of the Zambesi Valley’’: Rep. Brit. Assoc., 1905, 
pp. 292-301. (Also Nature, vol. lxxiii, pp. 111-14, 1905.) 

“On British Drifts and the Interglacial Problem’’: Presidential 
Address to Section C of British Assoc. York. Pamphlet, 1906; 
also Nature, Ixxiv, pp. 387-400, 1906, and Rep. Brit. Assoc., 1906, 
pp. 532-58, 1907. 

““Geology of the Zambezi Basin around the Batoka Gorge’’: Quart. 

. Journ. Geol. Soc., vol. lxiii, pp. 162-216. (Abstract in GEOL. 
MaG., Dec. V, Vol. IV, pp. 138-40.) 

‘‘ Estuarine Shells in the Alluvial Hollow of Sand-le-mere, near 
Withernsea in Holderness’’: Naturalist, January, pp. 7-11. 

“Notes on British Late-Glacial and Post-Glacial Deposits’’: Die 
Verdnderungen des Klimas, etc. (Geol. Congr.), Stockholm, 1910, 

p. 49-54. 

‘“On Movements in Rocks’’: Presidential Address to Herts Nat. Hist. 
Soc., Naturalist, May, pp. 180-3. 

““On the Shelly Moraine of the Sefstrém Glacier and other Spitsbergen 
Phenomena illustrative of British Glacial Conditions’’: Proc. 
Yorks Geol. Soc., vol. xvii, pp. 216-41, 1911. 

“* The Interglacial Problem in the British Islands’’: Internat. Geol. 
Congr. Toronto, XII Sess., Compte Rendu, pp. 427-34. 


GEOGRAPHICAL AND GENERAL PAPERS AND ESSAYS. 

““Notes on the Muir Glacier of Alaska’’?: Nature, vol. xxxiii, 
pp. 299-301. 

‘* Geologists in Canada (Journey of British Assoc. party from Toronto 
to Vancouver Island) ’’: ibid., vol. lvii, pp. 62-6. 

‘““ Geology of Surrey ’’: Victoria County History of Surrey, vol. i, ch. i. 

““Notes on the Occurrence of Stone Implements in the Valley of the 
Zambesi around Victoria Falls’: Journ. Anthrop. Inst., vol. xxxvi, 
pp. 159-69. 

““On, the Necessity for the Amateur Spirit in Scientific Work’’: 
Presidential Address to Yorkshire Nat. Union, Natwralist, March, 
pp. 71-80. 

‘“The Gorge and Basin of the Zambezi below the Victoria Falls, 
Rhodesia’’: Geogr. Journ., vol. xxxi, pp. 183-52, 287-303. 


346 8D. Balsillie—Hypersthene Andesite, Fifeshire. 


1908. ‘‘ Geology of Kent’’: Victoria County History of Kent, vol. i, ch. i. 
1909 & 1914. ‘* Physiographical Notes. I. On Hrosive conditions resulting 
from Snowfall’’: Geogr. Journ., vol. xxxiv, pp. 56-9. II. “‘On 
the Taming of Streams’’: ibid., vol. xliii, pp. 651-6. 
1910. ‘‘Man as an Instrument of Research’’: Presidential Address to the 
Herts Nat. Hist. Soc., Naturalist, May, pp. 187-98. 
** Stockholm to Spitsbergen: The Geologists’ Pilgrimage’’: Nature, 
vol. Ixxxv, pp. 152-7. 
1914. ‘‘ The Isle of Man’’: The Oxford Survey of the British Empire: The 
British Islands (Clarendon Press), ch. xx, pp. 498-510. 
Also numerous review-articles, letters, etc., on geological and geographical 
subjects, in GEoL. Maac., Nature, Geogr. Journ., etc. 


GEOLOGICAL SURVEY MEMOIRS, PUBLISHED BY H.M. STATIONERY OFFICE. 


1903. Geology of the Isle of Man (with Petrology by Professor W. W. WATTS, 
M.A., F.R.S.). 8vo. pp. xiv + 620, with 5 pls. and 110 text-figs. 
Cloth, 12s. 

1910. Geology of the Country around Nottingham (with W. GrBson). 8vo. 
pp. 72, with 7 pls. and 9 figs. Wrapper, 2s. 

1911. The Mesozoic Rocks in some of the Coal Explorations in Kent (with 
F. L. KitcHIN). 8vo. pp. 212, with 5 pls. and 5 figs. Wrapper, 
3s. 6d. 

1914. Water Supply of Nottinghamshire (with B. SMITH). S8vo. pp. 574, 
2 coloured maps, and 2 figs. Wrapper, 5s. 

1917. Summary of Progress for 1916: Appendix III, On a Deep Boring at 
Battle ; App. IV, The Underground Range of the Jurassic and Lower 
Cretaceous Rocks in Kast Kent, pp. 40-52. 


CONTRIBUTIONS TO THE FOLLOWING SHEET MEMOIRS. 
1899. Geology of the Borders of the Wash. 
1903. Geology of the Country around Chichester. 
Geology of the Country around Dublin. 
1904. Geology of the Country around Belfast. 
1905. Geology of the Country around Cork and Cork Harbour. 
Geology of the Country south and east of Devizes. 
1907. Geology of the Country around Limerick. 
1908. Geology of the Country between Newark and Nottingham. 
Geology of the Country around Oxford. 
1909. Geology of the Melton Mowbray district and 8.K. Nottinghamshire. 
1911. Geology of the Country around Ollerton. 
1913. Geology of the Northern Part of the Derbyshire Coalfield, etc. 
1915. Geology of the Country between Whitby and Scarborough, 2nd ed. 


IIl.—Nore on a HyprrstHene ANDESITE FROM PitcuLio, FIFEsHIRE. 
By D. BAusILuiz, F.G.S., Chemistry Department, University of Edinburgh. 


(T\WENTY-ONE years ago Dr. Flett in a valuable paper (Trans. 

Edin. Geol. Soc., vol. vii, 1897) described an exceedingly 
beautiful hypersthene andesite from the volcanic series of the Lower 
Old Red Sandstone at Dumyat in the Western Ochils. In the 
following brief communication I propose to give a short petrographic 
account of a strikingly similar rock that has occurred to me in the 
field in a more easterly portion of the same range of hills and which 
is of the same geological age. 

In East Fife the volcanic rocks of the Lower Old Red Sandstone 
rise abruptly above the southern shores of the Firth of Tay. They 
consist here as elsewhere of lavas, tufts, voleanic breccias, and 
agglomerates, with intervening belts of sediment that no doubt 


D. Balsilie—Hypersthene Andesite, Fifeshire. 347 


marked intervals of quiescence more or less prolonged in the course 
of their voleanic history. ‘lhe prevailing dip of the rocks is towards 
south-east, so that as we proceed in that direction progressively 
higher members of the sequence are encountered. As usual among 
the igneous products of this geological period, the most abundant 
extrusive types are andesites. More acid rocks, such as felsites, also 
oecur, but there is no evidence to prove conclusively that in the area 
in question these are ever true lavas. (Reference may here be made 
to the salmon-pink felsite of Lucklaw Hill, which has hitherto been 
regarded asa lava. The enormous extension of this mass at right 
angles to the general strike of the rocks and the manner in which it 
sends ramifications into the andesites that surround it, especially on 
its. northern boundaries, point only to one conclusion, viz. an 
intrusive origin.) The andesites vary greatly in their physical 
characters. Some are slaggy, having abundant mineral-filled 
vesicles, others being thoroughly compact with a platy system of 
joints and an occasional development of brecciation along their lower 
portions. These latter compact rocks afford excellent material for 
microscopic investigation, and as in many cases they have been laid 
bare in quarries for the provision of material to macadamize the 
public roads it is not difficult to collect representative examples of 
the fresher types of the district. It is in reference to a fortunate 
exposure in one of these artificial openings that this note has been 
written, and the remarks that follow are based entirely on the 
examination of rock specimens collected from one locality, viz. near 
Pitcullo in East Fife. 

Inspection of a 1 inch to the mile topographic map of Fifeshire 
will show that on the main road between the county town of Cupar 
and Dundee there is, about 1 mile to the north-east of the little 
village of Dairsie, a farm steading named Muirhead, from which point 
a road runs west across the hills towards Craigsanquhar. Less than 
half a mile along this road from the junction just mentioned, and 
immediately on its right-hand side, a quarry has been opened among 
the lavas. The main rock of the quarry, which is situated at no 
ereat distance from the mansion house of Pitcullo, and is con- 
sequently designated the Pitcullo Quarry, is not of such character as 
to attract any special attention, but high on the worked face, on the 
side remote from the road, a rock of remarkable freshness and with 
a pitchstone-like resinous lustre occurs. It is coated externally with 
a light-brown crust, perhaps as much as a quarter of an inch in 
thickness, but beneath this weathered zone is very black and 
compact, and shows on a freshly broken surface abundant porphyritic 
crystals of a glassy felspar. There is no line of demarcation between 
this fresh rock and that lower in the quarry face, and the probability 
is that it is merely a modification of the rock occurring there. 

Under the microscope confirmation of the fresh nature of the rock 
is immediately to be obtained. It consists of a remarkably homo- 
geneous, brown in colour, isotropic groundmass, in which are 
disposed numerous porphyritic crystals of glassy felspar, ortho- 
rhombic and monoelinic pyroxenes, as well as irregular grains and 
granules of magnetite. 


348 D. Balsillie—Hypersthene Andesite, Fifeshire. . 


The porphyritic felspars, which in many cases are beautifully 
zoned, belong to the albite-anorthite series and exhibit albite, 
carlsbad, and pericline twinning. They are often elongated along 
the crystal axis a, but are sometimes also equidimensional on the 
second pinacoid. Examination by Fouqué’s method shows that in 
sections normal to the bisectrix there is an angular divergence 
between the trace of the optic axial plane and (010) of 64°, the 
corresponding extinction angle on slices perpendicular to y, measure- 
ment being made to the (001) cleavages, amounting to from 20° to 
24°, these values agreeing well with an acid labradorite. Confirma- 
tion of this identification can be readily obtained from sections that 
exhibit both carlsbad and albite twinning by the well-known method 
of Michel Lévy, as also from slices cut normally to (010) and (001). 
The felspar phenocrysts are much more abundant than in the Dumyat 
rock, are equally fresh and unaltered, and as in its western counter- 
part the felspars here often contain glass inclusions and show 
evidence of resorption, though this phenomenon is not nearly so 
marked as in the rock described by Dr. Flett. Neither is there here 
the same indication of flow structure, the phenocrysts in the field of 
the microscope not showing the rough parallelism that immediately 
strikes one in the Dumyat rock. As noted, the felspar crystals are 
often elongated along the crystal axis a, and a single Baveno twin 
was observed cut almost normally to the bisectrices a, the two 
halves giving angles of 60° and 61° respectively between the optic 
axial plane and (010). Each half was in addition twinned on the 
albite law, and an albite lamella in the one half was seen to be con- 
tinued across the composition face and be prolonged in the other 
individual on the pericline law. ‘his optical distinction could easily 
be made out under high magnification and making use of a thin 
gypsum plate. 

The pyroxenes include, as has been said, both orthorhombic and 
monoclinic varieties. The former mineral, which predominates, is 
optically negative, markedly pleochroic, and may safely, I think, be 
taken as hypersthene. The crystal outlines are well-marked sections 
transverse to the crystal axis c, being rectangular in form, with 
the prism faces occurring as mere truncations of the corners. Such 
sections are invariably traversed by a set of irregular cracks, in 
addition to which there is a well-developed prismatic cleavage. - 
A pinacoidal cleavage I did not observe. The hypersthenes are 
usually quite fresh and have a tendency to occur as little coteries of 
small crystals, sometimes in association with the monoclinic pyroxene 
or in other places along with the felspars. The pleochroism is as 
follows: X pale reddish-brown, Y pale yellow, Z green. 

The monoclinic pyroxene is at once to be distinguished from the 
hypersthene by its oblique extinetions and higher interference 
colours. The dark borders that were noted by Dr. Flett to surround 
the augites in the Dumyat rock do not occur here. ‘The crystal 
outlines are but ill defined, and twinning occurs on one or more laws 
that I did not determine. The mineral is not pleochroic, and on the 
prismatic zone of faces exhibits very often roughly parallel cleavage 
traces. The angle between the bisectrix Z(=y) and (100) was 


D. Balsillue—Hypersthene Andesite, Fifeshire. 3849 


found to amount from 40° to 45°, this corresponding with augite, 
which I therefore take to be the monoclinic pyroxene present. 

Magnetite occurs disseminated as quadrangular and irregular 
grains throughout the rock, and is frequently enclosed in the 
pyroxenes. Apatite such as occurs in the Dumyat and Cheviot 
andesites I did not observe. 

The groundmass of the Pitcuilo rock examined under low powers 
appears remarkably isotropic, but is resolvable under higher 
magnification to a mass of little felspar crystals that le in an 
ultimate base of pale-brown or colourless glass with globulites. In 
addition to the felspars, which are twinned on the albite law and 
have only a small extinction angle, a second generation of pyroxenes 
also occurs, Magnetite, too, is an abundant constituent. 

In sections of the Dumyat rock a number of lighter areas made up 
of minute microlites and having a darker periphery were observed 
by Dr. Flett. In their most perfect form these occur ‘‘as rounded 
bodies which have some resemblance to spherulites’”’. Such circular 
ageregations of microlites I have not noted in the Pitcullo rock, 
though irregular areas of a similar kind, and often with a darker 
border, not uncommonly oceur. Comparison, however, with hand- 
specimens of the typical kugel andesite from Bath, Hungary, 
convinces me that it would be quite unwise to describe kugel 
structure as occurring in the Pitcullo rock. The Hungarian rocks 
have had a sort of pseudo-amygdaloidal structure conferred upon 
them by the physically separable character of their kugels. This 
certainly is not the case in the rock from Kast Fife. 

The rock that has now shortly been described is by far the freshest 
typical andesite that I know in the district in which it occurs. 
It is not, be it at once said, quite so glassy as the exceptionally 
fresh rock from Dumyat, but in the best specimens is only a little 
less so. 

The bulk of the material in the quarry consists, as has been 
indicated, of hypersthene andesite, but is really a rock quite 
different in appearance from that described in the foregoing notes. 
It is grey in colour, is obviously in a much less fresh condition, and 
suggests Im no way, macroscopically at all events, relationship with 
the fresh ‘‘ pitchstone”’ that comes on top of it. Notwithstanding 
this physical distinction, both appear to have belonged to the same 
parent mass. Under the microscope the felspars can be seen to be 
equally clear and glassy and to have an identical composition. Both 
orthorhombic and monoclinic pyroxenes occur, as in the unaltered 
rock, the former, however, now only represented by pseudomorphs 
made up of strongly absorbing fibres. Impregnations and veins of 
iron oxide are frequent, obscuring totally in some slices the real 
nature of the rock that carries them. The base is much less glassy, 
and the felspars of the second generation are larger. It will there- 
fore be seen that any distinction that occurs may only be due to 
differences in the cooling history of the two portions of the rock and 
to the fact that the glassy rock by virtue of its compactness has had 
conferred upon it a higher degree of resistance to the agencies of 
secondary change. 


350 R&R. M. Brydone—The Belemnitella mucronata Zone. 


Being interested as to the chemical nature of the unaltered 
andesite, Mr. R. K. 8S. Mitchell, one of the senior workers in this 
laboratory, kindly undertook to carry out for me a determination of 
the silica and bases present, which he did under the supervision of 
an exceedingly skilled analyst, my friend Dr. Sidney A. Kay. 
Mr. Mitchell’s figures are as follows :— 


Si O2 6 : , : : : . 61:37 
AleOs : 3 ; ; : . 18-80 
Fee Os 5 c 6 dl 6 6 5-46 
Mn O ‘ : : ; : 3 : — 
CaO F Gents : P ; ; 5-62 
IMO ee cau oaths 0) cutee rien yak os biel ba mone 
Nas O - 5 5 . . 5 6 3-83 
K,0 : : : : : : : 2-05 
99-01 


Comparison of these results with the analyses given by Sir Jethro 
‘Teall in his valuable papers on the Cheviot andesites (GrozLoeicaL 
Magazine, 1883) will at once show in what striking fashion there is 
chemical similarity between the Old Red “‘ pitchstone porphyrites ”’ 
of the borders and the example described above from Kast Fife. 

In conclusion, it is my duty to express very cordial thanks to 
Professor James Walker, F.R.S., for having added to the equipment 
of this Department several items of optical apparatus which have 
enabled me to carry out the foregoing mineral determinations. 


IJ].—Tue TricknEess oF THE ZonE oF BELEMNITELLA MUCRONATA 
In THE IstE or Wicut. 


By R. M. BRYDONE, F.G.S. 


N 1908 Dr. Rowe published an account of the Chalk of the Isle of 
Wight! with a zonal map in which the zone of Belemnitedla 
mucronata was shown as entirely absent at some points but generally 
present in substantial thickness. At the two ends of the island 
actual measurements were made, of 150 feet at Culver Down and 
475 feet at the Needles. How much of the latter thickness was 
measured in the cliffs and how much is made up of somewhat less 
satisfactory measurements at low tide on weed-covered reefs is not 
clear, but at any rate there must be well over 300 feet in the cliffs. 
This figure is sufficient to show how great a ravining of the 
pre-Tertiary surface of the chalk would be required for the repeated 
disappearances of the zone as mapped. It seems justifiable to pay 
some critical attention to the evidence on which such a state of 
things is alleged. 

It will be found on reference to the map in question that there 
are five points at which the zone of Belemnitella mucronata is repre- 
sented as disappearing completely, while in between them it swells 
out each time to a very substantial thickness. (I do not include the 


1 “The Zones of the White Chalk of the English Coast. V. The Isle of 
Wight’’: Proc. Geol. Assoc., vol. xx, pt. iv, p. 209. 


R. M. Brydone—The Belemnitella mucronata Zone. 351 


case at the east end of ‘apnell Down, as this is probably due to the 
combined effect of an imperfect junction between the sections and of 
exigencies of space leading to the exclusion of part of the chalk 
area.) Of these five cases, two appear to be arrived at by assumption 
only, but three are connected* with paleontological evidence from 
sections and will be considered first. 

The most interesting of these is undoubtedly the one just west of 
Freshwater by pit 11 (Rowe), for, as Dr. Rowe points out, it is but 
2 miles from Alum Bay with its great thickness of mucronata chalk. 
The paleontological evidence given by Dr. Rowe is that the shells in 
the pit are white, and that two examples of Hehinocorys of quadratus 
type were found. The former statement does not seem to have any 
bearing on the question unless it is established that no white shells 
are to be found in the lower mucronata chalk of the Isle of Wight. 
I know of no authority for such a proposition, and it is not in accord 
with any experience of mine, although Mr. Griffith and I long ago 
noted redness in the shells as a feature of the upper beds of the 
mucronata chalk. The phrase ‘‘ Hchinocorys of quadratus type”’ 
conveys no meaning to me. No shape of Echinocorys typical of 
upper qguadratus chalk has, so far as I know, been defined in any 
way by Dr. Rowe, much less one which while typical of quadratus 
chalk cannot be found in low mucronata chalk, and only such a form 
would be of any value for assigning a section to the former zone to 
the exclusion of the latter. Even if such a form had been defined 
and definitely recognizable specimens found in this pit they» would 
prove very little. All probability is in favour of Hchinocorys recorded 
from this pit having been found on the extensive talus, the surface 
of which is obviously derived from the chalk high up at the back of 
the pit. In ordinary horizontal or slightly inclined chalk the 
identification of the guadratus zone at the top of a pit close to the 
Tertiary boundary would afford a strong presumption that no 
mucronata chalk was preserved at that point. But the Isle of Wight 
chalk is nearly vertical, and therefore the identification of the 
quadratus zone at the top of this pit—as to the accuracy of which 
I do not suggest any question, it having also been made by 
. aves the whole thickness 
between the back of the pit and the Tertiary boundary, a distance 
of some 120 feet, corresponding to a thickness of at least 100 feet 
of chalk, open to reference to either the qguadratus zone or the 
mucronata zone. To carry the matter a step further, even if an 
absolutely decisive Echinocorys were found at the most northerly 
point where chall is still exposed in the pit, there would still 
remain between that point and the Tertiary boundary some 30 feet 
of chalk, and this could not be ruled out of the mucronata zone on 
any paleontological ground. 

As a matter of fact, there is some slight positive ground for 
holding the view that the mucronata zone is exposed within the pit. 
There is now a sideway extension, which I do not remember in the 
nineties, cut parallel with and close to the footpath, and some of the 
chalk exposed here is gritty and hard, contrasting rather sharply 
with the soft and fine-grained chalk at the back of the pit. I have 


352 Rk. M. Brydone—The Belemnitella mucronata Zone. 


recorded precisely this contrast between the guadratus and mucronata 

chalk in Portsdown as separated on paleontological evidence.! 
_ The second point at which paleontological grounds are quoted in 
support of the view that the mucronata chalk has been wholly 
removed is pit No. 3 (Afton Down). Here the position corresponds 
almost exactly with that at pit No. 11. There is a pit in which the 
presence of the quadratus zone is established by paleontological 
evidence, as Mr. Grifiith and I recognized in the nineties; but the 
principal face and talus, from which this recognition was made, are 
at the back of the pit, some 80 feet from the Tertiary boundary. 
The chalk towards the mouth of the pit seems of different character 
from that at the back, and in it I have found what appears to be 
a broken specimen of Vhecidea Brydoner, which is only known from 
the basal mucronata chalk of Portsdown. Here, again, there is 
nothing in the evidence cited by Dr. Rowe to warrant the statement 
that the quadratus zone extends to the mouth of the pit, much less 
to the Tertiary boundary; and there is some suggestion of evidence 
to the contrary. 

As zonal indications are so scarce, it is perhaps worth mentioning 
that it was in this pit that I found the type of Membraniporella 
Gabina® many years ago on the talus, but in what_part of the pit 
I cannot say for certain. I naturally attributed it to the zone 
undoubtedly represented in the pit, that of A. qguadratus. At the 
time of describing the species 1 had only two other specimens, one 
a very doubtful one from the floor of this same pit near the mouth 
aud one from the zone of B. mucronata at Portsdown. I have since 
recognized several other specimens all from indisputable mucronata 
chalk either in the Isle of Wight or at Portsdown. I think there is 
some justification for the view that this species, which has never yet 
been found in undotibted quadratus chalk, actively as the top beds of 
that zone have been exploited in Hants, is restricted to the mucronata 
zone, and has only been found in this pit because chalk of that zone 
is or has been exposed in it. 

The third place at which the zone of B. mucronata is represented 
on paleontological evidence as entirely removed is at Ryde Water- 
works (pit No. 45). Here we may remark, as in the two previous 
eases, that the critical section does not extend to the Tertiary 
boundary by some 90 feet, and cannot therefore afford evidence as 
to the nature of the chalk in contact with the Tertiaries. Kven for 
the alleged quadratus horizon of the section itself the paleontological 
evidence given by Dr. Rowe is very scanty and purely negative, and 
scanty negative evidence can hardly form a satisfactory basis for the 
assertion of an exceptional state of things. In this case again there 
are grounds for doubting the reference of, at any rate, the whole of 
the section to the quadratus zone. The barrenness of the chalk is 
not in the least exaggerated by Dr. Rowe, but I have found on the 
talus below the section a small damaged Hehinocorys likely to be the 


' The Stratigraphy of the Chalk of Hants, p. 8 (London, Dulau & Co., 
1912). 
2 GEOL. MaG., 1917, p. 494, Pl. XXXII, Fig. 8. 


Rh. M. Brydone—The Belemnitella mucronata Zone. 353 


var., subconicus characteristic of the mucronata zone. If this zone 
occurs at all in the section, there would be room for a minimum 
thickness of some 80 feet of it. : 

The two places at which no paleontological grounds are given for 
cutting out the mucronata zone altogether are at Burnt House (north 
of Garretts) and at the west end of Bembridge Down. It will be 
obvious on inspection that these disappearances of the zone are due 
solely to the thicknesses assigned to the other Upper Chalk zones 
exhausting all the available space between the Chalk Rock and the 
Tertiary boundary as mapped. These thicknesses appear at the 
points in question to be purely arbitrary; indeed, at the end of 
Bembridge Down the quadratus zone seems to have been deliberately 
given a special local increase of thickness but for which some 
mucronata chalk must have been shown at that point. Unexpected 
results obtained by such free methods of mapping seem to be much 
in need of testing before any authority is claimed for them. The 
prospect of being able to apply any test (except by making a special 
excavation) are naturally very small if Dr. Rowe found no exposure 


Fie. 1.—Tracing of a very small portion of a folding map (plate D), marked 
on map “‘ Garretts to Arreton Down ’’ as ‘‘ Downend Chalk Pit (21) ’’ on 
Gallows Hill. Illustrating Dr. Arthur W. Rowe’s paper on ‘‘ Zones of 
the White Chalk of the English Coast’’, part v, ‘‘'The Isle of Wight ”’ 
(see Proc. Geol. Assoc., vol. xx, pt. v, p. 209, 1908). 


at these points, but it so happens that in one of the cases I have been 
able to do so and to obtain a result. At Burnt House I recently 
detected a low face of massive chalk about 6 feet behind the out- 
buildings (a shed with pigstyes at the back) shown on the map. In 
this face I was fortunate enough to find a specimen of Belemnitella 
mucronata and a small Hehinocorys, which, although too much crushed 
for any certainty, appeared likely to be the var. subconicus. his 
evidence is sufficient justification for definitely identifying the 
mucronata zone at this point, which is about 150 feet from that zone 
as mapped. Ifthe upper boundary of the quadratus zone be rectified 
to this extent (and it may well be that a more extensive rectification 
is due), it will at once be clear that only an improbable disturbance 
would carry the quadratus zone up to the Tertiary boundary just 
west of Burnt House, as is represented. The same rectification 
would presumably have to be madein the Marsupites plus Uintacrinus 
zone, and this would cancel the arbitrary expansion which has been 
given to the coranguimum zone at this point. 

It therefore seems as if no reliance can be placed on the fluctua- 
tions of these zonal boundaries except where they are based on the 

DECADE VI.—VOL. V.—NO. VIII. 23 


354 Sir H. H. Howorth—Geological History of the Baltic. 


evidence of sections. They do not appear to be drawn with due 
attention to all available facts. They sweep across the deep valleys 
-in the Upper Chalk indicated by the contour-lines at e.g. Burnt 
House or Standen Copse without any deviation. This could only be 
truthful in vertical chalk, and there is no ground for supposing that 
the chalk is vertical in these valleys though inclined in all sections. 
Even direct evidence from sections is liable to be ignored, as can be 
readily seen in the case of the great Downend pit. In Fig. 1 there 
is reproduced the rough outline of the pit. There is a high con- 
tinuous face along the line a 6 c, while the line d e marks the 
strike as mapped for Dr. Rowe. If this strike is correct the highest 
chalk exposed in this face would be at the point 6, and from 6 to ¢ 
there would be a repetition of some of the beds exposed from a to 6. 
This is, however, not the case. There is no repetition from 6 to ¢, 
but a gradual passage to higher chalk. The strike must therefore be 
at least as nearly EK. and W. as the dotted line fg, and such a strike 
calls for zonal boundaries in this neighbourhood of a trend differing 
substantially from that given to them in the map and inconsistent 
with the thinning of the mucronata zone shown. (Incidentally I may 
say that close to the point 6 I have been able to identify the top bed 
of the upper band of Offaster pilula in the subzone of abundant 
Offaster pilula by its usual physical characters and large form of 
O. pilula. In downward succession from e to a there is first chalk 
without any marl seams. Below the first marl seam met with there 
are roughly 32 feet of chalk containing seven marl seams, and then 
come the two marl seams, 3 feet apart, with a flint line between 
them, which enclose this top bed.) 

In the face of the foregoing considerations it is hardly possible to: 
accept it as established that the mucronata zone has been entirely 
denuded away at any point in the Isle of Wight, and much of the 
alleged variation of that zone in thickness from point to point seems 
to rest upon a very insecure basis. 


TV.—Tue Recent Grotocicat History oF tHE Bartic anp ScanptI- 
NAVIA AND ITS IMPORTANCE IN THE Post-Trrtiary History oF 
WestERN Europe. - 


.By Sir Henry H. Howorta, K.C.1.E., F.R.S., F.S.A., F.G.S. 


Part I. ; 
OME years ago I was allowed to publish in the Groroetca 
\) Macazine? some papers on the recent geological history of the 


Baltic, in which I tried to bring before English readers the very 
important discoveries of the Northern geologists as affecting the 
general geology of the north-west of Europe and to extend their 
deductions. I was obliged to interrupt them for other work. 
Perhaps you will allow me to continue them some steps further, as we 
had reached a stage of some interest. 

The northern portion of the Baltic, generally known as the: 
Bothnian Gulf and comprising an area of over 1,877 square miles, 


1 For previous communications on this subject, see GEOL. MAG., Dee. II, 
Vol. II, pp. 311, 337; Vol. III, pp. 1, 550. 


Sir H. H. Howorth—Geological History of the Baltic. 355 


is formed of two ovals separated by a narrow stricture between the 
towns of Umea in Sweden and Vasa in Russia, where the Archipelago 
of Quarken is situated. The more northern of these ovals, with an 
area of about 662 square miles, is known to the Swedes as Botten- 
viken, while the southern one, with about 1,215 square miles, is 
known to them as Bottenhavet. The former is now virtually a fresh- 
water inlet. It contains but one living marine mollusc, and this 
only in its extreme southern part, namely, Dacoma solidula= Tellina 
Balthica, which Nordquist reports from lat. 63:52 N. 

As we have seen in previous papers, the latest raised beaches all 
round the coast of the Bothnian Gulf, including those at its head, prove 
that before the last changes of level took place in its shores there were 
four marine molluses living there which have all now migrated further 
south, owing to the sweetening of the waters, caused largely by the 
inflow of the rivers having dominated that from the North Sea. — 

The reduction of the salinity may be measured by the fact that 
two of these molluses, Litorina litorea and L. rudis, are both 
very adaptable littoral shells, seldom found at a greater depth 
than the low-water mark of spring tides, and often in large numbers 
in hollows of the rocks above the highest tides. Gwyn Jeffreys 
found the former living on the shore in a stream of perfectly fresh 
water during the recess of the tide (Br. Moll., 11, 106). The latter 
is often found in places overflowed by freshwater streams during the 
recess of the tide with its companions, the common mussel and the 
limpet (ibid., 11, 267). This means that they can live where 
the water is at one time fresh and at another salt, but not where, as 
in the Bothnian Gulf, the percentage of salt is always very small. 

Both species occur in the lower raised beaches of the Baltic, and 
Litorina rudis has been found in them at Neder Kalix at the very 
head of the Bothnian Gulf. From them, as characteristic shells, 
these beaches have been called Litorina beaches, and the Baltic, at 
the time when they formed its margins, has been named the Litorina 
sea. In their strict sense the Zitorina sea and the Litorina period 
came to an end when the uplifting of its bed and borders led to the 
shrinkage of the water from the area marked out by the Litorina 
beaches to its present contour. The change was limited to the 
restriction of its area and the re-arrangement of the range of dis- 
tribution of its living contents, otherwise the ZLitorina sea had 
a continuous life with the present Baltic. This I have tried to show 
was not the result of a gradual change of level but of a spasmodic one. 

The present conditions in regard to salinity and the present 
distribution of the mollusca, in the latitude of Bornholm represent 
very nearly what these elements were at the head of the Bothnian 
Gulf in the Litorina time. 

As I pointed out in the second paper of this series, the Litorina 
sea was the successor of a great freshwater lake whose limits 
are marked out by the wpper beaches of the present Baltic, and 
which contain no debris of marine life but only freshwater remains. 
From a notable shell the lake contained, it has been called the 
Ancylus lake or sea, which in turn gave its name to the Ancylus 
period. All this is now universally accepted and has been amply 


© 


SHO: | sie Jel, Jak Howorth—Geological History of the Baltic. 


proved by the researches of the Northern geologists, notably Schmidt, 
De Geer, Munthe, Holst, and Nathorst. 

There is also a complete agreement among them that the cause of 
the conversion of the freshwater Ancylus lake into the Litorina sea 
was the breaking down of the land barrier which once united 
Southern Sweden with Pomerania and Mecklenburg on the one hand 
and Jutland on the other, and the opening of the three channels 
known as the Oresund, or Sound, and the Great and Little Belts by 
which the salt water of the North Sea first got access to the then 
enclosed freshwater Baltic, and converted it into a more or less 
brackish sea. This I have tried to show was not the result of the 
slow and gentle operation of current and normal denuding causes, but 
of a violent and sudden or very rapid dislocation of the earth’s crust. 
It is necessary again to emphasize the difficulties of the opposite 
view, and the more so since I am constrained to believe that the 
dislocation was far greater, more wide-spread and important than 
has hitherto been thought. 

The opposite view is really based on a professed adhesion to the 
theory of uniformity which is held to be inconsistent with catastrophe. 
Not uniformity in the sense that Nature working with the same tools 
and with the same potency and speed produces similar results, which 
is the keystone of modern science, but that Nature’s operations at all 
times have been the same both in kind, potency, and rapidity as 
those which are working at this moment. ‘This view, which 
still prevails with some geologists, is contradicted by all the 
evidence now ayailable, notably by the gigantic and quite abnormal 
phenomena of the great mountain chains. 

Let us, however, turn to our immediate problem and see what the 
evidence is. 

First, we have the notable fact which, after a long discussion, 
seems to be now generally received, namely, that in Sweden, as in 
Britain and (as I shall point out presently) in Norway, there is no 
reliable evidence that the relative heights of land and water have 
altered in any appreciable way for a very long time, probably not for 
2,000 years. This is also notably true of the Cattegat and the three 
waterways between it and the Baltic. In the case of the Cattegat, 
as in its gulf the Limfiord, the position of the kitchen middens in 
reference to the sea-level is an excellent test. In that great inlet 
which is girdled with these refuse heaps of primitive man, there is 
clear evidence that only slight changes have taken place in the 
relative position of the middens to the sea-level since the earliest 
stage of the Stone Age of Scandinavia. In the Sound and Belts the 
only notable changes have been those of silting up of estuaries and 
river channels, and of certain small signs of elevation (to which we 
shall refer presently). On the other hand, the position of the old 
maritime villages and towns, castles, and large trees on the sides of 
the waterways, both in Western Sweden and Denmark, are conclusive 
that there has been no upheaval or subsidence here for a long time, 
and no widening of the channels by denuding causes. In the case of 
the Sound we have a remarkable piece of evidence emphasizing this 
conclusion. 


Sir H. H. Howorth—Geological History of the Baltic. 357 


The island of Saltholm is planted in the very middle of the 
Channel. It is only raised a very few feet above the water, 
- and is mentioned in the thirteenth century as a source of income to 
the Chapter of Roeskilde (see Geol. Proceedings, xi, 555), showing 
that there cannot have been much, if any, alteration there for many 
centuries. Nor, indeed (if we follow the teaching of rational 
uniformity), can we understand how, in a virtually tideless sea like 
the Baltic, the water could ever have had such potency as to bore 
through these channels. 

In the present case we haye no room for a draft on unlimited time, 
a favourite appeal of many geologists (who pursue deductive and not 
inductive methods), because, as has been pointed out by the Danish 
archeologists and geologists, the channels between the islands did 
not exist when the kitchen middens were laid down (see pt. 111 of 
these papers, p. 12, etc.). 

These arguments can be supplemented by others; thus, if the 
substitution of the Zitorina sea for the Ancylus sea had been due to 
the gradual opening of the Baltic channels, we ought to have had 
a mixing and overlapping of the faunee of the Ancylus and Litorina 
seas, which is not the case, but there is a complete gap between the 
two sets of deposits. On the other hand, it is virtually certain that 
the outpouring of fresh water from the Baltic, which, as we have seen, 
killed the oysters, Zapes, and other molluscs in the Cattegat, was not 
a gradual process. If it had been so we ought to have some evidence 
in the kitchen middens themselves, where the shells ought, under _ 
this maleficent influence, to have gradually become dwarfed and 
distorted, as they have elsewhere in similar circumstances, but of this 
there is no sign. 

Again, if the process of boring these channels was due to the mere 
slow attrition by the waters on either side, how comes it that we find 
no kitchen middens at all on the shores of the three great channels, 
especially in their northern portions, nor yet in the smaller and 
subsidiary channels between the various islands. Surely all this is 
overwhelming evidence against the notion of gradual eating back 
of these channels by slow denuding forces, and the burden of proof of 
proving the contrary is very much indeed, thrust upon the advocates 
of the opposite view. I would add, as another positive argument in 
favour of the openings being the result of fracture, that in the case 
of the Sound the two sides which approach each other within 
4,480 yards at Elsinore differ vastly in geological structure. On 
the Swedish side they are composed of Paleozoic rocks, and on that 
of Zealand of chalk, thus showing that the Sound forms a great line 
of fault where a rupture must sometime have occurred. 

I must, therefore, take it for granted that the Baltic breach was 
caused by a tectonic movement of the earth’s crust, and not by any 
slow denuding action. This tectonic movement has left, as 1 now 
believe, very notable evidences of its potency much beyond the 
narrow waters which intersect the Danish archipelago, and extending 
over a large part of the Chalk area of Southern Scandinavia and 
North Germany and its islands, and had the effect of completely 
shattering what were once continuous horizontal beds into their 


358 Sir H. H. Howorth—Geological History of the Baltre. 


present broken condition, and this, not in Tertiary times, but just at 

the threshold of the current geological period. 
' In order to set out the reasons for this important and really far- 
reaching induction I must be allowed to make some preliminary 
remarks on what may seem to be unnecessary to those who have not 
measured, as I have done, the wis imertie of the older type of 
geological mind which still survives among certain veterans of the 
science. 

There was a time when the various movements of the earth’s crust 
(of which the evidence is patent enough) were attributed to the 
operations of some unknown but postulated subterranean energy which 
was supposed to be able (in limited areas) to lft up by forces acting 
perpendicularly or to let down by similar impulses great masses of the 
earth’s strata, and thus to largely cause the diversified features of 
the earth’s crust. This view is now only held by a small and 
shrinking body of geologists. The great mass of them who have 
surveyed geological problems on a continental scale and realized how 
far-reaching the phenomena must in some cases have been, have found 
it impossible to maintain an hypothesis which will not meet the facts 
as we now know them. The more influential of the modern teachers 
of the science are no longer satisfied, like the extreme glacialists are, 
to rely upon causes for which no adequate physical justification has 
ever been preduced, and which necessitate the postulating of qualities 
and characteristics in the materials which build up the earth’s solid 
envelope which refuse to be verified by experiment. These newer 
men who recognize that geology must in the long run rely upon 
physics to supply it with a workable platform have found a perfectly 
satisfactory reason for earth movements on a very big scale and over 
very large areas. The postulate they stand upon in this matter is, 
that the earth is inevitably Josing its heat by radiation and in the 
process is shrinking, and in shrinking it has to compel its upper 
strata to accommodate themselves to a smaller space. The result is 
great lateral (and not perpendicular) thrusts which have squeezed 
the beds into wave-like and sinuous curves and ribbons, with 
alternating anticlinal and synclinal folds. 

On this point let me quote two excellent authorities, and as there 
must be no quarrel about their meaning I will quote their actual 
words :— 

Suess says definitely: ‘‘Es giebt keinerlei verticale Bewegungen 
des Festen, mit Ausnahme jener, welche etwa mittelbar aus der Falten 
bildung hervorgehen. Die Felsarten der Erde besitzen in keinerlei 
Gestalt jene vithselhafte elevatorische kraft welche man ihnen in 
einer Zeit Inzuschreiben geneigt, und vielleicht bis zu einem gewissen 
Grade berschtigt war, im welcher. . . . Wir werden uns enschliessen 
miissen letzte Form der Erhebungstheorie die Doctrin von den Saecu- 
laren Schwankungen den Continent zu verlassen.’’ Heim urged the 
same view (Jahrbuch k.k. Geol. Reichsanst Wien, 1880, p. 180). 

Lapparent is still more positive. He says: ‘‘Il ne s’agit pas 
d’avantage d’opposer a la doctrine des soulévements absolus 
produits par des forces qui agiraient directement de bas en haut, 
une protestation devenue sans objet. Car les partisans des impulsions 


Sir H. H. Howorth—Geological History of the Baltic. 359 


verticales sont, de nos jours plus, que clair semés et en dehors de 
quelques rares attardes, personne n ’oserent encore attribuer a wae 
telle action une part sérieux dans la formations des montagnes” 
(Bull. Soc. Géol. France, ser. 11, t. xv, p. 217). 

Again, the same graphic and lucid writer, speaking of what he 
calls. ss impulsions verticales”’, says: ‘‘ Ils s’expliquent sans difficulté 
si on les considére comme la production des movements généraux 
d’une écorce soumise a des efforts latéraux de compression, 
développées par la necessité ot elle se trouve de se plier aux 
changements de dimension du noyau interne. De cette manicre 
certaines parties se gonflent l’océan, tandis que d’autres semblent 
Vattirer dans les sillons qui vont se creusant de plus en plus”’ ( Zraiteé 
de Géologte). 

It is assuredly by this process that the tectonic changes in the 
earth which have diversified its surface into mountain and valley 
have been in the main induced. It is equally plain that this process 
of bending into undulations and curves cannot go on for ever with 
such very tough materials as the earth’s crust is largely formed of, 
without a break. The tension must presently be so great that the 
rocks will give way and split, and form huge rifts and crevasses and 
raw scarps and cliffs. Scandinavia presents us with most admirable 
evidence of the results of this crumbling process on a large scale in 
producing the diversified features of the country: a great many of us 
are witness to that.. They meet us at every turn in the contortions 
and folds made violently, and involving great breakages and gaping 
wounds in the hardest crystalline rocks as well as in those of 
Secondary age. ‘The Alps, the Pyrenees, and the Himalayas give us 
similar very notable samples from Tertiary times, of raw angular 
tears and rifts, gullies and nullahs, and perpendicular scarps and 
faults, as well as huge anticlinal and synclinal bends and overthrows. 
Mohn has picturesquely described the resultsin Norway. ‘‘ The oldest 
formations in Norway,” he says, ‘“‘are greatly bent, compressed, 
and distorted, and their parts forcibly dislocated, alike as regards 
situation and relative height. Formations that in the interior he at 
a height of several thousand feet are on the coast found level with 
the surface of the sea; strata resting on the summits bordering 
a lake or the shores of a fjord are again seen on islands in such lakes 
or fjords and level with the surface of the latter. One side of 
a valley exhibits a profile which, in regard to the height of the 
various strata, differs materially from the profile of the opposite side. 
The whole rocky shore is cut upin various directions, and the several 
laming are now sunk beneath, now raised above, those adjoining 
them. These dislocations have been caused by fissures, which in 
many places can be pointed out, and the number of such recorded 
faults of dislocation increases almost every year. ‘The direction of 
the fissures is manifestly of the greatest assistance in indicating the 
form exhibited by the surface of the country. The subsidence 
between two fissures produces a valley or fjord; its rise, on the other 
hand, a height or a promontory. Professor Kjerulf has succeeded in 
showing that the entire system embracing the valleys and fjords of 
Southern Norway may be easily referred to four principal directions 


360 Sir H. H. Howorth—Geological History of the Baltic. 


round about the principal directions of the valleys and fjords, and are 
found grouped with predominant frequency.” 

What Mohn says of Norway has been equally well said by De Geer 
about the tectonic structure of Sweden. ‘‘ Up to this time ”’ (i.e. 1893), 
he says, “‘I have levelled the marine limit at about seventy different 
points on the southern and central parts of Sweden and in a few 
places in Southern Norway. For Northern Sweden I have three or 
four approximate but important determinations by Hogbom, Suevonius, 


and Munthe. . . . All the observations relate to one system of 
upheaval with the maximum uplift in the central part of the 
Scandinavian peninsula along a line east of the watershed... . 


Here the land must have been upheaved somewhat more than 
1,000 feet (more than 300 metres), and around this cehtre the isobars 
are grouped in concentric circles, showing a tolerably regular 
decrease of height in every direction towards the peripheral parts 
of the region, until the line for zero is reached, outside of which 
no sign whatever of upheaval is to be found” (Bull. Amer. Geol. 
Soc., 1892). 

Elsewhere, De Geer, who has done so much for explaining the 
internal structure of the great Swedish anticlinal, has carefully 
co-ordinated the facts and drawn lines of isobars showing that they 

omt to a focus of elevation along the medial line of the upliit, 
curving down to lesser heights of similar altitude and synchronous in 
date on the eastern and western sides of Sweden respectively (see D. G., 
Over Scandinaviens Nivafirandringar under Quartarperioden, p.56). He 
tells us the first points he determined were in Scania, and the heights 
of the different points were nearly equal on both sides of the axis; 
some were 50 metres high, somewhat more towards the south; adding 
that he afterwards obtained these successively at 48, 42, 37, 32, and 
21 metres, and that in quite open localities. 

Such being the structure of the great Swedish anticlinal, is it 
strange or unexpected that it should in the south pass into a corre- 
sponding and complementary synclinal hollow, with evidences, not of 
rising, but of sinking? ‘hese are present (as I showed by much 
evidence in the fourth part of this series of papers) all over the South 
Baltic and extending to the North German coast. The line of 
greatest depression, known as Forchhammer’s line, runs east and west 
through the middle of the Southern Baltic. Would it not be strange 
if the lifting up of this long whale-backed peninsula and this corre- 
sponding synclinal movement in the south had taken place without 
any breaks and breaches at the points of greatest stress, namely, 
where the upheaval and the subsidence, caused by the lateral thrust, 
were the greatest? It would indeed be strange if it were not so. 
In the subsiding south, as we shall see, the material was chalk; in 
the north, as we shall also see, the uplifted Primary rocks were the ones 
to give way and be broken, and in both cases presenting the clearest 
evidence of violent or momentary dislocations in places on a great 
scale with tremendous breakages in the rocks. he great subsidence 
in the Southern Baltic is partially attested by submerged forests and 
peat bogs south of Scania. If the submergence had been gradual 
and progressive along a disappearing beach, these fragile relics would 


Sir H. H. Howorth—Geological History of the Baltic. 361 


have been long ago. destroyed, and, like similar remains elsewhere, 
they attest a sudden submergence. 

I mention all this to establish a prima facie case. Let us now 
turn to more direct evidence as displayed in the Danish islands and 
on the South Baltie coast. The greater part of the Danish islands 
are covered with drift beds in many places of enormous thickness. 
These largely hide the subjacent chalk. It is not so covered every- 
where, however. In the great Danish island of Zealand and in its 
small satellite Moen the chalk is in part exposed, and in both we 
have some yaluable evidence for our purpose. In the former the 
part of the chalk that is visible is in a great measure undisturbed, 
but not everywhere. 

Rordam tells us the chalk of Zealand is for the most part covered 
with diluvian beds sometimes 60 metres thick and enclosing large 
masses of chalk. He describes a section thus: “ On voyait la Craie 
recouverte d’argile morainique jaune-rouge, contenant aussi de 
grandes portions de masses de Craie triturée et petrée d’argile 
et de pierre. La figure 1, p. 8, fait voir incrusté dans l’argile 
morainique un assez grand bloc de Craie de forme irreguliere”’ 
(n.ed., vi, 128). 

Let us now turn to the small and geologically celebrated island 
of Moen, separated by a narrow passage from Zealand, the land 
on both sides of which channel consists of chalk. The tacts there 
were long ago carefully collected on the spot and their inevitable 
lesson pointed out by two excellent witnesses, namely, Lyell and 
Forchhammer. Lyell, writing in 1878, speaks of the phenomena 
presented by the island as being of a class which were thought 
by the earlier geologists to belong exclusively to epochs anterior 
to the existing fauna and flora, and quotes as examples faults 
and violent local dislocations of the rocks and sharp bendings and 
foldings of the strata, which we so often behold in mountain chains, 
and sometimes in low countries, especially where the rock formations 
are of ancient dates. He then proceeds to quote the island of 
Moen as a striking illustration of such convulsions, to which he 
assigns a post-Glacial or Pleistocene date. He describes it as about 
60 miles in circumference and as consisting of white chalk several 
hundred feet thick, overlaid by boulder-clay and sand made up of 
several divisions, some stratified and some unstratified, the whole 
having a mean thickness of 60 feet, but being sometimes twice that 
thickness, and containing in one of its oldest members fossil marine 
shells of existing species. He goes on to say, ‘Throughout the 
greatest part of the island the strata of the drift are undisturbed and 
horizontal, as are those of the adjacent chalk, but on the north-eastern 
coast they have been through a certain area, bent, folded, and shifted, 
together with the beds of the underlying Cretaceous formation.” ‘* Within 
this area they have,” he says, ‘‘ been even more deranged than in the 
English chalk-with-flints along the central axis of the Isle of Wight 
in Hampshire, or at Purbeck in Dorsetshire. ‘he whole displacement 
of the chalk is evidently posterior in date to the origin of the drift 
since the beds of the latter are horizontal or inclined, curved, or 
vertical where the ckalk displays signs of similar derangement.” 


362 Sir H. H. Howorth—Geological History of the Baltic. 


Again he continues, ‘‘ Although I had come to these conclusions 
respecting the structure of Moen in 18386 after devoting several days 
~ in company with Dr. Forchhammer to its examination, I should have 
hesitated to quote the spot as exemplifying convulsions on so grand 
a scale of such extremely moderate date, had not the island been 
since thoroughly investigated by a most able and reliable authority, 
the Danish geologist, Professor Puggaard, who has published a series 
of detailed sections of the cliff.”” Commenting on one of the sections 
showing great contortions, Lyell says, ‘‘ Where the cliff is 180 feet 
high there is a sharp flexion shared equally by the chalk and the 
incumbent drift. In each we observed a great fracture in the rocks, 
with synclinal and anticlinal folds exhibiting in cliffs 300 feet high, 
drift beds participating in all the bendings of the chalk.” 

Near the northern end of Moen’s Klint, ata place called Taler, more 
than 3800 feet high, are seen similar folds so sharp that there is an 
appearance of four distinct alternations of the Glacial and Cretaceous 
formations in vertical or highly inclined beds, the chalk at one part 
bending over so that the position of all the beds is reversed. But the 
most wonderful shiftings and faultines of the beds are observable in 
the Dronningestol, part of the same cliff, 400 feet in vertical height, 
where the drift is thoroughly entangled, and raised up with the 
dislocated chalk. Lyell comments on these facts and says, ‘‘It is 
impossible to behold such effects of reiterated local movements, all 
of post-Tertiary date, without reflecting that but for the accidental 
presence of the stratified drift, all of which might easily (when there 
has been so much denudation) have been missing, even if it had ever 
existed, we might have referred the verticality and flexures and faults 
of the rocks to an ancient period, such as the era between the Chalk 
with flints and the Maestricht Chalk, or to the time of the latter 
formation or to the Eocene or Miocene or older Pliocene eras”’ (Lyell, 
Antiquity of Man, 4th ed., pp. 888-98). Not the least wonderful of 
these dislocations 1s the height to which the chalk was thrown up in 
some of the cliff sections. Those who are familiar with the similar 
phenomena in Norfolk, which I have known well and commented on 
for many years, will see how in every detail they repeat those of Moen 
as here described by Lyell and which I have no doubt were caused in 
precisely the same way and at the same time. 

It seems very probable, says Reclus, that having subsided Moen 
was again raised above the waters. It is really composed of seven 
distinct islets whose intervening channels have since been filled up. 
In 1100 a.p. it still formed a group of three, and Borre (now lost 
among the fens) stood on the beach in 1510, when a Lubeck fleet 
anchored in front of the houses and burnt the place to the ground. 

Moen is a natural step to the island of Rugen and the southern 
coast of the Baltic. Here we meet with precisely the same kind of 
chalk beds covered with drift, and torn and dislocated in the same 
way and clearly at the same time. Reclus, in describing them, speaks 
of ‘‘ the rocky shores of Moen and the lofty headlands of Rugen for- 
merly united but now separated by a strait 33 miles broad and 
12 fathoms deep”. Rugen, again, has its counterpart in the Baltic 
coastlands near Stettin. 


Sir H. H. Howorth—Geological History of the Baltic. 363 


‘Neumayr (in his Hrdgeschichte, 11, 586-7), describing the Chalk 
beds at Rugen and Stettin, speaks of the way in which diluvial soft 
beds occur in masses detached from their matrix and transported 
elsewhere; and of their being occluded in beds of the same age but of 
different composition, with their internal laminee undisturbed, just as 
we find them in Kastern England. In other places the strata are 
largely crushed and squeezed and tossed about or faulted. ‘‘ Especially 
notable,’”’ he says, ‘‘is the phenomenon which occurs in the case of 
the deposits of white chalk on the shores of the Baltic as at Rugen 
near Stettin and in other places of North Germany ; huge masses of 
chalk have been here detached and planted in the midst of the boulder- 
clay and have caused great disturbances in it. Thus Remele found 
in the boulder formation at Stettin a huge slab (sehallen) of chalk 
almost 2 kilometres long, that is more than a mile long, and of the 
thickness of 25 metres, embedded in the drift beds. He also came 
across similar instances elsewhere.’? Neumayr speaks of the great 
cliffs of chalk facing the sea at Rugen and much broken. ‘These 
breakages have only taken place in certain places ; while in others the 
strata lie in their old horizontal position. Frequently there may be 
seen great masses of chalk built up out of a congeries of confused chali 
lumps, while in many places the chalk masses rest on diluvial sand 
clay and boulder-clay, or these latter have forced themselves between 
the boulders of chalk. 

The latest authority on the Chalk of Northern Germany is 
von Linstov of Berlin, whose paper entitled ‘‘ Die Techtonik der 
Kreide in Untergrunde von Stettin, etc.’”’? contains.some valuable 
materials for the elucidation of the problem, since they consist 
largely of borings and testings of the different exposures. In none of 
these borings has the chalk in situ been pierced; but in several 
cases great masses of chalk proved to be true boulders lying in the 
Drift like those of Norfolk. This was the case with the famous 
great chalk boulder found at Frickenwalde in the middle of the last 
century, and pronounced by Deecke in his Geology of Pomerania to be 
2 kilometres long and 34:41 metres thick. It was found to be 
underlaid by boulder clay, and what he calls glacio-fluviatile beds. 
So with the great mass of chalk found at Katharinenhof, which was 
of great size, thickness, and weight. A similar pair of great masses 
was described by C. Muller, one from Sparrenfelde, west of Stettin, 
and the other from the exercise ground at Kreckof. ‘These were 
found when bored in 1898 to give the same result, namely, they 
proved to be portentous boulders. 

Linstov (op. cit., 144) also gives profiles of numerous faults 
occurring in the chalk of the same district. He discusses the date 
when the great breakage occurred, and rejects as impossible the 
notion that they were pre-Glacial, and like Credner, in Rugen, he 
puts them between the so-called first glaciation and the second one, 
that is, makes them post-Pliocene. 

The following table gives the details of other great masses of rock 
occurring as boulders in the drift of chalk and Tertiery strata from 
North Germany, which have been similarly tested :— 


Bok” Sie TE oworth—Geological History of the Baltic 


GeroLtocicaL Bortnes 1n Srerrin Disrrict. 


Metres. 
Finkenwalde. Boulder of so-called chalk. over 35 long 
Gollnof, north-east of Stettin. Septaria clay. about 100 
Ziillehof. Boulder of Septaria clay. 2-36:5 
Gartz. Boulder of Septaria clay. 10-41 
Stralsund. Boulder of chalk. 100 
Gollenberg, near Késlin. Miocene and Oligocene. about 100 
East Diervinof. Senonian chalk. 10-27 
Treptov on the Rega. _ Boulder of Senonian Chalk. 31 
Fort Chernoy, near Sonnen- Miocene. 65-8 
berg (Neumark). : 
Steinitten in Samland. Under Oligocene, Miocene, and 7-20 
Senonian. 
Osterode in East Prussia. Miocene, Oligocene, and 34 
Senonian. 
Frankfort on the Oder. Miocene. 4-80 


According to Credner the drift beds overlying the broken and 
dislocated chalk of Rugen are divisible into two sets. One of them, 
the lower one, conformable with the chalk and which consists of two 
greyish-blue boulder-clays, separated by bedded sands, and which 
follow the fortunes of the chalk, and the other of certain boulder 
clays, gravels, and sands which overlie the chalk unconformably and . 
disregard its contortions. It is possible that the latter may be part 
of a secondary movement, which has since the great submergence in 
the Southern Baltic reversed the process to a small extent and left 
its traces in different places by certain later breaches at low levels. 

I now propose to say a few words about the exact parallel we have 
in Britain to these Danish and German Chalk dislocations in the 
disrupted chalk of Norfolk and elsewhere in England. ‘The pheno- 
mena are precisely the same in detail and belong; so far as we can 
judge, exactly to the same period, and were due to the same cause. 
In England they have been made the pet toys of the Ultra-glacialists, 
éspecially of those of them who were entrusted with surveying 
the surface beds of Eastern England, and who quite ignored these 
northern parallels which have been so carefully examined and 
exploited by German geologists with great ardour of recent years. 
I may, perhaps, be permitted to recall some of the arguments 
I adduced long ago against the notion that the dislocations in the 
chalk of Norfolk and the disposition of their broken debris were the 
handiwork of a hypothetical ice-sheet or of ice inany form, and were 
really the results of tectonic rupture of the chalk. The proposed and 
quite imaginary ice-sheet, the mode of production of which is 
admittedly an unsolved riddle, is supposed to have crossed the North 
Sea from Norway when that country must have been at a much 
lower level, as I propose to show later, to have crossed the vast 
submerged valley (then much deeper) which bounds Norway on the 
west, and to have travelled hundreds of miles without any adequate 
thrusting force from behind it: when therefore, if it moved at all, 
it must have been by a necessarily very slow progression of its layers 
over each other in the fashion of a plastic body with very little 
plasticity, and with a vertically extinguished motion at its base. 
In order to secure this, it must have been piled up to a portentous 


Sir H. H. Howorth—Geological History of the Baltic. 365 


height; all this is jauntily suggested, forgetful of the fact that 
the modulus of ice is such that it crushes and liquefies when sub- 
jected to a very moderate pressure. This fantastic machine is 
then supposed to have climbed up into Norfolk, and when only 
moving at the speed of an exhausted tortoise to have done two 
kinds of dynamical work quite inconsistent with each other, and at 
the same time, namely, passed over numerous beds of stratified crag 
sands without disturbing their layers, and at the same time to have 
completely broken up the solid chalk, causing the greatest confusion 
in its beds, which are crossed by endless faults, some of them scores 
of feet in extent. It then proceeded to detach huge cakes of solid 
chalk hundreds of yards long from the matrix (by what mechanical 
process has never been explained), and in the process to have shattered 
the great mass of the upper layers into myriads of unweathered 
angular lumps and boulders and thousands of tons of chalk dust, and 
to have bodily lifted up and carried in its terrific and destructive 
arms, not only the great cakes and ribbons of chalk just named, but 
also huge masses as big as houses, and whirled them along, and then 
deposited them in the midst of stratified and beautifully laminated 
sands without causing any breaks either in the lines or the curves of 
the layers, which it arranged in concentric form about the intruded 
masses, while in other places it laid down these sands in huge curves 
with re-entering curvatures without any breaks in the lines, and in 
other places to have torn up masses of these sands with their internal 
structure undisturbed, and then carried off these fragile lumps 
unbroken and uninjured at the time when it was pounding and 
smashing and tearing the chalk to the depth of scores of yards. 
All this°and much more I have set out years ago in papers in the 
GerotocicaL Maeazrne, notably in a discussion of the ‘‘ Dislocations 
in the Chalk of Norfolk” in the volume for 1907. 

Since, then, it has become plainer every day that these dislocations 
were not confined to Norfolk and Suffolk but were synchronous with 
great movements of the chalk south of the Thames entzrely out of reach 
of any ice-sheets; in the border of the English Channel, in Hampshire, 
the Isle of Wight, in Northern France, in Flanders, and elsewhere. 
The evidence seems to point to the same impetus haying been the real 
cause of a great deal of the shaping of the north and south Downs 
and of the synclinals which are correlated with these whale-backed 
ridges, which in places have pot-holes on their surface containing 
casts of Miocene shells, showing how late the upheaval must have 
been. The same movement doubtless threw down the’ chalk in 
Holland to a portentous depth, carrying with it in places hundreds 
of feet of rearranged Crag and Pleistocene sands. It is clear that 
the same portentous cause must also have operated in the Baltic 
lands, inducing there a repetition of precisely the phenomena we 
have in Norfolk, and, so far as the evidence leads, quite con- 
temporaneously. All this capacity and work has been attributed 
by a long dominant school especially potent in the arcana of Official 
geology to the handiwork of ice, whose proved impotence to compass 
such work they have entirely ignored, and who have refused to listen 
to those who had been trained in the more precise methods of 


366 Sir H. H. Howorth—Geological History of the Baltic. 


physics, and warned them over and over again of the blind alley they 
were following. They were faithfully copied for a long time by the 
- geologists of Germany, who dealt similarly with their domestic problem 
of explaining the shattered chalk of theirown country. Among them, 
the most notable champions of ice were Wahnschaffe and Scholz, 
and more lately Philippi. The first notable geologist in Germany 
to make an effective revolt against the once current explanation of 
these Cretaceous masses and their movements was Von Koenen, who 
attributed the gigantic dislocations and movements involved to 
tectonic earth movements on a great scale. He was presently 
supported by Berendt, Hermann Credner, Cohen, Deecke, R. Credner, 
and lastly by O. Jaekel and K. Keilhack. They were also at one 
in regard to the date of the dislocations and the accompanying 
phenomena, which they attributed to post-Tertiary times. 

These German explorers, especially the later ones, have sifted the 
evidence with skill and pains, and have tested some of the initial 
difficulties with the boring rod. They are agreed that the phenomena 
are not explainable by the action of ice, a view in which my friends 
Professor Bonney and the Rev. E. Hill completely concur. After 
paying two visits to Rugen they affirm that no evidence can be found 
there to support the ice “theory. “‘ We shall be ready,” they say, ‘‘ to 
admit the potency of ice-sheets as excavators, and benders or breakers 
of rock masses when any evidence worthy of the name can be pro- 
duced in proof that they operate in these ways; but though we have 
diligently sought for it in the field we can only find it asserted on 
paper” (Quart. Journ. Geol. Soc., lvii, pp. 16,17). This is precisely 
the conclusion I have maintained in regard to the English beds for 
many years. 

Lyell and Credner both agree that the drift beds which lie 
conformably to the Chalk in the Baltic lands and follow its 
convolutions and lines of fracture were deposited before the great 
disturbance took place, and Lyell distinctly describes it as post- 
Glacial, that is, as I prefer to say, posterior to the deposition 
of the drift, and it is a notable fact that that great master, 
who saw a good deal further than some of his professed disciples, 
should have so emphatically adhered to the view which seems the 
only view consistent with the doctrine of uniformity that periods of 
great disturbance in the earth’s crust were not confined to older 
geological periods, but have occurred as late as Pleistocene times. 
Those who were reproved by Lyeli so forcibly seem to forget that it 
is in the very earliest geological periods that we have the fewest 
evidences of contemporary dislocations on a great scale, and also the 
largest extent of still undisturbed sina, while all the greatest 
dislocations known to us took place in later periods, notably in 
Tertiary times, as the Alps, which have been lifted up 21,000 feet 
since Eocene days, and the western Himalayas quite as high since 
Pliocene times, bear witness.. Is there any reason under heaven why 
the process should have stopped in Tertiary times? How can anyone 
who believes in rational uniformity maintain such a theory ? 

Have not (as the Scandinavian geologists I have quoted have 
shown) the two gigantic peninsulas of Greenland and Scandinavia 


R. H. Rastall—The Genesis of Tungsten Ores. 367 


been bodily uplifted from far below sea-level to a height of many 
hundreds of feet in post-Tertiary times, as attested by the shell 
peaches that girdle their flanks, and when the present living 
mollusca were tenanting the present seas that wash their shores? Is 
it a rational induction or the reverse to argue that if such enormous 
movements in such tough rocks were the result of lateral thrusts 
caused by shrinkage of the earth’s crust, which both induction and 
experiment combine to establish, that thrusts on this scale could 
hardly occur without the most serious breakages and fractures? 

I have very little doubt, therefore, that the chalk dislocations of 
the Baltic were consequential on the uplift of the great hog-backed 
Scandinavian peninsula, and were almost certainly synchr onous with 
the opening of the Baltic breach, which certainly dates from the 
human period. 


(To be continued.) 


V.—Tue Genesis or Tunesten OREs. 
By R. H. Rastauyu, M.A., £.G.S. 
(Concluded from the July Number, p. 296.) 
Parr IV: Srconpary Tunesten Deposits. 


T the present time a large proportion of the world’s supply of 
tungsten ores comes from secondary (detrital) deposits of various 
kinds, formed by the normal denudation and redeposition of primary 
ores exposed at the surface to the agents of weathering and 
transport. It is impossible to form any idea of what fraction 
of the world’s output actually comes from these sources, since the 
published-statistics do not draw any distinctions in this respect, but 
the amount is undoubtedly large. Although of such great economic 
valne, the secondary deposits do not show any features of special 
interest, and a lengthy description is unnecessary. 

From this point of view the outstanding feature of the tungsten 
minerals is their great stability and resistance to any kind of 
chemical or mechanical alteration. Hence, like cassiterite and gold, 
they are particularly prone to occur in both residual and alluvial 
deposits. In many of the published descriptions, and especially in 
the technical journals, a good deal of confusion is found to exist 
between the residual deposits, where the material is still more or 
less in place, and the true alluvial or transported deposits. From 
their very stable character it follows that tungsten minerals must 
tend to remain unaltered in the gossan of lodes and other masses and 
also to concentrate in the shoad. Hence a kind of secondary enrich- 
ment is found on the weathered outcrops of lodes. This is, of 
course, not really an enrichment in tungsten ores, but rather 
a removal of other constituents of a less stable nature, leading to 
a concentration of the more resistant minerals of the weathered mass. 
From their stability and high density it also follows that the 
tungsten minerals are specially liable to occur as placers and other 
forms of transported deposits. The same properties also lead to 
a natural concentration in such deposits, especially in the lowermost 
layers, resting on the bed-rock, and in natural rifles. In this 


368 &. H. Rastall—The Genesis of Tungsten Ores. 


respect both wolfram and scheelite behave like stream-tin, gold, and 
platinum. In fact, the properties of wolfram are so like those of 
eassiterite that their separation by mechanical processes is very 
difficult, and it was not till the introduction of magnetic separation 
that this difficulty was overcome. 

Geologically the secondary tungsten deposits are so simple and 
straightforward that it seems unnecessary to describe any individual 
examples, while*the practical details of their exploitation, con- 
centration, and after-treatment do not fall within the scope of this 
paper. Essentially they consist mainly of breccias, gravels, and 
sands, formed to a large extent by water-action, and occasionally 
resulting from the effect of dry denudation in regions of small 
rainfall. The briefest possible reference may also be made to the 
““Head”’ of Bodmin Moor and other parts of Cornwall, so admirably 
described by Mr. Barrow.’ In this connexion it may also be 
mentioned that of late years it has been found profitable in many 
instances to work over the old tin-dumps for wolfram, which was 
thrown away as worthless by the earlier miners. 


Part V: Conciusions. 


In the foregoing pages an attempt has been made to give a general 
account of the mode of occurrence and mineral paragenesis of the 
tungsten ores. Attention has been paid chiefly to the theoretical 
side of the subject, with a view to elucidating as far as is possible 
the genesis of the ores and their relation to the associated minerals 
and rocks. 

Taking first the wolframite deposits, it is found that these occur 
most commonly along with cassiterite; other minerals also accom- 
panying them in nearly all cases are arsenopyrite and molybdenite. 
The gangue minerals nearly always include some that are char- 
acteristic of the pegmatitic or pneumatolytic dykes or veins. 
Furthermore, it appears that this general association of tungsten, 
tin, molybdenum, and arsenic may be further subdivided on the basis 
of the rarer metallic elements present into subtypes or local metallo- 
genetic provinces, such as the uranium province of Cornwall, the 
tantalum-mobinm provinces of Burma and Dakota, and so forth. 
Another major subdivision is afforded by the tungsten-tin-silver- 
germanium group of Bolivia. From the evidence brought forward it 
may be regarded as established that the tungsten-tin deposits are 
derived in all cases from granitic magmas. Wolfram and cassiterite 
are found as original minerals in granite, being direct products of 
the crystallization of the magma; as constituents of pegmatite dykes 
within and in direct continuity with the granite, while wolfram is 
also found in quartz veins, so-called, which are continuations in 
space of pegmatite dykes. Hence there is no real distinction 
between a pegmatite dyke and a quartz vein, and the study of these 
lodes lends strong support to the idea that many of the larger quartz 
veins are in fact formed by crystallization of the last residues of 
an acid magma. The separation of these residues is, of course, 


1 Quart. Journ. Geol. Soc., vol. lxiv, p. 384, 1908. 


kh. H. Rastall—The Genesis of Tungsten Ores. 369 


essentially a process of differentiation, which may be described as 
fractional crystallization. Processes of this kind are generally 
described as pneumatolytic, but there does not seem to be any need 
for the use of the word in this connexion, since as commonly under- 
stood it seems to imply something unusual and out of the common 
order of events. This kind of differentiation is perfectly normal; its 
final results depend mainly on the extent to which highly volatile 
compounds and water were present in the original magma. The 
more of these are present the lower will be the freezing-point of 
the final product. The effect of alkaline tungstates in lowering the 
freezing-point of acid silicate melts, and thus enabling quartz and 
acid felspars to crystallize, has long been known and used in petro- 
logical and mineralogical research. It appears that during the 
freezing of the residual magma cassiterite is formed first, then comes 
wolframite, while last of all quartz and fluorite are formed, resulting 
‘in veins of quartz and fluorite without metallic minerals, or even of 
fluorite alone. 

The evidence afforded by the wolframite lodes without tinstone is 
entirely in conformity with the foregoing considerations. There is 
a continuous gradation between the two types by diminution of 
tinstone; the series passes through the wolfram-quartz lodes, in 
which molybdenum and arsenic tend to disappear, whereas other 
sulphides tend to increase. As the final member of the series we 
have the association of wolfram with siliceous gold ores, as in 
Colorado, and of scheelite with gold ores in California. This 
relationship of tungsten to siliceous gold ores is of much interest in 
connexion with the classification of ore-deposits proposed by Spurr.’ 
This author regards all ore-deposits as due to differentiation of 
igneous magmas, the variations depending on the amount of water 
and rarer elements originally present in the magma. According to 
this scheme, the bulk of the tungsten deposits belong to the first or 
pegmatitic type, which is characterized by tin, tungsten, molybdenum, 
with tourmaline and topaz as gangueminerals. Some of the tungsten 
ores, however, both wolfram and scheelite, extend into the second 
group, ‘‘ the free-gold pyrite zone with quartz.” 

Spurr correlates these differences mainly with depth, since he 
regards all ores as deposited by ascending solutions. Although this 
idea is highly probable, it cannot yet be regarded as demonstrated 
that the tin-tungsten lodes were formed at a greater depth from the 
surface than the gold lodes or the cupriferous pyrite deposits. This 
point, however, is not of very great importance. It is a fact, 
however, that the occurrence of tungsten ores when studied in 
detail lends strong support to the idea of a definite sequence of 
differentiation of the rarer metallic contents of the granitic magmas. 

The tungsten ores are definitely oxidic in character, and in many 
ways afford a strong contrast to the behaviour of the sulphidic ores. 
They appear to belong characteristically to acid magmas, whereas 
most of the great masses of sulphides are connected with basic 
intrusions. There is also a strong contrast between the two classes 


1 Spurr, Heonomic Geology, vol. ii, p. 781, 1907. 
DECADE VI.—VOL. V.—NO. VIII. 24 


370 =6R. A. Rastall—The Genesis of Tungsten Ores. 


in the elements which act as ‘‘carriers”’. In the case of the 
tungsten ores the most important of these is undoubtedly fluorine; 
_boron is a very common associate, but it is not known whether it 
plays any actual part in the formation of wolframite or scheelite. 
A detailed study of the literature does not lend any support to the 
statement sometimes found in textbooks that apatite is a common 
associate of this group. In fact, minerals containing phosphorus or 
chlorine seem to be conspicuously absent. 

Another point of interest is that the tungsten minerals are all 
characterized by a high degree of stability and consequent resistance 
to chemical action of any sort. Hence they do not undergo any 
alteration in the zone of oxidation and are not carried down in 
solution into the zone of cementation. This is equivalent to saying 
that they do not undergo secondary enrichment. It follows from 
this that tungsten lodes are always primary in the narrowest sense 
of the term, and this is a fact which should be taken into considera- 
tion in the valuation of such deposits. The behaviour of tungsten 
lodes in this respect is on the whole very similar to that of the tin 
lodes, and shows no resemblance to the characters of the copper lodes, 
for example. 

To sum up, it may be said that the tungsten ore-deposits are of 
magmatic origin, being formed by the natural and normal con- 
centration in certain fractions of the magma of a group of 
constituents, metallic and otherwise, which tend to occur together 
owing to the similarity of their chemical and physical properties 
under the conditions that prevail during the later stages of magmatic 
consolidation. Of these constituents the most important are tungsten, 
tin, molybdenum, arsenic, fluorine, and boron. These constitute the 
general paragenesis, while certain regional subtypes can be dis- 
tinguished, characterized by uranium, mobium, tantalum, and possibly 
others not yet specifically distinguished. In certain cases transitions 
can be traced to other groups of ore-deposits containing gold, silver, 
copper, zinc, and lead. Some of these mixed deposits may be 
explainable by deposition of metals in the same locality at two or 
more distinct periods, while in other instances the differentiation of 
the original magma may have been incomplete and ill-defined. At 
any rate, it is clear that in the typical cases the prime factor at 
work has been differentiation of igneous magmas, and the study of the 
genesis of the tungsten ores lends the strongest support to modern 
views as to the origin of ore-deposits in general. It is now 
becoming increasingly manifest that the study of the characters and 
origin of the metalliferous rocks is an extraordinarily interesting 
and important branch of the science of petrology, and that in the 
past this branch has been unduly neglected by workers on the purely 
scientific and theoretical side. A detailed investigation of the 
chemical and physical laws governing the formation of the oxides 
and sulphides of the igneous rocks, on the same lines as already 
applied by many workers to the silicates, could not fail to yield 
results of the highest scientific interest and of the utmost practical 
value. 


Reviews—Geology of the Barberton District. 371 


REVIEW Ss.- 

I.—Tur Grotocy or tHE BaxBerton Gorp-minine Disrricr. By 
A. L. Hatt. Memoir No. 9 of the Geological Survey of the 
Union of South Africa. pp. 347, with 58 plates, 40 text-figures, 
and a coloured map. Pretoria, 1918. Price 7s. 6d. 

ie this comprehensive memoir Mr. Hall gives a detailed account of 
the physiography and geology of the important Barberton gold- 

mining district in the Eastern Transvaal and Swaziland. The 

physical characters of the region present many features of interest: 
in the west comes the great Drakensberg escarpment, here consisting 
mainly of strata of the Potchefstroom or Transvaal system. The 

‘“‘ Barberton Mountain Land’’, consisting of a large number of 

mountain ranges, is composed chiefly of the slate-quartzite group of 

the Moodies Series, while in the south is a great granite plateau. 

The area shows a typical development of the Swaziland system, 
which is subdivided into three groups, the Onverwacht Volcanic 
Series, the Moodies Series, and the Jamestown Series: each of these 
is penetrated by the older granite, while the Transvaal system rests 
on all of them with a major unconformity. It is shown con- 
clusively in this memoir that the granite is of later date than the 
Swaziland rocks, and the chief interest of this point les in the fact 
that the gold reefs are mainly to be found in the metamorphic 
aureole of this granite. The Karroo System covers only a small 
area, including the Komatipoort coal-field. The Moodies Series 
consists of sedimentary rocks, chiefly slates and quartzites, whilst 
the Jamestown Series now takes the form of chloritic and talcose 
schists and other types probably derived from basic igneous rocks, 
rather like the Keweenawan of North America. The later basic 
intrusions are of little or no economic importance. 

Besides the gold-tields of the De Kaap area and Northern Swazi- 
land, the district also possesses economic possibilities in the form of 
extensive deposits of magnesite and talc, while cassiterite has also 
been worked on a small scale in one or two localities. 


R. He R: 


I1.—Reporr or rHeE Mines Brancw oF THE DEPARTMENT oF Mines, 
CANADA, FOR THE YEAR 1916. pp. 183, with 14 plates and 
10 figures. Ottawa, 1917. Price 25 cents. 

HIS report contains a general summary of the work of the 
Department for the year, together with individual reports on 
various subjects that have been specially investigated. Among 
these are notes on occurrences of iron-ores and building and orna- 
mental stones, and on a reconnaissance for phosphate in the Rocky 

Mountains and for graphite in British Columbia. In Canada, as in 

England and in the United States, much attention is now being paid 

to sands suitable for metallurgical purposes, and a large amount of 

work has been carried out by the Department on this subject. 

Attention was also paid to the possibility of removing lime from 

impure magnesite, such as is found in the Grenville district; this is 


372 Reviews—Geology of the Bawdwin Mines, Burma. 


contaminated with dolomite, and when the mixed rock is heated to 
about 1,000° C. in an electric furnace the magnesite becomes darker 
-in colour. On slaking the magnesite material forms a very coarse 
gritty powder, while the dolomite lime forms a milky paste which 
can be easily removed by washing; hence a separation can be readily 
effected. The fuel-testing and ore-dressing sections of the Depart- 
ment have also conducted much useful work in various special 
directions, and the whole report gives evidence of much energy and 
activity. 
Dipdals he 


IIlI.—Gronocy AnD Ore-pDEpPosITs oF THE Bawpwin Mines, Burma. 
By J. Coaatn Brown. Rec. Geol. Sury. India, vol. xlvii, pt. ii, 
pp. 121-80, with 8 plates, 1917. 


f{\HE Bawdwin ore-deposits are enclosed in a series of rhyolites and 

rhyolitic tuffs, which form a kind of dome protruding through 
the younger Pangyung (Cambrian or Ordovician) strata. Above 
these is a regular sequence to the Devonian, and then an uncon- 
formable series of Jurassic sandstones, clays, and limestones. At one 
horizon in the Silurian many specimens of Monograptus have been 
found. The rocks of the volcanic series are much weathered, and 
their original character is not always easy to determine, but all the 
ore-bodies seem to lie in the tuffs rather than in the rhyolites. The 
ore-bodies all lie in a well-marked zone or channel about 8,000 feet 
long and 400 or 500 feet wide, possibly connected with an ancient 
fault system. 

There are three distinct lodes of lead-silver-zine ore, but of much 
more importance is the Chinaman ore-body, which is an enormous 
replacement deposit of zinc-lead-silver ore, lying on the hanging- 
wall side of the ore-channel. The essential constituents of the 
ores are galena and zine-blende with a little pyrite and chalco- 
pyrite. The ore is always argentiferous, showing on the average 
about 190z. to the ton. The gangue consists of metamorphosed 
country rock and a little quartz. The zine ore appears to be as 
a rule of earlier formation than the galena, while the copper and 
iron sulphides are intermediate. Carbonates, sulphates, and other 
oxidized ores of lead and zinc have long been worked by the Chinese, 
but are now nearly exhausted. 

The author considers that the origin of the ores is to be attributed 
to the intrusion of granite masses into the ancient volcanic rocks, 
hot solutions having risen along shattered fault-planes previously 
produced and replacing rocks readily susceptible of mineralization, 
such as these rhyolitic tuffs would appear to be. The reserves of 
sulphide ores are very large, and after many vicissitudes the mines 
appear to be now in a flourishing condition, largely owing to the 
construction of a narrow-gauge railway 50 miles long, and bid fair 
to become one of the great zinc-lead producers of the world. 


Reviews—Corundum in South Africa. 373 


1V.—Rerort on cprrain Minprals USED IN THE ARTS AND 
Inpusraizs. V. Corunpum. By P. A. Waener. South 
African Journal of Industries, vol. i, No. 9, pp. 776-97. 
Pretoria, 1918. 
WING to the stoppage of the supplies of crude emery from 
Turkey and Greece the demand for the purer forms of corundum 
has greatly increased, especially as the better qualities are much 
more satisfactory in use, and are now very largely employed in 
munition-making. None of the artificial substitutes are found in 
practice to give such good results for the finer kinds of work and for 
specially hard materials. The output of South African corundum 
for the year 1917 amounted to 2,628 tons, so that the Union is now 
the largest producer of any country in the world. At the present 
time the corundum is mainly derived from surface deposits of one 
kind or another: gravels, more or less cemented conglomerates and 
boulders of disintegration : its original home is, however, undoubtedly 
in the gneisses and schists of the Swaziland series, where it is 
associated with a typical assemblage of metamorphic minerals, while 
the rocks are traversed by pegmatite dykes and veins: corundum 
is sometimes found in these also. The crystals are often very large, 
up to 10 inches in length by 5 inches in diameter. They are 
remarkably free from inclusions, and hence very pure samples can be 
obtained. 

The chief corundum fields at present known are in the Zoutpansberg 
and Leydsdorp districts in the Northern Transvaal; some considerable 
deposits are also known in Little Namaqualand, while less important 
occurrences arenumerous. This industry appears to have a promising 
future. 

Rij H.R: 


V.—Furmr Iuprtemenrs 1n SUFFOLK. 


On some Human anp Animat Bones, Frurnt ImpLemeEnts, ETC., 
DISCOVERED IN TWO ANCIENT OccUPATION-LEVELS IN A SMALL VALLEY 
near Ipswich. By J. Rerp Morr. Journ. Roy. Anthrop. Inst., 
vol. xlvii, pp. 867-412, pls. xv, xvi, 1917. 

Tue Ancimyt Friyvr Imerements or Surrorx. By J. Rem Morr. 
Proc. Suffolk Inst. Archeol. and Nat. Hist., vol. xvi, pp. 1-88, 
UOT. 


OR two years Mr. Reid Moir had under close observation two 

well-marked occupation-levels in the deposits covering the sides 

of a small valley near Ipswich. A grant from the Percy Sladen 

Memorial Fund provided him with the requisite labour to make 

careful excavations. We now welcome his results, published in 

detail with numerous beautiful illustrations of the flint implements 
and other discoveries. 

On the lower floor examined were found numerous bones of stag, 
roe deer, ox, pig, goat, and horse, besides some doubtful traces of 
mammoth and Irish deer. There were also three human bones, 
indistinguishable from those of modern man. The associated flint 
implements are of late Mousterian type, and there are also fragments 


374 Reviews—Geology of the Birmingham District. 


of very rough and primitive pottery. ‘The flint implements from the 
upper floor are all Aurignacian, and two specimens from a still later 
deposit are clearly early Solutrean. The succession of the deposits 
in the valley near Ipswich is therefore the same as that already 
noted in the caves of France and Belgium. 

Flint implements of all ages since the appearance of man have now 
been recognized in Suffolk, and Mr. Reid Moir has also published an 
interesting and useful summary of these, with excellent illustrations 
of the principal types, and a bibliography. We commend his paper 
to those who desire a clear elementary statement of the subject. 


VI.—Gerotoey or tHE BrruincuHam Disrrict. 

THE Downrontan or Sour Srarrorpsarre. By W. Wicksam 
Kine and W. J. Lewis. Proc. Birmingham Nat. Hist. and Phil. 
Soc., vol. xiv, pp. 90-9, 1917. . 

On Buarrorp AND oTHER Insect REMAINS FROM THE SouTH STAFFORD- 
SHIRE CoaLrieLp. By H. Boron. Ibid., pp. 100-6, pl. vii. 
Mammatran Remains In tHE GuractaL GRAvELS AT SrovuRBRIDGE. 

By W.S. Bourton. Ibid., pp. 107-12, pl. viii. 


fF\HERE are three papers of special interest to geologists in the 

latest part of the Proceedings of the Birmingham Natural History 
and Philosophical Society. Messrs. King and Lewis have continued 
their researches on the Downtonian of South Staffordshire since their 
contribution to the Groroetcat Macazine in 1912 (Dec. V, Vol. IX, 
pp. 437, 484), and they now publish a detailed summary of their 
results. They have found numerous fish-remains which determine 
the age of the deposits with certainty ; and as these rocks are on the 
faulted fringe of a great coal-field, a knowledge of their precise 
sequence is of economic as well as of scientific importance. 
Mr. Herbert Bolton describes three wings of insects from the Coal- 
measures, probably of Coseley, one representing a new species of 
Phylloblatta, the others belonging to Brodia priscotineta. Professor 
W. S. Boulton gives an account of a sand-pit at Amblecote, 
Stourbridge, in which teeth of Hippopotamus have been found with 
remains of Hlephas primigenius, Rhinoceros antiquitatis, and Bison 
priscus. All the bones and teeth are very fragmentary, but they 
show httle evidence of having been rolled or water-worn. Careful 
search has been made for stone implements, but none have hitherto 
been identified. The spot is evidently well worth continued 
observation. 


VII.—Tae Paytoceny anp Curassirication or Reprines. By 
S. W. Witutsron. Contributions from Walker Museun, vol. i, 
No. 3, 1917. 

ROFESSOR WILLISTON states that in this paper for the first 
time he ventures to express in tabular form his views as to the 
phylogeny and classification of the Reptilia. As he remarks, he has 
no startling novelties to offer, but nevertheless he makes a clear 
statement of the results of recent work which will receive the assent 


Reviews —G. A, Boulenger — Eocene Lizards. 375 


of most paleontologists. The idea that in Hatteria we had the 
most generalized type of reptilian skeleton found among recent 
reptiles, and the belief that Paleohatteria was a member of the same 
group, for a long time misled most writers as to the inter- 
relationships of the Reptilia. Cope, however, had already pointed 
out that the temporal region of the skull supplied the surest basis 
for forming an opinion as to reptilian affinities, and this idea was to 
a great extent carried out by A. 8. Woodward. Osborn & McGregor 
made still more extensive use of these characters in drawing up 
their well-known system of classification. Professor Williston 
jikewise employs the same characters, but has arrived at somewhat 
different conclusions from the two last-mentioned writers. 

The main divisions he adopts are (1) Anapsida, (2) Synapsida, 
(3) Parapsida, (4) Diapsida. ‘he first includes the Cotylosauria and 
the Chelonia, the former having no temporal opening in the skull and 
being probably directly derived from the same stock as the Stego- 
cephalia. ‘The second includes the Theromorpha, Therapsida, Sauro- 
pterygia, and Placodontia, in which there is a single temporal fossa 
which he believes arose from a separation of the jugal and squamosal. 
In the third, which includes the Ichthyopterygia, the Squamata, 
Proganosauria, and Proterosauria, there is likewise only a single 
temporal opening, which, however, is regarded as having been formed 
independently of the openings found in other phyla, the streptostylic 
type of skull found in the Squamata having arisen from the cutting 
away by the lower edge of an originally broad squamosal bar such as 
is found in the Permo-Carboniferous Areoscelis. Vhe fourth group, 
the Diapsida, includes the remaining reptiles, in which there are two 
temporal fosse (lateral and superior), of which the lower one is 
regarded as the older, the upper having arisen as the result of a 
secondary separation of an orbito-squamosal arch. The introduction 
of the name Parapsida for a separate phylum including such, at 
first sight, dissimilar types of reptiles as the Ichthyosauria and the 
Squamata is the chief innovation in this paper, but the writer gives 
good reasons for its introduction, as he does for his other conclusions. 


VIIJ.—Eocrne Lizagps Iv France. By G. A. Bourenenr. 


N a recent note published in the Comptes Rendus of the Academy 
of Sciences, Paris (vol. 166, p. 889), Mr. Boulenger has shown 
that some of the genera of lizards (e.g. Placosaurus, Gervais, and 
Plestiodon, Filhol), from the Upper Eocene Phosphorites of France, 
belong to the family Helodermatide, which at the present day is 
represented only by the poisonous Gila Monster (Heloderma) of 
Arizonaand Mexico and by Lanthanotus of Borneo. ‘The determination 
of the relationships of these Phosphorite lizards was made possible 
by the discovery of a skull showing the rudimentary condition of the 
squamosal characteristic of the family. Mr. Boulenger is also able 
to state definitely that the dermal scutes described by Filhol under 
the name WVecrodasypus, in the belief that they belonged to an 
Armadillo, are in fact cranial scutes of these Helodermatid lizards. 


376 Reviews—C. Gaillard on Heterosorex. 


IX.—Novveav GENRE DES MUSARAIGNES DANS LES DEPOTS MIOCENES 
pe LA Geive Sarnt-Atpan (Ishre). By Cr. Garttarp. Ann. 
Linn. Soc. Lyon, tom. lxii, p. 88. 


1 this paper Professor Gaillard gives a very detailed description of 

the skull and mandible of an interesting new Insectiyore 
(Heterosorex delphinus) which, while evidently referable to the shrews, 
shows some primitive characters, and in some respects approaches the 
moles, e.g. in the possession of a complete zygomatic arch and in the 
form of the fourth upper premolar. ‘The skull is notable for its 
shortness and for the relatively great width of the cranial region. 
The mandible, so far as its posterior region goes, seems to be very 
similar in structure to that of Neomys fodiens, but is about one-third 
larger. The dental formula is as in Crocidura. The new form is 
said to be most nearly related to certain Asiatic genera of shrews, 
and also to have some resemblances with Urotrichus, a mole from 
East Asia. Probably it had undergone considerable modifications as 
a burrowing animal, but unfortunately the limbs are at present 
unknown. The last part of the paper consists of a careful comparison 
of Heterosorex with the fossil shrews hitherto known. 


X.—Paracortan GroLoey. 
Tae Proprem of tHe Creraczous—Trertiary Bounpary 1n Sourn 
AMERICA, AND THE STRATIGRAPHIC Position oF THE SAN JORGE 
Formation 1n Paraconta. By A. Winpuausen. Amer. Journ. 
Sci. [4], vol. xlv, pp. 1-58, 1918. 
N California, Chile, and Patagonia it has been claimed that there 
is a gradual transition from the Cretaceous to the Tertiary faunas, 
with a remarkable mingling of types. Dr. Windhausen maintains 
that this is not the case, but that there is good evidence of a marked 
unconformity in all these regions. He describes and discusses the 
Upper Cretaceous and Lower Tertiary formations which he has 
examined in Patagonia, and concludes that they are distinctly 
separated both by a stratigraphical and by a faunistic break. He 
agrees with the brothers Ameghino that mammalian remains have 
been found associated with bones of Dinosaurs; but he considers that 
this association occurs in Paleocene, not in Cretaceous, deposits. 
Both sauropodous and theropodous Dinosaurs are met with in the 
Cretaceous of Patagonia, but only the latter range upwards into the 
Tertiary. 


XI.—On tHe CrrstattocrapHy anp Nomencnaturr oF HoLnanvire. 
By L. L. Fermor. Rec. Geol. Surv. India, vol. xlviii, pt. iu, 
pp. 103-20, 1917. 

tC a former paper the author showed that hollandite is a crystalline 
mineral having the same composition as psilomelane. Further 

study of specimens from the original locality has shown that it 

belongs to the pyramidal class of the tetragonal system. It is also 
pointed out that the name romanéchite was applied by Professor 

Lacroix in 1900 to a mineral from Romanéche in France, which 

appears to be identical with or closely allied to hollandite. 


Reports & Proceedings—Geological Society of London. 877 


XII.—Inon-orr Occurrences 1n Canapa. Vol. II. By E. Linpeman 
and L., L. Borron. Canada, Department of Mines. pp. 222 and 
33 maps. Ottawa, 1917. 


f{\HE first volume of this publication has already been noticed in 

these pages; the second volume contains detailed descriptions 
of all the known occurrences of iron-ores within the Dominion. 
These include almost every known variety of ore, but the great 
majority of them seem likely to be of small commercial importance, 
at least under the present economic conditions. 


XIII.—Sprecran Reports on vHe Minerat Resources oF Great 
Brarrain. Vol. Il]: Gypsum anp ANnuHyYDRITE, CELESTINE AND 
SrRONTIANITE. Second edition. By R. L. Surrrock and B. 
SmirH. pp.iv+64. 1918. Price 2s. 

HE second edition of this memoir is in the main a reprint of the 
first edition, but some further particulars have been given of 
deposits of gypsum in Nottinghamshire and Somerset, together with 
estimates of the reserves of gypsum still available in different 
districts. 


Pe @ Pepe ss) Aan) gtk @ Cane) TING S= 


I.—Geotoeicat Society or Lonpon. 
1. May 15, 1918.—G. W. Lamplugh, F.R.S., President, in the Chair. 


A lecture on ‘‘The Geology of the Italian Front’? was delivered 
by Professor E. J. Garwood, M.A., Sc.D., F.R.S. The lecture was 
illustrated by lantern-slides, geological maps and sections, and tables 
of strata. 

The President expressed to the Lecturer the thanks of the 
Fellows present. 


2. June 5, 1918.—G. W. Lamplugh, F.R.S., President, in the Chair. 

(1) ‘“‘The Kelestomine, a Sub-Family of Cretaceous Cribrimorph 
Polyzoa.” By William Dickson Lang, M.A., F.G.S. 

The Kelestominz are a sub-family of Pelmatoporide. The latter 
are a family of Cretaceous cribrimorph Polyzoa, whose cost are 
prolonged upwards as hollow spines from the median area of fusion 
of the intraterminal front-wall. The broken ends of these spines 
form a row of pelmata (or, if small, pelmatidia) on the intraterminal 
front-wall. 

The Kelestomine are Pelmatoporide with an apertural bar each 
half of which is bifid; and the proximal and distal forks of each half 
are fused with the corresponding forks of the other half. The fused 
distal forks are also fused with the proximal pair of apertural spines, 
which are greatly enlarged. 

The simplest known form of this arrangement is seen in the genus 
Kelestoma, Marsson. elestoma is characterized among the Keles- 
tominee by its great cecial length, and by the great number of costa. 
Kelestoma has the following three species, which form a single 


378 Reports & Proceedings—Geological Society of London. 


lineage: (1) elestoma elongatum, Marsson, with an incrusting 
asty ; (2) a new species, with a bilaminar, erect asty; (8) &. scalare, 
Lang, with an erect, cylindrical asty. There is, in this series, 
a slight catagenetic decrease in the number of cost, and the 
avicularian aperture becomes somewhat more pointed. The genus 
occurs in the Senonian, zone of Belemnitella mucronata, in the island 
of Riigen. : 

Morphasmopora, unlike Kelestoma, retains a small number of cost 
and a short cecium; but the thickness of the proximal apertural 
spines, which are hardly recognizable as such, is enormously 
increased; the thickness of the bifid apertural bar is also increased. 
In Jdforphasmopora brydonet, Lang, there are four circum-apertural 
avicularia; and the proximal apertural spines and the apertural bar, 
though enormously developed, are not so large as in Wf. gukes-browner 
(Brydone). ‘The latter species has fewer coste than the former, and 
but one pair of circum-apertural avicularia. There are also differences 
in the intereecial and interstitial secondary tissue of the two species. 
Mf. brydonet occurs in the island of Riigen and I. jukes-browner at 
Trimingham; both from the Senonian, zone of Belemnitella mucronata. 

(2) ‘The Geology and Genesis of the Trefriw Pyrites Deposit.” 
By Robert Lionel Sherlock, D.Sc., A.R.C.Sc., F.G.S. 

This pyrites deposit 1s worked at Cae Coch Mine, on the western 
side of the Conway Valley (North Wales), about 1 mile north of 
Trefriw. : 

A band of pyrites, about 6 feet thick, and of considerable purity, 
rests on the inclined top of a thick mass of diabase which is shown 
to be intruded into the Bala Shales that cover the ore-body. The 
shales immediately above the pyrites are shown by the graptolites 
contained to belong to the zone of Nemagraptus gracilis, and are the 
equivalents of the Mvdrim Limestone of South Wales and of part of 
the Lower Cadnant Shales of the Conway Mt. succession: that is, 
they are near the base of the Bala Series according to the Geological 
Survey classification (Carmarthen Memoir, 1909). Northwards the 
intrusive is bounded by an overthrust mass of volcanic ash, which 
itself is cut off by an east-and-west fault against rhyolite, well seen 
in a roadside quarry and in the crags of Clogwyn Mawr. 
Intrusions of dolerite of much later age, probably late Devonian, or 
Carboniferous, are found in the rhyolite, and form the plateau above 
the mine, passing over shales, diabase, ash, and rhyolite in turn. 

Pyrites deposits are classified by Beyschlag, Vogt, and Krusch in 
four groups: (1) Magmatic segregations, (2) formed by contact- 
metamorphism, (3) lodes, (4) of sedimentary origin. None of these 
modes of origin, however, will account for the Trefriw pyrites. 
The conclusion arrived at is that the diabase was intruded below a 
bed of pisoliticiron-ore. Hot water containing sulphuretted hydrogen 
given off from the intrusion, combined readily with the pisolites, 
which were in the form either of oxide or of silicate of iron, and 
formed pyrites. The graptolitic horizon at which the pisolitic ore 
occurs usually contains some pyrites, and this would be added to 
that derived from the above reaction. The pyrites was not formed 
by ordinary contact-metamorphism; because the intrusion is seen, 


Reports & Proceedings—Geological Society of London. 379 


at places where the pyrites is absent, to exert only a slight hardening 
effect on the shale. In North Wales pisolitic iron-ore is known to 
occur in several places at the horizon of Vemagraptus gracilis. From 
the mode of origin assigned above to the pyrites it follows that the 
mineral is of Bala age, since it was formed before the intrusion, 
itself of Bala age, had cooled. The pisolitic ironstone must have 
been in existence in Bala times, and this supports the idea that the 
ironstone is a bedded contemporaneous deposit. 


3. June 19, 1918.—G. W. Lamplugh, F.R.S., President, in the 
Chair. 

A lecture on ‘‘Some Features of the Antarctic Ice-cap”’ was 
delivered by Major Sir Douglas Mawson, D.Sc., F.G.S. In the 
course of his lecture, which was illustrated by a large series of 
lantern-slides, Sir Douglas Mawson said that the ice mantle of the 
south formally involved sub-Antarctic Islands, Patagonia, Southern 
New Zealand, and the higher mountains of Tasmania and of the 
neighbouring portions of Australia, but it retreated to its present 
confines—a circum-Polar Continent—at a time apparently concurrent 
with the disappearance of the extensive Pleistocene ice-sheets of the 
Northern Hemisphere. 

The existence of a great land mass situated on the face of the © 
globe just where the sun’s rays fall most obliquely has the effect of 
intensifying the Polar conditions. This result is achieved by reason 
of the elimination of the ameliorating influence of the ocean and as 
a result of the acceleration of the circulation of the moist atmosphere 
from the surrounding sea to the land, owing to the wide difference in 
temperature pertaining over the oneand the other. Thus the presence 
of extensive land at the Pole, in contradistinction to ocean, results, 
under present cosmical conditions, in increased refrigeration, and 
consequently in greater extension of the Polar ice-cap. This in 
turn reflects on the average temperature of other regions of the 
globe, for an ice surface absorbs but a relatively small proportion of 
the sun’s radiant heat. The existence of the Antarctic Continent 
must therefore have some bearing on the climate of the Northern 
Hemisphere and be reckoned with as a factor contributing to the 
refrigeration thereof. 

The lecturer laid great stress upon the work of the outflowing 
surface winds in developing the domed form of the ice-cap. These 
winds, owing to their persistence and violence, strip the surface of 
much of the newly fallen snow, and otherwise ablate the marginal 
zone, thereby considerably reducing the volume of ice that would 
otherwise reach the sea by glacial flow. Crevasses in the ice-cap 
observed far inland at ‘‘The Nodules” indicate that the ice of the 
hinterland is in motion. 

In the seaward termination of the ice-sheet at Cape Denison, a 
basal zone, attaining as much as 50 feet in thickness, bearing 
englacial drift, is a well-marked feature. 

The shelf-ice formations, including the Ross Barrier and the 
Shackleton Shelf were specially referred to: mention was made 


380 Reports & Proceedings —Mineralogical Society. 


of their growth and decline, of a method of determining their depth 
below water, and of the probability of specialized life existing 
beneath such formations. 

The President expressed to Sir Douglas Mawson the thanks of 
the Fellows and visitors for his lecture. 


I].—MinrratogicaL Socrery. 
June 18, 1918.—W. Barlow, F.R.S., President, in the Chair. 


W. A. Richardson: ‘‘On the Origin of Septarian Nodules.’’ 
Septarian structure consists not of a simple combination of radial 
and concentric circles, but of irregular polygons closely simulating 
mud-cracking. By experiments with clay balls and films and 
comparison with timber cracks it was shown that radial cracks 
widening inwards are produced by internal circumferential contrac- 
tion, radial cracks widening outwards by internal expansion, con- 
centric cracks by contraction towards the centre, and polygonal 
cracks by either free or chemical desiccation. Moreover, analysis 
shows that septarian nodules are more aluminous towards the centre 
than the outside, and are therefore capable of contraction. The 
evidence disproved the expansion theories, and showed that con- 
traction on numerous centres in a colloidal medium caused the 
cracking, and desiccation by chemical agents the contraction. The 
central portions are not merely enclosed clay, but clay that has 
undergone considerable chemical modification, and the original 
colloidal nature of the medium is so changed that closing of the 
cracks by absorption when placed in water cannot take place. 
Finally, the occurrence of the nodules suggests their origination by 
rhythmic precipitation according to the laws of Liesegange from 
solutions of bicarbonates diffusing through a colloidal medium. 

Dr. G. T. Prior: ‘‘The Composition of the Nickeliferous Iron of 
the Meteorites of Powder Mill Creek, Lodran, and Holbrook.’ 
A simple and expeditious method of determining the amount and 
chemical composition of the nickeliferous iron of a meteorite was 
described. The method depends upon the use of dimethyl glyoxime 
for the separation of nickel. Its application to the meteorites 
of Powder Mill Creek, Lodran, and Holbrook gave percentages 
respectively of about 42, 30, and 63 of nickeliferous iron, in which 
the corresponding ratios of iron to nickel were about 18, 114, and 5. 


CORREHSPON DEHN CHE. 


eames 
MOUNTAIN BUILDING. 

Str,—The aim of my article in the Grotocicat Magéazine for 
May was to point out that those data for the earth’s thermal condition 
and past history that agree best with evidence derived from totally 
different sources lead directly to an amount of compression of the 
earth’s crust in cooling that is of the correct order of magnitude to 
account for mountain building. Mr. Deeley in his reply makes no 
attempt to answer this statement. What he does is to suggest that 


COorrespondence—C. N. Bromehead. 381 


different data, less satisfactory on other grounds, might lead also to 
a less satisfactory amount of contraction or even to an expansion. 
This is an argument in favour of the data and of the theory, and not 
against them. 

His assertion that I would have readers ‘‘ believe that the thickness 
of the radio-active layer has been fairly accurately measured”’, and 
his charge of ‘‘dogmatism”’, are definitely untrue. It was because 
itis not accurately known that I determined the available compression 
on two hypothetical distributions of radio-active matter, both per- 
missible on other grounds, but widely different; the results they 
gave were not very different and were stated in the article. 

I introduced no new theories regarding the properties of matter. 
What I did was to classify in a convenient way the known behaviour 
of different types of matter under shearing stress. The statement 
quoted from Maxwell that liquids and perhaps most solids are 
perfectly elastic as regards stress uniform in all directions is irrelevant 
to my discussion, which was explicitly limited to the differences 
between the stresses in different directions. In the light of present 
knowledge the account of shearing stress in Maxwell’s book needs 
revision; for it makes no reference to elastic after-working or to the 
elasticity of such a substance as pitch, which in my classification 
would be a plastic solid with a very low limiting stress-difference. 
The common practice of regarding as a liquid a substance so elastic 
that tuning forks can be made of it is exceedingly inconvenient. 

Had the conclusion, that my views on the solid and liquid states are 
quite inadmissible, been accompanied by the slightest argument, it 
might have been more impressive; or it might not. 

Hanrotp JEFFREYS. 


THE PRE-THANETIAN EROSION OF THE CHALK. 


Sir,—I have read with much interest the suggestive paper by 
Mr. H. A. Baker on the ‘“‘ Pre-Thanetian Erosion of the Chalk in the 
London Basin”. I have for some time past been accumulating 
evidence for a similar study, but in 1915 wrote that ‘‘ the evidence 
. .. is as yet too slight to allow of a definite map being made” 
(Geology of Windsor and Chertsey, Mem. Geol. Surv., p. 14). 

Mr. Baker’s map (Fig. 1) includes the area to which I referred, and 
appears to be based upon less evidence than that which my work for 
the Geological Survey had afforded. In the construction of such 
a map it seems natural to ascertain as far as possible the zone of the 
Chalk immediately underlying the Tertiary at the boundary of the 
latter, and to check the zones whose presence beneath the Tertiary is 
deduced from borings by these facts. This has not been done by 
Mr. Baker. The zone of Chalk on which the Tertiary rests has been 
ascertained by the Survey in the south-western part of the area 
shown on Mr. Baker’s map, and a portion of the results has already 
been published (op. cit.). From the neighbourhood of Beaconsfield to 
the western margin of the map forming Fig. 1 he shows the base of 
the Tertiary as resting on the zone of A. quadratus. The fact is, 
that the zone is that of WU. cor-anguinum at Beaconsfield, Marsupites 


382 Obituary— William Lower Carter. 


and possibly quadratus at Taplow, cor-anguinum again south and 
west of Taplow to the margin of the area, where Marsupites comes on 
again. In this part of the area, at any rate, Mr. Baker’s zonal 
boundaries, deduced from borings, are m marked discordance with 
the facts ascertained and published. 

I do not, however, wish to suggest that the method of deducing 
the Sub-Tertiary zones from boring records is useless; on the 
contrary, when the amount of evidence available is larger, the 
method may be of some value. The results obtained by Mr. Baker 
show that his evidence is insufficient, but that may be because he 
has apparently not made use of all the evidence available. For the 
benefit of those interested in the subject I may add a few points not 
mentioned in the paper I am criticizing; all are referred to in the 
memoir I have quoted, while the first was published in 1886. At 
Egham the Chalk Rock has been proved at a depth from the surface 
of 700 feet, or 346 feet from the top of the Chalk, suggesting the 
presence of quadratus zone; at Ottershaw the total thickness of 
Chalkis known to be 646 feet, suggesting Marsupites ; at Windsor the 
Chalk is exposed below the Tertiary and probably belongs to the 
lower part of cor-anguinum. 

From this evidence, combined with that referred to by Mr. Baker, 
I inferred that the plane on which the Tertiary rests ‘‘ has been cut 
across a series of gentle folds whose axes run about EK. 15° 8.” 
(op. cit., p. 14). Ido not regard the above as more than a tentative 
solution of the problem, and it refers only to the southern half of the 
area mapped by Mr. Baker (Fig. 1), but I wish to point ont that his 
conclusions must at any rate be regarded as ‘‘ not proven”’. 

T donot understand the suggestion on p. 299 that ‘‘ the Streatham— 
Beckton fault is pre-Tertiary’’. It is certainly post-Tertiary, since 
it involves the Tertiary strata and dislocates the upper surface of 
the Chalk. Whether there was pre-Tertiary movement along the 
same line we have as yet no means of ascertaining. 

C. N. Bromeneap. 

GEOLOGICAL SURVEY AND MUSEUM, 


JERMYN STREET, LONDON, S.W. 1. 
July 9, 1918. 


(Qs SveseOpy NAS Se ge 
WILLIAM LOWER CARTER, M.A.; F.G.S. 
Born AvGust 9, 1855. DIED JUNE 19, 1918. 


Witiiam Lower Carrrr was born at Stafford and educated at Derby 
School, where he distinguished himself in Natural Science. On leaving 
school he commenced work in a bank, but having a strong desire for 
theological studies he entered as a student at Springhill College, 
Birmingham, matriculating with first-class honours at London 
University. From Springhill he proceeded to Cambridge, having 
coned an Exhibition scholarship at Emmanuel College, where he 

gain took up Science classes and passed the Natural Science Tripos 
Toston with honours, specializing in Geology. Leaving 
Cambridge he spent some time at the Univer sity of Halle in Germany, 


Obituary—James Watson. 383 


and then returned to Springhill College for a final theological 
course. 

In addition to his pastoral labours, he was ever keen on scientific 
research, and did some valuable original work. He was for many 
years also the Honorary Secretary of the Yorkshire Geological and 
Philosophical Society, editing its important journals and initiating 
efforts for the study of fresh Fel ds in geology. He filled the office of 
Recording Secretary to Section C (Geology) of the British Association 
for the Advancement of Science, Scanlae all the annual meetings. 


WILLIAM LOWER CARTER, M.A., F.G.S. 


In 1908 Mr. Carter accepted the important position of Lecturer in 
Geology and Crystallography to the East London College, a post 
which he continued to retain until the time of his death, also 
lecturing in Geography and Botany at various colleges and technical 
institutes in London. In this sphere he proved most successful, 
being an indefatigable teacher to whom preparation was never any 
hardship, and his pupils regard him not only with the esteem due to 
a careful instructor but also with affection. It was while lecturing 
on June 7 at Queen’s College, Harley Street, W., that he was seized 
with cerebral apoplexy, from which he never rallied, but passed 
peacefully away on June 19, 1918, at his residence, 9 Belmont Road, 
Watford. 


5 JOHN WATSON, M.A.; F.G.S. 
Born 1842. DIED JULY 3, 1918. 


Tur death of Mr. John Watson, of Bracondale, Cambridge, deprives 
the geological world of a follower of the economic side of our science 
ities possessed a very wide and full knowledge of the geology of 
building-materials. 


384 Obituary—Professor Voldemar Amalitsky. 


Mr. Watson was born in the North of England in 1842, and spent 
most of his life in Newcastle-upon-Tyne, where he became Managing 
Director of the Gateshead Works for the manufacture of Portland 
cement. Some years ago, on retiring from business, he removed to 
Cambridge, where he resided until his death. Disdaining a life of 
ease, he devoted his special knowledge and great energy to the 
acquisition of an unrivalled collection of building-stones, ornamental 
marbles, and other materials connected with building. These he 
presented to the Sedgwick Museum, and spent his leisure in arranging 
them and writing descriptive catalogues. Two of the catalogues 
have already been published, and are well known to geologists and 
to those connected with building, namely, British and Foreign 
Building Stones and British and Foreign Marbles and other Ornamental 
Stones. At the time of his death he was engaged in the preparation 
of manuscripts for books on slates, limes, and cements, and it is 
hoped that the material is in a state which will permit of its 
publication in the not distant future. 

Mr. Watson made many journeys at home and abroad in order to 
render his collection as complete as possible, for he spared neither 
time nor money in carrying out his self-imposed task; accordingly 
the collection remains with us, a worthy monument to his labours, 
specially valuable at a time when the claims for the teaching of 
economic geology have become insistent. 

In 1911 the University of Cambridge recognized the value of 
his labours by conferring upon him the honorary degree of Master 
of Arts. 

He died as the result of an accident—a fall from a ladder—on 
July 3. ; 
Mr. Watson was greatly esteemed for his sterling character, 
singular modesty, and charm of manner. His colleagues at 
Cambridge will greatly miss the cheery ways and eager enthusiasm 
of their old friend, butit is satisfactory to know that he had completed 
so much of the work which he set out to accomplish, which was to 

him veritably a labour of love. 
J. EB. M. 


PROFESSOR VOLDEMAR AMALITSKY. 


News has just been received, by a letter posted in Petrograd on 
March 2, that Professor Voldemar Amalitsky died suddenly from 
heart disease on December 15/28, 1917, at Kislovodsk (North 
Caucasus). Many friends in this country would wish to convey 
their sympathy to his widow, who we trust may emerge safely from 
these terrible times. 

We hope later to publish a full notice of Amalitsky’s great work 
in the discovery and rescue of numbers of entire skeletons of 
Permian (or Triassic) reptiles from the banks of the Northern 
Dwina, near Archangel, in Northern Russia, 1904 and earlier (see 
Grou. Mae., 1905, p. 514). 

aR. AaB: 


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I. ORIGINAL ARTICLES. Page REVIEWS (continued). Page 
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Professor W. G. WOOLNOUGH, Columibiaks sec eeaae eee nee 42 
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ORIGIN AL AI AES ER ES are ( atig 
NAME eo 
1.—Tuer PrysrograrHic SIGNIFICANCE OF ftir IN WESTERN 
AUSTRALIA. 


CAN 


By W. G. WoounouGH, D.Se., F.G.S., Professor of Ges. University of 
Western Australia. 
URING the last six or seven years a series a zafdbote’ papers 
bearing on the origin of laterite has appeared in the Grotoercar 
Macaztne.! The conclusions arrived at have been somewhat div erse 
and contradictory. Dr. Fermor, on the one hand, regarded the 
laterites of India as residual in character, and believed that they 
represented the insoluble residues left in the process of rock 
weathering after the soluble constituents had been removed in 
solution. Mr. Simpson, at the other extreme, suggested that they 
represented the soluble material, leached out of the subjacent rocks 
during weathering under peculiar conditions, and deposited as a 
chemically-formed “rock by precipitation at the surface of the earth. 

Mr. Holmes and Professor Lacroix both appear to hold much the 
same view as that enunciated by Mr. Simpson. The fact that 
Dr. Fermor, in his admirable review of the work of Lacroix, does 
not dissent from the statements of the latter, suggests that Dr. Fermor 
and Mr. Simpson may really hold very similar views, and that the 
apparent differences may be, after all, due to method of expression 
and not to actual divergence of opinion. 

It is quite possible that different methods of formation may occur 
under the widely different conditions of climate and geology exhibited 
by the various regions from which laterite has been described. 
Whether this is so or not, the author is wholly in agreement with 
Mr. Simpson in his explanation of the chemistry of laterite formation 
in Western Australia, but desires to go further and to extend and 
amplify the physiographic processes involved in the genesis of this 
peculiar rock. 

A very brief summary of the physiography and geology of the 
south-western portion of Western Australia? will assist in the 
understanding of the problem. ‘he most important feature of all is 
the Darling Range Escarpment. This extends asa straight line for 
at least 200 miles in a north and south direction from near Gingin 

1 Notably L. L. Fermor, ‘‘ What is Laterite?’’: Grou. Mac., 1911, 

pp. 507-16, 559-66 ; HK. 8. Simpson, “* Laterite in Western Australia”? : i bid., 
1912, pp. 399- 406; A. Holmes, “‘ The Laterite Deposits of Mozambique ”’ 
ibid., 1914, p. 529; L. L. Fermor, “The Laterites of French Guinea”? : ibid., 
1915, pp- 28-37, 77- 82, 123-9. 

2 For a more detailed account see J. T. Jutson, Bull. No. 61, Geol. Sury., 
Western Australia. 


DECADE YI.—VOL. V.—NO. IX. 25 


386 Prof. W. G. Woolnough—Laterite in W. Australia. 


(30 miles N.N.E.)1 toa point near Capel (110 miles 8.S.W.). These 
points do not mark the limits of the feature in question, but beyond 


MAP OF 
WESTERN AUSTRALIA 


os 


pe a 


Sarceis™ 


x ole on 


\ 
‘ Coo \gerdie 
\ Southern! Cross 


errs | 
Nore a 
= 


War y) KE r 
3a 
¥ 
cal SITS sok “9 g 4 
Yoon bala sey, 
ng 


FIG. 1. Dy of Ween ay showing positions of places mentioned in 
the text. In order to avoid confusion places in the immediate vicinity of 
Perth have not been inserted. Helena River is a tributary of Swan River. 
Brunswick and Preston Rivers are tributaries of Collie River. 


1 For simplicity in finding localities on the map the approximate direction 
and distance from Perth will be given in each case. 


Prof. W. G. Woolnowgh—Laterite in W. Australia. 387 


them the structure becomes complicated in marked contrast to its 
extreme simplicity within the specified zone. The escarpment has 
an extremely uniform altitude of about 900 feet above sea-level, and 
marks the boundary between the Coastal Plain on the west and the 
‘‘ Darling Range” on the east. 

The Coastal Plain is very uniformly about 15 miles wide and 
consists almost exclusively of sandy deposits of recent age. In the 
neighbourhood of Perth these have been proved by artesian bores to 
extend to a depth of at least 2,000 feet below sea-level. The surface 
of the Coastal Plain is undulating, but does not, asa rule, rise to more 
than 150-200 feet above sea-level. 

The name ‘‘ Darling Range”? is really a misnomer for the highlands 
to theeast of the scarp. These highlands form actually one of the most 
perfect peneplainsin the world, and they will be referred to, therefore, 
throughout this communication as the Darling Peneplain or Darling 
Plateau. The surface of this unit is gently undulating for the most 
part. Its average altitude increases gradually as we proceed east 
and north, so that it is 1,046 feet at Merredin (145 miles E.N.E.), 
1,400 feet at Coolgardie (320 miles E.N.E.), 1,506 feet at Laverton 
(450 miles N.E.), 1,755 feet at Sandstone (3830 miles N.N.E.), and 
1,708 feet at Meekatharra (400 miles N.N.E.). The plateau is built 
up almost exclusively of extremely ancient crystalline rocks, some of 
which are of acid composition (granites and gneisses), others of which 
are basic (quartz-dolerites, epidiorites, ‘‘ greenstones,” etc.). 

The escarpment is deeply trenched by streams which flow westwards 
into the Indian Ocean. ‘he larger streams like the Swan, Helena, 
Murray, Brunswick, Collie, and Preston, have reached base level 
and have begun to widen their valleys just within the edge of the 
plateau. The smaller streams and all but very insignificant stretches 
of even the larger ones are, however, strikingly juvenile throughout 
their intra-plateau portions. The whole of the western part of the 
plateau is therefore intensely dissected and roughened by deep 
narrow gorges. This is an important point to remember in discussing 
the origin of the laterite. The zone of intense dissection is not very 
wide, and, from Chidlow’s Well (20 miles E.N.E.), the levels on the 
Eastern Goldfields Railway (to Coolgardie, Kalgoorlie, and Laverton) 
indicate clearly the very slight relief of the area. Very rarely indeed 
do depressions fall more than about 200 feet below the average level 
of the surrounding country. 

In the western zone of the plateau crystalline rocks in situ are met 
with only in the valleys of the young rivers which have dissected the 
surface. As soon as the peneplain level is reached the surface is 
covered with a dense shield of laterite. As Simpson has pointed out, 
the composition of the laterite varies sympathetically with that of the 
underlying bed-rock; where the latter is granitic the laterite is 
aluminous, where it is basic the laterite is ferruginous. In every case 
the laterite, which is usually solid for a thickness of from 8 to 6 feet, 
rests on a bed of kaolin. ‘The basement is very well exposed in some 
of the railway cuttings, as, for instance, at Baker’s Hill (80 miles 
E.N.E.), Hoddy’s Well (50 miles E.N.E.), Gooseberry Hill (10 miles 
\.), and other places. The leaching of the rock has been so thorough 


388 Prof. W. G. Woolnough—Laterite in W. Australia. 


that the residual material is suitable for the manufacture of fire- 
bricks. These, and brick arches for locomotive fire-boxes, are made 
at Smith’s Mill (15 miles E.N.E.) and at Clackline (50 miles E.N.E.). 
That the leached material is in situis very clearly demonstrated by 
the preservation of minute aplite, pegmatite, and quartz veins 
through it (as at Hoddy’s Well), and by the slight differences in 
colour and consistency of the kaolin caused by the presence of basic 
dykes through the granites. Some of these structures are only 
a fraction of an inch in thickness; yet, though they have been 
cracked into short sections, they preserve their continuity for 
considerable distances. This is clear proof of the residual character 
of the pipeclay foundation of the laterite, and indicates that the 
volume of the pipeclay is very little less than that of the rock from 
which it has been derived. 

The laterite capping, as above noted, is usually from 3 to 6 feet thick. 
In many instances where it has not been stripped off (for railway 
ballast or road-making) the apparent thickness is greater because of 
the collapse of the capping through erosion of the pipeclay substratum 
at the edge of the outcrop. The laterite extends as larger and 
smaller continuous cappings over the plateau areas which have not 
yet come under the action of the dissecting streams. These cappings 
are thus the residual portions of a once continuous sheet which 
mantled the entire peneplain surface. 

As we pass inland, beyond the area which is in process of active 
dissection by coastal streams, into the broad extent of undulating 
country forming the wheat belt of Western Australia, the distribution 
of crystalline rock and laterite becomes different from that near the 
western scarp of the plateau. The characteristic elements of the 
land surface are broad, exceedingly mature, meridional valleys 
alternating with low ridges. The valleys are heavily aggraded, and 
the slopes are well mantled with soil, though extensive outcrops of 
granites and greenstones are also met with at intervals. The ridges 
are partly of the same character as the slopes, that is, soil-covered, 
but are rather more than half composed either of ‘‘ Sand Plain”’ or of 
large granite outcrops. The latter (the granites) form immense flat 
domes, sometimes several miles in circumference, and have played 
a very important part in the exploration and prospecting of the 
country. On their surfaces are found the ‘‘rock-holes” and 
‘‘onamma-holes’’ whence the earlier travellers obtained their water 
supplies. The ‘‘ Sand Plains” are extensive areas of light, friable 
sandy soil, beneath which, at all events in many instances, occurs 
a bed of sandy lateritic material. The perfect pisolitic structure of 
the escarpment laterites is almost completely wanting in those of the 
sand plain, though well-defined concretionary structure is plainly 
discernible. Solid masses of concretionary laterite forming extensive 
cappings of the higher residuals are not encountered through the 
wheat belt. 

Further east, again, the physiography alters once more. The 
meridional valleys are no longer definite stream channels, but have 
degenerated into strings of salt lakes, whose floors, consisting for the 
most part of comparatively insignificant thicknesses of detrital 


Prof. W. G. Woolnough—Laterite in W. Australia. 389 


material, are covered with crusts of salt and gypsum. The ridges 
are, to a large extent, very rocky, and are frequently, but not always, 
capped by lateritic material. This laterite is again very different in 
general aspect from that which mantles the western zone of the 
Darling Plateau. It is not decidedly pisolitic, but is rather cellular 
and cavernous in structure. Nevertheless, the effects of concretionary 
action are abundantly apparent throughout, and it shows every 
evidence of a mode of origin generally similar to that insisted on by 
Simpson. The author is by no means so familiar with these eastern 
areas, distant from Perth 200-400 miles, as he would like to be, but 
quite numerous traverses of the area have beenmade. In the western 
part of the Goldfields Belt, near Southern Cross (205 miles E.N.E.), 
for instance, the laterite in many cases, if not always, lies directly 
on the surface of the crystalline rocks and schists, without the 
intervention of any extensive layer of thoroughly leached pipeclay. 
The rock, however, 1s deeply weathered, and the lower parts of the 
laterite crust represent an impregnation of the very much rotted 
original rock. 

Further east, again, for instance, at Coolgardie (220 miles E.N.E.), 
there is a partial return to the conditions of occurrence met with in 
the Darling Plateau, The ‘‘ Red Hill” in this town is a very typical 
laterite-capped butte, strongly concretionary rock resting on a well- 
leached substratum, but one which is much more ferruginous than 
that which is characteristic in the extreme west. Throughout the 
Eastern Goldfields, so far as I have been able to observe, there is very 
little tendency to laterite formation on anything but the basic rock 
types. Granites, quartzites, or siliceous schists are entirely free 
from laterite coverings. In these eastern areas laterite cliffs often 
constitute what are known as ‘‘ Breakaways”’, which form the shores 
of the salt lakes. 

This brief and inadequate outline of the physiographic conditions 
under which the laterite is distributed in the south-western portion 
of Western Australia, indicates that the problem of its formation is 
more complicated than Simpson has shown. The author is wholly 
in accord with him with regard to the chemistry of the process of 
laterite formation, namely, by leaching of the soluble constituents of 
the subsoil, transportation of the materials in solution to the surface 
by capillarity, and precipitation of certain of the dissolved matters 
there, through alternate saturation and desiccation of the subsoil 
consequent on seasonal alternation of extremely wet with intensely 
dry seasons. Simpson, however, appears to believe that the laterite 
may have formed on the surface of the Darling Peneplain, and it is om 
this point that I disagree with him. The drainage of the area is far 
too perfect at the present day to admit of the upward leaching of 
solutions to any considerable extent. The rapid fall in the level of 
water in wells sunk through the laterite capping on the plateau, 
even at very considerable distances from the nearest deep valley, 
indicates the effectiveness of lateral drainage under existing 
conditions. In November and December, 1916, the author noted 
a fall in the level of one such well (at 50 miles on the Perth—Albany 
road) of upwards of 30 feet in six weeks. 


390 Prof. W. G. Woolnough—Laterite in W. Australia. 


The thesis I wish to establish is that the laterite was produced 
- under.peneplain, not plateau, conditions, that is, when the land surface 
stood at a very slight elevation above sea-level. Youthful streams 
cut down their valleys to base-level before they begin to widen them 
at all sensibly. Hence the development of maturity of river erosion, 
that is, the evolution of a peneplain, can be completed only at a slight 
altitude above base-levei, which in this case was undoubtedly 
sea-level. 

With a very gentle gradient mechanical transportation of sediment 
would be insignificant, and even in solution the lateral movement 
of material would be extremely slow. Chemical weathering, however, 
would be strongly favoured, and, given alternations of wet and dry 
seasons, the conditions for laterite formation, postulated by Simpson, 
would be ideally fulfilled. 

If this view is correct it follows that the importance of laterite, 
from an historic point of view, is greatly enhanced. It owes its 
present position on the summit of the plateau to the uplift of the 
peneplain, the criteria for such an elevation along the Darling 
Escarpment, with down faulting of the coastal strip towards the 
Indian Ocean being complete in every particular. Hence it follows 
that the laterite capping serves as a stratigraphic horizon of no mean 
value. If we find areas of laterite markedly elevated above, or 
depressed below the general laterite level, we have a prima facie 
reason to suspect earth movement as a cause. In applying this 
principle, however, it is important to remember that the peneplain 
was never a perfect plane, but was always an undulating surface. 
Under these circumstances certain initial differences of level of the 
laterite capping must be postulated. In the Darling Plateau area it 
seems probable that these differences of level were of the order of 
200 feet.! 

Another possible source of error is the fact, mentioned by Simpson, 
that considerable areas of redistributed laterite occur. When due 
allowance has been made for these possible sources of error, a sufficient 
number of outstanding cases has come under notice to indicate that 
the importance of the general principle has not been overrated, and 
that extraordinary differences of laterite level in adjacent areas indicate 
block faulting. In most instances other criteria of faulting may be 
discovered which convert probability into certainty. As examples 
may be cited the occurrence along the foot of the Darling Range 
Scarp, in the immediate neighbourhood of Perth, of isolated 
remnants of a laterite-covered shelf or step. At Greenmount and | 
Ridge Hill (10 miles E.), where two railway lines enter the scarp, 
this shoulder of laterite is prominent, while it can be detected at 
least three points immediately to the south of those mentioned. 
At Armadale (15 miles 8.E.) and Waroona (60 miles 8.) similar 
areas of low-level laterite occur. From these occurrences I believe 
we may suspect that the faulting of the Darling Range Scarp is of 
the nature of a step fault and not simply a single fault (see Fig. 2). 

1 The difference in altitude of Chidlow’s Well (30 miles E.N.E.) and 


Wooroloo (37 miles E.N.E.) on the eastern railway, both on the laterite 
““level’’, amounts to 256 feet. 


Prof. W. G. Woolnough—Laterite in W. Australia. 391 


In this case the collateral evidence is not so strong as it is in some 
others. The Collie Coalfield (100 miles S.8.E.) is a Senkungsfeld in 
which a wedge of Permo-Carboniferous Coal-measures has been let 
down into a trough amongst the granites. This faulting was no 
doubt pretty ancient, but the movement has evidently been rejuvenated 
in very recent geological time. Here we have a difference of level of 
the solid laterites of 213 feet between Yokain and Penrith on the 
railway line immediately west of Collie. This difference is not 
enough per se to establish the faulting, but other criteria, both 
geological and physiographic, taken in conjunction with the laterite 


zz SE 
Zi Ze 
ae ion an 
ee < a. 
Ue tat 
ee oa! ae 
hia z 
ees = Zz @u 
== (0 ia ls 2) 
O Sa au = aa 
22: ei uy a Fi 
= Se 2 oc = 
Za @ Ce Ls ane 
Ta: 


Scales Horizontal _ emule eNegilcall  eOOudn, 


Fie. 2.—Sketch-section of the Darling Range Escarpment at Armadale, 
Western Australia (slightly generalized), showing relation of high-level 


and low-level laterites to possible slip- faultings. Laterite is shown black, 
and its thickness is exaggerated. 


evidence, are amply satisfactory. Again, at Brookhampton (115 miles 
S.), a sudden jump of 200 feet in the laterite level was what first 
attracted the author’s attention to a very decided recent fault there. 
Within the wheat belt and the Kastern Goldfields no test as to the 
applicability of the theory has been made. Inthe Eastern Goldfields 
Maclaren believes that the laterite is still growing. While this may 
be so at isolated and favourably situated points it is quite possible 
that the statement cannot be substantiated generally. In the south- 
west it is found that many of the coastal streams have heavy cappings 


392 Prof. W. G. Woolnough—Laferite in W. Australia. 


of laterite on their alluvial terraces in the neighbourhood of the 
_ highlands. This is markedly the case, for instance, with the Preston 
River at Donnybrook (210 miles 8.). It is quite possible that 
laterite may be actually forming at this and similar points, and the 
formation may be explained as follows :— 

Most of the streams in question are fed by the subsoil drainage 
which flows beneath the laterite capping of the plateau. Their 
waters are, even in the wet season, hard and somewhat mineralized. 
As the dry season advances they all, with few exceptions, become 
unpleasant for drinking purposes. Many of them deposit iron 
abundantly, and give rise to iridescent films of iron oxide on the 
surfaces of pools. These films have been mistaken repeatedly for 
indications of petroleum. When the active flow of the streams 
ceases early in the summer, capillary action through the porous 
alluvium of the terraces may induce the upward concentration of the 
dissolved salts and give rise to normal laterite. It is to be noted 
that some of these river-terrace laterites are much more like the 
ordinary plateau laterite than are the detrital laterites. For this 
reason it may be advantageous to recognize a third river-terrace ty pe 
of laterite in addition to the two varieties (solid high-level type and 
secondary detrital type) defined by Simpson. This mode of occurrence, 
if it is correctly understood by the author, may possibly explain the 
very common occurrence of laterite in the breakaways on the shores 
of salt lakes in the Eastern Goldfields. 

The author doubts whether the occasional torrential rains of the 
arid areas are competent to produce laterite as supposed by Simpson. 
The latter authority (loc. cit., p. 401) mentions falls of 3°30 inches of 
rain at Mulline in one day and of nearly 4 inches at Coolgardie in 
two days. It is the universal experience that such torrential down- 
pours cause comparatively little saturation of the soil. Even in verv 
porous sandy areas the proportion run off to soakage is very high, and 
it is extremely doubtful whether the cycle of events necessary for 
laterite formation could follow such sudden downpours as those 
mentioned. Matters are quite otherwise when the rainfall is seasonal 
in character, asis very typically the case in the areas nearer the coast. 

To explain the heavier laterization of the goldfields than of the 
wheat belt I would suggest that the question must be referred back 
to the previous geographic cycle. It has been shown that there has 
been a net uplift of the Darling Peneplain of nearly 1,000 feet on the 
west, and probably of considerably more on its eastern side. If the 
theory of laterite formation under low altitude conditions is correct 
it follows that the goldfields laterite must have been formed when 
the land stood much lower than it does now. 

The presence of marine fossils at peneplain level at Norseman 
(350 miles E.S.E.) indicates that, at no very distant epoch, the sea 
extended much further inland than the present head of the Great 
Australian Bight. It is well known that in comparatively recent 
geological time the climate of Central Australia was much moister 
than it is at present, and it is reasonable to suppose that a much 
increased humidity was experienced in the Goldfields area. Under 
these circumstances it is very easy to account for the extensive 


+ 


Prof. W. G. Woolnough—Laterite in W. Australia. 393 


laterite formations of the region. The wheat belt was probably 
sufficiently distant both from the known coastline on the west and 
from the problematical coastline on the east to experience so light 
a rainfall as to preclude extensive laterite formation of the normal type. 

Before leaving the subject of origin of laterite it may be of interest 
to point out that somewhat similar formations abound in Australia 
under conditions pointing very conclusively to conditions of formation 
identical with those laid down by Simpson forthe Western Australian 
laterite. 

In South Australia, where eruptive rocks are comparatively rare, 
and where marine sediments and schists predominate, the place of 
laterite is taken by almost ubiquitous ‘‘ travertine”’’, an impure lime- 
stone with highly perfect concretionary and pisolitic structures 
encountered under conditions quite similar to those of the western 
laterite. 

Throughout the area occupied by the highly siliceous Upper 
Cretaceous Desert Sandstone formation in Central Australia, very 
widespread concentration of silica has followed a course identical 
with the concentration of lateritic materials. The result has been 
extensive opalization of the sandstone and the formation of 
porcellanites and quartzites. 

Particularly in the wheat belt and goldfields of Western Australia 
it is usual to find granite outcrops ‘‘ case-hardened ” to adepth varying 
from a few inches to several feet. This phenomenon is evidently due 
to a superficial concentration of materials derived from the somewhat 
soft and crumbly internal portion of the rock, and it is to be explained 
in the same way as the production of laterite. This ‘‘case-hardening”’ 
of granite outcrops is an important factor in the production of the 
‘Conamma-holes”’ or natural tanks in which so much of the scanty 
water supply of the arid interior is conserved. 


SUMMARY. 


The author is of opinion that— 


1. Laterite in Western Australia is formed by the leaching of 
subsoil salts during seasons of heavy rainfall, and capillary attraction 
of the solution to the earth’s surface during intervening dry periods ; 
the dissolved matter being deposited in a concretionary fashion in the 
surface layers of the soil. 

2. Laterization can occur only in areas where drainage is almost 
at a-standstill. This usually involves the existence of a peneplain 
almost at sea-level. 

3. High-level laterite is a criterion of elevation of the land. 

4. Difference in laterite level suggests faulting, which can often 
be proved by collateral evidence. 

5. Outstanding differences of opinion with regard to broad features 
in the physiography of Western Australia may be reconciled by 
recognition of the essentially low-level nature of laterite. 


394 Prof. J. Park—Pleistocene Glaciation, New Zealand. 


I1.—P.eisrocene Guacration or New Zeatanp. 
_ By Prof. JAMES PARK, F.G.S., University of Otago, Dunedin, New Zealand. 
_ (PLATE XIV.) 
N the June issue of the GuoLoercaL Macazine’ for 1917 there 
appears an article by Mr. C. T. Trechmann, D.Sc., F.G.S., on 
“The Glaciation Controversy in New Yealand’? in which he 
traverses my views as to the extent of the Pleistocene glaciation 
of this Dominion. I regret that my recent journeys to the Isle of 
Pines and Cape Yorke Peninsula and the irregularity of the oversea 
mails arising from the war conditions have prevented an earlier 
reply. Mr. Trechmann deals first with the glaciation of the 
North Island. He says it seems to him that the question of 
the glaciation cf the North Island stands or falls with the origin 
of the striations on the large andesitic boulder lying near Mangaweka 
in the Rangitikei Valley (see Plate XIV). He selects these striations 
as the sole criterion of former glaciation, and argues that ‘‘if the 
scratches are not glacial the boulder is not glacial, and if this 
boulder is not glacial none of the others are glacial, and the chief 
evidence for a glaciation of the North Island fails”. Asa matter 
of fact this great striated boulder was not discovered by me till 
1915,” or some five years after the close of the glaciation controversy 
between Dr. P. Marshall and myself.* Its existence was unknown 
in 1909. At that time I relied on other evidences of glaciation that 
Mr. Trechmann passes over with little or no comment. 

I will briefly summarize the other evidences. In 1909* I dis- 
covered at Turangarere, in the Hautapu Valley, a great tumbled pile 
of angular and semi-angular boulders of andesite that range in size 
from 1 to 6 feet in diameter; still greater piles and larger masses at 
Mataroa and Taihape, and a smaller pile at Utiku. These boulders 
are foreign to the Hautapu basin, which is composed of Pliocene 
marine Glays that are interbedded with a few thin beds of shelly 
limestone. The only possible source of these andesitic masses is the 
great volcano Ruapehu (9,000 feet), which is separated from the 
Hautapu Valley by the Wangaehu Valley and the Waiouru plateau- 
like ridge that forms the divide between the Wangaehu and the 
Hautapu Rivers. 

The present distribution of the andesitic piles would tend to show 
that, when originally deposited, they extended across the Hautapu 
Valley, and formed barriers that have since been breached by the 
Hautapu River. The smaller material was resorted during the 
process of excavation, and spread out as gravelly deposits along 
the present course of the river. 

In 1909 I postulated that the agent which transported the 
andesitic material across the Wangaehu Valley and the Waiouru 
divide, and deposited it in widely separated piles in the Hautapu 
Valley at distances ranging from 20 to 40 miles from its source, was 
a Pleistocene extension of the existing Ruapehu glacier. 

1 GEOL. MAG., Vol. IV, pp. 241-5, 1917. 
Trans. N.Z. Inst., N.S., vol. xlviii, pp. 1385-7, 1915. 
Trans. N.Z. Inst., vol. xlii, pp. 589-612, 1909. 
Trans. N.Z. Inst., vol. xl, pp. 575-80, 1909. 


= 0 


Prof. J. Park—Pleistocene Glaciation, New Zealand. 395 


In 1915,! near Mangaweka, on the west side of the Rangitikei 
River, a few miles below the junction of the Hautapu, and nine 
miles farther down than the lowest previously known pile of 
andesitic blocks, I discovered the solitary conspicuously striated 
andesitic boulder to which Mr. Trechmann refers. This block lies 
on the Rangitikei terrace at the foot of a ridge of Pliocene marine 
clays, 1,070 feet above sea-level. It measures about 14 X 6 X 55 
feet, and weighs over 37 tons. The underside and one end for a 
height of two feet are smoothed, rounded, and scored with innumer- 
able fine strie and hundreds of deep grooves, most of which run 
parallel with the longer axis of the block (see Pl. XIV, Fig. 2). The 
smoothed and striated surface has an area of some 90 square feet. 

Mr. Trechmann always refers to the markings as ‘‘scratches”’. 
He makes no reference to the deeper grooves which occur so plenti- 
fully. By this omission and the constant reference to scratches, 
he unconsciously conveys an erroneous impression as to the extent 
and nature of the markings. And this minatory impression is not 
diminished when he states that the surface of the boulder is much 
decomposed and weathered. As a matter of fact all andesites are | 
prone to weather rapidly ; andif the striae and grooves are Pleistocene, 
as I contend, the wonder is that weathering has permitted any trace 
of the striz to remain. In my opinion, the preservation of the 
markings is due to the protection afforded by the clays and soil on 
which the boulder rested, and in which the underside is still 
partially embedded. 

Mr. Trechmann says that the decomposed surface can almost be 
scratched with the finger-nail, and that scratches can easily be made 
on it with a knife blade. The ‘‘scratches’’ could, in his belief, 
easily have been made by the boulder moving downhill over 
gravelly soil or ofer other stones. According to this view the 
decomposition of the surface had already taken place before the 
boulder began its downhill movement. As this seems to be 
the essence of his contention, I have again examined the boulder and 
find that in all the deeper grooves the skin of decomposed rock 
conforms to the contour of the groove. Clearly the weathering 
took place after the grooves were formed, and not before, as 
Mr. Trechmann’s suggestion would seem to imply. 

The smoothing, scoring, and grooving of a rock mass by its down- 
ward movement under the influence of gravity is perhaps not 
accomplished with the ease assumed by Mr. Trechmann. There is 
no. evidence that the Mangaweka erratic does not now lie in the 
place where it was left by the agent which carried it from Ruapehu. 
The old flood-plain of the Rangitikei is about 250 feet above the river 
terrace on which the boulder lies. Even if we assume that the 
boulder did at one time lie on the surface of that old plain it will, 
I think, be difficult to prove that its downhill movement could 
produce the smoothing and grooving we now see on the under 
surface of the block. It seems to me that when the excavation of 
the old flood-plain reached the boulder one of two things would 


1 J: Park, Trans. N.Z. Inst., vol. xlviii, p. 136. 


396 P. rof. J. Park—Pleistocene Glaciation, New Zealand. 


happen. Hither the boulder would incontinently tumble down to 
_ the present level, or it would slide down if the slope of the terrace 
face exceeded the angle of rest. When a heavy body descends on 
a gravel face, the material in contact with the body moves downhill 
at the same time, and this flowage would not, in my belief, lend 
_ itself to the smoothing and grooving of the heavy body. 

The large size of this solitary erratic, its transportation across the 
Waiouru divide, its great distance from its source, its grooved and 
striated underside, and the existence of a considerable glacier on 
Mount Ruapehu, the place from which it originally came, have led 
me to the conclusion that it was carried to its present site by a 
Pleistocene extension of the Ruapehu Glacier that flowed down the 
Hautapu into the Rangitikei Valley. 

Further, I know of no agent but a glacier that could transport and 
pile up the tumbled masses of andesitic rock that occur at widely 
separated points of the Hautapu Valley. 

Turning to the South Island Mr. Trechmann deals mainly with the 
Taieri or Henley deposit. He says that in his opinion this drift is 
not glacial, and concludes that the glaciation was alpine and not of 
a regional type. This great deposit has been shown by the careful 
mapping of Mr. A. G. Macdonald, B.E., to extend from Saddle Hill, 
near Dunedin, to the Clutha Valley, a distance of some 32 miles. 
It occurs as a sheet on the west side of the coastal range that 
separates the Taier1 Valley from the sea. It rises from sea-level to 
a height of 1,000 feet, and in many places forms conspicuous cliffs. 
near the summit of the range. A distinctive feature is its proneness 
to form great landslides. Its thickness in the Taieri Gorge has been 
estimated at 1,500 feet, but this is probably an underestimate. The 
dip is to the westward at low angles. The lower portion is com- 
posed of rudely bedded angular fragments of mica-schist and an 
occasional large angular block of the same rock. The upper portion 
of the deposit Howe little sign of bedding, and generally the 
material is coarser and large angular blocks more plentiful than in 
the lower portion. 

As Mr. Macdonald’s maps! clearly show, this deposit near Dunedin 
rests on the Oamaruian (Miocene) Coal-measures, at the Taieri 
Gorge on Paleozoic mica-schist, at Milton on the Oamaruian Coal- 
measures, and further south on Kaitangatan (post-Senonian, probably 
Danian) Coal-measures. Although mainly composed of mica-schist 
blocks, slabs of limonitic penetra Tai: from the Oamaruian series. 
are not uncommon in the deposit on the range near Milton. The 
Taierl deposit was always considered by Mr. J. T. Thomson and 
Captain Hutton to be a glacial moraine, and Mr. McKay reported 
that it looked like a glacial deposit. I have described it as fluvio- 
glacial, and on no oceasion during the glacial discussion in 1909 did 
Dr. Marshall challenge its glacial origin. 

Mr. Trechmann states thet he was struck with the dissimilarity of 
this deposit to any glacial moraine that he had ever seen. ‘To this 
I would say that the rudely stratified fluvio-glacial drifts in the 


1 These manuscript maps are filed in Otago University. They were prepared 
in connexion with a research scholarship held by Macdonald. 


ie he 
i 
\ ; ; . M b, © 
: i ‘ vf K 4 
i 
% 4 
ck 
i H * 
i 
i { 
my » ) 
is Lan 
e ; : ne mn 4 
. 7] 
( 
i 


GEOL. Maa. 1918. PLATE XIV. 


> 


Fic. 1.—Great erratic of Andesite near Mangaweka, North Island, New Zealand. 
,, 2.—A portion of surface showing grooves and strie. 


Sur H. H. Howorth—Geological History of the Baltic. 397 


Cromwell and Manuherekia basins in Central Otago and the out- 
wash drifts at the end of the Tasman glacier present many features 
in common with the Taieri Moraine. 

He refers to the fault dislocations of the Blue Spur deposits; and 
expresses the opinion that they appear to be much earlier than the 
Pleistocene, but he gives no data in support of this view. | 

Mr. Trechmann says there is no evidence of transported erratics at 
the foot of the Otago Peninsula and Banks’ Peninsula. At the 
former I know of no erratics, but there are deposits near Dunedin 
that if not glacial are otherwise difficult to explain. I have never 
contended that an ice-sheet extended to the foot of Banks’ Peninsula, 
or even covered any portion of the Canterbury Plains. What I 
have postulated was that glaciers descended to the existing sea- 
strands where these strands coincided with the Pleistocene strands, 
as on the east coast of South Otago and in South Westland. The 
Pleistocene strand of South Canterbury followed the foot-hills that 
form the western boundary of the plains. At the maximum Pleisto- 
cene extension the Canterbury Plains were only in the early stage 
of formation. Perhaps the fault that I have been misquoted on this 
question lies at my own door. When discussing the Pleistocene 
extension of our glaciers I thought it would be self-evident that this 
glaciation could only refer to New Zealand as it existed in the 
Pleistocene. 

Reference is made by Mr. Trechmann to the freshness of the 
glacial phenomena in the Alpine regions of New Zealand. The 
glaciation there is that of to-day or yesterday. In my belief it 
would-be surprising to find the same freshness among the glacial 
phenomena developed during the Pleistocene extension of the 
glaciers. 

In conclusion, let me say that Mr. Trechmann was a most welcome 
visitor to the shores of New Zealand. His paleontological researches 
have thrown valuable light on some problems that long baffled New 
Zealand geologists; and for this reason I regret that I am unable to 
see eye to eye with him on the glaciation question. 


EXPLANATION OF PLATE XIV. 


Fic. 1.—Reproduction from a photograph of large Andesitic Boulder near 
Mangaweka in the Rangitikei Valley, New Zealand. Measures 14 x 6 x 
' 55 feet; weight over 37 tons. 
Fie. 2.—Portion of the surface of the same Boulder, showing grooves and 
striations. Reproduced by permission of the New Zealand Institute from 
the Trans. N.Z. Inst., vol. xlviii (N.S.), pp. 135-7, 1915. 


IIl1.—Tuer Recent Gerotoeicat History or tHe Barric anv Scanpi- 
NAVIA AND ITS IMPORTANCE IN THE Post-Trertrary History or 
Wesrern Evrorpn. 


By Sir Henry H. HowortH, K.C.1.E., F.R.S., F.S.A., F.G.S. 
(Continued from the August Number, p. 367.) 


E will now try and picture to ourselves how the circulation of 
the water was affected by the breach in the land bridge. 
We have seen in the earlier part of these papers that one of its effects 


398 Sir H. H. Howorth—Geological History of the Baltic. 


was that the southern and western part of the Baltic became 
rapidly richer in marine forms. ‘This is because the Straits between 
- Gjedserodde in the island of Falster and Darrserort on the mainland 
of Mecklenburg form a great barrier to the eastern migration of the 
marine mollusea, whose species increase greatly in numbers when we 
pass westward of them. This seems to again point to the fact that 
the inflow of salt waters into the Baltic from the North Sea passes 
chiefly through the deeper Belts and not through the shallower 
Sound, which is the chief outlet of the more brackish Baltic water. 
On the other hand, the Swedish side of the sea remains poor in fauna 
until we reach the latitude of the island of Saltholm, due partly to 
its greater shallowness, which only allows a smaller proportion of the 
incoming North Sea water to pass. Mr. Dickson, who has written 
a great deal on the coasts and currents of the latter sea, argues that, 
the rotation of the earth causes the outgoing water of the Baltic to 
cling to the Swedish side. It is, at all events, plain that the part 
of the Sound south of Saltholm is in its marine life to all intents 
and purposes a part of the Baltic. North of Saltholm, as Oersted 
has shown, the marine life becomes much richer. The wealtn of 
life, however, is limited to the deep water in the middle of the 
Sound, while the shallower water forming the littoral zone continues 
to be very poor on both sides as far as the exit of the Sound into the 
Cattegat. It seems plain that since the great submergence there has 
been a certain slight uplift of the land along the south coast of Skane 
and on both sides of the Sound; here again it is marked by a very 
poor and littoral fauna which has crept into the waterway from the 
Baltic. These later littoral beds lie on portions of sunken turf and 
other subaerial deposits. 

Let us now pass northwards into the Cattegat and compare the 
marine life of this Gulf with that of the Baltic. The contrast is 
graphically given in the following table which I take from Professor 
Brandt's memoir ‘‘ Die Fauna der Ostsee’’ (Verhand. Deutsch. Zool. 


Gesell., 1879, p. 10, etc.). 
Centraland Eastern Gulf of 


Cattegat. Kiel Gulf. Baltic. Bothnia. 
Fishes : : se 75 40 230 5 
Ascidia . ; 20 BY as ia 
Mollusea . : 88 23 6 4 
Prosobranchia_ . 85 ibe 3 1 
Opisthobranchia — 23 2 — 
Decapoda . : 55 Sey 2 (1) 
Amphipoda Ave SLs} 18 11 5 
Isopoda . : 41 7 7 3 
Cirripedia . : == 3 il 1 
Cheetopoda SoD 3 o) 1 
Bryozoa . : 65 17 1 1 
Echinodermata . 36 6 (2) - 
Actinozoa . : 16 4 a = 
Acalepha . : = 2 2 = 
Hydrozoa . é 48 15 1 
Spongia . : 26 13 — = 


We will now turn to the more detailed features of the Cattegat. 
It is divided very distinctly into two sections marked by their 
respective contents. The line between the two runs through the 


(Sioa va id a i Howorth—Geological History of the Baltic. 399 


island of Laesd, which, as I showed in a former paper, is surrounded 
by a shallow sea bottom and is covered with the debris of a 
littoral fauna; and which it is generally thought was at a not 
distant date joined to the mainland of Jutland. At all events it is 
plain that we have in this southern section of the Cattegat a very 
distinct marine sub-province which ought to be united, not with the 
northern section, but with the Sound, and is marked notably by the 
presence of a considerable number of shells which are absent in 
the northern section. 
The following shells are absentees there :— 


GASTEROPODA. 9. Trophon truncatus. 
1. Aclis ascarus. 10. Fusus (Neptunea) antiquus. 
Petersen, however, thinks the 11. Scutellina fulva, vulgar. 
dead shells so named found by Cattegat. 
Collin at Hellebach may be Aclis 12. Chiton albus. 
supranitida, which occurs in both Apparently only in the S. of 
lists, see pp. 71 and 80. Cattegat Sound. 
2. Parthenia spiralis. 
Also found in the Limfiord, ib., LAMELLIBRANCHIA. 
75. 1. Mytilus phaseolinus. 
3. P. wmterstincta. A new shell in 8. of the Cattegat 
Also found in the Limfiord, ib. only, and not found N. of Laesé. 
4. Odostomia acuta. 2. Cardium fascratum. 
Subfossil in the Virk Sound. Not found N. of Laeso. 
5. O. unidentata. 3. Astarte borealis. 
Also fossil in the Limfiord. In the W. Baltic and S. Cattegat ; 
6. Triforis perversa. dead specimens W. of Laesé. 


S.E. and S.W. of Laeso. 
7.. Natica islandica. 
8. Velitina levigata. 


A. compressa or sulcata. 
Cyprina islandica. 


Ot He 


The presence of those shells in the south, but not in the north, of 
the Cattegat I would explain as probably due to the erratic history 
of the great Danish gulf known as the Limfjord, which virtually 
separates Jutland from Wendsyssel and which discharges itself into 
the Southern Cattegat, of which it forms a kind of gulf. 

Through the Limfjord the Cattegat has had an intermittent com- 
munication with the NorthSea. Its eastern opening into the Cattegat 
has always been open, but its western one into the North Sea has at 
times been for a considerable period silted up and closed by a 
cul-de-sac, as I mentioned in a previous paper (Grov. Mae., Dec. Wis 
Vol. II, p. 11). The continual breaking down in the eighteenth and 
nineteenth centuries of the narrow isthmus separating the Limfjord 
from the North Sea occasionally flooded its western part with salt 
water from the latter sea, thus raising its salinity to 18 per thousand. 
This led to the importation there of a considerable number of North 
Sea fish and of certain molluscs lke the oyster, Zapes pudlastra, and 
the typical form of Cardiuwm exiguum, which does not live in the 
eastern part of the fjord. 

Morlot says the Canal of Agger by which the Limfjord entered the 
North Sea had become so narrow that only small vessels could pass, 
and it threatened to close altogether in 1859. 

It is not impossible that a number of the shells occurring in the 
Southern Cattegat and not in the Northern may have entered it from 


400 Sir H. H. Howorth—Geological History of the Baltic. 


the North Sea by way of the Limfjord during one of the intervals 
when it was open at both ends. Others may have been brought in 
accidentally by ships or otherwise. 

So much for the absentees from the northern section. On the 
other hand, the latter contains a considerable number of shells not in 
the southern part. 

On comparing Petersen’s lists of the shells from the two sections 
of the Cattegat I find the following absentees from the southern 
area :— 


GASTEROPODA. LAMELLIBRANCHIA. 
1. Scalaria tortosa. 1. Pecten maximus. 
2. S. Trevellyana. 2. Mytilus Adriaticus. 
3. S. lactea. 3. Modiolaria discors. 
4. Volvula acuminata. 4. Nucula decussata. 
5. Philine pruinosa. 5. Cardwum Norwegicum. 
6. Acera bullata. 6. C. nodosum. 
7. Lacuna pallidula. 7. C. edule. 
8. L. dwaricata. 8. Lucinopsis undatum. 
9. L. membranacea. 9. Isocardia cor. 
10. L. meonspicua. 10. Venus fasciata. 
Il. L. parva. 11. Dosinia exoleta. 
12. Natica Montagu. 12. Tellina pusilla. 
13. Capulus Hungaricus. 13. 7. tenwwis. 
14. Fusus propinquus. 14. Solen ensis. 


. Mactra stultorum. 

. Thracia convexa. 

17. Trochus nuliigranus. . Cochlodesma (Triforis?) perversa. 
18. Nacella pellucida. . Lyonsia Norvegica. 

19. Dentaliwm (Antalis) entale. 19. Neera cuspidata. 

20. Chiton ruber. 


lt is plain that while the southern section of the Cattegat ought 
zoologically to be joined with the Sound, the northern part ought to 
be united with the Skagerack and the Christiania Fjord. 

The reasons for the disparity in the contents of the two sections of 
the Cattegat is probably the absence of the necessary quantity of salt 
in the waters of the southern section. It may be also due partly to 
the fact that the waters of the latter are not deep enough, the 
greater part of it being in fact much shallower than the northern 
part. Let us now return to the raised beaches of the Cattegat. In 
them there is a marked contrast between their contents and the 
living fauna of the great waterway. 

I will now giye a list of the shells which have occurred in the 
raised beaches fan kitchen-middens. Those which are rare and only 
occur occasionally are marked with an asterisk. 


pp 
ON 


ee 
DIRE’ 


15. Mangelia costata. 
16. M. nebula. 


GASTEROPODA. Cerithiwm reticulatum. 
*Odostonvia sp. *Utriculus truncatulus. 
*Triforis perversa. * Neritina fluviatilis. 

Litorina rudis. * Rissoa striata. 
L. obtusata. R. membranacea. 
LL. litorea. Acera bullata. 


I. var. tenebrosa. 


Hydrobia sp. LAMELLIBRANCHIA. 
Lacuna inconspicua. Ostrea edulis. 
*L. diwaricata. Mytilus edulis. 


Nassa reticulata. Cardium exiguum. 


Sir H. H. Howorth—Geological H iney of the Baltic. 401 


Cardivum edule. ; Mellana (Macoma) Balthica. 

Cardium var. *Corbula gibba. 

Tapes pullastra. * Modiolaria discors. 

T. aureus. Montacuta bidentata. 
*T’..decussatus. Scrobicularia piperata. 


This list differs from that given by Petersen in excluding Anomia 
sgquamula and in retaining the name Scrobicularia piperata which he 
called S. plana. It is perfectly plain that it only represents a 
portion of the mollusca which were contained in the Southern 
Cattegat when the raised beaches were deposited. Here the beaches’ 
are all at a very low level; they form, in fact, the concluding factors 
of a series which occur at declining levels as we proceed southwards, 
but were doubtless deposited synchronously at different points on the 
coast from the Christiania Fjord to the Oresund, and represent only 
the littoral series. It is, in fact, interesting to compare a small section 
of the Gulf, namely, the Holbeck Fjord, where the following shells 
are now living which have not occurred in the raised beds. 


Buccinum undatum. Mactra subtruncata. 
Tectura testudinalis. Thracia papyracea. 
Abra alba. Saxicava rugosa. 

A. nitida. Mya truncata. 
Solen pellucida. M. arenaria. 


What is much more important and interesting is the absence from 
the present waters of the Southern Cattegat of a number of shells 
with a wide distribution which abound in the raised beaches and 
also in the kitchen-middens of that channel. I have described at 
some length the remarkable consequences which have been deduced 
from this absence in previous papers (Geox. Mag., 1905, pp. 12-15, 
557-9). The general conclusion of the arguments of Petersen and 
others is that the extermination or emigration of these molluscs was 
due to the Baltic breach which flooded the Cattegat with an excess 
of fresh water, and that this was coincident with the end of the 
kitchen-midden people. It enables us to roughly date that event at 
some eight or nine thousand years ago. The only fresh fact I need 
mention is the addition of Pholas candidus to the list of migrants. 
It is not now found nearer than the south of Norway. 

By far the most interesting of these absentees are the oyster and 
the three species of Zapes. Petersen named the beds in which he 
found this series of shells Zapes beds, and he proceeded to argue that 
when they were deposited the waters of the Southern Cattegat were 
not only salter but probably also warmer than they are now, and 
approximated more to those of the Skagerack than the North Sea. 

In regard to the connexion of the Baltic with the Cattegat, it is 
interesting that while the oyster has never occurred in the Litorina 
deposits in the Sound, it has occurred in the deposits of the Great 
Belt probably as far south as the Svendborg district (Aard. for Nord. 
Oldk. Hist., p. 321, Copenhagen, 1888), showing that before the 
Baltic breach the Belt was open from the north as far at least as the 
latter place. 

Morlot’s observations made long ago prove that the ‘“ kitchen- 
middens’’ in many cases show signs of stratification and of having 

DECADE VI.—VOL. V.—NO. IX. 26 


402 Sir H. H. Howorth—Geological History of the Baltic. 


been temporarily submerged. The kitchen-middens are ordinarily 
3 to 5 feet, but in some places, as at Meilgard to Kolindsund, they 
are 10 feet above the sea-level. Sometimes they are 1,000 feet long, 
with a breadth of 150 to 200 feet. In the latter cases their surface 
is undulating and often surrounds a depression free from them, as at. 
Haveln, near Frederiksund, where the habitations of the natives 
probably were. Their interiors in most cases are unstratified. 
Others found on the shore and near the waves are covered with 
sand and gravel, and the whole of their contents is more or less 
stratified, as at Biledt near Frederiksund. It is clear that in such 
cases the old mariners cooked their food on the shore after dis- 
embarking, and the tide has afterwards rearranged them. 
Morlot again called attention to the curious circumstance that 
the kitchen-middens, the greater portion of whose contents are 
stratified, yet consist of a heterogeneous mass of shells and other 
debris deposited out of the reach of the waves, and sometimes have 
a covering of rolled and stratified materials. This is only found up 
to.a height of 14 to 18 feet above the sea-level, and always on the 
slope facing the sea. At Oesterild in North Jutland this covering 
attains a depth of a foot, and contains pebbles as big as the eggs of 
a goose. Above the covering there is nothing. He concludes thus: 
‘‘T] parait donc, que l’Age des Mjoekkenmoedding a été clos par 
quelque catastrophe, qui a violemment agité les eaux de la mer, 
laquelle a fait alors irruption jusqu’a une hauteur peu considerable 
au dela de son domaine habituel. Ilse pourrait, que cet événement 
eat eu lieu a une époque quelconque postérieure a la fin de l’age des 
Kjoekkenmoedding. Cependant M. Steenstrup est disposé a le 
considérer comme marquant le terme méme de cet age.’’! 
Steenstrup also argued from another side that some uplift of the 
coast had taken place since the deposit of the kitchen-middens, and 
has shown that where the shores are low and shelving the midden 
mounds occur at only a few feet above high tide mark, but they 
reach a somewhat higher level when the coast is more abrupt. This 
distribution of the kitchen-middens seems to show that the land has 
not as a whole risen or sunk very much since they were deposited, 
for they are not likely to have been deposited either very far from 
the sea or at a great level above it. So much for the kitchen- 
middens. Turning to the raised beaches containing the same 
characteristic shells as the middens, namely, the Zapes beds, they 
are found on each side of the Cattegat, both in Jutland and on the 
Swedish side. They increase in number as we go northwards, 
although of the same age. Large numbers of dead shells of the 
Tapes also occur on the floor of the Southern Cattegat. In the upper 
part of the Cattegat north of the island of Laeso we meet with a much 
more abundant living marine fauna, which closely approximates to 
that of the Skagerack and the Christiania Fjord, due doubtless to the 
greater depth and salinity of its waters. In one respect in which 
this approximation takes place there is no relationship whatever 
between the two sections of the Cattegat, and the difference is 


1 Morlot, ‘‘ Etudes Géologico-Archéologiques en Danemark et in Suisse’’: 
Bull. Soc. Vaudoise, Sci. Nat., vi, No. 46, pp. 275-6, 1860. 


Sir H. H. Howorth—Geological History of the Baltic. 403 


fundamental and much more important. ‘This consists in the 
presence in the northern part of a series of raised beaches of an 
entirely separate class and which have not appeared in these papers 
before. They are the so-called Yoldia beds. ‘hese beds have been 
much misunderstood. I shall postpone their consideration for the 
present and will now limit myself to the other class, namely, the 
Tapes beds, which occur here associated with a much richer fauna 
than they do in the southern part of the Cattegat. The greater 
richness in forms of these more northern beds must not allow us, 
however, to disguise the fact that they are otherwise quite continuous 
with the Zapes beds further south, and are earmarked by the 
presence of the same critical species. 

In regard to the mollusca found in these Zapes beds of the northern 
Cattegat, a long list has been given by Erdmann, who says they do 
not occur there at a higher level than 100 to 150 feet, and are for 
the most part of littoral species. They are found in deposits of the 
so-called black clay (svartlera), in raised beaches and sometimes 
capping some of the @sar as in Eastern Sweden, but contain a much 
richer number of species and were clearly deposited under conditions 
of greater saltness in the water than those further south. 

Erdmann, in his account of the Quaternary deposits of Sweden, 
gives the following list of the shells found in the black clays :— 


GASTEROPODA. 


Litorina litorea. 

L. rudis. 

L. littoralis. 

Trochus cinerarius. 

T. tunidus. 

Natica nitida. 

N. Montagu. 

N. clausa. 

N. Groenlandica. 

NV. pulchella. 

N. borealis. 
Emarginula reticulata. 
Lacuna vineta. 

L. pallidula. 
Turritella communis. 
Cerithuum reticulatum. 
C. adversum. 
Odostomia rissoides. 
Purpura lapillus. 
Nassa reticulata. 

N. incrassata. 

N. pygmea. 
Aporrhais pes-pelicant. 
Buccinum undatum. 
Fusus undatus. 

F’. despectus. 


Trophon clathratus,var. minor. 


Mangelia linearis. 
Rissoa ebriata. 

R. labiosa. 

R. ulve. 

A. parva. 

R. wstrea. 


R. arctica. 

Patella vulgata. 
Acme@a virginea. 
Lepeta cocca. 
Pallidum rubellum. 
Dentalium (Antalis) entale. 
Puncturella Noacina. 
Peliscus commodys. 
Philine quadrata. 
Tornatella tornatilis. 
Cylichna cylindracea. 
C. truncata. 


LAMELLIBRANCHIA. 


Mytilus edulis. 
Mya truncata. 
Modiola modiolus. 
Solen ensis. 
Cyprina islandica. 
Nucula nucleus. 
Leda pernula. 

DL. caudata. 
Cardium edule. 

C. echinatum. 

C. fasciatum. 

C. Norvegicum. 
Lucina borealis. 
Montacuta bidentata. 
Isocardia cor. 
Pecten islandicus. 
P. maximus. 

P. septemradiatus. 
P. striatus. 

P. pusio. 


404 Sir H. H. Howorth—Geological History of the Baltic. 


Pecten varius. 
Sawicava rugosa: 
S. arctica. 
Tellina proxima. 
T. solidula. 

T. fibula. 
Syndosmya alba. 
S. intermedia. 
S. mtida. 
Astarte arctica. 
A. elliptica. 


Cochlodesma pretenue. 
Tapes pullastra. 

Venus striatula. 

V. ovata. 
Scrobicularia piperata. 
Ostrea edulis. 

Anomia patellaformis. 
A. aculeatum. 

A. ephippium. - 


Rhynchonella psittacea. 


A. sulcata. 


A. compressa. Echinus droebackiensis. 
Thracia villosiuscula. 

Mactra subtruncata. Balanus porcatus. 

M. elliptica. B. crenatus. 


See GEOL. MaG., 1897, pp. 355, 361; 1898, pp. 195, 257; 1905, 
pp. 407, 454. : 


Others who have devoted some time to the exploration of the later 
geology of Western Sweden have described the shell beds on its 
shores, which point the same moral as those of Denmark, namely, 
their occurrence at a gradualiy increased elevation as we proceed 
northwards. In Southern Bohuslan Olbers found the shell beds at 
a height of 15 metres. At Stromstad De Geer found them at a height 
of 40 metres, while at Bullaresjon, on the Norwegian frontier, 
Olbers again records having found them at 48 metres high (Nathorst, 
Sverige Geol., p. 275). (See Olbers, Bidrag till Goteborgs och Bohuslans 
geologt, Stockholm, 1870; see also on Halland, G.F.F., 1875.) 

Olbers separates the deposits into two series: one of them he calls 
Cardium lera, characterized by Cardium edule and C. echinatum, 
Cyprina islandica, and Turritella communis, while the other, which he 
calls Ostrea lera, and which he considers to be the younger, is 
marked by the presence of Ostrea edulis, with Patella, Cerithium, 
Rissoa, etc. There are, however, local variations, due not to 
difference of age, but of the level at which they lived, and the 
differing habitat. 

North of Bohuslan we reach the Gotha, a famous river, the gateway 
of a very interesting portion of Sweden, and specially noteworthy in 
view of the issues we are discussing. In an earlier page we had 
a good deal to say of the collapse that occurred in the lowest part of 
the synclinal depressions through which the Forchhammer line runs. 
We have now reached the part of Sweden through which another 
line and focus of movement runs, namely, the highest part of the 
anticlinal, and therefore also a district in which the tension must 
have been extreme and the likelihood of great dislocation very great. 
The Gotha River, in fact, leads us into a part of Sweden where the 
proofs of this are written on all sides. The Gotha itself now flows 
through the most tremendous gorges in Europe, the famous 
Trollhatten falls, which must have been caused by great breakages. 
They have all the appearance of being very recent and do not 
represent in any way the original drainage channel of the river. 
One fact suggesting a catastrophic cause for them is notable. The 
salmon which inhabit the great lakes which the Gotha drains must 


Sur H. H. Howorth—Geological History of the Baltic. 405 


once have had access to the sea at certain seasons, as is the case with 
these fish elsewhere. It is now imprisoned in the lakes all the year 
round. ‘his is no doubt due to the cutting off of its waterway 
thither by the dislocations I have mentioned, which are thus proved 
to have been sudden and paroxysmal. The gorge is closely associated 
with the numerous raised beaches in the district, both on the coast 
and inland, and which are at an abnormal height. There is no other 
explanation of the presence of the raised shell beds here, but the 
bodily and violent uplifting of the rocks on which they lie to the 
height of several hundreds of feet. This is shown by a remarkable 
and well-known fact. 

When Lyell examined the surface of the gneiss at Capellbacken 
immediately above the shell beds he found barnacles (Balan) 
adhering to it, showing the sea had remained there a long time 
and then been suddenly uplifted, for the barnacles (Balanz) do not 
occur at lower levels here. Lyell says he was able to verify this 
observation by finding in the summer of 1834 at Kured, about two 
miles north of Uddevalla and about 100 feet above the sea, a surface 
of gneiss newly laid open by the removal of a mass of shells used 
largely for making lime, etc., with the barnacles (Balani) so firmly 
adhering to the gneiss that he was able to break off pieces of the 
latter with the shells attached. The face of the gneiss was also 
covered with Bryozoa. Other beds with the same shells occur near 
Uddevalla, others again on the opposite island of Orust, as well as in 
that at ‘I’jorn and at points on the coast still further sonth (Principles 
of Geology, ii, 192). 

While this is the evidence-of the barnacles (Balan) in regard to 
the uplift of the rocks themselves, the evidence of the shells in the 
raised beaches is also most impressive. I have spent a considerable 
time among them on the spot and I have never seen anything like 
them. The number of different species coming from several zones of 
very different depths is phenomenal. Gwyn Jeffreys collected eighty- 
three species. ‘They occur here in immense masses which have been 
largely quarried, not mixed with sand and clay, but for the most 
part washed clean; quite different, therefore, from any deposits in 
the beaches to be found on ordinary shores. 

They are also very perfect and quite unweathered. I havea large 
collection of them, exceedingly few of which are broken, and there 
are a great many very fragile and tender shells such as big specimens 
of Pholas, with their internal hooks quite intact, among them. 
Attempts have been made to sort them out into different zones by 
Gwyn Jeffreys, but they have signally failed, as Brogger allows. 
If they were the current “deposits of different periods they would not 
le as they do in juxtaposition. The only solution of their condition 
and position is that they were collected by some great tidal wave 
from a sea bottom of varying depth. These shells are also of the 
most recent types, and except one or two insignificant varieties all 
are living in the adjoining seas. ‘lo my own eye nothing | have 
seen of the kind presents more complete evidence of the solid: arity of 
the beds in regard to the time and method of deposit. May I add 
that the fact of the Balani remaining attached to the polished 


406 Sir H. H. H oworth—CGeological History of the Baltic. 


rocks, and as fresh under their covering of shells as if recently dead, 
and showing no signs of weathering, absolutely proves to me that 
they were not exposed to the weather during a gentle or long- 
enduring elevation, but were lifted up suddenly by one impulse 
with the rocks to which they are attached and at once covered by 
the protecting shell beds to the height of 200 feet above sea-level 
or more. They attest most completely the cataclysm which 
must have occurred when the great Swedish anticlinal was lifted 
bodily up. 

Several of the great Scandinavian rivers, says NReclus, have 
changed their courses. There wasa time when the River Foenmund, 
now draining southward to the Cattegat through the River Klar, 
drained through the Dalelf south-east to the Gulf of Bothnia. The 
old bed of the river is still visible four or five feet above the present 
lake. The Gotha was recompensed by receiving from another source 
all the waters of the Glommen, so that its volume was more than 
doubled. 

The extent of country, too, where the shells have been found at 
high levels in Central Sweden is very great; they have been found in 
Jemteland, West Gothland, and Dalsland, while on the heights 
commanding the Lakes Wener, Wettern, and Mjosen, and the Malar 
Sea great beds of oysters occur, showing how much of the high land 
there has been submerged. These great lakes have clearly been 
lately united and formed a great gulf which was in fact an extension 
of the Cattegat. This was clearly seen and stated long ago by Lyell. 

In his Bakerian Lecture, printed in the Philosophical Transactions 
for 1835, Lyell said it is evident from the position of the fossil 
shells of several species on the coast of the Baltic between Gefle and 
Sodertelje, and on the shores of the ocean between Uddevalla and 
Gothenburg, that the tract of land which once separated the two 
seas in this region was much narrower at a comparatively modern 
period. Shells like those at Uddevalla have not only been found 
a few miles due east of that place, but as far inland as Trollhatten, 
in digging the canal there, and still further in the interior, about 
fifty miles from the coast at Tuscdalersbacken and other places near 
Rogvarpen in Dalsland on the west side of Lake Wener. Of these 
matters an account is given by Hisinger (Anteckningen, iv, 42). 
They are found in Dalsland as far above the sea as near Uddevalla, 
or about 200 feet high, so that when deposited we must suppose the 
whole of Lake Wener, the surface of which lies at an inferior level, to 
have formed part of the ocean. 

Another evidence of the extent of dislocation will be referred to 
presently when we discuss the so-called Yoldia sea and the distribu- 
tion of that much misunderstood and very important shell in the 
district we are considering, where it has been found at great heights 
and yet must have lived at very great depths. 

The contours and great depths of the Swedish lakes and their 
abnormal living contents also go to show that quite recently 
geologically they have been united and that they have been subject 
to disruptive movements. Although their surface is above the level 
of the sea the beds of most of them are much below that of the Baltic 


Sir H. H. Howorth—Geological History of the Baltic. 407 


Wener has a mean elevation of 144 feet, while its extreme depth is 
290 feet; Wettern is twice the altitude of Wener and is also deeper, 
measuring 417 feet in depth and being 126 feet below that of the 
adjoining sea. The Mjosen Lake, which is 197 square miles in 
extent, has an extreme depth of 1,480 feet with an altitude of 397. 

The curious fish and crustaceans contained in these lakes have 
been accepted as relics of former conditions when they formed part 
of the gulf already mentioned and when it was occupied by salt 
water, and they have since adapted themselves to freshwater con- 
ditions. The Norwegian lake of Mjésen, although it is so fardistant 
from Lakes Wener and Wettern, also contains one of these relics in 
the form of DMysis relicta. 

The evidence therefore abounds that in that part of Sweden 
where the upheaval has been the greatest there are the most potent 
proofs that it culminated in great changes of the earth’s crust on 
a mighty scale at a very recent period. This must, it is clear, be 
taken into account as a postulate when we are analysing the later 
geological history of the country. It seems to me also that sub- 
sidiary evidence of these fractures and breaks is to be found.in the 
utterly smashed condition of the Silurian beds in the upper parts of 
the Baltic region, the broken and angular debris of which have been so 
widely scattered, and also the existence of so many beds of quite sharp- 
edged unaltered stones, the equivalents of the angular drift of the 
English southern coast lands, which it would seem impossible to 
account for except as the result of enormous impacts caused by 
spasmodic movements. 

Let us now proceed further north. We have reached the frontier 
separating Sweden and Norway. The political frontier- position 
corresponds to no definite physical one. There is complete 
continuity in the geology across the political ‘‘divide”’ so far as it 
relates to the latest period. The raised beaches are clearly con- 
temporary in the coast-lands of Bohuslan and Central Sweden and 
those of the great inland bight or gulf formed by the Skagerack on 
the west and the Cattezat on the east, with the projecting pocket 
known as the Christiania Fjord. In both cases we have two 
definitely separated sets of raised beaches, one containing only a 
highly Arctic fauna and existing for the most part at a low level and 
the other characterized by the same fauna as still lives in the bight 
and for the most part at high levels. The details of the phenomena 
have been set out in an excellent and portly volume by Dr. Brogger 
on The Raised Beaches of the Christiania Hyord, to which I am greatly 
indebted. 

Before dealing with these details, however, I propose to say a few 
words in regard to the more general question in which Norway as 
a whole has the same story to tell as Sweden. 

The first point in which they agree is that both contain the 
strongest evidence that the land has been quiescent for many 
centuries. In a notable paper by Hansen, the latest authority on 
the subject in Norway, he first calls attention to the divergent 
opinions of older inquirers in both countries on the matter, and points 
out the uncertainty in obtaining fixed elements to enable the problem 


408 Sir H. H. Howorth—Geological History of the Baltic. 


to be definitely solved, namely, the variation of the barometric 
pressure, the height of the Atlantic tide, and the potency of the wind. 
_ These make it difficult to fix any norm or index by which to 
measure permanent changes of level, and he turns his inquiries from 
the physical data to archeological evidence as affording a more 
satisfactory result inasmuch as it enables us to cover a much longer 
period of observation. 

From the close of the Bronze or beginning of the early Iron Age, 
we have cairns very near the present beach, and from the later Iron 
Age we have also other fixed relics along the coast, which are now 
quite as near the sea-level as it is possible for them to be. From 
these it must be concluded, says our author, ‘‘that the sea-level has 
not been subjected to any permanent secular change on the 
Norwegian coast in the last millennium, very likely not in the last 
two thousand years”’ (op. cit., p.110). Some critical examples may 
be quoted in support of this generalization: Everest, in his travels 
in Norway, informs us that the Island of Munkolm, an insulated 
rock in the harbour of Trondhjem, proves that the land there has not 
altered in level for eight centuries. The island is not larger than 
a small village. By an official survey the highest point is only 
23 feet above river high-water mark, and a monastery was founded 
there by Canute the First in a.p. 1028, and thirty-eight years before - 
that it was used as.a place for execution (Lyell, Principles, 1i,. 
p. 195, 1875). 

In regard to the rate of the rise, Hansen again says: ‘‘ The 
present shore-line in Norway is of considerable age. It is impossible 
to believe that the present clearly defined, strongly developed beach 
extending from high to low water has been formed under any 
(however slow) secular shifting of the sea-level. The rocks 
immediately above show in some places the work of the breakers, 
which cannot be observed higher up, and the surface-profile in loose 
material does not answer at all to a regular rise of the land” 
(ibid., pp. 110-11). It is plain, therefore, that the raised beaches 
of Norway, as of Sweden and Britain, point to the jand having been 
long quiescent, while they index a period when the earth was 
subjected to great movements, which nevertheless were contemporary 
with the present marine fauna in the North Sea. These movements 
virtually ceased hundreds of years ago. In Norway, as in Sweden, 
therefore, we have the same kind of evidence that the uplift has not 
been continuous but spasmodic, which is again revealed by insulated 
raised beaches separated by stretches void of such testimony. They 
occur at different levels in different places, but as far as we know 
synchronous. The culminating point of the raised beaches with 
shells on the west of Norway is in the Trondhjem Fjord, where they 
reach to a height of 600 feet. There, as in Sweden, they descend in 
level both as we travel northward and southward. Von Buch, in the 
Breistad Fjord, some distance north of Trondhjem, found marine 
shells 140 feet above the sea-level (Reisen, pp. 1-251). M. Eugene 
Robert describes how, in the Island of Ham between North Cape and 
Hammerfest, he had found a great alluvial deposit running with 
a gentle slope to a height of more than 101:7 feet, and showing 


F, W. Harmer—Position of the Coralline Crag. 409 


seven stages or terraces faintly marked, formed of marine pebbles 
placed one behind another and separated by turfy soil. The whole 
of this system, he says, rests upon a thick layer of the debris of 
shells, among which we perceive fragments of Cyprina islandica and 
other molluses, identical with those now living in the Polar ocean. 
It is the same with regard to the Island of Qualse, and we have 
there an additional curious point, namely, his discovery in a depression 
behind the gate of the town of Hammerfest, and at a height of about 
82 feet above the sea a number of erratics, the interstices between 
which are filled with small pieces of blackish pumice-stone, similar 
to those which continue to be thrown ashore from time to time, even 
in the present day, on the coast of Norway, along with floating 
wood, whose origin is evidently to be assigned to the volcanic 
eruptions of Iceland, or of that of Jan Mayen (Chambers, Sea 
Margins, pp. 286-7). 

Bravais (‘‘ Former Sea-level in Finmark”: Q.J.G.S., i, p. 544, 
1845) points out how in Finmark the shell beds occur at a much 
lower level than further south. At Talvig, by digging about half 
_ a metre below the surface in a sheltered part df the bay, he laid 
open a clayey bank containing Mya truncata and Tellina Balthica, 
some of the specimens being remarkably fresh and even showing 
vestiges of the epidermis. This bed was 7 metres only above the 
sea-level and appeared identical with one described by M. Keilhau. 
‘7 have likewise,” he says, ‘‘received other shells (Patella and 
Venus) collected near Storvig, at the western extremity of the Island 
of Sorde, in a sandy deposit a few metres above the level of the sea. 
The elevation in this case was about 30 metres.” 

A similar drop in the shelly beaches has been noticed in pro- 
ceeding southwards from Trondhjem, showing that the movement of 
the land in Western Norway (as in Sweden) has been differential, 
with a culminating point at Trondhjem. ~ 


(To be concluded in our next Number.) 


TV.—Tue SrratigrRaPHicaL Posirion oF THE CoraLLINE Crag. 
By F..W. HAaRMER, F.R. Met. Soc., F.G.S. 


N an interesting paper lately published’ my friend Mae Be 
Newton has expressed the opinion that the Coralline Crag 
should be grouped with the Diestien and Anversien of Belgium as 
Upper Miocene, the fauna of the Suffolk boxstones being regarded by 
him as Middle Mageene. The recent researches of Mr. Miteed Bell? 
have led me to agree with Mr. Newton that the latter is pre-Pliocene, 
but I regret I cannot accept his view as to the age of the Coralline 
Crag, which I consider to be more nearly related to the Waltonian 
horizon of the Red Crag than to the Belgian Miocene. 
In the introduction to my Memoir on the Pliocene Mollusca of 
Great Britain, now in course of publication (pt. i, p. 5), I proposed 


1 Journ. of Conch., vol. xv, p. 115, 1915. 
2 GEOL. MAG., Dec. VI, Vol. IV, 1 AO AALS WOMENS 195 LG), JA UO. 
Figs. 3, 4, 1918. 


410 F. W. Harmer—Position of the Coralline Crag. 


the following classification of the various divisions of the Anglo- 
Belgian deposits, to which, with the exception of the point alluded 
to above, I still adhere: — 


Uprer PLIocENeE. 


Belgium and Holland. England. 
Amstelien. Butleyan and Newbournian. 
Poederlien Wenleoek ( Walton horizon. 

Scaldisien a aaa { Oakley horizon. 
Casterlien (zone a Jsocardia cor). Coralline Crag. 


Lower Prrocene. 
Diestien (zone a Terebratula grandis). Lenham Bed. 


In his synoptical list of 18741 Wood reported 430 species of 
Mollusca as known to him from the Coralline Crag; of these only 
about 90 had been found at that time at Walton, but even then 
he had come to the conclusion that there was a close connexion 
between the two deposits and that his original reference of the 
former to the Miocene had been a mistake. 

The investigations of Professor Kendall and the late R. G. Bell at 
Walton and my own at Little Oakley have strongly supported 
Wood’s later opinion. Of the 430 Coralline Crag species referred to, 
about 270 are now known from the Waltonian or some later horizon, 
while hardly any of the remainder can be considered common or 
representative Coralline Crag forms. To regard a species of which 
only one or at the most a very few specimens have been obtained 
during ‘the labours of a century as of equivalent value, for purposes 
of analysis, to others of which a large number could be found at any 
time in a few days, is misleading. It is by the general facies of 
a fauna—by the abundant and not by the rare examples—that we 
should be guided. 

While, therefore, nearly all the characteristic Coralline Crag 
species continued to exist in the Anglo-Belgian basin during 
Waltonian times, or even to a later period, no such correspondence 
can be traced between its fauna and that of the Belgian Miocene, 
zones & Panopea Menardi and Pectunculus pilosus of Van den Broeck 
(Anversien, Newton). Out of 230 species of mollusca reported 
from the latter horizon by the former observer, only 106 are known 
from the Coralline Crag, the rest being generally and distinctly of an 
older type.” 

The true Belgian equivalent of the Coralline Crag is the zone a 
Isocardia cor, the fauna of the two being practically identical. Of 
about 150 species given by M. Van der Broeck? or M. Bernays * from 
the latter (for which I have revived the name of Casterlien), all but 
about half a dozen have been obtained from the Coralline or the 
Waltonian Crags. The Casterlien, moreover, bears a relation to the 


' Mon. Crag Moll., 1st Suppl., pt. ii, p. 203, 1874. 

2 Ann. Soc. malac. Belg., vol. ix, pp. 118, 134, 1874. 

3 Op. cit., p. 187; Bull. Soc. Belge Géol., vol. vi (Mém., pp. 120, 130, 
1892). 

* Bull. Soc. Belge Géol., vol. x (Mém., p. 128, 1896). 


F. W. Harmer—Position of the Coralline Orag. 411 


Scaldisien of Belgium similar to that between the Coralline and 
Waltonian Crags. A reference to lists of fossils from all these 
beds shows that the connexion between the Coralline—Casterlien and 
the Waltonian—Scaldisien deposits is as clearly marked as is the 
difference between the former group and the Anversien (Miocene) of 
Belgium. 

In a well-known work the late Mr. C. Reid identified the Lower 
Red Crag with the Astian and the Coralline with the Plaisancian of 
Piedmont, placing the one in the Upper, the other in the Lower 
Pliocene.’ In the light of our present knowledge I cannot see any 
sufficient reason for such a division of these East Anglian beds, all of 
which I continue to regard as Upper Pliocene. The introduction to 
the Anglo-Belgian basin of some northern mollusca during the 
Waltonian period while many southern and Coralline Crag species 
continued to linger on was due, I think, to the tectonic movement 
described in one of my former papers, by which the Crag sea was . 
brought then and for the first time under the influence of marine 
currents from the north.’ 

I agree with Mr. Newton that the Lenham fauna is older than 
that of the Coralline Crag, though I don’t think that anyone who 
has a working knowledge of the subject could regard the list of 
Lenham fossils given by him or the specimens on his plates as a typical 
collection of Coralline Crag fossils. I hesitate, however, to regard 
them as Miocene. Stratigraphically they are connected with the 
sands of Louvain and Diest (zone of Zerebratula grandis) by a remark- 
able series of isolated remnants of that deposit (as shown on the 
annexed-map, copied from one of M. Rutot’s), which form a curved 
line, extending roughly from west to east, through Folkestone, 
Calais, Cassell, Tournai, Grammont, and Brussels. 


ANTWERP 


Leniiarg, 


o 


‘olkestone 
Cala; Oe 
BRUSSELS, Louvain 
(3) 
22) 
as Grammont 
Tournar 


Sketch-map showing the connexion between the Lenham Bed and the Diestien 
sands of Louvain and Diest (after Rutot). 


The Diestien sands have been always regarded as Pliocene by 
Belgian geologists. Until now I have never heard it suggested that 
they are Miocene, but if the stratigraphical evidence is of any value 
and the Diestien beds are Pliocene, the Lenham Bed must be Pliocene 
also, though Lower and not Upper Pliocene as is, I submit, the 
Coralline — Casterlien group. They contain some characteristic 
Miocene or Lower Pliocene species unknown from the Coralline 
Crag, but they contain also a considerable proportion of a more recent 


Pliocene Deposits of Great Britain, 1890, pt. i, p. 5. 
“ Quart. Journ. Geol. Soc., vol. lii, p. 761, fig. iv, 1896. 


412 Herbert A. Baker—Denudation of the Chalk. 


character which it seems to me would be out of place in a typical 
Miocene deposit. 

Leaving on one side the northern species which appear to have 
been more or less suddenly introduced into the Crag basin under the 
influence of the tectonic depression alluded to, and counting 
specimens rather than species, there is a general resemblance 
between the fauna of the Coralline Crag and that of Walton which 
does not exist between those of the former and of Lenham. For 
zoological as well as for stratigraphical reasons J draw the line 
separating the Lower and the Upper Pliocene divisions of the East 
Anglian deposits between the Coralline Crag and the Lenham beds 
rather than between the former and the Waltonian. 

I agree to some extent with Mr. Newton as to the age of the block 
of fossiliferous limestone described by him in 1917.1 From a very 
superficial examination I formed a strong impression that it was 
-pre-Pliocene, but I cannot admit, on the other hand, that it has 
anything to do with the Coralline Crag. It reminded me of some 
fossiliferous blocks which some years ago Mr. Van Watenschoot van 
der Gracht informed me were occasionally dredged in the North Sea. 
He seemed at that time to be under the impression that they were of 
Oligocene age.? I believe a collection of fossils had been made from 
them which « were then at The Hague. Hereafter it may be possible 
to compare these Dutch specimens with those identified by 
Mr. Newton. It seems not unlikely, moreover, that the latter may 
be of a similar character to those found by Mr. "Norregaard in some 
erratic boulders of Middle Miocene age obtained from a glacial clay 
near Esbjerg,® but this could be probably ascertained without much 
difficulty. 

Although I do not agree with the classification adopted by 
Mr. Newton, I welcome his recent papers as calling attention to an 
important series of deposits in which formerly much interest was 
taken, but of late years have been almost entirely neglected. 


V.—On Svccussive Stages IN THE DENUDATION OF THE CHALK IN 
East ANGLIA. 


By HERBERT ARTHUR BAKER, B.Sc., F.G.S. 


Nee ve attempt by the writer‘ to utilize the information at 
aE present available with a view to gaining some notion of the 
dominant characteristics of the denudation suffered by the Chalk of 
the London Basin prior to the deposition of the Eocenes yielded 
results of sufficient interest to encourage him to apply the same 
method of analysis to the East Anglian area. 

Sufficient data for the construction of a provisional map showing 
the isopachyte system of the Chalk of this area lie to our hand, 


1 Quart. Journ. Geol. Soc., vol. lxxii, p. 7, 1917. 

2 T understand that there is some difference of opinion among Continental 
geologists as to the correct division between the Oligocene and Miocene of 
Northern Europe. 

3 Danm. Geol. Undersdgelse [4], No. 5, p. 58, pls. i-iii, 1916. 

4 Baker, GEou. MaG., July, 1918, pp. 296-305. 


in Hast Anglia. 413: 


although, so far as the writer is aware, there is as yet no map giving 
direct information concerning the variation in thickness of the 
formation. 

We are in possession of a certain amount of information, from 
deep wells and borings, concerning the level of the base of the Chalk 
at various points throughout the area. While wishing that this 
information were more abundant we need not be deterred from 
proceeding with the investigation. Committing our data to paper 
and considering the items of information correlatively, we find that 
the base of the Chalk appears to slope away in a general east-north- 
easterly direction with remarkable uniformity, dropping at the rate 
of about 24 feet to the mile, throughout the whole of the eastern 
portion of the area. Further west the contours take on a slight 
sinuosity, assume a more or less north and south direction, and 
become somewhat more closely spaced, indicating an increase in the 
gradient. Since in the construction of this map we are able to use 
the information supplied by only about half a dozen levels, it follows 
that in our use of it we must not expect a greater degree of accuracy 
than it is capable of yielding. But our confidence in the utility of 
the map for the purpose which follows is maintained when we 
observe that it so happens that the available levels are well 
distributed, and further, that the contours over a great part of the 
area are practically straight lines. 

Haying represented cartographically our information concerning 
the level of the base of the Chalk, we next require a similar 
representation of our knowledge of the present level of its surface, 
and this we find to our hand. The Chalk-surface contours of this 
area have been mapped by Professor P. G. H. Boswell,’ and we are 
able to avail ourselves of the results of his labours. If the base of 
the Chalk were ‘‘ corrected’ in such a way as to cause it to occupy 
a horizontal plane at sea-level, and the Chalk surface were modified 
correspondingly, then lines joining points at which the surface of 
the Chalk is at the same height above the base of the formation 
would constitute the isopachyte system which we seek. We therefore 
superimpose the Chalk-surface map upon that showing the level of 
the base of the formation. At points where the contours intersect, 
the amount of correction necessary to bring the base of the Chalk to 
sea-level is indicated by the one map, and the appropriate correction 
is applied to the other. The completed series of lines thus obtained 
constitutes our provisional idea of the variations in thickness of the 
Chalk in Kast Anglia, and is shown in the map here presented. The 
sources of error are manifold, but every incorporated item of 
additional information will bring the-final result nearer to the 
truth—and however inaccurate the present map, it at least provides 
us with a notion of the general character of the isopachyté system of 
the East Anghan Chalk which we could never have conjured up had 
the attempt not been made—and, further, by its aid certain salient 
characteristics of the denudation undergone by this Chalk area jump 
at once before the eye. 


1 Boswell, Q.J.G.S., vol. Ixxi, pl. 1. 


— 414 Herbert A. Baker—Denudation of the Chalk 


In our study of the map it is helpful to bear one consideration in 
mind. It is a fair assumption to make that, at the beginning of 
Eocene times and again at the beginning of Pliocene times, the base 
of the Chalk in this area did not deviate markedly from horizontality. 
Consequently the lines upon our map give, for the area where the 
Chalk is yet covered by Eocene, a generalized representation of the 
pre-Eocene contours of the Chalk surface, and for the area where 
the Chalk is covered by Crag, the pre-Pliocene contours. For that 


Miles Meas Gis Oras i aaa 
i — o— Boundary o Eocene 


~ —— + — Boundary of Crag 
Bt Zonal boundaries} 


emnitella \ \ ucronata 


IS IK 


LOWER & MIDDLE CHALK 


Map showing Chalk surface contours in the East Anglian area, when the base 
of the Chalk is corrected to horizontality at sea-level. The lines also 
serve as the isopachytes of the Chalk. 


area where the Chalk is bare the lines serve to indicate the stage to 
which its denudation has proceeded at the present day. 

With regard to the pre-Kocene Chalk-surface contours, the most 
outstanding features are that there appears to be a drop from the 
figure of 1,350 feet at Happisburgh down to 1,000 feet at Aldeburgh, 
and the prevailing direction of the lines is N.E.-S.W. There can be 
very Itttle doubt but that we have here the last remaining evidence 


wm East Anglia. 415 


of the escarpment which in pre-Thanetian times faced south-east- 
ward and stretched away many miles to the west and south. Between 
Yarmouth and Aldeburgh there appears to be evidence of a drop to 
the eastward, which is most clearly shown between Beccles and 
Lowestoft, but we are hardly in a position to place much confidence 
in any explanation put forward concerning this interesting and 
somewhat unexpected feature. The writer thinks it not unlikely 
that, along a N.W.-S.E. line traversing the central part of the 
Norfolk area, there was, during the deposition of the Chalk, a definite 
movement of depression, whereby a greater thickness of sediment 
was deposited vertically above this line than was laid down farther 
east. If this was the case, the severity of the denudation suffered 
by the Chalk in, the central portion of the area is still further 
emphasized. 

The evidence of an advancement in the stage to which the 
denudation of the Chalk proceeded during post-Eocene and pre- 
Pliocene (i.e. Miocene) times, is very striking. The earth-move- 
ments which were in operation in Miocene times, governing the 
general character of the denudation, were, in this area, different in 
their direction from those whose activity resulted in the production 
of the old E.N.E.-W.S.W. pre-Eocene escarpment. A movement of 
uplift along an axis traversing the central part of Norfolk, and 
disposed in a general N.W.-S.E. direction, appears to have taken 
place, and denudation proceeded in such a way as to produce an 
escarpment facing west and making a pronounced feature in the 
landscape. A strong valley was eroded in the Chalk in pre-Pliocene 
times, but we are not in a position to state the age of the abrading 
stream with any precision. It may have been initiated in pre-Kocene 
times and perhaps entered the area at a spot somewhere between 
Happisburgh and Yarmouth. On the supervention of the new 
movement of uplift fresh river-systems were initiated, which are 
those of the present day, and one stream, the Waveney, throughout 
a part of its course, actually occupies the site of the old valley, thus 
providing us with an interesting illustration of reversal of drainage. 
The severity of this post-Eocene and pre-Pliocene denudation of the 
Chalk is well brought out by the map. Where the isopachytes 
emerge from beneath the Hocene cover they change direction most 
abruptly and exhibit a very pronounced tendency towards parallelism 
in a general N.W.-S.E. direction. A considerable thickness of chalk 
must have been removed from the exposed portions of the formation 
during this time, particularly in the northern part of the area. 
With the advent of Crag times a further portion of the chalk surface 
was covered, and that part which is yet concealed beneath the Crag 
has, of course, escaped all post-Pliocene denudation. This post- 
Pliocene denudation has effected the removal of much of the Crag 
cover and carried the attrition of the chalk beneath it to a still more 
advanced stage. 

In addition to bringing out the interesting points already 
considered, our map is of service in enabling us to insert the 
boundaries of the outcrops of the successive zones of the Chalk, 
for unless the zones vary in thickness throughout the area, the 


416, Reviews—The.Palceeontographical Society. 


outcrops of the successive boundaries will be in parallelism with 
the lines on the map. ‘To take the case of the small area where 
the Chalk surface is composed of the Ostrea lunata zone, Professor 
Boswell has estimated! the maximum thickness of this zone before 
it is overlain by Eocene deposits to be between 70 and 80 feet. © 
Consequently, on our map, the boundary between this zone and that 
of Belemnitella mucronata will occupy a position between the 1,250 
and 1,300 lines. Similarly, adopting Professor Boswell’s estimate of 
240 feet as the thickness of the B. mucronata zone at the point 
where the Eocene comes on, this will bring the position of its lower 
boundary on our map between the 1,000 ‘and 1,050 lines. In the 
same way, assuming the estimated thickness of about 135 feet for 
the Actinocamax quadratus zone, its lower boundary will coincide 
roughly with our 900 line; that of the MJarsupites zone, if its 
thickness is between 60 and 70 feet, as Professor Boswell estimates, 
will occur somewhat to the east of our 800 line; and that of the 
Micraster coranguinum zone, if its thickness is 210 feet, will occur 
a little to the east of our 600 line. The insertion of these zonal 
boundary-lines on the map brings out well the unconformities 
between the Kocene and Chalk and Pliocene and Chalk respectively, 
but particularly that of the former, since the Eocene is seen 
transgressing from Ostrea lunata Chalk in the north, across 
B. mucronata Chalk, on to A. guadratus Chalk in the south. 

Immediately to the south of the area under present discussion there 
occurs a notable disturbance of the Chalk, but the consideration of 
this feature lies outside the scope of the present brief paper. 


REV LTEws. 


oor me 
J.—TuHe ParaonroGRaAPHICAL Socrery. 


fF\HIS Society has just issued, for 1916, its Senemuen volume 
(dated February, 1918), containine :— 


1. Tue Weatprn anp Porseck Fisues. Part II. By 
Dr. A. 8S. Woopwarp, F.R.S. pp. 49, with 10 plates. and 
14 text-figures. 

2. Tus Prrocere Mozzvsca. Part III. By F. W. Harmer, 
F.G.8., ete. pp. 159, with 12 plates. 

3. Tae Patmozorc Asrerozoa. Part III. By W. K. Sprenczr, 
M.A., F.G.S. pp. 5Y, with 8 plates and 48 text-figures. 

4, Brirish Grapronites. Part XI. By Miss Exues, Sce.D., 
and Miss Woop (Mrs. SHaxssprar), D.Sc. Edited by Professor 
Larwortn, LL.D., F.R.S. pp. 60, with title-page and index. 

The volume before us, literally produced ‘amidst war’s alarms” 
~ (for the premises of Messrs. Adlard & Son, the printers, were upon 
one occasion bombed by an enemy aeroplane), displays neither in the 
quantity of its contributions nor their quality in authorship, illustra- 
tions, printed matter, or paper any deterioration as compared with 


1 Boswell, ‘‘ Notes on the Chalk of Suffolk’’: Journ. Ipswich and District 
Field Club, vol. iv, pp. 17-26, 1913. 


Reviews — The Paleontographical Socrety. 417 


the long series of seventy volumes with which it now takes an 
honourable place. Nor has the modest annual subscription of 
one guinea been increased, notwithstanding the advanced price in 
printing paper and illustrations and labour prevailing since the War. 

In his monograph on the Wealden and Purbeck Fishes (part i1) 
Dr. Arthur Smith Woodward gives an admirable series (pl. xi) of 
the remarkable rows of small enamelled round, crushing, palatal 
teeth in Lepidotus Mantella (one of the most characteristic of 
Wealden fishes), showing the mammaliform apices and successional 
teeth in sockets; also the large flank bony-enamelled scales (square 
or rhomboidal in form), fixed in place and pegged down by. bony 
processes like the slates upon a house-roof (described in parti, 1915). 
The genus J/fesodon of Middle Purbeck age from Swanage, etc., with 
its allied genera Homesodon (Lias and Portlandian), Mvcrodon(Purbeck), 
aud Celodus (Lower Cretaceous and Purbeck), introduces us to 
a singularly interesting series of Pyenodont fishes with flattened 
sides more or less covered by enamelled rhomboidal scales with 
small protruding, often beak-like, mouths and crushing teeth well 
adapted to feed upon coral-zoophytes, crustacea, and molluscs. 
This group of Mesozoic fishes is remarkably well preserved in the 
lithographic rocks of Solenhofen, the Purbeck of England, and down 
to the Lias, and without imaginary evolution the author is able to 
give us on p. 49 an actual picture of Mesodon macropterus, as seen in 
life, correct in every anatomical detail. There are numerous other 
valuable text-figures, as well as ten plates drawn by Gertrude M. 
Woodward, which add much to the interest of this important 
monograph. 

The third instalment of Mr. Harmer’s fine monograph of Pliocene 
Mollusca maintains the high standard of the earlier parts, both in 
the careful preparation of the author’s text and the very excellent 
quality of the collotype plates executed by Mr. J.Green. Mr. Harmer 
has been at infinite pains to trace the past history of each species 
with its geological and geographical distribution and the collections 
in which specimens are preserved, and in case of survivals their 
present habitats. Many forms also are now figured and described 
which occur in widely varied British and foreign localities, far 
beyond Kast Anglia, which region gave birth to the parent 
Crag monograph by S. V. Wood half a century or more ago. 

In Mr. W. K. Spencer’s monograph on the Paleozoic Asterozoa 
much attention is given by the author to the anatomical details of 
structure upon which their zoological arrangement depends; indeed, 
the external forms as shown in six out of the eight plates would 
hardly suffice without the explanatory structural figures given in the 
forty-eight text-illustrations and the anatomical details so carefully 
delineated on pls. vii and vili (some of those on the plates being 
perhaps needlessly large for the purpose of study, e.g. fig. 2, pl. vil, 
and figs. 1, 2,and 7 on pl. viii). On the other hand, such a beautiful 
form as Lepidaster Grayt (fig. 1, pl. vii) might well have been more 
enlarged to show its details to advantage. 

We congratulate the Misses Elles and Wood (Mrs. Shakespear) 
and Professor Lapworth on the completion of their elaborate 

DECADE VI.—VOL. V.—NO. IX. 27 


418 Reviews—Mineral Resources of Great Britain. 


monograph on British Graptolites. Part i was commenced in 1901, 
and now by the issue of part xi, containing title-page and index and 
23 pages of ‘‘ Historical Research”’, their labour, extending over 
fifteen years, is happily completed. We heartily rejoice with 
the threefold authors in the consummation of their most difficult. 
task. Of the usefulness of such a great work we prophesy future 
generations of students of paleontology will arise to bless the authors, 
and also to support the Society as subscribers. Many too, we trust, 
will likewise be found to add some good work to further the object of 
the founders of the Society, namely, ‘‘to figure and describe every 
species of British fossil.” 


If.—Memorrs or THE GroLogicaL SuRVEY. 


SpectaL Reports oN tHE MinERaL Resources or Great Brirarn. 
Vol. VI: Refractory Materials: Ganister and Silica-Rock—Sand 
for open-hearth Steel Furnaces—Dolomite—Resources and 
Geology. pp. vi-+ 233, with three maps. London: T. Fisher 
Unwin. 1918. Price 7s. 6d. net.. 

le this, the sixth volume of the reports on the mineral resources of 
Great Britain, we have the first part of what promises to be 

a comprehensive account of refractory materials. ‘The greater part. 

of the memoir is occupied by the descriptions of the raw materials. 

used in silica-brick manufacture. These comprise various rock- 
types, including quartzite, siliceous sandstone, ‘‘ Dinas rock,’’ 

““oanister,’’ ‘‘ crowstone,” etc., and in a somewhat similar fashion 

the manufactured materials are classified as silica-, ganister-, and 

Dinas-bricks. Unfortunately, such words as ‘‘ganister’’? and 

‘‘crowstone’’ are miners’ terms, and, owing to their use being local, 

their exact significance is not well defined. The word ‘‘ ganister ”’ 

originally applied to the silica-rock on a particular horizon in the 

Lower Coal-measures of the Sheffield district, has never been 

satisfactorily defined, and it is doubtful whether the definition given 

in the memoir settles the question. 

It is impossible to use as the main criterion the geological horizon, 
as not only does the rock vary in different areas but rocks practically 
indistinguishable from it are found on other horizons in other 
localities. The rock must be defined in terms of its petrographical 
characteristics, but in order that such definition be generally 
adopted, it must contain references to those properties which 
determine the utility of the rock as raw material for silica-bricks.. 
The Geological Survey definition is practically a petrographical 
description of the typical Sheffield rock, but little attempt is made 
to take into account the latter consideration. There is no doubt. 
that the chemical composition, size and shape of the quartz-grains 
and the amount and nature of the impurities are of great importance 
so far as the refractory properties are concerned, but the distribution 
of these impurities and the nature of the thin layers between the 
grains must also be considered, owing to their probable action as 
accelerators of the inversion of the quartz to the high temperature 
forms, cristobalite and tridymite. Owing to the great expansion 


Reviews—Mineral Resources of Great Britain. 419 


during these inversions, the best rock, other things being equal, is 
that in which as much of the quartz as possible can be transformed 
during manufacture and which therefore will show the smailest 
after-expansion in use. It is improbable that a really satisfactory 
definition will be obtained until more is known concerning the 
petrological properties which determine the usability of the rock. 

In the introductory chapter an account of the manufacture of 
silica-bricks is given, and this, considering its condensed nature, 
is satisfactory except with regard to the temperatures to which the 
bricks are fired. It is stated, for example, that in North Wales 
these range from cone 16 to cone 29, but these figures are much 
higher than those attained in general practice. It is very doubtful 
whether first-grade silica-bricks are ever fired in this country at 
temperatures above cone 16, and this can be verified by a comparison 
of British and American bricks. The latter are rarely fired above 
cone 17 or 18, and, even taking into account the more prolonged 
firing, the much smaller proportion of unconverted quartz which 
they contain, in comparison with the former, can only be explained 
by the lower temperature to which the British bricks have been 
subjected during firing. 

The major portion of the memoir is taken up by an account, with 
details of the occurrence, methods of working, reserves, etc., of the 
mines and quarries in ‘which siliceous rocks are obtained, short 
petrographical descriptions of the rocks being appended. The 
qualitative nature of the latter militates against the utility of the 
results. It is greatly to be regretted that practically no chemical 
details are given and also that the refractory tests mentioned in the 
preface as having been carried out are deferred, apparently to a later . 
volume. ‘These data would have been much more useful if they had 
appeared with the descriptive part. The latter seems to be fairly 
accurate and detailed so far as the materials already being worked 
are concerned, but the information regarding untouched English 
sources is very meagre, though there is a chapter on ‘‘ potential” 
Scottish supplies. 

In a chapter devoted to an account of the sand and clay pockets 
of the Peak District, the geological age of the deposits is given as 
possibly ‘‘ post-Triassic and pre-Glacial’’, while in a table earlier in 
the volume they are characterized as ‘‘ post-Glacial”’.. As a matter 
of fact, the post-Triassic age of some of these deposits cannot be 
regarded as definitely proved. 

‘The remainder of the volume describes the British deposits of 
sand suitable for open-hearth steel furnaces, and of dolomite for 
lining converters, the beds of open-hearth furnaces, etc. In con- 
nexion with the paragraph on the decalcification of dolomite, some 
recent work on the Grenville (Quebec) deposits may be noticed. 
Where the material is a mixture of magnesite and dolomite, it is 
possible to increase the proportion of magnesia by ‘‘slaking” the 
calcined minerals, but it has not been found possible to vary the 
proportions of lime and magnesia by this method in dolomite alone. 

The editing of the collected information has, as usual, been well 
done, though a few misprints occur: for example, the spelling 


420  Reviews—Coal Area, British Columbia, 


“ Keeleshall’’ should refer to the Staffordshire place of that name, 
the Sheffield place being usually ‘‘Ecclesall’’. Even when the 
increased costs. of publication are considered, the price seems 
somewhat higher than necessary. 


ee 


I1I.—Grotoey or a Porrron or THE FLATHEAD Coat AREA, Bririso 
Corumsra. By J. D. Macxenzin. Geological Survey of Canada, 
Memoir 87, 1916. pp. ii + 58, with 1 plate and 2 maps. 

fJ\HIS coalfield lies on the western side of the Flathead Walleye 

a little over 2 miles north of the 49th parallel, and 35 miles 
by road from Corbin Station, on the C.P.R., the nearest railway 
station in Canada, ‘The Flathead Valley runs ‘north and south, and 
is a rift faulted in between the Clarke and Macdonald ranges of the 

Rocky Mountains. The coal area, which is about 43 miles long by 

33 miles wide, is let down into the western side of the valley by two 

parallel normal faults striking N.W.-S.E. 

This district includes rocks from Devono-Carboniferous to Upper 
Cretaceous, all of which lie on one another in apparent conformity, 
a few Eocene lacustrine deposits and moraines and glacial drift. 

The coal-bearing formation is the Kootenay, of Lower Cretaceous 
age. This consists of about 1,100 feet of grey and brown sandstones 
and shales, which contain 80 feet of coal. The productive measures 
are all situated in the lower 400 feet of the series and contain five 
seams which are respectively 4, 7, 8, 25, and 36 feet thick. From 
the included fossils and the character and distribution of the rocks it 
is inferred that the Kootenay Series was laid down in a string of 
lakes or swamps along the main axis of the Rocky Mountain Chain. 
The coal is bituminous and soft, but on the whole of good quality, 
though the full thickness of the seams is not workable in all cases. 
The mines are still in the prospecting stage, but the conditions and 
quality are such that mining will be profitable as soon as railway 
transport is provided. In addition to the coal some thin lignite 
seams occur in the Tertiary beds, but these are not of any value. 
Also globules of bitumen have been noticed in the finer-grained 
calcareous beds of the Tertiary formation, which are supposed to 
indicate the presence of petroleum. Some prospecting has been 
carried out in these rocks, but no oil has yet been found. 


We Eeewe 


ITV.—Reports on cerrain MrNeRAts USED IN THE ARTS AND INDUSTRIES: 
Grapuitr. By P. A. Wagener. South African Journal of 
Industries, February, 1918. 

(JVHIS paper contains a good account of the properties and uses of 

graphite, with a detailed description of the South African 
sources of supply. Although these are not very large, they are at 
present supplying a considerable part of the local demand. The 
only locality actually being exploited is situated in the eastern 
portion of the Zoutpansbere district of the Transvaal. Here the 
mineral occurs as a lens lying between pyroxenite and quartzite. 

Samples assayed from 50 to 90 per cent of carbon, and several 


Reviews—<Asbestos. | 421 


different grades are now on the market. Several other occurrences 
are known in the Transvaal and Natal, but they do not seem to be of 
much commercial importance. 


V.—Assestos. By P. A. Waener. South African Journal of 
Industries, November, 1917. 
‘OUR principal varieties of asbestos are recognized, namely, 
chrysotile-asbestos, tremolite-asbestos, crocidotile-asbestos, and 
iron-amphibole. All of these occur in South Africa, the first in 
Rhodesia, the second in Zululand, the third in Griqualand West, 
and the last in the Transvaal. The reserves of chrysotile-asbestos in 
Rhodesia and of crocidolite in Griqualand West are enormous, and 
there seems to be every prospect of an important and flourishing 
industry in the near future, likely to compete with Canada as the 
world’s greatest producer. 


Vi.—Tur Zones oF tHE Karroo System AND THEIR DIsTRIBUTION. 
By eae ie Due Lom Procs (Geolt) Socs South) Airica:) 1918; 
pp. Xvll-xxxvi, with a map. 

OR the subject of his presidential address to the Geological 
Society of South Africa Dr. du Toit chose the general characters 

and distribution of the rocks of the Karroo System. Sufficient work 
has now been accomplished to allow of a discussion of the correlation 
of the subdivisions of the system in different parts of the Union. 

An important conclusion has been reached in the establishment of 

a stratigraphical break between the Dwyka and Ecca Series, 

beginning~ somewhere between East London and Pondoland and 

increasing in importance towards the north-east; this accounts for 
certain anomalies seen in Natal and the Transvaal, where there is no 
equivalent of the Upper Dwyka shales of the Cape Province. 

Paleontological study now tends to show that the Dwyka Series is 

of Upper Carboniferous age, while the Ecca and Lower Beaufort 

Beds are Permian, the Upper Beaufort, Molteno, and Red Beds are 

Trias, while the uppermost volcanics may possibly be Rhetic. The 

author is to be congratulated on an excellent summary of a large 


subject. 
Tiseelalg dts 


RHPORTS AND PROCHEHDINGS.- 
———~<__—- 


Gronocisrs’ AssocraTION. 


1. June 7, 1918.—J. F. N. Green, B.A., F.G.S., President, in the 
Chair. 

The following paper was read :— 

“The Skiddaw Granite: a Structural Study.” By J. Frederick 
N. Green, B.A., F.G.S. 

The problem of the age of the Skiddaw Granite can only be 
attacked by structural methods. The distribution of cleav age in the 
aureole points to pressure later than the intrusion. The Mosedale 
fault, which brings unaltered parts of the Carrick Fell complex 
against garnet-cordierite-hornfelses of the inner aureole, is of the 


492 Correspondence—H. A. Baker. 


type connected with the Devonian movements, and gives no 
indication of entering the Carboniferous. Microscopic examination 
of contact-altered rock suggests that the cleavage is later than the 
recrystallization. Thus the granite is older than the chief move- 
ments (Devonian). It is associated with an anticline demonstrably 
pre-Bala, running oblique to the Devonian folding, and is therefore 
probably itself pre-Bala and of the same age as the surrounding 
intrusions which belong to the Borrowdale suite. 

The following lecture was delivered :-— 

‘“« Diagrams illustrating the Significance of Rock Analyses.” By 
John William Evans, D.Sc., LL.B., F.G-.S. 

The diagrams are of two kinds: (1) Individual rock diagrams 
intended to indicate at a glance the significance of the analyses of 
a rock or complex mineral silicate; (2) Linear rock diagrams. The 
different types of linear or variation diagrams, in which the chemical 
constituents of different rocks are represented by vertical distances, 
were reviewed and a new type proposed in which each rock is 
represented by two diagrams: (a) alumina diagram, (6) silica 
diagram. 

In describing these diagrams, the lecturer discussed various 
problems connected with the genesis and composition of igneous 
rocks. 


2. July 5, 1918.—J. F. N. Green, B.A., F.G.S., President, in the 
Chair. 

The following lecture was delivered :— 

‘A Visit to Christmas Island and the Cocos-Keeling Islands.” 
By C. W. Andrews, D.Sc., F.R.S., F.G.S. 

The structure and physical geography of Christmas Island (Indian 
Ocean), a raised coral island, was described and compared with 
those of the Cocos-Keeling Islands, a typical atoll. Some account 
of the fauna and flora of Christmas Island was given, with special 
reference to the means of colonization of oceanic islands. 

The lecture was illustrated by lantern slides. 


CORREBSPON DANCE. 


THE PRE-THANETIAN EROSION OF THE CHALK. 

Sir,—I should like to express to Mr. C. N. Bromehead my 
erateful thanks for his criticism of my paper on the Pre-Thanetian 
Erosion of the Chalk of the London Basin. I am afraid I must 
plead guilty to the charge of not having made use of all the evidence 
available, in ignorance as I was of the appearance of the Geological 
Survey Memoir on Zhe Geology of Windsor and Chertsey. This 
memoir has, I suppose, been published since the outbreak of war 
and I have been continuously on active service, first flying in 
France and later serving afloat, since 1915. In any geological work 
with which I endeavour to beguile the tedium of life afloat I am 
greatly handicapped by being unable to make references to authorities, 
or even to consult earlier work of my own. The paper under present 
discussion was simply the outcome of an attempt on my part to apply 
cartographic methods to the data in my possession bearing upon the 


Correspondence—H. A. Baker. 423 


question at issue. The results seemed to me interesting and worthy 
of print. Yet while being the first to admit the scantiness of my 
data, I cannot bring myself to agree with a policy which refrains 
from any kind of cartographical expression until ample data have 
accumulated. Comparative treatment and correlation of items of 
information in ways such as I have adopted, as well as being the 
strictly scientific method of procedure, is that which puts each item 
to its maximum of utility. I am convinced that field-geologists 
would often save themselves much haphazard wandering if they 
made greater use of cartographical methods beforehand. It is true 
that very limited data produce very generalized results, but the 
method works out its own salvation in the long run, and the results 
then achieved are unattainable in any other way. It is very faint 
praise to say that ‘‘ when the amount of evidence available is larger, 
the method may be of some value’. Had I been in the more 
fortunate position of Mr. Bromehead, I should long ago have given 
cartographical expression to my data. The result would have been 
«a map full of imperfections, and doubtless in places at variance with 
field observations. Yet the steady incorporation of each fresh item 
of information would bring that map nearer and nearer to perfection 
and more and more in agreement with field observations. 

Much as [ should like to, I am unable, at the moment of writing, 
to discuss in any detail with Mr. Bromehead the other points which 
he raises. He remarks that ‘‘it seems natural to ascertain as far as 
possible the zone of the Chalk immediately underlying the Tertiary 
at the boundary of the latter, and to check the zones whose presence 
beneath -the Tertiary is deduced from borings by these facts”. 
I take it, then, that if Mr. Bromehead observed the Marsupites zone 
(say) immediately underlying the Tertiary at the boundary of the 
latter, he would naturally expect to find the same zone beneath the 
Tertiary cover. This seems to me a wilful ignoring of the teachings 
of tectonics, and since we already know that a strong unconformity 
exists between the Tertiaries and the Chalk, a most unsound view 
to take. 

With regard to the ‘‘series of gentle folds whose axes run about 
E. 15°S.”, referred to by Mr. Bromehead, I spent considerable time in 
1913 studying these as well as evidences of disturbances of quite 
different relationship. A fact which made a profound impression 
upon me was that whereas in the Isle of Wight the Upper Chalk is 
1,200 feet thick, in Dorset 1,000 feet, in Berks 800 feet, and in 
Norfolk 1,000 feet, yet in the London Basin, beneath the Tertiary 
cover, it is often less (and in places considerably less) than 300 feet. 
In view of this and many other facts, I concluded that while the 
evidence of a system of approximately east and west folds, including 
those referred to by Mr. Bromehead, was indisputable, yet this 
folding did not take the place of premier importance in determining 
the character of the denudation undergone by successive members of 
the Mesozoics, including the Chalk. The interesting items of field 
observation cited by Mr. Bromehead support his tentative suggestion 
of a set of approximately east and west folds in the Beaconsfield— 
Winkfield area, and it should be borne in mind that these 


4.24, Correspondence—J. A. Bartrum. 


undulations must affect the level of the base of the Chalk, and in 
constructing my map showing levels in the base of the Chalk I was 
without adequate data concerning these anomalous levels in this 
particular area. With the incorporation of a sufficiency of data in 
the maps the final result would agree with field observations—and 
while the data accumulate a ay map is better than no map. 

i HH. A. Baker. 


AFLOAT, 
H.M.S. ‘‘ CARYSFORT ’’. 
July 25, 1918. 


NOTES AND QUERIES FROM NEW ZEALAND. 

Sir,—I am forwarding two photographs in which perchance some 
of your readers may be interested. One represents the common 
rhombohedral multiple twin of calcite, seen on a weathered surface 
of the mineral, and the other an unknown fossil. [| We omit the 
description of the photographs, which is appended to the figures given 
below.—Ep. Grot. Mac.] 

I have discarded all thought of inorganic origin for the “‘ fossil” 
on account of the great regularity and the successive layers shown, 
but can offer no convincing suggestion as to the actual nature, and 
shall be grateful for any information thereon. 

Joun A. Barrrum (Lecturer in Geology). 

UNIVERSITY COLLEGE, 

AUCKLAND, NEW ZEALAND. 
May 6, 1918. 

Having referred Mr. Bartrum’s photographs to our colleagues 
Dr. G. F. H. Smith and Dr. F. A. Bather, of the British Museum 
(Natural History), Cromwell Road, we have been favoured with the 
following remarks thereon.—Ep. Grou. Mace. 


Fie. 1: Cancrre Creavacr.—This shows clearly the crossing lamelle 
seen on a weathered surface of a specimen of twinned calcite from 
Port Waikato, New Zealand. The lamelle are usually rendered 
conspicuous owing to readier solution along the composition planes, 
but occasionally it appears as if there has been differential solution 
‘of the opposed sets of twin-lamella.—G. F. H. S. 


bo 
Ot 


—Correspondence—J. A. Bartrum. A 


‘Fie. 2: Crustacean Tracks 1n New Zeatanp TeErrraRies.— 
This photograph, of natural size, depicts a portion of a large slab of 
soft sandstone recently exposed in strata of Middle Tertiary age 
along Beach Road, Auckland, New Zealand. The surface is covered 
with feather-like or fern-like markings which represent casts formed 
in the tracks left by some creature. The track (not the cast) consists 
of a median groove from which leaf-like imprints are given off on each 
side. ‘The groove, which has a semicircular section, is about 5 mm. 
wide and pursues a gently sinuous course. Each appendage is about 
138mm. long, has a curved free margin, the curve having a radius of 
about 19mm., and is overlapped by the corresponding margin of the 
adjacent imprint at a distance varying in different appendages from 
3°5to6mm. The greatest width in each case is at about two-thirds 
the distance from the point of origin. The axis of each appendage 
forms with the median axis of the whole imprint an angle varying 
between 35° and 75°, the greater angle usually being on the convex 
side of a sinuosity in the median track. It is hard to say whether 
the appendages are opposite’or alternate. 

Markings like those in Fig. 2 were formerly assigned to marine 
algee (Chordophycee) or to annelids (Werertes), but the observations 
of many naturalists, summarized and supplemented in Nathorst’s 


426 Obituary—Dr. BE. A. Newell Arber. 


classical memoir ‘‘Om spar af nagra evertebrerade djur, etc.” (1881, 
_K. Svenska Vet. Akad. Handl., vol. xviii, No. 7), have shown that 
they are almost certainly to be attributed to Crustacea. Such a 
track as the present one was probably formed by a large crustacean: 
swimming close to the sea-floor rather than crawling on a mud- flat. 
It is of the same general character as Polykampton alpinum Ooster, 
1869, from the Rheetic of Switzerland (‘‘ Protozoé Helvetica,” 
vol. i, p. 23, pl. iv), and Delesserites foliatus R. Ludwig, 1869, from 
the Upper ‘Devonian of Dillenburg (Palgontographica, vol. xvii, 
p. 113, pl. xx, fig. 4).—F. A. B. 


@OBtLDO AR Yi: 


E. A. NEWELL ARBER, 
MAS Seb GS. PinSuiie 


Born AUGUST 5, 1870. DIED JUNE 14, 1918. 
(WITH A PORTRAIT, PLATE XV.) 


Epwarp Atrxanper NewreLtt ArsBer was born at No. 5 Queen 
Square, Bloomsbury, in 1870. His father was Edward Arber, 
afterwards Professor of English at Mason’s College, Birmingham, 
and known as the editor of many English classics. His mother 
(née Marion Murray), the daughter of a “Glasgow publisher, was the 
niece of Dr. John Sutherland, an early authority on army sanitation, 
who was closely associated with Florence Nightingale’s work in the 
Crimea. 

Newell Arber had much illness in early boyhood, and at the age of 
fifteen he was sent, for the sake of his health, to Davos, where he 
spent more than a year. It was during his first Swiss summer that 
he awoke to the fascination of botany; his interest in geology was 
aroused later, apparently at the beginning of his Cambridge career. 
In 1895 he came up to Trinity College, and after an undergraduate 
period broken by ill-health, he took ‘the two parts of the “Natural 
Sciences Tripos in 1898 and 1899, specializing in Botany and Geology. 

In 1899 Professor T. McKenny Hughes nominated Newell Arber 
to a Demonstratorship in Paleobotany in the Woodwardian (after- 
wards Sedgwick) Museum. This post, which he held for the rest of 
his life, involved the curating of the paleobotanical collections, as 
well as elementary and advanced lectures and demonstrations in 
fossil botany. Newell Arber threw himself enthusiastically into 
museum work, and during his tenure of the Demonstratorship about 
5,000 plant fossils were added to the collections, almost entirely 
through his instrumentality. Between 1901 and 1906 he was also 
responsible—in the first year, under Dr. Henry Woodward, and after 
that, under his successor, Dr. Arthur Smith Woodward—for the 
naming and arrangement of the paleobotanical specimens in the 
Geological Department of the British Museum (Nat. Hist.). He 
consolidated his knowledge of fossil plants by repeated visits to most 
of the principal museums in Europe in which important collections 
are to be found. 

Research flourished in Newell Arber’s laboratory, where, in 


Grou. Maa., 1918. ; PEATE XY. 


Elliott & Fry, Paoto. Bale, Sons and Danielsson, Ltd. 


Be Che Sy aes 


hl; Ar, y 


clea 


Obituary—Dr, E. A. Newell Arber. 427 


addition to some sixty of his own memoirs, about twenty-five 
original papers were produced (either jointly or independently) by 
a group of students including at different times Bernard Smith, 
H. Hamshaw Thomas, L. J. Wills, W. T. Gordon, D. G. Lillie, 
R. D. Vernon, A. W. R. Don, R. H. Goode, and others. In 1905 
a moiety of the Lyell Fund was awarded to Newell Arber by the 
Geological Society, and in 1914 he was elected an Honorary Member 
of the New Zealand Institute in recognition of his work on 
Australasian geology. 

From the strictly geological standpoint, Newell Arber’s contribu- 
tion to the science may perhaps be summarized as consisting chiefly 
in the application of paleobotanical evidence to stratigraphical 
problems. One of his early memoirs (1903) dealt with the use of 
Carboniferous plants as zonal indices, a subject of which the founda- 
tions for this country had been so firmly laid by Dr. Kidston. 
Much of Newell Arber’s later work was concerned with further 
developments on these lines, and he produced a series of papers 
dealing with the fossil floras and geological structure of the English 
coal-fields. His book on The Natural History of Coal was sub- 
sequently translated into Russian. The economic bearing of his. 
paleobotanical work resulted in a consulting practice concerning 
the geology of coal both in this and other countries. Newell Arber 
did not confine his attention, however, to the Paleozoic period, but 
studied also the fossil floras of the Mesozoic rocks, especially those 
of the southern hemisphere. In this connexion his British Museum 
Catalogue of the Glossopterts Flora (1905) may be mentioned, and his 
recent account of the earlier Mesozoic Floras of New Zealand (1917). 
He continued his work to within less than three months of his death, 
leaving memoirs, in various stages of completion, relating to general 
paleobotany, and to Devonian, Carboniferous, and Mesozoic plants; 
it is hoped that some of these may eventually be published. 

Newell Arber had an exceptionally wide knowledge of geological 
literature, which embraced even its obscurest corners. His interest 
in bibliographical questions and his high standard of accuracy in 
such matters, were somewhat unusual in a scientific man and were 
probably due to his father’s influence. But he was no arm-chair 
geologist. He laid great stress on the importance of taking his 
research pupils into the open, where he initiated them into the 
methods of outdoor work. He had that instinct for the field, 
common to so many geologists, which on its material side results in 
a complete grasp of topography, and on its romantic side may rise 
to a capacity for being possessed by an absorbing passion for a tract 
of country. Botanically, Switzerland was his Mecca, while in his 
geological life Devonshire held a corresponding place. The desire 
to get there was often almost painfully intense; to quote from one 
of his letters—‘‘I have had a bad attack of the ‘ West [Devon] 
a calling’ . It gets worse and is getting beyond my control.” 
Newell ower made ‘twelve geological expeditions to North Devon, 
mainly in connexion with his study of the Upper Carboniferous 
rocks. The difficulties of the work were extreme. As he wrote 
after the appearance in 1904 of his paper on the Culm Measures of 


428 Obituary—Dr. E. A. Newell Arber. 


this part of England—‘‘In the old days in the train I approached 
Bideford with great sinkings of heart. The possibilities of failure 
-were immense and the chances of success seemed ml. Altogether 
I suppose it was the hardest nut I shall ever have to crack and 
I marvel at my luck.” Later, as a by-product of this stratigraphical 
study, he was drawn to an investigation of the physical geology of 
North Devon, and in particular of the coastal waterfalls, eto 
resulted in his book on the coast scenery of the region (1911). 
In much of this work D. G. Lillie and Inkermann Rogers were 
associated with him. 

That deep-seated delight in field-work, Gach is in some ways the 
ultimate joy of the geologist, is indicated by a passage from one of 
Newell Arber’s letters, which may perhaps not unfitly conclude this 
tentative outline of his geological life. ‘‘I thought I would take 
a holiday for the rest of the evening and indulge in a fit of ‘ field- 
fever’ or ‘field-dreams’. I wonder if you know what this is. Poor 
old Robert Dick heard or felt ‘field-work’ calling many a time. 
People who have been in the East, tell me they very often feel a great . 
longing to return again. .’. . A perfect day when one is in the 
field is one of the greatest things on earth. . My mania is quite 
a modest one. It is a desire to visit every spot in this country where 
fossil plants have ever been found. To gain that full power of know- 
ledge which can only be got by having been to the place, seen it, 
photographed it and collected from it. When you have done this 
you have a ‘grip’ which is masterly.” rion 


LIST OF THE MORE IMPORTANT GEOLOGICAL AND PALMOBOTANICAL BOOKS. 
AND MEMOIRS BY EH. A. NEWELL ARBER. (A number of titles, including 
all Dey botanical work, have been omitted for the sake of brevity. ) 

1901. ‘‘ Notes on Royle’s Types of Fossil Plants from India ’’: GEOL. Mag., 

Dec. IV, Vol. VIII, pp. 546-9. 
1902. ‘‘ On the Clarke Collection of Fossil Plants from New South Wales’? : 
Quart. Journ. Geol. Soc., vol. lviii, pp. 1-26, 1 pl., 1 text-fig. 
‘“Notes on the Binney Collection of Coal-Measure Plants. Part IIT: 
The Type Specimens of Lyginodendron Oldhamium (Binney) ”’ : 
Proc. Camb. Phil. Soc., vol. xi, pp. 281-5, 2 text-figs. 
1903. ‘‘The Fossil Flora of the Cumberland Coalfield, and the Paleobotanical 
Kyvidence with regard to the Age of the Beds’’?: Quart. Journ. 
Geol. Soc., vol. lix, pp. 1-22, 2 pls. 
(Conjointly with A.C. SEWARD. ) **Les Nipadites des Couches Hoceénes 
de la Belgique’’: Mém. du Musée royal d’hist. nat. de Belgique, 
t. 2, 16 pp., 3 pls. 
*“ Notes on some Fossil Plants collected by Mr. Molyneux in Rhodesia’’ 
Quart. Journ. Geol. Soc., vol. lix, pp. 288-90. 


“On the Roots of Medullosa anglica’’?: Ann. Bot., vol. xvii, 
pp. 425-33, 1 pl. 
“The Use of Carboniferous Plants as Zonal Indices’’: Trans. Inst. 


Min. Eng., pp. 371-89. 

‘“On Homceomorphy among Fossil Plants’?: Grou. MaG., Dec. IV, 
Vol. X, pp. 885-8. 

‘‘Notes on Fossil Plants from the Ardwick Series of Manchester ”’ : 
Mem. and Proc. Manchester Lit. and Phil. Soc., vol. xlviii, Man. 
Mem., No. 2, 32 pp., 1 pl., 1 text-fig. 

1904. ‘* Cupressinoxylon Hookert, sp. noy., a large Silicified Tree from 

Tasmania’’?: GEOL. MaG., Dec. V, Vol. I, pp. 7-11, 1 pl., 
2 text-figs. 


1904. 


1905. 


1906. 


1907. 


1908. 


1909. 


1910. 


Obitwary—Dr. E, A. Newell Arber. 429 


‘The Fossil Flora of the Culm Measures of North-west Devon, and 
the Paleobotanical Evidence with Regard to the Age of the Beds’’: 
Phil. Trans. Roy. Soc. Lond., ser. B, vol. exevii, pp. 291-325, 2 pls. 

(Conjointly with I. RoGERS.) ‘‘ Note on a New Fossiliferous Limestone 
in the Upper Culm Measures of West Devon’’: Guo. MAG., 
Dec. V, Vol. I, pp. 305-8. 

““On some New Species of Lagenostoma, a Type of Pteridospermous 
Seed from the Coal Measures’’: Proc. Roy. Soc., vol. lxxyviB, 
pp. 245-59, 2 pls. 

‘* On the Sporangium-like Organs of Glossopteris Browniana, Brongn.’ : 
Quart. Journ. Geol. Soc., vol. lxi, pp. 324-38, 2 pls. 

Catalogue of the Fossil Plants of the Glossopteris Flora in the 
Department of Geology, British Musewm (Nat. Hist.). Being 
a Monograph of the Permo-Carboniferous Flora of India and the 
Southern Hemisphere. London, lxxiv + 255 pp., 8 pls., 1 map, 
51 text-figs. 

‘On the Past History of the Ferns’’: Ann. Bot., vol. xx, pp. 215-32, 
1 text-fig. 


- “* Bibliography of Literature on Paleozoic Fossil Plants, including some 


of the more important memoirs published between 1870-1905.’’ 
Progressus Rei Botanice. Bd. i, pp. 218-42. 

““The Origin of Gymnosperms’’: Science Progress, vol. i, No. 2, 
pp- 222-37. - 

“*On the Upper Carboniferous Rocks of West Devon and North 
Cornwall’: Quart. Journ. Geol. Soc., vol. Ixiii, pp. 1-27, 
3 text-figs. 

““A Note on Fossil Plants from the Carboniferous Limestone of 
Chepstow’’: GEOL. MAG., Dec. V, Vol. IV, pp. 4-5. 

(Conjointly with JOHN PARKIN.) ‘‘On the Origin of Angiosperms ”’ : 
Linn. Soc. Journ. Bot., vol. xxxviii, pp. 29-80, 4 text-figs. 

_ (Translated into German as ‘‘ Der Ursprung der Angiospermen ’’ : 
Osterreich. bot. Zeitschr. Jahreg., 1908, p. 89, etc.) 

““On Triassic Species of the Genera Zamites and. Pterophyllum: 
Types of Fronds belonging to the Cycadophyta’’: Trans. Linn. 
Soc. Lond., ser. 11, Bot., vol. vii, pt. vii, pp. 109-27, 3 pls. 

““On a New Pteridosperm possessing the Sphenopteris Type of 
Foliage’’: Ann. Bot., vol. xxii, pp. 57-62, 1 pl. 

(Conjointly with H. HamsHaw Tuomas.) ‘‘On the Structure of 
Sigillaria scutellata, Brongn., and other Eusigillarian Stems, in 
comparison with those of other Paleozoic Lycopods’’: Phil. Trans. 
Roy. Soc. Lond., ser. B, vol. cc, pp. 133-66, 3 pls. 

“On the Affinities of the Triassic Plant Yuccites vogesiacus, Schimper 
and Mougeot’’: GEOL. MaG., Dec. V, Vol. VI, pp. 11-14. 

‘© On the Fossil Plants of the Waldershare and Fredville Series of the 
Kent Coalfield’’?: Quart. Journ. Geol. Soc., vol. lxv, pp. 21-39, 
1 pl. 

Fossil Plants. Gowans’s Nature Books, No. 21, 75 pp., 60 pls. 
Glasgow. ; 

(Conjointly with H. HAMsHAW THOMAS.) ‘‘ A Note on the Structure 
of the Cortex of Sigillaria mammillaris, Brongn.’’: Ann. Bot., 
vol. xxiii, pp. 513-14. 

**Note on a Collection of Fossil Plants from the Neighbourhood of 
Lake Nyasa, collected by Mr. A. R. Andrew’’: Quart. Journ. 
Geol. Soc., vol. lxvi, pp. 237-9. 

““Notes on a Collection of Fossil Plants from the Newent Coal-field 
(Gloucestershire) ’?: GEOL. MAG., Dec. V, Vol. VII, pp. 241-4. 
‘A note on some Fossil Plants from Newfoundland’’: Proc. Camb. 

Phil. Soc., vol. xv, pp. 390-2, 2 text-figs. 

““ Some Fossil Plants from Western Australia,’’ III. Paleeont. Contri- 
butions to the Geology of West. Aust.: Geol. Sury. Bull. 36, 
pp. 25-8. 


430 


1910. 


1911. 


1912. 


1913. 


1914. 


1915. 


1916. 


Obituary—Dr. E, A. Newell Arber, 


‘* On the Fossil Flora of the Southern Portion of the Yorkshire Coal- 
field in North Derbyshire and Nottinghamshire’’: Proc. Yorks. 
Geol. Soc., vol. xvii, pt. ii, pp. 132-55, 8 pls. 

‘“ A Note on a Fossil Wood from Intombi Camp, Ladysmith ’’?: Ann. 
Natal Museum, vol. ii, p. 233. ; 

The Natural History of Coal. x+163 pp., 21 text-figs. Cambridge 
University Press. (Translated into Russian, 1914.) 

The Coast Scenery of North Devon, being an account of the Geclngtaal 
Features of the Coast-line extending from Porlock in Somerset to 
Boscastle in North Cornwall. xxiv +261 pp., 70 pls., 12 text-figs., 
2maps. London: Dent. 

“The Culm-measures of the Exeter District ’’: GroL. MAG., Dec. V, 
Vol. VIII, pp. 495-7. 

‘“The Lower Carboniferous (Carboniferous Limestone) Flora of the 
Ballycastle Coalfield, Co. Antrim’’: Sci. Proe. Roy. Dublin Soc., 
vol. xiii, N.S., No. 12, pp. 162-76, 3 pls. 

‘“The Fossil Flora of the Ingleton Coal-field (Yorkshire) ’?: GEOL. 
MaG., Dec. V, Vol. IX, pp. 80-2. 

‘“A Note on some Fossil Plants from the Kent Coal-field’’: ibid., 
pp. 97-9, 1 pl. 

‘On the Fossil Flora of the Forest of Dean Coalfield (Gloucestershire), 
and the Relationships of the Coalfields of the West of England and 
South Wales’’: Phil. Trans. Roy. Soc. Lond., ser. B, vol. ccii, 
pp. 233-81, 3 pls. 

“On Psygmophyllum majus, sp. nov., from the Lower Carboniferous 
Rocks of Newfoundland, together with a Revision of the Genus and 
Remarks on its Affinities’’?: Trans. Linn. Soc. Lond., ser. 1, Bot.,. 
vol. vii, pt. xviii, pp. 391-407, 3 pls., 1 text-fig. 

‘“The Fossil Plants of the Forest of Dean Coalfield’’: Proc. Cotteswold 
Nat. Field Club, vol. xvii, pt. iii, pp. 321-32, 4 pls. 

‘*A Preliminary Note on the Fossil Plants of the Mount Potts Beds, 
New Zealand, Collected by Mr. D. G. Lillie, Biologist to: Captain 
Scott’s Antarctic Expedition in the Terra Nova’’: Proc. Roy. Soe., 
B, vol. Ixxxvi, pp. 344-7, 2 pls. 

‘On the Discovery of Fossil Plants in the Old Hill Marls of the South 
Staffordshire Coal-field’’: Grou. Mac., Dee. V, Vol. X, 
pp. 215-16. 

“On the Structure of Dadoxylon Kayi, sp. NOV. , from the Halesowen 
Sandstone at Witley (Worcestershire) ’ : Quart. Journ. Geol. Soc., 
vol. lxix, pp. 454-7, 4 text-figs. 

‘On the Fossil Floras of the Wyre Forest, with Special Reference to 
the Geology of the Coalfield and its Relationships to the Neigh- 
bouring Coal Measure Areas’’: Phil. Trans. Roy. Soc. Lond., 
ser. B, vol. cciv, pp. 363-445, 4 pls. 

““ A Revision of the Seed Impressions of the British Coal Measures’? : 
Ann. Bot., vol. xxviii, pp. 81-108, 3 pls., 8 text-figs. 

‘“On the Fossil Flora of the Kent Coalfield’’: Quart. Journ. Geol. 
Soc., vol. Ixx, pp. 54-81, 3 pls. 

‘‘ Geology of the Kent Coalfield’? : Trans. Inst. Min. Eng., vol. xlvii, 
pt. v, pp. 677-714. 

(Conjointly with R. H. GoopE.) ‘‘On some Fossil Plants from the 
Devonian Rocks of North Devon’’: Proc. Camb. Phil. Soce., 
vol. xviii, pp. 89-104, 1 pl., 3 text-figs. 

““On a little-known concealed Coalfield in Oxfordshire’’: ibid., 
pp. 180-3. (See also Trans. Inst. Min. Eng., vol. 1, pt. ii, 
pp. 373-84, 1916.) 

““ Studies of the Geolog : The Coal- 
measure records of four borings’’: Trans. Inst. Min. Eng., vol. 1, 
pt. ii, pp. 351-72. 

“* On the Fossil Floras of the Coal Measures of South Staffordshire ”’: 
Phil. Trans. Roy. Soc. Lond., ser. B, vol. ccviii, pp. 127-55, 3 pls., 
3 text-figs. 


Obituary—Prof. V. P. Amalitsky. 431 


1916. ‘‘ The Structure of the South Staffordshire Coalfield, with special 
reference to the concealed areas and to the neighbouring fields’? : 
Trans. Inst. Min: Eng., vol. lii, pt. i, pp. 35-70. 

1917. ‘‘ The Earlier Mesozoic Floras of New Zealand ’’: New Zealand Geol. 
Surv., Paleontological Bulletin No. 6, 80 pp., 14 pls., 12 text-figs. 
Wellington, N.Z. 

1918. ‘* A Note on Submedullary Casts of Coal-measure Calamites ’’?: QOL. 
Maa., Dec. VI, Vol. V, pp. 212-14. 


VLADIMIR PROCHOROVITCH AMALITSKY. 
Born 1860. DIED DECEMBER 28, 1917. 
We regret to learn that Professor Amalitsky, of Warsaw,’ died 
suddenly from heart failure last December at Kislovodsk, North 
Caucasus. He was born in Volhynia in 1860, and received his 
“scientific education at the University of Petrograd, where he was 
especially attracted to geology by Professor Inostransev. He soon 
became an accomplished student, and early in his career was 
appointed Professor of Geology in the University of Warsaw. After- 
wards he assumed the direction of the Polytechnic Institute in 
‘Warsaw, and was occupied with his duties there at the outbreak of 
war in 1914. 

Professor Amalitsky devoted himself with great success to the 
study of the Permian formations of Russia, and made a special effort 
to discover remains of terrestrial and freshwater faunas and floras in 
these rocks. He first met with unusually well-preserved freshwater 
bivalved shells of the family Anthracosiide, which he described in 
the Paleontographiea, vol. xxx1x (1892), and in the first part of 
a Russian work intended to treat all aspects of Permian geology, 
published in Warsaw, also in 1892. Three vears later he visited the 
British Museum, with his equally accomplished wife, who always 
shared his labours, and there he compared his Russian fossils with 
the corresponding shells from the Karoo formation of South Africa. 
The results of his researches were contributed to the Geological 
Society of London in a paper entitled ‘‘A Comparison of the 
Permian Freshwater Lamellibranchiata from Russia with those from 
the Karoo System of South Africa’? (Quart. Journ. Geol. Soc., 
vol. li, pp. 837-51, pls. xii, xili, 1895). 

While in London, Professor and Mrs. Amalitsky also studied the 
Karoo reptiles and other Permian and Triassic fossils. ‘hey then 
spent four seasons in exploring promising localities in the Permian 
region of the northern Dwina, and discovered not only more fresh- 
water shells but also the characteristic G@lossopteris Flora and great 
deposits of concretions containing the skeletons of Reptiles and 
Labyrinthodonts. In 1899 and 1900, with the aid of funds from 
the Russian Ministry of Public Instruction, they made extensive 
diggings in the beds of bone-bearing concretions and obtained a very 
large collection which was sent to the University of Warsaw. 
Skeletons of Pariasaurians proved to be especially abundant, and 
there were numerous remains of Dicynodonts, Theriodonts, and 
Deuterosaurians, besides well-preserved Labyrinthodonts. In 
December, 1899, Professor Amalitsky made a general report on his 
first year’s official work to the Imperial Society of Naturalists of 
Petrograd, and published this as a separate pamphlet at Warsaw in 


432 Obituary—Henry R. Knipe. 


1900 (‘Sur les Fouilles de 1899 de Débris de Vertébrés dans les 
Dépots Permiens de la Russie du Nord,” with 5 plates of photo- 
graphs of the excavations). In 1901 he made a more precise com- 
munication to the French Academy of Sciences (‘‘Sur la découverte, 
dans les dépéots permiens supérieurs du nord de la Russie, d’une flore 
glossoptérienne et de reptiles Pariasaurus et Dicynodon,’’? Comptes 
Rendus, 4 Mars, 1901). 

With much trouble Professor Amalitsky engaged and trained some 
skilled masons to extricate his fossil skeletons from the intractable 
matrix in which they were embedded, and more than one unfortu- 
nately succumbed to the effect of the peculiar siliceous dust which 
the work produced. At last, however, he secured a goodly series of ” 
specimens ready for study, and when I saw the collection at Warsaw. 
in 1908 he had already mounted six fine skeletons of Parzasaurus, 
one of the Theriodont Jnostransevia, and a large number of important 
pieces of Dicynodonts and Labyrinthodonts. Photographs of some 
of these were published in Sir Ray Lankester’s Extinct Animals 
(London, 1905), and plaster casts of a few characteristic specimens 
were given by Professor Amalitsky to the British Museum in 1913. 
Professor and Mrs. Amalitsky visited the British Museum several 
times during the progress of their work, but unfortunately the new 
duties at the Warsaw Polytechnic involved much distraction, and 
when I last met the Professor in London in 1912 he told me he had 
abandoned all hope of being able to describe the collection himself, 
and proposed shortly to send one of his students to the British 
Museum to make himself competent for the task. The War unfortu- 
nately disarranged this plan, and it is sad to realize that Professor 
Amalitsky will not now see the fruition of his labours. 

Professor Amalitsky was a single-minded student beloved by all 
who knew him, and while lamenting his premature loss to science, 
his friends will tender their heartfelt sympathy to the amiable help- 
mate who was his constant companion in research. 

A. Suira Woopwarp. 


HENRY ROBERT KINI RE) Rleso. 7 eGror 

Born 1855. DIED JULY 26, 1918. 
WE regret to record the death of Mr. Henry R. Knipe, who devoted 
much time and labour to the popularization of the study of extinct 
animals in this country. With the aid especially of the Staff of the 
British Museum, and utilizing its collections and library, he 
attempted to portray the animals of the past as they appeared when 
living, and, sparing no expense, he employed the most skilled artists 
to carry out his plans. Among those who produced his restorations 
may be mentioned Mr. John Smit and Miss Alice B. Woodward. 
His earliest efforts were published as a series of plates illustrating 
a long poem named Webula to Man (London, 1905). More recently 
a still finer series of restorations, chiefly by Miss Woodward, was 
issued in his more systematic work in prose, Hvolution in the Past 
(London, 1912). Apart from his scientific studies Mr. Knipe’s 
interests were wide and varied, and by his death Tunbridge Wells 
loses one of its most esteemed citizens and most generous 
philanthropists. 


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The Imperial Mineral Resources | Summary of Progress, Geological 
[BAUER DIE Sole SORE SBE BO Dano oe Bera aatos 433 Survey of Great Britain ......... 473 
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GEOLOGICAL MAGAZINE: 
NEW SERIES. DECADE VI. VOL. V. 
No. X.— OCTOBER, 1918. 


THE dmpertaL Minerat Resources Burnav. 


T will be remembered that asa result of the deliberations of the 
Imperial War Conference last year a Special Committee, under 
the chairmanship of Sir James Stevenson, was appointed by 
Dr. Addison, then Minister of Munitions, to prepare a scheme for 
the establishment, in London, of an Imperial Mineral Resources 
Bureau. ‘he proposal that the Committee was asked to examine 
was, that a Bureau should be formed to collect information from 
Government Departments and other sources in regard to the mineral 
resources and metal requirements of the Empire, and that it should 
advise what action, if any, might appear desirable to enable such 
resources to be developed and made available. 

The Committee reported at the end of July, 1917, and recommended 
the formation of a Bureau with the following duties :— 

1. To collect, co-ordinate, and disseminate information in regard 
to the resources, production, treatment, consumption, and require- 
ments of every mineral and metal of economic value. 

2. To ascertain the scope of the existing agencies, with a view 
ultimately to avoid any unnecessary overlapping that may prevail. 

3. To devise means whereby the existing agencies may, if 
necessary, be improved and assisted in the accomplishment of their 
respective tasks. 

4. To supplement those agencies, if necessary, in order to obtain 
any information not now collected which may be required for the 
Bureau. 

5. To advise on the development of the mineral resources of the 
Empire, or of particular parts of it, in order that such resources may 
be made available for Imperial defence or industry. 

After the consideration of the report the Government instructed 
the Minister of Reconstruction, in consultation with the Secretaries 
of State for the Colonies and India, to give effect to the findings of 
the Committee. As these provided that the administration of the 
Bureau was to be controlled by a governing body representing the 
various parts of the Empire as well as the mineral and metal 
industries, detailed proposals were submitted to the Dominion and 
Indian Governments, who nominated their representatives; while 
the remaining members of the governing body were nominated by 
the Minister of Reconstruction in consultation with the Institution 
of Mining and Metallurgy, the Institute of Metals, the Iron and 
Steel Institute, and the Institute of Mining Engineers. This con- 
stitution was ratified by the Imperial War Conference which met in 
London this year. 

The Bureau will be incorporated by Royal Charter, and the 
governing body, which will be under the presidency of the Lord 

DECADE VI.—VOL. V.—NO. X. 28 


434 Dr, Wheelton Hind—British Carboniferous Gomiatites, 


President of the Council, will have the following constitution :— 
Chairman: Sir Richard Redmayne, representing the United King- 
~ dom; and the following members: Dr. Willet G. Miller, representing 
Canada; Mr. W. 8S. Robinson, Australia; Mr. T. Hutchinson 
Hamer, New Zealand; The Rt. Hon. W. P. Schreiner, the 
Union of South Africa; The Rt. Hon. Lord Morris, Newfoundland ; 
Mr. R. D. Oldham, India; Dr. J. W. Evans, Crown Colonies; 
Mr. W. Forster Brown (Mineral Advisor to HSM. Woods and 
Forests); Professor H. C. H. Carpenter (President of the Institute 
of Metals); Dr. F. H. Hatch (Member of the Mineral Resources 
Advisory Committee of the Imperial Institute and Past President of 
the Institution of Mining and Metallurgy); Sir Lionel Phillips 
(late Director of the Mineral Resources Development Department, 
Ministry of Munitions); Mr. Edgar Taylor (of John Taylor & Son, 
and late President of the Institution of Mining and Metallurgy); 
Mr. Wallace Thorneycroft (President of the Institution of Mining 
Engineers). Mr. Arnold D. McNair is Secretary, and the offices of 
the Bureau are for the present at the Holborn Viaduct Hotel, E.C. 
Some department such as this has long been needed, and it is to 
be hoped that the new body will fulfil ‘the expectations that have 
been aroused by its appointment, and that its functions will not be 
restricted to the collection and dissemination of information, but 
that it will also institute such researches as may appear desirable as 
to the occurrence of important but little-known minerals, both in 


this country and in the Colonies. The exigences of the War have. 


=shown how important for the welfare of the State the discovery of 
new sources of such minerals may become; examples will occur to 
everyone. In the present war the cutting off of overseas supplies 
has necessitated the search for and development of home resources of 
manganese, wolfram, iron pyrites, phosphates, petroleum, etc. ‘This 
country has been well served in the past by its purely scientific 
institutions, but the economic side has been unduly neglected. We 
wish the Bureau a successful career in the important work assigned 
to it. 


ORIGINAL ARTICLES. 


en 


J.— On vue Disrripurion or tHE British CARBONIFEROUS 
GoNIATITES, WITH A DESCRIPTION OF ONE NEw GENUS AND SOME 
New SpOTTS. 


By WHEELTON HIND, M.D., B.S., F.R.C.S., F.G.S. 
(PLATE XVI.) 

ART IIT of the Catalogue of the Fossil Cephalopoda in the British 
Museum (Nat. Hist.), by A. H. Foord and G. C. Crick, was 
published in 1897. Since then much fresh material has come into 
my hands and it is now possible to give much more accurate and 
fuller details of the horizons and localities at which the various 
species oceur. ‘his is of special importance, in view of the fact that 
the Goniatites can be used as zone indices of the Carboniferous Series 
from the upper part of the Dibunophyllum beds (Dy of Dr. Vaughan) 


‘ 


Dr, Wheelton Hind—British Carboniferous Goniatites, 435 


up to the Middle Coal-measures. This I showed to be the case in 
my Presidential address to the Yorkshire Naturalists’ Union, and 
published in the Naturalist, April to July, 1909, and elsewhere. 
Many details have, however, been added since then, and an elaborated 
and emended table will be published in a forthcoming paper by 
myself and Dr. Wilmore, F.G.S., on the Carboniferous succession of 
some Midland areas. 

The zones published in the Yorkshire Naturalist, op. supra cit., 
p. 154, were as follows:— 


MILLSTONE GRITS ; p Gastrioceras listert. 
PENDLESIDE SERIES . : Glyphioceras bilingue. 
G. spirale. 
G. reticulatum. 
Posidonomya bechert. 
Cyathaxonia. 
CARBONIFEROUS LIMESTONE. Upper Dibunophyllum. 


It may be briefly stated that the Goniatites mentioned above 
occur with the utmost regularity wherever these horizons are 
exposed. Of the zones in the above list the G. retzculatum zone is 
the least satisfactory, on account of the persistence of the species from 
Pendleside to Middle Coal-measure times. Several other Goniatite 
zones will be indicated in the forthcoming paper, with greater detail 
as to their extent. Many of the localities given in the Museum 
Catalogue (op. supra cit.) are unsatisfactory, partly because, at the 
time when it was published, the zones of the Carboniferous rocks 
had not been made out, and partly because the real history of many 
of the specimens in the Natural History Museum was not known. 
Collections were largely referred to the town where the collectors 
lived, e.g. Halifax, Todmorden. Halifax is given as a locality for 
a large number of species which could not have come from the 
Lower Coal-measures. I suspect that many of these, if not all, 
came from the collection of the late J. W. Davis, of Halifax. I see 
this fact was mentioned by Mr. Crick, Q.J.G.8., vol. 1xvii, pp. 400-4. 
Long lists of fossils are given by J. W. Davis in his portion of the 
volume, West Yorkshire, part i, Geology, 1878 (Davis and Lees), 
but none are referred to Halifax as a locality. ‘The ‘‘ Hardbed Coal ”’ 
occurs there with the marine fossils of the Mountain Mine or 
Bullion Coal, and the locality is correct for Gastrioceras listert, 
G. carbonarium, Dimorphoceras gilbertsoni, D. looneyi, and D. discrepans. 
The locality Halifax must therefore be called in question for all 
Goniatites other than the above. ‘Todmorden is also unsatisfactory, 
for, though the Goniatite beds occur at that town, the majority of 
the collections have been made from Horsebridge Clough, Crimsworth 
Dean, and High Green Wood, north of Hebden Bridge, from the 
valley of Hebden Water and its tributary. The two former localities 
are in the same little valley. 

The Natural History Museum is fortunate in possessing nearly all 
the types of Phillips’s Goniatites, but the localities given by him are 
practically valueless. Bolland is a large district, partly in Lanca- 
shire, partly in Yorkshire, and practically the whole of the Lower 
Carboniferous rocks occur therein. Black Hall, near Chipping, and 


436 Dr. Wheelton Hind—British Carboniferous Goniatites. 


some of the Devonshire Culm localities are, however, sufficiently 

detailed to determine the exact horizon. ‘‘ River Ribble”’ is, of course, 
~ too vague. The Scottish localities are copied from the Handbook, 
Brit. Assoc., Glasgow, 1901, p. 503, where there is a list of 
Carboniferous Cephalopoda from the Clyde area, drawn up by 
J. Neilson. Many Devonshire localities are quoted from Mr. Crick’s 
paper, Q.J.G.S., vol. Ixvii, pp. 309-408. 

Several Irish localities are quoted from Foord’s Carb. Ceph., 
Ireland, part v, Pal. Soc., vol. lvii, 1903. Several Irish specimens 
which are known only from a single locality are not dealt with, 
because I have no knowledge of the exact horizon at which they 
occur. Unfortunately, it will be noted that all known British 
Goniatites occur in the upper beds of the Carboniferous Limestone 
and the succeeding series, and except in Ireland no Goniatites are 
noted from beds below the Upper Dibunophyllum zone. I suspect 
that Kniveton, however, will be eventually found to be of a much 
lower horizon, and there I have obtained species which I refer to 
G. corpulentum, M’Coy, and a variety of G. truncatum, and I possess 
a large specimen of this variety from Clitheroe. The presence at 
Kniveton of Pericyclus fasciculatus is interesting. De Koninck 
has described the following species: From Tournai— Brancoceras 
rotatorius, Glyphioceras complanaius, G. rotella, G. ryckholti, 
G. crenulatus, G. perspectivus, G. belvalianus, Pericyclus divisus, 
P. funatus (princeps). From Pauquys— Glyphioceras inconstans, 
G. spheroidale, M’Coy, P. fasciculatus. From Veve—P. impressus. 
At least four of the above species occur in Ireland. 


TABLE OF DISTRIBUTION OF BRITISH GLYPHIOCERATIDA. 


COAL-MEASURES . 2 . Glyphioceras reticulatum, Phillips. 
G. micronotum, Phillips. 
Dimorphoceras gilbertsoni, Phillips. 
D. looneyi, Phillips. 
Gastrioceras listert, Martin. 
G. carbonarius, V. Buch. 
G. coronatum, Foord & Crick. 
Nomismoceras ornatun, Foord & Crick. 


MILLSTONE GRIT s . Pericyclus impressus, de Koninck. 
P. divaricatum, Hind. 
Glyphioceras reticulatum, Phillips. 

i. beyrichianwm, de Koninck. 

. bilingue, Salter. 

. calyx, Phillips. 

. phillapsii, Foord & Crick. 

. davisi, Foord & Crick. 

. platylobum, Phillips. 

. spirale (var.), Phillips. 
Dimorphoceras gilbertsont, Phillips. 
D. looneyi, Phillips. 
D. discrepans, Brown. 
Gastrioceras listeri, Martin. 

PENDLESIDE SERIES . .  Glyphioceras reticulatum, Phillips. 
G. bilingue, Salter. 
G. davisi, Foord & Crick. 
G. phillipsti, Foord & Crick. 
G. spirale, Phillips. 


RRARARAR 


Dr. Wheelton Hind—British Carboniferous Goniatites, 437 


beyrichianum, de Koninck. 

. striolatwm, Phillips. 

bidorsale, Phillips. 

calyx, Phillips. 

vesica, Phillips. 

mitidum, Phillips. 

platylobum, Phillips. a 
Dimorphoceras gibsont, Phillips. 

D. looneyi, Phillips. 

D. discrepans, Brown. Mh 
Nomismoceras rotiforme, Phillips. 
N. spirorbis, Phillips. 

N. vittager, Phillips. zi 
Prolecanites serpentinus, Phillips. es 
P. compressus, Sowerby. 


DADARAAN 


CARBONIFEROUS LIMESTONE Pericyclus funatus, Sowerby. — 
(Dz beds) P. fasciculatus, M’Coy. 
P. doohylensis, Crick. 
Brancoceras enniskillent, oord, 
Glyphioceras crenistria, Phillips. 
G. striatum, Sowerby. 
G. sphericum, Martin. 
. fimbriatum, Foord & Crick. 
. obtusum, Phillips. 
: implicatum, Phillips. 
. truncatum, Phillips. 
. nucronotum, Phillips. 
. vesica, Phillips. 
. mutabile, Phillips. 
. excavatum, Phillips. 
. vesiculifer, de Koninck. 
. complicatum, de Koninck. 
Nomismoceras vittager, Phillips (very rare). 
Dimorphoceras gilbertsoni, Phillips. 
Prolecanites cyclolobus, Phillips. 
P. discoides, Foord & Crick. 
P. mizxolobus, Phillips. 
Pronorites cyclolobus, Phillips. 


RADRARRVRRARR 


Norrs on rach Sprecrms oF Carsonirerous GoNIATITES, WITH 
‘Disrrisution anp Locatriries. 
Genus Brancoceras. 
BRANCOCERAS ENNISKILLENI, Foord. Dibunophyllum zone, Dg. 
Derbyshire: Carsington. 
Ireland: Blacklion, near Enniskillen. 
Genus Pericyclus. 
PericycLus Fascicutatus, M’Coy. ? Dibunophyllum zone, Dj. 
Derbyshire: Kniveton. 
Ireland: Little Island, co. Cork; Clane, co. Kildare. 
Pericycrus Doonyiensis, Foord & Crick. Dibunophyllum zone, Dy. 


Derbyshire: Kniveton. 
Ireland: Doohyle, near Rathkeale, co. Limerick. 


438 Dr. Wheelton Hind—British Carboniferous Goniatites. 


Pericycius pivaricatus, Hind. Base of Pendleside Series to 3rd Grit. 
Yorkshire: Cracoe Knolls, Flasby, Horsebridge Clough, near 
Hebden Bridge. 
Lancashire : River Ribble at Dinckley Hall, 3rd Grit Shales, Eecup. 
Cheshire: In the G. spirale beds, Congleton Edge. 
Isle of Man: P. bechert beds, Poolvash.. 


Genus Glyphioceras. 


GLYPHIocERAS spHmericum, Phillips. Carboniferous Limestone, 
upper beds of Upper Dibunophyitlum zone, Ds. 

Lancashire: Black Hall. - 

Yorkshire: Keal Hill, Craven. 

Derbyshire: Crowdecote, Castleton, Chrome Hill. 

Devon: Fremington, Bonhay Road, Exeter. 

Isle of Man: Poolvash. 

Scotland: Upper Limestone Series: Gare. Lower Limestone 
Series: Corrieburn. 

Ireland: Loughshinny, co. Dublin; Bantry, co. Cork. 


GLYPHIOCERAS CRENISTRIA, Phillips. The upper beds of Upper 
Dibunophyllum zone, Ds. 


This is an important zone fossil. It occasionally passes up int 
the Prolecanites zone just above it. 

Lancashire: River Ribble at Dinckley Hall, Black Hall, and Cold 
Coats, near Chipping. 

Yorkshire: Keal Hill, Kl Bolton, Rilstone. The Knotts, Bolland 
and Brockthornes, both 5 or 6 miles 8.E. of Long Preston. Salter- 
- forth Railway Cutting. 

Derbyshire: Castleton, Gluttondale, Chrome Hill. 

Staffordshire: Wetton, Narrowdale. 

Devonshire: Venn, Swimbridge, Bampton, and Bonhay Road, 
Exeter; Burlescombe. 

Isle of Man: Poolvash. 

Ireland: Foord quotes Queen’s County and co. Fermanagh. 


GLYPHIOCERAS FIMBRIATUM, Foord & Crick. 


The validity of this species is doubtful, and its locality is not 
recorded. 
GLYPHIOCERAS sTRIATUM, Sowerby. 


An important zone fossil which is common to the G. ecrenistria 
and Prolecanites compressus beds, and also in the Posidonomya becherv 
shales. Often crushed flat in shales, but easily recognized by its 
spiral ornament. 

Lancashire: River Ribble Dinckley Hall, Cold Coats. 

Yorkshire: El Bolton, Keal Hill, Flasby, Eastby. Beck half-mile 
N. of Ashnot inlier, Upper Hodder at D: ulehead, between Hammerton 
Hall and Birch Hill. 

Derbyshire : Chrome Hill. 

Devonshire: Fremington. 

Isle of Man: Poolvash. 

North Wales: Teilia. 


Dr, Wheelton Hind—British Carboniferous Goniatites., 439 


Ireland: Courtlough, Garristown, and Newton, co. Dublin; 
Drumscra, co. Tyrone. 

Seotland: Upper Limestone Series: Gare. Lower Limestone 
Series: shale above Hosie Limestone, Campsie. Main Limestone: 
Carluke. 


GLyPHIocERAS optusuM, Phillips. The G. crenistria beds. 


Not at all a common species. 

Lancashire: Black Hall, near Chipping. 

Ireland: Co. Cork: Blackrock, Little Island, and Middleton. 
Co. Waterford: Ballyduff. Co. Limerick: Ballynacarriga. 


GLYPHIOCERAS PHILLIPSI, Foord & Crick. Base of Pendleside Series 
to Milistone Grit. 

Lancashire: River Ribble Dinckley Hall; Caton Green (Millstone 
Grit). Butler’s Clough, Billington. 

Yorkshire: Horsebridge Clough and Crimsworth Dean, Hebden 
Bridge (G@. retvculatum zone); stream below Weets Head; stream 
north-west of Ashnot, Rilstone. 

Staffordshire : Waterhouses (G@. reteculatum beds). 

Devonshire: Pinhoe Brickfield, Exeter. 

North Wales: Holywell. 


GLYPHIOCERAS MIcRonotuM, Phillips. Upper Dibunophyllum zone to 
Middle Coal-measures. 


Lancashire: River Ribble Dinckley Hall; Rough Lee (Sabden 
Shales); River Hodder above the great falls. 

Yorkshire: Rilstone and Lothersdale, 704 feet above Barnsley 
Coal, Brodsworth. 

Staffordshire: Narrowdale, Wetton; above the Gin Mine Coal, | 
North Staffs Coalfield. 

Derbyshire: Castleton, Park and Chrome Hills, Thorpe Cloud. 

Isle of Man: Poolvash. 

Scotland: Upper Limestone Series: Orchard and Garngad Road. 
Lower Limestone Series: Shale over Hosie Limestone, Campsie, and 
Thornton. 


GLYPHIOCERAS TRUNCATUM, Phillips. Seminula -beds to Upper © 
Dibunophyllum. 

Lancashire: River Ribble Dinckley Hall, Black Hall, Cold Coats; 
?Salt Hill, Clitheroe (S. beds). 

Yorkshire : Keal Hill and El Bolton. 

Derbyshire: Chrome Hill, Park Hill, Castleton, Thorpe Cloud, 
and Kniveton. 

Staffordshire: Wetton, Narrowdale. 

Isle of Man: Poolvash. 

Scotland: Upper Limestone Series: Thornlebank. 

Ireland: Drumscra, co. Tyrone; St. Donlaghs, co. Dublin; Clane, 
co. Kildare; Little Island, Tankardstown, Middleton, co. Cork; 
Lisnakeny, Nantenan, Ballyeahane, and Kilmacot, co. Limerick. 

N.B.—The specimens quoted from Redesdale, Northumberland, in 
the Catalogue probably belong to a new species of Pericyclus, but 


440 Dr, Wheelton Hind—British Carboniferous Goniatites, 


I have a specimen, a fragment of the body-chamber, which I think 
should be referred to G. “truncatum. 


GuyPHioceRas VESICA, Phillips. From the G. erenistria zone to the 
G. spir ale zone, Ds, and Pendieside Series. 
Lancashire: Black Hall, River Ribble W. of Dinckley Hall. 
Yorkshire: Crimsworth Dean. 
Scotland: Upper Limestone Series: Bowertrapping, Gare, Rob- 
royston, Auchenbeg. Lower Limestone Series: Kast Kilbride, 
Thornton. 


GLyYPHIocERAS ImpLicatuM, Phillips. The G. crenistria zone, Do. 

I have not met with this species in any of the collections from the 
Hebden Bridge area that I have examined. 

“Lancashire: Black Hall, River Ribble at Dinckley Hall. 

Derbyshire: Chrome Hall, 

Isle of Man: Poolvash. 

Scotland: Upper Limestone Series: Gare, Robroyston. 


GLYPHIOCERAS MUTABILE, Phillips. From the G. crenistria zone to 
G. spirale zone. 
Lancashire: River Ribble, W. of Dinckley Hall. 
Yorkshire: Quarry 1 mile 8S. of Rilstone. 
Derbyshire: Castleton, Storrs quarry, Bradbourne. 
Staffordshire: Narrowdale. 
Scotland: Upper Limestone Series: Gare, Robroyston. 


GLYPHIOcERAS PLatyLoBum, Phillips. Pendleside Series to Millstone 

Grit. . 

Yorkshire: valley of the Nidd. Sabden Shales, Rough Lee; 

Gillbeck, S8.E. of Lothersdale. Foord & Crick quote the species 
from Wetton, Staffordshire, and Todmorden. 


GLYPHIOCERAS stENoLopuM, Phillips. 


This must be a rare or doubtful species. It must be noted that 
the suture-lines figured by Phillips and by Foord & Crick are quite 
different. Neither Phillips’s or their figures show that the shell 
has a wide peripheral sinus as stated in the text. Unfortunately 
the “type” has been lost, and the original locality, ‘‘ Bolland,” 
gives no information as to the horizon whence the type-specimen 
was obtained. 


GuiyPHIoceRAs niTIpUM, Phillips. G. crenistria beds to Millstone 
; Grit. 
Lancashire: River Ribble Dinckley Hall, Black Hall, near 


Chipping; Millstone Grit beds, stream N. of Haws House, 6 miles 
E. of Lancaster. 


GLYPHIOCERAS BILINGUE, Salter. 


An important zone fossil. At Pendle Hill it characterizes 300 feet 
of Black Shale below the Upper Pendle or Farey’s Grit. It occurs 
in the Sabden Shales, W. of Sales Wheel, M.G. 


Dr. Wheelton Hind—British Carboniferous Goniatites, 441. 


Lancashire: Pendle Hill, Butlers Clough, Billington, and near 
Lango; River Ribble E. of Sales Wheel, Longridge Fell; streams 
N. of Chipping, Marsden Tunnel, Pule Hill. 

Yorkshire: east bank of Winterburn Reservoir, stream half-mile 
N.E. of Thorlby, shales S. of El Bolton, stream half-mile S., and 
Clough, 1 mile 8. of Ashnot; Hareshaw, S. of Lothersdale, below 
Weets Head and Kastby beck. Above Weston Grit, Clifton Bank, 
1 mile N. of Otley. Millstone Grit Shales, Moreton Bank. 

Derbyshire: River Dove, Glutton Bridge, Mam Tor, River Noe, 
Bradwell and stream W. of Bradbourne. 

Cheshire: River Dane half-mile E. of railway viaduct; Wild Moor, 
Bank Hollow, E. of Macclesfield. 

South Wales: Bishopton, near Swansea. 

Ireland: Caher Lane and Rathcahill, near Abbeyfield, co. Limerick. 


G:LYPHIOCERAS RETICULATUM, Phillips. Pendleside Series to Middle 
Coal-measures. 

An important species which when very young is strongly ribbed 
and has a wide and deep umbilicus and a deep groove on the 
periphery. As it grows the ornament becomes more delicately 
reticulate and in the old stage the shell may be almost smooth. 
Like G@. spirale and G. bilingue the aperture is curved at the sides 
like a reversed S, and there is a deep sinus at the periphery. It is 
quite open to doubt whether the horizon at Hebden Bridge may not 
be Millstone Grit rather than Pendleside Series. 

Lancashire: River Ribble W. of Dinckley Hall above . the 
G. spirale beds, Pendle Hill above Hook Cliff; Sabden Shale, 
Rough Lee. 

Yorkshire: Holden Clough, Bolland; High Green Wood, Crims- 
worth Dean, and Horsebridge Cough, Hebden Bridge; Millstone Grit 
Shales at Eecup and Wadsworth Moor, 705 feet above Barnsley. 
Coal, Brodsworth. 

Derbyshire: River Noe and Mam Tor. 

Staffordshire: River Dane, Dane Valley; Morridge. Shales below 
3rd Grit, Shirley Brook, near Froghall. 

Cheshire: River Dane, N. side of Dane Valley; Bosley Minn. 

Devonshire: Doddiscombleigh; Pinhoe, near Exeter; Dunsford 
Road above Pocomb Bridge, bottom of Ashlake Road, Mincing Lake, 
Newton St. Cyres, under Slope Wood and Willhayes Copse ; 
near Barnstaple. 

South Wales, Pembrokeshire: Penally, near Tenby. 

Scotland: Upper Limestone Series: Gare. 

Ireland: Pendleside Series: Lisdoonvarna Doon, Mt. Phelim, and 
cliffs of Moher and Kilkee, co. Clare; Foynes Island and Rath- 
eahill, co. Limerick; Mullaghtumy (Clogher), co. Tyrone; 5 miles 
N. of Maynooth, co. Meath; marine bands, Castlecomer Coalfield. 


GLypHioceras DAVISI, Foord & Crick. G. reticulatum beds, Hebden 
Bridge to Sabden Shales. 

Hitherto this fossil has only been found associated with 

G. reticulatum, and the study of a series of specimens in my 

collection has led me to suspect that it may be an old-age form of 


442 Dr. Wheelton Hind—British Carboniferous Goniatites, 


that species. Haug, Mém. Soe. Géol. France, Pal., tom. vii, p. 90, 
has expressed the same view. Hind & Howe, on ‘the strength of 
the locality quoted in the Cat. Foss. Ceph. "Brit. Mus: ;)7p.)) um 
erroneously recorded this species as passing up into the Coal: 
measures (Q.J.G.S., vol. lvii, app. B). 

Yorkshire: The @ reticulatum beds of Horsebridge Clough. 

Lancashire: Sabden Shales of Rough Lee. 

Staffordshire: River Dane, W. of salmon ladder. 

Devonshire: Mincing Lane, near Exeter. 

Ireland: Rathcahill and Foynes Island, co. Limerick; Puffing- 
hole, Kilkee, co. Clare; Coor Spa Well, near Ennis. 


GLYPHIOCERAS ExcavAtuM, Phillips. G. crenistria zone. 
Derbyshire: Castleton, Thorpe Cloud, Park Hill. 
Staffordshire: Narrowdale. 
Isle of Man: Poolvash. 
Scotland: Upper Limestone Series: Orchard, Gare, Thornliebank. 
Lower Limestone Series: Thornton. 


GLYPHIOCERAS BIDORSALE, Phillips. 


A species of doubtful value. The late Mr. Crick referred 
a specimen in my collection from Horsebridge Clough to this species. 
Foord & Crick, op. supra cit., think it may be a form of 
G. reticulatum, and observe that the double median saddle on which ~ 
Phillips founded the species does not exist in well-preserved 
examples. 


GLYPHIOCERAS BEYRICHIANUM, de Koninck. Middle Pendleside Series 
to Millstone Grit. 


This species has a most variable form. In the young stage the 
umbilicus, is wide and deep, inclusion small, the shell strongly 
marked with transverse ribs, the periphery broad and flattened, 
and like G. reticulatum has a central spiral sulcus. 

In more mature shells the inclusion is more complete, the ribs 
more delicate, and the periphery more convex. Haug (op. supra cit., 
p. 92) describes and figures seven distinct varieties, all of which 
seem to come from Chokier. Similar varieties occur at Lisdoonvarna, 
co. Clare, and Rough Lee near Sabden. 

My own observations lead me to suppose that the young stage of 
all the varieties are identical and occasionally persist, but the 
species was plastic and adopting new forms, or there may have been 
actually crossing going on between G. reticulatum and G@. beyrichi- 
anum. Many specimens are very difficult to refer definitely to one 
or other of these species. 

Gastrioceras circumplicatile, Foord,is probably a variety of the species. 
Haug points out that G. diadema is a synonym of G. striolatum, 
Phillips, and that as he adopts the latter as a distinct species the 
name diadema disappears and G'. beyrichianum, de Kon., 1843, takes 
its place. 

Lancashire: Sabden Shales, Rough Lee (Millstone Grit). 

Yorkshire: Gillbeck, 8.E. of Lothersdale (Millstone Grit); Horse- 
bridge Clough, Hebden Bridge. 


Dr. Wheelton Hind—British Carboniferous Goniatites, 443 © 


Devonshire: Pinhoe Brickfield, near Exeter. 

Derbyshire: Spoil-heaps, Edale Tunnel. 

Cheshire: Silica quarry, Congleton Edge. 

Denbighshire: Holywell Shales. 

Pembrokeshire: Black limestones, seashore, Tenby. 

Scotland: Upper Limestone Series: Orchard, Thornliebank. 
Middle Limestone Series: Black Band Ironstone, Dalry. 

Ireland: Lisdoonvarna, co. Clare. 


GLYPHIOCERAS sTRIOLATUM, Phillips. 

Foord & Crick have included this species as a synonym of 
G. diadema. Haug (Trans. Geol. Soc. France) | distinguishes 
G. striolatum from G. beyrichianum, and I follow him. 

It occurs in the G@. reticulatum beds of High Green Wood and 
Horsebridge Clough, near Hebden Bridge. 

Devonshire: Pinhoe, Barley, and Dunsford Road, ? Ashlake Road, 
Mincing Lake, and Perridge Tunnel. 

Scotland: Upper Limestone Series: Gare, Robroystone, Orchard, 
Auchenbeg. 


GLypaioceras caLyx, Phillips. Pendleside Series to Millstone Grit. 


Yorkshire: Horsebridge and Crimsworth Dean; stream S.W. of 
Browsholm Hall; River Hodder; Sabden Shales, Gillbeck, S.W. of 
Lothersdale. 

Ireland: Foynes Island. 


GLYPHIOCERAS CompLicatuM, de Koninck. Zone of G. crenistria. 


Derbyshire: Castleton, Bradbourne. 
This is the first note of the occurrence of this species in England. 


GLYPHIOCERAS VESICULIFER, de Koninck. Zone of G@. crenistria. 


Yorkshire: El Bolton. 
Lancashire: River Ribble, Dinckley Hall. 
Isle of Man: Poolvash. 


GLYPHIOCERAS PAUCILOBUM, Phillips. 


Only one specimen known, possibly the type. Phillips recorded 
no locality. 

GLYPHIOCERAS SPIRALE, Phillips. 

An important Middle Pendleside zone fossil, occupying only a few 
feet of strata. 

The species occurs at Clavier, Belgium, and in Ireland. Hitherto 
all British specimens have been found crushed. I have, however, 
been fortunate enough to extract a few uncrushed examples from 
nodules near Dinckley, one of which shows the suture-line to agree 
with the figure quoted by Foord & Crick after Roemer. 

Lancashire: River Ribble, W. of Dinckley Hall; Pendle Hill, 
above Lower Pendle Grit; Sabden Shales, Rough Lee, a var. with 
fine ornament. 

Yorkshire: Embsay Moor, black shales in beds N. of Eastby, 
beck three-quarters of a mile 8. of Ashnot; Parkhead, Lothersdale. 

Cheshire: Silica quarry, Congleton Edge. 


444 Dr, Wheelton Hind—British Carboniferous Goniatites, 


Derbyshire: Lower beds of Mam Tor. 

Devonshire: Waddon Barton; Bampton; Hele, east of Venn; 
Popehouse Close, Christow. é 

Ireland: Foynes Island, co. Limerick; Loughshinny; Summerhill, 
and near Trim, co. Meath; Killorglin, co. Kerry. 

Probably Goniatites granosus, Portlock, from Tyrone, should be 
referred to this species. 


Genus Nomismoceras, Hyatt, pars. 
NomIsMocERAS sprrorBis. G. crenistria to G. striatum zones. 
Lancashire: Above the great falls, River Hodder; Ribble at 
Dinckley Hall ; Black Hall. 
Yorkshire: Rilstone, Crimsworth Dean. 
Derbyshire: Storrs Quarry, Bradbourne. 
Devonshire: Waddon Barton. 
Ireland: Foynes Island, co. Limerick. 


NoMisMocERAS RoTIFoRME, Phillips. Generally confined to the 
Posidonomya bechert beds. 
Lancashire: River Ribble Dinckley Hall. Pendleside Limestone : 
above great falls, River Hodder. 
Yorkshire: River Hodder below Sandal Holm, and below 
bathing cots. 
Staffordshire: Pepper Inn Wetton, and Narrowdale. 
Isle of Man: Black marble quarry, Poolvash. 
Ireland: Loughshinny. 
Nomismoceras virracer, Phillips. Upper beds of D2 to 
Pendleside Limestone. 
Lancashire: Pendleside Limestone: above great falls, River 
Hodder. 
Derbyshire: Storrs Quarry Bradbourne; Castleton. 
Staffordshire: Narrowdale. 


Nomismoceras ornatum, Foord & Crick. 
Roof of Bullion Coal, Sholver. 


Genus Dimorphoceras, Hyatt. 
DimoreHoceras GILBERTSONI, Phillips. Base of Pendleside Series to 
Middle Coal-measures. 

A very widespread form. 

Lancashire: River Ribble Dinckley Hall; Rough Lee (Sabden 
Shales). 

Yorkshire: marine beds of Coal-measures and Pendleside Series: 
Crimsworth Dean and Horsebridge Clough; 705 feet above Barnsley 
Coal, Brodsworth. : 

Staffordshire: River Dane near Dane Bridge; marine bands of 
Coal-measures below Gin Mine Coal, 71 feet below 4th Coal, Cheadle ; 
the coombes near Leek. 

Derbyshire: Pendleside Series of Mam Tor. 

Devonshire: Gastrioceras beds, Instow. 

Ireland: Pendleside Series of Lisdoonvarna, Foynes Island; 
marine bands of Castlecomer Coal-measures. 


Dr. Wheelton Hind—British Carboniferous Goniatites, 445 


Scotland: Lower Limestone Series: shale over Hosie Limestone, 
Thornton, Braidwood, and South Hill, Campsie. 


DiworPHOCERAS DISCREPANS, Brown. [Pendleside Series to Coal- 
measures. 
Yorkshire: Horsebridge Clough and Crimsworth Dean, Hebden 
Bridge; Sabden Shales, Rough Lee. 
Lancashire: Lower Coal-measures, Sholver, near Oldham. 
Ireland : Foynes Island and Lisdoonvarna. 


DiworpHoceRas Looney, Phillips. Pendleside Series to Coal-measures. 
Lancashire: River Ribble, Dinckley Hall. 
Yorkshire: Crimsworth Dean and Horsebridge Clough. 
Devonshire: Pinhoe, Exeter. 
Ireland: Lisdoonvarna and Foynes Island (Pendleside Series). 
Scotland: Lower Limestone Series: Boghead; Raesgill, Carluke ; 
Thornton, over Hosie Limestone. 


Genus Gastrioceras, Hyatt. 
GASTRIOCERAS CARBONARIUM, von’ Buch. Upper Millstone Grit to 
Middle Coal-measures. 

Lancashire, Yorkshire, Cheshire, and Staffordshire: above the 
Upper Mountain Mine or Bullion Coal. 

Staffordshire: below the Gin Mine Coal, above Stinking Coal, 
Cheadle. 

Devonshire: Instow and Clovelly. 

South Wales: Rosser veins, Glan Rymney. 


GAsTRIOCERAS LisreRI, Martin (?). 


There is a great deal of doubt as to what was the original of 
Martin’s figure, which resembles a Jurassic ammonoid. This, added 
to the fact that the species does not occur at the localities given, 
should, I think, cause us to utterly disregard Martin’s figure, and to 
accept that drawn by J. de C. Sowerby, Min. Conch., vol. v, pl. D1, 
fig. 1, right- and left-hand figs. 

Martin says of his shell: ‘‘a common species. It is found in 
most of our limestone tracts, particularly near Eyam and Middleton.”’ 
Sowerby, speaking of the occurrence of the shell, states: ‘‘ This 
stratum may be traced from Middleton to near Leeds, and perhaps 
further.” 

The maximum of G. Lister’ is in the roof of the Bullion, Upper 
Mountain, or Hard-bed Coal, and it has not been found higher up 
than the Lower Coal-measures, but it certainly occurs below the 
Ist Grit or Rough Rock. 

Spencer states that he found the species with G. reticulatum at the 
Hebden Bridge localities. ‘‘ G. Lister? is very rarely found in the 
Millstone Grit rocks of this district (Halifax) . . . and it is only 
when we come to the Upper Millstone Grit shales that we find 
G. Lister’ occurring in great numbers” (Trans. Manch. Geol. Soc., 
vol. xiii, p. 110). 

Yorkshire and Lancashire: Everywhere over the Upper Mountain 
Mine or Bullion Coal. 


446 Dr. Wheelton Hind—British Ourboniferous Goniatites, 


Staffordshire: Below the Rough Rock, Millstone Grit, near po 
Devonshire: Instow. 
Treland: marine bands, Castlecomer Coalfield. 


GASTRIOCERAS coRonATUM, Foord & Crick. Lower Coal-measures. 


Lancashire; above the Mountain Mine, Bacup. 
Yorkshire: above the Mountain Mine, Shibden. 


Genus Prolecanites, Mojsisovics. 
PRoLEcanires compressus, J. Sowerby. 

A most important zone form denoting the base of the Pendleside 
Series, and only occupying as a rule a few feet of beds, except on 
Pendle Hill, River Hodder, and Longridge Fell, where a great local 
expansion of the Pendleside Limestone occurs. 

Lancashire: Warsaw End, Hook Cliff, Little Mearley Clough, 
Pendleton Clough, River Hodder below bathing cots, River Ribble 
at Dinckley Hall, at dip 2° in stream about one mile N. of 
Chipping. 

Yorkshire: River Hodder below Sandal Holm, Salterforth railway 
cutting, Rilstone, Ingsbeck at base of Pendleside Limestone. 

Cheshire: Old limestone quarry near Astbury, below Congleton 
Edge. 

Devonshire: Coddon Hill, near Barnstaple. 

' Isle of Man: Scarlet Quarry. 

Ireland: Co. Cork, Little Island and Black Rock, Middleton, 

Ballynabintra; Co. Galway, 4 miles east of Loughrea. 


PRoLECANITES MicoLoBus, Phillips. 
Very rare. Phillips gave Bolland as the locality. 


PROLECANITES DISCcoIDES, Foord & Crick. Carboniferous Lime- 
e stone, De. 
Yorkshire: El Bolton, near Cracoe. 
Derbyshire: Park Hill and Brassington. 
PROLECANITES SERPENTINUS, Phillips. 

A very small shell. Base of Pendleside Series. 

Lancashire: River Hodder, River Ribble at Dinckley Hall, 
Black Hall. 

Pronorites, Mojsisovics. 
PronoritEs cycLoLozus, Phillips. 
Very rare. Carboniferous Limestone, Dg. 
Yorkshire: El Bolton, probably ; Gr assington is quotedin Phillips's 


list of errata. 


Derbyshire: Thorpe Cloud. 


NEW GENUS. 
Saeirroceras, Hind. 

The genus is founded on a single specimen which consists of 
three-fourths of a complete individual. A large portion of the body- 
chamber is present, which on removal reveals the greater part of 
the penultimate whorl with the camere and suture-lines. 

I obtained the specimen from Keal Hill, one of the well-known 


Dr. Wheelton Hind—British Carboniferous Goniatites. 447 


Craven Knolls, It was in a block, on the south side of the hill, and 
from the accompanying fossils and nature of the rock came from the 
immediate vicinity. ‘he beds on Keal Hill belong to the Upper 
Dibunophyllum horizon and are succeeded by the shales and black 
limestones of the Pendleside Series. Glyphioceras crenistria, 
G. striatum, and G'. truncatum are common at the horizon at which 
the fossil was found. 

I showed the specimen to the late Mr. G. C. Crick and left it 
with him for description, but his untimely death prevented him 
from publishing our views. He agreed with me that the suture- line 
denoted an ammonoid genus quite new to science. 

Generic Characters.—Shell involute, discoidal, compressed with 
an acute periphery. Sides flattened. Umbilicus large and open. 
Camere numerous. Suture: an acute median saddle, external 
lobe broadly rounded, external saddle acutely linguiform, lateral 
lobe deep, rounded, linguiform, lateral saddle raised, acutely 
pointed, second lateral lobe broad and obtusely rounded. 


SaGITTOCERAS AcuruM, sp.nov. (PI. XVI, Figs. 1, la, 16.) 


Specific Characters.—Shell discoidal, much compressed, with an 
acute periphery. Whorl sagittate in section, much higher than 
broad, inclusion about three-fourths; whorls 3 or 4. Umbilicus large 
and open, sides smooth, very gently convex, sloping towards the 
umbilicus, the edge of which is subangular and its margin convex. 

Body-chamber occupies about one complete whorl. Camere 
many, about 20 to the whorl. 

Suture as given under description of the genus above. ‘Test thin, 
apparently smooth. 

Dimensions. — Diameter, 83 mm. approximate; transversely, 
30mm. estimated. 

Locality.—Upper Dibunophyllum zone of Keal Hill, Craven, 
Yorkshire. 

Observations.—Dr. Foord! described under the name Brancoceras 
enniskillent an acutely keeled Goniatite from the Carboniferous Lime- 
stone of Blacklion, near Enniskillen, in the Griffiths’ Collection in 
the Science and Art Museum, Dublin, but the small umbilicus and 
general shape of the shell do not show any relation to that now 
under description, and Dr. Foord states that he saw the sutures and 
had ‘‘no doubt as to their being those of Brancoceras”’ 

I obtained a fragment, two-thirds of a shell, which I refer to Foord’s 
species, from the Carboniferous Limestone of Carsington, Derbyshire. 
The small umbilicus and greater thickness and less acutely angled 
periphery separate it at once from Sagittoceras acutum. 

In external appearance S. acutum has a close resemblance to 
Phacoceras oxystomum, and may easily be mistaken for it if the 
suture-line is not seen. 

The suture-line distinguishes the genus from all other Carboniferous 
forms by the rounding of the peripheral lobe, the acutely pointed 
external saddle, the presence of two lateral lobes, and a_ well- 
developed lateral saddle (Pl. XVI, Fig. 1a). 


1 Carb. Ceph. Ireland, p. 208, pl. xlvii, figs. 3a, b. 


448 Dr. Wheelton Hind—British Carboniferous Goniatites. 


Pericyclus virgatus, de Konineck, has a lateral saddle and lateral 
lobe, but the shape of saddles and lobes are quite distinct from the 
genus under description. Pl. XVI, Fig. 1, shows the specimen 
after the body-chamber has been detached. 


PericycLus pivaricatum, Hind, 1905. (Pl. XVI, Figs. 2-6.) 
Glyphioceras diwaricatum, Hind, Proc. R. Irish Acad., vol. xxv, ser. B, No. 4, 
p. 144, pl. vi, fig. 6. 
? Pericyclus virgatus, Foord & Crick, Cat. Foss. Ceph. Brit. Mus. Nat. Hist., 
pt. iii, p. 146. 

Since the publication of this species much fresh material has 
accrued from many localities. The suture-line has also been seen 
and more perfect specimens examined. I now think it should be 
more correctly placed in the genus Pertcyclus, Mojsisovics. I showed 
much of my material to the late Mr. Crick, and he expressed agree- 
ment with my conclusions. In many of the fossil lists I have 
published this species has been confused with G. beyrichianum. 
As the species was erected on fragmentary specimens I think it 
best to redescribe and refigure it in more detail. Its lowest known 
occurrence is in the Posidonomya becheri beds of the Pendleside 
Series, but it goes up as high as the 3rd Grit Shales of the Millstone 
Grit. 

Specific Characters.—Shell discoidal, compressed, umbilicated, 
attaining a diameter of 70mm. Greatest thickness at umbilical 
margin. Height of outer whorl, four-sevenths of the diameter of the 
shell. Whorls seven or eight, inclusion in the inner whorls almost 
mil but becoming in the outer three or four more and more complete. 
Umbilicus deep, open in the young, becoming relatively more 
narrow with the growth of the shell, its margin rounded, the 
under surface bevelled. Whorl elliptical in section, deeply im- 
pressed by the preceding one. Periphery narrow, convex, becoming 
obscurely keeled centrally in fully grown shelis. Very feebly 
convex at the sides. Body-chamber occupies two-thirds of the last 
whorl. Suture-line as shown in Fig. 6. 

Test ornamented with many flattened ribs which bifurcate about 
half-way between the umbilicus and the periphery. The grooves 
between the ribs, linear at first, become broader and equal, about 
half the measurement of the ribs in breadth. The ribs arch 
forward on the side, but on the periphery form a fairly deep sinus 
with concavity towards the younger part of the shell. A specimen 
from Cracoe Fells shows also spiral marking on the ribs. 

Dimensions.—Greatest diameter, 70 mm.; width at umbilicus, 
25mm. 

Localities. —Pendleside Series: silica quarry, Congleton Edge, 
Dinckley Hall River Ribble, Flasby, in watercourse between 
Butterhaw and Shelterton, andS. of Shelterton, Horsebridge Clough, 
near Hebden Bridge. Posidonomya becheri beds: Poolvash, Isle of 
Man.: Millstone Grit Shales: Eccup, near Leeds. Ireland: Foynes 
and Foynes Island; Lisdoonvarna, in the Pendleside Series. 

Observations.—The flat dichotomous ribs distinguish this species 
from all other described forms of the genus. P. virgatus, 
de Koninck, sp., has more rounded ribs, and these are not dichotomous. 


Dr. Wheelton H ind—British Carboniferous Goniatites, 449 


Foord & Crick, Cat. op. supra cit., refer doubtfully some specimens, 
said to be from Halifax, to P. wirgatus; they remark, ‘‘ De Koninck 
says the ribs are not dichotomous, but they certainly are in these 
specimens up to a diameter of 16mm.’’ hese shells most probably 
belong to the species under description. The species alters its habit 
with age. In the young the shell is much more globose and the 
ribs more transverse than in the adult, when the shell is more 
discoidal and compressed and the ribs sinuously curved on the side 
with a deep peripheral sinus. 

The young stage may be confused with some forms of G. beyrichi- 
anum, but the umbilicus in the latter is much wider and inclusion 
less. ‘he transverse ribs less close and more acute. 


Pericyclus impressus, de Koninck, 1880. (Pl. XVI, Figs. 8-10, 12.) 
Ann. Mus. Roy. d’hist. Nat. Belgique, tom. v, pt. ii, p. 118, pl. xlix, fig. 3. 

Specific Characters. —Shell subglobose, involute, umbilicated. 
Whorls six, inclusion extensive, somewhat obtusely lunate in 
sections not very high. Umbilicus large and open in the young 
stages, becoming narrow with age; its border rounded, sides convex ; 
the periphery convex. 

Body-chamber occupies the last whorl. Camere four to a 
quarter of an inch. Suture as drawn below (Pl. XVI, Fig. 126). 

Test thin, with many simple transverse subangular ribs, the sulci 
between which have numerous fine spiral lines. On the periphery 
the ribs have only a suspicion of a hyponomie sinus. 

Dimensions.—Fig. 9, Pl. XVI, measures, diameter 18 mm., trans- 
versely 10mm. 

Loculity.—Millstone Grit Shales (Sabden Shales). Gull beck, near 
Cowling, Yorkshire. 

Observations.—De Koninck’s types were obtained from Véve, 
assise i. ‘The umbilicus at once distinguishes the species from 
others of the genus. 

In the young the ribs are much less numerous, and the umbilicus 
wide, inclusion very small (Pl. XVI, Fig. 10). 

All the specimens obtained were from one bullion in shale, a quarter 
of a mile above Stonehead Farm. 


Prricyctus vireatus, de Koninck, 1880. (Pl. XVI, Fig. 7, 7a.) 
Ann. Mus. d’hist. Nat. Belgique, tom. vy, pt. ii, p. 118, pl. xlix, fig. 4. 

I have two fragments of the body-chamber and one crushed 
example of this species from the Redesdale ironstone. 

In his description de Koninck says, ‘‘ Umbilie assez étroit a bords 
anguleux et infundibuliform,”’ but his figure shows a moderately 
sized umbilicus with a convex border. The ribs are more numerous 
and flatter than in P. funatus, Sow., and less flat and less regularly 
dichotomous than in P. divaricatus, Hind. De Koninck’s specimen 
was obtained at Visé. ‘ 

PERICYCLUS REDESDALENSIS, sp. nov. (Pl. XVI, Figs. 13, 13a, 130.) 

Specifie Characters.—Shell moderately inflated, sides flattened. 
Eyolute, umbilicus about 3%;in. in diameter, greatest thickness half- 
way between the periphery and umbilicus. Inclusion extensive. 

DECADE VI.—VOL. V.—NO. x. 29 


450 Dr. Wheelton Hind — British Carboniferous Goniatites. 


Height of last whorl about half the diameter. Whorls ?4, oval in _ 
section, broader than high, indented by preceding whorl. Umbilicus 
with somewhat raised and rounded margin and convex inner area, 
infundibuliform. Periphery very convex, marked off, in casts, from 
the lateral area by a spiral groove. Body-chamber occupies almost 
a complete whorl. Test unknown except on inner area of umbilicus, 
where there are many distinct, closeribs. The cast shows indications 
of numerous strong curved ribs, with a deep sinus backwards on the 
periphery. Suture-line as figured (Pl. XVI, Fig. 130). 

Dimensions.—Diameter, 43 mm.; transversely, 17 mm. 

Locality.—Redesdale Ironstone, Northumberland. 

Observations.—Hitherto this shell has always been confused with 
G. truncatum, Phillips, from which it differs essentially in the shape 
of the periphery, which is less angular, the lateral area is less 
compressed, and possesses a spiral groove. The suture, too, has 
marked differences in the central saddle and peripheral lobe. 

The late Mr. Crick pointed out to me that Fig. 13, Pl. XVI, shows. 
an interesting condition of growth. The last septum is perfectly 
formed (a), a second septum was being formed (d), and a third 
septum is faintly indicated by a line forming the boundary of the 
muscle attachment. The sudden rise forward of this line indicated 
the commencement of the shell muscle. The spiral line on the left 
side of the shell is half an inch away from the margin of the 
umbilicus, while that on the right is much closer, only a quarter 
of an inch away. A younger specimen shows no spiral groove at 
all, so it probably is only an old-age character. 


EXPLANATION OF PLATE XVI. 
FIG. 
1. Sagittoceras acutwm, sp. noy. #3 nat. size. 
la. Id. The suture-line. 4 nat. size. 
1b. Id. In profile. 3 nat. size. 
2. Pericyclus diwvaricatum, Hind. 2 nat. size. 
2a.Id. Inprofile. #2 nat. size. 
3. Id. Showing the ornament. 4% nat. size. 
4, Id. The young stage. 
4a. Id. In profile. 
5. Id. The ornament and orifice in adult. 4 nat. size. 
6. Id. The suture-line. #% nat. size. 
7. P. virgatus, de Koninck. 4 nat. size. 
7a. Id. In profile. 3 nat. size. 
8. P.wmpressus. Showing the ornament. x 2. 
Sa. Id. In profile. x 2. 
9. Id. Cast. 
9a. Id. In profile. 

10. Id. The young stage. x 4. 

12. Id. Side view showing the ornament. x 2. 

12a. Id. Inprofile. x 2. 

12b. Id. The suture-line. x 2. 

13. P. redesdalensis. Showing (a) last suture completely formed, (b) new 
suture commencing, (c) line forming the boundary of the muscular 
attachment. 4 nat. size. 

13a. Id. In profile. 

136. Id. The suture-line. 


Grot. Maa., 1918. 2 Prate XVI. 


G. M. Woodward, del 


Bale, Sons and Danielsson JI_td 


BRITISH CARBONIFEROUS GONIATITES. 


Sir H. H. Howorth—Geological History of the Baltic. | 451 


Il.—Tue Recent Grotogican History oF rHE Bartic anpd ScaANnnDI- 
NAVIA AND ITS IMPORTANCE IN THE Post-Trrtiary History oF 
Wesrern Europe. 


By Sir Henry H. HowortsH, K-C.1.H., F.R.S., F.S.A., F.G.S8. 
(Concluded from the September Number, p. 409.) 


ET us now turn to the lessons presented by the Mollusca found in 

the raised beaches of Norway and Western Sweden. 

Milne-Edwards was the first to discriminate the European 
molluscan fauna into geographical provinces. This he did in 
a paper in the Ann. Sci. Nat., 1838, p. 10. He separated our 
European seas into two provinces, which he called the Seandi- 
nayian and the Celtic. The latter included the English Channel, 
the coast-lands from Ireland to Gibraltar, and those of the 
Mediterranean. 

S. P. Woodward, in his Manual of the Mollusca (1851-6), pt. 111, 
ch. ii, ‘‘Geographical Distribution,” pp. 357-61, 1856, makes the 
Faeroe and Shetland Islands and the coast of Norway from the North 
Cape to the Naze a part of his ‘‘ Boreal province” (ii, p. 857) and 
leaves the British Islands, Denmark, Southern Sweden, and the 
Baltic in Milne-Edwards’ Celéie province (ili, p. 359).? 

The coasts southwards from the English Channel to.the. Canary 
Islands, and those of the Mediterranean, 8. P. Woodward named 
the Zusitanian province (iv). These names have maintained their 
place. To these provinces has been added an Arctic one, which was 
apparently first suggested by S. Loven in 1896. The names were 
accepted by the elder Sars, who, however, limited them; thus the 
Arctic province with him comprised only” the cireumpolar area 
bounded by the Arctic Circle. The Boreal region he extended from 
the Arctic Circle to Cape Finisterre, in about lat. 48°. South of this 
and including the west coast of France, Spain, Portugal, the 
Mediterranean, the Azores, and the north-west coast of Africa to the 
Canaries he included in his Lusitanian region. The younger Sars 
in his fine work on the Arctic fauna of Norway altered the boundary 
of his father’s Arctic province so as to include the Lofoten Islands. 
His new boundary passed through the North Cape. He justified 
the diversion of the line in the latter place because of the Gulf 
Stream, which causes a great difference between the east and west 
coasts of that promontory, thus creating a similar frontier to that 

caused by Cape Cod in North America. 

These divisions (like all classifications of natural objects) are, 
of course, very largely arbitrary, for the different classes naturally 
overlap. Wherever we put down our dredge in the European area, 
or wherever we sort the shells from a raised beach, we shall meet 
with the fact that some of the molluscs have a very elastic and 
adaptable constitution. They can live and thrive in many varied 
conditions if they can only get food, and we always have to be 
careful in making general inductions from a single species or small 


' Of 289 Scandinavian shells catalogued by Dr. Loven, 217, or 75 per cent, 
are common to Britain, 


452 Sir H. H. Howorth—Geological History of the Baltic. 


group of species, especially if we are tied down to some theory 
which has to be supported at all costs and which distorts our vision 
when we look the facts in the face. It is only too easy to select 
a number of shells which seem to thrive as well in the Scandinavian 
or British seas as in the Arctic Ocean, to dub them Arctic and 
then to apply the term Glacial to a deposit. Again, even the best 
of the older conchologists have at times failed to discriminate 
small differences and varieties which may entirely sophisticate the 
conclusion. I will quote a good example which happens to be very 
familiar to me because I wrote a monograph on the shell, viz. Mya 
arenaria, which was published in the Proceedings of the Zoological 
Society... There can be no doubt from the evidence that JL arenaria 
is a new addition to the fauna of the North Sea and its outliers. 
There is no evidence that it existed there before the beginning of the 
seventeenth century. It was first described by Lister in 1678. 

Gwyn Jeffreys, who did not know this, in his account of the 
Mollusca of the Uddevalla raised shell-bed, not only claimed to have 
found this species of J/ya there, but made a somewhat characteristic 
deduction in regard to it. He described it as an Arctic shell, and 
says of it, ‘‘ The occurrence of this cireumpolar shell-fish so near the 
Tropic of Cancer probably indicates the most southern limit in space 
of the Glacial epoch”? (British Conchology, 111, pp. 65-6). 

Jensen, a much more critical person than Gwyn Jeffreys, has, in 
fact, proved most completely that Jf arenaria is not an Arctic shell 
at all and does not exist in the Arctic regions. Gwyn Jeffreys 
had mistaken another and very different species with an entirely 
different habitat for it, namely J. truncata, var. ovale, which is 
a very high Arctic shell and has been found in Iceland, Greenland, 
Spitzbergen, Nova Scotia, and the Kara Sea. The mistake of Gwyn 
Jeffreys was a particularly unfortunate one, because it was copied 
into several geological works and made the basis of several most 
illegitimate deductions. (For details of the whole discussion I must 
refer to my paper in the Proceedings of the Zoological Society, 
1909, pp. 745-67). 

On several other occasions, as it seems to me, Gwyn Jeffreys used 
the word “ Arctic’? as applied to the habitat of certain shells from 
the raised beaches in a very arbitrary way. 

It does not follow, again, that when truly Arctic shells are found 
in more southern waters they should be always dubbed as Arctic. 
Before so naming them we must be careful to consider measurements 
and other differenti. Many Arctic shells occur in our Northern seas 
which only attain their normal and typical size in very high latitudes 
and become dwarfed in size and otherwise modified further south. 
There are others which ought not to be called Arctic at all, because 
they thrive just as well in temperate regions as they do in Arctic 
ones, having the adaptability of Scotchmen. So that considerable 
care and judgment are required in order to justify the application of 
the term ‘‘ Arctic” to groups of Northern shells. 

1 “* Some living Shells, their recent Biology, and the light they throw on the 


latest Physical Changes in the Earth [| Mya arenaria],’’ by Sir H. H. Howorth 
(Proc. Zool. Soc., 1909, pp. 745-67). 


Sir H, H. Howorth—Geological History of the Baltic. 458 


In Brogger’s admirable monograph on the molluscs of the raised 
beaches in the Christiania Fjord he has compared the living fauna of 
this great Norwegian bight or inlet with that in the later raised 
beaches of Norway, and has shown that a certain number of the 
molluscs now found living in Norwegian waters are not found in 
these beaches at all, and he very naturally infers from this that they 
have invaded these waters since the latest beaches were deposited, 
a large proportion of them having probably come as a direct or 
indirect consequence of human effort. 

It is interesting to analyse these immigrants. Five of them 
which seem to thrive and flourish in the temperate waters of the 
Christiania Fjord belong to the highest latitudes. They are Acmea 
testudinalis, Lophyrus albus, Scalaria Groenlandica, Cerrthropsis 
costulata,’ and Nucula delphinodonta.- The notable thing about 
these five high Arctic shells is that not only are they not found in 
either of the two sets of raised beaches in the Christiania Fjord, they 
are also not found on the Arctic shores of Northern Asia from the 
Kara Sea eastwards, but occur abundantly in the Arcticlands of the 
New World from Behrings Straits to Greenland, and Brogger has no 
hesitation in treating them as Nearctic shells which have migrated 
in late historical times to Europe, having, not improbably, been 
transported by whalers and seal-fishers. The notable thing to 
remember about them is that they seem to thrive under such new 
conditions. 

We will now turn to a number of Bornan species which have, 
probably, found their way into the Norwegian waters in recent years, 
notably :— 


Mya arenaria (of which we have spoken above), Tellina pusilla, Macoma 
tenuis, Psammobia tellinella, Rupicola distorta, Neera rostrata, and Risso- 
stomia octona, all recent introductions from the West. 

_ Lastly the Lusrranrawn species, which have immigrated since the 
latest raised beds were laid down, viz. :— 


Lima hians, Modiolaria marmorata, Nucula nitida, Sphena Bingham, 
Teredo navalis, Trochus zz yphinus, Hydrobia ventrosa, Onoba costata, 
Cingula senustriata, Turbonilla scalaris, Stulifer Turtont, Mangelia attenuata, 
M. striolata, Scalaria Tur toni, Aplysia ‘punctata. 

It is not possible to know how these vagrants found their way into 
Scandinavian waters during a period when the climate, as we shall 
see presently, has been only slightly changed, nor would a change of 
climate avail as a reason, for the newcomers belong to different 
marine climatic regions. In regard to the Lusitanian migrants 
I have a theory which I think interesting, but must postpone to 
another paper. 

From these recent comers we will turn to the shells which are 
found in the /ater raised beaches, but no longer live in the neigh- 
bouring sea. The total number of shells from these beaches is 255. 
Forty of these are Arctic, 103 Boreal, and 112 Lusitanic. Of these 
210 are now living, leaving 45 species represented in the beaches 


1 This species, which does not occur in the beaches of the Christiania Fjord, 
has been found in those at Uddeyalla and in Britain. 


454 Sir H. H. Howorth—Geological History of the Baltic. 


but not now living in this region, 14 of which are Arctic, 9 Boreal, 
and 22 Lusitanic. 

The 14 Arcric forms are :— 
Terebratella Spitzbergensis, Pectenislandicus, Portlandia lenticula (?), Tridonta 
borealis, Panopea Norvegica, Molleria costulata, Margarita Groenlandia, 
M. cineraria, Morvillia undata(?), Marsenina micronphala, Trichotropis 
borealis, Littorina palliata (?), Sipho togatus (?), and Utriusculus pertenuis. 


The 9 BorEaL species are :— 


Gwynnia capsula(?), Montacuta Viringit, Solen ensis (?), Cadulus propinquus, 
Lamellaria latens, Auriculina diaphana, Sipho gracilis (?), Neptunea 
antiqua (?), and Utriculus obtusus. 


The 22 Lusrranic species are :— 


Arca tetragona, Cardiwm tuberculatum, Tapes decussatus, Levton syuamosum, 
Scrobicularia piperata, Lasea rubra, Tellina crassa, Macoma fabula, Psam- 
mobia vespertina, Solecurtus antiquitatus, Pholas candida, Cingula soluta, 
Onoba vitrea, Alvania reticulata, Aclis ascaris, A. unica, Turbinella lactea, 
Odostomia albella, Culinella nitidissima, Clathurella purpurea, Mangelia 
nebula, Philine pruinosa. 


(Brégeger, op. cit., pp. 577, 578.) 


Some species like Jsocardia cor, existing both in the beaches and 
living, were formerly very common in the Christiania Fjord, but are 
now very rare; others are decidedly rarer now than they were, such 
as Pecten varius, P. septemradiatus, P. opercularis, and the oyster. 

In one matter I would take exception to Brogger’s classification of 
the later beaches, which he groups together under the name post- 
Glacial beds. Having named the greater number of them Zapes beds 
from the presence in them of that very characteristic shell, he 
proceeds to treat others, which agree with the Zapes beds virtually 
in all their other contents but in which the Zapes have not been 
found, as belonging to a different horizon. This seems to me to 
introduce a quite unnecessary complication into the problem, 
unjustified by the evidence. There are only a limited number of 
molluscs which are sufficiently elastic to live under very different 
conditions of food and bottom, and the occasional absence of a 
particular shell is often merely due to peculiar local conditions. 

Every shell-collector knows as an elementary fact that when we 
pass from clay to mud or sand or gravel or rocks, we at once lose 
certain of the species which are perfectly contemporaneous and 
which are now living in different parts of the coast of the same 
sea. The complete absence of the Zapes and the oyster from the 
modern Cattegat, although they were abundant there before the ~ 
Baltic breach, shows that they were not capable of tolerating certain 
changed conditions like others of their companions could, and we 
must in such cases take the general facies of the contents of the beds, 
and not the presence or absence of a particular shell, as justifying us 
in creating a new horizon. 

In regard to the dying out of the forms it is not easy to give an 
entirely satisfactory explanation, for they belong to all three of the 
geographical provinces into which the mollusca have been divided 
by Brogger. It is possible that the reduction in the salinity of the 


Sir H. H. Howorth—Geological History of the Baltic. 455 


water due to the outflowing of so much fresh water from the Baltic, 
which certainly destroyed some, may have had a wider influence 
than we know. Another cause to which we will turn presently is the 
great shallowing of the water in certain cases, and a third a possible 
change of the temperature of the water affecting the supply of food. 
What is important to remember is that the mollusca represented by 
the so-called post-Glacial beds belong essentially to that of the 
Tapes beds of the Cattegat beaches, and that although Tapes is 
extinct in the Christiania Fjord, two species of the genus are no 
longer found there, but are still found living in the North Sea and on 
the Western Norwegian coast. Dr. Brogger, in fact, as I have said, 
calls the greater number of the beds occurring in the Christiania 
Fjord, which he classes as post-Glacial, the Zapes beds. 

I would venture very deferentially, therefore, to differ from him 
in allocating anything more than a quite relative value to the 
presence or absence of any particular shell from a bed as a test of its 
age or homotaxis. JI would treat them as the result merely of 
different local surroundings and as being entirely local divisions, and 
in this case I would name them all Zapes beds, and use that name 
in the sense in which Dr. Brogger uses the name post-Glacial beds. 

-Turning to these lJater or so-called post-Glacial beaches in the 
Christiania Sound, I will give a list of some of their heights above 
sea-level as reported by Sars (op. cit., p. 3):— 


On the east side of that Gulf. Heights above sex level: 

eet, 
Skullerud in Héland . : | : 437 
Nordby on the Ogdered Lake : : : 516 
Sververud (Oppegaard) near Hidsberg . ‘ 540 
Killebo and Damholt in Rakkestad : 440, 475 
Kolbjérnsvik in Aremark . é . 400, 410, 455 
Skjaedal, Hellesaa : : : : 3 476-454 
Bjérndal in Aremark . 5 : : : 385-375 
Sandbol-Skjaeldal : p ‘ : ! 350 
Moen in Aremark : : : : : 457 


To each of these numbers Sars would add 90 feet in order to ascer- 
tain the actual depth at which the molluscs live. 

Let us now turn to the high Arctic beds, which have a good deal 
more importance and interest for us than the later or post- 
Glacial ones. 

I have stated that in the Christiania Fjord and in the northern 
part of the Cattegat, in addition to the Zapes beds which occur at 
different levels, we have another series unmistakably contrasted with 
them, since they only contain shells belonging to an extreme Arctic 
type, while on the other hand the two sets of beds have none of their 
shells in common, so that in dealing with them we get rid of all 
the difficulties of overlapping. These beds have been called from 
their most characteristic shell Yoldia clays. They present some 
eritical problems in which I find myself in sharp difference with the 
Northern writers. 

The fauna of these beds comprises the following twenty-six species 
of molluscs and a number of varieties. 


| 


456 Sir H. H. Howorth—Geological History of the Baltic. 


SPECIES AND VARIETIES OF SHELLS CHARACTERISTIC OF THE 
: YOLDIA CLAYS. 


1. Macoma (Tellina) calcarea, var. 14. Neptuneadespecta, var.carinata. 


maxima, 15. N. denselirata, n.sp. 
2. Saxicava arctica, var. 16. Sipho togatus, var. Pfaff, var. 
Uddevallensis. sinuosa, var. vallensis. 

3. Pecten rslandicus. 17. S. brevispira. 

4, Leda pernula, var. costugera. 18. S. islandicus. 

5. Nucula minuta. 19. S. Verkriitzent, var. plicifera. 

6. N. tenuis, var. expansa. 20. Trophon truncatus, var. major. 

7. Lyonsta arenosa. 21. Cylichna Remhardti. 

8. Lepeta cocca, var. major. 22. Modiolaria mgra. 

9. Natica affinis, var. clausa. 23. Portlandia arctica = Yoldia 
10. Lunatia Groenlandica. arctica, var. siliquwa, var. 
11. Astarte undata. portlandica, var. inflata, var. 
12. Buccinumterra-nove,var.grandis 24. Yoldia hyperborea. 

and var. a. 25. Admete viridula. 
13. B. hydrophatium, var. elata, 26. Bela nobilis, var. rugulata. 


var. fusco-rufescens, var. textw- 
lata. 


(Brégger, op. cit., pp. 31, 32.) 


Of these species and their varieties 26 have been found at 
Glommen between Sarpsborg and Frederikstad, 11 at Sandefjord, 
8 at Tonsberg, and 9 at Moss. 

From the Voldia clay at the last named of these places Brogger 
also enumerates a number of Foraminifera, and among them he 
characterizes Polystomella arctica as being a high Arctic species 
(op. cit., 33 and 670). 

I will now give the living habitat of some of the above shells :— 


Macoma calcarea. The coasts of North Siberia and North America, 
Greenland, and Spitzbergen. 

Saxicava arctica. The Kara Sea and North Siberian coast and West and 
North Greenland. 

Pecten islandicus. Greenland and Finmark. 

. Leda pernula, var. costigera. North Siberian coast and Greenland. 

Nucula tenuis. North Siberia coast, Spitzbergen, Melville Bay, and 
Greenland. 

Lyonsia arenosa. Nova Zembla and West Greenland. 

Lepeta cocca. Greenland and Grinnell Land. 

Natica affinis: The Kara Sea and generally circumpolar. 

Lunatia Groenlandica. North coast of Asia, Greenland, and generally 
circumpolar. 

Astarte undata. Kara Sea, north coast of Asia, Spitzbergen, and 
Greenland. 

Buccinum terra-nove. Nova Zembla, North Siberian coast, the islands 
of the St. Lawrence, and Greenland. s 

B. hydrophanum. Kast Greenland and Spitzbergen. 

Neptunea despecta. Finmark, Nova Zembla, and north coast of Asia. 

Sipho togatus. Kara Sea, north coast of Asia, and Spitzbergen. 

S. islandicus. Nova Zembla, north coast of Siberia, Gulf of St. Lawrence, 
Spitzbergen, and Greenland. 

Trophon truncatus. North coast of Siberia and Greenland. 

Cylichna Reinhardtt. Nova Zembla and north coast of Asia. 

Modiolaria arctica. Finmark. 

Portlandia arctica. Nova Zembla, the Yenissei, Franz Joseph Land, and 
Greenland. 

Yoldia hyperborea. Greenland, Spitzbergen, and Finmark. 


od 


Sir H. H. Howorth—Geological History of the Baltic. 457 


In a few instances we find that these shells have occasionally 
wandered somewhat south of the Arctic Circle, but generally” the 
more southern specimens are dwarfed and distorted. 

These deposits of Arctic shells have been named after a very 
characteristic Arctic molluse formerly ‘Sowa as Yoldia arctica and 
now as Portlandia arctica. 

It is only lately that the widespread occurrence of the Yoldia in 
the raised beds of Scandinavia has been ascertained. Hisinger was 
the first to find it in Scandinavia at Aker in West Gothland in 1837, 
while Torell found it in a submarine clay at Varberg in 1848. It 
was found on the shores of the Malar Sea in 1852. Sars found it in 
Southern Norway in 1861 and described it from there in 1868 and | 
1865. Presently Esmark found it on the west side of the Bight at. 
Sandefjord and Ranviken. It was Brogger, however, who added 
so greatly to the number of its known sites, thirty of which are now 
known. Ofthese he enumerates twenty-four from the Christiania 
Fjord (op. cit., 669-70). He gives full details with a map on 
pp- 8-454 to the same work. 

At Wenersborg A. Lindstrom found the shell and other shells, 
while at Gothenburg Torell met with it a few metres above the sea; 
V. Munthe found the same shell at Kollekan and on the island of 
Tjorn in Bohuslin, in the former case at a height of 5 to 7 feet and 
in the latter at 10 feet above the sea-level. With it occurred 
Pecten wslandicus, Portlandia arctica, Macoma ( Tellina) calearea, and 

Saxicava rugosa. 

Crossing over the Cattegat we have a similar set of beds which 
have been described by Johnstrup, V. Madson, and A. Jessen from 
Vendsyssel, that strip of North Jutland forming a long narrow 
peninsula separated from the mainland by the Limfjord. The species 
found in the Yoldia beds of this district consist of Modiolaria discors, 
Nucula tenuis, Leda pernula, Portlandia arctica, P. lenticula, Axinopsis 
orbiculata, Axinus flexuosus, Macoma calcarea, M. mosota, M. crassula, 
Lyonsia arenosa, Mya truncata, Saxicava pholadis, Natica sp., Bela 
nobilis, Trophon clathratus, Buccinum Groenlandicum, Neptunea despecta, 
Cylichna Reinhardti, Utriculus pertenuis. On this list Brogger 
comments thus: The commonest species are Saxicava pholadis, 
Portlandia arctica, Modiolaria discors, Macoma calcarea, M. crassula, 
and Cylichna Reinhardti. 

All these species, with the exception of Azinopsis orbiculata, are 
living in the Kara Sea and also in the Greenland seas. The fauna 
from Vendsyssel, he continues, has the same Arctic character as that 
of the Yoldia beds of the Christiania Fjord, although not quite the 
same species. Jessen has found the Yo/dia clay in this district as 
high as 33 metres. 

In the island of Laes6é in the Cattegat, according to Jessen, the 
same high Arctic species have been found at an elevation of 3 metres 
and more. From Halland and Dalsland in Western Sweden the 
Yoldia beds have long been known. Hisinger was the first to find 
Yoldia at Akersvass and Trollhatten, and with it a number of other 
molluscs from 12 to 15 metres or 40 to 50 feet above the sea-level. 

In Western Norway Torell found it in 1860 at Lademoen and 


458 Sur H. H. Howorth—Geological History of the Baltic. 


Baklandet in Trondhjem, and his discovery was recorded by Sars in 
1865. Here it was 123 metres above the sea. Kjerulf reported 
similar finds at Klabu, Selbu, and Nidelven in the same province, 
apparently up to 130 or 150 metres (ibid., 124-9). In Nodland 
and at Nidelven it was found by Rekstad. j 

I have described the localities where the Yoldia fauna has occurred 
in considerable detail because of the important place which it 
has filled in geological polemics, and because for a long time the 
deductions based upon it had to be supported by very limited 
examples. It is now. cbvious that the fauna was widely spread 
over the area once occupied by the Christiania Fjord, the northern 
Cattegat, and the Eastern Gulf, which included the Great Lakes of 
Sweden. 

Let us now turn to the lesson which these beds have to teach us 
and which I claim have been completely misunderstood. There is no 
question about Yoldia and its companions being very high Arctic 
shells, nor is there any ambiguity in interpreting the evidence caused 
by the mixture of shells occurring in other beds or living under more 
temperate conditions. It is perfectly plain that at the horizon 
where these shells lived the temperature must have been very low. 
This is indisputable. There are other facts, however, which preclude 
the explanation of their surroundings offered by Brogger, and which 
have led him and many others, including the late Professor James 
Geikie, to postulate that when they were living Scandinavia must 
have been under glacial conditions. I especially propose to deal 
with Brogger’s arguments. 

First, then, about the relative position of the Yoldia beds to the 
later or Tapes beds, and especially in the Christiania Fjord where they 
occur together. The Yoldia beds in this district do not occur higher 
than from 40 to 50 metres or a little more above thesea-level, while 
the later beds in which the molluscs are virtually the same as those 
now living in, the adjoining sea have been found by Mr. Oyen at 
Grefsen and Arvold, near Christiania, as high as 203 to 208 metres 
(Brogger, op. cit., 698). I have given a series of other heights 
attained by them in this district in an earlier page. The Yoldia 
clay, says Broégger, occurs at the height of 40 to 60 metres in some 
places. At lower levels, he says, they occur at Nevlung, Laven, 
Sandefjord, Tonsberg, Asgards Strand, Horlten Moss, and Rade, by 
the Glommen, etc., on the present shore-line and only a few metres 
above it. ‘I'hat is to say, in this district. the Zapes beds lie far above 
the Yoldia beds. Elsewhere the two sets of beds occupy the same 
relative position towards each other wherever they occur together in 
other parts of Scandinavia. It seems to me inevitable that this 
involves the conclusion that the Zapes beds emerged from the sea 
before the Yoldia beds. That is the conclusion Brogger has himself 
drawn in the similar case of the Ancylus beds and the Lztorina beds 
of Sweden, and it cannot be evaded. 

It is also plain that the molluscs of the upper or Tapes beds, which 
are rich in the number of species, are, with very slight and negligible 
exceptions, all of the same forms as those now living in the 
adjoining seas, while none of those in the Yoldia beds are now 


Sir H, H. Howorth—Geological History of the Baltic. 459 


living there. Not only so, but it is plain that whenever and where- 
ever they lived they were surrounded by Arctic conditions. This is 
indisputable. What I dispute is that they in any way testify to — 
a Glacial period. If they did so, that Glacial age must have inter- 
vened between the period when the Zapes beds were uplifted and the 
present conditions of climate in the Scandinavian seas, which 
biologically are duplicates of each other. This would mean, first, 
that the postulated Glacial period was intercalated between two 
periods marked by the same temperate marine fauna. In other words, 
the fauna of the Zapes beds must have been entirely exterminated by 
the extreme Arctic climate of the Yoldia period, and then the latter 
must in turn have been similarly exterminated and replaced by the 
older inhabitants, after which a return to precisely the same 
conditions again took place. 

Apart from all other considerations, the proposed theory involves 
not merely a gradual change of climate, but a sudden and drastic 
one, or else there would be some evidence of a gradual transition of 
fauna, whereas there is none, but a complete and drastic change of 
the whole fauna. Secondly, there is the puzzle of explaining 
whither the remnants that escaped the extermination fled, and 
whence they could return to their old homes in better times. 

Surely such a position is preposterous and unbelievable unless 
supported by overwhelming evidence. As a matter of fact, 
Dr. Brogger produces no evidence at all, but only a quite fallacious 
deductive argument. He says quite rightly that in the high 
Arctic sea where the Yoldia and its companions are found, they 
mostly hve at a depth of from 10 to 30 metres, a number of them, 
he adds, living at greater depths (op. cit., 681). He then goes on 
to argue that the same species of molluscs when it lived in the 
Scandinavian seas must have lived at about the same depths, 
notwithstanding the great difference in latitude. To justify the 
immense postulate he relies on the still more wilful one of a Glacial 
nightmare as his deus ex machina, and entirely ignores the two 
fundamental difficulties I have just pointed out. 

It seems to me that a very much more simple explanation of the 
phenomena we are discussing is available which needs no fantastic 
postulates to support, but only an accurate induction from the known 
facts. I would urge in answer to Dr. Brogger that what the Yoldia 
and its companions require for their existence is not a uniform 
depth of water in all latitudes where it lives, but a fairly uniform 
temperature in the water. That temperature exists now not only in 
the Arctic Circle but in the depths of the Atlantic and of the North 
Sea, and needs no Glacial nightmare to create it in those latitudes. 
It has not truly been proved to do so by a great many deep-sea 
soundings, and itis an inevitable corollary from the interchange of 
warm and cold water between the temperature of Arctic regions as 
a result of natural laws of ocean circulation. 

We all know the elementary example which has been so often 
quoted, namely, the existence of living northern molluscs, not only 
in the boreal latitudes of Christiania, but in the southern one of the 
Mediterranean. These molluses do not occur there at the same depth 


460 Sir H. H. Howorth—Geological History of the Baltic. 


that they doin the more northern latitude regions, but very much 
deeper. They occur in its abysmal depths, and we know quite 
certainly that they occur there in very cold water. We also know 
that the cold water in question is brought in by a deep current of cold 
water from the Atlantic and has its complement in an outgoing upper 
current which flows outwards. Not only so, we have an example 

of the concurrent and contemporaneous effects of the presence of 

a warm and an Arctic current side by side in Finmark and 
the Lofoten Islands. In the former case the two zones of life 

are separated by the North Cape, and in the latter by the islands just 

named. In each case, within a few miles of each other, we have the 
Yoldva fauna and the Tapes fauna living quite happily at the very 

same time, the one supplied by an Arctic current and the other by the 
Gulf Stream. Not only so, but off the north-west of the Lofoten 

Islands, the Yoldva occurs living, not as Brégger demands, at a depth 

of 10 to 80 fathoms, but of 60 to 100 fathoms, as we should expect. 
with the change in the latitude. We naturally conclude that if 
these conditions, but on a greater scale, were repeated in the latitude 
of the Christiania Fjord by a sufficient depression of the sea bottom, 

the Arctic water would necessarily find its way thither and the 
Yoldva and their friends would thrive there, while at a higher level 

quite close by, there would be living precisely the same fauna as 

lives there at this moment. This is what is actually occurring on 

some of the Norwegian fjords, where the great depth of water at 

their lower end has induced a contrasted fauna between their upper 
and lower reaches. 

Now it is quite certain that the molluscs in the raised Tapes beds 
of the Trondhjem and Christiania Fjords were living several hundred 
feet below the present raised beach levels, or rather at a greater 
depth still, for we must add probably 90 feet to the level of the 
latter in order to secure them a sufficient submergence. Inasmuch 
as the difference in the present level between the YVoldia beaches and 
the Zapes beaches in the Christiania Fjord is very considerable, at 
least 400 feet, it follows that the former must have been submerged 
to a much greater depth than the latter, and in fact to-a depth 
approximating to 800 or 1,000 feet. In that case the necessary 
conditions for the life of Yoldia must have existed there in 
the same way that they exist in the North Lofoten waters now, 
only at a greater depth. This seems to me to be an exceedingly 
simple explanation, and it is conclusive for those who do not believe 
in transcendental causes. It further dispenses with all the see-saw 
and rocking-horse machinery of earth movements against which Suess 
protests so strongly, which are incompatible with these movements, 
having been caused by lateral thrusts, as now generally held, and 
which the glacial theory requires to explain the facts. This is not 
all, we can produce direct evidence of a very interesting kind that 
the explanation here maintained is the true one. 

It is at all events a very remarkable fact that while the Yoldia 
has become extinct in the Norwegian seas except in the north-west 
corner of the Lofoten archipelago and perhaps the extreme north of 
Finmark, the whole sea bottom along the coast of Norway is 


Sir H. H. Howorth— Geological History of the Baltic. 461 


covered with its dead shells, and it would seem almost certain that 
this extinction of the shell was due to some uplift having interfered 
with the Arctic water reaching that latitude in sufficient quantity. 
Apart from this, the depth at which these dead shells are found (in 
an area where the latest movements have been those of elevation) 
shows that the Yoldia when living in Norway lived at a very much 
greater depth than that suggested by Dr. Brogger as a necessity of 
its life. : 

There is another fact which is equally or still more impressive in 
this behalf. We owe this notable piece of evidence to the researches 
of Sars. He describes a famous reef near Drodbak, south of 
Christiania, with an area of some 100 kilometres. This is in places 
submerged to the depth of several fathoms, and in others it rises above 
the sea at Barholmen, Kaholmen, etc., to a height of 30 metres above 
the water-level. This reef is covered with a great deposit of the 
dead coral Lophohelia (Oculina) prolifera, which is bush-shaped and 
forms growths two feet in diameter and is accumulated in vast masses. 
It cannot have been washed thither by the tide or a stream, for it is 
firmly attached to the solid rock just as it grew. Although it only 
occurs dead here, it is found living at vast depths in the deeper 
fjords. Sars says at 150 to 200 fathoms, i.e. 900 to 1,200 feet more 
or less. A.M. Norman found it in Bokkenfjord and Korsrjord at 
a depth of 80 fathoms. Sars and Brogger both claim for its habitat 
a very great depth. With it occur the very interesting shell Zima 
excavata, together with Pecten vwitreus, Arca nodulosa, Cardium 
minimum, Waldheimia cranium, Terebratella Spitsbergensis, and T. caput- 
serpentis., 

This is a clear proof that when the coral was living the depth 
of the Christiania Fjord at Drobak must have been quite great 
enough to admit the Arctic current into that gulf, which then 
extended as we have seen in a great inlet as far as the Malar Sea 
and including the Cattegat, the peninsula of Vendsyssel, the great 
lakes of Wettern and Wenern, of Mjosen and the Malar Sea, in 
whose depths we have a number of still living relics of the same 
cold conditions once prevailing there. 

In conclusion, I wish, among other things, to emphasize in these 
pages that the molluscan contents of the raised beaches completely 
confirm the geological evidence of the very recent, continuous, and 
cataclysmic uprise of Scandinavia and of the sea bottom round its 
coasts, thus affording a complete parallel to the similar rise of the 
other great peninsula of Greenland which I have described else- 
‘where. One or two consequent results I have no space at 
present to enlarge upon and can merely mention. One is that the 
breaking of the Baltic breach created a complete gap in the history 
of the fauna and flora of Scandinavia, which from that date to our 
own can have altered very slightly and adventitiously ; and secondly 
that the rise of such a mass of land in these high latitudes must have 
considerably lowered the temperature and affected the internal 
distribution of the plant and animal life in both of which respects 
the evidence of biology completely concurs. I hope to enlarge on 
these issues and to apply directly the arguments here used to Britain 
on some other occasion. 


462 Dr. H. Woodward—Carboniferous Arthropods. 


III.—Nores on some Fossit ARTHROPODS FROM THE CARBONIFEROUS 
Rocks or Cape Breton, Nova Scotra, RECEIVED From Dr. H. M. 
Amt, M.A., F.G.8., F.R.S. (Can.). 


By Henry Woopwarp, LL.D., F.R.S., F.G.S. 


OME years ago I published, with the late Professor 1’. Rupert 
Jones, F.R.S., a description of two small Limuloids referred to 
the genus Bellinurus, sent me by my friend Dr. H. M. Ami (then of 
the Canadian Geological Survey), who obtained them from the 
Lower Carboniferous Marine Series on the Intercolonial Railway of 
Canada, in Colchester County, Nova Scotia (Gror. Mae., 1899, 
pp. 887-95, Pl. XV, Figs. 2 and 38), under the specific name. of 
B. grandevus. Fig. 2 was collected from the sixth cutting east of 
Riversdale Station and Fig. 3 from the third cutting east of Colnary 
River. 

Dr. Ami subsequently sent me a further collection of specimens 
made by him in 1907, from the Carboniferous Series, Glace Bay 
Mines, Cape Breton, Nova Scotia. Before describing these, how- 
ever, I venture to give a few notes on the country whence they 
were obtained, taken chiefly from Dr. Ami’s account of Nova Scotia.’ 

Nova Scotia, New Brunswick, and Prince Edward Island form a 
group of provinces known as ‘‘the Maritime provinces”’, on the 
eastern flank of the Dominion, and with Newfoundland represent 
the most approximate land to our shores in North America. 

«The peninsula of Nova Scotia, 268 miles in length, varying from 
60 to 100 miles in width, forms a part of the ancient Acadia, being 
connected by an isthmus with the Province of New Brunswick at 
the head of the Bay of Fundy (well known for its high tides), its 
main axis being from north-east to south-west, and its mountains, 
with its appendage Cape Breton Island being, geologically, outliers 
of the Appalachian system on the mainland to the south-west. The 
northern limit of the Carboniferous system touches the Gulf of 
St. Lawrence at Miscou Head, and extends in a broad band along 
all the inner coast of Nova Scotia and into Cape Breton, and comes 
out near Sydney upon the coast of the Atlantic, where the waves 
wash the coal-seams on the sea-shore. Carboniferous rocks also 
occur in the Magdalen Islands and at the south-western point of 
Newfoundland, where a seam of coal 8 feet thick crops out near the 
shore. 

The Island of Cape Breton is really a continuation of Nova Scotia, 
from which it is ouly separated by the Strait of Canso; it is 
108 miles long, and contains the important coal-field of Sydney, 
which extends along the Atlantic shore for 32 miles and covers an 
area of over 250 square miles. Thirty-four seams occur in this 
section, but only a few of them have been worked. 

Pictou Coal-field, situated on Northumberland Strait, has the 
finest harbour on the whole north coast of the province. Here the 


1 Stanford’s Compendium of Geography and Travel (new issue), 1915, 
North America, vol. i, Canada and Newfoundland; edited by Henry Ami, 
M.A., D.Sc., F.G.S., F.R.G.S. F.R.S. (Can.); S8vo, 2nd ed. revised, 
pp. xxviii + 1070. 


Dr. H. Woodward—Carboniferous Arthropods. 463 


largest vessels resort to ship coal from the adjacent mines. The 
field is 85 square miles in extent, and is remarkable for the great 
thickness of its seams. In one section the main seam is 34 ft. 7 in., 
and what is known as the deep seam is 22 ft. 1] in. thick. Other 
seams range from 12 feet, 11 feet, 10 feet, 5 ft. 7 in., 3 ft. 3 in.; in 
all 107 ft. 10 in. of coal have been recorded in this area. 

The Carboniferous formation extends from the high land of 
Cape George .westward along the whole coast of the peninsula 
bordering Northumberland Strait, and across the country to Chignecto 
Bay and the Minas Basin, at the head of the Bay of Fundy, 
occupying Cumberland County and the greater part of Pictou, 
Colchester, and King’s Counties. This forms the Cumberland Coal- 
field and has an area of 430 square miles, worked chiefly at Springhill, 
where eight seams occur with an aggregate thickness of 52ft. 7 in. 
of coal. Mines have, however, been opened at several other places, 
as at River Herbert, at Macdan, and at Jogeins, whose port and rail- 
head is at Amherst. 

At the Joggins, on the shore of Chignecto Channel, at the head of 
the Bay of Fundy, is a unique natural exposure of @ continuous section 
of Middle and Upper Carboniferous strata, which gave Sir William 
Logan an actual measurement of 14,570 feet. It is a classic region 
for geologists, and Sir Charles Lyell, who examined it in 1842, and 
in 1845, and lastly in 1852, pronounced it to be the finest example in 
the world of a natural exposure of uninterrupted coal-measures in 
a continuous section 10 miles long. 

The beds, says Lyell,’ are all seen dipping the same way, their 
average inclination being at an angle of 24° S.S.W., the vertical 
height of the cliffs being upwards of 300 feet. He observed seventeen 
trees in an upright position, or, to speak more correctly, at right 
angles to the planes of stratification; he counted nineteen seams of 
coal, varying in thickness from 2 inches to 4 feet. At low tide 
a fine horizontal section of the same beds is exposed to view on the 
beach. The thickness of the beds alluded to is about 2,500 feet, the 
erect trees consisting chiefly of large Sigillarie, occurring at ten 
distinct levels, one above the other; but Sir William Logan, who 
afterwards made a more detailed survey of the same line of cliffs, 
found erect trees at seventeen levels, extending through a vertical 
thickness of 4,515 feet of strata, everywhere devoid of marine 

‘organic remains. The usual height of the buried trees seen by him 
was from 6 to 8 feet; but one trunk was about 25 feet high and 
4 feet in diameter, with a considerable bulge at the base. In no 
instance could he detect any trunk intersecting a layer of coal, 
however thin; and most of the trees terminated downwards in seams 
of coal. Some few only were based in clay and shale; none of them, 
except Calamites, insandstone. The erect trees, therefore, appeared 
in general to have grown on beds of coal. In the under-clays 
Stigmarie (the roots of the Sigillaria) abound. 

In 1852 Sir William Dawson and Lyell made a detailed examina- 
tion of one portion of the strata, 1,400 feet thick, where the coal- 
seams are most frequent, and found evidence of root-bearing soils at 

1 Elements of Geology, 1865, 6th ed., p. 482. 


464 Dr. H. Woodward—Carboniferous Arthropods. 


sixty-eight different levels. Like the seams of coal which often 
cover them, these root-beds, or old sols, are at present the most 
destructible masses in the whole cliff, the sandstones and laminated 
shales being harder and more capable of resisting the action of the 
waves and the weather. Originally the reverse was doubtless true, 
for in the existing delta of the Mississippi those clays in which the 
innumerable roots of the deciduous cypress and other swamp-trees 
ramify in all directions are seen to withstand far more effectually 
the undermining power of the river, or of the sea at the base of the 
delta, than do beds of loose sand or layers of mud not supporting 
trees. 

As regards the fossil plants (of which Sir William Dawson records 
over 150 species in the Coal-measures of the South Joggins),' they 
belong to the same genera, and most of them to the same species, as 
those met with in the distant coal-fields of Europe. Many of the 
still erect trunks of Svgzlaria and Lepidodendron had their interiors 
filled up with layers of sandstone, in which Lyell frequently observed 
fern-leaves, and sometimes fragments of Stegmaria, which had 
evidently entered together with sediment after the trunk had 
decayed and become hollow, while still standing under water. 

When the Carboniferous forests sank below high-water mark 
a species of Spirorbis or Serpula attached itself to the outside of the 
‘stumps and stems of the erect trees, adhering occasionally even to 
the interior of the bark—another proof that the process of envelop- 
ment was very gradual. These hollow upright trees, covered with 
innumerable marine annelids, resemble a ‘‘cane-brake’’, as it is 
commonly called, consisting of tall reeds of Arundinarva macrosperma, 
which Lyell saw in 1846, at the Balize, or extremity of the delta of 
the Mississippi. . Although these reeds are freshwater plants they 
were covered with Balani, having been killed by an incursion of 
salt water over an extent of many acres, where the sea had for a 
season usurped a space previously gained from it by the river. Yet 
the dead reeds, in spite of this change, remained standing in the 
soft mud, showing how easily the Sigillarie and Lepidodendron, 
hollow as they were but supported by strong roots, may have 
resisted for some time an incursion of the sea. 

The investigation of the organisms preserved in the interior of 
these hollow trunks of Szgillarie, at the Joggins Coal-measures, by 
Sir William Dawson, during many years, has resulted in the further 
discovery of quite a number of new and very interesting forms of 
terrestrial animals belonging to the Coal period. 

Of these we may mention the remains of some small Amphibian 
reptiles referred to Dendrerpeton Acadianum and Hylonomus Lyell, 
Dawson. To these have been added Baphetes planiceps ; numerous 
insect remains, and a atone Xylobius sigillaria ; | an air-breathing 
snail, Pupa vetusta, eben 


' Acadian Geology: The Geological Structure, Organic Remains, and 
Mineral Resources of Nova Scotia, New Brunswick, and Prince Hdward 
Island, by Sir Wm: Dawson, 8vo, 1868, pp. 694. 

aes Air-breathing Animals of the Paleozoic Rocks in Canada,’’ by Sir Wm. 
Dawson, C.M.G., F.R.S.: Trans. Roy. Soc. Canada, 1894. 


Dr, H, Woodward—Carboniferous Arthropods. 465 


Bivalve mollusca are extremely abundant in certain shale beds of 
the Coal-measures, and many have been described and figured by 
Sir Wm. Dawson, Dr. Wheelton Hind, and others.’ 


Fic. 1.—Anthracomya arenacea, Dawson. 1%. Found on the same slab 
with Huproops Annie, H. Woodw. From Donkin Pit, No. 6. Coal- 
measures : Glace Bay Mines, Cape Breton, Nova Scotia. 

The specimens of Limuloid Arthropods already described by me 
from Nova Scotia in this Macazinr (for September, 1899) were 
referred to the genus Bellinurus ; those about to be noticed were also 
obtained by Dr. Ami, but from the northern extremity of the province 
at Glace Bay Mines in the Islarid of Cape Breton, and are referred 
to the genus Huproops. (See Text-figs. 2-4, pp. 466-7, infra.) 


Order MEROSTOMATA, Dana, 1852. 
Sub-order II. XIPHOSURA, Gronovan, 1764. 
1. Genus Evrroors, Meek & Worthen, 1868, Geol. Surv. Illinois, 
vol. ii, 1868. 

SynonyMY.—Prestwichia (H. Woodward, 1867), having been preoccupied 
by Lubbock in 1863 for a genus of HYMENOPTERA, Hwproops becomes the 
type for the following species :— 

Huproops Dane, Meek & Worthen, Geol. Sury. Illinois, vol. iii, 1868. 
. (Prestwichia) anthrax, H. Woodw., Quart. Journ. Geol. Soe., vol. xxiii, 

Peoe ple toe 2) SG. 

. (Bellinurus) anthrax, Bailey, Ann. Mag. Nat. Hist., ser. II, vol. xi, 

p. 113, 1863. 

. Collettt, White, Fauna of Indiana Coal-measures, Geol. & Nat. Hist., 

pl. xxxix, fig. 2, 1883. 

. longispina, Packard, American Naturalist, vol. xix, p. 292 (not figured), 

1885. 


by 


E 

H 

#H 

E. (Limulus) anthraz, Prestwich, Trans. Geol. Soc., ser. 1, vol. v, pl. xii, 
figs. 1-4, 1840. 

Hi. (Prestwichia) anthrax, Bolton, Trans. Manchester Geol. Soc., vol. xxxiv, 
fig. 120, p. ix, 1915. 

E. (Prestwichia) Birtwelli, H. Woodw., Grou. MAG., Vol. IX, p. 440, Pl. X, 
Figs. 9, 10, 1872. 

EL. (Prestwichia) Birtwell, H. Woodw., Pal. Soc. Mon., Merostomata, pt. vi, 

p. 247, pl. xxxi, figs. 7a, b, 1878. 

E. (Prestwichia) anthrax, H. Woodward, Pal. Soc. Mon., Merostomata, pt. v, 

p. 244, pl. xxxi, fig. 6, 1878. 


Euproops Amie, H. Woodw., sp. nov. (Text-figs. 2-4, pp. 466-7.) 

The specimens referred to this species consist of an almost 
complete example and two detached head-shields of a new species 
of ‘‘king-crab”’, exposed on the surface of three slabs of black-grey 
shale, associated with specimens of a bivalve mollusc, Anthracomya 


1 See Quart. Journ. Geol. Soc., vol. 1, pl. xx, fig. 4, 1894 (W. Hind). 
DECADE VI.—VOL. V.—NO. X. 30 


466 Dr. H. Woodward—Carbonrferous Arthropods. 


arenacea, Dawson (Text-fig. 1), fragments of plant-remains, and some 
traces of fish-scales. 

Like the type of the genus (see supra, p. 465) in Kuproops Ama, the 
head-shield is remarkable by reason of its narrowness from back to 
front, and the extreme lateral expansion of its cheek-spines, which 
curve upwards and outwards from the posterior border of the head- 
shield towards the middle of the cheek before curving downwards to: 
their slender extremities, forming an are of about 55 mm. measured 
around the front border of the shield, and 36 mm. along the chord 
from the extreme points of the cheek-spines, or more than three 
times as wide as the head-shield is long. ‘The frontal border is 
narrow and slightly flattened, and the frontal doublure is less 
strongly marked. 


Fic. 2.—EHuproops Ania, H. Woodw., sp. nov. Xx 1%. (The telson is 
restored.) Donkin Pit, No. 6. Coal-measures: Glace Bay Mines, Cape 
Breton, Nova Scotia. 

The posterior border of the head where it unites with the 
thoracetron is 14 mm. broad, but it widens to 29 mm. (including 
the genal border). The glabella, which is slightly raised, is 10 mm. 
wide at the cervical border, but slightly widens across the line of the 
orbits, which are only obscurely to be determined, and is faintly 
circumscribed by a roundly protuberant rim, within which the 
glabella forms into a double arch in front, the two arches uniting 
in a V-shaped backwardly directed ridge in the central line, behind 
which are three small median lobes marked off by transverse furrows, 
the hindmost resting on the cervical furrow and the front one 
extending up to the V-shaped point of the axial ridge. The basis 
of the glabella ridges gives rise to two backwardly directed slender 
spines, each 9 mm. in length (these are broken off in Fig. 2, 
otherwise the most complete specimen, but are seen in the detached 
head-shields, Figs. 8 and 4). The thoracetron articulates along its 
anterior border with the posterior margin of the head-shield, which 
is roundly elevated and cordiform in outline, being 11 mm. broad 
anteriorly, 16mm. across at its widest part, and about 25 mm. to the 
extremity of its lateral marginal spines. The axial division of the 
cephalon, 5 mm. in width, is continued down the centre of the thora- 
cetron, diminishing gradually to about half that width posteriorly. 


Dr, H. Woodward—Carboniferous Arthropods. 467 


The longitudinal furrows of the axis serve to maintain the trilobed 
character of the whole body. The thoracetron consists of six nearly 
equal, coalesced segments (the ridge and furrow of each are marked 
on the central lobe) curving backwards to the margin, and bordered 
by a stout ridge, which in each segment terminates in a prominent 
marginal spine (of which there are seven, the seventh forming 
a part of the rudimentary abdomen); the spines are united to each 
other by a flat narrow-scalloped border of the shield. The extremity 
of the axis, composed of two or more coalesced segments and together 
with the telson or caudal spine (wanting in this specimen), form the 
rudimentary abdomen: (the telson or tail-spine being absent can only 
be vaguely estimated from other specimens). here are indications 
of tubercles along the axial lobe, the base of the largest of which is 
seen near the termination of the axis over the articulation for the 
telson. 


BG SeSH axle Fie. 4: x 18. 


Fies. 3 and 4.—Two detached head-shields of Huproops Amie, H. Woodw., 
showing long post-cephalic spines from the genal border of the head-shield. 
From Caledonia Pit, No. 4: Glace Bay Mines, Cape Breton (H. M. Ami, 
1907). 


Compared with the type of Huproops (EL. Dane, Meek & Worthen) 
the head-shield of #. Amie is deeper from back to front, the free- 
cheek spines are more laterally divergent and more hollowed out 
upon their inner posterior border; the axis is broader than in the 
type, in which the margin of the glabella is somewhat narrower 
and the eyes are said to be more anteriorly placed; in £. Amie 
the posterior border of the glabella, which is rounded, terminates in 
a pair of slender spines three times as long as those of the type 
(#. Dane). The thoracetron in #. Amie is roundly cordiform, and 
the scalloped marginal border is more definitely separated from it. 
[As Dr. Meek’s specimen is mainly known by his admirable restoration 
a strict comparison with less perfect materials leaves some points 
rather doubtful. | 

I dedicate this species to its discoverer, my friend Dr. Henry M. 
Ami, who has devoted many years to the study of Acadian geology. 


468 Dr. H. Woodward—Carboniferows Arthropods. 


2. Nore on Kuproors (Prestwicuia) Brrrwerur, H. Woodw. 
Prestwichia Birtwelli, H. Woodward, GEou. MaG., Vol. IX, p. 440, Pl. X, 
Figs. 9, 10, 1872. 
P. Birtwellr, H. Woodward, Pal. Soc. Mon., Merostomata, pt. v, pl. xxxi, 
figs. 7a, b, c, p. 247, 1878. 

After careful reconsideration of this species I have come to the 
conclusion that the nodules in which these two specimens were 
enclosed contained only the central portion of the body-shields, and 
that the flat marginal scalloped borders, with their spines, and telson 
were not preserved as they extended beyond the hard central con- 
cretion into the softer external concentric layers of clay (as frequently 
observed by Dr. Moysey and myself in the clay-ironstone nodules at 
Shipley, near Ilkeston, Derby, and those also of Rochdale, Lancashire, 
and Coalbrookdale, Shropshire), and so were not preserved. 

The general form of the raised rounded central portion of the body- 
shield resembles more that of Huproops than it does Prestwichianella. 
Assuming the margin to have been furnished with a scolloped border 
and the segments to have terminated in marginal spines upon the 
border of the thoracetron, the resemblance to Huproops Dane, 
FE. anthrax, and #. Amie would have been complete. 

Formation and Locality.—Coal-measures: Cornfield Pit, south bank 
of the River Calder, Padiham, Lancashire. 


3. Notre on THE GENUS PRestwicHia, H. Woodw., 1866. 


In reference to the genus Prestwichia I had for some time been 
doubtful as to the advisability of retaining the species named 
P. anthrax and P. rotundata under the same genus. The investigation 
of this matter led to the discovery [to which my attention was 
obligingly drawn by my friend Mr. Charles Davies Sherborn, of the 
British Museum (Natural History) ] of a note which had appeared in 
the American Geologist for 1905, p. 380, by Mr. T. D. A. Cockerell, of 
the University of Colorado, U.S., that the name Prestwrchia had been 
preoccupied for a genus of Hymenoprera by Lubbock in 1863, and 
suggesting the propriety of transferring the species so named to 
Messrs. Meek & Worthen’s genus ae oops, 1868. The specimen 
here referred to was first described in 1865 by Meek & Worthen 
under the name of Belinurus Dane; later on Mr. Meek assigned his 
specimen to a new genus between Belinurus and Prestwichia, for 
which he oaapeen the name Huproops, in allusion to the anterior 
position of its eyes.’ 

But although this form, like Prestwichia, has the segments of the 
thoracetron anchylosed, Euproops differs from it in the “quadraneular 
form of the glabella, and the eyes being situated forward on its 
anterior lateral angles, while in Prestwichia they are borne upon 
the lateral margins; the genal border must therefore be considered 
equivalent to the orbital suture, or (most probably) coalesced with it.? 


1 F. B. Meek, Amer. Journ. Sci. & Arts, May, 1867. See also GEOL. MaG., 
July, 1867, p. 320, and Geol. Rept. by Meek & Worthen, Survey of Illinois 
(Paleontology), vol. iii, 1868. 

2 In many of the Trilobita the eye-suture and the axial line of the glabella 
are close together; in young stages of the living American Limulus the axial 


Dr. H. Woodward—Carboniferous Arthropods, 469 


4, PRESTWICHIANELLA, gen. noy., 1918. 


Prestwichia, H. Woodw., November 21, 1866. 
P. rotundata, H. Woodw., Quart. Journ. Geol. Soc., vol. xxili, p. 32, pl. i, 
fic. 2, 1866. 
Limulus rotundus, Prestwich, Trans. Geol. Soc., ser. U, vol. v, pl. xli, 
fie. 5, 1840. 
Seeing that the name of Prestwichia, H. Woodw., was preoccupied 
by Lubbock in 1863, I now propose to substitute, for the species 
P. rotundata, the new generic name of 


Prestwichianella, H. Woodw., gen. nov.! 

Character amended.-—UHead-shield semicircular. The genal borders 
and frontal margin are broad and smooth, and curved roundly on 
each side towards the thoracetron and ending in moderately broad 
lateral genal spines; the glabella is divided along the centre by the 
axial furrow, and by two other slightly diverging parallel lines on 
either of the axes, reaching nearly half-way to the frontal border, 
where they are arcaded, forming a rounded raised confluent line in 
front of the glabella. ‘The circular line seen outside the border of 
the glabella may indicate the impression of the line of the broad 
incurved under-margin of the head-shield. 

The thoracico-abdominal series of segments are apparently united 
together into one buckler, as seen in the larval stages of living 
Limulus (see H. Woodward, Mon. Pal. Soc., Merostomata, pt. v, 
pl. xxxi, figs. 10-12, 1878). Central axis of body-segments 
narrow; abdomen rudimentary and coalesced with the hindmost 
thoracic segment, most probably bearing a short telson or tail spine. 
The broad membranous margin of the thoracetron extends nearly to 
the extremities of the seven strongly marked spines. Five short 
spines mark the posterior margin of the head-shield, and some small 
tubercles along the centre of the posterior axis with a more prominent 
spine near the base of the telson. 


5. Nore on Betiryurus TRECHMANNI, A NEW SPECIES OF LIMULOID 
ARTHROPOD FROM THE DurRHAM COAL-FIELD. 


I have been favoured by Mr. C. T. Trechmann, of Castle Eden, 
Durham, with the loan of a small specimen of a fossil ‘‘ king-crab”’, 
which he lately collected in the highest Coal-measures of the Durham 
Coal-field at Claxheugh on the Wear, near Sunderland. The beds 
are in the zone of Anthracomya Phillipsii, not generally known to 
occur in the Durham area, and as they will be shortly described by 
Dr. Trechmann he kindly permits me to notice this find in advance. 


In 1866 I communicated a paper to the Geological Society, ‘‘ On 
some points in the Structure of the Xiphosura, having reference to 


line and the orbital suture are quite distinct and apart from each other (see 
Mon. Merostomata, pt. v, pl. xxxili, fig. 10, after Packard; fig. 12, after 
Dohrn’s ‘* Trilobitenstadium’’). In the adult living Limulus the compound 
_ eyes occupy the lateral border of the glabella. 

1 P. anthrax and P. Birtwelli are now referred to Euproops. 

* See description in H. Woodward’s Monograph on the Merostomata, Pal. 
Soc. vol., 1878, pt. v, pp. 244-7, pl. xxxi, fig. 5. 


470 Dr. H. Woodward —Carboniferous Arthropods. 


their relationship with the Kurypteride”’: Quart. Journ. Geol. Soc., 
vol. xxill, pls. 1 andi, p. 32, 1867; and again, in my Monograph on the 
Order Merostomata, Pal. Soc., pt. v, 1878, sub-order Xiphosura, 
pp. 236-48, I discussed the arrangement of the several genera of 
these Palzozoic forms of Arthropoda and proposed to divide the 
Coal-measure species into two genera :— 

(A) Those having movable thoracic segments and anchylosed 
abdominal ones, under the genus Bellinurus (with 8 species, 1918). 

(B) Those in which all the post-cephalic segments are coalesced 
under the genus Prestwichia. The name being preoccupied, it has 
now been found necessary to subdivide this latter group into two 
genera, namely: (1) Prestwichianella, with 1 species; (2) Huproops, 
with 6 species. 

In Section A, Bellinurus, Konig, the earliest records of this genus 
in which intelligible figures are given are: by Mr. Charles Konig, 
Keeper of Geology and Minerals in the British Museum in 1820 
(Icones Foss. Sect., pl. xviii, fig. 280), and later, in 1836, by 
Buckland, in his Bridgewater Treatise, 1, p. 396; 11, p. 77, pl. xlv, 
fig. 3; Mr. Prestwich, in 1840, Trans. Geol. Soc., ser. i, vol. v, 
p. 491, pl. xl, fig. 8; H. Woodward, 1866, Trans. Glasgow Geol. 
Soc., p. 247, pl. iu, fig. 10, and Pal. Soc. Mon., Merostomata 
(Xiphosura), pt. v, 1878, p.-236, pl. xxxi, figs. 3a, 6, c, and 4. 


Genus Brtiryurvs, Konig, 1820. 
The species included under this genus are :— 


Bellinurus bellulus, Kénig, 1820, Icones Foss. Sect. 

. arcuatus, Baily, Ann. Mag. Nat. Hist., ser. 11, vol. xi, p. 112, 1863. 

. regine, Baily, Ann. Mag. Nat. Hist., ser. 111, vol. xi, p. 107, pl. v, 1863. 
kiltorkensis, Baily, Brit. Assoc. Rep., p. 75, 1869. 

. Kemigianus, H. Woodw., GEOL. MAG., p. 439, Pl. X, Fig. 8, 1872. 

. grandevus, Jones & Woodw., GEOL. MAG., 1899. 

. lunatus, Parker, Lancashire Naturalist, 1907, p. 44. 

. Baldwini, H. Woodw., GEoL. MAG., 1907, p. 540, Fig. 1. 

. longicaudatus, H. Woodw., GEOL. MAG., 1907, p. 541, Fig. 2. 


by by by bs by by by by 


Betiinvrvs Trecumanni, H. Woodw., sp. nov. 

Specific Characters. — Head-shield semicircular, being 9mm. in 
breadth and 4mm. in length, the genal spines moderately long, 
24mm. in length, directed outwards (the extremity is only preserved 
on one side); breadth of glabella 24mm., the length is not easily 
determined but probably about two-thirds that of the head-shield, 
and there is a faint trace of the arched axis. ‘he frontal border of 
the head-shield is distinctly marked and the centre is roundly 
elevated; the eyes are not distinct; the posterior border between 
the spines is fairly straight and measures 7}mm. The axis of the 
thoracetron agrees with that of the glabella in breadth (viz. 2} mm.), 
only very slightly diminishing towards the telson; its length is 
4mm. There are six free post-cephalic segments, which are markedly 
trilobed, directed slightly backwards, ending along the lateral margin 
in stout recurved spines; the pleurz of these free segments diminish 
rapidly towards the extremity of the thoracetron. There is a small 
coalesced abdominal portion bearing a tubercle above the insertion 


W. D. Varney—* Coal-balls,’ Ambergate, Derbyshire, 471 


of the stout tail-spine, which is 1mm. in breadth, but is only 
impertectly preserved (length unknown). 

There seems to be good evidence that the division (A) of Paleozoic 
‘‘king-crabs”’ represented in the Coal-measures by the genus 
Bellinurus contains the oldest form of the Xiphosura, which take 
precedence, in time, over those with anchylosed segments referred to 
the division (B) represented by the genera Prestwichianella and 
Euproops, as evidenced by their precursor, Weolimulus falcatus, 
H. Woodward,! 1868. 

This earliest known form from the Upper Silurian appears to have 
had ail its segments free and unanchylosed, and the later form 
Bellinurus kiltorkensis, Baily, from the Old Red Sandstone, probably 
represents the same genus as is met with in the Coal-measures with 
free thoracic, and most of them had anchylosed post-thoracic somites. 


Fic. 5.—Bellmurus Trechmanni, H. Woodw., sp. nov. x 4. Upper Coal- 
measures: Claxheugh on the Wear, Sunderland. 

The entire series of species of Gellinurus vary little in their general 
characters. ‘They are all of small size and possessed a long caudal 
spine and rather marked triangular thoracetron. 

The specific characters of the Durham specimen are the obviously 
shorter and outwardly directed cheek-spines, and the broader and 
more parallel-sided axis of the thoracetron, which is proportionately 
larger than in the other species of this genus. 

T dedicate this species, which is the ‘first that has been discovered 
in this great coal-field, to Mr. C. T. Trechmann, whose admirable 
contributions to the paleontology of New Zealand have already 
appeared in the pages of the GroLocican Magazine and elsewhere. 


ITV.—On vHe Occurrence oF ‘‘CoAL-BALLS’? NEAR AMBERGATE, 
DrRBYSHIRE. 
By W. D. VARNEY, B.Sc., University College, Nottingham. 
N the brick-pit cut into the Lower Coal-measures at Bullbridge, 
near Ambergate, the Alton Coal is exposed, immediately over- 
lain by a marine shale roof, containing large nodules (bullions) and 
marine fossils. 


1 See Grou. MaG., Pl. I, Fig. 1, and Mon. Pal. Soc., 1878, pt. v, Xiphosura, 
pp. 233-5, woodeut, and pl. xxxi, fig. 8. 


472 W. D. Varney— Coal-balls,” Ambergate, Derbyshire. 


This succession is similar to that occurring at Shore and other 
well-known localities in Lancashire, where the Bullion or Upper- 
Foot Mine contains numerous ‘‘ coal-balls’’. 

No such concretions have been found and recorded from Derby- 
shire, but the Alton Coal in the above-named exposure was found to 
contain large nodules of iron pyrites. Some of these have centres 
composed of calcite or calcareous material, suggesting that these 
nodules were originally wholly calcareous. 

One of these specimens, on being sectioned, was found to have a 
centre of calcite containing a Stigmarian rootlet, with the xylem (a 
fairly well preserved surrounded by the cortex (6), which, though 
in a poor state of preservation, is still quite recognizable. Other 
parts of the section contained plant tissue badly preserved, and 
partly obscured by pyrites. Pyritization seems to have taken place 
along lines of tissue running through the calcite groundmass as 
seen at (d) and (c) in the diagram and in other parts of the slide. 


Section of nodule showing plant-tissues (somewhat diagrammatic). a, xylem of 
Stigmarian rootlet; 6, cortex; c, d, other tissue, partly hidden by pyrites (e). 


At Bullbridge the Alton Coal is streaked with pyrites, which fills 
cracks and joints, and the thin veins often join on to the nodules of 
the same material. Hence the pyrites was deposited after the 
formation of the seam and its nodules. This fact, and the features 
of the nodule section described, show that the pyrites is secondary, 
and that the calcite and its petrified plant tissue were deposited 
before the pyrites, which has replaced the former and largely 
obliterated the vegetable tissue in so doing. In other words the 
nodules were true ‘‘coal-balls”, now partly or wholly replaced by 
iron pyrites. 

Hence the Alton Coal of Derbyshire contains nodules with petri- 
factions, though they are mostly altered to iron pyrites. Thus the 
seam shows a striking resemblance to the Bullion Seam of Lancashire, 


as described by Miss Stopes and D. M.S. Watson.’ 


‘ **On the Present Distribution and Origin of Coal-balls’’: Proc. Roy. Soc., 
VOIMNEe spans: 


Reviews—Geological Survey of Great Britain. 473 


A rough analysis of the specimen sectioned showed that it con- 
tained, in addition to iron pyrites, calcium and magnesium carbonates 
and calcium sulphate, the last-named being present in sufficient 
quantity to form a thick efflorescence when the nodule had been kept 
for some time. ‘his calcium sulphate is confined to the coal and its 
marine roof, where it is also abundant,' and to these two beds only, 
so that its occurrence seems intimately connected with the latter bed. 

A new locality, therefore, can be cited for the occurrence of 
‘‘coal-balls”’ or their equivalents, namely, the Alton Coal of Derby- 
shire, particularly near Ambergate, under conditions which help to 
confirm the theories enunciated by Professor Stopes and D. M.S. 
Watson,” namely, that in whatever coal tissue-bearing nodules occur, 
that coal is overlain by a roof of marine origin, and that the forma- 
tion. of these nodules was contemporaneous with that of the 
surrounding coal. 


REV LewS- 


I.—Summary or Proeress or THE GeroLtogicaL SURVEY oF GREAT 
Britain For 1917. 55 pp. London, 1918. Price 2s. 


i is a noteworthy sign of the times that this summary of the 
year’s work of the Geological Survey deals almost exclusively 
with matters of practical and economic interest. The depleted 
staff has given evidence of great activity, and an immense amount 
of useful information has been collected, with the assistance of 
certain specialists who were temporarily attached to the Survey. 
The most important work carried out was an investigation into the 
reserves of iron-ore still existing in Great Britain. Every possible 
iron-field seems to have been very thoroughly examined, and it is 
estimated that the grand total of ores of all kinds amounts to no less 
than 11,311,000,000 tons. However, much of this is of very low 
grade and unlikely to be worked for some time to come. 

The subject of refractories has also engaged much attention and 
a comprehensive memoir on the subject is in course of publication. 
The increased demand for tungsten ores has brought about important 
developments in Cornwall and Devon and new lodes have been 
reported on. A ‘special examination was also made of Scottish 
pegmatite dykes as possible sources of potash felspar for pottery, 
enamel, and other purposes. A magnetic survey of certain parts of 
England was undertaken with the object of ascertaining whether 
certain observed disturbances of the magnetic needle were due to 
concealed masses of iron-ore ; a report on the subject is in prepara- 
tion. The proposal to construct a ship-canal across Scotland has 
necessitated investigation of the depth of drift and other superficial 
deposits along the proposed lines, with interesting results. Good 
progress has also been made with the publication of memoirs on the 
Scottish coal-fields. 


1 R. D. Vernon, Grou. MAG., 1909, p. 289. 
{ ibides pe lee 


ATS Reviews—British Museum Annual Report. 


Three appendices contain accounts of the results of deep borings 
at Market Weighton, Newark, and Hitchin respectively. The first 
of these shows that the Trias and Permian do not thin away north 
of the Humber, as was hoped; the boring was stopped in Lower 
Permian Limestone at 3,100 feet from the surface. The boring at 
Kelham, near Newark, reached the Coal-measures at 1,401 feet, and 
penetrated to the Carboniferous Limestone Shales. Only 148 feet 
of strata can be assigned to the Millstone Grit, hence the boring 
probably passed through at least one fault. The Hitchin boring 
appears to indicate a thickness of 250 feet of drift near the western 
margin of the drift-filled channel already known to exist in that 
neighbourhood. 

R. H.R. 


II. — British Museum Rerorn, 1917. Published by H.M. 
Stationery Office, London, 1917. Price 6d. 
W\HIS report as usual contains a large amount of interesting 
information as to the progress of the various departments of 
the British Museum, together with the accounts of the special trust 
funds. The number of visitors at Bloomsbury naturally shows 
a great falling off, since for ten months out of the twelve the 
galleries were closed to the public. At South Kensington most of 
the galleries remained open during the year 1916 and the number of 
visitors was nearly as large as usual, amounting to 402,673. The 
staff carried out for the Government a large number of investigations 
on subjects directly connected with the War, as well as other special 
work of a more normal kind, and various topical exhibits have been 
arranged. The number of new acquisitions is somewhat smaller 
than usual, as might be expected, but the general routine work of 
the Museum has suffered little or no interruption, and the publica- 
tion of serial reports has been continued. A large number of 
valuable fossils have been presented to the Department of Geology, 
of which the most important are perhaps those comprised in the 
Hamling Collection from Devonshire, while the Department of 
Mineralogy has also acquired many specimens of interest, including 
several meteorites from various falls not hitherto represented in the 
collection. 


Ill.—Ter Work or Locat Socrerres anp Museums. 


iP spite of the adverse conditions of the present time as regards 
scientific work on subjects not directly connected with the 
War, it is gratifying to note that many local societies seem to 
pursue the even tenour of their way with little visible disturbance. 
For example, the fifty-first Report of the Rugby School Natural 
History Society for the year 1917 contains evidence of great 
keenness and enthusiasm among the members, who are carrying out 
useful observational work of several kinds, zoological, botanical, 
geological, and meteorological. The section of physics and chemistry 
has also been active, and the report contains reprints of two interesting 


Reviews— Materials required in Glass-making. 475 


papers by members, on the fixation of atmospheric nitrogen and on 
saccharine respectively. 

The first part of the third volume of the Hastings and Hast Sussex 
Naturalist, the organ of the Hastings and St. Leonards Natural 
History Society, also shows evidence of much activity on the part of 
that Society. It contains two papers of geological interest. The 
first of these, by Mr. Anthony Belt, is entitled ‘‘ Prehistoric 
Hastings’’, and comprises a very full account of the geological 
history of that interesting district, from the Wealden to the Roman 
occupation. Most space is devoted to the later phases, and special 
attention is paid to the history and development of man, as is only 
natural in a district so near to the home of Hoanthropus Dawsont. 
Another valuable contribution is a paper on the Brighton Rubble- 
Drift formation, by Mr. E. A. Martin. This, though short, gives 
a very good description of this peculiar and interesting formation, — 
illustrated by phot graphs. 

The annual report of the Norwich Castle Museum for 1917 shows 
that the Museum was the centre for the dissemination of much 
useful information, and the fact that it was visited by no less than 
132,751 persons shows that it has succeeded in fostering a widespread 
interest in historical and scientific subjects. 


TV.—Barririso Suppries or Porash FEnsparR, CONSIDERED FROM THE 
Guass-mMakine Potnr or View. By Professor P. G. H. Boswutt, 
D.Sc., F.G.8. Trans. Soc. Glass Technology, vol. ii, pp. 35-71, 
with 1 plate and 4 figures. 1918. 


OTASH-FELSPAR for use in the pottery and glass industries 

should satisfy the following requirements :— 

1. High content of potash, if possible more than 10 per cent and 
certainly not less than 8 per cent. 

-2. Low content of soda; preferably none and certainly not more 
than 2 per cent. 

3. Low content of quartz, not more than 5 per cent for the best 
pottery, and not in excess of 20 per cent for inferior pottery. In 
glass-making the quartz does no harm, but it can be bought at 
a lower rate than felspar. 

4. The amount of iron oxide should be small, and in the best 
pegmatites the percentage falls below 0:1. 

5. Lime should not exceed 0°5 per cent. 

6. The rock must be fresh, or there will be a considerable loss of 
potash owing to kaolinization of the felspars. 

It may be mentioned that 13 and 9 per cent of potash correspond 
respectively to 77 and 538 per cent of microcline or orthoclase, and 
3 and 1 per cent of soda to 25 and 9 per cent of albite. 

More or less workable deposits of potash-bearing felspar in the 
form of pegmatites occur in many localities in the British Isles. 
These are Tresayes, Trelavour Downs, Kernick, and Luxulyan in 
Cornwall; in Sutherland, between Lochs Laxford and Inchard, 
between Durness and Eireboll and near Overscaig, Strontiau 


476 Reviews—Materials required in Glass-making. 


(Argyllshire), Portsoy (Banff), and Monymusk (Aberdeenshire) ; 
near Belleek, on the borders of co. Donegal and co. Fermanagh, in 
-the Glenties area of co. Donegal, and the Bellmullet area of co. 
Mayo. 

Felspars of the best quality (grade 1) occur in Cornwall at 
Tresayes, Kernick, and Trelavour, and in the neighbourhood of Belleek 
in Ireland. These occurrences are all situated fairly near to road, 
railway, and the sea, but the quantity in each case is limited. 
Each area yields hand-picked material suitable for the best glass and 
pottery work, showing from 10 to 13 per cent K,O, but none of 
them can be worked on the large scale for the extraction of potash. 

Round Rhiconich and near Durness in Sutherland, on Erris Head 
near Bellmullet, and on the Gweebarra River in co. Donegal there are 
millions of tons of pegmatite of grades 2 and 3. These, however, 
would not yield more than 8 or 9 per cent of potash after hand- 
picking, and are almost unworkable on account of their inaccessibility. 
These large deposits might possibly be worked for the extraction of 
their potash, but the operations would have to be conducted on very 
efficient lines for such a project to be payable, the chief difficulty 
being the shipping of the felspar, on account of the distance of the 
deposits from available harbours. 

The supplies of high-grade spar in the Cornish and Belleek areas 

“might be sufficient for the requirements of our industry for a limited 
dime, but not for any considerable period, owing to the small reserves 
available. Certain felsites near Wicklow and Waterford and some 
Cretaceous glauconitic sands have been suggested as sources of 
potash, but unfortunately their potash content is in most cases much 
too low and never sufficiently high to render them worth working. 

The paper is furnished with numerous analyses of the felspars and 
pegmatites, including some foreign as well as the British examples. 
It represents a very considerable amount of work, since the author 
has visited all the localities which he describes, some of which, being 
situated in the wildest parts of north-west Scotland and the west of 
Ireland, are very difficult of access. 


Wie We 


V.—Bnririsoh Resources oF Sanps anp Rocks usEp in Grass-maxine.! 
By Professor P. G. H. Boswett. Second and complete edition. 
pp. xi +170, with 10 plates and 13 figures in the text. 
London: Longmans, Green & Co. 1918. 


ye this second edition the author’s two earlier memoirs on British 
glass sands are combined into one volume. A few parts have 
been rewritten and some further information has been added, but 
otherwise most of the matter is the same. The book in its present 
form is a comprehensive survey, not only of British glass sands, but 
of the more important foreign occurrences, and also of other deposits 

essential to the glass industry, such as those of potash and alumina. 

WE Wie 

1 See also GEOL. MaG., March, 1918, p. 131. 


Reviews— Western Australian Geology. ATT 


VI.—Own tae Sprirrine or Coat Seams By Parvines oF Drirr. 
Part 1: Spxrirs roar Reson. By P. F. Kenparzt. ‘Trans. Inst. 
Min. Eng., vol. liv, p. 460, 1918. 

(J\HE explanation of the splitting of coal-seams that has so long 

done duty in text-books is unsatisfactory and often inapplicable 
to actual instances, since it is frequently found that the upper 
portion of the split seam is convex upwards while the lower portion 
is horizontal. , Professor Kendall has made a careful study of split 
seams in the Yorkshire coal-field, especially in the Silkstone or 

Middleton Main and Haigh Moor seams at Whitwood, Ackton Hall, 

Methley, and South Kirkby. The explanation put forward depends 

on the well-known fact that peat on conversion to coal undergoes 

a very great reduction in volume, here estimated at 20 to 1. 

A trough-like wash-out in a bed of peat, filled with sand or mud, 

would be much less compressed than the peat; the whole mass 

would settle down in a ridge-like form with a thin layer of coal 
above and below the sandstone or shale, the form of the mass thus 
undergoing inversion in cross-section. 

By mapping the known position of the edges of split seams it has 
been found possible to trace out the courses of Carboniferous rivers 
over distances of several miles, and the method of investigation 
pursued seems likely to lead to results of great practical and 
scientific interest. 


Jaen Joly Dkk. 


VII.—Some Prosiems or Western AustraLian Grotoay. Presidential 
Address to the Royal Society of Western Australia, delivered on 
July 11, 1916, by A. Gipp Marrtanp, F.G.S. pp. 34, with 
38 figures. Perth, 1917. 

le this presidential address the author deals chiefly with the 
Nullagine formation. This series of rocks has a very wide 

distribution in the state, and is composed chiefly of sandstones, 
quartzites, conglomerates, dolomitic limestones and igneous rocks, 
dolerite dykes and sills, with lavas and ashes at one horizon. 
The series, the lower members of which are gold-bearing, rests 
with a very marked unconformity on the underlying rocks, which are 
everywhere metamorphosed and of pre-Cambrian age. The sequence 
begins with a basal conglomerate, which is followed by an outbreak 
of lavas and ashes, chiefly andesitic, but in places rhyolitic, which 
appear to have been produced by fissure eruptions, as few volcanic 
foci have been discovered. These rocks are followed by dolomitic 
limestones, which are in turn overlaid by a sandy series with 
hematite and magnetite, bearing quartzites or jaspers, having some- 
times as much as 37 per cent of iron. The ferruginous bands are 
thin and interbedded with light-coloured quartzites, so that a banded 
rock is produced. 

The dolerite sills are of very uniform composition and do not 
seem to have undergone much metamorphism since their intrusion ; 
they are accompanied in the more disturbed areas by quartz reefs 
with gold and copper. The reservoir which supplied this igneous 
material seems to have been situated about latitude 26° 8. There 


-— 


A78 Reviews—Canadian Geology. 


are several points which require elucidation in connexion with this 
formation ; firstly, the age is very uncertain, the rocks were affected 
_by pre-Permo-Carboniferous folding and rest on crystalline schists; 
H. P. Woodward thought they were Devonian, but this cannot be 
proved in the absence of fossils. Again, it is not clear whether the 
igneous rocks of the intrusive phase followed closely on those of the 
volcanic phase or not. Finally, the ore-bearing rocks of Western 
_ Australia are all more or less associated with the Nullagine formation, 
but it is uncertain whether the mineralization was associated with 
the pre-Cambrian mountain-building movements which produced the © 
metamorphism in the older rocks or whether it took place after the 
deposition of the Nullagine formation. 


Wo We 


VIII.—An Exptoration oF rae Tazin anp Tarrson Rivers, Norta- 
Wesr Turrtrories. By CuHartes Camsett. Geological Survey 
of Canada, Memoir 84. pp. 111+ 124, with 18 plates and map. 
Ottawa, 1916. 

N the North-West of Canada there are still vast tracts of country 

which are as yet unexplored; one of the largest of these 

‘‘blocks’’ forms the subject of this communication. The region is 

situated between the Great Slave Lake and Lake Athabasca; it is 

part of the Laurentian plateau region and abounds in lakes, while its 
rivers flow in irregular valleys which are rarely more than 100 feet 
deep. 

The oldest rocks, which occur now in isolated patches, are 
‘‘a series of schists, quartzites, conglomerates, limestones, argillites, 
and some volcanic rocks’’, which are grouped together under the 
name of the Tazin Series. These are Archeean rocks, probably 
Huronian in age. The Tazin Series is invaded by a great composite 
batholith of gneisses and granites with some quartz diorites. ‘These 
rocks, which occupy the greater part of the area, have a north and 
south trend, corresponding more to the Cordilleran lines than to 
those of Eastern Canada. At one place, at the north-east end of 
Tazin Lake, there is a remnant of the Athabasca Sandstone, which 
is a conglomeratic deposit of Keweenawan age, and probably of 
terrestrial origin. After this rock there is a complete absence of 
any deposit till those of the Pleistocene glaciation. The glaciation 
in this region was very intense, as is shown by the rounded, grooved, 
and striated character of the rocks, and by their fresh and un- 
weathered condition. Glacial deposits, boulder-clay, moraines, 
drumlins, and sand plains are found, but not in any great abundance, 
the rock being mostly left bare of any surface deposit. The direction 
of motion of the ice as shown by the striz seems to have been about 
S. 62° W., while there is evidence of a later feebler glaciation with 
a more northerly trend. The Tazin Series is cut by numerous quartz 
veins which contain pyrites in places, and seem to offer some 
prospects of valuable metalliferous deposits. The memoir contains 
also a detailed account of the canoe routes followed by the author, 
and is illustrated by many excellent photographs of the country. 


W. H.W. 


Correspondence—J. Wilfrid Jackson. 479 


IX.—Frozen Mock ry 1HE Kionpixe Disrricr, Yuron Trrerrory, 
Canapa. By J. B. Tyerenn, F.R:S:C. Trans. Roy. Soc. 
Canada, ser. 111, vol. ix, pp. 89-46, with 3 plates, 1917. 

‘W\HE valley floors of the Klondike District are the products of the 

third cycle of erosion since the last continental uplift of the 
region. In the Miocene period the Dome peneplain was produced by 
the first cycle of erosion. In Pliocene times the valleys in which 
the older White Channel gravels were deposited were carved out 
during the second cycle of erosion, while the present valleys and 
their alluvial gravels are connected with the third cycle, which lasted 
till the end of the Pliocene period. During this time the climate 
was temperate and the country was inhabited by a number of the 
larger mammals, but at the beginning of the Glacial period different 
conditions set in, and, though this region was not covered by an 
ice-sheet, the soil was certainly frozen all the year round., In con- 
sequence of this the alluvial gravels and the beds of the streams 
became impervious to water and resistant to erosion. When, 
therefore, the snow melted in the spring the water in the stream 
channels brought down, instead of sand and gravel, only vegetable 
debris from the hill-sides, which collected on the alluvial flats and 
was held fast and preserved by the large growth of bog mosses. 

In this way great thicknesses of this frozen bog or ‘‘muck”’ were 

accumulated, varying from 2 to 40 feet and even 100 feet in the 

narrower gulches, which have to be sunk through before the gold- 
bearing gravels can be worked. ‘‘ Muck”? is also found in the form 
of frozen bogs on the hill-sides, where it often contains layers of 
clear ice, tilted at steep angles by the slipping of the bog. The 

‘“muck’’? now forms the upper part of the valley deposits, which 

shows that little or no gravel has been transported since the 

beginning of the period of perennial frost, and that, therefore, the 
valley gravels are all pre-Glacial in age. 


CORRESPON DEHNCE. 


ON TEREBRATULA GRAYI, DAVIDSON. 


Sir,—In a former paper in this Magazine (Dec. VI, Vol. III, 
pp. 21-6, 1916) I proposed the name Zhomsonia for the Terebratula 
grayt of Davidson. This name, I find, has unfortunately been used 
for Insecta on two previous occasions, viz. in 1879 and 1884, and, 
therefore, cannot stand. In its place I now propose 

CoptorHyris, gen. nov. 

Coptothyris grayi has been placed in Waldheimia (now Magellania) 
and in Dallina by various authors, on account of the loop having 
reached the highest developmental stage in the Terebratellide; but 
it is distinct from either of these genera on other grounds. The full 
details of these differences are reserved for a future paper on the 
cardinalia of the Dallinine in general. In this paper I hope to 
show that the cardinalia (or hinge-processes of the dorsal valve) of 
the sub-family Dallinine can be readily differentiated into, at least, 


480 Correspondence—Dr, Wheelton Hind. | 


three distinct types, each being represented by forms which have 
attained the Dalliniform loop-stage of Beecher, viz. Coptothyris, 
Macandrevia, and Dallina. These three genera are also characterized 
by distinct types of beak characters, dental plates, ete. Thus three 
evolutionary stocks can be clearly recognized, in each of which 
Dalliniform loops have been attained by parallel evolution. There 
appear to be other stocks present, but in these there is as yet no 
evidence for the separate attainment of the Dalliniform loop. 

The study of the hinge characters of the species of Dallinine 
contained in my collection (comprising most of the known forms) has 
revealed many interesting features which have an important bearing 
upon the classification of both recent and fossil forms. For some of 
these forms it will be necessary to create new genera. 

J. Witrrip Jackson. 


MANCHESTER MUSEUM. 
September 4, 1918. 


THE CANINIA-SHMINULA HORIZON OF PRODUCTUS 
HUMEROSUS. 

ou —I have just received my copy of the Q.J.G.S., containing 
Mr. Parsons’ most excellent paper ‘‘On the Carboniferous Limestone 
of the Leicester Coalfield’’. I want to ask him to reconsider the 
question of the horizon of the beds containing Productus humerosus 
(P. sublevis). Following Professor Sibly, who referred the Cauldon 
Low (Staffs) Limestones to D,, he has not pointed out that 
P. humerosus is an important zonal fossil both in Belgium and the 
Clitheroe area, indicating a Caninia—Seminula horizon. Therefore, 
one must pause to think before beds containing it are assigned to 
a much higher zone. The paleontological evidence of the Cauldon 
Low beds is strengthened by the presence in them of other members 
ofthe C-S, fauna. Papillionaceous Chonetes, Bellerophon cornuarvetis, 
and other members of that genus, and several large Gasteropods 
which can be matched in Belgium and Clitheroe. I note that 
Cyrtina septosa oceurs with P. humerosus. This, too, indicates the 
lower zone. 

Then, again, the barrenness of the beds and the absence of 
LInthostrotion and a Dibunophyllum fauna are very noteworthy. 
I have, no doubt, in my own mind that the Cauldon Low beds are 
of Caninia age, and the whole question will be more fully discussed 
in a forthcoming paper on the Clitheroe area. 

Wueetton Hinp, M.D., B.S., F.R.C.S. 

ON SERVICE. 

September 7, 1918. 


STRATIGRAPHICAL POSITION OF THE CORALLINE CRAG. 
Mr. F. W. Harmer’s article in the September 
Number, ‘‘ Stratigraphical Position of the Coralline Crag,” p. 410, 
for Walton horizon read Oakley horizon= Poederlien, and for Oakley 
horizon read Walton horizon = Scaldisien—the names Walton and 
Oakley having been reversed. 


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NEW SeRle6. DECADE WIL VOL. Vv. 
No. XI.—_NOVEMBER, 1918. 


I.—Tue Jron-Fretps or LorRarne. 
By R. H. Rasta, M.A., F.G.S. 


ECENT events have again called attention to the enormous 
strategic and economic importance of the iron-fields of 
Lorraine; on these much of the commercial prosperity of Germany 
has been built up in the past, and on their possession her future as 
an industrial nation largely depends. For many years the output of 
iron-ore from the part of Lorraine under German control has been 
immense: in 1912, German Lorraine produced approximately 
20,000,000 tons, while the output of Luxemburg, which, for all 
practical purposes, is German, was about 6,500,000 tons. In the 
same year the French portion of the Lorraine iron-field yielded 
17,300,000 tons, making a grand total for this area of 43,800,000 
tons of ore. During the War the whole of the French productive 
region has been occupied by the enemy, and there is no means of 
ascertaining what has actually happened there, but certain 
inferences can be drawn from published facts and on a basis of 
probability. 

First, however, it is necessary to consider briefly the geographical 
distribution and geological structure of these regions. The Briey 
plateau forms a somewhat elevated region extending from the 
southern border of the Ardennes to a little south of Metz: it is 
dissected by the valleys of several rivers, including the Moselle, 
Orne, Fentsch, Algringen, and Meurthe. Geologically the plateau 
is composed of Jurassic rocks, chiefly Lias and Dogger, and it is near 
the boundary of these two series that the beds of iron-ore occur. By 
German geologists they are referred to the Dogger, by French 
authorities mostly to the Lias. According to Van Werveke they 
belong to the zone of Ammonites Murchisone. 

The Briey field is nearly 40 miles long, with a width of about 
15 miles, within which the ore is believed to be payable; south of 
it comes a barren region extending for some 15 miles and then the 
Nancy field, which is about 13 miles long. ‘The Lorraine plateau as 
a whole is divided by rivers and other natural boundaries into 
several subsidiary regions, while the basins of Longwy and Crusnes 
are of considerable importance. In the French portion of the Briey 
field the chief subdivisions recognized are those of Orne, Landres, 
and Tucquegnieux. 

The general geological structure is very simple, as the whole 
series dips gently to the west. The iron-bearing beds outcrop on 
the eastern side of the plateau a few miles east of the frontier and in 
the south of Luxemburg, hence they naturally become deeper and 

DECADE VI.—VOL. V.—NO. XI. 31 


482 R. H, Rastall—The Iron-fields of Lorraine. 


deeper towards the west in French territory. On the east and south 
the thickness is from 50 to 70 feet, but this increases to about 
200 feet westwards and in Luxemburg, with a corresponding falling 
off in quality. The ferruginous series consists of an alternation of beds 
of oolitic iron-ores of various colours with limestones and occasional 
marls. The iron-ores, which are locally known as Minette, have 
been formed by metasomatic replacement of calcareous oolitic grains, 
probably consisting originally of aragonite, while the cement has 
chiefly remained calcareous. As before stated, the percentage of iron 
varies regularly from north to south, and this has a most important 
economic bearing. In Luxemburg the average*iron-content is 30 
per cent or less, while in the south of the Briey plateau it rises to as 
much as 40 per cent, with 9 to 14 per cent of lime and 4 to 7 per 
cent of silica. In the Longwy and Crusnes fields the ores contain 
less lime, while the silica rises to 20 per cent in some cases; the 
proportion of phosphorus remains very constant throughout, averaging 
about 1°8 per cent. 

Hence the ores must be regarded as distinctly phosphatic, and it 
was the introduction of the Thomas-Gilchrist process in 1882 that led 
to the vast industrial development of this area. 

Several careful computations of reserves have been made, and the 
following figures are estimates of ore still available in the different. 
districts and workable under present economic conditions :— 


TONS. 
Briey . i : 5 ‘ . 2,000,000,000 
Longwy j 3 i - : : 275,000,000 
Crusnes i i : 500,000,000 
German Lorraine aindl Luxemburg . 2,000,000,000 
Total 3 . 4,775,000,000 


Of this total considerably more than half was in French territory, 
including practically the whole of the higher-grade portion. The 
potentialities of the western portion of the Briey plateau were not 
known to the German authorities when peace was concluded in 1870, 
and an endeavour to rectify the mistake then made must certainly be 
regarded as one of the causes of the present War. The whole of 
the Briey field as well as those of Longwy and Crusnes are 
occupied by the Germans, and it is of interest to consider what 
is now going on there. Lately published statistics relating to 
Tiuxembure throw some indirect light on the matter. In 1912 
the output of Luxemburg was 6,511,000 tons, and in 1916 
6,752,000 tons. In 1917 the output fell suddenly to 4,502,000 tons, 
and in August, 1918, some 450,000 tons still remained unsold in that 
country, owing to excess of supply over demand. The consumption 
of iron-ore in Germany at the present time is undoubtedly very 
great, and the natural inference is that Germany is now exploiting 
as largely as possible the richer ores of the Briey plateau and 
neglecting the poorer ones of German Lorraine and Luxemburg. 
It is also stated that there is an active demand for siliceous ores, 
as opposed to the more calcareous varieties, and it is a natural 
inference that ore of this kind is being obtained from the Longwy 


G. W. Tyrrell—Petrography of South Georgia. 483 


and Crusnes fields. Hence it is clear that German munitions of war 
are being very largely manufactured from French ore, thus 
diminishing the potential mineral wealth of that country, in addition 
to the actual damage inflicted by the said munitions during the War. 
These are facts which will have to be taken into consideration at 
the Peace Conference. 


I].—Apprrionat Nores on THE PerrrocRaPpHy oF SoutH Grorcia. 


By G. W. TYRRELL, A.R.C.8c., F.G.S., F.R.S.E., Lecturer in Geology, 
University of Glasgow. 
ee rocks which form the subject of this paper were collected by 
the captain of a whaling vessel belonging to the fleet of 
Messrs. Salvesen & Co., of Leith, stationed at Leith Harbour, South 
Georgia. ‘The collection reached me, for description, through the 
kind offices of Mr. D. Ferguson, Mem. Inst. M.E., who recently 
visited the island, and who has described its geological features.} 
Two previous collections of rocks from South Georgia have been 
described by me, one collected by Mr. Ferguson during his visit.,? 
the other collected in the same way as the present set.$ 
The collection consists of twenty-six specimens, nineteen of which 
are from Larsen Harbour, at the extreme south-eastern end of the 
island, in the midst of the ‘‘altvuleanischer’’ area found by Heim.* 
Three specimens are from Gold Harbour, on that part of the coast 
that trends nearly due north and south near the south-eastern end ; 
and four specimens are from King Haakon Harbour, about the middle 
of the long, icebound, southern coast. Most of the material is 
igneous, or derived from igneous rocks by alteration; the few 
remaining specimens belong to the sedimentary series of which the 
greater part of South Georgia is built. The rocks-may be classified 
as follows :— 
1. Ienrovs Rocks anp THEIR DERIVATIVES. 
(1) Spilite. 
(2) Soda-felsite (Quartz-felsite of previous paper).° 
(3) Greenstone (Albite-dolerite ?). 
(4) Epidosite and other Vein Rocks. 


2. Sepimenrary Rocks. 
1. Ienzous Rocks. 


(1) Spilite.—Several specimens belong to this type, all derived 
from Larsen Harbour. They are compact, grey-green, non- 
porphyritic rocks, carrying veins of quartz, chlorite, and epidote. 
In some specimens small amygdales of dark-green chlorite or 
yellowish-green epidote occur. 


1 “* Geological Observations in South Georgia’’: Trans. Roy. Soc. Edin., 
vol. 1, pt. iv, pp. 797-814, pls. lxxxi-xci, 1915. 
2 “ Petrography of South Georgia’’: ibid., pp. 823-36, pl. xciv. 

* “Further Notes on the Petrography of South Georgia’’: GEOL. MAG., 
dec. VI, Vol. III, 1916, pp. 435-41. 

* ““Geol. Beob. ii. S. Georgien’’: Zeit. Ges. Erdk., 1912, pp. 451-6. 


> Op. cit., p. 438. 


484 G. W. Tyrrell—Petrography of South Georgia. 


In section, the most typical rock (C10)! shows a thin network of 
slender striated felspars, with nearly straight extinction, interspersed 
with a few microphenocrysts which have a well-marked multiple 
twinning, and the extinction and refractive index of almost pure 
albite. he felspars of the groundmass are appreciably less sodic, 
and belong to albite-oligoclase. The interstices of the felspar 
network are filled with chalcedonic silica, chlorite (mostly in 
amygdales), epidote, a little quartz, very minute felspar microlites, 
and a dark-green indeterminate material. The chlorite amygdales 
are often lined with a thin layer of cryptocrystalline silica, and are 
further banded with concentric layers of slightly different varieties 
of chlorite, or chlorite mingled with grains and rods of epidote. 
There is not a trace of the original ferro-magnesian or iron-ore 
minerals. They have all been replaced by chlorite and epidote, 
with, no doubt, cryptocrystalline silica as a bye-product of the 
reaction. Thin veins of quartz, chlorite, and epidote occur in the 
rock. ‘his is a fairly typical spilite. 

Another specimen (C11) shows the felspars still more thinly 
dispersed in a dense groundmass, consisting mainly of a greyish- 
green indeterminate material, with chlorite and a few felspar 
microlites, still showing traces of its original texture. There are 
numerous amygdales of uniform bright-green chlorite. The micro- 
phenocrysts of albite tend to segregate into small groups; and 
mingled with them are a few crystals of untwinned felspar, mottled 
in polarized light, which appear to be soda-orthoclase. In one part 
of the slide rounded areas of granular epidote become common. 

A somewhat different type of spilite is- represented by other 
specimens. In the mass they are dark-grey, compact rocks, with 
numerous spherical cavities filled with radiating needles, of green 
epidote. In thin section they show numerous small laths of albite- 
oligoclase, with a few stouter microphenocrysts, in a dense 
groundmass consisting of minute felspar microlites, abundant grains 
of ragged skeletal iron-ores, and a pale yellowish-green fibrous 
chlorite which no doubt represents original pyroxene. Large 
euhedral crystals of magnetite are scattered sparingly over the 
section. Large rounded patches or amygdales of epidote and chlorite 
also occur, the epidote forming masses of radiating crystals, with 
rosettes of chlorite filling the remaining interspaces. Sometimes, 
however, chlorite fills the amygdale to the almost complete exclusion 
of epidote, and shows a remarkable violet polarization tint. Epidote 
and chlorite occur only sparingly in the groundmass of these rocks. 
They are to be regarded as falling midway between the typical 
spilites and the more mafic varieties described below. 

Two of the rocks (C 18, C19) are richer in mafic constituents than 
those described above. The hand-specimens are compact, dark-grey 
rocks, becoming grey-green upon weathering, and showing numerous 
veins and impregnations of white quartz, pyrites, and magnetite. 
The thin sections exhibit a dense, closely-woven mesh of minute, 
diverse, unorientated felspar laths (albite-oligoclase), with abundant 
small skeletal grains of iron-ore, chlorite, and an indeterminate grey 

1 The numbers within brackets refer to those of the specimens preserved in 
the Hunterian Museum, University of Glasgow. 


G. W. Tyrrell—Petrography of South Georgia. 485 


material probably representing original pyroxene. There are also 
rare microphenocrysts of oligoclase, and occasional small patches of 
quartz, epidote, and chlorite. The quartz is undoubtedly secondary, 
and introduced at the same time as the quartz veins by which the 
rocks are penetrated. ‘These rocks may be regarded as basic types of 
spilite intermediate between that rock and mugearite. 

(2) Soda-felsite.—Two non-spherulitic felsites (C14, C15), which 
differ in no essentials from those described in a previous paper as 
quartz-felsite,’ occur in the collection. The phenocrysts of quartz, 
albite, and orthoclase are perhaps less abundant, the groundmass 
finer-grained and more abundantly epidotized than in the formerly 
described specimens. These rocks greatly resemble the soda-felsite 
or soda-granite-porphyry of Porthallow Cove, Cornwall, which is 
also associated with a spilitic series.” 

With the soda-felsites may be described a quartz-trachyte (C 20) 
from the same locality (Larsen Harbour). In thin section this rock 
shows numerous irregular areas of turbid, mottled, untwinned 
alkali-felspar, together with a few, elongated, simply twinned laths 
of sanidine, and irregular areas of quartz, in a groundmass consisting 
of minute, fluidally arranged laths of albite-oligoclase, a little 
orthoclase, and abundant interstitial quartz. The sanidine laths and 
large quartz areas are frequently invested by an irregular, 
discontinuous zone of cloudy alkali-felspar, which envelops the 
fluidal laths of the groundmass. While many of the constituent 
minerals are quite fresh and undecomposed, the rock is impregnated 
with irregular areas of epidote and particles of pyrites. This rock is 
clearly related to the soda-felsites, but differs in being less quartzose 
and in possessing a trachytic groundmass. 

(3) Greenstone (Albite-dolerite?).—In. hand-specimens these are 
fine-grained ‘‘ greenstones”’ (C5, C6, C7), all from Larsen Harbour, 
penetrated by quartzose veins, and impregnated with pyrites and 
quartz. One rock (C6) shows numerous amygdales filled with 
greenish-black chlorite. In thin section the principal minerals, 
shown are albite-oligoclase in thin laths, enclosed ophitically in 
masses of chlorite which doubtless represent original pyroxene. 
The felspar laths are often cloudy and mottled on account of minute 
inclusions of quartz, epidote, and chlorite. Ilmenite in process of 
alteration to leucoxene is an abundant constituent, and there is a 
considerable quantity of interstitial secondary quartz and epidote. 
A prominent feature in one of the rocks (C6) is the occurrence of 
numerous, large, rounded vesicles filled with rosettes of yellow-green 
chlorite which shows in great perfection the characteristic ultra- 
blue polarization tints. C 5 is of finer grain than C 6, and is devoid of 
amygdales. C7 has abundant secondary quartz and pyrites. These 
rocks are much decomposed greenstones, but enough is left of their 
original minerals and texture to establish the fact that they belong 
to the spilitic series, and were probably oligoclase or albite- 
dolerites similar to the types that accompany spilites in other regions. 

(4) Epidosite and other Vein Rocks.—In the previous paper 

1 Geox. MaG., Dec. VI, Vol. III, pp. 438-9, 1916. 


2 Geology of the Lizard and Meneage (Mem. Geol. Surv.), 1912, p. 186; 
see pl. xii, fig. 6. 


486 G. W. Tyrrell—Petrography of South Georgia. 


progressive epidotization of certain obscure igneous rocks was shown 
to occur, resulting, in its final stage, in the production of a rock 
composed mainly of epidote and quartz.! The same characteristic 
reactions are exemplified in the series of rocks now under description, 
with the addition that veins of epidotic material are now seen to be 
common. ‘These are especially abundant in the spilites. Their 
average thickness is about 1 inch, but they may swell out to a width 
of 8 inches. They consist of a hard, dense, pale-yellow epidosite, 
containing irregular patches and segregations of greenish-black 
chlorite, and associated with a compact flint-hard, grey-green 
material. In thin section the epidosite appears extremely turbid, 
and is only translucent on the thinnest edges of sections, where it is 
seen to consist of an almost cryptocrystalline aggregate of epidote 
and silica. The grey-green flinty material is even denser. It is 
very feebly birefringent, and is irresolvable even under a +in. 
objective. It carries tiny patches of epidote and quartz. The 
epidosite encloses irregularly-shaped areas which have a narrow 
border of granular epidote, or of epidote and quartz, with the 
remainder of the space filled with radiate masses of chlorite in which 
particles of leucoxene are enclosed. Smaller areas are filled with 
epidote and quartz, or with epidote alone, suggesting that the order 
of deposition has been first epidote, then quartz, and finally chlorite. 
The boundaries of the veins against the enclosing spilite are generally 
marked by a shght segregation of iron-ores within the rock. 

Three specimens of massive epidosite occur in the collection 
(C9, C13, C24), all from Larsen Harbour. They are hard, dense, 
splintery rocks of yellowish-green colour, which, in thin section, 
show an intimate granular admixture of epidote and quartz. As 
noted in the previous paper, the epidote grows euhedrally into the 
quartz wherever the latter mineral forms plates large enough for 
the relation to be observed. Chlorite, and pyrites in euhedral 
erystals, occur in varying amounts. 

Quartz veins also occur abundantly in these rocks. In one 
specimen (C 18d) the rock (spilite) has been veined in all directions, 
leaving sharply angular fragments of country rock entirely surrounded 
by quartz. These fragments are highly silicified, as is also the rock 
adjacent to the sides of the veins. The quartz is very finely 
granular, except in some later veinules. Intermingled with the 
quartz are euhedral crystals of epidote and pyrites, with flakes of 
chlorite, and irregular masses of magnetite (strongly attracted by the 
bar magnet). In another specimen (C25) the quartz is much 
coarser in grain, and in addition to the above-mentioned minerals 
also carries irregular patches of a translucent, reddish, optically 
isotropic ore-mineral, which is probably chromite. In C18a@ there 
are curious, spherical, amygdale-like areas of very fine-grained quartz, 
which enclose sectors in which the quartz shows a concentric and 
radiate structure, as shown by the appearance of a black cross 
between crossed nicols. Other similar areas carry large euhedral 
crystals of pyrites. Still another shows a narrow border of minutely 


1 Grou. MAG., Dec. VI, Vol. III, pp. 439-40, 1916. 


G. W. Tyrrell—Petrography of South Georgia. 487 


granular quartz, followed by a discontinuous zone of chlorite, with the 
interior of the cavity filled by coarsely granular quartz. 

With these rocks may be described a fine, carnelian-red, jasper- 
rock (C26—Larsen Harbour), which shows, in thin section, a 
groundmass of cryptocrystalline silica thickly impregnated by 
hematite in peculiar globular, clubbed, or roughly radiate forms, 
viving a texture which, after an obvious resemblance, may be called 
ameboid. The rock also carries large irregular masses of pyrites. 
This rock may represent the siliceous material often found associated 
with spilites, especially in the interstices between pillow-form masses. 


2. Sepimentary Rocks. 


The collection includes typical mudstones from King Haakon 
Harbour (C3, C4), with only the beginnings of cleavage. These 
rocks are penetrated by a great number of very thin, fine veins of 
quartz. From Gold Harbour there comes a fine-grained, banded 
greywacke (C22), consisting of numerous thin alternations of 
arenaceous and argillaceous material. The interest of this rock is 
that it shows in a superlative degree the relative resistance of the 
two types of material to differential movement. The arenaceous 
bands show frilled and puckered folding; but in the adjacent 
argillaceous bands each pucker is represented by a line of strain-slip. 
As the argillaceous bands predominate, the rock, as a whole, splits 
easily along the strain-slip cleavage. Some of the arenaceous bands 
contain a few large crystals of quartz and albite, which are deformed, 
and in the case of the felspar sericitized, but which have nevertheless 
formed nuclei of resistance, causing the folds to pass round them. 
A similar rock has been described and figured in an earlier paper.’ 

Other rocks from King Haakon Harbour (C1, C2) are sheared 
erystal-tuffs with sporadic scapolitization, entirely similar to those 
described in a former paper.* They contain crystals of orthoclase 
and albite, and fragments of shale, as augen in a sheared, almost 
eryptocrystalline, groundmass, consisting apparently of sericitized 
felspar and chalcedonic silica. The scapolite occurs in compact, 
granular masses which appear to be pseudomorphs after rock- 
fragments, but the character of the latter is completely obliterated. 
The foliation is outlined by a wispy, greyish, argillaceous material 
the character of which cannot be determined. A considerable 
amount of pyrites has been introduced along the foliation planes. 

A specimen from Gold Harbour (C 23) appears to have been a tuff, 
but has undergone much more advanced shearing than the rocks 
from King Haakon Harbour. Only a few remnants of quartz and 
felspar are left as augen, in a thoroughly foliated, granulitized paste 
of quartz and felspar, with filmy sericitic mica. Similar rocks from 
Gold Harbour were described in a former paper.? 


3. ConcLuUsIons. 
The most striking new fact afforded by the study of this 
collection of South Georgia rocks is the recognition of a spilitic 
1 ** Petrography of South Georgia’’: Trans. Roy. Soc. Edin., vol. 1, pt. iv, 


p. 826, pl. xciv, fig. 1, 1915. * Tbid., pp. 827-30. 
3 GEOL. MaG., dec. VI, Vol. III, p. 436, 1916. 


488 G. W. Tyrrell—Petrography of South Georgia. 


series of igneous rocks in and about Larsen Harbour at the south- 
eastern end of the island. The tectonic inferences to be drawn 
therefrom are so important that it was thought advisable to send the 
slides to Dr. J. S. Flett, F.R.S., for his opinion as to their spilitic 
nature. He has very kindly confirmed this identification. The 
diabases and melaphyres, described (macroscopically) by Heim, no 
doubt belong to this series. Furthermore, the epidotized lavaform 
and tuffaceous rocks of doubtful affinities, described by me in the 
last paper, almost certainly belong to the series.! 

Associated with the dark-grey or grey-green spilites are light- 
coloured rocks which were previously identified as quartz-felsites. 
Dr. Flett prefers to call them soda-felsites; and this is undoubtedly 
the better term since the rocks are very rich in albite, and must be- 
regarded as consanguineous with the albite-rich spilites. The 
alaskite from Cooper Island, described in the last paper, is perhaps 
also to be correlated with this series. 

Furthermore, the badly decomposed rocks here described as green- 
stones were probably once dolerites with a sodic plagioclase, oligoclase 
or albite, petrographic types which elsewhere are closely associated 
with spilites and soda-felsites. The ophitic dolerite from Cumber- 
land Bay and the epidiorite (meta-dolerite) of Gold Harbour, 
described in previous papers, are probably also to be associated with 
the spilitic series. These rocks, however, differ entirely from the 
ophitic dolerites and basalts from Larsen and Slosarezyk Harbours in 
the last collection.2, The latter rocks are very fresh, with a much 
more calcic plagioclase than is general in the spilitic series, and 
furthermore have escaped the epidotization which is so characteristic 
of that suite. Hence it is believed that they belong to an intrusive 
series of much younger date than the spilitic series. 

From consideration of the evidence now accumulated South 
Georgia consists principally of a folded sedimentary complex, 
including greywackes, slates, mudstones, and tuffs, of uncertain 
age, probably Paleeozoic in the main, but perhaps ascending into the 
Mesozoic. It contains a spilitic series of igneous rocks at the 
south-eastern end of the island, and intrusive rocks of the same group 
occur within the sediments at least as far away as Cumberland Bay. 
Rising behind the dark, ‘‘altvulcanischer”’ region around Larsen ‘and 
Drygalski Harbours, Heim saw a great, light-coloured massif, the 
composition of which was believed to be granito-dioritic from the 
evidence of the moraine material within the area.2 The specimen of 
granite-porphyry collected by Mr. Ferguson from the glacial material 
at Moraine Fiord probably belongs to this or a similar complex.* 

Spilites are characteristically associated with rocks of Paleozoic or 
Pre-Paleozoie age; and if, this relation holds in South Georgia, 
the presence of spilites may be held to reinforce the view that the 
sedimentary series of the island is mainly of Paleozoic age. The 


Ibid., pp. 439-40. 

Ibid., p. 437. 

Op. cit., p. 454. 

Trans. Roy. Soc. Edin., vol. 1, pt. iv, p. 830, 1915. 


me O BH 


Herbert L. Hawkins—Studies on the Echinoidea. 489 


lithologically very similar sedimentary series of the South Orkneys 
is definitely known to be of Lower Paleozoic age (Silurian) from the 
evidence of graptolites.! It is a fact suggestive of close geological 
relationship between South Georgia and the South Orkneys that 
a small pebble of typical spilite was found by me in a series of rocks 
collected by the Scotia Expedition from Coronation Island in the 
South Orkneys.? 

According to Dewey and Flett spilites are the characteristic 
- voleanic rocks of districts that have been undergoing long-continued 
. subsidence.? This relation receives further exemplification from 
South Georgia, where the sedimentary series is of great thickness 
and continuity, and lithologically is of shallow-water origin. 
Benson has shown that spilites are not necessarily indicative of 
deep-water conditions as supposed by Steinmann and _ others.* 
Lastly, attention may be drawn to the fact that the South Georgia 
sediments are radiolarian, another character often exhibited by the 
sedimentary rocks associated with a spilitic suite. 

The existence of a spilitic suite in South Georgia and the South 
Orkneys has an important bearing upon the tectonic relations of 
these islands. The balance of evidence may now be said to tip 
definitely against Suess’s interpretation of their structure. He 
believed that they formed part of a great eastwardly-directed loop, 
homologous with the Antilles, connecting the Patagonian Andes 
with the mountain ranges of Graham Land. The continued absence 
of typical Andean volcanic rocks in spite of repeated collection of the 
rocks of South Georgia, as well as the existence of a spilitic series, 
favours the interpretation that South Georgia and the South 
Orkneys are remnants of an ancient continental land which once 
occupied the South Atlantic.° 


TiI.—MorpuHorogicaL Srupres on THE EcHINoIDEA HoLeEcryPoIpa 
AND THEIR ALLIES. 


By Hersert L. HAWKINS, M.Sc., F.G.S., Lecturer in Geology, University 
College, Reading. 
VIII. On Pyeasrrives, Lovin, A ProptemMaticaL Hovevryporp. 
(PLATE XVII.) 
1. Lyrropuction. 
[ may be thought that some apology is due to the readers of this 
Magazine on the ground of the largely zoological bearing of this 
paper. But in the opinion of the writer no such apology is necessary. 
Zoology is paleontology brought up to date, and ontogeny is but 
a compressed and individualistic type of phylogeny; so that in 
spirit, though not in matter, this paper is no less appropriate for 
1 J. H. Pirie, Proc. Roy. Soc. Edin., vol. xxv, pp. 463-70, 1905. 
2 Op. cit. supra, p. 833. 
3 Op. cit., p. 242. 
4 W. N. Benson, ‘‘ Spilite Lavas and Radiolarian Rocks of New South 
Wales’’: GEOL. MAG., dec. V, Vol. X, pp. 17-21, 1913. 


> J. W. Gregory, ‘‘ The Geological Relations and some Fossils of South 
Georgia’’: Trans. Roy. Soc. Edin., vol. 1, pt. iv, pp. 817-22, 1915. 


490 Herbert L. Hawlhins—Studies on the Echinoidea. 


publication here than its seven predecessors have been. According 
to Lovén himself, the minute Echinoid which supplies the text for 
the sequel is to be considered a survivor, not merely of the 
Holectypoida, but of the most primitive family of that Order— 
a kind of Lingula or Nucula among Irregular Kchinoids. Although 
one of the main purposes of the following pages is to offer reasons for 
disbelieving that contention, nevertheless Pygastrides, as far as the 
only specimen known is concerned, is for all practical purposes 
primitively Holectypoid in essential characters. This seeming 
paradox may be resolved by the anticipatory remark that Lovén’s _ 
so-called genus is believed to be an early post-larval stage in the 
development of some more completely Irregular adult form. It is 
ontogenetically related to that problematical adult, just as the 
Pygasteride must be phylogenetically ancestral to it. 

At the time of its description by Lovén Pygastrides was almost 
the only developmental stage of its kind known. Now there are 
several comparable ontogenetic phases available for comparison, 
notably the gnathostomatous young of Hehinonéus cyclostomus and the 
originally endocyclic early post-larval forms of Abatus cavernosus and 
Echinocardium flavescens. The three different ontogenetic lines thus 
indicated serve to prove conclusively the phylogenetic relationship 
of the Holectypoida to the Irregular Echinoids. Even if Hehinonéus 
be considered to be an Holectypoid (and I incline to believe that 
it should be so classed), its affinities with other groups are many 
and manifest. Pygastrides, as the following arguments seek to show, 
must be a young stage of some other type of Irregular Kchinoid, 
while Adatus is a Spatangid of the Spatangoids. 

In the course of the discussion on the affinities of Pygastrides, 
certain morphogenetic points arise. These are mainly concerned 
with the perignathic girdle, so that this paper is in some respects 
a direct sequel to its three immediate predecessors. It was thought 
better to keep it distinct from them because, while they were based 
upon direct observation, the substratum on which the following 
arguments rest is theoretical, although it seems to me to be more 
secure than mere conjecture. : 


2. Résumé oF THE CHARAcTERS oF PYGASTRIDES RELICTUS. 


In 1874 Lovén (Htudes sur les Hehinovdées, p. 79), in a footnote 
to a description of certain ‘‘ Echinoconide ”’ (Holectypoida), mentioned 
the existence of a small recent form from the Caribbean Sea that 
he believed to be a living species of Pygaster. He gave it the 
nomen nudum of Pygaster relictus. After a delay of fourteen years, 
during which ‘the little thing ’’ succeeded in avoiding capture, in 
spite of ‘‘most energetic exploration”’ of its habitat, Lovén gave 
a full and beautifully illustrated description of the solitary and 
imperfect specimen on which his previous comment had been bae d 
(1888, ‘‘Ona Recent Form of the Echinoconide’’). Detailed study of 
the small corona showed that it differed in many important respects 
from that of Pygaster, and caused Lovén to diagnose a new genus, 
Pygastrides, for its reception. Pygastrides relictus still remains 
unique, a sufficiently remarkable fact in view of the amount of 


Herbert L. H Tolinelsradies on the Hchinoidea. 491 


deep-sea exploration that has been achieved since 1888. Further 
discussion of its characters and affinities must needs be based on new 
knowledge of its alleged relatives. 

The following is an abridged account of its salient features taken 
from Lovén’s description :— 


Length. ; : : . 38-dmm. 

Breadth . “ : i . 3:41mm. 

Height . ; : : . 2-16mm. (0-62 of length). 
Peristome diameter . i . [1-015 mm.] (0-29 of length). 


Corona.—Obscurely subpentagonal; tumid. _ 

Apical system.—Wanting, apparently central in position. 

Peristome.—Central, very slightly invaginated. Outline irregularly 
circular. The epistroma not extending quite to the margin, leaving 
a delicate inner rim in which occur narrow branchial (?) incisions. 
Interradial margins built of large, single primordial interambulacrals. 
Ambulacral margins built of high, narrow primordial ambulacrals. 
Externally each ambulacral bearing a large ‘‘epistromal prominence ”’ 
with a glossy and minutely punctate surface, the pairs of these 
meeting adorally to a large, single, perradially situate spheeridial pit. 

Perignathie girdle.—Paired ambulacral processes of slightly 
cuneiform shape, expanding distally, meeting the floor of the test at 
a very acute angle. The processes are apparently placed over the 
adradial sutures. The figure (Lovén, pl. i, fig. 5; here Pl. XVII, 
Fig. 2) is hard to understand. It gives the appearance of a specially 
intercalated plate as the foundation of each process, a most anomalous 
condition. Possibly the apparent sutures represent the raised edges 
of the articulation between the processes and the corona. ‘here 
seem to be no interradial perignathic elements. 

Periproct.—Mostly broken away, but apparently projecting into 
interambulacrum 5 almost to the ambitus. Posterior margin broad 
and symmetrical. 

Ambulacra.—Composed of simple, rectilineal plates throughout. 
No biporous plates. (In Lovén, pl. i, fig. 5, the proximal ambulacral 
in column IIId seems to show two pores; but this is in contradiction 
to the statements in the text, and is probably due to an error in 
drawing or printing.) Pore-pairs confluent, dissimilar; external pore 
round, internal pore slit-like; placed near the adapical transverse 
margins of the plates. Peripodia sunken. 

Interambulacra.—Built of normal, mostly unituberculate plates. 
Proximal unpaired plate very large, variable in size and shape in the 
several areas. In Lovén’s figure (here Pl. XVII, Fig. 2) plate la, 2, 
is shown to be low and cuneiform, tapering towards the interradial 
suture. Similarly placed plates in other areas tend towards this 
character. 

Ornament.—Primary tubercles large, scrobiculate, crenulate, and 
with perforate mamelons. Approximately similar in size on inter- 
ambulacra and ambulacra, and in both arranged in regular series. 
Surface of both areas thickly studded with glossy, ovoid protuberances, 
often grouped into scrobicular circles around the main tubercles. 

Habitat.—Near Virgin Islands, between 200 and 300 fathoms. 


492 Herbert L. Hawkins—Studies on the Echinoidea, 


3. Is Py@asTripEs an Hotecryporp ? 

Ignoring the question discussed in section 4, it is a matter of 
considerable interest and importance to ascertain the systematic 
position which Pygastrides can occupy. There can be little doubt. 
that Lovén was right in regarding the ‘‘ genus” as one of the 
‘‘Hchinoconide’’, i.e. Holectypoida. Huis association of it with 
Pygaster, while still eminently reasonable, is not quite so inevitable. 
It would be difficult to locate it in any of the families of the 
Holectypoida as at present recognized—ait combines certain characters 
that occur in all families of the order, and possesses some that are 
not found in any of them. 

The Holectypoid qualities may be thus summarized :—The 
approximately radial symmetry of its outline; the central, circular, 
fairly large peristome with apparent ‘‘branchial incisions” and 
a perignathic girdle (hence presumably a lantern); the. adapically 
situated periproct, apparently in contact with the apical system and 
not located in a suleus; the non-petaloid podial pores; the serial 
arrangement of primary tubercles on both areas and their scrobiculate, 
crenulate, and perforate nature. Such an assemblage of characters, 
nearly all of a positive type, makes it impossible to regard Pygastrides 
as belonging to any order of Irregular Echinoids but the Holectypoida. 

Nevertheless, there are certain features in Pygastrides which do 
not agree with the Holectypoid diagnosis. The perignathic girdle 
seems devoid of interradial elements; the ambulacra show no trace 
of ‘‘plate-crushing”’, particularly near the peristome, and their pores 
are conjugate and dissimilar, perforating the plates near the adapical 
margins; the spheridia are single, deeply sunken, and perradial in 
position; the tubercles seem to be all primaries, and the granulation 
is pecuhar. It might reasonably be argued that these (chiefly 
negative) differences are due to the small size of the specimen. But 
in examples of Discordes divont and Conulus subrotundus of scarcely 
greater dimensions the full Holectypoid requirements are fulfilled. 

Pygastrides may, then, be considered as representing an Holectypoid 
in which certain features are lacking, and in which one set of 
structures, the spheeridia, is apparently abnormally situated. The 
disposition of the sphzeridia in the fossil Holectypoida is not yet 
known with certainty; they were presumably not deeply sunken; 
but in Hehinonéus they occur on the ambulacral plates, superficially 
placed, and to the number of three or four in each area. 

In an attempt to trace the affinity of Pygastrides with any of the 
families of the Holectypoida less definite evidence appears. To the 
Pygasteridee (and especially to Plestechinus) it is similar in symmetry,, 
peristome (save for the smallness of the branchial incisions), 
perignathic processes (apart from their angle of setting and the lack 
of buttresses), periproct, and tuberculation. The simplicity of its 
ambulacral plating, though too complete, is another link with this 
primitive family. Pygastrides resembles the Discoidiine in the 
relatively large size of the primordial coronal plates and in the 
feeble development of the branchial incisions. The peculiar structure 
of the interambulacra near the peristome is extraordinarily like that 
contiguous to the “false ridges” of Discoides. It suggests that the 


Herbert L. Hawkins—Studies on the EHchinoidea. 493 


primordial interambulacral plates block the path of the advancing 
columns, giving a type of ‘‘plate-crushing”’ comparable with that 

described by me in Lovenia forbes’. The minor ornament of the test — 
is suggestive of some of the guttate granules of Holectypus depressus, 
and perhaps of the glossy granulation of the adoral surface of Conulus. 

Thus, while showing a preponderance of Pygasterid characters, 
Pygastrides exhibits important differences from the known members 
of that family, combining in the one small corona qualities that are 
shared among all the families of the Holectypoida, and especially 
suggesting some affinity with the Discoidiine. It may be defined as 
a generalized Holectypoid with mainly primitive traits. 

Finally, there is one feature in which Pygastrides probably differs 
from the normal Holectypoida and is certainly different from their 
nearest living representatives. Itisa deep-water form. Although 
it is difficult to speak with certainty on the bathymetric range of 
fossil types, all the evidence seems to show that the Pygasteride 
(to which Pygastrides makes the closest approximation) were 
essentially denizens of shallow water. The latest Pygasterids, such 
as Anorthopygus, are only known from the littoral facies of the Chalk- 
sea deposits (e.g. the Hibernian Greensand and the Haldon Hill 
remanié), never being found in the regions of open-water ooze. 
Echinonéus abounds chiefly between tide-marks, and Micropetalon is 
not known from a greater depth than 24 fathoms. Possibly some of 
the Cretaceous Holectypoida, such as Conulus albogalerus, may have 
inhabited water of considerable depth, but there is no proof that they 
lived at such a depth as 250 fathoms. Moreover, they are morpho- 
logically- the least like Pygastrides of any members of the order. 
This point, though of little systematic value by itself, is worth 
noting in conjunction with the other divergences of Pygastrides trom 
the Holectypoid type. 


4. Is Pre@asrripes Apuutt, or A Post-Larvat Sracr? 


It follows from the discussion in the preceding section that 
Pygastrides, if it be a genuine genus, must find a place among the 
Holectypoida, although the diagnosis of the Order would need some 
modification for its inclusion. As at present known, it cannot 
possibly be associated with any other order of Kchinoids. 

Lovén seems to have been convinced that this small specimen is 
adult. He supported his contention by reference to the ‘‘rather 
thick” and rigid test, the character of the tubercles and epistromal 
prominences, and the depressed ambulacrals. He further remarked 
that, were it larger when adult, specimens would hardly have 
escaped capture. This last contention may be dismissed at once, 
since it is based upon the assumption that the adult form would 
closely resemble the small specimen. It does not follow that, 
supposing P. relictus to be an ontogenetic phase, the adult is not 
already known, the correlation of the two being at present 
impossible. Zoologists are painfully aware of the difficulty of 
identifying a larval stage with its adult form, even when both are 
fairly abundant. It is reasonable to suppose that, if P. relictus is a 
young stage, its adult equivalent has already been discovered. 


494 Herbert L. Hawkins—Studies on the Echinoidea. 


As Lovén admitted, it is difficult to derive satisfactory evidence of 
the age of Pygastrides owing to the absence of the apical system, but 
to my mind the indirect evidence that indicates its immaturity is 
conclusive. 

In point of size P. relictus is far smaller than any known adult 
Echinoid, fossil or recent. Lovén (Etudes, p. 79), regarding it as 
a Cretaceous survival, remarks, ‘‘La plupart des formes crétacées 
retrouvées vivantes a de grandes profondeurs sont comparativement — 
petites.’ But. Pygastrides is not ‘‘comparativement”, it is 
‘‘absolument petit”. In the paper devoted to this problematical 
Kchinoid Lovén admits that ‘‘ Littleness . . . seems to be another 
character by which it departs . . . from the recent forms among 
which it lives”. The minute size, », though not conclusive, is strong 
presumptive evidence for youth. 

In the absence of definite measurements of the thickness of the 
test, it is difficult to frame an opinion on the value of Lovén’s 
description ‘‘rather thick”. There is no evidence that young 
Kchinoids of as much as 3°5 mm. diameter are so little calcified as to 
undergo shrivelling when dried— a quality that Lovén apparently 
would have expected in Pygastrides were it truly neanic. chinonéus 
cyclostomus seems to have a perfectly rigid corona when it has 
attained comparable dimensions, and certainly Parechinus miliaris is 
quite massive at that size. 

Since P. relictus is an Irregular Echinoid, the tubercles, which 
Lovén cites as showing no specially youthful characters, are 
certainly disproportionately large, and remarkably sparse. They 
compare well with those of Abatus cavernosus (see Pl. XVII, Fig. 5), 
25mm. in diameter, as figured by Mortensen (Schwed. Sudpolar. 
Exped.). They are considerably larger in proportion to the size of 
the test than in any adult Holectypoid, and even than in examples 
of Plesiechinus ornatus of less than 8mm. in diameter. Since the 
tubercles of the Holectypoida are larger than those of other Irregular 
orders (excepting the specialized ones in some Heart Urchins), and 
they are constantly of fair dimensions in the relatively more 
primitive Regular Kchinoids, their large proportions in Pygastrides 
certainly suggest that youthfulness is the cause. 

So little is known of the early post-larval stages of many groups 
of Echinoids that the character of the ‘‘epistromal protuberances”’ 
can hardly be used as a criterion of age. There are plenty of 
granules and glassy tubercles on Hehinonéus when the diameter is 
only 4mm. 

Reference to the ambulacral plates of P. relictus seems to me to 
afford more indication of youth than of maturity. It is true that, 
with the exception of the primordial plates of the columns, the 
ambulacrals:are all ‘‘ Cidaroid’”’ in character; but they are not lower 
than those of Echinonéus at 38:7mm. diameter. Moreover, if 
Pygastrides is an Holectypoid, and an adult one, it is unique in the 
order in having no suspicion of ‘‘plate-crushing’’. In the small 
gnathostomatous Lechinonéus of about the same size there are already 
demi-plates in the ambulacra, and in specimens of Plesiechinus 
ornatus not exceeding 5mm. in diameter some of the plates are 


Herbert L. Hawkins—Studies on the Echinoidea. 495 


already distorted. Thus the extreme simplicity of the ambulacral 
plating is again suggestive of youth. 

Other features in P. relictus which are concordant with the view 
that it is a young form are: (1) the great size of the proximal 
coronal plates, (2) the general rotundity of the test, and (3) the 
relatively large size of the spheeridia. 

The position of the periproct gives little help in this discussion. 
Certainly, if Pygastrides were adult, it would prove to be the least 
progressive of all known living Irregular Kchinoids in this respect 
(excluding perhaps ‘‘ Vucleolites’’ recens), being no more advanced than 
the Lower Jurassic Plestechinus. But even so advanced a Spatangoid 
as Abatus cavernosus (Pl. XVII, Fig. 5) has the periproct on the 
adapical surface and in contact with the apical system when it has 
attained a diameter of 2°5mm., while at 1:9mm. it is definitely 
endocyclic. A less specialized Irregular Echinoid might well have 
a ‘‘ Plesiechinoid”’ periproct when it had reached the dimensions of 
Pygastrides. 

As a result of the considerations put forward above, I am 
conyinced that Pygastrides relictus is an early post-larval form of 
some larger species, the adult stage being, in all probability, some 
type of Irregular Kchinoid already known. 


5. CompaRIsoN oF PYGASTRIDES WITH E/CHINONEUS OF THE SAME SIZE. 


For the purpose of this comparison I have relied upon Westergren’s 
beautiful drawings (1911, Mem. Mus. Comp. Zool. Harvard, 
vol. xxxix, No. 2, pl. x1). 

The corona of Pygastrides is more circular in outline and more 
elevated than that of Hchinonéus at 3:7 mm. diameter. 

The peristomes of the two forms are similar in proportion and 
shape, but in Hehinonéus the primordial coronal plates are considerably 
reduced in size. There are three spheridia in each ambulacrum in 
Echinonéus, in contrast to the single one in Pygastrides. 

The perignathic girdle is in a far higher degree of development in 
Pygastrides than in Eehinonéus, and the processes are only partly 
based upon the ambulacral plates. 

The periproct of Hehinonéus has already reached its adoral situation 
at this stage of development—a marked advance on its condition in 
Pygastrides. 

The ambulacra of Hchinonéus have the primordial plates not 
strikingly dissimilar from the rest, while in Pygastrides these plates 
are very high. Demi-plates occur already in the former type, while 
there seems to be no trace of disturbance in the regularity of the 
shape of the ambulacrals in the latter. The pores of Hchinonéus are 
round, disjunct, and normally situated in oblique pairs on the more 
adoral parts of the plates—the reverse is the case in Pygastrides. 

In the interambulacra a similar relation of the primordial unpaired 
plates exists to that found in the ambulacra. 

The tuberculation of Hehinonéus at 4°4mm. is closely comparable 
with that of Pygastrides. 

The young forms of Hehinonéus occur between tide-marks with the 
adults, while Pygastrides was dredged from deep water. 


496 Herbert L. Hawkins—Studies on the Echinoidea. 


An analysis of the above comparison shows one feature of great 
significance. In practically every quality in which the two forms 
differ Pygastrides proves to be the less advanced from the Regular 
(or better, Pygasterid) condition. It is, like Pleszechinus, a Regular 
Kchinoid save for the (incomplete) posterior migration of the 
periproct. Thus, if it really is a young stage, it must be affiliated to 
some species that is less remote from a primitively Holectypoid 
condition than ZEehinonéus. At least, Pygastrides cannot be a stage 
in the development of that genus. 


6. Tur PropasteE ApuLT oF PYGASTRIDES. 


One of the most obvious qualities in the structure of Pygastrides is 
the position of the spheridia. ‘hese are single, and placed in 
considerable depressions on the perradial lines. ‘This is in complete 
contrast to their disposition in Hehinonéus (and probably in the 
fossil Holectypoida), and in the Cassidulide and Spatangide. It 
compares with their arrangement in Regular Echinoids, but such 
comparison is vitiated by the undoubtedly Irregular affinities of 
Pygastrides. The only groups of Irregular Echinoids which possess 
single, perradially situate spheridia are the three Clypeastroid 
families of the Fibulariide, Laganide, and Seutellide. In them, 
the spheeridia are deeply sunken, and in some cases entirely buried, 
in the test-surface; the spheeridial pits of Pygastrides are unusually 
deep. Unless it can be shown that spheridia are capable of migration 
during ontogeny (a most improbable occurrence), it must be assumed 
that the adult stage of Pygastrides has deeply sunken, perradial 
spheeridia. These need not of necessity be single, since new 
spheridia might be developed with advancing age; but among the 
known adult Irregular Echinoids that have median spheridia, they 
seem to be always solitary. ‘his evidence, then, limits the choice 
of an adult for Pygastrides to three families of the Clypeastroida, and 
I cannot imagine that it is deceptive. 

Turning now to the proportions of the proximal coronal plates: 
their great size in comparison with the others is at once apparent. 
They form a strong, broad border to the peristome, strikingly unlike 
the condition prevalent among most Echinoids. The superficial 
resemblance of this primordial cycle to the perignathic structures of 
Discoides has already been noted—it is doubtful whether a true 
morphological correspondence exists. The elongated ambulacrals 
are reminiscent of those adoral to the phyllodes in the Cassiduloida, 
while the irregularity of the interambulacrals enhances the 
resemblance. Indeed, apart from the presence of a perignathic 
girdle and the position of the spheeridia, the peristorial parts of the 
corona of Pygastrides might easily change into a iruly Cassiduloid 
pattern. The processes might be vestigial structures, destined for 
resorption as in Eehinonéus, but the singleness of the spheridia 
seems a fatal bar to the maintenance of the comparison. 

Again, the proximal coronals of Pygastrides are closely similar to 
those of Hehinocyamus (Pl. XVII, Fig. 4), a small genus that retains 
throughout life many primitive Clypeastroid features. For example, 


H. erbert L, Hawkins—Studies on the EHchinoidea. 497 


the corresponding plates of an Hehinarachnius of 6:5 mm. diameter 
(about twice that of Pygastrides), figured by Lovén (Htudes, 
pl. i, fig. 245), are practically identical in proportions with those of 
Echinocyamus. In the Clypeastroids, however, the succeeding 
ambulacral plates are high and hexagonal, unlike the ‘‘ Cidaroid ”’ 
ambulacrals of Pygastrides. Since all coronal plates undergo 
considerable changes in size, and often in shape, during the growth 
of the test, this difficulty, though real, is not insurmountable. The 
“‘ Bothriocidaroid’’ character of the extra-petaloid ambulacrals of 
the Clypeastroids is a sign of their obsolescence—they would hardly 
be in that condition when first developed. 

The globular form of Pygastrides makes it difficult to suppose that 
it would develop into a discoid Scutellid, although such a change 
would be by no meansimpossible. However, most of the Fibularide, 
especially /ibularza itself, have elevated tests that do not differ 
seriously in their proportions from those of Pygastrides. 

The peculiar multiporous plates of the ambulacra of the 
Fibulariide are certainly very different from those of Pygastrides, 
but there are indications of disturbance in the latter. The 
anomalous nature of the pore-pairs, with a round znternal pore, and 
their position near the adapical margins of the plates, seem to 
indicate some aberrant development. The rows of pores on the 
Fibularid ambulacrals are similarly placed. 

A review of the above arguments gives the following conclusions. 
The position of the spheeridia, if it be a reliable character, points 
definitely to the Fibulariid, Laganid, or Scutellid nature of the adult 
of Pygastrides. The relations of the proximal coronal plates do not 
earry the argument much further, but they are generally Clypeastroid 
in character, with some resemblances to the Cassiduloid quality. 
The general shape of the corona is more suggestive of a Fibulariid 
than of any other likely adult. So that the balance of evidence 
tends to indicate’ that Pygastrides is an early post-larval stage of 
some such genus as Pibularia. The characters of the perignathic 
girdle are not antagonistic to such a conclusion (see section 7), but 
the nature of the ambulacra introducesa difficulty. In Hchinocyamus 
and its allies, the extra-petaloid ambulacrals are high, and each 
plate is perforated by numerous minute pores arranged, for the most 
part, transversely near the adapical suture. This extremely 
specialized, perhaps degenerate, condition must have been derived 
phylogenetically from a more normal biporous state, and there is 
every reason to expect that such a change would be repeated in 
ontogeny. The features in which the podial pores of Pygastrides are 
aberrant all point towards a Fibulariid modification more than to any 
other. 

I therefore incline strongly to the opinion that Pygastrides relictus 
is an early phase in the post-larval ontogeny of some species of the 
Fibulariide. The conclusion reached at the close of the previous 
sectlon—that Pygastrides is a young stage of some form less remote 
from the primitive Holectypoid condition than Hchinonéus—is 
thus concordant with the result of this imdependent line of 
argument. 

DECADE VI.—VOL. V.—NO. XI. 32 


498 Herbert L. Hawkins—Studies on the Echinoidea. 


7. Tae MorpHocEeny or THE CriyprasTRoID PerienatHic GIRDLE. 
There are two strikingly different types of girdle-structure in the 
_ Clypeastroida. In the Fibulariide, Laganidée, and Scutellidz the 
‘‘auricles”’ are situated on the proximal interambulacral plates. 
In the rest more normal paired processes rise from the proximal 
ambulacrals. In one respect, however, there is a resemblance 
between these different structures; there is in all a strong tendency 
for the prominences to converge towards the interradii. In the 
Clypeastride the great development of the proximal ambulacrals, 
which often meet across the interambulacral, makes such a tendency 
possible without a dissociation of the processes from their normal 
foundations. But in the three families named above the proximal 
interambulacrals are present in unusually large development on the 
peristomial margin, so that no appreciable convergence of the 
processes would be possible if they remained on the ambulacrals. 

H. L. Clark has proved that the apparently single interradial _ 
‘“‘auricles”’ of the Fibulariid type are in reality double in origin and 
intimate structure—they are, in fact, dislocated processes which 
have carried their attempt at interradial convergence to the extreme 
limit. In the preceding paper of this series I showed how both 
types of Clypeastroid girdle could be derived from the Holectypoid 
type. Pygastrides, if its ascription to the Fibulariide is correct, 
gives an ontogenetic stage in the migration of the processes from 
the ambulacra to the interambulacra. The obscurity of Lovén’s 
figure in this respect is unfortunate, but it i-, sufficiently intelligible 
to show that the processes are as much on the interambulacra as on 
the ambulacra. Pl. XVII, Figs. 7a, 6, c¢, show in a diagrammatic 
fashion the possible stages through which this change might be 
brought about. As to the persistence of ax interradial element 
(ridge) carrying the protractor muscles there is, at present, no 
evidence in either direction. 

Pygastrides affords a valuable simplification to the problem of the 
derivation of the Clypeastroid girdle from the Holectypoid. Granting 
the very near relationship between the Clypeastroida and Discovdes, 
the difference between their perignathic structure is somewhat 
embarrassing. But if they pass through a Pygastrides-phase, which 
is simpler in some respects even than that of Pygaster, the girdles of 
the Fibulariid and Clypeastrid patterns need not be encumbered by 
the massive false-ridges of Discoides. The ontogenetic repetition 
preserves the essentials, and entirely leaves out the individual 
specializations of the ancestral adults. 

In this respect it is noteworthy that both Pygastrides and the 
young Hehinonéus are entirely without interradial ridges. In the 
case of the latter, the protractor muscles are fixed to the free edges 
of the proximal interambulacrals; these being, so far as appears, 
quite unmodified as special muscle-supports. In the fossil 
Holectypoida, as I have shown in this series of papers, there is 
always some small relic of an interradial ridge on the proximal 
interambulacrals, minute though these plates usually are. It may 
well be that the absence of these structures in the two young stages 
is due solely to their youth—they never appear in the edentulous 


Herbert L. Hawkins—Studies on the Echinoidea. 499 


Echinonéus, but at least the muscle scars develop later in 
Echinocyamus. In the Clypeastride, again, no interradial elements 
occur, the protractor muscles finding attachment on the processes 
themselves. 

The Fibulariide and Laganide are certainly less specialized in 
most characters than the Clypeastride. It is therefore strange to 
find the fused interambulacral processes—a highly specialized 
condition—occurring in the former groups, while more typically 
Holectypoid qualities are preserved in the latter. But if the 
theoretical structure of the ‘‘auricle’’ of Hehinocyamus given on 
Pl. XVII, Fig. 7c, is in any Way correct, that type of girdle is 
more closely akin to the Holectypoid (especially to the Discoidiid) 
type than the ridgeless girdle of Clypeaster. The two types of 
Clypeastroid girdle must, however, mark two distinct and divergent 
lines of descent; in one all structures become ultimately inter- 
ambulacral, in the other ambulacral, in position. Both types differ 
from the true Holectypoid, and it is premature to ascribe greater or 
less specialization to either. 


8. Toe Bearing or PyeasTrrmpes on Post-Hoiecrypoin PHyLoGEeny. 


It will be realized from the foregoing descriptions and arguments 
that Pygastrides is in most respects an Holectypoid, in many a 
Pygasterid, in some a Discoidiid, and is probably the young of 
a primitive Clypeastroid. Of the young Zchinonéus of similar size 
it may with equal j tice be said that it is in most respects 
an Holectypoid, in many a Pyrinid (or Conulid), and in some 
a Discoidiid. The young Abatus at a smaller size may be said to be 
Pygasterid in apical and periproctal characters, Pyrinid in shape, but 
already Spatangid iu coronal plating. The last-named form is 
evidently so accelerated in its ontogeny that no certain conclusions 
can be drawn without more evidence. The two others are more 
restrained in development, and their evidence on the phylogeny of 
their adults is intelligible and conclusive. Of Hchinonéus and its 
relatives I hope to treat in the near future, but it will suffice here to 
incorporate the evidence of Pygastrides into the scheme of post- 
Holectypoid evolution. 

Paleontological and morphological study link the Clypeastroida 
inseparably with the Holectypoida. The peculiar distribution of 
the madreporic pores and the development of internal supports 
associate them more particularly with the Discoidiine. Whether 
Lchinocyamus and its relatives be primitive or degenerate, they are 
certainly the simplest of the Clypeastroida. Pygastrides, if the 
above interpretation of its nature is correct, adds a conclusive 
ontogenetic proof of the near alliance between the two orders, and 
suggests that the Fibulariide are truly primitive. Almost the only 
features in which Pygastrides differs from a true Holectypoid consist 
in the omission of certain structures, most of which are obsolescent 
in the Holectypoida themselves. 


9. Summary. 
Pygastrides relictus, Lovén, is believed to be an early post-larval 
stage in the development of some Irregular Echinoid. Reasons are 


\ 


500 H. G. Smith—Basic Intrusions - 


given for the belief that this Echinoid is probably a Clypeastroid, 
and one of the Fibulariide. In view of its undoubted resemblance 
to the Holectypoida, particularly to the Pygasteridz and Discoidiide, 
Pygastrides is regarded as affording ontogenetic evidence of the 
phyletic connection of the Clypeastroida and Holectypoida through 
the Discoidiidee. 


EXPLANATION OF oben XVII. 

Fie. 

1.—External view of the peristomial region of Pygastrides relictus, much 
magnified (after Lovén). 

2.—Internal view of the same region. The perignathic processes are nase 
away in areas Jb, IVa, and Va. 

3.—Proximal end of an ambulacrum of a Scutellid (Hncope), showing ie 
single, perradial, deeply sunken spheridial pit (after Lovén).. 

4.—Plan of the peristomial region of the corona of Hchinocyamus, internal 
surface. The ambulacra are stippled. (Reversed and modified from 
Lovén so as to compare with Fig. 2 

5.—Adapical view of young Abatus cavernosus, 2-5mm. in diameter (after 
Mortensen). The periproct is Plesiechinoid in position, and the apical 
system Pygasterid in character. 

6.—Internal view of the peristomial region of young Echinonéus, 4:19 mm. 
- long (after Westergren). Note the reduced proximal plates and the 
progressive ambulacral structure. 

7.—Diagrams to suggest the possible origin of the Fibulariid Ginaiale’ 
The ambulacra are stippled. (a) Disjunct processes of Pygaster or 
Pygastrides. Retractor muscles single, protractors on edge of proximal 
interambulacral plate, with or without a rudimentary ridge. (6) Pro- 
cesses meeting across interradius, and based upon the interambulacral 
plate. Retractor muscles double, protractors on a raised (Holectypoid) 
ridge. (c) Auricle of Hchinocyamus. The dotted lines indicate its 
possible origin from stage 6. 


IV.—Txe Basic Inrrustons East or Gettr Hirt, Rapnorsuire. 


By H. G. Smiru, A.R.C.S., B.Sc:, F.G.S. ; with three analyses by 
J. H. WILLIAMS. 


(PLATES XVIII AND XIX.) 


URING the last few years I have spent a considerable amount of 

time studying the geology of the country east of Llandrindod, 

but much still remains to be done, and the present paper merely 

embodies a few of the points which seem ‘to be satisfactorily 

established with regard to a small portion of the area. Three 

distinct types of igneous rocks are recognized, and some facts and 
ideas with regard to each are put for ward. 


THE OLIVINE oe 
Forming part of the N.N.E.-S.8.W. ridge east of Tyn-y-coed, and 
best exposed in a quarry at its southern end, is a dark-coloured, 
almost black, fine-grained igneous rock, which, in the absence of any 
published descriptions,’ calls for some comment.,, The same type 
also occurs about a mile to the north in the neighbourhood of Bwlch- 


' Dr. Harker (Presidential Address to the Geological Society, Q.J.G.S., 
pt. i, 1917) mentions the existence of basalts in the Wells country, and 
considers them to be extrusive, 


GEOL. MAG. 1918. PLATE XVII. 


yy~ac! (Ge ¢) © 
aye vines Z 
SOT 


Post-LARVAL STAGES IN CERTAIN IRREGULAR ECHINOIDEA. 


> 


ee) 


Last of Gelli Hill, Radnorshire. a axon 


llwyn, notably forming a conspicuous elevation west of the Bog 
Wood.’ The specific gravity of the fresh variety is 2°86. 

Examined microscopically, the rock is seen to be a typical 
olivine basalt with remarkably fresh felspar and augite. The most 
abundant constituent is the lath-shaped felspar, the crystals of 
which reach a maximum of 1:4 mm.; there is no indication of two 
generations. In some cases there is an aggregation into groups, 
producing a structure with some resemblance to glomero-porphyritic. 
The refractive index is well above that of Canada balsam, and 
some individuals are partially replaced by a green substance, 
probably clinozoisite. Between crossed nicols the felspar exhibits 
the usual first order colours and lamellar twinning, and the angle ot 
extinction is rather high. Some zoning is to be seen. The refractive 
index and extinctions indicate a composition approximating to that 
of labradorite. 

A very pale, almost colourless, granular augite occurs between the 
felspars. It has the usual relief; a few fragments exhibit the 
rectangular cleavages, and it is commonly quite fresh. The polariza- 
tion colours are of the first and second orders. 

There are occasional pseudomorphs, maximum dimension 1:2 mm., 
preserved in some cases in a pleochroic serpentine, elsewhere in 
a mixture of serpentine and calcite or quartz. Their shape and 
structure leave no doubt as to their derivation; they were originally 
olivine. 

Ilmenite occurs moulded on the felspar; it is sometimes fresh, but 
the numerous grains of sphene present in the rock have probably 
resulted from its alteration. 

A devitrified glass occurs as a groundmass. Some vesicles are 
filled with similar material, which exhibits a system of black crosses 
in polarized light. One vesicle is occupied by an almost isotropic 
glass with a curious cellular structure, the cells in places near the 
margin elongating to tubes with approximately radial disposition. 
This structure appears to be a record of the infilling of the vesicle, 
the various streams of viscous magma having failed to amalgamate 
after entry. 

The observed occurrences of the basalt are all at or near a junction 
where fossiliferous felspathic ashes rest on shales with tuning-fork 
graptolites; hence the obvious conclusion that this rock represents 
the first product of the extrusive igneous activity responsible for the 
thick overlying ashes. But in spite of the fact that no metamorphic 
phenomena have yet been observed, its intrusive character is still 
considered to be a possibility. An Ordovician flow of this character 
would be absolutely unique in the igneous history of Wales,’ and 
the rock is remarkably fresh. On this question of possible intrusion 
the suggestion made by Professor Watts? that the area of Tertiary 
igneous activity outlined by Dr. Harker* may have to be extended 
to the south has a possible application to this locality. 


1 W. G. Fearnsides, Geology in the Field, 1910, p. 801. 
2 Proc. Geol. Assoc., vol. xix, p. 179, 1905. 
> Tertiary Igneous Rocks of Skye (Mem. Geol. Surv.), 1904, p. 3. 


502 HA. G. Smith—Basic Intrusions 


THe Drasase. 


This Ape cree an imposing show on, the. ‘eiaanale One sill 
(aligned with the Castle Bank intrusion described by, Mr. Woods’) 
commences just north of Camnant Brook, runs north-east. between 
Blaenkerry and Garn-fach, turns due north, and is continued on the 
eastern side of Gelli Hill to disappear under the ashes near the Bog, 
a distance of about two miles. The Llanvirn Shales are in contact 
throughout most of this distance. Another intrusion is exposed 
north of Frank’s Bridge. It runs N.N.E. for about a mile and stops 
short before reaching the River Edw. The same line is continued on 
the other side of the river at Graig-fawr, exposed as a sill dipping 
west, running just on the western “side of the farm, and dying away 
in, the vicinity of Llanwefr Pool. The northern part of the sill is 
shifted to the east by a dip fault. A shorter intrusion with the same 
trend is found west of Pye Corner, and, finally, a parallel sill runs 
from Cwm-maerdy to the Edw south of Pye Corner, but a portion of 
the sill is shifted to the east by trough faulting. The behaviour of 
some of these intrusions on approaching the rivers suggests that the 
serrated upper edges of the sills have not yet been obliterated, and 
the rivers have selected those places where the sinuous edge makes 
a downward bend. 

The rock is medium-grained with a general. erconishy tinge, showing 
a pale-grey network ona black background. 

In thin section the rock is seen to be made up principally of males 
brown augite and lath-shaped felspars related ophitically. No fresh 
specimens have been obtained, and in all the sections examined the 
felspar is more or less decomposed; but as far as can be determined 
the refractive index is never high enough for labradorite, and this 
impression is supported by the symmetrical extinction angles of the 
albite lamelle; the maximum value obtained is 16°, and it is 
suggested that ‘the felspar is andesine. Pericline twinning is rare, 
and. zoning has not been observed. 

The augite varies from colourless to a pale brown. It has the 
usual refractive index and cleavages, and alters, as a rule, to chlorite, 
which polarizes in ultra-blue or first order grey, but in one séction 
a brown amphibole represents an intermediate stage in the alteration. 
There is an occasional suggestion of pleochroism. ‘The polarization 
colours are of the first and second orders, and twinning, though seen, 
is rare; the double refraction is positive. The individuals polarizing 
in very low colours are invariably found to be approximately 
perpendicular to an optie axis, and for this reason it is considered 
that the fresh pyroxene is exclusively monoclinic. .There are, 
however, some pseudomorphs which show good cleavage, polarize in 
bright colours, and extinguish as a single unit which may be altered 
hypersthene.. Some of the pseudomorphs suggest derivation from 
olivine, but proof is wanting: 

Another constituent locally abundant is ilmenite. “Ip aeecnedl 
shows the characteristic white alteration product and is moulded on 
the felspar and augite. A few idiomorphic crystals of sphene 


1 Q.J.G.8., vol. 1, p. 576, 1894. 


PLATE XVIII. 


GEOL. MAG. 1918. 


4 
Ue 


Bastc INTRUSIONS IN RADNORSHIREI 


East of Gellt Hill, Radnorshire. 503 


embedded in chlorite are possibly the result of the further alteration 
of this mineral. Acicular apatite is present in small quantity. 

The amount of metamorphism effected by the diabase is never 
great, the most striking result being a rock resembling a spilosite, 
produced in consequence of the alteration of the shales which almost 
invariably occur at the contact. At one point, however, in the 
brook just south of Pye Corner the contact rock is a limestone 
containing fossils which Dr. Morley Davies recognizes as Sérick- 
landinia lirata (Sowerby), S. lens (Sowerby), Strophonella euglypha 
(Sowerby), Atrypa sp., Encrinurus sp., and Halysites sp. his fauna 
he considers to be sufficient to prove the Upper Llandovery age 
of the sediment, and it therefore becomes a matter of extreme 
importance to determine the relative ages of intrusion and limestone. 

A specimen of the diabase from near the contact includes a patch 
of calcite, which mineral is seen in thin section to be interstitial with 
regard to the felspars. The latter are not more basic than in the 
diabase remote from the limestone, but apatite is distinctly more 
abundant. 

The limestone varies from pale grey to black. In places it 
exhibits some resemblance to a conglomerate, containing subangular 
fragments of quartz. Occasionally on the bedding plane is seen 
a spheroidal projection which, broken across, is not to be dis- 
tinguished from the adjacent igneous rock, and similar igneous 
material is interbedded with the limestone, sometimes with a layer 
of crystallina calcite at the contact. Lenticles of calcite occur 
within the igneous material and patches of the igneous rock within 
the limestone. Some pyrite occurs at and near the junction. A thin 
section through one of the igneous spheres shows a diabase exactly 
comparable with that of the adjacent sill; the felspars interlock in the 
usual way and enclose angular patches of chlorite, and idiomorphic 
crystals of apatite occur in the felspar. The margin of the sphere is 
sharply defined; there is no transition into the limestone and, at this 
contact, there is no evidence of recrystallization of the latter. 

The part of the rock not obviously igneous in origin exhibits 
features of considerable interest. Some portions of the sections are 
made up of a network of felspar crystals related just as in the 
igneous rock, but instead of interstitial augite or chlorite there is 
crystalline calcite. Here again the felspars are not more basic than 
in the diabase, and there is no support for the idea that calcareous 
material has been incorporated by the felspars. Other crystals of 
felspar appear to be isolated; they are sometimes idiomorphic, but 
elsewhere are moulded on the calcite. Quartz, either as simple 
individuals or as aggregates, occurs scattered through the rock as 
subangular equidimensional grains, as extremely angular individuals 
of various shapes, and as idiomorphic crystals. In one particularly 
interesting case the felspar and quartz are intergrown to form 
excellent micrographic structure. This example is sufficient to 
demonstrate the igneous origin of some of the quartz in the lime- 
stone and to render it extremely probable that no detrital quartz is 
present in the rock. 

There is no question as to the relative ages of the two rocks; the 


504 H. G. Smith—Basic Intrusions 


intrusion is certainly post-Llandovery. But there remains the 
interesting question as to why the diabase has failed to cut through 
_ the limestone. We are compelled to suppose that a magma exercises 
a careful selection’ with regard to the rock invaded. In the case 
here considered the diabase magma readily penetrated the shales, 
but the overlying limestone presented an almost impassable barrier. 
Igneous material was injected along the bedding planes, and pockets 
containing the diabase were formed in consequence of a boring action 
on the part of the magma, while the areas occupied by a network of 
felspar with interstitial calcite resulted from the intrusion of 
a felspathic portion of the magma into a locally fused limestone area 
and subsequent crystallization of felspar followed by that of calcite. 

All the evidence supports the theory that the diabase, when 
intruded into its present position, was nearing the limit of its powers 
of penetration. ‘The still existing serrations of the upper edges of 
the sills, the failure to cut through the limestone, the very feeble 
metamorphism, and the fact that the silicates do not incorporate any 
of the calcium from the adjacent or containing limestone, aL point 
in the same direction. 

The conclusion here arrived at as to the age of the ajahaee is in 
direct opposition to that put forward by Mr. Woods? as a. result of 
his examination of the area to the south. He relies on the facts that. 
‘nowhere do they (the diabases) pierce the Silurian beds”’, and that 
at ‘‘the section exposed in the quarry next Pen-cerig Lake, where 
the diabase is seen in contact with both Llandeilo shales and the 
Llandovery beds, the former are metamorphosed, the latter quite 
unaltered’”’. But we have seen reason to suppose that failure to cut 
through a sediment is no proof that intrusion took place before that 
rock was laid down, and it follows from the facts put forward that 
striking metamor phic effects are not to be expected. 

If the post-Llandovery date of the diabase is accepted, then these 
intrusions are brought into, line with those of the Shelve area, where 
Professor Watts* has shown that the dolerites ‘‘come into ‘contact 
with and somewhat alter the Pentamerus limestones’’. 

Professor Fearnsides‘* concludes that the andesitic dolerites of 
Arenig ‘‘are of the same general age”. . 

Dr. “Harker,® under the impression that the cleavage and plication 
of the strata of Eastern Carnarvonshire were developed i in pre-Silurian 
times, assigned a Bala age to the diabases of that area, but Professor 
Fearnsides® points out that ‘‘with increase of knowledge the 
supposed gap in the continuity of sedimentation has been filled up, 
and now a Post-Silurian date for the cleavage is generally accepted”’. 

It appears, then, that this post-Llandovery intrusion of diabase or 


' This power of selection is implied, by Professor Watts in his description of 
the intrusions of the Shelve area Cit Geol. Assoc., vol. xiii, p. 342, 1894). 
2 Loe. cit., p. 577. 
> Loe. cit., pp. 339-40. 
. Q.J.G.S., vol. lxi, p. 631, 1905. 
° Bala Volcanic Series, 1889, p. 76. 
® Geology in the Field, 1910, p. 803. 


GEOL. MAG. 1918. PLATE XIX. 


DIABASE INTRUDED INTO LLANDOVERY LIMESTONE, River Epw, 
RADNORSHIRE. X 14, 


East of Gelli Hill, Radnorshire. 505 


dolerite is a fact of some considerable importance in the geology of 
Wales and Shropshire. 


Tur Gran-orr Type. 


At Glan-oer is exposed a fine-grained igneous rock, dominantly 
pale grey, but with small black specks and larger whitish spots. 
The same type is exposed in the quarry between Little Nant and 
Graig-fawr, also in a dyke running N.W.-S.E. from the ford in the 
Nant Brook below Hendy Bank to a point south-west of Llanwefr 
Pool. The specific gravity is 2°69. 

In thin section the rock is seen to be made up largely of a felted 
mass of felspar laths with somewhat ragged outlines. ‘They are very 
constant in length, averaging about 0°‘7mm. Alteration has gone on 
to a considerable extent, but they can be seen to polarize in first order 
colours and to exhibit lamellar twinning. Symmetrical extinction 
angles are always low, the maximum value observed being 12°; the 
.felspar must approximate to oligoclase in composition. Another 
conspicuous constituent is a pale-green alteration product which is 
sometimes moulded on the felspars; the relief is not great, but the 
refractive index is distinctly higher than that of Canada balsam ; 
polarization is first order grey and is of the aggregate character. 
There is an occasional suggestion of olivine in the shape of the 
pseudomorphs, and one particular case (1-2 mm. in length) places the 
matter beyond doubt; the substance is serpentine, and is the result 
of the alteration of olivine, almost certainly a variety poor in iron. 
It is possible that some of the felspar crystallized before the olivine, 
though the moulding of the serpentine on the felspar may be due to 
the expansion consequent on the alteration. In this connexion, 
though, it must be borne in mind that Professor Watts,’ in dealing 
with the olivine-dolerite dykes of Antrim, has described a case 
where the felspar crystallized before the olivine. Some varieties of 
the allivalite of Dr. Harker? also exhibit a similar sequence of 
crystallization. In that rock, however, the felspar is anorthite. 

Another interesting constituent is a pale-brown augite. This 
mineral is totally absent from some of the sections, and even in the 
case of those in which it occurs the distribution is somewhat 
eccentric. It is found in spots only large enough to enclose, perhaps, 
a score of felspar laths. When altered, it produces a cloudy 
aggregate containing much calcite; this is responsible for the whitish 
spots visible to the naked eye. Other constituents are apatite, 
fairly plentiful secondary sphene, and pyrite. 

The remaining mineral is clear and fresh, with a refractive index 
approximating to that of Canada balsam; it polarizes in first order 
grey with occasional yellow. Careful search resulted in the 
discovery of a definite cleavage, lamellar twinning, and the fact that 
the refractive index is distinctly below that of Canada balsam. The 
mineral is biaxial and the birefringence is positive. It is undoubtedly 
albite. Twin lamelle run interruptedly from one felspar to the 
other, though the angle of extinction changes. It is not possible at 


1 Guide to Rocks and Fossils (Geol. Surv. Ireland, 1895, p. 78). 
2 Petrology for Students, 4th ed., 1908, p. 103. 


506 A. G. Smith—Basic Intrusions, Radnorshire. 


present to say definitely whether the albite is magmatic in origin or 
is the result of weathering. 

This rock presents some points of resemblance to the Skomerite 
and Marloesite of Dr. Thomas,’ but the evidence available suggests 
that it is newer than the Lower Arenig, to which the Skomer 
Volcanic Series is assigned. 


ANALYSES BY J. H. WILLIAMS. 
1. OLIVINE BASALT. 


SiO» 48-66 
Ti Os 2-23 
Als O3 15-76 
Fee Oz 2-66 
FeO 8-16 
MnO ; 0-14 
(Ni Co) O 0-03 
Ba O ‘ none 
Sr O 0-16 
CaO 10-90 
MgO 5:68 
K,O 0:05 
Naz O 1-25 
Li, O ; 3 none 
He O at 105° C. : 0-70 
He O above 105° C. 8-04 
Po Os 0-22 
S Os 0-43 
C Oz 0-20 
FE traces ? 
Cl . - traces 
Total 100-27 
2. DIABASE. 
SiO. 45-82 
Ti O2 1-99 
Als Os 16-49 
Fe, O3 1:80 
FeO 7-48 
MnO 0-15 
(NiCo) O none 
Ba O none 
Sr O traces 
CaO 8:79 
MgO 8-95 
K.0 0-35 
Nag O 2-82 
Lig O none 
H.O helo 100° C. 0-50 
He O above 100° C. 4-89 
P. Os 0-18 
SOs traces 
C Oz 0-04 
Bike traces 
Cl traces 
Total 100-25 


1 Q.J.G.S., vol. Ixvii, pp. 196-201, 1911. 


Dr. F. A. Bather—Notes on Yunnan Cystidea, 507 


8. THE GLAN-OER TYPE. 


Si Os s ‘ ; ‘ 3 , . 60-76 
Ti Os ; 3 =) : ; i : 2-10 
AleOg  . R 3 , 4 a GO 
Fes O3 5 5 5 a . . 5 0-86 
FeO ‘ f 5 : F : ; 6-90 
MnO z : : ‘ : : 4 0-11 
(NiCo) O 5 ; ‘ ; : ; none 
Ba O F s : ; ‘ : : none 
Sr O { ; : ‘ E ‘ . traces 
CaO 4 : : ; f . : 3-55 
MgO : : 4 : : f . 8-02 
K20O 5 4 : 4 : f 5 0-81 
Nag O . 5 . 5 A a O 3°78 
Li, O - 3 : 3 s ; . traces? 
He O below 100°C. . ; ; : : 0-41 
H.O above 100°C. . ; : 2 : 5-33 
P2 Os : ; : : 4 s 5 0-26 
Fe Se : ' 4 ; : : : 0-41 
C Oz A é : : : d : 0-61 
1 : : g : ; 5 : none 
Gl . y : : : ; ‘ . traces 
Ivor 4 i . 99-92 


In conclusion, I wish to express my indebtedness to Miss 
Chamberlain, who placed her notes and maps at my disposal, to 
Dr. Morley Davies, who identified the fossils, and to Professor Watts, 
who looked through the proofs and made valuable suggestions. 


_EXPLANATION OF PLATES XVIII AND XIX. 
PLATE XVIII. 
Fic. 1.—Augite moulded on felspar, N. of Llanwefr Pool. (Diabase.) x 16. 
,, 2.—Ilmenite moulded on felspar and augite, Graig-fawr. (Diabase.) 
x 305. 
», 38.-—Olivine basalt, EH. of Little Wern. x 27. 
,, 4.—Pseudomorph after olivine, S.W. of Llanwefr Pool. (Glan-oer type.) 
STs 
», 5.—Ophitic structure, Glan-oer. (Glan-oer type.) x 34. 
PLATE XIX. 


Fies. 1-3.—Specimens of diabase intruded into Llandovery Limestone from 
River Edw, 8. of Pye Corner, Radnorshire. x 1% nat. size. 


V.—Norres on Yunnan Cysripgea. I. Szvocysris anp OvocyYsrTIs. 
By F. A. BATHER, D.Sc., F.R.S. 
(Published by permission of the Trustees of the British Museum.) 


EFORE returning to Calcutta the specimens described in his 
memoir ‘‘Ordoyician and Silurian Fossils from Yun-nan”’ 
(1917, Paleont. Ind., n.s., vol. VI, Mem. 3), Dr. F. R. Cowper 
teed very kindly lent to the Geological Department of the British 
Museum the figured cystids, in order that plaster casts of them 
might be made and kept there for reference. This was done, and 
a set of the casts was also furnished by the Department to the 
Sedgwick Museum, Cambridge. While preparing the specimens for 
the moulder, I had the opportunity of studying them with some 


508 Dr. F. A. Bather—Notes on Yunnan Cystidea. 


eare. Although Dr. Reed has published good figures, drawn with 
Mr. T. A. Brock’s usual exactitude, and descriptions, on the fulness 
of which he will perhaps allow me to compliment him, neverthe- 
less the notes made by me, when still unacquainted with his 
valuable work or with the views therein expressed, do contain 
supplementary matter, which it seems better to publish now rather 
than to reserve for some revision in an uncertain future. 
ORIENTATION. 

To avoid confusion, it is necessary to explain that the terminology 
and orientation here employed are the same as those used by me in 
describing the cystids from the Northern Shan States (1906, 
Paleont. Ind., n.s., vol. II, Mem. 3), also in Lankester’s ‘‘ Treatise 
on Zoology”’ (1900), and elsewhere. As regards the terminology of 
the various parts and organs, Dr. Reed and I are in general agree- 
ment; but the orientation adopted by Dr. Reed is unfamiliar. To 


; Aas 


bbe 
antervir 


Fic. 1.—A diagram of the adoral face of a simple five-rayed Pelmatozoon, 
showing peristome, hydropore, gonopore, and periproct; the orientation 
indicated according to F. R. Cowper Reed. 

Fic. 2.—The same ; the orientation indicated according to F. A. Bather. 

meet the difficulty that I found in interpreting it, Dr. Reed has 

kindly marked his main lines on the accompanying diagrams 

(figs. 1 and 3), beside which my own scheme (figs. 2 and 4) is placed 

for comparison. In both cases the ‘vertical axis’ runs from the 

oral centre (my ‘oral pole’) to the centre of the base (my ‘apical 
pole’), and all the diagrams are viewed from above the oral pole. 
From his diagrams and letters it appears that the basis of 

Dr. Reed’s scheme is the ‘ sagittal plane’, which he takes as passing 

through the vertical axis in the direction of the mouth-extension, 

or, in a normal five-rayed form, between the pair of rays enclosing 
the hydropore [ ‘ bivium’ | and the remaining three rays [ ‘trivium’ ]. 

The ‘antero-posterior plane’ of Dr. Reed cuts the sagittal plane at 

right angles on the vertical axis; the anterior face of the theca is 

that on which the hydropore lies, and (usually) the anus. 


Dr. F. A. Bather—Notes on Yunnan Cystidea. 509 


It is not necessary to enquire whether this scheme is used quite 
consistently by Dr. Reed; it is doubtful whether it could be. Nor 
need one do more than point out that Dr. Reed strays no less from 
general custom in his use of the terms ‘pole’, ‘meridian’, ‘right’ 
and ‘left’. 

Unfortunately Dr. Reed believes himself to have been following 
the chapters in the ‘‘Treatise on Zoology” as his ‘authority’, a 
compliment which is so effective a criticism of their lucidity that it 
is necessary to make their scheme plainer in so far as it applies to 
Cystidea. 

A pole is a point at which an imaginary axis cuts the circum- 
ference of the theca. . 

The oral pole coin ey with the centre of the peristome (wide 


infra). 


posterior anterior 
; fori live \ ; 
sagilial \ | 
\ 


— 


un peristomie 
julane 


proslerior 


Fic, 3.—A diagram of the adoral face of Sinocystis manswyi, after Reed, 1917, 
jolle IOUT atex TU; the orientation according to Reed. x 4. 

Fic. 4. —The same ; the orientation according to Bather. The evidence for 
the ‘‘ primitive sagittal plane’’ is given in the notes on S. loczyi (part II, 
fig. 8). 


The apical pole coincides with the centre of the basal attachment, 
or with the centre of the system of plates in that region. 

A specialized apical system of plates comparable with that of 
Crinoidea and Kchinoidea has rarely been attained in Cystidea. 

The vertical axis cuts the theca at the oral and apical poles. 

The region of the thecal surface surrounding the oral pole is the 
adoral face. 

The region surrounding the apical pole is the adapical face. 

The thecal openings are normally four: the peristome, often 
ealled the ‘mouth’, but that organ, strictly speaking, lay within it 
and may have occupied but a small part of the peristomial area; the 
periproct, often called the ‘anus’, but that organ lay within it and 
occupied only a part of the periproctal area; the hydropore, some- 
times in the form of a ‘madreporite’, usually lying close to the 


510 Dr. F. A. Bather—Notes on Yunnan Cystidea. 


peristome; the gonopore is the name frequently applied to the 
‘fourth opening’ on the assumption that through it the gonads were 
emitted, but Jaekel calls it the ‘parietal pore’ on the assumption 
that it was the opening of a persistent parietal canal—the two 
assumptions are by no means mutually exclusive. Primitively 
these four openings lie in a straight line which probably indicates 
the attachment of the dorsal vertical mesentery to the inner wall of 
the theca; their order is peristome, hydropore, gonopore, periproct. 

In this series the peristome (mouth) is anterior; the periproct 
(anus) is posterior. The line joining these two is the oro-anal axis. 

The theca being placed with its oral pole uppermost and with the 
anus towards the observer, then the right and left of the theca 
correspond with the right and left of the observer. In representations 
of all Echinoderma, figures representing the adoral or adapical faces 
should be placed on the paper so that the right side of the creature 
is towards the right side of the page. Side-views of Pelmatozoa 
should have the adoral end uppermost. 

The antero-posterior plane or anal plane passes through the oro- 
anal axis and the vertical axis. A line drawn in this plane and 
bisecting the vertical axis at right angles would be the antero- 
posterior axis. This does not coincide with the oro-anal axis, and 
the concept is rarely required. 

As regards the sagittal plane there is perhaps room for hesitation. 
When the thecal openings all he in the antero-posterior plane, then 
that plane is the sagittal plane, as it would be in any symmetrical 
animal. The plane at right angles to it and passing through the 
vertical axis 1s then the transversal plane (T'ext-fig. 2). 

In many cystid genera asymmetry is manifested in a migration of 
the anus and in a correlated or an independent shifting of the 
gonopore. The oral pole being regarded as fixed, then it appears 
that the hydropore (or madreporite) ‘undergoes less lateral change of 
position than the other organs. The plane through the vertical 
axis and the hydropore may therefore not coincide with the antero- 
posterior plane; it needs a distinct name, and I have called it the 
M plane (= madreporite plane) (Text-fig. 4). 

It seems best to limit the term ‘sagittal’ to its primitive 
morphological use, available only for outwardly symmetrical or 
almost symmetrical forms; and for asymmetrical forms to use the 
terms ‘anal plane’ and ‘M plane’. When a sagittal plane cannot be 
fixed, then it is inaccurate to use the term ‘transversal’, and another 
term (should one be thought necessary) must be found for the plane 
passing through the vertical axis and the peristomial extension, 
which plane in pentamerous Pelmatozoa separates the bivium 
(radii C D) from the trivium (radii E A B); it may be called the 
peristome plane. As a rule, but not always, the plane which 
Dr. Reed has termed ‘sagittal’ corresponds roughly to this 
peristome plane. In Pelmatozoa the peristome plane usually 
hes approximately at right angles to the M plane, but this arrange- 
ment is not inevitable. In the Spatangoid sea-urchins the peristome 
plane separates the bivium (A B) from the trivium (C D E)—quite 
a different plan; theoretically it forms an angle of 54° with the 


Dr, F, A. Bather—Notes on Yunnan Cystidea. 511 


M plane, and the plane (radius D; interradius A B) to which it is 
at right angles is the plane of test-elongation known as ‘ Loven’s 
plane’ (see ‘‘ Treatise”, 1900, pp. 19-22, fig. xviii). Such facts as 
these show that the peristome plane has been fashioned in different 
groups in response to different adaptations, and that in each group it 
is of later origin than the M plane and the anal plane, just as they 
are, ex hypothest, later than the sagittal plane. 


Sryocystis anpD Ovocysris. 


About ninety specimens from the Ordovician limestones and 
calcareous mudstones of Shih-tien (Reed’s rock-types g and h, 
Coggin Brown’s beds 5 and da) are relatively large cystids belonging 
to the family Spheronide of the Diploporita. Twenty-one of these, 
being figured specimens, were studied by me and will here be 
referred to by the numbers of the plate-figures, since they were 
unprovided with any other reference-number. They are distributed 
by Dr. Reed between his two new genera Sinocystis (S. loczyt, I, 1-8, 
and S. yunnanensis, I, 9, 10, II, 1, 16: n.spp.) and Ovocystis 
(O. mansuy?, n.sp., II, 2-11). They agree, however, in a number of 
characters, which may be summarized as follows :— 

Theea variable in shape but roughly ovate pyriform, tapering to 
the base of attachment which may be prolonged as a_ short 
unspecialized stalk; composed of numerous (100-600) irregular, 
polygonal, stout plates, bearing conspicuous diplopores. Oral pole 
approximately in the centre of the rounded summit of the theca. 
Peristome extended approximately at right angles to the anal plane 
(probably an elongate rectangular opening) with two short food- 
grooves diverging at each end (one at each corner) and each ending 
on a brachiole-facet (possibly more than one); mouth and epithecal 
food-grooves with irregular cover-plates interlocking across the 
middle line and apparently fixed. Periproct on the adoral face, 
about half-way between oral pole and periphery, hexagonal or 
pentagonal, with 6 or 5 covering valves. Hydropore slit-like, lying 
slightly to left of anal plane, close to peristome. Gonopore 
pentagonal to circular, on left of periproct. 

The three species are well founded: they may be distinguished by 
their diplopores, if by nothing else. S. yunnanensis is, no doubt, of 
the same genus as Sinocystis loczyz; but why is Ovocystis mansuyt 
separated? Examination of the generic diagnoses provided by 
Dr. Reed reveals the following alleged differences. 

The periproct of Svnocystis is hexagonal, of Ovocystis pentagonal. 
This is really a point of no importance; but in any case the rule is 
open to exception, for in O. mansuyz the outline seems to be 
hexagonal in specimen I], 6. 

The diplopores of Sznocystis are, it is said, covered by tubercles of 
epistereom ; those of Ovocystis are not covered by epistereom. This 
is a very doubtful point. In all three species there is a tendency for 
the stereom immediately surrounding each pore-pair to be raised, so 
as ultimately to form a sort of tubercle. In S. loczyi the pores open 
on a rounded elevation surrounded in some cases by a faint moat. 
This elevation may reach a height of 1:7 mm. above the test 


512 Dr. F. A. Bather—Notes on Yunnan Cystidea. 


(specimen I, 8), and as it grows upwards there is certainly a tendency 
for the epistereom to block the pores, but I was unable to convince 
myself that it ever actually succeeded (Text-fig. 5). In S. yunnanensis, 
where the pore-pairs are more numerous than in S. loczy, they have, 
for the sake of space, to assume a more regular arrangement, and so 
the long axis of each elevation is on a line radiating from the umbo 
of the plate; but they are not in continuous lines. At the umbo of 
each plate the growth of the elevations is such that the whole 
epistereom of the umbo is often raised into a kind of turret 
surrounding a few diplopores. These turrets were only found 
preserved on those regions of the theca from which the matrix had 
not been weathered away; probably they had been worn down in 
the other regions. On other parts of the plate there are sometimes - 
elevations similar but subsidiary to that at the umbo (e.g. I, 1); in 
some cases a plate with about five of these in a circlet round the 
umbonal turret resembles a cidarid plate with its primary and 
secondary tubercles. Excessive growth of epistereom, especially in 
the turrets, may perhaps close the pores occasionally; but I could 
not be any more sure that it did so in this species than in S. locayz. 


hale MEE ae 


— 


5 6 
Fie. 5.—Sinocystis loczyi: a group of tubercles bearing open diplopores, seen 
from the side, on a fragment extracted from soft matrix accompanying 
specimen I, 8. x #. 
Fic. 6.—Sinocystis mansuyt: an elevation bearing a diplopore, seen from 
above and from the side, on specimen II, 5. x §. 
Fic. 7.—A root attached to the theca of Sinocystis mansuyi, II, 6, a little 
above its base. x #. 

In O. mansuy: the fairly numerous but irregularly distributed 
diplopores appear in some cases (e.g. II, 2) to be sunk directly through 
the test, without either elevation or ‘peripodium. This appearance 
may, however, be due to wearing down; for in II, 8, each pore-pair 
is surrounded by a slight elevation dying away into the test, and in 
well-preserved tracts of II, 5 the elevation is still more definite and 
rises higher between the pores of each pair so that the openings le 
on its shoulders (Text-fig.6). In unworn tracts of II, 9, 10, and 11, 
the elevation is relatively high and well-defined, and occasionally 
suggests a tendency to be so directed that both openings face up- 
wards, i.e. in an adoral direction (especially in II, 9). In this 
species the epistereom does not grow up round the pores so strongly 
as in S. yunnanensis or even S. loczyi, and there is never any 
appearance of blocking. 

Although I was unable to prove the closing of any diplopores in 
these fossils, Dr. Reed presumably has satisfied himself that it does 
occur in both his species of Sznocystis. If so, it should probably be 
regarded as a character of old age, and not as diagnostic of a genus. 
It is difficult to believe that the closing of true diplopores by 


~] 


Dr. F, A. Bather—WNotes on Yunnan Cystidea. 5138 


epistereom can ever have been a normal character of the adult in any 
species: the structures seem so clearly adapted for the passage of 
some aérating organs (papule) through the test; and the very fact 
that the epistereom does grow up in tubercles and turrets indicates 
the constant outward extension of those organs. In opposition to. 
this view, the only previous evidence of weight has been Professor 
O. Jaekel’s account of a thin reticular layer covering diplopores in 
a fragment of ‘‘ Calix sedgewicki’’ from Bussaco (1899, Stammes- 
gesch. d. Pelmatozoen., p. 72), an observation as yet isolated and 
unconfirmed (see, however, discussion of Zrematocystis in Part I11). 

The last point of difference mentioned in Dr. Reed’s diagnoses is 
thus expressed: Sznocystis, ‘‘ No food-grooves on surface”’; Ovocystis, 
‘‘ Surface of theca provided with irregular shallow food-grooves 
meandering between plates, with local traces of stronger meridional 
and concentric or spiral grooves.’ It is, as previously stated, the 
case that Srnocystis, no less than Ovocystis, has short epithecal 
food-grooves leading from the corners of the peristome to the 
brachiole-facets. But certainly it has no others, and that is what 
Dr. Reed means. If Ovocystis has these meandering food-grooves in 
addition, it differs in this respect not merely from Sznocystis but 
from every pelmatozoon yet described, and is a remarkable form 
indeed. 

Unfortunately I was not acquainted with Dr. Reed’s observations 
till some time after the specimens had been returned to Calcutta. 
I had, however, carefully examined, under a binocular dissecting 
microscope, the whole surface of the ten specimens lent to the 
Museum, and it is difficult to believe that such unusual structures 
could have escaped notice. I have subsequently examined the 
plaster-casts carefully made by Mr. F. O. Barlow, and can see 
between the plates nothing that suggests a food-groove. Dr. Reed 
in his description (p. 8) certainly adds that the grooves are 
‘‘obscure’’, but he also gives a fairly definite account of their 
course. He distinguishes three kinds: (1) ‘‘shallow . . . grooves 
irregularly meandering along the suture-lines . . . and frequently 
uniting’’?; (2) ‘‘one or more stronger sinuous longitudinal trunks 
running meridionally down anterior face” [= posterior side]; 
(3) ‘fone or more concentric or obscurely spiral sinuous trunks on 
the posterior [= anterior] face in the lower third.” He figures no 
details of these grooves, and not one of Mr. Brock’s enlarged 
drawings of the surface shows the smallest trace of them. Only 
fig. 5 on pl. Il, which represents a theca with weathered and 
imperfectly preserved surface, is said to show ‘‘traces of spiral 
grooves’’ on the ‘‘ posterior side’”’. Actually the view is of the right 
side, the theca being compressed in the anal plane, and the hydropore 
lying under a prominence shown at the top of the figure about 1 cm. 
to left of the median line. The post-mortem compression of the 
theca has pushed the greater part of this right side in, so that there 
is a sharp bend or crack down the anterior edge (right hand of 
figure); and on the upper posterior edge (left of figure) the plates 
are pushed slightly under those of the other and less compressed 
half of the theca. The depression thus produced is continued as an 

DECADE VI.—VOL. V.—NO. XI. 33 


514 Dr. F. A. Bather—Notes on Yunnan Cystidea. 


irregular curved groove across the right side of the theca in its lower 
third, and this is clearly (perhaps too clearly) shown passing across 
the drawing. The groove was interpreted, with the specimen before 
me, as evidence of slight folding accentuated by weathering; some 
- fainter folds, also the result of post-mortem compression, are obscurely 
indicated below this main groove, and are brought out in the drawing. 
If this is all that Dr. Reed has to offer in support of his ‘food- 
grooves’, he must not be surprised if their existence is denied. 
Grooves and folds just as clear are shown in specimens of Sznocystis 
(see pl. I, figs. 6 and 7), a genus in which such ‘food-grooves’ are 
rightly said to be non-existent. 

Clear and undoubted evidence is required, for a priors arguments 
are certainly opposed to Dr. Reed’s interpretation. Dr. Reed | 
- compares the alleged food-grooves to those of Fungocystis, Pyrocystis 
pirum (apud Jaekel), and Gomphocystis. In the two former the food- 
grooves, as usual in Glyptospheride, cut across the thecal plates and 
do not follow their sutures. In Gomphocystis certain thecal plates 
have assumed a more definite arrangement as floor-plates of the 
grooves, which follow a spiral but quite definite course wholly unlike 
that described for Ovocystis by Dr. Reed. In all three genera, as 
indeed in all Diploporita, the epithecal food-grooves end on exothecal 
brachioles, of which the facets af any rate are visible. The cover- 
plates of the grooves are not preserved in all specimens of Diploporita, 
though the notches for their reception may often be detected; but in 
forms with such solid and well-preserved cover-plates as Sinocystes 
and Ovocystis, some traces of them would certainly be found on any 
extensions of the subvective system that might occur. No traces of 
cover-plates are visible on the alleged extensions in Ovocystis. 
Finally in all Pelmatozoa the food-grooves lead to the peristome ; 
and this arrangement is conspicuous in all Diploporita. In Ovocystis 
mansuyt, as in both species of Sinocystis, there is a particularly 
evident subvective system, with brachiole-facets and strong cover- 
plates. There is not the smallest trace of any extension from this 
compact system over the general surface of the theca, nor has 
Dr. Reed ventured to describe or portray any connection between 
this system and his vaguely meandering, or longitudinal meridional, 
or concentric spiral grooves. 

The simple fact is that the thecal plates of Ovocystis mansuy? are, 
as Dr. Reed puts it, ‘‘thick swollen”; in other words, the suture- 
lines are depressed. But there is no evidence that extensions of the 
subvective or any other system passed along these depressions. 

Many specimens of O. mansuyt (e.g. II, 8, 4, 6, 8, 10) are 
distinguished from all [?] the specimens of Sinocystes by bearing on 
some of their thecal plates structures which Dr. Reed calls ‘‘ small 
circular isolated raised cup-like pseudo-brachiole facets’’; and, 
when the specimens were in my hands, being unable to discern any 
other points of difference, I supposed in my ignorance that Dr. Reed 
had based his genus to some extent on these appearances. Therefore, 
though not in much doubt as to their true nature, I was led to 
examine them with some care. This is fortunate, since Dr. Reed 
seems undecided ‘‘ whether to interpret these structures as features 


Dr. F. A. Bather—Notes on Yunnan Cystidea. 515 


of classificatory importance or as individual peculiarities due to 
accident or as resulting from some extraneous cause”. He is right 
in regarding the last interpretation as the ‘‘most probable”; the 
structures are in fact the root attachments of some other Pelmatozoon, 
and similar appearances are familiar enough to those who have 
studied Ordovician cystids in the field. In II, 3, there is a small 
one near the base, and this, as drawn in fig. 3, has a circular lumen. 
In II, 4, there is near the base a rather large one, 4 mm. high, 
4-7 mm. wide at its summit, and 6°7 mm. wide where it rests on the 
theca; it is divided by a stellate lumen into irregular pentameres. 
By removing the thecal plate on which this rests and examining its 
inner surface it is seen that the encrusting root covers several 
diplopores. That the covering up of the diplopores took place 
gradually as the root extended appears from a few incipient roots on 
the better preserved face of the same specimen, for in them the pores 
still pierce the outer extensions of the incrustation. This face of 
the theca bears five such roots, and two of them, which also are 
quite small, have a sub-pentagonal cup-like excavation, reminiscent 
of the Liassic Cotylecrinus. Near the lower end of II, 6, there is a 
relatively large root-base which rises sharply from the test like 
a broken volcanic cone (Text-fig. 7); its diameter below is 8mm., 
and above about 4°5mm. In II, 8, a somewhat similar root covers 
the anal pyramid. On the anterior face of II, 10, which is the less 
flattened face and presumably lay upwards, there are three, perhaps 
four, root-bases, more or less merged in the test. The object which 
in II, 5, covers the hydropore (v. supra, p. 513, line 7 from end) may 
or may not be such a root. 

The preceding facts prove that the roots were independent of the 
cystid on which they grew, that in some cases they must have 
established themselves on the theca after the death of the cystid, 
but that in other cases they settled on it and continued to grow, at 
least for a time, during the life of the cystid: When in the last- 
mentioned case the cystid deposited its own stereom round and 
partly over the stereom of its unbidden guest, then a difficulty was 
created for the modern paleontologist. 

All the points of supposed difference between Ovocystis and 
Sinocystis have now been discussed and shown to be non-existent or 
unimportant. It follows that Ovocystis is a synonym of Sinocystis, 
which now contains the three species S. loczyi, S. yunnanensis, and 
S. mansuyt. The nomen nudum Sinocystis piroides Reed (in Coggin 
Brown, 1913, Rec. Geol. Surv. India, xliii, p. 332) is said in the 
1917 memoir (p. 60) to be a synonym of Pyrocystis(?) orientalis 
Reed; it was provisionally attached to the larger of. the two 
specimens from locality K 15/302. 

Since Dr. Reed has not named a Genotype for Sinocystis, the 
species S. Joczyz is hereby selected. 

Before the systematic position of Sinocystis is discussed, further 
notes on the specimens will be given. 


516 Reviews— Work on Mesozoic Floras. 


RAV LEW sS- 


I.—Somr Recent Worx on Mesozoic Froras. 


1. On He Creracrous Frora or Russtan Saxkwarin. By 
A. Krysmrorovicn. Journ. of the Coll. of Sci. Imp. Univ. of 
Tokyo, vol. xl, art. 8, pp. 73, with 15 text-figures, 1918. 

2. Mesozorc Froras oF Queenstanp. By A. B. Warxom. Part I 
continued: The Flora of the Ipswich and Walloon Series, 
(¢) Filicales, ete. Queensland Geol. Surv. Publ., No. 257, 1917, 
pp. 66, with 10 plates and 12 text-figures. Part I concluded: 
(d) Ginkgoales, (e) Cycadophyta, (f) Coniferaies. Queensland 
Geol. Survey Publ., No. 259, 1917, pp. 48, with 9 plates. 

38. Tur Eartrer Mesozoic Froras or New ZEatanp. By EK. A. 
Newett Arzer. New Zealand Geol. Survey Paleontological 
Ball., No. 6, 1917, pp. 80, with 14 plates and 12 text-figures. 


1. The Island of Sakhalin possesses a fossil flora, rich in species, 
which has hitherto been regarded as exclusively of Miocene age. 
Kryshtofovich—who recently visited the western coast of the 
island, examining nearly 200 outcrops with plant remains—claims, 
however, to have established that this so-called Miocene flora belongs 
to several geological horizons, not only of the Tertiary period but 
also of the Cretaceous. He points out that so-called ‘ Arcto- 
Tertiary’ floras in other parts of the world might also repay thorough 
revision. 

The part of the Cretaceous of Sakhalin known before, and repre- 
sented by marine deposits, has been hitherto considered as belonging 
to the Senonian, and its thickness estimated at 3,500 feet. But the 
present author’s work has indicated the presence of Turonian, 
Cenomanian, and probably even older divisions of the Cretaceous, 
thus making the total thickness at least 7,000 feet. He proposes 
a Classification of these Cretaceous rocks, based on the plant remains. 

2. The two memoirs by Walkom with which we are here 
concerned form the conclusion of his study of the flora of the 
Ipswich and Walloon Series, of which the first instalment appeared 
in 1915 as Publication 252 of the Queensland Geological Survey. 
Tt is pointed out that the results so far obtained indicate that the 
flora of the Walloon Series is Jurassic, probably corresponding to the 
Liassic or Lower Oolite of Europe, while the Ipswich Series is 
Triassic, or possibly equivalent to the so-called Rhetic beds of various 
areas. 

3. The plant impressions discussed in Arber’s memoir upon the 
Mesozoic Floras of New Zealand are derived from rocks whose age 
ranges from Triasso-Ithetic to Neocomian. Jn the provinces of 
Canterbury and Otago Rheetic floras occur. Jurassic floras are met 
with in the provinces of Canterbury, and especially Southland, 
while a Neocomian flora occurs in Auckland, but no evidence of an 
undoubted Upper Jurassic flora has yet been met with. Prior to the 
commencement of the work of which the results are recorded in the 
present paper, there were only eleven valid records of Mesophytic 
plants from New Zealand, but the author has been able to add 


Reviews—Memorr of John Michell. oli 


thirty-seven species to those already known. Of these at least 
fourteen species are new. 

Arber concludes from his examination of the fossil floras that 
there is no evidence, at the time of writing, of any terrestrial 
vegetation in New Zealand older than the Triasso-Rhetic, and he 
considers that, on the known evidence, New Zealand did not form 
any part of the Permo-Carboniferous continent of Gondwanaland, 
although in Rheetic, and probably also in Jurassic times, New 
Zealand and Tasmania were united with Australia as one large 
connected land area. Professor Seward is inclined to recognize 
a close alliance between the Mesozoic genus Linguifolium, which 
occurs in New Zealand, and the genus Glossopteris, which 
characterized the Gondwanaland flora, but Arber, in the present 
paper, gives detailed reasons for maintaining the distinctness of these 
two genera. 

The flora of Waikato Heads, Auckland, is of particular interest as 
being perhaps one of the oldest, in a geological sense, of the known 
Neophytic floras. Professor Laurent, of Marseille, contributes 
a description of two Angiosperms obtained from these beds, one of 
which is fragmentary, while the other consists of leaves which he 
refers to a new species of the genus Artocarpidium. 

A.A, 


Ji.—Memorr or Jonn Micuett. By Sir Arcurpatp Geinte, O.M., 
K.C.B., F.R.S. pp. 107. Cambridge University Press, 1918. 


EOLOGISTS owe a considerable debt to Sir Archibald Geikie 

for his contributions to the history of their science. That debt 

is further increased by the issue of this memoir, dealing, as it does, 

with the lfe and work of a man who, though little known at the 

present day, held a position of no small note among his 
contemporaries. 

John Michell, to use an often-repeated phrase, was a man of parts; 
he was one of those persons of wide interests and accomplishments 
who adorned the front rank of scientific men in the eighteenth and 
early nineteenth centuries, but who have, unhappily, been swept 
away by the advance of modern progress and its accompanying 
necessity for specialization. He was, of course, a classic and 
mathematician, and in addition to his geological work he carried out 
experiments in physics and devoted a considerable amount of time to 
astronomical observations, which he performed with a reflecting 
telescope made by his own hands. 

He was elected to a Fellowship of Queen’s College, Cambridge, at 
the age of 25, in the year 1749, and held a number of offices 
in the University till 1762, when he was elected to the Woodwardian 
Professorship of Geology. This office he only held for about two 
years, when he was obliged to resign from it on the occasion of his 
marriage. From this time onwards he held in succession the benefices 
of Compton, Havant, and Thornhill, at the last of which he died in 
the year 1795. 

Being a man of a somewhat modest and retiring disposition he has 


518 Reviews—Harly Man in America. 


left little published work; his most important geological communica- 
tion was his paper on earthquakes, which was read at five successive 
meetings of the Royal Society in 1760, and which met with such 
approval that he was shortly afterwards elected a Fellow. IJnaddition 
to this work he spent much of his leisure time in geological excursions, 
and in these obtained a wonderfully accurate idea of the correlation 
of the strata of the south and east of England, based entirely on 
lithological characters, which, fortunately, was put in writing by 
one of his friends and has thus been preserved. He was a friend 
of many of the chief men of science of his day and more especially 
of Herschell and Cavendish, with both of whom he frequently 
corresponded on scientific matters. It is on record that the first idea 
of using the torsion balance as a means of determining the density of 
the earth was suggested to Cavendish by Michell, who, indeed, made 
such an apparatus, but not, however, one of sufficient delicacy for 
the purpose, so that it-was left for Cavendish to carry the experiments 
to a successful conclusion. His only other published work was 
a small book on artificial magnets, which embodied much of the 
experimental work he did while at Cambridge. 

This memoir, written in the author’s accustomed literary style, is 
eminently readable, and contains a very interesting account of this 
little-known Woodwardian Professor. 


Woe 


I1{.—Recent Discovertes reLatine To Karty Man In America. 
By Aves HrpnitKka. Smithsonian Institution, Bureau of American 
Ethnology, Bull. 66, 1918, pp. 65, pls. xiv. 

CCORDING to Dr. Hrdlicka there is still no evidence of really 
fossil man in North America. He refers especially to the 
human remains found in the asphalt of Rancho La Brea, California 

(J. C. Merriam, Science, n.s., vol. xl, pp. 198-208, 1914), and to 

those found with Pleistocene mammals at Vero, Florida (see Guot. 

Mac., Dec. VI, Vol. IV, p. 4, 1917). The skeletons at Vero are 

said to be undoubted inter aLSINGS, and the remains from La iiea also 

appear to be those of a modern American Indian. 


LVY.—American Fosstz Horses. 


Eeumm or tHE Onicocenr, Miocenk, anp Priocrnn or Norra 
America, IconocrapHic Typr Revision. By Henry Farrrimerp 
Osporn. Mem. American Mus. Nat. Hist., n.s., vol. 11, pp. 1-217, 
pls. i-liv, and 173 text-figures, 1918. 

HE evolution of the horses in North America has long excited 
wide interest, and has been much discussed in popular writings 

as well as in scientific memoirs. ‘lhe statements of fact needed for 
this discussion, however, have hitherto been scattered in numerous 
technical notes and papers, often without adequate illustration, and 
it has been difficult to realize the nature of the evidence. We are 
now indebted to the American Museum of Natural History for an 
exhaustive summary of the known Oligocene, Miocene, and ‘Pliocene 
species, with exact copies of all the. original published figures of the 


Reviews—Cretaceows Dinosaur Gorgosaurus. 519 


fossils and with drawings of all the described specimens which have 
not hitherto been figured. It is a most valuable work of reference 
and indispensable for further progress. It is now possible to 
understand how fragmentary is our knowledge of the various genera 
- and species, and how much scope there is for differences of opinion 
on all points except generalities. The broad outlines of equine 
evolution are clearer than ever, and Professor Osborn has had 
prepared new series of beautiful drawings to illustrate the changes 
in the upper and lower molar teeth and in the feet. The excellent 
manner in which the stratigraphical position of the various fossils is 
determined is also fundamentally important. We are only inclined 
to ask for more, and would add to our congratulations our best 
wishes for the speedy accomplishment of Professor Osborn’s promised 
Monograph of the Equide. 


V.—Tue Crerackous THEroropous Dinosaur Goreosaurus. By 
Lawrence L. Lampe. Canada Dept. of Mines, Memoir 100, 
Geological Series, Ottawa, 1917. 


Ge this excellently illustrated memoir the author gives a full 
) account of a nearly complete skeleton of a large carnivorous 
Dinosaur, Gorgosaurus libratus, found in the Belly River (Cretaceous) 
beds of Alberta, Canada. This reptile is, in most respects, very 
similar to Tyrannosaurus, but is said to differ from it in several 
important particulars, e.g. in the structure of some of the teeth, the 
proportions of the limbs, and the great development of the plastron 
of ventral ribs. The fore-limb is curiously small, less than one- 
fourth the length of the hind-limb. It possesses only two complete 
digits (1 and 2), with powerful claws, and a vestige of the third 
metacarpal; the radius and ulna are very short. The hind-limb is 
remarkable for the great elongation of the foot, which, though much 
larger, is very similar to that of Ornithomimus. It possesses three 
complete digits (2, 3, 4) and the distal portion of the first, all claw- 
bearing. The fifth is represented by a vestige of the metatarsal 
only. The ventral buckler is very well developed, and consists of 
about nineteen transverse rows of ventral ribs, two pairs in each 
row. In the first and last the median pieces are fused, but in the 
others they remain distinct but overlap, and are firmly attached to 
one another, there being no median more or less V-shaped element 
such as usually occurs in reptiles with such a plastron. The author 
discusses the probable appearance and habits of this reptile, giving 
several restorations of it in what he believes to be characteristic 
attitudes. He considers that, although its mode of progression was 
bipedal, in a semi-erect position, and well raised from the ground, 
that when at rest the animal squatted, supported on the expanded 
ends of the pubes, or lay extended on its ventral surface. The 
absence of wear on the teeth suggests that the food was soft and 
obtainable without much effort, probably consisting mainly of the 
flesh of carcases of other reptiles such as the large Trachodont 
Dinosaurs. 


Co Wie AN: 


520 Reviews—Fossil Insects from Commentry. 


VI.—Fossiz Insects 1n CoaL-MEASURES. 


Two Insecrs rrom Commantry.—R. J. Tillyard (Proc. Linn. Soe. 
N.S. Wales, xlii, pp. 123-1384, March, 1918) discusses two fossils 
recently described by H. Bolton (Manchester Memoirs, May, 1917). 
He suggests that Megagnatha odonatiformis Bolton, is an ancient 
representative of the Order Embioptera, and erects for it a new 
family, Megagnathide, differing in greater size and more complex 
venation, as well as, probably, in the shorter comparative distance 
between the bases of the fore- and hind-wings.  Sycopteron 
symmetricum Bolton, ‘‘is very likely an archaic type of the Order 
Psocoptera, related to Amphientomum of the Oligocene, but con- 
siderably Jess specialised’ in its venation. 


VII.—Rocxk-portne Oreanisms as AcrNnrs In Coasr Erosion. By 
Professor T. J. Jenu. Scottish Geographical Magazine, vol. xxxiv, 
pp. 11, with 8 figures, January, 1918. 


i this paper the author lays stress on the importance of the part 
played by rock-boring organisms in submarine erosion, and more 
particularly in the lowering of the foreshore, with the consequent 
further exposure of the cliffs to the wearing action of the waves. 
He shows how this process is carried on to a very great extent near 
Cromer and Brighton, where the chalk forms the sea bottom and 
foreshore, and also at St. Andrews, where the rocks are sandstone, 
shale, and limestone. The rocks are perforated by the organisms, 
with the result that they are converted into a honeycomb-like 
network, which is easily broken down by mechanical agencies, at first 
to an irregular surface, which is soon planed down to an even 
platform at the new lower level. This destruction is not continuous, 
as it can only take place where the rock is free from loose overlying 
sediment, but in the absence of such sediment it proceeds in very 
many places, and at an average rate of about 1 inch per annum. 

The work is carried out by a great variety of forms, including 
annelids, sponges, molluscs, and echinoderms; these creatures mostly 
preter soft or calcareous rocks, but some, more especially Pholas, 
bore into any kind of rock, including sandstone, mica-schist, and 
gneiss. ‘’he means by which this animal bores the rocks are some- 
what obscure and many different suggestions have been put forward. 
These are summarized as follows :— 

1. That the perforations are made by rotations of the shell-vaives, 
after the manner of augers. 

2. That the holes are made by rasping, effected by siliceous 
particles in the foot, or mantle, or both. 

3. That the excavations are due to ciliary currents, aided by 
rasping. 

4. That the boring is carried out by the foot exerting suction. 

5. That the rasping is brought about by the friction of gritty 
particles of external derivation against the walls of the burrows. 

The balance of evidence goes to show that, at any rate in the 
case of the Pholadide, the action is mechanical, though acid secretion 
may play some part. In experiments carried out by Miss B. Lindsay 


Reviews—Dry Lakes and Lands of W. Australia. 521 


at the Gatty Marine Laboratory at St. Andrews, it was shown that 
the action was one of suction accompanied by scraping. 


W. 4H. W. 


VIII.—Tuer Dry Laxes anp Lanps or Western AUSTRALIA. 


Erosion AnD RESULTING Lanp Forms In suB-ARID WeEsrEkN AUSTRALIA, - 
INCLUDING THE ORIGIN aND GrowrH oF HE Dry Lakes. By 
J.T. Jurson. Geogr. Journ., pp. 418-37, 2 pls., December, 1917. 

On rHE Formation or ‘‘ NaruraL QUARRIES”’ IN SUB-ARID WESTERN 
Ausrramia. By J.T. Jurson. Proc. Roy. Soc. Victoria (n.s.), xxx, 
pp. 159-64, pls. xxviii, xxix, March, 1918. 

THe Iyrivence oF Satrs In Rock WEATHERING IN SUB-ARID WESTERN 
Austria. Tom. cit., pp. 165-72, pl. xxx, March, 1918. 


fJ\HE dry lakes of the Salt Lake Division, north of Coolgardie and 

Kalgoorlie, have been ascribed by some authors, e.g. C. G. Gibson 
and J. W. Gregory, to river-systems of Tertiary, probably Miocene, 
time. H. P. Woodward believed them to be wind-planed flats. 
Mr. Jutson, while admitting the possibility of Miocene rivers, does 
not believe that there can be any direct connection between them 
and the present lake system. Given an undulating surface, such as 
the present contour of the country suggests, then, in his opinion, the 
existing agents seem competent to produce all the existing 
phenomena, including valleys, plains, and lakes. The lakes appear 
to have been formed by the processes of advancing sands, formation 
of sand-bars, recession of lake-shore cliffs, and planing and hollowing 
out of rock floors. ‘These processes have resulted in the formation, 
dismemberment, migration, growth, capture, and union of lakes. 
Many factors are responsible for the results obtained, amongst 
which the wind is regarded as playing a prominent part. 

The ‘‘ Natural Quarries”’ are circular, rectangular, and triangular 
excavations, resembling artificial quarries, in the hillsides of various 
rocks, Mr. Jutson believes that they are due to the undermining 
action of rain under special conditions, which he describes. 

While the action.of wind and the variations of temperature are 
important agents in producing the configuration of the sub-arid 
region, as they are in other deserts, something must also be assigned 
to the crystallization of salts contained in the rocks in solution and 
brought to the surface by capillary attraction, when the water then 
evaporates. By the expansion due to crystallization flakes or grains 
may be forced off or a soft rock may crumble. To such a process 
Mr. Jutson restricts the term ‘‘exsudation’’. It is chiefly observed 
at the base of cliffs at the edge of a dry lake. It undermines 
the cliffs and the debris are carried away by wind, so that the 
billiard-table floor is produced. It is curious that no pronounced 
efflorescences have been noticed in these situations, though they 


seem to occur on rocks that are more exposed to the sun. 
Ws Av B: 


522 Reviews—Zine Ores. 
1X.—Imeerrat Instrrurr Monocrarus: Zinc Ores. pp. 64. Published 
by the Imperial Institute, 1917. Price 2s. 

Neos monograph is the first of a series now in preparation, under 

the auspices of the Mineral Resources Committee of the 
Imperial Institute. Its object is to give a general account of the 
world’s production and resources of zinc ores, with special reference 
- to the British Empire. The compilation is chiefly due to Messrs. S. J. 
Johnstone and ‘I’. Crook, who have carried out their work very 
thoroughly; all available sources of information have been effectively 
sifted and the results condensed into a handy form. The memoir 
contains sections on zinc minerals, the world’s production of zinc 
ores, the ore deposits of the British Empire and of foreign countries, 
the valuation, concentration, smelting, and price of the ores, 
commercial spelter, and on the properties and uses of the metal. 
The treatment adopted is partly geological and partly statistical, 
together with references to the methods of mining and degree of 
development of the individual deposits. The descriptions of the 
actual manner of occurrence of the ores are often somewhat slight, 
but thisis probably not the fault of the authors, since such information 
is usually very difficult to obtain from the scattered literature of 
mining geology. Furthermore, at the present time many new 
developments are taking place in this and other branches of mining 
as to which details are not yet available. However, the difficulties 
inherent in a work of this sort have been successfully surmounted, and 
the Committee are to be congratulated on having made an excellent 
beginning of a series which cannot fail to be of great permanent value 
to the mineral industries of the Empire. 


X.—Tue Limestonres or SourH AFRICA. 


HE Geological Survey of South Africa has published a memoir 
on the Limestone Resources of the Union, by W. Wybergh 
(Pretoria, 1918), containing a very full account of the known 
occurrences of limestone of various grades in the Transvaal and 
portions of Bechuanaland and Zululand. The total production of 
lime for the year 1916 is given as 78,222 short tons, and the demand 
is likely to increase in the near future. In the district under review 
the most widespread calcareous rock is dolomite, which occurs in 
enormous quantities both in the crystalline rocks of earliest date 
and in the Potchefstroom System. Both of these types, however, 
contain too much magnesia for many purposes, so that the most 
valuable deposits from the economic point of view are the surface 
limestones so common in many parts of the Union. 

The memoir also contains a special chapter by Dr. A. L. du Toit 
on the crystalline limestones or marbles of Port Shepstone and - 
Hermansburg, Natal. Detailed mapping has shown that the marble 
of Port Shepstone is a bent and twisted mass, enveloped and 
penetrated by sheets of igneous material; the limestone must have 
a thickness of several thousand feet, and the metamorphism produced 
in it is of extraordinary theoretical interest. A detailed description 
is promised in a future publication. 

ee ee 


Reviews—The Hurunur Valley. 523 


XI.—Srrucrurat anp Gractat Frarures oF THE Hurunur VALLEY. 
By R. Sperent, M.Sc., F.G.S. Trans. New Zealand Institute, 
vol. 1, pp. 93-105, 1917. : 


f{\HE chief interest of this valley is that it is an excellent example 

of a process of river development which is described by the 
author, following Dr. Cotton, as ‘‘ante-consequent”. The geological 
history of the district is as follows: On an incompletely levelled 
surface of greywacke a series of Tertiary beds consisting of limestones, 
marls, greensands, and conglomerates was laid down, the uppermost 
of these being of Pliocene age. As these beds rose from the sea 
a system of consequent drainage was established on the surface of 
the land with sub-parallel streams running eastwards. When these 
rivers had established their courses folding and faulting took place 
along lines inclined at about 45° to the course of the streams. ‘hese 
movements produced a number of parallel intermontane basins filled 
with Tertiary rocks and separated by ridges of greywacke, and along 
these basins most of the tributaries flow to the main stream. ‘These 
movements were of quite recent date and must have been very slow, 
since though in the upper parts of its course the direction of the 
stream is somewhat affected by them, in its lower reaches the river 
was able to preserve the direction of its channel and cuts straight 
through the greywacke ridges separating the basins along what must 
have been its original line. In this respect the Hurunui River is 
exceptional among the rivers of this region, since the courses of 
similar streams to the north have been much disturbed by these 
movements. 

In the succeeding Pleistocene glaciation the ice probably did not 
penetrate to the lower portions of the valley, but the upper parts 
were filled with glaciers and show evidence of strong ice action. On 
the northern branch of the river, the ice, after arriving at the head 
of a large lake called Lake Sumner, split into several distributaries 
which passed over cols between the hills standing inside a right 
angle formed by a bend in the course of the river. These cols have 
consequently been lowered, partly by the cutting back of the corries 
at the heads of the valleys running down from them and partly by 
the ice streams flowing over them from above. Lower down at the 
end of the eastern limb of the right angle these distributaries united 
with the main glacier and were also joined by that from the south 
branch of the river. 


W.4H. W. 


XIJ.—Tuer Grotocy or Banxs Penrysura. By R. Sprrent, M.Sc., 
F.G.S. Trans. New Zealand Institute, vol. xhx, pp. 365-92, 
with 3 plates and 4 figures, 1916. 


ANKS Peninsula, which is situated nearly in the middle of the 
east coast of the South Island of New Zealand, is a mass of 
voleanic rocks about 25 miles long by 18 wide, projecting almost at 
right angles from the coast. The surface is very hilly and rises to 
a height of between 2,700 and 3,000 feet in several peaks. It is 
bounded on the north, east, and south-east by the sea, on the west 


524  Reviews—The Geology of Banks Peninsula. 


by low-lying marshy plains, and on the south-west by a large 
shallow lake, Lake Ellesmere, which is separated from the sea by a 
long narrow shingle spit. The volcanic rocks were to a great extent 
poured out from two vents which are now represented by the two 
large calderas of Lyttelton Harbour in the western. and Akaroa 
Harbour in the eastern portion of the peninsula. , hese calderas 
have been converted into fjord-like inlets by erosion, and open on to 
the north-west and south-east coasts respectively. Part of the 
drainage of the region flows into the harbours, but most of it is 
roughly radial, and the consequent streams flowing outwards from 
the lips of the calderas enter the sea in a series of openings of the 
ria type which indicate recent submergence. 

The geological foundations of the peninsula are a series of slates 
and greywackes which probably ‘belong to the Trias—Jura Maitai 
system. On these rest the volcanics, which belong to four distinct 
periods of activity. The rocks belonging to the first phase are 
rhyolitic, and rest on the upturned edges of the older rocks; they 
are nearly all lavas, with only one irregularly distributed fragmentary 
deposit at the base. The vent was situated near Lyttelton, and, by 
analogy with similar rocks elsewhere,.the eruptions probably took 
place in Cretaceous times. The second phase was marked by the 
building up of the two great volcanoes whose sites are occupied by 
the calderas of Lyttelton and Akaroa Harbours. Both these 
mountains were made up of basaltic material and were composite 
cones of alternating lavas and fragmental deposits; they were both 
probably at least 10,000 feet in height. The lavas vary from fine- 
grained basalts to rocks largely made up of felspar phenocrysts. 
This voleanic phase was followed by a dyke phase. These dykes 
are mostly trachyte, but some are andesite and basalt; they have 
a roughly radial arrangement which allows the position of the vents 
to be determined with tolerable certainty. The strike is not, 
however, constantly radial, and mutual intersections of the dykes 
are numerous. In the Akaroa area there is a large mass of coarse- 
grained hornblende syenite ; this may be associated with the dykes, 
but it is cut by some of them and is probably part of the original 
land mass. 

Before the next volcanic phase the calderas had attained a form 
not far removed from that which they have at present; during this 
phase basaltic lavas were poured out from a vent in the neighbour- 
hood of Mt. Herbert, about half-way between Lyttelton and 
Akaroa, the date of the eruptions being probably Pliocene. 

The last volcanic phase was that which produced the basaltic 
flows and ashes of Quail Island in Lyttelton Harbour. The island 
is in the middle of the caldera and probably marks a final outburst of 
this vent. 

Some time after this last event the land was depressed to an extent 
of at least 700 feet, as may be shown by the occurrence of peat beds 
at this depth in boreholes in the plains to the west, and this move- 
ment has only lately given place to one of slight emergence. 

The author holds that the calderas are chiefly the product of 
subaerial erosion, partly river and partly wave action. There must 


Reports & Proceedings—Edinburgh Geological Society. 525 


have been an explosion to produce a hole of sufficient size for the 
rivers to work in, as the original crater would never have been large 
enough; but no great part of the excavation can have been done in 
this way, since, though the calderas were formed before the out- 
pouring of the lavas of the third volcanic phase, there is no 
fragmental deposit at their base, such as must have been produced 
by so great anexplosion. The forms of the inner slopes are also more 
in accordance with the theory of river erosion. After the initial 
explosions, then, the cone was breached, either by a lava-flow or by 
the cutting back of a stream, and finally carved out to its present 
shupe by subaerial agencies. 


XIII.—Tue Aprronpack INTRUSIVES. 
THe Prosiem oF tHE AnortHosites. By N. L. Bowen. Journal of 
Geology, vol. xxv, pp. 209-43, 1917. 
SrrucTuRE or tHe Anorrnosire Bopy in tHE Apironpacks. By 
H. P. Cusuine. Ibid., pp. 501-9. 
Aprronpack Intrusives. By N. L. Bowen. Ibid., pp. 509-12. 
Aprronpack Intrustves. By H. P. Cusine. Ibid., pp. 512-14. 


N the first paper Dr. Bowen discusses the origin of anorthosites in 
general, with special reference to those of the Adirondacks and 
of Morin, Canada. His general conclusion is that anorthosites are 
produced by the straining off of femic constituents by gravity from 
a)gabbroid magma; at a later stage of the cooling the crystals of 
more basic plagioclase sink in their turn, forming the anorthosite 
mass, while the acid residue forms a syenite. The Adirondack 
complex is thus interpreted as a sheet-like mass with syenite above 
and anorthosite below. 

In the second paper Professor Cushing expresses his general 
agreement with Dr. Bowen’s views as to the origin of the anorthosites, 
but dissents from his interpretation of the field relations ; he concludes 
that the syenite does not form an overlying sheet, but is mainly 
intrusive into the anorthosite, and the border of gabbro is to be 
regarded as a chilled margin. The two remaining papers continue 
the discussion of the points raised in the previous ones. 

levy Joba es, 


RP ORES (AINED PROC HazD» PNG S- 


I.—Epineurew GrotocicaL Socrery. 


March 20.—Dr. M‘Lintock, Vice-President, in the Chair. (Issued 
October 11, 1918.) 


1. ‘‘ Limits of the Valley Glaciation in the Basin of the Dee.” 
By Dr. Bremner. 

Ig late Glacial times an ice-stream descended the upper Dee 
valley and, reinforced by affluents from Glenmuick and Glengairn, 
formed a great valley glacier that extended to a point fully a mile 
east of Dinnet railway station. The limits of its extension have 


526 Reports & Proceedings—Liverpool Geological Society. 


been determined by mapping the lateral and terminal moraines, 
marginal channels, and overwash deposits. 

That the period of the valley glaciers formed a distinct phase in — 
the history of the Ice Age is suggested by the occurrence between 
Cambus o’ May and Dinnet of two boulder-clays: in two sections 
one can be seen superposed upon the other. The upper, the moraine 
profonde of the valley glacier, differsin composition and resistance to 
denudation from the lower, the product of the ice-sheet. 

The whole or a great part of Glentanner, also, seems to have been 
oe by a valley glacier. 


“Occurrences of Old Red Sandstone in and near Aberdeen.”’ 
nC De Bremner. 

Old Red Sandstone is known to occur at seven different places 
over a considerable area within the city boundaries. In a bore at 
Sandilands Chemical Works the rock was encountered about 96 feet 
below O.D., and at 625 feet below O.D. it had not been bottomed. 
A Lemon Street bore entered it at 60 to 65 feet below O.D. At 
‘Woolmanhill it was encountered at sea-level, and found to have 
a total thickness of 189 feet; the bore was Cae down 9 feet into 
the underlying metamorphic rock. 

A small ‘outerop occurs in the banks of the Millden Burn, 6 miles 
north of Aberdeen. 

All the rock proved is of Middle Old Red type. 


3. ‘‘ Notes on the Lochend Sill.””? By Robert Allan, B.Sc. 

Some particular features in the petrology of the Essexite intrusion, 
previously described in the G.S. Memoir on the Rocks of the 
Neighbourhood of Edinburgh, were pointed out and illustrated by 
means of lantern views. ‘The great variation which occurs throughout 
the sill, the characteristic feature of which is the presence of a sdda- 
rich felspar, was also indicated. Particular slides were shown in 
which the relationship between the ilmenite, biotite, and chlorite 
present in the rock was brought out. Both at Hawkhill and 
Lochend portions of the intrusion have a spotted appearance, and 
these spots in many instances were found to consist mainly of 
analcite, and seemed to be of the nature of ocelli, or local 
segregations of the residual magma late in crystallizing out. 


I1.—Lrverpoot Gxrorocican Socrery. 


October 8, 1918.—J. C. M. Given, M.D., M.R.C.P., F.G.S., President, 
in the Chair. 

At the annual meeting of this Society, which now enters upon its 
sixtieth session, the President read an address upon ‘‘ The Geological 
Position of Primates’’, in which he gave an account of recent 
research and discoveries bearing upon the origin and antiquity of 
man. The writings of Rutot and others on the so-called ‘“ Holiths’’, 
which they claim to be of human manufacture, would take back 
man’s origin to at least Miocene times, and had led to wild specula- 
tions on the subject, so that it seemed profitable to consider the 
question, not from the standpoint of the earliest appearance of man, 


Obituary—Bishop Mitchinson. 527 


but of his predecessors in mammalian evolution, for if man belongs, 
as he certainly does, to the highest order of the mammalia, namely, 
the Primates, it must be a waste of time to try to prove him to be 
earlier than these his manifest ancestors. The classification of the 
mammalia was first reviewed, and the modern distribution of the 
higher mammals over the face of the earth examined, as a preliminary 
to describing their fossil ancestors and_ geological relations. 
A description followed of the zoogeographical areas of the earth’s 
surface, and their characteristic faunas, and it was made clear that 
the Primates first appeared as very primitive lemurs in the Upper 
Eocene, as in the Wasatch formation of Wyoming, U.S.A., and in 
Europe in the Phosphorites of the Paris Basin, as also in Switzerland, 
and in Hampshire in this country, but that not until the Oligocene 
of the Egyptian Fayoum is reached are any traces of the real ape 
tribe to be found. In the Miocene they can be discerned a little 
more plainly, but only in the Pliocene do the larger man-like apes 
first manifest themselves. Therefore, in spite of the ‘‘ Koliths”’, it 
would seem, a priort, to be very unlikely that Homo sapiens, or his 
immediate lineal ancestors in the Anthropoidea, will be found earlier 
than this. 


(DIS CBEN OL NASg NaS 


LIEUT. GRAHAM JOHNS, 


Scots GuaRpDs. 


Lievr. Granam Jouns, Scots Guards, son of Mr. and Mrs. Cosmo 
Johns, of Sheffield, was killed in action on September 27. He 
matriculated at Caius College, Cambridge, but did not go into 
residence. He was severely wounded at Ypres, July, 1917, and 
returned to the Front in March this year. 


THE RIGHT REV. BISHOP JOHN MITCHINSON, 
DO i. DID ayGs 


BORN SEPTEMBER 23, 1833. DIED SEPTEMBER 25, 1918. 


We regret to record the death of Bishop Mitchinson, Master of 
Pembroke College, Oxford, who was a lifelong student of geology 
and a devoted friend of geologists. From 1859 until 1873 he was 
Head Master of the King’s School, Canterbury ; from 1873 until 1881 
he was Bishop of Barbados; from 1881 until 1899 he held the 
benefice of Sibstone, Leicestershire, and acted as deputy in much 
episcopal work; and in 1899 he was elected Master of Pembroke. 
While in Barbados he spent part of his leisure in making a collection 
of fossils, which he gave to the British Museum in 1892. While at 
home he made numerous excursions in search of fossils, and 
eventually brought together a good representative series, which he 
carefully studied and arranged in cabinets. After reserving for 
Oxford a few specimens, among which was the type of Olenus 
Mitchinsoni from the Shineton Shales, described by Dr. H. H. Thomas 


\ 


528 Obituary—Henry Shaler Williams. 


in 1900, he gave this valuable collection to University College, 
London. For several years Bishop Mitchinson was a valued member 
of council of the Geological and Paleontographical Societies, and he 
was never happier than when entertaining parties of his colleagues 
in the Master’s Lodge at Pembroke. The memory of these parties 
will always be cherished by those who shared his hospitality, for he 
was the most genial of hosts, the most lovable of friends, and full of 
lively interests. 


AS: We 


HENRY SHALER WILLIAMS, 
Pu.D., F.G.8. 

Born MARCH 6, 1847. Diep AUGUST, 1918. 
AMERICAN geology loses a distinguished representative by the death — 
of Professor H. 8. Williams, of Cornell University. He graduated 
as Ph.D. at Yale in 1868, and inclined at first towards biologieal 
studies, which stood him in good stead when he specialized later in 
paleontology. In 1879 he was appointed Assistant Professor of 
Geology and Paleontology in Cornell University, and in 1886 he 
became full Professor. In 1892 he succeeded Dana as Silliman — 
Professor at Yale, and in 1902 he returned to Cornell. In 1912 he 
retired with a pension under the Carnegie Foundation. Professor 
Williams devoted himself especially to the study of the Devonian 
invertebrate faunas and the correlation of the Devonian formations 
of North America. His results were published chiefly in the 
Bulletins of the Geological Survey of the United States. He was 
a pioneer in the modern methods of paleontological research, and 
his volume on Geological Biology (1894) is an admirable statement of 
principles. 


MISCHLILUIANHOUVUS. 


ES 
Tue Cuvier Prize. 


The French Academy of Sciences has awarded the Cuvier Prize for 
1918 to Dr. Arthur Smith Woodward, F.R.S., for his researches in 
Vertebrate Paleontology. This is a triennial prize and was first 
awarded in 1851 to Louis Agassiz. It has already reached Great 
Britain three times, having been given to Sir Richard Owen in 1856, 
to Sir Roderick Murchison in 1868, and to Sir John Murray in 1894. 


H. C. Beastry Gronoagicat Connection. 


The Liverpool Free Public Museums have recently acquired the 
valuable and unique collection of Triassic fossils, rocks, and minerals 
formed by Mr. H. C. Beasley, which has been purchased from him by 
Mr. C. Sydney Jones, M.A,, J.P., and presented to the City. The 
collection is chiefly a local one, and is especially rich in fine specimens 
of cheirotheroid, rhynchosauroid, and chelonoid footprints from the 
Lower Keuper of‘the well-known Storeton Quarries, and from 
Runcorn Hill. 


MEMOIR of JOHN MICHELL 


M.A., B.D., F.R.S., Fellow of Queens’ College, Cambridge, 1749, 
Woodwardian Professor of Geology in the University, 1762 


BY 
SIR ARCHIBALD CEIKIE, 0.M., K.C.B., D.C.L., D.Sc., F.R.S. 
Crown 8vo. 2s 6d net. 


‘*John Michell applied his high intellectual powers to geological questions, 
and, working without the key subsequently provided in the discovery of 
fossiliferous deposits, forecasted many of the conclusions established by later 
researches. In physics and astronomy he was the pioneer in devising the 
torsion balance, which yielded such important results in the hands of Coulomb 
and Cavendish. Though he enjoyed the esteem and respect of the most 
eminent men of science in his lifetime, his name, mainly because others 
entered into his labours and carried them to their full fruition, fell later into 
unmerited obscurity. The thanks of students of the scientific history of our 
country are due to our veteran geologist for the compilation of this valuable 
and interesting memoir.’’—The Glasgow Herald 


Cambridge University Press 


FETTER LANE, LONDON, E.C.4; C. F. CLAY, MANAGER 


METHODS IN PRACTICAL PETROLOGY 


Hints on the preparation and examination of Rock Slices. 


HENRY B. MILNER, B.A., F.CG.S., etc., and GERALD M. PART, B.A., F.G.S., etc. 
2s. 6d. net. Postage 4d. 


This volume is designed to meet the practical requirements of geologists, students, and 
others who employ the microscope as an aid to the determination of minerals and rocks. 
It contains detailed information on section cutting, preparation and examination of rock 
slices, together with many microchemical methods for the confirmation of certain 
ninerals difficult of recognition by optical means alone. A chapter is also devoted to 
nethods employed when dealing with comminuted material, and tables of useful 
nineralogical constants are distributed throughout the text. 


Cambridge: W. HEFFER & SONS, Ltd. 


Now READy. 
PALAONTOGRAPHICAL SOCIETY,‘1916.— Vol. LXX. £1 5s. net. 


Contents which can be had separately :— 


WOODWARD (A. S.). The Fossil Fishes of the English Wealden and 
Purbeck Formations. Part II, pages 49-104, Plates XI-XX. 10s. net. 

HARMER (F. W.). The Pliocene Mollusca of Great Britain. Part III, 
pages 303-461, Plates XXXIII-XLIV. 12s. net. 

SPENCER (W. K.). A Monograph of the British Palaeozoic Asterozoa. 
Part III, pages J09-168, Plates VI-XIII. 8s. net. 

ELLES (G. L.) and WOOD (E. M. R.).. A Monograph of British 
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No. 73.—JULY, 1918. 


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Notes on Yunnan Cystidea. Part II. 
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I. OrtGINaAL ARTICLES. Page | REVIEWS (continued). Page 
Coal in Spitsbergen. By W. H. | The Geology of Vancouver. By 
| WILCOCKSON, M.A., F.G.S....... 529 ee TENT 213) vsiawas lay eee aes 550 
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| Chief Sources of Metals in the Zealand. By J. A. Bartrum ... 552 
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taceous. By M. C. STopES...... 546 | Geological Society of London ...... 553 
Yorkshire Type Ammonites. By | Isiverpool Geological Society 5D. 
Sis Sin 1Beellaanap ay eaagomeeocoacdedaso0e 547 | Mineralogical Society.................. 558 
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NEW SERIES. DECADE VI. VOL. Ve 


No. XII.— DECEMBER, 1918. 


ORIGINAL ARTICLIEHS.- 


I.—Coat In SPprrsBERGEN. 
By W.H. Witcockson, M.A., F.G.S. 


LTHOUGH the existence of coal in Spitsbergen has been known 

for a very long time, it is only of recent years that development 

has been undertaken on any considerable scale. As early as 1610 

explorers brought back with them small amounts of coal to burn on 

the voyage home, and in 1614 the islands were formally claimed for 

James I by the Muscovy Company. The coal was also described 

from the scientific point of view by Nathorst and others at various 

dates, but no attempt was made to work it till about 1904, when the 

Arctic Coal Company, an American concern, opened a mine at 
Advent Bay. 

The Spitsbergen Avalide | is made up of a number of islands of 
a total area about equal to that of Ireland. The greater part of the 
land is divided between West Spitsbergen, which is by far the 
largest, and North-East Spitsbergen: the relative position of these 
two land-masses is imphed by their names. In addition to these 
there are Prince Charles Foreland off the west coast of West 
Spitsbergen, and Barents Island and Edge Island lying south of 
North-East Spitsbergen. Structurally, the islands are part of the 
old North Atlantic continent, and are broken up by subsidences and 
bounded by fractures, which were accompanied by eruptions. 

Along the west coast of West Spitsbergen there is a narrow belt 
of highly folded and crumpled rocks, which has been affected by 
several successive mountain-building movements, continuing down 
to Tertiary times; further east this folding, faulting and thrusting 
dies out, and the remainder of the island is made up of a high plateau 
with regular stratigraphy and gentle dips, deeply trenched by the 
inlets of Ice Fjord and Bell and Lowe Sounds, which extend far 
into the interior. In the western zone the older and newer strata 
are much folded together, and here the oldest rocks found in the 
island, the Hekla Hook formation, are exposed. These are lime- 
stones of Ordovician age, followed by Silurian quartzites, dolomites, 
and sandstones. ‘They are succeeded by Devonian beds, which are 
the oldest rocks seen in the interior, and are composed of a mass of 
red strata very like the British Devonian. On these Carboniferous 
limestones and cherts rest with a strong unconformity, and are in 
turn followed by a belt of sandstones and shales referred to the 
Permian. Above these lie the Triassic atpate, chiefly shales or clays 

DECADE VI.—VOL. V.—NO. XII. 34 


530 W. H. Wilcockson—Ooal in Spitsbergen. 


with thin limestones, sandstones, and phosphate beds, often rich in 
well-preserved marine fossils. After these follow Jurassic and 
Tertiary strata, which are very thick and in apparent conformity : 
these build up the high plateau of Ice Fjord. They are chiefly 
composed of sandstones and shales of marine origin, with occasional 
bands containing marine fossils. They also yield abundant plant 
remains and both contain coal, in consequence of which they are 
the most important strata in the islands from the economic point 
of view. 

The age of the coals is somewhat undecided: in 1897 Nathorst 
determined the age of some of the seams to be Upper Jurassic, and 
he considers that those on the west side of Advent Bay are Tertiary, 
while the American writers Stevenson and Morris believe that they 
are all Jurassic. Bituminous coal, cannel coal, and anthracite are 
all found in the islands. Generally speaking, the carbon percentage 
is very variable, especially between the top and bottom of the 
individual seams, and the ash content is high. The coals, however, 
are good for steam-raising, and especially so for use in closed stoves, 
which makes them particularly well suited for export to Scandinavia 
and Russia. Four analyses from the Green Harbour— Advent Bay 
district gave the following results :— 


Per cent 
Coke production . 3 ; : . 54-60 
Gaseous content . 5 ‘ : 5 87-44 
Ash é : ; : j 3 .  3:8-5-6 
Water at air drying : : ; 3 3-4 
Water at 100°C. . ; : 1-5 


The heating capacity of these samples was 12,000 British thermal 
units. 

The coal is mined both in the folded zone and in the plateau 
region. In the latter the beds have a gentle dip, and the seams can 
be seen cropping out on the hillsides generally between 450 and 
600 feet above the sea, though they are known to exist up to 
1,300 feet, but at this height they are unworkable, partly owing 
to the cold and partly to the steepness of the slopes. For the mining 
of these flat or gently dipping seams shafts are unnecessary, since 
all the seams can be worked by adits driven in from their outcrops. 
No fire-damp has been met with and the mines can be worked all 
the year round in spite of the temperature, which is always as low 
as —4°C.in the drives, so that the coal faces are covered with ice or 
hoarfrost. The steepness of the slopes renders transport somewhat 
difficult, and at one mine on Advent Bay the coal is brought down to 
the wharf by an aerial ropeway. On the other side of Advent Bay 
a tramway is in operation and a railway is projected from the 
Swedish concessions in Buntzow’s Land at the head of Ice Fjord to 
an ice-free harbour on Bell Sound. 

The coal-seams average about 3 feet in thickness, though some 
have been reported up to 12 feet thick: they are often pure coal 
throughout, though at some places, such as Green Harbour and 
Advent Bay, they are known to split. At the former locality there 
are two coal-seams, the upper one of which splits as follows :— 


W. H. Wilcockson—Coal in Spitsbergen. 5381 


ft. 
Pure coal : - A 5 3 A 3 
1 
i 


ee 


DOO 


Coal slate 
Pure coal 


while at Advent Bay there are two intermediate beds, aggregating 
2 feet, separating three coal-seams which together have a thickness 
of 5 feet. 

The coal areas in West Spitsbergen are nearly all included in an 
irregular quadrilateral, 100 miles from east to west by 130 miles 
from north to south, the boundary extending from the Brogger 
Peninsula on the west coast to Wiche Bay on the east, thence south 
to Whales Bay and across to the west coast again at Dunder Bay. 
In addition, coal claims have been taken up at Hope Bay and all 
over Prince Charles Foreland and Barents Island. The coal districts 
on the main land are all situated either near open sea or near 
navigable waters in Ice Fjord and Bell and Lowe Sounds, where the 
coal can be loaded directly on to the ship. They are owned by 
several different nationalities in the following proportions :— 


Square miles. 


British . 3 Z i ; : 3,574 
Norwegian : : ‘ : j 770 
Swedish . ‘ F ; 5 % 448 
Russian . 3 g ; : : 80 
German . ij ! : A ‘ 23 


The British claims are situated on Prince Charles Foreland and at 
Kings Bay and Brogger Peninsula, around Bell and Lowe Sounds, 
in the district west of Wiche Bay, at Hope Bay, and on Barents 
Island. The Norwegian and Russian claims are on the south shore 
of Ice Fjord, the Swedish in Buntzow’s Land at the head of Ice 
Fjord and at the head of Lowe Sound, and the German near 
Kings Bay. 

The chief British company operating in the islands is the Northern 
Exploration Company, which owns 2,000 square miles of claims and 
which instigated the large expedition organized by Sir Ernest 
Shackleton, which has recently returned to this country. Another 
British company is the Scottish Spitsbergen Syndicate, of Edinburgh, 
which puts forward claims to the Buntzow’s Land district, at present 
oceupied by the Swedish Spitsbergen Company. ‘There are also 
two large Norwegian companies, one of which recently acquired the 
American Arctic Coal Company’s mine at Advent Bay. 

The. last-named company, which began work in 1904, had an 
annual output of about 50,000 tons, and this together with some 
coal mined by a British company at Green Harbour, also on the 
south side of Ice Fjord, was the whole output of the islands till 
the outbreak of war in 1914: at that time development on a much 
larger scale was planned, but was unavoidably postponed, so that 
the total output for 1917 was only 100,000 tons, all of which was 
exported to Norway and Sweden. 

The coal reserves of the islands have recently been estimated at 
8,000,000,000 tons, a figure which is probably considerably below 
the mark, if the reports of the Swedish company may be trusted. 


5382 Dr. F. A. Bather—Notes on Yunnan Cystrdea. 


This company alone estimates whee the reserves in its holdings are 
as follows :— 


: Tons. 
Braganza District : : : 340,000,000 
Pyramide Mountain . é : 380,000,000 
Buntzow’s Land . ; ; . 38,000,000,000 


The Swedish holdings are small compared with the British, and, 
unless the former are abnormally rich, it must be assumed that the 
available reserves are many times as great as the figures quoted 
above, and it seems probable that Spitsbergen will ultimately be able 
to supply all the coal required by Scandinavia and North Russia. 
For this trade the British-owned fields are most advantageously 
situated; lying as they do chiefly north and south of Bell and Lowe 
Sounds they are nearer and more accessible for ships plying to these 
countries, and they can obtain and hold a dominant position if the 
requisite facilities are given. 

In addition to coal the islands possess other mineral resources, 
notably marble, which is said to be of good quality; the British- 
owned territories are highly mineralized and contain deposits of 
hematite, magnetite, copper ores, iron and copper pyrites, 
molybdenite, galena, zinc-blende, and other minerals, the develop- 
ment of which has been held back by the war. Very optimistic 
reports have lately been issued as to the resources of iron-ore, which 
are said to be of nearly as high quality as the Swedish ores, and to 
be of enormous extent: these statements, however, seem to need 
confirmation. 

The political situation in Spitsbergen is at present in rather an 
indefinite position; attracted by the success of the American and 
British enterprises, Norwegian, Swedish, and Russian prospectors 
landed and began to ‘‘ peg out”’ claims, and in 1912 the archipelago 
was visited by Prince Henry of Prussia and the late Count 
Zeppelin. A wireless station, which has since been dismantled, 
was erected by the Germans, who also ‘‘ pegged out’”’ coal claims. 
Spitsbergen, however, is one of the few remaining countries not 
under the government of any great Power, and may be classed as 
a No Man’s Land. In consequence of this there was no control of 
the claims, and aconsiderable amount of overlapping and ‘‘jumping”’ 
occurred. To settle this question an International Congress was 
held at Stockholm in 1912, at which delegates from Sweden, 
Norway, and Russia were present. This Congress, however, accom- 
plished nothing, and it now seems probable that the islands will 
become internationalized, since their British ownership long since 
fell into abeyance. 


II.—Nores on Yunnan Cystipra. II. Tue Sprcres or Sxvocystis. 
By F. A. BATHER, D.Sc., F.R.S. 
(Published by permission of the Trustees of the British Museum.) 
Sinocystis locsyt Reed. (Text-figs. 5, 8, 9, 10, 11.) 
Specimens I, 1-8 were studied. Probably those measured under 
Dr. Reed’s heads I and II refer to 1 and 3 respectively. Specimen 1 
is hereby selected as Holotype. 


Dr. F. A. Bather—Notes on Yunnan Cystidea. 5388 


The following are measurements in millimetres :— 


Specimen . 1 2 3 4 5 6 7 
Height . 74:7 71-0 79-0 60-0 17-5 

Greatest 44-5 40°/58-0 160°} 56-6 80°/45-3 25°)18-2 5° 

diameters 43-8 160°|43-0 60°) 53-7 0°|35-8 130°] 16-4 100° 


Diameters 11:0 13-9 ca. 8-5 15-0 7-3 10-7 an 9-0 
at base 9-0 10-4 10-3 6-3 8-1 °8-5 

Peristome 95° 106° 80° 95° 105°} — — 
plane 


Specimen 8 consists of two rather large but incomplete individuals in matrix. 

In order to indicate the planes of compression, the oro-anal plane 
is marked 0°-180°, 0° being anterior, or North in the usual 
orientation of drawings of the adoral face. The angle formed by 
each plane of compression with the oro-anal plane is reckoned in 
degrees on the right-hand side. The direction of the extended 
peristome is denoted in the same way. From this it will be seen 
that the compression bears no constant relation to any morphological 
plane, and is therefore due to causes acting after death. The theca 
was essentially ovate-pyriform, and its true diameters may be 
roughly estimated by taking the mean of the double measurements. 
The theca was upright (1, 3, 5?, and 6), or bent over on its stalk (2) 
so as apparently to have almost lain on the sea-floor; but since in 
this case the anus would thus be facing the sea-floor, it is more 
likely that the base was fixed to the side of some object. 

The variation of angle between the peristome plane and the anal 
plane may be regarded as due either to a shifting obliquity of the 
mouth or to the migration of the anus. If checked by reference to 
the hydropore, it will be found that the former is probably the truer 
statement. The bearing of this decision appears when one examines 
the four branches, their direction and diverse lengths. It will then 
be observed that the peristome is not an oblong, parallel to the 
hydropore and at right angles to the anal plane, with four equal 
branches, passing one from each corner at equal angles. It is the 
departures from that simple but imaginary scheme which are of real 
interest, as pointing to the original plan of which the existing ones 
are modifications (Text-fig. 8). The extreme of departure is provided 
by I, 2, but similar features are seen, though less marked, in I, 1, 3, 
and 4, First, as already shown by the table of measurements, the 
peristome lies at an angle to the anal plane of 106°, or 16° in excess 
of aright angle. Secondly, the hydropore slit, which is never quite 
straight, but concave towards the mouth in a more or less 
symmetrical curve, is neither parallel to the peristome nor 
symmetrically placed in regard to it; on the contrary a line joining 
the centres of hydropore and anus will, if produced, meet the 
peristome at its left end, just where the branches diverge. Thirdly, 
the branches do not form equal angles with the peristome. The 
two branches on the left include an angle rather greater than 90° 
(actually 110° in specimen 2), and the peristome plane does not 
bisect this angle but les anterior to its bisection. On the right the 
angle included by the branches is about 90°, and here the peristome 
plane lies posterior to its bisection, and that in an even greater 
degree. Fourthly, the branches are of diverse length; the left 


5384 Dr. F. A, Bather—N otes on Yunnan Cystidea. 


posterior is always the longest: in I, 2 it is 8mm. long; next comes 
the left anterior, 5-4mm.; then the right anterior, 4:5mm.; and 
lastly the right posterior, 33mm. ‘The length of the -peristome 
between the forks is 7mm. The conclusion to which these facts 
lead is that the four-rayed and approximately quadrangular 
subvective system of Sinocystis is really a modification of the three- 
rayed system, which I have previously held to be the primitive 
arrangement in Pelmatozoa (1900, Treatise on Zoology, p. 11, and 
elsewhere). On this view, the true or primitive oral centre lies at 
the axil of the left fork; the anterior of the two branches on the 
left is the true anterior ray, and it is noteworthy that, in I, 2 at any 
rate, its line if produced almost coincides with the line joining 
hydropore and anus; this, then, marks the true or primitive sagittal 
plane, coincident, as it should be, with the M plane (Text-figs. 2, 4); 


R 
R a fe a _ a 
) as \ J} 


\% a4 
ry Ay drop ore : “2 
g OnOpore / 


8 
2 {. 4 2 periproct’ z 


Fic. 8.—Sinocystis loczyi: diagrams, taken as accurately as possible from 
specimens I, 1, 2, and 3, to show the varying relations of the subvective 
system to the thecal openings. All are oriented with the anal plane 
running N. and S., the oral pole being taken as midway between the 
forks. If the oral pole were at the origin of the left-hand fork, then a line 
joining it with the anal pole would pass through the hydropore, and (in 
2 and 3 at any rate) would be continuous with the anterior branch of the 
fork. This line would then represent the primitive sagittal plane, and the 
branch would be the anterior of the primitive three rays (cf. fig. 4, antea, 
also Treatise on Zoology, 1900, p. 11, fig. IX). Nat. size. 


the posterior of the two left-hand branches is the primitive left 
posterior; and the line of the peristome marks the primitive right 
posterior branch. This last branch (one supposes) after a time bent 
shghtly towards the anus, and gave off a branch, which in Srnocystis 
is the right anterior. This is precisely the same change as took place 
in the evolution of any normal five-rayed pelmatozoon, but there the 
left posterior branch also forked in the same way, thus completing 
the quintet. 

The Brachiole-facets, which, owing to the biserial structure of the 
eystid brachiole in general, are composed of two halves, are seen in 
I, 1, 2, and 4,-but by no means clearly (Reed, pl. I, fig. 2a, left 
anterior branch, is the clearest representation). In some cases there 
is a suggestion of more than one facet at the end of a main branch. 
(see Reed, pl. I, fig. 4, right anterior branch); if there were actually 
two facets, it would imply a forking of the branch, in which there 
is nothing impossible. 

The relation of the adjacent thecal plates to the Subvective 


Dr. F, A. Bather—Notes on Yunnan Cystidea. 585 


System is not quite clear and does not seem to be constant. Each 
facet appears, as Dr. Reed says, to be ‘‘situated in the centre of 
a slightly swollen ordinary thecal plate’’. The hydropore seems at 
first glance to be on a single plate, adjoining the peristome and 
filling the posterior interradius. On the other side of the peristome, 
in the opposite interradius, two plates are discernible in I, 4, and 
perhaps in 2 and 3. The thecal plates adjacent to the hydropore- 
plate suggest that it too is really compound, and this view is 
supported by S. mansuy?, II, 9 (see Reed’s figure). It is usual for 
a hydropore-slit of this shape to cross a suture. This would give 
8 adoral plates, of which the right and left pairs would bear facets ; 
the posterior pair would bear the hydropore, and the anterior pair 
would bear nothing (Text-fig. 9). The occurrence in all species of 
Sinocystis of diplopores on all these plates, right up to the facets, 
grooves, ete., is noteworthy (Text-fig. 12). 


10 : 


DaUSDOY, 
ULL, VIMY, ; SSS 


12 


9 11 13 


Fic. 9.—Sinocystis loczyi: diagram of the eight adoral plates. The broken 
- lines are restored by me; all others are traced from Mr. Brock’s 
drawing (Reed, 1917, pl. i, fig. 4). x 3. 

», 10.—Sinocystis loczyz: section across the peristomial ridge; the exterior 
outline based on I, 4; the interior imaginary. The summit notch 
is due to weathering. x #. 

», 11.—Sinocystis loczyi: side-view of a part of the peristomial ridge in 
I, 4, to show how the cover-plates interlock. x #. 

,, 12.—Sinocystis mansuyi: section across a subyective groove as seen in 
II, 7. Note pore-canals of a diplopore on the right. x # 

5, 13.—Sinocystis mansuyi: the hydropore in II, 2. x circa?. 


Dr. Reed says of S. loczyz ‘‘mouth narrow, straight, slit-like, 
slightly raised’, It is not certain what he means by ‘‘ mouth ”’. 
Apparently the sentence quoted refers, to the thread-like slit clearly 
shown in pl. I, fig. 4 (cf. Text-figs. 9,10). This, however, is 
not a natural opening into the thecal cavity. The peristomial 
aperture is not actually visible in any of the figured specimens. 
From the disposition of the cover-plates, however, supported by the 
evidence of closely similar fossils from elsewhere, it may be inferred 
-that the peristome in I, 1 was an oblong, measuring about 4°5mm. 
by not more than 2mm. The aperture and the grooves leading from 
its corners to the brachiole-facets were, as Dr. Reed says, ‘* covered 
with a double row of small alternate polygonal plates set in a narrow 
rebate around their edges [i.e. of mouth and branches] and forming 
a roof-like ridge.” The arrangement of the cover-plates is shown, 
though not very clearly, in Reed, pl. I, fig. 2a. It may be better 
understood from the annexed side-view of the tegminal ridge in I, 4 


536 Dr. F. A. Bather—Notes on Yunnan Cystidea. 


(Text-fig. 11). Resting on the rebate is a series of squarish plates, 
with their upper angles irregularly bevelled off. On the larger 
shoulder of each such plate rests a triangular plate; in side view 
this does not appear triangular because its apex is bent over on to 
the other side (as seen in I, 2). The apices of the corresponding 
triangular plates of the other side, similarly bent over, are seen 
resting on the smaller shoulders of the squarish plates. There are 
slight deviations from this general structure, but the essential fact 
to notice is that the triangular plates cross the median line and 
interlock. The appearance forcibly suggests that the cover-plates 
did not open but formed a fixed tegmen. In any case a slit which, 
as in I, 4, cuts across the triangular plates, cannot represent a 
natural opening. 

The Hydropore has been mentioned in connexion with the 
orientation of the subvective system. It is always concave towards 
the peristome and tends to face its left corner (the supposed primitive 
oral polej. In I, 4 the slit seems to branch at its right end, but 
probably there is a small root of another cystid growing across it 
(omitted in Text-fig. 9). 

The following are some measurements in millimetres of the 
hexagonal Anal pyramid :— 


Specimen . 1 2 Ber 4 5 
Least distance of anal centre from 
edge of peristome . 5 : 18-0 17-0 12-8 10-2 4-8 
Diameter, side to side . ‘ 3-7 4-5 3°7 3-0 3-2 
i angle to angle 4 4-0 5:8 4-7 3-7 3°6 
Length of peristome, circa . 4-5 5:8 6-0 5:2 3-0 


The approximate length of the peristome is introduced for 
comparison with Dr. Reed’s statement that the anus is ‘‘ distant from 
it [the ‘mouth’ | about twice its [the ‘mouth’s’]length”. According 
to the fixed points selected for the above measurements, this ratio of 
2:1 holds for specimens 3 and 4; the ratio for I, 1 is 4:1; for 
I,2, 3:1; and for I,5, 1°6:1. Arranging the specimens in order 
of size, downwards, the ratios are 2, 3, 4, 2, 1:6. he chief interest 
les in the irregularity and lack of any correspondence between size 
and position, which indicate that the anus did not migrate appreciably 
during growth (v. supra, p. 534). 

The Gonopore is subcircular with a tendency to be pentagonal, this 
outline suggesting that the opening was closed by five valves, though 
no other traces of them are preserved. 

The following measurements in millimetres show that irregularity 
also obtains in the distance of this from the anus :— 


Specimen. : 1 2 3 4 5 
Distance of Gonopore centre from 
anal centre : : 9-2 6:0 3-7 4°3 3°7 
Diameter of Gonopore lumen, circa — 1-4 1:3 6 — 


The edge of the gonoporeis raised slightly in I, 3, 5, and conspicuously 
in 4; in I, 2 the rim is very faint, and in I, 1 not distinguishable. 
In I, 4 and 5 the line joining the anal and gonopore centres is 
parallel to the peristome; but in I, 2 and 3 the gonopore is slightly 
nearer the peristome. It is always to the left of the anal plane 
(cf. Text-fig. 8). 


Dr. F. A. Bather—Notes on Yunnan Cystidea. 587 


The actual Base of Attachment is well shown in I, 2 and 6; it is 
slightly expanded, very slightly excavate, and in I, 5 is extended in 
the anal plane. The ‘“‘stalk” is not a specialized stem, but merely 
a narrowing of the theca; in I, 6 and 7, however, the plates in the 
lower part of the theca are arranged transversely; and this is 
marked, especially in I, 6, by a transverse alignment of the pore- 
tubercles. 

There is little to add to Dr. Reed’s full account of the plates and 
their structure. The diameters of the plates in I, 1 range from 
‘7mm. to 65mm. There is an occasional tendency for a large plate 
to be surrounded by smaller ones. The diplopores have already 
been discussed (p. 512, Text-fig. 5). The inner face and the 
margins of the plates are not exposed. 


Sinocystis yunnanensis Reed. 


Of the four specimens mentioned by Dr. Reed, the three figured 
ones have been studied, viz. I, 9,10, and IJ, 1. Of these I, 10 is 
certainly identical with No. II in Reed’s table of measurements ; 
but, since his measurements are estimated, his No. I cannot be 
identified. ‘‘The largest,” he says, ‘‘is the best preserved”; 
probably this is I, 9. But II, 1 is hereby selected as Holotype, 
because it seems to show the openings more clearly than do the 
others. 

The following are actual measurements in millimetres :— 


Specimen . ; 9 i 10 1 
Height ~.. F : 97-0 44-0 76-0 
; ; f See lOn 35-8 ? 0° 65:0 25° 
Greatest diameters 1 37-0 110° 97-4 990° 30:6 110°« 
Diameters at base . { ; : 
Peristome plane . : 290° 290° 105° 


(For explanation of angles, see under S. loczy?.) 

The cover-plates are relatively large, irregularly triangular, 
alternating, and interlocking. 

Hydropore-slit concave towards peristome; its middle line about 
3°2 mm. from middle line of peristome in II, 1, a little furtherin I, 9. 

The Anal pyramid is seen in II, 1, its centre 20 mm. from edge of 
peristome; diameter of hexagon, side to side, 5°65 mm.; height above 
general surface, about 2'°2 mm. 

Gonopore seen in IJ, 1, at 7-7 mm. to left of anal centre. 

The Basal Attachment is seen only in I, 10; it is somewhat 
cylindrically excavate along its greater diameter, which corresponds 
approximately with the shorter diameter of the theca and with the 
peristome plane. The theca is rather sharply bent over on its stalk, 
apparently to the left, so that there was a mechanical advantage in 
this shape of the attachment. 

The plates may attain a diameter of about 7mm. in the larger 
specimens. They are about -7 mm. thick in the middle region of 
II, 1. ‘Their margins are irregularly crenelate, especially on the 
inside edge. The crenelle do not appear on the outer suture; they 
are in no relation to the diplopores. 


Specimen 2 3 5 6 7 8 9 OR es 
Height ./| 62:0 | 68 + 60 46-5 46:8 | 34-0- 69 + 65:0 58 + | 48-5 + 
Greatest | 43-0 115° | 39-8 295° | 39- 6 295° 30:0 210°} 25:2 |22-2 20°/ 46-5 0° | 45-0 170° | 40-4 295° | 30-9 25) 
diameters] 29:0 25° | 24-0 27:0 |27-02100°} 24:8 | 20-6 120° | 80:0 90° | 25-0 80°| 24-8 25° | 26-5 
Diameters | 5:8 6:4 not cae 5-1 4:8 not pre- | not pre- | not pre- | 6:0 
at base 5:4 5:7 served 4:0 broken | served | served | served | 5:5 
broken broken broker 
Peristome 295° 295° 295° | ? 100° 100° 95° 95° 100° 295° | not pre 
plane | | served 


5388 Dr. F. A. Bather—Notes on Yunnan Cystidea. 


The diplopores have already been discussed (p. 512); in spite of 
their radiating arrangement they never cross a suture. The canals 
pass in a straight line vertically or obliquely through the plate, 
emerging on the inner face in marked depressions, between, which 
the surface is raised in irregular prominences. 


Stnocystis mansuyt (Reed, 1917, sub Ovocystis). (Text-figs. 
3, 4, 6, 7, 12 13.) 

Of the ‘‘nearly sixty specimens’? mentioned by Dr. Reed the 
ten figured ones have been studied, viz. II, 2 to 11. None of these 
seems to correspond with either I or II of Reed’s table of measure- 
ments, which indicate much larger individuals; but II, 6 corresponds 
fairly with his III. Although one of the smaller individuals, this 
specimen is one of the more complete, and is therefore hereby selected 
as Holotype. 

The. following are actual measurements in millimetres :— 


(For explanation of angles, see under S. loczyt.) 


The crushing makes it difficult to get the orientation, and in 
several cases the anus is not preserved or not clearly seen. There 
appears, however, to be little variation in the angle formed by the 
peristome plane with the anal plane; it is between 95° and 100°. 

As may be seen from Dr. Reed’s pl. II, figs. 7, 8, and less clearly 
from figs. 6, 9, the relative positions of the thecal openings are as in 
S. loczy?; a line drawn from the anal centre through the hydropore 
would approximately coincide with the line of the left anterior 
food-groove. 

Reed’s figs. 7 and 8 also show that the branches of the subvective 
system are not really equal. As in S. loczyi, the left posterior 
branch is the longest, and the right posterior is the shortest 
(specimens 6, 7, 8). 

The angle at which the branches of each pair diverge may in some 
specimens be 60°-90° as stated; but as measured in the figured 
specimens, it varies between 90°, asin the left pair of II, 7 and 9, 
and 140°, as in the right pair of 7; in the right pair of 9 it is 130°; 
and in 8 itis 105° on the left, 106° or more on the right. These 
measurements are confirmed by Mr. Brock’s drawings. 

The Brachiole-facets are far from clear, so that one does not like to 
lay too much stress on the occasional sugeestion a two facets to the 
branch, as in S. loczyi (see Reed, pl. ah fig. 8, r. ant. branch), 
especially since Dr. Reed does not mention it. Note in fig. 8 how 
very close the diplopores are to the food-grooves (also our Text- 
fig. 12). The elevation of the thecal plate on which the facet 
rests is, in this species, called by Dr. Reed an ‘‘ oral boss”? : would 
not ‘‘ brachiole boss’’ or ‘‘ facet boss” be more appropriate ? 


iesaslsh 


Dr, F. A. Bather—Notes on Yunnan Cystidea. 539 


The cover-plates are perhaps a trifle heavier than in the other two 
species, and are swollen. A section across the grooves is afforded 
by II, 7 (Text-fig. 12). 

The Hydropore-sht (Text-fig. 13) is almost straight, has thickened 
edges, and the lumen expands slightly at the two ends (II, 2, 8, 9); 
in 5 it is covered by an attached object like the lower valve of a 
brachiopod; and in 10 it is crushed close up to the peristome. 
Dr. Reed describes it as ‘‘ parallel to the mouth in a line joining the 
right and left anterior [i.e. posterior] oral bosses’. It would 
perhaps be even more exact to substitute the words “ brachiole 
facets’’ for ‘‘oral bosses”, and to note that the line joining them is 
not quite parallel to the peristome, but further from it on the left 
side. Also the hydropore approaches this left end, and thus its 
deviation from perfect symmetry with reference to the peristome is 
in the direction of symmetry with reference to the left anterior 
food-groove. The bearing of this on the nature of the primitive 
symmetry is the same as in S. loczyi (see p. 535). 

Myre length of the) slit is 45mm, im Il, 2)-/2-3.mm: in: 16): 
‘9mm.in II, 7; 3:8mm. in II, 8; 4:4mm. in II, 9. Dr. Reed’s 
numbers are presumably over-all measurements. 

The Anal pyramid, according to Dr. Reed, is pentagonal. No 
doubt this is correct for most of the specimens, but in the figured 
specimens if was not so clear to me as to Dr. Reed and Mr. Brock. 
My notes run: ‘‘In II, 8, about 16mm. from peristome, hexagonal, 
but covered by a base with stem 4mm. long, 6:1 mm. wide below, 
34mm. wide above; diameter of pyramid, side to side, ca. 5°7 mm. 
In II, 6, 10mm. from peristome, ? hexagonal or pentagonal, diameter 
ca. 5 mm., rather elevated—say, 13mm. Elevated about 15mm. 
in II, 7? 

The Gonopore lies to the left of the anus, distant from the anal 
centre by 6°6mm.in II, 6; ca.9mm. in II, 8. In 8 it is elevated 
above the general surface ca. 1:5 mm. and has a diameter at the top 
of 16mm. ‘The diameter of the lumen is ca. 1mm. in II, 8; 
"6mm. in IJ, 5 and 6. In 6 the lumen is clearly pentagonal. 

The stem-like appearance of the Base is rather more pronounced 
in such specimens as II, 2 and 6 than it is in S. loczyi; but it is 
approached by S. yunnanensis, 1,10. Owing to its sudden contraction 
and projection from the ege- shaped theca, it has been broken off in 
most of the (figured) specimens. ‘This enables one to give the 
following additional measurements in millimetres :— 


Specimen . : : ; 3 5 6 
Thickness of plates . ; ; 0-85 1-8 0-9 
Diameter of lumen . é : 4-6 1:6 ca. 2°5 


From these it follows that the plates increase in thickness as the 
lumen contracts towards the distal end. 

The base in II, 11 (see Reed’s figure) is built of five sub-equal 
plates, about 3mm. high, slightly broken below. ‘These are 
succeeded by a circlet of seven plates. 

The thickness of the plates, as measured in II, 10, a little above 
the base, is ‘Smm. ‘The plates are described fully, and figured 


540 Dr. C. W. Andrews—Fossil Mammals from Salonica. 


accurately by Dr. Reed; but it may be added that the sutural edges 
are faintly crenelate (II, 2), and this appearance, though not 
specifically mentioned by him, may have, consciously or unconsciously, 
prompted his belief that subvective grooves ran along the depressed 
sutures. 


JiJ.—Norsz on somes Fosstr Mammats From SaLonica AND ImBROS. 


By C. W. ANDREWS, D.Sc., F.R.S. (British Museum, Nat. Hist.). 
(Published by permission of the Trustees of the British Museum.) 


de several occasions during the War, officers on active service 1n 

the Near East have found time to collect a few fossils, some of 
which have been sent to the British Museum. In three cases these 
were remains of mammals, and these discoveries are of importance 
as indicating the existence of bone-bearing deposits in localities 
where they were previously unknown, and where, not improbably, 
they may prove to be as rich as the well-known bone-beds of Samos 
and Pikerm1. 

The most interesting specimen from near Salonica is a nearly 
complete right maxilla, with portions of the premaxilla and jugal, 
of a very large species of Hyena. This fragmert is in a beautiful 
state of preservation: the second, third, and fourth premolars are 
entire, while the canine and first premolar are represented by their 
sockets and the first molar by its outer root. The bone is hard and 
nearly white, with irregular patches of black stain which give it 
a peculiar piebald appearance: some specimens from Maragha are 
in an almost identical state of preservation. An incomplete skull 
and other fragments of Hipparion from the village of Dudular, 
N.N.W. of Salonica, are in exactly the same condition, and no doubt 
the Hyena jaw was from the same deposit (see Text-figure, p. 541). 
This fixes the age as Upper Miocene, and therefore contemporary 
with the bone-beds of Samos, Pikermi, and other localities in which 
the Pontian fauna is found. 

In front the bone is preserved as far as the suture with the 
premaxilla, a narrow strip of which remains. Above, the - facial 
portion is somewhat incomplete, while posteriorly the bone joins the 
jugal, which bears a blunt, somewhat forwardly directed postorbital 
process. Above the canine the surface is very convex owing to the 
very large size of the alveolus of that tooth. The relatively small 
antorbital foramen is situated vertically above the anterior root of 
p.m. 3. The lower border of the orbit, so far as preserved, differs 
from that of other Hynas with which it has been compared 
(H. crocuta, eximia, ete.) in being less sharply separated from the 
facial surface, but passing into it by a gentle curve; the postorbital 
process of the jugal also differs in being blunt and turned forward, 
instead of pointed and more or less turned backwards: unfortunately 
this region is wanting in the type of H. brevirostris, Aymard,' to 
which the present species is in some respects similar. Judging 
from its alveolus the canine must have been a very large tooth, 


1 Boule, Annales des Sciences Naturelles, Zoologie, vol. xv, p. 85, pl. i, 
1893. 


Dr. C. W. Andrews—Fossil Mammals from Salonica. 541 


larger proportionately than in the other Hyzenas; it measured about 
25 mm. across at its root, and its hinder border is separated from the 
small round alveolus(diameter 6 mm.) for p.m. 1 by an interval of 8 mm. 
P.m. 2 is separated from p.m. 1 by a space of about 4mm.; it differs 
from p.m. 2 in 7. brevirostris, with which it is comparable in size, 
in not having the cingulum developed on its anterior or external 
faces, and in the much smaller size of its posterior accessory cusp ; 
the tooth is also less conyex on its outer face. P.m. 3 is similar in 
most respects to that of H. brevirostris, but narrows more towards its 
posterior end where it has a Jarger accessory cusp. The long axes 
of these two teeth are in the same straight line. P.m. 4 (the 
earnassial) is much like that of H. brevirostris, having a well- 
developed inner cusp (protocone), which distinguishes it from the 
contemporary H. eximia. In H. gigantea, Schlosser,’ a large Hyena 


j ef j LA Hit fl PT 
aH tN i pas ' NW, 
ee niet mT of i i wey 
ay a 
Has 


i) 
Wy 


Pr3. 


f 
| 
Vem || 
/ 


Prt 


Right maxilla of Hyena salonice, n.sp. p.m. 1, socket of first premolar ; 
p-m. 2-4, second to fourth premolars. One-half nat. size. From the 
Upper Miocene, near Salonica. : 

from a bed of similar age in China, there is only a greatly reduced 

inner cusp in p.m. 4. M.1 is represented by its outer root only, 
but was probably of considerable size as in A. brevirostris, and much 
larger than in HZ. erocuta, where it is very small or even wanting. 

The dimensions (in millimetres) of the teeth in the present species 
and in H. brevirostris are— 


Hyena salonice. Hyena brevirostris. 

Length. Width. Length. Width. 
pms2 sche UiaDss 15 22 16 
p.m Ss 67.5528 19 27 21 
p.m. 4 eeRAD 25 44-5 25 


The length and width of the carnassial (p.m. 4) in Hyena gigantea, 
Schlosser, are 44mm, (?) and 25 mm. respectively. 

As will be seen from the above measurements, this very large 
species is comparable in size with Hyena brevirostris, Aymard, and 
H. gigantea, Schlosser. From the former it is distinguished not only 


1 Schlosser, Abhand. bayer. Akad. Wissensch., Bd. xxii, p. 35, 1906. 


542 Dr. C. W. Andrews—Fossil Mammals from Salonica, 


in the several structural points referred to above, but by its much ~ 
earlier date, H. brevirostris occurring in Upper Pliocene beds in 
France, associated with Lquus stenonis. Hyena robusta, Weithofer,} 
from the Val d’Arno, is regarded as identical with ZH. brevirostris. 
From H. gigantea our fossil is sharply distinguished by the characters 
of the upper carnassial. ‘There seems no doubt that the present is 
a new species, for which I propose the name Hyena salonice, n. sp., 
the type-specimen being the right maxilla (B.M., No. M. 114138) 
above described and figured : it was collected by the ‘Rev. Wilberforce 
Cooper, C.F., and reached the Museum through the agency of Cyril 
Brett, Esq., in 1916. 

The remains of Hipparion, as already noted, are from the village of 
Dudular, N.N.W. Salonica: they were collected by Capt. Seymour 
W. aries R.A.M.C., and presented by him to the Museum. The 
specimens (M. 11585-6) include the occipital portion of a skull, 
both maxilla, premaxille, symphysial portion of mandible, and 
some fragments of limb-bones. 

The portions of the skull seem to have belonged to a rather large 
individual, which, judging from the presence of a well-developed 
canine, was probably a stallion. The teeth are in a most perfect. 
state of preservation, at least on the right side, where the outer coat 
of cement, so often lost, is completely preserved. There seems to be 
no doubt that these remains are referable to the widely-spread 
species Hipparion gracile. 

The length of the molar-premolar series is 149 mm., and the width 
across the occipital condyles is 78mm. The limb-bones are 
represented by portions of tibiz and of a radius and ulna. 

All the above specimens terminate in sharp, clean fractures, 
indicating that much was left behind, and that careful collecting 
might yield very important results. 

Portions of a mandible and limb-bones of a large Mastodon from 
the island of Imbros, off the mouth of the Dardanelles, were 
collected by Lieut. Riffault, R.A.M.C., and Col. Girvin, A.M.S., 
and were sent to the Museum by Capt. Percival T. Eniesbhye 
M.B., R.A.M.C., in 1916 (M.11587-8). 

The remains found in this case are unfortunately very imperfect, 
and were enclosed in a very refractory matrix. The chief specimen 
is the imperfect right ramus of a mandible with one broken molar 
in situ. This tooth seems to have been trilophodont: the outer 
lobes are worn into a trefoil pattern, the ends of the trefoils being 
formed by cusps blocking the transverse valleys, as in such forms as 
Tetrabelodon angustidens. The bone is broken away immediately 
behind the tooth, but extends in front of it as far as the posterior 
part of the symphysis, the length of which cannot be determined. 
The ramus is deepest at the back, narrowing gradually towards the 
symphysis. The sharp alveolar border is nearly straight, while the 
ventral border curves down slightly at the symphysis. There is 
some evidence that there was a lower incisor of considerable size, and 
in that case the species would be referable to the genus Zetrabelodon. 


1 Weithofer, Denksch. Akad. Wissensch. Wien, Bd. lv, p. 346, 1889. 


Chief Sources of Metals in the British Empire. 543 


Very probably it is Z. penéelicus, a form described by Gaudry * from 
Pikermi. 

The length of the portion of the mandibular ramus preserved is 
537 mm.; its depth behind the molar 170mm. (app.), the depth at 
the posterior end of the symphysis 145mm. ‘The length of the 
molar so far as preserved is about 120mm. The glenoid end of 
a scapula, in which the long diameter of the glenoid cavity is 
roughly 175mm., and part of a tibia were also collected. Numerous 
other bones seem to have been noticed in the same deposit, which is 
on and near the beach, and the locality is one which may prove of 
great importance, although the matrix is much harder than that 
of the probably contemporary bone-bed of Samos, and the difficulty 
of obtaining good specimens consequently greater. 


IV.—Tue Imerrmat Insrirure Map oF THE CHIEF SOURCES OF 
Merats in tHe Brivish Empire.’ 


f{\HE Imperial Institute, in continuation of its publications with 

reference to the mineral resources of the Empire, has now 
issued a map with diagrams indicating the sources within the Empire 
of the chief metals of commercial importance. The outline map 
shows the occurrence in each British country of the important 
metallic ores and also the existence of deposits at present unworked. 
The locality for each occurrence is not given in detail, but only 
a general statement, carried out by printing the names of the metals 
therein found in large type across the face of the country. Asterisks 
indicate existence of unworked deposits in producing countries, 
while brackets show the existence of unworked deposits in non- 
producing countries. Diagrams are also given, showing in a graphic 
form the production of metal or ore in each producing country ; 
these statistics are given for the year 1915: since that date many 
and important changes have occurred, although no doubt it would be 
difficult, if not impossible, to obtain complete and reliable figures for 
the later years. The diagrams also show in an instructive manner 
the relation of the output of the British Empire to those of other 
countries of the world. The facts here set forth, when carefully 
studied, afford much food for reflection. 

In the first place it is to be noted that practically every British 
country, colony, or dependency produces metal or ore of some kind 
or another, and the British Empire as a whole is a producer of nearly 
every metal of practical importance, the only really notable excep- 
tions being platinum and mercury; for these we are entirely 
dependent on foreign supplies. 

One of the most striking features disclosed is that more than half 
the total production of gold of the world comes from within the 
British Empire, the largest producer of any country being South 
Africa; the annual value of the gold output of this region is now 
in the neighbourhood of £40,000,000 per annum. Unfortunately, 


1 Gaudry, Animausx fossiles et Géologie de V Attique, 1862, p. 142. 
2 With diagrams of production for 1915. Published by the Imperial 
Institute, 1918. Price mounted on linen 5s. 6d. 


544 The Imperial Institute Map 


owing to the prevailing abnormal economic conditions, gold-mining 
is now labouring under peculiar difficulties, since gold is the only com- 
modity whose price cannot fluctuate; hence, while mining costs 
rise, the selling price cannot be increased to correspond. For this 
reason some low-grade propositions have been obliged to shut down, 
and the total output has fallen off. Since the Rand mines work on 
a very small margin of profit, they have been specially hardly hit by 
these untoward circumstances, and some form of Government 
subsidy has been suggested asa remedy. It is to be noted that gold 
occurs in every country of the Empire, even in the British Isles, 
though the amount now actually mined in the latter is very small 
indeed. On the other hand, Australia, Canada, and India are all 
the homes of well-known gold-fields. From the mineralogical point 
of view one of the most interesting occurrences is the telluride gold- 
ores of Western Australia; this is a rare type, but is known also in 
Colorado and in Hungary. 

Of silver the British Empire yields between one-fifth and one- 
sixth of the world’s annual supply, Canada being an easy first in 
this respect with 26,600,000 oz., Australia coming next with 
8,780,000 oz. South Africa and New Zealand show rather under 
a million ounces each, while the rest are nowhere. 

Perhaps the most striking fact in the mineral wealth of the 
Empire is the dominant position held by it in the tin industry. Out 
of a total annual yield of about 100,000 tons, in 1915 the Empire 
produced 67,000 tons. As is well known, tin has now reached 
fabulous prices, and the value of this output is very great. The 
Malay States alone are responsible for nearly 50,000 tons of tin, 
thus yielding considerably more than all the rest of the Empire put 
together, and half the total world’s output. The other important 
British tin-fields are the United Kingdom, Queensland, and Nigeria. 
In Cornwall there has lately been a considerable recrudescence in 
tin-mining, and this has been assisted to a certain extent by the 
tungsten boom. 

In lead and zine Australia easily takes the lead over all other 
British countries, producing about three-fourths of the lead and-nine- 
tenths of the zinc. <A very large proportion of this comes from the 
wonderful deposits at Broken Hill in New South Wales. A very 
notable recent addition to our resources of these two metals is the 
Bawdwin Mines in Burma, which are now undergoing rapid develop- 
ment and seem likely to become an important increment to the 
world’s supply in the immediate future. 

With regard to nickel the facts are very striking. There are only 
two really important nickel fields in the world, namely Canada and 
New Caledonia. In 1915 Canada yielded almost exactly three- 
fourths of the nickel of the world, mainly from the well-known 
occurrences at Sudbury in Ontario. This has been frequently 
described and is of great scientific as well as economic interest. 
A promising occurrence of a somewhat similar nature has lately been 
discovered at Insizwa in Zululand, and it is hoped that when con- 
ditions improve this may also turn out to be a practicable source of 
nickel. It seems probable that in the immediate future cobalt will 


of Chief Sources of Minerals in the British Empire. 545 


to a certain extent replace, or at any rate help to economize, supplies 
of nickel; the two metals are very similar in their properties, and 
for some purposes cobalt is actually superior; cobalt alloys, such as 
stellite, are already used for a good many purposes. 


eigeagt eat os 


Iron ips a 
Magnganese) se Pya 
PIES ree Ke tO 
| Ue Gord, | 
In, Coppe 
(Lead) 


a (Zinc) 


Gold* Silver* Antimony* 

pad™ Coppers Tungsten™ 
Ainc* Bismuth* G Aromuium x 
iF Mercury’  Flatinum* 
ron* Iridium . Manganese 
Molyhdenurm™ (Vana us) 


om (Aluminium) 


Note.—In the large sheet-map of the British Empire each British possession is 
coloured pink, and the names of the various minerals found are printed on 
or adjacent to the same county as shown in the above map of Australia, 
taken from the large world-chart. 

It is hardly necessary to enlarge on the importance assumed by 
tungsten in the last four years as a munition of war. Until 1914 
the tungsten metal industry was almost entirely in German hands, 
although the greater part of the ore was obtained from the British 
Empire and the United States. For atime Burma was the largest 
producer, but is now surpassed by the United States. Some 
countries already show signs of exhaustion, partly owing to 
improvident methods of mining in the last four years, but it seems 
probable that certain newly opened-up localities, such as China, 
Korea, and Manchuria, will be able to yield a good supply for many 
years to come. In addition to Burma, the Empire also possesses 
important tungsten resources in the Malay States, Australia, and New 

DECADE VI,—VOL. V.—NO. XI. 35 


546 Reviews—Bennettitean Cones, British Cretaceous. 


Zealand, while there is also a prospect of considerable development in 
the scheelite deposits of Rhodesia. In the last few years there has 
also been an increased demand for molybdenum and vanadium for 
the manufacture of special steels. The price of molybdenum is now 
very high, and important deposits are being worked in Canada and 
New South Wales. 

Turning now to the highly important subject of iron ores, some 
interesting facts are revealed. In the first place it is shown that 
the British Empire yielded in 1915 only about one-tenth of the 
world’s output, but the most notable fact is that the United 
Kingdom alone produced approximately seven-eighths of this, 
namely 14,235,012 tons out of a total of 15,890,827 tons: Among 
British colonies by far the most important source of iron-ore is 
Newfoundland; the Wabana mines in that island are among the 
largest in the world and the reserves: are enormous. Shipping 
facilities are also very good and prospects are most brilliant. 
During the War years very special efforts have been made to keep. 
up the supply of British ore in order to save transport, and the 
efforts of the Ministry of Munitions have been successful in this 
respect. Important developments have taken place, particularly 
among the Jurassic ores of the Midlands, and improved methods of 
mining and transport have been introduced. Efforts have also been 
made to develop home resources of manganese: in 1915 India 
produced more than half the manganese ore of the world and 
practically the whole of the output of the Empire, other British 
countries accounting for only 6,000 tons. In chromium ore 
Rhodesia takes the lead with nearly one-third of the world’s output, 
while Canada comes next. ‘he chromite deposits of Unst, in the 
Shetland Islands, have recently been worked to a considerable 
extent. 

From the facts above detailed it will be seen that the British 
Empire plays no mean part in the world of metals. In the case of 
most of them it occupies a position of prominence, and in some 
of pre-eminence. Furthermore, it is known that in many parts of 
the Empire there are large undeveloped, or partially developed, 
deposits forming a reserve for the future. It is to be hoped that in 
the period of reconstruction and development which will in all 
probability succeed the past disastrous years, those who control such 
matters will be inspired to adopt a wise and prudent policy, taking 
into account conservation as much as development, and thus laying 
the foundation of a long-continued period of prosperity and happiness 
for the inhabitants of the Empire. RARER: 


RAV LEws. 


I.—New BennerrirEan Cones From THE BririsH Cretaceous. By 
M. C. Sropes. Phil. Trans. Roy. Soc. Lond., ser. B, vol. cevii, 
pp. 389-440, 6 pls., 25 text-figs., 1918. 

ROBABLY no genus of Mesozoic plants has excited such interest 
among botanists as Bennettites, or, as Professor Seward and 
others prefer to call it, Cycadeoidea. This interest was greatly 


Reviews—Yorkshire Type Ammonites, - BAT. 


stimulated by the results of Wieland’s study of a large number of 
American fossil Cycadophytes, which were thought by some workers 
to throw light upon the vexed question of the origin of the 
Angiosperms. A full knowledge of these plants is thus particularly 
desirable, and we must welcome descriptive work dealing with 
them, even when—as is the case in the memoir before us—the 
author has not been so fortunate as to add anything of material 
importance to what was already known. 

The first section of Dr. Stopes’ paper consists of a description of 
a portion of a cone, Bennettites albianus, sp. nov., recently obtained 
from the Gault of Folkestone Warren. The specimen was petrified 
and proved suitable for sectioning. ‘The author concludes that this 
cone was ‘‘the giant fruit of the family”’. ‘The fragment available, 
however, measured only 5°5 cm. X 38cm. in transverse section, and 
the idea that the cone was of peculiarly large size is deduced from 
a reconstruction of its probable shape when complete; this may be 
perfectly correct, but it must be regarded as at present scarcely 
proven. The seeds with their embryos and seed-coats, and the 
interseminal scales, are discussed and figured in detail. ‘The author 
describes the outermost layer of the seed covering as a ‘‘cupule” or 
‘‘aril” of elongated tubular cells. She regards the plug of tissue 
closing the micropyle as nucellar in nature. 

Carruthers’ type-specimen of Bennettites maximus has hitherto 
been known only by its external characters, and so much of its 
anatomy as could be observed with a hand lens. In the second part 
of her paper Dr. Stopes records the results she has obtained by 
having this specimen sectioned. ‘The most notable feature is the 
occurrence of extremely young cones. One of these, of which 
preparations were obtained, shows in one section a collar of tissue 
surrounding the peduncle, which the author interprets as a whorl of 
male sporophylls. She writes: ‘‘ The discovery that this species had 
bisporangiate cones is, of course, the feature of supreme interest in 
the plant.” When we consider, however, that the existence of 
male sporophylls is deduced from a single section in which no 
synangia are preserved, we can scarcely avoid feeling that, although 
the truth of Dr. Stopes’ view is highly probable, it must at present 
be received with some degree of reserve. 

PAG ae 


IIJ.—Yorxsuire Type Ammonites. Kdited by 8S. 8S. Buckman; 
photographs mainly by J. W. Turcnuer. Part XVI. 8 plates, 
and descriptions Nos. 112-116. London: Wesley. 1918. 
Price 3s. 3d. net. 


(J\HE present part of this most systematically edited publication 

deals with five Ammonite species: Arnioceras semicostatus 
(Young & Bird); Perisphinctes rotifer (Williamson-Brown); Hildo- 
ceras bifrons (Bruguiére); Pachyceras rugosus (Leckenby); Vertumni- 
ceras vertumnus (Bean-Leckenby). This last is a new genus_of the 
family Cadoceratide; of the four paratypes of the species (which, 
with the holotype, are in the Sedgwick Museum) two are referred to 


548 Reviews—The Ossiferous Caves near Torquay. 


Quenstedticeras damont, Nikitin, and a third is made holotype of 
Vertumniceras spatiatum, n.sp. 

Of the species herein dealt with, Hi/doceras bifrons is probably the 
best, as it is also the longest, known. Mr. Buckman thinks it highly 
probable that the specimen represented in his plate cxiva is the 
original of Martin Lister’s figure (1678, Hist. Anim. Angl.), which, 
through Bruguiére’s reference to it, became the holotype. The 
specimen is now in the collection of Mr. V. KE. Robson, F.G.S., who 
‘purchased it in London”. London is a big place, so that this 
statement does not throw much light on the previous history of the 
specimen. Indeed, our friend Mr. S. Holmes, Intelligence Depart- 
ment, regards it as a transparent blind. 


IiI.—Tue OssirErous Caves nuar Torquay. 
ie the Journal of the Torquay Natural History Society for 1918 
i. Mr. Harford J. Lowe has given an interesting account of the 
comparatively little-known Tor Bryan Caves, near Torquay, together 
with a short biography of Mr. J. L. Widger, who spent some twenty 
vears of his life in excavating them. Unfortunately his enthusiasm 
appears to have been greater than his knowledge of what is required 
in making such an excavation, and consequently much valuable 
information has been lost. Mr. Lowe discusses the probable history 
of the caves and their relation to Kents Cavern and Brixham Cave. 
He considers that the human occupation of these caves was much 
later than that of Kents Cavern. The greater part of the Widger 
Collection is now in the British Museum. 
F. A. B. 


IV.—Rerort on CERTAIN MINERALS USED IN THE ARTS AND 
Inpusrries. III. Maenxstrz. By P. A. Waenzr. South 
African Journal of Industries, Pretoria, 1918. 

N this bulletin Dr. Wagner gives a general account of the 
properties and uses of magnesite and describes the occurrences of 
the mineral in South Africa. Since the supplies from Austria- 

Hungary and Greece were cut off by the War a considerable 

magnesite industry has developed in Canada and California, largely 

for use as a lining in basic open-hearth steel furnaces in the form of 
bricks. It is also much employed in the manufacture of cement 
for various purposes, such as floors and ceilings. For all these uses 
it must be fairly pure, and the supplies of really good quality 
material are somewhat limited. Up to the present magnesite 
mining in South Africa has been confined to the Barberton district, 
where it is found in considerable quantity in the basic and 
ultrabasic igneous rocks of the Jamestown series. There are also 
important deposits in the valley of the Olifants River, in the 

Lydenburg and Pietersburg districts, as veins in highly decomposed 

pyroxenite belonging to the Bushveld complex. The material 

produced is now for the most part used by the Union Steel 

Corporation for linings of electric furnaces at Vereeniging. Other- 

wise the local demand is small and the establishment of an export 

trade does not at present seem probable. 
Tiss) gy 1h 


Reviews—Corundum of the Zoutpansberg Fields. 549 


V.—Tue Corunpum or THE ZouTPANSBERG FIELps AND ITs Marrrix. 
By P. A. Waenrer. Trans. Geol. Soc. 8. Africa, vol. xxi, 
pp. 37-42, with 4 plates, 1918. 


OUTH Africa now ranks as the leading country in the production 
of corundum, having an output of about 400 tons per month. 
This comes chiefly from the Zoutpansherg and Leydsdorp fields. 
The greater part of the mineral occurs either as eluvial crystals and 
fragments, or as ‘‘boulder’’ corundum, that is rock-fragments 
containing it along with other minerals. In this paper the 
characters of the corundum crystals are fully described and analyses. 
given. It is shown that the mineral occurs as a constituent of 
a pegmatite of dioritic type (plumasite-pegmatite) intrusive in the 
Swaziland series and in various dioritic and gabbroid rocks, probably 
belonging to the same phase of igneous activity. 


ViI.—Conrrisutions To THE Muineratocy oF Brack Lake Area, 
Quresre. By E. Porrevin and R. P. D. Granam. Canada 
Department of Mines, Geological Survey, Museum Bulletin 
No. 27, pp. 82, with 12 plates and 22 text-figures. Ottawa, 
1918. 

fee Black Lake area is situated in Megantic county, province of 

Quebec, and includes one of the most productive portions 
of the great ‘‘serpentine belt”. Mining is carried on for asbestos 
and chromite, and in the course of these operations many interesting 
minerals have been found. Besides serpentine, other igneous rocks 
are found, including pyroxenite, gabbro, granite, and aplite, as well 
as other more basic varieties. The minerals include sulphides, 
carbonates, and a large variety of silicates: only a few of the more 
interesting types can be mentioned here, such as very well-developed 
erystals of diopside, garnet, vesuvianite, zircon, stichtite. Many of 
these minerals are rich in lime and are believed to be partly due to 
magmatic concentration after differentiation of an igneous magma, 
the solutions thus formed circulating through the rocks and reacting 
with their earlier constituents. 

BEC EG. 


VII.—Awnatyses or Canapian Fuers. Part I: Tae Maritime 
Provinces. Part IL: QursEec anp Ontario. Part IIT: Manirospa 
AND SaskatcHewan. By E. Sransrrerp and J. H. H. Nicotts. 
Canada Department of Mines, Bulletins 22, 23, and 24. 
Ottawa, 1918. 


fy sectan Bulletins consist of a collection of analyses of coal, peat, 

oil, oil shale, and natural gas from a large number of localities 
within the areas specified. The work has been in progress for 
several years, first at McGill University and afterwards at the 
Department of Fuels and Fuel-testing, Mines Branch, Department 
of Mines, Ottawa. The data given are proximate and ultimate 
analyses, calorific value, fuel ratio, and carbon-hydrogen ratio. The 
geological relations of the different deposits receive only the briefest 


550 Reviews—The Geology of Vancouver and Vicinity. 


mention, ‘but: the figures given will be very valuable to those 
interested in the study of fuels. 


VIII.—Tae Gxotocy or Vancouver anv Vicinity. By E. M. J. 
Burwasa. pp. 106, with 23 figures and 2 maps. Chicago, Ill. : 
The University of Chicago Press. 1918. 


f{\HE area covered by this report may be divided into two parts: 

the southern portion, which extends from the international 
boundary to Burrard Inlet, is part of the floor of the great structural 
valley in which lie Puget Sound and the Gulf of Georgia; the 
northern area forms part of the southern margin of the coast range 
of British Columbia. In the latter the relief of the land is high and 
yields a definite record of a succession of physiographic cycles. Five 
such stages can be recognized and correlated with those already 
worked out in the Cascades of Washington State; they are as 
follows: the Methow peneplain, represented by accordant summits 
and terraces, the Entiat stage when mature valleys were developed 
in this older surface, the Twisp stage when the Entiat valleys were 
over-deepened by canyons cut in their floors, after uplift, the Chelan 
stage of glacial modification, and the Stehekin stage of post-Glacial 
stream-denudation and deposit. 

The rocks found in the region include Devono-Carboniferous 
(Yexada and Britannia series), the first wholly volcanic, the second 
including slate and sandstone as well as lavas, some porphyrite 
intrusions assigned to the Trias, the Upper Jurassic coast-batholith, 
Eocene conglomerate, sandstone, shale, and clay, post- Eocene eruptives 
(Black Tusk basalts), the Garibaldi volcanic formation, and a variety 
of Quaternary deposits. Of each of these detailed descriptions are 
given, together with a very complete discussion of the structural and 
physiographic features attending the formation of each. 

The coast-batholith forms part of the immense series of pre- 
dominantly dioritic batholiths extending from the Frazer River into the 
Yukon territory. This particular igneous complex includes varieties 
ranging in composition from biotite-granite through granodiorite, 
diorite, and gabbro to hornblendite. here is clear evidence of 
differentiation with marginal basic facies, the latter being in some 
places intruded by more acid apophyses. Near the contacts gneissoid 
texture, due to flow, is in evidence, and orbicular types are also known. 
The Black Tusk basalts form the summits of certain conspicuous 
mountains, these being probably remnants of flows that filled 
a Miocene valley, while similar rock-types occur elsewhere as dykes. 
The Garibaldi volcanics form three cones which are clearly later than 
some of the Pleistocene glacial deposits: they are mainly basaltic in 
composition. 

Among. Quaternary deposits the moraines and various forms of 
drift are: the most noteworthy, since they indicate several stages 
of glaciation of the region. There are also numerous examples 
of deltaic and other alluvial deposits, as well’*"!erraces which the 
author considers to have been formed by glacial lukes. 


Reviews —_N, ew Zealand Geology. 551 


1X.—Tue Rorror Gracirr Laxes (PiepMonrese Axps). By C. S. 
Dou Ricue Pretier. Scottish Geographical Magazine, vol. xxiv, 
pp. 3380-342, with 5 text-figures, 1918. 


(has author gives a detailed description of several small lakes, 
some of very recent origin, formed in the course of the retreat 
of the Ruitor glacier, either at its margin or at the frontal base of 
the glacier tongue. Some of these lakes, which bear some 
resemblance to the Marjelen See of the Bernese Oberland, have at 
times been the cause of disastrous floods in the Dora Baltea valley. 


X.—New Zratann GeroLoey. 


1, Tur SrrarierapHy or THE Tertiary Beps or rue Castie Hu. 
on Tretissick Basty. By R. Sperenr. Trans. New Zealand 
Inst., vol. xlix, pp. 321-56, 1916. 

HIS basin, which is situated in the heart of the mountain region 

of Canterbury, is about 8 miles long by 4 miles wide, and 
contains an interesting series of sedimentary deposits, with some 
voleanic material. The strata, which consist of sands and sandstones, 
greensands, shale, coal, and limestones, are richly fossiliferous. 

Certain beds low in the series contain plant remains of decidedly 

Tertiary character, including Quercus, Planera, Dryandra, and Cassia, 

but these are overlain by marine sediments containing Cretaceous 

shells. Higher still the proportion of recent forms gradually 
increases, and the author considers that the succession from 

Cretaceous to Tertiary is continuous, since he finds no indication of 

unconformity, as maintained by earlier writers. 


Test el 1a 


2. An Unrecorpep Tertiary OvuriieR In THE VALLEY OF THE 
Raxara. By R. Sperent. Trans. New Zealand Inst., vol. xlix, 
pp. 356-60, 1916. 

fYVHE author gives in this paper a description of a newly-discovered 

occurrence of Tertiary strata in the valley of the Harper River, 

a tributary of the Wilberforce, which is itself one of the main 

feeders of the Rakaia, in the Canterbury district. The Tertiary 

deposits cover an area of some 5 miles long by 2 or 3 broad, and 
consist of sandy clays with impure lignite, greensands, concretionary 
sands, and shell beds, the fossils indicating a mid-Tertiary age. The 
occurrence of the outlier in this position is explained as being due to 
faulting, the main part of the series having been removed by erosion 
at higher levels. ‘he walls of the valley itself are remarkably 
straight and suggestive of a rift, and are parallel to the dominant 
fault-lines of the whole area, the Kaikoura fractures of McKay and 

Cotton. This region also affords evidence of some interesting 

modifications of drainage, which may be due either to very recent 


movements along “-u''-lines or to glacial barriers. 
BiB RN: 


552 Reviews—New Zealand Geology. 


38. ADDITIONAL Facrs coNCERNING THE DisrrisuTion oF IGNEOUS 
Rocks 1x New Zeatanp. By J. A. Barrrum. Trans. New 
Zealand Inst., vol. xlix, pp. 418-24, with 1 plate and 1 text- 
figure, 1916. 


‘W\HIS paper contains petrographical descriptions of nine specimens 
of igneous rocks from different parts of New Zealand, including 
both plutonic and volcanic types. A hypersthene basalt from near 
Whangarei is believed to be the first instance of this rock from that 
country, although hypersthene is well known in the basic andesites 
of Tarawera and Tongariro. A peculiar basalt with olivine, augite, 
and large phenocrysts of biotite from the Wairoa River is often used 
for ornamental work and is locally called ‘‘ Kaipara granite”’. 
A hornblende basalt is also noted from near Sumner in the South 
Island. The plutonic rocks include a coarse-grained troctolite with 
much serpentine from Wade, near Auckland, and various gabbroid 
and dioritic rocks from the Baton and Graham Rivers, Nelson. These 
are essentially very coarse-grained hornblende rocks with much 
ilmenite, epidote, apatite, sphene, and a varying amount of quartz: 
the hornblende seems to be secondary after pyroxene. Some 
boulders of dioritic rocks with gneissic structure were found at 
Albany, near Auckland: they probably come from a Miocene 
boulder-bed. Diorites seem to have formed an important element in 
the pre-Tertiary terrain of the Auckland district. A specimen of 
granodiorite from Reefton, in the Nelson district, which was 
apparently collected from a river gravel, is remarkable in that it 
contains what appears to be primary epidote. It is a rock of granitic 
appearance, with abundant biotite and a large variety of felspars, 
including perthite, microcline, and plagioclase. Both sphene and 
epidote are very abundant. The epidote, often occurs in well-formed 
crystals enclosed in felspar or in biotite. Crystals of brown horn- 
blende are often enclosed in the epidote, and the author regards 
the primary character of some at least of the epidote as established. 
Although the rocks here described come from widely scattered 
localities and may be of very different ages, nevertheless they all 
show more or less clear sub-alkaline characters. One specimen only, 
from Wairau Creek, Milford, Auckland, is described as a trachyte, 
and even this does not seem to be a very alkaline rock. However, 
no analyses are given, so that this point cannot be decided. 


R. He Re 


4. Tue Votcanic Rocks or Oamaru. By G. H. Urrrey. Trans. 
New Zealand Inst., vol. 1, pp. 106-17, 1918. 

N this district there are three horizons of voleanic rocks—the 
Waiareka tuffs, the Kakanui breccia, and an upper lava, the latter 
shows many of the characters of the pillow lavas, but they cannot 
be classed with the spilites, since the proportion of soda-felspar is very 
low. It was, however, erupted under marine conditions, but in 
shallow water. The stratigraphical breaks and the limestone 
conglomerate can be explained on the assumption that voleanic 
islands were rapidly formed and rapidly destroyed: hence the un- 
conformities introduced into the Oamaru system by other observers 


Reports & Proceedings—Geological Society of London. 553 


are of merely local value, and the succession is really continuous 
throughout, 


5. On tHe Acre oF tHE Warkonarrr Sanpstone, Oraco, By 
J. Artan THomson. ‘T'rans. New Zealand Inst., vol. 1, pp. 196-7, 
1918. 


OST geologists have correlated this sandstone with the Otatara 

limestone, but the discovery in it of Pachymagas abnormis 

leads the author to conclude that the sandstone belongs to the Upper 
Oamaruian, possibly to the Awamoan. 


REPORTS AND PROCHEHDIN GS. 


I.—Geroxnocicat Socrury oF Lonpon. 
November 6, 1918.—G. W. Lamplugh, F.R.S., President, in the Chair. 


The President read a communication that he had received from 
Professor Charles Barrois, D.Sc., F.M.G.S., in reply to congratulations 
sent on the occasion of the evacuation of Lille by the enemy forces. 

A discussion on the Antarctic Ice-cap and its Borders was 
introduced by Sir Douglas Mawson, D.Sc., B.E., F.G.S. 

Sir Douglas Mawson said that at the last meeting of the Society ' 
the subject of the Antarctic Ice-cap was reviewed in its broader 
aspects, ‘chiefly with the view of promoting a discussion among 
those specially interested in Glaciology. The present occasion had 
been reserved for the discussion, and he proposed to show certain 
lantern-slides in order to bring the salient features freshly to mind. 

Though much of the foundation of the Antarctic Ice-cap is 
certainly elevated land, it is quite possible that elsewhere the dome 
rests upon a floor actually below sea-level. In any case it is most 
probable that the smooth ice-surface masks a very irregular rock- 
basement. he thickness of the ice may, therefore, be expected to 
be extremely variable, no doubt reaching a maximum of several 
thousands of feet. 

An ice-formation of such magnitude introduces questions relating 
to the flow of its substance and the abrasion of its foundations which 
do not enter into the physics of ice-masses of smaller dimensions. 
Here the static pressure on the lower zones of the ice may reach 
1 ton per square inch. At the same time, the temperature may 
be so increased by ground heat as to be much higher than that 
prevailing above. As a consequence, when the ice-formation is 
very thick, a more plastic base must be admitted. 

The outflow of the inland ice is principally deflected at the coastal 
margin into depressed areas outlining the heads of gulfs and bays. 
In such localities the rate of movement and the volume of ice 
entering the sea are both great. So great indeed, that extensive 


1 See Reports and Proceedings Geol. Soc., June 19, 1918, GEOL. MAG., 
August, 1918, pp. 379-80. 


554 Reports & Proceedings—Geological Society of London. 


floating ‘‘ glacier tongues” are a feature of such situations, often 
extending 40 to 50 miles from the shore. 

Along other stretches of the coast less well placed for receiving 
contributions from the interior of the Continent, the outflow is so 
much less that the destructive influences at work on reaching the sea 
easily maintain its boundaries at approximately the true coastline. 

As exceptions to this latter prevailing condition, however, there 
are known already two notuble localities where the general overflow 
from the land maintains itself as an immensely thick floating 
structure extending far out over the sea—a veritable oceanic ice- 
cap. To this type of formation we apply Professor Nordenskjold’s 
term ‘‘shelf-ice’’. The formations referred to are the Great Ross 
Barrier at the head of the Ross Sea and the Shackleton Shelf off 
the coast of Queen Mary Land. 

‘The former occupies what is really the head of the Ross Sea— 
a somewhat triangular area. From apex to base it measures 
500 miles, with a base-length of about 400 miles. This great raft 
of ice presses forward to the open sea at the rate of a few hundred 
yards per annum. The available figures, quoted by David and 
Priestly, show that, at the present rate of advance, the ice now 
appearing at the sea-face must have left the inner extremity of the 
floating sheet at some time during the seventh century. A survey of 
the ice-cliff forming the sea-face indicates by its changing height 
that the Ross Barrier is of varying thickness. This has been 
explained by the presence, in localities where it is thickest, of the 
remnants of the massive ice contribution received during its course 
from certain of the large tributary glaciers. The ice from these 
glaciers, in fact, constitutes a strong framework which stiffens and 
contains the more crumbling structure derived from the consolidation 
of the annual snowfall. 

To a great extent this must certainly be so; but the influence of 
a varying snowfall, and the effect of violent periodic winds—a 
feature of the region—in sweeping the loose snow from certain 
areas and depositing it in other favoured localities, must be reckoned 
with. The snowfall is lighter on the eastern side than on the 
west. Furthermore, the snow tends to accumulate on the western 
side owing to the fact that the winds regularly blow from the 
quarter south to east, and not from the west. 

In the case of the Shackleton Shelf, this is the more remarkable 
because it maintains itself as a pontoon stretching into the open 
sea, even across the drift of the prevailing ocean-current. 

The deluge of ice, after descending to the sea, presses northwards 
as an integral whole, at first touching bottom at intervals, then 
forcing its way past several islands, eventually reaching an extreme 
distance of 180 miles from the land before it is mastered by the 
swell and currents of the Southern Ocean. It is somewhat 
triangular in form, with the apex out to sea. The base against 
the land, though not completely charted, extends in all probability 
for a distance of about 200 miles. 

The main body of. the shelf-ice advances rather slowly, but the 
Denman Glacier, which contributes to it, has a much more rapid 


Reports & Proceedings—Geological Society of London. 555 


movement, very well illustrated by the fact of its ploughing through 
the other shelf-ice with such force that a shatter-zone some miles 
wide is developed. 

The wall of the shelf-ice on the west side offers an excellent 
example for study, as it is a section from the point of its departure 
from the land to its crumbling apex. Im the case of the Ross 
Barrier, the cliff-face is a section across the direction of movement. 

At the land end, the Shackleton Shelf, from the surface down, is 
hard glacier-ice breaking with a characteristic fracture. A few 
miles farther out, away from the influence of the winds descending 
from the land slopes, a nevé mantle commences to make its appear- 
ance over the original ice-formation. As one steams along the face 
away from the land, this capping is observed to increase steadily in 
thickness. ‘The overburden of nevé is arranged in regular bands, 
each of which corresponds to a single year’s addition. This being 
so, it is possible to make some sort of an estimate of the age of the 
formation. 

The weight of these additions depresses the top of the original 
ice below the surface of the water. Though there is a regular 
annual addition above, it must not be imagined that the total 
thickness of the pontoon is correspondingly increased; for the 
solution of the lower surface by the sea has also to be reckoned 
with. Very often, however, in the nevé sections of glacier-tongues 
the cliff-face above the water is observed to stand higher than in the 
wholly ice zone at the land end. ‘This is to be expected on account 
of the lighter nature of the nevé ice added, there being a larger 
proportion of air sealed up in it. 

The observed height above sea-level of Antartic shelf-ice so far 
recorded ranges from about 20 toover 200 feet. A common figure is 
from 90 to 120 feet, suggesting a total thickness of 600 to 1,000 feet. 

Although the height of the cliff-face presented by shelf-ice gives 
some idea of its total thickness, a really accurate method of 
determination is badly needed. The Australasian Expedition hit 
upon a method which gives positive results in some cases at least. 
This consists in taking serial temperatures of the sea-water in depth 
near the face of the shelf-ice. As there is always a current flowing 
beneath the ice, the bottom of it is likely to be marked by a sudden 
slight change in the water temperature, easily observed when the 
observations are plotted as a graph. 

The President conveyed the thanks of the Society to Sir Douglas 
Mawson for his luminous description of Antarctic conditions and for 
his selection of the magnificent illustrative photographs on this as 
well as on a former occasion. The fact that the explorer was in this 
case a thoroughly competent geologist was indeed fortunate. The 
Fellows had been thus enabled to participate without effort in the 
new knowledge gained through heroic labour by the lecturer and his 
comrades. A further privilege was afforded to the Glacial geologists 
present by Sir Douglas Mawson’s readiness to impart the information 
that he, more than any other man, possessed, and, as time was 
limited, the President hoped that the speakers would take advantage 
of this privilege rather than give expression to their particular views. 


556 Reports & Proceedings—Geological Society of London. 


For his own part, he would like to ask at once whether the 
lecturer had formed any opinion as to the origin of the evidently 
bold land-features that were buried under the ice—could they have 
been carved out by the ice itself, or were they the relics of a time 
when the land was ice-free? 

In the discussion which followed, Professor P. F. Kendall, Sir 
Henry Howorth, Dr. J. W. Evans, Mr. G. W. Young, Mr. A. E. 
Kitson, and Dr. A. Strahan took part. 

The President supplemented the questions by asking whether the 
lecturer could express any opinion as to (1) whether, if the great 
table of shelf-ice continued to grow by accretion, it would eventually 
become merged into the main ice-sheet; (2) how much of the 
remarkable seaward extension of the huge ice-tongues was due to 
forward flow, and how much to growth-in-place by snowdrift; and 
(3) what happened when an advancing ice-front over-rode a rocky 
island well separated from the mainland ? 

Sir Douglas Mawson, in replying, said that he would take the 
President’s questions first. As to the origin of the land-features, 
he did not want to commit himself on this difficult point at present, 
but was inclined to think that the physiography, so far as one sees 
it, might all have been produced by ice. if no other agency had been 
available; but it was most likely that the ice started upon a surface 
already sculptured to some extent. He felt sure, however, that the 
Antaretic ice could and did cut deep channels, not only above but 
also below sea-level. Where the ice was thickest it burrowed 
fastest, and tended, therefore, always to accentuate any existing 
hollow. 

As to the growth of the shelf-ice, although there was a large 
accretion at the top by snow swept off thé land, there was also 
probably much dissolution below by the action of the sea-water; so 
that the net increase of the mass was not so rapid as appeared at 
first sight. 

That there was forward movement of the ice-tongues was proved 
by the way in which they ploughed through the fixed shelf-ice and 
by their upward bulging where they struck bottom; but most of 
their movement was over sea-water, and therefore easy and almost 
frictionless. | 

Where the ice-sheet abutted upon an island, it depended upon the 
relative proportions of ice and land whether the land was entirely 
over-ridden or the ice-flow split and diverted. Examples of both 
phenomena were observed. 

As to the rate of wastage by melting, the great ice-plateau by 
causing an outflow of cold air kept the temperature at the ice- 
margin too low for much melting. What melting there was 
depended mainly upon the lie of the ice-slope in relation to the sun. 
There was also a good deal of wastage both of snow and ice by 
direct evaporation, depending upon the season. But the main 
wastage was due to the descending winds, which fiercely and almost 
continuously swept the outer slopes. 

With regard to the thickness of the ice, there was perhaps no 
direct evidence, but a great amount of indirect evidence all indicating 


Reports & Proceedings—Lwerpool Geological Society. 557 


that it must in places be very thick—probably several thousands of 
feet. Boring had been thought of, but would be impracticable 
because of the movement of the mass at differential rates, so that the 
borehole could not be kept plumb or open. There were some new 
instruments, however, invented for marine purposes, which might 
eventually yield positive information. 

The banding of the ice was not due to dirt or dust, which was 
practically absent in the Antarctic, but to differences of structure 
and density, marking the seasons. 

The rugged surfaces of the “islets are probably due to frost- 
splintering and marine action, and do not imply that they have 
suffered no ice-erosion. 

The drift deposits are scanty, because there is so little flat land 
exposed on which they could accumulate. But the sea-bottom 
earries a great accumulation of clay with boulders for a long distance 
northwards from the present ice-front. 


The Secretaries of the Society are desirous of completing a record 
of the services rendered by the Fellows in connexion with the 
present War. Details of service, with a statement of rank, regiment, 
military honours, and any other information, will be gladly received 
from Fellows, either with reference to themselves or to those known 
to them. 


Il. Liverpoot Geronoeicat Socrery. 


November 12, 1918.—J. H. Milton, F.G.S., F.L.S., Ex-President, 
in the Chair. 

The following paper was read :— 

‘* Notes on Pebbles in their Geological Associations.” By William 
Hewitt, B.Se. 

The paper gave the results of a comprehensive study of the 
physical characters of pebbles and their production, and embodied 
a large amount of statistical and other information relative to their 
sizes and shapes, the transporting power and velocity of streams, and 
the varying conditions under which pebbly deposits have been 
accumulated. The more important conglomerates of the geological 
series were also briefly considered. Recent observations by 
Mr. Hewitt as to the number and size of the pebbles (from about 
one-tenth of an inch long and upwards) in the Bunter Pebble Beds 
in four different localitiesin the Liverpool district, where the pebbles 
are most conspicuous, gave the following result :— 


Total Total No. of Longest diameter. 
surface. pebbles. Uptol’’, 1-2’, 2-3'’. Over 3’. 
Vertical sections - 932 sq. feet 723 676 36 10 1 
Horizontal sections . 22? ,, 1,012 974 36 1 1 


The greater number of pebbles shown in the horizontal sections 
confirms previous observations as to the occurrence of pebbles mainly 
at distinct horizons; in some cases they constitute small gravel 
pockets. The majority of the pebbles were under half an inch in 
their longest diameter, the largest one seen was 6 inches long. An 


558 Reports & Proceedings—Mineralogical Society. 


estimate of the relative proportion of the surface of section occupied. 
by pebbles ranged in vertical faces from 3 to 9 per cent and in 
horizontal faces from 4 to 16 per cent with one exceptional case of 
32 per cent. (The percentage of the rock mass formed by the 
pebbles is certainly distinctly lower than the surface percentage.) 
This condition of the Liverpool Pebble Beds is in marked contrast to 
the Bunter conglomerate beds of the Midlands (Cannock Chase, etc.) 
or Budleigh Salterton. 


II1.—Miyeratoeicat Socirery. 


Anniversary Meeting, November 5, 1918.—Sir William P. Beale, 
Bart., K.C., M.P., President, in the Chair. 


The following were elected Officers and Members of Council: 
President, Sir William P. Beale, Bart., K.C., M.P.; Vice-Presidents, 
Professor H. L. Bowman, Mr. A. Hutchinson; Treasurer, Dr. J. W. 
Evans; General Secretary, Dr. G. T. Prior, F.R.S.; Foreign 
Secretary, Professor W. W. Watts, F.R.S.; Editor of the Journal, 
Mr. L. J. Spencer; Ordinary Members of Council, Mr. H. Collingridge, 
Mr. ff. Crook, Dr. G. 'F.> Herbert) Smith, Dr. He Dhomas, 
Mr. H. F. Collins, Mr. J. P. De Castro, Professor H. Hilton, 
Lieut. A. Russell, Dr. A. Holmes, Miss M. W. Porter, Mr. R. H. 
Rastall, Sir J. J. H. Teall, F.R.S. 

The following papers were read :— 

Dr. G. F. Herbert Smith and Dr. G. T. Prior: ‘On a Plagionite- 
like Mineral from Dumfriesshire.” Specimens of antimony-lead 
ore collected by Lieut. Russell from Glendinning mine contained 
small cavities lined with tiny black crystals, measuring less than 
0-4mm., and mostly less than 0°2mm. across. Some resembled in 
habit the crystals of plagionite from the Hartz Mountains described 
by Luedecke. Measurements made on the three-circle goniometer 
showed the crystals to belong to the semseyite end of the group, and 
the result of a chemical analysis of the compact material of which 
the crystals form part corresponded approximately to the formula 
5 PbS .2Sb,8,. Semseyite has not previously been recorded from 
the British Isles. 

Lieut. Arthur Russell: ‘‘The Chromite Deposits in the Island of 
Unst, Shetlands.’’ The bottle-shaped mass of serpentine which runs 
through the centre of the island from north to south contains 
chromite uniformly distributed, but varying greatly in character, 
being at times massive, but generally granular. Over thirty 
quarries are known, but only six of them have been worked to any 
extent. The associated minerals include kammererite (abundant in 
one quarry), uvarovite, copper, hibbertite, brucite, calcite, tale, and 
magnetite. The rocks other than the serpentine are poor in 
minerals. 

Dr. G. T. Prior: ‘‘The Nickeliferous Iron of the Meteorites of 
Bluff, Chandakapur, Chateau Renard, Cynthiana, Dhurmsala, Eli 
Elwah, Gnadenfrei, Kakowa, Lundsgard, New Concord, Shelburne, 
and Shytal.” The percentage of nickeliferous iron and the ratio 
of iron to nickel in the several instances were found to be 


Correspondence—L. M. Parsons. 559 


respectively—5, 64; 8, 9; 84, 61; 6,6; 33, 34; 64, 74; 214, 123; 
SeGeese, 5 108s TOs LOS Ge. 


CORRESPONDENCE. 


THE HORIZON OF PRODUCTUS HUMEROSUS. 


Srr,—In reply to Dr. Wheelton Hind’s letter in the October 
number of the Grorogican Macazinz, may I point out that there 
appear to be two forms of Productus humerosus occurring at different 
horizons. The earlier form is evidently characteristic of the 
Belgian ‘‘swb-/evis”’ level (C-S), while the later mutation is found 
in the Dibunophylium zone. The late Dr. Vaughan, in his paper on 
the ‘‘Correlation of Dinantian and Avonian’’, published in the 
Q.J.G.S., vol. lxxi, No. 281, refers to this matter, and mentions, on 
p- 47, that the Clitheroe form is the early variety of Productus 
sublevis. For the present I conclude, from evidence stated in my 
paper, that the Leicestershire beds contain the later advanced form 
of P. humerosus, and are of D, age, but I am looking forward to 
reading, with much pleasure, Dr. Hind’s forthcoming paper on the 
Clitheroe area, and will then carefully reconsider the question. 

- L. M. Parsons. 


110 LEWIN RoaD, 
STREATHAM, S.W. 16. 


OBITUARY. 


SAMUEL WENDELL WILLISTON, M.D. 
BORN JULY 10, 1852. DIED OCTOBER, 1918. 


VERTEBRATE paleontology loses a distinguished student by the death 
of Professor 8. W. Williston. After leaving school he entered the 
Kansas Agricultural College, where his interest in geology was 
roused by Professor B. F. Mudge. He was then employed by 
Professor O. C. Marsh as one of his fossil-collectors in Kansas and 
other western territories of the United States. At the same time 
he helped with the preparation of the fossils in the Yale University 
Museum, and also pursued medical studies, which eventually led to 
his graduating as M.D. He was deeply interested both in the fossils 
and in the living animals which he met with during his explorations, 
and so early as 1877 he began to publish small notes. Professor 
Marsh, however, discouraged Williston’s researches on fossils, and 
he therefore turned in earnest to dipterous insects, on which he 
became one of the leading authorities in the United States. In the 
early eighties he was appointed Professor of Geology and Paleon- 
tology in the State University of Kansas at Lawrence, where he 
brought together a great collection of fossils from the Cretaceous 
and Carboniferous formations of the State. In 1902 he removed to 
the newly instituted chair of Paleontology in the University of 
Chicago, where he continued active researches until nearly the time 
of his death. 


560 Obituary—Miss Maude Seymour. 


While at Lawrence, Williston’s most important work was his 
_ investigation of the reptiles found in the Chalk of Kansas, and the 
results were finally summarized in a well-illustrated volume of the 
University Geological Survey of Kansas (vol. iv, Paleontology, pt. i) 
published in 1898. In his early years at Chicago he continued these 
researches, and his valuable papers on Plesiosaurs and Pterodactyls 
in the Publication of the Field Columbian Museum, No. 78 (1903), 
may be specially mentioned. He also published a little semi-popular 
volume on Water Reptiles (1914). During the last decade he 
devoted attention chiefly to the Permian Reptiles from Texas and 
Missouri, describing important collections which he acquired for the 
University of Chicago. These form the subject both of numerous 
papers and of a small well-illustrated volume on American Permian 
Vertebrates, issued by the Chicago University Press in 1912. Many 
of the papers not only describe the fossils, but also discuss the 
bearing of the new facts on some of the most fundamental problems 
' of vertebrate morphology. A complete list of Williston’s papers up 
to date, prefaced by a beautiful portrait, was printed by 
J. T. Hathaway at New Haven in 1911. 

Williston was an attractive personality and left many devoted 
pupils, of whom some have already made important contributions to 
the science of which he was so successful an exponent. A.S.W 


MISS MAUDE SEYMOUR. 
Born 1887. DIED NOVEMBER 6, 1918. 


THosr Fellows of the Geological Society who have been 
accustomed to use the Library during the last few years will hear 
with much regret of the death of Miss Seymour, who was appointed 
as an assistant in the Library on September 1, 1915. The valuable 
experience gained during several years of training on the staff of the 
Royal Society’s Catalogue of Scientific Papers gave her the advantage 
of a special knowledge of the literature with which she had to deal. 
She devoted herself to the work with marked ability, and her 
unflagging zeal and amiability of disposition substantially relieved 
the pressure of an exceptionally harassing period. During this time 
she gained an intimate knowledge of the work involved in the 
preparation of the Geological Literature; and by her sudden and 
untimely death the Geological Society has lost a valuable official 
whom it will be difficult to replace. 


MISCHITLULANHOUS.- 


SCR FAUT 
Swingey Lecrures on Grotoey. 


The lectures for the years 1918-1919 will be given by Professor 
T. J. Jehu, M.D., F.R.S.E., at the Royal Society of Arts, John 
Street, Adelphia, W.C., on various days during the months of 
December, 1918, and January, 1919. The title chosen for the course 
is ‘‘ Man and his Ancestry ’’, and the published syllabus of the twelve 
lectures promises a comprehensive treatment of this important subject. 
Admission to the lectures free. 


Pe, isa ie anit se 


INDEX. 


DIRONDACK Intrusives, 525. 
Adirondacks, the Anorthosite 
Body in the, 525. 

Age of the Bolivian Andes, 838. 

Alkali Rocks in the Transvaal, Geology 
of, 225. 

Alkaline Felspar in Limestone, 135. 

Amalitsky, Vladimir Prochorovitch, 
Obituary of, 383, 431. 

Ammonites, Yorkshire Type, 547. 

Ananchytes quadratus, Occurrence ot 
the Zone of, 214. 

Andesite, Hypersthene, from Pitcullo, 
Fifeshire, 346. 

Andrews, C. W., A Visit to Christmas 
Island, 422; Fossil Mammals from 
Salonica and Imbros, 540. 

Anorthosites, the Problem of the, 
525. 

Antarctic Ice-cap, 553. 

Arber, HE. A. Newell, Submedullary 
Casts of Coal-measure Calamutes, 
212 ; Mesozoic Floras of New Zea- 
land, 516. 

Obituary of, 426. 

Artesian Waters of Australia, 177. 


Arthropods, Fossil, from Carboni- 
ferous, Nova Scotia, 462. 
Asterozoa, Paleozoic, 416. 
AKER, Herbert Arthur, Pre- 


Thanetian Erosion of Chalk, 
296, 422; Denudation of the Chalk, 
East Anglia, 412. 
Balsillie, D., Hypersthene Andesite, 
346. 
Baltic and Scandinavia, Recent Geo- 
logical History of, 354, 397, 451. 
Banks Peninsula, Geology of the, 
5B} |. 

Barberton Gold-mining District, 371. 

Bartrum, John A., Queries from New 
Zealand, 425. 

Basie Intrusions, Radnorshire, 500. 

Bather, F. A., Hocystis, 1. Hocystites 
primevus, Hartt, 49; Yunnan 
Cystidea, 507, 532. 

Beasley, H. C., Geological Collection, 
528. 

Belemnitella mucronata, Thickness of 
the Zone of, 350. 

Bell, Alfred, Suffolk Boxstones, 15. 


DECADE VI.—VOL. V.—NO. XII. 


| 
) 


Bennettitean 
taceous, 546. : 

Birmingham District, Geology of, 374. 

Blattoid and Insect Remains, South 
Staffordshire, 374. ‘ 

Bolton, H., Blattoid and Insect 
Remains, South Staffordshire, 374. 

Bolton, L. L., Iron-ore in Canada, 
377. 

Bouchardia (Brachiopoda) and Age of 
Seymour Island Beds, 258., : 

Boulenger, G. A., Eocene Lizards in 
France, 375. , 

Boulton, W.S8., Mammalian Remains, 
Stourbridge, 374. 

Bournemouth, Geology of the Country 
around, 220. 

Boswell, Professor P. G. H., British 
Supplies of Potash Felspar, 475 ; 
British Sands and Rocks used in 
Glass-making, 476. 

Bowen, N. L., Problem’ of 
Anorthosites, 525; 
Intrusives, 525. 

Boxstones, Suffolk, 15. 

Brachiopod genus Liothyrella, of 
Thomson, 73. 

Brachiopoda, Bouchardia, and Age of 
Seymour Island Beds, 258. 

British Museum Return, 474. 

Bromehead, C. N., Pre-Thanetian 
Erosion of the Chalk, 381. 

Brown, J. Coggin, Geology and Ore- 
deposits, Burma, 372. 

Brydone, R. M., Notes on Cretaceous 
Polyzoa, 1; New Chalk Polyzoa, 
97; ‘Thickness of the Zone of 
Belemnitella mucronata, 350. 

Buckman, 8. 8., Ammonites of York- 
shire Type, 547. 

Building and Ornamental Stones of 
Canada, 133. 

Burwash, EH. M. J., Geology of 
Vancouver and Vicinity, 550. 


Cones, British Cre- 


the 
Adirondack 


ALCITE Cleavage, 424. 
Camsell, Charles, Exploration of 
Tazin and Taltson Rivers, 478. 
Canadian Fuels, 549. 
Carboniferous Arthropods, 
Scotia, 462. 
Carboniferous Goniatites, British, New 
Genus and Species, 434. 


36 


Nova 


562 


Carter, William Lower, Obituary of, 
382. 

Chalk Foraminifera, W. Australia, 
83. 

Chilton, Charles, 
Crustacean, 277. 

Christmas Island, a Visit to, 422. 

Clays and Boulder-clays, Origin of, 
157. 

Coal in Spitsbergen, 529. 

““Coal-balls’’ near panera, Derby- 
shire, 471. 

Coal- boring at iBenstiatom, 47. 

Coal-fields of Eastern Canada, 31. 


Triassic Isopod 


Coal - measure Calamites, Sub- 
medullary Casts of, 212. 

Coal-seams, Splitting of, 477. 

Coralline Crag, Stratigraphical 


Position of, 409; (Erratum), 480. 
Corundum of Zoutpansberg, 549. 
Cox, Arthur Hubert, South Stafford- 

shire Fireclay, 56. 

Cretaceous Faunas, New Zealand, 226 
Flora of Russian Sakhalin, 516. 
Pelecypoda of Egypt, 37. 
Polyzoa, Notes on, 1. 
Theropodous Dinosaur, Gorgo- 

saurus, 519. 
Crustacean ‘Tracks, 

Tertiaries, 425. 
Cushing, H. P., Adirondack Intru- 

sives, 525. 

Cystidea, New Genus of, 49. 
Yunnan, 507, 532. 


New Zealand 


ATUM-LINES 
Keuper, 121, 
Davies, A. Morley, A Note on Isostasy, 
125: 
Deeley, R. M., Mountain Buiiding, 
111, 276. 
Denudation, of Chalk, East Anglia, 
412. 
Derbyshire, Occurrence of 
balls ’’ in, 471. 
Dewey, Henry, Origin of Land-forms 
in Caernarvonshire, 145. 
Distribution of British Carboniferous 
Goniatites, 434. 
Dolomitization and the Leicestershire 
Dolomites, 246. 
Drawings in Spanish Caves, 173. 
‘“Dry’’ Lakes in Western Australia, 
Rock-Cliffs and Floors of, 305. 
Dry Land in Geology, 333. 


in the English 


“* Coal- 


ARLY Man in America, 518. 
Kast Anglia, Stages in the 
Denudation of the Chalk in, 412. 
Echinoidea and their Allies, 4. 


Index. 


Economie Geology of the Central 
Coal-field of Scotland, 29. 

Edinburgh Geological Society, 42, 43, 
93, 143, 188, 525. 

Elles, Miss, & Wood, Miss (Mrs. 
Shakespeare), British Graptolites, 
416. 

Eminent Living Geologists : 
William Lamplugh, 337. 

Eocene Lizards in France, 375. 

Hocystis, I. Hocystites primevus, 
Hartt, 49. 

Erosion and Land Forms, Western 
Australia, 521. 

Pre-Thanetian, of the Chalk in 
the London Basin, 296, 381, 422. 
Eruptive Phenomena of Italian 

Voleanoes, 328. 

Etheridge, R., Leaves of Noeggerathi- 
opsis, Australia, 290. 

Evans, John William, Diagrams 
showing Rock Analysis, 422. 


George 


AULTS in the Californian Coast- 
range, 282. 

Fermor, L. L., Hollandite, Crystallo- 
eraphy of, 376. 

Fire-clays and Behaviour on Ignition, 
56. 

Flathead Coal Area, Geology of, 420. 

Flint Implements in Suffolk, 373. 

‘*Flint-meal’’ from the British Chalk, 
192. 

Flora of the Carboniferous of the 
Netherlands, 221. 

Folkestone Warren, 40. 

Foraminiferal and Nullipore Struc- 
tures, 203. 

Fossil Corals, New, from the Pacific 
Coast, 179. 

— Kchini of the Panama Canal 
Zone, 85. 

Insects, Colorado, 40. 

Mammals from Salonica and 

Imbros, 540. 

Man in South Africa, 128. 


AILLARD, Cl., Nouveau genre 
des Musaraignes, 376. 
Geikie, Sir Archibald, Memoir of John 
Michell, 517. 
James, the 
Geologist, 83. 
Genetic Classification of Underground 
Volatile Agents, 224. 

Geological History of the Baltic and 
Scandinavia, 354, 397, 451. 

—— Society of London, 45, 90, 136, 
179, 227, 284, 333, 377. 


Man and_- the 


Index. 


Geological Structure of the Forest of 
Dean, 23. 

Survey of Great Britain, 473; 

Summary of Progress, 28. 

of Canada, Department of 

Mines Report, 30. 

of Scotland, 30. 

Geologists’ Association, 46, 144. 

Geology of the Moonta and Wallaroo 

. Districts, 89. 

of North-Eastern Rajputana, 


175. 

of the South Wales Coalfield, 

174. 

of Transkei, South Africa, 135. 

— of Vancouver, 550. 

West Australian, Some Problems 

of, 477. ; 

Georgia, South, Petrography of, 483. 

Glacial Geology of Norfolk and 
Suffolk, 331. 

Glaciation, Pleistocene, of New Zea- 
land, 394. 

Glass-making, British Resources of 
Sands and Rocks used in, 476. 

Gorgosaurus, Cretaceous Theropodous 
Dinosaur, 519. 

Granular Ivon-ore, Buenos Ayres, 286. 

Graptolites, British, 416. ‘ 


ALL, A. L., Geology of the 
Barberton Gold-mining District, 
Byfale 

Hall, Richard, 336. 

Harmer, F. W., Glacial Geology of 
Norfolk and Suffolk, 331; Pliocene 
Mollusea, 416; The Stratigraphical 
Position of the Coralline Crag, 409. 

Haughton, S. H., Fossil Man in South 
Africa, 128. 

Hawkins, Herbert L., Echinoidea and 
their Allies, 4, 489; Occurrence 
of the zone of A. quadratus, 
214, 

Heterosorex delphinus, Gaillard, anew 
Insectivore, 376. 

Hewitt, W., Pebbles in their Geologi- 
cal Association, 557. 

Hind, Wheelton, British Carboni- 
ferous Goniatites, 434; Productus 
humerosus, 480. - 

Hinde, George Jennings, Obituary of, 
145,233: 

Holectypoida Echinoidea, 489. 

Hollandite, Crystallography, 
Nomenclature, 376. 

Homalonotus, Notes on the genus, 
263, 314. 

Homocline and Monocline, 227. 

Homeceomorphy, 39. 


and 


563 


Horses, Fossil, America; 518. 

Howorth, Sir Henry H., Geological 
History of the Baltic and Scandi- 
navia, 354, 397, 451. 

Hrdli¢ka, Ales, Early Manin America, 
518. 

Hurunui Valley, Structure and Glacial 
Features, 523. 

Hyena-den in Ireland, 127. 

Hypersthene Andesite from Pitcullo, 
Fifeshire, 346. 


CEH Age and Antarctic Research, 
129. 

Imperial Institute Map of Metals in 
British Empire, 543. 

Mineral Resources Bureau, 434. 

Insects, Fossil, in Coal-measures, 520. 

Tron, the Outlook for, 332. 

Iron-fields of Lorraine, 481. 

Iron-ore, Occurrences in Canada, 176, 
377. 

Isopod Crustacean, Triassic, Australia, 
277. 

Isostasy, a Note on, 125, 192, 233. 


ACKSON, Wilfred, New Brachiopod 
Genus, 73; Terebratula Grayi, 
479. 
Jeffreys, Harold, Causes of Mountain- 
building, 215, 380. 
Jehu, Professor T. J., Rock-boring 
Organisms in Coast Erosion, 520. 
Johns, Lieut. Graham, Obituary of, 
S2Ke 

Johnston, Robert Mackenzie, Obituary 
of, 288. 

Johnston-Lavis, H. J. 
Italian Voleanoes, 328. 

Jutson, J. T., Rock-Cliffs and Floors 
of ‘‘Dry’’ Lakes, W. Australia, 
305; Erosion and Land Forms, 
W. Australia, 521; Formation of 
“Natural Quarries’’, W. Australia, 
521. 


(the late), 


ALGOORLIE, Geological Fea- 
tures of the *‘ North End ’’, 225. 
Kaolin Veins, 79. 
Kendall, P. F., Splitting of Coal- 
seams, 477. 
Keuper, Datum-lines in English, 121. 
Kidston, R., and Jongmans, W. J., 
Flora of the Carboniferous of the 
Netherlands, 221. 
King, W. Wickham, Downtonian of 
S. Staffs, 374. 
Klondike District, Frozen Muckin, 479. 
Knipe, Henry Robert, Obittiary of, 432. 


564 


Kryshtofovich, A., Cretaceous Flora 
of Russian Sakhalin, 516. 
Kyson Monkey, the, 48. 


AMBE, Lawrence L., The Cre- 

L taceous Theropodous Dinosaur 
Gorgosaurus, 519. 

Lamplugh, George William, Eminent 
Living Geologist, 337. 

Land-forms in Caernarvonshire, Origin 
of, 145. 

Laterite in Western Australia, 385. 

Leaves of Noeggerathtopsis, Australia, 
290. 

Lebour, George Alexander Louis, 
Obituary of, 287. 

Leicestershire Dolomites and Dolo- 
mitization, 246. 

Lewis, W. J., Downtonian of S. Staffs, 
374. 5 

Lias of South Lincolnshire, 64, 101. 

Limestones of South Africa, 522. 

Lincolnshire, Lias of, 64, 101. 

Inothyrella of Thomson, 
Brachiopod Genus, 73. 

Liverpool Geological Society, 231, 526. 

Lorraine, Iron-fields of, 481. 

Ludlow Museum, 336. 


New 


ACKENZIEH, J. D., Geology of 
the Flathead Coal Area, 420. 
Maitland, A. Gibb, Problems of West 
Australian Geology, 477. 
Mammalian Remains, Glacial Gravels, 
Stourbridge, 374. 
Manson, Marsden, Ice Age and Ant- 
arctic Research, 129. 
Mesozoic Floras of Queensland, 516. 
of New Zealand, 516. 
Metals, Chief Sources of British 
Empire, 543. 
Metamorphism and its Phases, 223. 
Michell, John, and Martin Simpson, 
Pioneer Geologists, 131. 
Memoir of, 517. 
Mineral Industries of United States, 
281. 
Production of Canada, Report, 
Ottawa, 30. 
Resources of the British Empire, 


82. 


of Great Britain, 418. 

Bureau, Imperial, 433. 

Mineralogical Society, 44, 94, 230, 
380. 

Mineralogy of Black Lake Area, 
Quebec, 549. 

Minerals associated with Crystalline 
Limestone, California, 35. 

of Glamorgan, 40. 


Index. 


Minerals used in the Arts and In- 
dustries, Corundum, 373. : 

—. Graphite and Asbestos, 
420-1. § 

—— Maenesite, 548. 

Mining Operations of South Australia, 
33,178. 


of Thin Coal-seams, Canada, 


32. 

Mitchinson, the Rt. Rey. Bishop John, | 
Obituary of, 527. 

Moir, J. Reid, Flint Implements in 
Suffolk, 373. 

Monazite Sand Deposits of Travancore, 
Report, 38. 

Morphological Studies of the Hehi- 
noidea, 4, 489. 

Mountain-building, 111, 276, 380. 

Causes of, 215. 

Moysey, Captain Lewis, Obituary of, 
189. 

Musaraignes, Nouveau genres des, 
376. 


} EW Zealand, Igneous Rocks of, 
552. 

Newton, E. T., Exploration of Irish 
Caves, 127. 

Newton, R. Bullen, Foraminiferal and 
Nullipore Structures, 203. 

Jubilee of, 96. 

Noeggerathiopsis, Leaves of, Australia, 
290. 

Norite of the Sierra Leone, 21. 

Notes on new or imperfectly known 
Chalk Polyzoa, 97. 


AMARU, the Volcanic Rocks of, 
552. 
Obituary Notices: Amalitsky, Vladimir 


Prochorovitch, 3884, 431; -Arber, 
E. A. Newell, 426; Carter, 
William Lower, 382; Hinde, 


George Jennings, 146, 233; Johns, 
Lieut.. Graham, 527.; Johnston, 
Robert Mackenzie, 288; Knipe, 
Henry Robert, 432; Lebour, Pro- 
fessor George Alexander Louis, 287; 
Mitchinson, The Rt. Rev. Bishop 
John, 527 ; Moysey, Captain Lewis, 
189; Parker, William Albert, 95 ;. 
Seymour, Maude, 560; Watson, 
John, 383; Williams, Henry 
Shaler, 528; Williston, S. W., 559. 

Ordovician and Silurian Fossils from 
Yunnan, 330. 

Ore Deposits near Oda, Japan, 36. 

of Bawdwin Mines, Burma, 372. 

Origin of Clays and Boulder-clays, 
Malay States, 157. 


Index. 


Origin of some Land-forms in Caer- 
narvonshire, 145. 

Osborn, Henry Fairfield, American 
Fossil Horses, 518. 

Ossiferous Caves, Torquay, 548. 

Outlier in Valley of Rakaia, New 
Zealand, 551. 


ALA ONTOGRAPHICAL Society, 
416. 
Park, Professor James, Pleistocene 
Glaciation of New Zealand, 394. 
Parker, William A., Obituary of, 95. 
Parsons, L. M., Dolomitization and 
the Leicestershire Dolomites, 246; 
Productus hwmerosus, 559. 

Patagonian Geology, 376. 

Pebbles in their Geological Associa- 
tion, 5. 

Pecten-like Shell-fragments, 168. 

Pelecypod Shell-fragments (described 
as Cirripedes), 168. 

Permian of the Midlands, 232. 

Petrography of the Pacific Islands, 
281. 

of South Georgia, 483. 

Phosphates of Saldanha Bay, 133. 

Phylogeny and _ Classification of 
Reptiles, 374. 

Physiographic Significance of Laterite 
in W. Australia, 385. 

Pigeon Point, Minnesota, 282. 

Pleistocene Glaciation of New Zealand, 
394. 

Pliocene Mollusca, 416. 

Polyzoa, Cretaceous, Notes on, 1. 

New Chalk, 97. 

Potash Felspar, British Supplies of, 
475. 

Pre-Thanetian Erosion of Chalk in 
the London Basin, 296. 

Productus  humerosus, Canuvia- 
Seminula Horizon of, 480. 


eared coc of Canadian 

\ Mineral Springs, 222. 

Radnorshire, Basic Intrusions, 500. 

Rastall, R. H., The Genesis of the 
Tungsten Ores, 194, 241, 293, 367; 
Tron-fields of Lorraine, 481, 543. 

Reed, F. R. Cowper, Notes on the 
genus Homalonotus, 263, 314; 
Fossils from Yun-nan, 330. 

Report of Mines Branch, Department 
of Mines, Canada, 371. 

Reports on Mineral Resources of Great 
Britain, 377. 

Ripple-marks, Recent and Fossil, 33. 

Rock Analyses, Diagrams of, 422. 


565 


Rock-boring Organisms, Agents in 
Coast Erosion, 520. 

Rock-Cliffs and Floors of ‘‘Dry”’’ 
Lakes in W. Australia, 305. 

Royal Society of London, 41, 283. 

Ruitor Glacier Lakes, 551. 


ALONICA, Fossil Mammals from, 
540. 

Salts as Agents of Rock Weathering, 
W. Australia, 521. 

Sands used in Manufactures, 131. 

Scharff, R. F., Exploration of Irish 
Caves, 127. 

Serivenor, J. B., The Kaolin Veins, 
79; Origin of Clays and Boulder- 
clays, 157. 

Seymour, H. J., Exploration of Irish 
Caves, 127. 

Seymour, M., Obituary of, 560. 

Shand, Professor 8S. H., The Norite of 
the Sierra Leone, 21. 

Sherlock, R. L., Datum - lines in 
English Keuper, 121. 

& Smith, Reports on Mineral 
Resources of Great Britain, 377. 
Sibly, T. Franklin, Geological Structure 

of the Forest of Dean, 23. 

Sierra Leone, the Norite of the, 21. 

Simpson, Martin, a Yorkshire 
Geologist, 82. 

Swocystis, Species of, 532. 


Smith, H. G., Basie Intrusions, 
Radnorshire, 500. 
Societies and Museums, Work of 


Local, 474. 

South Staffordshire Fire-clays, 56. 

Speight, R., Geology of Banks 
Peninsula, 523; Structural and 
Glacial Features of the Hurunui 
Valley, 523. 

Spencer, W. K., Palzeozoie Asterozoa, 
416. 

Spitsbergen Coal, 529. 

Stopes, M. C., Bennettitean Cones, 
546. 

Stratigraphical Position of the Coral- 
line Crag, 409. 

Submedullary Casts of Coal-measure 
Calamites, 212. 

Subsidence Theory of Coral Reefs, a 
New Test of, 178. 

Suffolk Boxstones, 15. 

Swiney Lectures, 560. 


AZIN and Taltson Rivers, N.W. 
Territories, 478. 
Terebratula Grayi, Davidson, 479. 
Tertiary Beds of Castle Hill or Tre- 
lissick Basin, New Zealand, 551. 


566 


Tertiary Foraminiferal and Nullipore 
Structures, 203. 
Thomson, J. Allen, Bowchardia and 
Age of Seymour Island Beds, 258. 
Tillyard, R. J., Fossil Insects in 
Coal-measures, 520. 

Tin-fields, North Queensland, 34. 

Toit, A. L. du, Zones of the Karroo 
System, 421. 

Travancore, Geological Annual Re- 
port, 39. 

Triassic Isopod Crustacean, Australia, 
277. 

Tritylodon, 40. 

Trueman, A. H., Lias of South 
Lincolnshire, 64, 101. 

Tungsten Ores, the Genesis of, 194, 
241, 293, 367. 

Tyrrell, G. W., Petrography of South 
Georgia, 483. 

Tyrrell, J. B., Frozen Muck in 
Klondike District, 479. 


NIVERSITY College of Wales, 
Aberystwyth, 96. 


ANCOUVER and Vicinity, the 
Geology of, 550. 
Varney, W. D., Occurrence of Coal- 
balls, 471. 
Varro on Soils, 39. 
Veins of Kaolin, 79. 
Voleanic Studies in Many Lands, 86. 
Volcanoes, Active, of New Zealand, 
Q2ile 


AGNER, P. A., Minerals used in 
the Arts and Industries, 373, 
420, 421, 548. 
Waikonaiti Sandstones, Otago, 553. 


Index. 


Walkom, A. B., Mesozoic Floras of 


Queensland, 516. 

Watson, John, Obituary of, 383. 

Wealden and Purbeck Fishes, 416. 

White, H. J. Osborne, Geology of 

- Country around Bournemouth, 220. 

Wilcockson, W. H., Coal in Spits- 
bergen, 529. 

Williams, Henry Shaler, Obituary of, 
528. 

Williston, 8. W., Phylogeny and 
Classification of Reptiles, 374; 
Obituary of, 559. 

Windhausen, A. , Patagonian Geology, 
376. 


Withers, Thomas H., Pelecypod 
Shell-fragments described as Cirri- 
pedes, 168. 


Woodward, Dr. A. S., Wealden and 
Purbeck Fishes, 416. 

Woodward, Henry, Carboniferous 
Arthropods, Nova Scotia, 462. 

Woolnough, W. G., Laterite in 
Western Australia, 385. 

Worm-borings in Rocks, 46. 


ye Cystidea, 507, 532. 


INC-ORES, Imperial Institute 
Monograph, 522. 
Zone of Ananchytes quadratus in 
Berks, 214. 


of Belemnitella mucronata, 


350. 

Zones of the Karroo System and their 
Distribution, 421. 

Zoological Society of London, 285. 


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