THE

QUARTERLY JOURNAL

OF TIIE

GEOLOGICAL SOCIETY OF LONDON.

EDITED BY

THE ASSISTANT-SECRETARY OF THE GEOLOGICAL SOCIETY.

Quod si cui mortalium cordi et curve sit non tantum inventis hmrere, atque iis uti, sed: ad:ulteriora penetrate ; atque non disputando adversarium, sed opere naturam vincere ; denique.~non belle et:'probabiliter epinari, sed certo et osteusive scire ; tales, tanquam veri scientiarum fllii, nobis (si videbitur)~se adjunga~at. --Novura Organum, Pr~fatio.

V O L U M E THE SIXTY-FIFTH.

1909.

LONDON :

LONGMANS, GREEN, AND CO. P A R I S : C H A R L E S K L I N C K S I E C K , II R U E D E LILLF..

SOLD ALSO AT T H E A P A R T M E N T S OF T H E SOCIETY.

MDCCCCIX

OF TI lE

O F F I C _ E R S OF T I I E

GEOLOGICAL SOCIETY OF LONDON.

Elected February 19th, 1909.

tOrt~i~tnt.

Prof. William Johnson Sollas, LL.D., Se.D., F.R.S.

~ict,~rt~i~tnt~. George William Lalnplugh, :F.R.S. ~ J. J. Harris Teall, M.A., D.Sc., F.R.S. Horace Woollaston Monekton, Treas.L.S. P r o f . William Whitehead Watts, So.:D.,

i M.Se., F.R.S.

~ttrttarit~. :Prof. Edmund Johnston Garwood, M:.A. I Arthur Slnith Woodward, LL.D., F.R.S.

.$F'ordgn ~ttrttar12. ~ r t a ~ u r t r , Sir Archibald Geikie,K.C.B.,:D.C.L.,LL.D., ' ,~ubrey Strahan, Sc.D., F.R.S.

Se.D., Pres.R.S.

Charles William Andrews, B.A., D.Sc., Richard :Dixon Oldham. F.R.S.

George Barrow. Prof. William S. Boulto,1, B.Sc. Prof. SamuelHerbert Cox, F.C.S.,A.R.S.M. Prof Edmund Johnston Garwood, M.A. Sir Archibald Geikie, K.C.B., :D.C.L.,

LL.D., Sc.D., Pres.R.S. Alfred Harker, M.A., F.R.S. Robert Stansfield Herries, M.A. Finlay Lorimer Kitchin, M.A., Ph.D. George William Lamplugh, F.R.S. John Edward Marr, Sc.D., F.R.S. Horace Woollaston Monekton, Treas.L.S.

George Thnrland Prior, M.A., D.Se. Prof. Sidney IIugh Reynolds, M.A. Prof.Willialn Johnson Sollas, LL.D.,Se.D.,

F.R.S. Aubrey Strahan, Sc.D., F.R.S. J. J. Harris Teall, M.A., D.Sc., F.R.S. l~ichard Hill Tiddeman, M.A. Prof. William Whitehead Watts, Sc.D.,

M.Sc., F.R.S. Henry Woods, M'.A. Arthur Smith Woodward, LL.D., F.R.S.,

F.L.S. George William Young.

~ i ~ t a n t , ~ c r t t a r ~ , Cltda, Y.ibrarian, an~ ~urator. L. L. Belinfante, M.Se.

W. Rupert Jones. Clyde H. Black. Arthur Grelg.

STANDING PU~BLICATIOlq COMMITTEE. Prof. ~V. J. Sollas, President.

Prof. E. J. Garwood, ~ Secretaries. Dr. A. Smith Woodward, J

Dr. C. W. Andrews. Mr. G. W. Lamplugh. Prof. S. H. Cox. Dr. J. E. Marr. Sir Archibald Geikie. Dr. G. T. Prior. Mr. A. Harker. :Dr. A. Strahan. Mr. R. S. Herries. Prof. W. W. Watls. Dr. F. L. Kitchin. Mr. H. Woods.

TABLE OF CONTENTS.

Page 2~-RBER, E..~k. NEWELL. On the Fossil Plants of the XValdershare

and Fredville Series of the Kent Coalfield (Plate I) . . . . . . . . . . 21

BAILEY, EDWARD :BATTERSBY (& C. T. CLOUGH, & H. B. 3IAuFE). The Cauldron-Subsidence of Glen Coe, and the Associated Igneous Phenomena (Plates XXXII-XXXIV) . . . . . . . . . . . . . . 611

]3EADNELL, H. J. LLEWELLYN'. The Relations of the Nubian Sand- stone and the Crystalline Rocks south of the Oasis of Kharg~ b Egypt (Plate II) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

CARUS-~VILSON, CECIL. The Pitting of Flint-Surfaces . . . . . . . . . . 462

CLINCH, GEORGE. On the Sculptures of the Chalk Downs in Kent, SUrrey, and Sussex . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208

CLOUGIt, CHARLES THO~tAS (& H. B. MAUFE, & E. ]3. BAILEY). The Cauldron-Subsidence of G]en Coe, and the Associated Igneous Phenomena (Plates XXXII-XXXIV) . . . . . . . . . . . . . . 611

CODRINGTON, THO.~IAS. Some Notes on the Neighbourhood of the Victoria Falls (Rhodesia) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390

COLLINS, JOSEPH ItENRY. Note oil some Geological Features observable at the Carpalla China-Clay Pit in the P~rish of St. Stephen's, Cornwall (Plate VII) . . . . . . . . . . . . . . . . . . . . . . 155

.DAvIs, Prof. WILLIAM MORRIS. Gl,einl Ero,qion ill North Wales (Plate XIV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281

DEWEY, HENRY. On Overthrusts at Tintagel, Nolth Cornwall (Plate XIII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265

DOUGLAS, JA.~IES ARCHIBALD. The Carboniferous Limestone of County Clare, Ireland (Plates XXVI & XXVII) . . . . . . . . . . . . 538

DWERRYHOUSE, ARTHUR RICHARD. On some Intrusive Rocl~s in the Neighbourhood of Eskdale, Cumberland (Plate III) .. . . . . . 55

ELLES, Miss GERTRUDE L. The Relation of the Ordovician and Silurian Rocks of Conway, North Wales (Plate VIII) . . . . . . . . 169

ELSDEN, JAMES VINCENT. On the Geology of the Neighbourhood of Seaford (Sussex) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442

~EARNSIDES, WILLIAM GEORGE (& J. E MARR). The Howgill Fells and their Topoga-aphy (Plates XXVIII-XXXI) . . . . . . . . 587

a 2

iv" TABLE OF CONTE~'IiS.

Page FINLAYsON~ ALEXANDEa 5[ONCIIIFFF. The Nephrite and 3[a~nesian

l:toc]~s of the South Island of New Zealand (Plates XV & XV[). 351

GARDINF.R, CHARLES Irtvl.~G (& S. H. ]~EX'NOLDS). On the Igneous and Associated Sedimentary Rocks of the Tourmakeadv Dis- trict, County 3[ayo (Plates IV-VI) . . . . . . . . . . . . . . . . . . . . . . 104=

GLAt~EI~T~ LrDWIG. A New Species of Sthenuru~,' . . . . . . . . . . . . . . 462

Jo.,,'Es, OWE.'," T~o.~rxs. The IIartfell-Valentian Succession in the District around Plvnlimon and Pont Erwyd, ~-orth Cardigan- shire (Plates XXI~ ' -XX\) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463

�9 II~KES-BROWNE, ALFRED JOHN. The Depth and Suceessi~,n of the Bovey Deposits (Devon) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162

KENDALL, lieD. IIEx1~Y GEOR~I.: OMMANNEY. l'aheolithic Instru- ments, etc. from Ilaekpeu Hill, \Vinterbourne Bassett, ,and Knowle Farm Pit (Wiltshire) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166

LON6ST,tFF (DONALD), Mrs. JANE. On the Genus/,o.t'o~ema, with Descriptions of_New Proterozoic Species (Plates X & XI) . . . . 210

MARI~, JOHN EDWARD (& ~V. G. FEAI1NSIDI.:S). The IIowgill Fells and their Topography (Plates XXVIII -XXXI) . . . . . . . . . . . . 587

MARTIN, EDWARD ALFRED. Some Recent Observations on the Brighton Cliff-Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206

MAUFE, HEI~B]':IIT B1RANI"W00D (& C. T. CLOUGH, & E. B. BA~L~:Y). The Cauldron-Subsidence of Glen Coe, and the Associated Igneou~ Phenomena (Plates XXXI[-XXX[V) . . . . . . . . . . . . . . 611'

MOLYNI,:UX, ARTHt'R JOItN CHAI~LES. On the Karroo System in Northern ]lhodesia, and its 1'elation to the General Geology (Plates XVII-XXIII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408

0LDHAM, RICHAI~D DIXON. The Geological Interpretation of the Earth-Movements associated with the Californian Earthquake of April 18th, 1906 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

RAs'rALL, ROBERT HEllO=X- (& J. I{OMANES). On the Boulders r,t" tl!e Cambridge Drift : their Distribution and Origin . . . . . . . . . . o46

REED, FRED]':nlCK ~ICHAnD C0WrEIt. [On the Fauna of the Tourmakeadv P~ocks7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

I~EYNOLDS, Prof. SIDNEY IIUGtI (& C. I. GARDINEIQ. On the Igneous and Associated Sedimentary Rocks of the Tourmakeadv District, County Mayo (Plates 1V-'VI) . . . . . . . . . . . . . . . . . . . . 104

RO:MANES, JAMES (& 1~. ~II. IIASTALL). On the Boulders of the Cambl~,dge Drift: their Distribution and Orion . . . . . . . . . . . . 246

ScItlw,:Noa, JO~N B~oo~n~. The Lahat ' Pipe ' : a Description of Tin-01'e Deposit in Perak (Federated Malay States) . . . . . . . . 382

TABLE OF CONTENTS. V

l't~ge STOPnS, Miss MxnlV: C. Plant-containing Nodules from Japan,

considered structurally in their Relat ion to the ~ Coal-Bal ls ' and ' Root :Nodules ' of the European Carboniferous (Plate IX). ] 95

THO_~rAs, H E n I ~ n T HENRY. A Cont~fibution to the Pet rography of the New Red Sandstone in the West of England (Plate X I I ) . . 229

VOGT. Prof. JOI~A.x II. L. On Labradorite-Norite with Porphyri t ic I~abradorite Crystals: a Contribution to the S tudy of the~Gab - broidal Eutecti~c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

WATSON, D. M . S . On some Reptil ian Remains from the Trias of Lossiemouth (Elgin) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440

- - . On some Repti l ian Tracks from the Tria~ of l~meorn (Cheshire) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440

On the Ana tomy of Lepidophloios laricinus, Sternb . . . . . . . 44I

P R O C E E D I N G S .

Proceedings of the Meetings i, cxxiii

Annual Repor t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Lists of Donors to the Library . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

List of Foreign Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv

List of Foreign CorrespondCmt~ . . . . . . . . . . . . . . . . . . . . . . . . . xxv

List of Wollaston Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvi

Lis t of Murchison Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxviii

Lis t of Lyel l Medallis.ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxx

Lis t of Bigsby Medallists and of Pres twich Medallists . . . . . . . . xxxii

Applications of the Barlow-Jameson Fund and Awards of the Daniel Pidgeon Fund . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiii

Financial Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiv

Award of the Medals and Proceeds of Funds . . . . . . . . . . . . . . . xli

Anniversary Address of the President . . . . . . . . . . . . . . . . . . . . . . 1

Special General Meeting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv~ viii

SKOTTSBERG, Dr. C~nL. t IOn the Geolog.y of the Fa lk land islands] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

S.~IIT~I, Dr. G. F. IIFRBERT. [On Refractometers] . . . . . . . . . . cxxix

~VHITA~ZEI~, WILLIAMS. t on Arrested Pseudomorphs of Salt Crystals] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

LIST OF THE FOSSILS FIGURED A N D DESCRIBED

IN THIS VOLUME.

N a m e of Species. F o r m a t i o n . I Local i ty . I Pago

"EQuISETALES.

Annulari~ spheuoplq/[loitles, ]Upper Transi- [ [ Fredville and i 25 pl. i, fig. 1 . . . . . . . . . . . . . . . . . . . . . t ion Series I

Calamites cf. ci~ti . . . . . . . . . . . . . . . ) (Carboniferous) .[ "Waldershare . 24

SPIIENOPIIYLLALESo

'{Upper T r a n s i - [ F r e d v i l l e a n d } Spheno]~hgllum cuneifoli~m~ ... t ion Series

" . (Carboniferous) [ W a l d e r s h a r e . 25

~ILICALES ~ PTERIDOSPERME.Eo

Eremopteris el. artemesi~.folia. Mariopteri~ qnuricala, var.

~ervosa, pl. i, fig. 6 . . . . . . . 3-europteris obliqua, pl. i, fig. ;3.

rarinervis, pl. i, fig. 2 ... sche~whzeri ...............

- - teuu~fol~, pl. i. fig. 7 . . Odontopteris lb~dlejana, pl. J

fig. 4 . . . . . . . . . . . . . . . . . . . . . . . . . Sphenopteris ~zearol)teroide,~.

pl. i, fig. 8 . . . . . . . . . . . . . . . . . . . . .

t

i U p p e r Trans i - ' F redv i l l e and

t ion Series -( W a l d e r s h a r c . . C a r b o n i f e r o u s , ,

28 26

n 2(; 26 26

_~

i ,o9

LYcoro~)iAcr~e.

Lepidophloios laricinus ......... I Coal Measures . . [ Lancash i r e . . . . . . I 441

SE3IINA INCERT2E SEDIS.

Cardiocarpus acidly:s, pl. i . ( U p p e r Trans i - I F r e d v i l l e a n d t ion Series

fig. 5 . . . . . . . . . . . . . . . . i . . . . . . . . . . / (Carboniferous) . } W a l d e r s h a r e . I 2 9 - 3 0

FOSSILS FIGURED AI~D DESCRIBED. v i i

:Name of Species. F o r m a t i o n . I Local i ty . i Page

I~ADIOLARIA. ll . . . . . . 'f 111, Rhodosph~'a ~), fig. 4 . . . . . . . . . "~ M o u n t y a r t r y : Sponyosphmra hqtes?aeea (?),'~ Beds ,P., . Tou rn , akeady !

ag . 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . ! . . . . . . .

~RAPTOLITOI DEA.

fig. 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . Rheidol G r o u p . P o n t E r w y d 531-33 rheidolensi.r sp. nov..

fig. 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . j 535

Campophyllum pl. xxvii, fig. 8 . . . . . . . . . . . . . . .

sp., pl. xxvii, fig. 10 . . . . . . Caninia cor~ucoTke , pl. xxvii ,

fig. 14 . . . . . . . . . . . . . . . . . . . . . . . . . . aft. cornucopi~e, pl. xxvii,

fig. 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . Carcinophyllum sp., pl. xxvii,

fig. 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . Densiphyllum sp., pl. xxvii,

fig. 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . Dilmnophyllum aft. ~, pl. xxvii,

fig. 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . I 1)iphyphyllum aft: subibi-

cinum, pl. xxvii, fig. 13 . . . . . . Litho~trotion, Clis iophyl l id ,

pl. xxvii, fig. 3 . . . . . . . . . . . . . . . .Nematophpllum ~inus, p l.

xxvii, figs. 1 & 2 a - 2 b . . . . . . Zaphrenlis omaliusi var. de nsa,

pl. xxvii, fig. 9 . . . . . . . . . . . . . . . vavghani, sp. coy., pl:

xxvii, fig. 11 . . . . . . . . . . . . . . . . . . sp., pI. xxvii, fig. 4 . . . . . . )

MADREPORARIA RUGOSA.

cylindricum, ] : (

Ca rbon i ferous Limes tone ...

Coun ty Clare ...

( 578 579

579

579

581-82

578

581

580

581

580

I 1576

577 i,577

TRILOBITA.

Acidaspis (?) sp., pl. vi, fig. 8. '1 Apatoeephalus( 0 Sl)., pl. vi,i I

fig. 9 . . . . . . . . . . . . . . . . . . . . . . . . . . I Cybele connemariea, sp. nov.,' t

pl. vi, figs. 6 & 7 E~crinurus sp . . . . . . . . . . . . . . . . . . ', II&enus aft. chudleighensis ... 1 - - weaveri, sp. nov., pl. v i ; t T o u r m a k e a d y

figs. l a - l c , 2 , & 3 . . . . . . . . . ! ( Beds . . . . . . . . Pliomera aft. 5arrandei, pl. vi , /

fig. 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . - - - aft. fischeri, pl. , i , fig. 4. i ]

el. vi, figs 10 & 71 . . . . 1 )

T o u r m a k e a d y d is t r ic t . . . . . .

( '148

i 148-49

146-47 147

I m 142-44

145-46 144--45

t 1 4 9 - ~

. ~ V l l l F O S S I L S F I G U R E D A N D D E S C R I B E D .

:Name of Species. ] Format ion . Local i ty . P a g o

Acrotre{a (?) hibe~'Mca, sp.' nov., pl. vi, figs. 13 a - 1 3 c .

A/h!lris glabris&i, , pl. xxvi, fig. 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . '

hibernica, nora. nov., pl . xxvi, fig. 5 . . . . . . . . . . . . . . . ,

lamellosa, pl. xxvi, fig. 4 . Dielasma aft. ki~.qi, pl. xxvi, Sprig. 3 . . . . . . . . . . . . . . . . . . . . . . . . . . .

irifer aglcn.uagus, pl. xxvi. fig. 7 . . . . . . . . . . . . . . . . . . . . . . . . . . .

- - aft. claghragus, pl. xxvi, fig. 6 . . . . . . . . . . . . . . . . . . . . . . . . . . .

konineki, sp. nov., pl. xxvi, figs. l a & l b . . . . . . . . . . . . . . . . . .

Slreptis aj~nis, sp. nov., pl. vi. figs. 1 4 a & 141) . . . . . . . . . . . . . . .

] 3 R X C I I I O P O D A .

Tonr]nakead v B e d s . . . . . . . . . T o u r m a k e a d y . . ~ 150-51

( / 572

573 573

Carbonifer~ms L imes tone . . . .~ Comi ty C la re . . . -{ 571-72

I 574 J i 574

I 574-76 T( ,u rmakeady

Beds . . . . . . . . . Tou r ,nakeady . . . 151-39.

G A STERO P 0 I)A.

Hormotoma inceplor, sp. nov. , L l a n d e i i o F l a g s . Bui l th Br idge . pl . xi , f ig. 10 . . . . . . . . . . . . . . . . .

Zoxonema cornubicum, sp. | Midd le f South i nov., pl. x, figs. 2 a & 2 b . . . ( Devonian .. ~ I ' e the rwin "-'i

~ - g r a y i a n u m , sp. nov., L o w e r pl. xi, fig. 5 . . . . . . . . . . . . . . . . . . L l a n d o v e r y . . . Mul lock I l i l l i

-- intume~ccns(!), pl. x, ' fig. 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . [ L e d b u r y . . . . . . . . .

~ Stoke "Wood latouchei, sp. nov., pl. x, ~Lower Lud low. figs. 4 a & 4 b . . . . . . . . . . . . . . . . . . . ~ Q u a r r y . . . . . .

ledburiense, sp. nov., i pl. x, figs. 5 a & 5b . . . . . . . . . . Ledbury . . . . . . . .

- . perneri, sp. nor. , !)1. xi, U p p e r L u d l o w . fig. 1 . . . . . . . . . . . . . . . . . . . . . . . . . . .

- - - - , var. dud~e!/elzsc,} nov., pl. xi, figs. 2 & 3 . . . . . . L o w e r L u d l o w .

- - Tlanatum, sp. nov., pl. x, ] figs. 6 a & 6 b . . . . . . . . . . . . . . . . . . f Wen loek . . . . . . . . .

i

227

216-17 I

222

217 -18

218 -19

219

L u d l o w . . . . . . . . ; 221

reedi, sp. nov. , pl. x i , ~ U p p e r Ba la f igs . 4 a & 4 b . . . . . . . . . . . . . . . . . . ~ "'"

sinuosum, pl. x, figs. 1 a ] & 1 b . . . . . . . . . . . . . . . . . . . . . . . . . . . j L o w e r Lud low.

_l?habdostropha grindrodi . . . . . . pseudofasciata, pl. xi, / V(enlock Shale.

f ig. 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . (

stokei, sp. nov., pl, xi, ~ L o w e r Lud low. fig. 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . J

Slylonema (?) hibernieum, sp. ~ U p p e r Bala nov., pl. xi, fig. 8 . [ J

o a 4

c:~ p,.~,~,.;,,,,,, "i~iiiJ.i T.o~e,. pl. xi, fig. 9 . . . . . . i t L landovery .

( L e d b u r y T u n n e l ] & I )udlev ...~ 221-2"2

Garcoed, U.-k.. .! 220-21

{ Chai r of K i lda re . . . . . . . 222- '23

L e d b u r y . . . . . . . . . ' 224

D u d l e y I 224-25 . . . . . . . . . i

( U n d e r Stoke E 1 W o o d . . . . . . . . . 225 f Cha i r of 226 ] K i l d a r e . . . . . . :

Muliock II i l l ...! '226

~REPTILIA .

Or~.ithosuchus woodwardi . . . . . . ] Trias . . . . . . . . . . . . I Loss iemouth ...I 440

EXPLANATION OF THE PLATES.

PL.~TE PACE CARnOXIFEROUS PLANTS FnOM ](EST, to iUustrate ]

I Mr. E. A. Newell Arber's paper on the Fossil [ 21 Plants ,ff the XValdershare and Fredvil le Series of tile Kent Coalfield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

/GEoLoGICAL ~[AP OF TIlE LIBYAN DESEaT SOUTII OF '1 Tile OAsiS OV KuAImA, to illustrate Mr. I t . J . L1. ]

I I ~ Beadnell 's paper oil tile Relat ions of tile N u b i l e ~- 4 l S:mdstone and the Crystalii~le Rocks in that t area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . )

~[ICROS(OPE-SECTIONS OF IGNEOUS ]{OCK~ FROM I I I ESK0),LE, tO ilhlst.rate Dr. A. 1L D~'erryhouse's j. 55

paper on those rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

/GEoLOGICAb ~IAP OF TIIE TOUI{MXKEADY DISTItICT'~ I (Cou.~TV MAYo); and MICR0SCOPE-SECT[O.~S OF I t ]{~OCI{.S FROM TorR.~iAKE.~DZ, to illustrate the !

paper by Mr. C. I. Gardiner and Prof. S. It. ~ 10i t Reynold's on the Igneous and Associated Sedi- I

ntentary Rocks of that area . . . . . . . . . . . . . . . . . . . . . . . )

PAt.EgZOI(' FOSSILS Flr TOUR.~I.XKI~.~DY, to illus- ] u Irate Mr. F. R. C. Reecl's description of those ~ 14l

fossils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . )

+VInw OF CAI~PAI, LA CIIINX-CL.~.Y ].)IT, SIIOWINO TIIE~ r~OURMALINE-ScIIIST t OVERBURDEN ' RESTING UPON I

V i i ~ CIIINA-CLA.Y R')CK, to ilhlstrate Mr. J. H. Col- ~- 155 liEN'S paper on the Geological Features obsecv-I able in that pig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . . )

( GEOLOCdCAL MAl' OV CON~VAY, to illustrate Miss G. "l V I I I L. ElleN's paper on the Relation of the Ordo- I. 169

vician and Silurian Rocks of that neighbourhood. J

/ ~r - SECTIONS OF PLANT - CONTAINING 1 I X ~ NOI)Ut,ES Fl[O~I JAPAN, to i l lustrate Miss M.C.~ , 195

( Stopes's paper err the StrueLure of those Nodules. j

X & XI { LoxoxE.ua, to illustrate Mrs. J . LongstatFs paper "( 210 on that genus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J

" ~[INERALS PROM TIlE ~'EW RED SANDSTONE, ETC., t o ] X I [ ~ illustrate Mr. H. If. Tiloluas's 1)zper o'1 the 229

t Pet rography of that formation . . . . . . . . . . . . . . . . . . . . . ]

{ GEOLOGICAL .~t[AP OF A PORTION OF ~'ORTII CORN- ] X l I I W~LL, to illustrate Mr. H. Dewey's paper on } 265

Orer thrusts at Tintagel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . j

[ SKETCII-MA.P OF TIlE SNOWDON DISTRICT, to illustrate j X I V ~ Prof. W. M. Davis's paper on Glacial Erosion t 251

in North Wales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ) I

I V & V

EXPLANATION OF THE PLATES.

PLATE PAG E"

(~ICRO$COPE-SECTIONS OF :RocKs FROM TIlE SOUTII

XVI J ISLAND OP INEw ZE,L , t ,XD, to ilhlstrate Mr. A. M. XV & , ] Finlayson's paper on the ~Nephrite and Magnesian 351.

~, Rocks of that island . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

(~/.[AP S/lOWING AREAS OF TIlE ]kARRO0 SYSTEM IN ] ~'ORTilERN ~HODESIA ; CONGLOMERATE, CIIIGONA [

CREEK : DISINTEGRATED CONGLOMERATE~ FORMING THE ]~OOTIIILLS WEST OP ]~AKANUNGA CREEK; CONGLOMERATE IN r'LA('E ON TIll~ SOUTHERN FOOTHILLS OF LUPOPOSnWE ; ~BAsAL CLAYS

XVII-XXIII.~ AND 5"ODULAR IRONSTONES OVERLAIN BY COAL ~" 408 ~'IEASURES, MOLONGUSIII RIVER; YIEW OF TILE! MAL~)IBI S'rI~'CL1NE ; and FALLEN ]~LOCK IN E:tK. iNrNG,X CREEK, to illustrate Mr. A. J. O. Molyneux's paper on tile Karroo System in

I iNorthern Rhodesia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . )

( GEoLO(;I(',Xl, MAr" oP TIIE 1)LYNLI.~ION AND 1)ONT~ Eitwvn DISTRICT; and PLAX or' TIIE RIIEIDOL I

XX1V& XXV'~ GO,~6E gETWEEN P0.XT ERwYr~ AsI~ PARSON'S 463. BRI~e;E, to ithtstrate Mr. O. T. Jones's paper on i

I the lTartfell-Valentian Succession in the above-I I luentioned district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ,}

('AvolgL~,s Bl:.~,CiliOPOl~S : and AVOXIAN CORALS, FRO.~K] COI:~TY CLARE. to illustrate Mr. J. A. Douglas's ~_ XXVI &

X X Y I I | paper on the CarbonHerous Limestone o f - t h a t | 538.

k. cotmt3 �9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

(VIEW OF TIIE HOWGILL ~FELLS FRO3[ ASII FELL; I i ~,I,Xr" Or ThE RIVEr, S OV TIlE HO~','6ILI, FELI, S; I I MAP OF TIIE GLA('IERS OP TIlE HOWGILL FmLLS; [ I and SECTIONS SIIOWI,~G TIlE '])IIALWEG OP TIIE J

X X V I I I - X X X I ~ BEUEADEI~ ARTLEGARTIIDALE ~ ITS TRIBUTARY }- 587+ l V-ALLEYS, and ALONG TIlE 'Ii~'ATERSIIEDDING ~INI~ t WEST Or BOWDERDALE, to illustrate the paper by I Dr. J. E. Marr & Mr. W. G. Fearnsides on the [ Howgill Fells and their Topography . . . . . . . . . . . . . . .

( V I E w OF COIRE NAM BEITII. GLEN COE ; HORIZONTAl+ + SECTIONS TIIROUGII TIIE CAL+LI)RON-SuBsIDENCE OF I i I GLEN COE ; and CONTOURED GI~:OLOGICAL MAP OI,' ~. 61[

X X X I I - X X X I V ~ GLEN Coz, to illustrale the paper by Messrs. C. 1 T. Clougb, H. B. Maufe. & E. B. Bailey on the ( ~ Cauldron-Subsidence of that area . . . . . . . . . . . . . . . . . . )

FOLDING TABLES. PAGE

Table illustrating the Correlation of the Ordovieian and Silurian Rocks of Conway with those of other British areas, facing ...... 190

I. Correlation of tile :North Cardiganshire :Rocks with their Equiva- lents in other parts of Britain, facing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530

l I . Occurrence and :Range of the Graptolites in the Hartfell-Valentian Succession, facing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530'

P R O C E S S - B L O C K S A~ 'D O T H E R I L L U S T R A T I V E F I G U R E S ~

BESIDES THOSE IN THE PLATES.

2.

3.

4 & 5 .

Fro. Pt, GF~

1. Yariation of the vertical under the influence of the moon ... l m v i i

2. [Map showing isochlora in ~'orthern U.S.A.] . . . . . . . . . . . . . . . . . . xeviii

1. Map showing the course of the San Audreas :Fault and its eontinuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Diagram of displacements along the San Andreas Fault . . . . . . 4

Diagram showing couples and shearing stresses . . . . . . . . . . . . . . . . . . 9'

Two views of a model constructed to illustrate the displace- ments caused by the Californian earthquake . . . . . . . . . . . . . . . . . . 10

1. Summit of granite boss, 47�89 kilometres S. of Beris (Kharga Oasis) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

2. Plan and section of Exposure E, 61�89 kilolnetres S. of Beris ... 45

3. Junction of ~'ubian Sandstone and crystalline rocks at the same locality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

4. Plan of Exposure :F, 48~ kilometres S.S.E. of Beris . . . . . . . . . . . . 47

5. Plan and section of eentrodinal fold. 47 kilometres S.S.W. of Beris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

6. Part of the eentroclinal fold in the same locality . . . . . . . . . . . . . . . 50

1. Section from Wastwater to the Woolpack in Eskdale . . . . . . . . . . . . 60

2. Section from Easthwaite to Boot in Eskdale . . . . . . . . . . . . . . . . . . . . . 60

3. Junction-breccia near Stony Tam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

4. Hand-specimen of the same . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

5. Map showing the dykes and other intrusions near Peers Gill . 72

Xii PROCI-;SS-I;I.OCKS AND 0TIIER ILLUSTRATIVE FIGURES.

Ft~. X~Ao~ 6. Map showing the dykes on Kirk Fell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

1. Polished section of the coarse-grained 1)orohy1"itic labradorige- norite of Napp Farm. Flakstad6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

2a & 2b. [Diagram~ illustrati~g order of crystallization of minerals] ... 93

3. Do. do.

4. I)o. do,

5 & 6. 3)o. do.

7. Do. do,

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 ~

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0 0

1. Plan of part of Treanlaur stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

2. Section extending W.N.W, fl'om St. 3[ary's Monastery . . . . . . . . . 110

;3. Section a quarter of a mile N. of Drumcoggy lgeetory . . . . . . . . . 110

4. Sketches of radiolaria fl'om the cherts of the upper part of Stream C, W. of Oortanalderg, Tourmakeady . . . . . . . . . . . . . . . . . . 11:2

5. Section S. of Shangort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

6. Section .N-.W. from Shangort . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

7. Limestone breccia tieal" the upper part of Stream F . . . . . . . . . . . . 1:20

8. Limestone breccia from the same locality . . . . . . . . . . . . . . . . . . . . . . . . . . . 1:20

9. Limestone breccia from the lower part of Stream ~' . . . . . . . . . . . . 1:22

l . , , Sketch-plan of the Carpalla clay-pit and its immediate sur- roundings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156

'2. Section of tig. 1 along a line ~ short distance ~V. of the railway 157

Section across the middle of the ]3ovey ]lasin . . . . . . . . . . . . . . . . . . . . . 163

1. Section of the \V. end of Co:~way 5Iountain . . . . . . . . . . . . . . . . . . . . . 171:

2. Section of the Bodlondeb Ash Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

~. Section through the Deganwy tIills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

4. Section in Cuuuay railway-cutting . . . . . . . . . . . . . . . . . . . . . . . . 178

5. Section in Deganwy Quarry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 8 4

Sketch-map of the Cambridge district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251

1. Section fl'om the coast at West Quarry, through Treknow Valley to Trewarmett Lane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268

2. Section from IIigher Penhallie Point, through ~.'reven . . . . . . . . . 268

3. Section from Tinlagel Island across Treren~ Valley . . . . . . . . . . . . 270

X~IG~

4.

5.

6.

1.

2.

3.

17.

18 & 19.

20.

22.

23.

24 & 2.5.

. ,~ PROCESS-BLOCKS AND OTHEIt ILLUSTRATIVE FIGURES. X l l l

~AGE

Sectioq fi'om :Barras ~'ose through Trevena Valley. . . . . . . . . . . . . . . . 270

Tintagel Island, seen from the S.E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274

:Barras ~Nose, seen from the S.W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276.

Diagram of two cycles of erosion in Devon . . . . . . . . . . . . . . . . . . . . . . . . '29'2

:Diagram of normal subdued mountains . . . . . . . . . . . . . . . . . . . . . . . . . . . 294

Diagram of a cwm in a subdued mountain, based on a sketch of Cwm Du in Mynydd-mawr, looking southwards . . . . . . . . . . . . 296

4. Diagram of a young main valley, with normal hanging lateral valleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299

5. Diagram of a mature main valley, with accordant lateral valleys 299

6. Diagram of the pro-Glacial features of the Snowdon mass . . . . . . 307

7. Diagram of tile present features of the Snowdon mass . " 308

8. Diagram of protective glaciers in the valleys of a subdued mountain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308

9. Diagram of the effects of normal erosion on tim previous figure 30S

10. Successive profiles of a protective glacier . . . . . . . . . . . . . . . . . . . . . . . . . . . 309

1 I. Diagram showing an extension of the glaciers of fig. 9 . . . . . . . . . 310

12. Diagram showing the effects of normal erosio~l on the previous figm e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310

13. Diagram showing the origin of hanging lateral valleys under protective glaciers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312

14. Diagram of a large eroding glacier in the valleys of a subdued mountain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313

15. Diagram of a young main glacial trough, with hanging lateral glaciers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

16. Diagram of a mature main glacial trough, with accordant lateral glaciers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Diagram of a later stage of fig. 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31(~

Diagrams of successively later stages of the same figure . . . . . . . . . 316

Diagram showing the forms revealed by the disappearance of a protective glacier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

21. Diag~,'am showing the forms revealed by tile disappearance of a mature eroding glacier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317

Sketch of Crib-goch, looking N.E. from Suowdon summit .. . . . . 324

Sketch of Lliwedd, looking S.E. from Snowdon summit . . . . . . . . . 324

Diagrams illustrating the origin of the summit of Snowdon, on the theory of protective and of eroding glaciers . . . . . . . . . . . . 324

26. Sketch of a ewm on the S. side of h'anttle Valley . . . . . . . . . . . . . . . 327

:xiv P~toc~ss-]3~oc~:s .~.~I) O~a~.a ILLCSXR~TIVE ~'IGVRm.

FIo. PxoE 27. Sketch of the head ridge of tile previous figure, looking :E . . . . 327

28. Sketch of the N.W. spur of Snowdon, looking S.E. from Moel-.v-s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

29. Cross-profiles of a vormal mature valley and of a glaciated wdley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334

30. Sketch of crags near the head of Afon GwarfaiValley, looking E. 336

31. Sket.ch of rugged cliffs under Cwm Dyli, looking N. from near Lake Gwynant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337

-32. Sketch of the Craig-y-Bere, on the S. side of Mynydd-lnawr, looking ~'.E. from a cwm S. of .Nantlle Valley . . . . . . . . . . . . . . . 338

1. Map of the South Island of.New Zealand, showing the distri- butiou of' the magnesian rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352

2. Diagrammatic section across the peridotite-belt, Aniseed Valley 356

3. :Diagrammatic section across the peridotite-belt, Dun :Motmtain 356

1. Section of the Lahat 'pipe,' looking ~.N.E . . . . . . . . . . . . . . . . . . . . . . . . 38-1:

2. Section of the same, looking :E.S.E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

3. Photograph of a specimen from the Lahat ' pipe,' preserved in the :British M:useum (Satural ttistory) . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

4. Dingrammatic sketch of another specimen from the Lahat ' pipe '. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387

1. Map of the neighbourhood of the Victoria Falls . . . . . . . . . . . . . . . . . . 391

2. Section in a basalt-quarry near the Maramba Ir . . . . . . . . . . . . 392

�9 3. Gravel cliff at drift, Maramba l~iver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398

1. The Luano Valley seen from the Matakula Pass, looking E.N.E. 410

2. :Map of the W. Luano Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412

3. :Map of part of N.W. Rhodesia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416

4. Section across the Luano Valley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417

-5. Section showing the descent to the Danda Flats . . . . . . . . . . . . . . . . . 417

�9 6. Section showil)g the folding of the Karroo strata on the lg. margin of the Zambesi Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431

7. Sketch-map of the Malembi Valley, Lufua R . . . . . . . . . . . . . . . . . . . . . . 432

1. Geological map of the neighbourhood of Seaford . . . . . . . . . . . . . . . . . 444

2. Section fi'om Denton to Bishopstone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448

.~3. Section from Hobb's Hawth to the Ouse Valley at Foxholes.. . 448

4. Section from Seaford IIead to Hindover . . . . . . . . . . . . . . . . . . . . . . . . . . . 450

5. Section from Chyngton to Exceat New Barn . . . . . . . . . . . . . . . . . . . . . 452

4L Diagram illustrating the fault in the Cuckmere Valley . . . . . . . . . 453

PROCESS-BLOCKS AND OTHER I L L U ~ T R k T I V E F I G U R E S . X V

~i~. PAGE

7. Map showing the lines offlexure in S.E. England ............... 45~

8. Model illustrating the physiography of the Seaford district ... 456

1. Section showing the genev'd relations of the members of the Plynlimon Stage near/~lant-y-'~Ibch . . . . . . . . . . . . . . . . . . . . . . . . . . .... 470

2. Section from Drum Peithnant to Craig Yspio . . . . . . . . . . . . . . . . . . . . . 474

3. Section showing the Pont Erwyd Stage and its relations to the Plynlimon Stage near Eisteddfa Gurig . . . . . . . . . . . . . . . . . . . . . . . . . . . 476

4. Section from Craig Yspio to Cwm Ergyr . . . . . . . . . . . . . . . . . . . . . . . . . . . 476

5. Plan of the Fuches-gau locality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480

~. Section fl.om the Afon Castell over Bane Bryn-ehwith . . . . . . . . . 483

7. Vertical section through a part of the cyphus zone . . . . . . . . . . . . . . . 486

8. Vertical section through the cyphus zone,/r Gorge ...... 487

9. Plan of section along ~an t Fuches-wen . . . . . . . . . . . . . . . . . . . . . . . . . . . 49~

10. Plan showing the distribution of the Rheidol & Cast ell Groups near Dyffryn Casteli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498

11. Vertical section of the Pont Erwyd Stage . . . . . . . . . . . . . . . . . . . . . . . . . . 504:

12. Section from :N. of Yspytty Cynfyn to Llyn Rhuddna~lt ...... 508

13. Vertical section of the Ystwyth Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517

14. Plan of folding, about half a mile N. of Pont Erwyd . . . . . . . . . . . . 523

15. Section along the line A-B in fig. 14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523

16. Section illustrating the outline of the ground produced by pitching folds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524

17. Diagram illustrating the effe~t of pitch on the apparent dip of rock-outcrops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 526

18. .]lonow'aplus status, sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532

19. J'ffonograptus rhcidoleusis, sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53~:

1. Barren surface of limestone, with ' grikes,' Ballyvaghan . . . . . . . . . 540

2. :Results of pluvial & marine action on the limestone, Black Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540

3. Map showing the outcrop of the Garbonitbrous Limestone in County Clare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543

4. Terrace in the limestone escarpment, Burren . . . . . . . . . . . . . . . . . . . . . ,r~:4

5. Foot of the main escarpment, showing scree-formation, Burren. 545

,6. :Natural limestone amphitheatre of Ballyvaghan . . . . . . . . . . . . . . . . . . 546

7. Eastern edge of the Burren plateau, Gleneolumbkille . . . . . . . . . . . . 546

x v i

FI ( J .

1.

P R O C E S S - B L O C K S A N D O T H E R I L L U S T R A T I V E F I G U R E S .

.PAGE

Plan it~u~rati1~g ~t e drain'~ge (~f ~aekside & Wanclale Becks and Artlegm tl~,da~,e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590

2. Plan i]lustratil~g tl.e Carling Gill-Uldale diversions . . . . . . . . . . . . 596

.3. The eorrom : }3!aketh~aite I~otton~, looking east . . . . . . . . . . . . . . . 598

4. A V-shaped valley near Arant IIaw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600

5. Plan illustrating the Camley-Bowderdale diversions . . . . . . . . . . . . 603

6. Outline of Bowderdale, seen fi'om near Ravenstonedale rail~ny- statiolJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 608

7. Yiew of Uldale, a t.vpical U-shaped valley . . . . . . . . . . . . . . . . . . . . . . . 609

1. Sketch-amp of the vol(anic di.~trict of Northern Argyllshire . . 614

2. Sketeh-m~p of the Highland Schists of the Glen Coe district. 627

3. Porphyr i te dyke lravorsinff rhyolites, at the ti)ot of the N. front of the ]3uachaille l ' t i~e 12e~:g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 642

4. :Porphyrite dyke traversing tl~e Morn" of t /annoch Granite in the bed of the t l iver Eti(-c, above Kingshouse . . . . . . . . . . . . . . . . . . 643

5. Map showing the di.,tribt,t[on of tlJe local dykes of Glen Coe, 646

6. Geological map of Stob Bcilm a" Chrh!ai~te . . . . . . . . . . . . . . . . . . . . . . . . 648

7. Geological map of Stob 3Ihic Mhartuin . . . . . . . . . . . . . . . . . . . . . . . . . . 649

8. Diagram of the b(mndary-f:mlt as seen in the cliff of Stob Mhie Mhartuin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 650

9. Geological ,m~p of Coil e Cdl,~,r-n.h6r m:d C(Jire Nhora i r . . 654

10. Section lhrough the ridge \V. of Coire Odhar-mhbr . . . . . . . . . . . . 655

11. �9 Geological map of Coire 1:an Lab and Coire CSm . . . . . . . . . . . . . . . 658

12. Section through 1Ueall ])earg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 659

13. Sketch-map of the Askja Caldera in Central Ieelm:d . . . . . . . . . . . . 66~

14. ~ i ag ram illustrating su~ca~rial and subterranean cauldron- subsidences, accompanied by volcanic and plutonie accumu- lations of igneous rock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67(t'

(_.'OR]r G EN D A .

Page ivii, line 7 from tlle l:ottom, for ' F. S.,' r e a d ' T . S . '

Page 217, line 9 fi'om the top, (~f&r ' gasteropod,' a d d ' referred to the genus. ' :Page 3';6, line 2 from the top, j b r ' prying, ' ~.ead ' prizing.' :Page ~37, line 13 from the top, ./br ' ragged' read ' rugged.' :Page ;339, line 17 from the top,Jbr ' p. ~25, ' ;.cad ' p. 327.'