THE

QUARTERLY JOURNAL

OF THE

GEOLOGICAL SOCIETY OF LONDON.

BDITED BY

THE PERMANENT SECRETARY OF THE GEOLOGICAL SOCIETY.

Quod si cui mortalium cordi et curm sit non tantum inventis h~erere, atque iis uti, sed ad ulteriora penetrate ; a~:lue non disputsndo adversariam, sed opere naturam vincere denique:non belle et probabiliter opinari, sed eerto e~ ostensive scire ; tales, tanquam veri seientiarum fllii, nobis (si videbitur) se adjungant --.Nonum Organum, l'rGefatio.

V O L U M E T H E E I G H T Y - F O U R T H ,

fOR 1928.

LONDON :

LONGMANS, GREEN, AND 00. PARIS: CHARLES KLINCKSIECK, 11 RUE DE LILLE.

8OLD ALSO A T T H E A P A R T M E N T S OF T H E SOCIETY,

IICMXXTIII,

~,[51 OF THI

O F F I C E I ~ 8 OF THE

G E O L O G I C A L S O C I E T Y O F L O N D ( ) N .

Elected February 17th, 1928.

~r t6t~tnt . Prof. John Walter Gregory, LL.D., D.Se., F.R.S.

~i t t , Brt~i~nt~. $'raneis Arthur Bather, M.A., D.Sc., ] Edward Greenly, D.Sr

F.R.S. I Horace Woollaston Monckton, Treas.L.S. Prof'. Edmund Johnston Garwood, M.A.,

Sc.D., F.R.S. i

bttrttarit~. Walter Campbell Smith, M.C., M.A. I James Archibald Douglas, M.A., D.Se.

,:l~ortign b t t r t t a r p . ~ r t agu r t r . Sir Arthur Smith Woodward, LL,D., ] Robert Stansfield I[erries, M.A.

F.R.S., F.L.S. I

FrancisArthurBather, M.A.,D.Se.,F.R.S. Finlay Lorimer Kitehin 1, M.A, Ph.D., Thomas Crook. Ernest Edward Leslie Dixon, B.Se. James Archibald Douglas, M.A., D.Se. John Downie Falconer, M.A., D.Sc.,

F.R.S.E. Prof. Wi~-liam George Fearnsides, M.A. Prof. Edmund Johnston Garwood, kI.A.,

S,'.D., F.R.S. Prof. William Thomas Gordon, M.A.,

D.Sc., F.R.S.E. Edward Greenly, D.Sc. Prof. John Walter Gregory, LL.D., D.Sc.,

F.R.S. Prof. Herbert Leader Hawkins, D.Sc. Robert Stansfield tterries, M.A.

F.R.S. Horace Woollaston Monckton, Treas.L.S. John Pringle. James Romanes, :S[.A. Walter Campbell Smith, M.C., M.A. Leonard James Spencer, M.A., Sc.D.,

F.R.S. Prof. Henry Hurd Swinnerton, D.Se. Cecil Edgar Tilley, Ph.D., B.Sc., A.I.C. Arthur Elijah Trueman, D.Sc. Prof. William Whitehead Watts, LL.D.,

Se.D., M.Sc., F.R.S. Sir Arthur Smith Woodward, LL.D.,

F.R.S., F.L.S.

~ r m a n t n t ~r L. L. Belinfante, M.Sc.

~.ibrarfan. ~ i ~ t a n t ~ ib ra r i am Arthur Greig. Norman E. Pettitt.

STANDING PUBLICATION COMMITTEE. Prof. J. W. Gregory, President.

Mr. W. Campbell Smith. } Secretaries. Mr. R. S. Herries, Treasurer. Dr. J. A. Douglas.

Dr. F. A. Bather. Prof. E. J. Garwood. Mr. J. Pringle. Mr. T. Crook. Prof. W. T. Gordon. Prof. W. W. Watts. Dr. J. D. Falconer. Dr. E. Greenly. Sir Arthur Smith Prof. W. G. Fearnsides. Prof. H. L. Hawkins. Woodward,

'FABLE OF CONTENTS.

PAGE ~RKELL, WILLIAM JOSCELYN ((~ J. ~ . DOUGLAS). The Strati-

graphical Distribution of the Cornbrash : I. The South-Western Area (Plates IX-XII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

BARBOUR, GEOaGE BROWN. A Re-Excavated Cretaceous Valley on the Mongolian Border (Plates LII I -LV) . . . . . . . . . . . . . . . . 719

CARGILl,, HILDA KATHLEEN (& others). The Major Intrusions of South-Eastern Iceland (Plates XXXIII -XXXIX) . . . . . . . . . . 505

CHARLESWORTH, JOHN KAYE. The Glacial Retreat from Central and Southern Ireland (Plates X X l l I & XXIV) . . . . . . . . . . . . . 293

(~OX, LESLIE REGINALD. The Gastropod and Lamellibranch Mol- luscs [from the Belemnite Marls of Charmouth] (Plate XVIII) . 233

DOUGLAS, JAMES ARCHIBALU (& W. J. ARKRLL). The Strati- graphical Distribution of the Cornbrash : I. The South-Western Area {Plates IX-XII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

GREENLY, EVWARD. The Lower Carboniferous Rocks of the Menaian Region of Carnarvonshire: their Petrology, Succes- sion, and Physiography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382

. The Petrology of the [Pre-Cambrian] Complex [of South- Western Lleyn] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447

HAWKES, LEONARD (& others). The Major Intrusions of South- Eastern Iceland (Plates XXXII I -XXXIX) . . . . . . . . . . . . . . . . 505

HoPWOOD~ /~kRTHUR TINDELL. Oyrinodon quassus, a New Genus and Species of Toxodont from Western Buchivacoa (Venezuela) 573

ILLING, VINCENT CHARLES. Geology of the Naparima Region of Trinidad, British West Indies (Plates I & II) . . . . . . . . . . . . . 1

KING, WILLI~M BERNARD ROBINSON. The Geology of the District around Meifod, Montgomeryshire (Plate LII) . . . . . . . . . . . . . . 671

LANG, WILLIA~ DICKSON (& others). The Belemnite Marls of Charmouth, a Series in the Lias of the Dorset Coast (Plates XII I -XVII I ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179

a 2

iv TABLB OF CONTENTS. FAGK

LBDEBOER, JULIA AUGUSTA (& others). '['he Maior Intrusions of South-Eastern Iceland {Plates XXXIII-XXX'IX) . . . . . . . . . .

LEEs, GEORGE MARTIN. The Geology and Tectonics of Oman and of Parts ~f South-Eastern Arabia (Plates XLI-LI) . . . . . . . . . 585

MATLEY, CHARLES ALFRED The Pre-Cambrian Complex and Associated Rocks of South-Western Lleyn, Carnarvonshire ( m'lates XXVI-XXXII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440

MUIR-WooD, HELEN MARGUERITE. The Brachiopods ~from the Belemnite Marls of Charmouth] .......................... 245

�9 Brachiopods [from the Lower Carboniferous of the Menaiam Region of Carnarvonshire] .............................. 407

NUTTALL, WINFRED L,tURENCE FALKL*:ER. Tertiary Forami- nifera from the Naparima Region of Trinidad, British West Indies (Plates III-VIII) ................................ 57

OSMAN, CHARLES WILLIAM. The Granites of the Scilly Isles and their Relation to the Dartmoor Granites (Plates XIX-XXII) . 2.58

PARKINSON~ JOHN. A Note on the Pleistocene History of Western Buchivacoa (Venezuela) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570

PUGH, WILLIAM JOHN. The Geology of the District around Dinas Mawddwy, Merioneth (Plate XXV) . . . . . . . . . . . . . . . . . . . . . . 345

SMITH, STANLEY. Palmontology [of the Lower Carboniferous of the Menaian Region of Carnarvonshire] . . . . . . . . . . . . . . . . . . . . 400

SPAT~, LEOr~ARD FRASK. The Ammonites [from the Belemnite Marls of CharmouthJ (Plates XVI & XVII) . . . . . . . . . . . . . . . . 22'2

SWlNTON, WILLIAM ELGIN. Note on the Fossil Reptilia collected by Mr. Donald Stewart in Venezuela . . . . . . . . . . . . . . . . . . . . . . 583

TOMKEI]~FF, SERGEI IVANOVICH. The Volcanic Complex of Calton Hill (Derbyshire) ...................................... 703

TYRRELL, GEORGE WALTER. On some Dolerite-Sills co~,taining Avalcite-Syenite in Central Ayrshire (Plate XL) ............ 540

WALTON, JOHN. The Flora [of the Lower Carboniferous of the Menaian Region of Carnarvonshire] ...................... 408

T A B L E O F C O N T E N T S . V

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

Proceedings of the Meetings'. ............................... i, xcix

Annual Report .......................................... ~ii

...

List8 of Donors to the Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x m

Lis t of Foreign Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxiv

Lis t of Foreign Con'espondents . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxv

Lis t of Wollaston Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvi

Lis t of Murchison Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii

Lis t of Lyel l Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxviii

Lists of Bigsby and Prestwich Medallists . . . . . . . . . . . . . . . . . . . xxx

Applications of the Barlow-Jameson F u n d and Awards from the Daniel=Pidgeon F u n d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxi

:Estimates for 1928 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxii

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

Awards of the Medals and Proceeds of Funds . . . . . . . . . . . . . . . . xl

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

:BOSWELL, PERCY GEORGE H ~ N A L L . On the Geological Features , . . of the New Mersey Tunnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . c m

MAWSON, Sir DOUOLAS. On Algal Limestone in the McDonnell Ranges (Central Australia) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cv

MUSHK~.TOV, D~TI~I IVANOVICH. On the Tectonics of the Alai and Trans=Alai Chains (Southern Turkestan) . . . . . . . . . . . . . . iii

LIST OF THE FOSSILS FIGURED AND DESCRIBED

IN THIS VOLUME.

N a m e o f Spec ie s . : F o r m a t i o n . L o c a l i t y . ! P a g e

Anomalina grosserugosa, pl . v i i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

- - subtenuissima sp. nov . , fig. 6 & pl . vi i . . . . . . . . . . . . . . .

.Bigenerina eapreolus, pl . i i i . . . . pennatula, pl . iii . . . . . . . . .

Biloeulina dfln'essa , pl . viii - - - el. i n t c r m e d / a , figs. 12 &

1 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bolivina re#ularis, pl . iii . . . . . . ~Bulimina a:~nis, pl. i i i . . . . . - - tryrula, fig. 1 . . . . . . . . . . . .

inflata, pl. i i i . . . . . . Ohilostomelloides ovicula sp .

nov . , fig. 2 & pl . iii . . . . . . . . . Ci,sss~s asterise~, fig. 11 & pl .

. . . vln . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cristellaria artieulata, pl . v..

brevispinosa sp. nov . , fig. 4 & p l . v . . . . . . . . . . . . . . . . . . . .

- - calcar, pl . v . . . . . . . . . . . . . . . - - - - var . aspinosa, pl . v. - - - eassis, pl . v . . . . . . . . . . . . . . . - clereii, pl. v . . . . . . . . . . . . . . .

erassilimbata sp. nov . , fig. 3 & pl . v . . . . . . . . . . . . . . . . . .

decorata, pl . vi . . . . . . . . . . . . - - f o r m o s a , pl . v . . . . . . . . . . . . - gladi~s, pl. v . . . . . . . . . . . .

helena, pl . v . . . . . . . . . . . . . . . .. . orbicular va r . , p l . v . . .

papillosa, pl . vi . . . . . . . . . - - - - subaculeata, v a t . gla-

brata, pl . v i . . . . . . . . . . . . . . . . . . aft. vortex, pl . v . . . . . . . . .

Cyclammina oaneellata, pl . iii. ~ - - p l a c e n t a , pl . i i i . . . . . . . . . Ellipsoglandulina exponens,

pl . vi . . . . . . . . . . . . . . . . . . . . . . . . . . Ellipsonodosaria subnodosa, pl .

Y i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Frondicularia advena, pl . v i . . -= sagittula, v a t . laneeo-

lata, pL vi . . . . . . . . . . . . . . . . . . . . . Gaudryina hantkeni nora .

nov . , p l . i i i . . . . . . . . . . . . . . . . . . - subeylindriea sp. nov . ,

p l . i i i . . . . . . . . . . . . . . . . . . . . . . . . . . )

F O R A M I N I F E R A .

T e r t i a r y ......... N a p a r i m a

D i s t r i c t . . . . . .

99

100 7 3 7 3

107

107 74 77 77 77

78

1 0 5 - 1 0 6

88

I + 87

t+, 87--88 911 86 I" 8 ' / 86

9O 86 7 1 - 7 ~ 7 2

95

95 91

92

7 5 - 7 6

I, 7 6

FOSSILS F I O U R E D A N D DESCRIBED. vii

N a m e o f Spec ies . ] F o r m a t i o n . L o c a l i t y . ] P a g e

FORA~II~IFZRA (continued).

Gaudr2/ina triuitatensis sp . nov . , p l . iii . . . . . . . . . . . . . . . . .

Helizolepidina spiralis, pl . vi i i . Lagena asters , pl . iv . . . . . . . . .

marginata, pl . iv . . . . . . . . . - - o r b i g n y a ~ a , v a r . trini-

tateusis nov . , p l . i i i . . . . . . . . , orbignyana v a t . , p l . iv. staphyllearia, pl . iv . . . . . sulcata, pl. iv . . . . . . . . . .

JLepidocyclina subglobosa sp nov . , pl . vi i i . . . . . . . . . . . . . . . . . .

trinitatensis, pl . v i i i . . . IAngulina prolata, pl . v . . . . . . Marginulina costata, pl . vi . . . Nodosaria abyssorum, pl . v

boffalor~, pl . iv . . . . . . . . . - ~ comatula, pl . v . . . . . . . . . . . . - - eommunis pl. iv . . . . . . . . . - - crassielexjans n o m . nov . .

p I . iv . . . . . . . . . . . . . . . . . . . . . . . . . erbessina, pl . iv . . . . . . . . . intermittens, pl. iv . . . . . .

- - knihnitziana, pl. iv . . . . . . longiscata, pl . iv . . . . . . . . .

- - raphanistrum, pl . iv ... - - raphanus, pls . iv, v . . . . . .

schlichti, pl . i v . . . . . . . . . . . . .... sub~itida nora . nov . , pl .

i v . . . . . . . . . . . . . . . . . . . . . . . . . ~ . . . .

verneuili, pl . iv . . . . . . . . L sp . i n d e f , p l . iv . . . . . . . . .

Operculina trinitate~asis sp. nov . , figs. 7 - 9 & p l . v i i i . . .

Planorbulina larvata, v a r . trinitatensis nov . , pl . vi i .. .

Plectofrondicularia eal~forn-. ica, pl. v i . . . . . . . . . . . . . . . . . . . . .

Pleurostomella alternans, pl . i i i . . . . . . . . . . . . . . . . . . . . . . . . . . . . {

�9 brevis, pl . i i i . . . . . . . . . . . . . . , Pliolepidina tobleri, fig. 10 & I

p l . v i i i . . . . . . . . . . . . . . . . . . . . . . . . I Polymorphina byramensis, pl . I

Y 1 . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . I compressa, pl . vi . . . . . . . . . 1 elegantissima, pl . vi . . . . . . I

- - p r o b l e m s , pl . v i . . . . . . . . . I Pulvinulina elegans, pl . v i ! . . . I

menardii, pl . vi i . . . . . . . . . I ~iphogenerina raphanus, v a t . transversa, pl . v i . . . . . . . . . . . . ]

Textularia go~sii, pl . i i i . . . . . . I Truncatulina culter, pl . vi i .. . ~ f l o r i d a n a , pl . v i i . . . . . . . . . )

T e r t i a r y . . . . . . . . N a p a r i m a

D i s t r i c t . . . . . .

( 76

105 7 9 - 8 0 79

80 80 : 79 79

104 1 0 3 - 1 0 4

84 91 81 82 84 80

8 0 84 82 81 81 82--83 83 82

84 81 8~

1 0 2 - 1 0 3

97

9 2

74 74

105

9 2 - 9 3 9 3 9 3 9 2

101 101

94 73 98 98

viii FOMILS F I O U B ~ D AND D B S C B I B ] ~ .

N a m e of Speciee. [ F o r m a t i o n . [ Loca l i ty . [ P a g e

F o a s a n ~ i r a a x (continued).

Truncatulina haidingeri, pl. vii . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

- - illingi sp. nov., fig. 5 & pl. vii . . . . . . . . . . . . . . . . . . . . . . . . . . .

�9 �9 trinitate~sis sp. nov., pl. vii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . ~[ N a p a r i m a wudlerstorfi, pl. vii , T e r t i a r y . . . . . . . . . Uvigerina auberiana, pl. v i . . . t D i s t r i c t . . . . . . , .laygm~a var., pl. vi . . . . . . V~. inulina legumen, var. e/e-I

Vgernans, pl. vi . . . . . . . . . . . . . . . . . . euilina a.ff~xa, pl. vii ...

--- glabrata, var. trinitat. r nov., pl. iii . . . . . . . . . . . }

97

99

97 98 94 94

91 75

( 75

ECHL~OIDEA.

Conulus triadis sp. nov. , fig. ] 12 & pl. xlvi . . . . . . . . . . . . . . . . . f Campan ian . . . . . . t

Coptodiseus noemi~e, p]. xlvi . . . �9 Evhinanthus' pumilus, var . ]

abiadensis nov., pl. xlvi . .

t Faujasiaeccentriparasp. nov., Maea t r ioh t i an . . . " O m a n . . . . . . . . . . . . pl . xlvi . . . . . . . . . . . . . . . . . . . . . . . .

Heteraster aft. eouloni, figs. 9 "~ & 10 & pl. xliv . . . . . . . . . . . . . . . [ U p p e r Ju rass ic

musandamensis sp. nov. , [ (?) ............

pl. xl iv . . . . . . . . . . . . . . . . . . . . . . . . }

659-61 659

662

661-62

643-44

642 -43

"RRACHIOFODA.

Acanthothiris ( 0 sp., fig. 1 ...] IAas . . . . . . . . . . . . . . . Cererithyris dorsetensis nov., !

; , �9 J ( L o w e r pt. ix . . . . . . . . . . . . . . . . . . . . . . . . . . . h

iutermedia, pl. ix . . . . . . . . . I J Cornbras ... Cincta pernumismalis figs

9 ~ a 9b . . . . . . . . . . . . . . . ; . . . . . . . : ~ L i a s . . . . . . . . . . . . . . . Gibhirhynchia curviceps, fig. 2. J Kallirhynchia crassicosta, pl. )

X l . . . . ~ . . . . ~ . . . . . . . . . . . . . ~ . . . . .

- - elegantissima, pl. xi . . . . . . exalta, pl. xi . . . . . . . . . . . . . . . L o w e r

�9 multieosta sp. nov., p l . Cornbrash x i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " ' '

:- transversa sp. nov., pl. xi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

yax!eyensis, pl. xi . . . . . . i J Lower

Kutchirhynehia idonea, pl. xi. C o r n b r a s h ...

Lobothyris ovulum, figs. 8 a & 8 b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I Liaa . . . . . . . . . . . . . . .

Microthyris ealloviensis nov., I pl. x . . . . . . . . . . . . . . . . . . . . . . . . . . . , U p p e r

- - , var. globosa nov.,I Co rnb ra sh ... pl. x . . . . . . . . . . . . . . . . . . . . . . . . . . . t

Charmouth . . . . . .

t Corseombe . . . . . . . K i d l i ng ton . . . . .

1 0harmouth ......

I I

Var ious . . . . . . . . .

! )

Corseombe . . . . . .

2511

I 160 159

253 216-47

( 169 170

�9 I70

i 169

170 ~, 168-69

168

250-51 C h a r m o u t h . . . . . .

Fa i r fo rd , &c . . . . ( 1 6 6

167

F 0 8 S I L 8 F I G U R E D AND D ~ S C R I B E D . i x

Name of Species. I Format ion . Local i ty . Page

B&hCt I IOrODh (conti~ued). Microthyrislage~alis, pl.x...[}~ [~

siddi~gtonensis, pl. x .-. [ , var. elongata nov., U p p e r I

i pl. x . . . . . . . . . . . . . . . . . . . . . . . . . . . Cornbrash ... i ~ Fa i r to rd , &c . . . suhcalloviensis nov., pl. x. I [ sublagenalis, pl. x . . . . . . I ~ Uppe r

Ornithella arenaria, pl. x . . . . . . [ Cornbrasb

~z~sis nov.. vl. i~ ...... I Lower i foxleyensis nov., pl. ix.. . J Cornbrash

jaeulum nov., pl. x . . . . . . [ U p p e r - - miltonensis nov., pl. x ... ( Cornbrash .

ruffosa nov., pl. ix Lower Cornbrash .

�9 . sarthacensis, figs. 7 a & 7 b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lias . . . . . . . . . . . . .

-4"- [ Obovothyris] grandob- "1 ': ovata, pl. ix . . . . . . . . . . . . . . . . . . .~ Lower [~] magnobovata, pl. ~- Cornbrash , i x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

~ - [ - - ] obovata, pl. ix .. ) Rhaetorhynchia recta sp. nov., } Lower

pl. xi . . . . . . . . . . . . . . . . . . . . . . . . . . . Cornbrash .

i Corseombe, &e.

Eas t F l ee t . . . . . Wi l t sh i r e . . . . . Dorse t . . . . . . . . . . . . F a i r ford . . . . . . . . .

Y e t m i n s t e r , &e..

Cha rmou th . . . . . .

I Yetminster , &c..

I ) } Mahnesbu ry ...

( 167

165 167 167

163

162 161-62 163-64 164

162-63

251-53

160-61

161 160-61

170

pl. x ... . . . . . . . . . . . . . . . . . . . . . . . . el. x . . . . grem~fera, pl . . . . . . . l~vis sp. nov., fig 5 &

, p l . x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rudirhy~chia calcicosta, figs.

5a-5c .. . . . . . . . . . . . . . . . . . . . . . . j - - (?) .fallax, figs. 6 a - 6 r . . . . Tropiorhynchia thalia, figs. ] J

3a & 3b, 4a & 4b ......... [j [; i

LAMELLIB P~ANCII IATA

Astarte hilpertonensis, pl. xii. . . ~ Lower Corn- brash . . . . . . . . . ,

Ceratomya petricosa, pl. xviii Chlamys... milvus sp. nov., pl. ~Lias . . . . . . . . . . . . . . .

xvm . . . . . . . . . . . . . . . . . . . . . . . . . . . rollel, pl. xviii . . . . . . . . . . . .

Modiola bipartita, pl. xii . . . . . . Cornbrash . . . . . . Myopharia gigantea sp. nov.,

pl. x l i v . . . . . . . . . . . . . . . . . . . . . . . . ; Ostrea (? Exog~/ra ) blanfordi Upper Trias ...

sp. nov., pl. xliv . . . . . . . . . . . . . Parallelodon trapezium sp.

nov., pl. xviii . . . . . . . . . . . . . . . . . . i ,Pteria carixensis sp . nov., pl. ~Lias . . . . . . . . . . .

xviii . 2 . . . . . . . . . . . . . . . . . . . . . . . ) Trigeraia angulata, pl. xii ..

charltonensis nov., pl. xi: ~Lower Corn- .qriesbachi, pl. xii . . . . . . . . f brash . . . . . . . . rolandi pl. xii . . . . . . . . . . . . )

IFulsello~sis aft. caillaudi, fig. 11 & pl. xlv . . . . . . . . . . . . . . . . . . Maes t r i eh t i an . . .

Lias . . . . . . . . . . . . . . �9 Cha rmou th ... .

~ Uppe r Var ious . . . . . . . . . { 171 ] Cornbrash .. " 171

U p p e r Fa i r fo rd 171-72 Cornbrash . . . . . . . .

( 248--49 249

I t ~, 247-48

Hi lpe r ton . . . . . . 173--74

(244-45

Cha rmou th . . . . . . ~ 243 /

( 24'.)-43 Var ious . . . . . . . . . 174-75

/ t

Oman . . . . . . . . . . . . I 635-36

I 634

( C h a r m o u t h . . . . . . i 240

1241-42 |

( V a r i o u s . . . . . . . . . 172 J Malmesbury -"i 173 ] South Brewhaml 173

Var ious . . . . . . . . . 173

Oman . . . . . . . . . . . . I 644

FOSSILS F L O U R E D A N D D F ~ C R I B E D .

lqa,ne o f Species. F o r m a t i o n . ] Local i ty . Page

(~AST]IROPODA.

Amberleya auricipitis sp. nov.,i / pl. x , i i i . . . . . . . . . . . . . . . . . . . . . . . . t t

subimbricata, pl. xviii . . , f J Angaria arabica sp. nov.,]

pl xlv

. . .

x v m . . . . . . . . . . . . . . . . . . . . . . . . . . I f_/gria crassicos~ata, vat. oma-I

nica nov., pl. xlvi . . . . . . . . . . . . I N~rin~z cf. punetata, fig. 8 . . . [ Pugnellgs orientalis sp. nov., I

pl. xlv . . . . . . . . . . . . . . . . . . . . . . . . . . . i Pyrazus decagonum sp. nov.,

pl. xlv . . . . . . . . . . . . . . . . . . . . . . . . . . . ! stillans, race persioa,;

pl. xlv . . . . . . . . . . . . . . . . . . . . . . . . . . . !I Troohus grayi sp. nov., pl. xlv

o , m a n / v ~ , sp . n o v . , pl. I l v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

i Lias Oha rmou th . . . . . . . . . . . . . . ! . . . . . . I

Maes t r i ch t i an .i Oman . . . . . . . . . . . . i

Lias . . . . . . . . . . . . . . . ',i~ C h a r m o u t h . . . . . .

Maestr icht ian ...! ~ Oman . . . . . . . . . . . . P o r t l a n d i a n . . . i J

I

1 ~- Maes t r i eh t i an . . . Oman . . . . . . . . . . . . [ I I

)

239 238-39

648

237

668-59 638

658

655

6 5 4 - 5 5 648-49

AMMONOID]~A,

Trol~toceras aft. aet~eo., fig. 4 "~ & pl. xvi . . . . . . . . . . . . . . . . . . . . . . . .

calliploeoides, fig. 4 & pl. xvii . . . . . . . . . . . . . . . . . . . . . . . .

- . �9 elliptizum, fig. 4 & p l s xvi, xvii . . . . . . . . . . . . . . . . . . . . . . . . , Lias . . . . . . . . . . . . . . .

~ f u t t e r e r i , fig. 4 & pl. I v i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

lineatum, fig. 4 & pls. xvi, xvii . . . . . . . . . . . . . . . . . . . . . . .

~ I sparsieosta, pl. xvii . . . . . . - - aft. stahh:, pl. xvii . . . . . .

C h a r m o u t h . . . . . .

2 2 8 - 2 9

229-30

228 t 230-31

~ A U T I L O I D I A .

Nautilusjordaui, pl. xlvi . . . . . . I Maest r icht ian . . . [ O m a n . . . . . . . . . . . . l

BBLgMNIT01DgA.

Angeloteuthis gabriel sp. nov., r ' fig. 2 & pl. xv . . . . . . . . . . . . . . . E

miehael sp. nov., fig. 2 & pl. xv . . . . . . . . . . . . . . . . . . . . . . . . . . . I

raphael sp. nov., fig. 2 & I pl. xv . . . . . . . . . . . . . . . . . . . . . . . . . . .

uriel sp. nov., fig. 2 & ~" L ias . . . . . . . . . . . . . . . pl. xiii . . . . . . . . . . . . . . . . . . . . . . . . I

Clastoteuthis abrupta sp. nov., ] fig. 3 & pl. xiii . . . . . . . . . . . . . . . - stantonenMs sp. nov.. ] fig. 3 & pl. xiii . . . . . . . . . . . . . . . *)

h a r m o u t h . . . . . .

206-208.

2O9

208-209.

209

197

~. ~ 9 7 - 9 s

F O S S I L S F I 6 U R E D A N D D E S C R I B E D . Xi

Name of Species. Fo rnmt ion . i Local i ty . I Page

B E L E M N I T O I D E A (continued).

Hastites fitstiformis sp. nov.,i XV . . . . . . . . . . . . . . . . . . . . . . . . . . .

pl. spadix-ari, pl. xv . . . . . . . . . stonebarroensis sp. n o v , i

fig. 2 & pl. xiv . . . . . . . . . . . . . . . argillarnm sp. nov.,:

fig. 3 & pl. xiii . . . . . . . . . . . . . . . ! auricipitis sp. nov., fig. 2!

& pl. xiv . . . . . . . . . . . . . . . . . . . . . . . . ! dayi sp. nov., fig. 2 &i

pl. xiv . . . . . . . . . . . . . . . . . . . . . . . . . . . t --...elongata, fig. 3 & pl.]

X l l l . . . . . . . . . . . . . �9 . . . . . . . . . . . . . . . i

ima sp. nov., fig. 3 &t pl. xiii . . . . . . . . . . . . . . . . . . . . . . . . . . :t

ridgensis sp. nov., fig. 3 & pl. xiv . . . . . . . . . . . . . . . . . . . . . . I

seatownensis sp. nov.,! pl. xiv . . . . . . . . . . . . . . . . . . . . . . . . .

stonebarroensis, sp. nov., I fig. 2 & pl. xiii . . . . . . . . . . . . . . . i

westhaiensis sp. nov., i fig. 2 & pl. xiii . . . . . . . . . . . . . . . i

woottonensis sp. nov., pl. I xiv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ',

P~eudohastitss arundineus, sp.l nov., fig. 3 & pl. xv . . . . . . . . . 1 --eharmouthensis fig. 3 &l pl. xv . . . . . . . . . . . . . . . . . . . . . . . . . . . t

cultellus sp. nov., pl. xvl junceus, fig. 3 & pl. xv.. .

- - longissimus, fig. 3 & pl. xv . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lias . . . . . . . . . . . . . . . Charmouth ......

218 218-20

220

205-20~

2OO

2O4

204

201-292

199-200 ~

203-204

203

200-201

202

2 0 2 - 2 0 3

213-15

215 211 212-1S

L211-12

T O X O D O N T I A .

nov., figs. 1-6 . . . . . . . . . . . . . . . ~, Pl ioeenc (?)...! Buehivaeoa ...

PLANT~ INCERT2E SEDIS.

Rhodea sp., fig. 4 . . . . . . . . . . . . . . . { Lower Carboni- Menai 409 ferous . . . . . . . . . Strai ts . . . . . . . . . I j

EXPLANATION OF T H E P L A T E S .

,PLATES PaQB [ GROLOGICAI. SECTIONS across the Naparima Region

TT J of Trinidad ; and GEOLOGICAL MAP of the s a m e | �9 I & , , ] area, illustrating Prof. V. C. Illing's paper o n f 1

I, the Geology of that Region . . . . . . . . . . . . . . . . . . . . . . . . j

f TERTIARY FORAMINIFERA from the ~Naparima Re- } I I I - V l I I gion of Trinidad, illustrating Dr. W. L . F . 57

Nuttall's paper on those fossils . . . . . . . . . . . . . . . . . .

(Low~.E CORNBRASH BRACHIOPODS; UPPRR CORN-'~ [ BRASH ~BRACHIOPODS; and LOWRR OORNBRASH |

I X - X I I ~ LAMELLIBRANCHS, illustrating the paper b y f 117 ! Dr. ft. A. Douglas & Mr. W. J. Arkell on the �9 Stratigraphica/Distribution of the Cornbrash.)

f CLAsTOTEUTHIS, ,4NGELOTEUTHIS, & 2DASSALOTBU-'~ X I I I - X V rUES; PSEUDOHASTITES, HASTITES, & 2~NGELO- t 179

TEUTRlS, illustrating Dr. W. D. Lang's paper on | the Belemnite Marls of Oharmouth . . . . . . . . . . . . . . . J

{ TROPIDOCERAS, illustrating Dr. L. F. Spath 's} papsr on the Ammonites from the Belemnite 222 Marls of Oharmouth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

XVI & XVlI

PLATE

XVlI I

PLATES

X l X - X X l i I

x x l n & XXlV

I G'ASTROPODA and LAMELLIBRANCHIA from the

Belemnite Marls of Charmouth, ilhlstrating ~. . Mr. L. R. Oox's paper on thoss fossils ......... j

233

(MAP ILLUSTRATING THE GLACIAL RETREAT FROM~ CENTRAL AND SOUTHERN IRELAND; and MArl ILLUSTRATING THE GLACIAL RETREAT OF THE]

"{ NORTHERN IcE-StIEETS FROM TIlE WICKLOW [ MOUNTAINS, illustrating Frof. J. K. Charles-I

worth's paper on the Glacial Retreat from t i Central and Southern Ireland . . . . . . . . . . . . . . . . . . . . )

293

(INCLUSION, WHITE ISLAND ; ROOF-STRUCTURR R]~- [ MAINS, GIANT'S CASTLE; INLET SUBSIDENCE-[ :FISSURES, PRNINNIS ; C HAD GIRT, WHITE ISLA~V ; Junction of STAOES 2 B & 3 GRANITRS, TRmCO ; , SINGLE STAGE 7 GREISEN-LINE, ST. MARY'S; ~ O~8 and MAP OF THE SCILLY ISLES, SHOWING THE [

I DIRECTIONS OF FLOW OF INTRUSIONS, illu$ o } . trating Mr. C. W. OsInan's paper on the L Granites of" those Islands . . . . . . . . . . . . . . . . . . . . . . . . . . . J

;EXPLANATION OF THE PLATES. XUV,

PLATE PAGE~

I GEOLOGICAL MAP OF THE DISTRICT AROUND DINAS } XXV MAWDDWY, illustrating Prof. W. J. Pugh's 345

paper on the Geology of that area . . . . . . . . . . . . . . .

PLATES

i !

XXVI-XXXII

J

I

(DINLLAEN, WEST AND EAST SIDES, ]~LLIPSOIDAL~ 1 SPILITES AND SPILITE-TUFF OF THE GWNA I

GROUP ; DINLLAEN. WEST COAST AND COAST SOUTII OF ABER GEIRCH ; WESTERN SLOPE OF MYNYDD ~/[AWR AND NORTH SIDE OF PORTH } ~ELEN ; PARED LLECH-YMENYN AND COAST SOUTH J OF FORTH GWYLAN; COAST BETWEEN PERTH YCHAIN AND FORTH GWYLAN AND CLIFF AT, ~" TRAETH PENLLECH ; NATURAL ARCH SOUTH-WEST I OF FENRHYN CWM-IS-TIR AND EAST SIDE OF[ t

PARWYD; and GEOLOGICAL MAP OF PART OF TIlE LLEYN PENINSULA, illustrating Dr. C. A. I Matley's paper on the Pre-Cambrian Complex I of South-Western Lleyn ........................... )

440

XXXIII-XXXIX

( B R U N N I I O R N AND CLIFF BELOW KLIFATIND ; BRUNN- I IIORN AND INTRUSION'BRECCIA, VESTUR HORN ; I

THUFUHRAUNSTIND AND ~{REITHATIND~ OSTER HORN; NORTH-EASTERN SIDE OF SLAUFRUDAL; SKEGGTIND RIDGE, LoI~; SLAUFRUDAL STOCK

t AND CLIFF AT V IK; and MICROSCOPE-SECTIONS I OF IGNeoUS ROCKS, illustrating the paper by Dr. L. Hawkes & others on the Major Intru-

~. sio~ls of South-Eastern Iceland . . . . . . . . . . . . . . . . . . )

505

PLATE

PLATES

X L I - L I

! ]~ICROSCOPE-SECTIONS OF ~LNALCITE-SYENITE FROM 1 X L AYRSHIRE, illustrating Dr. G. W. Tyrrell's~,

paper on that rock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J

/'VIEW OF THE INTERIOR OF ELPHINSTONE INLET; RECUMBENT I~OLD IN ~F~USANDAM LI.MESTONI~ AND SHEARFD OVERFOLD OF ~|USANDAM LIMESTONE ; TROUGH-FAULT AT THE ENTRANCE TO ~/~ALCOLM INLm', BAIT AL ~ALAJ PLAIN, AND STRONGLY CONTORTED RADIOLARITES OP THE HAWASINA SERIES; TRIASSIC AND LOWER CRETACEOUS FOS- SILS FROM SOUTH-EASTERN ARABIA; UPPER CRETACEOUS ~FossILS FROM SOUTH ~EASTERN ARABIA ; ROUT~-MAP ; GEOLOGICAL SECTIONS ; ~[ELD-SKETCH OF THE DHAHIRA PLAIN; FIELD- SKETCH OF THE NORTH-WESTERN CORNER OF THE SAm HATAT; and GEOLOGICAL MAP OF

!

I

PART OF SOUTH-EASTERN ARABIA, illustrating i Dr. G. M. Lees's paper on the Geology and I Tectonics of that region . . . . . . . . . . . . . . . . . . . . . . . . . . . )

540,

585-

PLATE

=I{ GEOLOGICAL I~AP OF THE DISTRICT AROUND M E I - 1 FOD (MoNTGOMERYStI[RE), illustrating Mr. W . ~ B. R King's paper on the Geology of that area. J

67L

xiv EXPLANATION OF THE PLATES.

PLATES fHANoOR PASS AEOVE NAI~'V'IZ~Mm, VILLAGE ~ D ~ ! VIEW LOOKING TOWARDS THE SAME PEAK AS TIIAT I SHOWN IN FIG. 1 ; COAKSE BASAL CONGLOMERATE ,

[ IN THE NANTIENMEN SERIle~t AND DETAIL OF[ J CROss-BEDDING IN THE NANTIEN:~IEN SERIES,

L I I I - L V ] and MAP COMPARING Tile PRESENT RELIEF WITH I THE EROSION-SURFACE UPON WIIICH TIlE I~AN- I [ 'IIENMEN BEDS WERE DEPOSITED, i l l u s t r a t i n g [ ! Prof. O. B. Barbour's paper on a Be-Excavated I (, Cretaceous Valley on the Mongolian Border ... )

PA0e

719

FOLDING TABLES I & II , showing the STRATIGRAPItICAL DISTRIBUTION OF THE TERTIARY FORA.~IINIFERA in the Naparima Region of Trinidad, illustrating Dr. W. L. F. 51uttall's paper on those fossils, facing ... 60

�9 OF THE AREA AROUND HENDRE-DDU, showing the Details of the Folding in the ]-Iendre-ddu Syneline (fig. 3). illustrating Prof. W. J. Pugh's paper on the Geology of the District around Dines Mawddwy, facing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368

SECTION ACROSS VAYNOL PARK (fig. 7), illustrating Dr. E. Greenly's paper on the Lower Carboniferous Rocks of the Menaian :Region of Carnarvonshire, facing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416

]~A'AP OF THE SLAUFRUDAL STOCK (fig. 7), illustrating the paper by Dr. L. ttawkes & others on the Major Intrusions of South-Eastern Iceland, facing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518

SKETCH-MAP OF PART OF WESTERN BUCHIVACOA (VENEZUELA), illustrating Dr. J. Parkinson's paper on the Pleistocene History of that region, facing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570

E R g A T A .

P. 465. Line 5 from b o t t o m , . f o r 'spillites ' read 'spilites.'

P. 500. Line 9 fPom bottom,for 'vaulted ' read ' faulted.'

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

B E S I D E S T H O S E I N T H E P L A T E S .

Pro.

1~

2.

3.

4.

5.

6.

Fios. 7-9.

Fro. 10.

11.

FIGS. 12 & 13.

Fro. 1.

~AGE 1, Section across the Corial Thrust , immedia te ly eas t -nor th-

east of Wil l iamsvil le Es ta te House . . . . . . . . . . . . . . . . . . . . . . . . 26

2. D i a g r a m m a t i c section showing the la tera l var ia t ion of the Mar l and the Green Clay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3. Section across the P a l m y r a Thrus t -b lock on the P a l m y r a Es ta te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

4. Section across Union Hal l Es ta te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

5. Section f rom AlleylCreek t~) Mosquito Greek . . . . . . . . . . . . . . . 47

~Bulimina T y r u l a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

Chilostomelloides ovicula sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

Cristellaria crassiIimbata sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Cristellaria brevispiuosa sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

Truncatu l ina i l l ingi sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

Anomal ina subtenuissima sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

Operculina tr ini tatensis sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

Pliolepidina tobleri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Cisseis asteriscus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

~Biloculina el. in lermedia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107

Map showing the chief localit ies where the Cornbrash has been studied in the South-Western Area . . . . . . . . . . . . 126

2. Section in Swan I n n Quar ry , Long t t andbo rough . . . . . . . . . 128

3. Section a t Garsdon (Wil tshire) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

4. Section at Card 's F a r m , S o u t h B r o w s h a m (Somerset) ... 144

5. a2hynchonelloidea l~vis sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171

xvi

Fio. l.

FIGs. 2 & 3.

FIG. 4.

l~as. 1-5c.

6a-6c.

7a-9b .

F~G. 1.

2.

3.

4.

5.

6.

1.

2.

2~

3.

4.

5.

6.

8o

9.

I~

2.

PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES.

PAom

Detailed sequence of the Belemni~e Marls .................. 190

Median longitudinal sections of belemnitos viewed from the right side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210, 214

Suture-lines of Trogidoceras . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226

Brachiopods from the Belemnit~ Marls . . . . . . . . . . . . . . . . . . . . . 247

Do. do. do . . . . . . . . . . . . . . . . . . . . . 249

Do. do. do . . . . . . . . . . . . . . . . . . . . . . 251

Voussier-bloek formation [in Scilly granites] . . . . . . . . . . . . . . . 073

[Granite at] Peninnis, St. Mary's (Seilly Is.) . . . . . . . . . . . . . . . 274

[Granite at] Meldon Hill, Northern Dartmoor (Devon)... 274

Diagram of faulting producing pseudo-anticlines ... . . . . . . 275

Shore north of Cromwell's Castle, Treseo . . . . . . . . . . . . . . . . . . 278

Engine-house foundation, Round Island . . . . . . . . . . . . . . . . . . . . . 280

Map showing the extent of ' Lake Aherlow ', &c . . . . . . . . . . 313

Map showing the extent of the extra-glacial lake south- west of Newcastle West . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Sketch-map showing the position of the marginal channels on the southern slopes of the Castleeomer Plateau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326

Map of the extra-glacial lakes in the Keeper Hills, north- east of Limerick . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328

Vertical section through the Bala and Valentian rocks [of the Dinas M:awddwy district] . . . . . . . . . . . . . . . . . . . . . . . . . . . 349

Map of the area north of Abet Cowareh, showing the strike-faulting, fossil localities, &e . . . . . . . . . . . . . . . . . . . . . . . . . 354

Geological map of the area between the Bridges (Menai Straits) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385

Block o f augen-quartz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . : . . . . . . . . . 387

Finger-like purple processes in the yellow loam .. . . . . . . . . . . 389

Outline drawing of three pinnules of R~odea . . . . . . . . . . . . . . . 409

[Map of] the Carboniferous rocks of Arvon . . . . . . . . . . . . . . . 412

The visible unconformity in the cliff south-east of Swelly Reef . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414

Section across Treborth Park . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415

Section through the Cherts at Por t Dinorwic . . . . . . . . . . . . . . . 419

Spilites at Dinas B~ch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471

Section along the coast from Trwyn Maen-melyn to ~ Bychestyn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474

PROOE~-BLOCKS AND OTHER ILLUSTR&TIVE FIQURES. XVli

PAGm FiG. 3. Pared Lleoh-ymenyn: seams of grit in purple pbyll i~ . . . . . . . . breaking up into ]enticular fragments in a fold . . . . . . . . . 480

4. Plan of faulted Palaeozoic dykes cutting the Aber Geirch i~hyllites east of Penrhyn Cwm-is-tir . . . . . . . . . . . . . . . . . . . . . 484

5. Vertical section in the cliff" at the seaward end of Perth Iago (south side) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485

. . . . 6. Section at Parwyd, south-west of Aberdaron . . . . . . . . . . . . . . . 489

7. Columnar section of the Ez te~s~ Beds of the Aberdaron Synellne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :. 492

8. I)iagrammatic generalized section showing the suggested relation of the Pro-Cambrian Complex to the Arenig rocks at the southern end of the Lleyn peninsula ...... 498

i. Map iilustraLing the location of the intrusions [in South- Eastern Iceland] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506

2. Map of the Vestur Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508

3. Sketch illustrating the gabbro-basalt junction on the northern lace of Brunnhorn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509

4. Elevation of the cliff below Klilatind . . . . . . . . . . . . . . . . . . . . . . . . 510

5. Sketch of the Vostur Horn from the Fyr at Stokksnes ... 511

6. Ele~,ation of the ester Horn cliff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516

8. Plan to show the outcrop of sides and roof of the Slauf- rudal Stock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519

9. Sketch of Mosfol], showing layered structure in the granophyro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520

10. Elevation of the north-eastern slope of Slaufrudal . . . . . . . . . 522

11. I)iagrat,,matic sections of the Slaufrudal Stock . . . . . . . . . . . . ,523

12. Diagram showing the variations in the composition of the total felspar with the silica-content of the rocks... 532

l . Sketch of acid veins in a rock-face, as seen from Howford Bridge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543

�9 2. Vertical section through the Howford Bridge sill . . . . . . . . . 545

3. Crystallization and differentiation relations in the crinanite-analcito-syenite sills of Central Ayrshire ... 562

1. Horizontal section of the lower molars of Gift/nodes quassus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575

2. Skull-cap of GRr/~wdon qua.~us . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 576

3. Anterior and posterior aspects of the seventh cervical vertebra of Gyrinodou quass~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577

4. Anterior and posterior aspects of the first dorsal vertebra of Gyrbwdo~ qv~assu8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 578

5. :Distal extremity of humerus of Gyrinodon quas.vas, posterior aspect . . . . . . . . . . . . . . . . . . . �9 . . . . . . . . . . . . . . . . . 579

VOL. LXXXIV b

.o, X V I I I P R O C E ~ - B L O C K S AND O T H E R I L L U 8 T R A T I V E D ' I e U ] g l m .

PAeg l~e. 6. Proximal half of femur of GFr /z~ /~ q ~ posterior

z z l ~ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 580

1. Tectonic map showing the relation of Oman to the Indus Ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586

2. Stratigraphioal table of Oman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 598

3. Sections No. 1 & No. 2 [fr,Jm Ras Shaikh Masud to Ras Dills, and from Jabal Snmaini to Ajib] . . . . . . . . . . . . . . . . . . 616

4. Diagrammatic section of the north-eastern flank of the Saih Hatat complex along tim Wadi Adi . . . . . . . . . . . . . . . 620

5. Sketch-section at -~Iurbat (Dhofar Provioce) . . . . . . . . . . . . . . . 622

6. Outline-map showing the Omau pre-t~osau orogenetie zone and its continuation in Persia . . . . . . . . . . . . . . . . . . . . . . . . 628

7. Portion of L. Kober's tectonic map of the world 632

8. Ner/nea of. puncta ta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 638

FIGs. 9 & 10. Apical disc of Hetcraster mu~andamensis . . . . . . . . . . . . . . . . . . . 642

FrG. 11. Cross-section of V u l ~ l o p s i s cai l laudi . . . . . . . . . . . . . . . . . . . . . . . . t;44

12. Portion of posterior interambulacral area of Conulus tr/ad/s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . {~60

1. Gra~g Wen Quarry, looking south-westwards . . . . . . . . . . . . . . . (i82

2. Section in the River Banwy, from Upper Hall to the bend in the river . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 689

3. Sections across the Meifod di.-trict . . . . . . . . . . . . . . . . . . . . . . . . . . . 692

1. Geological sketch-map of the road-metal quarry at Calton Hill (Derb)shire) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 704

2. Profile of the quarry-cutting at Calton Hill . . . . . . . . . . . . . . . 705

3. West-to-east section of the quarry at Calton Hill . . . . . . . . . 706

4. Microscope-sections of oliviue-basalt from Miller's Dale and analcite-olivine-basalt from Calton Hill . . . . . . . . . . . . 711

1. Block-diagram showing the surface-features of the Kalgan area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 720

2. Geological column of the Kalgan area . . . . . . . . . . . . . . . . . . . . . . . 721

3. Section across the Hanoor Gorge at Nant'ienmen .. . . . . . . . 724

D a t e s o f I s s u e o f t h e Q ~ l y J o u r n a l fo r 1938.

No. 333--April 30th, 1928.

No. 334--July 31st, 1928.

No. 3;~5--October 31st, 1928.

No. 336--December 31st, 1928.