THE

QUARTERLY JOURNAL

OF TII~

GEOI,OGICAI SOCIETY OF LONDON.

EDITED BY

TIlE PI~RMANE I SECRETAI~u OF TI~E GEOLOGICAL SOCIETY.

q a o d si cui mor ta l ium cordi et cur~ sit non tantum inventis h~erere, atque iis uti,-sed ad u l ter iora penetrare ; atque non disputaudo adversarium, aed opere nuturam vineere denique non belle et probabili te opinari, sed certo et osten~ive seire ; tale~, tanquam veri aeientiar•m fl[ii, nobis (si videbi tur) se adjuugant --Novum O'fganum, Prwfatio.

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

FOa 1927.

LONDON :

L O N G M A N S , G R E E N , A N D C().

PARIS: CHARLES KLINCKSIECK, I1 RUE DE LILLE.

SOLD ALSO AT TEE APARTMENTS OF THE SOCIETY,

~ , c M x x v , , ~ .

~.t~t 0 g T I I R

O F F 1 C / ; I ~ S OF T i l e

GEOL()GICAL SOCIETY OF I ()NDON. Elected February 18th, 1927

Francis Arthur Bat, her, M.A., D.Sc., F.R.S.

John William Ev~ms, C.B.E., D.Sc., [ Edward Greenly, D.So. LL.B., F.RS. [ Horace Woollaston Monekton, Treas.L.S.

Prof. Edmund Johnston Oarwood, M.A., Sc.D., F.R.S

~ t c r ~ t a r i ~ , Walter Campbell Smith, M.C., M.A. ' James Archibald Douglas, M.A., D.So.

.-jf'or~i gn ~cc re t a rp . i~r~,1~;urcr.

Prof. John Edward Marr, M.A., Sc.D., I Robert Stansfleld Iterries, M.A. F.R.S. l

Francis Arthur Bather, M.A., D.Se.,F.R.S. Thomas Crook. :Ernest Edward Leslie Dixon, B.Sc. James Archibald Douglas. M.A., D.Sc. John William Evans, C.B.E., D.Sc.,LL.B.,

F.R.S. John Downie Falconer, M.A., D.Sc, Prof. William George Fearnsides. M.A. Prof. Edmund Johnston Garwood, M.A,

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

D.Sc., F.R.S.E. Edward Greenly, D.Sc. Prof. Herbert Leader Hawkins, D.Sc. Robert Stansfleld Herries, M.A.

Prof. Vincent Charles Illing, M.A. Finlay Lorimer Kitelli,,, M.A, Sc.D.,

Ph.D. Philip Lake, M.A. Prof. John Edward ~arl', M.A., Sc.D.,

F.R.S. Horace Woollaston Moncktorl, Treas.L.S. Tressilian Charles Nicholas, O.B.E.,

M.C., M.A. John Pringle. Waller Campbell Smith, M.C., M.A. Leonard James Sp(mcer, M.A., Se.D.,

F.R.S. Prof. Henry l:[i)rd Swinnorton, D.Sc. Arthur Elijah Truemau, D.Sc.

~ t ' m a n r n t ~r L. L. Belinfal~to, M.Sc.

~ibrar/an. Arthur Greig.

STANDING- PUBLICATION COMMITTEE. Dr. F. A. BaLher, President.

Mr. xN. Campbell Smith. } Secregaries. 3[r. R. S. Herries, Treasurer. Dr. J. A. Doughty.

Mr, T. Crook. ProF. W. T. Gordon. Prof. J. E. Marl'. Dr. J. D. FMconer. Prof. It. L. Hawkins. Mr. J. Pringle. Prof. W. G. Fcarnsides. Prof. V. C. Illing. Prof. W. W. Watts. Prof. E. J. Garwood.

TABLE OF CONTENTS.

PAGE ANNISS, LESLIE G~O~GE. The Geology of the Saltern Cove Area,

Torbay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492

BLACKIE, ROBERT CHURCHILL. The Geology of the Country between Llanelidan and Bryneglwys (Plate LV) . . . . . . . . . . . . 7 l l

BOSWELL, PERCY GEORGE ItAMNALL. The Salopian Rocks and Tectonics of the District South-West of Ruthin, Denbighshire (Plate LIV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 689

BUCKMAN, SYDNEY S. Jurassic Chronology: I I I - -Some Faunal Horizons in Cornbrash (Plate I) . . . . . . . . . . . . . . . . . . . . . . . . . . 1

BULI~IAN, OLIVER MEREDITH BOONE (~; 0: J. STU]]]]LVFIELD). The Shineton Shales of the Wrekiu District: with Notes on their Development in other Parts of Shropshire and Hereford- shire (Plates I I I -V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

CHUB]], LAWRENCE JOHN. The Geology of the Austral or Tubuai Isla~ds, Southern Pacific (Plate XX[II) . . . . . . . . . . . . . . . . . . 291

.. (• V~ r. CAMPBELL SMITH). The Petrography of the Austral or Tubuai Islands (Southern Pacific) . . . . . . . . . . . . . . . . . . . . . . 317

( ). On the Geology of Maiao (Society Islands) . . . . . . . . 342

COIl]]OLD, EDGAR STERLING. The Stratigraphy and Geological Structure of the Cambrian Area of Comley, Shropshire (Plate XLI[I) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551

CONNOLLY, MATT~IEW. Report on a small Collection of Fossil Freshwater Mollusca from Lake Nyasa . . . . . . . . . . . . . . . . . . . . 444

DXVIES, JOHN HENRY (& A. E. TRUE~IAN). A Revision of the Non-Marine Lamellibranchs of the Coal Measures, and a Discussion of their Zonal Sequence (Plates XVI & XVII) . . . . 210

DAVIES, L. MERSON. The Ranikot Beds of Thal, North-West Frontier Province of India (Plates XVII I -XXII ) . . . . . . . . . . . . 260

DlXEY, FRANK. Th0 Tertiary and Post-Tertiary Lacustrine Sedi- ments of the Nyasan Rift-Valley (Plates XXX-XXXIII ) . . . . 432

ELTON, CHARLES S. The Nature and Origin of Soil-Polygons in Spitsbergen (Plates X-XII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

a 2

iv TABLE OF CONTENTS. PAGE

GARDINER, CHARLES IRVING. The Silurian Inlier of ~roolhope, Herefordshire (Plates XXXVII I -X L) . . . . . . . . . . . . . . . . . . . 501

GEORGE, TBOI~IA8 NEVILLE. The Carboniferous Limestone (Avonian) Succession of a portion of the North Crop of the South ~Vales Coalfield (Plate II) . . . . . . . . . . . . . . . . . . . . . . . . . . 38

GLENDAY, VINCENT G. (~ J. PARKINSON). The Kateruk Series and Associated Rocks of the Northern Suk Hills. Kenya Colony (Plates LIX & LX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 790

HAWKINS, HERBERT LEADER (& Miss S. M. HA~PTO.~). The Occurrence, Structure, and Affinities of Echinocystis and Paleeo- discus (Plates XLIV-XLVI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 574

HEARD, A~.~.RT. On Old Red Sandstone Plants showing" Struc- ture, from Brecon, South %Vales (Plates XI I I -XV) . . . . . . . . . . 195

HOPWOOD, ARTHUR TINDELL. On some l~[ammalian Remains from Lake Nyasa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44~

LANG, "~VILLIAM DmKSON (& S. S~TH). A Critical Revision of the Rugose Corals described by "W. Lonsdale in Murchison's ' Silurian System' (Plates XXXIV-XXXVII ) . . . . . . . . . . . . . . 448

147

ODELL, I~OlgL EWART. Preliminary Notes on the Geology of the Eastern Parts of Central Spitsbergen; with special reference to the Problem of the Hecla Hook Formation (Plates VI-IX) . .

PARKINSON, JOHN (& Y. G. GLENDAY). The Kateruk Series and Associated Rocks of the Northern Suk Hills, Kenya Colony (Plates LIX & LX) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 790

PHILLIPS, 1;R^I~K COI~ES. Tile Serpentines and Associated Rocks and Minerals of the Shetland Islands (Plates XLIX & L) . . . .

REED, FRI~DERICK RICHARD COWPER. PalmontologicaI Notes on tile Silurian Inlier of ~Voolhope (Plates XLI & XLII) . . . . . .

�9 Description of Camarotwchia crebrilineata sp. nov. (Plate XLVII) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

622

531

619

SMITH, WALTER CAMPBELl. (& L. J. CHUBS). The Petrography of the Austral or Tubuai Islands (Southern Pacific) . . . . . . . . . . 317

( ~ ) . On the Geology of Maiao (Society Islands) . . . . . . . . 34~

SMITH, STANLEY (& ~V. D. LANG). .h_ Critical Revision of the Rugose Corals described by W. Lonsdale in Murchison's ' Silurian System ' (Plates XXXIV-XXXVII) . . . . . . . . . . . . . . 448

SHOTTON, FREDERICK WILLIA)I. The Conglomerates of the Envillo Series of the Warwickshire Coalfield (Plate XLVIII ) . . . . . . . . 604

RlCUEY, JA~tES ERNEST. The Structural Relations of the Mourne Granites, Northern Ireland (Plates L I -LI I I ) . . . . . . . . . . . . . . 652

TABLE OF CONTF, NTSo T

PAG~ STUBBLI~FIELD, CYRIL JAMES (& O. M. B. BULMAN). The Shineton

Shales of the %Vrekin Distr ict : wi th Notes on their Develop- men t in other Pa r t s of Shropshire and Herefordshire (Plates l I I - V ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TRUEMAN, ARTHUR ELIJAH (& J. H. DAVIES). A Revision of the Non-Marine Lamellibranchs of the Coal Measures, and a Dis- cussion of their Zonal Sequence (Pla tes X V I & X V I I ) . . . . . .

96

210

WALL.IS, FREDERICK STRETTON. The Old Red Sandstone of the Bristol District (Pktte LVI I [ ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 760

WHtTTARD, WALTER FREDERICK. The Strat igraphy of the Valent ian Rocks of Shropshire : the Main Outcrop (Plates L V I & L V I I ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 737

WILLIAMS, HOWEL. The Geology of Snowdon, Nor th ~Vales (Plates X X I V - X X I X ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346

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

Proceedings of the Meetings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7, cv

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

Lists of Donors to the Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv

List of Foreign Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvi

List of Foreign Correspondents . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii

List of Wollaston Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxvii i

List of Mm'chison Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxix

List of Lyel l Medallists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxx

Lists of Bigsby and Prestwich Medallists . . . . . . . . . . . . . . . . . . . . xxxii

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

Es t imates for 1927 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxiv

Financial Repor t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxxvi

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

Anniversary Address of the President . . . . . . . . . . . . . . . . . . . . . . . . lii

vi TABLE OF CONTENTS. PAGE

BATHER~ FRANCIS ARTHUR. On C o ~ u m enigmali~m . . . . . . . . i

�9 On a U-shal~ed W o r m - B u r r o w from the Upper D w y k a Shales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . cvi

~ . On Cora l -Rock from the l~ed Sea, near J e b e l Teir . . . . . . . . c ix

DAVID, Sir T. W . EDOEWOR'rH. On a Bor ing in the Great Barrier R e e f . . "r . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

~ . On Bathyuriseus from N o r t h - W e s t e r n Queens land . . . . . . . . cvi i

HAWKINS, HERBERT LEADER. On .Echinocystis pomum and Proto- seolex latus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

RAKA ]RAo, I,. On a Cervical Ver t eb ra of Megaloaaurua from the Tr ichinopoly Cretaceous Deposits . . . . . . . . . . . . . . . . . . . . . . . . . . cx

LIST OF THE FOSSILS F I G U R E D A N D DESCRIBED

I N THIS V O L U M E .

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

AAlVe.olina oblo~ga, fig. 5 . . . . . . "} ssuina rani~oti, ~)1. xxi . . . . . . I

JDict~/ovonoides conditi, pls. xxi[ & xxii . . . . . . . . . . . . . . . . . . . . . . . . . . . !

- - - haimei sp. nov., pls. xxi I & xxii . . . . . . . . . . . . . . . . . . . . . . . . . . . !

- newboldi, pl. xxii . . . . . . . . . ] Discocylina ranikotensis sp. I

nov., fig. 4 & pl. xxii . . . . . . .STummulites 91obulus var. in-

dicus nov., pl. xx . . . . . . . . . . . . - - . nuttalli sp. nov., pls.

xviii & xix . . . . . . . . . . . . . . . . . . . . I var. kohaticus nov.,!

pl. xix . . . . . . . . . . .

thalicus sp. nov., pl. xx .] �9 ar. gwyna~ nov.,I

pl. xx . . . . . . . . . . . . . . : . . . . . . . . . . . . I --- wadiai sp. nov., pls. xxi[ & xxii . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operculina ef. canalifera, pl.; �9 X . . . . . . . . . . . . . . . . . . . . . . . . . !

sinden~is sp. nov., pl. xix.: Siderolites mLscella, figs. 1-3

&p l . xx . . . . . . . . . . . . . . . . . . . . . . . . I �9 stampi sp. nov., pl. xxi..!

Acanthocgclus binus, pl. xxxvii. fletcheri, figs. 1 & 2 . . . . . . porpitoides nom. nov.,

fig. 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . Acervularia ananas, figs. 3 &4.

var. singularis nov . . . . . . . - - var. truncate, pl. xxxv. . . ArachnoThyUum diffluens, pl.

xxxiv . . . . . . . . . . . . . . . . . . . . . . . . . . . murehisoni, p [ xxxiv ... typus, figs. 5-7 . . . . . . . . . . . .

[ Chonophyllum ?] patellatum.. ! Cystiphyllum cylindricum, pl.

xxxvi . . . . . . . . . . . . . . . . . . . . . . . . . . - �9 siluriense . . . . . . . . . . . . . . . . . . ) Koninckophyllum columatum

sp. nov., pl. ii . . . . . . . . . . . . . . . Pal~ocyclus porpita, fig. 17 . .

F O R A ~ I I N I P E R A .

I

} R a n i k o t Beds . . . i Thal ( I , ,d ia ) ...! {

i

/ 282-83 2 7 i

279

280-81 279-80

281-82

271-73

266-68

269 268 269-71

271-73

273-74

276 274-76

277-78 278

A c ' r [ s o z o A .

t Si lurian . . . . . . . . .

I , ]

• . . . . . . . . . { S i lurian . . . . . . . . .

Var ious . . . . . . . . .

South Wales ... Various . . . . . . . . .

( 483

,t86 451 463-64 474

I

J 468 i 467-68 ] 452-53, I 469

482

~4~6

86-88 4 8 5 - 8 6

V I I I F O S S I L S F I G U R E D A N D D J E S C R 1 B E D .

.Name of Species . i F o r m a t i o n . I L o c a l i t y . I :Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. A . C T I N O Z O A (continued).

])atrophontes truncatus, figs. 8 - 9 & pl. x x x v . . . . . . . . . . . . . . .

Phaulactis angusta, fig. 10 & pl . xxxv . . . . . . . . . . . . . . . . . . . . . . . .

cgaghophylloides, pl. X X X V . . . . . . . . . . . . . . . . . . . . . . . . . . .

troch~/brmis, pl. xxxv .. . _Plasmoph!/llum brevilamel.

latum, pl. xxxvi i . . . . . . . . . . . . Ptycholopas murchisoni .....

turl)inata va t . verrucosa. Spong~..h!/lloides grayi, pl.

xxxv,, . . . . . . . . . . . . . . . . . . . . . . . . . . . Tryplasma flexuosum, figs. 11-

12 & pl . xxx iv . . . . . . . . . . . . . . . ' Tarbiuolopsis' elongata, pl.

xxxvi i . . . . . . . . . . . . . . . . . . . . . : . . . . . Xylodes articulagus, figs. 1 3 -

pl . xxxv . . . . . . . . . . . . . . . . . . . . . . . J

S i l u r i a n . . . . . . . .

(

1458 , i [ 4 6 9 - 7 1

470 4 7 1 - 7 2

V a r i o u s . . . . . . . . .

478-80 477 469

4 8 0 - 8 2

461, [464-65 48~

4 6 1 - 6 2 , [ 4 7 2 - 7 3 475-7( ;

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

Echinoeystis pomum, figs. 2--41 & pls. x l i v - x l v .. , . . . . . . . . . . . . '

Palcsodiscusferox, figs. 5 - 7 &' pls . xliv, xlvi . . . . . . . . . . . . . . . . . .

i 58]-ss S i l u r i a n . . . . . . . . . i L e i n t w a r d i n e . . .

5 8 8 - 9 6

Acrotreta uicho "lsoni ............ Camarotceehia erebriliueata sp.

nov. , pl . x lv i i . . . . . . . . . . . . . . . . . Cererith#ris magnifica nov. ,

B R A C H I O P O D A .

S h i n o t o n Sbales.i i

V a l e n t i a n . . . . . . i

C o r n b r a e h . . . . . . : ch~ l . i . . . . . . . . . . . . . ~ . . . . . . . . ~

onetes la.quessiana . . . . . . . . . . . ~ A v o n i a n . . . . . . . . i - - - sp. , pl. ii . . . . . . . . . . . . . . . . . . Eoorthis af t . wimani, pl . i i i . . . S h i n e t o n Shales .

J

Linqula woolhopensis sp. nov. , W o o l h o p e �9 L i m e s t o n e ...i p l . xl i . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lingulella nicholsoni, ,vl" i i i . . . I ) , t Obolus quadratus sp. nov. , l

p l . iii . . . . . . . . . . . . . . . . . . . . . . . . . . [ ~ -Shine ton Sha les . ni (Br6ggeria) salteri, pl. I �9 " J

Obocothyris grandobovata !') nov. , pl . i . . . . . . . . . . . . . . . . . . . . . I

---magnobovata nov. , pl . i. i ~ -Cornb ra sh . . . . . . Ornithella arenaria nor . , ] I

pl. i . . . . . . . . . . . . . . . . . . . . . . . . . . . l~roductus martini, pl . ii . . . . . . ] A v o n l a n . . . . . . . . . Rhynehonelloidea arguta nov. .

p l . i . . . . . . . . . . . . . . . . . . . . . . . . . . I C o r n b r a s h . . . . .

S h r o p s h i r e . . . . . 12'/: I

C o r l e y . . . . . . . . . . . . I 6 1 9 - 2 0

C i r e n e e s t e r . . . . . 33

S o u t h W a l e s f 89 "'" L 89

S I n ' o p s h i r e . . . . . . 124

L i t t l e l m p o . . . . . . . 531

i ( 1'')3

S h r o p s h i r e . . . . . ' ~ 1 2 1 - 2 2 I

' ~ 1 2 3

i B i e e s t e r . . . . . . . . . 3 2 - 3 8 -~ B i c e s t e r . . . . . . . . . :52 I t, C o r ~ e o m b e . . . . . . 3 1 - 3 2

S o u t h W a l e s ... 8 8 - 8 9

S c a r b o r o u g h . . . 31

F O S S I L S F I O U R ~ D A N D D I ~ S O R I B F ~ D . i x

N a m e of Species. t . . . . . . .

. . . . . l ...... . . . . . . . . . . . . . . . ;oa"*y . . . . . . . . . . ,a o

BnAcHIOPOD.~, ( c o n t i n u e d ) ,

R h u n c h o n e l l o i d e a cerealis nov., p l . i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

~ - g r e m i f e r a nov., pl. i .... S e m i m d a f i c o i d e s , figs. 7 & 8. . . i S p i r i f e r sub ins ign i s sp. nov.,!

figs. 1-5 . . . . . . . . . . . . . . . . . . . . . . . (Delth~tris) elegans va r .

spars i jo l icata nov . . . . . . . . . . . . .

( .) e levatus var. ...

- - - ( E o s p i r i f e r ) r a d i a t u s . .. '

T r e m a t i s subconeen~rica sp . nov., pl. xli . . . . . . . . . . . . . . . . . .

} I i, on Bingham. ( Cornbrash . . . . . . i Sut { 29-30 ', : ( 30

Avonian ! So,,th Wales ...{ 89-91 Wen loek L ime- D o r m i n g t o n I

s tone . . . . . . . . . ! W o o d . . . . . . . . . [ 534-35

LoWerupper L u d l o w i L u d l o w ! - Var ious . . . . . . . . . t Shales . . . . . . . . . ; 532-33

Old Suf ton . . . . . . 533-34 [ Beds . . . . . . . . . ! p

J L landoverv : )- Various 532

Wenloek Lime- sto,,e . . . . . . . . . Sellers H o p e 531-32

~ R Y O Z O A .

Trepos toma ta (?) gen. indet,.,i A~mest, 'y Lime-i I pl. xlii . . . . . . . . . . . . . . . . . . . . . . . . [ stone . . . . . Fownhvpe . . . . . . I 535--36

L A MEIJLI BI tANC| I I A T A .

A n t h r a c o m y a adams i i , pl. xvii. ") - cur taga . . . . . . . . . . . . . . . . . . . . . I

- dolabra~a . . . . . . . . . . . . . . . . . . I] i n d g n i s sp. nov., pl. xviiJ

. la~ ceolaga . . . . . . . . . . . . . I

- - - . , i . i m . . . . . . . . . . . . :: ... . :::1i modio lar i s . . . . . . . . . . . . . . . . . . L I obovata . . . . . . . . . . . . . . . . . . . . . I

- - obscara sp. not'. , pl. xvi. l Coal Measures . . ph i l l i p s i i . . . . . . . . . . . . . . . . . . .

?mlchra . . . . . . . . . . . . . . . . . . . . . i p u m i l a . . . . . . . . . . . . . . . . . . . robertsoni . . . . . . . . . . . . . . . . . . r u b i d a sp. nov., pl. xvi. "1 s~tbcenlralis . . . . . . . . . . . . . . . [ i

- - t enu i s sp. nov., pl. xvi. . . I I - - w a r d i . . . . . . . . . . . . . . . . . . . . . ]1 - - w i l l i a m s o n i . . . . . . . . . . . . . . I ) Av icu lopec te~ f l abe l lum sp. I

,,or., pl. ii . . . . . . . . . . . . . . . . . . . . . Carbonico la aeu ta . . . . . . . . . . . . . . .

ajTbds sp. nov., pl. xvi.. I aqui l ina , pl. xvii . . . . t - b~l~ sp. , ,o~, pl. L i :::

- - c o m m u n i s sp. nov., figs. I 2 -5 & pl. xvi . . . . . . . . . . . . . . . . . . I

d a w s o n i . . . . . . . . . . . . . . . . . . . . . I ~ ex igua nora. nov., pl. xvi. {

- - . f u l v a sp. nov., pl. xvii. . I - - f a ~ c a sp. nov., pl. xvi .. I n i t i da sp. nov., pl. xvii.

ovalis . . . . . . . . . . . . . . . . . . . . . . . . II - rhomboida l i , . . . . . . . . . . . . . . )

South Wales ...

!

i

Avouiau . . . . . . . . Sou th W a l e s ..

Coal Measures . . South ~ ' a l e s ...

( 233 229 23"3 229-30 25O 234-35 228 229 250-31 235 231-32 231 229

i 233-34 231 235-36 230 228-29

91-92 (222

225-26 1226-27

i 225

f 2 2 3 224 2"-'5 227-28 224 226-27 224

(,223

FOSSILS FIGURED AND DESCRIBED.

LA.MEIJLIB RANCIIIATA (continued).

Carbonicola ,imili, . . . . . . . . . . . . subconstricta . . . . . . . . . . . . . . turgida . . . . . . . . . . . . . . . . . . . . . venusta nom. nov . . . . . . . .

Cffpricardinia subplanulata sp. nov., pl. xlii . . . . . . . . . . . . . .

Cyrtodonta perovalis, pl. xli.. Goniophora (Cosmogonio-

phora) decorata sp. nov. pl. xlii . . . . . . . . . . . . . . . . . . . . . . . .

Gramme~sis (Gramm~/sioidea) mclearni sp. nov., pl. xlii...

Lunulicardium insulate sp. nov., figs. 6 & 7 . . . . . . . . . . . . '

Modiolipsis (Golpom.ya) con- ,ors SlY. nov., pl. xli . . . . . . . . . I

' (?) solenoides . . . . . . . . . . . . , M~jtilarca siluriana sp. nov.,t[

pl. xlii . . . . . . . . . . . . . . . . . . . . . . . . [J ~;aiadites earinata, ete . . . . . . . - - elongata . . . . . . . . . . . . . . . . . . {J 17uculites alreus vat. woolhop-

ensis nov., pl. xlii . . . . . . . . . . . . I I pseudodeltoideus sp. nov., I [

pl. xlii . . . . . . . . . . . . . . . . . . . . . . . . ] ])aracyelas insueta sp. n o v . , '

�9 i pl. xh . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pal~eoneilo sera sp. nov., pl. ?

xlii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I -Pterineea adjuneta sp. nov., pl. xlii . . . . . . . . . . . . . . . . . . . . . . .

Pterinotella permutata sp. nov., pl. xlii . . . . . . . . . . . . . . . . . . j

8anguinolites eontortu,, pl. ii.

Coal Measures.

Upper Silurian Ludlow Beds . .

Lower Ludlow Shales . . . . . . . . .

Lower Ludlow Beds . . . . . . . . .

Lower Ludlow Shales . . . . . . . . .

Coal Measnres. .

Lower Ludlow Shales . . . . . . . . .

A v o n i a n . . . . . . . . .

228 223

South W a l e s . , 225

.223-24 |

�9 Various . . . . . . . . . ~ 542-43 /

( 544

Cockshot Wood�9

Various . . . . . . . . .

Wooton . . . . . . . . .

Fownhope . . . . . .

Wooton . . . . . . . . .

540

543-44

545-46

541-42 542

540 41 South Wales ~( 236-37

"'" ( 237 ( I Wooton . . . . . . . . . 537

Clouds ..... 536

I Fownhope ~544--45 1

l L o w e r Bueken_ ~ 537-35

I hill . . . . . . . . . . . . 539-40 /

538- 39 South Wales .. "92

(~ASTEROPODA.

JBelleropho~ beweatus sp. nov.,[ Lower Ludlowl I pl. xli . . . . . . . . . . . . . . . . . . . . . . . . . . . [ Shales . . . . . . . . . I Various . . . . . . . . . I 54647_"

PTEROPODA.

I-Iyolithus air. arat~s, pl. iii... �9 belswardine~ds sp. nov., [

~]'ho~ffe~ifle'exu~{!P2p~ i i ,~ Shineton Shales.i

iii . . . . . . . . . ... ..... : . . . . . . ". .... : 1 lineata . . . . . . . . . . . . . . . . . . . . . . / |

i 126 125-26

Shropshire . . . . . . 124-25

126

CEPHALOPODA.

O~t~oc~a, (Kio,~oee~a$) a . I Lower Ludlow granodstriatum, pl. xli . . . . . . ! Shales . . . . . . . . . Baekbury Hill. . .[ 547

F O S S I L S F I e U t ~ E D A N D D E S C R I B E D , x i

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

TRILOBITA.

ginalis nov., pl. iv . . . . . . . . . ( 1 2 7

Shine ton Shales. Shropsh i re . . . . . . 136-37 var., pl. iv . . . . . . . . . . . . . . . . . . . . . I Cyclop~/ge geuatenta sp. nov., I [ L 1 3 8 - 4 0

pl. iv . . . . . . . . . . . . . . . . . . . . . . . . . . ) .Dalmanites caudalus var. hi. L o w e r L u d l o w

tuberculata nov., pl. xli ... JDikeloke~halina furea ......... I

Encrinurus mag~ilubereulalus. {

Hospes clonograp/i gem et sp.[ ] nov., pl. iv'. . . . . . . . . . . . . . . . . . . . . i I

H3t~terolenus i&mquisti (0 i

i var., pl. iv . . . . . . . . . . . . . . . . . . . . . [ Macropgge ehermi gen. et sp. I

nov.. pl. iv . . . . . . . . . . . . . . . . . . . . . ' i 2'llyinda urico~ii gen. et sp . ! ,

nov., pl. iv . . . . . . . . . . . . . . . . . . . . . [ OrometoIn~s puru.s sp. no,,'.,[ 1

pl. iv . . . . . . . . . . . . . . . . . . . . . . . . . . . I Shumardia curta sp. n o v , p l : [

iv . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i )

Shales . . . . . . . . . Sh ine ton Shales. Wen loek L i m e -

s tone . . . . . . . . .

Sh ine ton Shales.

W o o t o n . . . . . . . . . Shropsh i ro . . . . . . Buckenh i l l

W o o d . . . . . . . . .

Shropsh i re . . . . .

5 4 7 - 4 8 136

548-49

1 2 8 - 3 0

137-38

1 1 4 0 - 4 3

130-31

i 133 -36

L x 3 1 - ~

PL ANT.~',,

Gosslingia breconensis gem et' Lower Old Red sp. nov., pls. x i i i -xv . . . . . . . . . i S a n d s t o n e ... Brecon . . . . . . . . 198 -203

INCERT,~ SEDIS.

,Pachytheca (?), fig. o & pl. xv. { Lower Old Redl - Sands tone . . . ! } B r e c ~ . . . . . . . . . t 1203-204

EXPLANATION OF THE PLATES.

PLATE CORNBIIASI-I BRA('IIIOPODA, illustrating Mr. S. S. Buck- ]

I man's paper on some Faunal Horizons in Corn-~ brash ............................................................ " )

PAGe.

1

X I I I - X V f

f AvoNIAN FOSSILS FROM TIlE SOUTll WALES COALFIELD,'[ ilhlstrating Mr. T. N. George's paper r the Avonian t 38

I I Succession of a portion of tile North Crop of that coalfield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PLATES (BRACHIOPODA AND PTEROPODA FROM THE SIIINETON~

[ SIIALES : TRILOmTA fro,n the same ; and GEOLO- [ I I I - V ~ GICAL MAP OV THZ SmNETON S,IAL~S OF Tile WREKIN ~- 96

f DISTRICT, illustrating the paper by D:. C. J. Stubble- | I, field & Dr. O. M. B. Bul ,mn on that formation ...... }

(LowER PART OF BEAR BAY GLACIER and I-IgAD OV~ I NORDENSKJOLD GLACIER; TOP OF ~OUNT Ct{ERNI- I

SlIEr alld SECTION ACROSS TIlE STRIKE IN TIlE NEIGH- I BOURIIOOD OF :BEAR :BAY GLACIER; ~'IDNIGHT VIEW

V I I X ~ PltO.~I MOVNT ttOrE, the CITADEL. and SOUTHERN ~" 147 I PACIZ OF MOUNT TERRIER; and GEOLOGICAL ~AP OF I ] NEw FRIESLAND, illustrating Mr. N. E. Odell's paper l [ on the Geology of the :Eastern Parts of C, entral . I, Spitsbergen ................................................... )

(STONE STRIPS ON A SLOPS and MUD-POLYGONS NEAR 1 1 BRucECITY ; MUD-POLYGON OVERGROWN WITII PLANTS ]

and CONVEX MUD-POLYGONS, ]~RUCE CITY; EARLY X-XII '~ STAGES IN THE FOItMATION OF A 8TONE-I'OLYGON alld I

PART OF STONE-BORDER SURROUNDING TIIE MUD CENTRE ,~ 163 i I OFTIIE sTONE-POLYGON, illustrating Mr. C. S. Elton's I

paper on the Nature & Origin ef Soil-Polygons in Spitsbergen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . /

GOS.SLLvc, IA BRECO.VE:r and -PACIIYrltEC.4 (?.), i l lus - ] trating Dr. A. lIeard's paper on Old Red Sandstone j, 195 Plants from Brecon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CC.4RnO.VICOZ.~ and A.VrHRACOMrA, illustrating tile Ro-~ XVI & X V I I I vision of the Non-Marine Lamollibranchs of tile t

"~ Coal Measures by Mr. J. H. Davies & Dr. A. E. t . Trueman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . )

210

EXPLANATION OF THE PLATES. ..~

PLATES PAQI.

{ ~:~gb'Ltr~CS and OPs : and SrDEROLXTF.S, ] Dzcrrocoxo~DrS, DiscocrcLz~a, ~.TC., illustrating [ 260.

X V I I I - X X I I Major L. M:. l)avies's paper on the Ranikot | Be(is at Thai . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J

t:LATE AIC.UI LLES BEll i N D A IIURI~I VILLAGE, RAPA ; AllURE[ VILLAGE AND BAY; and ~ANORA311C SKETCI[ OF I

XXII I~ THE CRATI~R OF RAPA. illustrating M:r. L. J. ~. I Chubb's paper ou the Oreology of the Austral I ,. or Tubtmi Islan(ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . )

291

PLATES (SYNCLINE OF CLOGWYN ]-)U'R ARI)I)U ; LLIWEDD ;'~

~ACE OF SIIATTER-BELT NEAR 1)EN-AR-L()N ; CRIB (~OCII AND TIlE PINNACLES; ~ENERALIZED ~[aP i

X X ~ V - X X [ X ~ OF TIlE SUPERFICIAL DEPOSITS AgD GLACIAl, } ] STRI,E OF SNOWDON*; arid GEOLOGICAL MAP OF [ I SSOWBOS, illu,~trating Mr. Howel Williams's I (, paper on the Geology of that area . . . . . . . . . . . . . . . )

X X X - X X X I I I

t VIEW ACROSS TIlE MWAKASYUNGUTI VAI, L'EY; T l l l ~

LACUSTRINE SERIES NORTII OF TIlE EASTERN END I OF TIIE MrWERO GORC,~ ; TILTEI) BLOCK DE SUN- ]

, GWA ~EDS; SCARP OF SUNOWA BEDS; SECTIONS ] I ILI.USTRATING TIII.: STRUCTURE OF 'I'IIF~ COVXTRY

~{ LYING ALONG THE ~TORTII-WESTEItN SIIORt.s OF i [ LAKE NYASA: ant i GEOLOGICAL MAP OP TIRE] I SAM~ AREA, illustrating Dr. F. Dixey's paper] I on the Tertiary & Post-Tertiary Lacustrine I I Sediments of the Nyasan Rift-Valley . . . . . . . . . . . . )

346

432

( I

XXXIV-XXXVII 1 I I

TRYPLASMA " FZEX~rOSU)[, ETC. ; PHAULACTIS AN- GUSTA, ETC. ; CI'STIPIIYLLUM C]'LINDRICUM; and ] ~PONGOPHYLLOIDES GRAI'I, ETC., illustrating the , Revision of the Rugose Corals described by ( Mr. Lonsdale in Murchison's' Silurian Systeln,' | by Dr. W. D. L~mg & Dr. Stanley SImth ...... J

448.

( 1 I

X X X V I I I - X L 1

WOOLIIOPE LIMESTONE IN SCUTTERDINE QUARRY ; ') AYMESTRY LIMESTONE IX SUFTON COCKSHOOT I QUARRY; QUARRY AT PRIOR'S FROME; a n d I

GEOLOGICAL MAP OF T.E WOOLHOPE I,~LIER, ~ 50t illustrati~:g Mr. C. I. Gardiner's paper on that ! a r e a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . //

SILURIAN" FOSSILS FROM TIIE WOOLIIOPE INLIER, t XLI & XLII illustrating Dr. F. R. C. Reed's paper on those 53I

fossils .... " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

PLATE

fGEOLOC, ICAL h~AP OF Tile CAMBRIAN AREA O~"~ J CO.~LEY (SuaorSlllaZ), illustrating Mr. E. S.(_

X I , I I I | Cobbold's paper o,i the Stratigraphy & Geo- [ / logical Structure of that are~ . . . . . . . . . . . . . . . . . . . . . j

551

X i V E X P L A N A T I O N OF T H E PLATES.

PLATES f EOHINOOYSTI.'~ .PoMv.~ AND PA.L.,~ODISeU,.q .F.E.ROX, illus- "1

trating the paper by Prof. H. L. Hawkins & Miss [ X L I V - X L V I | S . M . Hampton on the Occurrence, Structure, & [

I Affinities of those fossils . . . . . . . . . . . . . . . . . . . . . . . . . . , ...... J

PLATE

XLVII {

XLVII I [

PLATES f.

XLIX & L [

PAOB

574

L I - L I I I

CAM.~ROrrEC.HIa CREBRILINEara sP. NOV.. illustratir.g i Dr. F. R. C.~Reed's description of that" fossil ........ ~ f 619

~EOLOGICAL SKETCH-~Ap OF TtlE AREA NORTH OF) COVENTRY, illustrating M:r. F. W. Shotton's paper[ on the Conglomerates of the Enville Series of the[ 604 Warwickshire Coalfield .................................... J

SERPENTINES, FTC. fl'oI]i the Shetland Islands, illustrat- ing Dr. F. Coies Phillips's paper on the Serpentines and Associated Rocks and Minerals of that area ... J

I INTRUSIVE GRANITE-~C~ARGINS AOAIN~T OLDER (~RANITES ; HORIZONTAL SECTIONS ACROSS TIIE MOURNE (~RANITES ; and MAP of" the same, illustrating Mr. J. E. Richey's

t paper on the Structural Relations of those Granites.

GEOLOGICAL MAP OP THE COUNTRY SOUTII~ OP~ RrTnIN (DENSIGIISIIIRE), ilhlstrating Prof. P. G. H. Boswell's paper on the Salopian Rocks & Tectonics | of that area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . )

G'EOLOGICAL SKETCH-MAP OF, AND SECTIONS ACROSS, TIIE COUNTRY BLTWEEN :LLANELIDAN AND :BRYN- | EOLWYS, illustrating Mr. R. C, Blackie's paper on the Geology of that area ....................................... /

]~ORIZONTAL AND ~rERTICAL SECTIONS TO ILLUSTRATE~ TIlE TIIINNINN-OUT OF TIIE VALENTIAN SUBDIVISIONS ; [ and MAP OF TIIE VALENTIAN I{OCKS IN THEIR MAIN ~- OUTCROP IN SIIROPSIIIRE, illustrating Dr. W. F. [ ~h i t t a rd ' s paper on those rocks . . . . . . . . . . . . . . . . . . . . . . . . )

~ICROSCOPE-SLIDES O1 ~ SANDSTONE, ETC., illustrating1 Dr. F. S. Wa]lfs's paper on the Old Red Sandstone ~, of the Bristol District . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J

PLATE (

1.1v

( ~v4

I / PLATES

( I

L v I & LVII

PLATE

L V I I I {

PLATES (CIILORITE-BIOTITE-ScIIIST FROM MOYALE and ]~ATERUK "~. I BEDS EXPOSED IN TIIE RIVER-BED; and IGNEOUS I j AND METAMORPHIC ~{.OCRS FROM TIIg NORTHERN SUK

LIX ~5 LX~ HILLS, illustrating the paper by Mr. V. G. Glenday , & Dr. J. Parkinson on the Katernk Series &l

[, Associated Rocks of those hills . . . . . . . . . . . . . . . . . . . . . . . . ]

6 2 2

653

689

711

737

760

790

~ORRELATION-TABLE Or TIlE SHINETON SIIALES, facing . . . . . . . . . . . . . . . . . . . . . . . . 118

:DISTRIBUTION OF THE NoN-MARINE LAMELLIBRANCHS IN TIIE COAL MEASURES OF THE WESTERN PART OF SOUTH WALES, facing ... . . . . . . . . . 240

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

BESIDES THOSE IbT T H E PLATES.

]-'AG E

FIG. 1. [Diagram illustrating ' overrunning' of beds] . . . . . . . . . . . . . . . 8

2. Map of the Southumbrian Gornbrash area . . . . . . . . . . . . . . . . . . 16

1. Map of the Carboniferous Limestone outcrop in the northern part of the South Wales coalfield, facing ... 40

2. M~ap of a portion of the South-Western Province, showing the outcrop of the Carboniferous Limestone, facing ... 40

3. Section i~ the Lower Limestone Shares at Ffynnon Cadachog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Fins. 4 a - 4 c . Limestone containing quartz-crystals . . . . . . . . . . . . . . . . . . . . . . . . 60,61

FIG. 5. Section in the Lower Limestone Shales at Cwm Byfre ... 70

6. Vertical sections in the Carboniferous Limestone along the North Crop between Kidwelly and Penwyllt .. . . . . 82

7. Variation in the shat)e of the shell of specimens of S e m i n u l a fwoides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

8. Sections through the hinge-region of S e m i n u l a f i c o i d e s . . . 91

Fins. 1 & 2. Geological maps of Oherme's Dingle . . . . . . . . . . . . . . . . . . . . . . . . 106,107

FIG. 3. ~orizontal section through Gherme's Dingle . . . . . . . . . . . . . . . 108

1. Diagrammatic section across a mud-polygon . . . . . . . . . . . . . . . 174

2. Diagram showing successive stages in the formation of stone-polygons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186

3. Rough diagram of stone-polygons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188

1. Sketch-map showing the locality of the Breeon O.I~.S. plant-assemblage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

2. Sketch of organism resembling Pach~/gheca . . . . . . . . . . . . . . . . . . 204

1, Diagrams illustrating terms used in the measurement of lamellibranchs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212

xvi PROCESS-BLOCKS AND OT[IER ILLUSTRATIVE FIGURES.

PAQZ

FIG. 2. Outlines of specimens of Carbouicola aft. communis ...... 214

3. Graphs illustrating the variation in communities of the same ............................................................... 216

4. Scatter-diagrams illustrating the same point ............... 217

5. Diagram illustrating tile ralation of the form of the lower border to the height of the shell in Carbonicola aft. c o m m u n i s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218

6. Scatter-diagram illustrating variation in specimens re- sembling A n t h r a c o m y a a d a m s i i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232

7. Diagram illustrating variations in A u t h r a c o m ~ / a and N a i a d i t e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242

8. Graph showing variation in height in Carbonico la aft. . fu lva . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

9. Section illustrating the sequence of lamellibranchs in the Ooal Measures of North Staffordshire . . . . . . . . . . . . . . . . . . 248

10. Section illustrating the sequence of lamellibranchs in the Coal M:easures of the North of France .. . . . . . . . . . . . . . 049

Fins. 1-3. Equatorial sections of Siderol i tes m i sce l la . . . . . . . . . . . . . . . . . . . . . 278

Fro. 4. Megalospheric protoconeh associated with Discocyc l ina r a n i k o t e n s i s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282

5. Meridian section of A l v e o l i n a ob longs . . . . . . . . . . . . . . . . . . . . . . . . 282

6. Geological sketch-map of the neighbourhood of Thai ... 285

7. Schematic section showing Kurram Picquet Ridge, facing 286

8. Section to east of the Ishkalai, facing 286

I. Map of the Austral or Tubuai Islands and neighbouring groups ... . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . o92

2. Map of Raps Island . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .094

3. Superimposed sections across Rapa . . . . . . . . . . . . . . . . . . . . . . . . . . 300

4. Marotiri, from the south-west . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302

5. Map of Rurutu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304

6. Generalized section across Rurutu . . . . . . . . . . . . . . . . . . . . . . . . . . . 308

7. Transverse section across an asymmetrical anticlinal fold on the ocean-bottom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

Fins. i & 2. View of Maiao and generalized section from the central volcanic island to the ree f edge, Maiao . . . . . . . . . . . . . . . . . . 343

Fro. 1. Tourmalinized grit from Bwleh Gwyn . . . . . . . . . . . . . . . . . . . . . . . . 356

2. Epidotized grit and quartz-magnetite-spessartite-schist... 361

3. Geological section from Gallt-y-llan to Llyn Gwynant ... 376

4. Chloritized pumice-tuff, spilitie bomb, and rutile-rich pumice-tuff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380

PROCESS-BLOCKS AND OTHER ILLUSTRA.TIYE I~IGURES. XVI1

PAGZ Geological section from Bwleh Cwmllan to Naut

Gwynant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386

Map of the acid intrusions of Tal-y-llyn, Llanberis Pass. 394

Spherulitie felsite and quartz-porphyry . . . . . . . . . . . . . . . . . . . . . 396

Albite-porphyritc and epidote concretion . . . . . . . . . . . . . . . . . . . . . 403

Amphibolite, cupriferous spilitic dolerite, and epidosite . 410

Map of part of the thrust-zone in Cwm Clogwyu . . . . . . . . . 412

Map of the thrust-zone near Rhyd-ddu . . . . . . . . . . . . . . . . . . . . . 418

Sections exposed 300 yards south of Pen-ar-lbn . . . . . . . . . . . . 420

Section exposed along Afon Treweunydd . . . . . . . . . . . . . . . . . . . . 422

Acanthocye lus f le tcheri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450

Acervu lar ia ananas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451

Arachnophy l lum typus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452, 453

Patrophoules t runcalas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456

Phaulac t i s an, f/usta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458

Trypla,~ma f l exuosum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461

Xz/lodes ar t icu la tus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462

Xylodes pseudodiauthus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475

Acan t hocyclus porp i / oides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486

Pal~eoc!/ches porp i la . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486

Geological map of tim Saltern Cove area, and section across the same . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494

1. Section through Woolhope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504

2. Section along a line due east of Holm Lacey Bridge ...... 506

3. Section through the ridge, 300 yards east of Ethelbcrt's Copse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510

4. Section in the quarry at Prior's Frome . . . . . . . . . . . . . . . . . . . . . 515

5. Map of the neighbourhood of Old Sufton . . . . . . . . . . . . . . . . . . 520

FIGS. 1--5. S p i r i f e r i~ubinsignis sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534

6 & 7. L u m d i c a r d i u m insulate sp. nov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545

1-6. Parallel sections across the Comley Cambrian area . . . . . . . . 558

Fro. 7. Enlarged map of Dairy Hill, Comley . . . . . . . . . . . . . . . . . . . . . . . . 562

8. Generalized section across the Comley Cambrian area ... 567

9. Hypothetical section of disturbed and eroded Lower Cambrian beds, during the deposition of the Middle Cambrian . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 569

VOL, LXX-XIII. b

FIG, 5.

6.

7.

8.

9.

10.

II .

12.

13.

Fins. 1 & 2.

3 & 4 .

5-7.

8 & 9 .

Fro. 10.

FIGs. 11 & 12.

13& 14.

Fro. 15.

16.

17.

XVIII PROCESS-BLOCKS AN]) OTHER ILLUSTRATIVE FIGURES,

PAoz Fro. 1. Sketch-map of the district near Leintwardine . . . . . . . . . . . . . . . 577

2. Echinocyst is p o m u m . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 583

3. do. do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586

4. Diagrammatic section across the ambulaerum and contiguous parts of Echinocys t i s . . . . . . . . . . . . . . . . . . . . . . . . . . . 587

5. _Palceocliscus f e rox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 590

6. do. do . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 592

7. Diagram.of ambulazrum of P. f e r o x . . . . . . . . . . . . . . . . . . . . . . . . 595

-- . Vertical section of the Enville Series, ere . . . . . . . . . . . . . . . . . . 606

1. Diagram illustrating tile probable derivation of the sand- stone-pebbles of the Arley Conglomerate . . . . . . . . . . . . . . . 614

2. East-to-west distribution-diagram of Valentian sand- .~tone ill the Corley Conglomerate . . . . . . . . . . . . . . . . . . . . . . . . 616

1. Geological sketch-map of Unst and Fetlar . . . . . . . . . . . . . . . . . . 624

2. Map of the Unst intrusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 626

3. :Banded chromite-serpentine, Nikka Vord . . . . . . . . . . . . . . . . . . 632

4. 0hromite-ore, Nikka Vord . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 634

5. Chromite-ore, showing translucent and opaque portions. 636

6. Diagram of the occurrence of anthophyllite at t[illswick. 642

1. Map of the Tertiary igneous rocks and Devonian granite of Newry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 654

2. Plan of junction of quartzose granite with Silurian shales, Glen River . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . {;[~l

3. View of the north-eastern portion of the Eastern Mournes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 666

4. View of the southern portion of the East0rn Mourm~s ... 668

5. View of the south-western portion of the Eastern Mournes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 672

6. View of' the junction of the Eastern and Western Mournes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676

7. Diagram illustrating the mode of iatrusion of the Mourne Granites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 685

1. Restoration of the Valentian shore-line between Gilberries and Morretl's Wood Farm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 740

2. Locality-map of exposures of Valentian rocks in Harper's Dingle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 744

t~ROCESS-BLOCKS AND O~:USR IL~USTR~.TIVE YmURES. x ix

PAGE

FIGS. 3 a & 3 b. Section on the northern bank of the O , n y River ......... 748

Fro. 4. Enlarged drawing of a portion of the disturbed strata in the Onny Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75{)

5. Map of the Silurian transgression in Southern Shropshire. 754

- - . Map showing outcrops of the Old Red Sandstone in the Bristol district . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 762

- - . Sketch-map of Turkana, showing the escarpment of the Northern Suk Hills . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792

D a t e s o f I s s u e of t h e Q u a r t e r l y J o u r n a l f o r 1927.

No. 329--April 23rd, 1927.

No. 330--July 19th, 1927.

No. 331--October 20th, 1927.

:No. 332--December 15th, 1927.

No. 332~--February 8th, 1928.