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Oca yy Per wre ha ignit Baste od te teh AM add NaS Had eee Gee it yah ae ae ih f ied a dd ti wh Oh Ried deed dt aot ee 1 ae 88 ‘ “ ach a eeee men ih" ee iy % {Ss aeew oda Ww La ida a ae Fi tuchidnad Aranda Cy RACAL Altaf a Rane wt an i Sad 4.8) i i pated a debe ll ee ALB aid 4 DARN a Tc MEW WUT RE DOOD iy, “ Qt tet ot Pie bes iH Ie do ed ee ES Hed ai Seer eran ane WR BOD WC ECTS id Lede a dd dad “a AAT tate he imei ir He Te bad aren) | VNC I CU SCH RUA SOC ROALSL Adhd bed GLO OM Par PURO RE a ee RT be aT are Wr a : aah stan Wy aE a tat he lariat i ir iid ‘ Lp-aok 594.009, wa ead apt Whi tA tt if UA “ais! nai Wah ddd eit ee ka aN ot cee de Tih, Aga a ie 4) 4 Gh ty with i Niiitiacy.@ kane i LY boat ‘ tail i eae Uae Thee Moats nal Aaah rai enn % Va) rete eo re tt es vet Ny Pave wen hehe WC? Bee) ‘ \ + 4A ‘ ait Hl agente a 4 ya" F y beh seaees * ‘ 4 iy ‘ PEN POL dee f a be . nae ate Geos rhe wait de met i aA ne Mae iy i i 1809 Hus. gst wee ye Ps oy, Sak : La if < / A ‘ 7} : we’) 7. » a . nt e \\ Fg he (ie ) i : v THE QUARTERLY JOURNAL - ? Bs Pie, OF THE EDITED BY {THE ASSISTANT-SECRETARY OF THE GEOLOGICAL SOCIETY. od si cui mortalium cordi et curz sit non tantum inventis hzerere, atque iis uti, sed ad ulteriora trare ; atque non disputando adversarium, sed opere naturam vincere; denique non belle et probabiliter ari, sed certo et ostensive scire; tales, tanquam veri scientiarum filii, nobis (si videbitur) se adjungant. ovum Organum, Prefatio. VOLUME THE SIXTY-FIRST. 1905. LONDON: © LAST LONGMANS, GREEN, AND CO. _ PARIS: CHARLES KLINCKSIECK, 11 RUE DE LILLE, SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. MDCCCCY. Zst OF TIM OFFICERS OF TILE GEOLOGICAL pOCIETY OF LON ~~ MARRARARALRADRAROIY Elected Februar yi 17 th, 1905. DY AININII ae John Edward Marr, Se.D., F.B.S. Wice-Presivents, Prof. Thomas George Bonney, Se.D., LL.D., |} Prof. Charles Lapworth, MSc. TDs ELR.S., F.S.A. E.R.S. PS Bide Robert Staneteldl Herries, M.A. ~ | Horace Bolingbroke Woodward, F.R.S. Secretaries. Prof. William Whitehead Watts, M.A., | Prof. Edmund Johnstone Garwood, M.A. M.Sce., F.R.S. Foreign Secretary. | Creagurer, Sir John Hyans, K.C.B., D.C.L., _ D., { Vacant. ] ERS. F. L. S.. ; Bh a COUNCIL. Francis Arthur Bather, M.A., D.Sc. Richard Lydekker, B.A., 1. B.S. Prof.Thomas George Bonney,Sc.D.,LL.D., | Bedford McNeill, Assoc.R.S.M. E.R.S., F.S.A. John Edward Marr, Se.D., F.R:S. Sie J ohn Kyans, K, C. B., D.C.L., LL.D., | Prof. Henry Alexander Miers, M.A., F.R.S. ERS. Horace Woollaston Monckton, F.L.S. Prof. Edmund Johnstone Garwood, M.A. | Frederick William Rudler, I.8.0, Sir Archibald Geile, Sc.D., D.C.L., LL.D., | Leonard James Spencer, M.A, Sec.R.8. Aubrey Strahan, M.A., F.R.S. Robert Stausfield Herries, M.A. Oharles Fox Strangways. Prof. John W. Judd, C.B., UL.D., F.R.S. | Prof. William AWilnicelenel Watts, M.A... Prof. Percy Fry Kendall. M.Sc., F.R.S. Philip Lake, M.A. The Rey. Henr y Hoyte Winw eat M.A. Prof. Charles Lapworth, M.8c., LL.D., | Horace Bolingbroke Woodward, F.R.S. E.R.S. | Assistant. sea vecllat Clerk, Librarian, anv Curator. L. L. Belinfante, M.Sc. Assistants tn Office, Library, anv fMuseum. W. Rupert Jones. Clyde H. Black. Alec Field. STANDING PUBLICATION COMMITTEE. Dr. J. H. Marr, President. Prof. W. W. Watts. Oa ee “Prof. EJ. Garwood. AG Dr. F. A: Bather. ~ Mr. R. Lydekker. Prof, T, G. Bonney. | | - Prof. H. A. Miers. Sir Archibald Geikie. Mr. H. T. Newton. Mr. R. S. Herries. ' Mr. A. C. Seward, Prof. J. W. Judd. Mr. H. B. Woodward. Prof. Charles Lapworth. TABLE OF CONTENTS. Page ARBER, I). A. NEWELL. On the Sporangium-like Organs of Glossopteris Browniana, Brongn. (Plates XXX & Nee) woe. oad ARrNnoLD-Bumrose, Henry Hown, & E. T. Newron. On an Ossiferous Cavern of Pleistocene Age at Hoe-Grange Quarry, Longcliffe, near Brassington, Derbyshire (Plates V- VIII) cine ee) Avusury, Lord. An Experiment in Mountain-Building: Part IT. 345 BEADNELL, Hugo Joun Lurwettyn. The Relations of the Eocene and Cretaceous Systems in the Hsna-Aswan suc of Line IN lle “Welly 20a Spee ce a ns rue ara ee PM a 667 Brake, the Rev. Joun Freprericx. On the Order of Succession of the Manx Slates in their Northern Half, and its Bearing on the Origin of the Schistose Breccia associated therewith...... 308 Bonney, Prof. Tuomas Grores, & Miss C. A. Rargin. The Microscopic Structure of Minerals forming Serpentine, and their velanompots Elistory (Plate XUV). i 0c. ceo ce. deen eet oe 690 BucKMaN, Sypney 8. On Certain Genera and Species of Lytocer ne Elo Gieg UIC NOV CC NEV Le) rath h tap tacalat dh sapuaiihe ptsbe ue (aun, ape Gut-hinee var 142 Davison, Dr, Cuarues. The Leicester Earthquakes of August zeeos,and sume 2st 1902 (Plated) on kes ccc. se 1 The Derby Earthquakes of July 3rd, 1904 (Plate H).... 8 ——. Twin-Earthquakes.............0.... SS Athy Sonne ee 18 Donaxp, Miss Jane. Observations on some of the Loxonematide, with Descriptions of Two New Species (Plate XXX VII pars) . 564 ———. On some Gasteropoda from the Silurian Rocks of Llanga- dock, Caermarthenshire (Plate XXXVII pars) .............. 567 Exspen, James Vincent. On the Igneous Rocks occurring’ be- tween St. David’s Head and S parma Head, Pembrokeshire CPlates! MOOK ME XN... Se ds. oho ae te ee ee Ra 579 FEARNSIDES, WILLIAM GEORGE. On the Geology of Arenig Fawr and Moel Llyfuant (Plate XL) MeaNar bets sha tcaner sre ain diy. a, xc ayide aoe 608 1V TABLE OF CONTENTS. Page FisuEr, the Rev. Osmonp. On the Occurrence of Elephas meri- dionalis at Dewlish (Dorset). Second Communication: Human Agency suggested (Plates WI & [V) ....... 2) see Hinp, Dr. WHEELTON. Notes on the Paleontology [of the Marine Bands in the North-Staffordshire Coal-Measures] (Plates XX XV ® ROC RV 1) ice tee OMe soe hie ke 527 Howr, Joun ALLEN. Petrological Notes [on Rocks from the Congo Free State] (Plates XLIII & XLIV) .............55% 655 Kipston, Ropert. On the Divisions and Correlation of the Upper Portion of the Coal-Measures, with special reference to their Development in the Midland Counties of England............ 308 Mextior, Epwarp T. A _ Contribution to the Study of the Glacial (Dwyka) Conglomerate in the Transvaal ............ 679 MiIppLETON, Francis Epwarp. On the Wash-Outs in the Middle Coal-Measures of South Yorkshire .................-0-000. Bod Moopy, Dr. Gkratp Tatrersaty. The Causes of Variegation in Keuper Marls and in other Caleareous Rocks .............. 431 Newton, Epwin Tuttry, & H. H. Arnoip-Bemrose. On an Ossiferous Cavern of Pleistocene Age at Hoe-Grange Quarry, Longcliffe, near Brassington, Derbyshire (Plates V-VIII) .... 43 Newton, RicHarp BuLLeN. The Tertiary Fossils of Somaliland, as represented in the British Museum (Natural History) (Plates X VIT-XXT) a. ee co oe nes & 155 Preumont, Gaston Ferix Josepy. Notes on the Geological Aspect of some of the North-Eastern Territories of the Congo Free State (Plate XID) . 000... 0... .0. pee 641 Raisin, Miss CATHERINE. A., & Prof. T.G. Bonney, The Micro- scopic Structure of Minerals forming Serpentine, and their Relation toits History (Plate XLV): ......... 4... 690 Rastatu, RoprertT Heron. The Blea-Wyke Beds and the Dogger in’ North=-Hast: Yorkshire’... 0.40). $02. ee ee 44] RicHarpson, Linspauu. The Rhetic Rocks of Monmouthshire (Plate SXOXTD) | och se eee a... a ol4 . The Rhetic and Contiguous Deposits of Glamorganshire (Pate XX ND) oo yee es Sisk lane eases os wus oes or 585 On the Occurrence of Rheetic Rocks at Berrow Hill, near | Dewkésbutyor i 2e. sen eee: chet oe sae wet a os 425 Srsty, THomas Franxuin. The Carboniferous Limestone of the Weston-super-Mare District (Somerset) wal eke and Oe 548 Sxeats, Prof. Ernest WILLINGTON.. _.On the Chemical and Mineralogical Evidence as to the Origin of the Dolomites of Southern Tyrol (Plates X=X1V) ..u34.52-4....50 ee 97 TABLE OF CONTENTS. Nf Spicrr, the Rev. E.C. Sarsen-Stones ina Claypit ............ 39 Sropss, JoHN THomas. The Marine Beds in the Coal-Measures of Nowéhe Statiordemine (Plate XXXIV) oo. eee ae 495 TreacHerR, Lurwevtyn, & H. J. O. Wuirr. On the Age and Relations of the Phosphatic Chalk of Taplow .............. 461 VaucuHan, Dr. ArtHuR. The Paleontological Sequence in the Carboniferous Limestone of the Bristol Area (Plates XXII- BOD NGIOXG) Pein ss ou, sme MONTES Hk by oun c-aluq. thn aiwlereaie b's 181 WatrorpD, Epwin A. On New Oolitic Strata in Oxfordshire. NE LUSIORIC Merwe Naty: s: cinta ceria & tanta ia incre nie we Cage MIO S.A 440 Waite, Haroup J. Osporne, & Lu. TREACHER. On the Age and Relations of the Phosphatic Chalk of Taplow .............. 461 Wooracott, Dr. Davirp. The Superficial Deposits and _pre- Glacial Valleys of the Northumberland and Durham Coalfield sete UNG lee eei male ee elms wefan eee ee te he 64. PROCEEDINGS. Proceedings of the Meetings ............... Spee iouacee tales i, Ixxxvii JS SOTITTEN TS EY2) 0X0) ¢ Seo eae Ss Ra cea ix MsrotWonorsvtol the Library 2... 2.6 nee. ns ee chee cee XI Picmotaloneron Went pens: i). oes a cies Seale sea eed eves os xxiii Mist of Horeion Correspondents . ....003 6. sense eave teens Xxiv istore\Wollaston Medallists... 01.0... eed vaeeins cue ese XXV mietorm Murcmison, Medallists. 50. 0s ae sls cc eedae ews «seve + XXVil Awards of the WanielEidceon Wund sy... | XXVIli, XCI1 Meta OnelayeleMledallistsiy. i. ic, newest oP lees valk Cee XX1X 2 PIRSSUATIGLE, JU XC ENN gae a enn Ri eeanast XXX isiqorbiaspy Medallists’! yogic .hs sence vedas eee es XXX1 Applications of the Barlow-Jameson Fund ................ 3 XXX1 HromermevaleRvepOlbs.c 5 sav ee de. se ac ae Etexstonhs containment XXX1i Award of the Medals andperoceeds ofiiunds, 94.5.0. a0... XXX1X Anniversary Address of the President ...............00005 xlvii vy] TABLE OF CONTENTS. BatHeR, Dr. Francis ArnrHur. On Danish Rocks illus- trating various Greolosical Conditions)... 22.2." see _Fearnsipes, Wini1amM Grorcr. On Llandovery-Tarannon Graptolites from the neighbourhood of Criccieth ...... _Garwoop, Prof. Epmunp Jounstonr. On the Use of Three- Colour Photography in demonstrating the Microscopic Characters of Rock-Forming Minerals in Polarized Light. Harcu, Dr. Freperick Henry. On the ‘ Cullinan’ — Diamond: vy. eta ees he eis ons «6 ee Newton, Enwin Tutitey. On Fayolia all. grandis........ ~Smirn, Grorer: FrepericK Hersrert. On his Hand- Retractometer. 2. o.4..5 10 a: Re EM op eae Page ~Txxxvii vil Ixxxix 1 LIST OF THE FOSSILS DESCRIBED AND FIGURED IN THIS VOLUME. Name of Species. | ‘Formation. | Locality. Page PLANTA. Glossopteris Browniana, pls.| { Permo-Carboni- Seis , ak OMI GT eds swwasiiile's meas { HEFHOWIS Goo ceroan } VEDTOUS (Xo, 00: | ook ACTINOZOA. Alveolites SCPtOSA ...csceeseeeee thio. 267 Amplexus cf. coralloides ...... Sea - Bristol district .' 128 Axophylium 0, pl. xxiv, fig. 4. it 282 Calanophyllia Aylmert ...... ocene ee. so.- Uradu, etc ...... 174 Campophylium alt. Murchisoni| \ if | (276-77 Caninia cylindrica, pl. xxili,| | - | | figs. 1 & la afeheyolaieverevousvera(elatete vols | | ihe ‘Clisiophyllum’ ( Coane tae te one a ald | | hyllwm) 6; pl. xxiv, figs. 3- arboniferous saris ely 2 5 eo eee Sonne: ee t Limestone ... 4 LeratsteaL CHS IMB 285 Cyathophyllum Murchisont ...| | | | Zone AU UUMU Rs fens Gee ceelone aces | | 275-716 === (8), oll esate) 4 Ree onence | | 274 ¢, pl. xxiii, figs. 3-30...) ). N yrs | 274-75 FOCHOTOACIS SPisenc.i-ocvecteaseced- inp eBOCeMer asanaeeee splat Dap -netGaecs| yy LL) Dibunophyllum @, pl. xxiv, | PMMA the dyasciw wees nee Carboniferous is a 283-84 Ca Gy pl: xxiv, fie. Pa)... | Limestone ... pee METH oer —— y, pl. xxiv, figs. 2 & 2a ; 284-85 Goniopora Parkinsoni ......... Eocene ......... Somaliland...... 174-75 _Koninckophyllum 9, pl. xxiii,) \ if / Bey skeet ore te oaintiere cain 282 _ Lithostrotion besaltiforme | 279 UT CGULONE vnicdniecssosunsh » | 279 EE CLUIUN: ener Sac NW cn, Peay as , aaa) ie ee Carboniferous |) Bristol district | 4 278 Lonsdalia floriformis ......... yee we Ieee a 286 Hii ee ae | 286 Michelinia cf. favosa ......4.. | 269 MUCGUSCOMGT nev ect skh 0 269 ef, tenuisepta s..cescecas ) Mie sied . |. 269 EPHLONASUT ED SP. vecrcsececusessece Eocene: s....c. Berbera ......... 174 Vill FOSSILS DESCRIBED AND FIGURED. = Name of Species. | Formation. AcTINozOA (continued). Syringopora cf. distans......... | SS Oh, GO IIONE Hoh acosoane | — cf. ramulosa —— Of, 7eCiCUlald...creccoreries nc@oabenttorn ete eis om ae Zaphrentis alt. cornucopte, pe | Oe ee eecresreeret&- coe xxii, figs. 83-3 d aff Phillips?, @ecoestce pl. xxii, figs. 2-2 ¢ EcHinorp@a, Archeocidaris sp., pl. xxxv, Pent ee eget tee) Wich aOR P ace eins Linthia (2) 1 i oF =eeerereoeoeeseereetose Eo ene Ascent ISCHUCGSUCT ASI gains sae ete eens cn i : ANNELIDA. BRACHIOPODA. Amboceliacarbonaria, sp. nov.,| | : pl. xxxv, figs. 7 & ae } SORELLE SEES « Camarotechia imitcheldean- | \ ensis, sp. nov., fig, 6 & pl. xxvi, figs. TO | Chonetes aff. comoides, fig. 4 & | Cis Doane Pol eayal, MH A ce ccmew ns Limestone .. —— cf. crassistriad ......06600. | —— ef. hardrensis, pl. xxvi,| | ie Oe De se Ne tains ap neous sy y) wer ge dred | | Coal Measures papilionacea, jolla” osx, OID Sa ine athlane cmatenen on eoeees Carboniferous Cliothyris glabristria, fig. 5.. Limestone. ... ——. nee Bate AN a us enh Orbiculoidea n os : ‘i _ XXxy, fig. 3 Orthotetes crenistria Corre r OeOsseererre-csevsccon Carboniferous Limestone Coecrec®@ecos Productus anthrax, sp. nov., pl. xxxv, fig. 6 eoeesceeeeccooe Coal-Measures . \ Coal-Measures . (Gs SS | | | | ( Loeality. Page Bristol! district . North Stafford-| Garrasgooi Somaliland shire shire COScorsee e@eevee @ecene Spirorbis sp., pl. xxxvi, fig. 10 Coal-Measures . ee sae eecreecese North Stafford- shire eeeeoecce Bristol district. North Stafford- shire eeeeeecee 4 Bristol district . 28 ee ceecces ristol district . orth Stafford- shire @oreveeee ( 267-68 268 268 | 268 4 968 | gig \ 269-71 529 173 173 Ou (=) iS | 294-95 1 297-98 | 297. ( j 529-20 FOSSILS DESCRIBED AND FIGURED. 1X Name of Species. Formation. | Locality. | Page BRACHIOPODA (continued), Productus bassus, 8). nov., pl.: \ (ee | mores: WAL ees vse | | 287-88 Cora, pl. xxv, figs. 4-4 b., 290-91 = GJUGANLEUS ..eeeeervececeeees 292 —— hemisphericus, pl. xxv, | Carboniferous | . as TERE Aosta nits dnc awianioes r Limestone aa ESOL SNE 4 291 ——- ef, Martini, pl. xxv, figs.| | | | | 26 2G rs | E 288 PRUPICUOEUS. Soe. ol oeaves | | il 292 WBUSUMOSUS sear cicaaesccaare: |) { \ 292 BGWORIGHIWS. \Siviecasccskan. Carboniferous... Various ......... 292-93, | 531 semireticulatus ........0.0. | Carboniferous . eee 289 mmo PI XV, HE. Bese... J Limestone ... \B Ishel asta { 389-90 SDep il exxmy, eNO 2... _ Coal-Measures . { ee ae 531 freticularia aff. lineatu......... \ if 299 PRhipidometla Michelini ...... || 297 Spirifer aff. clathratus, pl. SST G" S100 Rae Carboniferous |}... “eee 1) 800 Spiriferina octoplicata, pl. r Limestone ... EO Sel isha 4 oot y LE ae | | 300 Syringothyris aff. laivinosa ...| | | 300-301 CWSPUAHUG . vcacsccs+sscisin ) K i | 301 LAMELLIBRANCIIATA, ee | ee Saas } Mocene iret: jae aDobar x18... 166-67 ae cloacimum, ipl. Le | Lower Rheetic.... Bishton ......... 422-23 Cienodonta levirostris, pl. | ( BMV 2Oy cemacenieaiens abs eet eNTeasumes 4 North Stafford-| | 586 ——- undulata, pl. xxxv, figs.) ve cies WP SIMIC Jets cv D2 (SGV, | et ea \ ( 537 Fimbria ef. lameltlosa, pl. xxi, ) ee DIG) wins Snr no | | Garrasgooi ...... | 172-73 Gryphea Gregoryi, sp. nov., | 4 pl. xvi, fig. 4 & pl. xxi, > vere aie giek 3 4 : HGS ao ee lics sues SIN | | Somaliland ...... | 167-68 Say SIDS TUES oc si7e2 ee ppeaueeee y) | Upper Sheikh. ..} (168 me on alongirosiris, pl. xxx¥, | Coal-Measures -) (Cheadle .0...24 037 ig. sett eeeae se cccesenseeees COR . a Ss Diet) onite: Ties. «.| Coldkuap ay... 423-24 Lithophaga sp., pl. xxi, fig. 7...) \ Ce eDobaree a. mix 170 Lucina ef. gigantea, pl. xx, : if Heese ay a Meee feos. ei | 170-71 —— ef, Menardi, pl. xxi, fig. 8. PIDOOENE — casc5noe- ‘ Garrasgooi ...... 4172 -— ef. thebaica, pl. xx, figs, 4| | | i | Bee eeepc ease oe aa i ) i \ 171-72 pec eomeoicommressc, “pl. SV" | Coal-Measures Cheadle: 323;.0.):| 537 TTS (ee SRS as ee ee a _ Name of Species. FOSSILS DESCRIBED AND FIGURED. Formation. Local. | LAMELLIBRANCHIATA (continued). Nucula gibbosa, pl. xxxv, fig.| ) Moher en eae | oblonga, pl. xxxv, figs. 21] | (GB (ZZ Pe Sahai ida apm I ee S Coal-Measures Nuculana acuta, pl. xxxv, fig.| | 20 eee toate er er poeess ees avesene | i lw ; a shire | | \ Sharmant, pl. xxxv, fig. 19} ) our "ed Bristovi, ply sexsi) | ewer Rites MOM AU oka ooeeGre amen seas ese ne j ie Plicatula hettangiensis, _ pl.| \ SRI ON rake UAE, Re iver intus-striata, pl. xxxiii, r eu ES a SEM ict So crete tien hotad aacee Posidoniella levis, pl. xxxv,| \ Boe skh ed aaa ees shee eter ee sulcata, pl. xxxv, fig. 16. Pseudamusium fibrillosum, pl. xxxv, fig. 13 Pterinopecten carbonarius, pl. xxxv, fig. 15 papyraceus, pl. xxxv, fig. eeceer ese aero eseee @ecesseesceseeecor Scaldia minuta, pl. xxxv, fig. | 28 | Schizodus antiquus, pl. xxxv. = Sere er oer sesere tse esos sesesace | TGe) 2A Re amen eg Ae cee Solenomya primeva, pl. xxxv, OE emcee ae aaa aoe y Spondylus @ gyptiacus — somaliensis, sp. nov. xxl, figs. 5, 6, & 6a Syncyclonema Hudson, pl. xxxv, fig. 12 Vulselia (2) sp., pl. xxi, fig. 4.1 wercesces) Bembexia (2) Groomit, sp. nov., pl XXXvli, fig. 4 —— Lilo dit @ —— (2), sp. nov., pl. xxxvii, LUO OY, ak ed sor tate Hee fata | Campanile ef. giganteus, var.| \ Le eoressessece ee ceeerercoeeee .| + Hocene EKocene GASTEROPODA. es Or Oe. | | Wenlock Beds -j Upper Ludlow .. J | j Up. Sheikh, ete. ii | North Staffor d- eee cena e Cadoxton Coldknap eanceoe | “Cheadles taser | North Stafford- shire eovcecce’ Cheadle North Stafford-| shires:naceeeee i | } J) 1 | | | Garrasgooi, ete. North ‘Stafford- { shire Garrasgool ee-serees ee ot } Llangadock...... | | Sut, Wai, see seeee 4 Dongorreh, ete. | | | Berbera - eee coeeee || Bur Dab, ete. .. | Berbera \ \ | 169-70 534 168-69 | (569-70 2571 | 570-71 | 161-62 | 4 162-63 | 163 572 164 ve (164 i a tal FOSSILS DESCRIBED AND FIGURED. Name of eee Formation. | Locality. | GasTeRovopA (continued). Goniostropha Cambria, — sp. nov., pl. xxxvul, fig. 3 Gyronema Octavia, pl. xxxvii, OD Sisk caisecw senso em Liotina somaliensis, sp. nov., [DlLs: SS Tey a ae oie eee Loxonema acutum, pl. xxxv, NRE ULI See steko cies ase askew -—— Grindrodit, sp. nov., pl. Ram os. Vike T—9 ..5...0 6. —— pseudofasciatum, sp.nov., pl. XXXVI1, UO) amare rete are sinwosum (2) Naticopsis brevispira, pl. xxxv, HIM Olen reco as sas nce ticle ne Polytropina globosa, gen. et sp. nov., pl. xxxvii, fig. 16 . Raphistoma radians, pl. XXXV, TV ORO TCC, OF 1 eee aiwen om 0 Vn Solarium cf. pl. xix, figs. 5 & 6 Turbonellina formosa, pl. xxxv, 10 ie Ramat 1 g- Ulrichospira similis, subgen. canaliculatum,| \ et sp. nov., pl. xxxvii, fig. 3. Alocolytoceras dilucidum Germaint, fig. 3 --—— Pompeckji, nom. nov. .. — tematum, fig. 6 & pl. xvi, GSE MIE eer Areesacn dv san Dimorphoceras Gilbertsoni, pl. xxxv, fig. 32 Euphemus ef. Uret, pl. xxxvi, figs. 9 & 9a Gastriocerus carbonarium, pl. SONA EOL Ue as tee ovrcdlv es Glyphiocer as micronotwm, yl. BORK Oey ole rele tanetiass sree —~ Phillipsi (QE juleseedy, fig. 30 eect eters eset enone Ce en SC rr er ey —— reticulatunr, pl. XXXV, 11g a eg Ae tk a om y) Megetatvonts engin. || tatexior Oolte Nannolytoceras, gen. nov. SWOT! Sento ee Orthoceras aff. asciculare, pl. Cos Msaete ENKI MS, GML. Ti dese due vee Estee nen ti Pacha ylytoceras ~~ aalenianum,| | Northampton sp. nov., fig, 5 & pl. xv, Sands eS eee NS figs. 3-4 Seed eee ee wearers sseesees! ; Lower Ludlow . \ TU aVVicnlock, } Eocene Coal-Measures . Aymestry Lime- stone Bs Seis Lime-| — stone Wenlock Beds . | Coal-Measures 5 | Wenlock Beds . i Coal-Measures . eceeoere. I Kocene Coal-Measures . Upper Llan- Covetya sos. CEPHALOPODA. | Northampton r Sands (Aalenian)... | Coal-Measures . j (Aalenian) ... —— \ Llangadock...... Garrasgool ...... North Stafford- ' shire Ledbury & Llan- gadock eetttees eoecceeee Dirdlleye Wa... Llangadock...... | North Stafford- shire eeesteceeee Llangadock...... Various Garrasgool ...... ‘ North Stafford- 1 shire eeeceecves ( Northampton- . shire eee eesive Cheadle eecnesras | \ ieee | os i Nor th Stafford- \ Dorset hence { Nor th Stafford - shire as ss | 573- 79 165-66 5383 { 565-66, Os X1l FOSSILS DESCRIBED AND FIGURED. ™: ame ee Speies | Hatem Locality. Page CEPUALOPODA (continued). Pachylytoceras phyllocera oe Northampton Northampton- toides, sp. nov., pl. xv, figs. Sands Sipteors | 447 t=Ziconpl. xvi, Hees co (Aalemian) cc > an. on Plewronautilus costatus, sp.| \ ( ic nov., pl. xxxvi, figs. 5-5 0... 540-41 pulcher, pl. xxxvi,fig.3.| | 541 Solenocheilus aff. cyclostoma,| | x... : | North Stafford- | } pl, xxxvi, figs 2&2c ...... peal eae 4 549 Temnocheilus carbonarius, pl. | | SORT, GS AP pa snceconudeacoe: | O41 COMEDOUS Va ccratccaa sea hee ) \ \ 541-42 Thysanoceras onychogr cera AVO MIGNON | cee ae he cheer ee d OVE eee Ao ear ? 149 -— Orlhignyi, nom. nov, \ ieee ? 149 Phasanolytoceras, Gen. NOv....| {4 9 = 1) alone eugene 149 AMPHIBIA. SUT O CULGATIS™ sca. sees idee selene : { Longcliffe 57 TVOMG CCW OT OTL ae asec seaeh s | | PIECES coo, (Derbyshire) .| 57 AVES. ASUO QCCUPUTINUS wo. cecencesn-r ia ap 56 EKrithacus rubecula (2) ....100.. | Pleistocene ...... | | ae cay 56 WRONS UIGCUS ion saasne ce seus :| | { ee ee RopDeEntiA Lemus leminis (2) vccceccecees | \ lee (56 Lepus cuntewls, vies... s.cs- ees | | | 5D pas | : Hiorolus apres (| | Peisiooone | 4 Henge, | ag —— anuphibius (2) .s.cccsecee- | | | y | | 56 (Evotomys) glarcolus ... | | 5d-56 Mars sylumuicus (@)—.anacnneee \ | 56 Uncurata. US OSION IHUSONW) So tae ee ee eee ccee ( (51-52 Cupreolus caprea, pl. viii, | MORO ae ela nears attentreatitaniaxtee 54 Cervus dama, pl. vii, fig. 6 & AOL ASW MIRED oh easesraiacison eno . | Longcliffe | 52-54 elaphus, pl vin, fie 2 | aslgie Sa 4 (Derbyshire) . 4 52 giganteus, pl. viii, figs. 1 Re ABE he. | 52 Hlephas antiquus, pl. vii, figs. | ONO Senate cade ceonenn meee y) EN | 55 e TEAL S NPIS Gy ate. Dowie ae 35-37 rhinoceros leptor HDIUUS oo eter ee : _{ Longeliffe 55 SUSUSGTO) (hice Met aan rN } EUSIECORME ou: (Derbyshire) .. | 54 FOSSILS DESCRIBED AND FIGURED. Xill Name of Species. | Formation. | Locality. | Page CHEIROPTERA. é, ay ia, Sanenige | espertilio (Plecotus) auri- : : ee ‘a C ) | Pleistocene ...... CARNIVORA. MB DUSUUPUS) Mowedindn ccs eaeiis son. Felis catus, pi. vii, figs. 2&3 || | o Leompleevin, TeV) o. fs. ue. | CHO CHOCUOG, Teenacnsie cen ea0%0- c= | ees TUS Loe eee oLEISESGEIE oc. | @eesersee seseetssersvreosses 7 Longcliffe (Derbyshire) .. 50 Longcliffe |} 49 (Derbyshire) .| | 50 || 50 | (50 EXPLANATION OF THE PLATES. Puste ; Pace Mar or run AReA AFFECTED BY THE LEICESTER Harrnquake or Avueust 4rn, 1893, to illustrate ? Dr. C. Davison’s paper on that and other lbercesterieanthiqualtesn:s: gta. ste sac tonsa stowlse os ! -{ Mae. or tum AREA AFFECTED BY THE PRINCIPAL II Derby Harruauaks or Juny 3rp, 1904, to illus- 8 | trate Dr. C. Davison’s paper on that and other{ =~ ey Derbygeanthquakesi sit aes Rh ike tactices. wilscne (Views or tHe Wnepuant-Trencu: av Dewzist, \ LOOKING NORTH-WESTWARD AND LOOKING SOUTII- | III & IV mastwarp, to illustrate the Rev. O. Fisher’s} 35 | paper on the occurrence of Elephas mceridionalis | \eabetcatliaibylocalitiye: ea brcksaeta es aes. Wel Jealeaan eceuases ) ( Horizontan Suction anp Puans or Hon-Granee \’ Cavern; Views oF Hor-Granen Cavern; Anp | YV-VII 4 Mammantan Bonzs vrom ‘ris SAME, to illustrate \ 43 | Mr. H. H. Arnold-Bemrose’s and Mr. E. . | Wee Newton/sspaperonithat eawenme, h).-02252--2-2-004: C2 (Mar or ree Wedr, ‘Wasu,’ ano Tyne pre-) | Guaciran Vauzys, to illustrate Dr. D. Woola- | IX cott’s paper on the superficial deposits and} 64 pre-Glacial valleys of the Northumberland and | Dacha @ oabtielaly os). ¢c-jeceston-peiecet ed 2 ss-tos y “Microscorx-sucrions or Doomrric Rocks, to illus-" X_XIV trate Prof. E. W. Skeats’s paper on the ‘chemical 97 and mineralogical evidence as to the origin of f the Dolomites of Southern Tyrol ............. ea, XV & XVI ANUM, AND ALOCOLYTOCERAS T4NIATUM, to illus- 142 trate Mr. S. 8. Buckman’s paper on certain genera and species of Ly toceratide., Seatiiaraarbit hat atere XVILXXI (TM cite Sneius rrom SomALILAND, tu ae) 155 Mr. R. B. Newton's paper on those fossils ...... CarponiFerous-LinestonE CoraLts and Bracuto- } pops; Horizontau Section or THe Avon Gorcu anp Sknrcn-Map or THE SAME; ; VERTICAL SECTIONS | Av SoDBURY AND THE Avon; and RanGe-Dracrams ! or Carsonirgerous Corals and Bracuiorops, to & illustrate Dr. A. Vaughan’s paper on the paleonto- | logical sequence in the Carboniferous Limestone ; Gtethersnistolianean Gisele. vk escsscnvese antes eas tai } 181 4 | \ tf PACHYLYTOCERAS FHYLLOCERATOIDES, P. AALENI- (C | | XXII-XXIX { { | | ie Xvi EXPLANATION OF THE PLATES. PLATE PAGE ( SPORANGIUM-LIKE OrGaNns oF Giossoprerrs Brownri- XXX & XXXIj 4a, to illustrate Mr. E. A. Newell Arber’s paper | OMe MabESWID EC Gro ve-s a5 ge ee soeiriouee anes Si (Monmoutnsutre), to illustrate Mr. L. Richard- son’s paper on the Rheetic rocks of Monmouth- shite: sae iene: sib 6 Be Bb ope voli shin te eee Ea Sees XXXII Ruztic LAMBELLIBRANCHIATA, to illustrate Mr. L. XXXIII; Richardson’s *paper on the Rhetic and con- tiguous deposits of Glamorganshire ......... mene VuerticaL Section at GoLDCLIFF, NEAR = ( Ovuruine-Map snowine tue RatLway- and CANAL- | System or Norru STAFFORDSHIRE, AND THE | : Posit1oN oF THE COLLIERIES WHERE THE Marine | XXXIV 4 \ Bands HAVE BEEN TRACED IN THE CoAL-MBASURES, | to illustrate Mr. J. T. Stobbs’s paper on those | | \ 4: moaning bamtlsp tea. ceeeca a Rete MP ce scrasno50 ic ys ( Marine Fosstns From tTrE CoAu-MEAsurES OF Nortu STAFFORDSHIRE, to illustrate Dr. Wheelton 527 Hind’s notes on the paleontology of the marine bands in those Coal-Measures ..............-.40+ A XXXV & XXXVI “SrnurtAn GaAsreroropa, to illustrate Miss J.) 564, XXXVI} Donald’s papers on those fossils ............eeeee \ 567 ( GroLogicaL Sxutou-Map or tHE CountTRY BETWEEN ) FrsuGuARD AND St. Davin’s Heap; Norites anp ! ornEeR Enstratite-Rocks, Limz-BostoniItrEs, AND 579 Porpuyrires FROM PEMeroKkesnire, to illustrate r Mr. J. V. Hlsden’s paper on the igneous rocks | occurring along the Pembrokeshire Coast......... / XXXVIHI-XL 4 ao GroLocicaL Mar or Arrentig FAWR AND Mou Luyryant, to illustrate Mr. W. G. Fearnsides’s | 608 XLI paper on the geology of those mountains ......... j TERRITORIES OF THE Con@o FREE STATE AND THE 641 Lapo Encuave, to illustrate Mr. G F. J. Preumont’s paper on the geology of that area ... { GEOLOGICAL Skercu-MaAr oF tHE Nortn-HAsterNn XLIt Be cag or GNEISSES AND OOLITIC | Livestones From THE Conco Free Stare, to | XLII & XLIV: illustrate Mr. J. A. Howe's petrological notes } 655 | on rocks from the north-eastern portion of that | | State and the Lado Enclave ...... Re es: eect Microscorr-SecTions OF ANTIGORITE- AND ae | XLV Srerrentines, to illustrate Prof. T. G. Bonney’s 690 and Miss C. A. Raisin’s paper on those rocks ... j ee PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES, Fig. 1. 2. BESIDES THOSE IN THE PLATES. Pace Map illustrating the area affected by the Leicester earth- quakesoirdume: 2USt yd QO4 no fec2 see dase socuiet ncloe Adee chtetwe wstele lejos Map illustrating the area affected by the after-shock of our Layered Re tL A lees aed weal atouiapere nic athe e uations naa mates Oh tail Excentricity of isoseismals in twin-earthquakes .................. Variation of relative intensity in twin-earthquakes ............... 3-6, illustrating different cases of relative intensity in twin- as im 2. = 9. VOL. LXI. CALCIO MAKER Raiececeneee ues eNeacae disse stacy acticin ncien ecco neeese ah Map illustrating the areas of maximum intensity of the Colchester earthquake of 1884 ............c0...-eseereeeesceonens Sarsen-stone embedded in clay, at Walter’s Ash .................. Section from Fulwell Hill to Cleadon Hills ..................4+5 Pre-Glacial (or Glacial) gravel-deposit at Newbiggin, near the AHO MGMVOL tO w Was beki mre. sa rites sctctte scetceocsectoecansesees ING AEE VIC W HOME E SAINI? cote ce beceumion os cue atmawels vo daeecelabeoowiensiele Diagram illustrating the depth below sea-level at which the rock-surface has been proved to occur, by borings along the Tyne Valley, from Ryton to the river-mouth .................. Section from Billy Mill to Westoe, across the Tyne Valley ... Map showing the relation of the post-Glacial valleys of the Wansbeck, Blyth, and Sleekburn to the pre-Glacial ‘Sleek- HouimsasVallllenae te arey sor asd sett cstaat «lout «vat aat cMianamdiowanies'e neues Section across the pre-Glacial ‘Sleekburn Valley’ between Northy Seaton and epside (ach. shay anccecta punta dnclemereicsceeces «0 16 25 27 28 30 30) 66 6& 70 (pl XVII Fic. bs ener! bo PROCESS=BLOCKS AND OTHER ILLUSTRATIVE FIGURES. PAGE Section across the Fulwell Valley, from Corny Hill, South Shields,"to West: Boldom .....5:..26+s00.+00ees.cceenete eee eee 91 View of Hawthorn Dene, looking from the sea ..........2-..-+-- 92 Diagrammatic sketch-map of part of Southern Tyrol ............ 102 Suture-line of Megalytoceras confUuswmd ......02.ecccecncussseceeeces 150 Sielerons of superior lateral lobes [in Lytoceratide] ............ 152 Topographical map of British Somaliland...............00...00.00 156 Sketch-map showing the outcrop of the Carboniferous Lime- stone in the Bristol area .......0.00.<.0ceeecee.o.e eee eee 187 Tabula of Zaphrentis aff. Phillipsi, represented by contours ... 270 Muscular sears in the convex valve [of Productus spp.] ......... 293 Interior of a convex valve of Chonetes aff. comoides ,...........+- 295 Cast of pedicle-valve of Cliothyris glabristria ........sceceese renee 297 Brachial valve of Camarotechia mitcheldeanensis : plan of HI ee PEG UON i sae stag et tne techn mob ee ceiareis es vaiee vt view toh Cee 302 . [Map illustrating wash-outs in the Middle Coal-Measures of South: Yorkshire]: 0.4. 5.2.25 vacdeuenseccoocenseesiele ss eee 309 . Sections MN & JH [across the foregoing map] .................. 340 (Sectionsof the :Parkeate Seam) 220... -..c0-.ess-e chee 342-43 . [Figures illustrating experiments in mountain-building| ... 348-55 Section im ‘Glem Muldym \..3.oeccsecanenss en stuns este cee eee 362 Sketch of the folds in the overlying flags of Sulby Glen ...... 363 Junction of the Schistose Breccia with the overlying rocks at theeSullby-Gilem (Ores) oo enna lae eek sh econ te See eee ase eeee 363 Agneash Grit, looking east, seen nearly vertical at ‘Traie ETE Rann J. cic cele adeeb sie aiat nn cio hate siete eae ce er 364 Interpretation-section through the Manx Slates .,........ Redes 367 Section ab Mlanmartin) 2... ken ccucwss codeee ene ieee aon ce ae 378 Section aiulamwerm Py i aiad eae ase emt eceh cee tank Ge ee ee 381 View showing the upper surface of the Sully Beds and the Black Shales; Wayernock Poimt 2.)..c.0.28.-cl<.ee vee eee 390 “View showing the White Lias and its junction with the Lower Ihias at wavernoel Pointy...) cco. be) +n asnen ony ees ee 390 Diagrammatic section illustrating the relationship of the Pteria (Avicula)-contorta Black Shales to the subjacent deposits +. ee et Coo HUR SAF U SBF eho eee wDE se Her H oa OTE HEH OeH Fee Eee HOHE SE ee THEO toon ems ee Fia. bo PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES, XIX PagcE Diagrammatic section illustrating the relationship of the Lavernock White Lias to the Upper Rheetic, etc. of Glouces- (CeNHSI CUS) NORE nes MARU He HORE Ane HAC ACU Ue Maree ARE AeA te Erne eae ap 412 Diagrammatic section illustrating the relationship of the White Lias to the Upper Rhetic in the Cardiff District............... 415 Geological map of the country around Berrow .................. 425 Section from north to south, traversing Berrow Hill and Grarilouuiyees ari ken. wean ee Caiman ee My Wee Ui a A AN ie 426 Section from west-north-west to east-south-east, traversing Gadbury amie and series A Lote. otenate oe en ye creas 426 Contemporaneous erosion of the Lias, Hast Cliff, Whitby ...... 450 Section in the eastern quarry, Boulby alum-works ............... 452 Section at the South Lodge, Taplow Coat 2st eau heres 466 Diagram of the river-scarp at Taplow ............0.+0.-eseeereeeers 491 Vertical section illustrating the succession of the marine horizons in the Coal-Measures of North Staffordshire......... 499 Exposure of Coal-Measures at Weston Sprink, near Longton . 508 Vertical sections illustrating the correlation of the Coal- Measures in Yorkshire, Lancashire, and the Midland — (Shoat M BIE ee Se NES SP ORGS 5 ete lt a ee lee UMA UNTER ty aga PI 518 Geological map of the Weston- Worle ridge ........................ 550 Section across the eastern end of Worle Hill ..................... 5Dd4 Quarry at the eastern end of Worle Hill, in which the over- folded Seminula-Beds are Seen si c.c; sve. ccvecenctsevcedecsslcccst dD Diagram illustrating the difference in composition between the rocks of Penmaenmawr and Penberry Hill.................. 590 Diagram illustrating the comparison between the Abercastle rock and the lime-bostonite ob Meena... .5 00s... ces. seuesu sce. 598 Diagram [map] showing the relation of the Abercastle intru- sions to those of the South-Hast of Ireland ..................... 604 Section across the northern shoulder and eastern slopes of PAM CTIIC BIA) dee ale stats vain sinistiatl soniasen side lenin ee cewa ts nem seaisrip SON ite 610 Section across the western flanks to the summit of Arenig Fawr. 611 Section illustrating the possible relationship between the iron- ore beds of Mount Tena and Mount Gaima..................... 652 Section illustrating the disposition of the rocks near Mount INierPonnehedlettbam@t tile wNUe <0 cccceoasdarsiesindeoteekears 652 Section parallel to that shown in the preceding figure, but ArH MOT MON a NeNb MV UUs den ccleee edie we thai voeiianiods chckc wees euelte 653 xX Fic. PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES. Pace Sketch-map showing the course of the Nile from Aswan to Qoemay ied okie Winns aco tildgv ces vawenls sand botws bee ee 667 General map of the district east of Pretoria, illustrating the distribution of the Glacial Conglomerate ...............06008 es 680 Section through the Glacial Conglomerates and coal-bearing strata, north of Balmoral (Transvaal) ...............ceceeceseees Glacial Conglomerate at Toits Kraal, near the junction of the Elands and Olifants Rivers, Transvaal ...........scceccssces--ner 684 Glaciated surface at Klipfontein, 6 miles north-north-west of Balmoral (Vransvaal) an... ..c.0csesens 4. saceoeensleeee ee eee ieee 686 Microscope-section of antigorite, showing ophitie structure in MASHEtIbC Lacecebeeceee leew sceedee seu natse conden Ocoee een 702 Slaty serpentine from the Gorner Grat, sliced generally parallel with the microfoliation ...:.......04:0s:ssstue ee eeeeeneee 710 ERRATA. P, 51. The tabulated comparative measurements of metacarpals are to be read as given in inches, moz in millimetres. P. 424, line 13 from the top. Jor ‘St. Mary’s-Well Bay, Sully’ read ‘Cadoxton.’ Bea P. 470, line 19 from the bottom. or ‘ Halicodiadema read ‘ Helicodiadema. Vou. LX (1904). P. 394, second footnote. For ‘vol. iit (1891-92)’ read ‘vol. iv (1893-95) p. 90’; and add ‘ Trans. Manch. Geol. Soc. vol. xxiii (1894-95) p. 65.’ Pirate ee PROCEEDINGS OF THE GEOLOGICAL SOCIETY OF LONDON. SESSION 1904-1905. November 9th, 1904. J. E. Marr, Sc.D., F.R.S., President, in the Chair. Edward Battersby Bailey, B.A., of H.M. Geological Survey, 49 Alleyn Park, Dulwich, S.E.; Davidge Page, Assoc.M.Inst.M.E., F.C.S., F.R.G.S., Hotel Russell, Russell Square, W.C.; Edward Heton Roberton, B.A.Oxon., Lecturer in Mining in the University of Birmingham; and Arthur Young, M.A., B.Sec., Professor of Geology & Mineralogy in the South African College, Cape Town, were elected Fellows of the Society. The List of Donations to the Library was read. Mr. E. T. Newron, in exhibiting, by permission of the Director of H.M. Geological Survey, a specimen of Fayolia near to Fayolia grandis, found by Dr. L. Moysey, of Nottingham, in the Coal-Measures of Ilkeston (Derbyshire), pointed out that Fayolia was first described by Profs. Renault & Zeiller in 1884, in their monograph on the ‘ Houiller de Commentry.’ In 1894 Mr. Seward described the first British specimen, from Northumberland, in the Leeds ‘ Naturalist,’ but thought that it was not a plant. There was some resemblance to certain spiral egg-cases of Elasmobranchs ; but Dr. Ginther was unwilling to accept the Northumberland fossil as the egg-case of a fish. Mr. Kidston had not yet seen the specimen now exhibited; but, from a sketch, he recognized its relation to Kayoka. At present, there was still, a to the exact nature of this fossil. VOL. LXI. te eye ll PROCEEDINGS OF THE @HOLOGICAL SOCIETY. [Feb. 1905, The following communications were read :— 1. ‘Notes on Upper Jurassic Ammonites, with Special Reference to Specimens in the University Museum, Oxford: II. By Miss Maud Healey. (Communicated by Prof. W. J. Sollas, Sc.D., LL.D., F.R.S.)! 2. ‘Sarsen-Stones in a Claypit.? By the Rev. E. C. Spicer, M.A., F.G.S. 3. ‘On the Occurrence of EHlephas meridionalis at Dewlish (Dorset). Second Communication: Human Agency suggested.’ ey the Rev. Osmond Fisher, M.A., F.G.S. 4. In addition to the fossil mentioned on the preceding page, the following specimens, etc. were exhibited :— Specimens of Upper Jurassic ammonites, exhibited in illustration of the paper by Miss Maud Healey. Sarsen-stones and lantern-slides, exhibited by the Rev. E. C. Spicer, M.A., F.G.S., in illustration of his paper. Specimens, photographs, and lantern-slides, exhibited by the Rev. O. Fisher, M.A., F'.G.S., in illustration of his paper. Flint (scraper?) found in a gravel-seam in the Cromer Forest- Bed, near Runton Gap, exhibited by O. A. Shrubsole, F.G.S8. November 23rd, 1904. J. E. Marr, Se.D., F.R.S., President, in the Chair. Ellis Wright Heaton, B.Sc., 55 Thorold Road, Ilford (Hssex), was elected a Fellow of the Society. The List of Donations to the Library was read. The following communications were read :— 1. ‘On an Ossiferous Cavern of Pleistocene Age at Hoe-Grange Quarry, Longeliffe, near Brassington (Derbyshire). By Henry Howe Arnold-Bemrose, J.P., M.A., F.G.S., and Edwin Tulley Newton, F.R.S., V.P.G.S. 2. ‘The Superficial Deposits and pre-Glacial Valleys of the Northumberland and Durham Coalfield? By David Woolacott, D.Sc.,-F.G.8. 1 Withdrawn by permission of the Council, Vol. 61.] PROCEEDINGS OF THE GEOLOGICAL SOCIETY. iil The following specimens, ete. were exhibited :— Fossil-bones, photographs, and lantern-slides of the ossiferous eayern at Hoe-Grange Quarry, Longcliffe, exhibited by H. H. Arnold-Bemrose, J.P., M.A., F.G.S., and E. T. Newton, F.R.S., Y.P.G.S., in illustration of their paper. Maps and lantern-slides, exhibited by David Woolacott, D.Sc., F.G.8., in illustration of his paper. December 7th, 1904. J. E. Marr, Se.D., F.R.S., President, in the Chair. Charles Wilgress Anderson, Lyndhurst, Main Street, Georgetown (British Guiana); Lionel C. Ball, B.E., Assistant Government- Geologist, Department of Mines, Brisbane (Queensland) ; George Marmaduke Cockin, M.Inst.M.E., Mining Engineer, Brereton Hall, Rugeley; Arthur Edwin Dixon, Hampson’s Collieries, Waschbank (Natal); Sydney Fawns, 5 Sussex Mansions, South Kensington, S.W.; Hartley T. Ferrar, B.A., Sidney Sussex College, Cambridge ; George Herbert Fowler, B.A., Mining Engineer, Basford Hall, Nottingham; Reginald Walter Hooley, Ashton Lodge, Portswood, Southampton; C. Baring Horwood, A.R.S.M., Assoc.M.Inst.C.k., P.O. Box 1030, Johannesburg (Transvaal); Cosmo Johns, M.I.M.E., Burngrove, Pitsmoor Road, Sheffield; William Dickson Lang, B.A., Cricketfield Cottage, Harrow ; William Lockett, Oakwood, High Lane, Burslem (Staffordshire); the Rev. James Dunne Parker, D.C.L., LL.D., Bennington House, Bennington, Stevenage ; Thomas William Faraday Parkinson, M.Sc., 80 Ainsworth Road, Radcliffe ; B. Jaya Ram, Assistant Geologist, Geological Survey of Mysore, Bangalore (India); and William Bourke Wright, B.A., H.M. Geological Survey, 28 Jermyn Street, $.W., were elected Fellows of the Society. The List of Donations to the Library was read. The following communication was read :— ‘On the Chemical and Mineralogical Evidence as to the Origin of the Dolomites of Southern Tyrol.’ By Prof. Ernest Willington Skeats, D.Sc., F.G.S. The following specimens, etc. were exhibited :— Rocks, microscope-sections, and lantern-slides, exhibited by Prof. E. W. Skeats, D.Sc., F.G.S., in illustration of his paper. Plan of the Eastern Extension of the Witwatersrand, showing the main geological features, etc., by J. I. Hoffmann, presented by the Author. 1V PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 1905, December 21st, 1904. J. KE. Marr, Se.D., F.R.S., President, in the Chair. P. Charteris A. Stewart, Assoc. R.S.M., 51 Redcliffe Square, $.W. ; and William Hutton Williams, Assoc.R.S.M., Homefield, The Grove, Ealing, W., were elected Fellows; and Prof. Giuseppe de Lorenzo, Mineralogical Museum, Royal University of Naples, was elected a Foreign Correspondent of the Society. The List of Donations to the Library was read. The following communications were read :— 1. ‘On Certain Genera and Species of lLytoceratide. By S. 8S. Buckman, F.G.S. 2. ¢ The Leicester Harthquakes of August 4th, 1893, and June 21st, 1904.’ By Charles Davison, Se.D., F.G.S. 3. ‘The Derby Earthquakes of July 3rd, 1904.’ By Charles Davison, Se.D., F.G.S. 4, ‘Twin-Earthquakes.’ By Charles Davison, Sc.D., F.GS. The following specimens, etc. were exhibited :— Specimens of Lytoceratide, exhibited by 8. 8. Buckman, F.G.S., in illustration of his paper. MS. geological map of the Charnwood-Forest district, and lantern-slides, exhibited by Prof. W. W. Watts, M.8c., F.B.S., Sec.G.8., in illustration of Dr. Davison’s paper on the Leicester earthquakes. January 4th, 1905. J. EK. Marr, Sc.D., F.R.S., President, in the Chair. Oswald Hardy Evans, Pacific Smelting Co., Ltd., Taltal, Atacama (Chile), and Dr. A. Wollemann, 3 Bammelsburgerstrasse, Brunswick (Germany), were elected Fellows of the Society. The following Fellows, nominated by the Council, were elected Auditors of the Society’s Accounts for the preceding year: H. W. Moncxton, F.L.S., and H. Baverman, Assoc.M.Inst.C.E. The List of Donations to the Library was read. Vol. 61.] PROCEEDINGS OF THE GEOLOGICAL SOCIETY. Vv The following communications were read :— 1. ‘The Marine Beds in the Coal-Measures of North Stafford- shire. By John T. Stobbs, Esq., F.G.S. With Notes on their Paleontology by Wheelton Hind, M.D., B.S., F.R.C.S., F.G.S. 2,°The Geology of Cyprus.’ By Charles Vincent Bellamy, M.Inst.C.E., F.G.8. With Contributions by Alfred John Jukes- Browne, B.A., F.G.S.! The following specimens were exhibited :— Specimens from the Marine Beds in the Coal-Measures of North Staffordshire, exhibited by Wheelton Hind, M.D., F.G.S8., J. T. Stobbs, F.G.S., and John Ward, F.G.S., in illustration of the paper on that subject. : Specimens of Archwocidaris allied to A. vetusta, Phillips, and A. benburbensis, Portlock, from the grey shale underlying the Gin-Mine Coal, Nettlebank Colliery, Smallthorne (Staffordshire), exhibited by Dr. F. A. Bather, M.A., F.G.S. Microscope-sections of rocks from Cyprus, exhibited in illustra- tion of the paper by C. V. Bellamy, M.Inst.C.E., F.G.8., and A. J. Jukes-Browne, B.A., F.GS. Clypeaster altus var. portentosus (Helvetian) from Cyprus, and microscope-sections of the matrix. Collected by Miss D. M. A. Bate, and exhibited by Dr. F. A. Bather, M.A., F.G.S. January 18th, 1905. J. EK. Marr, Se.D., F.R.S., President, in the Chair. The List of Donations to the Library was read. Mr. W. G. Fuarnsipzs, in exhibiting a series of Llandovery- Tarannon graptolites from Llanystumdwy, near Criccieth (Caer- narvonshire ), remarked that the graptolites were beautifully preserved in pyrites, and were in full relief. They were from shales of the Birkhill or Stockdale-Shale type, and the four zones of Monograptus exiguus, M. turriculatus, M. fimbriatus, and Dimorphograptus were indicated. This was the first record of Llandovery-Tarannon rocks in the Lleyn Peninsula, since the time of Salter’s Catalogue, which recorded Llandovery fossils of May-Hill type from ‘The Hollies Farm, Pwllheli. Mr. G. F. Hersert Suirg, in exhibiting a hand-refractometer, remarked that, in that instrument, he had endeavoured to produce a refractometer which should be portable, and at the same time should furnish results of sufficient accuracy for the practical requirements of the mineralogist and the petrologist. The + Withdrawn by permission of the Oouncil. V1 PROCEEDINGS OF THE GHOLOGICAL SOCIETY. [Feb. 1905, refractometer designed by Prof. E. Bertrand in 1885 was portable, but in it no attempt had been made to compensate for the curvature of the hemisphere. The focal surface corresponding to the hemi- sphere was—apart from the effects of chromatic and spherical aberration—for rays which were parallel inside the glass, a spherical envelope concentric with the hemisphere. Hence the ocular scale could not possibly coincide with the focal surface for the whole range required, and the difficulties owing to parallax and bad definition of the shadow-edge rendered accurate results impossible. He (the speaker) had, in the present instrument, overcome this defect by introducing between the hemisphere and the scale a corrective lens, by means of which the focal surface became almost exactly a plane, and the edges separating the light and dark fields were sharply defined throughout the whole range. The scale was graduated by means of observations on known substances. Hach interval corresponded to a difference in refractive indices of about 0°010. In monochromatic light the shadow-edge appeared as a delicately-traced line, and an estimate of the refractive index might be obtained correct to two units in the third place of decimals. The instrument had been constructed to give the best results between 1°45 and 1°75. The glass of which the hemisphere was composed had a refractive index of 1:7938. The refractometer was to be used in the ordinary way. The indices of minute fragments might be determined indirectly, by finding with a microscope a liquid of the same refraction as them- selves, and then observing with the instrument the index of the liquid. Mr. J. H. Steward, of London, was the maker of this refractometer. The following communication was read :— ‘On the Geology of Arenig Fawr and Moel Llyfnant.’ By William George Fearnsides, M.A., F.G.S. In addition to the exhibits described on pp. v—vi, the following specimens were placed on the table :— Fossiliferous Arenig rocks and volcanic intrusives, with micro- scope-sections, exhibited by W. G. Fearnsides, M.A., F.G.S., in illustration of his paper. Reproductions of an interesting series of new sea-urchins, of the family Spatangide, recently found in blocks of a Middle Miocene rock, apparently brought up by ice-action from the floor of the Schaalsee, near Zarrentin (S.E. Holstein), exhibited by Dr. F, A. Bather, M.A., F.G.S8. Vol. 61.] PROCEEDINGS OF THE GEOLOGICAL SOCIETY. Vili February Ist, 1905. J. EK. Marr, Sc.D., F.R.S., President, in the Chair. Charles Griffith, M.A., Barnes Close, Winchester; V.S. Sambasiva Iyer, B.Sc., L.C.E., Curator in the Mysore Geological Depart- ment and Lecturer in Geology at the Central College, Bangalore (India); George Maxwell Lawford, M.Inst.C.K., 9 Bridge Street, Westminster, S.W.; Walter Reginald Gibson Rivington, Assoc.R.S.M., Assoc.I.M.M., Normanhurst, Northwood (Middlesex); Franz Eduard Studt, 13 Moscow Road, Stockport; Carl Adolph Siissmilch, Lecturer in Geology, Mineralogy, and Mining at the Sydney Technical College, Sydney (N.S.W.); and Isidore Tom, Assoc.R.S.M., Pyrenees Minerals Ltd., Alzen Mines, La Bastide de Sérou, Ariege (France), were elected Fellows of the Society. The List of Donations to the Library was read. Prof. Garwoop exhibited and commented on a set of twelve lantern-slides, illustrating the use of three-colour photography in demonstrating the microscopic eharacters of rock-forming minerals in polarized light. Mr. A. P. Youne said that he would like to learn what were now held to be the three primary colours, the practice in this respect appearing to have undergone some changes since the early days of colour-photography. Prof. Warrs pointed out the immense value of the photographs exhibited for teaching purposes. The colours were wonderfully accurate and beautiful; and, besides this, the refractive index was well-shown. He hoped that copies of these photographs might, some day, be available for teachers. Prof. Garwoop replied to Mr. Young that the slides were taken by the Sanger-Shepherd process, in which yellow, green, and red screens were used. In answer to a question from Dr. Teall, he said that it was not a process that could be used very easily, but one which required a good deal of time to produce really-accurate prints. Considerable difficulty was experienced in procuring objectives which were truly corrected for the spectrum, the tendency in the case of interference-figures being to give different-sized rings for different colours. He agreed with those who had taken part in the discussion, that the results did resemble very closely the phenomena seen under the microscope; and he had brought one or two rock-sections, shown on the screen, in case Fellows interested in the subject would like to compare the slides with the original sections. The following communication was read :— ‘On the Sporangium-like Organs of Glossopteris Browniana, Brongn.’ By EH. A. Newell Arber, M.A., F.L.S., F.G.8. Viil PROCEEDINGS OF THE GEOLOGICAL SociuTy. [Feb. 1905. In addition to the slides mentioned on the preceding page, the following specimens and maps were exhibited :— Specimens of Glossopteris, from Nagpur, Hislop & Hunter Col- lection, in the Museum of this Society; and specimens of Gilosso- pteris, from the Permo-Carboniferous of New South Wales, exhibited by Dr. A. Smith Woodward, F.R.8., F.G.S., in illustration of the paper by E. A. Newell Arber, M.A., F.L.S., F.G.S. Geological Survey of England and Wales: 1l-inch Geological Map, n. s., Sheet 261-262 (Solid & Drift), by R. H. Tiddeman, T. C. Cantrill, & A. Strahan (colour-printed), 1905, presented by the Director of H.M. Geological Survey. Five sheets of the Geological Map of the Auriferous Region of the Yenisel, by A. Meister, and one sheet of the Geological Map of the Auriferous Region of the Lena, by A. Gerasemov, scale 1 : 84,000, presented by the Imperial Russian Geological Survey. ANNUAL GENERAL MEKTING, February 17th, 1905. J. E. Marr, Se.D., F.R.S., President, in the Chair. Report or THE CounciIL FoR 1904. Tus Society continues in a generally-flourishing condition, although there is a small decrease in the total Number of Fellows. During the year under review 46 Fellows were elected (the same number as in 1903, and 2 less than in 1902), of whom 31 paid their Admission-Fees before the end of the year. Moreover, 13 Fellows, who had been elected in the previous year, paid their Admission- Fees in 1904, the total accession of new Fellows during the past twelve months amounting, therefore, to 44 (5 less than in 1903). Setting against this number a loss of 47 Fellows (28 by death, 13 by resignation, and 6 by removal from the List, under Bye- Laws, Sect. VI, Art. 5), it will be seen that there is a decrease in the Number of Fellows of 3 (as compared with a decrease of 4 in 1903, and an increase of 6 in 1902). This brings the total number of Fellows down to 1251, made up as follows :—Compounders, 281 ; Contributing Fellows, 934 (4 more than in both 1903 and 1902); and Non-Contributing Fellows, 36. Turning now to the Lists of Foreign Members and Foreign Correspondents, we have to deplore the loss of two of the former in 1904 (Prof. F. A. Fouqué and Prof. K. A. von Zittel), and also that of one Foreign Correspondent (Prof. C. E. Beecher). The . vacancies thus created (as well as two in the List of Foreign Correspondents left over from 1903) were filled by the transfer of Prof. J. P. Iddings and Prof. H. F. Osborn from the list of Correspondents to that of Members, and by the election of Prof. _ W.B. Clark, Prof. E. D. von Drygalski, Prof. G. de Lorenzo, the Hon. Frank Springer, and Prof. H. 8. Washington as Foreign Correspondents. With regard to the Income and Expenditure of the Society during the past year, the figures set forth in detail in the Balance-Sheet may be summarized as follows :— The total Receipts, including the Balance of £192 6s. 11d. brought forward from the previous year, amounted to £3187 3s. 9d., being £66 18s. 10d. more than the estimated Income. The total Expenditure during the same period amounted to £2777 16s. 2d., being £150 ie ton, less pra the estimated Expenditure for the year. VOL, LXI. x PROCEEDINGS OF THE GEOLOGICAL sociuty. [May 1905, The alterations in the Bye-Laws, necessitated by the new regulations which the Council at the time of the last Annual ~ Report had in view (in regard both to the publication of papers and to the admission of Visitors to Meetings), were agreed to, at a Special General Meeting summoned for the purpose of considering such alterations. The regulations made by the Council in accord- ance with the revised Bye-Laws as to Visitors have been published in the Proceedings, and also certain regulations as to Exhibits at Meetings. The appearance of the names of Members of the Standing Publication-Committee, on the inside of the cover of each number of the Quarterly Journal, is an indication of the change that has been made in the method of selecting papers for publication, The Council have to announce the completion of Vol. LX and the commencement of Vol. LXI of the Society’s Quarterly Journal. Mr, C. Davies Sherborn is making rapid progress with his manu- script Card-Catalogue of the Library, so rapid indeed that more cabinets have had to be purchased for the purpose of accommodating the Catalogue than could have been foreseen at the time when the Estimates for 1904 were framed. Mr. Sherborn has also undertaken to continue during the current year the preparation of the catalogue- slips for the International Catalogue of Scientific Literature. The approaching centenary of the foundation of the Society suggested to Mr. H. B. Woodward the propriety of celebrating the event by the publication of a Record which should embody the history of the Society. He accordingly placed before the Council a sketch of the principal features of the proposed Record, and a small Committee, of which he is a member, has been appointed to carry out the scheme. There is every reason to hope that the work will be completed by the centenary year 1907. In November, a further sum of £91 8s. 7d. was received from the executors of the late Sir Joseph Prestwich, making the total amount received on account of his bequest to the Society £709 2s. 10d., after deduction of legacy-duty. This additional sum has been invested in India 3 per cent. Stock, on account of the Prestwich Trust Fund. The second Award from the Daniel-Pidgeon Trust-Fund was made, on May 11th, 1904, to Mr. Linsdall Richardson, who proposed to extend his researches among the Rhetic and Inferior Oolite formations, apd to conduct excavations at Berrow Hill, near Upton-on- oe The following Awards of Whedale and Funds have also been made by the Council :— The Wollaston Medal is awarded to Dr. J. J. Harris Teall, F.R.S., in recognition of the value of his ‘ researches concerning the mineral structure of the Harth,’ and particularly of his valuable contri- butions to the science of Petrology in general, more especially to. our knowledge of the structure and composition of the rocks of the British Islands. The Murchison Medal, together with a Sum of Ten Guineas from the Murchison Geological Fund, is awarded to Mr, Edward a. “ee evil. 61: | ANNUAL REPORT. x1 John Dunn, of Victoria (Australia), in recognition of his valuable contributions to Geological Science in the form of geological maps of South Africa and researches on the modes of occurrence of gold in Australia. , The Lyell Medal, together with a Sum of Twenty-Five Pounds from the Lyell Geological Fund, is awarded to Dr. Hans Reusch, For.Memb.G.S., ‘as a mark of honorary distinction and as an expression on the part of the Council that he has deserved well of the science,’ especially by his contributions to our knowledge of the Geology of Norway. The Bigsby Medal is awarded to Prof. John Walter Gregory, F.R.S., ‘as an acknowledgment of his eminent services to Geology,’ both in the departments of Stratigraphy and Palsontology, in many parts of the world. The Balance of the Proceeds of the Wollaston Donation-Fund is awarded to Mr. Henry Howe Arnold-Bemrose, M.A., as an acknow- ledgment of the value of his investigations among the igneous rocks and cave-deposits of Derbyshire, and to encourage him in further research. The Balance of the Proceeds of the Murchison Geological Fund is awarded to Mr. Herbert Lister Bowman, M.A., in recognition of his services to Mineralogy, and as an encouragement to further work. A moiety of the Balance of the Proceeds of the Lyell Geological Fund is awarded to Mr. Edward Alexander Newell Arber, M.A., in recognition of his valuable contributions to our knowledge of Fossil Botany, and to encourage him in further investigations. The other moiety of the Balance of the Proceeds of the Lyell Geological Fund is awarded to Mr. Walcot Gibson, B.Sc., as an acknowledgment of the valuable work done by him among the Carboniferous and other strata of the Midland Counties, and as an encouragement to further research. Report oF THE Liprary-Anp-Mvusrnum Committrer ror 1904. — The Additions made to the Library during the past twelve months have maintained, both in number and in importance, the standard of previous years. During 1904 the Library received by Donation 141 Volumes of separately-published Works, 319 Pamphlets and detached Parts of Works, 261 Volumes and 48 detached Parts of Serial Publications, and 18 Volumes of Newspapers. The total number of accessions to the Library by Donation is thus found to amount to 420 Volumes, 319 Pamphlets, and 48 detached Parts. Moreover, no less than 98 sheets of Maps were presented to the Library, 27 of which came from the Ordnance-Survey Department. 62 xi PROCEEDINGS OF THE GEOLOGICAL socipry. | May 1905, | Among the numerous donations mentioned in the foregoing paragraphs, special attention may be directed to the following :— Report of the Coral-Reef Committee of the Royal Society on the Atoll of Funafuti; Prof. Zeiller’s great monograph on the Flora of the Coal-bearing strata of Tongking; the official handbook on the Geology of the Cameroons, issued by the German Foreign Office; Prof. H. S. Washington’s Manual of the Chemical Analysis of Rocks; Prof. Perner’s Monograph on the Silurian Gasteropoda of Central Bohemia, Vol. I; Herr Hauswaldt’s ‘ Interference- Phenomena in Polarized Light’; Vol. I of Miss Sollas’s translation of Suess’s ‘Face of the Earth’; the Geological Survey Memoirs on ‘the Kingsbridge and Salcombe Districts of Devon, on Merthyr Tydfil, on the Oolitic and Cretaceous Rocks south of Scarborough, on the country round Belfast, on the Tertiary Igneous Rocks of Skye, and the third volume of the ‘Cretaceous Rocks of England.’ From the Trustees of the British Museum the following volumes were received: Vol. I of the ‘ History of the Collections in the Natural History Department’; Vols. | & II of Mr. B. B. Woodward’s Catalogue of the Library of that Department; Vol. II of Mr. A. C. Seward’s Catalogue of the Jurassic Flora; Mr. L. Fletcher’s ‘Introduction to the Study of Meteorites’; and Dr. A. S. Wood- ward’s ‘Guide to the Fossil Mammals & Birds.’ From our Foreign Member, Prof. G. K. Gilbert, the volumes on ‘Glaciers & Glaciation,’ and ‘Geology & Paleontology’ of the Report of the Harriman Alaska Expedition were received; and our Foreign Correspondent, Dr. Th. Thoroddsen, presented to the Library a large collection of copies of his papers issued during the last 20 years. Moreover, numerous publications were received from the Geological Survey Departments of Egypt, India, Natal, the Transvaal Colony, Victoria, Hungary, Russia, Mexico, Ohio, and the United States. In addition to the Ordnance-Survey maps mentioned in a pre- ceding paragraph, 15 Sheets of Maps were received from H.M. Geological Survey; 16 Sheets from the Geological Survey of Canada; 9 Sheets from the Geological Survey of Western Australia ; 8 Sheets from the Geological Survey of Italy; and 5 Sheets from the Geological Survey of Japan. Mr. H. B. Woodward presented a copy of his new edition of Stanford’s Geological Atlas of Great Britain; and Dr. F. H. Hatch sent in a copy of the new edition of his Geological Map of the Southern Transvaal. The Books, Maps, etc. enumerated above were the gift of 162 Personal Donors; 113 Government Departments and other Public Bodies ; and 157 Societies and Editors of Periodicals. The Purchases, made on the recommendation of the standing Library Committee, included 32 Volumes and 6 Parts of separately- published Works; 24 Volumes of Works published serially ; and 7 Sheets of Maps. A set of the third series of photographs and the corresponding lantern-slides, issued by the Geological Photographs Committee of the British Association, was subscribed for, and is now deposited in the Library. . a - Vol. 61. | ANNUAL REPORT. Xili Great progress has been made during the past year in overtaking the arrears of binding and map- -mounting. The Expenditure incurred in connection with the Library during 1904 was as follows :— Books, Periodicals, etc. purchased.......... 67 8 5 Binding of Books and Mounting of Maps.... 139 15 6 Total 6207 va 11 With regard to the progress of the new Card-Catalogue of the Library, upon which he is engaged, Mr. C. Davies Sherborn supplies the following details :— ‘Work on the card-catalogue of the Library progresses favourably. The Annual Lists of Additions have been mounted and indexed, as to subjects and localities, up to and including 1897. There still remains about two years’ labour before current literature will be overtaken and the indexing of the early serials and “ Academies” can be commenced, at which time, it is hoped, money will be available for expediting this portion of the work. As each year’s *« Additions” demand the use of some 7,500 cards, some idea may be formed of the extent of the Catalogue projected for the convenience of the Fellows.’ Museum. For the purpose of study and comparison, the Collections were visited on 26 occasions during the year, the contents of about 67 drawers being thus examined. Moreover, the permission of the Council having been duly obtained, about 115 specimens were lent during 1904 to various investigators. No expenditure has been incurred in connection with the Museum during the past year. The appended Lists contain the Names of Government Depart- ments, Public Bodies, Societies, Editors, and Personal Donors, from whom Donations to the Library have been received during the year under review :— I. Government DEPARTMENTS AND orHER Pustiic Bopiks. Alabama.—Geological Survey, University (Ala.). American Museum of Natural History. New York. Austria.—Kaiserlich-K6nigliche Geologische Reichsanstalt. Vienna. Bavaria.—Ko6nigliches Bayerisches Oberber gamt. Munich. ean me Royale des Sciences, des Lettres & Beaux-Arts de Belgique. russels Musée Royal d’Histoire Naturelle. Brussels. Berlin.—Konigliche Preussische Akademie der Wissenschaften. Birmingham, University of. Bohemia.—Royal Museum of Natural History. Prague. —. Naturwissenschaftliche Landesdurchforschune. Prague. XIV PROCEEDINGS OF THE GEOLOGICAL soclery. [May 1905, British Columbia.—Department of Mines, Victoria (B.C.). British Guiana.—Department of Mines. Georgetown. British South Africa Company. London. Buenos Aires.—Museo Nacional de Ruenos Aires. California University. Berkeley (Cal.). Cambridge (Mass.).—Museum of Comparative Zoology, Harvard College. Canada.—Geological & Natural History Survey. Ottawa. ——, High Commissioner for. London. Cape Colony.—Department of Agriculture: Geological Commission. Cape Town. South African Museum. Cape Town. Carolina (N.).—Geological Survey. Raleigh (N. Car.). Chicago.— Field’ Columbian Museum. Denmark.—Commission for Ledelsen af de Geologiske og Geographiske Underso- gelser i Groénland. Copenhagen. . Kongelige Danske Videnskabernes Selskab. Copenhagen. Dublin.—Royal Irish Academy. Kgypt.—Department of Public Works: Geological Survey. Cairo. Finland.—Finlands Geologiska Undersékning. Helsingfors. France.—Ministére des Travaux Publics. Paris. Muséum d’Histoire Naturelle. Paris. Germany.—Kaiserliche Leopoldinisch-Carolinische Deutsche Akademie der Naturforscher. Halle an der Saale. Great Britain—Army Medical Department. London. ——, British Museum (Natural Histor y)- London. —. Colonial Office. London. ——. Geological Survey. London. Home Office. London. India Office. London. ——. Ordnance Survey. Southampton. Holland.—Departement van Kolonien. The Hague. Hull.—Municipal Museum. Hungary.—KGnigliche Ungarische Geologische Anstalt (Magyar Foldtani Tarsulat). Budapest. India.—Geological Survey. Calcutta. Surveyor-General’s Office. Calcutta. Iowa Geological Survey. Des Moines (Iowa). Treland.—Department of Agriculture & Technical Instruction. Dublin. Italy.— Reale Comitato Geologico. Rome. Japan.—Harthquake-Investigation Committee. ‘Tokio. Geological Survey. Tokio. Jassy, University of. Kansas.— University Geological Survey. Lawrence (Kan.). Kingston (Canada).—Queen’s College. London.—City of London College. Imperial Institute. ——. Royal College of Surgeons. University College. Mexico.—Instituto Geologico. Mexico City. Michigan College of Mines. Houghton (Mich.). Milan.—Reale Istituto Lombardo di Scienze & Lettere. Munich.—Konigliche Bayerische Akademie der Wissenschaften. Mysore Geological Department. Bangalore. Nancy.—Académie de Stanislas. Natal.—Department of Mines. Pietermaritzburg. Geological Survey. Pietermaritzbure: New Jersey.—Geological Survey. Trenton (N.J.). New South Wales, Agent-General for. London. ——. Department of Mines & Agriculture. Sydney. . Geological Survey. Sydney. New York State Museum. Albany (N.Y.). ‘New Zealand.—Department of Mines. Wellington. 7 Nova Scotia.—Department of Mines. Halifax. Ohio.—Geological Survey. Columbus (Ohio). Padua.—Reale Accademia di Scienze, Lettere & Arti. Paris.—Académie des Sciences. Perak Government. Taiping. Vol. 61. | ANNUAL REPORT. Peru.—Ministerio de Fomento. Lima. Pisa, Royal University of. Portugal.—Commissao dos Trabalhos geologicos. Lisbon. Prussia.—Muinisterium fiir Handel & Gewerbe. Berlin. . Konigliche Preussische Geologische Landesanstalt. Berlin. Queensland, Agent-General for. London. ——. Department of Mines. Brisbane. . Geological Survey. Brisbane. Redruth School of Mines. Rhodesian Museum. Bulawayo. Rio de Janeiro.—Museu Nacional. Rome.—Reale Accademia dei Lincei. Russia.—Comité Géologique. St. Petersburg. South Australia, Agent-General for. London. Geological Survey. Adelaide. Spain.—Comision del Mapa Geoldégico. Madrid. Stockholm.—Kongliga Svenska Vetenskaps Akademi. Sweden.—Sveriges Geologiska Undersékning. Stockholm. Switzerland.—Geologische Kommission der Schweiz. Berne. Tasmania.—Secretary for Mines. Hobart. Tokio.—Imperial University. College of Science. Transvaal.—Geological Survey. Pretoria. Mines Department. Pretoria. Turm.—Reale Accademia delle Scienze. United States.—Geological Survey. Washington (D.C.). Department of Agriculture. Washington (D.C.). —. National Museum. Washington (D.C.). Upsala, University of. Victoria (Austral.), Agent-General for. London. —— (——). Department of Mines. Melbourne. —— (—). Geological Survey. Melbourne. Vienna.—Kaiserliche Akademie der Wissenschaften. Washington (D.C.).—Smithsonian Institution. West Indies.—Imperial Agricultural Department. Bridgetown (Barbados). Western Australia, Agent-General for. London. ——. Department of Mines. Perth (W.A.). Geological Survey. Perth (W.A.). Wisconsin.—Geological & Natural History Survey. Madison (Wisc.). II. Socrerres anp Eprrors. Acireale-—Accademia di Scienze, Lettere & Arti. Adelaide.—Royal Society of South Australia. Agram.—Societas Historico-Naturalis Croatica. Alnwick.—Berwickshire Naturalists’ Club. Basel.—Naturforschende Gesellschaft. Bath.—Natural History & Antiquarian Field-Club. Belgrade.—Servian Geological Society. Berlin.—Deutsche Geologische Gesellschaft. Gesellschaft Naturforschender Freunde. ‘Zeitschrift fiir Praktische Geologie.’ Berne.—Schweizerische Naturforschende Gesellschaft. Bishop Auckland.—Weardale Naturalists’ Field-Club. Bombay Branch of the Royal Asiatic Society. Bordeaux.—Société Linnéenne. Boston (Mass.) Society of Natural History. ——. American Academy of Arts & Sciences. Brooklyn (N.Y.) Institute of Arts & Sciences. Brunswick.—Verein ftir Naturwissenschaft zu Braunschweig. : Brussels.—Société Belge de Géologie, de Paléontologie & d’Hydrologie. Budapest.—Féldtani Kézlény. Buenos Aires.—Sociedad Cientifica Argentina. Bulawayo.—Rhodesian Scientific Association. Section Géologique du Cabinet de S8.M. ?Empereur. St. Petersburg. xvi PROCEEDINGS OF THE GEOLOGICAL society. [May 1905, Caen.—Société Linnéenne de Normandie. Calcutta.— Indian Engineering.’ —. Asiatic Society of Bengal. Cambridge Philosophical Society. Cape Town.—-South African Association for the Advancement of Science. South African Philosophical Society. Cardiff.—South Wales Institute of Engineers. Chicago.— Journal of Geology.’ Christiania.—* Nyt Magazin for Naturvidenskaberne.’ Colombo.—Ceylon Branch of the Royal Asiatic Society. Colorado Springs.—‘ Colorado College Studies.’ Cérdoba (Argentine Republic)—Academia Nacional de Ciencias. Cracow.—Académie des Sciences (Akademia Umiejetnosci). Croydon Microscopical & Natural History Society. Dorpat.—Naturforschende Geseilschaft. Dresden.—Naturwissenschaftliche Gesellschaft. —. Verein fiir Erdkunde. Edinburgh.—Royal Scottish Geographical Society. Royal Society. Ekaterinburg.—Société Ouralienne d’Amateurs des Sciences N Aureos Frankfurt am Main.—Senckenbergische Naturforschende Gesellschaft. Freiburg im Breisgau.—N aturforschende Gesellschaft. Geneva.—Société de Physique & d’ Histoire Naturelle. Giessen.—Oberhessische Gesellschaft fiir Natur- & Heilkunde. Gloucester.—Cotteswold Naturalists’ Field-Club. Gratz.—Naturwissenschaftlicher Verein ftir Steiermark. Haarlem.—Société Hollandaise des Sciences. Halifax (N.S.).—Nova Scotian Institute of Science. Hanau.— Wetterauische Gesellschaft ftir Gesammte Naturkunde. Havre.—Société Géologique de Normandie. Hertford.—Hertfordshire Natural History Society. Hull Geological Society. Indianopolis—Indiana Academy of Science. J ohannesburg.—Geological Society of South Africa. Kiev.—Société des Naturalistes. Lausanne.—Société Vaudoise des Sciences Naturelles. Lawrence.—‘ Kansas University Bulletin.’ Leeds Philosophical & Literary Society. Yorkshire Geological & Polytechnic Society. Leicester Literary & Philosophical Society. Leipzig.—‘ Zeitschrift fir Krystallographie & Mineralogie.’ Liége.—Société Géologique de Belgique. . Société Royale des Sciences. Lille.—Société Géologique du Nord, Lima.—‘ Revista de Ciencias.’ Lisbon.—Sociedade de Geographia. Liverpool Geological Society. London.— The Academy.’ ‘The Atheneum.’ British Association for the Advancement of Science. British Association of Waterworks Engineers. ‘The Chemical News.’ Chemical Society. ‘The Colliery-Guardian.’ East India Association. ‘The Geological Magazine.’ Geologists’ Association. Institute of Sanitary Engineers. FA Institution of Civil Engineers. Pil Institution of Mining & Metallurgy. Iron & Steel Institute. ‘The Iron & Steel Trades’ Journal.’ ‘Knowledge.’ Linnean Society. ‘The London, Edinburgh, & Dublin Philosophical Magazine.’ Miner alogical Society. ‘Nature.’ Palzontographical Selene HW ee El Vol. 61.] ANNUAL REPORT, London.— The Quarry.’ hi RAereee Records of the London & West-Country Chamber of Mines. Royal Agricultural Society. Royal Geographical Society. Royal Institution. Royal Meteorological Society. Royal Microscopical Society. Royal Photographic Society. Royal Society. Society of Arts. Society of Biblical Archeology. ‘The South-Eastern Naturalist’ (S.E. Union of Scientific Societies). Victoria Institute. ‘Water.’ Zoological Society. Manchester Geological & Mining Society. Literary & “Philosophical Society. Melbourne.—Australasian Institute of Mining Engineers. Royal Society of Victoria. Mexico.—Sociedad Cientifica ‘ Antonio Alzate.’ Moscow.—Société Impériale des Naturalistes. New Haven (Conn.).—‘ The American Journal of Science.’ New York.—Academy of Sciences. ns ° American Institute of Mining Engineers. ‘Science.’ mee upon- Tyne. —Institution of Mining Engineers. e & Mechanical Engineers. me ihamiton. = Nolianiemenine Natural History Society. Ottawa.—Royal Society of Canada. Paris.—Commission Frangaise des Glaciers. Société Frangaise de Minéralogie. Société Géologique de France. ‘Spelunca.’ Penzance.—Royal Geological Society of Cornwall. Perth.—Perthshire Society of Natural Science. Philadelphia.—Academy of Natural Sciences. American Philosophical Society. Wagner Free Institute of Science. Pisa.—Societa Toscana di Scienze Naturali. Plymouth.—Devonshire Association for the Advancement of Science. Rennes.—Société Scientifique & Médicale de l’ Ouest. Rochester (N.Y.).—Academy of Science. Geological Society of America. Rome.—Societa Geologica Italiana. Rugby School Natural History Society. Santiago de Chile-—Sociedad Nacional de Mineria, Société Scientifique du Chili. Scranton (Pa.).—‘ Mines & Minerals.’ St. John (N.B.).—Natural History Society of New Brunswick. St. Petersburg.—Russische Kaiserliche Mineralogische Gesellschaft. Stockholm.—Geologiska Férening. Stuttgart.—‘ Centralblatt fiir Mineralogie, Geologie & Palaontologie.’ “Neues Jahrbuch fiir Mineralogie, Geologie & Palaontologie.” Verein fiir Vaterlandische Naturkunde in Wiurttemberg. ‘Zeitschrift fiir Naturwissenschaften.’ Sydney (N.S.W.).—Linnean Society of New South Wales. Royal Society of New South Wales. Toronto.—Canadian Institute. Toulouse.—Société d’ Histoire Naturelle. Truro.—Royal Institution of Cornwall. Vienna.—‘ Berg- & Hiittenmannisches Jahrbuch.’ Kaiserlich-K6nigliche Zoologisch-Botanische Gesellschaft. Washington (D.C.).—Academy of Sciences. Biolog ical Society. Wellington (N. Z.).—New Zealand cnet Wiesbaden.—Nassauischer Verein fiir Naturkunde. York.—Yorkshire Philosophical Society. XVli XV1l PROCEEDINGS OF THE GEOLOGICAL SOCIETY. Acland, H. D. Agassiz, A. Allanson-Winn, R. G. Angelis d’Ossat, G. de. Arber, E. A. N. Arsandaux, H. Baldwin, W. Bauerman, H. Bernard, H. M. Bistram, A. von. Blake, W. P. Bodenbender, G. Borredon, G. Branner, J. C. Brough, B. H. Brown, R. M. Bullen, Rev. R. A. Burns, D. Cayeux, L. Chamberlin, T. C. Chapman, F. Chewings, C. Clarke, W. W. Codazzi, R. L. L. Cole, G. A. J. Collins, J. H. Coomaraswamy, BRAK: Cornish, V. Credner, H. Crick, CG CG: Cumings, E. R. Cvijic, J.. Dalton, W. H. Davies, W. M. Davison, C. Delgado, J. F. N. Dewalque, G. Dollfus, G. F. Duparc, L. Katon, G. F. Emmons, S. F. Felix, J. Fisher, Rev. O. Foord, A. H. Forir, H. Foureau, F. Francis, W. Frazer, P. Fritsch, A. Garwood, E. J. Geikie, Sir Archibald. Gilbert, G. K. Gilpin, E, .) Jun. Gosselet, J. Greenwell, A. IIL. Prrsonat Donors. Gregory, J. W. Grundy, J. Guppy, R. J. L. Habets, A. Hamling, J. G. Harrison, W. J. Hatch, F. H. Haug, E. Hauswaldt, H. Hayden, H. Hendriksen, G. Hoek, H. Hoffman, J. J. Holmes, T. V. Horwood, C. B. Hovey, E. O. Howorth, Sir Henry. Hudleston, W. H. Hull, E. Imamura, A. Issel, Jensen, A.S. Jentzsch, A. Jones, T. R. Jukes-Browne, A. J. ” Kalecsinszki, A. V. Karpinski, A Kayser, E. Kendall, P. F. Kidner, H. Klein, C. Koch, A. Koert, W. Kolderup, F. Kossmat, F. Kzryzanoyski, J. Lacroix, A. Lake, P. Lambe, L. M. Lambert, G. Lamplugh, G. W. Latham, B Lempftert, R. G. K. Lewis, A. A. Liversidge, A. Londerbach, G. W. Loriol, P. de. Louis, H. MacAlister, D. A. Maclaren, J. M. Maitland, A. G. Marr, J. H. Martel, E. A. Mill, H, R. Monckton, H. W. Mrazec, L. Murray, Sir John. Nares, Sir George. Newton, R. B Ochsenius, C. Omori, F. Park, J. Parker, J. H. Parkinson, J. Pavlov, A. P. Poole, H. 8. Reade, ‘I’. M. Reed, F. R. C. Reid, C. Rice, W. N. R. Richardson, L. Robarts, N. F, Rosenbusch, H. Rowe, A. W. Sacco, F. Sauvage, H. E. Scaglia, S Schuchert, C. Shaw, F. G. Sheppard, F. Sherborn, C. D. Skinner, D. b. Spencer, J. H. Steinmann, G. Stobbs, J. T. Suess, H. Tassin, W. Teisseyre, W. Thoroddsen, 'Th. 'Toernquist, Sv. L. Twelvetrees, W. H. Vaughan, A. Waller, G. A. Walther, J. Ward, H. A. Warren, S. H. Washing ee Has Watts, W. We Whitaker, W. Wieland, G. Ric Wilckens, O. Woodward, H. Woodward, H. B. Woolacott, D. Wysocki, 8. Zeiller, R. Aittel, K. A. von. “May 1905, Vol. 61. ] oe: ANNUAL REPORT. XIX CoMPARATIVE STATEMENT OF THE NUMBER OF THE SOCIETY AT THE Crosb oF THE YEARS 1903 anp 1904. ; Dee. 31st, 1903. Dee. 31st, 1904. Compounders,.. 2... es 3 DN i ee 3 281 Contributing Fellows...... Oa Oars ier. sy. 934 Non-Contributing Fellows. . PO) ae eee RCTS 36 1254 1251 Foreign Members ........ A) Sie eee 40 Foreign Correspondents... . ENS) Eo eee eae 40 1332 1331 Comparative Statement, explanatory of the Alterations im the Number of Fellows, Foreign Members, and Foreign Correspondents at the close of the years 1903 and 1904. Number of Compounders, Contributing and Non- Contributing Fellows, December 31st, 1903 .. Add Fellows elected during the former year and ORCL sak LEE Se eles Ap ane ee cin Aeanc eee Add Fellows elected and paid in 1904 ........ Deduct Compounders deceased................ 13 Contributing Fellows deceased .......... 14 Non-Contributing Fellow deceased........ 1 Contributing Fellows resigned .......... 13 Contributing Fellows removed .......... 6 Number of Foreign Members and Foreign Cor- mg respondents, December 3lst, 1903 .......... : Deduct Foreign Members deceased ........ 2 Foreign Correspondents deceased .. 1 Foreign Correspondents elected Boreiem Members )0..¢25 246. } — 5) 79 Add Foreign Members elected .......... 2 Foreign Correspondents elected .... 5 : =e ( 31 1298 47 1251 SOx PROCEEDINGS OF THE GEOLOGICAL socrETY. [May 1905, DrcEAseD FELLOWS. Compounders (13). Browne, R. M. Myers-Beswick, W. B. Ferguson, W. Ricketts, Dr. C. Foster, Sir Clement Le Neve. Roberts, Dr. I. Fothergill, Lt.-Col. C. W. Serocold, C. P. Francis, Dr. W. Tomes, R. F. McMahon, Lt.-General C. A. Ward, H. Moore, 8. P. Resident and other Contributing Fellows (14). Fowler, P. | McDonald, J. A. Gurney, Rev. H. P. _ | Pearson, H. W. Harman, F. E. Prado, M. Hawell, Rev. J. Rutley, F. Hoskold, H. D. Swan, R. M. W. Jackson, W. Valpy, R. H. McClean, F. Wall, P. W. Non-coniributing Fellow (1). Brass, Rev. H. Decrasep Forrten MempBers (2). Fouqué, Prof. F. A. | Zittel, Prof. K. A. von. Decrasep Forrien CorresponpeEnt (1). Beecher, Prof. C. E. Fettows Restenep (13). Allhusen, E. L. | May, W. Ball, W. J. Moulden, J. C. Bradley, J. W. Oliver, T. A. Clifford, Rev. J. Smith, F. H. Ford, H. W. Spurrell, F.C. J. Haig, Lt.-Colonel H. de Haga. Vassall, H. Hanks, H. G. | Frttows Rumoven (6). Bolton, A. J. Heath, Rev. A. J. Lowles, J. I. Mackenzie, J. Monckton, G. F. Murray, R. A. F. Vol. 61.] ANNUAL REPORT. . xxl The following Personages were elected Foreign Members during the year 1904:— Prof, Joseph Paxson Iddings, of Chicago. Dr. Henry Fairfield Osborn, of New York. The following Personages were elected Foreign Correspondents during the year 1904 :— Dr. William Bullock Clark, of Baltimore. Dr. Erich Dagobert von Drygalski, of Charlottenbure. Prof. Giuseppe de Lorenzo, of Naples. The Hon. Frank Springer, of Burlington, U.S.A. Dr. Henry 8. Washington, of Locust, U.S.A. After the Reports had been read, it was resolved :— That they be received and entered on the Minutes of the Meeting, and that such parts of them as the Council shall think fit be printed and circulated among the Fellows. It was afterwards resolved :— That the thanks of the Society be given to Sir Archibald Geikie and Mr. EK. TI’. Newton, retiring from the office of Vice-President. That the thanks of the Society be given to Mr. R. S. Herries, retiring from the office of Secretary. That the thanks of the Society be given to the Rt. Hon. Lord Avebury, Prof. T. T. Groom, Mr, Alfred Harker, Mr. E. T. Newton, and Mr. G. T. Prior, retiring from the Council. After the Balloting-Glasses had been closed, and the Lists examined by the Scrutineers, the following gentlemen were declared to have been duly elected as the Officers and Council for the ensuing year :— XX1l PROCEEDINGS OF THE GEOLOGICAL SOCIETY, [May 1905, OFFICERS AND COUNCIL.—1905. PRESIDENT. John Edward Marr, Sc.D., F.R.S. VICE-PRESIDENTS. Prof, Thomas George Bonney, Sc.D., LL.D., F.R.S., F.S.A. Robert Stansfield Herries, M.A. Prof. Charles Lapworth, M.Sc., LL.D., F.R.S. Horace Bolingbroke Woodward, F.R.S. SECRETARIES. Prof. William Whitehead Watts, M.A., M.Sc., F.R.S. Prof. Edmund Johnstone Garwood, M.A. FOREL GN SECRETARY. Sir John Evans, K.C.B., D.C.L., LL.D., F.R.S., F.S.A. TREASURER, William Thomas Blanford, C.I.E., LL.D., F.R.S. COUNCIL. Francis Arthur Bather, M.A., D.Sc. William Thomas Blanford, C.I.E., LL.D., F.R.S. Prof. Thomas George Bonney, SeuDe. LL.D., F.R.S., F.S.A. ir ad) ohn Evans, 1D, FOR.S.; S.A. Prof. Edmund Johnstone Garwood, M.A. Sir Archibald Geikie, Sc.D., D.C.L., LL.D., Sec.R.8. Robert Stansfield Herries, M.A. Prof. John W. Judd, C.B., LL.D., F.R.S. Prof. Perey Fry Kendall. Philip Lake, M.A. Prof. Charles Lapworth, LL.D., F.R.S. MCB. D.C1., M.Se., Richard Lydekker, B.A., F.R.S. Bedford McNeill, Assoc.R.S.M. John Edward Marr, Sc.D., F.R.S. | Prof. Henry Alexander Miers, M.A., Horace F.LS. Frederick William Rudler, LS. 0. Leonard James Spencer, M. A. Aubrey Strahan, M.A., F.R.S. Charles Fox Strangways. Prof. William Whitehead Watts, M.A., M.Sc., F.R.S. The Rev. Henry ie Winwood, M.A. Horace F.R.S. Woollaston Monckton, Bolingbroke | Woodward, Vol. 6r.] ANNUAL REPORT. XXIIL LIST OF THE FOREIGN MEMBERS OF THE GEOLOGICAL SOCIETY OF LONDON, tw 1904. Date of Election. 1874, Prof. Albert Jean Gaudry, Paris. 1877. Prof. Eduard Suess, Vienna. 1880. Prof. Gustave Dewalque, Liége. 1880. Geheimrath Prof. Ferdinand Zirkel, Leipzig. 1884. Commendatore Prof. Giovanni Capellini, Bologna. 1885. Prof. Jules Gosselet, Lille. 1886, Prof. Gustav Tschermak, Vienna. 1888. Prof. Eugéne Renevier, Lausanne, 1888. Baron Ferdinand von Richthofen, Berlin. 1890. Geheimrath Prof. Heinrich Rosenbusch, Herdelberg. 1891. Prof, Charles Barrois, Lille. 1893. Prof. Waldemar Christofer Broegeer, Christiania. 1898. M. Auguste Michel-Lévy, Parvs. 1898. Dr. Edmund Mojsisovics von Mojsvar, Vienna. 1898. Prof. Alfred Gabriel Nathorst, Stockholm. 1894. Prof. George J. Brush, New Haven, Conn. (U.S.A.). 1894. Prof. Edward Salisbury Dana, Wew Haven, Conn. (U.S.A.). 1895. Prof. Grove Karl Gilbert, Washington, D.C. (U.S.A.). 1895. Dr. Friedrich Schmidt, St. Petersburg. 1896, Prof. Albert Heim, Ziirich. 1897. M. Edouard Dupont, Brussels. 1897. Dr. Anton Fritsch, Prague. 1897. Prof. Albert de Lapparent, Paris. 1897. Dr. Hans Reusch, Christiania. 1898, Geheimrath Prof. Hermann Credner, Ledpzzg. 1898. Mr. Charles Doolittle Walcott, Washington, D.C. (U.S.A.). 1899. Prof. Marcel Bertrand, Paris. 1899. Senhor Joaquim Felipe Nery Deleado, Lisbon. 1899. Prof. Emmanuel Kayser, Marburg. 1899. M. Ernest Van den Broeck, Brussels, 1899. Dr. Charles Abiathar White, Washington, D.C. (U.SAL). 1900. M. Gustave F. Dollfus, Paris. 1900. Prof. Paul Groth, Munich. 1900. Dr. Sven Leonhard Tcernquist, Lend. 1901. M. Alexander Petrovich Karpinsky, St. Petersburg. 1901. Prof. Alfred Lacroix, Paris. : 1903. Prof. Albrecht Penck, Vienna. 1903. Prof. Anton Koch, Budapest. 1904, Prof. Joseph Paxson Iddings, Chicago (U.S.A.). 1904. Prof. Henry Fairfield Osborn, New York (U.S.A.). XX1V PROCEEDINGS OF THE @HOLOGICAL socreTy. | May 1905, LIST OF THE FOREIGN CORRESPONDENTS OF THE GEOLOGICAL SOCIETY OF LONDON, tw 1904. Date of Election. 1866. Prof. Victor Raulin, Montfaucon d@ Argonne. (Deceused.) ° 1874. Prof. Igino Cocchi, florence. 1879. Dr. Emile Sauvage, Boulogne-sur-Mer. 1889. Dr. Rogier Diederik Marius Verbeek, The Hague. 1890. Geheimer Bergrath Prof. Adolph von Keenen, Gottingen. 1892. Prof. Johann Lehmann, Kiel. 1893. Prof. Aléxis P. Pavlow, Moscow. 1893. M. Ed. Rigaux, Bowlogne-sur-Mer. 1894, Prof. Joseph Paxson Iddings, Chicago, Ill. (U.S.A.). (Elected Foreign Member.) 1894, M. Perceval de Loriol-Lefort, Campagne Frontenex, near Geneva. 1894, Dr. Francisco P. Moreno, La Plata. 1894, Prof. August Rothpletz, Munich. 1894. Prof. J. H. L. Vogt, Christeania. 1895. Prof. Constantin de Kroustchoff, St. Petersburg. 1896. Prof. Samuel L. Penfield, New Haven, Conn. (U.S_A.). 1896. Prof. Johannes Walther, Jena. 1897. Dr. Louis Dollo, Brussels. 1897. M. Emmanuel de Margerie, Paris. 1897. . Prof. Count H. zu Solms-Laubach, Strasburg. 1898. Dr. Marcellin Boule, Parvs. 1898. Dr. W. H. Dall, Washington, D.C. (U.S_A.). 1899. Dr. Gerhard Holm, Stockholm. 1899. Prof. Theodor Liebisch, Gottingen. 1899. Prof. Franz Loewinson-Lessing, St. Petersburg. 1899. M. Michel F. Mourlon, Brussels. 1899. Prof. Henry Fairfield Osborn, New York (U.S.A.). (Elected Foreign Meméer.) 1899. Prof. Gregorio Stefanescu, Bucharest. 1899. Prof. René Zeiller, Paris. 1900. Commendatore Prof. Arturo Issel, Genou.. 1900. Prof. Ernst Koken, Jribingen. 1900. Prof. Federico Sacco, Turi. 1901. Prof. Friedrich Johann Becke, Vienna. 1902. Prof. Thomas Chrowder Chamberlin, Chicago, Til. ( U.S.A.). 1902. Dr. Thorvaldry Thoroddsen, Copenhagen. 1902. Prof. Samuel Wendell Williston, Chicago, Zl. (US.A.). 1908. Geheimer Bergrath Prof. Carl Klein, Berlin. 1903. Dr. Emil Ernst August Tietze, Vienna. 1904. Dr. William Bullock Clark, Baltimore (U. Sede 1904. Dr. Erich Dagobert von Drygalski, Charlottenburg. 1904, Prof. Giuseppe de Lorenzo, Naples. 1904, The Hon. Frank Springer, Burlington, Iowa (U.S.A.). 1904. Dr. Henry S. Washington, Locust, N.J. (U.S.A.). Vol. 1831. 1835. 1836. 1837. 1838. 1839. 1840. 1841. 1842. 1848. 1844. 1845. 1846. 1847. 1848. 1849. 1850. 1851. 1852. 1853. 1854. 1855. 1856. 1857. 1858. 1859. 1860. 1861. 1862. 1863. 1864, 1865. 1866. 1867. 1868. 61.| ANNUAL REPORT. XXV AWARDS OF THE WOLLASTON MEDAL UNDER THE CONDITIONS OF THE “DONATION FUND’ ESTABLISHED BY WILLIAM HYDE WOLLASTON, M.D., F.R.S., F.G.S., ere. To promote researches concerning the mineral structure of the Earth, and to enable the Council of the Geological Society to reward those individuals of any country by whom such researches may hereafter be made, —‘ such individual not being a Member of the Council.’ Mr. William Smith. Dr. G. A. Mantell. M. Louis Agassiz. Capt. T. P. Cautley. Dr. H. Falconer. Sir Richard Owen. Prof. C. G. Ehrenberg. Prof. A. H. Dumont. M. Adolphe T. Brongniart. Baron Leopold von Buch. M. Elie de Beaumont. M. P. A. Dufrénoy. The Rev. W. D. Conybeare. Prof. John Phillips. Mr. William Lonsdale. Dr. Ami Boué. The Very Rev. W. Buckland. Sir Joseph Prestwich. Mr. William Hopkins. The Rey. Prof. A. Sedgwick. Dr. W. H. Fitton. M. E. de Verneuil. Sir Richard Griffith. Sir Henry De la Beche. Sir William Logan. M. Joachim Barrande. M. le Vicomte A. d’Archiac. Herr Hermann von Meyer. Prof. James Hall. Mr. Charles Darwin. Mr. Searles V. Wood. Prof. Dr. H. G. Bronn. Mr. R. A. C. Godwin-Austen: Prof. Gustav Bischof. Sir Roderick Murchison. Dr. Thomas Davidson. Sir Charles Lyell. Mr. G. Poulett Scrope. Prof. Carl F. Naumann. VOL. LXI, 1869. 1870. 1871. 1872. 1873. 1874. 1875. 1876. 1877. 1878. Ish 1880. 1881. 1882. 1883. 1884. 1885, 1886. 1887. 1888. 1889. 1890. 1891. 1892. 1898. 1894. 1895. 1896. 1897. 1898 1899 1900 1901 1902 1903 1904 1905 Dr. Henry C..Sorby. Prof. G. P. Deshayes. Sir Andrew Ramsay. Prof. James D. Dana. Sir P. de M. Grey Egerton. Prof. Oswald Heer. Prof. L. G. de Koninck. Prof. Thomas H. Huxley. . Mr. Robert Mallet. Dr, Thomas Wright. Prof. Bernhard Studer. Prof. Auguste Daubrée. Prof. P. Martin Duncan. Dr. Franz Ritter von Hauer. Dr. William Thomas Blanfor J. Prof. Albert Jean Gaudry. Mr. George Busk. Prof, A. L.O. Des Cloizeaux. Mr. John Whitaker Hulke. Mr. Henry B. Medlicott. Prof.Thomas George Bonney, Prof. W. C. Williamson. Prof. John Wesley Judd. Baron Ferdinand von Richthofen. Prof. Nevil Story Maskelyne. Prof. Karl Alfred von Zittel. Sir Archibald Geikie. Prof. Eduard Suess. Mr. Wilfrid H. Hudleston. . Prof. Ferdinand Zirkel. . Prof. Charles Lapworth. . Prof. Grove Karl Gilbert. . Prof. Charles Barrois. . Dr. Friedrich Schmidt. . Prof. Heinrich Rosenbusch. . Prof. Albert Heim. . Dr. J. J. Harris Teall. Cc XXV1 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. AWARDS OF THE [ May 1905, BALANCE OF THE PROCEEDS OF THE WOLLASTON ‘DONATION-FUND.’ 1831. 1833. 1834. 1835. 1836. 1838. 1839. 1840. 1841. 1842. 1843. 1844. 1845. 1846. 1847. 1848. 1849. 1850. 1851. 1852. 1853. 1854. 1855. 1856. 1857. 1858. 1859. 1860. 1861. 1862. 1863. 1864. 1865. 1866. 1867. 1868. Mr. William Smith. Mr. William Lonsdale. M. Louis Agassiz. Dr. G. A. Mantell. Prof. G. P. Deshayes. Sir Richard Owen. Prof. C. G. Ehrenberg. Mr. J. De Carle Sowerby. Prof. Edward Forbes. Prof. John Morris. Prof. John Morris. Mr. William Lonsdale. -Mr. Geddes Bain. Mr. William Lonsdale. M. Alcide d’Orbigny. Cape-of-Good-Hope Fossils. M. Alcide d’Orbigny. Mr. William Lonsdale. Prof. John Morris. M. Joachim Barrande. Prof. John Morris. Prof. L. G. de Koninek. Dr. Samuel P. Woodward. Drs. G. and IF’. Sandberger. Prof. G. P. Deshayes. Dr. Samuel P. Woodward. Prof. James Hall. Mr. Charles Peach. Prof. T. Rupert Jones. Mr. W. K. Parker. Prof. Auguste Daubrée. Prof. Oswald Heer. Prof. Ferdinand Senft. Prof. G. P. Deshayes. Mr. J. W. Salter. Dr. Henry Woodward. Mr. W. H. Baily. M. J. Bosquet. 1869. 1870, 1871. 1872. 1873. 1874. 1875. 1876. 1877. 1878. 1879. 1880. 1881. 1882. 1883. 1884. 1885. 1886. 1887. 1888. 1889. 1890. 1891. 1892. 1893. 1894. 1895. 1896. 1897. 1898. 1899. 1900. 1901. 1902. 1903. 1904. 1905. Mr. William Carruthers. M. Marie Rouault. Mr. Robert Ltheridge. Dr. James Croll. Prof. John Wesley Judd. Dr. Henri Nyst. Prof, L. C. Miall. Prof. Giuseppe Seguenza. Mr. Robert Etheridge, Jun. Prof. William Johnson Sollas. Mr. Samuel Allport. Mr. Thomas Davies. Dr. Ramsay Heatley Traquair. Dr. George Jennings Hinde. Prof. John Milne. Mr. Edwin Tulley Newton. Dr. Charles Callaway. Mr. J. Starkie Gardner, Mr. Benjamin Neeve Peach. Dr. John Horne. Dr. Arthur Smith Woodward. Mr, William A. E. Ussher. Mr. Richard Lydekker. My. Orville Adelbert Derby. Mr. JohnGeorge Goodchild. Mr. Aubrey Strahan. Prof. William W. Watts. Mr. Alfred Harker. Dr. Francis Arthur Bather, Prof. Edmund J. Garwood. Prof. John B. Harrison. Mr. George Thurland Prior. Mr. Arthur Walton Rowe. Mr. Leonard James Spencer. Mr. L. L. Belinfante. Miss Ethel M. R. Wood. Mr. H. H. Arnold-Bemrose. Vol. 61.] ANNUAL REPORT. XXVii AWARDS OF THE MURCHISON MEDAL UNDER THE CONDITIONS OF THE ‘MURCHISON GEOLOGICAL FUND)’ ESTABLISHED UNDER THE WILL OF THE LATE SIR RODERICK IMPEY MURCHISON, Barr., F.R.S., F.G.8. ‘To be applied in every consecutive year, in such manner as the Council of the Society may deem most useful in advancing Geological Science, whether by granting sums of money to travellers in pursuit of knowledge, to authors of memoirs, or to persons actually employed in any enquiries bearing upon the science of Geology, or in rewarding any such travellers, authors, or other persons, and the Medal to be given to some person to whom such Council shall grant any sum of money or recompense in respect of Geological Science.’ 1873. Mr. William Davies. 1890. Prof. Edward Hull. 1874. Dr. J. J. Bigsby. 1891. Prof. Waldemar C. Brogge 1875. Mr. W. J. Henwood. Se liso? PR roie Aveta 4Greem. 1876. Mr. Alfred R. C. Selwyn. 1893. The Rev. Osmond Fisher. 1877. The Rev. W. B. Clarke. 1894. Mr. William T. Aveline. 1878. Prof. Hanns Bruno Geinitz. 1895. Prof. Gustaf Lindstroem. 1879. Sir Frederick M‘Coy. 1896. Mr. T. Mellard Reade. 1880. Mr. Robert Etheridge. 1897. Mr. Horace B. Woodward. 1881. Sir Archibald Geikie. 1898. Mr. Thomas F.. Jamieson. 1882. Prof. Jules Gosselet. Mr. Benjamin N., Peach. 1883. Prof. H. R. Goeppert. Boue te John Horne. 1884. Dr. Henry Woodward. 1900. Baron A. E. Nordenskiceld. 1885. Dr. Ferdinand von Roemer. | 1901. Mr. A. J. Jukes-Browne. 1886, Mr. William Whitaker. 1902. Mr. Frederic W. Harmer. 1887. The Rev. Peter B. Brodie. 1903. Dr. Charles Callaway. 1888. Prof. J. 8. Newberry. | 1904. Prof. George A. Lebour. 1889. Prof. James Geilkie. 1905. Mr. Edward John Dunn. 62 XXVlil PROCEEDINGS OF THE GEOLOGICAL society. | May 1905, AWARDS OF THE BALANCE OF THE PROCEEDS OF THE ‘MURCHISON GEOLOGICAL FUND’ 1873. Prof. Oswald Heer. 1889. Prof. Grenville A. J. Cole. 1874. My. Alfred Bell. 1890. Mr. Edward B. Wethered. 1874, Prof. Ralph Tate. 1891. The Rev. Richard Baron. 1875, Prof. H. Govier Seeley. 1892. Mr. Beeby Thompson. 1876. Dr. James Croll. 1893. Mr. Griffith J. Williams. _ 1877. The Rev. John F. Blake. 1894, Mr. George Barrow. — 1878. Prof. Charles Lapworth. 1895. Mr. Albert Charles Seward. 1879. Mr. James Walker Kirkby. | 1896. Mr. Philip Lake. 1880. Mr. Robert Etheridge. 1897. Mr. Sydney 8. Buckman. 1881. Mr. Frank Rutley. 1898. Miss Jane Donald. 1882. Prof. Thomas Rupert Jones. | 1899. Mr. James Bennie. 1883. Dr. John Young. 1900. Mr. A. Vaughan Jennings. 1884. Mr. Martin Simpson. 1901. Mr. Thomas 8. Hall. 1885. Mr. Horace B. Woodward. 1902. Mr. Thomas H. Holland. 1886. Mr. Clement Reid. 1903. Mrs. Elizabeth Gray. 1887. Mr. Robert Kidston. 1904. Dr. Arthur Hutchinson. 1888. Mr. Edward Wilson. . 1905. Mr. Herbert Lister Bowman, AWARDS OF THE PROCEKEDS OF THE ‘DANIELsPIDGEON FUND,’ FOUNDED BY MRS. PIDGEON, IN ACCORDANCE WITH THE WILL OF THE LATE DANIEL PIDGEON, E.G.S. ‘An annual grant derivable from the interest on the Fund, to be used at the discretion of the Council, in whatever way may in their opinion best promote Geological Original Research, their Grantees being in all cases not more than twenty-eight years of age.’ % 1908. Prof. Ernest Willington Skeats. 1904. Mr. Linsdall Richardson, ANNUAL REPORT. XX1X AWARDS OF THE LYELL MEDAL UNDER THE CONDITIONS OF THE ‘LYELL GEOLOGICAL FUND,’ ESTABLISHED UNDER THE WILL AND CODICIL OF THE LATE SIR CHARLES LYELL, Barr., F.R.S., F.G.S. The Medal ‘to be cast in bronze and to be given annually’ (or from time to time) “as a mark of honorary distinction and as an expression on the part of the governing body of the Society that the Medallist (who may be of any country or either sex) has deserved well of the Science, —‘ not less than one third of the annual interest [of the fund] to accompany the Medal, the remaining interest to be given in one or more portions, at the discretion of the Council, for the encouragement of Geology or of any of the allied sciences by which they shall consider Geology to have been most materially advanced, either for travelling expenses or for a memoir or paper published, or in progress, and without reference to the sex or nationality of the author, or the language in which any such memoir or paper may be written.’ There is a further provision for suspending the award for one year, and in such case for the awarding of a Medal to ‘ each of two persons who have been jointly engaged in the same exploration in the same country, or perhaps on allied subjects in different countries, the proportion of interest always not being less to each Medal than one third of the annual interest.’ 1876. Prof. John Morris. 1892. Mr. George H. Morton. 1877. Sir James Hector. 1893. Mr. Edwin Tulley Newton. 1878. Mr. George Busk. 1894. Prof. John Milne. 1879. Prof. Edmond Hébert. 1895. The Rev. John F. Blake. 1880. Sir John Evans. 1896. Dr. Arthur Smith Woodward. 1881. Sir J. William Dawson. 1897. Dr. George Jennings Hinde. 1882. Dr. J. Lycett. 1898. Prof. Wilhelm Waagen. 1883. Dr. W. B. Carpenter. 1899. Lt.-Gen. C. A. McMahon. 1884. Dr. Joseph Leidy. 1900. Dr. John Edward Marr. 1885. Prof. H. Govier Seeley. 1901. Dr. Ramsay Heatley Traquair, 1886. Mr. William Pengelly. 1902 ieee Anton Fritsch. 1887. Mr. Samuel Allport. ‘My. Richard Lydekker. 1888. Prof. Henry A. Nicholson, 1903. Mr. Frederick William Rudler. 1889. Prof. W. Boyd Dawkins. 1904. Prof. Alfred Gabriel Nathorst. 1890. Prof. Thomas Rupert Jones. | 1905. Dr. Hans Reusch. 1891. Prof. T. McKenny Hughes. xxX 1876. Wea 1878. 1879. 1879. 1880. 1881. 1881. 1882. 1882. 1883. 1885. 1884. 1885. 1886. 1887. 1888, 1888. 1889. 1890. 1891. 1891. 1892. 1892, PROCEEDINGS OF THE GEOLOGICAL SOCIETY. AWARDS OF THE [May 1905, BALANCE OF THE PROCEEDS OF THE ‘LYELL GEOLOGICAL FUND,’ Prof. John Morris. Mr. William Pengelly. Prof. Wilhelm Waagen. Prof. Henry A. Nicholson. Dr. Henry Woodward. Prof. F. A. von Quenstedt. Prof. Anton Fritsch. Mr. G. R. Vine. The Rey. Norman Glass. Prof. Charles Lapworth. Mr. P. H. Carpenter. M. Kd. Rigaux. Prof, Charles Lapworth. Mr. Altred J. Jukes-Browne. Mr. David Mackintosh. The Rev. Osmond Fisher. Dr. Arthur H. Foord. Mr. Thomas Roberts. M. Louis Dollo. Mr. Charles Davies Sherborn. Dr. C. I. Forsyth Major. Mr. George W. Lamplugh. Prof. John Walter Gregory. Mr. Edwin A. Walford. 1895. 1893. 1894. 1895. 1895. 1896. 1896. 1897. 1897. 1898. 1898. 1899. 1899. 1900. 1901. 1901. 1902. 1908. 1903. ‘1904. 1904. 1905. 1905. Miss Catherine A. Raisin. Mr. Alfred N. Leeds. Mr. William Hill. Prof. Percy Fry Kendall. Mr. Benjamin Harrison. Dr. William F. Hume. Dr. Charles W. Andrews. Mr. W. J. Lewis Abbott. Mr. Joseph Lomas. Mr. William H. Shrubsole. Mr, Henry Woods. Mr. Frederick Chapman. Mr. John Ward. Miss Gertrude L. Elles. : Dr. John William Evans. Mr. Alexander McHenry. Dr. Wheelton Hind. Mr. Sydney S. Buckman. Mr. George Hidward Dibley. Dr. Charles Alfred Matley. Prof. Sidney Hugh Reynolds. Mr. E. A. Newell Arber. Mr. Walcot Gibson. AWARD OF THE PRESTWICH MEDAL, ESTABLISHED UNDER THE WILL OF THE LATE SIR JOSEPH PRESTWICH, FE.B.S., F.G.S. ‘To apply the accumulated annual proceeds ... at the end of every three years, in providing a Gold Medal of the value of T'wenty Pounds, which, with the remainder of the proceeds, is to be awarded ...to the person or persons, either male or female, and either resident in England or abroad, who shall have done well for the advancement of the science of Geology ; or, from time to time to accumulate the annual proceeds for a period not exceeding six years, and apply the said accumulated annual proceeds to some object of special research bearing on Stratigraphical or Physical Geology, to be carried out by one single individual or by a Committee; or, failing these objects, to accumulate the annual proceeds for either three or six years, and devote such proceeds to such special purposes as may be decided.’ 1903. John Lubbock, Baron Avebury. Vol. 61.] ANNUAL REPORT. XXX1 AWARDS OF THE BIGSBY MEDAL, FOUNDED BY THE LATE Dr. J. J. BIGSBY, F.BS., F.C. To be awarded biennially ‘as an acknowledgment of eminent services in any depart- ment of Geology, irrespective of the receiver’s country; but he must not be older than 45 years at his last birthday, thus probably not too old for further work, and not too young to have done much.’ 1877. Prof. Othniel Charles Marsh. | 1893. Prof. William Johnson Sollas, 1879. Prof. Edward Drinker Cope. | 1895. Mr. Charles D. Walcott. 1881. Prof. Charles Barrois. 1897. Mr. Clement Reid. 1883. Dr. Henry Hicks. 1899. Prof. T. W. E. David. 1885. Prof. Alphonse Renard. 1901. Mr. George W. Lamplugh. 1887. Prof. Charles Lapworth. 1903. Dr. Henry M. Ami. 1889. Dr. J. J. Harris Teall. 1905. Prof. John Walter Gregory. 1891. Dr. George Mercer Dawson. AWARDS OF THE PROCEEDS OF THE BARLOW- JAMESON FUND ESTABLISHED UNDER THE WILL OF THE LATE Dr. H. C. BARLOW, F.G.S. ‘ The perpetual interest to be applied every two or three years, as may be approved by the Council, to or for the advancement of Geological Science.’ 1879. Purchase of Microscope. 1893. Purchase of Scientific In- 1881. Purchase of Microscope- | struments for Capt. F. I. Lamps. Younghusband. 1882, Baron C. von Ettingshausen, | 1894. Dr. Charles Davison. 1884, Dr. James Croll. HOS, Mille Sse ane ae a 1896. Mr. John Storrie. 1884. Prof. Leo Lesquereux. 1898, Mr. Hdward Greenly. 1886. Dr. H. J. Johnston-Lavis. 1900. Mr. George C. Crick 1888. Museum. 1900. Prof. Theodore T. Groom. 1890, Mr. W. Jerome Harrison. 1902. Mr. William M. Hutchings. 1892. Prof. Charles Mayer-Kymar. | 1904, Mr. Hugh J. Ll. Beadnell. XXXli PROCEEDINGS OF THE GEOLOGICAL socrETy. [May 1905, Estimates for INCOME EXPECTED. Coin positions ina utrn et ya ek aa eie coh @ sisrele oe oe ee eee 140 0 0 Due for Arrears of Admission-Fees .......... 94 10 0 ACCIMISSTOM—W Ces MOOS Mec ere de ss clea ie ceria 190 0 O === SATO en Arrears of Annual Contributions ............ 175-0: 20 Annual Contributions, 1905, from Resident and Non-Resident Fellows .....is...ic1s00--0 17710. Os Sale of Quarterly Journal, including Longmans’ PME COMME eietechs mieten ACTS crise ss « seule Rede whens Sale of Transactions, General Index, Library- Catalogue, Museum-Catalogue, Hutton’s ‘Theory of the Earth’ vol. i111, Hochstetter’s ‘New Zealand,’ and List of Fellows ........ 2 10 10% Dividends on £2500 India 8 per cent. Stock .. 75 O O Dividends on £300 London, Brighton, & South Coast Railway 5 per cent. Consolidated Pre- LETENCEOUOCK (hd alc. eck steno nee telat 15-090 Dividends on £2250 London & North-Western Railway 4 per cent. Preference-Stock ...... 90 0 0 Dividends on £2800 London & South-Western Railway 4 per cent. Preference-Stock ...... M2 Oe6 Dividends on £2072 Midland Railway 23 per cent. Perpetual Preference-Stock .......... ol 160 Dividends on £267 6s. 7d, Natal 3percent.Stock 8 O O ——_—— 351 16 0 £2936 16 0 Vol. 61.] FINANCIAL REPORT. the Year 1905. EXPENDITURE ESTIMATED. £8. a; House-Expenditure : HARES ee eae Winton vag esiapis siesiaieleusiceiets Seadie senses 15 0 Ie WASP AICE gi .). cc ea aien ve hae asenions a selec ee nes 15 0 0 Electric Taghinig and Maintenance .........0. 50 0 0 Siar t aia inns scale aeie'cnigear side bucoaate duimeaitan senses 12 0 0 Hien UN eens eich 8 we bilibe Seescwianoua ecu un bteiasioaes 35 0 O Marmiturre amd Ge pars. 5.265.502 ..c00sssnsescesn 50 0 0 House-Repairs and Maintenance ............... 30 0 0 Jainailell | ONE VOI! agp eben cusAGanense onto wey 0503005: 15 0 0 Mearate MiCet eS fascia. svcecins a seateovabnwedecuaels 20-0) 9 Washing and Sundry Expenses ................5. 35 0 0 Salaries and Wages, etc. : Assistant-Secretary PI cctatmere iad mneeawor aan 330 O O 3 half Premium Life-Insurance... 1015 0 PASSUSLAMMC-MLMORATIAM, s22:. cde cer seucwesieese ses .sese ek 150 0 0 PNGBISEATIG =O lE(kioas coascscntscueneessdnewanierenseeosven 150 0 O SUMO RPA S EUS HAIR e cartcioi saieiieise ss ocieeipien etn satecien ec ny 1D House-Porter and Upper Housemaid ......... 94 10 O Winder Housemaid | ocvagschsccccss saves emnseeceee? 48 18 0 Charwoman and Occasional Assistance......... 10 0 0 PREC OMIM AIMS MCC et nuracdoattoseaottsdeyecusivinw sade 10 10 O Office-Expenditure : bAMOMO Nye cee Acces Petia osiane cata Waits S02 SD Ow Miscellaneous Printing, ete. ..........0cceeseeeee 40 0 O Postages and Sundry Hxpenses .................. 80 0 0 International Catalogue of Scientific Literature .......... Library (Books and IBIHOTGNUIVED) = sn Sesser. setes er eer s Naren Publications: Quarterly Journal, ialtine Commission on NS Camere ote cciats et ci mo seat lacs aittone sclrdls ad’ Steek 900 0 O Postage on Journal, Addressing, ete. ......... 90 0 0 Abstracts, including Postage .................265 110 0 O Record of Geological Literature ............... 150 0 O HES 6 Of Mell Owiss Wotan ceca hein ace un uandsewnn nh bs 35 0 0 Milpraty-Cataloe ie ii ascnces tion deesacsnor sada ore Je Ww X¥xXxlil os. a. Zoe loueo 876 13 0 5 OO 60 0 0O 900 O O 13828 0 £2936 16 0 W. T. BLANFORD, Treasurer. January 20th, 1905, XXX1V PROCEEDINGS OF THE GEOLOGICAL socinty. [May 1905, Income and Expenditure during the RECHIPTS. s. >) Zoe seamen To Balance in the hands of the Bankers at January lst, VOOA ice erceeene: 176 12298 », Balance in the hands of the Clerk at Hamnuanyel sty LOA TS ee ew ene an 15 1432 —— 192° 6 al SAO OM POSIEOMSir mde ces Vien oor yuie a ee tcea ete cee 238 14 0 ,, Admission-Fees : PASETCAN S28 ngeiclyora Msi ateaieicance/Gek valet at (a) eo CinEKeniG wine uc.senener en aee eaeee 139" Ono ——— 26412 0 », Arrears of Annual Contributions .... 142 16 0 », Annual Contributions for 1904 :— Resident Fellows .................- TPA eS) 6 Non-Resident Fellows ............ 11 30 6 ,», Annual Contributions in advance .... 44 2 0O ——_——— 1919 8 0 », Publications : Sale of Quarterly Journal: * a Wols Sisho lx: uh nee h tenn at 93 14 0O 8 NYG) RTS oR Da ERIE ae ar ne ee aie 67 18 2 —— Lode Zee », Record of Geological Literature ... 214 0 oj.) LeAStiot Bellows GA ca Adoees sedans: 8 0 5g, BPaMSAChIONS © aiicersceeaaneseeras coset elas 15 0 ~., . Mitseum-Catalogue.s)5.).72- 3.04. are. oO) » Library-Catalogte ..0....cc.c..se sees ee) 5. sOumenod:s index eaeecceesaco sents. 3 6 » General Index to the Quarterly Journalevolss ato lyeeeeee ees nee 0 8 » Hutton’s ‘Theory of the Earth,’ Holgi he Oe ec a 12 0 » Hochstetter’s ‘New Zealand’ ...... © —— Oslin ant 7 vepaymient ot imeome Dax (Giyeats) >... 45-2 oe a8 8 4 » Prestwich Trust-Fund, part repayment of advance for Die of Medal ey 240. 257) Satan ce oe NS creme 10°" OS 6 5, Dividends (less Income-T'ax) :— £2500 India 3 percent. Stock.... 71 38 I £300 London, Brighton, & South Coast Railway 5 per cent. Consolidated Preference- SUC GN Seen RUMEN ees a nee 14 6 O £2250 London & North-Western Railway 4 per cent. Pre- ference-Stock .......... Souths eam £2800 London & South-Western Railway 4 per cent. Pre- ference-Stock” ...c....2 0. 106 15 0 £2072 Midland Railway 22 per cent. Perpetual Preference- SLOG ess 2 ier ene AD i 3 £267 6s. 7d. Natal 3 per cent.Stock 7 12 cane ———— 30a0 eee * Due from Messrs. Longmans & Co., in addition £3187 3 9 to the above, on Journal-Sales ............... 9 4 ye ¥ Vol. 61. ] FINANCIAL REPORT. XXKY Year ended December 31st, 1904. PAYMENTS. By House-Expenditure: een sae a Ea Suara) ITED eit ocgathe HONG span er aR crv NR eae 15 O fis hanee eae rae neta ade os cade naan thd oe ls 0 0 Hlectric Lighting and Maintenance ......... 50 17 2 Gasper eee arco aan Peon aaneneaesoacecr to ork FETE reee see cok echo oenGtee ome ctedols date slecsz acces 19) ier (0) Hurmibune andl ReEPAES ..0 0.2. ee sect. canes 23° 4° 3 House-Repairs and Maintenance............... 36 13 0 Arata r » per ci . Stoe © ¢ ? a a y ember 31st Be » Repayment eh lacoue: Tie re oy oo aes tae 5 7; 8 : ere aes 36) 4 = wee £66 9 4 ‘Murcuison Gerotogicat Funv.’ Trusv-Accounr. Recuiers, £ os. d. PAYMENTS 18 18 6] By Award to Prof. G. A. Lebour . (6 py CWC NIG coocecnecanncon » Award to Dr, A. 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See 2 IR | A ee: I al A ARS, SSS ey ee £37 3 8 HH ~ of any one mutation. i ‘From Waagen’s statement as to the constancy of mutations, it might be ‘ inferred that he believed them to represent discontinuous variations or ; saltations. This, however, is nowhere definitely expressed by him, and, ‘ since he favoured the view that they resulted from some law of development innate in the organism (1869, p. 239, & 1875, p. 243), it might equally well be i supposed that he regarded them as stages of a progressive, continuous growth, . appearing to us as separate steps only because of gaps in our knowledge. To-day the historian of Ammonites will probably maintain the latter view, ___and in this he will be.supported by many students of other fossil organisms, ‘ even of Vertebrata (see, for instance, Prof. H. F. Osborn, in ‘‘The Present Problems of Palzontology” Pop. Sci. Monthly, Jan. 1905, on p. 230). The question is one of fact, and the term mutation should be maintained, quite apart from the answer that may ultimately be agreed upon. ‘Therefore, palzontologists should protest against any attempt to restrict the term to professedly-discontinuous variations, especially as these are already provided | with the excellent term saltation. This, unfortunately, is the attempt that : has been made by Prof. Hugo De Vries, in his book “‘ Die Mutationstheorie ” (Leipzig, 1901: see especially pp. 46-51), a work of such importance and renown that the protest against this particular mutation of terminology must needs be a strong one. ‘A mutation, in the paleontological and original sense, may be defined as a contemporaneous assemblage of individuals united by specific identity of _ __ Structure znzer se, and by common descent from a known pre-existing species, from which they differ in some minute but constant character or characters. Such mutations are successive steps of a genetic series, and each may be con- sidered as of specific rank and may have its own contemporaneous varieties. ‘The term circulus, as Prof. J. F. Blake has kindly pointed out to me, was used by C. G. Ehrenberg, in ‘“‘Symbole Physice: Animalia Evertebrata, Series Prima” 1831, to denote a classificatory division less than a Class and greater than an Order. Thus the Anthozoa and Bryozoa each constitute a cirenlus of the Class Phytozoa. ‘In 1896 the term was employed by Prof. J. W. Gregory, in the British- Museum Catalogue of Jurassic Bryozoa, to denote “ certain convenient groups [of species], which are not altogether artificial, but which are not genera in the sense in which that term can be used among Hchinoidea and Mammals.” Study _ of the whole chapter shows that the term combined two conceptions, and this _ has led to a misunderstanding of it in certain quarters. ‘‘'The essential idea,” _ writes Prof. Gregory (in ditt., Nov. 18th, 1904), “‘ was that the members of such at : a circulus were not homogenetic, but a casual assemblage of individuals derived VoL. LXI. if ale Ried ]xxiv PROCEEDINGS OF THE GEOLOGICAL socinTY. | May 1905, from different groups of individuals.” ‘To the exposition of this idea, as applied to Bryozoa, eight pages were devoted in the Catalogue. But, in order to justify the adoption of the word circulus, the paragraph introducing it laid stress on the subsidiary idea of indefiniteness (p. 22): “A circulus was one of the small groups of individuals who clustered round speakers in the Roman forum. Most of the individuals in the forum were definitely attached to a particular group ; the groups were less crowded around their margins, and between them people were irregularly scattered and crossed from circulas to circulus. They thus prevented any rigid division of the crowd into definite groups.” It is clear, howeyer, from Prof. Gregory's own words, that the application of the term circulus to a group of individuals, whether of supposed generic or specific rank, implies not merely that the group has uncertain limits but that it 1s polyphyletie. ‘A circulus, in short, is an ill-defined assemblage of approximately- isochronous homceomorphs, which it is either inconvenient or impossible to distribute among well-defined homogenetic genera or species.’ That different organisms are of very different values for purposes of classifying the sediments is well known, and the reasons for the differences of value are in some cases known, in others obscure. Those organisms with a long range in time are, of course, mainly valuable for defining considerable thicknesses of strata; while those which had a shorter range may be utilized for separating the smaller divisions. We cannot always infer, however, which organisms will be found to possess a long and which a short range, for in the case of some groups certain genera have a very long range, and others that are closely allied have a brief one: compare, for example, the two brachiopods Discina and Trematis. Of shallow-water forms, those which belong to the benthos are particularly suitable for determining the facies of the containing deposits. This is especially true of the organisms appertaining to the sessile benthos, and in a less degree to those of the vagrant benthos, for the benthoal organisms existing in tracts where the physical conditions—such as temperature, amount of light, and characters of the sediments of the sea-floor—vary rapidly, are limited as to their horizontal range by the distribution of those conditions which determine their station. As these conditions often change im any area with considerable frequency, the organisms are of course locally useful for chronological division of strata, but, owing to the usually-restricted horizontal range of the forms, they are of little value for correlating strata over wide areas.! » For information concerning the uses of the planktonic, nektonic, and benthoal organisms of past times to the geologist, see J. Walther, ‘ Ueber die Lebensweise fossiler Meeresthiere’ Zeitschr. Deutsch. Geol. Gesellsch. yol. xlix (1897) p. 209. Vol. 61.1] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxxv As the physical conditions of the deeper parts of the ocean are more uniform over wide areas than those of the shallows, the deep- water benthoal forms are more valuable for purposes of correlation of remote sediments ; and this is, of course, especially true of the forms belonging to the vagrant benthos. But it is to the members of the nekton and the plankton (in- eluding in the latter the mero-plankton and the pseudo-plankton) that we turn with the greatest confidence as being likely to furnish us with the means of correlating strata over wide areas. These easily-distributed organisms may have spread over wide tracts of ocean soon after they came into existence, and if their period of endurance be long as compared with the time taken for spreading from their centres of origin, they will give most important in- formation for purposes of correlation. As their remains may be embedded in the sediments of the shallows and the depths alike, _ they are also useful for comparing the beds of shallow-water with elke eee. er FRR ee adil: those of deep-water origin; whereas the benthoal forms of these deposits will probably differ. To take an example, we may allude to the graptolites, which, according to Prof. Lapworth, constituted members of the pseudo-plankton of Lower Paleozoic times. The faunas of the normal graptolitic type of sediment often consist almost entirely of graptolites; while the deposits of the shallows of the same ages usually yield a variety of organisms belonging to many different zoological groups. Here and there, however, we come across a few graptolites associated with the other fossils, which enable us to correlate the shallow-water deposits with those of the normal graptolitic type, as has been done so successfully by Prof. Lapworth himself in the case of the richly-graptolitic deposits of the Moffat district and the contemporaneous shallow-water sediments of the Girvan area. In future work on the faunas of the sediments, the effects of homceomorphy musi be regarded more carefully than has been done in the past. Cases of contemporaneous homceomorphy, such as appear frequently to occur among the grantolites, do not vitiate the conclu- sions of the stratigrapher; but, when homceomorphy occurs in the case of organisms which lived at different times, it may lead the _ student to arrive at wrong conclusions. For instance, the graptolites of the genus Azygograptus might at one time have been mistaken for forms of Monograptus; indeed, before the significance of the position of the sicula was appreciated, the diagnosis of the genus Monograptus was so drawn up that forms of Azygograptus would have been referable to that genus. The apparent similarity in f2 RS. Ixxyvi PROCHEDINGS OF THE GEOLOGICAL society. [May 1905, outward form of these genera is not due, however, to a very close genetic relationship ; and whereas Azygograptus is characteristic of early Ordovician strata, Monograptus is confined to those of Silurian age. Similar cases of non-contemporaneous homcomorphic forms have been noted among the ammonites and the brachiopods, and will probably be detected in the future among fossils belonging to other zoological groups. Turning now to mutations, where the varieties which succeed one another are closely related genetically, we have to consider the necessity for very careful study in distinguishing one mutation from another, as proved by recent work. In the early days of paleontological investigation, the characters utilized for the purpose ot separating varieties were sufficiently obvious to be detected in single specimens, and the minute variations which have in some cases been found to mark off mutations from each other were un- known. ‘The researches of Mr. W. Bateson on the forms of Cardium in the Aralo-Caspian basin, and of Dr. A. W. Rowe on the variations of Micraster at different horizons, have proved the value of dealing with suites of specimens of each mutation, and subjecting them to minute and accurate measurement. It is obvious that much work of a similar nature remains to be accomplished in the case of other fossil forms; and those who follow Dr. Rowe’s line of research will naturally undertake the study of forms which are preserved in sufficient numbers in the fossil state. ‘This cannot be done by the examination of museum-specimens; but specialists in the different eroups of organisms must, as Dr. Rowe has done, obtain the specimens for themselves from the rocks in which they are entombed. Another matter too often overlooked is the frequency of occur- rence of individuals in a particular stratum or group of strata, and especially the relative proportions of different species in the strata. Sometimes forms are stated to be common or rare, and occasionally a more detailed division into ‘ very rare, rare, common, and very common’ is made. But it is very desirable that such groups of strata should be studied as contain a varied fauna composed of numerous individuals of easily-identified forms, and that the pro- portions of the different forms which occur at different horizons should be, as far as possible, ascertained. The rich graptolite- bearing beds of the Moffat district, or those of the Llandovery age in Lakeland, would be well adapted for this purpose; and a compa- rison of the strata of two or three sections situated at some distance Vol. 61.] ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxvil apart should be made, in order to ascertain the changes which take place laterally as well as those which occur in the vertical succession. The task would not be easy, owing to the frequent appearance of a particular form in exceptional abundance on one bedding-plane; and for this reason, notwithstanding very detailed work, some differences would be due to the non-detection of certain of the fossils. But, notwithstanding this, it is clear that such numerical estimates would go far towards adding to our knowledge of the changes which take place in the faunas, and many now obscure points might be cleared up; in particular, we should discover whether at certain horizons a marked change in the faunas takes place with exceptional suddenness, without any obvious change in the character of the sediments to account for it. In carrying out such a piece of work, all the lithological changes should of course be noted, and also the existence at some horizons of changes in lithological character without the presence of a bedding-plane (in the form of a plane of discontinuity marking temporary cessation of sedimentation), and at others of such planes of discontinuity severing in some places rocks of similar, and at others rocks of dissimilar, lithological characters. Work of this nature will go far to correct many inferences which have been drawn as the result of casual collecting. It is surprising how many fossil lists of the organisms contained in the strata of our own island have been drawn up as the result of a few hours’, or at most of a few days’, work by the collector. Little wonder that the faunas of contemporaneous beds at considerable distances should often be judged to be very dissimilar. The Shineton fauna described by Dr. Callaway as occurring in Shropshire was rightly referred by him to the age of the Tremadoc Slates, although the fauna was very different frem that of those slates at Tremadoc as then known. Recent research has proved that this particular 3 _ zone of Tremadoc rocks had not then been discovered in the Tremadoc district, and its subsequent detection has shown the similarity of the fossils of that band in the Tremadoc and Shineton neigh- - bourhoods. Consider the rich fauna of the Wenlock Limestone made known to us in a large degree by the work of Col. Fletcher, Dr. Grindrod, and others, carried on through many years. What should we have known of this fauna, if a collector had merely hammered at the rocks for a few days, as has been done in the case of so many other deposits ? The rough-and-ready methods which, in some cases, have been pursued in compiling lists of fossils of the different sediments would Ixxviil PROCEEDINGS OF THE GEOLOGICAL society. | May 1905, not be tolerated at the present day in any other branch of science, and it is time indeed that the stratigraphical geologist should apply himself to his own branch of work with the assiduity and attention to detail which are now expected of the paleontologist in the museum. — (6) Climatic Changes. Of all the recent changes with which the meteorologist has to deal, the most regular are those variations of temperature which are due to extra-terrestrial causes. An area may be subjected to fog, tempest, or drought, owing to irregular meteorological changes ; but, apart from these, we have constant diurnal and summer heat, constant nocturnal and winter cold. Less regular, though still, so far as we can judge from the scanty data at our disposal, recurring with some approach to constancy, are such temperature-changes as are indicated, for example, by the alternate periods of advance and retreat of glaciers. The question naturally arises: were thére not in past ages even more important cases of climatic recurrence, of which each phase may have existed through long periods of geological time? ‘This is, at any rate, suggested by the widespread occurrence of glacial conditions in the Permo-Carboniferous Period, and by the existence in so many areas of Tertiary deposits, showing a gradual diminution of temperature from early Tertiary times to the culminating stage of cold of Pleistocene date. If such recurrence happened as the result of important extra-terrestrial changes, we should expect its effects to be more widespread than those which were caused by terrestrial changes ; it is important, therefore, to collect evidence bearing upon thig question. JI cannot help believing that the changes noted when studying the geogram, both as regards litho- logical characters and faunas and floras, sometimes possess so extended a geographical range that ordinary terrestrial change is insufficient to account for them. I have again and again been struck with similarities, difficult to put into words, between the lithological characters of various Lower Palzozcic sediments from many parts of the Old and New Worlds, which would suggest the general age of the deposits, even if we could not corroborate the inference by examination of the included organisms. We also find examples of variation of fauna occurring during shorter geological periods, which in the present state of our know- ledge seem most readily explicable by climatic change, though I must ee fags Ss Vol. 61.] ANNIVERSARY ADDRESS OF THE PRESIDEN’. Ixxix confess that these cases are merely suggestive. I discussed one of them eighteen years ago in a paper read before the Cambridge Philosophical Society,’ and may be allowed to refer to it here. The Stockdale Shales of the Lake District contain bands of dark eraptolite-bearing shales, interstratified with lighter mudstones in ' which graptolites are rare or absent. Sometimes the alteration in fauna is accompanied by change in the lithological characters of the rocks, indicating that the faunistic change is not due to an inherent tendency in the organisms to undergo variation. At other times the faunistic change seems to be unaccompanied by any noticeable difference in the lithological characters of the rocks, save such as is produced by the absence of organic material therein. This suggests that the changes which produced the succession of faunas of the different zones were due to something which did not in these cases affect the lithological characters of the rocks ; and the only cause of which I can conceive is climatic variation in an area sufficiently remote from land to prevent the change from affecting the nature of the sediment supplied to the area. I had hopes of working at this subject in greater detail, but have hitherto been prevented from doing so. I believe that this work, in conjunction with that suggested previously (namely, the attempt to ascertain the variations in the proportions of the different species in successive zones), would well repay anyone who undertook it. That the plane separating groups of rocks which are distin- guished one from the other by differences in lithological characters or organic contents is not always coincident with the plane which divides a synchronously-formed group from one formed before or afterwards is well known. Let us take note of a few examples. As regards lithological characters, we find illustrations among the Cretaceous rocks of our islands. The Gault of the south is represented in Northern Norfolk, Lincolnshire, and Yorkshire by the Red Chalk, so that anyone mapping these formations by lithological characters would draw the basal line of the Chalk beneath rocks of Albian age in the North-East of England, and beneath rocks of Cenomanian age in the South of England. Again, we find glauco- nitic deposits of Lower Greensand age in the North-East of England, of Gault age in the South-West, and in Northern Ireland of an age when parts of the English Chalk were being deposited. If, therefore, we could trace the Cretaceous rocks continuously from 1 On Homotaxis’ Proc. Camb. Phil. Soe. vol. yi (1887) p. 74. lxxx PROCEEDINGS OF THE GEOLOGICAL society. [May 1905, Kent to Antrim, we should find a belt of sediments marked by the abundance of glauconite running obliquely to the planes which define synchronous deposits. Turning to belts characterized by definite organisms in this same Cretaceous system, we recollect that it is maintained by Mr. Jukes-Browne that the beds of the zone of Pecten asper in © France are of later date than those of the same zone in Britain; and Mr. Jukes-Browne, Mr. H. Woods, and Dr. W. F. Hume have shown the occurrence of a particular type of fauna at different horizons in the Upper Cretaceous rocks of the British Isles. Many other examples might be given, but the foregoing are sufficient for our purpose. In an ideal classification, therefore, of the sedi- mentary rocks we require a triple nomenclature, in order to subdivide the rocks according to lithological characters, organic contents, and periods of formation. It is true that, in some cases, the groupings based on each of these will be identical, but in others they will differ. The agreement, or want of agreement, of the groupings can only be determined as the result of detailed work. The necessity for this triple classification has long been tacitly recognized, and has indeed been largely carried out in the case of the Mesozoic rocks, but no definite scheme of nomenclature has been adopted for the whole of the sedimentary rocks, although it is clearly required. Such a scheme, to be acceptable, must not necessitate a violent change from the nomenclature at present in use. It is my wish to point out that the scheme which has been practically adopted in the case of the Mesozoic rocks is generally applicable to rocks of other ages, and does not demand any marked departure from the existing nomenclature. The lithological names proposed by William Smith were, at one time, largely used as chronological names also; but, as the result of fuller work, they have been almost entirely superseded for the latter purpose by other expressions, which are, it is true, in many cases modifications of the original word: for instance, we speak of a particular lithological group as the Kimmeridge Clay, but the rocks of the age of the Kimmeridge Clay are known as Kimmeridgian. J would suggest that the names adopted in a scheme of classification of strata divided according to their ages should always end in ‘ian,’ the termination adopted in the case of the time- subdivisions of the Mesozoic rocks. Vol. 61.] ANNIVERSARY ADDRESS OF THE PRESIDENT. xxx For the divisions founded on faunistic change, the name of a dominant organism or group of organisms should be applied, as zone of Micraster (sp.), zone of Stephanoceras Humphre- scanum, zone of Monograptus gregariwus. As the term zone has been so generally used by stratigraphical geologists in the sense of fossil-zone, it would be well to use it only in this way, it being distinctly understood that the term is applied to a belt of strata characterized by some organism or organisms, without any regard to the thickness of that belt. It has been customary to apply local names to the lithological belts, and this custom is in every way desirable. It is true that it necessitates the employment of new terms when a fresh area is worked out in detail, but the trouble thus caused is slight; whereas, if the name given in one locality be applied to another, endless confusion may arise, should it be proved that the beds to which the name is afterwards assigned are really of different age from those to which it was first given. In illustration of these remarks, I wish to direct your attention at some length to the strata of the Ordovician system, for the classification of those rocks is still in an unsatisfactory state. The time-divisions which I would, at present, propose to adopt for the rocks of this system are as follows :— | Ashgillian. Caradocian. | Llandeilian. Skiddavian. OrDOvVICIAN I say at present, for should modification’ be necessary in the future, it can be readily adopted. In proceeding to discuss the significance of these terms and the reason for their adoption, it will be convenient to consider them seriatum, beginning with the oldest—namely, the Skiddavian rocks. 1. The Skiddavian Series.—In Sedgwick’s final revision of the classification of the great mass of Lower Paleozoic rocks, which he studied with such success, he applied the term ‘ Arenig or Skiddaw Group’ to the rocks which we are now considering.’ I suggest the use of the term derived from the Cumbrian rather than from the Cambrian hill, because the age of the rocks of _Arenig is still under discussion, while the Skiddaw Slates have yielded a rich fauna which enables us to refer the great bulk of the 1 «A Catalogue of the Collection of Cambrian & Silurian Fossils contained in the Geological Museum of the University of Cambridge’ 1873, p. 19. Ixxxu PROCEEDINGS OF THE GEOLOGICAL SocIETY. [May 1905, fossiliferous beds of those slates to this age, although even there some of the fossils may belong to rocks of earlier and later date. Unfortunately, we are even now unable to indicate the exact position of the base of the division, for we do not know how far beds which have been assigned to it are contemporaneous with the — higher Tremadocian strata of the Cambrian system. (I follow British writers in retaining the Tremadocian rocks in the Cambrian system, though many Continental geologists place them with the rocks referable to the Ordovician system, for I see no reason to depart from the classification which was originally applied.) The graptolitic beds of Skiddavian age have been satisfactorily grouped, and I here reproduce the table drawn up by the latest worker on these beds in Britain, namely, Miss G. L. Elles,’ merely substituting the name ‘Skiddavian’ for ‘ Arenig Series,’ which appears in Miss Hlles’s paper :— WALES. SHROPSHIRE. | Laxu-Disreicr, SCANIA. ( Zone of || Glossograptus. Zone of —_| Lower Hope Hllergill Beds. + Zone of Didymograptus | Shales. | | Phyllograptus, cf. bifidus. G ty pus, Zone of Upper \ | Zone of Didymograptus | Mytton Flags. | Isograptus 2 hirundo. [ Upper gibberulus. S \ Tetragraptus- E Zone of Shelve | Beds. a \ Didymograptus| Church Beds. | r extensus. ye ie (| Zone of | || Phyllograptus ? Lower Mytton Dichograptus- ; densus. Flags. | Beds. Zone of | ; || Didymograptus | t balthicus. Garth Grit? | Stiper Stones | Lower Zone of Quartzite. | Letragraptus- Tetragraptus Beds. phyllograptoides. The beds tabulated above may, then, be taken as defining the upper and lower limits of the Skiddavian Series so far as the areas mentioned are concerned, and it only remains to correlate the Skiddavian Beds of other areas with these. It is especially impor- tant that we should discover what non-graptolitic beds are their equivalents, for, as is well known, it was maintained by the late 1 «Some Graptolite-Zones in the Arenig Rocks of Wales’ Geol. Mag. 1904, p. 199. | Vol. 61.| ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxxili Dr. Hicks that certain beds in South Wales, which he grouped as Lower Arenig, were contemporaneous with the Upper Tremadoc Slates of North Wales. This is a matter which requires clearing up. 62. The Llandeilian Series.—In South Wales the plane of demarcation between Skiddavian and Llandeilian rocks is well shown, and separates the beds with Didymograptus bifidus, which belong to the top of the Skiddavian, from the basal Llandeilian Beds with Didymograptus Murchisoni. In a paper in the ‘ Popular Science Review ’* Dr. Hicks proposed grouping the uppermost Skiddavian and lower Llandeilian Beds as a new series, to which he gave the name of ‘ Llanvirn.’ The fauna of this series is strongly developed in Central and North- Western Europe, although it is doubtful how far that fauna is of Llandeilian age. It may ultimately be found expedient to restrict the Skiddavian and Llandeilian groups, and to separate a Llan- virnian Series; but at present the divisions which were originally defined by Murchison and Sedgwick appear sufficient. Murchison’s Llandeilo division is perfectly-well defined, and in the typical area contains three faunas. We are enabled, therefore, to classify the Llandeilian as follows :— Upper beds with Nemagraptus (Cenograptus) gracilis. LLANDEILIAN | Mat beds with Asaphus tyrannus. Lower beds with Didymograptus Murchison, In the St. David’s region Hicks discovered a fair number of fossils other than graptolites in the upper and lower beds, which, with the faunas described by Prof. Lapworth in the Girvan area, have given us some knowledge of the nature of the Llandeilian faunas preserved in the non-graptolitic deposits. 3. The Caradocian Series.—The term ‘ Bala’ has been used in so many senses that it will be well in future to retain it for the lithological divisions in the Bala district. Sedgwick ultimately divided his Bala Beds into three groups, of which the lowest was the equivalent of the Llandeilo Beds, while the upper- most included strata which do not appear to be represented in the Caradoc area. The term ‘ Caradoc,’ on the contrary, was given by Murchison to a group of rocks which are clearly separated from the Llandeilo Beds beneath, and, as above. stated, do not include ' «The Classification of the Eozoic & Lower Paleozoic Rocks of the British Isles’ Pop. Sci. Rev. n.s. vol. v (1881) pp. 802-303. | Ixxxiv [ PROCEEDINGS OF THE GEOLOGICAL gocieTy. [May 1905, Sedgwick’s Upper Bala Beds. In these circumstances the term ‘Caradocian’ is adopted as not likely to cause any confusion—such as arises, for instance, from the use of the term ‘ Lower Bala,’ which may mean either the whole of the Llandeilo or the lower part of the Caradoc Series, according to the classification followed by various writers. The plane of demarcation between Llandeilian and Caradocian strata has been clearly distinguished in various parts of Britain, in beds which yield almost exclusively graptolitic faunas, and also in those which furnish mixed faunas. It is found between beds of the former type in the Southern Uplands of Scotland, between the Glenkiln (Llandeilian) and Hartfell (Caradocian) Shales, and between beds of the latter type in the typical Shropshire area. Details concerning the classification of these beds in South Shrop- shire, where the beds are spoken of as the ‘ Chirbury Series,’ will be found in a paper by Prof. Lapworth & Prof. Watts. in the heart of Wales the lower hmit of the Caradocian has not yet been definitely settled. In the border-region of the Lake-District Prof. Nicholson and I have given reasons for believing that there are two very well- marked faunas of Caradocian age, belonging to beds which I have elsewhere spoken of as ‘the Roman-Fell Group’ and ‘ the Sleddale Group.’* The latter fauna is so clearly that of the Bala Limestone and associated rocks of North Wales that there is no doubt as to their general contemporaneity ; but the former is an older fauna, and there is some reason to suppose that it has been detected in parts of North Wales, although there it has not been definitely distinguished from the fauna of the higher Caradocian rocks. 4. The Ashgillian Series.—The line of demarcation be- tween the Caradocian and the Ashgillian Series may be easily drawn, owing to the marked change in the faunas. As before stated, these Ashgillian Beds correspond generally with the series to which Sedgwick gave the name ‘ Upper Bala,’ though he never defined the exact position where the line should be drawn. In the Cambridge Catalogue of Cambrian & Silurian Fossils he says (p. 26): ‘‘* Upper Bala” comprehends the Aber Hirnant Beds above the Bala Limestone, with a peculiar set of ‘ 50,000 oy ) ’ ea 000 ? Berggrundskator, Nae 1904. Presented. by the Director of that Survey. Carte Géologique Internationale de ee a Livraison V, Sheets AACSB Van VAT AD NA ANG ae: Sato 1905, presented by the Permanent Map-Committee of the International Geological Congress. June 21st, 1905. J. KE. Marr, Se.D., F.R.S., President, in the Chair. The List of Donations to the Library was read. The Names of certain Fellows of the Society were read out for the second time, in conformity with the Bye-Laws, Sect. VI, Art. 5, in consequence of the Non-Payment of the Arrears of their Contri- butions. Vol. 61.] PROCEEDINGS OF THE GEOLOGICAL SOCIETY. XCV The following communications were read :— 1. ‘ The Relations of the Eocene and Cretaceous Rocks in the Esna-Aswan Reach of the Nile Valley.’ By Hugh John Llewellyn Beadnell, F.G.S. 2. ‘ A Contribution to the Study of the Glacial (Dwyka) Conglo- merate in the Transvaal.’ By Edward T. Mellor, B.Sc., F.G.S. 3. ‘On New Oolitic Strata in Oxfordshire.’ By Edwin A. Walford, 4, ‘The Causes of Variegation in Keuper Marls and other Cal- careous Rocks.’ By Gerald Tattersall Moody, D.Sc., F.C.S. (Com- municated by Prof. W. W. Watts, M.A., M.Sc., F.R.S., Sec.G.8.) The following specimens, lantern-slides, and maps were ex- hibited :— Specimens exhibited by HE. T. Mellor, B.Sc., F.G.S., in illustration of his paper. Specimens, microscope-sections of Oolitic rocks, and lantern-slides exhibited by HE. A. Walford, F.G.S., in illustration of his paper. Specimens and lantern-slide exhibited in illustration of the paper by Dr. G. T. Moody, F.CS. Specimen of anhydrite and other rock-specimens from the Boultham Boring at Lincoln, exhibited by W. Whitaker, B.A., F.R.S., F.G.S. Specimens of Oldbury Stone and Lower-Greensand chert from the grayel-pit at Bramble Hall, Rayleigh Hills (Essex), about 260 feet above Ordnance-datum, exhibited by A. EH. Salter, D.Sc., F.G.S. Specimens of fossiliferous ironstone from the Pliocene Sands of Netley Heath (Surrey), exhibited by W. P. D. Stebbing, F.G.S. Carte tectonique de la Belgique et des Provinces voisines, par G. Dewalque, 500,000" 1905, presented by the Author. Geological Survey of England & Wales: 1-inch Map, n. s., Sheet 249, Newport (Drift) ; colour-printed, 1905, Presented by the Director of H.M. Geological Survey. Geological Survey of ‘Scotland : l-inch Map, Sheet 70, Minginish (Skye), by C. T. Clough & A. Harker, 1905; and Vertical Sections, Fife Coalfield, Sheet 2a, Linch = 40 feet, 1904. Presented by the Director of H.M. Geological Survey. THE QUARTERLY JOURNAL OF THE GEOLOGICAL SOCIETY OF LONDON. Vou. LXI. ‘1. The Leicester Earruquakes of Aveust 41H, 1893, and June 21st, 1904. By Cuartrs Davison, Sc.D., F.GS. (Read December 21st, 1904.) [Pratt I— Map. | I. Iyrropvuction, THoueH an interval of nearly eleven years separated the Leicester earthquakes of August 4th, 1893, and June 21st,.1904, the two shocks were so closely related in their origin that it is convenient to regard them as members of a single series. The earthquake of 1893 is the subject of a former paper,’ but the more recent inves- tigation of twin-earthquakes has rendered that account incomplete, I have therefore re-examined the evidence, and, in the earlier part of the present paper, have briefly described the phenomena, in so far as the twio character of the earthquake and its connection with the earthquake of 1904 are concerned. II. EarrHauake or Aveust 41H, 1898. Time of occurrence, 6.41 P.m.; intensity, 5; centre of isoseismal 5, in lat. 52° 44-6’ N., long. 1° 13°8' W. Number of records, 391, from 298 places, and 103 negative records from 97 places (PI. I). The curves on the map (Pl. I) represent isoseismal lines of in- tensities 5,4, and 3. Of these, the first is 18 miles long, 113 miles ‘*On the Leicester Earthquake of August 4th, 1893’ Proc. Roy. Soe. vol. lvii (1895) pp. 87-95. In redrawing the isoseismal lines, some slight changes have been made. The expenses of both investigations were defrayed from grants received from the Government Research-Fund. Q.J.G.8. No. 241. B 2 DR. CHARLES DAVISON ON THE [Feb. 1905, wide, and 161 square miles in area. Its longer axis runs from W. 30° N. to EH. 30° 8., and its centre is situated at a point 2 miles S. 20° W. of Loughborough. ‘The isoseismal 4 is 46 miles long, 32 miles wide, and contains 1170 square miles. Its longer axis is directed from W. 40° N. to E. 40°8., and its distances from the isoseismal 5 are 8 miles on the north-east side and 5 miles on the south-west. The isoseismal 3, which forms the boundary of the disturbed area, is 59 miles long, 47 miles wide, and includes 2200 square miles, and its longer axis runs north-west and south- east. While, however, the two latter curves are normal, or nearly so, as regards their relative position, the isoseismal 5 shows a marked displacement towards the north-west, the distance of its centre from that of the isoseismal 4 being 84 miles. Another feature of some significance is the deviation of about 10° between the directions of the axes of the two inner isoseismals. Over a large part of the disturbed area—ranging from Burton- on-Trent to Ketton, and from Nottingham to Burbage—the shock consisted of two distinct parts, separated by an interval, the average duration of which was 24 seconds. The first part was the stronger at Borrowash, Burton-on-Trent, and Uppingham ; while at Ketton the two parts were regarded as approximately equal in intensity. The evidence derived from the nature of the shock is thus incom- plete ; but it is sufficient to show that, corresponding to each part of the shock, a distinct impulse must have taken place within the seismic focus. Much more definite is the evidence afforded by the isoseismal lines. From the excentric position of the isoseismal 5 with respect to the isoseismals 4 and 3, we may infer that, if a series of inter- mediate isoseismals could be drawn, there would be a second group of curves similarly placed with regard to the south-eastern portion of the two outer isoseismals. It is evident, indeed, that these lines are merely the resultants of two pairs of such curves, approxi mately concentric with the geometric foci of the isoseismals as drawn on the map and coinciding with those curves towards the north-west and south-east; for there is a marked absence of obser vations of intensities 4 and 3 from the districts near the ends of the minor axes of the curves. The component isoseismals cannot be drawn with sufficient accuracy to justify their reproduction on the map; but, from their approximate paths, it follows that the centre of the south-eastern isoseismal 4 coincides very nearly with the village of Tugby, which is 17 miles E. 34° §. of the centre of the isoseismal 5; and that the intensity of the vibrations from the south-eastern focus died out much more slowly than that of the vibrations from the north-western focus. Whether the north-western or the south-eastern focus was first in action is uncertain, but it is clear, from the brevity of the interval between the two parts of the shock and from the great distance between the centres of the two foci, that the interval between the occurrence of the two impulses was less than the time required for the earthquake-waves to traverse the region between Vol. 61. | LEICESTER EARTHQUAKES OF 1893 ann 1904. 3 the two foci.’ In this respect, the Leicester earthquake of 1893 resembles the twin-earthquakes of Hereford in 1896 and Derby in 1903 and 1904. III. Earrnauakes or Jung 21st, 1904. On this day there were two undoubted earthquakes, the first and weaker at about. 3.30 a.u., the second at 5.28 a.m. a. June 21st, 1904: about 3.30 a.m. Intensity, 3. Number of records 2, from 2 places. The only records of this shock come from Groby and Markfield, at each of which localities a slight quiver was felt. The epicentre was probably near these places, both of which are close to the south- eastern margin of the north-western epicentre of the earthquake of 1893. b. June 21st, 1904: 5.28 a.m. Intensity, 5; centre of isoseismal 5, in lat. 52° 35:2’ N., long. 0° 59:5’ W. Number of records, 249, from 130 places, and 56 negative records from 44 places (map, p. 4). Time of Occurrence. The total number of records of the time is 215, 18 of which, lying between 5.25 and 5.3¥, are regarded by their observers as accurate to the nearest minute. ‘The average of these estimates is slightly over 5.28 a.m., which agrees with the time given by a signalman at Lowesby station (6 miles from the epicentre). Isoseismal Lines and Disturbed Area. The continuous lines on the map (p. 4) represent isoseismal lines of intensities 5 and 4. The isoseismal 5 is 23 miles long, 17 miles wide, and 314 square miles in area, its longer axis running N. 42° W. and 8. 42° E. The centre of the curve is about half-a- mile north-east of Burton Overy: its distances from the probable epicentre of the previous shock being about 12 miles, and from the south-eastern epicentre of the earthquake of 1893 (measured parallel to the isoseismal axes) about 3 miles to the north-west. The outer isoseismal, of intensity 4, is 334 miles long, 26 miles wide, and 681 square miles in area, its longer axes being directed from N, 44° W. to 8. 44° E. Its distance from the isoseismal 5 is 3 miles towards the north-east, and 52 miles towards the south- west. The shock was also felt at 15 places outside this isoseismal and within, though close to, the boundary of the sound-area (represented on the map by the dotted line). The disturbed area was thus 43 miles long, 36 miles wide, and covered about 1200 square miles. 1 The greater intensity of the first part of the shock at Uppingham was, no doubt, due to the proximity of that place to the south-eastern focus. B2 + DR. CHARLES DAVISON ON THE [Feb. 1905, Nature of the Shock. In the central part of the disturbed area, the shock consisted of two distinct parts, separated by a brief interval of rest and quiet. At Slawston, for example, the first and stronger part lasted 4 seconds, the interval 2 seconds, and the second part about 2 seconds; the sound was also in two parts, the first and louder Map illustrating the area affected by the Leicester earthquakes of June 21st, 1904. ee QL S “N23 oc = VO “SS Melton Ww See SoOaiiab ° a Lowesby oKirby oLeicester reiueet ore oHoughton- on-the-hill olugby oBurton Overy . Slawston Nuneaton R Market Harborough o Coventry 0 being compared to thunder, the other dying away after the second part of the shock, and resembling a rushing wind. Nearer the boundary of the disturbed area, as, for instance, at Harrington, the shock consisted of. one continuous series of vibrations, 3 seconds in duration, increasing in intensity to a single maximum and then decreasing, and accompanied by a sound like the rumbling of a passing waggon. | The relative intensity of the two parts of the shock is given in 9 records. At Queniborough or Queenborough, according to two observers, the parts were roughly equal in intensity ; at 7 other places Burton Hall, Kirby Muxloe, Leicester, Little Dalby, Lowesby, = Vol.61.] | LEICHSTER EARTHQUAKES oF 18938 anv 1904. 5 Quorn, and Slawston) the first part is invariably described as the stronger. The interval between the parts is in every case estimated at 2 seconds. The boundary of the area within which the double shock was felt 1s represented on the map (p. 4) by a broken line. It is 29 miles long, 204 miles wide, and includes an area of 464 square miles; its axis is nearly parallel to those of the isoseismal lines, running from N. 40° W. to 8. 40° E. The centre of the curve is about half-a-mile south-west of Houghton-on-the-Hill, in lat. 52° 37°1' N., long. 1° 0°8' W., or 24 miles north-north-west of the centre of the isoseismal 5. As the boundary of the double-shock area is close to the isoseismal 5 towards the south and east, and to the isoseismal 4 towards the north and west, it cannot coincide with an isoseismal line corresponding to an intensity between 5 and 4. Thus, while the dotted line represents the boundary of the disturbed area of the first part of the shock, and the broken line that of the second part, it is evident that the foci of the two parts were not coincident, but, at the same time, were not completely detached. ‘The earthquake may therefore be described as a double one, rather than as a twin-earthquake. Sound-Phenomena. As already mentioned, the boundary of the sound-area (repre- sented by the dotted line in the map, p. 4) coincides approximately with that of the disturbed area. The district is too small, and the number of records insufficient, for the construction of isacoustic lines; but it is evident, from the descriptions given, that the sound was unusually loud within a central area bounded approximately by the isoseismal 5, which is very nearly concentric with the boundary of the sound-area. The sound was, however, heard by nearly all observers close up to the latter boundary ; for the percentage of audibility was 97 over the whole area, 98 within the isoseismal 5, 96 between the isoseismals 5 and 4, and 93 beoween the isoseismal 4 and the boundary of the sound-area. The sound was compared to passing traction-engines, etc., in 62 per cent. of the records, to thunder in 17 per cent., wind in 4, loads of stone falling in 7, the fall of a heavy body in 5, explo- sions in 4, and to miscellaneous sounds in 1 per cent. There is the usual tendency towards smoothness and monotony in the sound with increasing distance from the origin. Within the isoseismal 5, the percentage of comparisons to passing traction-engines, etc., is 52, 71 between the isoseismals 5 and 4, and 76 between the isoseismal 4 and the boundary of the sound-area. For thunder, the corresponding percentages are 20, 14, and 14. In the following table (p. 6), the figures in the columns headed p, c, and f indicate the number of records per cent. in which the be- ginning or end of the sound preceded, coincided with, or followed, the corresponding epoch of the shock; those in the columns headed g, ¢, and 1 indicate the number of records per cent. in which the 6 DR. CHARLES DAVISON ON THE [Feb. 1905, duration of the sound was greater than, equal to, or less than, that of the shock :— RELATIVE EWpD. BEGINNING. a ef Duration. Dp C BA: Coil peeled, e L Within isoseismal 5............ 10 | 23) 7) 10 | 5% | 389. Fos eas Between isoseismals 5 and 4..., 57 | 39 | 4) 7/| 71) 21) 51 | 46) 3 Between isoseismal 4 and eal Be was ae ae boundary of ete tea 50 a 25 | O.| 56 | 44 | 29 | 43 | 29 Ruoleicound-arenec see 621311 81 8161 82 | 58 Meena LV. Origin oF THE KARTHQUAKES. Taking first the earthquake of 1893, we obtain from the seismic evidence the following elements of the originating fault in the neighbourhood of the north-western focus :—(1) the mean direction of the fault is from W. 30° N. to E. 30° 8.; (2) the hade is to the north-east ; and (3) the fault-line passes a short distance to the south-west of the centre of the isoseismal 5, or about 1 or 2 miles to the south-west of Woodhouse Eaves. For the south-eastern focus, the elements are less clearly defined :—(1) the mean direction of the fault lies between that given above and north-west to south- east; (2) the hade is to the south-west; and (3) the fault-line _ passes a short distance to the north-east of the centre of the isoseismal 4 corresponding to the south-eastern focus, or not far from Tugby. These two sets of conditions are consistent with the existence of a single fault, in which the direction of hade changes in a district about midway between Markfield and Tugby. It may be remarked that this change of hade furnishes an ex- planation of the divergence of the axes of the resultant isoseismal lines of Pl. I. For, at the north-western focus, the isoseismal 4 — diverges farther to the north-east than in the opposite direction ; while, at the south-eastern focus, it diverges farther to the south-west than to the north-east. Thus, the axis of the resultant isoseismal 7 should be tilted more towards the north-west ; and the same should hold true of the resultant isoseismal 3. Again, for the principal earthquake of 1904, the elements of the earthquake-fault are:—(1) the mean direction of the fault is from W. 42° N. to EH. 42°8.; (2) the hade is to the south-west; and (3) the fault-line passes a short distance to the north-east of the centre of the isoseismal 5, and therefore not far from Tugby. It is thus probable that the earthquakes of 1893 and 1904 originated in one and the same fault. Por mais REE tg ere Pavol 7 , Quart. Journ, Geol. Soc. Vol. LXI, Pl. EF A. A.= Fault on the N.E.side of the Is. Charnwood axis. Sere ase Faults on the S.W. side of thai e Ray g CES fe) oGrantham oQakham Stamford oKetton oTugby Uppingham Oundle Rothwell fo} _ Leicester Harraquaxe or Avucusr 41x, 1893. oa 4 4 i Quart. Journ. Geol. Soc. Vol. LXT, P). I, Pee Faulton the N.E.side of Ue Charmwvood axis, | B.C.= Faults on the S.AV side of that axis. Nottingham o Grantham oBorrowash ° Burton-on- -Trent Shepshed 2 Longhborough ‘ScWoodhouse Eaves oOakham Stathford oKetton oLeicester oTugby Uppingham oBurbage Oundle oLutserworth Rothwell ° Coventry Scale of Miles () eB 3) es puquakE or Auausi 4ru, 1893. Map ILLustRATING 1H AREA AFFECTED BY THR LprorsteR HARTHQUAKE OF } 4 cs ny yaeey * i Vol. 61.] sO LEICESTER EARTHQUAKES OF 1893 ann 1904. 7 The faults of Charnwood Forest have been mapped by Prof. Watts, F.R.S.,' to whom I am indebted for information on the geo- logical structure of the district. In Pl. I, the more important strike-faults are reproduced from Prof. Watts’s map, the transverse faults of later date being omitted, for the sake of simplicity. The faults on the north-east side of the Charnwood anticlinal axis probably hade to the north-east, and those on the south-west side in the opposite direction. In Pl. I, the former are indicated by broken lines, and the latter by dotted lines. The fault which satisfies the seismic conditions most closely is that marked A in Pl. I. Its mean direction in the neighbourhood of Woodhouse Eaves is W. 27° N. and E. 27° S., it hades in all probability to the north-east, and it passes about 2 miles to the south-west of the centre of the isoseismal 5. Owing to the covering of Triassic rocks, it cannot be traced farther to the south-east than the village of Cropston; but there is no reason for supposing that it dies out at that point. Assuming, then, that the fault referred to extends to the neighbourhood of Tugby, trending there more nearly in a south-easterly direction, I will now trace briefly the history of the recent movements. In 1893, the displacements in the two foci took place almost simultaneously and apparently in opposite directions, the interfocal region remaining stationary or nearly so. The centres of the foci were about 17 miles apart; and it is clear, from the more rapid decline in intensity from the north-western epicentre, that the corresponding focus was situated at a less depth than the other. One effect of the double slip was to cause an increase of stress in the regions of the fault-surface bordering the margins of both foci, the greatest accession of effective stress being experienced by the interfocal portion of the fault. It is probable that the earlier slip in 1904 took place in or near the south-eastern margin of the north- western focus of 1893; but it may have been caused by a small slip along one of the faults marked B & Cin Pl. I. Two hours later, _ this was followed by a double (not a twin) slip in or near the north-western margin of the south-eastern focus; and, judging from the rapid decline in the intensity of the shock, at a less depth than either of the foci of 1893. The second part of this double slip showed a farther migration (of 2 or 3 miles) towards the north- west, and a still closer approach to the surface of the earth. EXPLANATION OF PLATE I. Map illustrating the area affected by the Leicester earthquake of August 4th, 1893, on the approximate scale of 8 miles to the inch. 1 Proc, Geol. Assoc, vol. xvii (1902) pl. xix. [For the Discussion, see p. 33. | 8 DR. CHARLES DAVISON ON THE [Feb. 1905, 2. The Dersy Harruquaxrs of Jury 3rp, 1904. By Cuarius Davison, Sc.D., F.G.S. (Read December 21st, 1904.) [Puats IIT—Map.] I. Inrropuction. Between the Derby earthquakes of March 24th, 1903, and July 3rd, 1904, there exist several points of intimate resemblance. The isoseismal lines of the two shocks, when drawn on one map, are so closely related that they might be the isoseismals of a single earthquake ; both earthquakes were twins; the two epicentres in 1904 were nearly or quite coincident with those in 1903; and both earthquakes were followed by an after-shock, originating for the most part in the interfocal region of the fault. The points in which they differ are of little consequence. The intensity of the shock of 1903 was greater than that of the shock of 1904; the impulses at the two foci were approximately of the same strength in 1903, and of unequal strength in 1904; they occurred at the same instant on the former occasion, while, on the latter, they were separated by a brief interval of time. The principal shock of 1903 occurred on a weekday at 1.30 P.m., that of 1904 at 3.21 on a Sunday afternoon. ‘Thus, although of less intensity, the recent earthquake was felt and heard over a much wider area than its predecessor. There was at the time practically no traffic in the streets, and many of the observers (especially of those at a great distance from the centre) were lying down— conditions that favoured the observation of the earthquake in places at which, on an ordinary occasion, it would have passed totally unperceived.* 7 There were at least three earthquakes in the series of 1904, namely :— (a) July 3rd, 2.28 p.m. . (0) July 3rd, 3:21 p.w. (Principal earthquake.) (c) July 3rd, 11.8 p.m. In addition to these, disturbances resting on the authority of a single record were reported at the following times :— ; July 3rd, 3.15 p.m.: Tissington.—Two persons, in one room, thought that they heard thunder. 1 T have to offer my best thanks to the very numerous observers who have placed their accounts at my disposal ; to the editors of many newspapers who have given a wide circulation to my requests for information ; and not least to those who on this, as well as on the former, occasion have been so kind as to collect records from other observers. Mr. H. H. Arnold-Bemrose has again aided me materially in this way, as have also Sir John G. N. Alleyne, Bart. ; Mr. W. Wells Bladen, honorary secretary of the North Staffordshire Field- Club; Mr. W. F. Blay, of Wallsall; Mr. J. EH. Bolton, of Eckington; Mr. W. J. Butcher, headmaster of the Grammar-School, Ashbourne; Mr, J. Clark, of Wol. 61.} DERBY EARTHQUAKES OF 1904. 9 July 3rd, 3.23 p.m.: Dalbury Lees.—A low distant rumbling, as of thunder. July 3rd, 4.20 p.m.: Grindon.-—A heavy rumbling, without any attendant shock. July 4th, about 1.80 a.m.: Matlock Bath.—A slight shock. July 4th, about 6 a.m.: Wirksworth.—A slight shock. Il. Forr-Snock. -a July 3rd, 2.28 P.M. Intensity, 3. Number of records, 5, from 5 places. A slight quivering was felt at Ambergate, Cromford, Matlock Bath, Mayfield, and Wirksworth (see map, p. 16). At Ambergate, a noise like a loud peal of thunder accompanied the tremor. May- field is about a mile south-west of Ashbourne. The other four places, however, are close to the north-eastern or Wirksworth epi- centre of the principal earthquake, and the shock probably originated in the corresponding focus. Ill. Tar Principat Harruevaxe. (PI. I.) 6. July 3rd, 3.21 p.m. Intensity, 7; centre of isoseismal 7, lat. 53° 0°4' N., long. 1° 41:6’ W. Number of records, 1467, from 653 places, and 46 negative records from 44 places. Time of Occurrence. Excluding approximate estimates, the total number of records of the time is 737. Of these, 113 are regarded by their observers as accurate to the nearest minute. The average of all the latter is 3" 213” p.m., and as the averages of the different zones included between successive pairs of isoseismals do not differ from this by more than a minute, it is probable that the time of occurrence at the epicentre was very nearly 3.21 p.m. Isoseismal Lines and Disturbed Area. The five continuous curves on the map of the earthquake (PI. IJ) are isoseismal lines of intensities 7 to 3, the broken-and-dotted lines referring to the earthquake of March 24th, 1903. Waterhouses, near Ashbourne; Mr. T. Gledhill, of Dronfield ; Mr. C. W. Groves, of Risley; Mr. 8S. E. Howse, of Ambergate; Mr. A. V. Jones, of Church Broughton ; Mr. T. W. Learoyd, of Rostherne, near Knutsford; the Rev. C. Price, of Denstone College ; Mr. S. Steele, of Chesterfield; Mr. P. K. Tollit, headmaster of the Grammar-School, Derby; Miss A. C. Tute, headinistress of the High School for Girls, Derby; and Mr. W. M. Wilson, headmaster of the Higher Grade School, Hanley. By kindly writing on my behalf to the local press, Mr. Arnold-Bemrose has also prompted the communication of many valuable records. The expenses of the investigation were defrayed from a grant received from the Government Research-Fund. 10 DR. CHARLES DAVISON ON THE | Feb. 1905, The isoseismal 7 is approximately circular in form, 7+ miles in diameter, and 41 square miles in area. Its centre lies about 13 miles east of Ashbourne in lat. 53° 0-4’ N., long. 1° 41-6’ W. The next isoseismal, of intensity 6, is roughly an ellipse, 37 miles long, 27 miles wide, and 804 square miles in area ; the direction of its longer axis is N. 31° E, and 8. 31° W., or very nearly parallel to the axis of the isoseismal 7 of the earthquake of 1908. The distance between the isoseismals 7 and 6 is 12 miles on the north- west side and 8 miles on the south-east. The most important feature in the two curves is, however, their oxcentricity : the distance between the centres of the two curves in the direction of the longer axis being about 2 miles. In the neighbourhood of Matlock Bath, there is another maximum of intensity 7 or nearly 7. The observations are insufficient to draw a second isoseismal in that district ; but it is clear that, if the isoseismal corresponding to an intensity between 7 and 6 could be drawn, it would consist of two detached portions, one concentric with the isoseismal 7, the other not far from Wirksworth and Matlock Bath, their centres being separated by a distance of 6 or 7 miles. Thus, the two epicentres of 1904 are approximately coincident with those of the previous year. The isoseismal 5 is the last which retains any trace of an elongated form. It is 72 miles long, 65 miles wide, and contains 3600 square miles ; its distance from the isoseismal 6 is 21 miles on the north-west and 17 miles on the south-east side. The next two isoseismals are very nearly circles, the isoseismal 4 being 114 miles long from north-east to south-west, 113 miles wide, and about 10,120 square miles in area; the isoseismal 3, which forms the boundary of the disturbed area, is 181 miles long from north-east to south-west, 179 miles wide, and about 25,000 square miles in area. Observa- tions were also made at a few places outside the latter isoseismal, at Aisgill, Appleby, Beckfoot, and Mallerstang in Westmorland ; at Bridlington, on the east coast of Yorkshire; and at Long Whittenham, near Abingdon, in Berkshire. Comparing the dimensions just given with those for the earth- quake of 1903, we see that the isoseismals 7 to 4 of that earthquake are all larger than those for the earthquake of 1904; in 1903, a few buildings sustained slight injury over an area of 112 square miles, while, in 1904, there was practically no damage to property. On the other hand, the earthquake of 1904, owing to its occurrence on a Sunday afternoon, could be traced to a much greater distance, its disturbed area being about double of that of the earthquake of 1903. Nature of the Shock In 1903, the twin-character of the earthquake was clearly defined ; it was recognized by two out of every three observers, and was perceptible close to the boundary of the disturbed area. In 1904, ~ only one out of five observers recorded the existence of two parts or Vol. 61. | DERBY EARTHQUAKES OF 1904. 11 two maxima, and this was no doubt due to the incomplete separa- tion of the two parts, an intermediate tremor being observed within the central area. Thus, at Ashbourne (14 miles from the centre of the isoseismal 7), the shock consisted of a single series of vibrations, which increased in intensity to a maximum, and then died away ; at Sudoury (about 9 miles to the south), there were two such maxima connected by weaker tremulous motion; at Birmingham (37 miles distant), two series of vibrations were felt, the first being distinctly stronger, the second series a mere shudder. The inter- mediate tremor was perceptible as far as Farnsfield near Southwell (27 miles from the centre); while the twin-shock was felt to the north at Bradford (54 miles), to the west at Ellesmere (50 miles), to the south at Stourport (52 miles), and to the east at Hough near Grantham (44 miles), or over an area of roughly 8000 square miles in extent. This area is, however, traversed by a band within which the two parts of the shock were superposed. It is difficult to trace the boundaries of this band with accuracy, owing to the continuity of the shock within the central district ; but the course of its median line probably does not differ much from that indicated by the broken- and-dotted line on the map (Pl. IT), especially towards the south- east of the epicentre. This band differs in two respects from that traced for the earthquake of 1903. In that case, the band was rectilinear and about 5 miles in width; in the earthquake of 1904, it was hyperbolic in form, the concavity of-the curve facing the south or south-west, and the width of the band is greater towards its extremities, being 15 or 16 miles at a distance of 30 miles from the . centre. It will be noticed that the median line passes a short distance to the north-east of the centre of the isoseismal 7. It is obvious from the distance to which the twin-shock was perceptible that there was some, although not much, difference between the intensities of the two parts. This conclusion is also borne out by the observations on the relative intensity of the two series or maxima. ‘To the south-west of the hyperbolic band, 49 observers regarded the first part as the stronger, 9 the second, while 2 thought them roughly equal in intensity ; to the north-east of the hyperbolic band, the corresponding figures are 20, 10, and 1. On the south-west side, however, 3 observers, and on the north-east side 8 observers, were doubtful as to the order of intensity. We may, I think, conclude from these figures that, while the first part was generally the stronger all over the disturbed area, the inequality was less on the north-east, than on the south-west, side of the hyperbolic band. Outside the hyperbolic band, the length of the interval between the two parts varied from 1 to 4 seconds, The average of 75 estimates is 2°1 seconds, and the average is practically uniform throughout the disturbed area, being 2°2 seconds within the iso- seismal 6, 2:0 seconds between the isoseismals 6 and 5, and 2:1 seconds outside the latter isoseismal.. 12 DR. CHARLES DAVISON ON THE (Feb. 1905, Origin of the Double Shock. There can be no doubt, from these observations, that the two parts of the shock originated in two foci lying along a line directed approximately from N. 31° E. to 8. 31° W. A slight movement, however, took place in the intermediate region, sufficient to cause the tremulous motion felt between the two principal parts of the shock. If the impulses had taken place simultaneously, the two series would, as in 1903, have been superposed along a rectilinear band. As it is, the curvature of the hyperbolic band towards the south-western focus shows that the vibrations from the north-eastern focus travelled farther than those from the south-western focus before the two series coalesced. In other words, although the two impulses were nearly simultaneous, the north-eastern focus was 10 action a short time, perhaps a second or less, before the other. In the present case, the positions of the two epicentres can be determined more accurately than in the earthquake of 1903. The south-western epicentre must coincide very nearly with the centre of the isoseismal 7, that is, it must be about 14 miles east of Ashbourne. The north-eastern epicentre probably lies near Wirksworth or Matlock Bath, and about 6 or 7 miles from the other. Corroborative evidence of these determinations is afforded by the observations on the apparent direction of the shock The sense of direction is more appreciable in houses in which the principal walls are at right angles to the direction of the epicentre; and it was found, in the case of the Hereford earthquake of 1896, that the average of a large number of observed directions, rough though they may be, points very nearly to the epicentre. For the recent Derby earthquake, it is possible to determine such average directions for two districts, one around Derby and the other around Nottingham, these two towns lying close to, but on opposite sides of, the hyper- bolic band. In the Derby district, the mean direction is from W. 37° N., or exactly in a line from the centre of the isoseismal 7 ; in the Nottingham district, the mean direction is from W. 39° N., and, produced backwards, this line passes through a point 3 miles west of Wirksworth. Lastly, the existence of the isoseismal 7 around the south-western epicentre and the practical absence of such a curve from the north- eastern epicentre lead to the conclusion that the impulse at the south-western focus was stronger, though not much stronger, than the impulse at the north-eastern focus. Consequently, on the south-west side of the hyperbolic band, the first part of the shock was the stronger; on the north-east side, the first part was as a rule the stronger, owing to the proximity of the north-eastern focus from which the first vibrations arrived. Seismographic Records. The seismographic records of the earthquake are of little interest, and do not add to our knowledge of its nature. Mr. W. E. Plummer, Vol. 61.] DERBY EARTHQUAKES OF 1904, 13 director of the Liverpool Observatory at Bidston, near Birkenhead, informs me that, although the shock was felt by many persons there, the trace of the Milne seismograph shows but the slightest disturbance at 3" 18:8" p.m. In Birmingham, there was apparently no movement of the Omori horizontal pendulum, and only a minute displacement of the pointer of the Ewing duplex pendulum. The absence of a clearer record is probably due to the comparative weakness of the original disturbance, to the irresponsiveness of long-period horizontal pendulums to rapid vibrations, and, in the case of Birmingham, to the fact that the direction of the epicentre lies very nearly in the plane of the pendulum. Isacoustie Lines and Sound-Area. In drawing the isacoustic lines for the earthquake of 1903, the whole area was divided into squares by north-to-south and east- to-west lines 10 miles apart. JI have made use of the same squares for the recent shock, but have calculated the percentage of audibility corresponding to the corners of these squares, making use of the records within the four contiguous squares. In this way a larger number of observations is at our disposal, the only effect of such a treatment being to smooth away local inequalities in the resulting curves. Notwithstanding this advantage, only one isacoustic line, corresponding to a percentage of 80, can be satisfactorily drawn. This is represented by the irregular dotted line on the map (PI. IT). Its peculiar form, especially the branches to the west and south- east, is evident at once. In the former direction, the number of records is too small to complete the curve, and its course may not be quite accurately laid down, but the branch evidently extends some distance farther towards the west. For the south-eastern branch, the observations are more numerous, and it will be noticed that it lies almost exactly along the course of the median line of the hyperbolic band. The explanation of this peculiarity, of course, is that the sound-waves from the two foci coalesced along the hyperbolic band, and were therefore audible to a larger number of observers. From the study of the sound-phenomena, we are therefore again led to the conclusion that the north-eastern focus was in action slightly before the other. With regard to the less- pronounced expansion of the curve towards the north, I can offer no satisfactory explanation. With a few isolated exceptions, the sound was heard within the area bounded by the outer dotted line in Pl. I, a line which in no place deviates more than 43 miles from the isoseismal 4, over- lapping that curve towards the east, south, and west, but not extending quite so far towards the north. Its dimensions are 121 miles from north-west to south-east, and 113 miles from north- east to south-west, and its area covers about 10,700 square miles. The exceptional records come from Branston Green (13 miles to the north of the boundary), Lytham (21 miles to the north-west) 14 DR. CHARLES DAVISON ON THE [Teb. 1905, Clunbury (6 miles to the south-west), and Wormleighton, Wroxton, and Brockworth (respectively 4, 11, and 27 miles to the south). Though the sound-area is greater than in 1903, owing probably to the conditions at the time of occurrence, the percentage of audibility is somewhat less. Within the isoseismal 7, 94 per cent. of the observers heard the earthquake-sound ; in the zone between the isoseismals 7 and 6, the percentage of audibility was 93; between the isoseismals 6 and 5, 79; between the isoseismals 5 and 4, 56; and outside the isoseismal 4, 38. The want of parallelism between the isacoustic line of percentage 80 and the boundary of the sound-area is probably due to the rapid decline in audibility as the latter curve is approached. Nature of the Soumdl The total number of descriptions of the earthquake-sound is 812. In 45 per cent. of these, the sound is compared to passing traction- engines, motor-cars, etc., in 26 percent. to thunder, in 15 to wind, in 5 to loads of stones falling, in 4 to the fall of a heavy body, in 2 to explosions, and in 2 per cent. to miscellaneous sounds. The variation in the nature of the sound with the distance is shown in the following table (1), in which the figures are per- centages of comparison to the different types for each of the districts mentioned :— g | gS _ ; rs S 3 2 eines 2/2 (ee TaBLe I. ap @ : cel Sy | 2 = = S Ss 12 S| Ors ° ar R S| 3s | oa © fey 2 = ee ae an | Be 2 is Ay = ae ca es = Within isoseismal 7 ...... 3}9) Al O 9 2 9 0 | Between isos. 7 and6...| 52 28 9 8 2 1 0 2 i se due reste eee 24 19 3 5 3 2 | 5; oe ate oe 24 25 4 4 2 6 Outside isoseismal 4...... 40 ao 27 8) 0 (0) 0 ! | The most noticeable variation is the increase with distance in the proportion of comparisons to the smooth and monotonous type of wind. Time-Relations of the Sound and Shock. In the following table (II, p. 15), the letters p, c, and f indicate the number of records per cent. in which the beginning or end of the sound preceded, coincided with, or followed, the corresponding epoch of the shock; the letters g, e, and J show the number of records per cent. in which the duration of the sound was greater than, Nol 6 1. | DERBY EARTHQUAKES OF 1904. 15 equal to, or less than, that of the shock. The last line of the table gives the percentages for the Derby earthquake of 1903 :— BEGINNING. Enp. s a ek bs URATION. Taare II, ARC R MnCl gs hee |. Wahi icosewsmal 7 2.....:.0s:e0e.0ie cc, 70|30| 0 | 7|47/|47)71|29! o Between isoseismals 7 and 6 ............08- 62 | 32) 5 | 24 | 52 | 241 51/39/10 i a: SAMOA | ne cor CMe om 68 | 24) 8 |12153| 35173) 25) 2 pe _ aia: Re eM 70 | 24] 6 | 28} 43) 28170! 9} 22 WANE SOUMG=ATCA oc. ssceecdcsca verses sewer 165/29; 6 | 18) 5] | 381|62)31) 7 » 9 Of the earthquake of 1903| 57 |37| 7 21)55/24/46/46) 9 For the epoch of maximum intensity, the number of records is only 37. The epoch when the sound was loudest preceded that when the shock was strongest in 30 per cent. of the records, coincided with it in 62, and followed it in 8 per cent. The chief result of the foregoing table is the rough approach to uniformity for the different zones, whatever their distance from the epicentre. If the sound-waves travelled more rapidly than those of larger amplitude, we should expect to find an increase with distance in the observations of the sound before the shock, and a decrease in those of the sound after the shock. Except in the central area, in which both fore-sound and after-sound would naturally be more sensible, there is no distinct trace of such variation. TV. Arrrer-SHock. é. Julyeord, 11.8) Bim, Intensity, 4; centre of isoseismal 4, in lat. 53° 2°8' N., long. 1° 39:5' W. Number of records, 76, from 42 places, and 2 negative records from 2 places (map, p. 16). | Inthe map of this after-shock (p. 16), the continuous lines repre- sent the isoseismals 4 and 3, the dotted lines are the corresponding isoseismals for the after-shock of May 3rd, 1903; the broken- and-dotted line is the isoseismal 7 of the principal earthquake of 1904. The isoseismal 4 is 16 miles long, 10 miles wide, and contains 125 square miles. Its centre is about half-a-mile south-west of Hognaston, and the direction of its longer axis about N. 27° E. and §.27° W. ‘The course of the isoseismal 3 is somewhat doubtful towards the north and south, but the error in either case is probably less than a mile. As drawn, it is 27 miles long, 20 miles wide, 16 | DR, CHARLES DAVISON ON THE [Feb. 1905, and contains 425 square miles. The distance between the two isoseismals is 6 miles on the north-west, and 43 miles on the south-east, side. The shock and sound were also observed, though very faintly, at Derby, 14 miles south-east of the isoseismal 3, and at Leek, 43 miles west of the same curve. Map illustrating the avea affected by the after-shock of July 3rd, 1904. les w Oo Bath is Matlock ae Cromford° A Wirksworth Tissington ome mm, oa =, : o™. es Hognaston \ \u oAshbourne j ° : Belper \oMayfield Fey es OF 3 Dalburyo Scale of Miles 2 6 The shock is uniformly described as a continuous series of rapid vibrations, the average of four estimates of its duration being 3% seconds. The sound was heard by 96 per cent. of the observers, and was compared to passing vehicles in 28 per cent. of the records, to thunder in 39 per cent., to wind in 11, to the fall of a load of stones in 6, and to explosions in 17 per cent. The beginning of the sound either preceded or coincided with that of the sheds. the end of the sound generally coincided with that of the shock. rn. Geol. r- Llandudno RS Chester tt oe Llandderfel 9 Ellesmere Clunbury o oPresteign oHay Hereford Scale of Miles OO a ; Boltono Oldhamo — ee oe P Manchestero .~ Newcastle-9) under-Lyme; Stokejupon- Trent S Wolverhamptons ~~ Bridgnorth oMalvern ©Gloucester © Stroud oCheltenham Bfadford °Halifax °Wakefield °Huddersfield Re \ y Matlock Bath 7 | _oSeél SWitksworth tt °Sudbury °. Leicester Birmingham o Coventry oWormleighton oEvesham \ Ss Lincolno cHough Bostono Grantham oWellingborouch MAP illustrating the AREA affected by the PRINCIPAL DERBY EARTHQUAKE of JULY 3% 1904. By CHARLES Davison, Sc.D., F.G.S.. LO SE oer? Vol, 61. | DERBY EARTHQUAKES OF 1904. 17 V. OricgiIn oF THE EARTHQUAKES. The elements of the originating fault, as determined by the seismic evidence for both the principal earthquake and the after- shock, are as follows :—(1) the mean direction of the fault is from N. 31° E. to 8. 31° W.; (2) its hade is to the north-west; and (3) the fault must pass through a point a short distance to the south- east of the centre of the isoseismal 7, that is, it must pass through or near the village of Hognaston. Comparing these elements with those obtained for the fault in action in 1903, we see that they are almost identical, the only difference being the slight one of 2 degrees in the mean direction of the fault. We may, therefore, conclude with some probability that the two earthquakes originated in slips along the same fault; and the pro- bability seems strengthened when we consider that the two epi- centres in both earthquakes were practically coincident. In 1903 there was no distinct preparation for the earthquake of March 24th; the impulses occurred simultaneously within the two foci and were very nearly equal in strength, and there was no sensible movement in the interfocal region of the fault. In less than 4 hours two small slips took place in unknown parts of the fault ; and 40 days later, on May 3rd, the increased stresses at both ends of the interfocal region resulted in a slip chiefly within that region, partly perhaps within the nearer lateral margins of the foci, but closer to the surface than the two principal slips of March 24th. In 1904, on the other hand, there was a preliminary slip within the north-eastern or Wirksworth focus, followed in less than an hour by the principal slips in both foci, that within the south-western or Ashbourne focus being the more pronounced and succeeding the other by about a second or even less. In this case the foci were not completely detached, for throughout the interfocal region there was a Slight displacement, comparable in magnitude with that which occurred in the marginal regions of the principal foci. In other words, the nearer margins of these foci coalesced. About 8 hours later the increased stresses resulting from these move- ments precipitated an interfocal slip, at about the same depth as the previous slips in the principal foci. With this, the series of movements seems to have terminated, unless there were two small creeps a few hours later within the Wirksworth focus. EXPLANATION OF PLATE IL. Map of the area affected by the principal Derby earthquake of July 3rd, 1904, on the scale of 15 miles to the inch. [For the Discussion, see p. 33. | Q.J.G.8. No. 241. | C 13 DR. CHARLES DAVISON ON [Feb. 1905, 3. Twin-Hartueuakes. By Cuaruirs Davison, 8c.D., F.G.S. (Read December 21st, 1904.) I. Inrropvction. Tux essential characteristic of a twin-earthquake is the existence in the shock of two maxima of intensity connected by weaker tremulous motion, or the division of the shock into two parts sepa- rated by a brief interval of rest and quiet. This feature, however, is not entirely peculiar to twin-earthquakes ; for, occasionally, one earthquake is succeeded by another so rapidly as to simulate a twin-earthquake in this respect. A closer investigation of the phenomena shows, as will be seen, that the two parts or maxima of a twin-earthquake originate in two detached, or practically- detached, foci; whereas, in a double earthquake, the foci are either coincident or overlapping. A further distinction, partly dependent on the former, may be noted. In all parts of the disturbed area the member of a double earthquake which occurs first is felt first. In a twin-earthquake, on the other hand, the second impulse may, but does not necessarily, occur before the vibrations from the first focus have reached the other; so that, over most of the disturbed area, the vibrations first felt are those which come from the nearer focus, whether that focus was first in action or not. In a double earthquake the second shock is a consequence of the first; in a twin-earthquake each is independent of the other. In other words, a double earthquake is the result of successive impulses; a twin- earthquake is due to a single generative effort. As examples of twin-earthquakes, may be mentioned the Col- chester earthquake of April 22nd, 1884; the Cornwall earthquake of May 17th, 1892; the Pembroke earthquakes of August 18th, 1892, and November 2nd, 1893; the Leicester earthquake of August 4th, 1893; the Hereford earthquake of December 17th, 1896; the Carlisle earthquake of July 9th, 1901; and the Derby earthquakes of March 24th, 1903, and July 3rd, 1904. Also, among the shocks of other lands, the Neapolitan earthquake of 1857, the Andalusian earthquake of 1884, the Charleston earthquake of 1886, the Rivieran earthquake of 1887, and the Calabro-Messinese earth- quake of 1894. The Cornish earthquakes of March 29th and April 1st, 1898, are typical examples of double earthquakes." It is also possible that a few earthquakes may belong to both classes. The Leicester earthquake of June 21st, 1904, was probably a twin, so far as regards the shocks at 3.30 and 5.28 a.m., while the latter shock was itself a double earthquake. During the last 16 years (1889-1904) the total number of — earthquakes recorded in Great Britain is 160. Of these, eight, or 1 in 20, were twins. They include five out of the seven ? Quart. Journ. Geol. Soc. vol. lvi (1900) pp. 1-7. Vol. 61.] TWIN-EARTHQUAKES. 19 shocks which, during that time, disturbed areas of more than 10,000 square miles; while the four strongest shocks of the last 21 years were all twin-earthquakes, Earthquakes of the first magnitude, however, such as the Japanese earthquake of 1891 or the Indian earthquake of 1897, are far more complex than twin- earthquakes, both in their nature and origin. II. BipiioGRaPHyY. 1. Davison,C. ‘On the Pembroke Earthquakes of August 1892 & November 1893’ Quart. Journ. Geol. Soc. vol. liii (1897) pp. 157-75. 2. Davison,C. ‘The Hereford Earthquake of December 17th, 1896’ Birmingham, 8vo. (1899) ; especially pp. 226-39, 243-45, & 294-95. . Davison, C. ‘The Carlisle Earthquakes of July 9th & 11th, 1901’ Quart. Journ. Geol. Soe. vol. lviii (1902) pp. 371-76. . Davison, C. ‘The Derby Earthquakes of March 24th & May 8rd, 1903’ Ibid. vol. 1x (1904) pp. 215-32. . Davison, C. ‘The Leicester Earthquakes of August 4th, 1893, and June 21st, 1904’ Ibid. vol. lxi (1905) pp. 1-7. . Davison, C. ‘The Derby Earthquakes of July 3rd, 1904’ Ibid. pp. 8-17. . Dutton, C. E. ‘The Charleston Earthquake of August 31st, 1886’ U.S. Geol. Surv. Ninth Annual Report, for 1887-88 (1889) pp. 209-529, especially pp. 260-64 & 270-320. 8. Matuet, R. ‘The Great Neapolitan Earthquake of 1857, &c.’ (1862), espe- cially vol. 11, pp. 162-63. 9. Metpona, R., & Wuitrt, W. ‘ Report on the East-Anglian Earthquake of April 22nd, 1884.’ (1885), especially pp. 37, 44, & 92-93. [Essex Field-Club Special Mems. vol. i, 1885. | 10. Mercauui, G. ‘Il Terremoto Ligure del 23 febbraio 1887’ Annali dell’ Uff. Centr. Meteor. & Geodin. ital. ser. 2, vol. vili, pt. iv (1888), especially pp. 567-76. 11. Mercanyi, G. ‘I Terremoti della Calabria meridionale & del Messinese’ Memorie di Mat. & di Fis. Soc. ital. Sci. ser. 3, vol. xi (1898), especially pp. 117-21 & 131-39. 12. Taramecni, T., & Mercary, G. ‘I Terremoti Andalusi cominciati il 25 di- cembre 1884’ Atti R. Accad. Lincei, Mem. ser. 4, vol. i11 (1885-86) pp. 116-222, especially pp. 165-68, 177-80, & 203-10. NO 7 & Oo Ill. Nature oF Twin-EarraQuakEs. Wide Area of Observation. The wide area over which the twin-shock is felt is perhaps the strongest evidence that the phenomenon is not of local origin. In the Hereford earthquake of 1896, the places where it was felt are distributed almost uniformly over the whole district bounded by the isoseismal 5, or over more than 40,000 square miles. Towards the north-west it was also perceptible in Westmorland, in the Isle of Man, and in Ireland, or very nearly to the boundary of the disturbed area. The twin-shock of the Pembroke earthquake of 1892 was also observed almost to the limits of the disturbed area, from Rhy] to the Scilly Isles, and from Worcester to Tullow in County Carlow. In the Pembroke earthquake of 1893 it was again noticed in nearly all parts of the disturbed area, and at places so near its boundary as Derby, Ashley, and Bournemouth. The twin-shock of the Derby earthquake of 1903 was recorded c2 20 DR, CHARLES DAVISON ON [Feb. 1905, by 68 per cent. of the observers, and was perceptible over the whole disturbed area of about 12,000 square miles. That of the following year was felt over an area of about 8000 square miles, or nearly one-third of the disturbed area. In the Andalusian earth- quake of 1884 both parts of the shock were felt as far as Madrid, which is 170 miles from the epicentre. In the Rivieran earthquake of 1887 they were observed at many towns and villages in the central zones, and even as far as Salo and Vicenza, which are distant respectively 177 and 210 miles from the epicentre; but the weaker part was imperceptible in Switzerland and in other regions near the boundary of the disturbed area. The twin-shock of the Charleston earthquake of 1886 was felt at several places more than 600 miles away from the epicentre. Relative Nature of the two Parts. As a general rule, the observations under this heading refer to the relative intensity of the two parts of the shock. In the Pembroke earthquake of 1892 the parts differed little in intensity ; but, over all the land-area disturbed, the second seems to have been slightly stronger than the first. In that of 1893, the second series was the stronger near the western end of the isoseismal 6 and farther west in Pembrokeshire, and the first in other parts of the area. For the Hereford earthquake of 1896 the observations are more detailed. These show that, in the north-western half of the dis- turbed area, the first part of the shock was the stronger, of greater duration, and consisted of vibrations of longer period; that, in the south-eastern half, the same features characterized the second part of the shock ; and, moreover, that the boundary-line between these two portions of the disturbed area was not straight, but concave towards the south-east. In the Derby earthquake of 1903, the two parts were so nearly equal in intensity that observers in the same place differed greatly in their estimates. All over the disturbed area, however, 61 per cent. of the observers state that the first part was the stronger, and 39 per cent. the second; and this pro- portion was nearly the same on both sides of the minor axes of the isoseismal lines. The first part of the Derby earthquake of 1904 was also generally regarded as the stronger, but the difference in intensity between the two parts was clearly greater in the south- western than in the north-eastern half of the disturbed area. In the Charleston earthquake of 1886 the two parts were of nearly- equal intensity, but at most places the first is described as the stronger; in the Rivieran earthquake of 1887, the second part of the shock was the stronger all over the disturbed area, except within a small area near Nice; and in the Calabro-Messinese earth- quake of 1894 the second part seems to have been everywhere - stronger than the first. Thus, not only does the order of relative intensity vary in different earthquakes, but in the same earthquake there may exist regions in which the order of intensity is reversed. Vol. 61.] TWIN-EARTHQUAKES, 21 Mean Duration of the Interval between the two Parts. In British earthquakes the duration of the interval between the two parts rarely exceeds a few seconds in length. Taking, first, the whole disturbed area, the mean duration of the interval was 2-1 seconds in the Derby earthquake of 1904; 2°3 seconds in the Pembroke earthquake of 1893; 2°5 seconds in the Leicester earth- quake of 1893; 3 seconds in the Pembroke earthquake of 1892, the Carlisle earthquake of 1901, and the Derby earthquake of 1903 ; and 3°6 seconds in the Hereford earthquake of 1896. For tho earthquakes of other countries estimates are somewhat rare; but the interval was only a few seconds in length in the Neapolitan, Andalusian, and Rivieran earthquakes. In the Calabro-Messinese earthquake of 1894 five estimates, varying from 1 to 3 seconds, give an average of 2°1 seconds. ‘The Charleston earthquake forms an exception from this point of view; for the two maxima were separated by about 34 seconds at Charleston, and the mean duration of the interval throughout the disturbed area was slightly less than half a minute. Again, the mean duration of the interval varies but little at different distanees from the epicentre. In the central district of the Hereford earthquake of 1896 it was 3:4 seconds, in the sur- rounding zone 3°3 seconds, and in the outermost zone only 4°1 seconds. In the Derby earthquake of 1903, the mean duration was 2°9 seconds within the isoseismal 6, 3°0 seconds between the isoseismals 6 and 5, and 3:0 seconds beyond the latter isoseismal. In the Derby earthquake of 1904 the averages for the corresponding zones were 2°2, 2:0, and 2-1 seconds. In the Neapolitan earth- quake, the duration was 1 or 2 seconds at Potenza, and a few seconds at Naples; in the Andalusian earthquake, 1 or 2 seconds close to the epicentre and in the surrounding zone, and 3 or 4 seconds at Madvrid, distant 170 miles. ‘The slight increase with the distance in some cases is no more than might be due to the gradual extinction of the weak vibrations at the end of the first series and beginning of the second; and it is therefore probable that the mean interval between the maxima of intensity is practi- cally constant at all distances from the centre. Coalescence of the two Parts. While, in most cases, the twin-shock is perceptible over the greater part of the disturbed area, there may exist within it a narrow band along which the two parts are no longer distinctly separated, but coalesce and form a single continuous series of vibra- tions. As the two movements are felt together in this band, I propose to call it the synkinetic band, and the median line of the band the synkinetic line. Such a band probably exists in most, perhaps nearly all, British twin-earthquakes, but in only three cases can it be definitely traced—in the Hereford earthquake 22 DR. CHARLES DAVISON ON [Feb. 1905, of 1896, and in the Derby earthquakes of 1903 and 1904. ‘The band is only a few miles in width, and crosses the central curves at right angles to their longer axes. In the Derby earthquake of 1903 the synkinetic band was straight, and in the other two earth- quakes curved, the concavity in the case of the Hereford earthquake facing south-eastward, and in that of the Derby earthquake of 1904 south-westward. In every case, it is worthy of notice that two maxima of intensity, connected by weaker tremulous motion, were distinguished by careful observers close to the boundaries of the synkinetic band. Sound-Phenomena. As a rule, though not invariably, the sound is heard with each part of the shock; sometimes the shock is not felt, and two sounds are alone observed. The stronger part of the shock is accompanied by the louder sound, but the two parts of the sound differ less in intensity than the two parts of the shock; also, the sound is often heard before and after the shock begins and ceases to be sensible. Thus, when the two parts of the earthquake coalesce within and near the synkinetic band, the sound receives a notable increase of strength over a comparatively-wide region; while the strongest vibrations of the two parts of the shock are of such brief duration that they coalesce only near the synkinetic line. Observations of the reinforced sound are therefore common, and those of the reinforced shock are rare: the result being that the isoseismals show little, if any, deflection near the synkinetic band; while the isacoustic lines (or lines of equal sound-intensity) are so much distorted that they cling to the synkinetic band, and share in its straightness or curvature. LV. Twin-EsaRTHQUAKES CONNECTED WITH A J'win-Focvs. In several earthquakes, the isolation of the two series of vibra- tions has been so marked that seismologists have felt it necessary to offer some explanation of their origin. ‘The brevity of the interval has been tacitly assumed to preclude a repetition of the impulse within the same focus; and the two series have been generally referred to a single impulse, the separation of the earth- waves being effected by subterranean reflection or refraction, or ascribed to the existence of direct and transverse waves. Thus, in the Neapolitan earthquake of 1857, Mallet noticed the difference in direction between the two parts of the earthquake, and regarded the second part as a reflected shock, although he offered a somewhat different explanation for the outlying region of Naples. In the Colchester earthquake of 1884, Prof. Meldola & Mr. White also attribute the second part to reflection ; they consider the existence of two initial disturbances as improbable, although they notice that the distribution of damage to buildings gives the impression that there were two separate foci. Profs. Taramelli & Mercalli suggest Vol. 61. ] TWIN-EARTHQUAKES. 23 that the two parts of the Andalusian earthquake of 1884 were respectively waves of direct and transverse vibrations, and they account for the greater intensity of the second part by supposing that the transverse vibrations were reinforced by reflected direct vibrations. A distinct advance was made, 2 years later, when Major Dutton, relying on the distribution of damage, determined the existence of two foci in the Charleston earthquake of 1886. In the following year Prof. Mercalli, in his investigation of the Rivieran earthquake of 1887, showed that the time-records and the obser- vations on the direction of the shock implied the existence of two submarine foci, one to the south of Oneglia and the other not far from Nice. The same seismologist, in his valuable memoir on the Calabro-Messinese earthquakes, concludes, from the form of the isoseismals and the observations on the direction, that the earth- quake of 1894 also originated in a double focus. I will now give some reasons for believing that this view offers the best interpre- tation of the evidence so far collected. In the first place, twin-earthquakes cannot be generally due to reflection or refraction of the earth-waves at the bounding surfaces of different rock-masses, although here and there the shock may be duplicated in this manner. The wide area over which the twin-shock is almost uniformly felt, shows that it is not a local phenomenon. Theexistence of a synkinetic band, the almost-constant brevity of the interval between the two parts, and the definite law of variation in their relative intensity, duration, and period of vibration, are equally opposed to a haphazard origin. Moreover, on this theory, the first part of the shock should be the stronger, for energy is lost by the reflection or refraction of a wave. And, again, of the earthquakes originating in a given district, a few are twins and the majority simple; yet, according to the explanation here considered, the earth-waves should undergo deflection at the same surfaces on every occasion.’ Nor can the two parts of a twin-earthquake be respectively waves of direct and transverse vibrations ; for, if they were, there would be no synkinetic band crossing the central district, and the relative nature of the two parts would be uniform throughout the disturbed area, Also, the interval between the two series does not increase, as it should do, with the distance from the origin ; at a distance of 170 miles it is only a few seconds, instead of 2 or 3 minutes, in length. The earthquake-sound accompanies both series in precisely the same manner; if the second series consisted of transverse vibrations only, it would be unattended by any sound. Both parts have been felt at sea,” and transverse vibrations cannot be propagated in a liquid. Lastly, if the second series consisted of transverse vibrations, every earthquake would be a twin-earthquake. 1 A few, but by no means all, of the after-shocks of the Andalusian earth- quake of 1884 were apparently twins. 2 In the Rivieran earthquake of 1887, two strong shocks at a few seconds’ interval were felt on board a steamboat, on its way from Genoa to Marseilles. 24 DR. CHARLES DAVISON ON [Feb. 1905, Further, twin-earthquakes are not due to a repetition of the impulse within the same, or an overlapping, focus; for, if so, the order of relative intensity, etc., would not vary in a definite manner throughout the disturbed area, the two parts of the shock would never coalesce, and the mean duration of the interval would not generally be confined between the limits of about 2 and 4 seconds. Thus, as twin-earthquakes are not due to the separation of the waves arising from a single impulse, nor to repeated impulses in the same focus or in overlapping foci, it follows that they must be caused by impulses in two detached, or practically-detached, foci. On this view of their origin, the phenomena described above admit of a ready explanation :— (1) The twin-character of the shock would be perceptible as far as the weaker of the two parts can be felt; and the fact that both parts are sometimes observed over the whole, or most, of the disturbed area, shows that the two initial impulses were of nearly- equal intensity. (2) In the neighbourhood of the epicentre corresponding to the weaker impulse, the vibrations from that focus may be of greater intensity than those from the more distant focus. The stronger impulse does not necessarily occur first; and thus the order of relative intensity may vary in different earthquakes, and in different parts of the disturbed area of the same earthquake. I shall return to this subject in the next section. (3) When, as seems to be generally the case, the interval between the two parts is less than the time required to traverse the distance between the two foci, the two series of vibrations must coalesce at the surface, along a band passing between the two epicentres and crossing the line that joins them approximately at right angles. From the form of the synkinetic band we can determine which focus was first in action. When the synkinetic band is straight, the two impulses must have taken place simultaneously ; when the band is curved, its convexity must face the focus first in action, for the vibratious from that focus have to travel farther before they meet the vibrations from the second focus. V. RELATIONS BETWEEN THE IsosEISMAL LINES IN A Twin-EARTHQUAKE. In a twin-earthquake, observations of the intensity of the shock refer, unless otherwise stated, to that of the stronger part; and thus, when the order of relative intensity varies throughout the disturbed area, the isoseismal lines so determined are a combination of the isoseismal lines corresponding to both foci. In such a case, the isoseismals often present certain features which are characteristic of their origin. Excentricity of the Resultant Isoseismal Lines. In a simple earthquake the isoseismal lines are roughly elliptical in form, their longer axes are parallel, er nearly so, to the strike of Vol. 61. ] TWIN-EARTHQUAKES. 25 the originating fault; and, in the neighbourhood of the epicentre, the distances between successive isoseismal lines are greater on the side towards which the fault hades than on the other side. In fig. 1 (below) the isoseismal lines corresponding to two foci are represented by dotted curves, and the impulses are supposed to differ in intensity, so that while, for the western focus, three isoseismal lines (of Fig. 1.—LEwcentricity of isoseismals in twin-earthquakes. intensities 5, 4, and 3) can be drawn, for the eastern focus there are only two isoseismal lines (of intensities 4 and 3). The resultant isoseismal lines would be drawn in the form represented by the continuous curves. Thus, when the two impulses differ in intensity, as in the Leicester earthquake of 1893, the Hereford earthquake of 1896, the Carlisle earthquake of 1901, or the Derby earthquake of 1904, the most marked characteristic of the resultant isoseismal lines is the excentricity of the inner curve with respect to the others. 26 DR. CHARLES DAVISON ON [Feb. 1905, Divergence of the Isoseismal Axes. The curves in fig. 1 (p. 25) illustrate another peculiarity of the resultant isoseismal lines. If the fault hades in the same direction in both foci, the axes of the resultant isoseismals will be approxi- mately parallel. If, as assumed in the figure, the fault hades to the north in the western focus and to the south in the eastern focus, the isoseismals of the western focus will be farther apart on the north side than on the south, while those of the eastern focus will be farther apart on the south side than on the north. The axis of the isoseismal 5 will therefore be directed eastward and westward, and those of the resultant isoseismals 4 and 3 will run from a few degrees north of west to a few degrees south of east. An example of this divergence of the isoseismal axes will be seen in the Leicester earthquake of 1893, in which the axis of the isoseismal 5 runs from W. 30° N. to E. 30°8., while those of the resultant isoseismals 4 and 3 are, respectively, from W. 40° N. to E. 40° S. and north-west to south-east. Areas of Opposite Relative Intensity. If the vibrations which proceed from the two foci differ initially in their intensity, duration, and period, the disturbed area may be divided into regions in which the order of relative intensity, etc., varies. In the case of the period of vibration, and roughly also in that of duration, the synkinetic line separates one such region from the other. The variation of relative intensity is, however, more complicated, as the intensity of either part depends on the distance from the corresponding focus. In fig. 2 (p. 27) the points A & B indicate the two epicentres, A corresponding to the focus in which the initial impulse was the stronger. The isoseismal lines for each focus are represented, for simplicity’s sake, by circles. At the points where similar isoseismals intersect, both parts of the shock are of the same intensity. The broken line passing through these points thus separates the dis- turbed area into two districts, within the smaller of which the vibrations from the weaker focus are stronger than those from the other. It is evident that the centre of this area does not coincide with the epicentre B, but is displaced on the side away from A; and that its boundary is practically an unclosed curve when the initial impulses are of nearly-equal intensity. The order of relative intensity at any point of the disturbed area depends on the order in which the impulses occur in the two foci, and on the length of the interval that elapses between their occur- rence. Figs. 3-6 (p. 28) illustrate the different cases that may arise. In each of these, the western focus is supposed to be that in which the stronger impulse takes place, while the small circle bounds the area within which the vibrations from the eastern focus were felt more Vol. 61. ] TWIN-EARTHQUAKES. 27 strongly at the surface. The districts in which the first part of the shock was the stronger are shaded by horizontal lines, and those in which the second part was the stronger by vertical lines. If the interval between the impulses be greater than the time taken by the earth-waves to travel from one focus to the other, and Fig. 2.— Variation of relative intensity in twin-earthquakes. the western focus be first in action, the distribution of relative intensity will be that represented in fig. 3. If the eastern focus be first in action, the order of relative intensity will simply be reversed. On the other hand, if the interval between the impulses be less than the time of transit from one focus to the other, a synkinetic band will cross the disturbed area between the two epicentres. In figs. 4-6 the synkinetic line is indicated by the hyperbolic curve. In fig. 4 the western focus, and in fig. 5 the eastern focus, is supposed to be first in action. Fig. 6 represents a modification of 28 DR. CHARLES DAVISON ON [Feb. 1905, fig. 4, in which the synkinetic line intersects the area within which the vibrations from the eastern focus are felt more strongly. It is evident that there is no corresponding modification of fig. 5, for the Figs. 3-6, illustrating different cases of relative intensity in twon-earthquakes, Fig. 3 Fig. 4. boundary of the latter area is always nearer to the eastern than to the western epicentre, while the synkinetic line is always nearer the epicentre of the focus last in action. VI. Etements or tart Twin-Foct. Distance between the Twin-Epicentres. The exact determination of the positions of the twin-epicentres is a problem of some difficulty, and it is only in one or two cases that it has been approximately solved. Major Dutton, in his Vol. 61.] TWIN-EARTHQUAKES. 29 valuable memoir on the Charleston earthquake, publishes two maps of the isoseismal lines which traverse the meizoseismal area, one representing the impressions of Mr. Earle Sloan, who surveyed the district with great care, the other giving his own interpretation of the same evidence. In neither case do the isoseismal lines cor- respond to the degrees of any definite scale of seismic intensity ; but, although differing widely in detail, they agree in their expansion around two small districts which probably represent the epicentres corresponding to the twin-foci. In the Neapolitan earthquake, the distribution of the seismic death-rate gives a fair approximation to the positions of the epicentres. The south-eastern epicentre must be close to Montemurro and Saponaro, where the death-rates were respectively 71 and 50 per cent.; while the north-western epicentre must be near Polla, where the death-rate was about 30 per cent., Polla being 4 miles from the single epicentre ascertained by Mallet from observations on the direction of the shock. More satisfactory materials for the purpose are provided by the Colchester earthquake of 1884. In their well-known report, Prof. Meldola & Mr. White note the existence of two areas of maximum destruction, one near Peldon and Abberton, the other near Wivenhoe and Rowhedge. They also give a table of the places where damage occurred, with the population of each in 1881 and the number of buildings repaired. Assuming that there are five persons on an average in every house, the percentage of houses needing repair may be calculated for each place, and from these may be drawn curves of equal percentages of such houses. In fig. 7 (p. 30) the continuous line represents the isoseismal 8, while the dotted lines are the curves corresponding to percentages of 60 and 30 respectively. As the Colchester earthquake is known from other evidence to have been a twin-earthquake, it is probable that the epicentres are closely surrounded, if not outlined, by the two inner curves of percentage 60. If the innermost isoseismal is excentric, the epicentre correspond- ing to the stronger impulse must be situated close to its centre, while the other epicentre probably occupies a similar position with regard to the centre of the next isoseismal, though perhaps slightly farther removed from it. In this way are determined approximately the positions of the epicentres of the Leicester and Pembroke earth- quakes of 1893, the Hereford earthquake of 1896, the Carlisle earthquake of 1901, and the Derby earthquake of 1904. In the Pembroke earthquake of 1892, the epicentre corresponding to the weaker impulse was probably submarine; while, for the Derby earthquake of 1903, we have to rely upon the form of the inner isoseismals. The following estimates of the distance between the twin- epicentres are therefore only approximate; those for British earth- quakes may err by as much as a mile, the others by even more. The highest estimate is that of about 35 miles for the Rivieran earthquake of 1887; but, in this case, there is some uncertainty as to the position of the secondary epicentre near Nice. In the 30 DR. CHARLES DAVISON ON [Feb. 1905, Neapolitan earthquake of 1857 the distance is 24 miles; in the Charleston earthquake of 1886, 13 miles. Turning to British earth- quakes, the distance is 23 miles in the Carlisle earthquake of 1901 ; Vig. 7.—Map iliustrating the areas of maximum intensity of the Colchester earthquake of 1884. WS Scale of Miles ONS] Pats 3 Manningtree v @ Colchester eee of) bal : / a “ Peaaenee 5 j ey, : or : é & . Rowhedgeo # oWivenhoe or Se Abbertono is i f= ‘A : Peldon: =} S= fy OF ; A Oo; 6 : 5 : 17 miles in the Leicester earthquake of 1893; 8 or more miles in the Pembroke earthquake of 1893; 8 or 9 miles in the Hereford earthquake of 1896 and the Derby earthquake of 1903; 6 or 7 miles in the Derby earthquake of 1904; and 4 miles in the Vol¢r.| TWIN-EARTHQUAKES. 31 Colchester earthquake of 1884. If we may regard the two Leicester earthquakes of 1904 as members of a twin-earthquake, the distance would be about 12 miles; and it is by no means impossible that the Inverness earthquake of 1901 was a twin-earthquake, in which the foci were so close as to give the impression of a double earth- quake with overlapping foci. Hxcluding the two last earthquakes, the average distance between the epicentres of recent twin-earth- quakes in this country is 10 or 11 miles. Form of the Twin-Foci. As a rule, the foci are elongated approximately in the direction of the line joining them. In the Charleston earthquake, the epicentral isoseismals in Mr. Earle Sloan’s map are elongated in the neigh- bourhood of both epicentres. Two of the strongest after-shocks of the Rivieran earthquake were connected, according to Prof. Mercalli, one with the Oneglia focus and the other with the Nice focus ; and the longer axes of the disturbed areas of both are roughly parallel to the line joining the foci. In the Leicester earthquake of 1893 and the Hereford earthquake of 1896, the axes of the excentric isoseismals are nearly parallel to those of the isoseismals which surround them. The Hereford earthquake of 1896, the Carlisle earthquake of 1901, the Derby earthquakes of 1903 and 1904, and probably also the Pembroke earthquake of 1893, were either preceded or followed by shocks which originated in the interfocal region of the fault and disturbed areas elongated in the same directions as the inner isoseismals of the principal earthquakes. It is difficult, therefore, to resist the conclusion that the two foci are portions of one and the same fault. Relative Depth of the Twin- Foci. Though estimates of the absolute depth of the seismic focus are in every case subject to considerable error, there is some reason for thinking that the two foci of a twin-earthquake may be situated at different depths. Major Dutton estimates the depth of the Wood- stock focus of the Charleston earthquake at about 12 miles, and that of the Rantowles focus at about 8 miles. Prof. Mercalli believes that the Oneglia focus of the Rivieran earthquake lay at a depth of about 102 miles; while, from the rapid decay of the vertical component of the motion, he infers that the Nice focus was nearer to the surface. In both these cases the weaker impulse seems to have been connected with the shallower focus. The British earthquakes, in which the innermost isoseismal is excen- tric, apparently lead to a different conclusion. The surrounding isoseismals are not oval in form, and wider in the neighbourhood of the excentric isoseismal than elsewhere, but nearly or quite elliptical. This implies that the intensity of the weaker part of the shock diminished more slowly outwards from the epicentre than 32 DR. CHARLES DAVISON ON [Feb. 1905, that of the stronger part; in other words, that the weaker part of the shock was connected with the deeper focus. Hade of the Fault within the Twin-Foci. On this point we have little knowledge. In the Leicester earth- quake of 18938, the fault hades to the north-east within the north- western focus, and in the opposite direction in the south-eastern focus. In the Hereford earthquake of 1896, the hade within the north-western focus is to the north-east, and within the south- eastern focus probably in the opposite direction. ‘There is, however, no evidence of any such change of hade in the Carlisle earthquake of 1901, or in either of the Derby earthquakes of 1903 and 1904. VIL. Ortery oF Twin-Earrua@vakes. In a simple earthquake, the immediate consequence of the parent fault-slip is a change of stress within and near the focus, especially an increase of stress along its margins. ‘The after-slips conse- quently take place, either in the focal region or just beyond it. Thus, the foci of successive earthquakes are not detached, but are either coincident or overlapping. A twin-earthquake is clearly of a different and more complex origin. Through a single effort, movements occur almost simul- taneously in two distinct regions of the fault ; and these regions are probably situated at different depths, and are separated by a portion of the fault in which there is little or no sensible displacement. Such a movement could hardly be due to an interrupted slip; for this would involve an interval of time between the component slips long enough for the increased stress resulting from the first slip to take effect in the second focus, and therefore longer than the time of transit between the two foci." It would, however, be caused by the growth of a fold cut transversely by the originating fault; a growth that would render the anticline of the fold more anticlinal and the syncline more synclinal, while the middle limb would remain practically undisturbed. The seismic focus would thus consist of two detached portions situated at different depths. Now, in recent British twin-earthquakes, the distance between the epicentres ranges from 4 to 23 miles, and, on an average, is about 10 or 11 miles. If, then, the above explanation be the correct one, this average should not differ much from the mean distance between successive anticlines and synclines. No series of measurements have, I believe, been made of this distance for British crust-folds; but a rough estimate can he obtained from Prof. Marcel Bertrand’s map of the synclinal folds of France. Along several different lines, varying in iength from 127 to 442 miles, the average distance between successive synclines lies between 18 and 24 miles, or the average distance between successive anticlines 1 The Charleston earthquake may have originated in this manner. ‘Vol. 61.] TWIN-EARTHQUAKES. 33 and synclines between 9 and 12 miles. The correspondence with the average distance between twin-epicentres is thus close enough to support or confirm the explanation given. A step in the growth of a crust-fold, such as that contemplated, would leave the middle limb subjected at both ends to increased stresses, which should, after a short interval, be relieved by a slip occupying the whole of the interfocal region, and possibly intruding on the areas of the twin-foci.t As these interfocal slips are simple in character—the shock showing no signs of duplication—it is probable that the movement of the middle limb is one of translation and not, as in the principal displacement, of rotation: as if the growth of the arches were followed by a much smaller bodily advance of the crust-fold. On the view here given, it follows that simple and twin-earth- quakes differ essentially in their origin. A simple earthquake is caused by movements connected with a single system of folding. The Caernarvon earthquake of 1903, for instance, was produced by a fault-slip belonging to the Caledonian system, the Somerset earth- quakes of 1893 and the Exmoor earthquake of 1894 by fault-slips of the Charnian system. On the other hand, the parent-faults of the Leicester earthquake of 1893 and the Hereford earthquake of 1896 belong to the Charnian system, while the earthquakes them- selves were due to the growth of Caledonian folds; and, in like manner, the Colchester earthquake of 1884 and the Derby earth- quakes of 1903 and 1904 were connected with the growth of Charnian folds, the slips taking place along faults belonging to the Caledonian system. Most of the earthquakes felt in this country are thus merely incidents in the growth of faults; and it is surely not without significance that the strongest of all should be mainly due to the con- tinued formation of some of our most important crust- folds. DiscUssION ON THE FOREGOING THREE PAPERS. Prof. Warts, referring to the paper on the Leicester earthquakes, drew attention to the map of Charnwood Forest which he exhibited, and described the general run of the faults observed by himself The normal faults and thrusts on the north-east side of the anticline probably hade to the north-east, while those on the opposite side seem to hade south-westward. But the anticlinal fault which the Author had selected as being the one that probably gave rise to the two Leicester earthquakes might hade either way, and might even hade north-eastward in part of its course and south-westward elsewhere. He further referred to the conversation which he had had with Prof. Lapworth on the third paper, who had pointed out to him how twin-earthquakes occurring along the lines of Charnian * In the Carlisle earthquake of 1901 the interfocal slip occurred after a lapse of 22 minutes ; in the Derby earthquake of 1903 after 40 days, in that of 1904 after less than 8 hours; and, probably, in the Pembroke earthquake of 1893 after 16 minutes. Q, J. G. S. No: 241. D 34 7 TWIN-EARTHQUAKES. [Feb. 1905, faults were almost certainly due to Caledonian movement acting from north-west to south-east. Charnian movement along the same lines would be more likely to produce single earthquakes. In conclusion, he read the following extract from a letter which he had received from the AurHorR :— ‘Having spent the greater part of my leisure-time during the last sixteen years in the study of recent British earthquakes, I propose now to continue my enquiry backward, so as to include all known earthquakes in this country, my objects being to determine as far as possible the distribution of seismic activity in space and time, and to investigate the laws according to which faults grow. ‘T am aware that to recover more than the scantiest data regarding long- past earthquakes is now an almost-impossible task, but an attempt to collect and preserve what is already known seems to me worth making. If any Fellow of the Geological Society should be able and willing to aid me in this work, to however small an extent, or mduce others to do so, I need not say how welcome such help would be. ‘The most useful notes would be those relating to earthquakes before the year 1891, and especially to the Hereford earthquakes of October 6th, 1863, and October 30th, 1868; the earthquakes felt in the North of England on March 15th, 1869, and March 17th, 1871, and in the North-West of Scotland on November 28th, 1880; the Colchester earthquake of April 22nd, 1884; and ‘the Inverness earthquakes of February 2nd, 1888, and November 15th, 1890.’ Vol. 61. | ELEPHAS MERIDIONALIS AT DEWLISH. 39 4. On the OccurRENCE of HLEPHAS MERIDIONALIS at DEwiisu (Dorstt). Srconp Communication: Human AceEncy suc- GESTED. By the Rev. Osmonp Fisuer, M.A., F.G.S. (Read November 9th, 1904.) [Puarss III & IV.] Iw June 1888 I read a paper before the Society on the occurrence of Llephas meridionalis at Dewlish in Dorset.’ Subsequent exca- vations were made by the late Mr. J. C. Mansel-Pleydell, of which he gave accounts in two articles in the Proceedings of the Dorset Natural History & Antiquarian Fieid-Club, vol. x (1889) pp. 12 et seqq. & vol. xiv (1893) pp. 139-41, the second of these being illustrated by photographs of the deposit. Mr. Clement Reid also, in the latter part of 1888, spent four days in investigating the locality, and described it in the Geological Survey Memoir on the geology of the country around Dorchester, 1899. This memoir contains a drawing (p. 35) copied from one of Mr. Pleydell’s photographs. The photographs themselves are now reproduced (Pls. III & IV). It is not necessary to describe the locality afresh, as that has been done already by Mr. Pleydell and by myself, and subsequently very clearly by Mr. Reid. The distant fence shown in Pl. III is on the brow of the hill, and the early finds were made just beyond it. ‘The deposit was then opened on the opposite side of it, where the pelvic bone lies, the fence being left intact. The trench was afterwards followed for about 103 feet, until it suddenly terminated in a smooth ‘apse-like’ end.” The photograph showing the pelvic bone (Pl. III) was taken from the farther end, looking about due north-west towards the brow of the hill. Both the views seem to show a quantity of straw lying about, which, with the hurdles, had probably been used to protect the bones. The site in which the elephant-remains were found has some very remarkable features. It was a deep and narrow trench, with nearly-vertical sides of undisturbed Chalk. Mr. Reid says: ‘The fissure (or rather trough) ended abruptly | Pl. IV], without any trace of a continuing joint; it was not a fault, for the lines of flint-nodules cor- responded on each side. As deep as the excavation was carried it was still in dust-like sand.’ ° This description agrees with what I saw at my last visit in September 1889. The pelvic bone shown in the photograph (Pl. IIL) was then lying where it is represented. When the trench was dug out by Mr. Mansel-Pleydell, it does not appear to have been bottomed, the examination having been carried down to about 10 feet. But in my memorandum of 1887, when I investigated the section on the hillside, I noted that the 1 Quart. Journ. Geol. Soc. vol. xliv (1888) pp. 818-28. 2 Teste Mr. Reid. , 3 *Geology of the Country around Dorchester’ Mem. Geol. Surv. (1899) p. d4. p2 36 THE REV. 0. FISHER ON THE OCCURRENCE OF [ Feb. 1905, base of the deposit was a smooth surface of Chalk, and Mr. Reid found it to be about 12 feet deep at this spot. It seems impossible to account, by any natural agency, for such a trench as this on a Chalk-plateau. A stream in such a locality would be unlikely to excavate a deep and narrow channel, much less, if it did so, would it come to an abrupt ending. And, even if we could account for the natural formation of such a trench, how came it that the remains of so many ae were found in it, and (so far as appears) of no other animals ? I have seen in a popular magazine a photograph of a trench, dug and covered with boughs, intended for the capture of elephants ; and this has led me to think that the trench at Dewlish may have been made by primitive men for the same purpose. Unfortunately I cannot recover the reference to this article. Sir Samuel Baker describes this method of taking elephants by natives of Africa.” He says that an elephant cannot cross a ditch with hard perpendicular sides, which will not crumble nor yield to pressure. Pitfalls 12 to 14 feet deep are dug in the animals’ routes towards drinking-places, and covered with boughs and grass. The pits are made of different shapes, according to the individual opinions of the trappers. When caught, the animals are attacked with spears while in their helpless position, until they at last succumb through loss of blood. Their flesh is eaten. The way in which they are cut up, and the flesh dried in strips, is illustrated in Mr. A. H. Neumann’s ‘ Elephant-Hunting in Kast Equatorial Africa’ 1898 (pp. 108 & 178). Probably in primitive times their flesh, and not their ivory, was the object for which they were killed.” If the stream which now runs at the bottom of the hill, despite subsequent changes in the contour of the country, already existed, then this trench would have been made in a position suitable to intercept the route to a drinking- place. There seems to have been hitherto no conciusive evidence that man was contemporary with Hlephas meridionalis in this country. Mr. W. J. Lewis Abbott has found what he believes to be worked flints in the Forest-Bed of Cromer, and he has kindly permitted me to examine them. They have also been found by Mr. Q. A. Shrubsole and by others. They have certainly been flaked, but whether artificially or not, it is difficult to determine. In the ‘Globe’ newspaper, however, of August 16th, 1895, reference was made to the discovery, by Prof. Marcellin Boule, at Tilloux (in the Charente), of a large number of fossil remains of elephant, rhinoceros, bison, and hippopotamus, together with flint-implements and utensils.” The diagram in my paper of 1888 (p. 819), having been drawn before the deposit had been further examined, is incorrect, for it 1 «Wild Beasts & their Ways’ vol. i (1890) pp. 95 & 98. 2 See, however, W.J. Lewis Abbott, Proc. Geol. Assoc. vol. xi (1891) p. 479, although this relates to E. promigenius. 8 See also ‘L’Anthropologie’ vol. vi (1895) pp. 497-509. Prof. Boule now thinks that the elephant of Tilloux is Hlephas antiquus, not meridionalis (as stated in the ‘ Globe’), and expressed himself to that effect at the International Anthropological Congress, held at Paris in 1900. Woll61.| ELEPHAS MERIDIONAL/S AT DEWLISH. OT represents the deposit as clinging to the face of the hill, whereas in fact the steep scarp cuts diagonally across the trench, and the remains of elephants were abundant at that spot, where the early finds were made. It is very remarkable that the surface of the ground here appears not to have been appreciably lowered by denudation since the Pliocene Period, unless Hlephas meridionalis lived on much later in this neighbourhood. ‘The trench is on a watershed, which may possibly help to account for this fact. The position of the trench, cut across diagonally by the scarp of the hill, is peculiar. It seems possible that, if the trench was artificial, this may have been intentional, because it would permit the dug-out stuff to be taken to the open end, and tipped down the hill, and so obviate the necessity of throwing it up along the sides of the pitfall. The diagonal position would also have been suitable, because, if it had been cut perpendicular to the brow of the hill, it would not have intercepted the animals going to their drinking-place ; while if it had been parallel to the scarp, it would not have enabled the earth to have been conveniently taken out. The ‘ dust-like’ sand is perhaps blown sand. Chalix-plateaux in the neighbourhood are, in some places, covered with a sand which is probably of the age of the London Clay. The large amount of flint-gravel may be a subsequent drift from the plateau-gravel, which occupies considerable areas in the district. In fact, there are many problems yet to be solved in connection with the trench at Dewlish: but my object is to suggest that we have here the earliest record yet discovered of the human excavator and trapper as an intelligent and social being, capable of combined labour; and I think that this hypothesis ought not to be rejected, until some more plausible explanation of this remarkable trench and its contents can be offered. © | EXPLANATION OF PLATES III & IV. [The original photographs were taken by Mr. Nesbitt, of Blandford, in 1891.] Puate IIT. The elephant-trench at Dewlish, looking north-westward. Puate IV. The same, looking south-eastward. Discussion. The Presipent regretted that the Author, who for so many years had contributed papers to the Society, was unable to be present on this occasion. The paper was reaily an addition to one which the Author had previously read to the Society on the Dewlish Elephant- Bed ; since the publication of the former paper new facts of interest had come to light, which were now recorded. 38 ELEPHAS MERIDIONALIS AT DEWLISEH. [ Feb. 1905, Dr. Henry Woopwarp said that he was glad to notice among the exhibits upon the table some eoliths, collected by the Author from the vicinity or from the trench in which the remains of Klephas meridionalis were discovered ; as, if this elephant had been really a contemporary with early man in Britain, it would be Holithie man whose weapons we should expect to find. Hitherto, how- ever, there had been no evidence to show that man was a con- temporary of HH. meridionalis, which was a Pliocene species of proboscidean. He was struck by the narrowness of the trench in which the bones were found, and doubted whether a full-sized elephant would have fallen into so narrow a ‘< pitfall.’ Mr. Hupiesron enquired whether the remains of many elephants were found in the trench. He had understood hitherto that the remains of only one elephant had been discovered there. From what he had seen of the trench he certainly would never have imagined that it could be of artificiel origin. He pointed out that the fall of bones of animals into clefts or fissures in the rocks of the district was no uncommon phenomenon, and it was frequently observed in connection with the Portland Limestone. There was no reason why the same should not also happen in the case of the Chalk. Prof. Sottas thought that the excavation presented a very artificial aspect, but wished for better evidence of its contem- poraneity with the elephant. The flint to which special reference had been made certainly appeared to be an ‘eolith,’ if oy that term the exclusion of human agency was implied. [ Postscript To THE Discussion. | [In reply to Mr. Hudleston’s enquiry as to the number of elephants, the AurHor points out that nine molars are preserved in museums, and two tusks of different individuals. Many detached plates were also found and much scattered ivory. The heap of white material, shown thrown together in Pl. III, is doubtless ivory. It is said that ‘ eoliths’ were exhibited by the Author: he did not doso wittingly. His specimens were intended to show the character of the gravel with which the trench was found filled up.— November 25th, 1904. | ‘ Vol. 61.1 SARSEN-STONES IN A OLAYPIT. 39 5. SarsEn-Sronus i a Cuaypir. By the Rev. HE. C. Spicur, M.A., F.G.8. (Read November 9th, 1904.) Mipway between High Wycombe and Princes Risborough, above Bradenham, 630 feet above sea-level, there is a plateau which is deeply entrenched by transverse valleys running to the Thames, towards which the plateau is inclined in accordance with the dip- slope. On riding from Lacey Green to Nap Hill through cultivated country plastered by the usual ‘ Clay-with-Flints, it appears Sarsen-stone embedded in clay, at Walter's Ash. surprising to find suddenly in the corn-fields a row of brick-kilns in full operation, among heaps of white stones symmetrically cut into kerbstones and paving-setts, with scattered mounds of white débris, pointing clearly to some features of great geological interest. The principal pit from which these materials are taken exhibits a structure in remarkable contrast with the surrounding country, as will be seen from the accompanying photograph, which shows a large sarsen-block measuring more than 10 feet across, embedded in a fine, clean, tenacious, grey and reddish clay. On the opposite side of the pit, which is about 40 yards across and roughly circular, another large stone (half uncovered) lies near 40) THE REV. E. C. SPICER ON [Feb. 1905, the surface, and slopes towards the centre of the pit. In the fore- ground is seen what the workmen call the ‘rock,’ forming a containing-wall for the clay in which the sarsens are embedded. There is no gradation from the ‘rock’ to the fine clay, and the line of demarcation is clear and hard, the large unworn flints in the * rock’ never protruding into the sarsen-clay, which is free from the admixture of any kind of pebble. It cuts as clean as a cheese. The large flints in the ‘rock’ are pressed back into it and form a hard, smooth, limiting surface. When the workmen reach the ‘rock ’ they know that profitable operations are over in that direc- tion, and follow the ‘head’ of clay elsewhere. This ‘ head’ ot clay with sarsens sometimes reaches a depth of 50 feet from the surface, as the present pit 1s expected to do. At a depth of 30 feet a large block estimated to weigh 50 tons is now being quarried for use in building operations at Windsor Castle. This block is the usual white saccharoidal sandstone with a siliceous cement, and shows no structure except on the weathered edges. In the centre of the pit, another large stone is known to lie under the clay, some 40 feet from the surface. There is a horizontal band of smaller sarsens, measuring 14 to 2 feet across, extending athwart the pit above the large blocks. Some 6 feet above them a short band of smaller sarsens, curiously blackened, les about 3 feet from the surface, looking like remnants of old workings. On the opposite side of the pit appears a long disc-shaped band of fine gravel in clay, bounded above and below by a layer of coarse worn flints and containing a lenticular sarsen of small size. Midway between these and on the same level is a larger Su Dames sarsen, measuring more than a yard across, containing a ‘ pot-hole.’ There are therefore in this pit (as in all those adjoining) three distinct formations :— (1) The ‘rock,’ or containing-wall, consisting of the ordinary Clay-with-Flints of the country, the flints being large and unworn. (2) The fine clay from which the bricks are made, containing the huge blocks of tumbled sarsens (one of which is said to have ag hot over 200 tons); and on the summit of this fine grey or reddish, homogeneous, tenacious clay there is :— (3) A thickness of roughly- -mingled material, containing hori- zontal bands with worn flint-pebbles and drifted sarsens of smaller size. Further enquiry and observation revealed a remarkable fact. Each ‘head’ of clay would fit roughly into a kind of crater or funnel-shaped depression in the containing ‘ rock’ of clay with large unworn flints, so that if the pits remained open after working had ceased and the pit-owners were not obliged to fill them in, the ground would present a kind of lunar surface pitted on the plateau with a number of irregular conical depressions, having hard smooth sides consisting of large flints thickly embedded in clay. The explanation, QUART. JOURN. GEOL. Soc. VoL. LX], PL. III. Benzrose, Collo. \ er =e St FT ™ ; She ieee Sea Be 1891. LOOKING N.W, ae 2 a S iu a - < a6 O Z ff of i + Z < r ise mm i uw mi ae kK sbitt, Photo. € iV in i Quart. JOURN. GEOL. Soc. Vot. LXI, PL. Ill. Bemroseé, Collo. Nesbitt, Photo. 1891. LOOKING N.W, THE ELEPHANT-TRENCH AT DEWLISH, i oe 08 pen Sls, Merle ‘168L “A'S ONINOOT “HSIIMAG LV HONSYL-LNVHda7a AHL "ON702) ‘ISOLMLIT > zi Q. 2 al Ai O > 3 O OG? =f & Ae Se Pe eth rw ee Vv 1891. ui o o Zz Zz fe) fo} a x a a = mf a k < = ° Zz Ww cc i = Zz 4 ae a Ww Z| Ww Ww x= = Vol. 61. ] SARSEN-SLONES IN A CLAYPIT. 4] then, seemed clearly that we are dealing here with swallow-holes formed by underground solution in the Upper Chalk. The flints . sank downward by superincumbent pressure against the sides and bottom of each, and the inflowing ooze of wet clay gave way beneath the heavy sarsen-blocks, which sank deeply into it. For the sarsens in clay show this remarkable arrangement :—They slope on all sides towards the centre of the pits, and at the bottom they are horizontal, and the quarrymen work the pits with this observed fact to aid them. The original containing-walls of the swallow-holes were Chalk-with-Flints, that by process of dissolution became Clay-with-Flints, the flints (large and unworn, having been subjected to no detrition by movements over any but a very small area) remaining in situ, like the flints found at the base of the Thanet Sands, which were clearly never deposited by marine action, but simply ‘remain’ in their old position while the chalk that contained them has disappeared. In conclusion, I wish to express my thanks to Mr. Bristow, under whose direction the pits are worked, for the help which he ccurte- ously afforded me in the pursuit of my investigations. Discussion. Mr. Barrow drew attention to the deep cuttings on the new railway between Uxbridge and High Wycombe. Near Gerard’s Cross the lowest Tertiary deposits (Woolwich and Reading Series) were exposed, and one here saw that a bed of white sand, when followed to a sufficient depth, passed first into isolated and rounded blocks of nearly-white sandstone, and finally into a solid bed. This material was almost certainly the same as that exhibited by the Author. It was clear that this bed, when near the surface, decomposed into loose sand more rapidly than ordinary denudation could remove that sand. ‘Thus the solid bed could never be found in a natural outcrop. But under special conditions, when these beds had once formed a continuous thin sheet above the Chalk, powerful floods or ice in motion had swept away the loose sand and picked up the remaining hard cores, involving them in the general mass of Drift of the country. The truth of the Author’s explanation of the inverted-cone shape of the hollows in which the sarsens were found, namely, that they were essentially swallow-holes in the Chalk, was firmly established by the cutting a little farther west of Gerard’s Cross. There a continuous series of these inverted cones (swallow-holes) had been cut open, and the basement-beds of the Tertiary rocks passed alternately over the edges and down to the apices of these cone-shaped hollows. Seen from a distance, the beds overlying the Chalk seemed as if they had been affected by some powerful earth-movements. The sections were so striking that they ought to be photographed. 42 SARSEN-STONES IN A CLAYPIT. [ Feb. 1905, Mr. Wartaxker said that, 40 years ago or so,' he had published a brief description of pits like those now described by the Author, and they were then, as now, worked for the greywethers which were used as building-material for Windsor Castle. The source of such greywethers was not confined to one horizon of the Lower Tertiary, and he had actually seen Eocene sandstone of Reading age in place. He thought that no other explanation of the facts than that given by the Author would hold good. Prof. Sorzas said that he had visited the pits described, under the guidance of the Author, and was glad to be able to concur with him in his conclusions as to the history of the sarsens. He thought that the more superficial deposits of the pits might require further ex- planation, and would not be surprised to find that ice in some form had played a part in their formation. Mr. W. P. D. Sressine, in commenting on the paper and on Mr. Barrow’s remarks, mentioned that the irregular dissolution of the Chalk of the North Downs (as seen in sections at Tadworth on the Chipstead-Valley Railway) had caused the Lower Tertiary formations above to sink into the hollows between the upstanding pinnacles of Chalk, and so, in the long railway-cutting, to give the effect of a wave-like contour to these beds. He also mentioned the eutting-through by this railway of a small bowl-shaped mass of pure white sand, which under certain past conditions might have been cemented into a sarsen-stone, and then would have occurred in the section just as those observed by the Author in the Chilterns. Dr. Satrer referred to similar deposits at Hyde Heath, near Chesham, in which big polished blocks of pebbly greywether are found. At Ayot Brickyard (Hertfordshire), the Kocene deposits dip down into huge pipes in the underlying Chalk. [1 ‘Geology of Parts of Middlesex, Herts, Bucks, &c.? Mem. Geol. Surv. (1864) pp. 66, 71. ‘se Sir Joseph Prestwich regarded the greywethers of this region in Buckingham- shire as belonging to the Reading Series. He mentioned that ‘on the Chalk- hills above Bradenham, 3 miles northward (of High Wycombe), sandstone- blocks are very numerous, and, although enveloped in a ferruginous clay- drift, they are, I believe, nevertheless, nearly iz situ.’ In a footnote he specifies Walter’s Ash and Napple Common Quart. Journ. Geol. Soc. vol. x (1854) p- 127.—Ep.] Vol. 61. | THE OSSIFEROUS CAVERN AT LONGCLIFFE. 43 6. On an OssIFEROUS CAVERN of PuiEtsrocenr AGE at Hon-GRANGE Quarry, Lonectirre, near Brassineron (Derpysuire). By Henry Hower Arnotp-Bemross, J.P., M.A., F.G.8S., and Epwin Tuttey Newton, F.R.S., V.P.G.S. (Read November 23rd, 1904.) [Puares V—-VITII.] CoNnrTENTS. Page Ape co CHE LION) aera ney acts Gute ca sion aactetss setceralnagt sescieindcoees += 43 II. The present Physical Conditions of the District, and a Deseription.ot the Qmanny (5c sesso tees eee ence 44 III. The Method of Working the Deposits, and the Results COIDUEUIOVETS a A A ne heln Suen RRCCHE Seon Tm eri OREM ERE cima: IV. Description of the Mammalian and other Remains ......... 48 Wee tabulation ofthe Specimens: 3).22.0.40ig-c se. dess es -cnececes- oe 59 Wiles (COmaGITENOLIN Je (Aa ne ose Gove UR ieee nee mR reo 61 I. Lyrropucrioy. : In April 1902, the south-south-eastern end of a cavern in the Hoe- Grange Quarry was broken into, in the course of the quarrying- operations (P]. VI). ‘The discovery was first made known to us by Mr. J. Ward, Curator of the Cardiff Museum, who was formerly a resident in Derby, and has worked out several caverns in the neighbourhood. One of us visited the quarry on April 26th, 1902, and subsequently, through Messrs. Holland & Rigby, solicitors (of Ashbourne), obtained leave from Major Nicholson, the owner of the quarry, to work the deposits on behalf of the Derbyshire Archeological & Natural History Society. The owner stipulated that the cavern should be worked in such a manner as would secure the largest amount of evidence possible under the circumstances. In company with Mr. C. Fox-Strangways we visited the quarry, and found that the cavern had been indiscriminately worked in the upper part, above the line AB in the horizontal section (Pl. V, fig. 1), for a distance of 34 feet north-north-west of the point where the quarrymen had first broken in at the south-south-eastern end. Our thanks are due to Messrs. Shaw & Lovegrove, the lessees of the quarry, who did their best, before we took the work over, to secure and retain, as far as they could under the circumstances, specimens which had been obtained. By this means they supplied us with 1577 spe- cimens, and we subsequently recovered other 679 specimens from the tip-heaps. Some of these were obtained by sifting the deposit in water; others were picked out by the quarrymen. All these specimens have been labelled ‘ General,’ because they were obtained previous to the time when we worked the cavern systematically (Table I, col. G, p. 58). As soon as the discovery became known, the locality was visited by numerous ardent collectors, some of whom came even at night- time; and many specimens were taken away, despite the efforts made 44 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN | Feb. 1905, by Messrs. Shaw & Lovegrove to prevent their loss. The foreman, Mr. George Walton, rendered us very great help, and so far as possible arranged the work of the men under him to suit our requirements. Messrs. Shaw & Lovegrove also provided quarrymen and labourers to carry on the excavations, which were paid for from funds collected mainly from Derby, Buxton, Bakewell, and Matlock. The excavating-work was for the most part carried out under the direction and supervision of one of us; but Mr. Storrs Fox, of Bakewell, visited the cavern a number of times in 1902, and on several occasions superintended the work. In July 1902, we decided to suspend operations until the quarry- face had been worked farther back, parallel to the length of the cavern, in order that the deposits might be worked at a lower level than that of the line AB in the horizontal section (PI. V, fig. 1). II. Tur present Puysican Conpirrons oF THE DisTRICT, AND A DescRIPTION 0} THE QUARRY. The Hoe-Grange Quarry (6-inch Ordnance-Survey map, XXXIII S.E.; l-inch Geological-Survey map, 72 N.E.) is close to the High Peak Railway, about a quarter of a mile north-west of Longceliffe Station (which is on the road from Matlock to Ash- bourne) and a little more than a mile north-west of the village of Brassington. It is situate on the south-eastern portion of the Mountain-Limestone plateau, which extends from near Wirksworth on the south-east to Buxton on the north-west, at a height varying from 1000 to 1200 feet above Ordnance-datum. ‘This portion of the plateau forms the water-parting between the rivers bradford and Wye, tributaries of the Derwent near Darley Dale, on the north-east, and Bletch Brook, Bradbourne Brook, and Bentley Brook, tributaries of the Dove near Ashbourne, on the south-west. The quarry is being worked back into the south-western slope of the plateau. The bottom of the quarry (into which runs a siding from the High Peak Railway) is 1090 feet above Ordnance-datum, and the top of it is about 30 feet higher. If we stand on the top of the quarry, it is obvious that we are standing on the edge of the limestone-plateau, and that the quarry is cut in the south-western face of a small knoll or hillock on that plateau. It is separated from another knoll on the north by a small - depression, which widens out into a valley lower down on the south- western slope, and from Harbro’ Rocks (1244 feet above Ordnance- datum) by a small depression at Longcliffe Station, which point forms a coi at a height of 1057 feet above Ordnance-datum. The upper beds in the quarry consist of cherty limestone, and the lower ones of more massive limestone. Some portions are completely dolomitized along the joints; but the lowest bed is a pure white limestone, used for making limestone-setts. The highest point of the hillock in which the quarry is situate is about 30 feet higher than the top of the swallow-hole mentioned below, and is a short distance nearly due east of it. Vol. 61. | OSSIFEROUS CAVERN AT LONGCLIFFE. 45 There are several joints in the quarry which run in a north-north- westerly and south-south-easterly direction. The cavern is evidently a master-joint enlarged by the action of water. A joint, 5 feet to the north-east of the cavern and farther back in the quarry, was found after our first year’s operations, but no bones were discovered in the clay with which it was filled. II. Tar Meruop oF Workine THE Deposits, AND THE ReEsuLrs OBTAINED. Before the cavern was discovered, various parts of the quarry, including that in which the cavern was found, had been let on ‘bargain’ or piecework to the quarrymen. We had, therefore, to carry on the excavations in such a manner as to fall in with these arrangements, by first removing a portion of the deposit from the cavern and then allowing the men to remove the cavern-wall up to the point to which we had worked. Careful measurements were | made and levels obtained during the progress of the work, and such bones from each layer or part of the cavern, -as it seemed neces- sary at the time to keep separate, were packed in different boxes. During 1902 we explored the upper part of the cavern, above the line AB in the horizontal section (Pl. V, fig. 1), and during 1903 the part below this line. Previous to our first visit to the cavern, the deposits had been indiscriminately worked to a distance of 34 feet from the point where the men first broke into it, and to a depth of about 9 feet below the cavern-roof. The outer or south-western wall of the cavern to this depth, and for a distance of about 27 feet, had’ also been quarried away. At our first visit, therefore, the cavern- entrance was 27 feet from the point where the men broke in, and the deposit had been cleared away from what was then the inside of the cavern for some 64 feet in a north-westerly direction. We commenced operations by fixing a wooden door (Pl. VI, fig. 1) at the entrance to keep out intruders, had the face of the deposit cleared, and obtained the following section :—- SECTION MEASURED oN May 131, 1902. 63 feet north-north-west of the wooden door, and above the line AB in Pi Vi, teas Feet inches. No. I. Layer of surface-soil, with angular fragments of limvesrone aiditew DOMES! -a 45-4202. steenaciesoteeen += 0 6 No. II. Yellowish sandy clay, showing traces of lamination I ANGECOMPAITMMEADOMES) 1, sa.c ott een sects «pets faves some’ 2 0 No. III. Breccia, rich in bones; consisting of bones and lumps of limestone, often cemented into a hard mass, especially on the south-west side of the cavern ; softer on the north-west side ............... 2 0 No. IV. Clay, with large angular blocks of limestone and ISOLIGS) Asch Ss eb Su SdaA Rot Gee Sue peeUs Beare ane caaneenn nes IL 2 No. V. Dark moist clay, with few bones; bottom not MC AIC HVE (lure neaa een een evan ae LEE wheat sk sds sds e oe ukO 8 46 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN [Feb. 1905, Layer No. I (Pl. V, fig. 1) was here 2 feet 5 inches below the roof of the cavern. ‘he layers were not horizontal, but dipped south-south-eastward, so that as we worked farther into the cavern towards the north-north-west they rose, and at a distance of 15 feet from the door layer No. I was touching the roof. These layers, with the exception of No. V, were traced to a distance of 18 feet from the door. They then became so indistinct that it was impossible to t ace them farther. At 20 feet from the wooden door we reached the fissure or swallow-hole. The 142 bones from these 2 feet (namely, between 18 and 20 feet from the door) were therefore kept separate (Table I, col. 8, p. 58). The 2 feet of deposit (measured horizontally) consisted of clay with bones and large angular blocks of limestone. At a distance of 16 feet from the door we found a layer of stalagmite, 1 to 3 inches thick, and below it an angular limestone-gravel cemented together in places by carbonate of lime. Neither of these layers contained bones; but 138 bones were obtained from the clay immediately above the stalagmite, and, as we could not correlate this clay with any of the other layers, the bones from it were kept separate (Table I, col. 6). The stalagmite-layer extended for a distance of about 12 feet to the north-north-west: at 16 feet from the door it was 3 feet below the top of breccia No. III. As the breccia was 2 feet thick and layer No. V was 14 inches thick, this layer No. V had apparently thinned out. Layers Nos. 6 & 8 were very near together, the bones from No. 8 being obtained from a place about 2 feet above those from No. 6. Entrance or Swallow-Hole. The width of the swallow-hole, which communicated with the eround-surface near the top of the quarry, measured in the same direction as the length of the cavern, was 74 feet; and from this 980 bones were obtained (Table I, col. 7), all above the line AB in Pl. V, fig. 1. The upper part of the material filling the hole consisted of large masses of cherty limestone with clay, and rested upon the stalagmite (Table I, col. 6) to the south-south-east. In the north- north-western portion of the swallow-hole only three layers could be distinguished, namely, (1) clay, (2) clay with bones, and (3) gravel (angular). The layers in the swallow-hole formed a slight anticline, dipping south-south-eastward and north-north-westward. To the north-north-west of the swallow-hole only about ten bones were obtained ; the deposits in that direction consisted of clay with large blocks of limestone, and a hard rubble with pieces of chert. Some 17 feet north-north-west of the swallow-hole, the cavern narrowed to a width of 2 or 8 feet, and a short distance farther on died out into a small joint. A ground-plan of the upper part of the cavern, along the line AB in the horizontal section, is reproduced in Pl. V, fig. 2. Wolk; 6x.) OSSIFEROUS CAVERN AT LONGCLIFFE. AT Lower Level, below the line AB. (PL. V, figs. 1 & 3.) In 1903, after the whole of the upper part of the cavern above the line AB had been removed, we proceeded to work on the lower level, between the lines AB and CD (PL. V, fig. 1), commencing at the south-south-eastern end. A number of bones were found under the spot where the wooden door had been fixed in the previous year. Although we could not definitely trace the connection, this deposit seemed to be part of the upper layers Nos. I & V, if indeed it was not really a part of No. V. North-north-west of this point (below the door) no bones were obtained, until we had worked 45 feet to the north-north-west; then a number were found in a clay (No. 11), which was above another bedded clay (No. 12), dipping at a high angle, underneath which was a well-bedded sand (No. 13), abeut 5 feet thick. Under this sand was a deposit of black * wad’ (No. 14). This ‘ wad’ was worked down to a depth of about 15 feet, and was found to rest upon a clay (No. 15). ‘The other parts of the cavern at the lower level, except those just mentioned, were filled with clay and rubble, and contained no bones. Near No. 11, beneath the bone-bearing beds, were found lumps of breccia with Helia- shells, and also a number of concretions of magnesian limestone. We believe that such concretions have never been found among the dolomitized limestones of the district, and may therefore have come from a distance. An examination of the horizontal section and the two ground-plans (Pl. V, figs. 1-3) shows that the cavern was about 120 feet long, and that at both ends it narrowed down to a, vertical joint at the level AB; also, that at the south-south-eastern end this narrowing continued at the lower level CD, but that the cavern did not thin out so rapidly north-north-westward at the lower level as it did at the higher one. In the wall of the fissure at the south- south-eastern end of the lower level, about 6 feet north-north-west of the place where the cavern was first broken into, fifty bones were found, consisting mainly of rabbit, with only one bone of a carnivorous animal, nameiy, Hywna. It is impossible to correlate these few bones with those from the other layers, so we have placed them separately in Table I, col. 10 (p. 58). The bottom of the cavern was reached at the south-south-eastern end, but deepened north-north-westward to an unknown extent. It was found possible, for economic reasons, to trace the beds at the north-north-western end of the cavern some 15 feet into the wad. But, as very few bones were found in the layer between AB and CD, and none in the deeper excavations at the north-north-western end, it was decided not to continue the exploration any farther. Summary of Results. Although the rubble and clay in many parts of the cavern showed no signs of stratification, there appear to have been three distinct groups of deposits. The upper deposits, which include layers I to 9, contained by far the majority of the bones. They were probably 48 MESSRS, ARNOLD-BEMROSE AND NEWLON ON AN { Feb. 1905, introduced mainly through the swallow-hole. The second group of deposits, consisting of clay and rubble, with a few bones in places (No. 11), was below the first group. The third and lowest group, found to the north-north-west, consisted of bedded clay (No. 12), sand (No. 13: quartz-grains, well rounded), and wad (No. 14); the whole dipped at an angle of 40° to 45° south-south-eastward, and contained no bones. It therefore seems that there were three main groups of deposits which were formed at various times, although there is no break of continuity between them. Some of them probably found their way through the master-joint at different points. We cannot say definitely which is the oldest deposit, though trom their relative positions it seems probable that the ‘ wad,’ sand, and bedded clay were deposited first from a north-north-westerly source; that from a somewhat similar source, or from numerous openings along the joint, the clay and rubble were introduced, and augmented by blocks which fell from the roof of the cavern from time to time; and that finally, at a later period, the majority of the bone-bearing beds were deposited, mainly through the swallow-hole. IV. DescriprTion oF THE MAMMALIAN AND OTHER REMAINS. - Carnivora. Fee iEo, Linn: idiom), (ely Viienes al) Among the many mammalian bones which have been recovered from this cave none, perhaps, are more interesting than those of the lion. One of these specimens is the ramus of a lower jaw of a young animal, and besides this there are parts of the fore and hind feet of one or more adult animals. The first-named specimen is an imperfect left ramus, with the milk-molars 3 and 4 still in place (Pl. VII, fig. 1), the latter showing the characteristic small, adpressed, hinder cusp. The germ of the first permanent molar (or carnassial tooth of the adult series) is to be seen within the substance of the jaw. ‘The foot-bones indicate a big animal ; but they are not so large as those figured by Prof. W. Boyd Dawkins in the Palewontographical Society’s Memoir. Two metacarpals, a cuboid, and an astragalus have each the characteristic feline form, and a penultimate phalange shows the hollowed side for the retracted claw. These remains can be unhesitatingly referred to the lion. Some of these leonine bones were obtained before particular notice had been paid to the different layers in the cave; but others were met with, deep in the undisturbed beds: one specimen was found in layer No. IV and others in the lower stratum, below the door, No. 9. (See the horizontal section, Pl. V, fig. 1.) Feuts catus, Linn. (Wild Cat.) (PI. VU, figs. 2 & 3.) Remains of the wild cat are known to occur in British caves, but they are by no means of common occurrence. It is interesting, Vol. 61.] OSSIFEROUS CAVERN AT LONGCLIFFE, 49) therefore, to find among the Longcliffe specimens several limb-bones referable to this species. Although no teeth or parts of the skull were met with, the limb-bones are unmistakably those of a cat. The straight femur, the angular shaft of the tibia, the perforated humerus, as well as the forms of the metatarsal and metacarpal bones, agree precisely with the corresponding parts of a large cat. These bones are much bigger than those of an ordinary domestic cat; but they agree in length and form with those of a male Kuropean wild cat in the Museum of the Royal College of Surgeons.' They are, however, much stouter, and indicate an animal of very robust proportions. The bones which have been recovered are parts of a humerus, a radius, an ulna, and a metacarpal, also an ilium with the acetabulum, two femurs, a tibia, and two metatarsals. MEASUREMENTS OF THE Femur AND TrpBia or tHE WILD Cart, IN MILLIMETRES. Bemur) ereatest lengths... Jc. d.tsceteeraed soe 136°6 Do. least circumference ..............sceeee: 30'0 Miia, erreabest (OMe, «4. cdcnclewee vcicideie onicis smens 146°0 Do» least GMCUMECTERECE .....0cccseccceceevese 31:5 It is just possible that these bones belonged to one animal, and they were all found in the lower stratum; but, seeing that some of them were found towards the south-south-eastern end (No. 9), and others towards the north-north-western end (No. 11), that is, 45 feet apart, this is uncertain. Besides the above-mentioned bones of wild cat, there is one ulna of a much smaller cat, which was found above the stalagmite-floor (No. 6), that is, some 13 feet above the wild cat’s remains. Hyana crocura, Erxleben. (Spotted Hyzena.) The remains of Hyena are much more abundant in this cave than are those of any other carnivore; indeed, if we except Bos and Cervus, Hyena is better represented than any other genus. Portions of jaws, teeth, and bones from all parts of the skeleton have been obtained, some in a very perfect condition, as well as coprolites; but the latter not very abundantly. Further evidence of the presence of living hyznas is to be seen in the gnawed bones of other animals which have been found. The hyzna-bones themselves need no special description: they evidently belong to the form so generally met with in caves, which has been called Hycna spelea, but is now believed to be the same as the living African spotted form, Hyawna crocuta. Remains of Hycna have been met with in all parts of this cave where bones have been found, and in every layer between No. I and No. 11. Canis Lupus, Linn. (Wolf.) This species is represented by four metapodial bones, which, at 1 We desire to take this opportunity of thanking Prof. Charles Stewart, the courteous Curator of the Hunterian Museum of the Royal College of Surgeons, for the facilities which he has afforded us, on this and many other occasions, for the examination of the unique osteological collection under his charge, as well as for valued help in the solution of some difficult osteological problems. Q.J.G.8. No. 241. E 50 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN’ [ Feb. 1905, first sight, resemble those of the hyena; but they are more slender, and the proximal articular surfaces are different. It is probable that these few bones represent at least three animals, for they were found at different times and at three different horizons, namely, Nos. II, IV, & 8. Vurrs atoprx, Linn. (Common Fox.) The only specimen that can be referred to this species is a lower carnassial tooth, rather broader proportionately than is usual, but agreeing in this particular with a tooth in a lower jaw of this species from the fissure at Ightham,in Kent. The present tooth was found in the swallow-hole (No. 7). Ursus HoRRIBILIS (?) Ord. (Grisly Bear.) (Pl. VIL, fig. 4.) Remains of bears have been met with in nearly every stratum between Nos. II and 9. Some of these evidently belonged to animals of great size; but none so big, or presenting such characters, as to justify their reference to the cave-bear, Ursus speleus. Most of the remains are foot-bones, but portions of humeri and several teeth have also been found. Unfortunately, we possess no example of the characteristic lower fourth premolar tooth. A left maxillary bone, with the two hindermost teeth in place, is in the possession of Mr. W. Storrs Fox, of Bakewell. The first tooth of this specimen (molar 1) measures 23°5 millimetres in length and 17°5 mm. in width. The hinder tooth (molar 2) is 41:0 mm. long and 18°5 mm. wide; it is comparatively long and parallel-sided, and the hinder end is less pointed than usual. The jugal process of this maxillary bone arises opposite the middle of the last molar, and in this respect resembles the grisly bear rather than the cave- bear. We have a last lower molar of moderate size (length =23 mm., width =17 mm.), which is pointed posteriorly, and in this respect is not unlike some examples of Ursus speleus, but we think it more likely to belong to U. horribilis (Pl. VII, fig. 4). Although we can point to no very positive evidence that some of these remains may not belong to small examples of cave-bear, we do not think it at all likely; it seems more probable that they belong to either the grisly or the brown bear, and on the whole we prefer to refer them provisionally to the former, Ursus horribilis. Motes raxus, Schreber. (Badger.) The badger is represented by two bones only, an ulna of a young animal wanting its epiphysis, and a metapodial of an adult. The horizon of one of these is uncertain, but the other was found in the south-south-eastern part of the lower level. Cheiroptera. VESPERTILIO (PLECoTUS) AURITUS(?) Linn. (Long-Kared Bat.) The distal half of a humerus of a bat agrees in size and form with that of the long-eared bat, andis with doubt referred to that species. It was found in the north-north-western lower layer, No. 11. Vol. 61. | OSSIFEROUS CAVERN AT LONGCLIFFE, bl Ungulata. Bos or Bison. Bovine remains were more numerous in the Longcliffe Cave than those of any other animal ; they include bones from all parts of the skeleton, but unfortunately there are no portions of the frontal bones and horn-cores sufficiently perfect to indicate the species positively. Many of the bones and teeth are of large size, and would compare favourably with the largest bovine remains that have beer found in Pleistocene deposits. There is, however, much variation in this respect, even among the bones that are obviously adult. Many young animals are represented, not only by limb-bones without epiphyses, but also by numerous milk-teeth. It is by no means easy to decide the species to which these bovine remains should be referred, or whether they represent more than one species. Differences in the proportions of some of the bones are obvious, such as would seem to show that two forms of large size are present, and one is naturally led to expect Bos bison and Bos primigenius ; but a closer examination makes one less certain that there are two species. The most obvious differences are seen in the proportions of the metatarsal and metacarpal bones, more especially in the latter. Some of these are exceedingly wide, while others, that are absolutely longer, are actually narrower. A comparison with the measurements of metacarpals, as given by William Davies’ in his Catalogue of the Antonio-Brady Collection, shows that our broad form agrees very closely with what he has referred to Bos primigenius, while our more slender form is the counterpart of his Bison. MEASUREMENTS (IN MILLIMETRES) OF Mrracarrats From LonecuirFe Cave, COMPARED WITII THOSE GIVEN BY W. Daviss, anp By Pror. Boyp Dawkins. : | Least Width of| Width | Per cent. Greatest width of proximal] of distal width to he TE \ shaft. \ end. end. | length. Bison (?) from Longcliffe | | GNGEAO) ST ct ees STO Mey, 2°85 315 | 17-4 Bos primigenius( Long- | Ghitte (INOW AT)\p aca: te. Td en 2 37 35 23'6 Bison, Ilford, exDavies.| 97 | 17 | 30 | 30 | 174 Bos primigentus, Ilford, | CUS DANNCS 12 eth saies8hs IOS" 1 422 36 Spt | £2270 Reon Wiidyeknel celles | Boe) a4 37 | 236 Dawkins, extremes. ST Vein, EO iy ors 2S. 1833 Bison, from Pleasley Vale, | ; ine in Mus. Pract. Geol. 8:25 1°63 2°8 30. |. 197 * These measurements are calculated from the circumference. + “Catalogue.of the Pleistocene Vertebrata from the Neighbourhood of Ilford, in the Collection of Sir Antonio Brady’ London, 1874, pp.46 &55. [Privately printed. ] B2 o2 MESSRS. ARNOLD-BEMROSE AND NEWTON oN AN’ [Feb. 1905, It seems, from the foregoing comparative measurements, that the two forms may be present in the Longcliffe Cave. When, however, these bones are further compared with the extreme measurements of the large series of bones from Windy Knoll given by Prof. W. — Boyd Dawkins,’ all of which he refers to Bison, one feels much less certain that the two species can be identified by their meta- carpal bones. The metacarpal bone of an undoubted Bison-skeleton from Fleasley Vale (Derbyshire), preserved in the Museum of Practical Geology, Jermyn Street, is proportionately rather wider than the more slender Longeliffe specimens; indeed, it comes about halfway between the two forms, and, further, lends support to Prof. Boyd Dawkins’s determination when he refers all the Windy-Knoll bovine remains to Bison. ‘This, however, leaves us in the difficulty with which we began, namely, the need of characters by which to distinguish the limb-bones of Bos from those of Bison. Bovine remains have been met with in every stratum of the Longcliffe Cave, from No. I to No. 9. Cervus eiganteus, Blumenb. (Great Irish Deer.) (PI. VII, figs. 1 & 5.) Only a few bones and teeth of this large deer have been found, but fortunately these leave no doubt as to the species being present in the cave. A series of six upper grinders in the maxillary bone is the most important of these remains; two large cervine metacarpal bones are, however, equally characteristic of the species. A big astragalus, that at first sight might be mistaken for one of Bos, has the wide, clearly-marked, oblique groove of the distal articulation, which seems to separate the astragalus of Cervus from that of Bos. One of the above-mentioned specimens came from layer No. III, but the horizon of the others is uncertain. Cervus ELAPHUS, Linn. (Red Deer.) (PI. VIII, fig. 2.) Although cervine bones and teeth are very numerous in this cave, comparatively few can be referred to the red deer. Limb- bones of a large size, including tibias, metacarpals, metatarsals, and other foot-bones, indicate a deer apparently larger than the ordinary red deer as we now know it, but doubtless belong to this species. Such fragments of antlers as have been found cannot be positively referred to this species; most, if not all, of them agree better with the fallow-deer. All the specimens that can be definitely termed red deer were found in the upper layers between No. I and No. 8. Cervus pAma, Linn. (Fallow-Deer.) (PI. VII, fig. 6, & Pl. VIII, fig. 3.) By far the greater number of the deer-bones and teeth from this cave are of such a size, that, had they been found in a recent deposit, they would, with little hesitation, we think, have been regarded as 1 Quart. Journ, Geol. Soc. vol. xxxi (1875) p. 247, t Vol. 61.] OSSIFEROUS CAVERN AT LONGCLIFFE, 53 ~ parts of fallow-deer; but, seeing that they accompany Pleistocene species and that fallow-deer has not hitherto been recorded as a British Pleistocene form, it becomes necessary to examine these remains much more care- fully ; and then it is that Sa = | eno | O°O10 a SSS i. 2 Se, Laces. Some doubts arise as to the SN SoS = rir |r | possibility of their belonging SSF oS =O =p : to small red deer. Sagas = Ia = Owe | oow Bones from all parts of : ea S35} eI OOD ; OOH > 4 ay 8 | aa | saan | the skeleton are present, ee pecthottds dks including portions of antlers ES ae > = | OOM | coo | with frontals, but none of R 5 S19 | Oo¢ 5 OB S | Aan | s- | these are sufficient to define SI ES macs a ______| the species. ‘The small size = Qs 5 2 =~ cel | eoenloow | 38 well as the curve of the “ e > = | San | S85 | beam immediately above the S a A burr, in one or two exam- ma ne iS ples, seem more like Cervus teal ors » Soi) Ow > ; ° s S Gan, ane | dama than C. elapius, SS ss e | me | or but one hesitates to speak ical D ns J ) 8 re hy sa] ss OD e,? a | Ast : ositively. The numerous es) a ) Sr ns = S19 D | Gon Ae ee eS ap aace!ooue | grinding-teeth are all small a | 8 5 BAA|/GaAN | 2 50 2 Re aS) for C. elaphus, although ao aly well Sa) = > 8 : some tew agree fairly wel F = ‘ A ye 3 | ee | with those of a female red ab ee re 2 xe = | ak | deer. On the other hand, D o fe > 6 g Qu oF the cheek-teeth of a fair- 3 SA Sp | cps | sized male fallow-deer are 3 a - | ak | so nearly the same as those 4 == : of a female red deer, that ae eae 3S | 19 OD | o.. | isolated teeth could scarcely g a3 < Cam, On : : Spent mH) 82. = | ms | sm | be identified. The limb- Oo .N . Ge ke 2| 388 bones present us with similar Sl Cuca S | one | 20oo! difficulties: for the most Sane of io) ° : ° Bes = = | aaa | “aa | part, they agree in size with SI ime the fallow-deer, and are too = ey | as ue | wor | small for the red deer: but > ~ od = : : ee) iS Si ee Lo | °S= | there are others which are D = ° . E 3. a intermediate. 3 = ae telly aahanaull Seas However, a large number & a = 22S oma jon | of these teeth and limb- Ry Ons bones appear to us to be too ah | a0 | small for red deer, and can ws Se only, we think, be parts of 2AR | RA | fallow-deer. If, then, we are be a ' compelled to accept certain of these remains as definite evidence of fallow-deer in this cave, it seems highly probable that a large proportion of the remains discussed, under the heading of this species, are referable to the same. 44 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN [Feb. 1905, The fallow-deer has not been recorded from any undoubted Pleistocene deposit in Britain, and its presence in this cave at once suggests a recent origin for the deposits. We think, however, that the physical conditions show this to be untenable (see p. 44). Prof. W. Boyd Dawkins’ says that the fallow-deer ‘was probably introduced by the Romans, since its remains occur in refuse- heaps of Roman age, . . . . while it has not been met with in older deposits.’ We must bear in mind, however, that the same writer had previously described the closely-allied Cervus Browni” from the Pleistocene of Clacton; this we only know by its antlers, and, although it may otherwise be indistinguishable from C.. dama, we cannot refer our specimens to that species. The remains which we here refer to fallow-deer were found at every horizon in the cave from which bones have been obtained. CAPREOLUS CAPREA, Gray. (Roebuck.) (Pl. VIII, fig. 4.) There are a few bones that can be accepted with more or less certainty as representing this species; these include metacarpal, metatarsal, and other foot- and limb-bones, with perhaps one or two pieces of antlers. These specimens were found in upper layers at Nos. III, [V, & 7, and also in the lower layer at No. 9. Sus SCROFA, Linn. (Wild Boar.) - Only four specimens belonging to this species have been found ; one of these is a large upper second molar, the crown of which measures 36 millimetres in length and 22 mm. in width, and indi- cates a fully-adult animal of large size. A right lower second molar, corresponding in size to the upper tooth just mentioned, measures 24 mm. in length and 16°5 mm. in width. The exact horizon of these teeth is not known, but the other two representatives of the species were found in layer No. II, and in the south-south-eastern lower layer (No. 9). RHINOCEROS LEPTORHINUS, Owen. The remains of Ahznoceros have been found rather plentifully, and include most parts of the skeleton; they are, however, all more or less broken. ‘This imperfection may be due, in some degree, to the carelessness of the workmen. We have been fortunate in securing two examples of the rare first upper premolar, besides other premolars, molars, and milk-teeth. These teeth are of the characteristic leptorhinus-form, and nothing has been detected that would point to the presence of Rhinoceros antiquitatts in the cave. Both species have been met with in British caves, and sometimes they have been found together. 1 «Cave-Hunting’ 1874, p. 77. 2 Quart. Journ. Geol. Soc. vol. xxiv (1868) p. 511. Vol. 61. | OSSIFEROUS CAVERN AT LONGCLIFFE. sy9) Recently there has been some question as to the propriety of using ~ the name of Fh. leptorhinus for this species of Rhinoceros, rather than Fh. hemitechus as was done by Falconer. The question was fully discussed by Prof. W. Boyd Dawkins,’ and for many years the former name has been adopted in this country. There is no doubt as to the British forms called by Owen Lhinoceros lepto- rhinus being the same species as those for which Falconer proposed the name of Rh. hemitechus ; but the synonymy of the Continental forms is a much more complex problem, the solution of which will not be attempted here; the matter is only referred to, for the purpose of making it clear that the species found in the Longcliffe Cave is that for which the two names above mentioned were used respectively by Owen and Falconer. Lthinoceros-remains have been met with in all the upper layers (Nos. II-8) except the topmost, and in the south-south-eastern lower layer (No. 9). ELepHas Anriquus, Falconer. (Straight-tusked Elephant.) (Pl. VII, figs. 5 & 5a.) Only a single specimen has been found, to indicate the presence of this species: and this is one half of a third milk-molar, with three plates and a talon preserved. The greatest length of this tooth is 44 millimetres, its greatest width 31 mm., and the length of the parts preserved is 33 mm. The enamel, where seen, is very coarsely wrinkled, but a cap of cement extends a good way down the sides of the crown. The tips of one or two points of the plates are just appearing through the cement. The base is very open, the plates seeming to consist of little more than the enamel, with but a slight infilling of dentine, showing that the tooth was not fully formed and that the animal was a young one. This tooth was found in layer No, III. Rodentia. Lepus cuntcutus, Linn. (Rabbit.) A number of bones, seemingly parts of one skeleton, were obtained from the fissure at the south-south-eastern end of the cave (No. 10); and a few others were found in layers Nos. I, II, & III. Lepvs sp. (Hare.) Two metapodial bones are probably referable to the common hare ; one of these was from the south-south-eastern lower layer CNio. 9). Microrus (Evoromys) GLaREoLvs, Schreber. (Bank-Vole.) This species is represented by an upper anterior cheek-tooth with fangs and an incisor, as well as by two or three humeri, which 1 Quart. Journ. Geol. Soe. vol. xxiii (1867) p. 215. 56 MESSRS, ARNOLD-BEMROSE AND NEWTON ON AN’ [Feb. 1905, in size agree best with this species. ‘These, in common with most of the small vertebrates, were found with the rabbit-bones in the fissure at the south-south-eastern end of the cave (No. 10). Microtus agrestis (?) Linn. (Field-Vole.) Two incisor-teeth and three limb-bones, which are larger than those of the bank-vole and agree in size with those of M. agrestis, are, with doubt, referred to this species. They are from the south- south-eastern fissure (No. 10). Microrus Amputisivs(?) Linn. (Water-Vole.) Part of a lower incisor-tooth, which is too large for any of the above-mentioned species and too small for the common rat, most probably belongs to this species.. Its horizon is uncertain. LemMvs LEMMUS(??). (Norway Lemming.) The middle portion of a tibia intermediate in size between the tibia of Microtus agrestis and that of MW. amphibius, but agreeing in this particular with the Norway lemming, may indicate the presence of this northern form, which we know was living even farther south in this country in Pleistocene times. Mus sytvaticus(?) Linn. (Long-Tailed Field-Mouse.) Among the remains of small rodents is one perfect tibia, which agrees most closely with that bone of the field-mouse. It was discovered in the lower north-north-western layer (No. 11). Aves. AsIo AccIPITRINUS, Pall. (Short-Hared Owl.) Two bones of this bird have been found—a perfect tarsometatarsus and a broken humerus; both of these agree with the correspond- ing bones of the short-eared owl. They were found in the lower layer (No. 9). Turpvs 11acus, Linn. (Redwing.) Two ulnas and parts of two tibias, representing at least two individuals, are placed in this species. The bones of thrushes are so alike in form that, except for size, they cannot be distinguished. The present specimens are too small for a common thrush, but are of the same size as these bones in the redwing. ‘Two specimens were found in the north-north-western lower layer (No. 11) and two in the south-south-eastern fissure (No. 10). EritHacus ruBecuLa (?) Linn. (Robin.) A single ulna, agreeing in form and size with this bone in the robin, is, with some hesitation, referred to the same species; it was found in the north-north-western lower layer (No. 11). Vol. 61. ] OSSIFEROUS CAVERN AT LONGCLIFFE. o7 Amphibia. Rana temporaria, Linn. (Frog.) About thirty bones of frogs were found, among the small bones obtained by Mr. Arnold-Bemrose by washing the cave-earth in fine sieves. Some of these are definitely referable to the above species ; others, although belonging to the same genus, are not specifically determinable: sixteen of these were from the north-north-western lower layer (No. 11), three from the south-south-eastern fissure (No. 10), and the remainder from the tip-heap made by our pre- decessors in this work. Boro vuiearis, Laurenti. (Toad.) Eleven bones, belonging to two individuals of large size, including three ilia, a humerus, and other limb-bones, are clearly referable to this species. Nine of the specimens were from the north-north- western lower layer (No. 11), and two from the tip-heaps. General Remarks on the Vertebrate Remains. Altogether, some twenty-seven or twenty-eight species of verte- brate animals have been identified from Longcliffe, which is nearly twice as many as had been previously known from Derbyshire caves. We must remember, however, that half of these are small rodents, birds, and amphibia which have not been mentioned by previous writers. The number of larger species (sixteen) is the same as that recorded by Prof. Boyd Dawkins from Robin-Hood Cave; but there are noteworthy differences in the species. We have no evidence of the presence of man at Longcliffe, neither have we detected Macherodus or leopard; all the other carnivora found in Robin- Hood Cave are present also at Longeliffe, and in addition we have the badger. Among the Ungulata there are some peculiar differences. The great Irish deer is present in both caves; but the only other deer recorded from Creswell is the reindeer: now, this is conspicuously absent from Longcliffe, and its absence is the more remarkable in that it occurs in nearly all the lists of mammals from Derbyshire caves.. On the other hand, we have at Longceliffe not only the red deer, which has been recorded from Pleasley Vale, but a great abundance of another form which we believe to be fallow-deer. The wild boar does not seem to have been previously recorded from Derbyshire. The rhinoceros present at Longcliffe is undoubtedly Rh. lepto- rhinus, Owen (= Rh. hemitechus, Falconer), whereas the Lh. antiquitatis (= Lh. tichorhinus), or woolly rhinoceros, is the only species hitherto recorded from Derbyshire, and it appears in nearly all the published lists. 1 [Since the reading of this paper we have detected one flattened fragment of an antler, which may perhaps belong to a reindeer, from layer No, I11.— January 11th, 1905.) 9008 9¢ee| seot! 8¢ | ¢9 | OBL) srt| o86| 88t| S& | 406) LST] 98st) 6 JO pauresqo coquinu [80], tore | 999 | 019 | 2 | St | mu | 92 | seo| s8 | 4 | 98 | Tes | seo | % | poutuezepun souog Jo roquinyy cpop | ogot| esr | te | og | et | ott | see] eo | 93 | Tot] 988 | Teg | ge fo peurem seuog jo tequinyy iil Z noe 6 see ane Hoo B00 aoe oso 309 tee 508 a00 jabied ohoanEtoNe (‘peog,) “1]U9INBIT ‘sxunbyna oft “LB ae e a re = Se Na ae ih ree Jesestesreces “CBonr) suUITy ‘ortntodma, DUDE “9G eae I eee eee sae toe ere eee see | eee eee Co Geman (“urqoxy ) “UULT (¢) pynaaqnd SNIDY PA "GG | aoe come re e aes tiers tase ra poe fee | tee ao6 sae nisteninse i pceyeinis etzieie (“SUIMpoyy) UU] ‘snanue SPM, "PZ ann aon wee see id ress one ftic mere tere Boo vie wes “(TMQ pareq-yt0Y9) Teel ‘snursqudvaap OUP “SZ wee tee T aes eee sae | sae see eee } eee see ase eee leew ee (‘esnoy(-plet) uu] (i) snaywajhs SNL BS | eee see sae vee sel 1 one oe eee eae aes eee eee (‘910 A 1998 MA ) UU () sniqvyduo SnjOLOUTT "IZ eee eee ene wae see oes eee eee wee ene wee June eee (‘e[0 A -PTetq) “UULT () sysatbho SnjoLIUTTT “OG | see wee eee ese | see wae aes eee vee wee ese eee (‘apo A ue) Jaqeayog ‘snjoawn)b snjoworpy “61 | eee Sod eee 6e eee eae if wae T eee tee z ee Soc nondod oU0 OGG (-g1qqey7) UU] ‘snpnovna sndarT ° Lt ane Asta axele Goo ara aon Gc anevd OOD meehs T aos Ao mUviedacave ivetsiieietaRsisipietelsicercletacris IouOooT BY ‘snnbuup soydaraT “91 PPL 09 Ay ore eee el G j Ll T 7 6 II jie eee Hoe eek ee ee OW (3) ‘snurysozday Souan0uryay "cL a T | one ses sieve V4 aia bar ado Sy ioe see iI wee Mere iemste fetes oot nites (‘1v0g PIEM) UU] “pfoLos SNS “PT erate oe BRO tee ove eae eee TooHoG Goa apa (‘yonqaoyy) AB.) ‘patdva snjoaudvp eT 66ST | S19 GVG g = 8g 69 6& V6 L Ty | O0€ | SEL V oss (TQOQ-MOT[RT) “UUIT] “vump snataD “BT ge | 1Z ose see eee T 1 | ca see ae ZS 9 e eee leas Serer non (-190q] poy) UU] ‘snydvja snasap Taf P | e an see vee fine ree was Add San ee | i Ane ae ene metee (-100q stay) ‘quoulny,q ‘snaqunbib snasay ‘OT if | eee wee i see | ove aoe ese eee wee ace eee wee eae (4eq palen-suo'T) UU] (i) snguinw ouryjsadsa 4 °g | ore I 550 Tee T OO CHG S00 nt oe ; on Ge Boe. aul Nano veata Maroons (‘tas peq) “1aqeayog “snag saan ‘L wid see T c 9 Z ooo '- 4] acacdod (aveg A]S.9) ‘plo (¢)surqitsoy SNS4() 9 Goo A609 vee vee ee sae cee cee ee cee eee eee (*xO,q) UU] ‘vadojp sadjn 4 ‘G wee we wae aoe I ae ee I ere eee eee see ene (FTO M) “UUTT ‘sndny SUL Y@) “p 199 VEE | 06 € T 1s V GE 9 L 06. TZ ov Gee aoe (‘eu Pde oA ee 586 Be T se oy Aes Me she Smee Ie st oO SOON HO ANOS aa re [op) ce ine) HH cir 1 Nem ies} ce ek} peyjodg) ‘[xaq ‘pn0000 nuwlhyT "gE Wakes Oars (‘ye9 PIL) UU] ‘snqwo SYAT SG i, | I G picks sien g Be cee eet een ee tee tee eens (‘uorT) “UULT, “0a) $10,7 “TL Se Oe Wie a | Ol | “6 |e | L | a ae An) ‘[ SIavy, Wol, 61. | THE OSSIFEROUS CAVERN AT LONGCLIFFE. 59 The absence of the horse from Longcliffe is another peculiarity, for this species is likewise present in most of the Derbyshire caves. The Longcliffe elephant, again, is peculiar, for there is no doubt as to its being Hlephas antiquus’; while it is the mammoth (H. primigentus) that has been found in Robin-Hood Cave and Church Hole. Both species are known to occur in caves in other parts of England. Very little is yet known of the small mammals and birds which existed in Derbyshire when the cave-earths were being deposited. Some of the Longcliffe deposits have been washed through sieves ; but, as we have seen, the results were not encouraging. We think, however, that the few small forms found are worthy of being recorded, although the species may now be living in the district ; for nearly all of them, we know from other evidence, were living in this country in Pleistocene times. VY. TABULATION OF THE SPECIMENS. The total number of specimens obtained was 8006. These were all washed, treated with glue, and sorted. Of these, 2582 were in such a fragmentary condition that they were placed on one side as useless for determination. The remaining 5424 were numbered and catalogued; of these 4545 have been determined, and the remaining 879 consist of vertebre and ribs, requiring more time for their determination than we have been able to devote to them, and of fragments which were in too broken a condition to be named. The accompanying Table I (p. 58) shows the number of each genus and species recognized from the various layers or portions of the cavern which we thought it necessary to keep distinct (see Pl. V), and the number of undetermined and broken specimens. Column M contains those specimens which we were unable to allocate to any special position worth noting, and column G those obtained before we began work. It will be seen from the horizontal section (Pl. V, fig. 1) that the specimens obtained before we commenced the work probably belonged to one or more of the layers Nos. I-V, because they came from that part of the cavern which extended from the south-south- eastern end to a point 34 feet to the north-north-west of it and on the higher level above the line AB. There is little doubt that those from layers Nos. 6, 7, 8, & 9 belong to the same group, and were introduced through the swallow-hole. We have, therefore, grouped together the specimens from layers Nos. I-9, and kept separate those from Nos.10 & 11 in Table II (p. 60). Of the 4545 specimens named, 4444 came from the upper series of bone-beds (Nos. I-9), 50 from the narrow joint below the south-south-eastern end of the cavern (No. 10), and 51 from the lower level above the bedded sand and clay (No. 11). 1 Prof. W. Boyd Dawkins has examined the tooth, and accepts it as evidence of Hlephas antiquus. 60 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN’ [Feb. 1905, Taste II. Upper beds. IL-9, ib), TT. otals. 1 DS CSN eine Setedeates eae | 7A 7 POA Gee A adn nMycooee 4 a 11 OMY EON, ores ose snes 663 1 3 667 BOWE Ys oes a esas 5 eee ae 5) Dyn o> aa eRe ae ae o, 1 1 Gx ibear 23h eoae 86 5 91 he Bader. gece. . ct 2 2 Sabb abi ana: snes ie cas if 1 QUIN OS oss soca ee 1855 va We 1855 10. Irish Deer ......... dbo ee se 4 J SRedsDeer eas B) ee ae 38 12. Fallow-Deer ..... 1587 tte 5) 1592 13. Roebuck i:.0 2.265 16 fe eth 16 TA Boars cee ee 4 ck ae 4 15: Rhimoceross......-- 144 144 16. Hlephas antiquus 1 ans Siac 1 fF aI, lec acecie. oe 4 39 we 43 NS! Meares a ee. 2 ; a3 2 19> Bank-Wole@: 2.52... 1 5 4 20. Field- Vole <:234. 2. 4 1 5) 21. Water-Vole ...... i ant igs 1 22..Field-Mouse ...... ae ae 1 1 DS AMD Ane Rute oe OL ae z 2 24. Redwing... ........ E: 3 3 6 2D.) EeOWiihesee. sce. ake e sod i l Oe MTOR ec iacc keene 11 3 16 30 DAO AGH, sasceenecceecel 2, : 9 Il GP Otaulise 0.0 | 4444 32> 750 51 4545 The 39 bones of rabbit in layer No. 9 probably all belonged to one animal. Although traces of Hyena were found in each of the three groups, the forty-three coprolites of that animal were confined to the uppermost group (Nos. I-9), and five out of these were obtained in the swallow-hole. The Pleistocene age of this assemblage of the mammalian remains we take to be abundantly proved by the presence of such forms as Elephas antiquus, Rhinoceros leptorhinus, Hycna, and lion. The only form that has not hitherto been regarded as a Pleistocene species is the fallow-deer, which, for reasons given elsewhere in this paper, we are now disposed to include in the British Pleistocene fauna (see pp. 52-53 & 61). Itis probable that the clay and sand (Beds 12-15) are of more ancient origin, but in so far as they could be examined they yielded nothing to indicate their age. As there are many duplicates of most of the species, it is hoped that a typical series will be placed in the Museums of Derby and Buxton respectivelv, and in the Museum of Practical Geology, Jermyn Street, London. Vol. 61. ] OSSIFEROUS CAVERN AT LONGCLIFFE. 61 VI. Concrvsion. There is no doubt that the cavern was eroded along a master- joint in the limestone by the action of water. This erosion must have taken place long before denudation had produced the present shape of the surface of the ground. There is little doubt that the majority of the bones were introduced through the swallow-hole ; others may have fallen or been washed in at various places along the joint or roof of the cavern where it communicated with the surface of the ground. In considering the origin and age of the bones, we may briefly examine the various alternatives : — 1. The cavern may have been a hyzena-den. The presence of a small number of gnawed bones and over forty hysena-coprolites tend to support this view. As far as we could tell from the extent of our excavations, the only entrance to the cavern was by the swallow-hole, a more or less vertical shaft 74 feet wide, the top of which was at least 12 feet above the top of the bone-deposits found in it. It is quite possible that the cave was accessible from the swallow-hole during the time when the bone-deposits were forming, and was used by hyenas until nearly filled up. 2. The mammalian remains may be merely those of animals that had fallen into the swallow-hole, but the isolated positions and fragmentary condition of the bones scarcely admit of this interpre- tation of the origin of the whole of the remains. 3. The deposits might have been formed at a date subsequent to Pleistocene times. That is to say, they might have been washed in from a hysna-den or other Pleistocene deposit, and mingled with later ones. In this way the occurrence of the fallow-deer with the Pleistocene species would be accounted for. The abundant remains of what we take to be fallow-deer in nearly all parts of the bone- deposits necessitate a very careful consideration of the possibilities of these deposits being of recent origin. But the supposition that they are of recent origin would imply that the surface of land in the neighbourhood must have been sufficiently elevated above the swallow-hole to collect water to wash the remains into the cavern: and that this land has been denuded, not indeed since Pleistocene times, but since the redeposition of the bones in Roman or post- Roman times, if the fallow-deer was really first introduced into this country by the Romans. Such rapid denudation does not seem possible, and we do not think the supposition tenable. We conelude, therefore, that the Hoe-Grange bone-deposits were of Pleistocene age; that some of the bones fell or were washed in through the swallow-hole and roof of the cavern ; and that others were introduced by hyzenas which used the cavern as their den. The presence of the small deer-remains with bones of undoubted Pleistocene mammalia, under the circumstances described by us, proves, we think, that the fallow-deer, or a form which we cannot distinguish from it, existed in Pleistocene times in Britain, & 62 MESSRS. ARNOLD-BEMROSE AND NEWTON ON AN [ Feb. 1905, [Since this paper was written, Mr. R. Lydekker has kindly called our attention to a most important memoir by Dr. Herluf Winge on the fossil mammalia of Denmark (Videnskabelige Meddelelser, 1894, p. 193), in which, at p. 263, remains of fallow-deer are described and figured from Interglacial beds in Denmark. The memoir is, unfortunately for us, written in Danish, but Mr. Lydekker has given an account of that portion of it which deals with Cervus dama, in his article on ‘The Fallow-Deer in Denmark,’ published in ‘The Field’ (March 5th, 1904, p. 403), where he also gives a very interesting summary of what has been written regarding the northward range in Europe of the fallow-deer in past epochs. The presence of fallow-deer so far north as Denmark in Inter- glacial times, makes it extremely likely that it extended its range westward also into England. This discovery by Dr. Winge, there- fore, lends considerable support to our contention that the small deer-remains found at Longcliffe belonged to fallow-deer which lived in that district in Pleistocene times.—January 11th, 1905. | EXPLANATION OF PLATES V-VIII. Puate V. Fig. 1. Horizontal section of the Hoe-Grange cavern. Scale: 1 inch=165 feet. 2. Plan along the line AB. Upper level. in Ge 3. Plan along the line CD. Lower level. \ Sele: Tine Prats VI. Fig. 1. View of the cavern, soon after we commenced the work, showing the wooden door at the entrance, 27 feet north-north-west of the place where the men first broke in. The rock on the left-hand side had been quarried before the cavern was discovered. (From a photograph taken by Mr. W. Walker, of Buxton.) 2. A more general view of the quarry, showing the position of the cavern. The line between A and B corresponds to the line AB in the horizontal section of the cavern Pl. V, fig. 1. (From a photograph taken by Mr. Arnold-Bemrose.) Prats VII. [All the figures are of the natural size, and are reproduced from photographs. ] Fig. 1. Felis leo: left. ramus of the lower jaw, with milk-teeth. No. 459. 2. Felis catus: left. femur, from the front. No. 4425, 3. Felis catus: right humerus, distal portion, from the front. No. 4427. 4. Ursus horribilis (2) : last lower molar. No. 4038. Figs. 5 & 5a. Elephas antiquus: half milk-molar 3, side- and end-views, No. 228°). Fig. 6. Cervus dama: three true molars of the left side. Nos. 2050 & 2909. Prare VIII. [All the figures are half the natural size, and are reproduced from photographs. | Fig. 1. Cervus giganteus: metacarpal. No. 130. 2. Cervus elaphus: metacarpal. No. 278. . Cervus dama: metacarpal. No. 3312. . Capreolus caprea: metacarpal. No, 3408. . Cervus giganteus: astragalus. No. 142. Our ne & EONS Quart. Journ. Geol. Soc. Vol. LXI, Pl. V. RN. Horizontal Section. Fig. 1. aw 4) & sf WD =p hl a a | eS . = bea sa ee , 1 AYO O ee af with eh I bones | ~ >_> ae _— Stay ae Helix-shells eae Wiese = Few bones SS Clay & rubble Bones Clay & rubble with few bones ‘ubble not worked;bottom not reached Clay & rubble not worked - I inch-15 feet Upper level. Fig. 2. ee ee Se ee a ee Wa ——= ete er it below door | (BS Dee ys 8 SS eee Se ee | zed in 1902, and the lower level in 1903. Scale:-1 inch=rs feet. Not worked{ Wad qiy, om helow this ayers of wad > hins outina |W. direction Clay & rubble with sand more or less stratified tenbones lay with large 8 Clay & rubble found g Jumps df} Th tp %20 Climestone Tome HOE-GRANGE CAVERN. Horizontal Section. Fi s oe 5 Quart. Journ. Geol. ee Vol. 3 > *re73h SS A Clay & rubble Clay & ruvble Boy uu 3 — 2 Hda-shells—>— Few bones cl bble Srnphle : small Breccia ay Sens Clay & rubble Bones hones with Helix Clay & rubbie ww with few bones LOeN . Clay & rubble not worked, bottom not reached Scale:- 1 inch-15 feet Plan along line A.B, Upper level. Fig. 2. Clay & rubble not worked LXI rh . gens -s me EVES = Breccia with Helix shells helow door The upper level froin A.B.to the roof was worked in 1902, and the lower level in 1903. Scale:-1 inch=r5 feet. Quart. JouRN. GEOL. Soc. VoL. LXI. PL. VI. 1 Hoe GRANGE CAVERN, LOOKING N.N.W. W, Walker, Photo. Fic. 1. = =i jae = | ay e) > re) {e) (ep) all Oo Ww © z oc =) e) = ray oc a =) © Bemrose, Collo. MAMMALIAN BONES FROM HOE GRANGE CAVERN. QuaRrT. JOURN. GEOL. Soc. VoL. LXI, PL. VIII. = wwe Seen Le ee SS eS EEE \ } i { 1 { Fia. 4. Bemrose, Collo. CERVINE BONES FROM HOE GRANGE CAVERN. Vol. 61. | OSSIFEROUS CAVERN AT LONGCLIFFE. 63 DiscussIon. Prof. Boyp Dawxins welcomed the paper as one of the most important brought before any Society in this country during the last few years. The physical conditions at Longcliffe were evi- dently the same as at Wirksworth Cavern, and pointed to the vast denudation which had taken place since the time when the remains were introduced into those caves. The Pliocene cave at Doveholes, at a level which was now part of the watershed instead of being in the valley, also exemplified similar conditions. It would be interesting to know whether the Authors had endeavoured to measure the denudation in the case of the Longcliffe Cave, and whether they had found any decomposed grits or foreign pebbles such as occurred in many Derbyshire rock-fissures. He doubted whether hyzenas could have leaped the minimum 12 feet postulated, down the swallet, and considered that the bones had been introduced by water-action from some upper source which itself was really a hyzena-den. The occurrence of Rhzno- ceros hemitechus and Hlephas antiquus, together with the absence of the mammoth and the woolly rhinoceros, assimilated the deposits to those of Kirkdale Cave, a much older group of cave-deposits than was usual in this country or in France. The probable classi- fication and relative antiquity of the Derbyshire cave-deposits would be, in chronological order: (1) Doveholes; (2) Longcliffe and the older deposits of Creswell Crags ( = Kirkdale Cave); (3) upper deposits of Creswell Crags; and (4) Windy Knoll. With regard to the fallow-deer, he must express a certain amount of scepticism. Not much importance could be attached to measure- ments of bones or teeth, in the case of a group which varied so enormously as the Cervide; and there were no points which distin- guished the teeth of the fallow-deer from those of the reindeer. The occurrence of the lower jaw of a lion’s whelp was, on the other hand, the most important recorded from any cave in this country. 64 DR. WOOLACOTY ON THE SUPERFICIAL DEPOSITS, Etc. [Feb. 1905, 7. The SuperriciaL Deposrts and pre-GuaciaL VALLEYS of the NortHUMBERLAND and Doream Coatriztp, By Davin Wootacort, D.Se., F.G.8. (Read November 23rd, 1904.) {Puare [X—Map.| ContrENTS. Page De Introdwetion 2.0 cs Ree ee nee 64 I, The Nature. of the Deposits. 0525. 2.0.02 ..c2- shee eee ee 65 III. The Distribution, Thickness, etc. of the Glacial Deposits. 72 IV. The pre-Glacial Surface of the Country ...............:..5 74 V. The pre-Glacial: Valleys sc oeic omc -uei-n-snsccqs eee 75 (a) The Tyne and its Tributary Valleys. (6) The ‘ Wash.’ (c) The Upper Wear and its Tributary Valleys. (d) The ‘Sleekburn Valley.’ (e) The Depression running out at Druridge Bay— the ‘ Druridge Valley.’ MI} General Remarks: > 22820 ee eee 86 WIL. Deductionsec.8. .ace8enu.5 ek. A Ie eee 88 VELL. .Conelastoms ics wcch tcc sbouases ie eke a ee 93 EX. Brbliograplaical: Uist 25 65. sok oooieip cian ysis ae eee 94 I. Inrropucrion. Neary the whole of the rock-surface of the Northumberland and Durham Coalfield is covered by superficial deposits of an extremely variable thickness. After I had made some study of the thickness of these deposits and the pre-Glacial contour of the north-east of County Durham, Prof. Lebour suggested to me that results of some importance might be obtained from a thorough investigation of all the borings and sinkings made in the Northern Coalfield, and the working out of this subject has occupied the greater portion of my leisure-time for the last three or four years. Nicholas Wood & E. F. Boyd, in a paper on the ‘ Wash’ published as long ago as 1864 (1)* first clearly showed that the deposits covering the rock-surface of this coalfield were not arranged in an irregular manner, but were found along valley-like depressions. Since then, little has been done towards the thorough elucidation of the Glacial and superficial geology of this area. Indeed, little of a detailed character could have been attempted until the publication in 1897 of the final volume of the ‘ Account of the Strata of Northumberland & Durham, as proved by Boring & Sinkings’ (4). The six volumes published by the North of England Institute of Mining & Mechanical Engineers give details of 2,353 borings made in the Northern Coal- field, or in its immediate neighbourhood. A large number of these are useless for our present purpose, because their exact position is not known, many of them are vague and indefinite, and some fail to give the thickness of the superficial deposits. All, however, that could possibly be of any service have been carefully analysed, and 1 Numerals between parentheses refer to the Bibliographical List on pp. 94-95, Vol. 6r.| OF THE NORTHUMBERLAND AND DURHAM COALFIELD. 65 their exact position accurately mapped; the.depth of the surface- deposits has also been worked out, and their character has been studied. The actual number of borings of which reliable data were avail- able, and could therefore be used for the purpose of this inquiry, was about 600, but several hundred others gave confirmatory evidence. The remainder, although carefully gone over, did not prove to be of much service, because the facts obtained from them were always uncertain. It has, however, been found possible to obtain exact information regarding the thickness and character of the Glacial deposits; to gain a rough idea of the contour of the country before Glacial times; to form a more accurate conception of the drainage of that period; and also to work out more thoroughly the relative changes of level before, during, and after the Glacial Period. Il. T’ae Nature or tHE Deposits. The superficial deposits of the great Northern Coalfield may be roughly divided into three main parts, namely :-— (a) The stony Boulder-Clay. (6) The Upper Clay, which has been generally derived from the lower stony clay, and is broadly divisible into two portions:—(1) The prismatic clay, and (2) the leafy clay. (c) Deposits of sand and gravel occurring below, in, or upon the Boulder- Clay, ; . (a) The Stony Boulder-Clay. The first, which is the only kind that should be called ‘ Boulder- Clay,’ is a firm unstratified clay, full of stones, varying in weight from a few grains to several tons. It may be examined in several sections along the coast, but perhaps best at Whitley, north of Cullercoats; between North Shields and Tynemouth, on the banks of the Tyne; and at Hendon, a mile south of Sunderland. It is sometimes seen resting directly upon the surface of the solid rock, although often there is a breccia, consisting of local fragments, intervening between it and the rock-surface. Sand and gravel are also proved to occur beneath it in some of the borings. This clay is often present as one complete mass, reaching in some cases a thickness of over 100 feet. with little or no change in character, except that the lower parts of it generally contain more boulders than the upper ; very frequently, however, deposits of sand and leafy clay are intercalated in it. Throughout nearly the whole district its colour is brownish or bluish, but south of Castle-Eden Dene the clay becomes distinctly red and sandy. Some of the boulders occurring in it are local, more especially near the base; but a very large number foreign to the district are also found therein, being principally derived from the district lying to the north and west. Pieces of Bernician Limestone, Whin Sill, and Cheviot Porphyry are especially common; but while something has been done towards a classification of the boulders in the different super- O-IeGes. No, 241. F 66 DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [ Feb. 1905, ficial deposits of the two northern counties, much detailed field-work must be undertaken before a thorough knowledge of this subject is obtained. The rock-surface upon which this clay rests is nearly always smooth, and is in some instances striated, polished, and grooved ; as are also many of the boulders contained therein, more especially those of Bernician Limestone. With one solitary exception, no remains of animal life have been found in-it, portions having been washed for micro-organisms without result. It is the true Boulder- _ Clay, and bears no evidence of having been deposited under water, being most probably the moraine profonde of an ice-sheet. Except where the solid rock comes to the surface, the whole district is more or less covered by it ; vertically, however, it is limited in height to about 1000 feet. (6) The Upper Clay. (1) The prismatic clay.—Resting upon the last, or separated from it by deposits of sand, there is, in the less elevated parts of the district, a brownish clay, containing few stones; these are unstriated, Fig. 1.—NSection from Fulwell Hill to Cleadon Hills. FW: C. C. H. mM) ea Level § W SS ater ait - a O 100 200 300 400 VERTICAL SCALE F.=150-foot raised beach, resting against the old sea-cliff at Fulwell. F.W.=Fulwell Waterworks; C.=Cleadon Village, which is built on gravel, sand, and sandy clay. C.H.=The raised beach and sea-cliff on Cleadon Hills. and smaller and more rounded than those in the stony Boulder-Clay. This brownish clay forms, when present, a layer on the lower deposit reaching a thickness of 30 feet, and is largely used for brick-making. It has a distinct tendency to vertical prismatic jointing, and was evidently laid down under water. It is derived from the Boulder-Clay, which in some places has been washed up and re- deposited (during the extensive floods that must have occurred on the melting of the ice.at the end of the Glacial Period), in other places has been washed down from the higher grounds by rain; but more generally the prismatic clay has been formed by the sea during Vol. 61.] OF THE NORTHUMBERLAND AND DURHAM COALFIELD. 67 the production of the raised beaches which are described hereafter (p.69). This clay can be especially well examined in the numerous brickfields around Sunderland, and along the line of the Cleadon pre- Glacial valley, having been here produced by the last-named cause. The relationship between the prismatic clay which occurs at the surface of Boldon Flats and the neighbouring district, and the raised beaches exposed on Cleadon Hill and Fulwell Hill, seems to me to be indis- putable. This is shown in the section drawn between these two hills (fig. 1,p.66), which illustrates a pre-Glacial valley, carved in Permian rocks, and filled with stony Boulder-Clay overlain by prismatic clay. Clay of this nature is also found in the north of Northumberland, there being a fine exposure of it in Birling Quarry, near Warkworth, a photograph and description of which were given by Prof. E. J. Garwood in ‘ The History of Northumberland’ vol. v (1899) p. 12. (2) The leafy clay that occurs in many parts of the district, as in the ‘ Wash’ and round Newcastle, lying above the Boulder-Clay, associated with deposits of sand and sandy clay, is also probably a water-formed deposit, and may have been laid down in lakes at the end of the Glacial Period. Prof. Lebour discusses, in a ‘ Note on a small Boulder, found in the later Glacial Deposits in a Wash-out near Low Spen, in the Derwent Valley ’ (16), the origin of this formation, and shows that it was deposited in a lake; and Mr. G. Brennan has obtained tracks of freshwater crustacea from it. (c) Deposits of Sand and Gravel occurring below, in, or upon the Boulder-Clay. - This type of deposit is fairly widespread, and may occur in three distinct positions, each having had a separate origin. Those found below the Boulder-Clay, asin the valley of the ‘Wash,’ were possibly formed by pre-Glacial rivers and streams, or by the torrents that must have flowed at the commencement of the Ice-Age from the higher valleys, when they were ice-filled and the lower valleys were not so filled. The most remarkable, however, of the deposits lying in this position is exposed on the Northumberland coast, north of the mouth of the Wansbeck. It consists mainly of coarse gravel containing flints, and rests upon the solid rock-surface. Since it is overlain by Boulder-Clay, it was formed before or during the Glacial Period, and may be either a raised beach or an old river-terrace (fig. 2, p. 68); but, as the height of the land was greater before and during that period than it is now, I am inclined to the latter view. ‘The occurrence in it of flints and other rocks foreign to the drainage-area of the pre-Glacial stream does not, however, lend support to this contention ; indeed, the nature of this deposit is not yet quite understood. The deposits of sand and sandy and leafy clay that are found embedded in the true Boulder-Clay were most probably formed by streams of water, which, resulting from the melting of the ice, would sp 68 DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETc, ' [ Feb. 1905, vary in volume with change of season and climate. So far as the available evidence from the district under consideration goes, there does not seem to be anything pointing to an Interglacial Period or ‘Periods. The deposits of sand and sandy clay found interealated in the true Boulder-Clay are, as a rule, most irregular in position, and » ies 2 — Pre-Glacial (or Glacial) gravel-deposit at Newbiggin, near the mouth of the Wansbeck. [From a photograph taken by Dr. J. A. Smythe in 1903. The gravel-deposit here rests upon Coal-Measures, and is overlain by Boulder-Clay. | vary laterally in thickness. Some of the thicker deposits may represent epochs when the ice was melting more quickly than others, but whether they can be considered as in any sense ‘ Interglacial’ is very doubtful. ‘While several eskers occur upon the Boulder- Clay in the north of Northumberland, outside the area of the coalfield, very few forma- tions of this character have been noticed within the district under review. There is, however, near Grindon, about 2 miles west of Sunderland, at an elevation of 300 feet, a hillock of sand and gravel some 60 feet high, which partakes of this nature. The mounds of sand and gravel, often designated ‘ Drift,’ that are found resting upon the Boulder-Clay, principally in the east and south- east of County Durham, may have been produced when the enormous Vol.61.| oF THE NORTHUMBERLAND AND DURHAM COALFIELD. 69 accumulations of ice were melting at the end of the Glacial Period; and also large portions of the Boulder-Clay must have been washed down from the higher ground and redeposited in the valleys, partly owing to the same cause, but also to the action of rain, etc. since | that period. Viewed broadly, there is considerable variation in the character of the superficial deposits over the whole area, and except that the ~ Boulder-Clay is found in one or two localities to be of considerable thickness, it seems utterly impossible to correlate the deposits in different borings : this, however, was to be expected. The discussion of the distribution GF tthe different boulders in the clay over the great Northern Coalfield, or of the various rocks found in the diverse superficial deposits, does not come within the scope of this paper. Collecting, however, the evidence from various sources, 1t may be asserted that in these deposits, treated as a whole, there have been found within the area of the Coalfield, or in its immediate neighbourhood, specimens of Criffel and other granites from the South of Scotland; Bor- rowdale Ash and other rocks from the Lake-District; Permian and Triassic sandstone from the Kden Valley; Shap Granite (which probably does not occur very far north of the Tees Valley) ; Cheviot Granite and Porphyry, Whin Sill, Tuedian Sandstone, Bernician Limestone, flints, as well as specimens of the rocks that form the surface of the country itself, namely, the Coal-Measures and the Magnesian Limestone (2, 6, 15). (It is extremely doubtful, by the way, whether any true Scandinavian rocks occur north of the Tees.) I have collected specimens of most of these from time to time, but there is still room for more detailed work on this subject before a full knowledge of it can be attained. Besides these beds, which may be considered to be more or less of true Glacial origin, there are the remains of a raised beach resting upon the solid rock and Boulder-Clay. This formation, or deposits associated with it, has been observed on Tynemouth Cliff, Cleadon, Fulwell, and Tunstall Hills, and can be traced along the coast from Seaham to Castle-Eden Dene. Richard Howse recorded a raised beach as having been exposed at Tynemouth, at an elevation of about 100 feet (2); sea-caves were discovered on Cleadon Hills, in 1878, at 140 feet above high-water mark, and the old sea-cliff with - beds of gravel and sand can still be seen (5 & 6); while on Fulwell Hills (11 & 12) there is a finely-exposed beach resting in places upon a sea-worn platform of rock, and elsewhere upon Boulder-Clay, and running up against an ancient cliff which is 150 feet above sea-level (figs. 3 & 4, pp. 70 & 71). Farther south, along the coast from Seaham to Castle-Eden Dene, a hard, strongly- -cemented conglomerate is traceable. At Tynemouth, Cleadon, and Fulwell many more or less fragmental portions of Cyprina islandica and Lnttorina littorea have been found. The most interesting point in connection with this raised beach is that it seems to decrease in height, both northward and southward, from what is probably the — [99d 7 “8g ar pazeysnyqr U0TOES JO OU] Ol} Suoye st Mota oy, ‘s}isodep [eroyaedns yIIM peyy ‘sXozpea [eIoepo-ead aoutut ayy Jo UO si “Joy oT} 04 Aeme Suryoyerjs pur UsIMyoq UT OTA “S][T}T UOPee|D Jo justdavose ouoysowLy-UvIsoMoR][ OY} SI IYSIA oy} UO eoUL}sIp ayy UT] ‘OO6T Wa vuayn, ydouhopoyd w wows ‘sppriFT jjanyng Uo yaneq pasmay —'G “Si Fig. 4.—Nearer view of the 150-foot raised beach on Fulwell Hills, from a photograph taken in 1900. 72 DE. WOOLACOTT ON THE SUPERFICIAL DEPOsITS, ETC. | Feb. 1905, exposure of maximum elevation at Cleadon and Fulwell. A gradual decrease in its height can be traced along the coast from its first occurrence south of Seaham, at an elevation of 80 feet, to Castle- Eden Dene, where it lies about 60 feet above sea-level. A raised beach, which was possibly formed at the same time, occurs at Saltburn, some 18 miles farther south on the other side of the Tees, its height there being 30 feet. If the height of the raised beach of County Durham is original throughout its course (and it seems to be so), we have evidence of differential north-and-south movements in the uplift that pro- duced it. The gradient is from 3 to 6 feet per mile. This aspect of the deposit has evidently a most important bearing on the con- clusion enunciated by Sir Archibald Geikie in his Anniversary Address to the Geological Society, Quart. Journ. Geol. Soc. vol. lx (1904) p. civ, namely :— ‘That the changes of level, of which our islands furnish such signal illustra- tions, have been primarily due, not to any oscillations of the surface of the ocean, but to movements of the terrestrial crust connected with the slow cooling and contraction of our globe. The raised beaches cannot be traced very tar inland, and this may imply that the uprise which produced them was greater near the coast ; in any case, a considerable extent of country must have been covered during the time in which they were being formed; and the action of the sea on the deposits of Glacial origin in levelling their surface, and forming derived beds of gravel, sand, and sandy clay from them, has been of great moment. The remains of submerged forests, which are exposed at irregular intervals, also occur, resting upon the other deposits at Howick, Whitburn, and West Hartlepool. I have had the oppor- tunity of examining the former two exposures, but more especially that at Whitburn, which is unmistakably the remains of vegetation that grew in situ. There seems thus to be undoubted evidence of two distinct movements since the Glacial Period—the first an elevation which produced the raised beach, and the second — a depression causing the submerged forests. Ill. Tue Distrisution, THickness, Erc. oF THE GuLactaL DEPpostts. The superficial deposits cover the larger portion of the great Northern Coalfield, comparatively little rock being exposed except in the higher portions of the district. Inthe South-East of Northumber- _ land the thicker masses of sandstone stand out above the mantle — of clay; while in Eastern Durham the Magnesian-Limestone escarp- ment forms a distinct feature, and its surface is not (except in the _ valleys) covered by any considerable thickness of superficial deposits — Some of the higher western ground of the Northern Counties was — never under ice, but stood out as nunatakkr during the Glacial - Period; and since the ice-flow mainly came down the valleys, the — higher parts of Mid-Durham have no Boulder-Clay upon them. The amount of rock exposed is shown on the Drift-maps of the Vol. 61.] OF THE NORTHUMBERLAND AND DURHAM COALFIELD. 73 Geological Survey in as accurate a manner as possible, and the maps appended to the present paper (figs. 7 & 9, pp. 82 & 85, & Pl. 1X) indicate the parts of the country where the rock comes to the surface. From some of the areas now bereft of a covering of clay, the superficial Glacial deposits have undoubtedly been removed, and the rock has been exposed along the courses of several of the post- Glacial streams, which have in many cases cut their way through rock rather than through Boulder-Clay. The surface-deposits lie arranged in the valleys formed before the Glacial Period, and in many of them reach a considerable depth. They thus fit upon and level up the pre-Glacial inequalities of the country, being thick along the hollows that existed before the Ice- Age, and rising to a considerable height along their sides. The deepest borings through these deposits are thus all found to le along the valleys, and, as a rule, to decrease gradually in depth as the higher ground along the flanks is reached. By mapping all the available sinkings it has been found possible to obtain the le of the rock-surface, and a true idea of the pre-Glacial surface of the country, provided that there have been no extensive differential movements since pre-Glacial times. The following are some of the deepest borings through the superficial deposits. It will be seen that many of them go to a considerable depth below sea-level before reaching the rock-surface, and that the maximum thickness attained by these deposits, so far as the data that I have been able to collect prove, is 283 feet at Newton Hall, Framwellgate, about 2 miles north of Durham. It is, however, very probable that they reach as much as 300 feet in the valiey of the ‘ Wash.’ | | HEIGHT oF Herenr (THICKNESS OF | ROCK-SURFACE | Locauity. | VALLEY, | ABOVE SUPERFICIAL ABOVE, OR SEA-LEVEL.| DEPOSITS. | DEPTH BELOW, | SEA-LEVEL: | | | Heed. Feet. Feet. Burdon Main ...... PAI aN cere Ah Sa i OW) 191 | —141 | Norwood New Pit ‘ Wash’...... 16 156 ee age UIT Blaydon vec. nae ae DO We ae are 195; Piwallsond! 1000 0 4. | Tyne ......... 72 ON paves 98 ) Percy Main ».....: | LON aaKen Lecomte ib LOO 193 | — 93 Sleek burn...) 02.2: | *Sleekburn {| 50 143 — 93 Clnietome..5 22. coos. +: PAINE cs ar. ahs rac 145 — 75 Camb OSes aes. alee. |‘Sleekburn’; 28 30 — 62 West Chevington.... ‘Sleekburn’ 55 102 | — 57 Pp ETAIEOM signi cca |‘Cleadon’...;| 86 128 — 37 Choppington ...... |‘Sleekburn’ , 105 Hoe Bails | — ll Newton Hall ...... (2 Washi use. _ 280 233 | — 3 Netherton....:......- ay eke | 210(?) 186 + 24 WOVVHaITO \.60../n ie Wee a Lcrociaits | 300 (?) 220 (?) + 80(?) Wabearparkeiy).:6.. ts: Browney 2 295 202 + 98 { SE aL oe § e oe [Throughout this paper the + sign indicates that the rock-surface lies above sea-level, the — sign that it lies below. ] 74 DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [Feb. 1905, The variation in the character of these deposits has been already discussed, and the following typical borings show the changing nature ae them clearly :-— Newton Hat, FRAMWELLG@ATE. Percy Main. Feet inches. Heet inches. SSO: Ba aration ane tee ees 6 Blue stony clay ......... 78 6 Namely clave ccs... a. cdr on ces 1 0 SMG cs ce eee a he ee 2 1 Sand, with ‘scares’ of coal 4 0 Blue stony clay ......... Ly) DSeae Sand, with water ......... 5 0 yee alemen Wentyclay 6.200) eee 1 6 Blue stony clay ......... soe Sand, with water ......... 1 6 Dry stony clay............ 5 ye Leafy clay, ‘scares’ of coal 8 6 Meat yelay 45.) neeee 2 6 Giavel me nc oa ae 4. Sands icac ue sede 1 8 Meaty olay. ce 6 2 Sanadand clays: 7s eeerer 2 3 aaiiy sande ees 8 0. Stony, clay). nee 2 4 Sbomvyaelawyimeuete caeaecer ae 2 5) co aetaecmmenp eo" ! u Sand, with water ......... D7 O ae and water ......... gl 5 ine Toamiys clave ayy seeenes ) if ae GIN Sos ccascsa025: Sandy clay WBE ead Aa 0 ® and ‘i Sonoda oduado0dsoCoN0N : th Cancitvitliana cae 10 9 Gravel 0). nc0s te eee ieee) Sott, leafy, claiy) eos.cnsee--: 7 Se ae seca ee 6g Total thickness ...... 1838 Uioamuyclaiye er sect shee ef) 0 Woamey Sande eee ee 10 ) Loamy sand and leafy clay ¢ 1 tomy clay a.-.esceece sneer . Sa aaa ae Stomiy Clave etat ese see 3 i) Total thickness ...... ZEN ENT) LV. THe pre-GuactaL SURFACE oF THE CouNTRY. A detailed study of the borings and of the exposed rock-surface enables us to form a fairly-accurate idea of the contour of the pre- Glacial surface of the country, and shows that the superficial deposits lie in a series of valleys which are (as will be more clearly proved afterwards) the courses of pre-Glacial streams. Therefore, if we had a sufficient number of sinkings, it would be possible to rec onstruct the pre-Glacial drainage of the country. An attempt is made in this paper, so far as the material at command admits, to do this. All the available borings have been put in on 6-inch maps, with their height above sea-level and the depth of the superficial deposits ; and then these have been transferred to 1-inch maps, which had the exposures of rock previously marked on them, and the height of the rock-surface above, or depth below, sea-level indicated. In this way the courses of the pre-Glacial valleys have been traced, - and the present contour of the rock-surface roughly mapped out. It has also been found possible to compare the pre- and post- Glacial drainage, and to show that the two differ considerably one from the other. The rock-surface in many of the valleys lies at a considerable depth beneath sea-level. The following are some of the deepest borings that prove this :— ~I Ov Vol. 61.| oF THE NORTHUMBERLAND AND DURHAM COALFIELD. DEPTH OF Locauiry. VALLEY. ROCK-SURFACE BELOW SEA-LEVEL. | Feet ee Burdon, Main se. ene. eID ye tee set est. | —141 2. Norwood New Pit ...... lesa WV atSlitaee Sater sat alan — 140 See laNlOM esc lo. sees, Pie CAVING eas tema e 5d —125 (?) Mer Waimesley sos. eee8ccsn0es [ee NN Falis lame pe a —116 5. Kibblesworth ............ CN Visita oe a Ne, 5. —108 Or Sleeks but s:.ccc0s-sne sna “Sleelsouimy eae. a: = Be felgency IMAI <.ssc0c.0ines Di yinek a Pecisaeidectiee — 95 Sem MIVbOM, —.i.6fcce ses cte es My inemeriees.ciudans — 7). Oe Cambois, sce SE Ane. GARI ‘Sleekburn’ ......... — 62 The maximum depth below sea-level at which the rock-surface is met is about 140 feet; and, judging from the number of borings, it is probable that this is about a true maximum. The height of the land is thus proved to have been in pre-Glacial times much greater than at present, and therefore the valleys in which the superficial deposits lie are the valley-track of a river-system, the streams having had their source in the Cheviots and Pennines, and the constructional shore-line lying far to the east of its present position. Indeed, at one time they may have been all tributary to a major stream running down the centre of the area now occupied by the North Sea (7). What the difference in height was we have no means of exactly judging, but that it was considerably over 140 feet higher is tolerably certain. Prof. James Geikie shows that, before the Ice-Age, Scotland stood at an elevation of from 300 to 600 feet greater than at present (3), and the borings discussed in this paper seem to point to a somewhat similar elevation for our part of the conntry. The principal pre-Glacial valleys were seldom entirely obliterated, because their lower portions only were filled with Boulder-Clay ; but the disappearance of some of the minor ones was complete. The ‘Sleekburn Valley’ (see p. 83) was entirely filled up, .and could not be determined from the surface of the country; but the pre-Glacial Tyne, the ‘Wash,’ and the upper part of the Wear were only partly masked by the covering of Glacial-deposits, and thus the solid rock still flanks the higher parts of these. V. Tue pre-GuacriAL VALLEYS. The principal pre-Glacial valleys and depressions are :— (a) The Tyne and its tributary valleys. (6) The ‘ Wash,’ (c) The Upper Wear and its tributary valleys. (d) The ‘Sleekburn Valley.’ ; (¢) The depression running out at Druridge Bay—the ‘ Druridge Valley.’ As these valleys are all fairly distinct one from the other, it will perhaps be best to give a detailed description of each, and to discuss their mutual connections as occasion arises. 76 DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [Feb. 1905, (a) The pre-Glacial Valley of the Tyne. This is perhaps of greatest interest, as some peculiarities occur in connection with it that are not found so distinctly in any of the ; na 1 f Oo. i) ule) UOPIng 2 . i=) f = 2 as UoWIUO MO7 aps S oH > Hy mn S e =~ f 5°38 AS ule) Aosed f ge = f x S (ea) esis aes dE PlO; UCR MCria uu S ss : = 23 ES : = ES 3 —— vt ) S§ pues]jeM | 8s e~ PA H Sie es | 25 SS s Ss 1 S — 5 x > SS Ss AIy\eM MOF 7 - ie XN SS vD N 2 Ss is SS v ee SS) es @ = Ss f ate = re FS Surya | = - H 5 > = Ss Sas iS > | ~S : I ao) ie) ~ ce} S = ‘Seo TS jane7 uSiIH aSeomen | Sem 3 = | og ee SSHIKG i z © 2) . | ae ers 4oIms|y | eke $3 | ose ms Se Se OIMS|F | $23 > | i ie) SS 136 OVS Hd MeN poomiony 2h a re > n - oO 2s SEs SS Bagh 5 o2a = 8 Se: Sd fs ss Bo oS = s kK pees SS uop eq ad Ss Sees SS page| mS" uophe|g | 2 aia = Bee SO S : : = ! pos Ss Oe = BAS = Age | H 32,8 } eae a ig Bok oe ‘s a 622 a A Zr + i ; uozAy | e (optometry ono nere i atTeco oat Or others. If borings down this river are examined, they are found to prove that the rock-surface lies at a certain level beneath that of the present river, but that the slope of it is not uniformly Vol. 61.] OF THE NORTHUMBERLAND AND DURHAM COALFIELD. tere eastward. Thus, at Norwood New Pit, about a mile above Newcastle, and at the confluence of the ‘Wash’ and the Tyne, solid rock is met with at a depth of 140 feet below sea-level, and at Burdon Main, 8 miles lower down, it is 141 feet below ; while, in between, all the borings prove it at a less depth, the maximum being 98 feet. This may be accounted for by supposing that none of the sinkings are in the deepest part of the pre-Glacial valley; if, however, they convey an accurate idea of the present real slope of the rock- surface, we have here (if the conception of the pre-Glacial valleys contained in this paper be correct) a definite proof of considerable differential east-and-west movements during or since Glacial times. The only way in which such an interesting point in the superficial geology of the Northern Coalfield could be settled, would be by making a line of borings across the Tyne Valley at some place between Norwood New Pit and Burdon Main, and thus obtaining the greatest depth of the rock-surface at some definite part. Until such a series has been completed, the explanation of one of the most interesting questions connected with the pre-Glacial valleys of the great Northern Coalfield, and with the geological history of the rivers of the North-Kast of England, must remain conjectural. It has been already stated that the raised beach cannot be traced very far inland, and that therefore the elevation that took place when it was produced may have been a differential one, being accentuated along the coast (p.72). If this beso, we may have here the explanation of the non-deepening of the rock-surface of the Tyne Valley as the sea is approached. The following are the principal borings down the Tyne, from Ryton to its mouth :— Dee ees HEIGHT OF ROCK- Locatiry, Autirupe, | superrrcian | SURFACE ABOVE, Be ass OR DEPTH BELOW SEA-LEVEL, Feet. Feet. Feet. | Ry LOTUS e, eam bo hike Sune 67 2 35 ISS) heer eo eaane ae oe ene 20 40 | — 20 AY COIR oe eas tein Se sat at: 20?) | 145 = II22 Necrwood New Pit ......... 16 156 — 140 TSSSING Sekt ane aya? aa Oe a 0 68 | — 683 Newcastle High Level ...... 0 70 | — 70 Ife raja ee ee ce ie eae 75 hy | — 57 How Walker \s ide eteeces. 60 | 133 — 73 NWallisencd: ya.. 4s sso acto: al | 170 — 99 Howdon Old Pit ............ 50 | 133 — 83 Perce Matinee. sans neces 100 | 193 — 93 | iBurdoms Main, —....00 662 50 191 —141 | ‘ The altitude of the G Pit at Wallsend is given as 172 feet in the ‘ Boriugs & Sinkings,’ but from the maps I suspected this to be wrong, and the manager, Mr. Phillips, kindly took the level for me. It proves to be 71:02 feet. 2 Two others give similar evidence, one of —109 and aonther —77. 3 Many borings along the Tyne at Elswick afford corroborative evidence. 78 DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [Feb. 1905, The accompanying section (fig. 6), drawn across the Tyne from Billy Mill to Westoe, is especially interesting and important, because tn ys ep) | fs = SS A i S | > i | < = & } z nF ie = S is ez S |= 3 I oO ‘S$ ‘SPIR1US “S ‘SPIIH “1g —-—.—. .—| , ypu Si 3 - SPISINS BS aror WN Sire cae earns | | oisty << 5 B = I 1 Ss o i | 2 Se hi Wa Ss Ei Ss 2 H SS i-wHi E IS a ft Zz mM @ 8 uA A214) 1! \Onisaees = Se eames sf Peilocs 8S Ny SS) , | jal ae ws ule) UOpang — co eal | cy BRS eS (7) YOY —-—-—.—} Palo Se Mw Y~ Su ii ee oS I oe 2s ()USHINO = | a5 ‘“~» Q | —_ Se [ 5 § s 3 uo WIYO MO —-:—:— - c ee Bs f| 8. 2B SS) ~ AOE = x a E = = Se oils dak Nn -« S&S S S SORTS ca s = le) Uke S eis Hd 11emedoy — -—- Ee a Se ) a 8 SS be oO ws By, 1 uw O § >! Yd VOURYD—'—— '—— * Fy ‘an fs S "Ss foes Oo Kee P AQ = Pi ont E : eel) Wa & S Q@eooae o}|| O ia S (1) YOY — -— -—- iy SH a = Pear eS 5S (oe a Te = | On] = 3 S || a ay a | oc o | i oe ro) > = g ee) RY) eer | — We) Was fi eb WAL Attia | fe i los ; nek | WHA Alig —-—-—- = SOSNOYAOO|/ --—- —- Vv = of the numerous borings through which it passes, enabling the lie of the rock-surface to be obtained with the greatest accuracy. Vol.61.] OF THE NORTHUMBERLAND AND DURHAM COALFIELD. © 79 The borings are :— | | Supmr- | hea | SupEr- ALTITUDE.| FICIAL Aurrrupn,, FICIAL | DEPOSITS. | | DEPOSITS. Feet. Feet. || Feet. Feet. (a) Moorhouses ... 230 6 (h) Low Chirton ... 1025 ot (6) Billy Mill ...... 215 15 (2) Chirton (3)... CO tt (e) Chitrton Hill...) 201 i) (7) Chirton (4) ...! 62 119 (ad) Chirton (1)... 160 42 (A) Burdon Main...! 50 191 (e) Chirton (2) ..., 158 Gare (iste elilcais 2p: | 30 58 (f) Chance Pit... 130 60 (m) St. Hilda’s, | '(g) Hopewell Pit...) 100 Chen South Shields. 40 | 35 Although throughout the greater part of its course the post- Glacial Tyne flows at a higher level above the rock than the pre-Glacial river, there being a considerable thickness of superficial deposits between the present river and the rock-surface, yet the general trend of the two valleys is the same, the one being super- imposed on the other. specially is this so in the higher reaches, where the courses of the two waterways are almost identical ; but in its lower parts, east of Newcastle, the rock is cut into at many places, as, for instance, at Felling Shore, Bill Quay, and St. Anthony’s, and therefore the agreement between the old and the new valleys is not so pronounced, the course of the present river differing considerably from that of the former river in this region. Tributary streams entered the pre-Glacial Tyne on the south side from the Allen, Devil’s Water, Stanley Burn, Derwent and Cleadon valleys, and the Wear flowed into it down the ‘ Wash’ ; while from the north it received the North Tyne, and a smaller stream through Newcastle, a little to the west of the Ouseburn. (0) The ‘ Wash.’ The course, depth, and characteristics of this valley were thoroughly worked out by Nicholas Wood & E. F. Boyd in 1864 (1), and, although the genesis of such a valley was not clearly understood at that time, yet the description of it is so excellent as to require little further addition in this paper. Those writers showed that _the ‘Wash’ extends from near Durham to the Tyne, and is filled throughout with a great thickness of Boulder-Clay and beds of sand and gravel. It is entirely carved out of the Coal-Measures, through the Hutton and other seams, and the workings in the various collieries along its sides have often been stopped by the coal abutting against the superficial deposits along this valley. At Durham the rock-surface, as proved by colliery-workings at Elvet a little to the south, lies a tew feet beneath sea-level, and the maximum depth of 140 feet is found at Norwood New Pit, near the junction of the ‘Wash’ and the Tyne. As shown by Wood & Boyd, its slope may be uniformly northward, but there is one part lying 80 DR, WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [Feb. 1905, between Chester-le-Street and Kibblesworth along which the borings do not conclusively prove this. At the former locality the rock- surface iies at 983 feet, and near Kibblesworth at 111 feet, below sea-level. Between these there is at Brown’s Buildings a boring, which was stopped in clay when a depth of 55 feet below sea-level had been reached. The greatest thickness of superficial deposits occurring in the ‘ Wash,’ as ascertained by the borings, is 283 feet at Newton Hall, Framwellgate (about 2 miles north of Durham), but the depth may reach as much as 300 feet near that city. In the paper just referred to, the course of the ‘ Wash’ appears to be a straight line, this being due to the manner in which it is drawn, as all the area, over which the depth of the deposits lying in it exceeds 40 feet, has been coloured; but the actual path of the deepest part of the valley, or line along which the pre-Glacial stream flowed, may be a sinuous one. The number of borings is, however, not sufficient to enable the course of the ancient river to be worked out with any great exactness. The depth of the rock-surface and the field-evidence prove that at its upper end the ‘Wash’ debouches into the valley of the pre-Glacial Wear, and that it was the route taken by the drainage-waters of the west of Durham County immediately before the Glacial Period. It received a tributary stream from the east by Harraton, as it is most probable that the watershed between the ‘ Wash’ and ‘Cleadon’ Valley (a tributary valley of the Tyne) had been lowered along the line taken by the present river Wear, by two streams, one flowing into the ‘ Wash,’ and the other down the ‘Cleadon’ Valley into the Tyne. Phe deposits filling the ‘ Wash’ are, perhaps, the most varied of all such deposits as have been studied in the district. Associated with the blue stony Boulder-Clay are beds of sand and gravel lying below, in, or upon it; and leafy clay occurs at many parts near the surface. The origin of these various formations has been already fully discussed. The Wear flows along the southern end of this valley, often, however, leaving the trend of it and cutting. down through the superficial deposits into the rock ; while the Team flows in a northerly direction over the top of them, high above the level of the rock-surface. The watershed between these two rivers is a very low and indistinct one. The course of this valley and its connections with the pre-Glacial Wear and Tyne can be clearly followed on the map (Pl. IX). (c) The Upper Wear and its Tributary Valleys. As in the case of the Tyne, the higher parts of the pre- and post- Glacial Wear valleys and their tributaries correspond. Those existing before the Glacial Period were partly filled with superficial deposits, which reach a thickness of 110 feet at Escomb and 81 near Bishop Auckland; but they were seldom entirely obliterated, Vol. 61.; O¥ THE NORTHUMBERLAND AND DURHAM COALFIELD. 81 and hence the new streams that formed after that epoch agreed in direction with the old. The chief difference is that, while the pre- Glacial streams ran over the rock-surface, the present watercourses flow in the same valleys over thick deposits of Boulder-Clay and the _ associated formations. Thus, the upper Wear and its tributaries (the Beechburn, Bedburn, and Linburn) all flow over Boulder-Clay in well-marked valleys of pre-Glacial development, and another tributary waterway of the same age is now occupied by the Gaunless. Below Bishop Auckland the trend of the old and new valleys still continues to be very much the same as far as Durham. At Page-Bank Colliery, near which the pre-Glacial course probably passes, there is a thickness of 108 feet of superficial deposits, with the rock-surface lying at an elevation of 150 feet. The old valley then runs a little to the east of Sunderland Bridge, and afterwards by Butterby Mill, where there is a thickness of 155 feet of surface- deposits ; then, stretching through by Shincliffe and Old Durham, it keeps on the east side of the city of Durham, and joins the valley of the ‘ Wash’ already described. The following are the principal borings down the Wear, from Bishop Auckland to Durham, and thence along the valley of the ‘Wash’ to Norwood New Pit :— | | Decut oo HEIGuT OF ROCK- Locauirty. Autitups.|surerricrat| SURFACE ABOVE, peposrrs, | 0% DEPTH BELOW, SEA-LEVEL. Higet ay | Heer Feet Ge Bishop Auckland: (2.2.0.2 .:.: 300 81 +219 (2) Page-Bank Colliery ............ Helo) 108 +150 @)ebutterby Mall fin. th ..s.ss 270 155 +115 Comullivetat ollltenye S iyssisnce da cant” scene 120 OF (5) Newton Hall, Framwellgate...| 230 233 — 3 (6) Ford Cottage, west of Cocken rallies Ser sch erchehateeerin 40 90 — 50 (7) Chester-le-Street ............... peal 134 — 93 (8) Brown’s Buildings ............ 110 (?) — 55°" ormore (9) Near Kibblesworth ............ 50 161 —l1l11 RONG Maines ley Fee sass anased. 05k t aeewe 50 166 —116 Cie Neat tieh, eam’ 4.5..c2..-22-- 25 158. —1383 (12). Norwood New Pit <........... 16 156 —140 ' The rock-surface lies slightly below sea-level at this point, as proved by ponkings) in Elvet Colliery. 2 This horing was discontinued in the superficial deposits, after passing > through 165 feet of them. a eckeoda Bishop Auckland and Durham the pre-Glacial Wear _ received several contluent streams, the principal of which came Q.J.G.8. No. 241. G [‘sqisodop je1oyzodns Xq poysvur st 41 etot[MasTO : 2dvJ.NSs oY} 0} SATIOD yooa pITos oy} ody L.1GUNOS O49 Jo s}Aed osoyy eyeorpuT suOTyIod popeys oy] NOLONITG3¢4 a2 ‘smotun oy) fg paworpur sr yoryan fo wuoyoourp apqngoud ayy ‘han 4 wingyaaqg , 7prwD79-24d ay) 07 UIngyaag pun ‘yripg ‘yooqsun yy 247 fo shanna ynwn)5-ss0d oy) fo uoynjan oy) Hurmoys doyy—' }, *S1q Vol. 61. ] SUPERFICIAL DEPOSITS, ETC. OF THE NORTHERN COALFIELD. 83 down the valleys of the Deerness and the Browney from the west. Both of these have a considerable thickness of Boulder-Clay in them ; the former 81 feet near Ushaw Moor, with the rock-surface at an elevation of 219 feet ; and in the latter, quite near the river, and opposite Witton Gilbert, is a boring showing 202 feet of super- ficial deposits, with the rock-surface at an elevation of 93 feet. From the east two other valleys, formed by obsequent streams, joined the pre-Glacial Wear: one came down by Bowburn and Shincliffe colliery—at the former of which localities there is 120 feet of Boulder-Clay, while at the latter there is 174 feet, the rock lying at an elevation of 126 ; and the other ran down from the Magnesian- Limestone escarpment, passed between Pittington and West Rainton, then through Sherburn, joining the Wear Valley a little to the south of Durham. | The pre-Glacial Wear thus appears to have received all the waters from the west of Durham County, and taking up several large tributaries between Bishop Auckland and Durham City, the whole drainage was, immediately before the Glacial Period, poured down the valley of the ‘ Wash,’ and eventually into the pre-Glacial Tyne. Not only does the evidence from the borings support this hypothesis, as already explained in the description of the ‘ Wash ’ (p. 79), but the field-evidence is entirely in favour of such a view. The Wear below Durham leaves the trend of its pre-Glacial course, and passes over what was (before Glacial times) probably the water- shed between the ‘ Wash’ and ‘Cleadon’ Valleys; thus it has perforce developed an entirely-new valley since the Glacial Period. The Wear, indeed, as in the case of many other of the rivers of post- Glacial development, seems to have preferred to carve its way through rock rather than over the superficial deposits ; the explana- tion of this most interesting phenomenon will be discussed later (p. $9). Its valley is cut deep through the Coal-Measures at Finchale Abbey, and it flows over similar strata at Hylton, while at Sunder- land it has carved a well-defined valley in the Permian rocks. The map of the pre-Glacial Wear, ‘ Wash,’ and Tyne (Pl. IX) enables the course and connections of these valleys to be traced, and their depths can be ascertained from the numerous borings shown. (d) The ‘Sleekburn Valley” (Figs. 7 & 8, pp. 82 & 84.) This valley is first distinctly proved by borings at Morpeth, at which place the rock-surface lies at a depth of 13 feet below sea-level. It may be traced through Choppington, Sleekburn, and Cambois, reaching a maximum depth of —93 feet at West Sleekburn Colliery. At Cambois, which is nearer the sea, the solid rock is proved at — 62 feet, but this may not be the maximum at this point; or, it may be that we have here evidence of Glacial or post-Glacial movements, as in the case of the Tyne (p. 77). G2 84 - DR. WOOLACOTT ON THE SUPERFICIAL DEPOSITS, ETC. [| Feb. 1905, The principal borings near the line of the pre-Glacial ‘ Sleekburn Valley’ are :— [oles ys ln | Duets HEIGHT OF ROCK- ‘ AxrirupE. jsuperricrat| SURYACE ABOVE, | pevosins. | Of DERHE BEnones | SEA-LEVEL. : y: Feet. | | Peet. Feet. | Korey oye! fl Saari amin, Aen 90 | 103 = |S Choppington (south)...... | 105 | 116 —1l Choppington (north) ..| 120 | 126 4g West Sleekburn ......... 50 | 143 —93 { ; | Cambor: setae ee [iets 90 —62 ! | Although the connection cannot be proved by borings, the field- evidence and the exposures of rock in this part of the country show that the ‘Sleekburn Valley’ is probably a continuation of that of Fig, 8.—Section across the pre-Glacial ‘Sleekburn Valley,’ between North Seaton and Bebside. ~~ LE! > vw NS (oD) apes = > o ed fe) se, 0 0 vd = OO = To) c Cc > O °° os ra ws o oO go vY oO bo (dp) = Sc 2 et eee 2) < S feee @ 3 ey. North Z2 @2 = o = jl Seaton ||| s | 7) 6 joe = LL ‘) ot 2l w “naiee S25 as MORE Raised bear, O— Se-6 +302: G&200 Ey n Fate De' Pan Unn Dyas 74407 2 BISHOP BUCKLE n= Map or raz Wrar, ‘Wasn,’ and Tyne pRu-GLACIAL VALLEYS. Ci Dh Pee, BPE pepasbet slr peopriee ere. irae. age cca ae alr Sa oe ye wis aa Can Sey ———— er Vol. 61.] oF THE NORTHUMBERLAND AND DURHAM COALFIELD. 95 8. Barrow, G. ‘The Geology of North Cleveland’ Mem. Geol. Surv. 1888, Quart. Sheets 104. 8.W., S.E. 9. Davis, W. M. ‘The Development of certain English Rivers’ Geogr. Journ. vol. v (1895) p. 127. 10. Fox-Straneways, C. ‘The Valleys of North- Kast Yorkshire & their Mode of Formation’ Trans. Leicest. Lit. & Phil. Soc. vol. 111 (1895) p. 333. 11. Wootacort, I). ‘On the Boulder-Clay, Raised Beaches, & Associated Phen oti elie of the East of Durham’ Proc. Univ. of Durham Phil. Soe. vol. 1, pt. iv (1899-1900) p. 247. 12. Woonacort, D. ‘Ona Portion of a Raised Beach on the Fulwell Hills, near Sunderland’ Nat. Hist. Trans. Northumberland, Durham, & Newcastle-upon- Tyne, vol. xiii (1900) p. 165. 13. CowrEerR REED, F. R. ‘ The Geological History of the Rivers of East Yorkshire 1901. [Sedgwick Prize-Essay for "1900. | 14, Kenpatt, PF. ‘Ona System of Glacier-Lakes in the Cleveland Hills’ Quart Journ. Geol. Soc. vol. viii (1902) p. 503. 15. DwerryuouseE, A. R. ‘The Glaciation of Teesdale, Weardale, & the Tyne Valley & their Tributary Valleys’ Quart. Journ. Geol. Soc. vol. Iviii (1902) 572. 16. note, G.A. Proc. Univ.of Durham Phil. Soc. vol. ii, pt. 1 (1901-1902) p. 81. ie Wooracort, D. ‘Geological History of the Rivers flowing over the Coalfield of Northumberland & Durham’ Proc. Univ. of Durh. Phil. Scc. vol. iy Pte Tt (1902-1903) p. 121. EXPLANATION OF PLATE IX. Map of the Wear, ‘ Wash,’ and Tyne pre-Glacial valleys, on the scale of 4 miles to the inch. The principal borings, giving the height of the rock-surface above, or its depth below, sea-level, are shown; the parts of the country where the rock comes re the surface are shaded, the other parts (left blank) are covered by superficial eposits. A = Height of the rock-surface on the higher ground, as obtained from the Ordnance-Survey maps. The names of the principal pre-Glacial valleys are marked by inverted commas, and the arrows indicate the direction of these valleys. The map also shows the post-Glacial course of the Wear from Durham to the sea. The country lying east of the Permian escarpment slopes gently eastward, and was denuded by a series of eastward-flowing streams before Glacial times, the present streams being superimposed upon the old watercourses. The position of the raised beach on Fulwell and Cleadon Hills is shown, and its ex posure along the coast is also indicated. Discussi0n. The Prestpent, while not venturing to discuss the theoretical questions dealt with by the Author, said that he was glad to welcome a collection of facts of great interest, namely, the scattered records of deep borings in Drift-accumulations, Capt. A. R. Dwerryuovss said that he had listened to the paper with considerable interest, and congratulated the Author upon the admirable and important work which he had accomplished. The pre-Glacial valleys which he had described were particularly inter- esting to the speaker, on account of their similarity to certain valleys in Yorkshire. In the southern portion of Yorkshire there were two types of pre-Glacial valleys running below sea-level, namely : the one, gorge-like valleys, such as that at Barnby Dun (near Doncaster), in which the rock-surface was reached at 170 feet 96 SUPERFICIAL DEPOSITS OF THE NORTHERN COALFIELD. [ Feb. 1905, below Ordnance-datum, while borings in the immediate neighbour- hood reached it at a considerably smaller depth ; the other, a wide and open type, was represented by the Vale of York, the rock-floor of which some 8 or 10 miles south of York would have a breadth of several miles at the contour of 50 feet below Ordnance-datum. In calling attention to this wide. pre-Glacial valley beneath the Vale of York, the speaker desired to point out that, from its form, it must be an ancient valley, and must have required a prolonged period for its excavation, during which the land stood at a higher level than at present. The Author had mentioned that several of the pre-Glacial valleys of Northumberland were apparently shallower near their mouths than they were inland, and the same was the case in Yorkshire, there being no records of any deep channel connecting the Vale of York or ane Barnby-Dun Gorge with the sea, alone a large number of records existed of boreholes (both in the neighbourhood of the Humber Gap and also in the town of Hull); while farther south, the solitary cutting through the barrier formed by the Oolite- escarpment was Lincoln Gap, where the rock-floor lay at a depth of only 23 feet below sea-level. With regard to the question of raised beaches, as pointing to a post- Glacial uplift of the coast-region, the only available evidence in Yorkshire was the pre-Glacial beach at Sewerby, which was now at sea-level, and could not therefore be correlated with the great depression of the Vale of York. In conclusion, the speaker enquired whether the valleys which the Author had ‘described were of the broad or narrow type. The AurHor expressed his thanks for the manner in which his paper had been received. In reply to Capt. Dwerryhouse, he said that the pre-Glacial valleys were all broad, the Tyne being 2 miles wide at sea-level near its outlet into the North Sea. The difficulty of the slope of the rock-surface of the Tyne not being uniformly eastward, might be explained either by the borings not being made in the middle of the valley; or, more probably, by the fact that there had been differential movements since pre-Glacial times. The main conclusions drawn from the study of the pre-Glacial valleys, namely: (1) that the land stood higher in pre-Glacial times, and (2) that the valleys were produced by a series of eastward- flowing streams—seemed to the Author indisputable. Vol. 61. | THE DOLOMITES OF SOUTHERN TYROL. 97 8. On the Coemicat and Mineratocicat Evipence as to the OriGin of the Dotomirss of Sournern Trrozt, By Prof. Ernusr Witiineton Sxzats, D.Sc., F.G.S. (Read December 7th, 1904.) [Puates X- XTV—Microscops-Secrions. | I. InrropvctTion. Tue country of the ‘ Dolomites’ has long been classic ground to geologists. The researches of Dolomieu’ at the end of the eighteenth century, and of L. von Buch * early in the nineteenth, first aroused the interest of geologists'in the district. Their attention at first was mainly directed to speculations concerning the mode of origin of the mineral, named after the French geologist, of which the moun- tains are so largely composed; this question, even at the present day, is far from settled. The stratigraphy of the district has always presented many points of difficulty. The earlier observers, struck by the contrast in scenery and composition between the bold, precipitous, dolomite-masses and the marls and stratified tuffs of the green pasture-lands or ‘ Alpen,’ were at a loss to explain their mutual relations, especially as very few fossils were at first discovered in any of the deposits. In 1834, however, Graf Miinster,’ who had examined the strata near St. Cassian, enumerated, and (in part) described and figured 400 species of fossils from them, and subsequent observers have added largely to the number. The precise age of these deposits, which had till then been a matter of discussion, was settled by the examination of their fossil contents. It was shown not only that the beds were of Triassic age, but that, unlike the Trias of most of the Kuropean areas, they had been deposited under marine conditions. In 1845 Bronn* suggested that the St. Cassian fauna had inhabited a shallow sea where coral-banks were numerous. The stratigraphy of the district was first systematically described by Baron Ferdinand von Richthofen,’ in a brilliant paper, in which he claimed that the curious relations of the dolomitic and non-dolo- mitic strata could be explained if it were assumed that the masses of dolomite represented altered coral-reefs formed during a period of subsidence, while the St. Cassian marly and tufaceous deposits were laid down in the lagoons, bays, and channels of a coral-sea. i ‘Observations sur la Physique, &c.’ vol. xxxix (1791) p. 3. 2 “Ueber Dolomit als Gebirgsart’ Abhandl. d. k. Akad. Wissensch. Berlin, 1822-23 & ‘ Hinige Bemerkungen iiber die Alpen in Baiern’ 207d. 1828, p. 84. 3 Neues Jahrb. 1834, pp. 1-15 & pls. i-ii; see also ibéd. 1842, p. 119. 4 Ibid 1845, pp. 504-508. > «Geognostische Beschreibung der Umgegend von Predazzo, St. Cassian & der Seisser Alpe in Siid-Tyrol’ Gotha, 1860, 4to. Q.J.G. 8. No. 241. a 98 PROF. EB. W. SKEATS ON THE [| Febienges. Richthofen gave a complete account of the literature on the subject which had appeared up to 1860. His views were amplified by the work of Dr. E. von Mojsisovics and the officers of the Austrian Geological Survey, and their results were published in 1879 in the former’s book.’ C. W. von Giimbel,? Dr. R. Lepsius,’ and others opposed the coral-reef theory of the origin of the Dolomites. In more recent years, Mrs. Ogilvie Gordon has paid much attention to the stratigraphy and the tectonics of this area, and in a series of papers * has considerably extended our knowledge of the geology of the district. She has emphasized the objections to the coral-reef hypothesis ; she regards the Schlern Dolomite as a deep-water marine deposit, and seeks to explain the reef-like character of the dolomite- mountains as a result of complicated earth-movements in Tertiary times. Among the latest publications on this district is a handbook of the International Geological Congress, published in 1903, by Prof. C. Diener and Dr. G. von Arthaber, which embodies the results of the most recent work in the area of which it treats, and includes a list of the most recent papers on the subject. In May 1904, the important work ‘ Bau & Bild von Césterreich’ was published, and Prof. Diener was responsible for that part of it which deals with the Dolomites of Southern Tyrol. While most geologists are now in agreement upon the general stratigraphical succession of the deposits in the Dolomites, it will be seen that antagonistic views are held as to the mode of formation of the rock-masses which now constitute the dolomite-mountains. Those who uphold the coral-reef theory point to :— (1) The great resemblance of the isolated dolomite-masses to upraised reefs, and the fact that corals are occasionally found preserved in them. (2) Their ‘ heteropic’ character, masses of dolomite thousands of feet thick representing in age, and tailing off laterally into, marly deposits of much less thickness. (3) ‘ Reef-blocks’ found on the slopes of the Dolomites, and apparently intercalated among the sedimentary deposits outside them. (4) The unbedded character of the rocks and their great thickness. (5) The fact that the rocks, like recent reefs, are often dolomitized. 1 ¢Die Dolomit-Riffe von Sid-Tirol & Venetien Vienna, 1879. 2 «Das Mendel- u. Schlern-Gebirge’ Sitzungsber. d. math.-phys. Classe d. k. bayerisch. Akad. d. Wissensch. vol. iii (1878) p. 14. 3 ‘Das Westliche Siid-Tirol’ Berlin, 1878, 4to. 4 «Contributions to the Geology of the Wengen & St. Cassian Strata in Southern Tyrol’ Quart. Journ. Geol. Soc. vol. xlix (1893) p. 1; ‘Coral in the Dolomites of South Tyrol’ Geol. Mag. 1894, pp. 1 & 49; ‘The Torsion- Structure of the Dolomites’ Quart. Journ. Geol. Soc. vol. lv (1899) p. 560; ‘Monzoni & Upper Fassa’ Geol. Mag. 1902, pp. 309 & 384; and ‘The Geological Structure of Monzoni & Fassa’ Trans. Edin. Geol. Soc. vol. viii (1902-1903) special part. Nol; 67. | DOLOMITES OF SOUTHERN TYROL. 99 The opponents of the coral-reef theory state that :— (1) The general absence of corals in the dolomite militates against the coral-reef hypothesis. Calcareous alge and echino- derms, but not corals, are the most common fossils. (2) The apparent thinning-out of the dolomite into marls and ashes is due to faulting, while the Schlern Dolomite really succeeds the St. Cassian Marls, and does not pass laterally into them. (3) The reef-like shape of the masses is a structural feature due also to faulting. In view of the large amount of work done within the last 10 years in the exploration of recent coral-reefs, and the examination of the materials of which they are composed, it may serve a useful purpose to enquire if the results obtained are of such a character as may prove helpful in determining the question whether the dolomite- mountains do or do not represent old coral-reefs. The researches of Prof. Alexander Agassiz in many parts of the Atlantic, Indian, and Pacific Oceans, the expedition to Christmas Island under Dr. C. W. Andrews,’ and to the eastern group of the Fiji Islands under Mr. E. C. Andrews of Sydney University,” have added largely to our knowledge of the structure and origin of up- raised coral-islands. Mr. J. Stanley Gardiner has put on record his observations at Funafuti and in the Maldives’; while the borings at Funafuti in 1896 and 1897 (under the leadership of Prof. Sollas, and afterwards of Prof. David) provided the means for the systematic examination of the materials composing a typical atoll down to a depth of 1114 feet. The Funafuti Report has recently (1904) been published by the Royal Society. The chemical examination of the cores was commenced by Dr. C. G. Cullis, and continued by Mr. J. Hart-Smith and myself, under Prof. Judd; and one of the most interesting results obtained, apart from the highly-dolomitic character of parts of the material, consisted in the discovery that the rocks forming the cores were of extraordinary purity, being practically free from insoluble residue. During the progress of the examination of the Funafuti materials, I had an opportunity of making a chemical and microscopical examination of the collection from the upraised mass of Christmas Island, and of a selection from the collections of Prof. Agassiz, Prof. David, and Mr. EK. C. Andrews from the Fiji Islands and other parts of the Pacific Ocean. The results obtained were published in June 1903, in vol. xlii of the ‘ Bulletin’ of the Museum of Comparative Zoology at Harvard College. There I drew attention to the fact that :— 1 Geogr. Journ. vol. xiii (1899) pp. 17-385 (with map) & ‘Monograph of Christmas Island’ Brit. Mus. (Nat. Hist.) 1900. > Bull. Mus. Comp. Zool. vol. xxxviii (1900) pp. 1-50 & pls. i-xxxix. 3 Proc. Camb. Phil. Soe. vol. ix (1898) pp. 417-503. : ii ¢ 100 PROF. E, W. SKEATS ON THF [Feb. 1905, (1) In those coral-islands which are remote from land-areas and volcanic rocks, the amount of insoluble residue in the hme- stones was negligible. (2) In coral-islands associated with volcanic rocks many of the limestones were found to be practically devoid of residue, but those in the proximity of the volcanic masses contained a larger quantity, amounting in some cases to over 4 per cent. It will be noticed that in a recent coral-reef, either the whole or some part of the materials of which it is composed is devoid of insoluble residue. It is obvious that this total or partial absence of insoluble residue ought to hold good as well for a fossil coral-reef as for a recent one. I determined, therefore, to visit the Dolomites of the Tyrol, to make representative collections in this much- debated region, and to see whether a chemical and microscopical examination of the specimens would afford any evidence as to the mode of origin of the deposits. By the favour of the Council of this Society in making me the first recipient of the proceeds of the Daniel-Pidgeon Fund, I was enabled to spend a considerable part of the summer-vacation of 1903 in making typical collections of the Triassic rocks in the district. I am indebted to Prof, Judd for giving me the opportunity of analysing the material collected, and I am glad to be able to lay before the Society the results of the investigation. The area visited is all included within the roughly-circular basin in which the typical dolomites of Southern Tyrol are best seen. The fundamental rocks, exposed only at the border of the area, consist of quartz-phyllites and schists of great antiquity, possibly of Archean age. The earliest sediments are Permian, and succeeding these are the Triassic deposits, which cover the greater part of the basin. The Alpine movements of the mid-Tertiary age originated a series of flexures and faults, of which the majority trend roughly north-and-south and east-and-west. The shallow anticlines formed as a result of these movements have, to some extent, determined the directions of the valleys. The northern and southern valleys include those of the Eisack, Fassa, Agordo, and Ampezzo. The eastern and western valleys are not so well defined (with the exception of the Pusterthal in the north of the area), and for the most part form subsidiary depressions joining the more prominent northern and southern valleys. Over the greater part of the area, the dolomite-rocks of the Upper Trias are exposed at the surface, while the Middle and Lower Triassic deposits are only seen on the flanks of the valleys. The Permian rocks are occa- sionally exposed in the deepest parts of these valleys. The strati- graphical succession varies somewhat in different areas, owing to the heteropic character of the deposits. In three typical localities it is as follows :— Vol. 61. ] DOLOMITES OF SOUTHERN TYROL. 101 oo ae Seiser Alp. Tre Croci and Cortina. Dackstem Dolomite. | 9 rscsecrse. Dachstein Dolomite. emivleiedige a ee) Raibl Beds. Pachycardium-Tufts. Schlern or St. Cassian Dolomite. Schlern Dolomite. St. Cassian Marls, St. Oassian Marls and Limestones. Upper Wengen Beds. Wengen Sandstones. Augite-Porphyrite Augite-Porphyrite Wengen volcanic rocks. (Lower Wengen). (Lower Wengen). Buchenstein Limestone. | Buchenstein Limestone. Mendola Dolouite. Mendola Dolomite. Dont Schiefer Dont Schiefer. (Lower Muschelkalk). Campiler Schiefer. : eiser Schiefer, } WGTESE bea, Permian. The dolomite seen on the north-eastern flank of the Schlern Mountain, and in the Marmolata, Langkofl,* and Plattkofl massifs corresponds in age both to the Wengen and to the St. Cassian Beds. When followed eastward and northward, the dolomite is seen to rest upon St. Cassian deposits, and represents only the upper part of the dolomite from the areas just mentioned. The Schlern Dolomite is the massive deposit that gives the characteristic appearance to many of the isolated massifs. It is this deposit which is generally claimed as being of coral-reef origin, and it is this horizon which I have particularly examined. The Mendola Dolomite has also been supposed to owe its origin to coral- reef conditions in mid-Triassic times. Il. Tue Cuemicat EvipENcE. The results of the chemical analyses of the specimens obtained from the localities visited will now be given. A few complete gravimetric analyses were made, and the results of these are recorded to two places of decimals. In the case of the majority of the specimens, only the insoluble residue and the iron and alumina, when present, were gravimetrically determined ; the calcium was estimated volumetrically by a method described fully in a previous paper, and the amount of magnesium was obtained by difference. The results of the volumetric analyses are recorded only to one 1 The section of the rocks on the north-western flank of the mountain shows that the massive dolomite is underlain by bedded dolomitic limestones closely resembling the Buchenstein Limestone. Mrs. Ogilvie Gordon, however, has proved St. Cassian Beds on the eastern flanks of the mountain, and believes that: the dolomite-masses overlie the St. Cassian Beds. 2 Bull. Mus. Comp. Zool. vol. xlii (1903) p. 53. DIAGRAMMATIC SKETCH-MAP OF PART OF SOUTHERN TYROL. 4 iy PERN IRIE iia i (a Schluderbach Nj 7 = y OD wy LIN, WW Mii 32) e Milli. a) AS USMij._ Bs » wos w, &h Z Hy SS me ANS Tay, Swe, RRA Na {i > N\ FAW, Mp his” Wy My Gisifz itt MY Up G STI SLE ION LOTy (y NWS P2ligos The? KLAUSEN te.Cristallo an 4 D a S) P=) Z NSW roci C J Tass wy Sy Ml ns Ty oy Cortinalo Y 7] : Mann Z Sq tn’ RS 33 Zi 2 3 Y a avego & LY Z w me iy } : ; io 66 ... Ones ee OEE Alp. No. 72 came from the es Heer Aas 0-026 eastern base of the Strudelkopf, 68...) 55:2 439 1:93 the southern continuation of the 62 ...| 544 44°3 1:26 Diirrenstein massif. Nos. 68 & CE a 69 contain a_ relatively - high amount of residue, the remaining three specimens practically none, while all are dolomites of well nigh theoretical composition. 108 PROF, E, W. SKEATS ON THE [Feb. 1905, The Drei Zinnen Area. CaCO,. | MgCO,,. | Insol. res. | The three specimens were col- No. | Per cent.| Per cent. lected during the descent of te 87 | 453 | ase the upper part of the Rienz ty ik ue on | ey Thal, on the western flanks of “f i the Drei Zinnen. No, 714 was not in place. All three specimens represent dolomites devoid of insoluble residue. it now remains to record, for comparison with the Schlern Dolomite, analyses from rocks below and above it. Analyses from Beds below the Schlern Dolomite. Wengen Limestone. The Wengen Beds of CaCO,. ; MgCO,. | Fe,O,. | Insol. res. , : No. | Per cent.| Per cent. Per cent. the Seiser Alp include 22 cal 64:9 47 4-62 20°84 some limestones, and an analysis of one of them (No. 22) shows that a very high percentage of insoluble residue and less than 5 per cent. of magnesium-carbonate are present. Buchenstein Beds. Immediately below the dolomite of the Schlern, Langkofl, and Marmolata comes a nodular siliceous limestone—the Buchenstein | Limestone. Two analyses were CaCO,.| MgCO,. Residue.| made from this horizon. No. 18 me Per cent, P pee = eee is from the base of the Schlern, Seal). Shy, ale hsG | 9:73 above Bad Ratzes; No. 88 from the Gader Gorge, in the Valley of Abtei, about 1 mile north of St. Leonhard. Both analyses show a high percentage of insoluble residue and a small amount of magnesium-carbonate. Mendola Dolomite. The Mendola Dolomite occurs only in certain districts, and represents a local modification of the Upper Muschelkalk. No. 19 is from the Schlern massif, below He CaCO. | MgCO,, | Residue.) the Buchenstein Limestone and a es ae Per cent.| Per cent. above Bad Ratzes. No. 26 is 26 | By4 ive 73 from the Putels Schlucht, north of the Seiser Alp, and leading into the Groden Valley. The insoluble residue in each case approaches 1 per cent., and the magnesium-carbonate falls short of ae Mm a theoretical dolomite by i or 4 per cent. Vol. 61. | DOLOMITES OF SOUTHERN TYROL. 109 Lower Muschelkalk. Only one analysis was made from this horizon, the specimen (No. 86) being taken from the Gader Gorge in the Valley of CaCO,. | MgCO,. | Residue. : J HO Por cont Per con | Pow cone,| Abtei. Ib will be noticed that co eee 566 | 122 , 31:20 | therock contains comparatively- little magnesium-carbonate, but much insoluble residue. Aualyses from Beds above the Schlern Dolomite. _ Succeeding the Schlern Dolomite is a deposit of variable character, marls containing gypsum, coral-limestones, or dolomitic rocks. They are known as the Raibl Beds, are usually iron-stained, and are never of any great thickness. Following these comes a great thickness of limestones or dolomites, usually of a bedded character, known as the Dachstein Beds. These form the uppermost beds of the Trias, corresponding in age to the Rheetic deposits, and they are in some places more than 3000 feet thick. Dachstein Dolomite. No. 1 is from the summit of the CaCO,. | MgCO,. | Insol. res. 7 Te eRe bei ct ante Be No. 0. rom the southern flanks o Per cent.| Per cent.. Per cent, Monte Cristallo, below Tre en, OOD 43:4 07 a A te Hes fate No. 61 from the Val de Travernanzez, eA er ite 45°9 pees west of Moute Tofana. oe ease No. 104 from the western end of Sett Sass. In each case the specimens were collected from the base of the deposit, immediately above the junction with the red Raibl Beds. It will be noticed that the base of the deposit is a dolomite of very great purity and approaching the theoretical composition. The Dachstein Beds are not always so devoid of insoluble residue, for Profs. Doelter & Hoernes’ record two analyses of dolomites containing respectively ‘67 and ‘98 per cent. of residue, the first from the summit of Pordoi (south of Monte Sella), the second from the Fanis Alp. Croci. Raibl Beds. No. 4 is from the Schlern plateau, just below Burgstall; while No. 73 is from below the CaCO,. | MgCO,.| Insol. res. | military post on the western No. | Per cent.| Per cent.| Per cent. flanks of the Diirrenstein Fs ° ° 9 cS a se Ba oper Be: above the Seeland Alp. In each case the amount of in- soluble residue present is considerable. 1 Jahrb. d. k.-k. geol. Reichsanst. vol. xxv (1875) pp. 322, 328, 110 PROF. E. W. SKEATS ON THE [Feb. 1905, III. Discussion oF THE CHEMICAL RESULTS. In considering the results of the foregoing analyses, two points of especial interest arise :— (1) The mode of formation of masses of dolomite. (2) The significance of the presence or absence of insoluble residue in a limestone. The first point will be dealt with in considering the mineralogical evidence. Sir John Murray’s work in connection with the Challenger Kx- pedition added largely to our knowledge of the nature, composition, and mode of formation of the deposits which are now being laid down on the sea-bottom. It was found that in all the deep-sea deposits insoluble residue was present in amounts which rarely, if ever, fell below 1 per cent., often reached 3 to 5 per cent., and occasionally rose to as much as 20 per cent. It is generally agreed that deep- sea deposits rarely attain any great thickness, since they accumulate with extreme slowness. The presence in deep waters of carbon- dioxide under pressure determines the solution of much of the calcareous parts of the tests of the minute organisms which form the deposit, and as solution proceeds the proportion of insoluble to calcareous material becomes greater. From external sources other products, such as finely-divided volcanic material and cosmic dust, also contribute to the amount of insoluble matter in deep-sea formations. When a deposit composed of the skeletons of calcareous organisms is being laid down near a coast formed of non-calcareous rocks, finely-divided detrital matter intermingles with the calcareous skeletons, so that the resulting limestone is rendered impure. Some thin fringing coral-reefs may be of this character. I have recorded an analysis of such a reef-rock from Singatoka (Viti Levu). Shallow-water impure limestones may also be formed by the intermingling, not of detrital matter, but of finely-divided volcanic débris with the purely-calcareous material. Recent coral- reefs growing in the vicinity of volcanoes ejecting ashes often have such insoluble matter included within them. Mango, an upraised coral-island in the Lau group of the Fijis, provides an ee ns of an impure limestone of this character.* A chemically-pure limestone must have been deposited under some such conditions as the following :— 1. The material must have accumulated rapidly. If it had been slowly deposited, solution of the calcareous parts of the organisms and the raining-down of volcanic material and cosmic dust would raise the percentage of insoluble residue. 2. The deposit must have been laid down in shallow water, since only under these conditions do calcareous organisms exist in sufficient abundance to give rise to thick and rapidly-formed deposits. 1 Bull. Mus. Comp. Zool. vol. xlii (1903) p. 79. ; 2 Ibid. pp. 71-78. Vol. 61.] DOLOMITES OF SOUTHERN TYROL, ah a! 3. In general, such a limestone would not be deposited near a non-calcareous shore-line, nor in the vicinity of volcanoes ejecting ashes. These conditions are fulfilled, so far as I am aware, by only one kind of deposit forming at the present day, namely in coral-reefs, especially in those remote from great land-masses. I have already drawn attention ' to the high degree of purity of the limestones from many of the upraised coral-islands of the Indian and Pacific Oceans ; while, in the Report on the Atoll of Funafuti,* the chemical results demonstrate that this typical atoll is composed entirely of Jimestone and dolomite almost wholly free from insoluble residue. In considering the origins of limestones of geological antiquity, we may Say in general that :— 1. A chemically-pure limestone has been formed under ‘ coral- reef’ conditions. 2. A limestone which, throughout its bulk, does not contain less than 1 per cent. of insoluble residue, has been formed either in deep water or as a detrital deposit, or has been laid down within the range of the finer ejectamenta from a volcano. 3. A limestone which in parts is pure, and in parts contains residue, has probably been formed under ‘ coral-reef’ conditions, but from time to time the area of deposition has been invaded either by detrital or by volcanic material. We are now in a position to interpret the results of the analyses, so far as the amount of residue which they contain may throw light upon the mode of origin of the deposits. Wengen and St. Cassian Dolomites. Area of the Schlern. From a consideration of the amount of residue alone, one might be led to conclude that the rocks in this area represent deep-sea deposits, since most of the analyses show well over 1 per cent. of residue. One specimen, however, contains only :2 per cent. If the deposit were of deep-water origin, we should expect it to be thin and well-bedded. We have to deal, however, with a mass of unbedded dolomite approaching 3000 feet in thickness, laid down contemporaneously with a much thinner series of shallow-water limestones, marls, and tuffs, formed over the area of what is now the Seiser Alp, to the north of the Schlern massif. The probability is, then, that this mass of dolomite represents a lime- stone rapidly formed in a subsiding area, and impreg- nated with very finely-divided volcanic material from submarine volcanoes lying to the north. This view is supported by the fact that, interbedded with the Schlern Dolomite a few hundred feet above its base, there occurs a deposit, a few feet thick, in which the volcanic fragments are bigger 1 Bull. Mus. Comp. Zool. voi. xlii (1903) pp. 103-104. * Roy. Soc. 1904, pp. 368 ez segg. 112 PROF, E, W. SKEATS ON THE [Feb. 1905, and so numerous that the rock assumes the character of a submarine caleareous tuff. In this connection it may be mentioned that a partial analysis of the insoluble residue from specimen No. 7, near the Schlern plateau (p. 103), gave 64:26 per cent. of silica and 23°23 per cent. of ferric oxide and alumina. Slight reactions for calcium, magnesium, and sodium were obtained, and a stronger indication of the presence of potassium. A short distance below the summit of the Schlern, on the southern and western sides, a later outpouring of the augite-porphyry lava is interbedded with the Schlern Dolomite. Area of the Langkofl. The two specimens which contain much residue come from material lining the steep eastern slope of the mountain, and possibly represent a reef-talus. Analyses from the solid mass of the mountain show only a trace of residue. This, in conjunction with the great thickness of the deposit, supports the view that it was a coral-limestone formed during subsidence. Area of the Marmolata. Of the specimens collected in situ, two contain no residue, and two analysed by Profs. Delter & Hoernes’* are similarly free from insoluble matter. The only specimen containing an appreciable quantity (-6 per cent.) was collected from near the junction of the dolomite with the contemporaneous lava poured out to the north of the area. The facts again favour the view of the formation of the deposit as a coral-limestone during a period of subsidence. _ The three areas just considered were subjected to similar condi- tions of deposition, during a movement of subsidence commencing not later than the Wengen period (in the Schlern area it commenced in the Upper Muschelkalk period), and continued until a ‘negative’ movement which set in at the commencement of the Raibl period. In the remaining areas to be considered, the formation of the deposit, which now consists mainly of dolomite, did not commence until after the deposition of the Lower St. Cassian Marls and Lime- stones. It is not surprising to find, therefore, that the dolomite is much thinner than in the areas already considered; at Tre Croci, near Cortina, for instance, the thickness is reduced to about 300 feet. St. Cassian Dolomites. Area of the Sella. An examination of the results of analyses from the dolomite of the Sella shows a progressive decrease in the amount of residue present, from below upwards. It would seem that to the north and east of the Schlern, Langkofl, and Marmolata massifs we 1 Jahrb. d. k.-k. geol. Reichsanst. vol. xxv (1875) p. 319. Ps sain Wolk, 61. | DOLOMITES OF SOUTHERN TYROL. 113 have an area which, after the cessation of volcanic activity in St. Cassian times, consisted probably of shallow-water depressions and lagoons in which the subsequent deposit was laid down. At first, no doubt, the reefs were contaminated by detrital fragments from the volcanic deposits in the neighbourhood, and this is borne out by a chemical examination of the deposits. As subsidence and deposition continued, the volcanic detritus was gradually sealed up, and the subsequently-deposited material became freer from residue, as is seen from an inspection of the results of the analyses from higher horizons. It may or may not be significant that the later-formed limestones have been more completely dolomitized than the older deposits in this area. The St. Cassian District. The analyses would appear to indicate that the Lavarella mass is free from residue, and is probably of coral-origin. At Sett Sass, south of St. Cassian, the first-formed deposit, like that of the Sella, was mixed with insoluble material, and the origin of the two deposits appears to be the same. ‘The Richthofen Reef, a lenticular mass in the earthy St. Cassian Limestone, below the dolomite of Sett Sass, appears to have been formed during a quiescent period, in clear water devoid of sediment. The Cortina District. The faulted dolomite-mass of Col Crepa and Belvedere contains little or no residue, and appears to have been a coral-limestone formed rapidly in clear water. The analysis from the Hexenfels rock near Cortina also indicates a dolomite of great purity. The remain- ing analyses, from scattered localities in the neighbourhood, show generally more residue, and the rocks were possibly deposited in a coastal area supplying detrital material to the deposits. The Durrenstein Area. The dolomite in this northern part of the district is much thicker than near Cortina. Rapid deposition under reef-conditions in a subsiding area would appear to have set in at the commencement of the period (an analysis from the base of the Strudelkopf shows no residue), and to have continued until the close, with intermittent deposits into which detrital matter was introduced (Nos. 68 & 69). The Drei Zinnen Area. The specimens from the Rienz Valley at the base of the Drei Zinnen are dolomites of great purity, in all probability deposited under reef-conditions. We have now to consider the composition of the beds below and above the Schlern and St. Cassian Dolomites, In areas outside the Schlern, the Langkofl, and the Marmolata, Q.J.G.S. No. 241. I 114 PROF. E, W. SKEATS ON THE [ Feb. 1yo5, the dolomite rests upon limestones and marls, named after St. Cassian, where they are well seen. They are for the most part earthy lime- stones, oolitic in places, and probably of detrital origin, since for the most part they contain a rather large amount of residue. Locally, as at Sett Sass, they become very rich in beautifully- preserved branching corals, and an analysis of one of these shows that, while it is very ferruginous, it is almost devoid of insoluble residue. On the Seiser Alp, intercalated with the voleanic tufts of St. Cassian age, lenticular masses and blocks of limestone or dolomite, which are known as ‘ Cipit’-limestone, occur. Ananalysis of a specimen taken from one of these blocks shows it to be highly dolomitic and to contain surprisingly-little residue (-73 per cent.), considering its intimate association with the St. Cassian tuffs. As these blocks not infrequently contain reef-forming corals, there seems little doubt that they represent scattered reef-like patches of corals, which established themselves during a temporary abatement of volcanic activity in the areas in which they are found. An analysis of one of the earthy Wengen limestones found on the northern slopes of the Seiser Alp, shows a great admixture of insoluble matter, probably volcanic in origin. Proximity to land is indicated by the local occurrence (in the Gader Valley, for instance) of plant-remains in the Wengen deposits. The Buchenstein Limestones, while not. so earthy as those of Wengen age, are shown in two cases to contain between 7 and Y per cent. of residue, and are probably of detrital origin, as contemporaneous volcanic rocks of Buchenstein age appear to be rare. The Mendola Dolomite contains over 40 per cent. of magnesium- carbonate, and rather less than 1 per cent. of residue in the two examples analysed. It presents, therefore, a considerable resem- blance to some of the Schlern Dolomites, and may have been formed as a reef to which some detrital material had access. The only remaining limestones from the Older Triassic rocks are of Lower-Muschelkalk age. These are very impure, an analysis of one from the Gader Gorge showing over 30 per cent. of residue. They are, in all probability, of detrital origin. Possibly the older crystalline rocks of the neighbourhood were not entirely submerged, and these would serve to account for the presence of so much insoluble matter. After the formation of the Schlern Dolomite the area of deposition was restricted, in consequence of ‘negative movements’; some of the area was raised above sea-level, and the succeeding Raibl Beds were laid down in lagoons, salt-water lakes, etc., for we find that in different places the Raibl deposits vary greatly in character. Reddish marls, sandstones, gypsum, dolomite, and patches of coral are all represented. Possibly some of the magnesium in these beds is to be attributed to direct deposition from concentrated salt-water, and the erosion and solution of some of the Schlern Dolomite, as well as the presence of minute volcanic fragments, would suffice to account for the 3 or 4 per cent.’ of insoluble residue found in ds nee eee ta ae dial Vol. 61.] DOLOMITES OF SOUTHERN TYROL. 115 some of the dolomites of Raibl age. At the close of the Raibl period a further depression of the district became general, and thoroughly-marine conditions supervened. The first-formed Dach- stein deposits were probably of the nature of coral-reefs, since the base of the dolomite is very free from residue. The bedded character of most of the deposit and its fossil contents make it probable that, for the greater part, it was of sedimentary origin, and Profs. Doelter & Hoernes record two analyses from the upper part of the mass in which the residue approaches | per cent.' TV. Tue MIneratoGicat EVIDENCE. About eighty of the specimens collected were sliced, with a view to the examination of any organisms which might be recognizable, and for the study of the mineralogical characters exhibited by the various limestones and dolomites. The results of the examination of the sections of Schlern Dolomite will be considered first, and afterwards the results obtained with rock-sections from other horizons will be stated briefly. The Schlern Dolomite. Area of the Schlern. No. 7. Bedded dolomite, from the edge of the Schlern plateau. Transverse and longitudinal sections of echinoderm-spines occur, while similarly-orientated coral-sections are recognized somewhat doubtfully, owing to loss of structure during dolomitization. Both allotriomorphic and idiomorphie crystals of dolomite are present, the idiomorphic crystals having cloudy centres. Minute iron-stained patches scattered throughout the section may represent finely- divided volcanic matter. No. 8. About 500 feet below the edge of the Schlern plateau. No organisms can be identified. The former presence of corals may perhaps be inferred from the meandrine arrangement of those dolomite-crystals which have regularly-arranged dark centres. Minute brown inclusions present are almost isotropic, and may be volcanic. : No. 10. About 800 feet below No. 8. (See Pl. XI, fig. 1.) The section consists largely of allotriomorphic, dark-centred dolomite-crystals exhibiting a meandrinearrangement. Some minute opaque iron-stained fragments are to be seen. No. 11. About 300 feet below No. 10. No organisms have escaped the loss of structure consequent upon dolomitization. The section consists of allotriomorphic cloudy crystals of dolomite, with scattered fragments of magnetite and green augite, the latter being similar in appearance to the pyroxenic constituent of the tuffs and lavas of the Seiser Alp. 1 Jahrb. d. k.-k, geol. Reichsanst. vol. xxv (1875) pp. 322, 328. ho 116 PROF. E. W. SKEATS ON THE [Feb. 1905, No. 12. About 300 feet below No. 11. This is a submarine calcareous tuff. Numerous fairly-large and rounded fragments of a fine-grained decomposed basalt or melaphyre occur. lLath-shaped crystals of plagioclase and irregular fragments of magnetite are set in a brown structureless matrix, while steam- cavities are lined or filled with low-polarizing chlorite. Two or three basic types of basalt are present, some so dark in colour as to be almost opaque; others are much more felspathic, while some brown and almost isotropic palagonite-fragments occur. These are enclosed in a matrix consisting partly of clear calcite, partly of dolomite with regularly-arranged brown inclusions. The volcanic fragments are in contact indifferently with dolomite and with calcite. This association lends no support to the view that the volcanic fragments constitute the source of the magnesium present in the rock. No. 13. This specimen occurs below No, 12, at the foot of the vertical cliff, and at the top of the talus-slope passed on the descent of the mountain towards Bad Ratzes. 7 The rock consists of a very fine-grained allotriomorphic dolomite, and contains no recognizable organisms. 3. Rolled block from the stream, just above Bad Ratzes. (See Pl. XITI, fig. 2.) Dark-centred dolomite forms the bulk of the rock, and is arranged in a meandrine way which suggests the former presence of corals. The rock is cavernous, and the cavities have been lined by a secondary deposit of clearer dolomite deposited from solution, and showing alternate layers of clearer and more cloudy dolomite. No. 31. Summit of the Rosszihne. Much meandrine dark-centred dolomite is present, together with later-formed, bigger and clearer dolomite-crystals. Some small reddish fragments, possibly voleanic, are seen in the section. No. 27. ‘Cipit-dolomite’ from a block on the Seiser Alp. A fine-grained rock, consisting mainly of idiomorphic erystals with cloudy centres. Some of the rhombohedral kernels of the crystals have been removed, either by solution or by grinding when making the slice. A few reddish fragments occur, and are probably of volcanic origin. Area of the Langkofl. No. 95. Fallen block from the eastern flank of the mountain. A rock which shows both concentric and radial structures in the hand-specimen, but radiating crystals only in section. No idio- morphic crystals are present. No. 94. Material lining the eastern flank of the mountain. A fragmental rock which, from its appearance and mode of occurrence on the flank of the mountain, is suggestive of a reef- talus. A dark calcareous cement embeds broken, idiomorphic, dark- = Pavol. Gr. | DOLOMITES OF SOUTHERN TYROL. 117 centred dolomite-crystals. Some of the dark centres of the crystals are composed of calcite, as they are stained by Lemberg’s solution. The majority of the crystals are cavernous on a microscopic scale, and this gives the appearance of cloudiness to these individuals. Onc clear crystal of orthoclase, showing both cleavages, is to be noted, and exceedingly-minute, dark-reddish to opaque particles are possibly of volcanic origin. No. 92. Above the bedded dolomite, at the head of the valley above Wolkenstein. . An allotriomorphic, slightly-cavernous dolomite. The former presence of meandrine organisms is indicated by the arrangement of the dolomite-crystals with dark centres. Area of the Marmolata. No. 35. Southern shore of the Fedaja See; from a height of 6500 feet. A limestone crowded with small branching structures, which under the quarter-inch objective appear to be chambered. A few dolomite-crystals and fragments of crystals are present. Some of these have regularly-arranged dirt-inclusions, while others consist of alternate zones of dolomite, calcite, and again dolomite. Meandrine patches of cloudy material represent decomposed organisms. Much of the calcitic groundmass is cloudy, and polarizes not in distinct crystals, but as an aggregate. Planes of movement and recrystallization are noticed inplaces. Where recrystallization has resulted in the formation of large twinned and cleaved crystals, these are in places found to be crowded with minute acicular bodies. At first these seem to be opaque, but when closely examined they are seen to be translucent. One fragment, possibly volcanic, is present. No. 34. West of No. 35 and lower down the valley, northern part of the Marmolata. Similar generally to No. 35. The branching chambered structure © is common. ‘The section has been stained with Lemberg’s solution, and some of the branching structures appear to be cavities in the slice filled with the stain, since they do not affect polarized light. The great majority, however, show pclarization- colours, and, as is usual with organisms, they are stained more deeply than the background. Most of the slice consists of calcite, twinned and cleaved, and showing planes of movement and small veins of secondary calcite. A few crystals and fragments of idiomorphic dolomite occur. Some of the fragments look clastic, and extinguish not’uniformly but as an aggregate, which would suggest that a secondary change in the mineral had occurred. No. 33. A few feet above No. 34. No dolomite is present, and planes of movement are very con- spicuous. In other respects it closely resembles Nos. 34 & 38, and the branching structure is again common. 118 PROF, B, W. SKEATS ON THE [Feb. 1905, No. 32. From an immense fallen block, lower down the valley than No. 33. (See Pl. X, fig. 2.) A large part of the slide consists of idiomorphic rhombohedral dolomite-crystals. The crystals are cloudy, with inclusions arranged parallel to their boundaries, and some of these inclusions are calcite. The rhombohedra are porous on a minute scale, and show the characteristic cleavages. The dolomite-crystals are set in a background of large platy crystals of calcite, which show lamellar twinning as well as cleavage. Signs of movement in the rock are common, and no organisms remain. Area of the Sella. The following specimens were collected from the slopes of the mountain, near the head of the Groden Pass. No. 101. Block fallen from above. The greater part of the section is composed of cloudy allotrio- morphic dolomite-crystals, often arranged in a circular manner and suggesting sections of corals. Empty spaces in the rock are lined and nearly filled with clearer and more idiomorphie crystals of the same mineral. No. 100. Near the summit of the Groden Pass. (Pl. X, fig. 1.) Large areas of calcite include partly-disintegrated organisms resembling calcareous algee (Spherocodium 2?) which are only recog- nized by a ‘dirt-line’ marking the external boundary of the organism, apparently devoid of organisms. VI. RELATIONS BETWEEN THE FossIts AND THE ORIGIN or THE Rocks CONTAINING THEM. Before attempting to interpret the results arising from the examination of the fossil contents of these rocks, especially of the Schlern Dolomite, it will be convenient to consider briefly our present knowledge as to the organisms composing coral- limestones, and the changes that they undergo. In the first place, it has been shown that corals play a much less important part in building up coral-reefs than was formerly supposed.! Calcareous alge are often more abundant than the corals; foraminifera and echinodermata often bulk largely; and polyzoa, lamellibranchiata, and other organisms are occasionally present in fair abundance. The sequence of mineralogical and structural changes which coral- limestones undergo—a subject originally studied by Dr. Sorby—has in recent years been rather closely investigated. I have already dealt with some of the more striking changes occurring in upraised coral-islands?; while Dr. C. G. Cullis* has examined in greater detail the mineralogical constitution and structural changes in thin sections of the rocks from the Funafuti boring. It is found that organisms, the skeletons of which are composed of aragonite, are abundant in the most recent limestones, but gradually become recrystallized as calcite; and this change is accompanied by a loss of structure in the organism. For this reason, all the reef- forming corals, the gasteropoda, and some of the calcareous alge, 1 R. L. Sherlock, Bull. Mus. Comp. Zool. vol. xxxviii (1903) p. 349; EH. W. Skeats, 2bid. vol. xlii (1903) p. 53; & G. J. Hinde, ‘ Funafuti Report’ Roy. Soe. (1904) p. 882. Bull. Mus. Comp. Zool. vol. xlii (1903) p. 53. 3 ‘Punafuti Report’ Roy. Soc. (1904) p. $92. Wol. 61. | DOLOMITES OF SOUTHERN TYROL. 127 such as Halimeda, are much less readily recognized in thin sections of limestones in which this change has taken place. When, as not infrequently happens, dolomitization of the limestones occurs, not only are all traces of the organisms previously mentioned generally obliterated, but the more stable organisms with calcite-skeletons, like the echinodermata, the foraminifera, and most of the calcareous alge, begin to lose structure, owing to the invasion of crystals of dolomite. In general, the more complete the dolomitization, the more complete is the destruction of the organisms composing the rock, until a perfectly-structureless, homogeneous dolomite may be formed. In recent coral-limestones these changes can be traced gradually in a succession of sections; but the early stages in the life-history of the Triassic dolomites of Southern Tyrol are closed. Allthe rocks are altered. Where they are not dolomitized, they have been recrystallized as the result of earth-movements ; and where the rocks are undisturbed, dolomitization has been so complete that many of the rocks are dolomites of theoretical composition. In recent coral-limestones the rocks are often quite devoid of organisms ; and it is therefore not surprising to find in rocks of Triassic age, which are often more completely dolomitized than any recent lime- stone, that organisms are always scarce, and in 45 per cent. of the sections are apparently unrepresented. It will be seen that, with regard to the origin of the Schlern Dolomite, the evidence afforded by a consideration of its organic contents alone is inconclusive. The question is not whether the Schlern Dolomite was originally a coral-limestone entirely composed of corals, but’ whether or no it was a coral-limestone of a more common type (of which Funafuti and Christmas Island yield examples), wherein calcareous alge and foraminifera bulk largely, while corals occupy an important but relatively-subordinate position. It is not possible to say definitely from this evidence that it was originally a coral-limestone; on the other hand, it seems to be equally unsafe to conclude with some geologists that the comparative absence of corals in the present condition of the rock proves that they were never present in the original limestone. The solution of the question as to the origin of the Schlern Dolomite should be sought on other than paleontological evidence, which, so far as it goes, does not preclude the possibility of the deposit having originated as a coral-limestone. VII. MINERALOGICAL SLRUCTURES AND CHEMICAL CHANGES In THE LimEstonges AND DoLomIreEs. Mineralogical Structures. The examination of numerous thin sections from recent coral- limestones’ has served to show that, in general, three types can 1 EH. W. Skeats, Bull. Mus. Comp. Zool. vol. xlii (1903) pp. 105 et segg..; & C. G. Cullis, ‘Funafuti Report’ Roy. Soc. (1904) p, 404. 128 _ PROF, E. W. SKEATS ON THE [ Feb. 1905, be recognized, each being characterized by some mineralogical peculiarity. 1. Many of the more recent limestones, while consisting largely of calcite, contain also organisms, the skeletons of which consist of aragonite; and not infrequently secondary aragonite has been deposited in crystallographic continuity with the aragonite of the organism. 2. Gradual alteration and recrystallization of the first type of limestone leads to the production of a rock in which organic remains and matrix alike consist entirely of calcite. 3. The replacement of calcium-carbonate by magnesium-car- bonate in limestones either of Type 1 or Type 2 leads to the formation of a third type, characterized by the presence of crystals of dolomite ; in some cases, the replacement proceeds so far that the limestone is entirely converted into dolomite. | (1) Examination of many sections of rocks belonging to the horizon of the Schlern Dolomite shows that the first type of lime- stone, characterized by the presence of aragonite, is now wanting. The St. Cassian Limestone of Sett Sass, however, provides a very interesting example of the aragonitic type of limestone. A section of a coral, when examined under a high power, shows a remarkable preservation of the original aragonite-fibres of the coral and of the secondary aragonite formed in crystallographic continuity with them. With this single exception, none of the rocks examined contained any crystals of aragonite. (2) The Marmolata massif affords good examples of limestones consisting entirely of the mineral calcite. The rocks have been much recrystallized asa result of earth-movements, so that lamellar twinning is very common in the calcite-crystals, which are generally allotriomorphic. Many of the St. Cassian Limestones also consist entirely of calcite and calcite-organisms. (3) Among the rocks in which the mineral dolomite occurs we have :— (a) Dolomitic limestones, and ({3) Dolomites proper, In rocks belonging to the group a magnesium-carbonate gene- rally forms from 10 to 30 per cent. of the mass, so that a larger or smaller amount of calcite is always present. In these lime- stones, the dolomite-crystals are generally markedly idiomorphie. One of the Marmolata rocks (No. 32) shows fine idiomorphic dolomite-crystals, surrounded by a matrix of calcite (Pl. X, fig. 2). The same feature is seen on a minute scale in No. 77, one of the St. Cassian oolitic limestones, in which tiny rhombo- hedra of dolomite occur, and are restricted to the matrix of the rock (Pl. XI, fig. 2). No. 34, one of the Marmolata rocks, is a limestone containing broken fragments of dolomite-crystals which have no definite extinction, and are possibly of detrital origin. No. 37, a dolomitic limestone from the Giau Pass, contains a longitudinal section of a coral with dolomite-crystals deposited in a Vol. 61.1] DOLOMITES OF SOUTHERN TYROL. 129 definite arrangement within the coral. What is still more inter- esting, is the occurrence within the mass of the coral of extremely- minute, perfectly-clear, doubly-terminated quartz-crystals, which constitute about 1 per cent. of the rock (Pl. XIV, fig. 2). When the dolomitization of a limestone is nearly complete, it is noticed that the dolomite-crystals mutually interfere, so that the erystals are mainly allotriomorphic. Among the Schlern rocks, No. 7 affords a good example of a rock approximating to a dolo- mite of theoretical composition, and containing both idiomorphic and allotriomorphic crystals. With the production of a pure dolomite, the rock usually becomes quite structureless and the crystals almost entirely allotriomorphic. No. 56, from the Hexentels, is a good example of this type of dolomite. Dolomite-crystals are sometimes quite clear and transparent. More generally, however, they are seen to contain cloudy matter ; and this is generally orientated within the crystal, sometimes constitufing a dark centre, sometimes being arranged in one or more zones parallel to the rhombohedral outline of the crystal. These cloudy centres and zones may originate in several different ways. Prof. Watts has shown, in the case of the dolomites of the Carboniferous Limestone,’ that this cloudy material is insoluble matter caught up and regularly arranged during the growth of the erystals. My own observations indicate four additional causes :—- ii a some dolomites, staining with Lemberg’s soiution has shown that the cloudy matter is calcite. 2. In other dolomites, especially those of theoretical composition, there is little doubt that the cloudy matter consists of finely- divided dolomite, which does not stain with Lemberg’s solution. 3. In some of the St. Cassian limestones the dolomites are zoned _ with cloudy chalybite, more or less altcred to iron-oxide. 4. Occasionally, these cloudy areas, when examined under a high power, have been seen to be due to numerous minute ‘cavities in the crystals. There is no direct evidence to show whether these cavities are original, or due to subse- quent solution of certain parts which, owing to their physical state or chemical composition, were more susceptible to the solvent action of sea-water. ‘Their irregular distribution in the parts of the crystals in which they occur 1s against the latter view of their origin. Quite apart from the zoning in dolomite-crystals produced by this si ‘ Geology of the South-Wales Coalfield, pt. ii: The Country around Abergavenny ’ Mem. Geol. Surv. (1900) pp. 34-36. G.3.G.S. No. 241. K 130 PROF. E. W. SKEATS ON THE (Feb. 1905, cloudy material, another type of zoning is occasionally seen ! both in dolomites from Mango (Fiji), and also on a smaller scale in certain of the Tyrol dolomites. Before a rock is stained, it may appear to contain perfectly-homogeneous, clear, idiomorphie crystals of dolomite. Staining with Lemberg’s solution shows, however, that the crystal is composite in character, and is composed of alternate layers of calcite and dolomite (less frequently chalybite forms one of the mineral-layers). The layers are in optical and crystallographic continuity, and the whole appears to form a single crystal. Chemical Changes in the Limestones and Dolomites. Compared with recent coral-limestones, these ‘Triassic rocks present one or two interesting, if minor, points of difference :— 1. Only very minute traces of calcium-phosphate are found. In coral-limestones ‘2 per cent, is a fairly-common amount, and occasionally beds of phosphate are met with, as at Christmas Island. The circumstance that the earliest bird so far discovered is of Kimeridge age, is sufficient to account for the absence of beds of limestone altered to phosphate in the area of the Dolomites. 2. Recent coral-limestones show no trace of silicification. This is remarkable, in view of the fact that among the living organisms present in coral-reefs, siliceous forms sometimes constitute at least 1 per cent. of the whole. The colloid silica of which their skeletons are composed must be peculiarly soluble under the conditions existing in a coral-reef, for no trace of siliceous organisms has ever been found in a recent coral-rock. The same is true of the Tyrol limestones and dolomites, with the significant exception of the quartz- crystals occurring in the coral-section of No. 37. This quartz may represent the colloid silica of siliceous organisms, redeposited in the crystalline state. 3. In the Tyrol dolomites dolomitization is often more complete than in the case of any recent coral-limestone. From Christmas Island * and from the Funafuti boring, two dolo- mites which were analysed gave just over 43 per cent. of magnesium-carbonate; but, in general, a condition of stability ensued when the percentage of magnesium-carbonate amounted to about 40. Many of the Tyrol rocks are pure dolomites, containing 45°65 per cent. of magnesium- carbonate, but no rock has been found to exceed the latter amount. 1 K. W. Skeats, Bull, Mus. Comp. Zool. vol. xlii (1903) pp. 117-18. 2 Ibid. pp. 96, 162. . Vol. 61.] DOLOMITES OF SOUTHERN TYROL. 131 Formation of the Dolomites. The most important chemical problems in Southern Tyrol are, perhaps, the following :— 1. The mode of origin of those wide-stretching and thick masses of dolomite, of which the Schlern Dolomite is the most con- spicuous example. 2. A second problem is encountered in the attempt to explain the circumstances under which some areas, such as the Marmolata massif, escaped dolomitization, while most of the limestones of the same age are almost completely dolomitized. 3. The association of some of the dolomites of the Raibl Beds with gypsum-deposits suggests a different origin for these rocks. 4. The local dolomitization of some of the St. Cassian limestones along cracks in the rock would seem to require a special explanation. The early views of L. von Buch on the origin of dolomite were formed as a result of the examination of the dolomites of the Tyrol, and they involved the ascent of heated magnesium-vapour from the outpourings of the Triassic volcanic rocks, which are found in association with the dolomites. Modern chemists would not agree with the chemical reactions involved in such a process, and, apart from this, the distribution of the dolomites has no causal relation to the distribution of the volcanic rocks. The analysis by Silliman, of a dolomitized limestone from the raised coral-island of Makatea, led Dana to propound the view that sea-water constituted the source of the magnesium, and that it was probably introduced from the concentrated waters of the lagoon. This view forms the basis of the modern explanations of the formation of such dolomites. In some of the Tyrol limestones examined by me, magnesium- carbonate is present in the rocks, in varying amounts up to 6 or 7 per cent., without leading to the formation of visible dolomite- erystals. In a paper published in 1903, I quoted analyses from rocks at Christmas Island and elsewhere, in which lime- stones containing over 11 per cent. of magnesium-carbonate were similarly devoid of visible dolomite. Following Dana, [ believe that the magnesium is introduced from the sea-water, and is absorbed by calcite up to 10 to 15 per cent. of its mass without any visible change of form, but above that amount the stable compound dolomite crystallizes out.” A similar result was obtained on ana- lysing specimens from the upper part of the Funafuti borings.” 1 Bull. Mus. Comp. Zool. vol. xlii (1903) p. 102. 2 Mr. L. J. Spencer has described somewhat analogous behaviour in the mutual relations of copper and silver-iodides, Min. Mag. vol. xiii (19U1) pp. #3-44. 3 J. W. Judd, ‘Funafuti Report’ Roy. Soc. (1904) pp. 373 et segg. K 2 132 PROF, E. W. SKEATS ON THE [Feb. 1905, In this case as much as 16 per cent. of magnesium-carbonate is present in the rock, and no dolomite-crystals can be traced. Prof. Judd gives a different explanation of the presence of so much magnesium-carbonate in the rock—an explanation depending on the relative solubilities of the two carbonates in sea-water. He quotes Gustav Bischof’s and Hégbom’s experiments in support of the view that under atmospheric pressure calcium- carbonate is much more soluble than magnesium-carbonate. The skeletons of calcareous organisms contain in the living state a small amount of magnesium-carbonate, sometimes reaching | per cent. in amount. If, then, the rock composed of such organisms is attacked by water bearing carbon-dioxide in solution, calcium- carbonate will be dissolved more quickly than magnesium-carbonate, and the percentage of magnesium-carbonate in the remainder will as a consequence be raised, and may eventually reach 16 per cent. In this way, Prof. Judd explains the composition of the Funafuti. rocks between the limits of 20 to 50 feet below the surface of the water. This process of differential solution is one whith no doubt coral-limestones undergo to a greater or smaller extent, and it is probably the correct explanation of the origin of the all but structureless limestones containing magnesium-carbonate in in- sufficient amount for the production of dolomite-crystals. Very extensive solution and removal of calcium-carbonate is needed, however, before the percentage of magnesium-carbonate in the residual rock is appreciably raised. Assuming the original lime- stone to contain 1 per cent. of magnesium-carbonate, an amount which is probably near the superior limit for the fresh organisms composing the rock, and further, assuming that only the calcium- carbonate is dissolved by carbonated water, 80 per cent. of the original rock must be removed by solution before the magnesium- Dosen in the remainder reaches 5 per cent., 90 per cent. must be dissolved before the magnesium-carbonate reaches 10 per cent., and over 93 per cent. before the magnesium-carbonate reaches 16 per cent. So extensive a removal of the original substance of the rock would largely destroy the structure of the organisms that it contained. In the case of the limestones from Christmas Island, Niue, and elsewhere, examined by me, in which magnesium-carbonate was present in the rock in amounts up to 11 per cent., the structure of the contained organisms was in general wonderfully preserved ; and not only was there no evidence of solution in the rock, but on the contrary secondary calcite and secondary aragonite were deposited upon the organisms to a considerable extent. I was, in consequence, forced to the conclusion that in these limestones the magnesium-carbonate was introduced into the rock from the sea-water, resulting in the partial replacement of calctum- by magnesium-carbonate. Prof. Judd suggests that the conversion of a magnesian liatsehebar > coutaining about 15 per cent. of magnesium-carbonate, into a rock containing 40 per cent. or more of that carbonate, may be due i Vol. 61.] DOLOMITES OF SOUTHERN TYROL. 133 to the operation of the forces of segregation, forces which are concerned in the formation of concretionary structures like the Septaria in the London Clay and the ‘ doggers ’ in the Oolites. Prof. Garwood,’ in 1891, published the results of his in- vestigations ‘On the Origin & Mode of Formation of the Concre- tions in the Magnesian Limestones of Durham.’ He showed that certain bands in the rock have practically the composition of dolomite, while in other layers, by subsequent solution, segregation of the calcium-carbonate has been set up, and concretionary struc- tures are formed which consist mainly of calcium-carbonate. Prof. Garwood’s results are interesting in this connection, because the effect of the segregative forces in the formation of the concretions is not the enrichment by magnesium-carbonate of a slightly- magnesian limestone, but the dedolomitization of a rock which formerly had almost the composition of a dolomite. Under other conditions than those obtaining in the Magnesian Limestone of Durham, it is quite possible that the calcium-carbonate may be removed altogether by solution, and that segregation of the re- maining mass will give rise locally to the formation of dolomite. In some localities where dolomitic limestones are found, their occurrence is often of a patchy character, the dolomite disap- pearing horizontally and vertically in a short distance. It may very well be that some of these occurrences of dolomite could be best explained by a process of segregation, especially as in general the effects of the segregative forces (as exemplified by septaria and ‘ doggers ’) are of a quite local character. In the Dolomites of the Tyrol, however, the dolomitization is not local, but on a very extensive scale. The Schlern Dolomite extends over many square miles, and in places exceeds 3000 feet in thickness, so that no local cause can explain its production over such large areas. The rock was without doubt originally a lime- stone, composed entirely of organisms, and was subsequently con- verted into dolomite. There can be no question that the magnesium was obtained from the sea-water. Chief interest is centred in the conditions under which this partial replacement o calcium-carbonate by magnesium-carbonate took place. The Tyrol rocks are so completely en that they do not, of themselves, afford much indication of the conditions under which they were formed. Examination of specimens from upraised coral- islands, such as Christmas Island, the Fijis, etc., led me to the conclusion that the formation of dolomite can proceed in quite shallow waters.* In Christmas Island a band of dolomite occurs immediately below beds of calcium-phosphate, which cap the highest points of the island. These were low islets in the ancient lagoon, on which bird-droppings fell. The occurrence of dolomite immediately beneath these phosphate-beds points to its formation in superficial waters. Many of the Fiji islands are also dolomitized 1 Geol. Mag. 1891, pp. 433-40. * Bull. Mus. Comp. Zool. vol. xlii (1903) p. 125. 154 PROF, E. W. SKEATS ON THE [Feb. 1905, at their summits ; some of their fringing-reefs, too, are dolomitized, while the raised fringing-reefs along the coasts of the Red Sea are also occasionally dolomitized. Dana was of opinion that magne- sium was introduced into the rock from the waters of the lagoon during concentration. Many lagoons, however, are quite open to the sea, and concentration of the water is not possible in most of them; while, on the other hand, the outer parts of fringing-reefs facing the open ocean are sometimes dolomitized. My view, then, is that the Schlern Dolomite originated first as a limestone, composed of organisms, in a slowly-subsiding area. Dolomitization of the limestone in superficial waters kept pace with the slow subsidence, so that the whole thickness of 3000 feet or more of rock was continuously and uninterruptedly converted into dolomite during the Triassic Period. Some areas in the Tyrol are only partly dolomitized, while others, like the Marmolata, are for the most part undolomitized limestones. One important factor in the dolomitization of a limestone i is the time during which the limestone is submitted to the conditions producing dolomitization. If it be true that dolomitization of sub- merged limestones takes place in shallow water, then the extent to which a limestone can be dolomitized will depend, other things being equal, upon the length of time during which the limestone remains in Shallow water, that is, upon the rate of subsidence or elevation of the mass. Complete dolomitization will only be effected under stationary conditions in shallow water, or as a result of a very slow subsidence or elevation; while, conversely, a limestone which is raised or lowered compar atively rapidly, may undergo no dolomitization. The problem is certainly complicated by. other considerations. Among these, an important question is the extent to which the rock is permeable to sea-water. The growing part of the reef just below the surface is generally very porous, and admits of the free penetration of sea-water, and sometimes the older part of the limestone is also sufficiently porous to admit of the introduction of water throughout its mass, Perhaps more generally, however, that part of the structure upon which the living reef rests loses its porosity, and is converted into a dense limestone by the filling-up of the cavities by detrital material, or the fine mud produced by the partial solution of the loosely-consolidated upper part of the rock. Since the conversion of such a limestone into dolomite is effected by an interchange between magnesian salts in sea-water and the calcium-carbonate of the rock, it follows that the production of a compact rock is one of the factors which shields a limestone from dolomitization. Prof. Branner has adopted this view, in order to explain the local character of the dolomitization of the Brazilian reefs.” I think that the varying power of sea-water to dissolve limestones is another factor in the question of the formation of dolomite. This power depends mainly upon the amount of carbon- 1 Bull. Mus. Comp, Zool, vol. xliv (1904) p. 265. fe Se we FP te ee, Wol. 61. | DOLOMITES OF SOUTHERN TYROL. 135 dioxide dissolved in the water, or liberated on the decay of the or- ganisms composing the rock. Probably the interchange of magnesian for calcium-salts is most readily effected at the moment of solution of the calcium-carbonate of the rock. If this beso, the carbon-dioxide slowly liberated on the decay of plants and animals would help to determine the introduction of magnesium. We should, in that case, expect that unstable forms like the corals would be more rapidly affected than organisms the skeletons of which are built of calcite; and among the calcite-forms we should expect those to be most dolomitized which contain the largest quantity of organic matter in their tissues. Examination of thin sections of coral-limestones affords evidence in favour of this view, since aragonite-forms, like the corals, and Hatimeda among the calcareous alge, contain much organic matter in their tissues, and are the first organisms to suffer dolomitization and loss of structure. Among the calcite-organisms, too, we find that forms such as foraminifera and echinoderm-spines, containing little organic matter in their skeletons, resist disintegration and dolomitization longer than Lathothammon and Lithophyllum among the calcareous alge. So far, the evidence given of the distribution of dolomite in lime- stones of organic origin points to the change having taken place in shallow water, while contributing causes are porosity of the limestone, slow upheaval or subsidence, and the presence of carbon-dioxide in the water, to serve as a solvent for part of the limestone. What, however, are the precise conditions governing the change from limestone to dolomite in the case of great rock-masses, and the exact chemical reactions which take place, it is very difficult to say. Chemists are not all in agreement as to the relative solubilities of the two carbonates in carbonated water, and it may be that the reactions which take place in pure water are modified in sea-water. There is, however, considerable evidence to show that under atmospheric pressure calcium- carbonate is more soluble than magnesium-carbonate. Simi- larly, there is no doubt that, when dolomite is subjected to fresh water containing carbon-dioxide at a pressure of about 5 atmo- spheres, the magnesium-carbonate is dissolved and the calcium- carbonate remains almost unaffected. This, indeed, was the process formerly employed in the production of Epsom salts from magnesian limestone. It would appear to follow, then, that at some pressure between 1 and 5 atmospheres carbonated water will dissolve the two carbonates in molecular proportions, and under saturated con- ditions the double carbonate, dolomite, may be deposited. In this connection it may be stated that Mr. Stanley Gardiner has quoted experiments showing that dolomite is more insoluble in carbonated water than either calcium-carbonate or magnesium-carbonate alone.’ The change from calcite to dolomite invoives a considerable shrinkage in the bulk of the rock, amounting to about +;)th of the original mass. In view of this contraction, it is quite in accordance with _ + Proce. Camb. Phil. Soc. vol. ix (1898) p. 496. 136 PROF, E. W. SKEATS ON THB [Feb. 1905, the well-established ‘principle of least work’ to find that this change is facilitated by an increase of pressure. Translated into depths, the limits may be expected to lie between the surface and 150 feet below it, and probably nearer the upper than the lower limit. The solid matter in solution in sea-water consists of 78°32 per cent. of sodium-chloride, 1°69 per cent. of potassium- chloride, 9°44 per cent. of magnesium-chloride, 6-40 per cent. of magnesium-sulphate, 3:94 per cent. of calcium-sulphate, and traces of bromine, iodine, etc. What we require to know are the conditions under which the magnesium-chioride and sulphate present in such considerable amount in sea-water will react with the calcium- carbonate dissolved by carbon-dioxide and in contact with the mass of the limestone. Dr. C. Klement’s experiments’ demonstrate that this reaction can take place under pressure, and at a temperature of about 100° C. He subjected calcite, aragonite, and aragonitic organisms to water saturated with sodium-chloride and magnesium- sulphate, enclosed under pressure in a sealed tube, and heated for one or two days at a temperature of 90° to 100°C. The resultant action was a selective one. The calcite took up only a trace of magnesium- carbonate, aragonite absorbed 38 per cent., and corals and other aragonitic organisms over 41 per cent. The chemical instability of the aragonite was here the determining factor in the rapidity of the interchange. It is possible that, if the calcite had been exposed to the conditions of the experiment for a much longer period, the introduction of magnesium-carbonate would have proceeded farther, and probably the action would have been accelerated if the calcium- carbonate had been brought partly into solution by carbon-dioxide. The high temperature no doubt quickened the chemical changes, which probably proceed more slowly at the temperature of one sea-water. While, in general, dolomitization takes place as a result of the interchange of magnesium- for calcium-carbonate, the question arises whether it is ever deposited directly from solution. Perhaps most chemists are unfavourable to this view of its formation, and direct experiments bearing to some extent on this question have in general produced negative results. Dr. Sorby found that magnesite, and not dolomite, was formed by the action of magnesium-sulphate upon calcium-carbonate under high pressure. ‘There is, however, mineralogical evidence in favour of the view of direct deposition of dolomite. The lining of calcite-crystals by an outer zone of. clear dolomite, described by me* as occurring in sections from Mango (Fiji), and also noticed in some of the sections of Tyrol dolomite described above, is difficult of explanation, except on the hypothesis that the dolomite was deposited from solution in optical continuity with the calcite. It sometimes happens that one crystal is built up of successive zones, alternately calcite and dolomite. As these crystals are but rarely recognized in thin sections, it is clear that they were not formed under the conditions 1 Tschermak’s Min. & Petr. Mitth. n. s. vol. xiv (1895) Pp. 581 et seqgq. ? Bull. Mus. Comp. Zool, vol. xlii (1908) pp. 117-18. Vol. 61.] DOLOMITES OF SOUTHERN TYROL, 137 governing the general dolomitization of the mass of the rock. It may be that they were formed in cavernous parts of the rock, more or less shut off from the free passage of the sea-water; and, indeed, these crystals are sometimes found lining the walls of cavities. Dr. C. G. Cullis, in the mineralogical report on the Funafuti boring,’ describes and figures a somewhat analogous case, of the deposition of the two minerals in alternating coats lining the walls of cavities, in a way that simulates on a microscopic scale the appearance of the structure of an agate. It would appear from this that the composition of the solution or its physical state varied from time to time, in such a way as to lead to the alternate deposition of dolomite and calcite. Possibly, in these restricted areas, the sea-water becomes saturated with calcite and the double carbonate in turn, and the conditions of equilibrium may resemble those investigated by Prof. Van’t Hoff and others in connection with the Stassfurt salts and similar deposits. Besides this peculiar and local formation of dolomite by direct deposition from solution, in the Tyrol we have to consider two other modes of occurrence of dolomite in some way resembling that just described. Some of the St. Cassian Limestones which immediately underlie the massive Schlern Dolomite of the Sella and Sett Sass, for example, contain in general only a small amount of magnesium-carbonate and usually show no visible dolomite. In both these areas, however, microscopical examination shows that in places certain parts of the groundmass of the rock contain very minute dolomite-crystals. These are generally confined to the neighbourhood of some crack in the rock. No doubt, in this case, carbonated water, passing through the Schlern Dolomite above, dissolved some magnesium-carbonate, and, traversing the cracks in the St. Cassian Limestone below, deposited its magnesium-car- bonate as small crystals of dolomite. Occasionally, these minute erystals are zoned with layers of calcite, and in one case with the isomorphous carbonate chalybite. In the Raibl Beds overlying the Schlern Dolomite local dolo- mites are found, and these are sometimes intimately associated with beds of gypsum, in such a way as to leave little doubt that movements of upheaval during the Raibl period led to the enclosure of limited areas or lagoons, and caused the concentration of the sea- water and deposition of the calcium as gypsum and the magnesium as dolomite. We have then, within the area of Southern Tyrol, to deal both with local and regional dolomitization. The mode of occurrence of some of the dolomites of the Raibl Beds, and the very partial and local dolomitization of the St. Cassian Limestones, makes it easy to suggest a probable explanation of their origin. The great problem of the origin of the Schlern Dolomite is, as has been seen, a more complex one, and a complete solution of all the difficulties will only be found when the chemical problems involved have been more fully investigated. 1 Roy. Soe. (1904) p. 410 & fig. 44. 138 PROF. E. W. SKEATS ON THE [Feb. 1905, VIII. Summary or Conciusions. 1. Recent work on modern coral-reefs has extended our know- ledge as to the chemical composition of the rocks of which they are built up, especially as to the general absence of insoluble residue in the limestones. i 2. The study of the relative proportions of the organisms com- posing coral-reefs and the alterations which they undergo has shown ~ that corals generally play a subordinate part, and that calcareous alge, foraminifera, and other organisms form the bulk of the rocks composing the reefs. I have applied this information in the examination of collections — from the much-debated area of the Dolomites of Southern Tyrol. 3. 1 find that many of the dolomites are devoid of insoluble residue, and that where residue is present it can be generally attributed, as in the raised reefs of Fiji, etc., to association with contemporaneous volcanic rocks. 4, Examination of thin sections of the rocks shows that the limestones have undergone mineralogical and chemical changes similar to those which have affected the limestones of modern reefs, and that similar organisms are represented in the Tyrol Dolomites, allowing for the loss of structure due to more complete dolomitization. 5. That the Schlern Dolomite of Southern Tyrol probably re- presents Triassic ‘ coral-reefs,’ using the term in the modern, more extended sense, 6. With regard to the origin of the dclomite-masses, it is shown that the general conditions favourable to their formation were :— (w) Shallow water between 0 and 150 feet in depth, and corre- sponding to a pressure of 1 to 5 atmospheres. (b) The presence of carbon-dioxide in comparative abundance, causing the partial solution of the limestones and the - possibility of chemical interchange with the magnesium- salts in sea-water. (c) Porosity of the limestones, allowing of the percolation of sea- water through the mass of the rocks. (d) Sufficiently-slow subsidence or elevation to render the change from calcite to dolomite complete. 7. Locally, dolomite is deposited directly from solution in confined areas or cavities in the rock, while some of the Raibl Dolomite associated with gypsum was formed by the concentration of sea- water in land-locked areas. QuarT. JOURN. GEOL. Soc. VoL. LXI, PL. X.. Fig. 1. X 11 DIAM. No. 100 Fic. 2. X 32 DIAM. _f. T. B. Photomicro. Bemrose, Collo. QuarT. Journ. GEOL. Soc. VoL. LXI, PL. XI ‘ | Fig. 1. x 32 DIAM. ; Bentrose, Colto. ; Quart. JOURN. GEOL. Soc. VoL. LXI, PL. XII. b i Fig. 1. x 2380 DIAM. No. 88. FF, T. B. Photomicro. ; Bemrose, Colo. a = > = 1S) Lal 4 S S = < im S : el e) > ° O ¢p) a (e) WW oO z : a = = = ie) . (a) (ep) « O @ a (a9) (ae) = < oa : = 1 © é e) bewe. “GN o zZ 2 L. : ' 8 N 8 | aS | q m9 N . ica , r ie) hace QuarT. JOURN. GEOL. Soc. VoL. LXI, PL. XIV. FIG. 1, X 11 DIAM. NOt 2. : Fig. 2. X 250 DIAM. No. 37. _ £. T. B. Photomicro. Benrose, Collo, 7 « 4 Bevo: 61.) DOLOMITES OF SOUTHERN TYROL. 139 EXPLANATION OF PLATES X-XIV. [‘The rock-sections are preserved in the Author's private collection, but numbered hand-specimens of the rocks from the Dolomites have been deposited at the British Museum (Natural History). The Author is indebted to his friend, Mr, Franklin T. Barrett, for the photographs from which these Plates have been prepared. | PLATE X. Fig. 1. Slightly-dolomitized limestone (No. 100), from the Sella. x 11 diam. Sporadic rhombohedra of dolomite are scattered through the rock, which contains badly-preserved calcareous alge, foraminifera, anc other organisms. (Stained with Lemberg’s solution.) ; . Dolomitized limestone (No. 32) from the Marmolata. x 32 diam. Some of the dolomite-crystals are allotriomorphic; but those pro- jecting into calcite are well-formed, and show cloudy zones. (Stained with Lemberg’s solution.) Prats XI, Fig. 1. Dolomite (No. 10), from the Schlern. x 32 diam. Dolomitization is so nearly complete that no calcite remains, and the large majority of the dolomite-crystals are allotriomorphic. A few crystals with cloudy centres exhibit, however, rhombohedral outlines. Oolitic and partly-dolomitized St. Cassian Limestone (No. 77) from St. Cassian. x 50diam. ‘The oolitic grains are well-preserved, show both concentric and radiating structure, and include foraminifera and fragments of other organisms. Minute rhombohedra of dolomite occur in the calcite-matrix, but do not extend into the oolitic grains. Prats XII, Fig. 1. Buchenstein Limestone (No. 88), from the Gader Gorge. X 230 diam. A limestone containing zoned crystals, consisting of calcite and dolo- mite in alternate layers, which are in crystallographic continuity. The calcite-layers are stained with Lemberg’s solution, and appear dark in the illustration. . Transverse section of a coral (No. 109), from the St. Cassian Limestone of Sett Sass, x 18diam. The original aragonite and the minute structure of the coral remain. The stages in the conversion of calcareous mud into clear crystalline calcite are also shown. To this change the preservation of the coral is probably to be attributed. Prater XIII, Fig. 1. Part of No. 109, more highly magnified. x 240 diam. The middle line of the septa is shown, as also prismatic crystals of secondary aragonite, formed in crystallographic continuity with the coral-fibres, which project from the walls of the coral into the space between the septa. 2. Dolomite (8), from the stream at Bad Ratzes. X 30 diam. The dark areas probably represent septa of a coral, the structure of which has been largely destroyed by dolomitization. The lighter dolomite-crystals in the matrix show cloudy zones. Puate XIV. Fig.1. No. 112. Schlern Dolomite of Sett Sass. x 11 diam. Transverse section of organisms (Gyroporella ’), the structure of which has been destroyed by dolomitization. The dark crysta!s defining the outer margin of the organisms have originated by the extrusion of im- purities during the process of recrystallization. 2. Insoluble residue from partly-dolomitized coral (No. 37), from the Giau Pass. X 250 diam. The insoluble residue consists entirely of very minute, doubly-terminated crystals of quartz, showing occasional distortion and striation on the prism-faces. lo i) to ~ 140 PROF. E. W. SKEATS ON THE [Feb. 1905, DiscussIon, The PresipEnt said he felt that the Fellows, after listening to the Author’s presentation of the work which he had done in great detail in the Tyrol and also in the laboratory, would agree that the Council had made a wise choice when they had made the first award of the Daniel-Pidgeon Fund, ‘to be used in whatever way may in their opinion best promote geological original research,’ to the Author. Prof. Jupp congratulated the Society upon the valuable results secured by the first: award of the Daniel-Pidgeon Fund, and at the same time complimented the Author on the lucid and effective manner in which he had marshalled his facts and arguments, He bore testimony to the great skill and patience with which the in- vestigation had been carried outs He further ventured to express the hope, that the founder of this Fund would feel satisfied as to the success of the means which she had adopted to carry out the wishes and perpetuate the memory of her late husband. With respect to the arguments of the Author, he pointed out that the very important conclusion, that coral-rocks yield only minute traces of insoluble residue, was established not only by the Author’s own analyses, but by those of several other chemists, including Mr. Stanley Gardiner. That other calcareous sediments contain a sensible proportion— 1, 2, 3, or more per cent.—of insoluble residue is proved by the analyses of the Challenger-materials and many investigations of later date. The Author, by an application of the method described in the Funafuti Report to the classic dolomite-district of the Tyrol, had given a confirmation of the value to geologists of this crucial test concerning the origin of limestones. In addition, he had supplied a number of observations bearing on the yery difficult chemical problem of dolomitization, which could scarcely fail to be of service in its ultimate solution. Dr. KE. F. Armsrrone remarked that, in the course of Prof. Van’t Hoft’s Stassfurt investigations, with which he had been associated, the problem arose as to the order in which salts would separate out from sea-water. It was a question whether dolomite existed as a true chemical compound, or was merely an intimate mixture of magnesium- and calcium-carbonates. In view of the great number of double salts known to exist, the former hypothesis seemed at least plausible. So much being granted, the problem next arose as to the conditions which governed the separation of dolomite from solution. Here, perhaps, pressure was a more important factor than any other variation that could be suggested. The Author had drawn attention to material containing a small percentage of magnesium-carbonate, but showing no evidence of dolomitization. One explanation might be that, owing to some variation in pressure, or other causes, not dolomite but magnesium-carbonate pure and simple had been deposited from solution ; and it would be inter- esting to know whether this could be distinguished by microscopic methods from calcium-carbonate. It was noticeable, in this con- nection, that the uppermost rocks in the Funafuti borings, where Vol. 61.| DOLOMITES OF SOUTHERN TYROL. 141 the pressure was consequently lowest, yielded the smallest per- centage of dolomite. Dr. C. G. Cutis said that it was very satisfactory to find that the Author’s investigations had led him to conclusions which were, in the main, harmonious with those already arrived at, along other lines of evidence, by such eminent geologists as Baron F. von tichthofen and Dr. HE. von Mojsisovics, namely, that these great limestone-masses of Southern Tyrol represent the denuded remains of Triassic atolls and coral-reefs, and that the peculiar lithological characters of the rocks, as well as the distinctive physical features of the region, were merely expressions of this fact. The Author had been led to this conclusion by observing the great similarity which the rocks presented, in their chemical composition and detailed microscopic characters, to those which enter into the con- stitution of recent coral-reefs. From what he himself had seen of the microscopic character of coral-reef rocks, as exemplified by the cores of the Funafuti boring, he was glad to be able to confirm this resemblance, which in many cases is so striking as to make it almost impossible to avoid the conclusion that, notwithstanding their great difference in age, the two sets of rocks must have come into existence under substantially the same conditions, Referring to the explanation of dolomitization, in terms of the relative solubility of calcium- and magnesium-carbonates under varying pressures, Which the Author had suggested, he hoped that this would secure the favour and support of chemists. Speaking from recollection, he could not recall any fact or phenomenon presented by the dolomitization of the Funafuti rocks which did not find a satisfactory interpretation in the light of this simple but ingenious explanation. It seemed to him to provide the key to a problem which had puzzled geologists since the days of Leopold von Buch. Mr. Dixon referred to the evidence that some dolomite in the Carboniferous Limestone of Pembrokeshire and Caermarthenshire is - associated with shallow-water conditions. Prof. Warts drew attention to the probably shallow-water dolomites near Charnwood Forest, and to the base of the Car- boniferous Limestone in Ireland, frequently either a dolomite, or a conglomerate or grit cemented by dolomite. He further pointed out that, although the Author had made an extremely-important comparison between the dolomites of Southern Tyrol and coral- limestones, and had shown that both of them lacked insoluble residue (which was a common ingredient in calcareous deposits), the com- parison could not be followed to its logical conclusion until other calcareous sediments, such as those of the Gulf of Mexico and the Gulf-Stream areas, had been thoroughly examined. The AvurHor thanked the previous speakers and the Fellows present for their generous reception of his paper, and, in reply to Dr. Armstrong, stated that microscopical examination of lime- stones containing 10 or 12 per cent. of magnesium-carbonate failed to show the presence of magnesite as recognizable crystals. 142 MR. S, 8S. BUCKMAN ON CERTAIN [ Feb. 1905, 9. On Crrrain Genera and Specizs of Lyroceratipz. By 8. 8. Buckman, F.G.S. (Read December 21st, 1904.) [Puates XV & XVI.] I. Cerrain LyrocERATIDa FROM THE NORTHAMPTON Sanps (AALENIAN). Some time ago Mr. Beeby Thompson, F.G.S8., sent to me for identi- fication certain species of Lytoceratide from the Northampton Sands. As one is new and remarkable for its homeeomorphy to Phylloceras, and the others are interesting, I desire to offer the following notes to the Geological Society. In order to classify the series of Toarcian-Aalenian Lytocera- tides, to which these species belong (jurense and allied groups), it is necessary to note that there is ontogenetic evidence that they have passed through a more or less definite sequence of phylo- genetic stages. In regard to ornament, there is a sequence of deveiopment—first some elaboration, but, later, simplification from a costate (or corrugate) to a completely-smooth stage. In regard to whorl-shape, there is a constant tendency to pass, more or less in pace with the decline in ornament, from the Lytoceratan to the Phylloceratan form—that is, from an evolute to an involute whorl, the umbilicus constantly contracting. Conjointly with such change there is a further tendency, to pass from stout to constantly more compressed whorls. Now, Lytoceras originally “ek its name from the evolute character of its whorls (Aurés) ; Phylloceras from the character of its lobe-line (@vAXov). But the whorl-character of Phylloceras is the opposite of Aurds: it is involute; and that is what is implied by saying ‘ phylloceratan whorl-shape.’ The main difference between the Lytoceratidze and the Phylloceratidee may be ex- pressed in this way: the first have the whorl-shape more primitive and the lobe-line more advanced (less of the phylloid, more of the elaborately-denticulate pattern); the second have the whorl-shape more advanced and the lobe-line more primitive (more phylloid). Consequently, when the Lytoceratide advance in regard to whorl- shape to the Phylloceratan style, they become characterized by an advanced whorl-shape and an advanced lobe-line. The whorl- shape being, then, similar to that of the Phylloceratids, there is a certain external homcomorphy ; but the more advanced lobe-line remains a feature of distinction, showing that a given species belongs to the Lytoceratan stock, however. much it may simulate the Phylloceratan shape. It may be desirable to explain that, in speaking of the Aurds- character as primitive, I refer only to that portion of the Cephalopod- Vol. 61. ] GENERA AND SPECIES OF LYTOCERATIDZ. 143 eycle to which the Lytoceratacea belong. The whole Cephalopod- eyele is from straight to coiled up (involute) and back to straight again; but within this main cycle are found many subsidiary cycles, of successive retreat and advance, from involute to evolute, on again to involute, and so on. Through the phases of one of such subsidiary cycles the Lytoceratacea pass. Like the Am- monacea, they have evidently come through an involute, Goniatitic, stage; they revert to the evolute stage, and advance again towards involution—the evolute is therefore more primitive than the later involute. However, in reverting towards evolution and the Orthoceratan style, the Lytoceratide went much farther than the Phylloceratide, and they retain the evolute character longer. Then, changing this process, going again towards involution, the Phylloceratidz begin first, at a time when their lobe-line is still more primitive than that of the Lytoceratide. The latter, starting later on the same way, seldom progress so far towards involution as the former; but the interesting species which I have to describe is the most noticeable case of how far they do travel in that direction. Now, in the jurense-groups—to one of which this species beiongs —the development in regard to ornament presents, more or less completely, these stages :—subcostate, costate (crassicostate, or corrugate), returning tosubcostate, and levigate. But the develop- ment of the phyletic series does not end here. The levigate character is attained while the species are somewhat evolute ; it is retained while they become (in one case) truly involute (Phyllo- ceratan). These successive stages of development may be indicated in terms of species:—(1) Germaini, (2) torulosum, (3) annulose, the species not yet named,! (4) jurense, (5) phylloceratoidan; and the species mentioned are adults, more or less in these respective stages of development. That the species like jurense were levigate developments of Germain-like forms I have pointed out before.” But a cursory examination of these species shows that they belong to more than one genetic series, that the smooth forms are polygenetic, and have passed through independent costate stages. Two of such genetic series Hyatt has separated as genera: Pleurolytoceras, the hircinawm- group ; Alocolytoceras, the Germaini-group.’ To neither of these can the torulosum-group be fitted. Although toruloswm shows that it came through a Germaini-like stage, yet its corrugate stage differs from that of the Germaini series, and its levigate developments differ from those of that series also. It seems, therefore, necessary 1 Lytoceras Germaini, Janensch (non dOrbigny), Abh. z. Geol. Specialk. von Hlsass-Lothringen, n. s. pt. v (1902) pl. ii, fig. 3 only, shows this stage. Compare also Lytoceras dilucidum (Oppel), Pompeckj. 2 *The Reported Occurrence of Ammonites gurensis in the Northampton Sands’ Geol. Mag. 1892, p. 260. Dr. J. F. Pompeckj also has given much in- formation concerning the development of these forms, in his ‘ Beitrage zu einer Revision der Ammoniten des Schwabischen Jura’ pt. ii (1896) pp. 95 et segq. 3 Kastman-Zittel, ‘Text-book of Paleontology’ vol. i (1900) p. 572. 144 MR. S. S. BUCKMAN ON CERTAIN [Feb. 1905, to give to toruloswm and its smooth derivatives a new generic designation ; and the three genera may be compared as follows :— Prevrotyroceras, Hyatt. Characterized by peripheral compres- sion making the whorl-section triangular, which character is developed even in the costate stage. Species :—Stage 1. A. hircinus (Schlotheim) (Quenstedt). Stage 2. A. tah Lycett ; A. hircicornis, Schloenbach. Apparently this series does not progress to the further (levi- gate) stage. AxocotytocerAs, Hyatt. Peripheral compression slight; whorls passing from round to oval, to elliptical in the costate stage, to compressed elliptical in the smooth stage. Species :—Stage 1. Lytoceras coarctatum, Pompeckj ; A. Ger- main, d’Orbigny. Stage 2? Al. Pompeckji, nom. nov. (see below, p. 145). Stage 3. Lytoceras dilucidum (Oppel), Pompeckj. Stage 4. Lytoceras sigaloen, S. Buckm.; L. Wrighti, 8. Buckm. ; L. teniatum, Pompeckj (Stages 2, 3, in inner whorls). PACHYLYTOCERAS, gen. nov. (torulosum-group).' No triangularity, no peripheral compression; but, rather, whorls somewhat inflated towards the periphery. Whorls round in the costate stage, to stout oval in the levigate. Genotype, A. torulosus, Zieten. Species :—Stages 1, 2. A. torulosus, Zieten. Stage 4. A. juren- sis, Zieten; P. aalenanum, sp. nov., with stage 2 in inner whorls (see below, p. 146). Stage 5. P. phylloceratotdes, sp. nov. (see below, p. 147). So there are, in these genetic series, as morphic equivalents distinguished by their whorl-shape: in Stage 1, Pl. hircinum, AL. Germaini, P. torulosum (young); in Stage 2, Pl. Leckenbyi, P. torulosum (adult); in Stage 4, Al. sigaloen, Al. Wrighti, and P. jurense, P. aalenianum, respectively ; while in Stage 5 there is no morphic equivalent to P. phylloceratoides. Stage 2, or the corrugate stage, seems to be particularly well-developed in two series, and the contrast between Pleurolytoceras Leckenbyi and Pachylytoceras torulosum is especially marked ; but in Alocolytoceras this stage does not seem to be developed in a noticeable manner— the species presumably to be reckoned to it is Al. Pompeckji. If there is this difference in development, it will be a still more im- portant distinction between Alocolytoceras and Pachylytoceras, In these genera the lobe-lines are of very similar pattern: the saddles retain much of the primitive phylloid character, the lobes are wide-stemmed, and not spreading, while thev lack the high development of the typical Lytoceras-lobes. For ‘further remarks on these lobes, see p. 151. | 1 Tlayds, stout. .- Vol. 61.] GENERA AND SPECIES OF LYTOCERATID®. 145 The following are the notices of Mr. Thompson’s species, with remarks on certain allied forms to which consideration has to be given. ALOcoLyrocERas GerMAINI (d’Orbigny). (Fig. 3, p. 152.) 1845. Ammonites Germaini, d’Orbigny, ‘ Pal. Frang. Terr. Jur.: Céphalopodes p. 320 & pl. ci, figs. 4-5 only. _ Dr. Pompeckj* chooses the form above-quoted to be the type of @Orbigny’s species, and therefore it is necessary to follow him. But I cannot agree with him, that what he figures as the smooth form of this species, really belongs to it (op. cit. fig. 27, p. 145). Tt is a smooth form, which has the inner whorls of the Germaini- stage certainly ; but, surely, it is of another stock altogether: the long lobes and the broad inner margin of the stout whorls are characters which, in my opinion, separate it from any of the three genetic series now under consideration. 2 ALOCOLYTOCERAS PoMPECKSI, nom. noy. 1845. Ammonites Germaini, VOrbigny, ‘ Pal. Franc. Terr. Jur.: Céphalopodes ’ p. 320 & pl. ci, figs. 1-2 (not 4-5, and not 6). Description.—Dr. Pompeckj described this form as follows :—- ‘ Lytoceras,n. sp. Rarer than the preceding species [ Germaini], with higher whorls, with more oval cross-section and more closely-set ribs.’ (Op. cit. p: 146.) Remarks.—Although Dr. Pompeckj separated this form, he did not name it, and so I have much pleasure in dedicating it to him, as a mark of appreciation of the value of his critical studies, particularly in regard to his revision of Quenstedt’s last work. ALOCOLYTOCERAS DILUCIDUM (Oppel). In naming his species, Oppel gave as a synonym a term of Quenstedt’s, which that author had applied as the designation for ‘A. cornucopie dOrbigny tab. 99.’ Quenstedt did not quote any figure of d’Orbigny’s plate, and therefore I presumed that he meant figs. 1 & 2;* but Dr. Pompeckj has now figured one of Oppel’s types,’ from which it is evident that Oppel and Quenstedt intended d’Orbigny’s pl. xeix, fig. 4. The question now is, what must be taken as the holotype of Oppel’s species? It seems to me that, as Oppel gave a definite reference which led to d’Orbigny’s pl. xcix, one of the species thereon must be the holotype. As it is now seen that fig. 4 was intended, therefore that must be the holotype. Oppel’s other examples must be regarded as paratypes; and it does not neces- sarily follow that they belong to the same species as the holotype— that is far too often the result in such cases. The original references, therefore, would be :—Al. dilucidum (Oppel): Description— Die * ‘ Beitrage zu einer Revision der Ammoniten des Schwabischen Jura’ pt. ii (1896) p. 146. 2 « Ammonites jurensis, Geol. Mag. 1892, p. 260. ° ‘Beitr. Rev. d. Amm. d. Schwab. Jura’ pt. 11 (1896) p. 166 & pl. xii, fig. 8. Q.3.G.S. No. 241. 7 146 MR. 8. S. BUCKMAN ON CERTAIN [Feb. 1905, Juraformation’ (1856) p. 372; figure of holotype—d’Orbigny, ‘Pal. Franc. Terr. Jur.: Céph.’ (1845) pl. xeix, fig. 4 only. ALOCOLYTOCERAS THN1atTuM (Pompeckj), 1896. (PI. XVI, figs. 1-2, & text-fig. 6, p. 152.) 1896. Lytocerasteniatum, Pompeck}, “Beitrage zu_eimer Revision der Ammoniten des Schwabischen Jura’ pt. 11, p. 164 & pl. Made lose =? Lytoceras Wrighti, 8. Buckman, 1888, ‘ Monoer. Inf. Ool. Amm.’ (Pal. Soc.) pt. 11, p. 44, footnote 2.1 Remarks.—The specimen submitted by Mr. Thompson agrees with the above-quoted figure of Dr. Pompeckj’s species, so far as comparison can be made; but the example is deficient in the umbilical whorls. The Northampton specimen shows, in the um- bilicus of the side not depicted in the Plate, strize indicative of the annulose stage; Dr. Pompeckj’s figure shows both this and the Germaini-stage. But the Northampton specimen does not differ in shape from my Lytoceras Wrightt. Is, therefore, Pom- peckj’s species the same as mine ? or is it acase of homceomorphy ? So far, these characters of the Germazni and annulose stages have not been noted in my species. The specimens are large, and the inner whorls seem to be particularly smooth. Dr. Pompeck} (0p. cit. p. 171) has misread the position of Al. Wright in the genetic series, when he thinks that it may be the same as his Lytoceras dilucdum; my L. sigaloen is the species which occupies’ that position, so that the comparable species in the same stage of development are L. dilucidum, Pomp. (? Oppel) and L. szgaloen ; L. teniatum, Pompeckj, and L. Wrighti, respectively. Now, according to Pompeckj’s figures, there is considerable difference in the ontogeny of his L. dilucidum and L. teniatum—a difference which suggests that they really belong to separate genetic series. That may be the explandtion of the likeness of L. tenzatwmn and L. Wrightt.: 1t may be a case of homceomorphy. ‘To settle this, in fact, before one can dogmatize on the identity of any smooth cutagenetic species, it is necessary to be well-intormed concerts their ontogeny. Locality and Horizon.—Spratton Ironstone Workings, Brix- worth, near Northampton, in the Northampton Sands. Date.—Hemera scissi, presumably. Ammonites of the genera Lnoceras and Tmetoceras indicate that the Northampton Sands are of this date ; and there is no evidence of any earlier date as yet. The date of Al. Wr ighti is hemera aalensis; in strata of that hemera 1 have found it both in the Cotteswolds and on the Dorset coast. Dr. Pompeckj quotes Al. teniatum from ‘Zone of Lyt. torulosum, Br, Jura a Quenstedt.’ (Op. cit. p. 166.) PACHYLYTOCERAS AALENIANUM, sp. noy. (Pl. XY, figs. 3 & 4, & text-fig. 5, p. 152.) ; i | Description.—A Lytoceratoid like jurense, but with a smaller + The type-figure is Lytoceras gurense, Wright (non Zieten), * Monogr. Lias Amn,’ eat Sue.) 1884, pt. vii, pl. lxxix. Vol. 61.] GENERA AND SPECIES OF LYTOCERATID®. 147 umbilicus. Inner whorls subcostate, showing the toruwlosum-stage ; outer whorl smooth, stoutly oval. Inclusion about two-thirds. Umbilicus gradate. Distinction.—From P. jurense, a smaller umbilicus, broader whorls, greater inclusion. Remarks.—The inner whorl, showing the toruloswm-stage, is a most interesting fact in the ontogeny, important for indicating genetic affinity. Such an inner whorl is the morphic representa- tion of P. torulosum. Locality and Horizon.—Spratton noms poie Workings, Brix- worth, near Northampton, in the Northampton Sands. Date.—Hemera scissi, presumably; see under Alocolytoceras teniatum (p. 146). PACHYLYTOCERAS PHYLLOCERATOIDES, sp. nov. (PI. XY, figs. 1-2 & eee VM fies 3s) Description.—A Lytoceratoid with a phylloceratan aspect ; outer whorl stoutly oval, smooth ; umbilicus quite small, umbilical border fairly steep. Distinction.—The parvumbilicus, and the phylloceratan aspect of the fossil. hemarks.—In the ‘Geology of the Country around Cheltenham ’ (Mem. Geol. Surv. 1857), Prof. Hull notices (p. 30) ‘a large ammonite | ft. 8 in. in diameter,’ which, he says, ‘strongly resembles A. heterophyllus, in Sands [scissum-beds| at Clapton, near Sher- borne (Gloucestershire). I suggest that it is a parvumbilicate Lytoceratoid closely allied to, or the same species as, the one now under consideration. I do so, because some 20 years ago I saw in the possession of the late Dr. Moore, at Bourton-on-the Water, several giant parvumbilicate Lytoceratoids which had been obtained, during the making of the Banbury & Cheltenham Railway, from the first cutting on the west, presumably from the Sands. That they were Lytoceratoids with phylloceratan aspect attracted my attention at the time. From Dorset I have long had a similar large parvumbilicate form; but I fancy that itis not the same species as Mr. Thompson’s. T cannot examine it now. Locality and Horizon.—Spratton Ironstone Workings, Brix- worth, near Northampton, in the Northampton Sands. Date.—Hemera scissi, presumably. See note to Al. tenratum. Il. Orner Groves or Jurassic LytoceRATIDzA. In connection with the Lytoceratide which have been reviewed, it seems desirable to note certain new or incompletely-known genera of this family. It is important for all systematic work to give to each genetic series (or Formenreihe) its own generic name. For museum-work, for cataloguing, for classification, and for ready identification, the more this system is tried the better does it Te 148 MR. 8. $. BUCKMAN ON CERTAIN [Feb. 1905, prove, and the more completely does it show the true genetic affinities. ‘The American paleontologists have proved these state- ments in regard to the Palaozoic Brachiopoda. ‘To use a generic term in a wide sense, and then to group the species under their respective Formenreihe is hardly satisfactory: the formula is much longer and more difficult to remember than a generic name. Therefore, after noting some already-established generic names, { venture to propose certain generic appellations for other genetic series, with the species of which we are more particularly concerned in our British Jurassic rocks. Genus Lyrocrras, Suess, 1865. Genotype, Ammonites fimbriatus, Sowerby. 1865. E. Suess, ‘ Ueber Ammoniten’ Sitzungsberichte d. nat.-wiss. Classe d. k. Akad. d. Wissensch. Wien, vol. lii, p. 78. Another species, Lytoceras lineatum, Wright (non Schlotheim ?), ‘Monogr. Lias Amm.’ (Pal. Soc.) pl. lxx, fig. 1, 1882, & p. 409, 1883. Genus Tuysanocreras, Hyatt, 1867. Bes! pe, Ammonites cornucopia, d’Orbigny (non Young) = Thysanoceras Orbigny?, nom. nov. 1867. Thysanoceras, Hyatt, Bull. Mus. Comp. Zool. vol. i, pp. 86, 96. Remarks.—Hyatt selected no genotype. ‘The first species that he mentions is Ammonites fimbriatus; but this had just before been taken by Suess as his type of Lytoceras. In Thysanoceras, however, Hyatt placed many other Lytoceratoid species ; and, as it is now necessary to divide them into genera, it seems permissible to take as the type of Thysanoceras a species most allied to Am. fim- briatus. Therefore I select Am. cornucopia ; but, under this name, Hyatt included the species of Young and of d’Orbigny. They are two distinct species: as the latter is far the better illustrated, I select that as the type of the genus; it will require a new name, Thysanoceras, then, will be the name for the genetic series of Am. cornucopia, @Orbigny ; Lytoceras for that of Am. fimbriatus. The two genera differ particularly in their shell-sculpture ; and also that’ in Lytoceras the periodic ‘ flares’ are plain and prominent, but in Thysanoceras they are crenulate and not prominent. These two genera attain to a high degree of development in their suture-lines,! differmg in that respect markedly from any of the genera of the jurense-groups (Pachylytoceras and like genera; see above, p. 144): those still retain the phylloid saddles, indicative of the original common ancestry of Lytoceratide and Phylloceratide ; these have practically lost that ancestral trait; however, they retain the primitive Avrds-character. They do not seem to develop smooth forms like the jwrense-groups. ? Skeleton L, fig. 7, p. 152. Wolk Ox. | GENERA AND SPECIES OF LYTOCERATID&. 149 - THYSANOCERAS ORBIGNYI, Nom. nov. 1845. Ammonites cornucopia, VOrbigny (non Young), ‘ Pal. Frane. Terr. Jur. : Céphalopodes’ p. 316 & pl. xcix, figs. 1-8 (not fig. 4). 1867. Thysanoceras corwucopia, Hyatt, Bull. Mus. Comp. Zool. vol. 1, p. 96 (pars). Remarks.—The difference in coiling and the fact that the whorls are depressed, instead of being compressed, separate this species entirely from Young’s. Figs. 1 & 2 are not Oppel’s dilucidus (see Al. dilucidum, above, p. 145): so a new name is required. D’Orbigny’s figure is reduced to 3-linear according to the dimensions which he gives: he says that it is ‘ reduced one- half’ (‘réduite de moitié,’ op. cit. p. 318). THYSANOCERAS ONYCHOGRAPTUM,! nom. nov. 1883. Lytoceras cornucopia, Wright (non Young, nec d’Orb.) ‘ Monogr. Lias Amm.’ (Pal. Soc.) pt. vi, p. 410 & pl. Ixxiii, figs. 1, 2 (3 P). This species differs so entirely in its proportions from Am. cornu- copia, Young, that a new name is necessary. ‘The sculpturing, which is similar to the marks made by pressing a finger-nail into wet clay, suggests the term now proposed. From d’Orbigny’s species it differs by less coarse sculpturing, and by a more elevated periphery, making the whorls compressed instead of depressed. In this respect it is nearer to Am. cornucopia, Young, than is d’Orbigny’s species. Other species are: 1. Thys. sublineatum (Oppel) = Am. sublineatus, Oppel.” 2. Thys. cornucopia (Young)= Am. cornucopia, Young, ‘Geol. & Min. Surv. Yorks. Coast’ (1822) pl. xii, fig.6 = Am. fim- briatus, Zieten (non Sow.) ‘ Verst. Wirt.’ (1830) p. 16 & pl. xu, fig. 1 = Am. Siemenst, Denckmann, ‘ Fauna des oberen Lias von Dornten’ Abhandl. d. k. Preuss. Geol. Landesanst. vol. viii (1887) p. 156 & pl. i, fig. 5. Genus ‘lHYsANOLYTOCERAS, Noy. : Genotype, Ammonites Hudesianus, d’Orbigny. Definition.—A Lytoceratoid genus, which in suture-line most resembles Lytoceras (fimbriatum-group), in ornament follows partly Lytoceras, partly Thysanoceras (cornucopia-series); for the main ornament is more of the type of the former, while the crenulate ‘ flares’ are more of the pattern of the latter, yet in these details the genus agrees with neither. Examples.—Thysanolytoceras sp., a heavy stout shell of the Eudesianum-type, Sonninie- Witchellie hemera; Sherborne (Dorset) ;* =? Am. subamplus, Quenstedt, ‘ Ammoniten des Schwabischen Jura’ vol. 11 (1886-87) p. 477. 1”Ovvé, a nail; yeamrés, written. 2 «Pal. Mitth.’ pt. iii. (1862) p. 142 & pl. xliii, figs. 4-6. 3 There is a giant of this species in the Cephalopod-Gallery of the Natural History (British) Museum [No. C 3184], from the Collection of Mr. Darell Stephens, now Mr. R. D.S. Darell, F.G.S. 150 MR. S. 8. BUCKMAN ON CERTAIN [ Feb. Taont ar Am. Hudesianus, VOrbigny (op. cit. 1846, p. 386 & pl. exxviil) ; niortensis hemera. Am. Adeloides, Kudernatsch, ‘ Die Ammoniten von Swinitza’ Abhandl. d. k.-k. Geol. Reichsanst. vol. 1 (1851) Abh. 2, p. 9 & pl. ii, figs, 14-16. feat e Genus MEG@ALYTOCERAS,’ nov. Genotype, Lytoceras confusum, S. Buckman. Definition.—A genus which has much the aspect of the jurense-group, smoothness being very noticeable ; but it possesses an ornate suture-line, with narrow-stemmed, highly-developed lobes (see fig. 1) like Lytoceras, or Thysanoceras. Like Lytoceras it shows plain periodic ‘flares,’ but they are not associated with sculpturing, in the species at present known, and they are confined to the young stage. The development of a broadly-deltoid cross- section of whorl, and the fact that in the smooth stage the whorls are still evolute, are also important features. Fig. 1.—Suture-line of Megalytoceras confusum (8. Buckman) from the type-specimen, obtained by the removal of the test ; some of the finer details may have suffered im the process. (Natural size.) fy)» z VAs ‘fe Mueatyroceras conrusum (8. Buckman). (Fig. 1, & fig. 9, p. 152.) 1881. Lytoceras confusun, 8. Buckm. ‘Amm. Inf. Ool. of Dorset’ Quart. Journ. Geol. Soc. vol. xxxvii, p. 601 (description). [1883] L. confuswm, S. Buckm. Proc. Dorset Nat. Hist. Field-Club, vol. iv, pl. 1, fig. 1 & p. 143 (fig. & deser.). Remarks.—I give these references, because on the Continent the fact that this species is figured has been overlooked; and it has been confounded with others of more recent date. A tracing of the suture-line of the holotype is appended (fig. 1, above). * Meyas, large; peya-, for weyado-: the Greeks themselves warrant this; and it is very desirable in the present case. * The genotype obtained its name, because it had been mistaken for P. gurense, and had thereby caused confusion in stratal correlation. eee mevol. 61.] GENERA AND SPECIES OF LYTOCERATIDZ. 151 Other species are :— Megalytoceras rubescens (Dumortier)= dim. rubescens, Dumortier, ‘Dépots Jur. du Bassin du Rhone’ pt. iv (1874) p. 114& pl. xxix, fig. 5; & Vacek, ‘Die Fauna der Oolithe von Cap $. Vigilic ’ Abhandl. d. k.-k. Geol. Reichsanst. vol. xii (1886) p. 63 & pl. 1, fig. 5. Megalytoceras sp. = Lytoceras, n. sp. indet., Vacek, op. cit. | p- 64.& pl. 1, figs. 6-7. ? Megalytoceras rasile (Vacek) = Lytoceras rasile, Vacek, op. cit. p- 63 & pl. iii, figs. 5-8. Megalytoceras amplum (Oppel) = Ammonites amplus, Oppel, ‘Pal. Mitth.’ pt. 11 (1862) p. 145 & pl. xlv. Genus NANNOLYTOCERAS,'’ nov. Genotype, Ammonites pygmeus, d’Orbigny.” Definition.—A primitive Lytoceratoid genus; whoris smooth, evolute, compressed, with distant, ill-marked periodic constrictions. Distinction.—From Lytoceras and like genera by the absence of sculpturing and ‘ flares’; from Pachylytoceras and like genera by the association of smoothness with an evolute, compressed whorl. In those genera the smoothness is a catagenetic feature; in this genus all the evidence points to its being an anagenetic character— the genetic series not haying passed through the ornate stages. Comparison of Superior Lateral Lobes. The accompanying figures (p. 152) show the contrasts and affinities of various superior lateral lobes (LL), in skeleton outline, omitting minor details. Fig. 2 shows a supposititious normal triooulate lobe, with the terminal lobule, A, isosceles. Fig. 3 shows the L (outline) of Al. Germain (Pompeckjt), after d’Orbigny ; and if A be rightly interpreted as the terminal lobule, then this lobule is ultra-brachysceles (short-legged on the outer part). The same feature, even more pronounced, is seen in figs. + & 5; and the greater development of the inner lobule (C) in proportion to the outer (B) causes the lobe to assume a bifid pattern. In all the figs. 3-6 belonging to the jurense-groups, the wide-stemmed character of the lobe and its want of ‘spread’ are noticeable—they are all of a similar plan, in marked contrast to the narrow-stemmed, wide- spread lobes depicted in figs. 7-9. In these there is the ultra- brachysceles character of A, but in figs. 8 & 91t may be noted that B is rapidly enlarging and becoming more equal to C,—in fact B begins to usurp the functions of the siphonal lobe, see fig. 1 (p. 150). The difference between fig. 9 and figs. 4-6 shows how distinct is Megalytoceras from the jurense- groups, in spite of a somewhat similar aspect. But, if the inferior lateral lobe of Megalytoceras (fig. 1) be compared with the L of the jurense-groups (figs. 4-6), it will be 1 Navvos, a dwarf. 2 «Pal. Frang. Terr. Jur.: Céph.’ 1846, p. 391 & pl. exxix, figs. 12-13. [ornqoy-eaqur =o * Q[NQoT-B19[N = q ‘ eTNqQOT] [euIM4ey = AO] 9}U[NGOTI1] B YIM snosofowMoyY oq 0} pasoddns sjaed ay eyorput ‘CO ‘“q ‘Vy < azoAr] 8 ¢ © SNOVHawNn O O ve ‘ad {yoo oy} Woy “unsnfwoo sosao0jhyobayy Jo | = “AUSIQIO,p Ioize ‘wnumsapniy spsa00jhjounsh7 JOT = “AUSIQIC, P 104 v 6 ungorquiyl sp.12009VvT JOT = eg ldad AUYAHd 2D i d 5 y G ral 9 a ‘6 SF ‘AX ‘Id ‘oanqeu moa ‘wnuvuayon svsoo0phjhyovog FOU eC ‘(saswaunl sapouowwmp) KUSIGID,p 109Je ‘woojnbis yp joy =F ‘AUSIQIO,p 109Jv “(2lyoodwog) vumutway sv.tao0ghjoo0j~ JO ie | ‘uitou pesoddns ey4y—-etnqoy b- © Sd ‘TAX ‘Td ‘oanyeu wos wngnrua, spsao0jhjos0)7 JO TT = 9 SI | [eUrUI4y sojoasost ue YAM ‘oqoT 9}B[NQoTIAy snorytisoddns y = Z ‘Sly "$aq0) 101090) Lowadns {0 SsuojapaygG— G-G *SBIyT Vol. 61.] CERTAIN GENERA AND SPECIES OF LYTOCERATIDE. 153 seen to have a similar pattern—that is, a lobe of later phylogenetic origin in a more highly-developed lobe-line is similar to a lobe (L) of earlier origin in a less-developed line. While the L of Mega- lytoceras has passed far beyond the L of the jurense-groups, the / (the lobe of later origin) of the first has come up to about the same stage as the L of the second. This observation somewhat confirms those of R.:T. Jackson,’ with a difference. He noted that a law of progressive and successive development, a kind of ontogenetic repetition of phylogeny, applied to the elaboration of any parts of an individual as much as to the whole ; and he adduced as instances the individual lobes of the same specimen during ontogeny, and the various lobes and lobules of the same suture-line. Inthe present case, there appears to be a similar law of development in the lobes of different stocks considered as parts of a family, the stocks having elaborated their suture-lines to different degrees of development. In the case of two stocks, one of which has carried the development of its suture-line much farther than the other, the less-developed lobe of the most-developed stock is found to be similar to the most-developed lobe of the less- developed one. ° Ill, Summary. New Genera. Pachylytoceras, Genotype Ammonites torulosus, Zieten. Thysanolytoceras, - Am. Hudesianus, d’Orb. Megalytoceras, 55 Lytoceras confusum, 8. Buckm. Nannolytoceras, ‘ Ammonites pygmeus, VOrDd. New Species. Pachylytoceras aalenianum, Aalenian. phylicceratoides, 4 29 New Names. Alocolytoceras Pompeckji for Ammonites Germain, d'Orb. pl. ci, figs. 1 & 2. Thysanoceras Orbignyi for Am. cornucopia, d’Orb. (non Young), pl. xcix, figs. 1-3. Thysanoceras onychograptum for Am. cornucopia, Wright (non Young). Generic name revised. Thysanoceras, Hyatt. Type selected, Am. cornucopia, d’Orb. = Th. Orbignyt, nov. Species figured. Alocolytoceras tenratum (Pompeck)). Pachylytoceras aalenianum, nov. be phylloceratoides, nov. Megalytoceras confusum (S. Buckm.), lobe-line of. * ‘Localized Stages in Development in Plants & Animals’ Mem. Boston Soc. Nat. Hist. vol. v, No. 4 (1899) pp. 134 e¢ seqg. 154 CERTAIN GENERA AND SPECIES OF LYTOCERATIDE. [Feb. 1905, EXPLANATION OF PLATES XV & XVI. [All the figures are of the natural size. ] PLATE XY. Northampton Sands, Aalenian [Hemera sciss?]. Figs. 1 & 2. Pachylytoceras phylloceratoides, sp.nov. Spratton Ironstone Work- ings, Brixworth, near Northampton. Collection of Mr. Beeby Thompson, F.G.S. Fig. 1. Side-view. 2. Section of whorl at A (restored) outline. Figs. 3&4. Pachylytoceras aalenianum, sp.nov. Spratton Ironstone Workings, Brixworth, near Northampton. Collection of Northampton Museum. Fig. 3. Side-view: inner whorl showing toruloswm- stage. Fig. 4. End-view. Pirate XVI. Northampton Sands, Aalenian [Hemera scéss7]. Figs. 1 & 2. Alocolytoceras teniatwm (Pompeckj). Same locality and collection as P. aalenianum. Fig.1. Side-view. 2. End-view. Fig. 3. Pachylytoceras phylloceratoides. Peripheral view, in outline (restored). | For the excellent photographs from which these Plates have been reproduced, my cordial thanks are due to my friend Mr. J. W. Tutcher, who happily com- bines great photographic skill with extensive geological knowledge. | Bemrose, Collo. “QUART. JOURN. GEOL. Soc. VoL. LXI, PL. XV. y PACHYLYTOCERAS PHYLLOCERATOIDES ano P. AALENIANUM. W. Tutcher, Photo. QuarT. JOURN. GEOL. Soc. VoL. LXI, PL. XVI. mf Fia. 8. - ALOCOLYTOCERAS TANIATUM anp PACHYLYTOCERAS PHYLLOCERATOIDES. I. W. Tutcher, Photo. Bemrose, Collo. Yolo. | THE TERTIARY FOSSILS OF SOMALILAND. 155 10. The Tertiary Fosstts of SoMALi~ann, as represented in the British Mvussum (Narvrat History). By Ricnarp Burien Newron, F.G.S. (Read June 22nd, 1904.) [Puares XVII-XXTI._] ConTENTS. ‘ Page eeinbrodiuetion 03.2... <..2. os doe irieze okie BEM sce seb Mara eae eC ee 155 Li La PEPeND Nie aoe aaa OS tie eee cece aeeeg ts Je eee 158 III. Description of the Fossils :— iG) GPRS) SOT) a ie enc ea es a 160 (oy ealGametiibmemeliion s.r BER a ee koa s law saiga ow alee 166 eg PERRO TELE ei ee oes cae er Ae ie os als ne Seale sae as Sulaiee Senta 173 RO PMC IMO TOA CC ONAIS))| eis. ees ss oe eda dihs ovaries Sun «eteecnees 174 1V. Notes on the Foraminiferal Structures in the lertiary Limestones DIP SOUR NIG ICE 28 ee RCo cea ges nae 175 V. List of the Tertiary Fossils from Somaliland ........................++- 17 I, Inrropvuctrion. Since the publication in the fifty-sixth volume of this Journal (1900) of Prof. J. W. Gregory’s paper on the Geology of Somaliland, which was founded upon specimens in the British Museum (Natural History) mostly collected and presented by Mrs. Lort-Phillips, the National Collections have been enriched by two further series of fossils from the same country—that obtained by Dr. Donaldson Smith from the neighbourhood of Berbera, and presented by His Highness the Gaekwar of Baroda; the other presented by Major R. G. Edwards Leckie (of the Canadian Mounted Rifles), and collected by him during an exploration-tour, from Upper Sheikh and Garrasgooi in the Golis- Range district, and also from the Eilo Range of mountains. In the course of my official duties at the British Museum, I have been entrusted with the examination of these new collections, with the view of describing the individual specimens, as well as of ascertaining their importance with regard to the stratigraphy of the country. In carrying out this work, a large amount of comparison with species already known from Somaliland and elsewhere has been imperative, while the limestone-matrices surrounding the different specimens have been microscopically examined in several cases, in order that the best confirmatory evidence should be obtained as to geological horizons. This examination has rendered necessary a revision of some of the geological and paleontological conclusions referred to in Prof. Gregory’s memoir, for which I am largely respon- sible in connection with the determination of certain molluscan remains therein mentioned. The new material before us is, generally speaking, better preserved than that dealt with previously, and especially does this remark apply to the mollusca. There are good 7 09 op oz (o} SOTA JO TPIS oo apoyog 70S0N I ANVTITIVNOS NVINISSAdGV x Jeie NS Ho “yy MN, 5 WWy YI SHS WIPO OWS Es : TS PS IOO.SSPIEL)O ysreys teddy 29 ITS LS HAS AS WS ~ se > Z n oe) 2 3 Ss = nal a 1o) Vol. 61.] THE TERTIARY FOSSILS OF SOMALILAND. 157 fragmentary casts of large turriculate shells belonging to the genus Campanile of the family Cerithiide, which, on account of certain plications on the columella, were erroneously considered as Nerinca and consequently of Cretaceous age; there are also large casts of Luciniform shells, as well as other lamellibranchs and gastropods to which special reference need not now be made. It is sufficient, for the present, to state that the forms of mollusca here indicated are characteristic of Eocene rocks generally, and that with regard to the specimens from Somaliland further evidence is afforded of their Hocene age by the presence of certain foraminifera which enter into the minute structure of the limestone-matrices. The new collections embrace no older fossils than may safely be ascribed to an Hocene age, excepting some remains of ammonites and belemnites found by Major Leckie in the Hilo Range of Western Somaliland, which belong to Mesozoic rocks, and are therefore not considered in this paper. The corals described by Prof. Gregory came from the ‘ Uradu’ and ‘Dobar’ Limestones, these formations being regarded as Turonian and Neocomian respectively, although he thought that the upper part of the Uradu Limestone might be of Eocene age, on account of the discovery in its structure by Messrs. Sherborn & Chapman of Nummulites, Amphistegina, and Orbitoides dispansa, all of which were found associated with a large Conoclypeus (?) sp. described in the same memoir. No nummulites have been detected in the present material, but Operculina complanata ' has been determined, together with Amphistegina and Orbitoides dispansa. This par- ticular form of Orbitoid, exhibiting rectangular chambers in the median plane, is acknowledged by most authorities on the Foraminifera to be indicative of an Eocene age. It is evident, from an examination of the specimens in these different collections, that there are two limestones represented— an upper one, which is a massive cherty rock, frequently reddish- brown externally; and a lower, of less cherty character, and generally of a lighter colour, although sometimes red-stained. According to Major Leckie, these two sets of limestones are conformable to each other, and therefore without any great difference in age to account for. Further, they may be regarded as the equivalents of the so-called ‘ Uradu’ and ‘ Dobar’ Lime- stones, previously diagnosed as Cretaceous but which now appear to belong to Tertiary times. These Somaliland limestones are probably capable of correlation with those of South-Eastern Arabia, as well as with those of Scind and Cutch in India; for, according to the researches of H. J. Carter, Orbitoides dispansa, Operculina, etc., occur in all three regions of Asia. Carter’ also referred to the occurrence of molluscan casts in the ? As understood by W. B. Carpenter, W. K. Parker, & T. R. Jones, pe ceeon to the Study of the Foraminifera’ Ray Soc. (1862) pp. 247-62 . XViI. P ‘Memoir on the Geology of the South-East Coast of Arabia’ [reprinted, with alterations and additions, from the Journ, Bombay Branch R. Asiat. Soc. 1852, vol. iv], Geological Papers on Western India, ete. (1857) pp. 551-627. 158 MR. R. B. NEWTON ON THE [Feb. 1905, Arabian deposits, especially large Naticoid shells, a small Gryphea, and Spatangoid echinoderms. A collection of Tertiary fossils from Ras Ghissa (Arabia) was made a few years ago by Lieut.-Col. Dr. A. 8. G. Jayakar, and presented to the British Museum, containing yellowish limestone-casts of Naticoid shells and a Cam- panile resembling those from Somaliland, while the matrix of these specimens exhibited foraminiferal organisms, particularly an abundance of Operculina and Amphistegana. But, as well as this correlation of the Somaliland Tertiary limestones with those of Arabia and India, somewhat similar paleontological resemblances may be traced in the Eocene rocks of Egypt and other countries of Northern Africa (Nigeria, the Cameroons, etc.), through Southern Europe to the Paris Basin, and so on to the Bracklesham Beds of England. Il. Liveratrure. A brief review of the various papers on the entire paleontology of Somaliland will now be given in chronological order. The earliest record of fossils from Somaliland was made by H. J. Carter* in 1857, who determined the following specimens, but without descriptions or illustrations, obtained by Capt. (after- wards Sir Richard) Burton from the neighbourhood of Berbera, and correlated them with the Jurassic fauna of Cutch in India :— Belemnites canaliculatus, Schlotheim. Area (sp. in Terebratula intermedia, J. Sowerby. Kxogyra auricularia, Goldfuss. Terebratula microrhyncha, J. de C. Sowerby. A number of specimens from Ouarsangueli (= Warsangeli) were described and partly figured by Dr. A. T. de Rochebrune? as of Neocomian age, the horizonal fossil being Ostrea Couloni, Defrance. New names were given to the other species, the whole series com- prising three gastropods, seventeen lamellibranchs, one echinoid, and one coral. Miss C. A. Raisin,’ in a petrographical paper, referred to some limestones containing foraminifera (Amphistegina, Globigerina, ete. ), polyzoa, ete., which she considered might be late Cretaceous or 1 A. de Lapparent [Northern Nigerian Eocene], Comptes Rendus Acad, Sci. Paris, vol. exxxvi (1905) p. 1118; R. B. Newton, Geogr. Journ. vol. xxiv (1904) pp. 522-24, & Ann. & Mag. Nat. Hist. ser. 7, vol. xv (1905) pp. 83-91 & pl. v; and F. A. Bather, Geol. Mag. 1904, pp. 292-304 & pl. xi. 2 P. Oppenheim [Eocene Fossils from the Cameroons], Centraiblatt fir Min. Geol. Pal. (Stuttgart) 19038, pp. 373-74; and ‘Beitrage zur Geologie von Kamerun’ 1904, pt. iii, pp. 243-85, pls. vi-ix. 5 [Jurassic Fossils from near Berbera], ‘Memoir on the Geology of the South-East Coast of Arabia’ in Geological Papers on Western India, ete. (1857) p. 622. : 4 ‘Observations Géologiques & Paléontologiques sur la Région habitée par les Comalis & plus spécialement sur les Montagnes des Ouarsanguélis’; in Georges Révoil’s ‘ Faune & Flore des Pays Comalis’ 1882, pp. 39 & pls. i-iv. | > “Rock-Specimens from Somaliland’ Geol. Mag. 1888, pp. 417-18. Vol. 61. ] TERTIARY FOSSILS OF SOMALILAND. 159 Tertiary—possibly Miocene age. This material was obtained by Capt. King at Mount Eilo, south of Zeila (lat. 10° 30’ N., and long. 43° 35’ E.). A series of Neocomian fossils were described and figured by Prof. C. Mayer-Eymar * during 1893, which had been collected by Prof. Keller on the south-western slopes of the Somali plateau, along the valley of the Faf, a tributary of the Webi Shebeli. It consisted of cephalopods, gastropods, lamellibranchs, and echinoids, which in the aggregate were referred to four already-known species and eleven new forms. During the year 1896, Prof. J. W. Gregory * published a list. of Jurassic fossils from Bihin collected by Mrs. Lort-Phillips, which were determined by Messrs. G. C. Crick,’ R. Bullen Newton,* and F. A. Bather as Belemnites subhastatus, Zieten, Parallelodon Eger- tonianus, Stoliczka, Rhynchonella Edwardsi, Chapuis & Dewalque, and Ith. subtetrahedra, Davidson. In the same paper Prof. Gregory described a new species of coral, under the name of Cryptoceenia Lort-Phillipsii, found in the Duba Limestone, which he doubtfully referred to the Neocomian age. _ Prof. Gregory ° noted the value of a single specimen of thyncho- nella subtetrahedra, determined by Dr. F. A. Bather, which was found by Dr. Donaldson Smith in Somaliland, as indicating the presence of Jurassic rocks in that region. Four forms of Perisphinctes collected by Dr. Donaldson Smith from the rocks of Tug Turfa, were described by Mr. G. C. Crick ° and regarded as characteristic of an Upper Jurassic horizon. Prof. Gregory’s’ most comprehensive paper on the Somaliland fossils was published in 1900. It contained descriptions of the corals and echinoids found in the raised-reef and plateau-lime- stones of that country, together with certain molluscan determina- tions made by the present writer, as well as forms of foraminifera identified by Messrs. C. D. Sherborn & F. Chapman, and some brachiopods determined by Dr. F. A. Bather. The horizons recog- ~ nized were post-Pliocene, Eocene (?), Turonian (or Cenomanian?), Neocomian, and Jurassic. 1 ‘Neocomian-Versteinerungen aus dem Somaliland’ Vierteljahrsschr. naturf. Gesellsch. Zurich, vol. xxxviii (1893) pp. 249-65 & pls. i-11. 2 A Note on the Geology of Somaliland, based on Collections made by Mrs. K. Lort-Phillips, Miss Edith Cole, & Mr. G. P. V. Aylmer’ Geol. Mag. 1896, pp. 289-94. * «Note on some Fragments of Belemnites from Somaliland’ Geol. Mag. 1896, 296-98. Me On the Occurrence of an Indian Jurassic Shell, Parallelodon Egertonianus, in Somaliland, Eastern Africa ’ Geol. Mag. 1896, pp. 294-96. 8 ‘Note on Dr. A. Donaldson Smith’s Geological Collection’ [from Somaliland], Appendix E to Donaldson Smith’s ‘Through Unknown African Countries’ 1897, 423-25. res On the Fossil Cephalopoda from Somaliland collected by Dr. Donaldson Smith’; ; Appendix F, op. cit. pp. 426-29. 7 ¢On the Geology & Fossil Corals & Hchinids of Somaliland’ Quart. Journ. ee Soe. vol. lvi (1900) pp. 26-45 & pls. i-ii (with sketch-map & sects. in the text 160 MR. R. B. NEWTON ON THE [Feb. 1905, A new form of Heliopora collected by Mrs. Lort-Phillips from the Uradu Limestone near the Rugga Pass, was described and figured by Prof. Gregory’ as Heliopora somaliensis, and regarded as of Turonian age. In 1901, Herr Oscar Neumann* announced the discovery of Jurassic and early Cretaceous fossils at various localities in Galla- Land, material which is under description by Dr. Edgar Dacqué,? a first fasciculus having been issued in 1904 on the ‘ Untere Kreide,’ containing figures and descriptions of mollusca—LHwogyra Coulona, Defrance, Cucullea Gabriels, Leymerie, Pholadomya Pictett, Mayer- Eymar, etc., from the Neocomian; and Tirigonia Pictet?, Coquand, etc., from the so-called Aptian(?). Astrocenia subornata, d’Orb. var. africana, Weissermel, is also described by Dr. Dacqué from Neocomian strata of this part of Africa. III. Descrtprion oF THE FossiIts. (a) Gastropoda. Remarks on the Genus Campanile as found in Somaliland. Among the specimens mentioned in Prof. Gregory’s memoir of 1900, were some more or less silicified limestone-casts of large gastropodan shells which, on account of possessing the plaited columella, were identified by the present writer as Nerinwa, and consequently classed as Cretaceous in age. ‘They were referred to as fossils of the ‘ Nerincwa-Limestone’ from Dongorreh and Bur- Dab, and regarded as Neocomian, under the following identifica- tions—Nerinwa, sp. nov., and Nerinwa allied to Renauxiana, Orb. The further material from Somaliland that has now been studied embraces some better specimens than were formerly available, so that these shells can be recognized as belonging to the family of the Cerithiide and to the genus Campanile,‘ the type of which is Cerithium giganteum of Lamarck, a species characterizing the Lutetian or Middle Eocene rocks of England, the Continent of Kurope, Northern Africa, Asia Minor, ete. It is to this type that the different forms from Somaliland are undoubtedly related. There is always considerable difficulty in dealing with casts at any time, but careful comparison of them on the present occasion with many 1 § Polytremacis & the Ancestry of Helioporidx’ Proc. Roy. Soc. vol. lxvi (1900) p. 298 & pl. 11, figs. 8 a-c. 2 ‘Ueber jurassische & die ersten cretaceischen Versteinerungen aus den Galla-Landern’ Zeitschr. Deutsch. Geol. Gesellsch. vol. lit (1901) Verhandl. pp- 100-102. 3 ‘Beitrage zur Geologie des Somalilandes: I. Untere Kreide’ Beitr. zur + Campanile of Bayle, in Paul Fischer’s ‘Manuel de Conchyliologie’ fase, vii (1884) p. 680. Vol. 61. | TERTIARY FOSSILS OF SOMALILAND. 161 specimens from other localities, has enabled me to prepare the following notes on the examples from Somaliland now preserved in the British Museum. Before entering upon these descriptions, 15 may be interesting to point out that casts of Campanile have been previously mistaken for Nerinea. A notable case was that of Bellardi’s Nerinwa Sera- pidis,, founded on the cast of a fragmentary whorl from the Nummulitic formation of Kgypt, showing internal characters, with the markings of three prominent plications which were originally produced by the columella. Similar fragments from Egypt are in the British Museum, as well as more perfect specimens, all of which exhibit this strongly-plicated columella extending through the entire axis of the shell, which, as a cast either in limestone or aS an impression taken in ordinary modelling-wax, will produce a result exactly similar to that figured by Bellardi. ‘That is, it would appear that, in all these natural casts, the original solid columella has been dissolved away during the process of fossiliza- tion, but not before leaving its plicated character fully impressed on the internal walls of the volutions. Moreover, in all true specimens of Nerinea, the outer lip is plicated as well as the columella; but, in members of the Cerithiide, such a character is wanting. With regard to another form of Neinca described as N. supracretacea, Bellardi, from the Nummulitic rocks of Nice, it is possible, as suggested by Stoliczka,* that the absence of plications on the outer lip of that specimen may be due to its worn condition; and that, instead of coming from the Nummulitic rocks, it probably came from the Cretaceous deposits which also occur in the neighbourhood of Nice. So far, therefore, as can be ascertained, no authentic Nerinea is known in the Tertiary Period, and it appears to be a genus absolutely restricted to Secondary rocks, All these large forms of Campanile appear to be characteristic of Middle Hocene times. F. Bayan has described and figured C. Bedechei, with a basal diameter of 61 millimetres, from the Tanie Basin, as well as C. Lachesis, measuring from 65 to 90 mm., from the * Nerita Schmiedeli-beds ’ of Ronea.? From Asia Minor, A. d’Archiac figured and described C. Tchihatcheffi, which has a basal measure- ment of 90 mm., and is found associated with Nummulites Ramondi and NV. scabra; also C. Leymerict, with a basal width of 140 mm., from the same horizon.* CAMPANILE cf, cieanteus (Lamarck) Var. A. (Pl. XVII, fig. 1.) Cer ithium gigantewm, Lamarck, Ann. Mus. Hist. Nat. Paris, vol. 111 (1803) p. 489 ; J. Sowerby, ‘ Mineral Conchology’ vol. ii (1818) p. 199 & pl. elxxxviii, fig. 2 A 1. ¢ Mem. R. Accad. Sci. Torino, ser. 2, vol. xv (1855) } pulieidé pl.a, fig. 9: 2 *Paleont. Indica: Cretaceous Fauna of Southern India,’ Mem. Geol. Surv. India, vol. ii (1867-68) p. 179. 3 «Etudes faites dans la Collection de |’Ecole des Mines: Fossiles nouveaux ou mal connus’ Fasc. i, Moll. Tertiaires, 1870, pp. 31-33. 4 In Tchibatcheff’s ‘Asie Mineure’ Paléontologie (1866-69) pp. 126-29 & pl. i, figs. 1-2, pl. ix, figs. 2-3, & pl. u1, fig. 1. OnoG.s. No 241. M 162 MR. R. B. NEWTON ON THE [Feb. 1905, Deshayes, ‘ Description des Coquilles Fossiles des Environs de Paris’ vol. it (1838) p. 300 & pl. xlu, figs. 1-2. Campanile gigantewn, Bayle, in Fischer’s ‘ Manuel de Conchyliologie’ fase, vil (1884) p. 680, This specimen consists of a large limestone-cast exhibiting the basal and penultimate whorls only, the remainder of the spire being absent. The whorls are shallow, infundibuliform, postero-horizon- tally depressed, obtusely angulate at and between the margins, and separated by a deep suture; the margin of the inner or columella- lip is smooth, rounded, thickened, and excavated; the aperture 1s filled with matrix and not definable, but, where this is rubbed down, columella-plications are observed to be present. The surface of the whorls shows indications of one or two obscure spiral bands, which give rise to obtuse angulations apart from that produced by the Senet carination. DIMENSIONS IN MILLIMETRES, Dee a iaametertan ase =100 : | Diameter ... =60 Basal whorl sagen ee — 70 Penultimate whorl 1 Height ...... — 30) Although not quite so rounded in its whorls, this specimen is closely related to a large internal cast in the British Museum (Mantell Coll. 32578) labelled Campanile cf. giganteus, from the Kocene (Lutetian) strata of Verona, Italy, which exhibits three prominent columella-plications extending through its whole axis. The specimen now described was previously regarded as ‘a Nerina of Neocomian affinities’; * but a further study of its characters removes all doubt as to its proper place being with the large Cerithiide, so characteristic of the Kocene Period. ‘That it belongs to this horizon is a fact further strengthened by the presence of Amphistegina and Operculina cf. complanata in the limestone- matrix (see §$ P in the Notes on the Foraminiferal Structures, etc., pa li: Locality.—Bur Dab (Somaliland). Collector.—Mr. F. B. Parkinson. [G. 12053. | Matrix.—Cream-coloured limestone, weathering a straw-colour, CAMPANILE cf. cigantEus (Lam.) Var. B. (PI. XVII, figs. 2 & 3.) This form is represented by a basal fragment possessing four whorls, which have been more or less distorted or compressed through the process of fossilization. The whorls are obtusely angulate on both margins, infundibuliform, deeply sutured, depressed and concave above; they are of uniform height, with the exception of the last, which is about double that of the others. The base shows two strong columella-plications, and there may be a third, but it is not exposed. ‘The surface of the last whorl possesses distant concentric sulcations, about midway between the lower marginal angulation and the basal area. 1 See R. B. Newton in Gregory, Quart. Journ. Geol, Soc. vol. lvi «4900) p. 43. Vol. 61.] TERTIARY FOSSILS OF SOMALILAND. 163 DIMENSIONS IN MILLIMETREs. Height of the specimen ...... =70 | Height of the last whorl ...=30 Basal diameter (maximum)... =65 The example here described was collected at Dongorreh by Mrs. Lort-Phillips, its matrix containing Amphistegina, Opercu- lina, ete. (see § O in the Notes on the Foraminiferal Structures, p.- 177). There is a second specimen of this variety, which was obtained by Mr. F. B. Parkinson at the same place, and was erroneously recognized as Nerinea allied to Renauatana, WOrb." A further specimen was collected by Major R. G, Edwards Leckie about 4 miles south of Camp, Upper Sheikh, at an altitude of over 5000 feet, showing similar lithological Ghana to the others. It is, foeen of smaller size, bovine a basal diameter of od millimetres, although the whorls are of precisely the same type ’ of structure as that described. Localities.—Dongorreh ; 4 miles south of Camp, Upper Sheikh. Collectors.—Mrs. Lort-Phillips, Mr. F. B. Parkinson, and Major R. G. Edwards Leckie. Matrix.—Heavy cherty limestone, red-stained externally. CAMPANILE SOMALIENSIS, Sp. nov. (Pl. XVIII, figs. 1 & 2.) There are two limestone-casts now to be noticed, of still larger proportions than those previously described, which apparently belong to one and the same species. The best-preserved and largest of these exhibits a conically-shaped body of oblong circumference with the four last whorls, all the earlier ones being absent. The latest whorl shows a maximum height of 72 millimetres, while the penultimate measures 40 mm. in the same direction, the next giving a height of 35 mm. ‘The basal diameter of the specimen measures 165 by 145 mm. Its base is much covered with matrix, but con- centric plications are observable round the columellar region, where a flattened area is noticed circumscribing the axis, The whorls of this specimen are not funnel-shaped anteriorly, nor is the suture so deep as in the forms previously described. Moreover, it is doubt- less of much shorter spire also, and is probably a form not yet described. Indications of a short anterior canal are also present. The smaller of these specimens (having a diameter of 135 by 120 millimetres) has been cut through longitudinally, for the exposi- tion of internal characters. This exhibits a wide cylindrical axis showing columella-plications, having on each side large quadrate chambers with rounded outer margins, and curving obliquely and anteriorly inwards. Locality.—Specimens collected by Dr. Donaldson Smith in the neighbourhood of Berbera, and presented to the British Museum (Natural History) by the Gackwar of Baroda. Matrix.—A cream-coloured cherty limestone, containing Orbr- toides, Operculina, etc. (see § Lin the Notes on the Foraminiferal Structures, p. 176). 1 See R. B. Newton in Gregory, Quart. Journ. Geol. Soe. vol. lvi (1900) p. 48, footnote. M 2 L64 MR. R. B. NEWION ON THE [ Feb. 1905, Eusrrra cf. scALARIFORMIS (Deshayes). (Pl. XIX, figs. 1 & 2.) Ampullaria scalariformis, Deshayes, ‘Description des Coquilles Fossiles des Environs de Paris’ vol. ii (1825) p. 138 & pl. xvi, figs. 8-9. , Euspira scalariformis, Cossmann, ‘Catal. illustré Cog. Foss. Eocénes des Environs de Paris’ Ann. Soc. Roy. Malacol. Belg. vol. xxiii (1888) p. 175. This form of gastropod is represented by a fragmentary limestone- east, exhibiting the penultimate and last whorls of a large shell of ovately-conical shape. The last whorl is convex, long, and sur- mounted by a somewhat flattened area, bordered by an angulated margin. The umbilical region is excavated, although partly filled with matrix; and the aperture is of distinctly-oval contour, vertically elongate, narrow, with nearly-parallei sides, and showing a measurement of 63 by 35 millimetres. The specimen has all the appearance of a close relationship to Euspira scalariformis, having been probably furnished with just as prominent a spire as that which characterizes that species when in a more perfect condition. The species was originally recorded from the Middle Kocene of France. Locality.—Near Berbera. Collector.—Dr. Donaldson Smith. Presented to the British Museum (Natural History) by the Gaekwar of Baroda. M atrix.—Greyish cherty limestone. Kusprra cf. HyBripa (Lamarck). (PI. XIX, figs. 3 & 4.) Ampullaria hybrida, Lamarck, Ann. Mus. Hist. Nat. Paris, vol. v (1804) p. 33. Natica hybrida, Deshayes, ‘ Description des Coquilles Fossiles des Environs de Paris’ vol. ii (1829) p. 172 & pl. xix, figs. 17-18. 3 Huspira hybrida, Cossmann, ‘ Catalogue illustré des Coquilles Fossiles Hocénes des Environs de Paris’ Ann. Soc. Roy. Malacol. Belg. vol. xxiii (1888) p. 175. Natica allied to Hugardiana, R. B. Newton, in Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 43 (footnote), 20n d’Orb. This specimen was originally recognized as Cretaceous, under the name of Natca allied to Hugardiana, but it is apparently a form not far removed from Huspia hybrida, so characteristic of most HKocene localities. It shows a graduated and conical spire with the prominent ‘rampe’ or platform constituting the summit- area of each whorl. ‘The last whorl is inflated, and excavated at the base, where there are indications of a large rounded callosity. The aperture is semi-oval. Parts of four whorls are traceable in this cast, the more delicate earlier ones not, of course, being present. DIMENSIONS IN MILLIMETRES, Height of the specimen ...=65 | Height of the last whorl ...... =37 Diameter (dorsal view) ...=63 There is also a smaller cast, which may be referred to this species. Localities——Bur Dab (Parkinson); and Garrasgooi, 3 miles south-west of Upper Sheikh (Leckie). Collectors.—Mr. F. B. Parkinson and Major R. G. E. Leckie. Matrix.—Cream-coloured limestone. Vol. 61.] TERTIARY FOSSILS OF SOMALILAND. 165 Another Naticoid shell, of far larger dimensions than that just described, but probably related to Huspira hybrida, is among the specimens obtained by Dr. Donaldson Smith. It consists of a limestone-cast with four whorls, the last being of considerable size and showing a well-defined ‘ramped’ area. The basal region appears to have been removed by longitudinal splitting or weather- ing, so that a flat surface only is seen, representing a section with a large central umbilical space. The spiral diameter of this speci- men measures 125 by 95 millimetres. In a microscope-slide of the matrix, Operculina, Amphistegina, etc. are seen to enter largely into its minute structure (see § M in the Notes on the Foraminiferal Structures, p. 176). Locality.—Near Berbera. Collector.—Dr. Donaldson Smith. Presented to the British Museum (Natural History) by the Gaekwar of Baroda. Matrix.—Cream-coloured limestone. SOLARIUM cf. CANALICULATUM, Lamarck. (Pl. XIX, figs. 5 & 6.) Solarium canaliculatwm, Lamarck, Ann. Mus. Hist. Nat. Paris, vol. iv (1804) p. 53; Deshayes, ‘ Description des Coquilles Fossiles des Environs de Paris’ vol. 11 (1832) p. 220 & pl. xxiv, figs. 19-21; J. de C. Sowerby, ‘ Mineral Con- chology ’ vol. vi (1826) p. 43 & pl. dxxtiv, fig. 1. Represented by two weathered limestone-specimens, in the collec- tion formed by Major Leckie, which mostly agree in shape, sculp- ture, and size with this well-known European Hocene shell. The granulose spiral lines of the upper surface, as well as those of the basal region, are well defined, although probably more regular than in the type. DIMENSIONS IN MILLIMETRES. Eletaita(probable)) esese wees... -% =8 | Diameter of the base ......... 1) One of the specimens is associated in the same matrix with Liotina somaliensis and a coral, probably Calamophyllia Aylmera of Gregory ; while the other example occurs with an Astartiform shell of doubtful determination. Locality.—Top of Garrasgooi Mountain, 5200 feet above sea- level, south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—Heavy, compact, cherty limestone, of reddish colour externally. LIoTIna SOMALIENSIS, sp. nov. (PI. XIX, fig. 7.) Shell small, turbinate, summit depressed; whorls convex, deeply sutured, and ornamented with an elevated trellised sculpture, composed of numerous longitudinal and spiral coste, forming regular quadrangular spaces. Margin of aperture thickened, varixed, and reflected. Basal characters not seen. DIMENSIONS IN MILLIMETRES. 1s Geo tL eee iene ae =D) Dia MOtCL same. 0s «oot = 12 166 MR. R. B. NEWION ON THE [Feb. 1905, Represented by a beautifully-weathered example on the limestone- matrix, associated with Solarium ef. canaliculatum and a coral, probably Calamophyllia Aylneri, Gregory. This form differs from Liotina (Delphinula) fimbriata, Deshayes, from the Paris-Basin Eocene, which it somewhat resembles in sculpture, by its much smaller trellised ornamentation, caused by the greater number of spiral and longitudinal coste. A minute tuberculation is also apparent in the ornamentation, which is caused by a thickening at the junctions of the two sets of coste. The spire consists of five or six whorls, the last of which has a height at the aperture of 8 millimetres, or nearly three times that of the succeeding one. Locality.—Top of Garrasgooi Mountain, 5200 feet above sea- level, south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—Heavy cherty limestone, reddish-brown externally. Indeterminable Gastropoda. Among Major Leckie’s fossils from the limestones of Garrasgooi are some further forms of gastropods which, although possessing a certain Eocene facies, are unfortunately not capable of identification. These include natural casts of a Z’rophon (?); Turritella, showing two elongate whorls of a large species; and a Conus resembling somewhat C. deperditus of Bruguiere, or C. diversiformis of Deshayes, from the English and Continental Eocene deposits, or the Indian (Cutch) species C. imlitaris, figured and described by J. de C. Sowerby,’ from beds of similar age. Locality.—Garrasgooi, 3 miles south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—A light-coloured limestone, and found below the more cherty rock containing Liot:na somaliensis and other fossils. (6) Lamellibranchia. AEctRyonis cf. Marrinsr (d’Archiac). (Pl. XX, figs. 1 & 2.) Ostrea orbicularis, J. de C. Sowerby, Trans. Geol. Soc. ser. 2, vol. v (1840) pl. xxiv, fig. 8; now Linneus. Ostrea Martinsii, A. d Archiac, ‘ Descr. Foss. Groupe Nummul.’ Mém. Soc. Géol. France, ser. 2, vol. iii, pt. ii (1850) p. 488 & pl. xiii, fig. 25. Ostrea Alectryonia Martinsi, Frauscher, Denkschr. d. k. Akad. Wissensch. Wien, vol. li (1886) pt. 11, p. 68 & pl. i, figs. 4-6. Alectryonia rectangularis, R. B. Newton in Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 43; 2o0w Roemer. Ostrea (Alectryonia) semipectinata, Schatheut] in Oppenheim, Paleontographica, vol. xxx, pt. 11 (1908) p. 43. This specimen was previously regarded by me as a Cretaceous — shell, under the name of A. rectangularis of Roemer, but re- examination shows that its true place is in close association with Alectryonia Martinsi, originally described by J. de C. Sowerby from the Nummulitic formation of India under the pre-occupied name * Trans. Geol. Soe. ser. 2, vol. v (1840) pl. xxvi, fig. 34. laa Vol. 61. | TERTIARY FOSSILS OF SOMALILAND. 167 of Ostrea orbicularis. It represents a fragment of a slightly-convex valve, showing a shallow ligamental area with a straight horizontal inner margin, The ribs are prominent and bifurcating, the channels between them being deeply excavated, and so producing a plicated margin. The surface is much worn, consequently there are no traces of an imbricated structure. It resembles very closely J. de C. Sowerby’s original figure, as well as Dr. Frauscher’s illustrations of examples from districts of the Northern Alps. Dr. Oppenheim regards this species as equivalent to Schafhzutl’s Ostrea sem- pectinata, suborbrculata, and abscissa, and unites all three under the first-named species; but Schafheeutl’s figures are so obscure for such a determination, that it is far better to retain Martins: of A.d’Archiac. It is, however, interesting to know from Dr. Oppen- heim’s memoir that this shell is recognized in the Egyptian Eocene ; and the present Somaliland example appears to offer characters of such close relationship as to make it almost certain that it is a second instance of its occurrence in Northern Africa. Locality.—Dobar, south of Berbera. Collector.—Mrs. Lort-Phillips. Matrix.—tThe so-called ‘Dobar Limestone.’ [B.M.—L. 14927. ] GRYPHHA GrReeoryI, sp. nov. (Pl. XVII, fig. 4 & Pl XXI, figs. 1 & 2.) | Gryphea vesiculosa, R. B. Newton in Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 43; non J. de C. Sowerby. Shell small, thin, strongly arched, sides abrupt, subrhomboidal, summit depressed; growth-lamelle irregular and sinuated at the lateral lobe; umbonal area incurved; anterior margin extended at the hinge, and forming a small auricle; posterior lobe well- . defined, expansive and moderately concave externally. DIMENSIONS IN MILLIMETRES. Umbono-ventral ............... =27 | Convexity of the left valve ...=25 Antero-pOsterion.....30-.5<:-. = 2 This species is founded on external characters of the lower or left: valve only, of which there are several examples more or less fragmentary, both in Major Leckie’s collection and in that formed by Mr. Parkinson, referred to in Dr. Gregory’s paper as a Cenomanian fossil with the name of Gryphca vesiculosa. The specimen described and figured belongs to this latter collection, being preserved in the British Museum under the registered number L. 12666. The present species is related to several Eocene forms of this genus, such as Gir. eversa, Melleville, from France, Gir. laticeps, Schafheeutl, from Kressenberg, and Gir. Escheri of Mayer-Eymar, which includes Gir. gryphovicina, 8. V. Wood, and Gir. pscudovesicularis, Giimbel, from England, the Northern Alps, and Kressenberg ; but it is well separated by its subrhomboidal form, its strongly-arched central region, the somewhat steep sides, and rather wide but not produced lobe of the posterior area. For synonymy and further particulars of these species reference should be made to an important 168 MR. R. B, NEWTON ON THE [ Feb. 1905, memoir by Dr. K. F. Frauscher, ‘ Das Unter-Kocin der Nordalpen & seine Fauna’ Denkschr. d. k. Akad. d. Wissensch. Wien, vol. li (1886) pt. 1, pp. 49-55. The specific name is given in honour of Prof. J. W. Gregory, my former colleague in the Geological Department of the British Museum (Natural History), who at the time of the reading of this paper was Professor of Geology in the University of Melbourne, but now occupies a similar position in the University of Glasgow. forthern Somaliland [B.M.—L. 12666]; and top of Garrasgooi Mountain, at an elevation of about 5200 feet, 3 miles south-west of Sheikh. Collectors.—Mr. F. B. Parkinson and Major KR. G. Edwards Leckie. Matrix.—Cherty limestone, coloured reddish-brown externally. GryPHwa sp. (Pl. XXI, fig. 3.) Major Leckie has collected three fragments of a large Gr yhieee which, from want of better evidence, ib is difficult to associate with any known form of this genus, although possibly they may be related to an Indian Nummulitic species described by J. de C. Sowerby as Gryphea globosa.' The largest of the pieces represents the central portion of a lower valve, which gives an umbono-ventral measurement of 75 millimetres. It is considerably arched and incurved at the TEAenel region, and the external surface, although in a worn condition, still shows some wide lamelle of growth with occasional obscure concentric banding between them. ‘This specimen also exhibits a shell-wall of great thickness (15 milli- metres) at the umbonal arch, which gradually decreases, however, towards the ventral margin, where it is only about 6mm. thick. No ligamental or other internal characters are “definable. “Locality. —About 31 miles south of Camp at Upper Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—Cherty lmestone, coloured reddish-brown externally, and containing Discocyclina dispansa, Operculina, and Ainiphi- stegina (see §§ B & C in the Notes on the Foraminiferal Structures, p. 176). . Vouuseita (?) sp. (Pl. XXII, fig. 4.) This specimen consists of a narrow elongate valve, showing a convex and a somewhat acuminate umbonal region, the remainder of the surface being depressed. The lateral margins are imperfect, and consequently the original antero-posterior measurements are unknown. ‘The principal feature of the specimen is its sculpture, exhibiting a regular series of concentric lamelle, which are very thin, nearly equidistant, and smooth. In this ornamentation there is a certain agreement with some forms of Vulsella, recently described and figured by Dr. P. Oppenheim, from the older Tertiary strata of Egypt.” But it is hazardous to say more in regard to the 1 Trans. Geol. Soc. ser. 2, vol. v (1840) pl. xav, fig. 16. > Paleontographica, yol. xxx, pt. iii (1903) pl. vi. Vol. 61.] TERTIARY FOSSILS OF SOMALILAND. 169 present imperfect material, especially as the specimen here figured is without hinge or internal characters. It might even represent the upper valve of a Giryphea, similar to the larger form referred to in this paper. DIMENSIONS IN MILLIMETRES. Umbono-ventral ............... =58 | Antero-posterior (about) ...... =37 Locality.—Garrasgooi Mountain, about 5200 feet above sea- level, sonth-west of Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—Cherty limestone, coloured reddish-brown externally. SponpyLus zeypriacus, R. B. Newton. Spondylus egyptiacus, R. B. Newton, Geol. Mag. 1898, p. 536 & pl. xx, figs. 4-6 ; Cossmann, Bull. Inst. Egyptien, ser. 4, no. 1, fasc. vi (1901) p. 190 & pl. un, fig. 21; P. Oppenheim, Palzontographica, vol. xxx, pt. 11 (1903) p. 63 & pl. 1, figs. 1-2 The examples referred to this species are very fragmentary, although showing typical sculpture-details, including the two orders of radial costs, presenting a more or less zoned appearance caused by the occasional presence of finer coste between the interstitial spaces. The coste also exhibit minute spinous projec- tions, an additional character pointed out by M. Cossmann since the publication of the original description. This species was first described from the Eocene of Egypt, and it has since been identified from the same country by M. Cossmann and Dr. Paul Oppenheim, in rocks of similar age. Localities.—Hill about 4 miles south of Upper Sheikh at a height of 5000 feet ; top of Garrasgooi Mountain, about 5200 feet, south-west of Upper Sheikh; Bur Dab.’ Collectors.—Major R. G. Edwards Leckie and Mr. F. B. Parkinson. Matrix.—Cherty limestone, of reddish colour externally. SPONDYLUS SOMALIENSIS, sp. nov. (Pl. XXI, figs. 5, 6, & 6a.) Species of variable size, sub-ovate, regularly convex, and nearly equivalve ; external surfaces ornamented with numerous (probably about 60) well-defined, rounded, longitudinal coste, all of one order, which are covered with frequent infundibuliform annulations having thin and elevated margins: these occasionally protrude beyond the others to form spinous projections, more especially on the lateral regions. ‘The coste are separated by extremely narrow and rather deep grooves; the hinge-line is short, with its umbono-lateral areas obliquely ribbed. No internal characters are seen. DIMENSIONS IN MILLIMETRES, (Imperfect specimen with con- ; Antero-posterior (about) ......... —25 tiguous valves.) Maximum depth)... 0.0..s08s.0.. 9) Winibono=ventral. soc. .cs.ss ese « =42 EEE 1 Fragments referred to a Cenomanian age under the name of Spordy/us sp., by R. B. ” New ton, in Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 45.. 170 MR. R, Bs NEWTON ON THE [ Feb. 1905, This species is represented by fragmentary specimens showing a variation in size, the most perfect of which possesses both valves and is of medium measurement (see dimensions as above); two fragments of considerably larger specimens exhibit the sculpture- characters in a good state of preservation. It differs from Spondylus cegyptiacus in its surface-ornamentation, having ribs of only one order, that is, without secondary or intermediate ribs ; in the closely- imbricated character of its costae; and in its nearly-equivalve condition. The fragment from Bur Dab, referred to by me, in Prof. Gregory’s paper, as belonging probably to a new species of Pecten, is, on comparison with the later improved material, found to be a fragment of the Spondylus now described. Localities. v001 Mountain, at an elevation of about 5200 feet ; and Bur Dab. Coliectors. —Major R. G. Edwards Leckie and Mr. F. B. Parkinson. Matrix.—Cherty limestone, red-stained externally. LirnopHaca sp. (Pl. XXI, fig. 7.) Modiola Ferreti, R. B. Newton in Gregory, Quart. Journ. Geol. Soe. vol. lvi (1900) p. 48; non A. T. de Rochebrune. These examples of a Lithophaga are represented by crypts, con- tained in a compound coral which Prof. Gregory has named Prion- astrea crassisepta. The molluscan part of this fossil was erroneously identified by me in Prof. Gregory’s paper as Modiola Ferreti, a species described by Dr. A. T. de Rochebrune' from the Antalo Limestones of Abyssinia, and supposed by that author to be of Neocomian age. Unfortunately, a very feeble description was given of the species, and unaccompanied by figures. It would appear, however, from the obscure nature of the Somaliland specimen, of which the crypts only are seen, that the cavities are more cylindrical than those from Abyssinia, their diameter measuring 12 millimetres. Beyond this there are no decided characters to speak of, although the lithological aspect of the specimens corresponds with other examples of the Lower Limestone fossils in the collections under description. Locality.—Dobar, south of Berbera. Collector.—Mrs. Lort-Phiilips. [B.M.—L. 14928. ] Matrix.—Creamy-white limestone, equivalent to the ‘ Dobar Limestone’ of Prof. Gregory. Lucina cf. eigantna, Deshayes. (PI. XX, fig. 3.) Lucina gigantea, Deshayes, ‘ Description des Coquilles Fossiles des Environs de Paris’ vol.i (1825) p. 91 & pl. xv, figs. 11-12. Pseudomiltha gigantea, Fischer, ‘Manuel “de Conchyliologie’ fase. xi (1887) p. 1144. Lucina (Miltha) g gigantea, Gregorio, ‘Monogr. Foss. Eocéniques (Parisien) de Mont Postale’ Ann. Géol. Pal. Palerme, pt. xiv (1894) p. 35 & pl. vii, figs. 208- 216. * ‘Mission G. Révoil aux Pays Comalis: Observations Géol. & Paléont.’ 1882, p- 10 [Lithodomus Ferreti]. Wool, 6x. | TERTIARY FOSSILS OF SOMALILAND. dic _ Lucina gigantea, Gregorio, ‘Monogr. Faun. Hocenica Ronca’ Ann. Géol. Pal, Palerme, pt. xxi (1896) pp. 94, 95 & pl. xvi, figs. 4-10; P. Oppenheim, Palzontographica, vol. xliii (1896) p. 152 & ibid. vol. xxx, pt. 111 (1903) p. 129. This specimen consists of a large but rather rough limestone-cast with compressed valves, related probably to this species. The adductor-scar markings are well defined, and the pallial line can be seen for some distance in the ventral region accompanied by some fine vertical striations. ‘There is also a strong indication of the long, ligulate, anterior adductor-scar on the lateral face of the right valve, which is of rather crescentic shape. Large forms of Lucinide are very characteristic of the Kocene Period, being fre- quently found in the Paris-Basin area ; in the neighbourhood of Ronca and Monte Postale (Italy); andin the Nummulitic rocks of Kgypt and India. Another species, with which the specimen from Somaliland may be compared, attains an even larger size than gigantea: this is the Lucina corbarica, var. regularis of Leymerie,* which belongs to the Ypresian stage of the Eocene,’ situated immediately below the Lutetian; but that species possesses much more convex valves, although somewhat similar in general contour. Limestone-casts of L. corbartea, var. regularis are found in the Lower Eocene deposits of Farafra, in the Libyan Desert of Egypt. DIMENSIONS IN MILLIMETRES. Umbono-ventral ............... =85 | Maximum convexity with closed Antero-posterior ...... GO5oH BOs =90 VIR ES Sc GaH oases Le meena nee =33 Locality.—Garrasgooi, 5 miles south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. — Matrix.—Limestone occurring below the more cherty beds. Lvctna ef, rHepatca (Zittel), Oppenheim. (PI. XX, figs. 4 & 5.) Lucina thebaica, Zittel, Paleontographica, vol. xxx, pt. 1 (1883) pp. 100, 102, etc. (list-name only; species neither figured nor described); P. Oppen- heim, ibid. pt. 111 (1903) p. 128 & pl. xiil, figs. 3-3. a. . This species of shell, although known under Zittel’s list-name of Lucina thebaica since 1883, has only just been figured and described by Dr. Oppenheim. It is of common occurrence in Egypt, and characterizes the Middle Suessonian or the ‘ Libysche Stufe’ of Zittel. The majority of the specimens that have come under my observation have a greater antero-posterior measurement than umbono-ventral, although Dr. Oppenheim’s figures represent a shell having almost equal measurements. The specimen from Somaliland is not so ventricose as those from Egypt, but it has much the form of this species, besides possessing similar subcentral beaks, and a sculpture showing indistinct con- centric lines as well as straight longitudinal striations radiating from the summits, a character so frequently seen in members ot the Lucinide. Both valves (closed) are represented in the specimen 7 *Mém. sur le Terrain 4 Nummulites des Corbicres, etc.’ Mém. Soc. Géo!. France, ser. 2, vol. i (1846) pt. ii, p. 361 & pl. xiv, fig. 5. * A. de Lapparent, ‘ Traité de Géologie’ 4th ed. (1900) p. 1435. 172 MR. R. B. NEWTON ON THE [Feb. 1905, described’; the right shows the sculpture and general configuration, while the other valve exhibits the cast with the muscular-scar impressions, pallial line, and radial striations spreading down from the umbonal area. It certainly bears a very close relationship to some forms from Thebes in Egypt, preserved in the British Museum. There is a second specimen of this shell which is entirely a cast and also with closed valves, exhibiting the usual markings as previously observed. DIMENSIONS IN MILLIMETRES. Umbono-ventral ............... =60 | Convexity (valves closed) ......... =25 Antero-posterior .........-.+-.. =73 Locality.—Garrasgooi, 3 miles south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. : Matrix.—Limestone occurring below the more cherty limestone- beds, containing foraminifera, such as Operculina, etc. (see § G in the Notes on the Foraminiferal Structures, p. 176). Luctna cf. Mrnarpi, Deshayes. (PI. XXI, fig. 8.) Tucina Menardi, Deshayes, ‘ Description des Coquilles Fossiles des Environs de Paris’ vol. i (1825) p. 94 & pl. xvi, figs. 13-14. Lucina Menardi (?), Bellardi, ‘Catal. Foss. Nummulitici dEgitto’ Mem. RK. Accad. Sci. Torino, ser. 2, vol. xv (1855) p. 188. This specimen consists of a well-preserved fragment of a Lucini- form shell with large subventricose valves, showing fairly-regular concentric striations and a portion of the postero-lateral depressed area. Indications of the ligament are also present in the dorsal region, although beyond the summits in the anterior direction the shell is fractured and all further characters are wanting. Judging from Deshayes’s figures of this species, the present specimen appears to resemble it very closely. It differs from Lucina gigantea in possessing the well-defined area of the posterior region. DIMENSIONS IN MILLIMETRES. Umbono-ventral ............... =65 | Maximum convexity (valves | closed) .i...0.sc.2.. eee =30 Bellardi has doubtfully recorded the occurrence of this species in the Eocene formation of Egypt; it was originally described from the Middle Kocene of France. | Locality.—Garrasgooi, 5 miles south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—Sandy-limestone occurring below the more cherty limestone-beds, with a reddish tinge. Fimeria cf. tAmELLosA (Lamarck). (Pl. XXI, fig. 9.) Lucina lamellosa, Uamarck, Ann. Mus. ae Nat. Paris, vol. vii (1806) p. 237, & vol. xii (1808) p. 458 & pl. xhi, fig. Corbis lamellosa, Deshayes, “Description i Coquilles Fossiles des Environs de Paris ’ vol. 1 (1824) p. 88 & pl. xiv, figs. 1-3. Fimbria lamellosa, Frauscher, Denkschr. d.k. Akad. d. Wissensch. Wien, vol. li (1886) pt. 11, p. 172. This fossil consists of a fragmentary impression of a longi- Vol. 61. | TERTIARY FOSSILS OF SOMALILAND. 173 tudinally oval-shaped valve, belonging in all probability to the genus Mimbria. It exhibits a regular series of equidistant oval coste with intervening broad sulcations, which are marked by closely-set and fine transverse striew. Only about half the valve is preserved, and this only as an impression in the limestone- matrix ; yet its sculpture is of interest, as suggesting affinities with Pimbria lametlosa of Lamarck—a familiar Eocene shell found in Kurope, Northern Africa (Egypt, etc.), Asia Minor, ete. The original umbono-ventral measurement of the specimen must have been about 40 millimetres, and the antero-posterior about 60mm. The posterior side appears to bear a slightly-excavated narrow and elongate area (as seen in a wax-squeeze), which recalls a character more suggestive of Lucina than /imbia, and therefore the present identification of this specimen must be more or less provisional. Locality.—Garrasgooi, 5 miles south-west of Upper Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—The upper or more cherty limestone-beds, showing a reddish tinge. The rock contains Operculina and other fora- minifera (see § F in the Notes on the Foraminiferal Structures, p. 176). : (c) Echinoidea. SCHIZASTER sp. A few remains of Schizaster are represented in these collections, one being an entire specimen, though much worn and without properly-detailed characters. Dr. F. A. Bather is inclined to refer them all to one species; he states that this ‘ undoubted Schizaster is enough to prove the Tertiary age of this rock, but the ornament and contour of the specimens are scarcely preserved well enough to enable the species to be determined with certainty.’ Loecalities.—Top of Garrasgooi Mountain, at about 5200 feet above sea-level, 3 miles south-west of Upper Sheikh; Main Golis, 2 miles south-west from Sheikh Camp; and near Berbera. Collectors.—Major R. G. Edwards Leckie and Dr. Donaldson Smith. Linrara (?). Another echinoid has been referred doubtfully to the genus Linthia by Dr. F. A. Bather, with the following remark : ‘It is so worn and crushed, and the actinal surface so obscured by hard matrix, which I have not succeeded in removing, that closer identification is not possible on the present evidence.’ A horizontal section of a small Rotaline is seen, on a fragment of matrix attached to the test of this specimen. Locality.—Top of Garrasgooi Mountain, 5200 feet above sea- level, south-west of Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—aA cream-coloured limestone. 174 MR. R. B. NEWION ON THE [Feb. 1905, (d) Actinozoa (Corals). CALAMOPHYLLIA AYLMERI, Gregory, Calamophyllia Aylmeri, Gregory, Quart. Journ, Geol. Soc. vol. lvi (1900) p. 31 & pl. 1, fig. 3 Major Leckie’s collection contains a remarkably-good example of this coral in the cherty limestone. Localities.—Near Uradu, north of the foot of the Rugga Pass; about + miles south of Camp, Upper Sheikh, elevation over 5000 feet. Collectors.—Mrs. Lort-Phillips and Major R. G. Edwards Leckie. Matrix.—Cherty limestone (=the Uradu Limestone of Prof. Gregory), coloured externally a reddish-brown, containing Opercu- lina complanata (see § A in the Notes on the Foraminiferal Struetures, p. 175). PRIONASTREA Sp. Among Dr. Donaldson Smith’s specimens is a silicified coral resembling Prionastrwa crassisepta of Gregory. The calicular details are somewhat obscure, but at the base individual corallites are seen to be longitudinally costated with closely-packed beaded lines, a character not mentioned in the original description, and therefore this specific name is not applicable to the present specimen. Locality.—Near Berbera. Collector.—-Dr. Donaldson Smith. Matrix.—Cherty limestone, with a reddish tinge. Gontopora Parxrnsoni (Gregory). Litharea Parkinsoni, Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 37 & pl. i, figs. 138-14. Goniopora somaliensis prima, H. M. Bernard, ‘ Catal. of the Madreporarian Corals in the British Museum (Natural History)’ vol. iv (1908) pp. 154, 155, & 195. There is a fairly well-preserved example of this coral in the Leckie collection, exhibiting portion of a subcylindrically-branched corallum, having a length of 40 millimetres and a maximum diameter of rather more than 30 mm. The corallites are broad and with shallow calices, and in every way they conform to the charac- ters pointed out in the original description. Mr. Bernard, in the British Museum Catalogue above quoted, has called attention to this species, and regards it as belonging to the genus Goniopora, on account of that generic name having priority over Litharea, a view which is adopted here. Prof. Gregory’s specific name of Parkinsoni should, however, be retained, not only because it was the first used to designate this coral, but because it is not advisable to favour the trinomial system of nomenclature suggested by Mr. Bernard. Localities.—Above the Miriya Pass and around God-la-Yareh, south of Bur Dab (type); top of Garrasgooi Mountain, at an eleva- tion of 5200 feet, 3 miles south-west of Upper Sheikh. Vol. 61.] TERTIARY FOSSILS OF SOMALILAND. 175 Collectors.—Mr. F. B. Parkinson (type) and Major R. G. Edwards Leckie. Matrix.—Cherty limestone, with external reddish coloration. DenpRACis sp. Dendracis sp., Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 38. Among Major Leckie’s specimens is a fragment of a Dendracis which agrees with the specimen described by Prof. Gregory, and it is interesting to note it from another locality in Somaliland. Localities.—South of Bur Dab (type); Main Golis, 2 miles south-west of Sheikh camp. Collectors.—Mr, F. B. Parkinson and Major R. G. Edwards Leckie. Matrix.—Cherty limestone, coloured a reddish-brown. LY. Nores on tue FoRAMINIFERAL STRUCTURES IN THE TERTIARY LIwESsTONES OF SOMALILAND. The prevailing organism in the Tertiary limestones of Somali- land is Operculina, most probably of the species complanata, as understood by W. B. Carpenter, W. K. Parker, & T, R. Jones.! Several vertical sections of this form show the bossed character of the margin, as well as the great thickness of the wall of the pen- ultimate chamber, when compared with that of the outer volution. There is an apparent absence of Nummulites in all the sections that have been examined, but other genera are observable, especially Amphistegina, trochoidal Rotalines, Vewtularia, Biloculina, Milio- line, and Globigerina. An Orbitoid is also present, possessing rectangular chambers in the median plane, which is recognized as Discocychina cf. dispansa of J. de C, Sowerby, a species originally described from the Nummulitic deposits of Cutch.* It is allowed by most authorities’ on the Foraminifera, that Orbitoids with rectangular chambers are characteristic of the HKocene Period ; this organism is, therefore, of considerable importance in the deter- mination of such an horizon among the Somaliland Limestones. The following list includes the principal foraminifera seen in a sevies of microscope-slides of the Somaliland Limestones, Mr. Richard Holland having kindly assisted me in the various determinations. ‘The slides are lettered from A to R. A. Opereulina complanata (Defrance) accompanying Calamophyllia Aylmeri, Gregory. Locality.—Huill about 4 miles south of Camp, Upper Sheikh, at an elevation of over 5000 feet. . Collector.—Major R. G. Edwards Leckie. Matrix.—Cherty limestone, stained externally a‘reddish-brown. 1 «Introduction to the Study of the Foraminifera’ (Ray Soc.) 1862, p, 255 & pl. xvii, fig. 11. 2 Trans. Geol. Soe. ser. 2, vol. v (1840) pl. xxiv, fig. 16 = Lycophris dispansus. 3 See Ch. Schlumberger, Bull. Soc. Géol. France, ser. 4, vol. iii (1908) pe 273. 176 MR. R. B. NEWLON ON THE [ Feb. 19055 B. Discocylina, possibly dispansa (J. de C. Sowerby), accompanying the large Gryphca sp. é Same locality, collector, and matrix as A. C. Operculina and Amphistegina associated with large Gryphwa sp. Same locality, collector, and matrix as A and B. D. Operculina complanata (Defrance), showing examples of the bossed margins, etc., associated with an indeterminable lamellibranch. Locality.—Top of Garrasgooi Mountain, south-west of Sheikh. Collector.—Major R. G. Edwards Leckie. _ Matrix.—Cream-coloured cherty limestone. E. Operculina, Miliolina, and possibly Amphistegina, accompanying a compound coralliferous organism showing obscure internal structure. Locality.—Top of Garrasgooi Mountain, 5200 feet above sea- level, south-west of Sheikh. Collector.—Major R. G. Edwards Leckie. Matrix.—Cream-coloured cherty limestone, slightly tinged with red, F. Operculina, a trochoidal Rotaline, etc., associated with Minbria cf. lamellosa. Locality.—Garrasgooi, 3 miles south-west of Upper Sheikh ; same collector and matrix as EH. G. Tewtularia and Operculina, found in the matrix of Lucina ct. thebarca. Same locality, collector, and matrix as F. H. Amphistegina, Operculina, and Globigerina. - Locality.—Near Berbera. Collecter.—Dr. Donaldson Smith. ~ Matrix.—Cream-coloured cherty limestone. I. Operculina, Amphistegina, Brloculina, and other Miloline. Same locality, collector, and matrix as H. J. Operculina and other organisms ; indistinct and obscure, accom- panying a large indeterminable shell-fragment. Same locality, collector, and matrix as H & I. K. Operculina, Milioline, Textularia, associated with a large indeterminable shell-fragment. Same locality, collector, and matrix as HJ. L. Good examples of Operculina associated with Campanile somahensis. Same locality, collector, and matrix as H-K. M. Operculina, Textularia, Milioline, and possibly Amphistegina ; in matrix accompanying the large Naticoid-looking shell. Same locality, collector, and matrix as H—L. Vol. 61.] TERTIARY FOSSILS OF SOMALILAND. Aber N. Operculina and Amphistegina associated with the large Cono- clypeus (2) referred to by Prof. Gregory (Quart. Journ. Geol. Soc. vol. lvi (1900) p. 42); no Nummulites observed in this matrix, as previously determined by Messrs. C. D. Sherborn & F, Chapman in Prof. Gregory’s paper just quoted. Locality.—? Kirrit, south of Bur Dab. Collector.—Mr. F. B. Parkinson. Matrix.—Cherty limestone, coloured reddish-brown externally. O. Possibly Operculina, Amphistegina, and Gilobigerina; forms rather obscure; in matrix accompanying casts of Campanile ef. giganteus, var. B. | Locality.—Dongorreh. Collector.-Mrs. Lort-Phillips. Matrix.—Cherty limestone, exterior deeply iron-stained. P. Texiularia, Operculina, probably Orbitolites, and some Rotaline, associated with Campanile cf. giganteus, var. A. Locality.—Bur Dab. Collector.—Mr. F. B. Parkinson. Matrix.—Cream-ccloured limestone, weathering a fawn-colour. Q. Discocyclina dispansa, etc., from the type-specimen of Column- astrea bicoronata, Gregory, Quart. Journ. Geol. Soc. vol. lvi (1900) p. 32 & pl. i, figs. 7-9. Locality.—Duban District, south of Dobar. _ Collector.—Mrs. Lort-Phillips. Matrix.—Cream-coloured limestone. R. Discocyclina, ete., from the type-specimen of Columnastrea bicoronata, Gregory. Same locality, collector, and matrix as Q. V. List oF tHE Tertiary Fossits rrom SOMALILAND. GASTROPODA. Campanile cf. gigantews (Lamarck), Solarium ef. canaliculatum, Lamarck, vars. A & B. Liotina somahensis, sp. nov. Campanile somaliensis, sp. nov. Conus sp. Euspira cf. scalariformis (Deshayes). _ Trophon (2) Euspira cf. hybrida (Lamarck). | Turritelia sp. _ LAMELLIBRANCHIA. Chama cf. calcarata, Lamarck. Astarte (%) Lucina cf. gigantea, Deshayes. Alectryonia cf. Martinsi (d’ Archiac). Gryphea Gregory, sp. nov. -Gryphea sp. Vulsella (%) Lucina ef. thebaica, Oppenheim. Spondylus egyptiacus, R. B. Newton. | Lucina cf. Menardi, Deshayes. Spondylus somaliensis, sp. nov. Fimbria ef. lamellosa (Lamarck). Lithophaga sp. HcHINOIDEA. Conoclypeus (2) sp. _ Linthia Schizaster sp. | OG. Ss No, 241. N 178 MR. R. B. NEWTON ON THE [Feb. 1905, AcTINozOA (CoRALs). List of Prof. Gregory’s new species of corals, described and figured in 1900 (Quart. Journ. Geol. Soc, vol. lvi & Proc. Roy. Soc. vol. Ixvi) as of Cretaceous age, but which must now be recognized as Tertiary : — Calamophyllia Aylmert. Favia somaliensis. Dendracis sp. Cyclolites Phillipsie. Stylina (Cryptocenia) Lort-Phillipsi. | Litharea Cole. Stylina subtabulata. Iitharea Parkinson. Stylophora frondosa. Prionastrea crassisepta. Columnastrea bicoronata. Metethmos asymmetrica. Columnastrea maxina. Heliopora somaliensis. Columnastrea Phillipsie. FoRAMINIFERA. Operculina complanata (Defrance). | Amphistegina. Nummulites (according to Sherborn | Textularia. & Chapman). Biloculina. Discocyclina dispansa (J. de C. Trochoidal Rotalines. Sowerby). Globigerina, ete. Fig. 1. Fig. 1. EXPLANATION OF PLATES XVII-XXI. [All figures are of the natural size, except where otherwise stated. | Puate XVII. Campanile ef. giganteus, var. A. Front view, with indications of the plicated columella on the rubbed- down surface of matrix filling the aperture. Locality.—Bur Dab; collected by Mr. F. B. Parkinson. (B.M.—G. 12053. ] Campanile ct. giganteus, var. B. . Specimen showing the four later whorls, with plications and orna- mental details at the base. Locality.—Dongorreh ; collected by Mrs. Lort-Phillips. [B.M.—G. 16071.} _ Basal view of a smaller example of the same variety. [B.M.—G. 16072. ] Locality.—Four miles south of Camp, Upper Sheikh, at an altitude exceeding 5000 feet; collected by Major R. G. Edwards Leckie. Gryphea Gregoryi, sp. nov. . Dorsal view of a lower valve, showing the concave posterior area and small anterior auricle, Locality.—Northern Somaliland ; collected by Mr. F. B. Parkinson. [B.M.—L. 12666. ] Pratt XVIII. Campanile somaliensis, sp. nov. Front view of specimen with short central canal. [3 nat. size.] [B.M.—G. 16073.] . Longitudinal section of another specimen, exhibiting the cylindrical axis with its plications, and the large quadrate chambers on each side. [B.M.—-G. 16074. ] Locality.--Both specimens were collected near Berbera, by Dr. Donaldson Smith. Nol: 61. | TERTIARY FOSSILS OF SOMALILAND. 179 Fig. 1. Fig, I. Puats XIX, Euspira cf. scalariformis (Deshayes). Front view of limestone-cast, showing the umbilical area and the narrow elongate aperture with its nearly-parallel sides. . Dorsal view of the same specimen. Locality.—Near Berbera; collected by Dr. Donaldson Smith. [B.M.—G. 16075.] Euspira cf. hybrida (Lamarck). . Dorsal view of limestone-cast showing the ‘ ramped’ character of the whorls. The curious pattern on the body-whorl represents rough cracks in the cast. . Basal aspect of the same specimen, showing the strong callosity. Locality.—Bur Dab; collected by Mr. F. B. Parkinson. [B.M.—G. 12052.] Solarium ef. canaliculatum, Lamarck. . Dorsal view, showing part of the spire. 2. . Basal view of the same specimen. X 2. Locality.—Tlop of Garrasgooi Mountain, 5200 feet above sea-level, south-west of Upper Sheikh; collected by Major R. G. Edwards Leckie. [B.M.—G. 16076.] Inotina somaliensis, sp. nov. . Dorsal aspect of a specimen, showing the slightly-reflected margin of the aperture and the trellised sculpture of the shell. x 2 Locality.—Top of Garrasgooi Mountain, 5200 feet above sea-level, south-west of Upper Sheikh; collected by Major R. G. Edwards Leckie. [B.M.—G. 16077.] PuaTe XX, Alectryonia cf. Martinsz (@’ Archiac). Internal view of valve, showing the ligamental region, ete. . External aspect of the same specimen, showing the bifurcating coste. Locality.—Dobar, south of Berbera; collected by Mrs. Lort-Phillips. [B.M.—L. 14927.] Lucina cf. gigantea, Deshayes. . Limestone-cast, showing the internal surface of the right valve, with indications of the adductor-scars and pallial markings. Locality.—Garrasgooi, 5 miles south-west of Upper Sheikh ; collected by Major R. G. Edwards Leckie. [B.M.—L. 16883. ] Lucina cf, thebaica, Oppenheim. . Right valve, showing obscure concentric and radial sculpture. . Umbonal aspect of the same specimen, showing the convexity of the valves. Loecality.—-Garrasgooi, 5 miles south-west of Upper Sheikh; collected by Major R. G. Edwards Leckie. [B.M.—L. 16884.] Puate XXI, Gryphea Gregoryi, sp. nov. Dorsal view of a lower valve of this species, showing a more produced anterior auricle than that represented in Pl. XVII, fig. 4. . Dorsal aspect of a similar valve of another specimen, representing the smallest example of this species that is at present known. Loecality.—Top of Garrasgooi Mountain, 5200 feet above sea-level, south-west of Upper Sheikh; collected by Major R. G. Edwards Leckie. [B.M.—L. 16885. ] 180 THE TERTIARY FOSSILS OF SOMALILAND. _[ Feb. 1905. Gryphea sp. Fig. 3. Section of a fragmentary lower valve of a large species, showing the thickly-laminated shell-structure. Locality.—Hill about 33 miles south-west of the Camp at Upper Sheikh ; collected by Major R. G. Edwards Leckie. [B.M.—L. 16886.] _ Vulsella (2) 4, Outer aspect of a valve, showing smooth, concentric, lamellate sculpture. Locality.—Garrasgooi Mountain, 5200 feet above sea-level, south-west of Sheikh; collected by Major R. G. Edwards Leckie. - [B.M.—L. 16887. ] Spondylus somaliensis, sp. nov. 5. View of a specimen with closed valves. 6. Fragment of a larger specimen, with more distinct sculpture. 6a. Costz enlarged 4 diameters, showing the annulated ornamentation. Locality.—Top of Garrasgooi Mountain, about 5200 feet above sea- level; collected by Major R. G. Edwards Leckie. [B.M.—L. 16888. ] Lithophaga sp. “I mass of Prionastrea crassiscpta, Gregory. [B.M.—L. 14928.] Locality.—Dobar, south of Berbera; collected by Mrs. Lort-Phillips. TIacina ef. Menardi, Deshayes. 8. Posterior lateral view of a fragmentary specimen, with both valves attached, showing the angulated area and concentric ornamentation. Locality.—Garrasgooi, 5 miles south-west of Upper Sheikh ; collected by Major R. G. Edwards Leckie. [B.M.—L. 16889.] Fimbria ef. lamellosa (Lamarck). 9. View of a fragmentary valve, occurring as a limestone-impression, showing external sculpturing. Locality.—Garrasgooi, 5 miles south-west of Upper Sheikh ; collected by Major R. G. Edwards Leckie. [B.M.—L. 16890.] Discussion. Major R. G. Enwarps Leckie said that the localities from which he made his collection of fossils were at Garrasgooi and at various points along the Golis Range, west of that mountain. The Golis Range had an elevation of 5000 feet above sea-level, and formed the northern edge of the great inland plateau of Somaliland. All this plateau was covered by a bed of fossiliferous limestone, averaging, so far as he could judge, about 250 feet in thickness. In the Guban, or Maritime Plain, between the piateau and the coast, the limestones which occurred at the Eilo Range and Bihendola were, in the opinion of those who had examined the fossils, of Jurassic age. He had not observed Tertiary limestones in the Maritime Plain. uThe AurHor thanked Major Leckie for his remarks, and ,the Fellows present for their reception of his paper. . Specimen exhibiting the crypts of Lithophaga (= Lithodomus) in a small Quart, Journ.Geol.SocVol.LX1,P1.XVII. tense ghley ‘delat Tith : | Mintern Bros.imp. EOCENE SHELLS FROM SOMALILAND. Quart.Journ. Geol. Sco Vol LLP ees Neil el, et ; Th Alc MinternBros.imp. SOC NE woe hoo PROM SOMALILAND. PHighley d Quart.Journ.Geol. Soe Vol.LX] Pra ee ; 12 ETighley del. et Ith. Mintern Bros.imp. HOCENE SHELLS FROM SOMALILAND. , aS ‘A : hy j w J 1 tua we " = Ls a) a Be ed, ee i ek ed aOR ae Ee ee | = Ly Ay WARIS NOS eTEREEL ® 4 4 ; fe) _ ps O) bee o < op) ) =e = © | 6 S 3 (i) r O = E & % ne o fa as u) =| el IH w) ] tx] U OQ fx Plighley delet ith Quart Journ.Geol. Soo Vol 2 ear auenirtee PS RMN Hix? ros. imp. Mintern B EOCENE SHELLS FROM SOMALILAND. P. Highley del.et lith. ae - Ses 7% “— 4 ~d , = Vol. 61.] $PALMONTOLOGICAL SEQUENCE IN THE BRISTOL AREA. 181 Al. The Patmonrotocical Sequnnce in the Carsontrerous LiMx- STONE of the Briston Area. By Arruur Vaueuan, B.A., D.Se., F.G.S. (Read June 8th, 1904; rearranged, and additional matter incorporated, October 1904. NS. [Puates XXII-XXIX.] ConTENTS. Page J'., IUNGROGMNGUTOI | Sects. sboaag sdpes aac pce nOmn een abere EEL OTE eee CEE en aEr eee 181 Il. Detailed Description of Continuous Sections and Isolated Exposures Angee we TIS Ol WAN rig | Seis occas aaa t Osiaaiid. < SEMINULA 1.1.0... be Productus semireticulatus ae (mut.). § Cs) Syringoruyris.,.| (C) Syringothyvis aff. laminosa. |( Canryra-Zone.) 2 = ee ex : TiproeNtie a8 (Z,) Schizophoria resupinata. a Rae { (Zi) Spirifer aff. clathratus. Dee = =< ~ ve Z p a ie bb A oS o ( (Ke) Spiriferina octoplicat Cees er { (Ke) Sp ina octoplicata. Sui ay trace cai ‘| | (Kj) Productus bassus. a va << Ye (Modiola-phase) ..... (M) Modiola lata. The correlation of the faunal divisions (enumerated in the fore- going table) with the lithological divisions previously in use, 1s fully set out in the detailed description of the Avon section (p. 188). The discussion of the reasons for choosing the zonal indices and for dividing the whole Carboniferous-Limestone Series into two great divisions can only be undertaken after the detailed account of the whole area has been set out. The general scheme of this detail is sufficiently explained by the Table of Contents (p. 181). O Portskewett ji SODBURY SHCTION Beach j Wrington Z O< a fe SNSECTION : < Emborough 8 SKETCH-MAP ae showing the Outcrop of the Carboniferous Limestone in the Bristol Area OW fina 2y Sy G7. SMuiles 9 — 2,000 4,000 6,000 5,000 10,000 12.000 14,000 Yds Blaize Castle Brentry v i 3 enpury Hill Portishead qs) ie eae Wick: Bristol 4 ) O, On O,, i < © Ashto RQ Urto, Q ee od’s Quarry BATH 188 DR. A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, II. Derarnen Description or Continvous Sections AND ISOLATED EXPosuRES IN THE Bristot AREA. (i) Continuous Sections. (a) Tur Avon Section. Tournaisian or Lower Carboniferous Limestone. M = Zone’ of Modiola lata (Movrora-Zone). Lithological character.—Shales with subsidiary limestones, ending with a series of red limestones (Horizon a). Former designation.—The lower portion of the Lower Lime- stone-Shales, ending with the ‘ Bryozoa-Beds.’ Where exposed in the Avon section :— Clifton side: The cuttings on both the Avonmouth lines near Cook’s Folly. Leigh Woods side: A riverside exposure, and the cutting on the Portishead line. Coral-fauna.—None as yet recorded. Brachiopod-fauna: [ Cliothyris Royssit. Bat. Orthotetes crenistria. Abun- | Humetria (‘ Retzia’) sp. are: | Leptena analoga. dant. | Camarotechia aft. mitchel- And probably (see analysis of Stod- deanensis. dart’s paper, p. 201) :— Spiriferids (fragments of Lingula sp. Rare. ' Spirifer sp. aud Syringo- (Discina) sp. thyris sp.). Chonetes cf. hardrensis. Other groups: Lamellibranchia. Bryozoa. Modiola lata and M, sp. Rhabdomeson cf. rhombiferum Sanguinolites spp. and Rhabdomeson sp. Gasteropoda. Fenestellids. Murchisonia spp. Polycheta. Bellerophon sp. Spirorbis sp. Ostracoda, several forms. Scales of fishes and plant-remains. Note on the definiteness of Horizon a in the Bristol area.—In so far as the brachiopod-fauna is concerned, Horizon a is characterized by :— (i) The occurrence of forms which become enormously abundant in the succeeding zone. Hxamples are :—Orthotetes crenistria, mut. K, ; Leptena analoga; Chonetes cf. hardrensis. 1 It is pointed out, at the end of this paper, that the Modiola-Zone had better be regarded as a shallow-water phase of the Cleistopora-Zone, than as a distinct zone; but the invariable occurrence of similar bathymetric con- ditions, wherever the Upper Old Red Sandstone is conformably overlain by the Carboniferous Limestone, renders the distinction of this phase a matter of considerable stratigraphical importance. Vol. 61. | SEQUENCE IN THE BRISTOL AREA. 189 (ii) The presence of forms which, in the Bristol area, are confined to the upper portion of Zone M and to Subzone K. Examples are:— Eumetria (‘ Retzia’) spp.; Cliothyris Royssii; Camarotechia aff. mitcheldeanensis. If account be taken of the other groups :— The rare occurrence of Modiola lata and of ostracods in Horizon a, links that horizon with Zone M. The abundance of Rhabdomeson links Horizon a with Zone K. Hence Horizon a forms, from a palzontological point of view, a somewhat indefinite level of overlap, in which the Modzola-ostracod phase passes gradually into the faunal phase characteristic of the Cletstopora-Zone. From a lithological standpoint, the development of the highly- characteristic red, crystalline, encrinital limestone at this level throughout the Bristol area appears to give to Horizon a a definite- ness which its paleeontological characters scarcely warrant. K = Zone of Cletstopora aff. geometrica (Crzersroror4-Zone). Lithological character.—This zone has the ‘ Palate-Bed’ for its base, and includes the whole of the thick series of shales (with subsidiary limestones) which lie between that bed and the base of the massive limestones of the Zaphrentis-Zone. Former designation.—The whole of the Lower Limestone- _ Shales which lie above the ‘ Bryozoa-Beds.’ Where exposed in the Avon section :— Clifton side: Occasional exposures along the Avonmouth line, near Cook’s Folly. Leigh Woods side: The lowest beds are shown in the riverside exposure; the topmost beds are shown in Quarry 1 (see Pl XXVI11). Coral-fauna: Cleistopora aff. geometrica. Brachiopod-fauna: Cliothyris Royssti vars. & mut. 3. Rhipidomella aft. Michelini. Spirifer aff. clathratus & var. Productus bassus. Spiriferina octoplicata. Productus ef. Martine. Syringothyris aff. cuspidata. Chonetes cf. Buchianu, Ch. ef. crassi- Humetria (‘ Retzia’) aff. carbonaria. . stria, and intermediate forms. Camarotechia initcheldeanensis. Chonetes cf. hardrensis. Leptena analoga. Lingula sp. Orthotetes crenistria (especially (Discina) sp. mut. K,). Subdivisions :— K,=Subzone of Productus bassus (Bassvs-subzone). This includes only the lowest portion of the zone, and is charac- terized by the great abundance of :— Camarotechia mitcheldeanensis, Leptena, Orthotetes crenistria, mut. K,, Productus bassus, and small Chonetes. 190 T DR. A. VAUGHAN ON THE PALMONTOLOGICAL [| May 1905, Eumetria (‘ Retzia’) aff. carbonaria, Productus bassus, and Chonetes cf. Buchiana are practically confined to this subzone. Syringothyris aff. cuspidata becomes common towards the top of the subzone; but Spirifer spp., Spiriferina octoplicata, Rhipidomella, and Productus ef. Martini are either absent or very rare. K,=Subzone of Spiriferina octoplicata (ocropricara- subzone). his includes the upper and main portion of the Cleistopora- Zone, as well as the horizon of overlap with the Zaphrentis-Zone (Ho B rizon £). rachiopods: Leptena, Orthotetes, Chonetes cf.-crassistria, and Ch. ef. hardrensis are still abundant ; but Orthotetes shows a mutational change. Camarotechia mitcheldeanensis is still common, but diminished in numbers ; and Spirifer aff. clathratus becomes increasingly numerous as we approach Horizon p. Rhipidomella, Productus cf. Martini, and the mutation of Cliothyris froysstt which is characteristic of the lowest subzone of the Zaphrentis-Zone begin to make their appearance. Spiriferina octoplicata reaches its acme at the top of this subzone. Corals: Cleistopora aff. geometrica is nowhere common, but is most abundant in the upper part of this subzone. L=ZLone of Zaphrentis aff. Phillips: (Zapurenris-Zone). Lithological character.— Massive limestones, usually very encrinital. Former designation.—The Lower Limestone (omitting the uppermost beds). Where exposed in the Avon section :— Clifton side: The Black Rock (see below, pp. 191-93). Leigh Woods side: Quarries 1 & 2 (see Pl. XX VII). Coral-fauna: ad Zaphrentis aff. Phillipsi. Amplecus ef. coralloides. Zaphrentis aff. cornucopie. Michelinia spp. Caninia cylindrica, | Syrengopora 6. Brachiopod-fauna: Chothyris glabristria & mut. | Orthotetes crenistria (especially Cliothyris Royssii & vaut. mut. Z). Spirifer aff. clathratus & var. Rhipidomella aff. Michelini. Reticularia aff. lineata. Productus ef, Martine. . Spiriferina octoplicata. Productus semireticulatus, muts, Syringothyris cuspidata, muts. Productus aff. pustulosus. Syringothyris aff. laninosa. Productus aff. Cora mut. Z. Camarotechia initcheldeanensis, muts. | Chonetes ef. crassistria. Camarotechia cf. pleurodon. Chonetes cf. hardrensis. Leptena analoga. Chonetes papilionacea. Schizophoria resupinata. Vol. 61. | SEQUENCE IN THE BRISTOL AREFA. 191 Subdivisions :— 8=Horizon ~. This includes the very lowest beds of this zone; these beds might, probably with equal truth, be considered as the very topmost beds of the preceding zone, for Zaphrentis and Spiriferina octoplicata co-occur here, while all the brachiopods pass con- tinuously from the series below into this horizon. It is, then, a well-marked horizon of overlap, and is lettered accordingly. I include it as the base of the Zaphrentis-Zone rather than as the top of the Cleistopora-Zone, for three reasons :— (a) Zaphrentis is first met with here, and is immediately fairly common, whereas Cleistopora has not been registered here. (b) Chothyris glabristria first occurs (so far as I know) at this horizon. (c) Spirifer aff. clathratus becomes extraordinarily abundant, and con- _tinues so for some time. Where exposed in the Avon section :— Clifton side: The lowest part of the Black Rock (that is, the small separate quarry, which is now closed and forms part of a private estate).* Leigh Woods side: Quarry 1. Special faunal characters.—This horizon is only to be dis- tinguished from the rest of the lower portion of the Zaphrentis- Zone by the common occurrence of Spiriferina octoplicata ; all its other characters are exactly those which distinguish the clathratus-subzone. Z, = Subzone of Spirifer aff. clathratus (crarHRrarus- subzone). [So named from the enormous abundance of the index-fossil.] Where exposed in the Avon section :— Clifton side: All the beds of the Black Rock, up to the slope at __ the northern end of the present quarry. Leigh Woods side: Quarry 1, and the lowest part of Quarry 2 Special faunal characters :— Brachiopods: Chothyris Royssii (mut. 3), Lhipidomella, and Producius ct. Martim reach their maxima, while Spirifer aff. clathratus and its varieties mamtain their extreme abundance throughout the subzone. Spiriferina octoplicata, as already stated, is rare above the lowest beds (Horizon {3). LTthynchonella mitcheldeanensis, Leptena analoga, Chonetes ct. hardrensis, and Ch. cf. crassistria are abundant at certain levels. See note under Cliothyris glabristria, p. 297. 2 This quarry is named ‘ Press’s Quarry,’ on the sketch-map of the Avon quarries (Pl, XXVII). 192 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, Syringothyris cuspidata and Orthotetes crenistria are abundant: in those panmenllen mutations which characterize the Zaphr entis- Zone. Chothyris glabr istria and Reticularia aff. lineata ee and gradually increase in abundance. Chonetes papilionacea occurs rarely, for the first time, near the top of the subzone. Corals: Zaphrentis aff. Phillipst is common in certain . beds. Syringopora 6 occurs rarely. No other corals have been recorded. Z,=Subzone of Schizophoria resupinata (rEsuprnar4- subzone). Where exposed in the Avon section :— Clifton side: The main Black-Rock Quarry (that is, that ornon of the present quarry which has been worked back to a con- siderable distance from the line) not including the southern end. (See Horizon y and Zone C, p. 193.) Leigh Woods side: The upper part of Quarry 2. Special faunal characters :— Brachiopods: ; Clhiothyris Royssvi, Spirifer aft. clathratus, Camarotechia mitcheldeanensis, Leptena analoga, and Chonetes cf. crassistria are nowhere common. Syringothyris cuspidata and Orthotetes crenistria are abundant in the mutations typical of the Zaphrentis-Zone. thipidomella aff. Michelint is common, but has passed its acme. Cliothyris glabristria and Schizophoria resupinata reach their, maxima, and are prolific. Chonetes cf. hardrensis teems in certain beds, where it is more and more frequently associated with Ch. papihonacea. Productus cf. Martini becomes rare, and. is replaced by a larger form closely allied to Pr. semireticulatus. Productus aff. Cora, mut. Z, is rare. Syringothyri is aff. laminosa makes its entrance in this sub- zone. Corals: teem throughout the subzone, and reach their maxima near the top of it. Amplexus cf. coralloides enters towards the top, and quickly attains its maximum. Canima cylindrica and Michelinia occur rarely in the very topmost beds. Syringopora @ is common at certain levels. Zaphrentis aff. Phillipss Zaphrentis aff. cornucopre EN ey ol. 61, ] SEQUENCE 1N THE BRISTOL ARBA,. 193 = Horizon y. (The top of the Zaphrentis-Zone and the bottom of the Syringothyrs-Zone. ) Where exposed in the Avon section :— Clifton side: The southern end of the present Black-Rock Quarry. Leigh Woods side: Towards the top of Quarry 2. Special faunal characters :— Brachiopods: | Syringothyris cuspidata, S. aff. lamenosa, and Orthotetes creni- stria, muts. Z and C, are common. Chonetes papilionacea becomes abundant and Chonetes cf. hardrensis rare. Productus aif. semireticulatus is occasionally found. All the other brachiopods cited as typical of the es Zone are rare at this horizon. Corals: Michelinia and Amplexus are not uncommon, but the important feature of the horizon is the co-occurrence of Zaphrentis and Caninia in remarkable abundance. ‘The level is thus a well- marked ‘horizon of overlap’ of the Zaphrentis- and Caninia- Zones, and is consequently designated Horizon y. C = Zone of Syringothryis aff. laminosa = Lower Canima-Zone. (Syriveornyris-Zone.) “Lithological character.—The following rocks are met with in ascending order : (1) Encrinital limestones, which are appreciably dolomitic. (The laminosa-dolomites.) (2) A thick band of oolite. (The Caninia-Oolite.) (3) Shales with thick bands of dolomite and subsidiary beds of oolite (lower part only). Former designation.—In ascending order: | (1) Top beds of the Lower Limestone. - (2) Gully Oolite. (5) Middle Shales (lower part only). Where exposed in the Avon section :— Clifton side : (1) Occurs between the Black-Rock Quarry and the Gully- path and at the base of the Gully Oolite-quarry. (2) Forms the main portion of the Gully Oolite-quarry. (3) Is exposed in the low railway-cutting between the Gully and the Great Quarry (lower part only). Leigh Woods side: The topmost beds of (1), (2), and the very lowest beds of (3) | are seen in Quarry 3. 194 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, Special faunal characters :— Brachiopods: Orthotetes crenistria, mut. C, and Chonetes aff. papilionacea crowd the beds at certain levels (often the Chonetes passes into a strongly-convex variant, Ch. ef. comoides). Syringothyris cusprdata and Productus aff. semireticulatus are met with occasionally. Syringothyris aff. laminosa, though never actually abundant, ean always be found, and is highly characteristic of the zone. Corals: Syringopora cf. reticulata occurs. Michelimia megastoma is not uncommon. Amplexus probably occurs here. Zaphrentis is seldom found, except at the base (in Horizon y). Caninia cylindrica attains its maximum at the base. Note.—In the Avon section the uppermost beds of this zone are unfossiliferous, so that there appears to be a remarkable paleontological break between this zone and the succeeding Seminula-Zone ; this break is, however, partly filled in by certain beds found in neighbouring parts of the Bristol area (see under Failand and Clevedon). JI shall consequently defer the necessary discussion, as to the advisability of retaining a single zone (the Caninia-Zone) to cover both the zone C and the subzone §,, until a later portion of the paper (p. 260). Viséan or Upper Carboniferous Limestone. S= Zone of Seminula ficoidea and its allies (Seuzwvza-Zone). Lithological and paleontological details are more conveniently set out under the separate subzones. The essential faunal characters of this zone are the extreme abundance and the association of Seminula spp., Lithostrotion Martini (vars. & muts.), and giganteid Products (including Productus aff. Cora). The lower subzone (S,) is distinguished by the survival of Tournaisian forms, such as Syringothyris spp., Productus aff. semireticulatus, Canina aff. cylindrica. The upper subzone (5,), on the other hand, is characterized by the incoming of forms which abound in the Dibunophyllum-Zone, such as Clisiophyllids, Cyatho- phyllum Murchison, Alveolites. Subdivisions :— ~$,=Subzone of Productus semireticulatus, Mut eo Upper Cawzvzra4-Zone. Lithological character: (1) Shales and thick bands of dolomite and occasional beds of oolite. Succeeded by (2) Massive limestones with thin shale-partings ; many of these limestones are appreciably dolomitic, and are beautifully Vol. 61. | SEQUENCE IN THE BRISTOL AREA. 195 compact in texture, with good conchoidal fracture ; others are granular and encrinital. Former designation: (3) Middle Shales (upper part only). (4) Mitcheldeania-Beds, at the base of the Middle Limestones. Where exposed in the Avon section :— Clifton side: The upper part of the cutting between the Gully Oolite-Quarry and the Great Quarry, and the lower third of the Great Quarry. Leigh Woods side: The lowest beds in Quarry 4 (see IPL, OSMAN) Special faunal characters :-— Brachiopods: Seminula ficoidea and its allies become extremely abundant, and are associated with prolific specimens of a giganteid Productus Pr. 6). Productus semireticulatus still occurs, and a well-marked muta- tion with very long spines characterizes a bed at the top of the suvzone (the so-called ‘ longispinus ’-bed). Productus aff. hemisphericus is not uncommon. Syringothyris aff. laminosa and Athyris (?) sp. occur in con- siderable numbers at one level. Orthotetes crenistria, in a characteristic mutation, is found somewhat rarely in the upper beds, and the gens has entirely lost that predominance which is so noteworthy a feature of the Tournaisian facies. Corals: Caninia cylindrica (especially in its mutation bristolensis) is abundant chiefly in the upper half, and with it are associated (probably) occasional specimens of Amplewus and Michelinia. Syringopora becomes common at the top in a distinct form (cf. S. distans). Lithostrotion Martini appears early in the subzone, and, in the upper portion, whoie beds are made up of this species and of one. of its varieties. Inthostrotion basaltiforme (var. bristolense) has long been known. to collectors ; it abounds in a few beds near the top of the sub- zone (one of these beds, which is stained black by petroleum, is. known as the ‘ Aranea-Bed ’). Alveolites sp. and Cyathophylluin are rare. A characteristic bryozoan in this subzone is Heterotrypa tumida. S.=Subzone of Productus Cora, mut. 8,. (The main portion of the Seminula-Zone. ) Lithological character.—Chiefly massive limestones, containing a thick series of oolites near the base, and concretionary limestones. (with shale-partings) at the top. 196 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, Former designation.—The whole of the Middle Limestones, with the exception of the very topmost beds (which form the lower part of Zone D) and of the lowest beds (already described under subzone 8, ). Where exposedin the Avon section :— Clifton side: (1) The upper two-thirds of the Great; Quarry, and the rocks at the side of the line up to the bottom of the new Zigzag Path. Norr.—All the beds above the base of the oolite (which occurs about the middle of the Great Quarry) are repeated by the Great Fault in St. Vincent’s Rock. (2) In this repetition the higher portions of the Seminula-Zone are exposed, from the Great Fault (near the bottom of Bridge- Valley Road) almost up to the wall at the bottom of the old Zigzag Path. Leigh Woods side: (1) Quarry 4, except the lowest beds; along the side of the line ; Quarry 5 and the lower part of the series through which the tunnel is bored. (2) (Owing to the repetition by the Great Fault). Along the _side of the river-path, from Nightingale Valley to the end of the riverside exposure. (3) Also in the disused quarry to the right of the road, immedi- ately after crossing the Suspension-Bridge. Coral-fauna: Alveolites septosa. Cyathophylium Murchisoni. Syringopore cf. distans. Clisiophyllum (Carcinophyl- Lithostrotion Martini & muts. lum) @. Brachiopod-fauna: Seminula ficotdea and closely- | Productus Cora, mut. §,. allied forms. Productus ‘ giganteus? Orthotetes crenistria, mut. 8. | Chonetes papilionacea. Productus aff. hemisphericus. Chonetes aff. comotdes. A characteristic bryozoan in this subzone is Chettetes (?) radians. Special faunal characters :— Lithostrotion Martint, Seminule, and Products abound throughout. Chonetes papilonacea and Syringopora sp. are common at re- curring levels. Clisiophyllids occur sparingly from the base of the oolite onwards, and are chiefly represented by Clistophyllum @. Orthotetes, Alveolites, and Cyathophyllum Murchisoni are rare. Productus ‘ giganteus’ becomes abundant at the top of the subzone. Productus Cora, mut. 8,, attains its maximum in the Seminula- oolite. Productus aff. hemisphericus gradually increases in numbers. Wolk6r. | SEQUENCE IN THE BRISTOL AREA, TST D=Zone of Dibunophyllum aff. turbinatum (DipunopyyitituM-Zone). Lithological character.—Iin ascending order: (1) Massive limestones. (2) Shales and grits. (3) Massive limestones, (4) Shales. Former designation: (1) The upper part of the Middle Limestone. (2) The Upper Limestone-Shales (lower part). (3) The Upper Limestone in the Upper Limestone-Shales. (4) The Upper Limestone-Shales (upper part). W here exposed in the Avon section :— Clifton side: On either side of the new Zigzag Path and, along the side of the railway-line, between the bottom of that path and the tunnel-entrance (near Point Villa). In small exposures along the riverside path, from the entrance to the new Zigzag up to Point Villa, and in a continuous ex- posure from that point to the wall at the bottom of Bridge Valley- Road, also along the side of Bridge Valley-Road. _ In the repetition of the series after the fault, this zone is met with just before the wall at the bottom of the old Zigzag Path; and, after passing the entrance to that path, it extends con- tinuously up to the Rocks Railway. Beyond this point the beds are hidden by the Colonnade, and, farther on, by St. Vincent’s Parade. Leigh Woods side : Near the point on that side and, after a considerable break, in Quarry 6 at the foot of Stokeleigh Camp and in the exposures on the side of the camp. In the repetition of the series after the fault, the zone can again be studied in the Quarry on Rownham Hill. Coral-fauna: Alveolites septosa and varieties. | Cyathophyllwin Murchisoni and Syringopora ef. distans. variants. Syringopora cf. geniculata. Cyathophylium regium. Lithrostrotion Martini and vari- Campophyllum aff. Murchison. Clisiophyllids of numerous types ants (especially towards J. (such as Clisiophyllum 0 and irregulare and Lonsdalia). Lithostrotion irregulare and vari- | the group of Dibunophyllum ants. aff. turbinatum),. Lithostrotion guncewm. . Lonsdalia floriformis. Lithostrotion Portlocki and vari- | Lonsdalia aff. rugosa. ants (such as L. M‘Coyanum, _ Aaophyllwin 0. L. ensifer). ) Qod.G.8. No, 242. p 198 DR. A. VAUGHAN ON THE PALHONToLOGICAL [May 1905. Brachiopod-fauna: (?) Dielasma hastata. | Productus aff. Cora, mutations. Seminula ficoidea and allied Productus giganteus. forms. | Productus hemisphericus & vars. Orthotetes crenistria, mut. D. Chonetes aff. comoides. Subdivisions :— D,=Subzone of Dibunophyllum 6 and Dibunophyllum (@d-subzone). Where exposedin the Avon section :— Clifton side : Of the exposures already mentioned as included in the whole zone, those up to a little beyond Point Villa before the fault, and the whole of the exposure mentioned after the fault, belong to this subzone. Norz.— Fossils labelled ‘Point,’ ‘Hotwell House,’ ‘ Boiler-Bed,’ and ‘ Behind the Colonnade,’ etc. are derived from beds in this subzone. Leigh Woods side : The beds near the Point on that side of the river. Special faunai characters :— Brachiopods: Productus ‘ quganteus’* abounds towards the base, and the thick-shelled Chonetes aff. comoides is not rare. Productus aft. Cora occurs in a well-marked mutation. ; Pr. hemisphericus is abundant just above the rich coral-band. Seminula ficordea is uncommon and Orthotetes rare. 21 Corals: Cyathophyllum Murchison. teems in several well-marked varieties, between which there are complete transitions. Clisiophyllids belonging to both the Clistophyllum- and Dibuno- phyllum-sections reach their maximum, the most abundant forms being cylindrical or elongate members of the group of Dibwno- phyllum aft. turbinatum, which are here designated D. 6 and D. ¢. Syringopora and Alveolites are both abundant (the commonest species of Syringopora being NS. cf. distans and S. cf. geniculata). Campophyllum aff. Murchisoni reaches its maximum. A Koninckophyllid Cyathophyllum occurs rarely. Lithostrotion Martini and its mutations are not uncommon, but are far less abundant than in the zone below. Inthostrotion wrregulare becomes important. Lithostrotion gunceum occurs, but is never abundant. In the Avon section this subzone is chiefly recognized by the enormous abundance of simple Cyathophylla and of elongate Dibunophylla, both of which groups reach their maxima. 1 Productus ‘giganteus’ merely implies large, convex Producti, with close and flexuous, longitudinal ribbing and broad, over-rolled beak. It is a con- venient field-term, but I am ignorant of the hinge-characters. ea Vol. 61. | SEQUENCE IN THE BRISTOL AREA, 199 D,=Subzone of Lonsdalia floriformis (Lowspara- Subzone). Where exposed inthe Avon section :— Clifton side : (1) In the riverside exposure, from a little above Point Villa to the end of the exposure (that is, to the wall at the bottom of Bridge Valley-Road). (2) At the side of Bridge Valley-Road. (The first-named exposure is known as ‘ Round Point’). Leigh Woods side : In Quarry 6 and in the exposures on the side of Stokeleigh Camp. In the quarry on Rownham Hill. Special faunal characters :— Brachiopods: Productus ‘giganteus’ and Pr. cf. latissunus are not uncommon. Spiriferids and Athyrids are very rare, and their identification awaits further material. Corals: OCyathophyllum regium, the group of Lithostrotion typified by L. Portlocke and L. ensifer, and Lonsdalia floriformis and its variants only occur in this subzone, where they are abundant and highly characteristic. The Clisiophyllids are common, especially in the conical forms of the Dibunophyllum aft. turbinatum-group which are here designated Dibunophyllum w. Lithostrotion Martini in its typical form is rare, but the mutations towards L. irregulare and towards Lonsdalia are very characteristic. Lithostrotion irregulare reaches its maximum. Lithostrotion yunceum occurs sparingly. Axophyllum is cOmmon. Alveolites is fairly abundant, as is also one of the Syringopore (cf. Syringopora distans). Cyathophyllum Murchisoni, although common, is not so prolific as in the lower subzone. e = Horizon e. Lithology.—Shales and hard grits (somewhat calcareous). Former designation.—Millstone-Grit (lower part). Where exposed in the Avon section.—Now bricked up, but formerly exposed at the farther end of St. Vincent’s Parade (behind the ‘ General Draper’ public-house) on the Clifton side. PZ 200, DR. A. VAUGHAN ON THE PALMHONToLOGIcAL [May 1905, Fauna: Productus aff. scabriculus crowds the beds. (The form common in the Avon section is better described as a scabriculate variety of Pr. costatus.) Orthotetes and Productus aff. Cora are apparently not uncommon. Nore.—My whole knowledge of this horizon in the Avon section is derived specimens preserved plentifully in local collections. Analysis of Stoddart’s paper dealing with the Palzontological Sequence in the Avon Section." (Solely with reference to the Corals and Brachiopods.) The fossils cited in that paper will, for convenience, be designated by different letters, according as they fall into one or other of the following classes :— A. Those represented in the collection under the name cited in the paper and so localized as to suggest the horizon at which they are recorded. (With one or two exceptions the horizon is stated very broadly ; as, for example, Black Rock, Lower Limestone-Shales, Middle Limestone, etc.) C. Those unrepresented in the collection (at least so far as the particular bed. under consideration is concerned), The class C will be subdivided into :— C 1. Those which may be accepted as really occurring at the horizon stated. (Here Linclude those fossils which are usually identified correctly in the collection, or could not easily be mistaken for any of the other fossils known to occur at the particular horizon.) C 2. Those which should be rejected as erroneous determinations. (Here I include all fossils which are habitually determined erro- neously in the collection.) The fossils are grouped into the zones that I have suggested ; the number in front of the name is that employed by Stoddart to denote the particular bed in which the fossil occurs; the letter after the name has the meaning explained above ; and I append the name under which the fossil is recorded in my own work. In some cases, the alteration in name consists merely in the employment. of more recent generic nomenclature; in others it consists in more accurate specific identification ; while in several, Stoddart’s determination undoubtedly was entirely erroneous. The names given in inverted commas are those cited by Stoddart, and they are here considered to denote the fossils so named by him in the Stoddart Collection: as, for example, ‘ Rhynchonella pleurcdon, in the sense implied by Stoddart (that is, Pugnax pugnus), is not known to occur in the Modiola-Zone ; whereas the common Rhynchonella in this zone is called ‘ Retzia radialis’ by Stoddart, and would probably have been passed by Davidson as a variety of Rhynchonella pleurodon. Moproté-Zonz. (Beds | to 5.) (2 & 4) ‘ Athyris Royssit’; A; Cliothyris Roysstt. * (2) ‘Spirifera rhomboidea’; C2; probably indicates a Spiriferid of considerable transversity. (2) ‘ Retzia radialis’; A; Rhynchonella mitcheldeanensis, ? Proce. Bristol Nat. Soc. n. s. vol. i (1875) pp. 3818 e¢ segg. Wol.'61. | SEQUENCE IN THE BRISTOL ARBA. 201 (4) ‘ Rhynchonella pleurodon’ ; © 2; (specimens labelled ‘ Rh. pleuro- oe aye certainly not from this zone). (4) ‘ Lingula and Discina’; C 1. (4) ‘ Chonetes hardrensis’; C 1. (4) ‘ Streptorhynchus erenistria’ ;C 1; Orthotetes crenistria. (4) ‘ Spiréfer bisulcatus’; C 2; merely denotes a Spirifer of no great transversity. (4) ‘ Terebratula hastata’; C2; possibly Cliothyris Royssit, Horizona. (Bed 6.) (6) (The ‘ Bryozoa-Bed’) ‘ Producta sp.’; A; Leptena analoga. Cieistoporé-Zonn. (Beds 8 to 12 and possibly 13; the position of Bed 13 is doubtful, as the fossils recorded are not Obtained from the actual Avon section ; it may occur either just below or even above Bed 14, or it may be the equivalent of that bed.) (7) (The ‘ Palate-Bed ’) ‘ Discina and Lingula’; A. (8) ‘ Camarophoria globulina’; C2; possibly Rhynchonella aff. smit- cheldeanensis (that is, the small globu- lar form in which the pleats are few and coarse, and are indistinct near the beak). (8) ‘ Athyris Royssw’; C1; Chothyris Royssit or a mutation. (8) ‘ Athyris lamellosa’; C2; probably a transverse variety of Cliothyris Roysstt. (8) ‘ Retzia radialis’; A; Rhynchonella mitcheldeanensis, (8 & 13) * Spirifer duplicicosta’ A; Spirifer aff. clathratus. (9) ‘ Chonetes Buchiana’ A; ‘Chonetes cf, Buchiana. (9 & 12) ‘ Chonetes sordida, ‘var. perlata, ’ «napilionacea’; A; Chonetes cf. . hardrensis, (9, 11, & 13) ‘ Orthis resupinata’; A; Rhipidomella aff. Michelini & Pro- ductus sp. (9, 11, & Bee: Streptorhynchus crenistria, ‘var. arachnoidea’; A; Orthotetes crenistria (var.). i he var. ‘arach- noidea’ is merely the flatter valve. (10) ‘Rhynchonella pleurodon’ ; C 2; aspecimen of Pugnax pugnus is so labelled, but is insufficiently localized. (13) ‘ Terebratula hastata, ‘var. ficus, ‘var. sacculus, ‘var. vesicu- laris’; A; Cliothyris Royssi (mut.). (13) ‘ Rhynchonella acuminata’; A (?); Pugnaz acuminata (a speci- men is labelled ‘ Lr. Carb.’).? (13) ‘ Spirifer mosquensis’; A; Spirifer cf. bisulcatus, an axially-elon- gate variety. (13) ‘ Spirifera glabra’; A; ? Martinia glabra, var. linguifera (or Spiriferina rostrata from the Lias), (13) ‘ Strophomena analoga’; A; Leptena analoga. Horizon. (Bed 14, and probably Bed 13.) (14) ‘Spirifera striata’ and var. ‘ attenuata’; A; Spiriter aff. clathratus and its variety. (14) ‘Spirifera cuspidata’; A; Syringothyris aff. cuspidata, (14) ‘ Producta punctata’; C 2. (14) ‘ Producta pustulosa’; C 2; probably the interior of the concave valve of Productus aff. semireticulatus, which is not uncommon. But a Productus with discontinuous ribbing does oceur at this horizon in the Bristol area. (14) ‘ Athyris Royssii’; ?; Cliothyris Royssti (mut.). ' J do not know Pugnax below D ; the specimen in the Stoddart Collection was derived from a matrix with which I am unacquainted in the Tournaisian of the Bristol area. 202 DR. A. VAUGHAN ON THE PALAONTOLOGICAL [May 1905, ZAPHRENTIS-LONE and Horizon y. Although there are numerous specimens in the collection from these beds, the only bed cited is the ‘ Fish-Bed ’ (15). STRING OTHYRIS-ZONE. No fossils are cited from the main portion of this zone. SEMINULA-ZONE. S, Suszonn. (Beds 16 to 19, and probably Beds 20 & 21.) (16) ‘ Terebratula hastata’; A; Seminula ficoidea. (17) ‘ Lithostrotion Aranea’; A; Lithostrotion basaltiforiie (var.). (17) ‘ Lithostrotion irregulare’; A, Lathostrotion Martini (small var.). (17 & 18) ‘ Lithostrotion juneeum’; C2; probably Syringopora sp., which is common at this level, but not cited. (17) ‘ Producta punctata’; ?; a specimen of Pr. elegans is represented in the collection, but not horizoned. (18) ‘ Producta longispinosa’; A ; Productus semireticulatus (mut. §,). (19) ‘ Producta Martini’: ?; Productus aff. semireticulatus. (19) ‘ Producta Cora’; A; Productus 0. (19) ‘ Rhynchonella acuminata’; ?; 1 feel doubtful that the specimen in the collection is local. (20) ‘ Lithostrotion Portlocht’; C3; probably a small form of L. basal- tiforme (var.). (20) * Cyathophylluin regiwn’?; C2; i one or other name must (20) ‘ Cyathophylium turbinatum’ ; C2; { denote the abundant Caninia cylindrica var. bristolensis, which is well represented in the collection. (20) ‘ Michelinia tenuisepta’ ; A (?); can only be regarded as probable evidence of Michelinia. (21) ‘ Cyrtina septosa’; C 2; may denote Syringothyris aff. laminosa. (21) ‘ Spirifera lineata’ C 2. S, Suszone. (Beds 40 & 41.) (40) ‘ Terebratula hastata’; A; Seminula ficotdea. (40) ‘Syringopora geniculata’ ; ? (41) ‘ Producta’; A. (41) ‘ Rhynchonella pugnus’; C. DIBUNOPHYLLUM-ZONE. 06-Suszonn. (Beds 23 to 29 and Beds 42 to 45.) (23) ‘ Aulophylium fungites’; C;] probably denote the Clisiophyl- (23) ‘ Clistophyllum coniseptuin’ C ; { lids which are represented in the collection. But Cyclophyllum does occur at this horizon, although very rarely. (23) ‘ Lithostrotion concinnum’; C; probably Lithostrotion Martini (mut.). (23) ‘ Cyathophyllum regiwn’; C3; most probably Cyathophyllum Murchisoni, which teems at this hori- zon and is well represented in the collection. (25) ‘ Terebratula vesicularis’; C; probably Seminula sp. (26 & 42) ‘ Chetetes radians’; A; Chetetes bristolensis. (26) ‘ Lithostrotion irregqulare’ ; ? (27) ‘ Chonetes comoides’ ; C 1; probably Ch. aff. comoides. (27) ‘ Producta Cora’; A; Productus att. Cora, mut. 8,. (27 & 42) ‘ Alveolites septosa’; A. (28) ‘ Zaphrentis Griffithsi’; C 2. (28) ‘ Amplexus coralloides’; C2; (probably named from a vertical section of Campophylluin aff. Murchi- sont, which is common at this horizon). (29 & 42) ‘ Producta gigantea’; C 1. ‘ (42) ‘Syringopora reticulata, S.geniculata,and S.lamellosa’ (? ranulosa) ; A; Syringopora spp. (awaiting accurate separation). Vol. 61. | SEQUENCE IN THE BRISTOL AREA. 203 (42) ‘ Lithostrotion guncewm’; ? (42) ‘ Lithostrotion affine’; A; Lithostrotion Martini (mut.). (44) ‘Rhynchonella pugnus’; C. LonspaLi4-Supz0ne. (Beds 31 to 35 and Beds 46 & 47.) (31 & 34) ‘ Lithostrotion irregulare’; A; Lithostrotion irregulare and L. Martini (mut. towards L. irregulare). (33,35, &47) * Cyathophyllum regiwm’; A. (35 & 47) ‘ Cyathophylium Stutchburyi and C. Murchisoni’; A; Cyatho- phyllum Murchisoni. (33) ‘ Lithostrotion ensifer’; A. (33 & 47) ‘ Lithostrotion Martini’; A. (33) ‘ Lithostrotion basaltiforme’ ; C 2;) probably Lithostrotion (47) ‘ Lithostrotion carnea’ (? Aranea) ; C 2; } Portlocki, which teems at this horizon and is well represented in the collection, but not cited in the paper, (47) ‘ Lithostrotion M‘Coyanuni’ ; ? (33) ‘ Lithostrotion gunceum’ ; ? (83 & 47) ‘ Lonsdalia florifornis’; A. (33) ‘ Aulophyllum fungites’; C,; \ probably denote members of (33) ‘ Clisiophyllum coniseptum; C; | the Dibunophyllum-turbinatum roup. (33) ‘ Alveolites depressa’; A; hea septosa, vay. (47) ‘ Canypophyllum Murchisoni’ ; C1; (no specimens are so labelled ; the ones that [ have noticed are from Bed 44). Horizon e. (48) ‘ Spirifera rhomboidalis’ or ‘ convoluta’; C 2. (48) ‘ Cyrtina septosa’; C 2. (48) ‘ Producta Martim’;.C 2; \ probably Productus aff. scabri- (48) ‘ Producta longispinosa’; C 2; culus. The following corrections of my own observations seem to be the only ones that can be reliably deduced from Stoddart’s paper, and from the fossils in his collection which are adequately horizoned :— I. The following brachiopods probably occur in the Modiola-Zone below Horizon a :— (4) Lingula sp.; (Discina) sp.; Orthotetes crenistria ; Chonetes ef. hardrensis; (2 & 4) Spirifer sp. or Syringothyris sp. II. Productus bassws may extend nearly up to Horizon f. (A specimen in the collection is labelled ‘ Below the Black Rock.’) III. Michelinia possibly extends up into the Seminuwla-Zone (S, subzone). (6) Introduction to the Sodbury Carboniferous Limestone. Chipping Sodbury lies about 11 miles in a direct line east 30° north of the Clifton Suspension-Bridge.* The exposures from which the following account has been derived are :— _ (1) The railway-cutting on the new South-Wales Direct Line. (2) The two large town-quarries at the west of the town, north of the Bristol road. 1 The Suspension-Bridge is chosen as the point from which all distances in this account of the Bristol area are measured, because it spans part of the Avon section. The rocks upon which it rests belong to the upper part of the Seminula- Zone, in the repetition of that zone caused by the Great Fault. 204 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, The railway les nearly half a mile south of the town; it cuts 2500 feet (measured horizontally) of Carboniferous-Limestone rocks which dip almost due westward at an average angle of 44°. The cutting exhibits a complete sequence, from the top of the Old Red Sandstone up to the lowest part of the 0g-subzone, but ends before the Lonsdalia-Subzone is reached. In a new cutting, made through hard rocks entirely by blasting, the utmost care has to be exercised that all the fossils recorded have been found absolutely 7 setu. Loose material must be entirely dis- regarded, since it may have been brought from any distance, dropped from the trucks, and have reached its final position as the result of subsequent blasting-operations. On the other hand, the loose material in a quarry may, with more safety, be assumed to have been derived from the beds exposed in the quarry. It is also to be remembered that, since a fresh cutting shows no weathered surfaces, any fossils, but especially corals, are apt to escape notice which, in the disused part of a quarry, immediately arrest the attention. For these reasons the failure to record any particular species in the Sodbury cutting cannot be considered to prove more than its non-abundance. For example, no Clisiophyllid was recorded in the cutting from the whole of the Seminwla-Zone, whereas several specimens from this zone were detected in the first quarry. SODBURY. Tournaisian. Modioia-Zone (M). Lithological character.—Shales, grits, and calcareous bands ending with a series of red limestones (Horizon a). Exposure.—The upper portion of the small Paleozoic pro- jection which is separated from the main Carboniferous Lime- stone elevation by a broad valley, deeply filled in with the Lower Jurassic strata. Fauna :— (1) From the beds below Horizon a. An ostracod is not uncommon (this is apparently the same as the common Avon species). Fragments of a lamellibranch (possibly Modiola). (2) From Horizon a. Rhabdomeson and fragments of crinoids are very abundant. Chothyris Roysstt. Correlation with the Avon section.—The few fossils recorded above are all abundant at the same levels in the Avon section. Cleistopora-Zone (K). Lithological character.—A well-marked ‘ Palate-Bed’ at the base, followed by a thick series of shales with subsidiary limestones. Wol= 61. | SEQUENCE IN THE BRISTOL AREA. 205 Hxposure.—the greater part of this zone lies at, or beneath, the level of the roadway, so that it can only be examined in the occasional bands cf harder limestone or in the drainage- trenches at the foot of the slopes. The basal beds of the zone can, however, be more easily worked, since they form the western extremity of the small Paleozoic projection already mentioned. The zone may be considered to end at the base of the massive Limestone-series which commences at Kingrove-Farm Bridge." Fauna.—tThe ‘ Palate-Bed’ is crowded with coprolites, and palatal teeth are abundant in it; similar teeth are found less frequently in the overlying beds, for a considerable distance. Corals: none found. Brachiopods: (1) bassus-subzone (K,). Humetria (‘ Retzia’) aff. carbonaria. Camarotechia mitcheldeanensis. All extremely Leptena analoga. abundant. Orthotetes crenistria, especially mut. K,. Syringothyris ait. cuspidata. Spirifer aff. clathratus. Cliothyris Royssit. Chonetes cf. hardrensis. (2) octoplicata-subzone (K,). Spirifer aff. clathratus and its variety become common in the verv poor exposures near the top of the zone. Correlation with the Avon section.—All the above fossils occur at the same levels in the Avon section. No specimen of Clastopora, Spuriferma octoplicata, or Productus bassus has as yet been discovered at Sodbury. The failure to find the two first- named fossiis is not a matter of surprise: (1) because of the practical absence of exposures in the upper part of the zone; and (2) on account of the difficulty of noticing either fossil except on weathered surfaces, which are necessarily rare in a new cutting. K,.—Though Productus bassus itself has not yet been met with at Sodbury, the subzone is well characterized by the great abundance of Camarotechia mitcheldeanensis, Leptena, Or- thotetes, and Humetria; moreover, the particular forms of Syringothyris cuspidata and Orthotetes crenistria which occur in these basal beds are precisely those that are found at the same level in the Avon section. K,.—This subzone may be said to be practically unexposed in the Sodbury cutting, but the increasing abundance of Spirifer aff. clathratus has been mde out in its upper portion. 1 This bridge crosses the railway-line, about 300 yards north of Kingrove Farm. ee 206 DR. A. VAUGHAN ON THE PALHONTOLOGICAL | May 1905, Zaphrentis-Zone (Z). Lithological character.—Massive limestones, usually very encrinital. Ex posure.—Massive limestones crowded with brachiopods, ex- tending some 450 feet westward from Kingrove-Farm Bridge. Fauna :— Corals: Laphrentis aff. Phillipsi. Brachiopods: Cliothyris Royssit (mut.). Cliothyris glabristria. Spirifer att. clathratus and variety. Reticularia aft. lineata. Syringothyris aff. cuspidata. Leptena analoga. Subdivisions :— (1) Horizon £p. Syringopora sp. Orthotetes crenistria (mut. Z). Schizophoria resupinata. Productus cf. Martini. Chonetes cf. hardrensis. Chonetes papilionacea. Since Zaphrentis has not been found below the resupinata- subzone, and no specimen of Spiriferina octoplicata has been met with in the section, this horizon at Sodbury has no characters other than Thay common to the whole clathratus- subzone, of which it forms the base. (2) CLATHRATUS-subzone (Z,). This subzone is well characterized by the extreme abund- ance of Spirzfer aff. clathratus and its variety. Orthotetes crenistria, in the mutation characteristic of the Zaphrentis-Zone, is abundant. Leptena analoga and Chonetes ef. hardrensis are common. Chiothyris glabristria, Retieularia aff. lineata, Chothyros Royssu (mut.), and a Syringopora are not infrequent. | Productus cf. Martini is only recorded doubtfully. (3) RESUPINATA-subzone (Z,). This subzone is well defined by the abundance of Cho- thyris glabristria and Schizophoria resupinata, as well as by the fact that in 1t Zuphrentis attains its maximum. Chonetes cf. hardrensis crowds the beds at the bottom of the subzone, while, at the top, Chonetes papilionacea is the predominant form and is equally prolific. Syringothyris aff. cuspidata occurs abundantly in the lower half of the subzone, and that mutation of Orthotetes which is characteristic of the Zaphientis-Zone is common throughout. Leptena and Productus cf. Martini (large form eff. Pr. semi- reticulatus) are met with not infrequently. Syringopora @ has been noted at two levels. (4) Horizon y. : This horizon is not defined with precision, since no specimen of Canna has been found in association with Zaphrentis ; ole On. SEQUENCE IN THE BRISTOL ARBA. 207 if may, however, be fixed within very narrow limits, as embracing that portion of the zone in which Zaphrentis is still common, but Cliothyris glabristiia becomes scarce ; the band of Chonetes paprlionacea may thus be taken as occurring at the base. Correlation with the Avon section:— (1) Resemblances: In both sections:—The maximum of Spirifer aff. clathratus is followed by that of Cliothyris glabristria, while Zaphrentis attains its maximum when Cl. glabristria becomes scarce. Schizophoria is abundant, and confined to the resupinata-subzone. Chonetes ct. hardrensis is predominant in the lower part of the Zone, but yields place to Chonetes papilionacea at the top. The same mutation of Orthotetes abounds throughout, and the same species of Syringopora is found. (@) Differences: No specimen of Zaphrentis has been found at Sodbury before the upper part of the resupynata-subzone, and no Caninia, Ampleaus, or Michelina has been discovered in any part of the Zaphrentis- Zone (though specially looked for). The presence of Zaphrentis in the lower part of the zone and of Ampleaus and Michelma at the top might, perhaps, have escaped notice, even if they occur in the same numbers as in the Avon section; but the failure to find a single Caninia at the top of the zone seems to point definitely to the conclusion that the incoming of this genus suffered a great retardation towards the north-east. (A point of some interest is the fact that in both the Avon and Sodbury sections there is, in this zone, a thick series of relatively-unfossiliferous beds which are characteristically inter- laced with veins and patches of calcite; this series occurs at the top of the clathratus-subzone at Sodbury, but is found in the middle of that subzone in the Avon section.) Caninia-Zone. This zone includes :— C =The Syringothyris-Zone at the top of the Tournaisian ; and §,=The semireticulatus-subzone at the base of the Viséan. hese two subzones are conveniently considered together in this place, in order to emphasize the paleontological break between the Tournaisian and the Viséan in the northern part of the Bristol area, where that break is most evident. Lithological character:— ((1) At the base relatively-unfossiliferous, massive, encri- nital limestones. C< (2) A band of colitic limestone (unfossiliferous except for occasional fragments of crinoids). (3) A series of shales, including thick beds of dolomite and an occasional bed of oolite; ending in a 8, prominent band of pure quartzose orit, (4) Massive fossiliferous limestones. 208 DR. A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, Exposure.—The middle part of that portion of the section which lies between Kingrove-Farm Bridge and Lilliput-Farm Bridge. Faunal character :— Top of the Tournaisian: C. Zaphrentis is not uncommon in the lower part of (1). Chonetes aff. papilionacea and Orthotetes crenistria, associated together, crowd certain bands near the top of (1), and the last-mentioned fossil passes on into the base of (2). Syringothyris aff. laminosa occurs in considerable numbers, just below (2). Base of the Viséan: §,. Seminula ficordea and its variants enter about the middle of (3), and from that point become increasingly abundant. Productus 6(?)* occurs sparingly in (8). Both these fossils teem throughout (4). Canina cylindrica (var. bristolensis) and Lithostrotion Martini enter together at the top of (4), and are there extremely abundant. Syrigopora cf. distans is common in the upper part of (4). The zone is considered to end where Caninia dies out. Correlation with the Avon section :— Resemblances: All the fossils which occur at Sodbury enter in precisely the same relative order as they do in the Avon section. In both sections :—After Zaphrentis has died out Syringothyris aff. Jaminosa becomes an important distinctive fossil, and certain © beds are crowded with Orthotetes and Chonetes aff. papilionacea. Orthotetes ends its long predominance at the same level and, throughout the rest of the Carboniferous Limestone, plays an extremely-minor part. Seminula becomes abundant, before giganteid Producti and Lithostrotion Martini are met with in any numbers. At the top of the zone Caninia cylindrica var. bristolensis is as abundant at Sodbury as in the Avon section, and is similarly associated with crowds of Lithostrotion Martin, Productus 6 (?), and Seminula, as well as with the same species of Syr¢ngopora. Differences: Owing to the absence (or scarcity) of Cuninia at the base of the zone, the lower part of the Caninia-Zone (Syringothyris-Zone) appears to be entirely distinct from the upper part (semreticulatus- subzone). In fact, at Sodbury, the paleontological facies of the Lower Carboniferous Limestone (which comprises the zones of Oleistopora, Zaphrentis, and Syringothyris) is so entirely distinct from that of the Seminula-Zone above, that it would seem impos- sible to include the whole series in one system. The only genera which bridge the gap at Sodbury are Syringo- pora, Productus, and Orthotetes. The species of Syringopora that 1 A field-determination, and possibly including Productus aff. hemisphericus, Vol. 6r.| SEQUENCE IN THE BRISLOL ARBA, 209 occur above are certainly not identical with those that are found below. Orthotetes, which is enormously prolific throughout the lower portion of the Carboniferous Limestone, becomes extremely rare (and distinct in form) in the upper. The Producti of the upper portion belong to the giganteid group, of which group no representatives have been found in the lower part at Sodbury. This sharp distinction of a lower system (Tour- iaisian) irom an upper (Viséam) is at Sodbury a definite fact which cannot be overlooked. It is only by the study of the whole series in other parts of the Bristol area, where the transition becomes more gradual, that the com- plete distinction of an upper and a lower system is seen to break down. At Sodbury the occurrence of Canina is an isolated phenomenon of the Lower Viséan; farther south and west, this genus is seen to be the result of direct evolution from Zaphrentis in the Upper Tournaisian. [The general resemblance of the lithological character of this zone in the two sections is striking :— The poorly-fossiliferous encrinital limestones at the base (top of the Lower Limestone), the band of oolite (eyuivalent to the Gully Oolite), the shales and dolomites (equivalent to the Middle Shales), and the massive limestone at the top (equivalent to the bottom of the Middle Limestone) are represented in the same order in the two sections, and the beds have similar textures. The differences are of less importance, and consist (1) in an inflation of the dolomite-bands at Sodbury: therefore, in that section, the Middle Shales would be more aptly termed ‘the Middle Dolomites’; and (2) in the occurrence of the highly- quartzose grit-band. | Viséan. ' Seminula-Zone (including 8, and 8,). S, has already been discussed under the Caninia-Zone, but is again included here for the reasons already given. Lithological character :— s | Shales, dolomites, and grits. 1| A long series of massive limestones, containing thick oolitic ( beds, are succeeded by a thick series of concretionary beds (‘ mottled limestones’) with shale-partings. ‘The mottled | limestones exhibit the peculiar character of Cotham R |! Marble, and have a very similar concretionary surface ; \ Mr. A. Strahan? has pointed out their similarity to the | Mumbles-Head Beds. | The uppermost part of the zone is composed of thick shales \_ with several bands of grit. 1 Mem. Geol. Surv. ‘Summary of Progress Report for 1902’ p. 193. 10 DR, A. VAUGHAN ON THE PALMONToLocIcAL [May 1905, ix posures :— S&S (1) In the cutting on both sides of Lilliput-Farm SS, l 2 Bridge. s (2) In the two quarries at the western end of the 2 town, north of the Bristol Road. The first, or easternmost, of the two quarries exhibits the massive limestones, with a thick oolite-band at the top. The second affords a splendid section of the mottled-limestone series and of the shales and grits above. Faunal character :— Corals: Syringopora ct. distans. Cyathophyllum Murchisoni (2).* Lithostrotion Martini & variants. | Clisiophyliuin 6. Brachiopods: Productus @ (?). Chonetes paptlionaced. Seminula ficotdea and its allies. Productus ‘ giganteus.’ Productus aff. Cora. Notes :— Oaninia occurs only at the top of §,, as already stated. Lithostrotion Martini starts at the top of 8,, reaches its maximum a little above the very top of that horizon, and greatly diminishes in numbers afterwards. Syringopora cf. destans is not uncommon throughout the same range. Blissoph yllum @ occurs in some numbers in the main oolite- band. Cyathophyllum Murchisoni (?) occurs rarely in the concretionary series, and in some of the limestone-bands included in the thick shales. Seminula ficoidea starts at the very base of 5, (that is, in the middle of the dolomites) and remains extremely abundant right up to the top of the shales. Productus @(?) occurs in 8, (the specific determination is doubtful). Productus aff. Cora (mut.) is common in §,, up to the concretionary beds. Productus ‘ guganteus’ attains a maximum just below the concretionary beds, and is also common in them. Chonetes papilionacea teems at two or three levels Recor the top of S, and the bottom of the concretionary beds. Correlation with the Avon section.—The similarity of faunal distribution amounts almost to identity ; the only difference seems to be the retardation at Sodbury of the entrance of Litho- .strotion, which, there, first appears at the maximum of Caninia, whereas in the Avon section it enters a few beds below. In lithological character, the chief point of difference is the great inflation at Sodbury of the concretionary limestones and a the shales above them. 1 This is a field-determination. - Vol. 61. ] SEQUENCE IN THE BRISTOL ARBA. 211 Dibunophyllum-Zone. O-subzone (D,). Lithological character.—Massive limestones, to a large extent oolitic, containing a band of quartz-conglomerate with ‘ veinstone-quartz’ pebbles. Exposures :— (1) The end of the Carboniferous-Limestone exposure in the cutting. (2) The uppermost beds of the second quarry. Notn.—Only the lowest part of the subzone 0¢ is exposed at Sodbury ; the higher part of that subzone and the whole of the Lonsdalia-Subzone - are entirely unexposed. Faunal character :— Corals: Alveolites septosa. Cyathophylium Murchisoni and va- Syringopora ef. distans. riants. | Lithostrotion Martin (mutations | Clisiophyllids, including C?isiophyl- towards L. affine). | lum 0, Dibunophyilum 0 and 4g, Lithostrotion irregulare. Koninckophylluni 0. Brachiopods: Productus ‘giganteus,’ | Orthotetes crenistria (mut. D). Productus hemisphericus & vars. Seminula ficoidea. Chonetes aff. comoides. Athyris ct. expansa. Correlation with the Avon section.—The two sections are paleontologically identical, the same fossils occur in each and in the same relative abundance. Campophyllum aft. Murchison which, in the Avon section, attains its maximum near the top of the @g-subzone has, however, not been found at Sodbury. (c) THE Farnanp Area (including Flax Bourton). Failand Inn lies 3 miles west 22° south of the Clifton Suspension- Bridge; it may be taken as the centre of the area. Just 1200 yards west of the Inn, measured along the Clevedon road, is a branch- road running northward to Portbury. After following this branch- road for 500 yards, exposures in the Carboniferous-Limestone Series begin to occur, and successively-lower beds are here and there exposed until, near Millpond Farm (some 1200 yards from the commencement of the road), the uppermost beds of the Old Red Sand- stone are reached. This somewhat-discontinuous section includes almost the whole of the Tournaisian division of the Carboniferous Limestone, and will be referred to in this paper as the Failand section. | Turning back at Millpond Farm, we will retrace our steps towards the Clevedon road, so as to examine the beds in ascending order. The lowest beds in the section have to be made out from the low roadside-cuttings, in which the rocks are only partly and occasionally exposed; this portion of the section (some 350 yards 212 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, horizontally) includes the Modiola-Zone (with Horizon a well marked) and the greater part cf the Cleistopora-Zone (only the lowest portion of this zone being at the time of my visits at all satisfactorily exposed). Still proceeding -southward, it was found that the sides of the road had, for the next 150 yards, been recently cut back, in such a manner as to afford a good section through Horizon 3 and the lower portion of the Zaphrentis-Zone. A short distance farther south is a quarry in work (the ‘ Horse- Race’ Quarry), which contains beds belonging to the upper part of the Zaphrentis-Zone. For the next 200 yards there are no exposures that can be easily examined; but, at the end of this distance, there are large quarries in the thick oolite-band which forms the middle portion of the Caniiia-Zone. The remaining 500 yards of the road, to its junction with the Clevedon road, is destitute of exposures. The thick band of oolite which forms the top part of the Failand section is the equivalent of the Gully Oolite in the Avon section, and, on account of its peculiar value for the manufacture of lime, this oolite is quarried at several points of the Failand area; it consequently serves as a very valuable horizon, from which to estimate the stratigraphical position of neighbouring exposures. Before, however, an isolated quarry in this oolite can be used as a datum-level, it is imperative that the oolite in the quarry should be definitely proved to be the oolite from the Caninia-Zone, and not the thick oolite-band which, throughout the Bristol area, forms the middle part of the Seminula-Zone. The following diagnostic characters completely distinguish these two oolitic bands :— (i) The Cuninia-Oolite. At the base, Orthotetes (in association with Chonetes papilionacea) is extremely abundant, and Syringothyris aff. laminosa is common. In the main part of the oolite fossils are uncommon, but Semnula, Lithostrotion, and Productus aff. Cora are never found. (ii) The Seminula-Oolite. This oolite is usually prolific in fossils, and Seminula, Lithostrotion, and Productus aff. Cora can always be found. Chonetes papilionacea is, at the base of this oolite, quite as abundant as it is beneath the Caninia-Oolite; but Orthotetes is extremely rare. Above the oolite of the Caninia-Zone occur the ‘ Bellerophon- Beds’ (Horizon 6), the most interesting paleontological horizon in the Failand area. These beds are well shown in two isolated quarries only; the stratigraphical position of these quarries can, however, be very accurately fixed by means of the Cunia-Oolite which is worked near each of them. The first of these ‘ Bellerophon ‘-quarries lies just behind Failand Inn, and about 100 yards south of the Clevedon road; its position is fixed by a shallow quarry, 350 yards west of Failand Inn, on the south side of the Clevedon road. ‘The shallow quarry contains the lowest beds of an oolitic band, which is proved to belong to the Vol, 61. } SEQUENCE IN THE BRISTOL ARBA. 213 Caninia-Lone by the abundance of Orthotetes (in association with Chonetes afi. papilionacea) and the occurrence of Syringothyris aff. daminosa, at its base. The strike in the ‘ Bellerophon ’-quarry and in the neighbouring Canima-Oolite quarry is almost due east and west, while the dip in the former reaches 27°; by plotting these data on the 6-ineh map the ‘ Bellerophon-Beds’ are found to lie about 150 feet normally above the base of the oolite. . The second ‘ Bellerophon’-quarry lies about 1000 yards west, very slightly south of the Failand-Inn quarry, in a direct line which almost exactly coincides with the strike at either quarry; the height of each quarry above sea-level is the same (450 feet). Hence the identity of the two beds in the two quarries, which is sufficiently clear from paleontological considerations, is confirmed stratigraphically, and the determination of the position of the _ beds in the one quarry fixes that of the beds in the other. It is, however, easy to fix the position of the second quarry by independent evidence. Wraxall Piece is a wooded patch bounded on the south-west by the Clevedon road ; on the west by a branch-road to Failand Farm; on the north by a grass-grown road running east and west; and on the south-east by the road to Clifton, which branches off from the main Clevedon road at a point about 1250 yards east of Failand Inn, The second ‘ Bellerophon’-quarry lies on the west side of the branch-road to Failand Farm, about 120 yards from its commencement in the Clevedon road. Some 375 yards along this branch-road, opposite the western end of the grass-grown road, is a small disused quarry in which Chonetes aff. papilionacea, Chonetes cf. hardrensis, Orthotetes, and Spirifer were found in situ, while Zaphrentis sp. (cf. Caninia) was picked up among the loose material. Hence, the beds in this exposure may be, most probably, regarded as not higher than Horizon y. About 100 yards from this point, along the grass-grown road north of the Piece, is a small quarry in the lowest beds of the oolite, which is proved to belong to the Cammnia-Zone by the abundance of Orthotetes (in association with Chonetes aff. papilionacea) at its base. In the north-eastern corner of the Piece, by the side of the Clifton road, there is a large quarry in this oolite, but the lowest beds are very badly exposed, and the fossils are few and fragmentary, though Orthotetes was recognized. ‘There can be no doubt that this is the same Caninia-Oolite, and that the beds here are a little higher than those in the quarry just described. The strike both in the second ‘ Bellerophon ’-quarry and in the small oolite-quarry north of the Piece is almost due east and west, and the dip is nearly 20°. Plotting these data on the map, the ‘ Bellerophon ’-Beds are again found to lhe about 150 feet above the base of the Caninia-Oolite. The chief interest of these beds is, consequently, that they are the Q.J.G.8. No. 242. Q 214 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, fossiliferous equivalent of part of the unproductive Middle Shales and Dolomites of the Avon section. Quarries in the Seminula-Zone :— (1) At the corner where the Clifton road branches off, immediately west of Longwood House, is a small quarry containing Senvnula in abundance and traces of Productus, but no Lithostrotion. 'This quarry lies due south of the small oolite- quarry north of Wraxall Piece, and the strike is again almost due east and west. Calculation from the map proves that the beds here are about 850 feet normally above the base of the Caninia- Oolite; hence, assuming the general thickness of the Caninia- Series to be the same here as in the Avon section, this quarry should represent the very lowest beds of the. Great Quarry. | (2) The large lime-quarry in the Seminula-Oolite lies 900 yards east of Longwood House, at the side of the Clevedon road ; a rough calculation from the map makes the beds in this quarry about 300 feet normally above those of the last — quarry, and this accords well with the position of similar beds in the Avon section. The other exposures mentioned below can only be referred to their correct stratigraphical position by the fossils found in them, since they lie isolated in those parts of the area where both strike and dip undergo rapid variation. Consequently, the results deduced from such exposures do not help to determine the zonal sequence, except in so far as they demonstrate the constant co-occurrence of the same forms. Detailed Description of Zones. Tournaisian. Modiola-Zone (M). Lithological character.—Shales with thin limestones, capped by a thicker band of red limestones (Horizon a). Exposure.—In the Failand section, near Millpond Farm. Fauna.—An ostracod (? Leperditia), identical apparently with the one which is very common in the Avon section, is extremely abundant in one of the limestone-beds below Horizon a. At Horizon a the red limestone is crowded with crinoidal débris. Ahabdomeson is abundant, and palatal teeth are not uncommon. Cleistopora-Zone (K) and Horizon £. Lithological character.—Shales with beds of limestone, the limestone predominating at the top. Vol, 61. ] SEQUENCE IN THE BRISTOL AREA. 215 Exposures :— (1) In the Failand section (above Horizon a up to, and including, the lower portion of the roadside-cutting west of the Horse-Race Quarry). (2) Roadside quarry near Failand-Hill House (Horizon £). Faunal character :— (i) Of the bassus-subzone (K,). _ All the fossils here mentioned were collected from the lowest part of the Failand section. Syringothyris aft. cuspidata. Chonetes cf. Buchiana. Leptena analoga. Chonetes cf. crassistria. Orthotetes crenistria (mut. K,). Productus bassus. (ii) Of the octoplicata-subzone (K,) and Horizon (. The fossils here mentioned were collected only from the top of the zone in the Failand section, and in the quay near Failand- Hill House. Cliothyris Royssit (mut. GB). Rhipidomella aft. Michelinz.' Spirifer aff. clathratus, in gradually- Productus ef, Martini. increasing numbers. Chonetes cf. Buchiana. Syringothyris aff. cuspidata. Chonetes cf. crassistria (very Camarotechia mitcheldeanensis. abundant). Leptena analoga. Chonetes cf. hardrensis. Orthotetes crenistria. | Zaphrentis-Zone (Z). Lithological character. — Massive encrinital limestones which are thinner towards the bottom, where thin shales are intercalated among them. Clathratus-subzone (Z;). Exposures :— (1) In the Failand section (the upper part of the roadside- cutting west of the Horse-Race). (2) Small exposures near Failand-Hill House. (3) A small quarry at the northern end of Fifty-Acre Plantation (east of the golf-links). Fauna :— Zaphrentis aff. Philiipsi. | Leptena analoga. Cliothyris Royssti (mut. 8). Orthotetes crenistria (mut. Z). Spirifer aff. clathratus and var. Rhipidomeila aft. Michelini. in great abundance. Chonetes cf. crassistria (rare). Syringothyris aff, cuspidata. Chonetes cf. hardrensis. ii. Resupinata-subzone (including the lowest part of Horizon ¥). Exposure. —- The ‘Horse- Race Quarry’ in the Failand section. 1 Only found in the quarry near Failand-Hill eae Q 216 DR, A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, Fauna :— Zaphrentis aft. cornucopie (very Syringothyris aff. laminosa. abundant). Cliothyris glabristria (abundant). Zaphrentis aff. Phillipsi, Reticularia aff. lineata, Caninia aff. cylindrica (at the top of | Leptena analoga. the quarry, that is, in Horizon y). Orthotetes crenistria (cf. var. Kellit) Syringopora 0. Schizophoria resupinata (abundant). Spirifer aff. clathratus(not uncommon | Rhipidomelia aff. Michelini. at the base, rare at the top). Productus aff. Cora (mut. Z). Syringothyris aft. cuspidata. Productus aff. pustulosus. The fossils of this subzone in the Failand area bear a remark- able resemblance both in forms and relative abundance to those at the same horizon in the Clevedon area (see pp. 225 et seqq.). Comparison with the Avon section.—Up to the top of the Zaphrentis-Zone, the differences in the faunas of the two sections are too slight for special notice. Syringothyris-Zone (C). In ascending order the sequence is : — (1) Limestone with Caninia and Zaphrentis. (2) Limestone and shales poorly exposed, containing Orthotetes, Chonetes, and an occasional Zaphrentis (cf. Caninia). (3) Oolitic limestone (the Caninia-Oolite), practically un- fossiliferous, resting upon a band in which Orthotetes and Chonetes aff. papilionacea teem, while Syringothyris aff. laminosa is not uncommon. (4) Thin shales and dolomitic limestones, poorly exposed. (5) The ‘ Bellerophon-Beds’ (chiefly composed of massive fossiliferous oolite). Exposures :-—— (1) Forms the top of the Horse-Race Quarry in the Failand section. | The upper part of (2) can be seen in the small quarry already described, which lies opposite the north-western corner of Wraxall Piece. | (3) Comprises (a) the oolite-quarries at the top of the Failand section ; (6) the shallow quarry west of Failand Inn; (¢) the small quarry north of Wraxall Piece; and (d) the large quarry in the north-eastern corner of Wraxall Piece. (4) Can be made out very imperfectly, along the side of the field-path leading from Failand Inn to the first Bellerophon- quarry. (5) The first and second Bellerophon-quarries already de- scribed, and a disused quarry about 300 yards east of Failand Inn. The last-mentioned quarry lies a little north of the line joining the first and second Bellerophon- quarries, owing to the rise in the ground between those two quarries. Vol. 61.] SEQUENCE IN THE BRISTOL AREA, DAN Faunal character.—The beds composing (1), (2), (3), and (4) have already been sufficiently discussed; their fossils agree precisely with those found at the same levels in other parts of the Bristol area. The Bellerophon-Beds (5) are of great interest: firstly, because they occur at a horizon which is unfossiliferous in the Avon and Sodbury sections ; and secondly, because they contain certain transitional forms between Cyathophyllum and Caninia. The fossils found in these beds are Orthotetes crenistria (uiut.). ‘ Chetetes’ tumidus (a bryozoan). Syringothyris cuspidata. Bellerophon sp. (cf. costatus). Syringothyris ait. laninosa. Euomphalus sy. Cyathophylium 9. | and at the top— Seminula aff. ambigqua. Productus sp. (cf. Productus @). Seminula aff. ficoidea. For convenience of reference, I have adopted the title ‘ Bellerophon- Beds,’ since Bellerophon is extremely abundant in certain of the ~ beds. Cyathophyllum @ is also very abundant, and in chance- sections is easily mistaken for Cyathophyllum Murchisont, a coral which, in the Bristol area, is only common in the Dibunophyllum- Zone. The abundance of this Cyathophyllum, combined with the fact that specimens of Seminula and of a giganteid Productus can be picked up on the stone-heaps in the quarries, at first led me to believe that I was dealing with beds near the top of the Car- boniferous-Limestone Series. But when I found that Orthotetes occurred in large numbers, and that the characteristic Syringo- thyris aft. laminosa as well as Syringothyris cuspidata were to be frequently met with, it became evident that my first view was incorrect. A very careful examination of the beds in place showed that the Productus was only to be found in the very topmost beds, and that Semimula was practically confined to the upper part of the quarry, whereas Syringothyris aff. lamimosa occurred near the base. I had also found the same beds in a quarry near West Ticken- ham (see ‘Isolated Exposures’ p. 231), and a vertical section of the Cyathophyllum seen in situ revealed the fact that the Failand Cyathophyllum is very different from Cyathophyllum Murchison (the former shows as marked a relationship to Caninia as the latter does to the Clisiophyllids). This view has been confirmed by the sections which I have had cut from specimens of Cyathophyllum o collected in the Failand quarries. Hence, on paleontological grounds, the Bellerophon-Beds must be assigned to the top of the Syringothyris-Zone, immediately below the base of the Semnula- Zone (that is, immediately below §,). [It will be pointed out in the general summary that, if the Carboniferous Limestone is to be divided into two great systems, a lower (or Tournaisian) and an upper (or Viséan), the line of ‘separation must be drawn at the top of the Bellerophon-Beds. | 218 DR. A. VAUGHAN ON THE PALMONTOLOGICAL | May 1905, The manner in which the same position for these beds has been fixed by stratigraphical reasoning has already been sufficiently described. Comparison of the Syr eee -ZLone in the Failand area with other sections.—lIt has been sufticiently emphasized that, with the exception of the Bellerophon-Beds, there is a complete similarity, both lithological and paleontological, between the Failand and Avon development of this zone, but that the Bellerophon-Beds of the Failand area are represented in the Avon section by unfos- siliferous shales and dolomites. The fact that the Bellerophon-Beds are found ina presen -similar development in the Clevedon area (near Tickenham) illustrates once more the essential similarity of that area with the Failand area. Viséan. — Seminula-u.. > (S; & 8.). Exposures: ae (1) Thinly-bedded limestones, immediately above the Bel- lerophon-Beds in the first and second quarries, 1 | (2) Massive limestones, in the small quarry west of Long- wood House. g ee assive limestones, with a thick band of oolite, east of a Longwood House. 8 Of these: (1) and (2) contain Seminula ficordea and Productus 0 (2), while Zithostrotion 1s rare or absent. Hence these exposures may be assigned to the base of the Seminula-Zone. (3) contains Productusaff. Cora (mut. §,), Lithostrotion Martini, and Seminula ficoidea in abundance. Hence (3) may be assigned to the middle of the Seminula-Zone. Comparison with the Avon section.—As already pointed out, from stratigraphical considerations (2) probably corresponds to the very lowest beds in the Great Quarry, and (8) to the thick oolitic band which occurs near the top of the same quarry, while (1) represents part of the Middle Shales and Dolomites. The absence of Caninia cylindrica var. bristolensis in the list of fossils from the lower part of this zone in the Failand area is probably due entirely to the fact that the horizon at which that fossil is abundant in the Avon section is here unexposed. Dibunophylium-Zone. 1. Op-subzone (D,). Lithological character.—Massive limestones, with shales and some rubbly limestones. Exposure.—Two quarries near Flax-Bourton Station (nearly 14 miles south, slightly east, of Failand Inn). Nolet 67. | SEQUENCE IN THE BRISTOL AREA, 219 Fauna:— Alveolites septosa. vs { Dibunophytlunr 6 Syringopora cf. geniculata. Clisiophyllids and D. @¢. Lithostrotion Martini (cf. L. affine). | Clisiophyllum @. Cyathophyllum Murchisoni and | Productus ‘ giganteus.’ variants. Productus hemisphericus. Koninckophyllid Cyathophylium, Chonetes aff. comoides. Campophyllum aft. Murchisont. Cyrtina carbonaria (mut.). Campophyllum sp. Comparison with other areas.—The general resemblance, as indicated by the above list of fossils and their relative abundance, amounts almost to identity; in fact, the Flax-Bourton quarries afford the best collecting-ground in the whole district for fossils of this subzone. n. Lonsdalia-Subzone (D,) is unexposed. (d) Tur TyrHERIneton Section. Introduction.—tlytherington lies about 11 miles north 30° east of the Clifton Suspension-Bridge, and about 42 miles north 35° west of Chipping Sodbury. The Carboniferous Limestone (Lower or Tournaisian Division only) is now imperfectly exposed, in the cutting on the branch-line from Yate to Thornbury, between Grovesend and Tytherington ; and a slightly-higher portion of the series (bottom-beds of the Upper or Viséan Division) can be examined in the limestone-quarries at Tytherington. Prof. Lloyd Morgan! has given so excellent an account of the general geology of the district, and has illustrated his description by so good a map, that I can proceed without further introduction to the detailed paleontology of the section. Details of the Grovesend-Tytherington Section. Tournaisian. Modiola-Zone (M). Lithological character.—Shales and thin calcareous bands, capped by red limestone (Horizon a@). Exposure.,—Entirely unexposed at the time of my visit, and so the beds could only be examined by unearthing them here and there. Prof. Lloyd Morgan estimates the shales and calcareous beds, below Horizon a and above the Old Red Sandstone, at a little over 200 feet horizontal (which is equivalent to about 100 feet normal thickness). He records no fossils. 1 Unobserved at Sodbury, probably on account of the poorness of the exposure. See p. 205. Vol. 61.] SEQUENCE IN THE BRISTOL AREA. 225 As might have been anticipated from its geographical position, the section at Tytherington is most closely related to that at Sodbury, both paleontologically and lithologically. The scarcity of Caninia just above the resupinata-subzone, where it is so abundant in the southern part of the Bristol area, is a feature common to both sections, while the relative abundance of the brachiopods is almost identical in the two sections, Again, the increase in the predominance of dolomites over shales in the middle of the Carboniferous-Limestone Series which was noticed in the Sodbury section is, at Tytherington, a very striking feature. So massive do these dolomites become in this section that the tunnel has been bored through them, and left unbricked. A minor feature of some interest is the occurrence of beds of highly-quartzose sandstone, both at Sodbury and at Tytherington, in the lower part of the Seminula-Zone; at Sodbury these sandstones occur at the base of 8,, while at Tytherington they occur near the top of that subzone. (e) THe CLevepon AREA. Clevedon lies 107 miles west, slightly south, of Clifton Suspension- Bridge, on the south side of the Severn estuary. Tournaisian. Exposures and lithological character :— 1. The sequence, as exposed in ascending order along the coast, from north-east to south-west. (a) The Cletstopora-Zone, composed of shales and subsidiary limestones, is exposed on the foreshore between the pier and Clevedon Bay. (>) The clathratus-subzone (massive limestone) is excellently shown in the cliffs and on the foreshore, extending from Clevedon Bay to a little south of Littleharp Point. (¢) The seswpinata-subzone forms the cliffs at Salthouse Point. (d) The uppermost beds of the Zaphrentis-Zone, including Horizon y, occur near the Pill, where specimens of Zaphrentis and Canima, washed out of the cliffs, can be picked up in hundreds. II. The sequence, as exposed in ascending order along the path on Strawberry Hill, the Carboniferous ridge which lies about three quarters of a mile east of the beach, west of the road from Clevedon to Portishead. Starting at the north of the hill, where the Pennant Grit rests upon the Carboniferous Limestone, and proceeding southward, the zones enumerated below are met with in the following order ;:— (a) The uppermost beds of the clathratus-subzone. (6) The resupinata-subzone, chiefly characterized by the pre- dominance of Zaphrentis aff. Phillipsi (the subzonal index being scarce). 226 DR. A. VAUGHAN ON THE PALMONTOLOGICAL | May 1905, (c) The uppermost beds of the Zaphrentis-Zone, including Horizon y. These beds are well seen in a quarry east of the Fir Wood, and here Zaphrentis and Caninia occur together in great abundance. (d) The lowest part of the lamznosa-subzone. This is repre- sented by a few beds at the very top of the quarry just mentioned. These beds are pale yellow and highly dolomitic ; they are friable and soft, and do not readily effervesce in acid; they contain few fossils beyond fragments of crinoids, and will be referred to as the * laminosa-dolomites.’ Til. Exposures in Horizon y and the lowest beds of the laminosa- subzone. There are five such exposures, which lie (after making correc- tions for differences of contour) upon a line of strike running west 25° south; the distance between the quarries at the two ends of the line is about 14 miles. They are, tracked from east-north-east to west-south-west :— (1) An exposure on the west side of the Portishead road, cut into the base of Strawberry Hill under the path already followed. (2) The quarry, already described, east of the Fir Wood on Strawberry Hill :—Upper resupinata-subzone, Horizon y, and the bottom of the ‘ laminosa-dolomites.’ (3) A roadside exposure on the north side of High-Dale Avenue :—Upper part of Horizon y and a long series of the ‘laminosa-dolomites, which here contain bands of Chonetes and Orthotetes at frequent intervals, (4) Hangstone Quarry (at the foot of Hangstone Hill) :— ‘ Laminosa-dolomites’ with bands of the same fossils ex- posed on the dip-slopes. (5) A quarry near the Old Church, south of Salthouse :— Upper reswpinata-subzone and Horizon y as well as the lowest part of the ‘ daminosa-dolomites.’ IV. Exposures on Court Hill, east of the Portishead road, facing Strawberry Hill on the west. On the crest of the hill Pennant Grit (worked in the large Conygar Quarries) comes into contact with the Carboniferous Limestone. Tracking the beds southward down the slope of the hill (at the foot of which lies All Saints’. Church), and then proceeding along the road to Court Farm, the following zones are met with :— (a) The resuprnata-subzone, well displayed on the slope wherever the rocks are uncovered. (6) Horizon y and the ‘ laminosa-dolomites ’ are concealed. (c) The Canima-Oolite occurs behind Court Farm. The sequence is identical with that on Strawberry Hill. Vol. 61. SEQUENCE IN THE BRISTOL AREA. IO VY. The sequence at Walton Castle. This locality is a little more than three quarters of a mile due north of the quarry on Strawberry Hill, and can be reached by turning off the Portishead road along Holl Lane. (a) The upper part of the Cleistopora-Zone and the lower beds of the clathratus-subzone are well exposed to the east of Castle Farm. (6) The resupinata-subzone is exposed at the top of Walton- Castle Hill and in a quarry near the western end of Holl Lane. (c) Horizon y and the ‘laminosa-dolomites’ are not exposed. (d) The Caninia-Oolite is splendidly exposed in the large lime- quarries on each side of Holl Lane, between the Castle and the Portishead road. Fauna’ :— Cleistopora-Zone. Cleistopora aff. geometrica has been found in Clevedon Bay (that is, in the upper part of the zone). ‘There is a speci- men from this locality in the Natural History Museum, South Kensington. Spiriferina octoplicata is very common in the upper beds near Castle Farm. Clathratus-subzone. Spirifer aff. clathratus and var. occur in enormous abundance, and are associated with the same forms us elsewhere. Zaphrentis is extremely rare. Lower resupinata-subzone. | Laphrentis aft. Phillips is the dominant representative of the genus. Cliothyris glabristria is uncommon, although I have found it both on Strawberry Hill and Court Hill. Upper resupinata-subzone and Horizon y. Syrmgopora @ is a characteristic and easily-distinguished form. Zaphrentis att, cornucopie becomes the dominant species, but Z. aff. Phillipse is still common. Canina cylindrica and its mutations are abundant, and mark out Horizon y. Syringothyris aft. laminosa and Michelinia occur somewhat frequently. Lamimosa-subzone. Bands of Orthotetes and Chonetes aff. papilionacea are well seen in the ‘ laminosa-dolomites,’ especially in Hangstone Quarry. The Caninia-Oolite contains the usual fossiliferous basal beds, in which Orthotetes and Chonetes are abundant. ' Reference is made here only to points of especial interest. 228 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, The most interesting points in the Clevedon develop- ment are as follows :— (1) The great abundance of Zaphrentis in the resupinata-subzone and the strong demarcation of Horizon y by the abundance of OCanma cylindrica. (2) The dominance of Zaphrentis aff. Phillips: in the lower part of the resupinata-subzone, and of Zaphrentis aff. cornucopice in the upper. (3) The occurrence at Horizon y of transitional forms between Laphrentis, Caninia, and Cyathophyllum (compare Spring Cove). (4) The occurrence of a characteristic form of Syringopora in the upper part of the Zaphrentis-Zone. This form is found at the same horizon in the Failand, Sodbury, and Avon sections. (5) The light which the accurate determination of the age of the Carboniferous Limestone that surrounds or is included in the Pennant Series, in the Clevedon and Clapton areas, is likely to throw upon the relation of the Coal-Measures to the Carboniferous Lime- stone in the district. So far as I have yet been able to form an opinion, a considerable unconformity seems the only possible solution. (f) Tae PortisnEap District, Portishead Railway-Station lies 47 miles north-east of Clevedon Station, and 64 miles west 20° north of the Clifton Suspension- Bridge. The Carboniferous-Limestone ridge stretches continuously along the west side of the road, from Clevedon to near Portishead, where it is abruptly interrupted ; but the Carboniferous Limestone again reappears on the foreshore, in front of the Esplanade, and also extends in a west-and-east ridge, from Battery Point to Portishead Dock. The Portishead district has been briefly described by Buckland & Conybeare, and later, in considerable detail, by Prof. Lloyd Morgan.? The last-named author dissents from the conclusions of the earlier observers in several important points, only one of which, however, concerns my present object, namely, the interpretation of the beach-sequence near Battery Point. The facts, as 1 read them, are as follows:—Beds identical with the Avon ‘ Bryozoa-Beds’ emerge from beneath the alluvium at the northern end of Woodhill Bay, and form a low cliff; these beds bend completely over. For a few yards north of this roll, there is a confused jumble in which no arrangement can be detected. Still proceeding northward, we next meet with four or five small, sharp flexures (broken in places) in a series of shales and thin limestones. In these beds Cleestopora is very common. The last of the small 1 «Observations on the South-Western Coal-District of England’ Trans. Geol. Soe. ser. 2, vol. i (1824) p. 210, 2 Proc. Bristol Nat. Soe. n. s. vol. v (1885-88) p. 17, Wolo. | SEQUENCE IN THE BRISTOL AREA, 229 flexures rolls over at a small angle to the north, and the Paleozoic rocks are concealed from view for about 100 yards. They again emerge in the cliff at Battery Point, and their age can here be definitely fixed as Horizon (. The abundance cf Cleistopora in the flexed beds indicates the upper part of K, and the small distance between these beds and Horizon 6, at Battery Point, confirms this conclusion. Hence, we have the ‘ Bryozoa-Beds’ (just below K,) in juxtaposition with the upper part of K,. This phenomenon necessitates a big fault, and, if we assume a reversed fault to separate Horizon a (the ‘ Bryozoa- Beds’) from the flexed beds of the upper part of K,, we have a simple explanation of the series of small sharp flexures. This view is in partial agreement with that expressed by Buckland & Cony- beare more than eighty years ago.’ Tournaisian. Exposures and lithological character :— Horizon a (the ‘ Bryozoa-Bed ’) is well shown in a low cliff of red limestone on the beach. The upper part of the Clezstopora-Aone can be examined on the foreshore, between the outcrop of Horizon a and Battery Point. The clathratus-subzone is excellently displayed at Battery Point, and in the cliffs for some distance east of the point. The resupinata-subzone, extremely rich in Zaphrentis, is well seen in two quarries in the Portishead-Clevedon ridge, that is: (1) A quarry, cut into the side of the Big Weston Wood, which can be seen from the road; and (2) A disused quarry a short distance up Nightingale Vale (past the large quarry referred to below). ; Horizon y and the ‘laminosa-dolomites’ can only be made out in poor exposures at the side of Nightingale Vale, between the resupimata-quarry and the large quarry already mentioned. The Caninia-Oolite is well seen in this large quarry; it has the fossiliferous band at the base, and is capped by compact dolomites. Fauna “:— Modiola-Zone. Horizon a (the only part of the zone that 1s exposed) occurs, as already stated, in a low cliff. The beds in the cliff are re- markably similar to those at the same horizon in the Avon section, and the fossiliferous strata contain an identical assem- blage of organisms : namely, prolific crinoid-débris with abundant Rhabdoneson, but very few other fossils. The title ‘ Bryozoa-Bed ’ is well deserved, but the abundance of bryozoans has been absurdly overstated. habdomeson is the only bryozoan that is at all common, and this fossil is not more abundant here than it is in certain beds in the Oleistopora-Zone 1 Trans. Geol. Soc. ser. 2, vol. i (1824) p. 246. 2 Only the most interesting points are noticed. @-J.G.S. No, 242, R 230 Dk. A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, ° (see immediately below). No doubt the fragments of crinoids have been mistaken for bryozoans, on account of their peculiar microscopic structure." Cleistopora-Zone. (Upper K, only.) Cleistopora aff. geometrica is abundant in certain beds. A very short distance north of the cliff already described, and lying in a small syncline, is a red earthy limestone crowded with Rhabdomeson, crinoid-débris, and small gasteropods; the following fossils * occur abundantly in this bed :— Palatal teeth. Scaphopod......... Dentalium (%). Pteropods ......... Hyolithes, Tentaculites. Gasteropods ...... Loxonema, Macrocheilus (?), Straparollus, Bellerophon; Pleurotomaria (at least two species); Murchisonia (two or three species). Opisthobranch ...Actgonina. Brachiopods ...... Syringothyris aff. cuspidata, Orthotetes aff. crenistria, Lingula mytilotdes. Ostracod ......... Leperditia (%. Crimoids ee. sn Débris probably of several forms. Clathratus-subzone. This subzone presents its usual features. Horizon (3 contains Spiriferina octoplicata. Resupmata-subzone. The following fossils have been obtained from the quarry in Big Weston Wood :— ZLaphrentis aft. cornucopie \ extremely | Orthotetes crenistria. Zaphrentis aff. Phillipsi abundant. | Leptena analoga. Spirifer aff. clathratus (rare). Schizophoria resupinata. Syringothyris att. cuspidata. Rhipidomella aft. Michelini. Syringothyris aff. laminosa. Productus aff. semireticulatus. Cliothyris glabristria. The simultaneous occurrence of Chothyris glabristria and Schizophoria resupinata, together with the abundance of Zaphrentis and the entrance of Syringothyris aff. laminosa, serves to fix the position of the beds with complete definiteness, and to emphasize the essential similarity of this subzone throughout the Bristol area. (Compare the Avon and Sodbury sections.) Laminosa-subzone, At the base of the Caninia-Oolite, Orthotetes and Chonetes are abundant, in association with an occasional specimen of Syringo- thyris aff. laminosa. * Dr. F. A. Bather has kindly confirmed the fact, that the most abundant organisms seen in a thin section of the Avon ‘ Bryozoa-Bed’ are fragments of crinoids. * The determination of the genera may need revision, as I have no special knowledge of Carboniferous gasteropoda. I have to thank Mr. W. H. Wickes for his kindness in presenting me with my best material. ° Large palatal teeth, similar to those found in the same subzone in the Avon section, are occasionally obtained from this quarry. Vol. 61.] SEQUENCE IN THE BRISTOL AREA. 231 (ii) Isolated Exposures in the Bristol Area. (A) In the Clifton-Clevedon Ridge. I. Between the Clifton and Failand Areas. (1) Near Cadbury Camp (38 miles east of Clevedon Railway-Station). (a) The upper Zaphrentis-Zone is seen in small exposures, at the side of the road which runs along the crest of the ridge. Zaphrentis is abundant, associated with the same brachio- pods as in the Clevedon area, and it is this abundance that immediately fixes the horizon. (6) The lower lamznosa-subzone (the ‘ laminosa-dolomite ’) 1s well shown in a quarry on the southern flank of the ridge, north-west of Tickenham (halfway between Cadbury Camp and Kast Clevedon). Bands of Chonetes aff. papilionacea and Orthotetes crenistria fix the horizon. (c) Horizon 6 (the ‘ Bellerophon-Beds’) is splendidly displayed in a quarry a little north-west of Tickenham, on the north side of the Clevedon road, at the western end of the village of Middletown. This quarry is cut into the southern side of a lower ridge, which runs parallel to the main ridge on its south side, and is separated from the main ridge by a depression. This depression is doubt- less caused by the more rapid denudation of the thick ‘ laminosa-dolomites,’ of the ‘* Caninia-Oolite, and of a thin series of the superjacent ‘ Caninia-Dolomites.’ From this quarry I have obtained :— ‘ Chetetes’ twmidus. | identical with that at Horizon 0, Cyathophyllum 9. Failand, and ef. var. Kel/i). Syringopora sp. i Productus sp. (ef. Productus @). Syringothyris aft. cuspidata. | Productus ait. semireticulatus (mut.). Syringothyris att. laminosa. fieticularia sp. Seminula spp. Dielasma sp. (Athyris) sp. Bellerophon sp. (cf. costatus). Orthotetescrenistria(a mutation | Muomphalus sp. The above list leaves no doubt as to the identity of the horizon. (d) Clapton-in-Gordano,—Clapton lies nearly 6 miles west (slightly north) of the Clifton Suspension-Bridge. The quarry occurs in an isolated mass of Carboniferous Limestone which les just north of the road from Port- bury to Clevedon, about a quarter of a mile east of Clapton Church. This mass of imestone comes into contact with the Pennant Series on the south, but on all other sides it is surrounded by Triassic rocks. There are several other smaller masses * of Carboniferous Limestone in the * In the Geological Survey Memoir (‘ Geology of East Somerset & the Bristol Coalfields’ 1876, p. 21) these small, isolated masses are merely mentioned, with the remark that it is difficult to account for their presence. ‘They are accounted for by Prof. Lloyd Morgan as the result of a ‘flat-lying fault’ which sliced and heaved the Carboniferous Limestone, subsequent denudation pro- ducing the isolated patches, Proc. Bristol Nat. Soc. n.s. vol. v (1885-88) p. 15. R 2 232 DR, A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, immediate neighbourhood of Clapton, at least one of which is entirely surrounded by the Pennant Series (see Sheet 19, Geol. Surv. 1-inch map). The quarry is on Horizon (3, as indicated by the following fossils :— Spirifer alf. clathratus. Abundant. Orthotetes crenistria. Syringothyris att. cuspidata. ZLaphrentis att. Phillipsi. Spiriferina octoplicata. Abun- Cliothyris Royssit (mut.). { dant. It is, in my opinion, entirely out of the question that there is a complete sequence from the Tournaisian up to the Coal-Measures anywhere in the Clapton-Clevedon-Portishead area. There is no- where sufficient space between the outerops of these two formations to allow of the complete sequence being developed; in fact, I have seen no Viséan strata north of Tickenham Church. tam strongly inclined to believe that there is, in this region, evidence of post-Tournaisian upheaval and denudation, and that the area Was not again submerged until the Coal-Measures were laid down in a narrow inlet, bounded on the west by the Clevedon- Portishead ridge and on the south by the western part of the Clevedon-Failand ridge. Within this inlet, the masses of Carbon- iferous Limestone in the Clapton district stood up as small islands. (¢) Tickenham.—The lower beds of the Seminula-Zone can be made out im a field immediately east of Tickenham Church. Here I found Productus sp. (cf. P. 6), Seminula ficordea, and Orthotetes crenistria (mut.). We may unhesitatingly compare these beds with the lowest beds in Dod’s Quarry (see p. 241); a result in complete accord with their stratigraphical position. I strongly doubt the completeness of the sequence between these beds (of lowest Viséan age) and the Coal-Measures which are found a few yards farther south. There is certainly no room for the Upper Seminula-Zone, the Dibunophyllum-Zone, and the Millstone- Grit. (2) A quarry near Moat-House, north of the Clevedon road, 12 miles west of Failand Inn. Upper clathratus-subzone and Lower resupinata-subzone. From this quarry I have obtained :— Zaphrentis aff. Phillipsi. Rhipidomella aff. Micheline. Cliothyris glabristria. Schizophoria reswpinata. Cliothyris sp. (?). Productus cf. Martini. Spirifer aff. clathratus. Productus aff. pustulosus. Syringothyris aft. cuspidata. Productus aff. semireticulatus. Syringothyris aff. laminosu. Chonetes cf. hardrensis. Orthotetes crenistria (mut. Z). Chonetes aff. papilionucea. Leptena analoga. Note.—Cliothyris glabristria and Rhipidomella aft, Michelini are extremely abundant ; Zaphrentis and Schizophoria are rare. Vol. 61.] SEQUENCE IN THE BRISTOL ARFA. 233 II. Between the Failand Area and the Avon Section. (1) A quarry near Abbot’s Leigh, north of the Portishead road about 13 miles from the Clifton Suspension-Bridge. Zaphrentis-Zone. Clathratus- and resupinata-subzones. In the lower beds of the quarry Spirifer afi. clathratus and var. crowd the beds, and are associated with the following fossils in great abundance : — Syringothyris aff. cuspidata, Orthotetes crenistria (mut. Z), Leptena analoga, and Chonetes cf. hardrensis. Cliothyris Royssti (and mut. @), Camarotachia aff. mitcheldeanensis, Productus cf. Martini, and Rhipidomella aft. Michelini In the higher beds ZLaphrentis aff. Phillipsi is not uncommon, Cliothyris glabristria is abundant, and a single specimen of Schizophoria resupinata was discovered. Reticularia aff. lineata, Productus cf. Martini occur, and Chonetes ef. laguessiana is extremely abundant. The beds resemble so closely those in the Avon section that no further discussion of this horizon is necessary. are also conimon. (2) Exposures near Long Ashton," about 12 miles south-west of the Clifton Suspension-Bridge. In the grits which are usually considered to form the base of the Millstone-Grit Productus aff. scabriculus is fairly common, affording evidence of Horizon e. (B) In the Clifton-Westbury-King’s Weston Ridge. (1) Exposures on Durdham Downs. (a) In the broken ground south of the Reservoir. The lower Seminwla-Zone is shown, as evidenced by the following fossils :— Caniniacylindricavar. bristolensis. | Productus 9. Lithostrotion Martini and var. Seminula ficoidea. Syringopora ef. distans. | Also occasional specimens of Orthotetes crenistria (mut.) and Euonphalus sp. (>) In the disused quarry at the top of Pembroke Road, the upper part of the Seminula-Zone is shown, as evidenced Seminula spp. Lithostrotion Martini, and Productus ‘ giganteus.’ an occasional specimen of Clisiophyllum @. T have not personally examined the section, but localized specimens are in the collection at University College, Bristol. 234 DR. A. VAUGHAN ON THE PALHONTOLOGICAL {May 1905, (c) Along the edge of the Downs, between the top of Pembroke Road and the Fountain, higher beds come in very gradually, as the southern edge of the Downs nearly coincides with a line of strike. Between College Road and the Fountain, the lowest part of the Dibunophyllum-Zone is shown, as evidenced by :— Lithostrotion Martini. | Dibunophyllum spp. Syringopora ct. distans Productus ‘ giganteus.’ Cyathophyllum Murchison, These exposures merely confirm the sequence in the Avon section, and could have been foretold by continuing the lines of strike across the map. (2) In Westbury Park, near Cold-Harbour Farm, The Carboniferous Limestone is here exposed, dipping at a high angle, and the Rhetic rests unconformably upon it. The Seminula-Zone (probably the lower part) is shown by— Seminula sp. and Productus 6 (?). (Fossils are scarce and poor, and the exposure is very small.) (3) Near Southmead (three quarters of a mile east of Westbury- on-Trym). The laminosa-subzone is excellently shown in the large quarries near Southmead. The following divisions are exhibited (in ascending order) :— The ‘ daminosa-dolomite’ (here only slightly dolomitic, but conspicuously encrinital). The ‘ Caninia-Oolite, resting upon an extremely-fossiliferous band (as is usual throughout the Bristol area). The lowest beds of the ‘ Caninia-Dolomites ’ (thinly-bedded compact lime- stones). The following fossils have been collected, from the top of the laminosa-dolomite and from the base of the oolite :— Syringothyris aff. laminosa (common). | Chonetes cf. hardrensis (not common). ’ Semenula sp. (rare). Chonetes aff. papilionacea and Ch, cf. Orthotetes crenistria, muts. Z & C (very comoides (extremely abundant). abundant). A Zaphrentid (cf. Caninia) is occa- ’ Rhipidomelia att. Michelini (rare). sionally seen, sectioned 72 sit. This horizon is of considerable interest, since it shows the first appearance of a Viséan fauna at the top of the Tournaisian. The cornute Zaphrentid, Chonetes cf. hardrensis, Rhipidomella aff. Michelint, and the convex, grooved Orthotetes (cf. var. Kelli), are characteristic survivors from the Zaphrentis-Zone. Semimula sp., Chonetes papilionacea in its convex, thick-shelled mutation (Ch. cf. comordes), and the mutation of Orthotetes crenistria which exhibits strong periodicity of ribbing, combined with con- spicuous reticulation, are characteristic of the Viséan stage. Vol. 61. ] SEQUENCE IN THE BRISTOL AREA. 235 Syringothyris aff. lamanosa is characteristic of the whole Caninia-Zone, and is associated at one end of the zone with a typical Tournaisian fauna, at the other with a typical Viséan fauna. This horizon exhibits the same characteristics in the Tythering- ton section, at Wickwar, and at Cromhall. (4) Brentry Hill, three quarters of a mile north of Westbury-on- Trym. (Two quarries, one on the main road to the Passages, the other on the branch road to Charlton.) The upper part of the Semnula-Zone and the base of the Dibunophyllum-Zone are shown, as evidenced by :— Seninula ficoidea and 8. cf. ambigua | Productus aff. hemisphericus. (mut, 8,). Orthotetes crenistria (mut. D) (rare). Productus aff. Cora. Lithostrotion Martini and variants. These fossils abound throughout the lower and middle beds, indicating the Upper Seminula-Zone. The concretionary structure is splendidly shown in the upper- most beds of this zone, and some layers almost exactly resemble Cotham Marble. In the upper beds we find :— Alveolites septosa. 1 Tnthostrotion Martini (mut. towards Cyathophyllum Murchisona. L. affine). 1 Syringopora cf. distans and S. cf. | 1 Dibunophyllum 0 and Did. ¢. geniculata. Clisiophyllum @. These fossils definitely indicate the 66-subzone. (5) Blaize-Castle Wood, near Henbury. An exposure by the side of the Rhododendron Walk yielded the following corals :— Lithostrotion trregulare. Syringopora cf. distans, Lithostrotion Martin and mutation Cyathophyllum Murchisoni var. (ef. L. affine). Axophylium 0. Lonsdalia floriformis var. (cf. LZ. ru- | Productus ‘giganteus. gost). Mr. 8S. G. Perceval informs me that he has also found here :— Lithostrotion ensifer, and Lithostrotion junceun, Cyathophyllum regiwm. The position of the beds is thus completely fixed in the Lons- dalia-Subzone. (6) Henbury Hill. A little south of Blaize-Castle Wood, west of the Westbury and Henbury road, there is a quarry in Upper Seminula-Beds. The usual fossils are found, and many of the beds are oolitic. 1 These fossils are included, on the evidence ot localized specimens in the Clifton-College Museum. 236 DR. A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, (C) In the Wickwar-Sodbury Ridge. (1) The ‘Wick Rocks,’ and other exposures near Wick. Wick lies on the east of the Bristol Coalfield, 85 miles due east of the Clifton Suspension-Bridge. The Carboniferous projection at Wick is an inlier which marks the southern extension of the Wickwar-Sodbury ridge, below the capping of Mesozoic beds: it lies 6 miles due south of the end of that ridge at Sodbury. The general geology of the Wick district has been so thoroughly de- scribed by Prof. Lloyd Morgan’ that any detailed account of the topography is rendered unnecessary. (a) The ‘ Wick Rocks’ (including several quarries). This is a fine section through the Seminula-Zone, from above 8, up to the concretionary beds at the top of the zone. So exactly does the paleontological sequence agree with that observed at Sodbury, that ttle more than a bare list of fossils will suffice :— Lithostrotion Martini and variants. | Productus ‘ giganteus.’ Syringopora cf. distans and var. Chonetes aff. comoides. Clisiophyllid. Chonetes papilionacea. Productus aff. Cora. Seninula ficoidea and allied forms. Productus aff. hemisphericus. Lithostrotion Martini teems at the base. Productus aff. Cora, in a characteristic form (mut. 8,), occurs in the thick oolitic band. Seminula ficoidea crowds certain beds in the upper part of the zone ; and near the arch, where these beds are wéll weathered, specimens showing the spiral arms beautifully weathered out, are abundant. (Beds on the same horizon, just below the Observatory, on Observatory Hill, Avon section, exhibit the same character.) Chonetes papilionacea crowds certain bands, which occur at intervals from the colite onwards. A. Clisiophyllid is not common, but occurs occasionally from the oolitic band onwards. These beds correspond exactly to those at Sodbury, east and west of Lilliput Bridge, and, in the Avon section, to the upper part of the Great Quarry. (b) The section at the Ochre Works. Lonsdalia-Subzone (Dibunophyllum-Zone). This section is almost identical with that at Wrington (see below, p. 242) and in Bridge-Valley Road, on the Clifton side of the Avon, as is shown by the following fossils :— Lithostrotion ensifer. Lithostrotion irregulare. LI. rugosa). Lithostrotion Portlocki (var. M‘Coy- Koninckophyllid Cyathophyllum. anum). Dibunophyllum w. | Axophyllum 0. Lousdalia floriformis (and var. ef. 1 Proe. BristoleNat. Soc. n. s. vol. vi (1889-91) p. 183. Vol. 61; SEQUENCE IN THE BRISTOL AREA. 237 Productus aff. seabriculus (of two | Spirifer aff. mosquensis. types: cf. Pr. costatus and Spirifer cf. ovalis. Pr, semireticulatus). Reticularia lineata (cf. Dav. Spirifer ef. grandicostatus. pl. xiii, fig. 10). Note.—All the corals, with the exception of Cyathophyllum, are very abundant. Productus aff. scabriculus teems, the more finely-ribbed form being by far the most abundant. Reticwlaria lineata is a common fossil, but the Spirifers are rare. Horizon e. Above the thickly-bedded limestones of the D, subzone occurs a series of thinly-bedded limestones, shales, and sandstones. The lime- stone-bands in this series are crowded with brachiopod-fragments. Productus aff. scabriculus (cf. P. costatus) | Orthotetes crenstria (mut.) Chonetes cf. crassistria. Seminula ef. ficoidea and 8. cf. ambigua, less common. Phillipsia-fragments are of frequent occurrence. Note.—The Chone?es is very similar to the form found in the Tournaisian, but its average dimensions are much smaller. On account of its small size, unbroken specimens are not unusual. (c) The lowest Millstone-Grit Quarry. At the base of this quarry, immediately above the highest calcareous beds which are usually regarded as closing the Upper Limestone-Shales, ig a sandstone crowded with casts of brachio- pods, etc. very - common. Productus aff. scabriculus is extremely abundant, and indicates Horizon e. This Productus is a different variant from that found in the Avon section ; for, whereas the Avon form may be regarded as a scabriculate mutation of Pr. costatus, that at Wick is a scabriculate mutation of Pr. semireticulatus. The chief interest of the Wick exposures centres in the fact that they complete the Sodbury section, by exhibiting the Lonsdalha- Subzone and Horizon e which are there absent. (2) Quarries at Wickwar, 4 miles north of Chipping Sodbury. This district has already been described by Prof. Lloyd Morgan, in the British Association Handbook issued at the Bristol meeting in 1898. Detailed Account. Zuphrentis-Zone., Resupimata-subzone. Lithological character.—Massive limestones. Exposures.—Two adjacent quarries, immediately north of Wickwar, on the west side of the Charfield road. Fauna :— ZLaphrentis aff. Phillipst. Michelinia sp. Zaphrentis aff. cornucopia, Syringopora @. 238 DR. A. VAUGHAN ON THE PALZONTOLOGICAL [May 1905, Cliothyris glabristria. Rhipidomella aff. Michelini. Cliothyris sp. (transitional form). Leptena analoga. Spirifer aff. clathratus and var. Productus cf. Martint. Syringothyris aff. cuspidata. Productus aff. pustulosus. Camarotechia aff. mitcheldeanensis. Productus aff. semireticulatus. Orthotetes crenistria (mut. Z). Chonetes cf. hardrensis. Schizophoria resupinata. Chonetes papilionacea. Notes.—Spirifer aff. clathratus, Cliothyris glabristria, and Schizophoria resupinata are commonest in the lower part of the subzone, but rare above. Cliothyris glabristria and Schizophoria resupinata are extremely abundant together. Chonetes cf. hardrensis teems in certain beds. Chonetes papilionacea only occurs abundantly in the upper part of the subzone. Huomphatus, Bellerophon, and seer very interesting bryozoans also occur." Horizon y is indistinguishable, since no specimen of Caninia was found above the resupinata-subzone and under the ‘ Zaminosa-dolomites.’ Laminosa-subzone. Sequence in ascending order :— (1) ‘ Laminosa-dolomites,’ (2) ‘ Caninia -Oolite’ resting upon a highly-fossiliferous band (the ‘sub-Oolite’). Exposures :— (1) can be seen at the top of the southernmost of the two quarries in the resupinata-beds. (2) is shown in a quarry a little farther west, and also in a very large disused quarry farther north, on the west oe the Charfield road. In both quarries the ‘ sub-Oolite’ is well displayed. Fauna:-— The ‘laminosa-dolomites’ are unfossiliferous, except for crinoid- fragments. ‘The ‘sub-Oolite’ contains Caninia cylindrica. Orthotetes crenistria (mut. indaneaee Syringothyris aff. laminosa. C) and bane “ Seminula sp. (very small form). Chonetes aft. papilionacea : Rhipidomella att. Michelini. Orthotetes is common in the base of the Caninia-Oolite. Seminula-Zone (Upper 8, and Lower §,). Lithological character.—Massive limestones, with shales, and a highly-quartzose grit. Exposure.—a large quarry still. farther west of the resupinata- quarries. ' Palechinus is common at this horizon throughout the Bristol area, a fact which was pointed out to me by Dr. Wheelton Hind (see also below, p. 256). Vol. 61. | SEQUENCH IN THE BRISTOL ARMA. 239 Fauna:}—. Lithostrotion Martin and vars. | Productus 0. Seminula ficoidee and allied | Productus aff. heiisphericus. forms. | Productus aff. Cora mut. Comparison with other Sections.—BSo closely does the Wickwar development correspond to that in the Sodbury and Tytherington sections, that the enumeration of all the points of resemblance would be practically a repetition of the foregoing faunal lists. The most interesting points are :— (1) The absence of Caninia just above the resupinata-subzone, so that Horizon y is not differentiated. (2) The occurrence of Caninia in the ‘ sub-Oolite,’ as at Tytherington. (3) The early occurrence of an occasional Seminula in the sub-Oolite, as at Tytherington and Southmead. (D) In the Olveston-Tytherington-Cromhall Ridge. This ridge forms the northern boundary of the Bristol Coalfield ; it runs west-and-east, and is continuous with the north-and-south Wickwar-Sodbury-Ridge, which bounds the Coalfield on the east. (1) Old Down.—Kast of Olveston, about 9 miles north of Bristol, and 4 miles west of the Tytherington section. Large quarries in the Upper Seminula-Zone. Fauna :— Lithostrotion Martini (abundant). | Seminula ficoidea. Abun- Clisiophyllids (occasional specimens ; Productus aff. Cora, mut.8,. { dant. of Clisiophyllum @). (2) The Ridge Way.—There is a disused quarry, also in the Upper Seminula-Zone, at the junction of the road to New Passage with the Gloucester road, about 11 miles north-east of Almondsbury. , (3) Cromhall District. (a) Ley-Hill Quarry.—A little more than half a mile north of Cromhall is a large road-meta! quarry in the Upper Zaphrentis- Zone (resupinata-subzone), Horizon y, and base of the laminosa- subzone. 1 [As the result of a recent visit to this quarry, in the company of Dr. Wheelton Hind, I am enabled to add the following fossils to the above list :— Upper 8,: Productus semireticulatus (mut, §,). Lower 8,: Productus fimbriatus (only previously recorded in the south-west by Dr. W. B. Gubbin from South-Western Gower, where it occurs at the same level: Proc. Bristol Nat. Soc. ser. 4, vol. i, pt. i, p. 45). Cyrtina carbonaria (very abundant, and occurring at the same level as at Weston and Kidwelly : see below, p. 254). Gasteropods belonging to several genera (Bellerophon, Huomphalus, Loxonema, etc.) a abundant (cf. Dr. Gubbin’s paper, op. cit. pp. 46, 47).— A. V., April: 26th, 1905. 240 DR. A. VAUGHAN ON THE PALMONTOLOGICaL [| May 1905, In the lower beds Zaphrentis aff. cornucopie is abundant, and fine speci- mens can be obtained. ‘The uppermost beds show an unequalled development of the ‘laménosa-dolomites.’ Chonetes aff. papilionacea and Orthotetes crenistria mut. C occur in profusion. (b) A limestone-quarry.—This quarry lies a short distance south-west of the last. It is mainly composed of an unfossili- ferous limestone, which is perfectly white (the ‘ Caninia-Oolite ’). At the base are the uppermost beds of the ‘ laminosa-dolomite,’ teeming with Chonetes aff. papilionacea and Orthotetes cremstria, (c) ‘Near’ Cromhall.—In Mr. Champion’s Collection there are specimens of Lithostrotion Martini, which certainly indicate the Seminula-Zone. I have no doubt that a very complete section could be con- structed, from all the exposures between Cromhall and Charfield ; the exact resemblance of those exposures which I have examined, to those already described in other parts of the Bristol area, suggests, however, that the results would present no special interest. (1) The Backwell-Wrington Mass. This triangular mass of Carboniferous Limestone, which mea- sures 54 miles from west to east and 34 miles from north to south, lies south-west of Bristol and due west of Dundry Hill. The general structure of the mass is an anticline, the crest of which runs west-and-east, a little south of Broadfield Farm, thus dividing the mass into two very unequal parts, namely, a broad northern part and a much narrower southern part. ‘The crest of the anticline had been eroded in post-Carboniferous times and is now partly concealed, immediately south of Broadfield Farm, beneath Rheetic and Liassic deposits. Detailed Account. Upper Tournaisian. Resupimata-subzone (including Horizon y). Exposures.—Along the crest of the anticline and, under- lying the lavas of Goblin Combe, on both sides of the anticline.’ Fauna:— Laphrentis aff. Phillipsi. Spirifer aff. clathratus. ZLaphrentis aff. cornucopia. Syringothyris aff. laminosa. Caninia cylindrica. Chothyris sp. Amplexus cf. coralloides, The only point that is worth emphasizing is the strong definition ot Horizon y, a fact which indicates our approach towards the Mendip area, where Cuninia and Amplexus occur abundantly. 1 C. Lloyd Morgan & S. H. Reynolds, Quart. Journ. Geol. Soc. vol. lx (1904) p. 137. Vol. 61.] SEQUENCE IN THE BRISTOL AREA. 241 Laminosa-subzone. Exposure and fauna.—lThis subzone is represented by beds, above the lavas.on both sides of the anticline, which contain Orthotetes crenistria and Chonetes aff. papilionacea, as well as. Oh. cf. comoides, in extreme abundance. An occasional speci- men of Syringothyris aff. lamimosa is found, associated with the fossils just mentioned. These beds are, in all probability, the equivalent of the ‘ sub- Oolite.’ Viséan. Seminula-Zone. The whole or part of the series, from the top of S, up to the top of the zone (that 1s, up to the concretionary beds or. ‘ mottled limestones’), is well exposed at several points. Hxposures :— (1) Dod’s Quarry on the north-eastern edge of the mass, about 1 mile west of Dundry Hill, and three quarters of a mile south of Barrow Gurney.’ (2) Backwell Quarry, on the northern edge of the mass, nearly 24 miles west of Barrow Gurney. | (3) A quarry on the southern edge of the mass, about*1 mile west of Wrington, on the north side of the Yatton- Wrington road. (4) At Cleve, near the entrance to the Combe. (5) Near Yatton, in the small separated mass which lies. off the south-western corner of the Backwell-Wrington mass. Since the beds exposed in (2), (3), (4), and (5) are smaller portions. of the series, which are included in the longer sequence represented in (1), and since they have no lithological or palzontological pecu- liarities, it will suffice to enumerate the paleontological characters. exhibited by exposure (1). Lithological character.—Massive limestones, with a thick band of oolite, and, at the top, ‘mottled limestones’ with thin shales, ated e— ’ Caninia cylindrica mut. Orthotetes crenistriamut.§, (oceasional).. Lithostrotion Martini. Productus aff. Cora. Syringopora ct. distans. Productus ‘ giganteus,’ Syringopora ct. ramulosa. Productus sp. (cf. Pr. @). A Clisiophyllid (rare). Chonetes cf. conordes. Seminula ficoidea and allied forms. | Chonetes papilionacea. The faunal sequence and the lithological details are so remark-. ably similar to those of the beds in the Wick-Rock Series already described (p. 236), that no further comment is necessary. 1 Barrow Gurney lies about 44 miles south-west of the Clifton Suspension-. Bridge. 249 Dibunophyllum-Zone. DR. A. VAUGHAN ON THE PALHONTOLoGIcAL [May 1905, (a) The lower part or 0¢-subzone is, so far as I know, unexposed. (6) The upper part or Lonsdalia-Subzone. Exposure.—In the large quarry now worked, on the southern edge of the mass, immediately north of Wrington. Lithological character.—Massive limestones shales, and rubbly limestones. Fauna:— Alveolites septosa. Syringopora ef. distans, Lithostrotion ensifer. Lithostrotion Martini and especially a mutation towards L. irregulare. Lithostrotion M‘Coyanwimn. Cyathophyllum regium (simple and | compound). Oyathophyllum Murchisont (var.). Lonsdalia floriformis and the var. ef. rugosa. Clisiophyllids of three main types, Portlockt and var. . with some Spirifer ef. grandicostatus (cf. David- son, ‘Monogr. Brit. Palzoz. Brachiop.’ Palzontogr. Soc. pl. vi, fig. 8). Spiriferina (1) ef. integricosta (C-: Davison, pl. ix, fig. 16). Reticularia lineata. Camarotechia pleurodon (cf. Davidson, pl. xxiii, fig. 2). Productus aff. Cora (mut.). Productus hemisphericus. Chonetes sp. Aviculopecten sp. Fenestellids. Fistulipora (2). namely: Dibunophyllum , Axo- phyllum 0, and Koninckophyllum 9. Seminula aff. ficotdea (scarce). Notes.—The Wrington quarry is now the best exposure in the Bristol area, from which to collect the corals of this subzone. ‘The coral-fauna is identically that of the same horizon in the Avon section, as exhibited in the exposures on the river-side of Stokeleigh Camp, in the quarry on Rownham Hill, and at Round Point on the Clifton side of the river. The brachiopods and lamellibranchs occur crushed in a thin shale, consequently their determination is a matter of considerable difficulty and uncertainty. A eurious form of Fenestellid is met with, both at Wrington and at Round Point. I have now completed the detailed account of the several zones, as they are displayed in the different parts of the Bristol area. Before proceeding to compare the zonal sequence in the Bristol area with that in other districts, it will be necessary to compile a table of the commonest corals and brachiopods, which shall show the range and maximum of each species-group (or gens) throughout the zonal sequence adopted in this paper for the Bristol area. By comparing this table with similar tables for distant areas, it will be possible to plot accurately the directions and amount of the ereat geographical variations in relative sequence, which the different species-groups undergo. The smaller variations, which take place within the Bristol area itself, have been noticed here and there in the detailed description of the different parts of that area, and the importance of such observations, when completed, has been pointed out in the Introduction (p. 185). Wel, O1-| SEQUENCE IN THE BRISTOL AREA. 243 The table and the range-diagrams (which express the same results graphically) are compiled for the Bristol area as a whole, and from the data supplied by that area alone: that is, no account is taken, either of any district outside the Bristol area, or of the smaller variations within the area itself. III. Ranees anp Maxima or rHe Corats AND BRACHTOPODS IN THE Bristror Arga. (Pls. XXVIII & XXIX.) CORALS. Alveolites. Species-group: Alveolites septosa. Very rare at the top of 8, ; commoner in8,; abundant through- out D; maximum in D.. . Syringopora. Genus: rarein Z,; abundant at numerous levels throughout all _ the higher zones. Circuli:— (1) Syringopora 6: Z; maximum in Z, and y. 2) S. ef. distans : common throughout S and D. (3) S. ef. ramulosa: not uncommon in 8. (4) S. ef. geniculata: maximum in D,. (5) S. ef. reteculata ; maximum in C,. Michelinia. Genus: rare in Z,; maximum at the top of Z, and in C. Species-groups (?): not satisfactorily differentiated. The form in Z, is Micheluma cf. favosa; the commonest form in Z, and C is ‘M. mec gastoma. Cleistopora. Species-group: Cletstopora aff. geometrica. Confined to K ; maximum at the top of K,. Zaphrentis. Species-groups :— (1) Zaphrentis aff. Phillipse. Not infrequent in Z, ; extremely abundant in Z, and y; rare in C. (2) Zaphrentis aff. cornucopie. Z, and y (abundant); maximum at the top of Z,; rare in Gs e Caninia. Species-group: Caninia cylindrica. Occasional at the top of Z,; maximum in y; rare in C; 2nd maximum in §,. Mutational stages :— (a) Caninia cylindrica: y and C, (b) Canina cylindrica var. bristolensis: C and § Amplexus. Species-group: Aavotenis ef. coralloides, Z,, y, ©, and probably 8, ; maximum near the top of Z,. 244 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May rgo5, Lithostrotion. (A) The Siphovneletch oh on-Section. Species-groups :— | (1) Lithostrotion Martini. Abundant from the middle of Sis throughout all higher zones ; maximum in 8. Mutations :— Towards Lithostrotion irregulare: D (common). Lithostrotion affine: S, and D. ee Lonsdalia: D, (common). (2) Lithostrotion wregulare (doubtfully a distinct species- group). Abundant throughout D; maximum in D.. (8) Lithostrotionjunceum. Never abundant, but not uncommon at certain levels in D.— (B) The Nematophylium-Section. Species-groups:— (4) ZL basaltiforme : upper part of S, and lower part of §,. (5) L. Portlockt (including the variants L. M‘Coyanum and L. ensifer). D, (abundant). 2? Cyathophyllum. Species-groups :— (1) Cyathophyllum Murchisoni-group. “Mutational stages :— (a) Cyathophyllum ¢: C (maximum at the top). (b) Cyathophyllwm Murchisoni (s.s.): rare in 8; abundant in D ; a maximum in D,. (2) Cyathophyllum regium. D, (abundant). (3) Koninckophyllid Cyathophyllum. D; maximum in D.. Campophyllum. Species-group: Campophyllum Murchison. D; maximumin D.. Clisiophyllids. Not uncommon in §,; maximum in D. (i) Clisiophyllum. (Carcinophylium.) Species-group: Chstophyllum 6. §%,; D, (maximum). (i) Dibunophyllum. Specie’-group: Dibunophyllum turbinatum. Mutational stages :— (a) Dibunophyllum @ and Dib. ¢: S, (rare); D, (maximum). (b) Dibunophyllum Pp: D, (?); Dz (maximum). (111) Cyclophyllum: D, (ware locally). (iv) Koninckophyllum : D (common locally). (v) Axophyllum: D, (common). (vi) Lonsdaiia. Species-group: Lonsdalia floriformis aint tare varsd. Cf. rugosa). D, (very abundant). Quart. Journ. Geol. Soc. Vol. LXI, Pl. XXVIII. TOL AREA ula Sepa ee CoV dalia 2 »~f SN fo ™N > a SE ee ee —, S555 1S SS ee bee see eee eo we eo eo ew eee ew ol a Poe. | Ia ec een ag ee ee ee je) — eee ose aired ee ine epee Me ani ss ES I ) | ee I | (| a. Thick continuous lines indicate common occurrence. Two or three parallel lines indicate abundance. To face p. 244.] Quart. Journ. Geol. Soc, Vol. LXI, Pl. XXVIII. 2 RANGE- DIAGRAM OF CORALS IN THE BRISTOL AREA ZONES = Cleistopora a Zaphrentis Syringothyris Seminula Dibunophyllum SUBZONES| & | bussus | octoplicata | | UN | yesupinata laminosa semireticulalus Cora 0% Hon = Q HORIZONS|M|a K, K, |}| Z Za | Cc 0 S? S3 D, Dll G Alveolites uincchesnoodpe. leonoscas|oso0 quand alkene ea ooaoteny : Syringopord..... Loddbaccocodlon00 woo00d 6 Oicestees Looe berincaul bean waar CL dist€aNs see ele ne dene eee cde cer eee ees =f}. ef. geniculata & CL VAMUTOSA. «fee ele ee ce ee dee ee eee es speeeeed Michelinia. ....++ Lnodbavsdondioou cosa ——— Cleistopora... 2 |... .} — — — — Sse Laphrentis Fd Op 6/7710) el Pee) PEC] (CCC Cn wf. cornUCOpids |... Je cee ee le ee ee eee bfleree viele . Caninia CYLINATICM ve cele e efew ane e elec ent ecree biiano0g Amplecus.....-, Loodboobebadbbacnoosbdbitoaaned Lithostvotion Martini. ss... basdbucosbodbaceppooodptlopoode ETT COULCIE” olnre|s ei e)e|sivreis eieis\s| Sunceum ....- bidarbaosoa0d Ue e) Pondbaodbooouu od bon pobdoad S Portlovki 2.05 Siete CaciSicncicnced PiCiCiCnC i iC nCicaC) . Cyathophyllin Murchisonie.. |r. ..fe. e+. es TEQULIN, «oe wale ne Campophyllim..|..« ‘Clisiophyllun’ (Carcinophyttan)D. |.0 Jee cee! Dibunophyllim )@ @ucondboodbosvessdbansdpooone Hloosondbodnooovodbd Cyclophyllum & Koninckophyllum|: 0. jeccce cc heve eee eae b ALnophyllun & LOPE 005-0|ho0dpoooconnd oooobnn mod p\icaoaadhoo ) Notes;- ey 3 6 2 5 , i P 1. Caninia cylindrica vay, bristolensis. The circles indicate approximate positions of maxima, Thick continuous lines indicate common occurrence. 2, Maximum of the mutation with Clisiophyllid affinity, Thin continuous lines indicate rarity. Two or three parallel lines indicate abundance. Vol. 61. ] SHQUENCE IN THE BRISTOL ARBA. 245 | BRACHIOPODS. Athyrids. (i) Cliothyris. Species-groups :— (1) Chothyris Royssti. The typical form is abundant in M and K.. A mutation (mut. 8) is abundant in K, ; it reachesa maximum at £, and is not uncommon in J). (2) Chothyris glabristraa. Rare in K; abundant through- out Z; maximum in the lower part of Z,. (3) Chothyris sp. (a transitional form between Clothyris and Seminula). Top of Z, and C; maximum near y. (ii) Seminula. Species-group: NSeminula ficoidea. Rare in C; prolific throughout S; scarce in D. Spiriferids. (1) Reticularia. Species-group: feticularia aff. lineata. Rare in K; abundant in Z (maximum in Z,); a mutationin Cand§; a well-defined mutation in D, (Reticularia lineata). (1) Sparifer. Species-groups :— (1) Spirifer tornacensis, represented by Sp. aff. clathratus and its variety, and by Sp. aff. cinctus. Rare in K,; in- creasing in abundance in K,; prolific in 6 and Z ; declining in Z,; very rare after y. (2) Spirifer mosquensis, represented by a local variation. Rare in D.. (i) Spiriferina. Species-group: Spiriferina octoplicata. Rare in K, ; abundant in K, and at 6; scarce in Z.. (iv) Syringothyris. Species-groups :— (1) Syringothyris cuspidata. Mutational stages:— (a) Syringothyris aff. cuspidata (ef. S. subcuspidata) (probably more than one stage is here represented). Probably occurs in M; abundant from the top of K, to 6, and extends into Z. (b) Syringothyris cuspidata (the typical form). Occurs in Z, ; pro- lific at the top of Z, and at y; not uncommon throughout C. (2) Syringothyris att. laminosa. Common in Z,, y,andC; a mutation occurs in §,; maxi- mum in Z,. Q. aGe S. No. 242. g 246 DR. A. VAUGHAN. ON THE PALMONTOLOGICAL [May 1905, Retzids. Eumetria; M and K,.’ Rhynchonellids. Camarotechia. Species-group : Camarotechia mitcheldeanensis (in- cluding two or more mutational stages). Abundant in M, K,and Z,; rare in Z,; very scarce in C. Orthids. (1) Schizophoria. Species-group: Schigophoria resupinata. Very rare in Z ; abundant in the lower part of Z,; rare in y. (11) Rhipidomella. ° Species-group: Rhipidomella aff. Michelini. Rare in K,; abundant in Z (maximum probably at the top of Z,); rare in C, Strophomenids. (i) Orthotetes. Species-group: Orthotetes cremstria. This group persists throughout the whole of the Carboniferous Limestone; but, whereas it is extremely abundant all through the Tournaisian, it becomes comparatively unimportant in the Viséan. The group undergoes well-marked mutational change, and the following stages in mutation can be easily distinguished :— Mut. K,: maximum in K, ; extends into K,,. Mut. Z: K,, Z, and C. | Mut. C: Z,, y, and C. Mut. S: 8 (chiefly 8,). Mut. D,: 8, and D,. (u) Leptena. Species-group: Leptena analoga. Occurs in a; abundant in K and Z; unknown in C. Productids. (Very much more work must be done, both in the field and in the laboratory, before the true inter-relationship of the several members of this family and their ranges in time can be considered as satisfactorily established in the Bristol area.) (i) Productus. Species-groups :— (1) Productus bassus. Very abundantin K, ; doubtfully recorded from K,,. (2) Productus cf. Martini (ncluding variations towards Pr. longispinus and Pr. semireticulatus). Abundant in 1 A single specimen has been discovered near the top of K, in the Failand section. . Quart. Journ. Geol. Soc. Vol. LXI, Pl, XXIX. > IN THE BRISTOL AREA. Seminula | Dibunophyllum | 2 5 784 Cl ae mi a ¢ sONS- reticulatus Cora p Bedi D2 S1 | 52 Dy Se a a a -=s eeevovoee es &© © © *ewspeveeosedsvaeeagaeseBovoees se peeve elo eo ee te eeee se 6 ff EY EAS ae, a, thotetes crenistria mut. S. ae ” 5 mut. Dy. , -roductus semireticulatus nrut. Sy (spinous form) -yoductus 0. 9a. Prod.Cora [Dav] mut. Sz. fax. of coarse-ribbed form (Chonctes ct. crassistria) honetes cf. comoides and early Papilionaceans. ee the diagram of Corals. No face p. 246.] B 2. . ZONES § = M Quart. Journ. Geol. Soc. Vol. LXI, Pl. XXIX. RANGE-DIAGRAM OF BRACHIOPODS IN THE BRISTOL AREA. Cleistopora_ | Zaphrentis Syringothyris Seminula Dit hyll SUBZONES bassus | octoplicata \chathratus) resupinata laminosa seyniveticulalus Cora (is ¥ Bua Dp pt he HORIZONS iz Kr Zr WED Se S. D daha A : ; I 2 Cliothyrvis LLL SS WMoipinCcoonddhaadbaocucnqho005 Seminula ficoldea Ke. eeee dees 4 Teticularia alf. lineata ....J..-. Spiri aff. clathratus. ole. de af. mosquensls. |. ee je es Spiriferina octoplicala s+... 4 heer, Syringothyvis aft. cuspidala & cuspidata aff. laminose. Bumetvia Camarotachia mileheldeancnsls ee % fa Schizophoria Tesupinatit sseesdeeee Rhipidomella aff. Michelini....|... + Orthotetes Crends(Vld «ss. +s-} Leptena ANGOYO severed) Productus DASSUS os vee ne Eon ef, Martinis. sede eee xemireticulats. |... + SCUDVICULUS «weed ss | 8 .& Cora (Dav) giganteus . hemispherleus ©. | Chonetes Buehiana (Dav. |... ef, hardrensis --. ef, comoides & paptlionacea , aff, comulides . Notes:- 1, Cliothyris Royssii mut. B G. Orthoteles crenisiria mut, S. 2. Syringothyris att. cuspidata. Tk . mut. Dx duPypical large form of Syn. cuspidala, 8. Productus ireticulatus mut. Sy (spinous form) 3. Orthotetes crenistvia mut. Kx. & Productus 0. 9a. Prod.Cora (Dav) mut. S2 4. » ” mut. Z 10, Max. of coarse-ribbed form (Chonctes ef. crassistria) 5: ” ” mut. C. 11. Chone comoides snd ely Papilionaceans. For the explanation of the conventional signs see the diagram of Corals. Le ee # ihe = Fah Se ig ir eer one ee ae Seth ieomtiniate ce 3h yh hal: ot er TN nace ine ih nance sl ¢ ¢ ) } 4 Sse ee mene, Vol; 61./] | SEQUENCE IN THE BRISTOL AREA. 247 K,, 3, Z,; the typical form is rare in Z,, where it is replaced ‘by a mutation towards Pr. semir Foner (3) Productus semirciiculatus. The mutation from Pr. Mar- time occurs in Z,, and becomes abundant in Z,. A spinous mutation is characteristic of 8.. (4) Productus aff. scabriculus (including two distinct varia- tions; the one Pr. cf. costatus, the other Pr. cf. semz- reticulatus). Typical of Horizon e; less common in D.. Gia) The Giganteid Producti (a group having subgeneric value). (5) Productus aff. Cora [Dav.] (= Pr. corrugatus). Rare in Z and C; abundant in $,; common in D, and extending nn to Horizon e. The different zones are characterized by distinct mutations (thus mut. Z, mut. C, mut. S,, and mut. D, are easily distinguished). | Productus 6 is abundant in §.. (6) Productus guganteus. Rare at the bottom of 8,; maximum at the top of S, and the bottom of D, ; ‘extends on into D, ina distinet mutation (5 Chonetiproductus ays (7) Productus hemisphericus. The typical form is only abundant at the top of 8, and in D.. (ii) Chonetes. Species-groups :— (1) Chonetes ‘ Buchiana ’* (as figured by Davidson, ‘Monogr. Brit. Paleeoz. Brachiop.’ Palecontogr. Soe. pl. ais, 12) has its maximum at the top of K,. (2) Chonetes cf. hardrensis: K; Z; C,. Variants :— (a) Chonetes ef. crassistria. Rare in M; very abundant in K; extends into Z,. A somewhat similar form reappears in e. (b) Chonetes cf. laguessiana. K and Z. (3) Chonetes paptlionacea. Rare in Z,; common in Z,; abundant at y, in C, and at intervals throughout 8. Variants :— (a) Chonetes cf. comoides is locally abundant in C. (b) Chonetes aff. comotdes is characteristic of D,. Inarticulate Brachiopods. Lingula and (Discina). Paucity of material has prevented any.attempt to separate the forms which occur at different levels. 1 Tam not satisfied that this form is correctly referred to Chonetes Buchiana, de Kon. g 2 248 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, TY. Comparison oF THE Bristol SEQUENCE WITH THAT in NEIGHBOURING AREAS. My only object in this section is to demonstrate that the pro- gression of zonal faunas, which has been established for the Bristol area alone, holds true throughout the South-West of England and South Wales. Since each area to which [ shall refer is now undergoing detailed examination, 1f would be premature, as well as out of place, to attempt here anything beyond a statement of the broad outlines of the faunal succession. The lithological development will be entirely passed over, except in so far as the occurrence of dolomites or grits may interrupt the faunal sequence. GQ) Tue Menpip Arna. The brief account which follows is mainly compiled from an examination of the following localities :— (a) Burrington Combe.’ Zonal extent: All the zones and subzones are here excellently exposed and typically developed, from M up to and including D.. (6) Traverse from Cheddar to Charterhouse. ~ Zonal extent: Same as at Barrington, but the sequence is not completely exposed. The Cheddar Gorge displays the Seminula- Zone ending in J), ; there are numerous exposures in the Zaphrentis- Zone (both Z, and Z,) between the Gorge and Charterhouse. (c) Emborough. Specimens collected by Prof. $8. H. Reynolds and Mr. T. F. Sibly point clearly to the presence of a normal D, facies in the Mendip development.” Interruptions of faunal sequence by dolomites or grits: practically none. Hence the prolific fauna of the Syringothyris- and lowest Seminula-Beds is in striking contrast to its rarity in the Bristol area. Correlation of the Mendip and Bristol Areas. So closely does the faunal sequence in the two areas agree, that it is only by dint of detailed study that the small differences become apparent. The following points of resemblance, selected from a very long list, will serve to give an idea of the practical identity of the 1 This section has been more recently examined in great detail by Mr, T. FB. Sibly, and his results are published in the Proceedings of the Bristol Naturalists’ Society, ser. 4, vol. i, pt. i, p. 14. 2 The detailed examination of the Carboniferous Limestone throughout the Mendip area is being undertaken by Mr. T. F. Sibly, and to him I am indebted for several of the facts stated below. Vol. 61,] SEQUENCE IN THE BRISTOL AREA. 249 sequence in the two areas. All the statements refer equally to either area. 1. Zi, Ss) Ore *Géologie de la Belgique’ vols. i & ii (1880-81). ‘Prodréme d’une Description géologique de la Belgique’ 2nd ed. (1880) chap. vi. 3 Nol..6r. | SEQUENCE IN THE BRISTOL AREA. 257 Asstsr II. No fossils cited. Asstsp IIL. Orthis resupinata. Correlation: Z, (lower part). AsstsELV. Spurifer cuspidatus. Prof. Dewalque mentions the occurrence of Ampleaus coralloides in the lower part. Correlation: Z, (upper part): y; lower part of C. AssisE V. Large Huomphali. Correlation: top of C and 6 (the Bellerophon-Beds, in which large Huomphah are common). Asstsp VI. Productus Cora and Pr. giganteus. Correlation: § and D. It is interesting to note that all the brachiopods mentioned by M. Mourlon and Prof. Dewalque occur in the same order in the Bristol area as in Belgium, and that they are correspondingly characteristic of the beds. C. The Parallelism of the Bristol and Belgian Sequence, by Prof. Max. Lohest.* Paleontologically.—The conclusion that the general resem- blance is complete rests on the occurrence at the same broad levels of the following fossils :—Small Rhynchonellw in M; Sp. tornacensis in K (Prof. Lohest comments on the absence of Spiriferina octoplicata in K, but this is, of course, a mistake); teeth of fishesin Z; Productus Cora and Pr. giganteus in 8 and D. Lithologically.—The writer cites the encrinital character of the Tournaisian, but comments on the absence of cherts from the Upper Tournaisian (Zaphrentis-zone). In the Viséan he states that the Avon section is continuously oolitic, and comments on the absence of compact dark limestones.” The amount of similarity expressed by the above facts seems scarcely to warrant his conclusion. To sum up the comparison :—Such facts regarding the Belgian sequence as I have been able to quote are in agreement with the sequence as here set out for the Bristol area; but the fauna is too scanty to allow of close correlation. VI. Summary anp ANALYSIS. The faunal sequence in the Bristol area is summed up in the table of ranges and maxima (pp. 243-247) and in the two range- diagrams (Pls. XXVIII & XXIX, facing pp. 244 & 246). These diagrams depict the rise and decline of each species-group, and the positions at which its mutations are most abundant. ‘To a ' Ann. Soe. géol. Belg. vol. xxii (1894-95) Mém. p. 7. 2 The lithological character of the Viséan in the Avon section is erroneously described, as dark compact limestones form there a very characteristic feature of the Seminula-Zone. 258 DR, A. VAUGHAN ON THE PALMONTOLOGICAL [| May 1905, first approximation, it has been demonstrated, beyond all question, that the relative position of the various groups is constant throughout the whole of the Bristol area: that is, that the species succeed each other always in the same order, This statement holds true to a much higher degree of approxi- mation, when we consider the corals alone, or the brachiopods alone. In fact, the only deviations from absolute constancy in this case consist in displacements in the positions of the maxima, as we pass ‘from one point of the area to another. When, however, we measure the relative position of the corals by the brachiopod- sequence, or vice versa, there is a more important deviation which, although unimportant in a small area, would, if continued in the same sense to a considerable distance, need to be carefully allowed for. We can therefore obtain a second approximation which shall hold true at considerable distances, by leaving the relative suc- cession of the brachiopods unaltered, as also the relative succession of the corals, but by slightly displacing the one class relatively to the other. Very much more work must, however, be done in the Bristol and neighbouring areas (for example, in the Mendips and in South Wales) before the exact law of relative acceleration can be fixed. In so far as the Bristol area is concerned, the table of ranges is sufficient to enable any worker to determine the horizon of any exposure which lies within the area, to a considerable degree of accuracy. If he registers all the fossils that he sees, and also notes their absolute and relative abundance, he will have no difficulty in determining, from the diagrams, the approximate horizon at which the exposure lies. I have tested this over and over again, and the results have always agreed with the position of the exposure as determined by stratigraphical reasoning (whenever such reasoning was possible). Before studying the neighbouring areas, I claimed that the main object of my prolonged work was to this extent achieved, that any fossiliferous exposure, lying within the Bristol area, could be horizoned to an adequate degree of approximation by the use of the range-tables ; and I now go farther, and claim that the sequence established for the Bristol area holds good throughout the South-West of England and in South Wales. Analysis of the Faunal Characters of the Zones and Subzones. The Modiola-Zone. This zone is a pre-Cleistopora-Zone, in which the typical Cleisto- pora-fauna makes its entry, but in which this fauna is as yet very incompletely represented. The occurrence of Modiola-like forms — associated with ostracods and Spirorbis does not in itself indicate any particular horizon, but rather marks a phase of sedimentation. The same association is to be found at several horizons in the Carboniferous Limestone of the neighbouring areas: for example, bo Vol. 61. | SEQUENCE IN THE BRISTOL AREA. 259 in K, and again in 8. But it is a very suggestive fact that the transition from the Upper Old Red Sandstone into the Carboniferous Limestone, whenever that transition is continuous, is in the Bristol and surrounding areas always accompanied by this faunal phase. So far as I am capable of judging, the Modiola-like form which occurs in 8, is quite distinct from J. lata; but,on the other hand, I cannot distinguish the form which occurs in K, from the index- form of the Modiola-Zone. Hence, it must be confessed that the Modiola-Zone is not yet satisfactorily separated from the succeeding zone by the presence of distinct forms, but 1s merely an earlier series of beds in which the Cletstopora-fauna makes its entrance. I do not, however, think that the Modiola-Zone should on this account be merged in the succeeding zone; for the Rhynchonellids are, at least in the Avon section, distinct from those occurring in the Cleistopora-Zone. It is also probable that some one among the numerous small gasteropods, which are so characteristic of these early beds, may ultimately afford a good zonal index. The Cleistopora-Zone. Whenever corals can be found, this zone is distinctly separated off from the Zaphrentis-Zone above by the presence of Cleistopora and the absence of Zaphrentis. To a certain extent, however, this separation is a mere matter of definition. It rests upon the fact that directly the early Zaphrentis-fauna is fully established, Za- phrentis is found and Cleistopora is absent; but a sharp separation of the two zones is impossible, for, throughout the upper part of the Cleistopora-Zone, the brachiopods characteristic of the lower Zaphrentis-ZLone enter one by one, and become gradually and continuously commoner. Hence, from a purely-paleeontological point of view, the separation of the ‘ Lower Limestone-Shales’ is a complete impossibility. The faunal facies of the included limestones, at the top of the ‘shales,’ is practically identical with that of the lowest beds. of the massive Limestone-Series, and the faunal continuity from the one into the other is perfect. Furthermore, the small variations at different points of the area in the faunal contents of the lowest beds of the massive Limestone-Series indicates that the junction of shales and limestone is not exactly at the same horizon throughout the area. The bassus- and octoplicata-subzones, These two subzones are the expression of an important change of facies. The bassus-subzone contains :— (1) Representatives of the earlier Modiola-fauna: for example, the same type of Retzid and the same form of Cliothyris Royssu. (2) Characteristic forms, such as Productus bassus, Chonetes * Buchiana,’ (3) A characteristic fish-fauna (see above, p. 253). 260 DR. A. VAUGHAN ON THE PALHONTOLOGICAL [May £905, The index-fossil is subject to small geographical variation, but is widely distributed (Bristol, Mendips, Forest of Dean, Tenby), and I have not myself found it outside its own subzone. The octoplicata-subzone contains :— (1) The early representatives of the Zaphrentis-fauna, which become more and more numerous in species and indi- viduals, until at Horizon 8 a characteristic Zaphrentis- facies is developed. (2) Very few characteristic forms ; the maxima of Cleistopora and of Spiriferina octoplicata, however, fall within this subzone. The Zaphrentis-Zone. This zone witnesses faunal changes of the greatest importance. (1) At the base Zaphrentids enter; in the upper part the typical Zaphrentis-group becomes the dominant faunal factor; and at the very top of the zone the Cannia- group is evolved from a Zaphrentis-ancestor. (2) This zone includes the maximum development of the Orthids. (3) Starting with the maximum of Spercfer, it ends with that of Syringothyris. (4) The zone witnesses the mutational change of the small Productus cf. Martint into the typical Pr. semireticulatus, (5) At the top of the zone, Chonetes papihonacea supplants Ch. cf. hardrensis as the dominant Chonetes. (6) A characteristic fish-fauna is developed (see above, p. 253). The clathratus- and resupinata-subzones. Whereas the clathratus-subzone exhibits a direct continuity and expansion of the Cleistopora-fauna, the resupinata-sub- zone witnesses the introduction of the laminosa-fauna (Caninia, Syringothyris aff. laminosa). The resupinata-subzone is well cha- racterized by containing the maxima of Zaphrentis, Schizophoria resupinata, and Chothyris glabristria. The Caninia-Zone. If we adhere to a coral-basis for zonal division, Caninia is the only possible index that can be selected to succeed that of Zaphrentis; and, although I have ultimately decided to relegate this index to a secondary place, it has undoubtedly a very considerable value, both from the point of view of field-work and from an evolutionary standpoint. The displacement of Canina is based on the following con- siderations :— (1) When measured against the brachiopod-progression, the range of Caninia does not cover the same terms at different points of the Bristol area, as already pointed out (p. 185). Vol. 61. ] SEQUENCE IN THE BRISTOL AREA, 261 (2) If we take the limits of the Caninia-Zone to be defined by the two maxima of the gens C. cylindrica in the Avon section, the lower part of the zone contains a fauna which is characteristically Tournaisian, while the upper part exhibits a typically Viséan facies.+ The Caninia-Zone has consequently been divided into a lower subzone, the Syringothyris-Zone, which forms the top of the Tour- naisian ; and an upper subzone, which forms the base of the Viséan and is included in the Seminula-Zone, of which it forms the base. The Syringothyris-Zone. This zone is characterized by the dying-out of the Tournaisian fauna and the evolution of the Viséan. Examples: (1) Orthotetes crenistria occurs in profusion, as it does throughout the Tournaisian, but is associated with abundant Chonetes papilionacea. (2) Camnia cylindrica, which is enormously abundant at the base, gives rise by mutational change to the earliest member of the gens of Cyathophyllum Murchisoni (namely, Cyathuphyllum ¢). (3) Productus Cora becomes more abundant, and Seminula appears for the first time. (4) The earliest forms of Lthostrotion and of the Clisiophyllids occur very sparingly. The zone is further characterized by the dominance of Syrigo- thyris, which is represented by typical forms of S. cuspidata and S. aff. laminosa. The Seminula-Zone. The abundance in individuals of Lithostrotion, Seminula, and giganteid Productus may be said to typify the Viséan facies. The Semimula-Zone is characterized by recurring layers, made up almost entirely of the shells of Seminula. This zone is naturally divided into two subzones :— The lower subzone or semireticulatus-subzone, in which the Seminula-fauna contains a few survivors of the Tour- naisian facies, such as Oaninia, Syringothyris, Productus seni- reticulatus. The upper subzone or Cora-subzone, in which the Dibunophyllum-fauna is making its appearance. This subzone is characterized by the occurrence of a particular mutation of the gens of Productus Cora. The Dibunophyllum-Zone. This zone is one of the easiest to distinguish, on account of its characteristic coral-fauna. The attempt to separate an ‘ Upper Limestone-Shale’ division, starting at the point where shales become prevalent in the Avon 1 To avoid any interruption of the zonal discussion, the distinctness of these two faunas is demonstrated in a separate note. Gee G. on Non242, T 262 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, section, is, from a paleontological point of view, indefensible, for the following reasons :— (1) At the point where the shales start the Didwnophyliuwm-fauna is already well established, and the limestone-bands included in the shales contain a fauna which is indistinguishable from that in the topmost beds of the under- lying massive Limestone-Series. (2) In many localities the whole series is composed of massive limestones (for example, Tenby, the Mendips). The essential fact in the Dibunophyllum-facies is the dominance of the Clisiophyllid-family, and the ultimate impression of a Clisiophyllidan character upon the whole of the coral-fauna. The 0¢ and Lonsdalia-Subzones. The 0¢-subzone is characterized by Clisiophyllids belonging to several sections ; the subzonal index itself represents a generalized division of the gens of Dibunophyllum turbinatum. This subzone contains the maximum of Cyathophyllum Murchisona in its type-form. In this form the Zaphrentid characters, which were so noticeable a feature of the early Cyathophylla (Cyatho- phyllum o, C, and §,), have, in the Dibunophyllum-Zone, become almost entirely lost. In the Lonsdalia-Subzone the acme of the Clisiophyllidan phase of structure is reached. Lithostrotion which, up to this subzone, forms the staple element in the Viséan coral-fauna, gradually adopts the Clisiophyllidan character and becomes merged in Lonsdaha. Cyathophylla of the type of Cyathophyllum Murchisoni, yielding to the same tendency, evolve forms of the type of C. reqiuwm. The gens of Dibunophyllum turbinatum reaches its maximum specialization in the group represented by Dibunophyllum w. Horizon e. This horizon is well characterized by a group of scabriculate and spinose Producti (Pr. cf. costatus and Pr. cf. semwreticulatus), and contains the remnants of a Carboniferous-Limestone facies in the presence of Orthotetes crenistria and Productus Cora (mut.). The horizon being represented in widely-distant areas, and being the highest horizon at which a Carboniferous-Limestone fauna. is found, forms a valuable datum-line for fixing the uppermost limit of the Carboniferous Limestone. The ‘ Millstone-Grit.’ The base of this lithological division is, as I have shown, a variable horizon. At Kidwelly it occurs immediately above Horizon e; at Bristol it occurs immediately above D,, so that Horizon ¢ is included in the ‘ Millstone-Grit’; at Mitcheldean it Roly or. SEQUENCE IN THE BRISTOL AREA, 263 occurs in S,; and at Clee Hill it occurs soon after the close of the Tournaisian. Notes on the Distinctness of the Tournaisian and Viséan Faunas, tested by the Sequence in the Bristol Area. The following genera of corals occur in the Tournaisian, but do not extend into the Viséan :—Cleistopora aud Zaphrentis. The following brachiopod-groups are confined to the Tour- naisian :— Productus cf. Martini. | Camarotechia mitcheldeanensis. Chonetes ct. crassistria. Humetria spp. Chonetes cf. laguessiana. _ Spirifer aff. clathratus. Leptena analoqa. Spiriferina octoplicata. Schizophoria resupinata. Syringothyris cuspidata. Rhipidomella aft. Michelini. Cliothyris glabristria.' The following coral-groups are confined to the Viséan :— Alveolites septosa. | Cyathophyllum Murchisoni (type). * Tithostrotion (all species). | Cyathophylliun regiwm. 2 The family of the Clisiophyllids |. (including Lonsdalia). | The great brachiopod-group of the giganteid Producti is prac- tically confined to the Viséan (a few early forms. of Productus Cora are met with below). The following genera and gentes of corals pass up from the ‘Tournaisian into the Viséan :— Syringopora: the only common Tournaisian circulus is Syringopora 0; the circuli in the Viséan are of ramulose and geniculate types. Michelinia: in the Bristol area I only know this genus in the Upper Tour- naisian ; it may extend into the base of the Viséan, where it is certainly rare. Caninia cylindrica: by its mutations this gens undoubtedly links the Upper Tournaisian with the base of the Viséan, and, on this fact, the Caninia- Zone was originally founded. Amplexus is essentially characteristic of the Upper Tournaisian, but probably extends, with Caninia, into the bottom of the Viséan. Cyathophylium @ is characteristic of the very top of the Tournaisian and of the base of the Viséan. The following genera and gentes of brachiopods pass up from the Tournaisian into the Viséan :— Productus semireticulatus: this gens, by its mutations, constitutes a genuine link between the two divisions. Chonetes papilionacea may be defined as a Viséan form, which has already become important in the Upper Tournaisian. Orthotetes crenistria is also a link of great importance; but, whereas it is enormously abundant throughout the Tournaisian, it is rare in the Viséan. Seminula is an essentially-Viséan genus, and is only found rarely at the very top of the Tournaisian. 1 See note under Cliothyris glabristria, p. 298. 2 Very few early forms have been found in C, tr 2 264 DR. A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, Cliothyris: it is doubtful whether the form found in §, really belongs to this genus. Syringothyris aff. laminosa is found rarely in §,, but is essentially character- istic of the top of the Tournaisian. From the foregoing analysis, it seems to me beyond question that, in the Bristol area, the division of the Carboniferous Limestone into an upper anda lower part is thoroughly justified on purely-paleonto- logical grounds, and is also of great practical utility. In recognition of the great amount of exact work done by Belgian geologists, in elucidating the paleontological sequence in the Carboniferous Lime- stone of their own country, we are, I think, bound to accept the names which they have adopted for the two divisions. On the other hand, the designation Dinantian, as including the whole of the Carboniferous Limestone, seems hardlly justified by the continuity or clearness of the sequence in the district which has suggested the title. It cannot, however, be denied that it would be extremely convenient to have a single designation (other than a misleading lithological term) which should include the ‘ Lower Limestone-Shales’ at the base and the ‘ Upper Limestone-Shales ’ at the top, as well as the main mass of limestone. [As I have pointed out above, the detailed examination of the faunal sequence in the Bristol area demands that the division-line between a lower series (Tournaisian) and an upper (Viséan) should be drawn at the top of the Syringothyris-Zone. But, if | am correct in correlating the Lower Viséan of the Belgian Geological Survey with the Syringothyris-Zone of the Bristol area, the terms Tournaisian and Viséan, as employed by me in this paper, do not bear their original connotation: the zone C being included in the Viséan by Belgian geologists, and in the Tournaisian on my system. Under these circumstances, it seems better to avoid all chance of confusion by employing new indices for the whole of the Carboni- ferous-Limestone Series as developed in the South-West of England and in South Wales, as well as for its two great divisions. I consequently suggest the following classification :— ! Dibunophyllum. KIDWELLIAN = eee | AVONIAN ...... Syringothyris. CLEVEDONIAN ... ) Zaphrentis. Cleistopora. Avonian, as synonymous with Lower Carboniferous, seems warranted by the completeness of the sequence in the Avon section (Bristol) and by the fact that the Avon Gorge has been recognized as a Classical section, since its minute description in Trans. Geol. Soc. ser. 1, vol. iv (1811-17) p. 197 & vol. v (1818-21) p. 95, by George Cumberland. Clevedonian satisfactorily connotes the Lower Avonian, since, in the neighbourhood of Clevedon (Somerset) :— (1) The zones of Cleistopora, Zaphrentis, and Syringothyris are all well- displayed ; and (2) The Upper Avonian is practically absent. e Wol, or. | SEQUENCE IN THE BRISTOL AREA. 265 Kidwellian is suggested * as the index of the Upper Avonian, since, in the neighbourhood of Kidwelly (Caermarthen) :— (1) The Lower Avonian appears to be very incompletely developed ; (2) The Seminula- and Dibunophylluwm-Zones are magnificently displayed.—A. V., April 8th, 1905.) Epitome of Conclusions. 1. The faunal sequence is constant throughout the extended area in the South-West of England and South Wales. 2. The study of the fauna affords clear evidence of evolution. 3. The Tournaisian and Viséan facies are essentially distinct. 4. The separation of a ‘ Lower Limestone-Shale’ Series at the base, and an ‘ Upper Limstone-Shale’ Series at the top, is opposed to the paleontological evidence. 5. The base of the ‘ Millstone-Grit’ is not a definite level, but occurs at different levels in the Viséan in different localities. 6. The transition of the Upper Old Red Sandstone into the Car- boniferous Limestone, where perfectly continuous, was accompanied by a particular faunal phase. I owe so much to the kindness of other geologists, who have so readily helped me during my work, that an adequate acknow- ledgment is entirely out of the question. My thanks are due to Dr. A. Smith Woodward, Dr. F. A. Bather, and Mr. Lang, at the Natural History Museum; to Mr. E. T. Newton, Mr. J. Allen Howe, and Mr. H. A. Allen, at the Museum of Practical Geology ; and to Mr, H. Bolton, at the Bristol Museum, for the great assistance which they have given me during my work at the collections housed in their respective institutions. Also to Mr. H. C. Piayne for permission to examine the Clifton-College collection ; and to Prof. 8. H. Reynolds for much assistance during my work at the Stoddart Collection, preserved in University College, Bristol. I have also to thank Dr. Bather for naming crinoids, Mr. Lang for great assistance with the bryozoans, Dr. Wheelton Hind for naming my lamellibranchs, and Mr. J. F. Walker for very generously assisting me in brachiopod work by the loan of papers and specimens. To Prof. Lloyd Morgan I am indebted for much valuable in- formation, and above all for his unwearying appreciation and encouragement, I have to thank Mr. E. Dixon for his invaluable help during my visit to the Kidwelly and Tenby areas. To Prof. 8. H. Reynolds I am under a deep obligation for his continuous help, and in particular for his very valuable assistance in the examination of the Sodbury section. 1 The final acceptance of this index-term must, however, await the detailed results of the present re-survey of the Kidwelly area by the officers of H.M. Geological Survey. 266 DR. A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, To Mr. T. F. Sibly I am deeply indebted for continuous help in the field-work, and without his assistance the examination of the Bristol area would have been far less comprehensive than it is. I have to thank Mr. W. H. Wickes and Mr. L. Richardson for some of my finest specimens. To Mr. J. W. Tutcher I owe the excellent photographs (reproduced in Pls. XXIJI-XXV1I) illustrating this paper, to the preparation of which he has devoted so much care. Several of the photographed specimens belong to his fine collection. JT have also to thank the Director of H.M.Geological Survey and the Committee of the Bristol Museum, for permission to photograph specimens in the Jermyn-Street and Bristol Museums. T cannot sufficiently thank Mr. L. L. Belinfante, M.Sc., for the very great trouble which he has taken in editing an extremely- technical paper. VII. Norrs on tHe Cornats AND BRACHIOPODS REFERRED TO IN THE Faunat Lists. The object of these notes is merely to explain the faunal lists, by indicating the interpretation which I intend each name to bear. For this purpose, no historical research into the priority of names is necessary, nor is it absolutely essential that the names should cover the original type. So long as the explanation and references, here given, are sufficient to particularize the form which each name is intended to denote, my object will have been completely achieved. On the other hand, I have endeavoured to employ each name in what I believe to be the meaning attached to it by accepted authorities, so that reference to easily-accessible figures is, in most cases, sufficient. For example: Productus Cora is employed in the sense in which I believe it to have been used by Davidson, not- withstanding the fact that it is doubtful whether the original type of the species is very closely allied to the forms here intended. In the case of important stratigraphical forms which only bear a limited resemblance to forms already figured, I have merely indexed. the forms by the addition of the letters 6, ¢, W to the generic name. This method has the advantage of conveying definite information, without asserting relationship to somewhat similar forms the position of which, on the chronological scale, is at present unknown. Should both the Bristol form and the one already figured, to which it bears a certain resemblance, be found, later, to occupy the same chronological position, it will be rendered probable that both are mere local variants of the same gens, and they can then receive the same name. I have followed the same plan in cases where I consider that very distinct forms have been included under the same name, and where I wish to indicate only one of the forms so included. Vol. 61. ] SEQUENCE IN THE BRISTOL AREA. 267 (1) Notes on tHE Corts. Introductory Explanation. For the determination of the corals, horizontal sections are indispensable, but the nature of the vertical section can usually be deduced from an examination of the horizontal section. Calicular views are of far less value, because they are rarely met with in the field, and, when seen, are as a rule partly obscured by matrix, or destroyed by weathering; they also give a misleading idea of the internal structure, both by exaggerating the relative importance of the secondary series of septa and by disguising that of the tabule. The horizontal sections figured in Pls. XXII-— XXIV are photographed from thin slices by Mr. J. W. Tutcher, by a process which he has himself invented. The full titles of the works, referred to in these notes, are as follows :— Micueuty, H.: ‘ Iconographie Zoophytologique.’ 1840-1847. M‘Coy, F.: ‘Synopsis of the Characters of the Carboniferous-Limestone Fossils of Ireland.’ Dublin, 1844. Folio. M‘Coy, F.: ‘Systematic Description of the British Paleozoic Fossils in the Geological Museum of the University of Cambridge.’ 1851. Miuye-Hpwarps, A., & Haimn, Jutzs: ‘ Monographie des Polypiers fossiles des Terrains Paleeozoiques’ [ex Arch. Mus. Hist. Nat. vol. v]. 1851. Mitnz-Epwarps, A., & Haine, Jutus: ‘Monograph of the British Fossil Corals’ pt. iii (1852) pp. 150 e¢ segg. Paleontographical Society. Tromson, JAMES: ‘On the Development & Generic Relation of the Corals of the Carboniferous System of Scotland’ Proc. Phil. Soe. Glasgow, vol. xiv (1883) p. 296; and earlier papers of the same author, in the same Proceedings. Vaucuan, Arruur: ‘ Notes on the Corals & Brachiopods obtained from the Avon Section & preserved in the Stoddart Collection’ Proc. Bristol Nat. Soc. n.s. vol. x (1903) p. 90. See also the general introductory remarks on p. 266. Alveolites. ALVEOLITES SEPTOSA (I'lem.). Here I include :— A, septosa, Hdwards & Haime, ‘ Monogr, Brit. Foss. Cor.’ p. 157 & pl. xlv, figs. 5-5 6, — A, depressa, Edwards & Haime, ibid. p. 158 & pl. xlv, figs. 4-4. The relation of these forms is discussed in Proc. Bristol Nat. Soc. n. 8. vol. x (1903) p. 95. Syringopora. It is very doubtful whether the so-termed ‘ species’ of this genus are anything more than circuli. SYRINGOPORA Cf. DISTANS, Fischer. As interpreted in Edwards & Haime, ‘ Polypiers Foss. Paléoz.’ p. 286 & pl. xx, fig. 1. See also Proc. Bristol Nat. Soc. n. s. vol. x (1903) p. 98. 268 DR, A. VAUGHAN ON THE PALHONTOLOGICAL [May 1905, The Bristol forms which I include here have the following characters :— The tubes are moderately spaced, and have a general parallel trend, but are subramuiose at considerable intervals. Horizontal Section.—Moderately-spaced single rings and dumbbell-like pairs are almost equally numerous ; elongated inter- sections are rare. Range.—Throughout the Viséan. SyRrineopora cf. genicuLaTA, Phill. . As interpreted in Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. ii, p. 168 & pl. xlvi, figs. 2-2 a. Tubes closely packed and parallel; connectors very numerous. Horizontal Section.—Closely-placed rings, the majority of which are connected. Range.—lI only know the typical form from D.. SyrineoPora cf, RamuLosA, Goldf. As interpreted in Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. i, p. 161 & pl. xlvi, figs. 3-3 ¢. Tubes greatly spaced and strongly flexed; the connectors are of equal diameter with the tubes. The Bristol form has narrow tubes. Horizontal Section.—The intersections are very sparsely distributed, and elongated intersections are frequent. Range.—lI only know this form with certainty from $. Syringopora 6. (Pl. XXII, figs. 1 Gla.) (Cf. S. laxa, Phill.) Corallites cylindrical, and arranged in parallel grouping. Con- necting-tubes distant. Geniculation scarcely noticeable at the junctions of the corallites with the connecting-tubes. Tabule distant and funnel-shaped. In a horizontal section, only a few of the cross-sections are connected, and there is seldom more than one oval tabular inter- section, within the cross-section of a corallite. Diameter of corallites=2to 24 millimetres. The distance between the axes of adjacent corallites averages 4mm.; the distance apart of connecting-tubes averages 10 mm. - Syrineorora ef. RETIcULATA, Goldf. Tubes very narrow, parallel, and close-set. Horizontal Section.—The frequent grouping of four or five tubes, in such a manner that their cross-sections form short chains, produces a marked Halysites-like appearance. Range.—This form is highly characteristic of C,. Cleistopora. Creistopora aff. ceomerrica (Edwards & Haime). As interpreted in Vaughan, Proc. Bristol Nat. Soc. n.s. vol, x (1903) p pp. 99- 100 & pl. 1, fig. 3. Vol. 61. | SEQUENCE IN THE BRISTOL ARHA,. 269 Michelinia. The reference of specimens to particular species can only be approximate, since the characters of the base are seldom seen. I have consequently, in most cases, contented myself with recording the genus. ; Micueninia cf. ravosa (Goldf.). As interpreted in Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. i, p. 154 & pl. xliv, figs. 2 6-2 ¢. Here may be placed the specimens from Z.. Micusrinia cf. tenvisepra (Phill.). As interpreted in Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. iii, p. 155 & pl. xliy, figs. 1-1 0. Here I include tall forms, composed of few corallites, with thin walls. 1 have only seen a few specimens from Z,. MicHELINIA MEGastoma (Phill.). As interpreted in Edwards & Haime, ‘ Monogr. Brit. Foss. Cor.’ pt. i, p. 156 & pl. xliy, figs. 3-3 6. Here [ include forms with thick walls and large corallites. This is probably the commonest species; it characterizes the top of Z, and the lower part of C. Amplexus. AMPLEXUs cf. CORALLOIDES, Sow. As interpreted in Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. 11, p. 173 & pl. xxxvi, figs. 1-1 e. I include here all the large cylindrical forms of the genus. Zaphrentis (restricted). = Zaphrentis as employed by Edwards & Haime, with the omission of tho group of Z. cylindrica, which is here referred to Caninia. ZaPHRENtIS aff. Parties, Edwards & Haime. (Pl. XXII, figs. 2- 2e & text-fig. 2, p. 270.) Ineludes :— ( Zaphrentis Phillipsi, Edwards & Haime, ‘ Monogr. Brit. Foss. Cor.’ pt. ii, p. 168 & pl. xxxiv, figs. 2-2 0. Laphrentis Griffithi, Edwards & Haime, ibid. p. 169 & pl. Xxxiv, figs. 3-3 a. Prox. Zaphrentis Phillipsi, Edwards & Haime, ‘ Polypiers Foss. Paléoz.’ p. 332 & pl. v, fig. 1. Non Zaphrentis Phillipsi, Thomson, Proc. Phil. Soc. Glasgow, vol. xiii (1881-82) p. 222 & pl. iv, figs. 3- 3a, Corallum small, conical, and usually curved. The length seldom reaches 3 centimetres, average specimens being under 2 cm. long. Epitheca thick, with strong ruge. Calyx very deep, with a thin margin. Primary septa strongly thickened at the wall and also at their inner ends, where they are attached to the tabule. 270 DR. A. VAUGHAN ON THE PALZONTOLOGICAL [| May 1905, The secondary septa are rudimentary, and are only represented, in a horizontal section, by a slight projection of the wall between ~ primary septa; they are, however, more conspicuous in the calyx. Grouping of the primary septa.—On each side of the fossula there is a lateral group, composed of from five to seven septa, which unite at their inner ends to form the walls of the fossula ; the remaining (thirteen to fifteen) septa form a nearly-continuous antifossular series. There is a single, long but thin, fossular septum. Septal breaks and fossula.—The fossula forms a conspicuous break between the two lateral groups. Between each lateral group and the antifossular group, there is usually a less-marked septal break indicated by :— (1) The stronger development of a Fig. 2.—A tabula of Zaphrentis secondary septum, which bends aff. Phillipsi, represented by round and- unites with the contours. : antifossular group. (2) The stronger development of the a.d two terminal septa of the anti- fossular group, which frequently join across the centre of the section, so as to bisect it. This feature is extremely marked in the very young stage, when the fossula is in- conspicuous. Ved eis yy There is, usually, some indica- tion of an antifossular septal break. - The tabula have a complex Posenlty flexure, but their essential cha- racter is that of a dome with a.d, = Antifossular depression. | four grooves down its sides, as i.d. = Lateral depression. represented in the accompanying contoured diagram (fig. 2). Discussion.—The original figure of Zaphrentis Phillipsi in the ‘Polypiers Foss. Paléoz.’ pl. v, fig. 1, differs from the Bristol form in the presence of :— (1) More numerous septa, which are consequently less widely spaced. (2) Greater radial symmetry. (3) Indistinct lateral septal breaks. On the other hand, the description given in the ‘Monogr. Brit. Foss. Cor.’ pt. iii, was largely founded upon specimens in the Bristol Museum, which were derived from the Mendip area, and are quite typical Bristol forms. The authors attribute the differences between this form and their type to the suggestion that all the British specimens that they had examined were young forms. From the examination of thousands of specimens, I am, however, convinced that the above differences are constant, and represent true varia- tions of the adult stage. The position of the fossula is emphasized Woll 61x. | SEQUENCE IN THE BRISIOL AREA. 271 by Edwards & Haime as an important diagnostic character; but I have collected, from the same bed, specimens in which the fossula is as often on the short side of the horn as on the longer one: whereas, in all the specimens, the characters of the septa and tabulee are identical. Zaphrentis Griffitht agrees with our forms in all the essential characters of septal grouping and tabular flexure, and only differs in its short and broad form agd in its more numerous septa. Zaphrentis Phillips: (Edwards & Haime), Thomson, is illustrated by a very inadequate figure. From the author’s description, it is evident that the form with which he deals differs markedly from ours in the following characters :— The septa are thin, and pointed towards their inner ends. Three of the septa extend into the fossula, ef which the central one is considerably the shortest and not more than half a line in length. ZAPHRENTIS aff. cornucoprm (Mich.)," Edwards & Haime. (Pl. XXII, figs. 3-3 d.) Prox. Zaphrentis cornucopie, Edwards & Haime, ‘ Polypiers Foss. Paléoz. p. 331 & pl. v, figs. 4-4 a. Form: elongate, cornute. The average length is between 3 and 4 centimetres. Epitheca with indistinct rugee and a few distant constrictions. Calyx circular, deep and cup-shaped, with bevelled rim. Primary septa strongly thickened at the wall, 35 to 40 in number, close and very regularly spaced, so that the symmetry is strikingly radial. Secondary septa short and thick, just projecting beyond the thick wall. Wall dense and thick, being formed by the thickening of the ends of both series of septa. Septal breaks and fossula.—tThe only conspicuous break is the fossula, which extends from the centre to the wall of the coral, and is bounded by vertical walls; in cross-section, it is slit-like and typically keyhole-shaped. The fossula is open throughout its length, but, near the outer wall, it is constricted by the elongation of two secondary septa, which bend round and become united with its lateral walls; a single rudimentary primary septum projects for a very short distance into the fossula. The fossula is, in every specimen that I have seen, on the side of the longer curve of the horn. Two inconspicuous lateral breaks are usually indicated by the elongation and bending ef a secondary septum on each side. In the very young form, the structure approximates to that seen in Zaphrentis aff. Phillipsi; the horizontal section is bisected by the meeting of the two terminal septa of the antifossular group, 1 The figure given by Michelin, ‘Icon. Zooph.’ pl. lix, fig. 5, is characterized by Edwards & Haime (‘ Monogr. Brit. Foss. Cor.’ pt. iii, p. 167) as a very bad figure ; it agrees better, however, in elongated form, with the specimens common in the Bristol area than does the figure in the ‘ Polypiers Foss. Paléozoiques.’ s 272 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, while the fossula is less marked and is occupied by a prominent primary septum. The tabule are domes, with only one strong groove which forms the fossula. Discussion.—The species, as described and figured by Edwards & Haime, differs from our specimens in having (1) a short, broad-- angled form ; and (2) an oval calyx. It agrees, however, in all the essential characters of septal grouping and tabular flexure. Evolution and mutation.—From the characters of very young specimens, it is most probable that Zaphrentis att. cornucoprw was derived from an ancestor closely allied to Z. aff. Phillips: ; on the other hand, the radial symmetry of the septa and the flexure of the tabule indicate early Caninia-like characters. ‘These sugges- tions are in agreement with the time-range of Zaphrentis aff. cornucopie ; it makes its first appearance in Z,, after Z. aff. Phillapse was well established, and reaches its maximum at the top of Z,, where Caninia begins to appear; it dies out in the lower part of the Syringothyr is-Zone. Caninia, Michelin ; emended, M‘Coy, ‘ Brit. Paleeoz. Foss.’ p. 28. = Zaphrentis cylindrica and allies, Edwards & Haime, ‘ Monogr. Brit. Foss. Cor.’ pt. iii, p. 171. = Campophyllum, Thomson (non Hdwards & Haime), Proc. Phil. Soe. Glasgow, vol. xiv (1883) p. 375. = Caninia, Vaughan, Proce. Bristol Nat. Soc. n. s. vol. x (1903) p. 102. This genus resembles Zaphrentis in the well-developed fossula and the consequent axial symmetry. It differs from Zaphrentis in: (1) The predominance of the tabulate over the septate structure. (2) The insignificance of the outer wall and its replacement by a thick shell of vesicles. The genus Caninia was originally founded by Michelin to cover all corals having deep fossular depressions, the type being C. gigantea (in which were included both the Devonian and the Carboniferous forms). M‘Coy restricted the genus to its type-species, and re- defined it by the vesicular character of the wall. The differences of this genus from Campophyllum, Kdwards & Haime, and from the Carboniferous Cyathophylla will be noticed later (p. 276). These differences have already been discussed in Proc. Bristol Nat. Soc. n. s. vol. x (1903) pp. 102-108. CANINIA CYLINDRICA (Scouler). Siphonophyllia eg cylindrica, Scouler, in M‘Coy, ‘Syn. Carb. Limest. Foss. of Treland’ p. 187 & pl. xxvii, fig. 5. Zaphrentis cylindrica, Edwards & Haime, ‘ Polypiers Foss. Paléoz.’ p. 339. Caninia gigantea, M‘Coy, ‘ Brit. Paleoz. Foss.’ p. 89. Zaphrentis cylindrica, Kdwards & Haime, ‘ Monogr. Brit. Foss. Cor.’ pt. ii, p. 171 & pl. xxxv, figs. 1-1 0. (Y) Campophyllum Mur chisont, C. cylindricum, C. giganteum, Thomson, Proc. Phil. Soc. Glasgow, vol, xiv (1883) pp. 276, 377, 378 & pl. vu, figs. 4, 9, 11. ols 61, | SEQUENCE IN THE BRISTOL AREA. 273 The general characters of this species have been sufficiently described by previous writers, but the following notes are intro- duced to explain the mutational stages. The central portion of the calyx, at an adult stage of growth, is a broad, flat tabula, surrounded by a circular, moat-like groove; the wall of the calyx is very thick, and its inner face slopes down to the groove. The septa are numerous, and are strongly developed in the region of the groove; from this region they stretch inwards, along the face of the tabula, and outwards, along the sloping face of the wall. It is, as a rule, only in the immediate neighbourhood of the groove that the prolongations of the septa are sufficiently tall to reach from tabula to tabula, or from one layer of the vesicles, which form the inner surface of the wall, tothe next layer. Hence, the characters of a horizontal section are as follows :— The outermost vesicles of the thick wall usually show no septal projections, but these projections become longer and stronger as we pass inwards. : The septa usually are strongly thickened in the region of the groove, though not uniformly so all round the whole circumference, the septa in the neighbourhood of the fossula being always the most strongly thickened. ‘This phenomenon is probably connected with the fact that the tabule slope down to the fossula. The septa are cut off sharply where the plane of section cuts across a tabula. The interruptions of the septa, and the abrupt change from a thick septum to a thin one, are due to the fact that the plane of section, after cutting through one tabula, intersects the septa which lie on the next lower tabula. Mutational Forms. Mctation y. (Pl. XXIII, fig. 1.) This form is characterized by the slight extension of the septa over the vesicular wall, so that, in a horizontal section, the septa are only represented by short projections from the vesicles in this region. Moration §,. (Pl. XXITI, fig. 1a.) Caninia cylindrica, var. bristolensis, Vaughan, Proc. Bristol Nat. Soe. n. s. vol. x (1903) p. 103 & pl. i, fig. 4. _ Here, the septal prolongations are more strongly developed over the vesicular wall, so that, in a horizontal section, the external vesicular area is delicately radiated by continuous prolongations of the septa. There is also a greater development of vesicles in the interseptal spaces. In both these characters there is an approach towards a Cyatho- phyllidan structure, but the strong fossular depression, and the marked thickening of the septa in the middle of their length, separate this form as a true Caninia. 274 DR. A. VAUGHAN ON THE PALAONToLOGICAL [May 1905, The Carboniferous Cyathophylia. The characters of the typical members of this single, compre- hensive gens are as follows :— (1) Very numerous septa, alternately long and short. (2) All the septa are of nearly-equal thickness, and the thickness of each septum is almost uniform along its length. (3) The long septa reach nearly, or quite, to the centre; and all the septa extend to the wall. (4) In the external area, which is radiated by both series of septa, the inter- septal spaces are crowded with small vesicles. (5) In the medial area, which is radiated only by the long septa, the inter- septal spaces contain few vesicles. CyatHopHytium @. (Pl. XXITI, fig. 2.) This type may be considered to represent the Zaphrentis-like ancestor of the gens. Form: short, cornute, and broad-angled. The septa are of uniform thickness along their length, and only differ, one from the other, in being alternately long and short; they are considerably more wide-spaced than is the case in the more typical members of the gens. The long septa do not reach the centre, which is occupied solely by the broad tabule. There is a strongly-marked septal break at the fossula, which is occupied by a single, short septum; there is, also, a lateral inter- ruption of the septal sequence, marked out by the greater elonga- tion of one of the shorter septa. The interseptal vesicles are distributed, as in the typical members of the gens. The tabule are broad and vaulted, with a oe) and narrow depression which forms the fossula. CyatHopHytium ¢. (PI. XXIII, figs. 3-3 6.) = Cyathophyllum Stutchburyt, Hdwards & Haime (pars) ‘Monogr. Brit. Foss. Cor.’ pt. iii, p. 179. Besides the characters already noted as common to all the typical members of the gens, the following characters are important :— (1) In a vertical section : The tabule are low, broad plates, which occupy the whole region within the inner wall, but only the minority stretch continuously across from side to side ; the majority are merely very broad, low vesicles which overlap one another. In this respect, the vertical section differs from that of a Caninia. (2) In a horizontal section : The numerous interseptal vesicles in the medial area represent the intersection of the tabular vesicles by the plane of section. The centre is usually free of septa, and occupied only by a few curvilinear intersections with the tabular vesicles. In the adult, this area is very reduced in size by the extension of the long septa almost or quite to the centre ; but in the young form (see Pl. XXIII, fig. 3a) there is a broad, central tabular area, free of septa. The Vol. 61.| SEQUENCE IN THE BRISTOL AREA. 275 fossula is merely indicated as a narrow septal break, occupied by a single primary septum of shorter length than the others, and by the small, inward shift of the tabular intersections in that region (as in the representation, on a contoured map, of a valley in a hillside). The fossula is much more strongly marked in the young form. (3) External form: The general form is an elongated cone. The middle of the floor of the calyx is flat, in the few specimens in which I have been able to see this feature. Discussion.—Fig. 4, pl. xxxii, Edwards & Haime, ‘Monogr. brit. Foss. Cor.’ undoubtedly represents the species that I am here describing ; but, as I haveshown in Proc. Bristol Nat. Soc. n. s. vol. x (1903) pp. 110 et seqq., Cyathophyllum Stutchburyi, Edwards & Haime (as originally defined* by certain external characters), is identical with C. Murchison, Edwards & Haime. In their later work,” Edwards & Haime give an almost iden- tical definition of the species, although they draw attention to the vertical section, which almost certainly belongs to a specimen of Cyathophyllum ¢. They group, however, under C. Stutchburyi certain short, tur- binate forms, with a broad everted rim to the calyx. I have examined the vertical sections of similar forms, and I find that the central structure is purely vesicular, and agrees entirely with that characteristic of Cyathophyllum regiwm. These forms I have there- fore separated, as simple forms of C. regium. Under these circumstances, it does not seem possible to adopt C. Stuichburyi as the name of our species, and I have tentatively represented it by Cyathophyllum @. CyarHopHyLLumM Murcuison1, Edwards & Haime. Besides C. Murchisoni, as defined and figured by Edwards & Haime, ‘ Monogr. Brit. Foss. Cor.’ pt. 111 (1852) p. 178 & pl. xxxiii, figs. 3-36, I include here all those elongate specimens of C. Stutchburyt which have not an essentially-tabulate structure. The characters of this species that essentially distinguish it from Oyathophyllum », are the predominance of purely-vesicular structure in the central space and the extreme reduction of tabu- late structure. A full account of this species is given in Proc. Bristol Nat. Soc. n. s. vol. x (1903) pp. 110-14. CYATHOPHYLLUM REGIUM, Phil. I here include :— Cyathophyllum regium, Kdwards & Haime, ‘Monogr. Brit. Foss. Cor. pt. iii (1852) p. 180 & pl. xxxii, figs. 1-4. Cyathophyllum Stutchburyi, Edwards & Haime, ibid. pl. xxxi, figs. 1 & 1a. In Proc. Bristol Nat. Soc. n.s. vol. x (1903) pp. 114-15, I have given reasons for regarding the short, turbinate type of 1 ¢Polypiers Foss. Paléoz.’ 1851, p. 373. 2 ‘Monogr. Brit. Foss. Cor.’ pt. iti (1852) p. 179 & pl. xxxi, figs. 1-2 a. 276 DR. A. VAUGHAN ON THE PALMONTOLOGICAL [May 1905, Cyathophyllum, with broad everted rims, as the simple form of C. regiuum. The essential structure consists in the vaulted arrangement of fine vesicles in the central space, and in the absence of tabule. Evolution and Mutation of the Carboniferous Cyathophylla. All the forms that we have just considered constitute a single gens, in the exact sense in which that term is here employed. It seems probable that, at the top of Z, or in y, occurred the ancestral Zaphrentis-like fornt, from which Caninia, Lithostrotion, the Carboniferous Cyathophylla, and the Clisiophyllids were evolved. Cyathophyllum 6, from just below y, only differs from Zaphrentis in the development of a vesicular external area. The relationship of such a form to Zaphrentis aff. cornucopie is, in reality, very close; for, if a horizontal slice of Z. aff. cornucopie be examined under a microscope, the thick wall is seen to be veined by wavy, discrete, dark lines which run between the ends of adjacent septa, and the dense wall is due to the deposit of stereoplasma on each side of these dark lines. It is, then, possible that the dense wall of Zaphrentis aff, cornucopie differs from the vesicular one of Cyathophyllum 6, only in the amount of the deposit of stereoplasma. Cyathophyllum , which characterizes the Syringothyris-Zone and reaches its maximum at ¢, resembles Caninia in the character of its tabule. It is, therefore, an interesting instance of parallel _ development and cozeval assimilation. ) Cyathophyllum Murchisoni shows a further divergence from the simple tabulate structure. It reaches its maximum at the bottom of D,. In Cyathophyllum regium, which is confined to D,, the original tabulate structure is entirely lost, and the Clisiophyllidan tendency is exhibited in the vaulted layers of fine vesicles which occupy the central space. Campophyllum, Edwards & Haime (non Thomson). This genus is distinguished from Caninia by the following characters :— (1) Almost perfect radial symmetry, due to the uniformly-developed ring of short, thick septa. : (2) The absence, or very feeble development, of a fossular depression. (3) The uniformly-thick shell of vesicles between the two walls. (4) The strongly-developed outer wall. [See also Proc. Bristol Nat. Soc. vol. x (1903) p. 102.] Campopayiium aff. Murcnisoni, Edwards & Haime. I here include, tentatively :— (1) Campophyllum Murchisoni, Kdwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. 111 (1852) p. 184 & pl. xxxvi, figs. 2, 2a, 3. (2) Campophyllum aff. Murchisont, Vaughan, Proce. Bristol Nat. Soc. n. s. vol. x (1903) p. 116 & pl. i, fig. 5. Jt will be safer to wait for more material, before attempting to Vol. 61.] SEQUENCE IN THE BRISTOL AREA. 277 separate the different forms which I have tentatively referred to this group. All the specimens that I have collected occur in the Dibunophyllum-Zone. Form (1) has a narrow external area, of a Lzthostrotion-type of structure. Form (2) is characterized by strong rugs and a thick outer wall; the septal ring is separated from the outer wall by very large vesicles. The septa are well spaced. Lithostrotion. Until a very much larger series of accurately-horizoned specimens has been collected and studied, it will be vain to attempt a natural classification of this group founded upon true evolutionary modi- fication. I have, consequently, adhered, as closely as possible, to the artificial system of species recognized by Edwards & Haime in their ‘ Monograph of the British Fossil Corals.’ It is, however, important to draw attention to the principal modifications which affect the typical Lithostrotion-structure. The typical Lithostrotion-structure may be defined as follows :— (1) Well-spaced, alternate septa, all of which extend to the wall; all the septa are of nearly-equal thickness, and each septum varies very little in thickness along its length. (2) An external vesicular area in a horizontal section. This area forms a ring, of uniform width, within the wall; it is radiated by both series of septa, and the interseptal spaces are each occupied by one or more vesicles ; the inner boundary forms the inner wall of the corallite. (3) The tabula are conical or gently dome-shaped, without any definite fossular depression ; the septa extend inwards, for a greater or less distance, along the upper faces of the tabule. (4) From the centre of each tabula, an erect, laterally-compressed columella projects upward, and usually reaches the tabula immediately above. The following are the most important structural modifications :— (1) Diphyphyllidan modification. The columella is either absent, or does not stretch from tabula to tabula. ‘This type of structure is always associated with very broad, flattened tabule. It is common in the group of Lithostrotion Martin, but is extremely rare in LZ. wregulare and throughout the Nematophyllum-section. In this modification, the septa stop well short of the centre. (2) Koninckophyllidan modification (compare the structure of Koninckophyllum 0, Pl. XXIII, fig. 4). The external vesicular area is very broad, and the interseptal spaces are crowded with small vesicles. Lithostrotion affine and the whole Nematophyllum-section are examples of this type of structure. (3) Clisiophyllidan modification. (Pl. XXIII, fig. 5.) In a horizontal section, the central area shows the characteristic spider-web structure. This type of structure results from the shape of the tabule, which are strongly conical and radiated by a regular series of lamelle. ? Q.J.G.8. No. 242. U 278 DR. A. VAUGHAN ON THE PALZONTOLOGICAL [May 1905, The figure illustrates a Lithostrotion characteristic of the Dobuno- phyllum-Zone ; this form resembles ZL. aregulare in its external characters. L. irvegulare and the members of the greup of L. Portlocky show a simple type of Clisiophyllid-structure. In a horizontal-section of any of these forms, a few of the larger septa are seen to extend to the thick columella, and they are crossed, in the central area, by two or three tabular intersections. (4) Lonsdalia-like modification. The septa are inconspicuous near the wall, and there is a peri- pheral area which is almost entirely vesicular. This type of structure is often partly developed in the typical Inthostrotion Portlocki, but is especially characteristic of its variety, L. ensifer, in which the walls themselves are feebly developed. Notes on the Species recorded in the Stratigraphical Portion of this Paper. The Siphonodendron-Section. Corallites cylindrical ; growth dendroid. Lrrnostrorron Martini, Edwards & Haime. Here I include :— Lithostrotion Martini, Edwards & Haime, ‘Monogr. Brit, Foss. Cor.’ pt. iii (1852) p. 197 & pl. xl, figs. 2-29. Ii. Phillipsi, Kdwards & Haime, ibid. p. 201 & pl. xxxix, figs. 3-3 Gl. Diphyphyllum tateseptatum, M*‘Coy, ‘Brit. Paleoz. Foss.’ 1851, p. 88 & pl. iti, figs. 10-104. The principal characters are as flows: — (1) The presence (except in D. lateseptatum) of a distinct columella, not specially thickened. (2) Broad, nearly-flat tabule. (3) The larger septa fall short of the columella, leaving a free space round it. : (4) A small number of vesicles occurs in an interseptal space of the external area. There is great variation in :— (1) The diameter of the corallite, which varies, in specimens occurring at the same horizon, from 6 to 11 millimetres. (2) The grouping of the corallites—The same mass is often, in. parts, extremely flexuous and coalescent (when it is usually named Lethostrotion Phillipsi); while, in other parts, the corallites are almost parallel. (3) The number of vesicles in the interseptal spaces of the external area.—This depends, mainly, upon the size of the corallites; a radial row of three or four vesicles may be regarded as the ‘usual type, but in the smaller forms this number may be reduced to one only. Vol. 61.1] SEQUENCE IN THE BRISTOL AREA. 279 LirHostRotioN IRREGULARE (Phill.). Here I include :— Lithostrotion irregulare, Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. i (1852) p. 198 & pl. xh, figs. 1-1 e. Petalaxis Portlocki, HKdwards & Haime, did. p. 204 & pl. xxxviii, figs. 4-4 a. I include the last-named coral, on the evidence of specimens which appear to be merely forms wherein the corallites of Zitho- strotion irregulare are very closely packed. Since it is customary to refer any narrow dendroid Lithostrotion to this species, and since no horizontal section has been figured by Edwards & Haime, I append the following detailed account of the structure which I connote by the specific name :— (1) The corallites are narrow and closely packed, in parallel grouping. (2) Ina horizontal section, the two walls are usually in contact, but when they are separate, the space between them is only divided up by the two series of septa. (3) In a horizontal section, a certain number of the larger septa extend to the columella, and the columella is usually con- tinuous, in the direction of its length, with two of the larger septa, so that the section appears to be bisected. (4) The tabule are close-set and conical, so that, in a horizontal - section, the central area exhibits a simple Clisiophyllid- structure. LirHostRorion JuncEumM (F'lem.). As interpreted by Edwards & Haime, ‘Monogr, Brit. Foss. Cor.’ pt. iii (1852) p. 196 & pl. xl, figs. 1-1 6. The Nematophyllum-Section. Corallites prismatic, forming a compact mass. LirHOsTROTION BASALTIFORME (Phill.). As interpreted by Edwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. iii (1852) p. 190 & pl. xxxviii, figs. 3-3 0. A very common Bristol variety is described in Proc. Bristol Nat. Soc. n. s. vol. x (1903) pp. 106-108. The Group of Lirnosrrotion Portiocki (Bronn). Here I include :— Lithostrotion Portlocki, Kdwards & Haime, ‘Monogr. Brit. Foss. Cor.’ pt. iii (1852) p. 194 & pl. xlii, figs. 1-lg. L. ensifer, Edwards & Haime, ibid. p. 193 & pl. xxxvili, figs. 2-2 a. L. M‘Coyanum, Kdwards & Haime, ibid. p. 195 & pl. xlii, figs. 2-2 0. For descriptions, see Proc. Bristol Nat. Soc. n. s. vol. x (1903) pp. 108-10. v2 280 DR. A. VAUGHAN ON THE PALZONTOLOGICAL [| May 1905, The typical member of this group, ithostrotion Portlocki (Bronn), Edwards & Haime, differs from LZ. basaltiforme in (1) its smaller size; (2) its very strong columella; and (3) the common tendency to Clisiophyllidan and Lonsdalia-modifications. Mutations of Lithostrotion. Nothing can be stated with certainty concerning the evolution of this group. The earliest form with which I am acquainted occurs near the top of the Syringothyris-Zone ; it resembles Lithostrotion irregulare in its smaller size, in the strength of its columella, in the fewness of the septa, and in the conical tabule, but the inner and outer walls are never coalescent, and the septa do not extend to the columella; it also differs in its ramulose manner of growth. The commonest forms of the two sections that are found in the Senunula-Zone are Lithostrotion Martinc and L. basaltcforme. L. affine and L, aff. Portlockt make their appearance in §.,. The Dibunophyllum-Zone is characterized by both Konincko- phyllidan and Clisiophyllidan modifications of the Siphonodendron- section, and by both Clisiophyllidan and Zonsdalia-like modifications of the Nematophyllum-section, as represented by members of the group of Lithostrotion Por flock, The Clisiophyllids. In order to explain the terms employed in the explanatory notes which follow, it is necessary to describe, in detail, the horizontal section of a typical Clisiophyllid. Such a section exhibits four areas: central, medial, external, and peripheral. The central area is occupied by a system of curvilinear intersections, the fundamental plan of their arrangement being that of a spider’s web. The medial area is radiated only by the primary septa, and has few dissepi- ments in the interseptal spaces. The external area is radiated by the primary septa and, usually, by a less- developed secondary series. The interseptal spaces are crowded with dissepiments which, by their closer approximation at the mner margin of the area, form the inner wall. The peripheral area, at its inner boundary, usually merges, quite insensibly, into the external area; it is distinguished by the predominance of vesicular over radial structure. Septa :— The primary septa are, usually, very thin and inconspicuous in the peripheral area, but much thicker in the external and medial areas, the maximum thickness being attained at about the inner wall. The secondary septa are always very thin, and seldom extend inwards as far as the imner wall; they are often practically absent, or but partly developed. The various genera of this family which have been created by Thomson, Thomson & Nicholson, and Thomson & Duncan, are described and illustrated 1 in Proc. Phil. Soc. Glasgow, vol. xiv (1883) pp. 296-502, pls. i—xiv.* 1 This paper is a summary of numerous peueher papers which appearent in the same Proceedings. Vol. 61.] SEQUENCE IN THE BRISTOL AREA; 231 These genera may be grouped in sections, as follows :— Section I. (The Koninckophyllum-Group.) This group is composed of Clisiophyllids in which the central area contains a thickened mesial plate, surrounded by a very simple network of few meshes. Here Koninckophyllum, Awophyllum, and Acrophylluin may, for the present, be placed together. Konincxopuyttum, Nich. & Thoms., may be regarded as having close affinity to Lithostrotion, combined with a Clisiophyllidan tendency. The affinity to Lithostrotion is shown in :— (1) The lath-like columella, and the simplicity of the structure of the central area, (2) The markedly-alternate septa; the two series are of almost-equal strength, and each septum is nearly uniform in thickness throughout its length. (3) The secondary septa reach almost, or quite, to the inner wall. The Clisiophyllidan tendency is conspicuous in :— (1) The very broad external area, closely packed with vesicles. (2) An extremely-simple type of Clisiophyllid-structure,in the central area. Axopuytium (Edwards & Haime), Thomson. This genus has apparent resemblance both to Koninckophyllum and to Lonsdalia, but its true affinity is to the latter. It resembles Lonsdalia in :— (1) The highly-specialized Clisiophyllid-structure of the external area. (See under Dibunophylluim w, p. 284.) (2) The development of a purely-vesicular peripheral area. It apparently resembles Koninckophyllum in having a_ thick columella, surrounded by a very simple network; but, in the only form from the Bristol area that I include under this genus, the columella, when examined under the microscope, is seen to, be complex in structure and to contain, in itself, the probable repre- sentative of the entire central area of a Lonsdalia. Hence, the true place of this genus is probably in Section V (p. 286.) Acropuytium, Nich. & Thoms. This genus { propose to omit, at least for my present purpose. Those species which only differ from Koninckophyllum in the greater extension of the mesial plate across the central area, may well be placed in the genus Koninckophyllum ; while those species, in which the external and peripheral areas exhibit a highly- specialized Clisiophyllid-structure, may be included in the genus Axophyllum. This separation will also be in accord with the periods at which the two divisions of . eee Observato seat ry Bridge Valley Rd. — New Zigzag eS Eroserpesncn Se ee —_ =< D2——€ IS2i(repeated 4500 5000 feet Railway -Cutting al River Avon Railway-Cutting Qy.1. TOURNAISIAN ‘k= CLeistopor Great Quarry XY Black RO Gully Oolite S 7 . d x / SEN pe y- Qy. | te : e ¢ Qy.3. Qy.s: | ] Qy.2. Qy.4 SKETCH-MAP OF QUARRIES, &c. Zonrs and Supzonns. { M= (Mopror4- Phase), { K, =Subzone of Productus bassus, VAIN) ps opun Grats : oR | K, = Subzone of Spiriferina octoplicata, Lower STF 3 WEN ZL=Z Z S e of Spinife f R Canpontrerous Limestone, | Z ZsPHRENTIS- Zone Oran se: { Z, Subzone of Spirifer aff. clathratus, ‘cst Z,,=Subzone of Schizophoria vesupinata. : YCOTHYRIS-Zone (including laminosa-subzone (C,) and Horizon 8) VISEAN Shy S ; Se SEMIN A-Zone S, = Subzone of Productus semireticulatus (mut.). eon Pate)! oro. 0bioy Subzone of Productus aff. Cora (mut. S,). Upper Carnonirerous Liwestonr, 7 +2 DR 1 [D=D IBUNOPHYLEUM-Z, LLUM-Zone ,,.- < 5 9 a 3 5 Subzone of Lonsdalia Jloriformis. Hortzoxs (that is, faunal overlaps of Zones), - Top of M, bottom of K, » Top of K, bottom of Z. C Top of Z, bottom of C. - Lop of C, bottom of Sy - Top of Carboniferous Limestone, bottom of * Millstone-Grit ’ in the Bristol area. [The Cayrv11-Zone includes Horizon y, Zone C, and Subzone S,.] Subzone of Dibunophyllum @ and Dibunophyllum @. iS tunnel Round Point polsredsn Qy.6. Stoke Leigh Camp. TIAXX ‘Id ‘TXT 104 ‘20g oan ‘uamop “yzeng Vol, 61. | SEQUENCE IN THE BRISTOL ARDA, 307 questions were treated in this way, although he had lately heard the opinion expressed that the Carboniferous Limestone did not seem to lend itself to zoning. The AurHor thanked the Fellows for their flattering reception of his paper, and expressed his especial gratitude to those who had taken part in the discussion, for their very kind remarks. In answer to Mr. H. B. Woodward, he regretted that he had not been able to find room, in a short abstract, either for a correlation of the zones, suggested in his paper, with the earlier lithological divisions, or for a reference to the work done by the late W. W. Stoddart in the Avon section. Both these subjects were, however, fully dealt with in the paper itself. In reply to Dr. Bather, he said that the term circulus was employed, throughout his paper, in a very definite sense. A circulus included all the forms which were very closely related to the type-species and were in perfect continuity with that species, either horizontally or vertically; it excluded all apparently-similar forms which were separated by a long vertical interval from the occurrence of the type, and were not connected with the type by a chain of similar forms. The Author had adopted the term circulus from Prof. Gregory’s work on the Jurassic Bryozoa under the same impression as the Rey. J. F. Blake, that it very conveniently covered the whole group, which was composed of the type-species and its close relatives. Should, however, Dr. Bather’s interpretation be the correct one, namely, that the term circulus was originally intended to cover a heterogeneous assemblage of similar forms, for which even genetic relationship could not be claimed, a new term would have to be introduced to convey the meaning in which the term circulus was employed in the present paper. With regard to the use of the term mutation, it was undoubtedly employed in this paper to denote lateral, as well as vertical, varia- tion from a type-species. The Author considered that both lateral and vertical variation were equally cases of evolutionary change, seeing that at least one important factor in lateral variation was direct evolution during migration. It would be impossible to dis- - criminate between the action of this factor and of the other recognized cause, namely, direct evolution from distinct members of a circulus, which took place contemporaneously at distant points. 308 MR. R, KIDSTON ON THE DIVISIONS OF tHE | May 1905, 12. On the Divisions and Corretarion of the Upper Portion of the Coat-Mrasurns, with special reference to their DEVELOPMENT in the Miptanp Countizs of Enetanp. By Roszrr Kupsron, F.R.S. L. & E., F.G.8. (Read April 5th, 1905.) Waite working out the flora of the British coalfields, I have found no group of rocks more interesting than the group of sandstones and marls, frequently of a red, purple, or mottled colour, and their associated limestones, which lie above the Middle Coal-Measures of the Potteries Coalfield. When preparing my paper on ‘ The Fossil Flora of the Coalfield of the Potteries,’ the classification which I adopted was that used by Mr. John Ward,” but at that time little was known about the thickness and stratigraphical relationship of the beds forming this group. The classification adopted by Mr. Ward is as follows :— { Red Marls. Red Sandstone. _ ( 1. Upper Coal-Measures. | 2. Middle Coal-Measures. | 4 3. Lower Coal-Measures. 7 CARBONIFEROUS ROCKS ......... | t NElleconee Gna . Yoredale Rock. | 6. Carboniferous Limestone. IP PRMUNN ROCKS soos a eee ee In the present paper my remarks will be restricted to the rocks here called Permian and Upper Coai-Measures. Any reference that may be made to the underlying group will be merely incidental. | At the time when my paper on the fossil flora of the Potteries Coalfield was written, I had seen no plants from the so-called ‘Permian’ of that area, and, in regard to these rocks, Mr. John Ward says, in the work already mentioned :— ‘I may here remark that a considerable development of red, purple, and variegated marls which have been coloured by the Geological Survey as Permian are, I am inclined to think, in reality Upper Coal-Measures.’ (Op. cit, p. 14 [sep. cop. |.) That these rocks were Carboniferous and not Permian, I felt quite certain: for, apparently, the same so-called ‘ Permian ’ rocks were passed through while sinking the shaft of the Hamstead Colliery at Great Barr, near Birmingham ; they contained a typical Upper Coal-Measure flora ; and with this series I classed them at the time.” 1 Trans. Roy. Soc. Edin. vol. xxxvi (1890-92) pp. 63-98. > «The Geological Features of the North Staffordshire Coalfields, their Organic Remains, their Range & Distribution ; with a Catalogue of the Fossils of the Carboniferous System of North Staffordshire’ Trans. North Staffs. Inst. Min. & Mech. Eng. vol. x (1890) p. 4 [sep. cop.]. 3¢QOn the Fossil Flora of the Staffordshire Coalfields. Part I. On the Fossil Plants collected during the Sinking of the Shaft of the Hamstead Colliery, Great Barr, near Birmingham’ Trans. Roy. Soc. Edin. vol. xxxv (1888-90) pp. 317-385. Vol. Oita | UPPER PORTION OF THE COAL-MEASURES. 309 Messrs. F. G. Meachem & H. Insley had previously referred these rocks to the Upper Coal-Measures.! I shall have occasion to refer to the Upper Coal-Measures of Great Barr later on in this paper. The dividing-line between the Upper and Middle Coal-Measures, adopted in the Potteries Coalfield, was a Spirorbis-Limestone, 12 yards above the Bassey-Mine Lronstone. From the entire series of rocks above this line, the only plants met with up to the time mentioned above were :— Pecopteris arborescens (Schl.). Calamites Suckowt, Brongn. Pecopteris cyathea (Schl.). Calamocladus equisetiformis (Schl.). Mariopteris muricata (Schl.). Lepidostrobus variabilis, L. & H. Alethopteris aquilina (Schl.). Sigillaria Brardi, Brongn. Alethopteris lonchitica (Schl.). Stigmaria ficoides (Sternb.). Odontopteris sp. Rhabdocarpus sulcatus (Presl). Neuropteris ovata, Hoffm. The whole of these species, except Lhabdocarpus sulcatus, occur in the Upper Coal-Measures, though some are very rare therein, and several of the plants are much commoner in the Middle and Lower Coal-Measures. When dealing with the general classification of the British Carboniferous rocks as determined by their fossil plants,” I mentioned that Dr. Wheelton Hind* had discovered, in rocks a few yards above the Spirorbis-Limestone, specimens of Neuropteris gygantea, Sternb., NV. heterophylla, Brongn., and Sphenophyllum emarginatum, Brongn., and, at a later date, Sigillaria ovata, Sauveur.* Of these, the only one known to occur in the Upper Coal-Measures was Sphenophyllum emarginatum, and of the other three, Sigillaria ovata was a typical Middle Coal-Measure species, while the two Neuropterids were common to both the Middle and Lower Coal- Measures ° ; it was therefore evident that the lower part, at least, of the group which had been referred to the Upper Coal-Measures belonged to my Transition Series, a division that I had proposed for certain beds lying between the Middle and the Upper Coal-Measures, and the flora of which was characterized by an admixture of Upper and Middle Coal-Measure species. This series forms a most natural and important group. When preparing the ‘Additional Records & Notes’ (op. cit. p. 129), in referring to this Transition Series, I said :— ‘This series appears to be very feebly developed in the Potteries Coalfield, though it may form a more important group than is at present suspected.’ This suggested possibility has proved to be the case, and the rocks ? Rep. Brit. Assoc. 1886 (Birmingham) p. 626. 2 “On the Various Divisions of British Carboniferous Rocks, as determined by their Fossil Flora’ Proce. Roy. Phys. Soc. Edin. vol. xii (1893-94) pp. 183-257. ENO DN Gite Wa 229: + * Additional Records & Notes on the Fossil Flora of the Potteries Coal- field, North Staffordshire’ Trans. North Staffs, Field-Club, vol. xxxi (1897) pale Ps A single example of Newropteris heterophylla has quite recently been found in the ‘ Keele Group ’= Upper Coal-Measures. Q.J.G.8. No. 242. ve 310 MR. R. KIDSTON ON THE DIVISIONS or THE [May 1905, | to which I applied the name of Transition Series have proved to be a most important group, not-only in the Potteries Coalfield, but in other areas of the Midland Counties of England. In 1895, the Geological Survey commenced a re-survey of the Potteries Coalfield, and in 1902 the Memoir of ‘The Geology of the Country around Stoke-upon-Trent’ was published.’ Here, for the first time,? Mr. Walcot Gibson gives a full account of the rocks lying above the Middle Coal-Measures of the Potteries Coalfield, and accepts as their base the Bassey-Mine Ironstone. ‘This brings down the dividing-line between the Middle Coal-Measures and the overlying strata 36 feet; but Mr. Gibson considers the Bassey- Mine Ironstone a more convenient line of division than the Sprrorbis-Limestone previously accepted, and this ‘ line’ has now been adopted. The following are the subdivisions of the rocks overlying the Middle Coal-Measures of North Staffordshire, as tabulated by Mr. Walcot Gibson (Mem. Geol. Surv. jam cit. p. 37) :— | Name o | : Ri Characters. Thickness. KEELE Grovp.! Red and purple sandstones and marls. Oc- j;Over 700 feet at casional seams of coal. Thin black and| Keele Park. grey limestones, and subordinate bands of | Summit nowhere grey sandstone and shale. Base, entomo- | visible, unless at, stracan shale. | Moddershall. | ! NeEwcastLz- | Grey sandstones and shales, with four thin |300 feet. UNDER-LYME seams of coal. Base, entomostracan lime- GROUP. stone. ETRURIA- Chiefly mottled red and purple marls and |800 to 1100 feet. Mart Grovp. clays. Thin beds of green grit very charac- teristic. Limestone-bands near the summit and base. Lenticular mass of grey sand- stone overlying a laminated ironstone and thin coal 150 feet above the base (Chester- ton only).. Base, often a greenish fine- erained sandstone. BuiacKBAND | Chiefly sandstones, marls, and clays. Some |300 to 450 feet. GROUP. lenticular bands of grey grit and slightly- + mottled marls. Numerous thin seams of | coal and Blackband ironstones. Thin bands of limestone throughout the series, one of which is constant at 36 to 40 feet above the Bassey-Mine Coal. Since my last notes on the fossil flora of the Potteries Coalfield were published in 1897, the fossil plants from this group have been 1 Mem. Geol. Surv. 1902, ‘The Geology of the Country around Stoke-upon- Trent. (Explanation to Sheet 123.)’ By Walcot Gibson & C. B. Wedd; with Notes by George Barrow. 2"A preliminary account of these rocks was given by Mr. Gibson, in his paper, ‘On the Character of the Upper Coal- Measures of North Staffordshire, Denbighshire, South Staffordshire, & Nottinghamshire; & their Relation to the Productive Series’ Quart. Journ. Geol. Soe. vol. lvii (1901) p. 251. Vol. 6r.| UPPER PORTION OF THE COAL-MEASURES. 31k carefully collected ; but such remains are very scarce in these rocks, and are especiaily rare in the Htrurza-Marl Group, from which I have only been able to identify a single species.! So far as known to me, the following table embodies a list of all the fossil plants observed in the upper series of the Potteries Coal- field :— Tasie or Tie Fossin Puanrs or THe Kreis, Newcastie, HTRURIA, AND BLACKBAND GROUPS. SPECIES. te Keele ‘Group. Sphenopteris obtusiloba, Brongn. ...... ....-6..) ieccopcer’s anvorescens (ScWl.) ......66.iese2- ee | CeOpoeris CYatned (Selil.)...s..2ci21-+-esscenees | eCEOMUCHISMVLUCOMe CALUIS) ...0+creseseeeer sees Moariopierts muntcata (SChl.) ..c.cic..0eere0e es Alethopteris aquilina (Schl.) . ...........002065- Alethopterts lonchiteca (Schi.) ...............+--| Alethopteris valida, Boulay ..............- 2065 | ClUDITO/DUCIPUS SOs eet chee Ree Sere Neuropteris acuminata (Schl.)? ........ BSA a Newropteris heterophylla, Brongn. ............ Neuropteris macrophylla, Brongn. (?) ......... | Newropteris tenwifolia (Schl.)? .............-. INCU RO PUCRIS OUAG) IAOWMN,.~.isscnacec ever stesso: Neuropteris rarinervis, Bunbury ............! Neuropteris gigantea, Sternd. ........66..66005- Neuropteris Scheuchzert, Hoffm... ........ ... | Tynopteris Mimstert (Hichw.) .......2..s.0.++-: Wanopterts obliqua (Bunbury) .. ...:....2-..:- Calamites Cisti, BYONEN, 42.5.0. g0.0.2. see eee es | Caldaites SChUCZEL. SUUN’. . 5. s.ccsenisss-cee mass Calamites undulatus, Sternb. .............6.... Calimites ISUCHOWL, BYONEM. ....ncss0.. 000 00- | Calamites vartams, Stermb. .......0.2...008..e. Calamites waldenburgensis, Stur.............5. | Calamocladus equisetiformis (Schl.)............ | Annularia galioides (Li. & H.)........c10c:s000 | Annularia radiata, Brongn. .............6065. | Macrostachya infundibuliformis (Brongn.)...| Sphenophyllum cuneifolium (Sternb.) - ...... | Sphenophyllum emarginatum, Brongn. ...... | Lepidodendron lycopodioides, Zeiller (Stbg.).. Lepidodendron ophiurus, Brongn. ...........- Lepidodendron Worthent, Lesq. .........+..++. | Lepidophyllum lanceolatum, L. & H. ...... Lepidostrobus variabilis, L. & H. .........+-- * x 3K 3K Neweastle- |Htruria- under-Lyme ! II Group. KOK OK OK: ITT. Mari Group. IV. Black- band Group. eRe % XK OK KK “ ay 1 [ am indebted to Mr. John Ward, F.G.S., Dr. W. Hind, F.G.S., and to Mr, John ‘I. Stobbs, #.G.S., for kindly submitting to me their plant-collections from these groups ; to them my knowledge of the flora is almost entirely due. T have also had sent to me some specimens collected by the late Dr. Garner, which are contained in the collection of the Stoke-upon-Trent Museum. ¥ 2 312 MR. R. KIDSTON ON THE DIViSIONS OF THE [May 1905, TABLE OF THE Fosstu Prants oF tHE Kuxxe, Etc. Groupes (continued). I, > SPECIES. Wecele Lepidostrobus anthemis (Konig) ............+ Sigillaria tessellata, Brongn (?)...........6.-.-! Sigillana Brandt, BrOngw. 22. ..s00.0.-.-60--- | Sigillaria discophora (Konig) ..........0. 2.6. Sigillaria ichthyolepis, Sternb. (Weiss) igwlaria ovata, Sauveul) Ve... vss. .04-5 ey Stigmaria ficotdes (Sternb.) ...........0.-.2++0-. Cordaites borassifolius (Sternb.) ............0- Artisia transversa (Artis) Trigonocarpus Parkinsont, Brongn. .. Rhabdocarpus sulcatus (Presl)' @eorecocecoresoeesseoscasses eeecerees ees eon) Group. II. II. IV. | Newcastle- \Etruria-\ Black- under-Lyme| Marl | band Group. | Group. |Group. * * ie x % x * * 2 Reference has already been made to the plants found in the so-called ‘ Permian’ rocks, passed through in sinking the shaft of the Hamstead Colliery, Great Barr, near Birmingham. The beds which yielded the plants extended from a depth of 729 to 1233 feet below the surface, and are undoubtedly referable to the Upper Coal-Measures; they are, I think, equally certainly the Keele Group of the Potteries Coalfield. Beds above these, extending downwards from 627 feet below the surface, belong, I believe, to the same group, but they did not yield any fossil plants. | The following isa list of the fossil plants observed in the Newstead Boring, Trentham (North Staffordshire), all of which are included in the above list :— SPECIES. Pecopteris cyathea (Schl.) Pecopteris Miltont (Artis) ..............0.000+: IN ROROSORA RUS (SJ Seeaoubaoooda5éce5 aco dobadhe doonBanae Newropteris acuminata (Schl.)? .............-. Neuropteris heterophylla, Brongn. ........... Neuropteris tenuifolia (Schl.) ? Neuropteris rarinervis, Bunbury Neuropteris Scheuchzeri, Hoffm...... ........- Linopteris Miimstert, Wichw. .................- Linopteris obligua, Bunbury ............:.-..- Calamites undulatus, Sternb. ...............06. Calamocladus equisetiformis (Schl.) Annularia radiata, Brongn. .................. Sphenophyllum emarginatum, Brongn. ...... Lepidodendron lycopodioides, Zeiller (Sthg.). WHE DUDOSEROUUSIS) Liat tke ce Ratctrs ecient Cordaites borasstfolius (Sternb.) ............... eeeccarececesres cevas eect er eer eeeses eeereccscevece dale Newcastle- under-Lyme Group. WA (meh, IV. Etruria-| Black- Marl | band Group. |Group. % % * *¥ % Vol. 61.| UPPER PORTION OF THE COAL-MEASURES. ole A bed reached at a depth of 1320 feet from the surface, and 72 feet thick, may belong to the Keele Group; but I am -rather inclined to regard it as referable to the Newcastle-under-Lyme Group. The plants from this bed, though all but one occur in the Upper Coal-Measures, are commoner in the Middle Coal- Measures, and there is no characteristic Upper Coal-Measure plant found among them. The supposed unconformity, which brings the Newcastle-under- Lyme Group (?) against the Middle Coal-Measures in this section, is much more probably the result of a fault: since, with the exception of this possible unconformity, the Keele Group has been found always conformable to the underlying Coal-Measures. List or Fossr PLANTS OBTAINED WHILE SINKING THE SHAFT oF THE HamsTEAD Couuiery, Great Barr, NEAR Brrmincuam. [For condensed section, see Trans. Roy. Soc. Edin. vol. xxxv (1888) p.318. The Upper Coal-Measures probably end at a depth of about 1233 feet. | { I i Keele Group | Newcastle- sae, = Upper Coal-| under-Lyme precias, Measures. Group (2). Depth: 729 | Depth: 1236 to 1233 feet. | to 1320 feet. iRecopieris anvorescens (Schl) .. 5... ..052.-+-+5-| * HECOPUChIS WVULCONT (ATS) vivdeatesenesoceee ees REcoplends: WHttd,, BROMOM. ceccew-t cece cases: Alethopteris aquilina (Schl.) ..............000 Odontopteris Lindleyana, Sternb. ............ | Neuropteris flecwosa, Sternb. ...........0...+5- | % INCUTOOLERIS OUGLA, NAOUIM., -sceecencucesscesses | Neuropteris rarinervis, Bunbury Neuropteris Scheuchzeri, Hoffm. ROOT ONUECS SI sate tae tistsie osiieisisibclenis vino vein des ie 82 Anmularia stellata (SCD\.)) -s...ctersceceecwsese| * Sphenophyllum emarginatum, Brongn. ...... | % Lepidophyllum lanceolatum, L. & H. ...... % IDG RUGIOEHHOOUIS S00, :oo5Ahasedins6.40a o8 so 0REREOROCe | * Stigmaria ficoides (Sternb.)...... Bae ahaa crea Cyperites bicarinata, L. & H. ..............606- x Cordaites angulosostriatus, Grand’Hury ... % Walehtarimoricatay Schimper. .s.ie.c.++--0-- | % * 3 7 Calamites Suckowt, Brongn. ..............+06- Ay * Calamites undulatus, Sternb. — ..........0.-+- oe x Calamites varians, Sternh. ..........0.68 seeee- | Mes * Lepidodendron Wortheni, Lesq. .........++++.- | oe * Lepidostrobus variabilis, L. & H. ............ ey % ISIGUUATIO Sp. ... +22. .0ce+0s A ose atcha Orr ee ee ta % Artisia approximata (Brongn.) ........-..+.- on % Pinnularia capillacea, L. & H. ..............- a * Alethopteris decurrens (Artis) — ........000600. | oe * 314 MR. R. KIDSTON ON THE DIVISIONS oF THE [May 1905, In 1876, Mr. D. C. Davies pointed out that certain upper beds in Denbighshire, which had been mapped as Permian, should probably be classed as Carboniferous." This area was subsequently visited by Mr. Walcot Gibson, who identified in these supposed ‘ Permian’ rocks of Denbighshire and Upper Coal-Measures, the three Car- boniferous subdivisions which occur in North Staffordshire, and named by him the Keele Group, the Newcastle-under- Lyme Group, and the Etruria-Marl Group. As equivalent terms for the Denbighshire representatives he has proposed the following :— Norn STAFFORDSHIRE. DENBIGHSHIRE. Keele Group = Wrexham Red Sandstones and Marls. Newcastle-under-Lyme Group = Coedyrallt Group. Etruria-Marl Group = Ruabon Mars.’ While collecting fossil plants in Denbighshire in 1903, Mr. J. Pringle gave particular attention to the examination of these rocks, but found them very barren of plant-remains. The only species collected were :— Se < E S See nis Ss lS = Srecrus. Sats s=$ sose ee (82 Seleeee SEG |SSSS|S5E8 Nl ae is) ll IGG TITS CUCM, LETHOWIEING “psnocacoedoenasasedenar la eae Pecopteris Miltont (Artis) ............ Ect ee x Pecopeeris(Ceauveices) sy. aera eee. net eeeee coe ga | aan Alethopteris aguilina (Schl.) .......2.2--1-+00+5.: | % Neuropteris rarinervis, Bunbury ............... Shot aee uals 5 Calamocladus equisetiformis (Schl.) ............ ea * Lepidodendron lycopodioides, Zeiller (Stbg.)...) ... x | Cordattes principalis (Germar) .......4.......0-. Rk ** | From the Ruabon Marls not a single specimen was found. This agrees with the almost-total barrenness of the Etruria Marls of North Staffordshire, from which a single species is recorded. The few species found in these groups in Denbighshire agree with those observed in the corresponding groups in North Staffordshire. ° Passing northwards to Cumberland, a series of red and purple shales, occurring in Jockie’s Syke, 1 mile east by north of Riddings Junction, were found by Mr. A. Macconochie, in 1879, to contain Upper Coal-Measure plants. This locality was again visited by 1 Quart. Journ. Geol. Soc. vol. xxxiii (1877) p. 10. 2 Tbid. vol. lvii (1901) p. 261. Vol. 61.] UPPER PORTION OF THE COAL-MBASURES. 315 ‘Mr. Macconochie and myself in 1902, when the following species were collected :— Pecopteris arborescens (Schi.). Calamites undulatus, Sternb. Pecopteris (Cyatheites) sp. Calamites sp. Alethopteris aquilina (Schl.). Calamocladus equisetiformis (Schil.). Alethopteris Grandini (Brongn.). Annularia radiata, Brongn. Alethopteris Serli (Brongn.). Annularia stellata (Schl.). Neuropteris flexuosa, Sternb. Lepidodendron fusiforme (Corda). Neuropteris ovata, Hofitm. Lepidophyltium sp. Neuropteris Scheuchzeri, Hoffm. Stigmaria ficoides (Sternb.). These beds I unhesitatingly refer to the Upper Coal-Measures, but at the same time regard them as identical with the Keele Group of North Staffordshire.* Before proceeding further, it will be well to collect all the plant- records from the Keele Group, with which I correlate the plant- bearing beds of Jockie’s Syke (Cumberland), and the upper part of the ‘ Red Rocks’ passed through in the Hamstead Boring at Great Barr, near Birmingham; those from the Newcastle-under-Lyme Group, the Etruria-Marl Group and the Blackband Group of North Staffordshire, as these have been defined by Mr. Walcot Gibson.” These beds are known, in part or in whole, to occur in South Staffordshire, Shropshire, Denbighshire, Nottinghamshire, Lanca- shire, and Cumberland, and also in the South-Wales Coalfield, Somerset, and the Forest of Dean; and they may occur in York- shire as well. But in some of these counties, although there is no doubt as to the occurrence of these groups in part or in whole, they still require further examination before their full extent can be determined. In connection with this subject, reference must be made to the fossil plants of the ‘ Ardwick Series’ of Manchester (which have been described by Mr. EK. A. N. Arber), and the evidence which they afford as to the age of the beds discussed, with the result that he ascribes the Ardwick Series to my ‘Transition Series.’* ‘This is most probably their position, but the exact horizon of the specimens examined by Mr. Arber was not ascertainable. The plant- evidence, however, shows clearly that part of the Ardwick Series, if not the whole, belongs to that group of rocks which have been termed the Transition Series, and are so well developed in the Potteries Coalfield (North Staffordshire). 1B. N. Peach & J. Horne, ‘The Canonbie Coalfield: its Geologieal Structure & Relations to the Carboniferous Rocks of the North of England & Central Scotland’ Trans. Roy. Soc, Edin. vol. x1 (1903) p. 858; and R. Kidston, ‘The Fossil Plants of the Carboniferous Rocks of Canonbie (Dumfriesshire), & of Parts of Cumberland & Northumberland’ ibid. p. 802. 2 Mem. Geol. Surv. 1902, ‘ The Geology of the Country around Stoke-upon- Trent’ pp. 35-47. 3 Mem. & Proc. Manch. Lit. & Phil. Soe. vol. xlviii (1903) no. 2, pp. 22-238. 316 MR. R. KIDSTON ON THE DIVISIONS OF THE [May 1905, ry a 7 ‘i . Taste or tue DrsrripuTion of tun Puants in Tin Kente Group, THE Newcastie-unper-Lyye Grove, toe Errurta-Mart Group, AND TIE BiLackBAND Grove. SPECIES. Sphenopteris obtusiloba, Brongn. ............ | Pecopterts arborescens (Sehl:)) ih) 2s.42.0..-2---4) Pecopteris cyathea, Brongn. ................+. | IACCOPUCIIS NILA, LOWEN. ei) iy-neeeen ene ee IEG CO NE CTROS MQUEOO, (CEU) en acocsnonsea anos 00s Mariopteris muricata (Schl.) .......... te ce Alcthopters tonehetica (CSchals) Wyss yee ee Alethopteris decurrens (Artis) .............4: Alethopteris aquilina (Schl.) ........ earn | Alethopteris Grandini (Brongn.) ............ | Alethopteris Serla (Brongm.) — ..3...-..1-+2.0.- Alethopteris valida, Boulay .........0...006-. Odontopteris Lindleyana, Sternb. ............ | Od on tOpte#nys Side wesesns ance coon see tose eee Ws Newropteris heterophylla, Brongn. ............ Neuropteris acuminata (Schl.)? ......see0..0+: Neuropteris macrophylla, Brongn.(?) ...... Neuropteris tenuifolia (Schl.)? ..........2..- INeuroptenis ovdia, AON... eee seston Neuropteris rarinervis, Bunbury ~............ INCULOPUCHES GUGAMLEG, SUCEIND: seem ue ree see Neuropteris flexuosa, Sternb. ..........c00.0005 Neuropteris Scheuchzert, Hoffm. ............ | Linopteris Mimstert (Michw.) ............+..... Linopteris obliqua (Bunbury) .............5. Calamites Suckowt, Brongn. .............. ne Calamites undulatus, Sternb. ...............+6- | (ClalloaouTas (COSCAy VCO NG oSensande anpocnoakacseer COlagiiGeSSGMIZCU SUT es. tusek he eee sens Calamites TATIONS Str: fee. .ce- sec. sae one e Calamites waldenburgensis, Stuy ...-........ Calainocladus equisetiformis (Schl.) ......... Macrostachya infundibuliformis (Brongn.) . ANNUM ANIG TOAIGCA, "BXOURM. .ice25.2. 2. bone Annularia sphenophylloides (Zenker) ......... Ain UOT IG SUC LCCOM SCUN)P pcre richie s+ once vee Annulania gatiowdes (Uc) 00... 5.8... Pinnularia capillacea, L. & H. ............... Sphenophyllum emarginatuin, Brongn. ...... Sphenophyllum cunerfolium (Stbg.) ......... | Lepidodendron fusiforme (Corda) ............ Lepidodendron lycopodioides, Sternb. (Zeer Nratatehee eens etecieniienieh Yecanctes | Lepidodendron ophiurus, Brongn. ............ Lepidodendron Wortheni, Lesq. ............... Lepidostrobus variabilis, L. & H. ............| Lepidostrobus anthemis (Konig) .........6..4. | Lepidophyllwin lanceolatum, L.& H. ...... Lepidophyllwm intermedium, L. & H. ...... Sig Tid Brand i MSVONeM, asec. s- eee 1 Keele Group.| II. JUL. TV. | Newcastle Etruria Black- Group Cran | band . P- Group. | xk | | *K | | 3K | 3 % % | (?) % (?) ae @) (3) () * aT \ % % a * ie ae (?) | (?) % ; * (2) cy | x ie % i | “ 20 is ~I Vol. 61.| UPPER PORTION OF THE COAL-MEASURES. Sill TABLE OF THE DISTRIBUTION OF TILE PLANTS IN THE Keen, ETc. Groups (continued), ie JOE; EET SV SPECIES. Keele |Newcastle| Etruria eae Group.| Group. | Growp. Group Sigillaria discophora (Konig) .......-......66- Sigillaria ichthyolepis, Sternb. ...........605. is be si SAGUGMEE OUALE, SAUVEUL ve sacccenuesen, sense. ane ne a * Sigillaria tessellata, Brongn. (?) .........00006. x DS UNUCTUG SDs a rsicischre desis seiicioeantn oui stue seed rich ce es, * Cyperites bicarinata, WU. & HW. ..........0.2.000- * SGmmania ficordes (SterMD.)) ..ss.socssse100. +. * * os * Cordaites angulosostriatus, Grand’ Hury ...) * Cordaites borassifolius (Sternb.) .........+-. * yi Cordaites principalis (Germar) ............+.. ee % Trigonocarpus Parkinsoni, Brongn. ......... Rhabdocarpus sulcatus (Presl) ............... ae * Artisia approximata, Brongn. ........ ne ee (?) AEMISUCRULUNSUCTS@) CATEIS) nitude Stn cece ees n * Wialchiaomonicata, Schimper... 22.2022. -0+0-5- If the distribution of the species recorded from these four sub- divisions be analysed, it will be found that of the 29 species observed in the Keele Group, all have previously been found in the Upper Coal-Measures, except Lepidodendron fusiforme (Corda), Sigillaria tessellata, Brongn. (?), and Cordaites borassifolius(Sternb.). The former, like a few other species of Lepidodendron, extends throughout all the divisions of the Coal-Measures, while the latter occurs at the very base of the Keele Group. Newropteris hetero- phylla, Brongn., has not previously been found in Britain at so high a horizon, but it has been recorded by Prof. Zeiller from the Lower Series of the Upper Coal-Measures.' As yet, only a single specimen has been collected from the Keele Group. Stgillaria tessellata (?) is also new to the Upper Coal-Measures, for the specimens that 1 formerly recorded from the Radstock Series under this name are Sigillaria cumulata, Weiss.” It is also noticeable that there is an entire absence in the Keele Group of the small Sphenopterids and of the Sigillarians generally, which are so characteristic of the Middle Coal-Measures. These are always very rare in the Upper Coal- Measures, and their absence is one of the characteristics of that flora. On the other hand, the Keele Group contains many most typical Upper Coal-Measure species, such as Pecopteris arborescens (Schl.), P. cyathea (Schl.), P. wnita, Brongn., Alethopteris aquilina (Schl.), 1 «Bassin Houiller & Permien d’Autun et d’Kpinac: Fase. ii. Flore Fossile’ pt. i (1890) p. 144 (Gites minéraux de la France). 2 «Die Sigillarien der preuss. Steinkohlengebiete: I. Die Gruppe der Fayu- larien’ Abhandl. d. KGénigl.-Preuss. geol. Landesanst. vol. vii (1887) p. 255 & pl. ix (8) figs. 35-36. 318 MR. R. KIDSLON ON THE DIVISIONS OF THE [May 1905, A. Grandini (Brongn.), A. Serli (Brongn.), Odontopteris Lindleyana, Sternb., Newropteris flexuosa, Sternb., V.ovata, Hoftm., N.Scheuchzeri, Hoftm., Annularia sphenophylloides (Zenker), A. stellata (Schl.), Sphenophyllum emarginatum, Brongn., Cordaites angulosostriatus, Grand’ Kury, and Walchia imbricata, Schimper; and, although some of these occur in lower horizons, still the Upper Coal-Measure horizon is where ‘all of them attain their maximum development, and it is the horizon of which they are typical species. There can, therefore, be no doubt that the Keele Group must be classed as Upper Coal-Measures. Passing to the plants recorded from the Newcastle-under-— Lyme Group, we note that, of the 22 species observed, Pecopteris arborescens (Schl.), P. cyathea (Schl.), Newropteris flexuosa, Sternb., and JV, ovata, Hoffm., are typical Upper Coal-Measure species ; but they are here associated with other species which are characteristic of the Middle and Lower Coal-Measures, such as Pecopteris Miltons (Artis), which also is plentiful in the Upper Coal-Measures and frequent in the Middle Coal-Measures, Newropteris gigantea, Sternb., Lepulodendron lycopodioides, Sternb. (Zeiller), L. ophiurus, Brongn., Sigillaria Brardi, Brongn., and Cordaites primcipalis (Germar). So there is clearly here a mixing of species, some of which are characteristic of the Upper, and others of the Middle, Coal- Measures. From the Etruria-Marl Group only a single species, Neuropteris Scheuchzert, Hoffm., has been collected. This is a very common Upper Coal-Measure plant; it is met with, however, though rarely, in the Middle Coal-Measures. The absence of plant-remains in this group is, nevertheless, not of so much im- portance, as a fair lst has been obtained from the overlying Newcastle-under-Lyme Group and the underlying Blackband Group. Lhe Blackband Group has yielded 24 species. It contains a few which occur in the Upper Coal-Measures; these are Peco- pteris Miltont (Artis), which, as already mentioned, is also not uncommon in the Middle Coal-Measures, Macrostachya infundibu- liformis (Brongn.), Annularia sphenophyllordes (Zenker), also known from the Middle Coal-Measures, where it is, however, very rare, and Sphenophyllum emarginatum, Brongn., which is a very common Upper Coal-Measure plant; but the great majority of the species from the Blackband Group are Middle and Lower Coal-Measure forms. Of the characteristic Middle Coal-Measure plants, Aletho- pteris valida, Boulay, Linopteris obliqua (Bunbury), and Sigillaria ' ovata, Sauveur, may be mentioned. In this group, the Middle Coal-Measure plants become more strongly represented, and the Upper Coal-Measure plants are clearly reduced in number. In fact, from the Neweastle-under-Lyme Group to the base of the Blackband Group, a gradual change in the -flora is taking place from below upwards. Upper Coal- Rol61.] UPPER PORTION OF THE COA’.-MEASURES. 319 Measure species are beginning to appear, and the species which occur in the Middle Coal-Measures are gradually dying out. In such a list as that tabulated on pp. 316-17, the mere names of species do not fully represent this change; the plants of the Middle Coal- Measures become, however, rarer, not only in species, but in the number of the individual specimens found; and as these lower- horizon forms become rarer in individual quantity, the Upper Coal- Measure species become more plentiful in kind and numbers. The three subdivisions—the Newcastle-under-Lyme Group, the Ktruria-Marl Group, and the Blackband Group, represent, therefore, a series of rocks, wherein the flora is a mixture of plants, some of which are characteristic of the Upper Coal-Measures, while others are characteristic of the Middle Coal-Measures. It is consequently impossible to class these rocks, either with the Upper Coal-Measures above them, or with the Middle Coal-Measures upon which they rest, as they form a distinct botanical province, easily separated by their mixed association of species. It was for this group that I originally used the term of ‘ Transition Series ’.’ When this term was proposed, I did not know the important place that this group would hold in the classification of the Upper Carbon- iferous; but, in recent years, the work of the Geological Survey of Great Britain, as well as evidence obtained from mining opera- tions, has shown the Transition Series to be a widely-extended and important group, and one of great importance in determining the position of the more valuable underlying coal-bearing strata of the Middle Coal-Measures in our ‘ concealed’ coalfields. As, however, the term ‘Transition Series’ is a somewhat in- definite one, and naturally raises the question ‘Transition between what’? I propose to substitute the term Staffordian Series for the inclusion of the Newcastle-under-Lyme Group, the Etruria-Marl Group, and the Blackband Group of North Staffordshire, as in that county these rocks have been worked out more fully in detail than in any other area where they occur. To Mr. Walcot Gibson we are largely indebted for the clear knowledge that we possess of the Staffordian Series, though others have helped in their elucidation, and of these, I would wish especially to refer to the work of Mr. T. C. Cantrill in the Enville and Forest-of- Wyre districts.” For the Upper Coal-Measures I would propose the term Rad- stockian Series; for the Middle Coal-Measures, Westphalian Series, with which the flora of the Middle Coal-Measures appears to agree ; and for the Lower Coal-Measures, the term Lanarkian 1 Proc. Roy. Phys. Soc. Edin. vol. xii (1893-94) p. 228 ; also ‘ Additional Records & Notes onthe Fossil Flora of the Potteries Coalfield’ Trans. North Staffs. Field-Club, vol. xxxi (1897) p. 128. 2 Quart. Journ. Geol. Soc. vol. li (1895) pp. 528-48. e 520 MR. R. KIDSTON ON THE DIVISIONS oF THE [May 1905, Series, as there is no area in which this series is better developed than in Lanarkshire. This change of nomenclature is absolutely necessary, as the terms ‘ Upper,’ ‘ Middle,’ and ‘ Lower’ Coal-Measures have been so loosely applied in the past, that in many cases these terms have only a local significance, having been applied to rocks of different ages in different districts. It is therefore necessary, in order to avoid further confusion, to introduce a new and distinctive termin- ology for the various divisions of the British Coal-Measures. : These proposed changes are shown in the following tabular orm :— CoaL-Mnrasurgs. Radstockian Series (including the Keele Group). Staffordian Series. Westphalian Series. Upper Coal-Measures = | Transition Series Middle Coal-Measures Lower Coal-Measures ae iF is Cae (including the Millstone-Grit). { — aang 2 ll {I Before concluding this paper, I wish to refer to an interesting pit-sinking made at Bradford Colliery, Manchester, last year, at which the fossil plants were carefully collected from the shales associated with the Bradford Four-Foot Coal. A considerable number of specimens from these shales were submitted to me for examination by Mr. W. Hemingway and Mr. P. Whalley. A list of the plants from this sinking has already been published by Mr. John Gerrard, along with a section of the strata from which they were derived.’ I append a list of the species contained in the collections examined by me; they were derived from shales extending from 24 feet to about 321 feet above the Bradford Four-Foot Coal. A comparison of this list with the species noted from the Black- band Group will show the great similarity of the two floras. There are still here two species, Sphenophyllum emarginatum, Brongn., and Annularia sphenophylloides (Zenker), characteristic of the Upper Coal-Measures, and some which are common to that horizon ; but these are accompanied by an overwhelming pro- portion of species characteristic of the Middle Coal-Measures. The plant-evidence, therefore, indicates that the rocks from which the specimens came at Bradford Colliery belong to the Blackband Group of the Potteries Coalfield, and that the Bradford Four-Foot Coal occurs at the base of the Group, and would therefore occupy a position on or about the horizon of the Bassey-Mine Ironstone and Coal of the Potteries Coalfield. 1 ¢Notes on Fossils found above the Bradford Four-Feet Coal at Bradford Colliery, Manchester’ Trans. Manch. Geol. & Min. Soc. vol. xxviii (1904) p. 909. Vol. 61.] UPPER PORTION OF THE COAL-MEASURES., 321 List or Fossiz Puants rrom BraprorD CoLiiery, MancuEsTEr, FROM SUALES EXTENDING FRoM ABOUT 24 To 321 FRET ABOVE THE BraAprorp Four- Foot Coat. Staffordian Series. (Subdivision, Blackband Group.) Sphenopteris artemisiefolioides, Crépin. Sphenopteris Ascherborni (Stur). Sphenopteris dilatata, L. & H. Sphenopteris obtusiloba, Brongn. Oligocarpia Guthieri, Goppert.* Pecopteris Miltoni (Artis). Dactylotheca plumosa (Artis). Mariopteris muricata (Schl.). Neuropteris cf. callosa, Lesq. Newropteris heterophylla, Brongn. Newropteris obliqua (Brongn.). Neuropteris rarinervis, Bunbury. Neuropteris Scheuchzeri, Hoftm. Neuropteris tenuifolia (Schil.). Linopteris Miinsteri, Kichw. Aphlebia. crispa (Guthier). Calamites Cisti, Brongn. Calamites ramosus, Artis. Calamites Suckowi, Brongn. Calamites undulatus, Sternb. Calamocladus charefornvis (Sternb.). Calamocladus equisetiformis (Schl.). Calamocladus grandis (Sternb.). Annularia radiata, Brongn. Annularia sphenophylloides (Zenker). Pinnularia capillacea, L. & H. Pinnularia columnaris (Artis). Sphenophyllum cuneifolium (Sternb.). Sphenophyllum emarginatum, Brongn. Lepidodendron lycopodioides (Sternb.), Zeiller.? Lepidodendron rimosum, Sternb. Lepidostrobus variabilis, L. & H. Lepidophylium lanceolatum, L. & H. Bothrodendron minutifolium (Boulay). Bothrodendron sp. nov. Sigillaria discophcra (Konig). Stigmaria ficoides (Sternb.). Stigmaria ficoides, var. undulata, Goppert. Rhabdocarpus clavatus (Sternb.). 1826. Carpolithes clavatus, Sternb. ‘ Essai @un Exposé géogn.-botan. de la Flore du monde prim.’ fase. iv, p. xl & fase. i, pl. vii, figs. 14 a-0. 1826. Carpolithes lagenarius, Sternb. ibid. fase. iv, p. xli & fase. i, pl. vii, fig. 16. 1855. Rhabdocarpos clavatus, Geinitz, “Versteinerungen d. Steinkohlenforma- tion in Sachsen’ p. 42 & pl. xxii, figs. 12- 14. Westphalian Series. (Mrppie Coau-MraAsurEs.) Species from shale immediately below the Bradford Four-Foot Coal, Bradford Colliery, Manchester :— Neuropteris gigantea, Sternb. Neuropteris tenuifolia (Schl.). Linopteris Miinsteri (Hichw.). Linopteris obliqua (Bunbury). Calamocladus equisetiformis (Selil.). Lepidodendron lycopodioides (Sternb.), Zeiller. Lepidostrobus anthemis (Konig). Lepidostrobus variabilis, L. & H. Lepidophyllum lanceolatum, L. & H. Species from shale 264 feet below the Bradford Four-Foot Coal, Brad- ford Colliery, Manchester :— Sphenopteris cf. schatzlarensis (Stur). Mariopteris muricata (Schl.). Linopteris obliqua (Bunbury). Calamites Cisti, Brongn. (?). Calamites undulatus, Sternb. Calamocladus equasetiformis (Schl.). Annularia sphenophylloides (Zenker). Sphenophyllum cuneifolium (Sternb.). Sphenophyllum majus, Bronn (?). Lepidophiotos sp. Lepidostrobus anthemis (Konig). Discussion. Dr. Warecton Hinp said that he would enter a caveat against the adoption of the new classification of the Coal-Measures proposed by the Author. The study of paleobotany was of the highest importance, but plants were not the only fossils found in the Coal- Measures ; the evidence of all the fossils alike, fishes and mollusca 1 The Discopteris (2?) Ralli of Mr. Gerrard’s list, op. cit. p. 561. 2 As figured by Prof. Zeiller, in his ‘ Description de la Flore fossile du Bassin houiller de Valenciennes’ (Gites minéraux de la France) 1886, pl. Ixix, figs. 2-3 copliixx, fig. 1. 322 MR. R, KIDSTON ON THE DIVISIONS OF THE [May 1905, as well as plants, must be taken into account, and the story told by cach must agree in the main details, else classification, founded on the study of one group alone, would probably lead to erroneous results. It was difficult to criticize a paper from a mere abstract, but the questions which at once occurred to him were :—‘ How sharp are the proposed lines of subdivision? Are they exact and | absolute? Can they be traced from coalfield to coalfield? Are they of practical utility?’ The speaker felt strongly that there was no good reason for taking the Bassey-Mine Ironstone as the base of a subdivision; a similar flora and fauna occurred both above and below this horizon, and he (the speaker) had made his subdivision at the horizon of the Gubbin Ironstone, where Anthracomya Phillipstt came in for the first time, on lithological grounds. He entirely objected to the term Staffordian, for two reasons. It was unnecessary, for there were already in use the terms Etruria Marls and Blackband Series, which were more topical and exact. As the Blackband Series was not developed in South Staf- fordshire, the term Staffordian was inexact and included too much. Indeed, used in the Author’s sense, it ought to be North Staffordian. | The speaker also entered a protest against the use of the terms Westphalian and Lanarkian. There was neither unconformity nor faunal break in the Coal-Measures of the Midlands, and any sub- division must be therefore wholly artificial and empirical. Further, he did not believe that the Lanarkshire Coalfield was merely the homotaxial equivalent of the lower part of the Staffordshire Coal- Measures. The molluscan fauna strongly contradicted such an assumption. The heresy of the subdivision into Upper, Middle, and Lower Coal-Measures had taken a long time to kill, and the speaker failed to see that the Author’s proposition had any more real basis. At any rate, in North Staffordshire there was no strati- graphical or faunal evidence in favour of drawing a subdivision at the Ash Coal. | Mr. Srranan agreed with the previous speaker in deprecating the introduction of the new names suggested for the subdivisions of the Coal-Measures. ‘They were inferior to the old names, in being in no way self-explanatory, while they placed an unnecessary tax upon the memory. It had been said during the evening that horizons in the Coal- Measures could be determined both by plants and lamellibranchs, but he would point out that a problem of the greatest economic importance, which had exercised the minds of the Coal-Commissioners of 1871 and of mining engineers ever since, remained still unsolved. The difficulty lay in correlating the Measures proved at Bradford with those at Astley, and in determining the relative positions of the Bradford Four-Foot Seam and the Worsley Four-Foot Seam. There were more than 3000 feet of strata in question. So far, they had been told that the Bradford Seam was associated with plants of ‘Transition’ (Staffordian) type, and a correlation was suggested Vol. Or. UPPER PORTION OF THE COAL-MEASURES. Be with the Bassey Mine of Staffordshire, but none was attempted with its immediate neighbour, the Worsley Seam. As a fact, when the question came up for consideration by the Royal Commission of 1905, no help was forthcoming from paleontologists. The Author’s views with respect to the general distribution of the plants and the absence of hard-and-fast lines between the floras seemed to be quite in accordance with facts, and the paper was an important addition to the Author’s previous contributions on the subject. Mr. J. T. Sropss said that, as a worker among the Coal- Measures, who collected plants, shells, and fishes, he felt compelled to protest against the proposed general classification of the Coal- Measures for the following reasons :—(1) It was based on partial evidence, and neglected the valuable aids to be derived from the fossil mollusca Pia fishes. Above the base of the Etruria Series, no doubt that, together with the evidence of thin entomostracan bands, the plant-evidence was of paramount importance; but, below that line, he stated without hesitation, after a daily experience extending over several years, that the lamellibranchs were of ereatest use for the correlation of the Measures. (2) It was un- necessary : all that the paper demonstrated was the accuracy and soundness of Mr. Walcot Gibson’s work in subdividing the Upper Measures of the Midland Coalfields: to add the term Radstockian to that of Keele was quite unnecessary. (3) The upper and lower limits of the ‘Staffordian’ were very definite zoological lines, and it was more than doubtful that they coincided with so sweeping a change in the fossil flora. The Bassey-Mine Ironstone was not a well-chosen base, as the plants from beds below were similar to those in the overlying marls. Could the Author have dis- tinguished the Keele Series from the Newcastle Series, simply by the aid of the plant-evidence which he had examined from the Newstead boring ? Mr. Watoor Grnson stated that the terminology suggested by the Author was founded on strictly _palesobotanical lines, and paleo- botanists must decide as to its value. for local purposes of the correlation of one seam of coal with another, the plant-evidence was of less value than the shells; but instances had recently occurred when the plant-remains had proved of great service, in determining whether a red sandstone reached in a boring belonged to an horizon above the Productive Measures or to one wholly below them. 324 MR. E. A. NEWELL ARBER ON THE [May 1905, 13. On the Seorane1uM-LIkE Oreans of GLossoPrerss BROWNIANA, Brongn. By EH. A. Newetn Arper, M.A., F.L.S., F.G:S., Trinity College, Cambridge; University Demonstrator in Paleobotany. (Read February Ist, 1905.) [Puates XXX & XXXTI_] ConrENTS. Eetintroduchons..ca8.5e aseeanen ee etre Bie tana aso IT; Deseription of the Specimens) 42.6. -e-o setee eee eee eee III. The Morphology of the Sporangium-like Organs............ 327 IV. The Evidence for the Attribution of the Sporangium-like Oreans to Glossoplents hast: -tccescec ecco nencee tee ee eee EEee V. The Morphological Nature of the Sporangium-like Organs. 330 VI. Historical Sketch of the present Evidence as to the Bructification tot (Glossoprenis: aaiacc.dece--4--eeee oe eee 332 VIL. ‘(General Conclusioms, .22.sedanescnncdes coe oo stinoks See EE 334 VIELE, sBilblioprappliy. 2. usicteence.ccesetescessemseun tees iectise Ueceae eee 336 I. Inrropvuction. GLOSSOPTERIS 18 now among the most familiar of all fossil plants. The tongue-shaped fronds of this genus, with their reticulate lateral nervation, are exceedingly characteristic of the Permo- Carboniferous rocks of India, Australasia, and Southern Africa, and occur also in the Permian of Russia, and in beds of Rhetic age in Tongking and China. So great is the abundance of these fern-like leaves in the Lower Gondwana Series of India, and its homotaxial equivalents in the Southern Hemisphere, that this plant has given its name to the flora of that former continental region. Although a very large number of Gilossopteris-fronds have been described by different authors, it is only within the last few years that we have learnt anything as to the general habit of this plant. We are chiefly indebted to the researches of Prof. Zeiller, of Paris, for progress in this onee It has now been ascertained that this plant was heterophyllous,"—a fact which was first suggested by M‘Coy in 1847.° In addition to tbe larger and often tongue- shaped fronds, much smaller leaves, generally spoken of as scale- fronds, were borne on a rhizome-like stem, which has been long known under the name of Vertebraria.? The nervation of the scale-fronds resembles that of the larger leaves, except that there is no midrib. In shape they are, as a rule, ovately triangular, pointed at the apex, and strongly concave. An average specimen measures 14 centimetres or more in length. 1 Zeiller (96!) p. 865. [Numerals in parentheses after authors’ names refer to the dates in the Bibliography, § vil, p. 336.] 2 M‘Coy (47) p . 151; see also Arber (02) p. 9. é Zeiller (96° wand Oldham (97). Vol. 61. | SPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS. 395 Up to the present time we are without any definite information as to the fructification, and consequentiy we know nothing of the true systematic position of this genus. It is admitted that the sporangia of this plant have never been observed.’ NSeveral authors, however, have drawn attention to certain features occasionally exhibited by the larger fronds, which they have interpreted as indications of the position of sori. ‘The evidence on this point will be discussed at a later stage in this paper (p. 332). Some months ago, when cataloguing the large collection of fronds of Glossopteris in the Geological Department of the British Museum (Natural History), I discovered some specimens from New South Wales exhibiting numerous and well-preserved scale-leaves, with which were associated groups of minute bodies almost invisible to the naked eye. On microscopic examination these proved to be sac-like organs which, so far as [ am aware, are new to science. These bodies will be fully discussed here, and it will be shown that they resemble the sporangia of certain living and extinct plants closely enough to permit us to speak of them as sporangium-like organs, ‘The specimens which exhibit these sac-like structures are unfortunately few in number; and despite the fact that similar, but less perfect, examples have since been discovered in the collections at Cambridge, the material available in the museums of this country for the study of these new organs is at present too limited to permit of a complete or final elucidation of their nature or structure. While, therefore, some of the con- clusions expressed here are to be regarded as provisional, pending the discovery of further specimens, there is reason to believe that the present evidence is sufficiently strong to show that these bodies, whatever may be their precise nature, may be attributed with confidence to the fossil plant known as Gilossopteris Browniana, Brongn. Il. D&scriprion or THE SPECIMENS. Before describing in detail the structure and possible nature of these sac-like organs, a brief description may be given of the specimens on which they occur. In no case is the anatomical structure preserved. The sacs are preserved merely as casts or impressions, and, as such, the preservation is often exceedingly pertect. V. 7202, in the Geological Department, British Museum (Natural History)—This specimen is a nearly- square piece of pinkish shale, obtained from Port Stephens (New South Wales), and belongs to the Odinheimer Collection, which was transferred to the Museum about the year 1859. ‘Typical fronds of Glossopteris Browniana occur on both sides of the specimen ; in fact, the rock appears to consist largely of impressions of these leaves. Several well-preserved scale-fronds are seen on one surface, and closely associated with them are groups of minute prominences ' Seward (971) p. 319. Q.J.G.8. No. 242. Z 326 MR. E. A. NEWELL ARBER ON THE [May 1905, scarcely visible to the naked eye. ‘These are the clusters of sporangium-like bodies. Enlarged drawings of some of these organs are shown in Pl. XXX, figs. 1 & 3 & Pl. XXXL, fig. 3. The scale-fronds have a bluish tint, which is a natural feature. A group of these fronds, somewhat flattened, occurs at one angle of the specimen, of which the largest is 1:7 centimetres long, and about 1 em. broad at its widest part. Close to them, a considerable number of the sporangium-like bodies are scattered over the surface of the shale, some of which are represented in Pl. XXX, fig. 1, and Pl. XXXI, fig. 3. Smaller portions of scale-leaves are also found, some of which appear to show the prints, or scars of attachment of the sporangium-like bodies, and some fragments of these organs possibly still in continuity. The best example is figured in Pl. XXX, fig. 4. Several other groups of these organs occur on the same specimen, in close proximity to scale-leaves, of which that figured in P]. XXX, fig. 3 is a typical instance. V. 7211 is a similar specimen, in the same collection, and from the same locality.—lIt is a triangular piece of pinkish scale, on which are to be found twenty or more examples of the scale-fronds, and a few fragments of the larger fronds. Associated with the scale-leaves, numerous scattered groups of the sporangium-like bodies may be observed, of which two speci- mens are figured in Pl. XXX, fig. 2 and Pl. XXXI, fig. 4. There also appears to be some evidence, though not very distinct, of scars, possibly the scars of attachment of these organs, on some fragments of the scale-fronds. 39,149 is another, and similar piece of shale, in the same collection, and from the same locality, which shows several, nearly-perfect specimens of the larger fronds, and a good example of a strongly-convex scale-frond, as well as other less perfect fragments of the scale-leaves. The groups of sporangium- like bodies are fairly well-preserved, but are not perhaps quite so satisfactory as in the previous specimens. In one instance, a small portion of a scale-frond appears to exhibit one or two scars, possibly the prints of attachment of these organs, and also several sporangium-like organs have the appearance of being still in con- tinuity, but, in this case, the evidence is less trustworthy than that of the previous specimen (Pl. XXX, fig. 4). Many of these sporangium-like bodies, in this as in other specimens, have opened or dehisced (Pl. XXXI, fig. 1). The inner surface is strongly concave, and may be distinguished from the outer by the fact that the cell-walls of the inner limiting-layer are much less conspicuous. The detached sporangium-like organs often occur in groups (Pl. XX XI, fig. 2), arranged as if several were borne together in a cluster or sorus. No. 65 in the Sedgwick (Woodwardian) Museum, Cam- bridge (Foreign Plant-Collection), was obtained from the Vol. 61.] SPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS. 327 Neweastle Series of New South Wales, and belongs to the Clarke Collection presented to the Museum in November 1844.—This spe- cimen is especially interesting, for M‘Coy,! in 1847, first ascertained from it the existence of the scale-fronds of Glossopteris. Several good examples of the scale-leaves are shown, some of which measure from 1:5 to 2 centimetres or more in length. Near one of them, a group of detached sporangium-like bodies occurs, similar to those seen in the preceding specimens, but not quite so well preserved. No. 104 is a specimen recently acquired by the Sedg- wick Museum, from Adamstown (New South Wales).— The rock is largely composed of felted masses of the fronds of Glossopteris, with an occasional scale-frond. Near one of the scale-fronds, a few, rather indistinct impressions of these sporan- gium-like bodies may be seen. No. 446, in the Bunbury Collection, in the Botany School, Cambridge, was obtained from the Hunter River at Newcastle (New South Wales).—A portion of this specimen has recently been figured by Mr. Seward,’ to whom I am indebted for an opportunity of examining the material in the Bunbury Col- lection. ‘he rock consists of a pinkish shale, in many respects similar to the specimens in the British-Museum Collection, and, like those specimens, was originally acquired through the Geological Survey about the year 1859. In addition to the scale-fronds figured by Mr. Seward, other and less perfect examples occur; and, in one case, where a portion of the highly-convex scale-frond has been broken away, a group of these sporangium-like bodies is exposed, lying beneath the scale-leaf. One of these sacs shows the neck-like extremity very clearly. A few other groups can be made out, but they are not distinct, nor is the preservation very good. IIL. Tar MorpuonoGy oF THE SPORANGIUM-LIKE ORGANS. From a study of the groups of detached sporangium-like bodies occurring on the specimens above described, the following points in their morphology can be determined. They are somewhat elliptical in shape, tapering at either extremity (Pl. XXX, figs. 1-3 & Pl. XXXT, figs. 2-4). They measure from 1-2 to 1°5 millimetres along the major axis, and their greatest breadth varies from ‘6 to°8 mm. The shape of these bodies naturally differs somewhat, according to the particular manner in which they have come to rest upon the clay, and according to the aspect which they present (Pl. XXXI, figs. 3&4). In some examples, one extremity appears to be bent into a short neck-like prolongation, measuring about -2 mm. in length (Pl. XXXI, fig. 3 at a, & Pl. XXX, fig. 3 at x), and thus the whole body resembles somewhat a retort in shape. In others, the neck is flattened on the main portion of the body, 1 M‘Coy (47) p. 151; Arber (02) p. 9. 2 Seward (97') p. 318 & pl. xxiii, fig. L. 328 MR. E. A. NEWELL ARBER ON THE [ May 1905, while in others again no such neck can be recognized (P!. XXX, fig. 1 & Pl. XXXI, fig. 4). In many of the specimens, especially those in which the preserva- tion is particularly good, the cell-walls of the outer lmiting-layer of the sac are conspicuous (Pl. XXX, figs. 1-2 & Pl. XXXI, fies. 3-4); and the sac has the appearance of being strongly striated in the direction of its greater axis. ‘These walls are united by very short cross-walls, placed more or less obliquely, and thus the cells are rhomboidal in shape, and of much greater length than breadth (Pl. XXXI, fig. 4). At the apex of the sac, which is probably the extremity opposite to the neck, the cells appear to be somewhat smaller and narrower. Such evidence as there is to be found in these specimens, points to the fact that these sporangium-like bodies were probably attached by the neck-like prolongation. In the few, and perhaps not wholly trustworthy instances, in which fragments of these organs seem to be still in continuity with the scale-leaves (Pl. XXX, fig. 4), this appears to be the case; and supplementary evidence may be found in the way in which the detached bodies are often grouped together, which distinctly suggests in many cases an aggregation into sori, like the sporangia of many fossil and recent ferns. In Pl. XXX, fig. 3, portions of four of these bodies are seen, in one of which (#) the neck is evident, and is turned towards what was probably the common point of attachment of ail the organs of this group. Another such group, similarly arranged, is figured in Pl. XXXIJ, fig. 2. The evidence for the attribution of these sac-like structures to. Glossopterts Browniana will be dealt with in the following section of this paper. It will be shown that there are some grounds, although not as conclusive as one could wish, for the view that these sporangium-like organs were borne on the concave surface (possibly the lower surface) of the scale-leaves. These organs are not solid bodies. They were undoubtedly sac- like structures, and, in the living state, must have contained something. Their appearance is essentially that of a distended sac (Pl. XXX, fig. 2). Further, they seem to have opened or dehisced longitudinally, that is, in the direction of the major axis (Pl. XXXIJ, fig. 1). The exact mode of dehiscence cannot be ascertained. The splitting may have begun first at the apex (Pl. XXX, figs. | & 2), but this is not quite certam)) Une evidence is, however, sufficient to show that such dehiscence was, in all probability, a natural feature at a certain stage in their development. The wall of the sac, so far as one can judge from specimens in which the anatomical structure is not preserved, was probably more than one layer of cells in thickness. Not only does. it appear to be comparatively thick (Pl. XXX, fig. 1 a), but the cell- walls of the inner limiting-layer are much less conspicuous than those of the outer, and in many cases can hardly be distinguished (Pl. XXXI, fig. 1). The three sporangium-like bodies figured in Pl. XXXI, fig. 1 have probably all dehisced, and are viewed from a.) Vol. 6r.] SPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS. © 329 the inner surface, as is shown by the shape and concave surface, as well as by the much less prominent character of the cell-walls. Unfortunately, no trustworthy evidence can be obtained as to the contents of these sacs. In cases where the splitting appears to have just begun, a solid mass of grey material projects (Pl. XXX, fig. 2a), but the nature of the contents cannot be distinguished. In other examples (Pl. XXXI, fig. 1) a few very minute bodies, dissimilar to the matrix of the rock, can be seen on the inner surface of the fully-opened sacs, but these afford no evidence of any value on this point. LY. Tur Evipencr ror tHe ATTRIBUTION OF THE SPORANGIUM-LIKE ORGANS TO G'LOSSOPTERIS. There would seem to be little doubt that these sporangium-like organs belong to Glossopteris Browniana, although the evidence is, in part, indirect. These sac-like bodies have never been observed, except in close relationship to the scale-leaves of Glosso- pteris. ‘The fact that specimens, which do not show the scale- fronds, are also wanting in respect to these retort-like sacs is especially significant, and argues a connection between these two organs. Hxamples of the scale-fronds are comparatively rare, both at the British Museum and at Cambridge, and are probably not very abundant, at present, in any foreign collection. This fact probably explains why these sporangium-like organs have remained un- observed until the present day, although many authors (including Bunbury, Feistmantel, Zeiller, and others) have closely studied the larger fronds of this genus, with the view of obtaining evidence as to the fructification of Glossopteris. I have, myself, recently had occasion to examine carefully the considerable collections of the larger fronds in the British and Sedgwick Museums, which include the best examples in this country, but I have not, in any single instance, observed these sac-like bodies on specimens which do not also show scale-leaves in close proximity. As a further test of the value of this evidence, I asked Prof. Zeiller to search for these organs among the specimens of Glosso- pteris from the Transvaal, which he described in 1896. This he very kindly undertook to do, and was successful in finding an example, which again occurred in close proximity to a scale-leaf.’ I may here express my thanks to him for his kindness in this matter. The evidence, detailed above, is admittedly of a negative nature, but it is now recognized that, as such, it is not without weight, when based on a sufliciently-large number of observations. In addition, there is also some direct evidence to be gained from these specimens. It has been already pointed out that, in a few cases, none of which perhaps are so conclusive as one could wish, 1 The sac in question occurs on the left-hand border of the scale-leaf figured by Prof. Zeiller, (96') pl. xvi, figs. 138 & 13a. a 330 MR, E. A. NEWELL ARBER ON THE [May 1905, some of the fragments of the scale-leaves show what may possibly be interpreted as the scars of attachment of these sporangium-like bodies, and also portions of the sac-like bodies themselves, which have the appearance of being stillin continuity. The best example is that seen enlarged 15 times in Pl. XXX, fig. 4. It consists of a small portion of a scale-leaf, which, at the lower extremity, is obscured by a confused mass of these sac-like bodies resting upon it. The leaf is undoubtedly a scale-leaf, as is shown by the absence of a midrib, and the nervation, which, although somewhat faint, is that of a Glossopteris. Several oval scars are seen (at a, b,c), and in two cases (6 and c) fragments of the sacs are apparently still in continuity. No great weight is, however, laid on the latter point, for, in such impressions, it is often a matter of the greatest difficulty to show that features which suggest continuity may not be equally well explained on the grounds of chance association. Similar, but less clear evidence is to be gained from fragments of some of the other scale-leaves exhibited by these specimens. In this connection, the absence of any trace of the rhizome, Vertebraria, in association with these organs is remarkable, and the probability is thereby increased that these sac-like bodies were not borne on a stem-structure. ‘There is also no suggestion of any aggregation into a strobilus-like arrangement, however lax. This evidence, in addition to that of the constant association of these sac-like bodies with the scale-fronds already discussed, while it may not be quite conclusive as to the exact manner in which these organs were borne, is, I think, sufficient to place beyond doubt their attribution to the fossil Glossopteris Browniana. V. Tun MorpnonogicaAL NATURE OF THE SPORANGIUM-LIKE ORGANS. There remain to be discussed the nature and probable function of these sac-like bodies. It would seem certain that, whatever may be the true solution of this problem, these organs are not ramenta or chaffy scales, such as occur on many ferns, both living and extinct. Their hollow, sac- like structure, as well as other features of their morphology, is totally opposed to any such inference. On the other hand, there is much to be said in favour of the conclusion that these organs were true sporangia. We have seen that there is some evidence for the provisional view, that they were borne on the scale-fronds of Glossopteris Browniana, that is on a foliar organ. The aggregation of these sac-like bodies into groups, recalling the sori of the true Ferns, lends further support to this argument. In their structure also, these bodies exhibit characters common to the sporangia of both living and extinct plants, although, so far as | am aware, they do not agree so closely with any one type of sporangium as to remove at once all doubt concerning their - real nature. In size, they are neither larger nor smaller than certain fossil sporangia. They agree very nearly in this respect with those of Vol. 61.| sPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS, 301 Sphenophyllum, as described by Prof. Zeiller.. They are somewhat larger than the sporangia of Discopteris,? but not so large as those of Zygopteris.3 There is also a certain similarity in shape and structure with the sporangia of Discopteris Rallu, Zeill., and of Sphenophyllum cunei- folium (Sternb.); although in both cases such sporangia exhibit features which are not present in the specimens described here, The shape of the cells of the outer limiting-layer is, however, an especially-conspicuous character in common. An even closer com- parison may be found in the microsporangia of recent Cycads, such as Stangeria paradoxa, Th. Moore (compare, in Pl. XX XI, fig. 4 with fig. 5: the latter representing the Cycad-sporangium), which are neither dissimilar in size, shape, nor mode of dehiscence, and on the whole agree better with these new specimens than any other type of sporangium with which I am acquainted. It has been pointed out that the wall of these sac-like organs was probably more than one layer in thickness, so far as it is possible to judge of such a character in cases in which the anato- mical structure is not preserved. This feature is also common to fossil sporangia, such as those of Zygopteris, and many others. Further, if these bodies are rightly interpreted as sporangia, then the sporangium of Glossopteris was exannulate, and in this respect resembled a very large proportion of Palozoic fern-like plants. If an annulus had been present; or if these sac-like bodies had been united into synangium-like groups; or, again, if the anatomical structure had been preserved, their morphological nature would have been obvious. But the fact that no annulus is present does not militate against the sporangial nature of these new specimens. In addition to the Paleozoic plants, some recent Ferns, the Marattiaceze in part, are exannulate, and the microsporangia of recent Cycads, which these bodies so closely resemble, are also probably without a true annulus.* We have a further confirmation of this view in the fact that these sac-like bodies tend to open longitudinally, in a manner somewhat closely similar to the microsporangia of such a Cycad as Stangcria, or the sporangia of the recent fern Angiopterts. That these sporangium-like bodies dehisced appears to be abundantly evident from these specimens, and their manner of dehiscence is not unlike that of many Paleozoic fern-like plants. Thus, there seems to be little doubt, in the face of the whole of this evidence, that the probable nature of these sac-like bodies was that of a sporangium. A sporangium, however, should contain spores, but unfortunately I have so far failed to obtain any evidence as to the contents of these sacs. It is quite possible that the spores may have been very minute. Certainly, if they were as small as the pollen-grains of Stangeria, we should be hardly able 1 Zeiller (93) p. 21. ? Zeiller (99) p. 18 & text-figs. 3-4. 3 Scott (00) p. 288. * Lang (97) p. 481 & (00) p. 297; Treub (81) pl. iti, fig. 2. 332 MR, E. A. NEWELL ARBER ON THE [May 1905, to identify them in such impressions, Even in petrified material, spores cannot always be found in certain types of sporangia. In the absence of any recognition of spores, and in view of the some- what provisional nature of some of the other conclusions arrived at, | prefer to speak of the sac-like bodies for the present as sporangium-like organs. On the evidence presented here, I regard their sporangial nature as highly probable, and I am unable to suggest any alternative hypothesis. VI. Histrorican SKETCH OF THE PRESENT EVIDENCE AS TO THE FRUCTIFICATION OF GLOSSOPTERIS. The conclusion that the organs described here are probably, though not beyond all doubt, of the nature of sporangia, and therefore the whole or part of the reproductive apparatus of the sporophyte of Glossopteris, calls for some brief remarks on the numerous views which have been already expressed by different authors concerning ~ the subject of the fructification of this plant. As has been already stated, no one has so far recognized any bodies that could be regarded as the sporangia of Glossopteris, although several have figured features which have been considered as indicative of sori. The sori of Glossopteris have been described by one or other writer in every possible relationship to the larger fronds, and to them alone. Mr. W. Carruthers! has detected what he believed to be sori on some fronds from Queensland, which he describes as ‘indications of fruit, in the form of linear sori running along the veins, and occupying a position somewhat nearer to the margin of the frond than to the midrib.’ : Such sori occur in several recent ferns, Antrophyum reticulatwn, Kaul., among others, which possesses a frond not unhke that of Glossopteris. It is, however, very doubtful whether the sori were borne on the secondary nerves in the latter genus. The preservation of some of the fronds from Tasmania and New South Wales is so exceptionally good, that it is almost certain that such sori (if they had existed) would have been detected long ago. Feistmantel * described and figured a number of fronds which he regarded as fertile. Among these, one of the linear type, Glossopteris angustifolia, showed a narrow portion of the lamina at the margin, which was not traversed by the lateral veins, and this Feistmantel regarded as indicative of marginal sori. It is hardly necessary to point out that this alone is not trustworthy evidence in favour of such a conclusion. But by far the most numerous examples, figured by various authors as possibly fertile fronds of Glossopteris, are those in which circular or oval spots, patches, or holes occur in the lamina of the frond, often of considerable size, and sometimes arranged more or less parallel to the midrib. 1 Carruthers (72) p. 354. Feistmantel (80) p. 106 & pl. xxxix a, figs. 1, la, 2. Vol. 61.] | SPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS. 3393 Brongniart,’ himself, first pointed out the occurrence of patches — of this type on the frond named by him Glossopteris Browniana var. andica, which he stated were probably indications of sori. In 1861, Bunbury * figured further fronds from India of a similar nature, which he regarded with little doubt as indicating sori, although he admitted that he could find no organic structure. Mr. Seward * has recently re-examined Bunbury’s specimens, which are in the Museum of the Geological Society of London, and ha concluded that ee: : i may be that the patches are merely holes in the leaf, and not the impressions of sori.’ With this conclusion I quite agree, having also had an opportunity of seeing the specimens in question. We may pass over the figure given by Ralph Tate* in 1867, under the name of Rubidgea Mackayi, which was supposed to be a fertile frond of a somewhat similar kind, since the type-specimen has never been in this country, nor examined by a competent authority. His figure is simply a reproduction of a sketch sent from South Africa, and now in the Museum of the Geological Society. Feistmantel’ figured fronds of Glossopteris Browniana and Gl. indica, showing features which he interpreted as indications of sori, but most of these would appear to be holes in the fronds, somewhat irregularly arranged on either side of the midrib, and very unequal In size. Prof. Edgeworth David® described in 1891 a Glossopteris from the Greta Coal-Measures at Richmond Vale, near Maitland (New South Wales), showing dark oval-shaped bodies symmetrically arranged on the leaves, which might possibly represent the fructi- fication. Mr. Etheridge, jun., however, who also examined the specimens, regarded the evidence in this case as inconclusive. Somewhat similar specimens, also from New South Wales, were described and figured by Mr. John Mitchell” in 1893, in which three suboval, convex impressions occurred between the midrib and the margin, which were regarded as sori. In 1894, Mr. Etheridge, jun.,° discussed at some length the evidence as to the fructification of this genus, and, like Feistmantel,’ laid perhaps more stress on this character, from a systematic standpoint, than the present position of our knowledge altogether justifies. In 1896, Prof. Zeiller ® figured an apical portion of a frond of Glossopteris angustifolia, which seemed to show indications of sori on each side of the * Broneniart (28) p. 224 & pl. lsii, fig. 2. Bunbury (61) p. 827 & pl. viii, fig. 1. * Seward (977) p. 180. * Tate (67) p. 141 & pl. v, fig. 8. 5 Feistmantel (80) pp. 97-98, 101 & pl. xxvi A, figs. 1-4, pl. xxviia, figs. 1, 2,5; dd. (82) p. 32 & pl. xxi, figs. 13-14. ° David (91) pp. 424-25. 7 Mitchell (93) p. 377 & text-fig. 8 Etheridge (95) pp. 236, ete. 9 Feistmantel (80) & (82). 10 Zeiller (96) p. 369 & pl. xviii, fig. 3. to = Re Se a B04 - MR. E. A. NEWELL ARBER ON THE [May 1905, median nerve. These patches are oval in shape and fairly well- defined, consisting of three or four slight depressions, which recall the sori of certain recent Polypodiums. On the other hand, in the following year, Mr. Seward figured @ specimen very similar to Prof. Zeiller’s leaf, also from South Africa, which showed irregular elliptical or circular holes in the frond instead of sorus-like patches. Mr. Seward has called attention to the ‘danger of attaching any great importance to characters of this kind.’ In the same year, he? also concluded a summary of the present evidence with the following remarks : ‘On the whole, it would seem the safer course to admit that as yet no trust- worthy example of a fertile Glossopteris-frond has been recorded from either India or Australia, and we have certainly no data on which any classification can be legitimately founded.’ Before leaving this subject, I may point out that a provisional suggestion of my own,*® put forward in 1903, when describing some Glossopteris-fronds from Rhodesia, is probably quite mis- leading. Although I am still unable to account satisfactorily for certain features presented by the fronds in question, | do not now regard them as in any way connected with the fructification, as I then suggested. Such, so far as I am aware, is practically all the evidence that we have at present on the subject of the fructification of Glossopteris. No organ of the nature of a sporangium has ever been described. The evidence of the position of sori has been gathered from spots, patches, or holes occurring on the lamina of certain of the larger fronds. I have myself observed such occurrences, but in no case have I obtained any real evidence that they are in any way indicative of sori. In order to ascertain whether such holes and patches occur among recent ferns of similar habit, I have looked through the specimens in the Cambridge herbarium, and I have found that holes are far from rare in such fronds. Spots or patches also occur, here and there, on fronds, which are quite with- out any connection with the fructification. A particularly-good instance was found in a sterile frond of Seward (97°) p. 181. ° Arber (03) pp. 288-89. Vol. 61.| SPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS. 335 sporangia—if these retort-shaped bodies are really of this nature— were possibly borne on the smaller scale-fronds, is a new one, and does not in any way involve the larger fronds. It has this merit, that definite organs, which in size, shape, and structure have been shown to be not unlike the sporangia of certain recent and Paleozoic plants, and are also aggregated into sori, are described for the first time. Although the final proof of the sporangial nature of these organs—the recognition of spores—is wanting, the resemblance is sufficiently striking to warrant the term sporangium-like organs. If, as is suggested here provisionally, it should eventually prove that these bodies are true sporangia, then it would seem to be impossible to regard Glossopteris as a Fern allied to any recent family of the true Ferns. It may have belonged to some extinct race of Ferns, but it must be borne in mind that, although this plant has been regarded as a Fern by most of those who have studied it in the past, this view has been based on the similarity of habit and leaf-form, rather than on any real knowledge of the fructification. While itis true that the fronds of Glossopterts agree fairly closely with those of certain species of the recent ferns Dry- moglossum, Acrostichum, Onoclea, and others, as Prot. Zeiller’ and Mr. Seward’ have pointed out, they are quite unlike any recent family of Ferns in the characters of their sporangia. Dimorphic ferns exist, in which the fertile fronds are smaller than the sterile, and in which the lamina is not markedly reduced, as for instance, among others, Acrostichum villosum, Sw.’ But in the case of Glossoptercs, the sporangia, if such be the real nature of these sac-like bodies, would seem to agree more closely with the microsporangia of a Cycad than with the sporangia of any living fern. Or again, even if the sporangial nature of the organs described here be admitted, it may be doubted whether our knowledge of the affinities of Glossopteris is thereby much advanced. Such evidence as there is would tend to remove the genus from proximity to the recent Ferns, despite its fern-like habit, and it has yet to be ascertained whether Gilossopteris was an isosporous or a hetero- sporous plant. In the latter event, these sac-like bodies are probably microsporangia. At present, however, there is no means of solving this problem. There is still a further possibility to be borne in mind. It has been recently shown that some of the most fern-like of all the fronds of the Coal-Measures did not belong to the true Ferns, but to a race of seed-bearing plants, for which the name Pterido- spermez* has been recently suggested. Some of the British Sphenopterids and Neuropterids* are of this nature. There 1s at least the possibility that G'lossopteris may eventually prove to be a seed-plant, in which case the similarity of these sporangium-like 1 Zeiller (96') p. 369. 2 Seward (97') p. 319. * Hooker & Greville (51) pl. xcv. * Oliver & Scott (04) p. 239. 5 Kidston (04). 306 MR..E. A. NEWELL ARBER ON THE [May 1905, bodies to the microsporangia of the Cycads, which has been emphasized here, would have a special significance. It is hoped . that, by calling attention to the importance of a further study of the scale-fronds of Glossopteris, a stimulus will be given to the collection of additional specimens, which may throw further light on these problems. In conclusion, I wish to express my great obligations to Dr. D. H. Scott, F.R.S., who has, throughout this work, most kindly given me the benefit of his opinion and advice on the more difficult problems which have arisen. I would also express my thanks to Dr. A. Smith Woodward, F.R.8., Keeper of the Geological Department of the British Museum (Natural History), for obtaining for me the loan of the specimens in that Museum, and for the interest which he has taken in the progress of the work. VIII. Bretrograrny. Arpur, E. A. N. (02). ‘On the Clarke Collection of Fossil Plants from New South Wales’ Quart. Journ. Geol. Soc. vol. lviii, p.1. 1902. : ARBER, E. A. N. (08). ‘Notes on some Fossil Plants collected by Mr. Molyneux in Rhodesia’ Quart. Journ. Geol. Soe. vol. lix, p. 288. 1903. Broneniart, AD. (28). ‘ Histoire des Végétaux fossiles.’ Paris, 1828. Bunypury, Sir Cuartes J. F. (61). ‘ Notes on a Collection of Fossil Plants from Nagpur, Central India’ Quart. Journ. Geol. Soc. vol. xvii, p. 325. 1861. CarrutueErs, W. (72). Appendix I], in R. Daintree’s ‘Notes on the Geology of the Colony of Queensland’ Quart. Journ. Geol. Soc. vol. xxviii, p. 350. 1872. Davip, T. W. E. (91). ‘ Note on the Occurrence of Glossopteris in a Remarkable State of Preservation, in the Greta Coal-Measures at Richmond Vale, near Maitland’ Proc. Linn. Soc. N.S.W. ser. 2, vol. v, p. 424. 1891. Erneripes, R., jun. (95). ‘On the Mode of Attachment of the Leaves or Fronds to the Caudex in Glossopteris’ Proc. Linn. Soc. N.S.W. ser. 2, vol. 1x. p. 228. 1895. FEISTMANTEL, O. (80). ‘The Flora of the Damuda-Panchet Divisions: Fossil Hora of the Gondwana System’ vol. i111, pts. 11 & iii. Mem. Geol. Surv. India, Pal. Indica, ser. xii. 1880-81. FEISTMANTEL, O. (82). ‘The Fossil Flora of the South Rewah Gondwana Basin : Fossil Flora of the Gondwdna System’ vol. iv, pt. 1. Mem. Geol. Surv. India, Pal. Indica, ser. xii. 1882. Hooxer, W. J., & Grevitie, R. K. (81). ‘Icones Filicum’ vol.i. London, 1831. Kipston, R. (04). ‘On the Fructification of Newropteris heterophylla, Brongniart ’ Phil. Trans. Roy. Soc. ser. B, vol. cxcvui, p.1. 1904. Lane, W. H. (97). ‘Studies in the Development & Morphology of Cycadean Sporangia: I. The Microsporangia of Stangeria paradoxa’ Ann. of Botany, vol. xi, p. 421. 1897. Lane, W. H. (00). ‘Studies in the Development & Morphology of Cycadean Sporangia: II. The Ovule of Stangeria paradoxa’ Ann. of Botany, vol. xiv, p. 281. 1900. M ‘Coy, F. (47). ‘On the Fossil Botany & Zoology of the Rocks associated with the Coal of Australia’ Ann. & Mag. Nat. Hist. vol. xx, pp. 145, 226, & 298. 1847. MircHeExy, J. (93). ‘Note on the Fructification of Glossopteris’ Proc. Linn. Soc. N.S.W. ser. 2, vol. vii, p.377. 1893. OxtpHam, R. D. (97). ‘On a Plant of Glossopteris, with Part of the Rhizome attached, & on the Structure of Vertebraria ’ Rec. Geol. Surv. India, vol. xxx, p. 45. 1897. Otiver, F. W., & Scort, D. H. (04). ‘On the Structure of the Paleozoic Seed Lagenostoma Lomaxi’ Phil. Trans. Roy. Soc. ser. B, vol. exevii, p. 193. 1904. ‘ Scort, D. H. (00). ‘Studies in Fossil Botany.’ London, 1900. Quart.Journ.Geol.Soc.Vol. LXI, PL XXX. TR REARS ! iW QO, ae te) q sa) q u 0) Dp § Ss o a fx] b+ A, © Ww (ep) @ 1 oO « fry O 2 3 aa O) fr] SS rt i ea 2 ) 4 << aa O 4 Cp) G.M.Woodward del.et lith. SEI oer synen G.M.Woodward. del.et lith . Mintern Bros. imp . SPORANGIUM-Like, ORGANS OF CLOSS OP imsyrites Vol. 61.| SPORANGIUM-LIKE ORGANS OF GLOSSOPTERIS. ag SewaRD, A. C. (971). ‘On the Association of Sigillaria & Glossopteris in South Africa’ Quart. Journ. Geol. Soc. vol. litt, p. 315. 1897. 3 SEWARD, - C. (97°). ‘The Glossopteris-Flora’ Science Progress, vol. vi, p. 178. 1897. Tarr, R. (67). ‘On some Secondary Fossils from South Africa’ Quart. Journ. Geol. Soc. vol. xxiii, p. 189. 1867. TreuB, M. (81). ‘Recherches sur les Cycadées’ Ann. Jard. Botan. Buitenzorg, VOleipt. 1 pasa. LSS, ZEILLER, R. (93). ‘Etude sur la Constitution de VAppareil fructificateur des Sphenophyllum, Mém. Soc. Géol. France, Pal. Mém. No. 11, vol. iv. 1893. ZEILLER, R. (961). ‘ Etude sur quelques Plantes fossiles, en particulier Vertebraria & Glossopteris, des Environs de Johannesburg (Transvaal)’ Bull. Soc. Géol. France, ser. 3, vol. xxiv, p.349. 1896. ZEILLER, R. (967). ‘Sur l’ Attribution du Genre Vertebraria’ Comptes Rendus Acad. Sci. Paris, vol. cxxii, p. 744. 1896. (Transl. H. Vredenburg, in Rec. Geol. Surv. India, vol. xxx, p. 43. 1897.) ZHILLER, R. (99). ‘ Etude sur la Flore fossile du Bassin houiller d’Héraclée (Asie Mineure) ’ Mém. Soc. Géol. France, Pal. Mém. No. 21, vol. viii. 1899. EXPLANATION OF PLATES XXX & XXXI. [The drawings are by Miss G. M. Woodward. All the specimens figured, except Pl. XXXI, fig. 5, are in the Geological Department of the British Museum (Natural History). | Puare XXX. Fig. 1. Sporangium-like organs of Glossopteris Browniana, Brongn. Detached sac-like bodies: the larger specimen shows what was probably the apex (a) of the organ, at which point dehiscence appears to have begun. In the smaller, the dehiscence is well marked, but the specimen is more fragmentary. X 35. Reg. No. V. 7202. 2. A nearly-perfect specimen of one of the detached sporangium-like organs, showing the apex (a), at which the sac appears to have opened, and the contents to be exposed. A small portion of the neck (0) is also seen. The cell-walls of the outer limiting-layer of the sac are very conspicuous. xX 30. Reg. No. V. 7211. . od. A group of four detached bodies, arranged in a sorus-like manner. In specimen 2, the neck-like extremity, by which the sporangium was probably attached, is indicated. In specimen y the sac appears to have dehisced, and the inner concave surface is seen, the cell-walls of which are much less conspicuous than those of the outer. x 30. Reg. No. V. 7202. 4, A fragment of a scale-frond of Glossopteris Browniana, showing the inner, strongly-concave surface. The nervation is preserved, although somewhat faintly. At the lower portion of the figure (d@), a confused mass of the sporangium-like bodies occurs, resting on the scale-leaf. Higher up may be seen a row of oval scars or prints (a, 4, ¢), possibly the points of attachment of sori. The scars, Gand c, are well defined, and here fragments of the sac-like bodies appear to be still in con- tinuity. At e, some of these sac-like bodies are better preserved, but it cannot be determined whether they are attached to the scale- frond: x 15. Reg. No. V. 7202. PLATE XXXII. (Figs. 1-4: Sporangium-like organs of Glossopieris. ig. 5: A micro- sporangium of Stangeria parado.xa. | Fig. 1. Three of the sac-like organs, which appear to have dehisced : the inner, -concave surface being seen. The cell-walls of the inner limiting- layer are much less conspicuous than those of the outer. x 80. Reg. No. 39,149. 338 THE SPORANGIUM-LIKH ORGANS OF GLOSSOPTERIS. | May 1905, Fig.2. A group of several detached bodies arranged in a sorus-like manner. Some of them appear to have dehisced; those on the right hand exhibit the outer surface, while those on the left exhibit the inner, of which the cell-walls are much less conspicuous. X 30. Reg. No. 39,149. 3. A typical group of detached sporangium-like organs, showing the shape of the sac-like bodies and the conspicuous cell-walls of the outer layer. The neck-like extremity, probably the point of attach- ment, is seen at a. The inner surface of a fragment of a sac which has dehisced is shown at 6. x 30. Reg. No. V. 7202. 4, Fragments of the sac-like organs of Glossopteris, showing the shape of the cells of the outer limiting-layer of the sac. x 30. V. 7211. 5, A microsporangium of a recent Cycad, Stangeria paradoxa, Th. Moore, for comparison with the sporangium-like organs of G/lossopteris. x 30, Discussion. Dr. D. H. Scorr said that he thought that the Author had a good case: he would not go beyond that. The sac-like form of the organs appeared to dispose of the suspicion that they might be merely concave ramenta. ‘The fact that no spores had been found, though unfortunate, was no argument against the sporangial nature of the bodies; even in well-preserved petrifactions, certain types of sporangia were almost always found empty. Hxannulate sporangia were so common, that the absence of an annulus had no weight whatever as anegative argument. He agreed with the Author as to the worthlessness of the evidence formerly adduced for the presence of sori on the ordinary fronds. He would like to ask the Author, about on what proporticn of the specimens of scale-fronds the supposed sporangia had been found. He thought that the systematic position of the genus was still quite an open question ; there was nothing as yet, even assuming the correctness of the conclusions suggested by the Author, either to prove or disprove that Glosso- pteris was a true Fern. Analogies for the supposed position of the sporangia on the scale-fronds might be found both among Ferns and Cycads, although in either case the analogy was somewhat remote. | The AurHor thanked the Fellows for their kind reception of a paper, which, he was afraid, was more of botanical than of geological interest. Replying to a question raised by the previous speaker, the Author pointed out that very few specimens of the scale-fronds of Glossopteris Browniana existed in this country, but that, with few exceptions, those which he had examined were associated with detached groups of the sporangium-like organs. The Author had pointed out that the characters of the sac-like bodies differed from those of the sporangia of any family of the recent Ferns, but he had not intended to imply that Glossopterts must necessarily be removed from the class Filicales. He was quite prepared to regard the question of the true affinities of this genus as an open one at the present time. Vol. Oia | WASH-OUTS IN THE MIDDLE COAL-MEASURES, 339 14. On the Wasu-ours in the Mrppie Coar-Measures of Sourn YorxksHirE. By Francis Epwarp Mippreron, F.G.8S. (Read February 22nd, 1905.) Dvurine the past 20 years the South Yorkshire Coalfield has been developed and explored in the neighbourhood of Aldwarke and Thrybergh, lying 4 miles north-west of Rotherham, where the principal seams have been extensively worked, namely :— Mthe Barnsley Seam ile ccc ale esctewetemacs Tz feet thick. The Swallow-Wood Seam .................. 5 feet thick. tive danioabeSeawol \ra.csscdss », WI Warren Ville ee arnslen' ec 2 yar B lev Seam 1.42: / . | H} ah i I) Be ab irybergt Hathtottierf) iC Barnsley 287 vards fi Thryb 1 i a SN OAldiwarke Main Collterys 4) Parkgate go2 yards 7 Thrybergh Common (0 : Bayynsiey Scant af Aldwarke VW arke ce FiO } ‘ & TOUR r WTS } Silverwood Collie Res Wc ‘ z 400 (e) Ley © aie a = ilc Barnsley Sean 745 yavas Scale:-rZinches =1 mile y ‘ N £ As the workings have extended, large areas have been proved to exist, where the coal has been removed by wash-outs which have Jaa OCH YIU TF IPVIS 1VI1AIA Joay CET= YIN LI] VIS [v0] WOZLLOPT SspieA oS1 e i LEA Te ageucutudeleia il SS H (6g -d ‘7 bf und sg) “TP woun0g—'s ‘Sy oimb a = OME he ange v op sour ef, EM ery 9g Sapte 5 ; SO]LUL & YIU £ F a BT SS a EE a aE ws afte oe ee . = 2 Ivsyl Dt eas POOM 940772 ae panotd 10 NS Co oe tt ey { (OSWALD ET 2S SSG eS ee es Le se Z 3) |e gage YS Ve Cd Sis 1 ae emt Gy ee ee ea Ns i & oS Pal ie 8 NS > & ] of > ) NORMAL SECTION or PARKGATE SEAM t = Lop Softs:1:5" ae inte Wie hud ae a ee ee ee ae 4:6" ee ee ee a SL 344 WASH-OUTS IN THE MIDDLE COAL-MEASURES. [May 1905, THe PARKGATE SEAM, In fig. 4 (pp. 342-43), the sections A, B, C, D, E, F, & G are also taken from actual measurements, and their positions are defined on the plan (fig. 1, p. 339). The average thickness of this seam is 4 feet 6 inches, as described in fig. 4. In most cases the Parkgate Rock overlies the coal: from these sections it will be clearly seen where the seam has been removed. The material that has replaced the coal differs very slightly from the ordinary rock overlying the coal, but sometimes a bind or argil- laceous shale (which decomposes into a clayey soil on exposure to the atmosphere) interposes between the rock-roof and the coal for a few yards, at other times for 200 to 300 yards. In some cases, this bind thickens to 4 or 5 yards. In sections C, D, and G (fig. 4), a conglomerate-rock interposes, with pebbles ranging in size from about half an inch in diameter to oval-shaped boulders 18 inches long. In conclusion, my opinion is that the wash-outs occupy the sites of winding streams or rivers; these, during the formation of the coal-seams, meandered through the alluvial tracts in which the seams were being laid down, and washed the vegetable matter away, replacing it with sediment of a different character which the streams held in suspension. - Discussion. Mr. Fox Srraneways said that these wash-outs were very common in the Leicestershire and South Derbyshire Coalfield, but there was one curious case on the western side of the Coalfield to which he ventured to draw the attention of the Society. This occurred in the Eureka seam of coal in the Netherseal Colliery, and was pointed out to the speaker by Mr. G. J. Binns. In this case the wash-out, instead of being one broad hollow, consisted of numerous confluent streams, which united together into a main channel like the head-waters of a drainage-system. It would, therefore, appear that some wash-outs were caused by stream- denudation after the formation of the coal-seam. Prof. P. F. Krenpatt pointed out the unusual interest attaching to the superposition of two wash-outs, in seams separated by a considerable interval. At Silverwood the depth to the Barnsley Bed was 745 yards and at Cadeby 750 yards, and this was the typical area of development of the Red Rock of Rotherham, inter- preted by the late Prof. Green as a wash-out. There might be some significance in the proximity of the pre-Permian Don-Valley Faults, and it was just possible that wash-outs were explicable on the theory of conteraporancous movement. Vol. 61. | AN EXPERIMENT IN MOUNTAIN-BUILDING. 345 15. An Experiment in Mountarn-Buitpine: Parr II. By the Right Hon. the Lord Avezury, P.C., F.R.S., P.S.A., For. Sec. ' R.A., F.G.S. (Read March 22nd, 1905.) In 1903 the Society did me the honour of publishing a short paper on this subject." I may, perhaps, just repeat that Sir James Hall many years ago, and others since, have illustrated the formation of folded mountains by placing layers of cloth under a weight, and then compressing two of the sides so that the cloth was thrown into folds. Since then, other and more complete, experiments of the same kind have been made by Favre, Cadell, Daubrée, Willis, Ruskin, and others. In these investigations the compression was from two sides only. If, however, folded mountains are caused by contraction due to the cooling of the earth, the compression must take place from all sides. With the view of illustrating this, I requested the Cambridge Philosophicai Instrument Company to make for me an apparatus consisting of four square beams of wood, resting upon a floor, which by means of screws could be moved nearer to, or farther from, each other. The beams left between them a space 2 feet across and 9 inches in depth. . In this square central space | placed layers of cloth, baize, oil- cloth, cement, etc., separated by layers of sand. The machine was then set in motion, and compressed so that the central space was reduced from 24 inches square to 22. Since last year I have made other experiments, changing the arrangement in various ways. ‘The results differ in details in almost every case, the initial movements being probably determined by slight differences in the texture of the substances employed. As a typical case I may cite fig. 1 (p. 348), representing a piece of compressed baize. It will be observed that there are two main folds, which cross at a right angle; that the elevation is greatest where the two folds meet; and that, while one fold is continuous, the other and lower one is shifted somewhat to one side, for a reason to which I will presently refer. Fig. 2 (p. 348) represents another specimen also showing the cross-ridges. Fig. 3 (p. 349) exhibits similar features, but the hills and valleys are more complex, and therefore more like those in Nature. Secondary cross- folding is well shown, and there is the same lateral shifting of one arm of the cross. ‘The elevation is shown by fig. + (p. 849) which gives a lateral view. 1 Quart. Journ. Geol. Soc. vol. lix, pp. 348-55 & figs. 346 LORD AVEBURY ON AN [May 1905, Figs. 5-8 (pp. 350-51) represent a series taken in January. The machine was packed as follows :— 4 inches of sand. Thin oilcloth. 12 inches of sand. Cloth (medium thickness). 13 inches of sand. Thin oilcloth. 13 inches of sand. Cloth, as before. 2 inches of sand. The screws were then turned 3 inches. Fig. 5 (p. 350) represents the upper layer of cloth, thrown into sharp ridges. Fig. 6 (p. 350) represents the layer of oilcloth. ‘The general plan is the same, but the ridges are fewer. Fig. 7 (p. 351) represents the second, lower, layer of cloth. The ridges are numerous, and have a well-marked tendency to arrange themselves in squares, as, for instance, in Kjerult’s map,' but are less pronounced than they would have been if they had not had the oilcloth over them. Fig. 8 (p. 351) represents the lower layer of oilcloth : the ridges are less numerous than in the softer and more flexible cloth. For contrast, I give figs. 9-13 (pp. 352-54), which represent another series taken at the beginning of this year. The machine was packed as follows :— 3 inches of sand. Clsth as before. .4 in_hes of sand. Linoleum. 13 inches of sand. Cloth. 13 inches of sand. Linoleum. 2 inches of sand. The screws were then turned 3 inches, reducing the square from 24 inches to 22. Fig. 9 (p. 352) represents the upper layer of cloth, which was similar to that used in the preceding series. It will be seen, how- ever, that the folding is altogether different, owing to the influence of the underlying linoleum. This is shown in fig. 10 (p. 352). The bold sweeps are striking, and the curved valley will recall many which occur in Nature. Fig. 11 (p. 353) represents the lower cloth, which, as will be seen, shows more numerous minor folds. Fig. 12 (p. 353) represents the lower layer of linoleum. The general arrangement is the same, but the folds are sharper; in fact, the linoleum was broken along the principal ridges. Fig. 13 (p. 354) gives a lateral view. On the other hand, the case is very different if we introduce a stiff layer of some substance such as cement. ‘This cannot throw itself into folds, but breaks and tilts itself up, assuming the 1 *Geologie des sidlichen & mittleren Norwegen’ 1880, p. 330, figs. 279 S260 oe Vol. 61.] PXPERIMENT IN MOUNTAIN-BUILDING, 347 so-called ‘ writing-desk’ form of Sir Leslie Stephen, so familiar to us in the Alps, and finally breaks into fragments. In some experiments these were irregular, much broken up, and in that ease forced irregularly into the sandy layers in a manner that would be very puzzling to geologists, and may throw light on some difficult problems. In others, they broke across in two rectangular fractures, as in fig. 14 (p. 354). In such a case one half (fig. 14, a, 6) was forced over the other, c,d, There was also an overthrust of a over 6, and of c over d. Fig. 15 (p. 354) gives a lateral view, from c¢ to d, showing the overthrust of ¢ over d. The result of these fractures and overthrusts is that, instead of two cross-lines, there is a three-legged ridge consisting of a single main elevation, with a break at, or near, the centre, from one side of which a main-cross line proceeds nearly at right angles. The corresponding cross-line (fig. 1, p. 348) on the other side is lower, and is shifted to some distance, according to the amount of over- thrust. The result is, that along the lines of overthrust a boring would pass twice through the originally-single calcareous stratum, and near the central nucleus of fracture even four times. 7 This accounts for the shifting of the lower ridge in figs. 1 & 2 (p. 348). One is reminded of the great arch of the Alps lying at right angles to the ridge of Italy, and that of the Himalayas with India, the plain of Lombardy corresponding to that of Bengal. In other cases, the edges of the primary fractures broke off more or less regularly. The detached pieces were then pushed up, assuming eradually a very steep angle (fig. 16, p. 355), or even becoming vertical, The main plates of plaster having now room, were able to approach one another as in fig. 17 (p. 355), without any need for more fractures or folding. Such a case is illustrated in the accompanying diagrams (figs. 16 & 17, p. 355). It will be observed also that a layer of pliable material above the plaster would be thrown into one or a few extensive folds; while a similar layer below is prevented from doing soa, the under side being comparatively flat. It accommodates itseif, therefore, to the circumstances by assuming a greater number of smaller folds. Speaking generally, it may be said, firstly, that the thicker and stiffer the materials which alternated with the sand, the bolder and fewer are the folds; secondly, that the folds are more numerous and more accentuated in the lower layers; and thirdly, that the folds tend to be at right angles one to the other. Discussion. The Presipent observed that there were some who believed that laboratory-experiments threw little light upon Nature’s work, but we could approximate more and more closely to the conditions which obtained in Nature, though we could never actually imitate [ 348 J Fig. 1. (See pp. 345, 347.) [ 349 J Fig. 3. (See p. 345.) — Fig. 4.—Lateral view of the above. Q.J.G.8. No. 242. 2B [ 350 ] Fig. 5. (See p. 346.) [3a Fig. 7. (See p. 346.) Fig. 8. (See p. 346.) 5s A i ME [ 852 ] ) . 10. (Seep. 346. 1S ny Fig. 11. (See p. 346.) Fig. 12. (See p. 346.) [ 354 ] Fig. 13.—Lateral view of the cast illustrated in fig. 12. Fig. 14. (See p. 347.) Cc b d a Fig. 15. Lateral view of the above. c,d = plaster; b = sand. [ 355 ] Fig. 16. (See p. 347.) aa = Two halves of a layer of plaster fractured in the middle, and again a second time. bb = Pieces broken off and forced up. cc = Layer of flexible material above the plaster. dd= Layer of flexible material below the plaster. Fig. 17.—Showing the same materials as in fig. 16, but more compressed. | 396 AN EXPERIMENT IN MOUNTAIN-BUILDING. [May 1905, them: for instance, it was doubtful whether we could ever get sufficient pressure to imitate exactly that flow of solids of which there was evidence among the rocks. The initial experiments of Favre were simple, but others, as Cadell and Willis, had made more elaborate experiments, and the Author had introduced further complications. The paper which had just been read was a continuation of one previously presented to the Society by the Author, and the President hoped that Lord Avebury would continue his interesting experiments and bring further results before the Society. Dr. BLanrorp said he thought that the Society were greatly indebted to the Author for a most interesting series of experiments. He was particularly impressed by the crossed faults produced in the layer of plaster, as this probably showed the way in which lateral pressure might act on a rigid bed intercalated among more flexible strata. The form of the surfaces produced naturally differed from that of the usual superficial features of the land, because of the absence of the erosive action of denudation. Prof. Garwoop asked the Author whether sections cut through the models showed the formation of cavities such as might induce the intrusion of igneous rocks in Nature, and such as seemed to have taken place in mountain-ranges like the Hastern Himalaya. Mr. LamprueH remarked on the close resemblance of the plica- tions on the surface of the models which contained linoleum, to the corrugations sometimes shown by compressed gritty flags in the Isle of Man and at Bray Head in Ireland. Mr. Srrawan thought that the imitation of forms of surface produced by denudation, by the surfaces of the models as produced by folding, was apt to mislead, and suggested that a truer com- parison with Nature might be obtained by planing off the surfaces of the casts to a level, and developing valleys and escarpments by erosion. The model showing two intersecting overthrusts was especially instructive. Though contemporaneous with it, one overthrust clearly broke through, and displaced the other. More- over, the one that was broken through was overthrust from opposite directions in its two halves, in this respect resembling belts of overthrusting and compression in Nature, which, unlike normal faults, were apt to change their throw. It would be interesting to see a reproduction of a structure that he had recently observed in Pembrokeshire. There a gentle anticline was accompanied by a multitude of small overthrusts. Without ex- ception, the overthrusting was from the south on the south side, and from the north on the north side of the anticline. Even in the few yards of nearly-level strata in the crest, four or five little over- thrusts strictly followed this rule. He joined previous speakers in hoping that these interesting experiments would be continued. Mr. WuirakEer enquired what was the amount of pressure exerted on the top during the whole of the experiments. The Autor thanked the President, and the other Fellows of the Society who had spoken, for their kind remarks, It was said that Vol. 61. ] AN EXPERIMENT IN MOUNTAIN-BUILDING. 307 the casts ‘too closely’ resembled Nature. He observed that when the surface on which rain, etc. had to act was so irregular as in the casts exhibited, the result would mainly be to deepen the original valleys. There would be, as the models showed, at first some lakes, which would be drained by more or less deep and narrow gorges. In reply to Mr. Whitaker, he said that there was a thickness of 3 or 4 inches of sand overlying the top layer of cloth. The actual materials used showed such hollows as those suggested by Prof. Garwood, and into these sand had been forced up, but the hollows could not, of course, be reproduced in the casts. Wd. G.s. No. 242. 2¢ 308 THE REV. J. F. BLAKE ON THE [May 1905, 16. On the OrpeR or Succession of the Manx Staves in their Norruern Hatr, and iis Brarine on the Ortcin of the SCHistosE BRECCIA ASSOCIATED THEREWITH. By the Rey. Jonn Freverick Bran, M.A., F.G.8. (Read February 22nd, 1905.) 7 I. Inrropuction. Amoneé the slates of the Isle of Man some strata have been found which represent, in the opinion of Mr. G. W. Lamplugh, so distinct a type of phenomenon that he assigned thereto a special name—that of a ‘crush-conglomerate.’ In the earlier announcement of this result in 1895,! he defined the rock as ‘made up of scattered frag- ments set in a slaty matrix,’ and considered it ‘due to the breaking- up under pressure of alternations of flaggy slate and thin grit-bands” (op. cit. p. 565). So far as this general statement goes, we shall find it included in the description of many fragmental rocks ; but when we seek further information, and enquire concerning the. fragments whether they be angular or round, scattered or crowded, uniform or various, composed of neighbouring rocks or of remote- ones, and of the pressure, whether it be shearing or otherwise, metamorphosing or not—then our troubles begin. The paper in the Quarterly Journal was only a preliminary account of what had been observed, and a full statement was promised when the Geological Survey-Memoir on the island should be published, which took place in 1903. I had early, however, taken an interest in the question, owing to the inclusion by Sir Archibald Geikie of some rocks in Anglesey in the same. category.2 But I had not to wait so long as 1903, for, with the greatest kindness, Mr. Lamplugh lent me some advance-proofs. of the principal passages involved, and thereby enabled me to spend portions of four successive summers in the island, amounting in all to about seven weeks of consecutive work, in examining all parts. likely to throw light upon the subject, with the aid of the 6-inch maps as shown in the office of the Geological Survey. From a study of the literature thus made available, it soon becomes apparent that a primary stage of the investigation consists in a determination of the lie and position, and thereby of the order of succession, of the Manx Slates in which these strata lie. Il. Tur Orper or Succession oF THE Manx Srates. The determination of the order of succession of the various. members of the Manx-Slate Series is a matter, on the whole, of considerable difficulty: owing, in the first place, to the relative. paucity of exposures over wide areas, the solid rocks being much_ + Quart. Journ. Geol. Soe. vol. li, p. 564. > Geol. Mag. 1896, p. 481. irra Vol. 61.] ORDER OF SUCCESSION OF THE MANX SLATES. 359 concealed by the abundance of their own débris, which may be more or less mixed and removed from their original site; and, in the second place, to the similarity in many of their aspects of portions of the different members themselves, when seen otherwise than in mass. And when, to these difficulties, we add the easy confusion so often introduced by cleavage of a complicated character, and the indubitable contortion to which parts are subject, we have all the elements united which might lead us to despair of ever solving the problem. There is no cause for wonder, then, that we read such expressions as the following in Mr. Lamplugh’s recent Survey-memoir :— ‘It cannot be pretended that more has been done than to trace out the broader elements of their stratigraphy. .. . There are broad tracts ... in which the different varieties are so closely intermingled as to be practically inseparable. . . . Their relative order has not been established with any certainty, and still remains a matter of inference. . . . The chief impediment to more detailed stratigraphical work has been the failure to find bands -smaller than the[se] main divisions, with characters distinct enough to be constantly recognizable. . . . The apparent dips are altogether misleading as a nee eo and stratigraphical relations of the strata.’ (Op. cit. pp. 28, Phrases such as these, together with the adoption of no colour for a wide area left as ‘ unseparated,’ show that the order of succession has not been determined; and we are left without the knowledge whether the fragments contained in some of the rocks called con- glomerates are derived as usual from the strata below them, or, by exception, from the strata above them ! In determining the order of succession in a series of unfossiliferous strata, we are deprived of the direct guidance of recognizable fossils, and have consequently to depend on stratigraphical considerations which have been less studied but which, from experience, render it more probable that fine-grained deposits follow coarser-grained, except for ‘episodes’ ; and show that the more metamorphosed rocks are usually ceteris paribus the older. Details of structure, such as cleavages of various kinds, do not affect the order of succession, and may therefore be neglected, for a rock when uncleaved will have the same position relatively to its neighbours as when cleaved.’ These and many similar axioms render it unnecessary to determine the nature of every rock if, by the selection of suitable spots, we can determine the order of succession in parts, and unite the observations into a whole. (1) The Barrule Slates. We commence with the rocks which form the central axis of the island, and rise to the greatest height. They are called the Barrule Slates by Mr. Lamplugh, and are of great visible thickness. They are black and characterless where most fully developed, the only apparent divisional planes being due to cleavage.” 1 Further details with regard to ‘nappes de charriage’ are required; see Marcel Bertrand, Bull. Soc. Géol. France, ser. 3, vol. xxvi (1898) p. 632. 2 By this term it is intended to include all the smaller changes commonly assigned to ‘ earth-movement.’ 202 360 THE REV. J, F. BLAKE ON THE [May 1905, We note that ‘where its outcrop descends to below 900 feet in crossing the deep intervening glen between Snaefell and Beinn-y- Phott,’! it is contracted to a less breadth than that which it occupies at a greater height. On descending the slope into this glen from the east, near the inn where the tram-line crpsses the road at a height of 1341 feet, we meet with numerous exposures of ‘ striped slates with gritty alternations, * which at the base cross the stream with a steady dip north-westerly in direction, and are followed in the same direction by the (practically) dipless Barrule Slate till the lead-mine is reached, near which the section ceases. This section gives the first indication that, if the beds be not over- turned, of which there is not the slightest sign, we see here the lower, eastern, border of the Barrule Slates, and that they are followed below by ‘striped slates.’ (2) The Snaefell Laminated Slates. This subdivision of the strata is included in the Geological Survey- Memoir among the ‘Strata of the Unseparated Tracts’ (p. 54), apparently on account of their similarity to some portions of slates found at other horizons, a point which does not here concern us ; but Mr. Lamplugh more particularly speaks of them as ‘ altered slate of Snaefell,’ as well as ‘ striped slates.” As ‘altered’ has reference to a later effect, and ‘ striped’ is indefinite, it is proposed to speak of them here by their main character as ‘ laminated,’ that is, divided into thin flat bands of different petrographical character. This group is characteristically described by Mr. Lamplugh as a ‘belt of banded slates with gritty intercalations, which form the passage-beds between the Barrule Slates on the west and the Agneash Grits on the east’ (op. ett. p. 527) ; while in a neighbouring mine, situated on or near a fault, the ‘deeper northward workings appear to enter the Barrule Slates’ (op. cu. p. 527). Small exposures of the same rock called ‘striped and puckered slate’ are seen all along that part of the mountain-road that has passed to the east side of Snaefell. This, therefore, is the next member in the downward succession. It is defined by an alternation, not merely of colour, but of substance also. By the reduction of the proportion of the gritty bands, it merges insensibly into Barrule Slate; by the reduction of the slaty partings, it— becomes altogether a laminated grit, in which the dark, soft lines are very narrow and often approximate, and the rock passes into the true Agneash Grit. (3) The Agneash Grit. The rock which underlies the Snaefell Laminated Slate is a fine- grained subcrystalline quartzite, or hardened grit, arranged in groups " Mem. Geol. Surv. ‘ Geology of the Isle of Man’ 1903, p. 51. ? Ibid. p. 189. Vol. 61.] ORDER OF SUCCESSION OF THE MANX SLATES. 361 of fine lamine. It is a very distinct rock, though it may become less so in places. It may be seen, however, in its true form on both sides of the upper part of Glen Laxey, that is, in the tram-line cuttings on the opposite side of the valley from Laggan Agneash, and on the same side as Laggan Agneash in various exposures (the beds always dipping at various angles in a westerly direction), and may be traced thence over the slopes above. No other grit is comparable to this, in its altered form and laminated structure; and it is essential to distinguish it by those constant characters from those other less-altered, but unlaminated grits to which the same name has been applied. It is the lowest stratum, according to my observations, anywhere exposed on the surface of the island, at least in the northern part, unless some crystalline quartzite, also without lamination, seen near Slieau Ouyr, represent something lower. With this stratum ends on the surface the typical triad of the older Manx Slates, exhibiting a steady north-westerly dip, though at various angles, with which any indications of folding do not interfere on a large scale. The order of their succession is the same as that adopted by Mr. Lamplugh, but there is nothing among them at all resembling a schistose breccia. ‘To see this and its relations to the other strata, we must pass to the north-western side of the axis. Here, along a stream running a little to the north of the road which leads from Snaefell to Sulby, and enters the glen by the waterfall at: Tholt-e-will, we get in the upper reaches a ‘reappearance of the striped slates, with gritty alternations like those seen higher up. These are accounted for by Mr. Lamplugh as an upturn of the same strata, but there is no evidence of any change of dip ; they continue the same dip as before, and are followed by the Barrule Slates as before ; in other words, there is a repetition of the upper part of the typical series, which was left behind when the Snaefell range was uplifted along a strike-fault. We are, therefore, on an ascending series’ as we descend the gorge of Tholt-e-will, and at the end we find a series of slates of an ordinary appearance, but on breaking them up we find them full of fragments. We are thus introduced to the Schistose Breccia.? It is associated with the Barrule Slate, of which it appears as forming a part; but we must seek for this more certain proof, for in this part of the island there are many places where rocks are marked as ‘crush-conglomerate,’ in which no sign of a fragment is seen, included, we must suppose, 1n the ‘certain bands in which the bedding-planes are only partially disrupted’ (op. cit. p. 65). (4) The Schistose Breccia. Glen Auldyn.—In the upper part of Glen Auldyn, a mass of Barrule Slate occupies the lower ground, and a stream descending 1 See l-inch Geol. Surv. Map, Sheet 100. 2 See Mem. Geol. Surv. ‘Geology of the Isle of Man’ 1903, pp. 133-34. 362 THE REY. J. F. BLAKE ON THE [May 1905, from Skyhill joins the River Auldyn from the left. At the base of the crag forming the lower corner of this stream-valley, the slate is worked, and ascends the crag as far as it is accessible; the more level ground above this is crossed by a band of breccia, and this 1s followed farther up by highly-cleaved slate-rock (see fig. 1, below) of rather mongrel-character. This shows a definite ascending sequence, commencing with the Barrule Slate at the base, followed above by a schistose breccia with contained fragments, and ending with a mongrel slaty rock. From this spot, if we follow the probable outcrop of a regularly-bedded rock, we recognize the same Schistose Breccia crossing this branch-stream farther up, and on the hill-slope beyond Fig. 1.—Section in Glen Auldyn. (Diagrammatic. ) < \ “ous \ S\N < We XY SQN q WW Cleaved slate Schistose Breccia S & \\ Barrule \ \\ Slate ES the valley the same bed may be seen about halfway up the zigzag path. In all these cases the beds geologicaily above the Schistose Breccia are not well defined, as may be judged by the fact that all three have been included in the area referred to the Barrule Slate. Sulby Glen.—The lower part of Sulby Glen stands nearly at right angles to the rest of the valley. Its north-eastern slope exposes a section, of which Mr. Lamplugh writes :— ‘ Nowhere can the development of the structure [of the ‘‘ crush-conglomerate” | and its relation to the accompanying strata be more satisfactorily studied than in these crags. . . . South-eastward it passes gradually into the dark Barrule Slate of Ballaneary, and north-westward into highly-contorted banded slaty and gritty flags’ (op. cit. p. 60); with the Schistose Breccia occupying a large breadth in the centre. These crags are almost vertical at the summit, and crowded with obstacles, such as thick gorse and slippery bracken; yet we can see that the Breccia is not separated from the Barrule Slate by any mark of motion, but apparently passes into it gradually by the cessation of the fragments. It is different, however, with the contorted flags: these are thrown into the most magnificent folds, visible at a distance, or seen close at hand. The final direction of the upper folds in no way leads towards the breccias, but it is or Vol. 61.] ORDER OF SUCCESSION OF THE MANX SLATES, 363 entirely separated from them by structures, seen in figs. 2 & 3 (below),* especially by the clearly-defined straight boundary seen in the latter figure. On the evidence of the probable assumption, therefore, that the Barrule Slates form a definite horizon, which is recognizable from place to place, we establish the existence of an additional member, namely, the Schistose Breccia, occupying a position near, or at the summit of, the black slate. We thus have four consecutive members definitely ascertained, composing the Manx Slates in Fig. 2.—Sketch of the folds in the overlying flags of Sulby Glen. Fig. 3.—Junction of the Schistose Breccia with the overlying rocks at the Sulby-Glen Crags. ascending order :—The Agneash Grit, the Snaefell Laminated Slate, the Barrule Slate, and the Schistose Breccia. There may be further members of the same series developed locally above the breccias ; indeed there appear to be signs of the existence of such, but no adequate proof has as yet been worked out. Ill. Tur Generat DistRipurioNn oF THE MAnx SLATEs, Considerable exposures of one or more members of the above- described series of Manx Slates may be recognized in various parts of the northern portion of the island (thanks to the Geological Survey- 1 This is, apparently, the spot described in the Geologicai Survey-Memoir (p. 62) under the words ‘ Every stage in the breaking-up of these sandy slates and grits can be distinctly traced.’ 364 . HE REV. J. F. BLAKE ON THE [May 1905, Map and Memoir serving as guides), from Gob-y-Deigan on the west, to Maughold Head on the east. | Thus, the Agneash Grit, characterized in the field by being finely quartzitic, laminated (often closely), having a north-westerly dip of various degrees (often high), being succeeded by laminated slates, may be followed over the high ground above Agneash to Trinity Church, west of the Douglas road and south of Corrany; and the Grit is seen in nearly-vertical bosses in the cliffs, and on the overlying surface at Maughold Head (see fig. 4, below). So far have I traced it towards the north. It doubtless continues to the south as mapped, and occurs again in the same relative position, with the slates of South Barrule and Cronk-ny-Arrey Lhaa. But, from all the areas to the north-west of the Barrule main axis, the above-described Fig. 4.—Agneash Grit, looking cast, seen nearly vertical at Trae Harkan. characters are absent, and the rocks mapped as ‘ Agneash or other grits ’ must belong to the latter category, and have no connection with the Slate Series. _ The overlying strata, that is, the Snaefell Laminated Slates, in like manner may be traced from the hills behind Agneash to Maughold Head, where they cap the head itself ; and this headland, though not high as compared with the axial range, 1s higher than, and sharply protrudes from, the country immediately surrounding it, which is made up of rocks of a different character. We may see the Laminated Slates extruded at the sea-level to Port-e-Myllin, close up to the (mapped) commencement of the Barrule Slates, recognizing them by their dark colour, soft texture, and lamination combined, as well as by the curious cross-cleavage, which looks more like areas of contraction filled in with a lighter-coloured secre- tion, crossing irregularly from hard band to hard band, without moving them by anything like ‘ strain-slip.’ Since the Barrule Slates have been taken as the standard of comparison, there is no occasion to discuss their distribution, which will not differ from that indicated on the 1-inch Geological Survey- > Vol. 6r. | ORDER OF SUCCESSION OF THE MANX SLATES. 265 map. It may be noted, however, that the successive ranges diminish towards the north in the northern part, and also to the west, the last two having little of the high dip of the first two: namely, that from Ballameanagh northward ranging from 60° to 20°, while the height at the end is not much above 500 feet; and that at Gob-y-Deigan being nearly horizontal, and on the sea-shore. This seems quite as easy of explanation by a series of subparallel faults radiating from the south of the island, as by infolds of the strata to which their regular north-westerly dip in a graduated amount does not correspond. The distribution of the Schistose Breccia is dependent on the range of the Barrule Slate, with the western side of which it is always closely connected, and of which, except for the fragments it contains, it would appear to be a mere accident. Many, indeed, are the localities, especially in the north, which are included under ‘erush-conglomerate ’ in the Geological Survey-map, in which there is no sign of a fragment. The presence of this sign, however, usually indicates that the rock is harder and ‘shorter’ in the erain. In the large range of Barrule Slate, which extends from the west side of Snaefell to Ramsey, the fragment-bearing breccia is found at its highest point in the island, 1100 feet, on the water- shed of the Glen-Auldyn river. It is here very remarkable in its contents. JI call it the Hill-Series. ‘Thence we pass by the road south of Parkneakin, through the three localities on the west side of Glen Auldyn, on to Elfin Glen at the top of the quarry, and finally to the Albert-Tower Crags, the mountain-road, and the lower road to the Reservoir, all more or less in the direction of the strike. The dip, though variable, might take it to the low ground near the Ramsey road, and we find it north of Skyhill at the base of the road slanting up the hill. The next series of exposures of the Schistose Breccia is connected with the great mass of Barrule Slate, which rises to 1257 feet in Slieaumonagh, but is lost sight of at either end. At one end is the magnificent river-section under the farm of Druidale, terminated by a fault crossing the river, and at the other, the equally, but differently, magnificent crag, before described. ‘The rest of the section, from Tholt-e-will to Narradale and Cronk Sumark, is so interfered with by faults and other displacements, that it is of no _ use for teaching, but only for testing progress. In the third range of the Barrule Slate, which occupies the hills to the north-east of Peel, we find the Schistose Breccia, where we expect now to find it, on the west, running parallel to its boundary, the intervening space being marked as Drift-covered ; while, in the last locality where the slate occupies the shore, we find the breccia faulted down at the south-western boundary at Gob-y-Deigan caves, and mounting (fide Geological Survey-Memoir) at the other end upon the slate. We thus find that the members of the series of the Manx Slates are repeated again and again in the order as they are first deter- mined, according as they are raised above the surface of the earth. 366 ORDER OF SUCCESSION OF THE MANX sLAtes. [May 1905. IV. Tae Posrrton oF tap Lonan anp Nriargsyt Fraes. The rocks, the description of which has just been concluded, are surrounded on their east and west sides by another series of rocks, which have been called Lonan Flags on the east side, and Niarbyl Flags on the west side. Another portion is left as ‘ unseparated,’ in other words is left unmapped. Nevertheless, Mr. Lamplugh says that it is more probable that the contorted grits and flags so largely developed at the lower levels of the island, pass as a highly- folded platform, beneath the argillaceous mass out of which most of the central hills are carved. From this conclusion we must omit all those portions coloured with a common tint and marked a which includes these flags, and confine the statement to those which are coloured and marked a’. As these latter are not directly connected with the Schistose Breccia, their position is not immediately important; but that there are portions of the former group overlying the Schistose Breccia and its associates, is shown in many places, and it seems to me that they are part and parcel of the latter group. The evidence regarding the latter group is as follows :— (1) On the west side of the vertical Agneash Grit which forms Maughold Head there is comparatively low ground, in which at the sea-side there is massive material, colour-banded and obliquely cleaved, nearly horizontal ; at Port Mooar there is the same kind, almost like Lias, becoming folded inland ; higher up, by Ballajora, is a quarry, with characteristic flags of Lonan type (coloured as Agneash), dipping west at 40°; on the coast-region between Port-e-Myllin and Maughold Head, is a quarry showing straight folds and undulating surfaces, with uncleaved slates and grits ; and nearer Maughold is a slaty stone-quarry, all of which resemble in no way the members before enumerated. (2) At the great quarry near Ramsey, where the mountaumeeed turns up from the plain, some mongrel-rock is secn, dipping away from the Schistose Breccia behind it ; and in Skyhill, the upper part shows well-bedded schists of Lonan type, with the Schistose Breccia passing beneath from side to side. (3) At the Salby-Glen great crag, we have the ‘ contorted grits and flags’ before noticed overlying the great mass of Schistose Breccia ; on the other side of the valley, they are seen by the road- side still highly contorted; and in the great quarry by Gob-y- | Volley they are repeated in the same style where the contortions guide us, whence they continue bed after bed (no doubt contorted on a large scale) to form the high hills as far as Ballaugh and beyond: these might be called the Sulby Flags. Above the breccia-bed at Druidale we enter this series, which continues far away to the distant hills of Sartfell and Freeoghane. (4) Above the railway, near Lady-Port, where it crosses the road, slaty grits and flags with no relation to Agneash Grit form long bands at a lower level, where the Schistose Breccia occurs still lower, between these grits and flags and the Barrule Slate. Fig. 5.—Interpretation-section through the Mana Slates. Snaefell Slieu Curn S.L.S v B.S e ZY. Hf MH ie fail Kirkmichael LK. Barrule Slates. A.G. = Agneash Grit. S.L.S. = Snaefell Laminated Slates. S.F. Schistose Breccia. S.B. = Other localities afford the follow- ing further evidences :— (5) (Mem. p. 149) ‘ The remark- able difference in the number, character, and direction of the dykes in these slaty rocks [| Nos. 2-4] as compared with those in the Niarbyl Flags [No. 5] seems at first sight to suggest that the Flags belong to a later system than the Slates’ (Mem. Geol. Surv. pp. 87-88). Further, ‘in the coast- section the slates are seen to be greatly crushed and confused in the vicinity of the junction, and they appear to pass beneath the flags.’ Among the presumptive reasons for belief in the later age of the Lonan Flags it may be mentioned that :—(1) No locality is recorded, nor can I discover one, where the Lonan Flags are seen underlying any member of the Slate Series. (2) Whereas every member of this latter series is more or less sub- crystalline and metamorphosed, every member of the Sulby-Flag Series is more or less earthy and largely unaltered. (3) Every appearance, real or imaginary, of an organic remain has been found only in the flaggy beds, and none anywhere in the Slate Series. (4) Occurrences of a flag are usually more accompanied by fold- ing than any of the Slate Series, eleven out of twelve such illustra- tions being given in the Survey- Memoir, and this frequency argues for the lightness of the load that they had to bear. (5) The long series of flags in Laxey Valley, though commencing with con- tortions, but becoming more regular, extend over 23 miles to their end, and even more if we include Clay Head, and yet show no sign of infolds of the supposed higher strata to which they are supposed to approach. These are the chief reasons which lead to the conclusion that the 368 THE REV. J. F. BLAKE ON THE [May 1905, only history of the Manx Series of Slates which will satisfy the various conditions is as follows :—First, the triad of Agneash Grit, Snaefell, and Barrule Slates were laid down in regular order ; next, part of them, with possibly something additional, was broken up, and their fragments scattered over the still-forming mud, forming the Schistose Breccia; after which they settled down along sub- radiate faulted blocks, each accompanied by the common breccia. These blocks united form a nucleus (as, in like manner, did Malvern, the Longmynd, and Charnwood), round (and partly over) which the long series of Sulby or Lonan Flags accumulated, without their stratification being governed by the strata buried beneath them ; but they partook of the later movements which modified both older and newer formations (see fig. 5, p. 367). This account, however, sagel 5 the conclusions as to the character and origin of the Schistose Breccia, into which we are now prepared to enter. V. Tar CHARACTERS AND ORIGIN OF THE SCHISTOSE BRECCIA. The rocks, to which the name of ‘ crush-conglomerate’ was first applied by Mr. Lamplugh, have been subsequently recognized as having a supposed origin to which the name of ‘ autoclastic’ had been previously applied by H. L. Smyth in 1891. That author defines it thus: ‘Schists formed in place from massive rocks by crushing and squeezing, without intervening processes of disinte- gration or erosion, removal and deposition.’ Five years later, Prof. C. Rk. Van Hise, recognizing that a schist was only an advanced stage of fracture, added the words ‘ frequently broken into frag- ments.’ Rocks, however, of this character had been known before the *nineties, such as the schists at the entrance of Bardon-Hill Quarry, near Charnwood Forest, but the rocks of the Isle of Man do not exhibit those characters. All the rocks of either kind have abundant fragments, and most of the fragments lie in a schistose matrix. But Prof. C. R. Van Hise, in the 16th Annual Report of the United States Geological Survey (1894-95) pt. i (quoted above), discussing the ‘Origin of Autoclastic Rocks’ (quoted by Mr. Lamplugh), points out, under ‘Relations of Autoclastic Rocks to Basal Conglomerates’ (pp. 680— 81), the criteria which distinguish between them, saying practically that the fragments of an autoclastic rock must be derived from the adjacent materials, whether they be below or above; and the rock itself may be traced into an ordinary brecciated form. ‘This is not a mere question of nomenclature, but of the origin of the rocks themselves. If two rocks are rubbed together, and fragments are produced, these fragments must be recognized as belonging to the rocks that have been rubbed ; that they belong to the same series is nothing—they must be adjacent before they can be separated in an autoclastic 1) Amer. Journ. Sci. ser. 3, vol. xlii, p. 331. Vol. 61.] ORDER OF SUCCESSION OF THE MANX SLATES. 369 manner; and, since normally only two rocks can be adjacent to one spot, three or more varieties of rock in one schistose breccia will prove it to be of a different origin. This is more particularly the case when the rocks on one side of the breccia are all of one kind, and those on the other all of the same or of one different kind, and the fragments in the breccia distinct from either. To determine whether a given breccia is of autoclastic origin or not, we must examine the fragments that it contains with as close a care asif it were a fossil, or a boulder in a glacial clay, and not be satisfied with calling it a grit or a slate, any more than in the parallel case with calling it a lamellibranch or a diorite. I have accord- ingly obtained a considerable number of fragments from numerous samples of schistose breccias, of which the following is a list :— Hill Series west of Snaefell: middle bend of the zigzag, Glen Auldyn; top-section in Glen Auldyn; base of the road north of Skyhill; Elfin Glen, Ramsey; Narradale, lower bend of the stream crossing the road; Albert-Tower Crags; Mountaiu Road, Ramsey; part of Druidale stream; Sulby Crags; Gob-y-Deigan Caves. Of these, the examples denoted «by the spaced type are the most instructive ; and the best exposure of all is at Gob-y-Deigan Caves, as it is easily accessible at most tides, and well spread out over the foreshore and cliffs. But it is broken up, at its junction with the black slates or shales, into numerous angular faulted portions. Among the rocks here represented by isolated fragments, the following varieties may be recognized :— (1) Many big pieces of hard laminated grit, like Agneash Grit, with an irregular waterworn appearance. (2) Coarse-grained hard grit. (3) Light, fine-grained grit, with irregular outline; seems to have been partly weathered before inclusion. (4) Small specimens of hardened dirty clay-rock (compare A in fig. 12 of the Geological Survey-Memoir, p. 67). (5) Unaltered beyond hardening, light shale, very brittle. (6) Small piece finely laminated, and another coarser piece, closely resembling Snaefell Laminated Slate. I find it impossible to conceive how such a set of rocks, so distinct one from the other, and so different from any that can be found around them, could be assembled in proximity to one another by any act of an autoclastic nature. It is the same with the other schistose breccias ; the fragments that they contain are in the same way distinct among themselves, and not to be matched with the material which surrounds them in the solid state. In particular may be noted certain other cases; for example, in Sulby Crags the fragments in the Schistose Breccia are of various kinds mixed indiscriminately, while the fragments in the area between the Schistose Breccia and the contorted flags are all of one kind. In the Druidale section there is a coarse grit with ferruginous hollows, conspicuously unlike anything found elsewhere; and similarly, among the Hill Series, is found a large quantity of porous decayed 370 THE REV. J. F. BLAKE ON THE [May 1905, rock (sandstone, tuff or igneous), only to be matched in the Series itself,’ Regarding the second criterion of an autoclastie rock, that they will contain fragments of the overlying rock*: this involves our knowing which is the overlying rock, and thereby the order of succession. If the order of succession were that adopted in the Geological Survey-Memoir, it would be easy enough to prove that this criterion was satisfied ; and one only wonders why no use was made of this in arguing for a ‘ crush-conglomerate.’ But, when the order of succession is reversed, as in the present instance, the three uppermost strata have in places an obscure colour-banding, which is somewhat difficult to distinguish in a fragment from the lamination exhibited by beds below both the Schistose Breccia and the Barrule Slate. Regarding the third criterion, that an autoclastic rock may generally be found graduating into a brecciated or semi-brecciated form: although there are numerous examples, I have found none graduating into anything else than their original form. Sulby Crags are no exception to this; the nearest breccias are all of one kind, they are separated from the Schistose Breccia by a well- marked line, and the adjoining contorted flags are only bent, not broken ; moreover, this is not the direction in which the structure is continued. The only case somewhat resembling an exception is the Hill Series west of Snaefell: on tracing the rounded samdstone- like pebbles from Ramsey up the strike to the Hill Series, we should find there such a majority like them, that we cannot be far from the centre whence this rock was dispersed; but these are mixed, at Ramsey, with many other varieties, which would prove too much. From the failure of ail the special characters of an autoclastic rock, I think we may conclude that none of those enumerated are of that. character; the fragments which they contain have never been brought to their present position by two rocks shearing together under pressure, but consist rather of ‘rock of an original fragmental character,’ rendered schistose, and crushed out sometimes into smaller fragments, of which the cause is obvious in their later contortions. There are also some peculiarities about the Schistose Breccia which vias strong weight in the same direction. (1) To call the © rock a ‘ conglomerate’ is to convey a wrong impression : it is very seldom that any of the fragments are rounded ; the problem is. rather to realize how they may possibly be removed from their original home with so little change, even with the freest motion, 1 It may be noted in this connection that Prof. Watts, who assisted in the establishment of the term crush-conglomerate, writing three years later in his ‘Geology for Beginners’ (1898) says that they will differ from those depo- sited by water-action in three ways, of which No. 3 is ‘the pebbles are all made of one kind of rock, while a ‘thrust-conglomerate will not differ much from a crush-conglomerate, except that two or three types of fragments may be present in it. (Op. cit. p. 111.) 2 See also J. E. Marr, ‘ Principles of Stratigraphical Geology’ 1898, p. 81. — es) Vol. 61.| ORDER OF SUCCESSION OF THE MANX SLATES. 371 as, for example, in the Hill Series, in which the outlines are very distinct and clean, without any shading-off into the matrix. They are often soft enough to be scratched with the finger-nail, yet they end off in fine angles which the slightest shearing process would have broken away. (2) Again, in Gob-y-Deigan Caves, the large piece like Agneash Grit is much too hard to be touched by the matrix in which the fragments are embedded, or even by the black slates, and must have been rounded irregularly before being buried. But, though the bulk of the Schistose Breccias, as at Gob-y-Deigan Caves, Druidale, Sulby, and Ramsey, and many others, show characters incompatible with ‘crush-conglomerate’ or auto-. clastic rocks, there are also examples of the latter, as those. figured in figs. 2-5 & 11 in Quart. Journ. Geol. Soc. vol. li (1895) pp. 568, 570-71, 582, which have been confounded with the Schistose Breccia. The best, however, and most indubitable example of a true auto- elastic rock or fault-breccia, is the example described long ago by- Henslow, which Mr. Lamplugh appears to have missed, as he says (Quart. Journ. Geol. Soc. vol. li, p. 563) of ‘the headland south of Gob-y-Deigan ’ :— ‘It is here that the structure was noticed by Henslow. It is on the coast at Ballanayre Strand, where a stream runs over the surface of some angular fragments of clay-slate imbedded in a clay-slate paste .. . . sufficiently apparent by the fragments assuming different tinges of colour,’ ' These expressions could not possibly be used of the Gob-y-Deigan breccia, for there the fragments are perfectly distinct from the matrix at all states of the tide; but at Ballanayre it is ‘ curious’ te see them only appear when wetted. In another part of the cliff some thin bands of grit are separated and drawn out like the well- known ‘ Belemnites’ of the Nufenen Pass. The locality is probably a faulted one, as the Niarbyl Flags are seen nearly vertical in the sea close by, and the position of the slates is probably the same as that of the thin grit-bands, more nearly horizontal. In comparing these two localities, Ballanayre Strand and Gob-y-Deigan caves, we have an admirable illustration of the several characters which belong to each class of rock. Other examples figured,’ not from the band of Schistose Breccia, are from places where the rocks are so rapidly folded that parts of the same band divide into obviously-connected fragments, all of the same kind. These would probably be included among auto- clastic rocks; asalso would the masses of unmixed fragments between the contorted flags and the boundary of the Schistose Breccia, on one side of the Sulby river, and a similar mass near the corner of the road on the other side. From none of these examples can anywhere passages be found into the mixed and widely-separated fragments of the Schistose Breccias. In conclusion, I may be allowed to remark, that to make two 1 Trans. Geol. Soc. ser. 1, vol. v (1820) p. 490. 2 Quart. Journ. Geol. Soc, vol. li (1895) pp. 570 & 582, figs. 8 & 11. 372 THE REV. J. F. BLAKE ON THE [May 1905, blades of grass grow where one grew before can in no way injure the credit of him who first made the first grass grow, and compared it with a ‘ crush-conglomerate.’ Discussion. Mr. Lampiven said that he strongly appreciated the kindly attitude of the Author, and recognized the pains which had been bestowed upon the investigation. But, after full consideration of the evidence brought forward by the Author, he found it necessary still to adhere to his previous interpretation, both of the succession and of the crush-conglomerate. In studying this extremely-com- plicated area the Author had placed far too much confidence in apparent dips, which had been shown to be misleading as indications of the sequence ; and he had also called in faults to his aid, without any proof that these faults were of more consequence than the innumerable other fractures by which these rocks were traversed that apparently had no structural significance. The speaker was well satisfied to find that three parts of the sequence proposed by him had been accepted by the Author, who, however, wished to reverse the order of the one remaining part by postulating a great unconformity, for which no acceptable evidence was forthcoming. All the facts known to the speaker were utterly opposed to the view that there could be an unconformity between the Lonan or Niarbyl Flags and the rest of the Manx-Slate Series. As for the crush-conglomerate, the speaker did not feel called upon to defend the definitions of other workers: he relied entirely upon the field-evidence in the Isle of Man, which he held to be convincing for the ‘ autoclastic ’ origin of the fragmental beds. The disrupted strata were not homogeneous, but a mixture of laminated slates and gritty greywackés; and he failed to find any other material among the specimens exhibited on the table. The Author acknowledged the autoclastic structure in that portion of the crush- conglomerate where disruption was incomplete, but denied it for the portion in which the process had gone a step further. The speaker admitted that there was room for further work in the Manx Slates, but he was doubtful whether the present attempt had really advanced our knowledge of this extraordinarily-difficult series. Mr. Barrow, who said that he had seen part of the area discussed, in company with the previous speaker, agreed with his interpreta- tion of the nature and origin of the crush-conglomerate. But this rock differed somewhat from the commoner type, in which the matrix and the pseudo-pebbles had the same original composition. In the case described by Mr. Lamplugh, the pseudo-pebbles were embedded in a matrix originally of softer composition. The exceptionally-large scale on which the phenomenon had occurred, was probably due to the original nature of the rocks and their order of superposition. A thick bed of soft shale was underlain by a id Nol Ow. ORDER OF SUCCESSION OF THE MANX SLATES. ate comparatively-thin band of laminated sandy shale, or passage- material, which in turn reposed on a thick mass of sandstone, During the process of intense and complicated folding seen in the area, the passage-beds, owing to their less-resisting nature, were broken up and forced outward from the minor folds of the harder erit. The easily-yielding mass of still softer shale in front greatly facilitated this process, and many fragments of the passage-beds were forced into this shale. ae Prof. Watts pointed out some of the difficulties presented by the field-work in such a district as that in question. His microscopic investigation of the rocks collected by Mr. Lamplugh, showed that the individual pebbles were often beginning to exhibit a crush- structure which was undistinguishable from the general structure of the conglomerate. Further, he had been unable, after con- siderable search, to discover in the conglomerate any rock-fragment of a type different from the grits and slates found in immediate contact with the conglomerate itself, Mr. Crement Rerp thought, as the result of his recent examination of the Ordovician rocks in Cornwall, that true conglomerates (though sheared) could be distinguished from crush-breccias, if the softer material was ignored, and attention concentrated upon the frag- ments of whatever rock was hardest. In a sheared conglomerate the hardest pebbles still remained as pebbles, the softer material flowing past them; in a crush-breccia the hardest fragments, on the contrary, were the most angular, especially if they were rare. The Avtror thanked the Fellows present for their reception of his paper, and the various speakers for their remarks. His friend Mr. Lamplugh spoke of the Lonan-Flag Series as occurring both below and above, which was, of course, different from his experience, and hard in any case to explain. Prof. Watts spoke of the frag- ments composing the Breccia as being broken up—which they very often were, as was natural; but this did not affect their original character. Q.J.G.8. No, 242, 2, 374 ' MR. LINSDALL RICHARDSON ON THE [May 1905, 17. The Ruzmric Rocxs of Monmourusuire. By Linspay Ricwarpson, F.G.S. (Read March 22nd, 1905.) [Prats XXXII—Verricau Section. | ConrTENTS. Page iL; Dntroduction ic. ji skec sic nae atoas ce eee eee o74 IT. Description of the Sections. (A) Goldcliff ..... Sua TP digest oe ee ee 374 CB), ‘Bishitom .. 20) sean. salanownccme teen eee 31 (C) ilammdartin’ 2s. deaeenat once sont ene cc eee 380 (BD) ilanwern. 2 sPhe eae he, ee eee 380 CHD) MilGot’ i aceon ts cick eens aen ance ek eee 381 CB) Bishipool oii sc ovoM cee ce dates onnreae eel eee 382 (G:) Luis "Weeny, 6.0 e.c semnciet ogteucgess ose arene — 882 TH: ‘Comclusioms 6 ges ss sitecs nh oncs case 383 I. InrRopucrion. In Monmouthshire the Rhetic does not extend over a large area, and occurs only in the neighbourhood of Newport. Here it has attracted very little attention until quite recently, when the resurvey of the South-Wales Coalfield necessitated a fresh examination of the deposits, in order to complete the geology of Sheet 249 (New Series). Certain sections which came within the area were described, but hardly in sufficient detail, as the only lamellibranch recorded was Modiola minima. | In the present paper four new sections and three new exposures are described: the Goldcliff and Lis-Werry sections being included in the former category, because hitherto comparatively little was known about them. IJ. Drscriprion oF THE SECTIONS. (A) Goldcliff. About 34 miles to the south of Llanwern Station, and rising from the alluvial flat called Caldicot Level, is the little inlier of Keuper, Rhetic, and Lower Liassic rocks denominated Goldcliff. Although the occurrence here of Rhetic and Lower Lias has long been known to geologists, details of the section have been difficult to obtain; and, until the present time, it has been possible to investigate only the basement-beds of the Rhetic and those at the base of the Lower Lias. This is due to the fact that the cliff had to be faced with masonry, in order to continue the sea-wall. About the year 1824 Buckland & Conybeare noted the occurrence ~~ ew ee hd bm te eo aie ee oe : . é . : : : ¥ r 33 bs Mol. Gr. | RH WIC ROCKS OF MONMOUTHSHIRE. OTe here of Lias and Red Marl, but remarked that the section ‘is now almost entirely concealed by a high sea-wall erected in front of it.’! _ In a paper communicated to the British Association,” and again in his ‘ Note-Book of an Amateur Geologist,’® J. E. Lee drew attention to the occurrence of a bone-bed in the Keuper Marls; but apparently it did not occur to him that the fact was of any interest, for it was not until 1888 that it was remarked by Mr. Horace B. Woodward, F.R.S., that Lee had ‘omitted to point out that the Bone-Bed there occurs beneath 3 feet of the greenish-grey marls, which are thus shown to be intimately linked with the Avicula contorta-Shales above.’ * . In a recent memoir published by the Geological Survey, Mr. A. Strahan, F.R.S., has given some interesting and valuable details concerning the junction of the Rhetic and Keuper, and commented upon the fact that ‘the base of the Rheetic is conspicuous and sharply defined, and the green marls below it exhibit the cuboidal weathering so commonly seen in the Keuper, The occurrence in them, however, of a “bone-bed” is quite exceptional.’ ® It will be observed from the foregoing quotations that, although certain details concerning both the Rhetic and the Lower Lias have been recorded, the description nevertheless remained very incom- plete, as nothing was known about the middle portion of the series; Therefore it was fortunate, when I visited the section, to find that a breach in the wall was being repaired, and that the sequence of deposits, from about where Mr. Strahan’s record ended, up to the Lower Liassic beds, was visible. Mr. Strahan gave details of the deposits up to, and inclusive of, that numbered 15 in the present record ; but, when the writer visited the locality, that bed, according to the foreman, had just been hidden by the masonry. Many pieces, however, were lying about, so that the rock could be examined for fossils. Owing to the interest which is attached to this section, the complete record is appended (Pl. XXXII). _ Concerning the Lower Lias no particular comment is necessary : the faunal and lithic characters of the beds are similar to the equivalent beds at Sedbury Cliff—indeed, they correspond almost bed for bed. According to a detailed record of the Lower Liassic beds in the Sedbury-Cliff section that I made, the first appear- ance of Psiloceras planorbis was in the deposit corresponding to the stratum which should come immediately above the deposit numbered 1 in the section accompanying this paper (PI. XXXII). As the ground at Goldcliff rises somewhat away from the sea-wall, - 1 Trans. Geol. Soc. ser. 2, vol. i (1824) p. 305. _? Rep. Brit. Assoc. (Brighton) 1872, Trans. Sections, p. 116. ® London, 1881, p. 72 & pls. clxxi-clxxii. 4 Proc. Geol. Assoc. vol. x (1888) p. 538. , 5 Mem. Geol. Surv. ‘The Geology of the South-Wales Coalfield’ pt. 1: ‘The Country around Newport, Monmouthshire’ 1899, p. 79. 316 MR. LINSDALL RICHARDSON ON THE [May 1905, the planorbis-zone must be present in the hill; and, as a matter of fact, Mr. Horace B. Woodward has recorded the zonal ammonite. So far as could be seen, however, the beds near the barn (where these measurements were taken) were of pre-planorbis date—a deposit better known as the Ostrea-Beds. Near Llanwern Station these beds, together with the planorbis-limestones, are quarried for the supply of lime-kilns. The topmost bed of the Rheetic is an interesting stratum. Its upper surface is conspicuously waterworn, while in the super- incumbent shales are often found small pebbles derived from this bed ; this is evidently, therefore, the horizon at which the line of demarcation between the Rhetic and the Lower Lias should be drawn. The Hstheria-Bed was located, but no remains of Lycopodites lanceolatus were observed. However, it may be advisable to state that they do occur in association with the Hstherie at certain localities. J have found this to be the case at Garden Cliff and Redland (Bristol). In a hand-specimen of the bed from the latter locality (and now in my collection) numbers of the phyllopod occur intermingled with the plant-remains. A cast of Schizodus Hwaldi was found in the Hstherta-Bed: a somewhat high horizon for this lamellibranch. The various beds of the Lower Rhetic (contorta-age) much resemble their equivalents at Aust Cliff. More limestone-bands occur in the deposit of this date in the Newport district, than in that to the north of Purton Passage. Although, from a study of this section alone, they seemed to be intermittent, similar lime- stones are found occupying the same stratigraphical horizons throughout the district; but, of course, in some places they are more developed than in others. The bed numbered 13 is the most persistent in the Goldcliff section, and represents the Pleurophorus- Bed of Aust Cliff. Paleontologically, the most interesting fact is the abundance of Cardiwm cloacinum, Quenstedt. This. fossil escaped identification for a considerable time, but it was obtained many years ago by that successful and ardent collector, Charles Moore, from the Rhetic exposed in the railway-cutting at Wills- bridge, near Bath, and was recorded in his section as Cardita.” The specimens of Protocardim Philippranum in Bed 6 are very well-preserved, for fossils from the shales. The deposit which has caused the Goldcliff section to become so well-known is the Bone-Bed in the Green Marls. The explanation suggested by Lee, and accepted by Mr. Strahan, is that ‘the bones occur in what seem to have been sinuous and irregular runlets excavated in a mud-flat. . . . The runlets became filled in with coarse quartz- sand mixed with many scales and teeth of fish[es], and by the hardening of their contents now resist denudation better than the marl in which they were enclosed. They are well-shown in the foreshore at the foot of the wall, about ' Quart. Journ. Geol. Soc. vol. xxiii (1867) p. 498. Vole or. RHHTIC ROCKS OF MONMOUTHSHIRE. 377 5 feet below the base of the Rhetic beds; they vary from 3 to 12 inches in width, and can sometimes be traced for 7 or 8 yards. Among the fish[es], Gyrolepis Alberti, Ag., and Hybodus minor, Ag., have been recognized by Mr. H. T. Newton: Saurichthys, also, is quoted by Mr. Lee.’ ! Mr. Horace B. Woodward’ (as I have already mentioned) has commented upon the importance of finding a bone-bed containing remains of Rheetic vertebrates in the ‘Tea-Green Marls,’ since, in his opinion, it links the deposits in which they occur with the Rheetic. The mode of formation, however, of these ramifying veins of quartz- sand is obviously not that under which a continuous stratum was laid down. ‘They are certainly distributed, so far as can be seen, along a definite stratigraphical horizon, but the suggestion that the material accumulated in runlets in a mud-flat is not altogether satisfactory, although it very nearly explains the phenomenon. (B) Bishton. To the east of Newport a considerable traet of country is com- posed of Rhetic and Lower Liassic rocks. In this area are several excellent sections, which have hitherto remained undescribed. ‘The first to be noticed is at Bishton. At the northern end of the village a lane leaves the Llanmartin road on the right, and leads to Poolhead Cott. This lane is now frequently occupied by a stream, but the steep banks afford a magnificent and accessible section of the ‘Tea-Green Marls,’ the Lower Rhetic, and most of the component beds of the Upper: the only deposits of which it is a little difficult to obtain measurements being those immediately above and below the Hstheria-Bed. Hstheria was not recorded here, but it was observed at Goldcliff, and the lithic structure of the limestone is identical. As will be noticed from the following record, this section much resembles that at Goldcliff :— Lowrr Liss. Limestones and Clays. Feet. inches. (1a. Cotham-Marble equivalent. Green Marls.’ Pale green- ish-grey and yel- lowish-grey marls, slightly harder at IC WO]9) Gs ncooee about 14 0 il. Red Marls. Uprrr KnuPeER. The section in the tram-cutting in Coed Goleu described by Mr. Strahan is over- 1904); but the lower portion is similar 1 Mem. Geol. Surv. ‘The Country around Newport’ 1899, p. 79. Oe. Gs 0. No.242. QE 382 MR. LINSDALL RICHARDSON ON THE [May 1905 apparently to the Llanmartin section (p. 380), in that there is a deposit below the grit of contorta-age—distinguished as bed 16 at Lianmartin. : Near Bishpool, the escarpment formed by the Keuper and the Rhetic, and capped by the Lower Lias, is very conspicuous; and at Pinkham Hill it is breached by a road-cutting. (F) Bishpool. Feet inches. 14. Shales, light-coloured, clayey, with two thin gritty seams passing up into black clayey shales. [ a. Quartz-sand, richreddish-brownand black. 0 9 15. } 6. Sandstone-layers and shaly matter ......... 7 | c. More massive layers: Modiola minima ... 0 3) 16. Shales, black, with sandy layers .................. 0) 4 I. ‘Tea-Green Marls.’ Pale-yellow: visible...... 4) 0 The last section to be described is at Lis-Werry, near the well- known quarries in the Lower Liassic limestones: indeed, the cutting in which the Rheetic beds are exposed was made for the road to the quarry. This section also has received attention from Mr. Strahan,’ but the following record is much more detailed. The Lower Liassic beds are given on that writer’s authority. (G) his-Werry. Feet inches. ; Limestones, irregular, with partings of nelanyvantl slates s,.2, santa taee deere a Limestones, more even, with very thin Pakkuine sof slale mre. ase eec teste coe UW) Paper-shales 1. Limestone, blue-hearted but weather- ing white; the upper and lower parts shelly, with Modiola minima abundant, the middle part smooth- textured and pale; faintarborescent J markings in places (equivalent to Cotham Stone). [¢este A.Strahan] 1 0 2. Pale-brown, thinly-laminated shales. 1 4 3. Pale greyish-green, earthy nodular limestone passing into shale ...... 1 O - Cardinia sp.,- Cardium | +, Pale greyish-green marly shales : cloacinum, Protocar- about... o 65 dium Philippianum, Modiola minima, Gy- rolepis (scale}. Lower LiAs Urrrr Ru atic. ' Mem. Geol. Sury. ‘The Country around Newport’ 1899, p. 75. ° The form identified as Cardinia concinna (Sow.) aff. regularis, Terq., Quart. Journ. Geol. Soc. vol. 1x (1904) p. 204 & pl. xviii, fig. 4. _ Vol.61.| RHETIC ROCKS OF MONMOUTHSHIRE, 383 (Lis-Werry section, continued.) Feet inches. f Same fossils as in Bed 4, - ; with the addition of an stales; DlACK ~...cue.de. about 4 | Soh eoaie alae aaa Pteria contorta. 50. Limestone, dark-grey, earthy ; ‘beef’ on the upper surface. Immedi- ately below these are occasion- ally present hard nodules with Pecten (Chlamys) valoniensis and Pteria contorta adhering to them: very variable deposit ............... OSS Gales ei NAG Kiraa. as esetisis vinsteieiee sine ss 1 1 Limestone, dark: selenite......... 10 1 Pecten (Chlamys) valo- 3 Clay, black, indurated and arena- Niensis. SP My Ceous im, places: .c....... about 0 2 Schizodus Ewaldi and fe many shell-fragments. 6 a Wamestome, Gaile. 02h. Madeley-Road Station " Normacot Station % Scale of English Miles I 2 Trentham Siation Trentham Hall OUTLINE-MAP SHOWING THE RAILWAY- AND CANAL-systEm OF NORTH STAFFORDSHIRE AND THE Posrtron OF THR COLLIERIES WHERE THE MARINE BANDS HAVE BEEN TRACED IN THE Coat-MmBasurgs. eee ei gs, Sat Soe? ~ Dy Ce Sha vpn lL VRE Huipseae se Whar ebay Cola ate rae Vol. 61.] IN THE NORTH-STAFFORDSHIRE COAL-MEASURES. 515 obtained were Pterinopecten papyraceus, Goniatites, and Lingulu mytiloides. ‘The last-named species often occupies a distinct portion of the deposit—a peculiarity which has been previously noticed by William Molyneux’ and Mr. John Ward.’ In these layers, as a rule, it is not associated with any other genera (with the exception of Orbiculordea mitida). In the following horizons, it is confined to the uppermost portion of the deposit, namely :— The Florence Marine Bed. The Seven-Feet Banbury Marine Bed. The Upper Marine Band in the Cheadle Coalfield. The fact that plant-remains are not rare in these horizons which are so strongly marine in character, has been mentioned previously. Another observation has been emphasized by these researches, and that is the clear and distinct separation of the marine mollusca from those freshwater forms that are so common in the Coal-Measures, particularly in North Staffordshire. It is all the more necessary to lay stress upon this fact, because statements to the contrary are made by such authorities as Jukes and J. W. Saiter respecting South Staffordshire’; and Prof. Hull, respecting the North-Stafford- shire and other Coalfields.» The question in doubt, however, is whether those workers examined the beds in situ, or simply collected from the spoil-heaps of mines. In my opinion, there is no more fruitful source of error than the latter method, unless the precaution be taken, there and then, of verifying the results by observation of the beds in place. This distinct separation of the freshwater and marine faunas is corroborated by such careful workers as Phillips in Yorkshire,’ Kirkby in Durham,° Molyneux‘ and Mr. John Ward? in North Staffordshire, and Mr. George Wild in Lancashire.’ In North Staffordshire two interesting examples of the close proximity, but definite separation of these faunas, have been noted, namely :—The Moss-Cannel horizon and the Upper Marine Band in the Cheadle Coalfield. In the former instance, it requires very careful examination of the shales to be convinced of the distinctness of the layers containing Myalina compressa and Carbonicola acuta. When we consider the number of individuals of each class and the fact that they are usually scattered through the shale, it would not be surprising if an odd individual of either character should be found among a colony of the other class. The same peculiarity in the case of the Cheadle Upper Marine Band has already been mentioned (p. 511). 1 Rep. Brit. Assoc. 1865 (Birmingham) p. 48. ? Trans. N. Staffs. Inst. Min. & Mech. Eng. vol. x (1890) p. 43. 3 «S. Staffs. Coalfield’ 2nd ed. Mem. Geol. Surv. 1859, pp. 27, 58. * Quart. Journ. Geol. Soc. vol. xxxiii (1877) pp. 628, 643, > Encyclopedia Metropolitana, vol. vi (1845) art. Geolog BY, Pavel. § Quart. Journ. Geol. Soc. vol. xvi (1860) p. 414. T Rep. Brit. Assoc. 1864 (Bath) p. 348. 8 Trans. N. Staffs. Inst. Min. & Mech. Eng. vol. x (1890) p. 31. ° Proce. Yorks, Geol. Soc. vol. xiii (1895-99) p. 305. Oa a ~ 516 MR. J. T. SIOBBS ON THE MARINE BEDS _—‘[ Aug. 1905, The almost immediate succession, in order of deposition, of a coal-seam by a marine shale is a circumstance that may throw light on the conditions under which these seams were laid down. So far as attention has been directed to the nature of the coals overlain in this fashion, they do not differ in appearance or quality from the other coals of the district. The following seams are associated in this way with marine bands, namely :— The Bay Coal. The Priorsfield-Ironstone Coal. The coal below the Gin Mine at Florence Colliery. The Moss Cannel. The Seven-Feet Banbury Rider Coal. The coal below the Four-Feet at Draycott. The Crabtree Coal. VI. Scorme or SUBDIVISION oF THE CoAL-Muasurus In Norte STAFFORDSHIRE BY MEANS OF MARINE BANDS. Numerous attempts have been made in many of our coalfields to correlate the coal-seams in different localities ; but, because palzon- tological evidence has been almost totally ignored in these efforts, to that extent the results may be regarded as guesses, more or less unsatisfactory. Such correlations lack anything of the nature of rigid proof. In North Staffordshire, the tracing of these marine horizons has placed the correlation on a different footing. This is attested by the fact that, in certain operations of mining, such as boring, sinking, and proving faults, these marine horizons have been of actual service when otherwise there would have been doubt. In all Coal-Measure stratigraphy, however, it is advisable that the knowledge of marine bands should be supplemented by that of such other strata as satisfy the requirements of index-beds. In the district in question, several bands of thin limestone crowded with entomostraca have been traced; and the subdivision of the Coal- Measures, based on these paleontological ‘lines’ (which are not more than 450 feet apart in the series) simplifies the work of identifica- tion of certain seams. : | In the following synopsis are enumerated, in descending order, the seams of coal and ironstone occurring between the index-beds mentioned above :— SPIRORBIS- LIMESTONE. Bassey-Mine Ironstone and Coal. Little-Row or Gutter Coal. Pascoe Cie Pe aa era act Rich plant-bed. Spencroft Coal. Gubbin Ironstone. Great-Row Coal. Lower limit of the range of SPIRORPIS-UIMESTONE « jcc cede hee eens eee eee { Anthracomya Phillipsi. Cannel-Row Coal. Wiood=Mimewiroustome —2.. 24.0. -eeni see eeeeee Rich fish-bed. Pennystone or Blackstone Ironstone. Deep-Mine Ironstone ................ PP eh eee Rich fish-bed. Vol. 61.] IN THE NORTH-STAFFORDSHIRE COAL-MEASURES. Chalkey-Mine Ironstone. New-Chalkey or New-Mine Ironstone. Bungilow Coal. Hanbury Ironstone-Measures. Rag-Mine Ironstone. Marine BAnp. Bay or Lady Coal. Knowles or Winghay Coal. Marine BAnp. Priorsfield Ironstone-Measures .................. Rich fish-bed, Rusty-Mine Ironstone. Brown-Mine Ironstone Gold-Mine Ironstone. PNSMMOEMROWIMUTS Coal... ....0...-s.ccceesseees es Rich plant-bed. Binghay or Bingey Coal. New-Mine Ironstone. By RA Oe ANE aR Rich fish-bed. Burnwood or Little-Mine Ironstone ............ Anthracomy a Adamsi. Pottery, Gin-Mine, or Twist Coal ............... Plant-bed. Marine Banps (Line A, in fig. 3, p. 518). Bee Coal. Doctor’s Mine. Birchenwood Coal. Marine Banp. Granville Coal. Moss, Mossfield, Easling, or Single Four-Feet Coal. Marine Bann. Moss-Cannel or Single Two-Feet Coal. Single Five-Feet Coal scaemneln (CCal wes ita aacee eee ene are Rich plant-bed. Rough Seven-Feet Coal } Yard Coal. Haims Coal. Old Whitfield or Birches Coal. Ten-Feet Coal. SPIRORBIS- LIMESTONE. Bowling-Alley, Top Two-Row, Magpie, or Tatchinend Coal. aac ls POR ik de atte arenee Rich plant-bed. Holly-Lane or Two-Row Coal. 517 See Uk CS 5: Bak OPS 9A Moe § Carbonicola subconstricta. Hard-Mine, Sparrow-Butts, Muck-Row, or { Anthracomya Williamsoni. Bowling Alley Coalints.. eaeristane es coved aces | Naiadites carinata. PA er ee «Sat ett sk SONAR GERAD, ca hate Rich plant-bed. Stinker’s Coal. Marine Banp (Line B, in fig. 3, p. 518). Little-Mine Ironstone and Coal. Seven-Feet Banbury, Seven- Feet Nabs, or { Carbonicola acuta, NRO SON COM vans asec aa crac site eS od acerca se . var. rhomboidalis. Whitehurst Coal. Bullhurst Coal. Winpenny Coal. Silver Mine. King Coal. Fig. 3.— Vertical sections illustrating the correlation of the Coal-Measures in Yorkshire, Lancashire, and the Midland Counties. LANCASHIRE N. STAFFS. S. STAFFS. Dppen sown Raa Anthracomya Dt or hippy the Dao YORKSHIRE & NOTTS. Ackworth ;Rock Barnsley or Top Hard Coal iv f ip Ue Deep Hard Ty f i Coal ff Bree rae Silkstone Mine / oal td / Kilburn i oal / f Cc H ard Bed Ms iS ‘Bullion Coal Milistone Tit Millstone Ml rit 70a COALBROOKDALE Fungous j)Brooch Can Coal Thick Coal A Bénnystone ra Pennystone i) ° fe) nr n > C) i) ay Coal Crabtree Coal Millstone Grit Vertical Scale: I inch =1,000 feet. REFERENCE . A-=1'! Marine Horizon as Connecting Lines B — Quad 29 93 99 9 é C =3rd 2? Oe) 99 29 } : Noll: 61. | THE MARINE BEDS IN THE COAL-MEASURES. a19 It should be mentioned that the highest and lowest horizons marked by Spwrorbis-Limestones in the foregoing succession have been traced over practically the whole Coalfield, wherever they have not been removed by denudation. VII. Corre cation oF VARIOUS COALFIELDS BY THE USE oF Marine Horizons, The existence of these definite horizons may be of service, not only for correlating the seams in any one coalfield, but they also offer the best means of correlating one coalfield with another. There can be little doubt that, at the time of their deposition, they formed absolutely the same plane-surface corresponding to sea-level, and in this respect they are of greater value than the freshwater molluscan zones of the Coal-Measures. With reference to the latter, we cannot overestimate the valuable work done by Dr. Wheelton Hind in establishing the order of succession of these mollusea; for, after scores of opportunities of testing their merits, their first failure in North Staffordshire has yet to be experienced. In comparison, however, the marine bands are more easily dis- tinguished by practical mining-men, and they mark with greater precision a definite plane of deposit over wide areas of country. Their supreme adaptability, when present, for this purpose was recognized by earlier workers, who unfortunately assumed that marine bands were of rare occurrence, at any rate, in the most valuable portion of the Coal-Measures. The following instances, however, of attempts to correlate different Coalfields by these horizons may be enumerated, namely :— (1) The Pecten, Hard, or Gannister Coal of Yorkshire was con- sidered identical with the Bullion Coal of Lancashire by E. W. Binney,’ and the latter was correlated with the Crabtree Coal of North Staffordshire by Warington Smyth.* From the fauna and the position of these coals in the sequence, this identification may be considered as established (line C, fig. 3, p. 518). (2) The Pennystone of South Staffordshire, in the opinion of J. W. Salter,* was the equivalent of the Pennystone of Coalbrook- dale, because of the character of the marine mollusca found in connection with those deposits. It was adopted as a datum-line for the correlation of these coalfields by 8. Bowkley * and Mr. Daniel Jones’; and this met with the approval of Sir Andrew Ramsay.° _ (3) The Bay Coal and Priorsfield horizons of North Staffordshire were regarded as correlative of Green’s marine bed at Ashton- under-Lyne by the late Robert Etheridge,’ but with this view IL ' Trans. Manch. Geol. Soc. vol. iv (1862-64) p. 18. 2 “The Iron-Ores of Great Britain’ pt. iv, Mem. Geol. Surv. 1862, p. 264. > «The South Staffordshire Coalfield’ 2nd ed. Mem. Geol. Surv. 1859, p. 27. * Trans, 8S. Midland Inst. vol. ii, p. 65. > Rep. Roy. Coal-Comm. vol. i (1871) pp. 121-22. ° «The South Staffordshire Coalfield’ 2nd ed. Mem. Geol. Sury. 1859, p. 58. * «Geology of the Country round Stockport, Macclesfield, &c.’ Mem. Geol. Surv. 1866, p. 94. 520 MR, J. T. STOBBS ON THE MARINE BEDS (Aug. 1905, cannot agree. ‘The fauna contained by the last-named horizon was said by J. W. Salter to be ‘comparable with that of the Lower Coal-Measures of Shropshire,’ by which, I presume, was meant the Pennystone of Coalbrookdale. This identification, by the evidence of the fauna and the position of each horizon in the Coal-Measure Series, is, in my opinion, correct. The extraordinary fauna contained in these beds in Lancashire, Coalbrookdale, South Staffordshire, and in the Gin-Mine or Twist Coal of North Staffordshire, leaves little room for doubt that this horizon may be used as the first connecting- line extending between those coalfields (A, in fig. 3, p. 518). The following analysis of the lists from all these districts, together with the stratigraphical position of the horizon in each coalfield, constitutes the justification of this conclusion :— | Nortu | Sourm |CoaLBroox-| Lanca- Starrs. | STAFFs. DALE. SHIRE. wee SS SS | SS eee ——— Wes Fal ROCUUNGHUS nae ocamnce duc tan noseepsoe| * | x | Lingula mytiloides, Sow. ...........- eae fe | Orbiculoidea niiida (Pimlls) 3. es) ee |e * | Productus scabriculus, Sow. ......... | % ater Bs. * Ctenodonta levirostris, Portl. ......!| x Layee Bes *% UNUCUWIOME GCULO SON.) secee seers es | * h Huet x % Pseudamusium fibrillosum (Salt.) ... x | ies % Pterinopecten papyraceus (Sow.) ... | % Ephippioceras costatum, Foord ...... * * Orthoceras aff. asciculare, Brown ... x % Temnocheilus concavus (Sow.)........ a * Conularia quadrisulcata, Sow. ...... re a * x WESURACCIICNUSH a Rereece nin nee oe | x | as ot x | | The second line (B, fig. 3, p. 518) may be taken as the Seven- Feet Banbury marine bed in North Staffordshire. Mr. Walcot Gibson, of the Geological Survey, kindly showed me the marine bed discovered by him in Nottingham, and reported as lying about 80 feet below the Furnace Coal (or 76 feet above the Blackshale Coal) of that district? On the occasion of that visit I expressed the opinion that the suite of fossils collected from the band corre- sponded most nearly with that of the Seven-Feet Banbury bed, and this view has been confirmed by subsequent work. In both coalfields this marine horizon is similarly situated with respect to the zone of Carbonicola robusta (a good zoning form), which in Nottinghamshire is found in connection with the Silkstone or Black- shale Coal, and in North Staffordshire occurs near the Cockshead Coal. It is most interesting to recall the fact that Henry Denny in 1845 recorded the existence of a marine band containing Lingula, 82 feet above the Silkstone Coal,’ verifying in a remarkable way the identity of the Silkstone Coal of the Barnsley area with the ' * Geology of the Country around Oldham’ Mem. Geol. Surv. 1864, p. 65. * ‘Summary of Progress of Geol. Surv. U.K. for 1902’ 1903, p. 16, 3 Proc. Yorks. Geol. & Polytechn. Soc. vol. ii (1842-48) p. 298. Vol. 61.) IN THE NORTH-STAFFORDSHIRE COAL-MEASURES. 521 Blackshale Coal of Nottingham. Prof. Hull, referring to the Silkstone Coal of Yorkshire, says that it is ‘ undoubtedly identical with the Arley Mine of Lancashire,’ but he adduces no evidence In support of this statement. We now know, however, that the Arley Mine of Lancashire is the Carbonicola-robusta Zone ; and very recently Mr. John Gerrard announced the discovery of a marine band in its proximity at Victoria Colliery, Standish. Consequently, the identity of the horizon in the coalfields of Yorkshire and Nottinghamshire, Lancashire, and North Staffordshire rests upon the following facts:—(a) Its proximity to the zone of Carbomcola robusta; (6) its relation to one of the most noted coal-seams in each district ; (c) its position near the base of the most valuable portion of the Coal-Measures ; and (d) the nature of the fossils collected from the horizon in each coalfield. The following list is common to the different coalfields :— Nort None: Lanca- STAFFS. SHIRE. ingula mytilotdes, SOW. (...t2..s..ecene es * + Myalina compressa, Wind ...........0...... % * Pterinopecten papyraceus (Sow.)......... .. x * % Oi AOCCRCSIS IV Ne aden cn bs wees shea ne eie. % * * COMMAUIECS I ee NS akan onneds 2 Meee ceewe % % * FAME SREMIAIIS Sc o6 vee soci - -aicoan destin) dic ane nao % % The third line (C, in fig. 3, p. 518) is that suggested by Phillips, Binney, and Warington Smyth, namely, the marine shales overlying | the Hard Bed of Yorkshire, the Bullion Coal of Lancashire, and the Crabtree Coal of North Staffordshire. The fauna found at this horizon, common to these coalfields, is tabulated in the following list :— Norru Yorx- Lanca- STAFFS. SHIRE. SITRE. Lingula mytiloides, Sow. .............. * a: * | Posidoniella levis (Brown) ............ 2 | ae * Pterinopecten papyraceus (Sow.) ... = | * 2 Gastrioceras Listert (Mart.) .........) Xe 2 2 COROT TLC SIAR Is se SA Lah isle od 2 x X* ORCL OCCROS Mergers (2 ROH Ho 0 x sci * * 2 Its position in relation to the Millstone Grit is also confirmatory of the correctness of this identification. The southward attenuation of the Coal-Measure Series in the great area connected during deposition, which is represented in * “The Coalfields of Great Britain’ 3rd ed. (1873) p. 241. 022 MR. J. T. STOBBS ON THE MARINE BEDS [ Aug. 1905, section by fig. 3, has been frequently noted within narrow vertical limits, as in the case of the Warwickshire Coalfield from Tamworth to Bedworth, and of South Staffordshire from Cannock Chase to Dudley—indeed, this is shown quite diagrammatically in the Thick Coal itself, while the evidence for it in North Staffordshire has been referred to in this paper (p.505). The remarkable persistence of seams of coal in comparison with the general thinning-out of the Coal-Measures is worthy of special attention. This collective decrease in thickness is clearly shown in fig. 3 (p. 518), which indicates that the strata between the lines A and hi have been most affected by this process. VIII. Concruston. These marine beds, which have been described at length in the foregoing pages, are seen to be true zoological zones, indicative of special conditions of deposit: they are persistent, and their contained fossils are abundant and easily recognized. Recent work has shown that they are more numerous in the Coal- Measures than has been hitherto suspected. They are generally to be met with in shaft-sinkings, borings, and cross-measure drifts, if | carefully looked for: in such circumstances, however, the discoverer should not rest satisfied until he has personally located the horizon m situ. : In accounting for the presence of these bands among Strata of freshwater origin, it is not necessary to assume vertical oscillation of the ground, for they are sufficiently explained by the occasional recurrence of somewhat excessive subsidences during a general and prolonged movement of depression. Thus, inroads of the sea would be permitted over an extensive area, which we may consider was land-locked. This area embraced the sites of the coalfields of Uanceashire, Yorkshire, Derbyshire and Nottinghamshire, Leicester- shire, Warwickshire, North and South Staffordshire, and Shropshire, the measures in which were laid down as continuous deposits; for the existence of these marine beds renders untenable the theory that each coalfield was a ‘separate area of deposition.’ Furthermore, these recurrences of marine conditions cannot be regarded as more characteristic of the lowest portion of the Coal- Measures, for the richest horizon of all is the Gin-Mine or Penny- stone Bed, which is high up in the ‘ true Coal-Measures.’ While the stratigraphy of nearly every formation has been based on paleontological data, it is to be regretted that (in this respect) the Coal-Measures have been comparatively neglected ; but increased attention is now being given to the abundant material at our disposal. In conclusion, I desires to express my indebtedness to Messrs. G. A. Mitcheson, F.G.S., and J. Lockett for allowing me to examine in situ, and to collect from, several marine horizons at collieries under their charge; to Mr. EK. P. Turner for preparing Vol. Oma | IN THE NORTH-STAFFORDSHIRE COAL-MEASUBES. 523 diagrams in illustration of this paper, and for assistance in carrying out these researches; and to the following students for similar help, namely: Messrs. W. Plant, W. G. Salt, and W. Scrivens. The authoritative naming of the fossils was essential, and to this matter Dr. W. Hind and Mr. J. Ward have devoted much time and trouble: it is due to these two geologists to acknowledge the assistance derived from their pioneer-work in connection with the paleontology of the North Staffordshire Coalfield, which promises results equally valuable when applied to the other British coalfields. To the following experts my thanks are also tendered, for naming fossils mentioned in this paper, namely: Dr. F. A. Bather, Mr. G. C. Crick, Dr. A. H. Foord, Mr. R. Kidston, F.R.S., Mr. E. T. Newton, F.R.S., Dr. A. 8. Woodward, F.R.S., & Dr. Henry Woodward, F.R.S. IX. BreiioGRAPHy. While it is not put forth as absolutely complete, the following list may be useful to workers :— (a) North-Staffordshire Coalfields. Roof of the Bay or Lady Coal. 1864. Motyneux, W. Rep. Brit. Assoc. (Bath) p. 348. 1865. Motyneux, W. Rep. Brit. Assoc. (Birmingham) p. 49. 1865. Warp, J. Dudley “ Midland Geol. Soc. vol. i, p. 23. 1865. Anon. Quart. Journ. of Science, vol. ii, p. 528. 1866. GreEn, A. H. ‘The Geology of the Country round Stockport, &c.’ Mem. Geol. Surv. pp. 86, 94-95. 1870. Warp, J. Trans. Midland Sci. Assoc. pt. 11, p. 29. 1873. Hutt, E. ‘The Coalfields of Great Britain’ 3rd ed. p. 177. 1875. Warp, J. N. Staffs. Nat. Field-Club: Addresses, Papers, &c. pp. 190-91. 1877. Huy, E. Quart. Journ. Geol. Soc. vol. xxxiii, pp. 628, 644, & 648. 1890. Warp, J. Trans. N. Staffs. Inst. Min. & Mech. Eng. vol. x. p. 49. 1894. Hinp, W. Pal. Soc. vol. xlviti: ‘ Monogr. Carbonicola, &c.’ pt. 1, p. 7. 1895. Warp, J. Trans. N. Staffs. Nat. Field-Club, vol. xxix, p. 131. 1901. Stogpss, J.T. Trans. Inst. Min. Eng. vol. xxii, pp. 235, 237, 238 & vol. xxiii, p. 110. 1902. Gipson, W. ‘ The Geology of the Country around Stoke-upon-Trent’ Mem. Geol. Surv. p. 49. 1903. Hinp, W. Proc. Geol. Assoc. vol. xviii, p. 175. Roof of the Priorsfield Ironstone. 1864. Motyneux, W. Rep. Brit. Assoc. (Bath) p. 342. 1865. Motynreux, W. Rep. Brit. Assoc. (Birmingham) pp. 45, 50. 1866. GreEn, A. H. ‘The Geology of the Country round Stockport, &c.’ Mem. Geol. Surv. pp. 86, 94-95. 1870. Warp, J. Trans. Midland Sci. Resot pt. ii, p. 30. 1875. Warp, J. N. Staffs. Nat. Field-Club: Addresses, Papers, &c. pp. 190-91. -1890. Warp, J. Trans. N. Staffs. Inst. Min. & Mech. Eng. vol. x, p 48 1895. Warp, J. Trans. N. Staffs. Nat. Field-Club, vol. xxix, p. 186. Beds below the Gin-Mine or Golden Twist Coal. (a) The Speedwell and Nettlebank Bed. 1865. Motynreux, W. Rep. Brit. Assoc. (Birmingham) p. 50. 1865. Warp, J. Geol. Mag. dec. 1, vol. 11, pp. 234 & 286. 1865. Lucas, S. Geol. Mag. dec. i vol. ii, pp. 569-70. 524 MR. J. T. STOBBS ON THE MARINE BEDS | Aug. 1905, 1875. Warp, J. N. Staffs. Nat. Field-Club: Addresses, Papers, &c. p. 192. 1877. Hut, E. Quart. Journ. Geol. Soc. vol. xxxiii, pp. 628 & 644. 1890. Warp, J. Trans. N. Staffs. Inst. Min. & Mech. Eng. vol. x, pp. 42-43. 1894. Hinp, W. Pal. Soc. vol. xlviii: ‘ Monogr. Carbonicola, &c.’ pt. 1, p. 7. 1895. Warp, J. Trans. N. Staffs. Nat. Field-Club, vol. xxix, p. 135. 1896. Hinp, W. Pal. Soc. vol. 1: ‘Monogr. Brit. Carb. Lamellibranchiata’ pt. 1, pp. 6 & 51. 1902. Gipson, W. ‘The Geology of the Country around Stoke-upon-Trent ’ Mem. Geol. Surv. p. 48. 1903. Hinp, W. Pal. Soc. vol. lvii : ‘ Monogr. Brit. Carb. Lamellibranchiata ’ vol. 11, pp. 120-21. 1903. Woopwarp, A.S. Geol. Mag. dec. 4, vol. x, pp. 486-88. 1904. Newton, KE. T. Quart. Journ. Geol. Soc. vol. lx, pp. 1-8. (G) The Florence Marine Bed. 1865. Lucas, 8S. Geol. Mag. dec. 1, vol. 41, p. 570. 1875. Warp, J. N. Staffs. Nat. Field-Club: Addresses, Papers, &c. p. 192. Marine Bed over the Moss Coal. 1895. Warp, J. Trans. N. Staffs. Nat. Field-Club, vol. xxix, pp. 129 & 134. 1901. Stopss, J.T. Trans. Inst. Min. Eng. vol. xxii, pp. 235 & 238-40. 1902. Gipson, W. ‘The Geology of the Country around Stoke-upon-Trent’ Mem. Geol. Surv. p. 48. Marine Bed over the Single Two-Feet or Moss Cannel. 1901. Stropss, J.T. Trans. Inst. Min. Eng. vol. xxu, pp. 235 & 238-40, 1902. Stogpss, J.T. Trans. N. Staffs. Nat. Field-Club, vol. xxxvi, pp. 86-88. Weston-Sprink Bed. 1899. Warp, J., & Hinp, W. Trans. N. Staffs. Nat. Field-Club, vol. xxxiv, . 87-94, 1899. Gancow. W. ‘Summary of Progress of the Geol. Surv. U.K. for 1898’ Mem. Geol. Surv. p. 124. 1900. Gipson, W. ‘Summary of Progress of the Geol. Surv. U.K. for 1899’ Mem. Geol. Surv. p. 108. 1902. Gipson, W. ‘The Geology of the Country around Stoke-upon-Trent’ Mem. Geol. Surv. pp. 24 & 48. Marine Bed over the Seven-Feet Banbury Coal. 1900. Sropss, J.T. Trans. N. Staffs. Nat. Field-Club, vol. xxxv, pp. 110-13. 1901. Sroszss, J.T. Trans. Inst. Min. Eng. vol. xxii, pp. 235, 242 & vol. xxiu, Dele: 1902. Gipson, W. ‘The Geology of the Country around Stoke-upon-Trent’ Mem. Geol. Surv. pp. 24, 48. Roof of the Crabtree and Two- Feet Coals (of Ipstones, Wetley Moor, Goldsitch Moss). 1859. Garner, R., & Motyneux, W. Rep. Brit. Assoc. (Aberdeen) Trans. Sect. p. 104, 1860. GarnEeR, R. ‘Nat. Hist. of the County of Stafford ’ Supplement, p. 42, 1862. SuytH, W. W. ‘The Iron-Ores of Great Britain’ pt. iv, Mem. Geol. Surv. pp. 264, 277, & 296. * 1862. Binney, E. W. Trans. Manch. Geol. Soe. vol. iii, p. 317. 1862. Taytor, J. Trans. Manch. Geol. Soc. vol. iti, pp. 298-99. ‘ 1863. WarpuLz, T. Reprint from J. Sleigh’s ‘ Ancient History of Leek’ pp. 2385 & 259. 1864. MonynEux, W. Rep. Brit. Assoc. (Bath) p. 343. Vol. 1865. 1865. 1865. 1866. 1869. 1873. 1881. 1894. 1895. 1900. 1901. 1903. 1853. 1858. 1860. 1869. 1872. 1873. UST 7. 1877. 1888. 1893. 1898. 1902. 1869. 1892. 1895. LOI. 1839. 1840. 1845. 1862. 1872. 1873. 1877. Weis 1878. 1894 1861. 1873 1877 61.| IN THE NORTH-STAFFORDSHIRE COAL-MEASURES. 525 Motynevux, W. Trans. Midland Sci. Assoc. pp. 13-17 & 34. Motynevux, W. Rep. Brit. Assoc. (Birmingham) pp. 44-45 & 48. Warp, J. Dudley & Midland Geol. Soc. vol. 11, p. 24. Green, A.H. ‘The Geology of the Country round Stockport, &c.’ Mem. Geol. Surv. pp. 27 & 94. Motynevx, W. ‘Burton-on-Trent: its History, &c.’ p. 163. Hutt, E. ‘The Coalfields of Great Britain’ 3rd ed. p. 173. Moityneux, W. Plant’s ‘ History of Cheadle’ pp. 290-91 & 310. Hinp, W. Pal. Soc. vol. xlviii: ‘ Monogr. Carbonicola, &c.’ pt. 1, p. 7. Warp, J. ‘Trans. N. Staffs. Nat. Field-Club, vol. xxix, pp. 132-33. ‘Barrow, G. ‘Summary of Progress of the Geol. Surv. U.K. for 1899’ Mem. Geol. Surv. p. 106. Wepp, C. B. ‘Summary of Progress of the Geol. Surv. U.K. for 1900’ Mem. Geol. Surv. p. 105. - Barrow,G. ‘The Geology of the Cheadle Coalfield’ Mem. Geol. Surv. pp. 11, 13, & 15. (6) South-Staffordshire Coalfield. JuKES, J.B. ‘On the Geology of the South Staffordshire Coalfield’ Rec. School of Mines, vol. i, pt. 11, p. 194. JuKeEs, J. B. ‘The Iron-Ores of Great Britain’ pt. 11, Mem. Geol. Surv. pp. i112, GARNER, R. ‘ Natural History of the County of Stafford’ Supplement, pp. 40 & 42. Motynevx, W. ‘ Burton-on-Trent: its History, &c.’ p. 154. Jones, D. Trans. 8S. Midland Inst. Min. Mech. & Civil Eng. vol. in, pamphlet, p. 14. Hutt, E. ‘ The Coalfields of Great Britain’ 3rd ed. p. 165. Hout, HE. Quart. Journ. Geol. Soc. vol. xxxiii, p. 630. Ranpatt, J. Proc. Dudley & Midland Geol. Soc. vol. iui, p. 44. Kirxsy, J. W. Quart. Journ. Geol. Soc. vol. xliv, p. 752. Kinston, R. Proc. Roy. Phys. Soc. Edin. vol. xii, p. 187. Lapwortu, C. Proc. Geol. Assoc. vol. xv, p. 367. Hinp, W. Trans. N. Staffs. Nat. Field-Club, vol. xxxvi, p. 88. (c) Leicestershire Coalfield. Motynevux, W. ‘Burton-on-Trent: its History, &c.’ p. 154. GreEstEy, W.S. Trans. Manch. Geol. Soc. vol. xxi, p. 525 & vert. sects. Hout, E. Trans. Nat. Assoc. Colliery-Managers, vol. vil, p. 93. (d) Coalbrookdale and Forest-of-Wyre Coalfields. Darwin, Erasmus. ‘The Botanic Garden’ Ad. Notes, pp. 63, 66, & 121. Murcuison, R. E. ‘The Silurian System’ pp. 104-105. Prestwicu, J. Trans. Geol. Soc. ser. 2, vol. v, pp. 484, 442-43, & 445. Puitiips, J. Kneyclopedia Metropolitana, vol. vi, art. ‘Geology’ p. 593. Smyru, W. W. ‘The Iron-Ores of Great Britain’ pt. iv, Mem. Geol. Surv. pp. 241-42. Jones, D. Trans. 8. Midland Inst. Min. & Civil Eng. vol. i, pamphlet. p. 14. Hout, HK. ‘The Coalfields of Great Britain’ 3rd ed. p. 136. Hutt, E.. Quart. Journ. Geol. Soc. vol. xxxiii, pp. 629 & 644. RANDALL, J. Proc. Dudley & Midland Geol. Soe. vol. 111, p. 44. Ramsay, A. C. ‘The Physical Geology & Geography of Great Britain’ 5th ed. p. 128. . Hinp, W. Pal. Soc. vol. xlviii: ‘ Monogr. Carbonicola, &c.’ pt. i, p. 5. (¢) South Wales Coalfield. Satter, J. W. ‘The Iron-Ores of Great Britain’ pt. iii, Mem. Geol. Surv. pp. 221-22 & 228-29, . Huuy, EH. ‘The Coalfields of Great Britain’ 3rd ed. pp. 61 & 99-100. . Huw, E. Quart. Journ. Geol. Soc. vol. xxxiii, p. 632. 5026 MR. J. T. STOBBS ON THE MARINE BEDS [ Aug. 1905, 1877. Ranpaut, J. Proc. Dudley & Midland Geol. Soc. vol. iti, p. 44. ‘ 1896. Hinp, W. Pal. Soc. vol. 1: ‘Monogr. Brit. Carb. Lamellibranchiata ’ pt. 1, p. 32. 1900. Stranan, A., & Greson, W. ‘The Geology of the South Wales Coalfield : pt. ii—The Country around Abergavenny ’ Mem. Geol. Surv. pp. 84-87. (f) Flintshire and Denbighshire Coalfield. 1873. Hut, HE. ‘The Coalfields of Great Britain’ 3rd ed. pp. 61, 143, & 149. (g) Lancashire Coalfields. 1839-40. Binney, E. W. Trans. Manch. Geol. Soc. vol. i, pp. 76-78 & 80-89. 1861. Satter, J. W. ‘ The Jron-Ores of Great Britain’ pt. 111, Mem. Geol. Surv. eee | 1862. Taytor, J. Trans. Manch. Geol. Soc. vol. ii, pp. 298-99. 1862. Hux, E., & Santer, J. W. ‘Geology of the Country around Bolton-le- Moors, Lancashire’ Mem. Geol. Surv. pp. 6-7, 34-35, & 43. 1862. Hux, EK. Trans. Manch. Geol. Soc. vol. 11, pp. 348-50. 1862. Binney, E. W. In Pal. Soc. ‘Monogr. Fossil Hstherie’ by T. R. Jones, pp. 28-30. 1863. Binney, HE. W., &c. Trans. Manch. Geol. Soc. vol. iv, pp. 69-70. 1863. Dickinson, J..& Witp, G. Trans. Manch. Geol. Soc. vol. iv, pp. 161 & 189. 1864. Hut, E., & Saurer, J. W. ‘Geology ofthe Country around Oldham’ Mem. Geol. Surv. pp. 19, 21, & 62-66. 1864, Taytor, J. ‘Geological Essays’ pp. 187, 148, 152, & 190. 1864. Huu, E., & Grenn, A. H. Quart. Journ. Geol. Soc. vol. xx, p. 245. 1865. WHITAKER, J. Trans. Manch. Geol. Soc. vol. v, p. 96. 1867. Binney, E. W. ‘Trans. Manch. Geol. Soc. vol. vi, p. 104. 1869. Motynreux, W. ‘ Burton-on-Trent: its History, &.’ p. 154. 1873. Hut, E. ‘The Coalfields of Great Britain’ 3rd ed. pp. 187, 192, 194-95, & 198. 1873. Binney, E. W., & others. Trans. Manch. Geol. Soe. vol. xu, p. 19. 1877. Hut, E. Quart. Journ. Geol. Soe. vol. xxxiil, pp. 627 & 644. 1880. Witxp, G., & others. Trans. Manch. Geol. Soc. vol. xvi, pp. 87-42. 1881. Binney, E. W., & others. Trans. Manch. Geol. Soc. vol. xvi, pp. 125-27. 1882. Hux, HK. ‘ The Geology of the Countr y around Prescot, Lancashire’ 8rd ed. Mem. Geol. Surv. jOnth 1887. Duepatsz, C., & Stirrup, M. Trans. Manch. Geol. Soc. vol. xix, pp. 220-33. 1889. WiLp, G. Trans. Manch. Geol. Soc. vol. XX, p. 224, 1892. Wiip, G. Trans. Manch. Geol. Soc. vol. xxi, pp. 366-78. 1894. Hinp, W. Pal. Soc. vol. xlviii: ‘ Monogr. Carbonicola, &c.’ pt. 1, p. 6. 1896. Hinp, W. Pal. Soc. vol. 1: ‘Monogr. Brit. Carb. Lamellibranchiata’ pt. i, p. 382. 1904, Botton, H. Trans. Manch. Geol. & Min. Soc. vol. xxviii, pp. 380-82 & 387— 415. (h) Yorkshire, Derbyshire, and Nottinghamshire Coalfield. 1845. Puitires, J. Encyclopedia Metropolitana, vol. vi, art. ‘Geology’ p. 590. 1845. Denny, H. Proc. Yorks. Geol. & Poly. Soc. vol. 11, pp. 292-93 & 299. 1873. Huw, E. ‘The Coalfields of Great Britain’ 8rd ed. pp. 60-61, 241, & 244. 1877. Huw, E. Quart. Journ. Geol. Soc. vol. xxxiii, p. 627. 1878. Green, A. H. ‘The Geology of the Yorkshire Coalfield ? Mem. Geol. Surv. pp. 76, 85, 87-88, 108-11, 122, & 471. 1878. Ceeek, A. H. ‘The Geology of the Neighbourhood of Barnsley’ Mem. Geol. DOE [De ae ; 1878. Davis, J. W. ‘West Yorkshire’ pp. 181 & 137-88. 1884. Stocks, H. B. Proc. Yorks. Geol. & Polytechn. Soc. n.s. vol. viii, p. 393. 1889. TEALE, "T.P. Proc. Yorks. Geol. & Polytechn. Soc. n.s. vol. x, pp. 71-72. 1894, Hinp, ‘W. Pal. Soc. vol. xviii: ‘ Monogr. Carbonicola, &c.’ pt. ily 106 ( 1897. Spencer, J. Proc. Yorks. Geol. & Polytechn. Soc. n. s. vol. xiii, pp. 802-303 & 306-307. 1903. Gipson, W., & Wepp, C. B. ‘Summary of Progress of the Geol. Surv. U.K. for 1902’ Mem. Geol. Surv. pp. 12 & 14-16. ll a al TA ee eS Vol. 61.] IN THE NORTH-STAFFORDSHIRE COAL-MEASURES, 527 (i) Northumberland and Durham Coalfield. 1860. Kirxpy, J. W. Quart. Journ. Geol. Soc. vol. xvi, pp. 412-14. 1861. Davipson, J. Pal. Soc.: ‘Monogr. Brit. Foss. Brachiopoda’ vol. 11, p. 209. 1873. Hun, HE. ‘The Coalfields of Great Britain’ 3rd ed. p. 257. 1886. Lepour, G. A. ‘Outlines of the Geology of Northumberland & Durham ’ 2nd ed. pp. 43, 54, 68, & 109. 1888. Kirxpy, J. W. Quart. Journ. Geol. Soc. vol. xliv, p. 752. 1897. Lepour, G. A. Proc. Univ. of Durham Phil. Soc. vol. i, p. 69. X. Nores on the Patmontotogy. By Dr. Wuentton Hrinp. Introduction. Ir has been known for some time that thin bands containing marine shells occur in several coalfields, and from time to time figures and descriptions have been published. Among the earliest of these publications were Sowerby’s descriptions and figures of the marine mollusca from the Pennystone Ironstone of Coalbrookdale, in Prest- wich’s memoir.” Perhaps the other most important publication is that by Mr. George Wild, in which a large number of marine mollusca were figured. So well known was the occurrence of marine fossils, as distinct from the bands of Curbonicola, Anthracomya, and Navadites, that Prof. Hull, in his paper on ‘The Upper Limit of the Essentially- Marine Beds of the Carboniferous Group of the British Isles’, included the Gannister Series or Lower Coal-Measures with the Millstone Grits and the series of shales and black limestones below them, which he erroneously correlated with the Yoredale Series of Wensleydale. This classification is obviously unsound; (1) because the Gannister Series is not wholly marine in origin, for it contains beds in which the marine fauna is absent; and (2) a marine fauna is not limited to the Gannister Series, but recurs at several horizons in the middle portion of the Coal-Measures, which are therefore not ‘ essentially freshwater or estuarine beds.’ Indeed, there is an unbroken succession from the base of the Pendleside Series to the top of the Coal-Measures, at times marine, at times estuarine, or of freshwater origin. This thick series contains two distinct molluscan faunas, which recur with irregular alternations. One fauna is characterized by the Unio-like genera Carbonicola and Anthracomya, and the Dretssensia-like Naiadites; the other by Pterinopecten papyraceus, Posidoniella, with many species of Cephalopoda: and the two never mix. 1 Trans. Geol. Soc. ser. 2, vol. v (1840) pp. 442-44, 490-93, & pls. xxxix—xli. 2 Trans. Manch. Geol. Soe. vol. xxi (1891-92) pp. 364-400 & pls. i-iii. 3 Quart. Journ. Geol. Soc. vol. xxxili (1877) pp. 613-50. 528 DR. WHEELTON HIND ON THE PALZONTOLOGY [ Aug. 1905, It is important to note in the Coal-Measures certain species which are found in Carboniferous rocks of a much earlier age, especially in the case of lamellibranchs, gasteropods, and brachiopods. It is curious that, in the majority of these forms, changes in the organism due to evolution cannot be demonstrated, and therefore apparently the number of marine forms found, as yet, only in the Coal-Measures is small. Of all the marine bands, that which occurs below the Gin- Mine Coal contains the richest fauna, alike in the number of genera, of species, and of individuals. Certain of the species which occurred here were new to science; others had not previously been described ~ from British rocks; and the majority of species, if not identical, have a very close affinity to forms which are known at much lower horizons in the Carboniferous sequence. Paleontological Description. Pisces. The fish-fauna of the Marine Band associated with the Gin-Mine Coal is very peculiar, and has been the subject of two important papers. One by Dr. A. Smith Woodward, on Listracanthus,' the other by Mr. E. T. Newton on Hdestus.” The occurrence of Lestracanthus had previously been noted by Mr. H. Bolton from the roof of the Bullion Mine, Lower Coal- Measures, and the Marine Band of the middle part of the Coal- Measures, in the River Tame, at Dukinfield.* Species of Lastracanthus have been found in the Culm-Measures of Herborn*; also in the Culm of Magdeburg, by Wolterstorff.? These beds I regard as the homotaxial equivalents of the Pendleside Series of the Midlands. JLzstracanthus has also been collected from beds, at Clavier, near Dinant (Belgium), which contain the typical fauna of the Pendleside Series. LL. G. de Koninck has described a specimen, under the name L. hystriv, from Castiaux, near Mons, Assise vi° and Dr. X. Stainier quotes the genus from Argenteau, near Liége." Both of these localities are situated on beds below the horizon of the Lower Coal-Measures, and in both places Listracanthus is associated with a marine fauna. We may therefore consider that Listracanthus always had a marine habitat. Many of the fishes associated with it in the bed below the Gin Mine are also found with a non-marine fauna. 1 Geol. Mag. 1903, p. 486. 2 Quart. Journ. Sl Soe. vol. Ix (1904) p. 1. 3 Geol. Mag. 1896, p. 424. + A. von Kenen, Neues Jahrb. 1879, p. 341. 5 «Das Untercarbon von M agdeburg ’ De Usk 6 Ann. Mus. Roy. d’ Hist. Nat. de Belg. VOL min LSS) amos 7 «Matériaux pour la Flore & Ja Faune du Houiller de Belgique’ Ann, Soe. géol. de Belg. vol. xix (1892) p. 348. Nols /61-..| OF THE MARINE BANDS IN THE COAL-MEASURES. 529 The list of fossil fishes from the bed below the Gin Mine is as follows :— Acanthodes Wardi, Kdg. Megalichthys rugosus, Young. Celacanthus elegans, Newb. Orodus sp. (?). Diplodus gibbosus, Ag. Platysonus parvulus, Ag. Edestus triserratus, FE. '. Newton. Platysomus Forsteri, H. & Atth. Etionichthys Egertoni, Ag. Pleuroplax Rankinei, Ag. Listracanthus Wardi, A. 8S. Woodw. Lthizodopsis sauroides (Will.). Megalichthys Hibberti, Ag. Sphenacanthus ? (teeth). Megalichthys intermedius, A.S.Woodw. Echinodermata. Archeocidaris sp. (Pl. XXXYV, figs. 1 & 1a). is represented in the marine band below the Gin Mine by numerous spines, teeth, and a few interambulacral plates. The radioles are very long and slender, with numerous, comparatively-large, opposite spinules, which project upwards and downwards. The plates have the general character of the genus. Some of the material has been submitted to Dr. F. A. Bather, F.G.S., who hesitates to refer the specimens to any particular species, as much uncertainty exists in regard to the type. Archeocidaris has been previously noted from the British Coal- Measures. Jukes quotes, on the authority of Edward Forbes, ‘an Echinus very much broken up, probably Archeocidaris, in the lower part of the New-Mine Ironstone, Oldbury.? Brachiopoda. The Brachiopoda are represented in the Coal-Measures by seven species, and the individuals are nearly always dwarfed. LinevLa mytinoipes, Sow. (Pl. XXXV, fig. 2.) This species is not uncommon at several horizons. Asa rule, it occurs in a black shale by itself; in the case of the marine band below the Gin-Mine Coal, it is found immediately above the bed containing the other marine shells. The shell is usually much dwarfed, and the biggest specimen that I have seen measures only 8 millimetres in its greatest diameter. Mr. John Ward mentions the occurrence of Lingula squamiformis from the North-Staffordshire Coalfield? but I think that he was misled by crushed specimens. I have seen no specimens properly referable to this species in his collections. Localities.— North Staffordshire: above the Bay Coal; in the roof of the Priorsfield Ironstone ; below the Gin-Mine Coal (two beds); over the Moss Coal; above the Moss Cannel-Coal; marine band, Weston Sprink; above the Seven-Feet Banbury Coal ; 71 feet below the Four-Feet Coal, Cheadle; above the Crabtree Coal. Leicestershire Coalfield: at 453, 606, and 663 feet from the surface at Nailstone Colliery. Nottinghamshire Coalfield: 524 and 1 «Geology of the South Staffordshire Coalfield’ Ree. of the School of Mines, vol. i, pt. ii (1853) p. 194. 2 Trans. North Staffs. Inst. Min. & Mech. Eng. vol. x (1890) p. 128. Q.J.G.8. No. 24:3. 2 Pp 530 DR. WHEELTON HIND ON THE PALMONTOLOGY [ Aug. 1905, 258 feet above the Top-Hard Coal; 80 feet below the Furnace Coal. Durham Coalfield: 17 feet 4 inches above the Five-Quarter Coal. Lancashire Coalfield: 2070 feet below the surface at Brad- ford Colliery, above the Bullion Coal. Yorkshire Coalfield: above the Middleton-Mine and Silkstone Coals. Cannock-Chase Coalfield : Tair Oaks Colliery. This species also occurs in the Pendleside Series of North Staffordshire. ORBICULOIDEA NiTtDA (Phillips). (Pi, XXXYV, fig. 3.) This species is much dwarfed, and rare in the marine band below the Gin-Mine Coal. Mr. John Ward figured a specimen (op. supra eit.) of this species from the Lower Coal-Measures of Cheadle (North Staffordshire). Above the Pennystone Ironstone, Coalbrook- dale, it occurs very well-developed, but in this bed Productus scabriculus and Spirifer bisulcatus are also very fine. Localities.—North-Staffordshire Coalfield: above the Bay Coal; above the Priorsfield Ironstone; below the Gin-Mine Coal, Nettlebank ; marine band, Weston Sprink. South Staffordshire: Pennystone. Coalbrookdale Coalfield: with the Pennystone and Chance Pennystone Ironstone. Nottingham- shire Coalfield: 524 feet above the Top-Hard Coal. Durham Ceal- field: 148 fathoms below the Hutton seam. This species also occurs in the Pendleside Series of the River Hodder (Yorkshire), and 500 feet below the Third Grit at Congleton Edge (Cheshire), and as low down as the Redesdale Ironstone, Northumberland. CHONETES LAGUESSIANA, mutation 6. (Pl. XXXYV, fig. 4.) A peculiar mutation of Chonetes occurs in the band below the Gin-Mine Coal. Its distinguishing characters are :— . The transverse form in the adult. . The extended hinge-line, and rolled ear-like projections (an adult character). . The comparatively- lar ge area. . The intercalation of ribs. . The tendency to deep, irregular, concentric grooves in the adult. This shell is fairly abundant at the horizon mentioned above, and I know this special mutation from the Coal-Measures of one of the Somerset Coalfields. Jukes quotes a small Chonetes from the Pennystone Ironstone of South Staffordshire, on the authority of Edward Forbes. On comparison with the form of Chonetes which occurs 500 feet below the Millstone-Grit Series at Congleton Edge (Cheshire), the Millstone-Grit form is seen to have much finer ribbing and to be less transverse. I have noted the same elongate hinge- line and pointed extremities in specimens of Chonetes from the Lower Limestone Series of Beith (Ayrshire). The fact that in the young state the Coal-Measure form does not exhibit the peculiarities of its adult, indicates that these characters are the result of evolution. 1 Mr. H. Bolton has discovered a rich marine bed at Ashton-Vale Colliery, near Bristol, 270 feet below Gay’s-Vein Coal. Sue 9 ho = Vol. ine OF THE MARINE BANDS IN THE COAL-MEASURES. d3l1 PRoODUCTUS SCABRICULUS (Martin). _ Acrushed example of what I take to be this species is found in the marine band, 71 feet below the Four-Feet Coal of Cheadle. It is not surprising that this species should occur at this horizon, for it is common in the Pennystone Ironstone of Coalbrookdale, and is also known in the bed 500 feet below the Millstone Grit at Congleton Edge. Jukes reports this species, on the authority of Edward Forbes, from the Pennystone Series of South Staffordshire, and it also occurs 60 feet above the Thick Coal, at Hamstead Colliery. Proptcrus sp. (Pl. XXXYV, fig. 5.) Severa] imperfect and immature examples of a scabriculocostate Productus have been obtained ; these had been previously assigned to Pr. semireticulatus, a form which must be rigidly detined in the near future. PRODUCTUS ANTHRAX, sp. nov. (Pl. XXXYV, fig. 6.) Dr. Arthur Vaughan, F.G.S., has kindly studied this form, and i append his remarks as follows :— ‘ Productus 3. (Gin Mine). (A pedicle-valve.) ‘J. A descendant of the generic series of Productus Cora (Dav.), as shown by 1) The short hinge-line (see the growth-lines on the brachial valve). (2) The Orthotetes-like sculpture on the flanks. (3) The emphasized wrinkles on the wings. “II, Strong convergence towards Productus hemisphericus is indicated by (1) The transversity and general convexity, but especially by the form and ornament of the beak and beak-region. (2) The gradual and gentle slope of the medial area into the flanks. “TIl. Homeomorphy with Productus aff. burlingtonensis (=my Productus ef. Martint) is distinctly suggested in the general aspect of the medial area. (1) The medial line has an almost constant curvature. (2) The medial area is flattened transversely, so as to be almost truly cylindrical. (The broad, very shallow sulcus and the few distant spines increase the resemblance.) “TV. The edelburgensis-type of ribbing is very marked in this specimen, but is most probably (judging from other groups) merely a varietal character.’ Locality.—North-Staffordshire Coalfield: below the Gin- Mine Coal. AMBOCGLIA CARBONARIA, sp. nov. (Pl. XXXYV, figs. 7 & 7a.) Specific characters.—Shell small, pedicle-valve elongate, tumid, with a broad, shallow, median furrow extending from the beaks. The beak is pointed and much curved. The brachial valve is much flatter, transverse, with a median, broad, shallow sulcus and a compressed zone near the front part of each lateral margin. The valves are almost smooth, the brachial showing distinct lines of growth. 2 Pe 532 DR. WHEELTON HIND ON THE PALMONTOLOGY [ Aug. 1905, Locality.—North Staffordshire Coalfield: below the Gin-Mine Coal, Nettlebank. Observations.—I have referred this shell to a new species, because it differs widely from Ambocelia Urei, being less transverse; and the median groove is much broader and less linear, A. Ure is known from the Limestone Series of Carluke and a specimen has been figured from the marine band beneath the Farewell Rock at. Glan Rhymney, in the South-Wales Coalfield. Gasteropoda. Rapaistoma RADIANS, de Kon. 1881. (PI. XXXV, figs. 8 & 8a.) Euomphalus radians, L. G.de Koninck, ‘ Descr. des Anim. Foss. Terr. Carb. de Belg.’ 1843, p. 442 & pl. xxxiii bis, figs. 5 a—-5e. Raphistoma radians, L. G. de Koninck, Ann. Mus. Roy. d’Hist. Nat. de Belg. vol. vi (1881) p. 185 & pl. xii, figs. 12-14. This shell has not been previously described from British rocks. It does not attain to any great size, having a transverse diameter in the adult of 10 millimetres. The whorls number 6 or 7, and are much depressed and flattened. There is a large shallow umbilicus. The margin of the whorls is angular, and immediately below it is a. very fine, shallow, spiral groove. The whorls are smooth above, but below (near the suture) there is a band of regular linear tubercles. The aperture of the shell is obliquely ovate. In Belgium, according to L. G. de Koninck, this species is not rare in the Calcareous Shale of Tournai; that is to say, it occurs in the lowest stage of the Carboniferous Limestone of that country. The same author also describes a somewhat bigger shell from the Viséan, under the name of Raphistoma junior, separating the two on account of the greater dimensions of the latter and the larger spiral angle. But the latter condition is a necessary corollary of larger growth, and I see no reason for the establishment of two species. The Rev. G. F, Whid- borne’ notes the occurrence of &. junior in the Pilton Beds; but, judging from the figures given by him, the ornament is more linear and not tubereulate, and I doubt whether his shell ought to be referred to L. G. de Koninck’s species. Localities.—The marine band below the Gin-Mine Coal, North- Staffordshire Coalfield ; 500 feet below the Third Grit, Congleton Edge (Cheshire), | TURBONELLINA FoRMosA, de Kon., 1881. (Pl. XXXYV, fig. 9.) Turbonellina formosa, L. G.de Koninck, Ann. Mus. Roy. d’Hist. Nat. de. Belg. vol. vi (1881) p. 79 & pl. ix, figs. 59-61. Like the foregoing species, this shell has never been previously found in British rocks. If I am correct in referring it to de Koninck’s species, it is rather larger than the unique example on which that species was established, which came from the Viséan 1 «Devonian Fauna of the South of England’ (Monogr. Pal. Soc.) vol. iii, pt. 1 (1896) p. 54. Vol. 61.1 OF THE MARINE BANDS IN THE COAL-MEASURES, - 533 of Belgium. Some half-dozen specimens have been found in the marine band below the Gin-Mine Coal at Nettlebank, only one of them being well-preserved. The others, although retaining the spiral ornament, are much distorted by crushing. The shell may be recognized by its small (10 millimetres high), semiglobular form, consisting of five whorls, the last of which composes the greater part of the shell. The smaller whorls appear to be almost in the same plane. The aperture is nearly circular, and the surface is orna- mented with several fine, spiral, linear ridges, which are separated by broader, concave, spiral spaces. Localit y.—North Staffordshire: below the Gin-Mine Coal. Naricorsts BREVISPIRA (de Ryckholt) 1847. (PI. XXXV, fig. 10.) Naticodon brevispira, P. de Ryckholt, ‘ Mélanges paléontologiques’ pt. i, 1847, p. 78 & pl. iii, figs. 8-9. (Ha Acad. Roy. de Belg. Mém. couronnés, &e. vol. xxiv.) Naticopsis brevispira, LL. G. de Koninck, Ann. Mus. Roy. d’Hist. Nat. de Belg. vol. vi (1881) p. 22 & pl. i, figs. 23-26. I have obtained three small specimens of a shell, which I now refer to Naticopsis brevispira (P. de Ryckholt). They are much dwarfed, the biggest measuring only 7 millimetres in height and 8 mm. in breadth. Like the two preceding species, this one has not been previously recorded as occurring in British Carboniferous rocks. It is recognized by its short globose spire of about four whorls, the last occupying by far the major portion of the shell. The aperture is large and oval. There is no decided ornament, and the shell is almost smooth; but, under the microscope, fine lines and striz of growth may be observed. : Locality.—North Staffordshire Coalfield: below the Gin-Mine Coal. Loxonema acurum, de Kon. 1881. (Pl. XXXYV, fig. 11.) Loxonema acutwm, L. G. de Koninck, Ann. Mus. Roy. d’ Hist. Nat. de Belg. vol. vi (1881) p. 46 & pl. iv, figs. 34-37. It is often very difficult to determine species of this genus, owing to the fact that the shell generally adheres to the matrix, and I have been able to examine only a single example (Pl. XXXV, fig. 11) that has the test preserved. Other examples have occurred in the state of casts of the interior, or with the outer layer of shell removed, ‘The peculiar marking is to be seen with the aid of a microscope, and consists of a number of incised curved lines on each whorl, better defined on the upper and more convex portions. Our shell measures only 10 millimetres in height, and its spire consists of about sixteen small convex whorls, the portion of the whorl which envelopes the preceding one having a moniliform ornament. Like the other gasteropoda, this species has not been _ previously recorded from British Carboniferous rocks. Locality.—North-Staffordshire Coalfield : below the Gin-Mine Coal, Nettlebank. O34 DR. WHEELTON HIND ON TILE PALXZONTOLUGY [ Aug. 1905, Lamellibranchiata. SYNCYCLONEMA CARBONIFERUM, Hind. (Pl. XXXYV, fig. 12.) This species was erected on a number of specimens from the marine band below the Gin Mine at Nettlebank (North Stafford- shire). Figures and description were published in my Monograph of Brit. Carb. Lamell. vol. 11, pt. 11, p. 120 & pl. xix, figs! 3=6 (Pal. Soc. vol. lvii, 1903), Subsequently Mr. John Smith, of Kilwinning, sent me a shell from the Upper Coal-Measures of Dalziel (Lanarkshire), which he said was the only Pecten that he had ever seen in the Coal-Measures of the West of Scotland. This specimen proved to be Syncyclonema carboniferum, and is of importance as showing the wide horizontal distribution of the species. Probably others will be found in the Lancashire and Cumberland Coalfields, if a thorough search is carried out. PsEUDAMUSIUM FIBRILLosUM (Salter). (PI. XXXYV, fig. 13.) This species is redescribed and figured in my Monograph (op. supra cit. p. 106 & pl. xvi, figs. 16-22). Specimens were obtained from the band below the Gin Mine at Nettlebank. It occurs also in the Coal-Measures of Ashton-under-Lyne, 450 feet above the Great-Mine Coal; in the Coal-Measures of Slieve Carna (Mayo) ; and.at various localities in the Pendleside Series. PTERINOPECTEN PAPYRACEUS (Sow.). (Pl. XXXYV, fig. 14.) This shell occurs at many horizons in the Coal-Measures and Pendleside Series. I regard it of importance as denoting a definite though thick zone, especially at the base, where its presence in- dicates a sudden change in the fauna. Although found in Scotland, in the Carboniferous Limestone Series of East Kilbride, it is, in Ireland and England, limited to the Pendleside Series, Millstone Grit, and Coal-Measures# It occurs in Co. Clare and Derbyshire in beds, which immediately succeed the Carboniferous Limestone with Productus giganteus and a Viséan fauna, indicating the sharp faunal change which takes place. In the North-Staffordshire Coalfield it occurs: below the Gin-Mine Coal; above the Bay Coal-shale; Longton, the Florence marine bed; at Weston Sprink, the exact horizon being unknown; above theSeven- Feet Banbury Coal; and in the roof of the Two-Feet and Four-Feet Coals of Wetley Moor. In the Cheadle Coalfield it occurs 50 feet above and upon the Stinking, Coal, and 71 feet below the Four- Fect Coal; also above the Crabtree Coal of the Goldsitch basin. In the Lancashire Coalfield it is abundant over the Bullion Mine, and is found over the Featheredge, the Gannister, and the Bullion Coals of Oldham. Yorkshire Coalfield: over the Hard-Bed Coal. Coalbrookdale Coalfield: over the Pennystone Ironstone. PTERINOPECTEN CARBoNARIUS, Hind, 1904. (Pl. XXXV, fig. 15.) Pterinopecten carbonarius, Hind, ‘Monogr. Brit. Carb. Lamellibr.’ vol. ii _ pt. iii (1904) p. 128 & pl. xxv, figs. 14-16. (Pal. Soe. vol. Iviii.) I erected this species on shells obtained from the Cheadle Coal- Vol. 61.] oF THE MARINE BANDS IN THE COAL-MEASURES. 535 field and the Pendleside Series of Bosley Mine. It is important to distinguish it from Pterinopecten papyraceus, for which purpose the following characters may be relied upon :— (1) It is a much smaller shell; (2) its shape is quadrate-subcircular ; and (3) the external ornament and arrangement of ribs. Its ribs are broader and much less numerous, the anterior ribs being curved outwards near the lower margin; the ribs become obsolete over the postero-superior angle of the right valve, and the anterior ears have well-marked radiating ribs. Localities.—North-Staffordshire Coalfield: marine band below the Gin-Mine Coal; 71 feet below the Four-Feet Coal, Cheadle. Black shales of the Pendleside Series, Bosley Mine (Cheshire) ; 270 feet below Gay’s-Vein Coal, Bristol Coalfield. PostponteLLa sutcata, Hind, 1904. (Pl. XXXV, fig. 16.) Posidoniella sulcata, Hind, ‘Monogr. Brit. Carb. Lamellibr.’ vol. 11, pt. i11 (1904) p. 184 & pl. xxv, figs. 2-6. (Pal. Soc. vol. Ivii..) This shell attains a size of 25 by 35 millimetres, and it is very important to distinguish it from Posidonomya Becheri, which species indicates a zone at the base of the Pendleside Series. Posidoniella sulcata has the narrow hinge-line of its genus, and no anterior ear. Its ornament, consisting of concentric angular ridges, separated by wide, concave sulci, differs from the close, flattened, concentric ribs of Posidonomya Becherr. I am of opinion that I saw, several years ago, a specimen of Posidoniella sulcata from the Lancashire Coal-Measures, in the cabinet of the late Mr. Neild, of Oldham, but all attempts to trace the specimen have failed. Mr. H. Bolton’ quotes Posidonomya laterals, a synonym of P. Becherz, as occurring in the Lower Coal-Measures of Lancashire. Possibly he may have mistaken a specimen of my species for it. Localities.—This species was founded on numerous specimens from the marine band below the Gin-Mine Coal, North-Staffordshire Coalfield. It has also been found 71 feet below the Four-Feet Coal of Cheadle. PosIDONIELLA Lavis (Brown). (Pl. XXXV, fig. 17.) This species has its maximum in the Pendleside Series, and 1s not common in the Coal-Measures. I have not been able to observe any characters pointing to evolution in the later specimens. ‘This may be due to the fact that, as it nearly always occurs in shales, the shell is so often crushed. Localities.—North Staffordshire Coalfield: above the Stinking Coal, and with Pterinopecten papyraceus near. Froghall Station, in the Cheadle district; 29 feet above the Seven-Fect Banbury ; below the Gin-Mine Coal. . Lancashire Coalfield: above the Bullion Mine at Colne, Sholver, Starring, and Dearnley; above the Gannister Coal, Pimho, near Wigan ; below the First Grit, Ipstones; 500 feet below the Third Grit, Congleton Edge. 1 Trans. & Ann. Rep. Manch. Microsc. Soc. 1895. 536 DR. WHEELTON HIND ON THE PALMHONTOLOGY [| Aug. 1905, Nucuta erpposa, Fleming. (Pl. XXXV, fig. 18.) This species has a very wide vertical range. It is found in the Calciferous Sandstone Series of Fife, and recurs at various localities, with an increasingly-higher horizon as the beds pass southward, until in the Midlands it ranges from the Pendleside Series to the Coal-Measures, and throughout this great thickness of strata appears unchanged in character. It is never found in pure lime- stone, but had always a muddy habitat. Specimens from the Coal-Measures are in no way dwarfed. Localities.—Below the Gin-Mine Coal, North Staffordshire Coalfield ; 300 feet below the Third Grit, Congleton Kdge. Nucura optonea, M‘Coy. (Pl. XXXV, figs. 21 & 21 a.) A single fragment of this somewhat rare species was obtained by the collector of the Geological Survey at Nettlebank (North Stafford- shire). I was enabled to examine it, by the kind permission of Dr. F. L. Kitchin, F.G.S. Previously I had not known this species to occur above the shales which overlie the Little Limestone of the Yoredale Series. Locality.—North-Staffordshire Coalfield: below the Gin-Mine Coal. Noucvrana SHarmant, R. Eth. fil. (Pl. XXXYV, fig. 19.) I have seen two examples of this species from the Coal-Measures, one of which shows the multidenticulate hinge, and the narrow escutcheon. ‘This last character is important, as therein it differs from Nuculana attenuata, for which, from its shape, it might be mistaken. But N. Sharman is more curved from before backwards. Nuculana attenucta occurs in the Coal-Measures of South Stafford- shire, 60 feet above the Thick Coal at Hamstead. Localities.—North-Staffordshire Coalfield: below the Gin-Mine Coal. In Scotland, NV. Sharmani ranges from the Calciferous Sandstone Series to the Upper Limestone Series. Nvucutana acuta (Sow.). (Pl. XXXV, fig. 20.) This is a form which is, so far as known at present, confined to the Coal-Measures; it is much shorter and more acute than the other species of the genus. Localities.—North-Staffordshire Coalfield: below the Gin-Mine Coal. Coalbrookdale Coalfield : above the Pennystone Ironstone. CrenopoNnTA La&vIRosrRIs (Portlock). (Pl. XXXYV, fig. 23.) This species is relatively more abundant than the other nuculi- form shells. Practically, it has the same range as Nucula gibbosa, with which it is nearly always associated. Localities.—North-Staffordshire Coalfield: below the Gin-Mine Coal. In the Pendleside Series, 500 feet below the Millstone Grit at Congleton Edge. Vol. 61. | OF THE MARINE BANDS IN THE COAL-MEASURES, Don CreNoponTA uNDULATA (Phill.). (Pl. XXXV, figs. 22 & 22a.) In my monograph on the British Carboniferous Lamellibranchs I have figured the cast of a shell from the roof of the Gin Mine, Longton, as Vucula undulata. The genus should be more correctly Ctenodonta, and it would have been more correct to have given the horizon as below the Gin Mine. This species is much more tumid and cylindrical than Ctenodonta levirostris. Several other examples occurred in the Nettlebank marine band, below the Gin Mine, on the same horizon as that in which the shell was first found at Longton. Locality.—North-Staffordshire Coalfield: below the Gin-Mine Coal. SoLENOMYA PRIMmVA, Phillips. (Pl. XXXV, fig. 24.) A single specimen was obtained by Mr. John Ward, many years ago, from below the Gin-Mine Coal at Longton; and I possess a specimen from the Pennystone Lronstone of Coalbrookdale. ScHizopUs antiquus, Hind. (Pl. XXXV, fig. 25.) This specimen was also obtained by Mr. John Ward from below the Gin-Mine Coal at Longton. The species ranges from the upper part of the Pendleside Series to the Coal-Measures. It also occurs above the Four-Feet Coal, Wetley Moor (North-Staffordshire Coalfield), and in the roof of the Bullion Mine, Carre Heys, Colne ( Lancashire). LEIOPTERIA LONGTRosTRIS, Hind. (Pl. XXXYV, fig. 26.) A single specimen, with the valves somewhat slipped on each other, has been found in a marine band with Pterinopecten papyra- ceus and Pt. carbonarius, 71 feet below the Four-Feet Coal in the Cheadle Coalfield. The type-specimens of this species were obtained from one of the black limestones at the base of the Pendleside Series, Mam Tor, near Castleton. It is also found at Pendle Hill, Flasby Fell, and Horse- bridge Clough, in beds of the same age. Myazrna comeressa, Hind. (Pl. XXXV, fig. 27.) This species has now been obtained at several localities in the North-Staffordshire Coalfield, some few feet below the Moss Coal, in the Weston-Sprink marine band, and above the Seven-Feet Banbury. It also occurs 71 feet below the Four-Feet- Coal of the Cheadle Coalfield, and at some horizons in South Staffordshire ; also 80 feet below the Furnace Coal near Pilsley, in the Nottingham- shire Coalfield. ScaLDIA MINUTA, Hind. (Pl. XXXYV, fig. 28.) I described under this title! a little shell, which occurs in large numbers with other marine fossils. Locality.—Marine band at Weston Sprink, near Longton (North-Staffordshire Coalfield). ' Trans. North Staffs. Nat. F.-C. vol. xxxiv (1899) p. 98. 538 DR. WHEELTON HIND ON THE PALMONTOLOGY [ Aug. 1905, Cephalopoda. In the determination of the cephalopoda I owe thanks for assistance to Dr. F. L. Kitchin, F.G.S., and Mr. G. C. Crick, F.G.S. Evenemus cf, EK. Urner. (Pl. XXXVI, figs. 9 & 9 a.) Several specimens which I refer to this species occur in the marine band below the Gin-Mine Coal at Nettlebank and Longton. GLYPHIOCERAS RETICULATUM (Phillips). (Pl. XXXV, fig. 29.) This species occurs at certain horizons in the Pendleside Series, in practically every locality in the Midlands where these beds occur. It is a shell which differs very much in outward appearance with regard. to its age. Its aperture has a peculiar shape. The edge of the periphery is concave, making an acute angle with the margin, on either side; then a narrow lobe projects forward, below which the lateral margin is concave. In the young, the shell is strongly and coarsely ribbed ; but in the adult, the ribs give place to fine sinuous strie reticulated by fine spiral lines, Glyphioceras bilingue has a very similarly-shaped aperture. Glyphioceras reticulatum occurs below the Gin-Mine Coal, Nettle- bank (North Staffordshire). GLYPHIOCERAS PHILLIesI (?) Foord & Crick. (Pl. XXXY, fig. 30.) This is a species which occurs in the Pendleside Series of High- Green Wood, Hebden Bridge, Coldcoates, and at Foynes Island (Co. Limerick). It has never been found 1 in the Carboniferous Lime- stone Series. oe ity AN SHEeSt nace Coalfield: below the Gin-Mine Coal at Nettlebank. GLYPHIOCERAS MicRoNnotrum (Phillips). (Pl. XXXV, fig. 31.) This species is known from the Pendleside Series near Todmorden, and some of the British-Museum specimens are labelled‘ Halifax’; but the exact horizon is not stated. This species does not seem to have so restricted a range as Gl. Phillipst, for it is stated that specimens have been obtained from the Carboniferous Limestone Series of Wetton. Phillips quoted Bolland as the locality for his type. Unfortunately Bolland is the name of an extensive district, in which the Pendleside Series and the Carboniferous Limestone are both well developed. It may be pointed out that Wetton is situated on Carboniferous Limestone, of the white and grey varieties, containing a Viséan fauna; but the village is not far from the black limestones of the Pendleside Series. The matrix of the specimen from Wetton, which is No. C. 4399 in the National Collection at the British Museum (Natural History), will eG whether the specimen is from the Pendleside Series or no. ’ Brit. Mus. Catal. Foss. Cephal. pt. iii (1897) p. 172. Vol. 6r.| OF THE MARINE BANDS IN THE COAL-MEASURES. 539 Glyphioceras micronotum is a smooth compressed form; the inclusion is almost complete, and there is a very small umbilicus. Locality.—North-Staffordshire Coalfield: below the Gin-Mine Coal. GLYPHIOCERAS PAUCILOBUM (Phillips). Dr. A. H. Foord has recognized this species in concretionary nodules which occur over the Seven-Feet Banbury seam. So far as I can ascertain, only one specimen of this species, probably the type, is in the National Collection at the British Museum (Natural History). The locality of the specimen was unfortunately not recorded. J. W. Salter records the occurrence of this species from the Holcombe-Brook Series above the Second Coal (Millstone-Grit Series).’ DimorpPHoceras Giipertsoni (Phillips). (Pl. XXXYV, fig. 32.) This species is, when well preserved, very finely marked with sinuous lines and ridges. It is much compressed, and has a minute umbilicus. Its maximum appears to be in the Pendle- side Series. Its lowest appearance is in beds immediately suc- ceeding the Carboniferous Limestone, alike in West Clare and in the Valley of the Hodder. It is also plentiful in the Lower Coal- Measures of Lancashire. Now, its range 1s extended much higher in the Coal-Measures. Mr. J. Neilson reports the occurrence of Dimorphoceras Gilbertsont from the Lower Limestone Series of the West of Scotland. Localities.—North-Staffordshire Coalfield: 71 feet below the Four-Feet Coal, Cheadle ; below the Gin-Mine Coal, Nettlebank. Lancashire Coalfield: above the Bullion Mine, Sholver. Pendleside Series: in ‘ bullions,’ Horsebridge Clough, and Crimsworth Dean, near Todmorden ; The Coombs, Leek (North Staffordshire). GASTRIOCERAS CARBONARIUM (L. von Buch). (Pl. XXXVI, fig. 1.) This species appears to have its maximum in the Lower Coal- Measures, but also occurs in the Pendleside Series at Horsebridge Clough, near Todmorden ; and now we know it from the marine band below the Gin-Mine Coal in North Staffordshire. This species is also plentiful in the Upper Culm-Measures of Instow and Clovelly (Devon). Gastrioceras carbonarium generally occurs in association with G. Lnstert and Dimorphoceras Gilbertsont; it is relatively somewhat more compressed, and its periphery is more convex than in Gastrioceras Lnstert. | Localities.—North-Staffordshire Coalfield: below the Gin-Mine Coal; over the Stinking Coal, Cheadle. Lancashire Coalfield: above the Bullion Coal and its equivalents. 1 “Geology of the Country around Bolton-le-Moors, Lancashire’ Mem. Geol. Sury. 1862, p. 54. 540 DR, WHEELTON HIND ON THE PALMONTOLOGY [Aug. 1905, Yorkshire Coaltield: above the Hard-bed Coal, Halifax. South- Wales Coalfield: under the Farewell Rock, Glan Rhymney. In beds of Millstone-Grit age: Stibden (Yorkshire); Ipstones (Staffordshire). GasTRIOCERAS LisTERI (Martin). This species has only been noted by Mr. John Ward as occurring in the Cheadle Coalfield ; but the specimens that he figured should be more correctly referred to Gastrioceras carbonarium. IL have no personal knowledge of its occurrence in North Staffordshire. PLEURONAUTILUS cosTATUS, sp. nov. (Pl. XXXVI, figs. 5, 5a, & 5 0.) Specific characters.—shell discoidal, composed of three rapidly-enlarging, closely-applied, quadrate, ribbed whorls. Um- bilicus large, showing nearly the whole of the whorls. The whorl is almost square, but somewhat narrower at the periphery than at the umbilical margin; the periphery is very slightly concave, each margin being raised into a ridge, a character absent in the cast; the sides are very slightly concave above, convex below. ‘The umbilical slope is smooth, moderately rapid, rounded in the young, subangular in the adult. The body-chamber is large, and occupies apparently about one- third of a whorl. The aperture is not seen, but there must have been a broad and deep hyponomic sinus on the periphery. I can give no details of the chambers (camere). Siphuncle small, subcentral, somewhat nearer the periphery than the lower margin. Nepionic stage not free, contiguous to the next whorl. Ornament.—The shell is adorned with broad, arched coste, separated by broad sulci, except over the body-chamber, which is smooth. These coste rise on the umbilical margin of the whorl, and are somewhat swollen at the junction of the umbilical and lateral surfaces. They become broader and flatter, and arched somewhat forwards, and are inflated again at the junction of the lateral surface with the periphery. The coste are more arched in the younger portion of the shell. The sides of the shell are covered with minute lines of growth ; on the periphery these lines show a deep, broad sinus with the concavity directed backwards. ‘The nepionic stage is devoid of costes, and has well-marked parallel strie. Dimensions.—The most complete specimen has a diameter of 84 millimetres. Locality.—North-Staffordshire Cvalfield: below the Gin-Mine Coal. | Observations.—tThis species is founded on one fairly-complete specimen and several fragments, casts, and crushed examples. I have compared them with Pleuronautilus armatus (Sow.) and Pl. falcatus (Sow.). In the former the coste are fewer, more sigmoid ; in the latter the costs are more numerous and more regular in character, Vol. 6r.| OF THE MARINE BANDS IN THE COAL-MEASURES, 541 without any tendency to become nodose. Another Coal-Measnre example is Plewronautilus rotifer (Salter), from the marine band at Ashton-under-Lyne, but this species seems to have more affinity to Sowerby’s Pl. falcatus than to the Staffordshire specimen. PLEURONAUTILUS PULCHER, Crick. (Pl. XXXVI, fig, 3.) This species has been very recently described by Mr. G. C. Crick, F.G.S., from specimens obtained from the Pendleside Series near Hebden Bridge. I have now to record the occurrence of the species in the Coal-Measures. Locality.—North-Staffordshire Coalfield: 71 feet below the Four-Feet Coal, Cheadle. EPHipPiocERas cosratum, Foord. Several fragments of this species have been found, showing the peculiar and characteristic suture-lines and the costate body- chamber, which distinguish the species from others. This species. was already known from the Coal-Measures of Coalbrookdale, in the Pennystone Ironstone. It is found below the Gin Mine at Nettlebank (North Staffordshire). NAUTILOIDS. Several fragments of a form which probably belongs to Temno- cheilus, bearing well-marked, short, conical tubercles along the margins of the periphery, have been obtained below the Gin-Mine Coal at Nettlebank. Unfortunately they are neither large enough, nor do they show details sufficiently well to determine the species ;. but the form is most probably new to Great Britain. TEMNOCHEILUS CARBONARIUS, Foord. (Pl. XXXVI, fig. 4.) Fragments which, I think, must belong to this species, occur in the marine band 71 feet below the Four-Feet Coal of Cheadle. One fragment shows a broad periphery, and an angular margin, with elongate tubercles. The periphery has fine longitudinal lines crossing the deeply-sinuated lines of growth. Dr. Foord’s type, a fragment, is from Coalbrookdale (Shropshire). In the description he says :— ‘A little below the border of the periphery there are three not very prominent. and rather elongated nodes, with faint indications of two more towards the aperture.’ (Brit. Mus. Catal. Foss. Cephal. pt. ii, 1891, p. 151.) I possess a specimen from Coalbrookdale, consisting of the body- chamber and two septa, which shows on the body-chamber five nodes, and one other is faintly indicated near the aperture. The number of nodes is, therefore, not a specific character. ‘TEMNOCHEILUS CoNcAvUS (Sow.). Two fragments of the body-chamber may, I think, be safely referred to this species. They show the sulcus along the median ’ Proc. Malacol. Soe. vol. vi (1904) pp. 15-20 & pl. ii. O42 DR. WHEELION HIND ON THE PALEONTOLOGY [Aug. 1905, part of the periphery and also a portion of the test, which exhibits a well-marked hyponomic sinus on the periphery. The siphuncle was placed a little way above the centre of the shell. _ Locality.—North-Staffordshire Coalfield: below the Gin-Mine Coal. Coalbrookdale Coalfield: Pennystone Ironstone. Sorenocuxrtus aff. cycLosroma (Phill.). (PI. XXXVI, figs. 2 & 2a.) I refer to this species a fragment, the body-chamber of an adult shell, which has been found below the Gin-Mine Coal at Nettlebank. The siphuncle is seen to be near the peripheral margin. The periphery is broad, smooth, and convex, and has along its centre a fine raised line. The impression of the preceding whorl is only moderately deep and narrow. ‘The section of the whorl is circular when young, but is transverse in aged specimens. I have met with this species below the Third Grit of Wadsworth Moor. Its vertical range is, therefore, much increased by the present discovery. C@&LONAUTILUS cf. suBsULcArUS (Phillips). Two much-compressed fragments suggest reference to this species. Locality.—North-Staffordshire Coalfield: below the Gin-Mine Coal. . Yorkshire Coalfield : Shibden. ‘ORTHOCERAS. At least two species of this genus occur below the Gin-Mine Coal of Nettlebank. One is small, elongate, and slender, and for the present I refer it to O. ascrculare, Brown. Another fragment belongs to a much more robust species (Pl. XXXVI, fig. 8), with ‘moderately-distant chambers and a slow rate of tapering, but it is ‘too indefinite for the accurate determination of the species. ‘ORTHOCERAS aff,.AscICcULARE, Brown.’ (Pl. XXXVI, figs. 6 & 7.) Localities.—North-Staffordshire Coalfield: below the Gin-Mine ‘Coal, above the Crabtree Coal; 71 feet below the Four-Feet Coal, ‘Cheadle. Lancashire Coalfield: above the Bullion Mine, Sholver. Coal- ‘brookdale Coalfield : Pennystone Ironstone. Mr. George Wild figured a small slender Orthoceras from the ‘Soapstone-bed, above the Bullion Coal, Trawden, Colne,’ calling it O. minutissimum, Phillips. I think that this is Brown’s species, the original of which came from the Pendleside Series near Todmorden. I have just figured specimens of this species from the Pendleside Series of the West of Ireland,’ considering Baily’s O. menimum as a ‘synonym of Brown’s shell. Probably O. pygmeum, de Koninck, from Chokier, belongs really to the same species. Apparently the ‘Coal-Measure shell was much longer than those met with in the _Pendleside Series. 1 Trans. Manch. Geol. Soc. vol. i (1841) p. 220 & pl. vii, fig. 39. 2 Ibid. vol. xxi (1891-92) p. 400 & pl. ii, fig. 4. 3 Proe. Roy. Irish Acad. vel. xxv (1905) p. 112 & pl. vi, fig. 23. Vol. 61.] OF THE MARINE BANDS IN THE COAL-MEASURES. On IS LANCASHIRE. [he ea 33 |S List or Fossizs rrom Tun Marine Banps | fs a | = | 2 mr [St S| A | In THE Coat-MeAsures or ENGLAND | Diy lS & WALES. Pees lel le Berne [Norz.—The fishes in the marine bands, & = Is S| = being only known from North Stafford- ~~ 7% 2.37 34 shire, are omitted here; for them,see & 5 : eles S| the list on p. 529.] ies Sisie By | | ie alls ECHINODERMATA. | | PACH EOCARTUS BD. srcllin cee nonce ca tpadeansnaneael [ele] | | | j | ANNELIDA. | ear | IS QULORDUSISPS WOW, . Piya valhscneccessitacamoece} Ol | | | ARTHROPODA. | Dithyrocarts testudimewit ....0.....eceeeenenes | * | BRACHIOPODA. | | Ambocelia carbonifera, sp. NOV. ......0605 Soe eee esl oe Chonetes aff. laguesstana, de Kon. ............! # |...).0.|e0-| # Orbiculoidea nitida (Phill.) ....... See Nee |] ee]... | Lingula nvytiloides, Sow. ....... Ustienen steno || j...] | TG OAUCHUS GNONTAL, 8). NOV: ...+5.4+s wathnleie Ie Real @oblaea ie Productus scabriculus (Mart.) 22... .0...0.2.| * | ¥ | * | Productus, seabriculocostate species ......... % aa Spirifer bisulcatus, SOWiaen- ae eases tale Ball Octal Rhipidomella Michelini, Léveillé .. ........ |. % LAMELLIBRANCHIATA. | | Aviculopecten gentilis, SOW.......6....eceees peas ee ec Pseudamusium fibrillosum (Salter)............ % [eee 2 lee Syncyclonema carboniferum, Hind ......... Lorian | | | Pterinopecten carbonarius, Hind ....... Boles mea Prerimopecten papyraceus (SOW.) ....eve0sre-| % |ee-| ¥ [ae|e..| Posidontella levis (BYOWD) ..0..s00s0000..00000- Heo ieee ep ak oc Posidoniclla minor (Brown) ......... Svat is xe Posidoniella sulcata, Hind ...... neds eeoee 2. aie | gio pLeria LONGUROSETIS, MAING 82200564 ese2 9560. le] | Wa aiina compressd, TIGMA «i isicc. cacceconsene| EI |e : Schizodus antiquus, Hind ...... eee eee me al | Schizodus axiniformis, Sow. ....... ms eas acl (cae del Re SCHUZOMUS COPVONATIUS, SOW. voc. c aie. .cuesen|e->|oe+| ® loan | 4 Nucula equalis, Sow. ............ Briere ery ce lial Malco ce |e Nucula gibbosa, Flem. .......... Be Henan: eal mal al bead Nucula oblonga; MOC Oy, v.0....0.0.3...0085 eed sea eee INGHAM OP UCILO (SOWa) ean. c cas aencecce. eae Hie) ee] Nuculana Sharmant, R. Eth. filvocsseie- * | | Ctenodonta levirostris (Poril.) ............0.- pain ee bow e Ctenodonta undulata (PMill.) .........000)00000| Kleoelees |. | % Scaldia minuta, Hind............ pet ciei Pease ue Hdmondia accipiens, SOW: 2. .c.eccesscessceou: je?) 1 | Hdmondia aff. laminata, Phill. ...............| * | Hdmondia senilis, Phill. ..:......... Srna re) et baie | ag a AILONSING x 3c K > ee 544 DR. WHEELTON HIND ON THE PALMONTOLOGY [| Aug. 1905, Ee Fetepee see a z > alelalel |e a8 List or Fossiis From THE Marinn Banps |5| 2/8 | of |asg As IN THE Coat-Mrasures or HNGLAND Es E a 3 5 Sie = z & Watzs (continued). wD E ee te S = eA Se fe) Bie a S| lle |S S/E/S/BIE|S Sisjzis4 RIP S/S/Si/2 Siz Slay ° 2 Sle Sas) “|| SS |S Aim\|Ols | hy iA a Pt GASTEROPODA. Raphistoma (@) ornatas Boltoniyr .5.-05.006 ee kee ae| ee ee te Raphistoma radians, de Kon. .......:....4.. viv ole £2 seal cee) cel eee Turbonellina formosa, de Kon. ............... x Naticopsis brevispira (de Ryck.)............... ee Naticopsis globularis, Bolton ...... csonane cs PPPOE Aniiacols sus | of Loxonema acutum, de Kon. ...............02.| ¥ ‘ The following are described in Prestwich’s memoir on Coalbrookdale :— GlObUlUs VOTUSTES. SOW. Gee. 02s ka eeerottien a eeloen locale | IO GED UMD) DOSCURT, SO WTS con kegoadeboscacncooe| sor| bea) ez Lar ritella, COECULUCLO ms A aaa Aten een dHalieote| 3 Turritella (2) minima, Sow. ...... stat soso somes Polyphemus (2) fusiformis, Sow. ......0.s0..|.+.|...| ® nochusi(€) USOCONG SOW: acer tr ements cess lane Ics CrEPHALOPODA. Ephippioceras clitellarium (SOW.) ........00- |ss.jae.| ®[eoeleee| eee | ¥ Ephippioceras costatum, Foord ..............- Se [ec .| Rilo |e allie i phCinUs UVC Mcewet esse =: susita outa | 6 Celonautilus quadratus, Flem. ............... wos [ess| OF). cell ae ea Celonautilus ef. subsuleatus (Phill.) ...... woe | 3 [ons |+sis| sie} realy eae eal ee Plewronautilus armatius (SOW.) ...ccccesseceeeleo./ee-| * Pleuronautilus costatus, sp. NOV. ....-....00.| ¥ Pleuronautilus falcatus (SOW.) ......0..cecseeree|e0.| ® [eo e| ® Pleuronautilus pulcher, Crick .........000006| % Plewmonancilus rotzjer (Salter)... ... sass tele |e ainas eee eee Temnocheilus carbonarius, Foord ............ eiloiell eal peulierys * Temmnochetlus cOnCavUs (SOW) .scccceceesece| O leeeh PR |e Ge) eee Temnocheilus tuberculatus (SOW.) ......00.00.Je0.|ee.er|e-- oon oleate eels Solenocheilus aff. cyclostoma (Phill.) ......} x SOVENOCICHUSIS nena ace eee Re rant welled) salle PPPS ace], $22 Glyphioceras micronotum (Phill.) . shine ch | SRR ep Pac ws saves Giyphioceras paucilobum (Phill.) . PE HMeAReeecleeel Ses | Glyphioceras Phillipst, Foord & Ome eee Pan eer is Glyphioceras reticulatum (Phill.) ............|%#|...|.2-|-scle-n) se< (ES Dimorphoceras discrepans (Phill.) ...... wo dee clive |e s| oteleteiflei-cel ee ee Dimorphoceras Gilbertsoni (Phill.)............| # |...Jee-/.. Renee a Dimorphoceras Loonyt (Phill.) .............4. nic cal | Sag aitatt mali Nomismoceras ornatum, Foord & Crick .. |...|...J.../... Pes es ot Se Gastrioceras carbonarium (L. von Buch) ...| #|...|...|...)*| ... | le..| % Gastrioceras coronatwm, Foord & Crick ...|...|...!...|...| Pel aaa Gastrioceras Hastent, (Miami) mens. -a2-260 cee ee eee Reece She 2 cael aay Orthoceras att. asciculare, Brown ...... Benes ; % bow. |e. coe Orthoceras scalpratum, Sow. .........000.5- Br eo. % Orthoceras Steinhawert, Sow. ......cccecceecees scat ecaiiee ae Po mean ee ONETOG ETS SSD Wists csi sep nis, Ses welsortanh Nae ee OG Conularia quadrisulcata, Sow. .........0...0./00.| ¥ | % fo. | % | ier, Jot coomooc. ol LAK pp Ne BE ts os. oo = J qt elsson. Jam. E & 1 Bale AH. Searle del.et Ix MARINE, FOSSILS From the Coal-Measures of North Staffordsh ire mp. iid sSo0n J \s e & Danie Bal th. 1 A.H. Searle del.et | MARINE FOSSILS From the Coal- Measures of North Staffordsh Ger Vol. 61.] OF THE MARINE BANDS IN THE COAL-MEASURES. 545 EXPLANATION OF PLATES XXXV & XXXVI. [The figures are of the natural size, unless otherwise stated. | PuaTE XXXV. Figs. 1 & la. Radiole of Archeocidaris, sp. Below the Gin-Mine Coal, Nettlebank. (See p. 529.) Fig, 2. Lingula mytiloides. x 3%. Above the Moss Coal, Longton Hall. (See p: 029.) 3. Orbiculoidea nitida.. x 3. Above the Lady or Bay Coal, Chell. (See p. 530.) 4, Chonetes laguessiana, mut. 8. Below the Gin-Mine Coal, Nettlebank. (See p. 530.) 5. Productus, scabriculocostate form. Below the Gin-Mine Coal, Longton, (See p. 531.) 6. Productus anthrax, sp. nov. Below the Gin-Mine Coal, Nettlebank. (See p. 531.) Figs. 7&7 a. Ambocelia carbonaria. x 2. Pedicle and brachial valves. Same locality. (See p. 531.) . 8 & 8a. Raphistoma radians. Same locality. (See p. 5382.) Fig. 9. Turbonellina formosa. Same locality. (See p. 552.) © 10. Naticopsis brevispira. _X 3. Same locality. (See p. 533.) 11. Loxonema acutwm. x3. Same locality. (See p. 533.) 12. Syncyclonema carboniferum. Same locality. (See p. 534.) 13. Pseudamusiwm fibrillosum. Same locality. (See p. 534.) 14. Pterinopecten papyraceus. ‘1 feet. below the Four-Feet Coal, Cheadle. (See p. 554.) 15. Pterinopecten carbonarius. Same locality. (See p. 534.) 16. Posidoniella sulcata. Below the Gin-Mine Coal, Nettlebank. (See p- 535.) 17. Posidoniella levis. ‘71 feet below the Four-Feet Coal, Cheadle. (See p. 535.) 18.’ Nucula gibbosa. Below the Gin-Mine Coal, Nettlebank. (See p, 536.) 19. Nuculana Sharmani. Same locality. (See p. 536.) 20. Nuculana acuta. 2. Same locality. (See p. 536.) Figs. 21 & 21a. Nucula oblonga. x 2. Same locality. (See p. 536.) 22 & 22a. Ctenodonta undulata. Below the Gin-Mine Coal, Longton. (See p. 537.) Fig. 23. Ctenodonta levirostris. Below the Gin-Mine Coal, Nettlebank, (See . 536.) 24. Sotenwna primeva. Below the Gin-Mine Coal, Longton. (See p. 537.) 25. Schizodus antiquus. Same locality. (See p. 537.) 26. Leiopteria longirostris. 71 feet below the Four-Feet Coal, Cheadle. (See p. 537.) 27. Myalina compressa. Same locality. (See p. 537.) 28. Scaldia minuta. x 4. Weston Sprink. (See p. 537.) 29. Glyphioceras reticulatum. Below the Gin-Mine Coal, Nettlebank. (See p. 538.) 30. Glyphioceras Phillipsit. Same locality. (See p. 538.) 31. Glyphioceras micronotum. Same locality. (See p. 538.) 32. .Dimorphoceras Gilbertsoni. 71 feet below the Four-Feet Coal, Cheadle. . (See p. 539.) Puate XXXVI. Fig. 1. Gastrioceras carbonartum. Below the Gin-Mine Coal, Nettlebank. (See p. 539.) Figs. 2.& 2a. Solenocheilus aff. cyclostoma. Same locality. (See p. 542.) Fig. 3. Plewronautilus pulcher. Same locality. (See p. 541.) 4. Temnocheilus carbonarius. Same locality. (See p. 541.) 5. Pleuronautilus costatus, X 3. Showing nepionic stage. Same locality. (See p. 540.) 5a. Pleuronautilus costatus. Same locality. (See p. 540.) 5b. Plewronautilus costatus, showing periphery. Same locality. Q.J.G.8. No. 243. 0) 546 THE MARINE BANDS IN THE j Aug. 1905, Figs. 6 & 7. Orthoceras aff. asciculare. Same locality. (See p. 542.) Fig. 8. Orthoceras, sp. Same locality. (See p. 542.) Figs. 9 & 9a. Huphemus cf. Urei. 3. Same locality. (See p. 538.) Fig. 10. Spirorbis, sp. 3. Same locality. (See p. 502.) Discussion. The Presrpenr said that he welcomed the paper, as adding a number of new facts to those which we already possessed. The paper was an example of those which (themselves concerned with pure science) were nevertheless likely to be of much economic value. He was glad to hear the Authors bring forward what appeared to be conclusive evidence that Nazadites, Carbonicola, and Anthracomya did not occur in association with the marine forms. Mr. Watcor Gipson congratulated the Authors on an important piece of work which had a practical bearing, especially on the question of determining one’s position in the Coal-Measure sequence in concealed areas. He did not think that the presence of Lingula alone was a safe index of position in the absence of other data. He would like to ask Mr. Stobbs in what sense he used the term ‘ true Coal-Measures.’ Dr. Txatt associated himself fully with the complimentary remarks which had been made on the paper, but said that he had not quite gathered what were the main features upon which the Authors relied for the identification of particular marine bands. He enquired whether they relied on the limitation of the range of some particular forms, or on the general association. Prof. P. F. Knnpatt desired to associate himself with the ex- pression of approval which had fallen from previous speakers. The Authors were engaged upon a piece of work, the progress of which he and other geologists in Yorkshire were watching with the keenest, interest and gratification, and he expressed the hope that they would extend their researches to the coalfields on the eastern side of the Pennine Chain. He remarked that the arguments which had been employed to prove that there were two molluscan faunas in the Coal-Measures, one marine and the other containing «Silurian Gastropoda & Pteropoda of Gotland’ Kongl. Svensk. Vet.-Akad. Handl. vol. xix (1881-84) No. 6, p. 99 & pl. xis, figs. 15-16. 3 Ibid. p. 100 & pl. xix, figs. 17-20. Vol. 61.] THE SILURIAN ROCKS OF LLANGADOCK, 571 the band, which is below the middle of the whorl, instead of being submedian. As the specimen is very imperfect, it seems unadvisable to assign to it a specific name, for it might possibly be a worn example of an already described species, such as Bembexia (2) Lloydii, for instance. Dimensions.—The length of the fragment consisting of four and a half whorls = 10 millimetres; the width of the penultimate whorl = 6°5 mm. Horizon.—(90) Wenlock. BrmpBexta Luoypir? (Sow.). A fragment of a shell appears identical with this species. Dimensions.—tThe length of the fragment, consisting of about six whorls, is 14 millimetres. Horizon.—(67a) Upper Ludlow. Etheridge gives the range of Plewrotomaria Lloydii as from the Wenlock Shale to the Upper Ludlow inclusive. ‘ Murchisonia’ sulcata, M‘Coy,’ which is identical with Pleurotomaria Lloydir, is recorded from the Lower Llandovery. Lindstrom records its occurrence in all the Silurian strata of Gothland. Family Murcutsoniipm, Koken. Genus GonrosrropHa, (Khlert. GontostropHs CamBria, sp. nov. (Pl. XX XVII, fig. 6.) Diagnosis.—Shell very small, slender, turreted, composed of more than ten whorls. Whorls increasing very gradually, angular rather above the middle of the body-whorl, concave above, slightly convex below. Surface smooth, no lines of growth being seen. Band situated on the angle, grooved, and bounded on each side by a Strong raised thread. Base convex. Aperture imperfectly known, subovoid. Remarks and Resemblances.—There is only one specimen of this species, but it is fairly well preserved, the grooved band and contour of the whorls being clearly seen. It resembles Gonio- stropha (?) elegans (Sollas),” from the Lower Wenlock of Rhymney, but is much smaller, the band is proportionately more widely grooved, the whorl less concave above, and it is also devoid of the keels above and below the suture. Dimensions.—The single specimen consists of ten whorls, and the apex is broken; if it were intact, there would probably be two or three more whorls. Length = 8 millimetres ; width = 2°25 mm. Horizon.—(63) Lower Ludlow, Aymestry Limestone included. ' ‘Synopsis of the Silurian Fossils of Ireland’ 1846, p. 17 & pl. i, fig. 20. * Quart. Journ. Geol. Soc. vol. lviii (1902) p. 321 & pl. vii, figs, 2-4. 572 MISS J. DONALD ON GASTEROPODA FROM [Aug. 1905, Subgenus Cyrrostropaa, Don. CYRTOSTROPHA TORQUATA ? (M‘Coy). Two, very imperfect, external moulds possibly belong to this species, but the state of preservation is so bad that it is impossible to be sure. Dimensions.—The best specimen consists of about six whorls in a length of 8 millimetres ; width = 3 mm. Horizon.—(67a) Upper ‘Ludlow. This species is characteristic, elsewhere in Britain, of the Upper Ludlow. It is not recorded from Gothland. Family Loxonemaripm, Koken. Genus Loxonema, Phillips. LoxonEMA sINvosUM ? (Sow.). A much-worn internal mould bears a great resemblance to this species, but I can only refer it here with a query, as it is so imperfectly preserved. Dimensions.—The specimen is embedded in the matrix, and shows only three whorls, which have a length of 14 millimetres. Horizon.—(99) Wenlock. Elsewhere in Britain Etheridge recorded it from the Upper Llan- dovery, Lower Ludlow, and Aymestry Limestone. I have also seen specimens from the Wenlock of Dudley. An example from the Middle Devonian of South Petherwyn is referred to this species by Phillips, and Mr. Whidborne considers that it has been correctly identified. In Gothland it occurs in the Upper Llandovery and Wenlock, that is, in Lindstroém’s stratum a. Loxonrema Grinpropit (?) Don. (Pl. XX XVII, figs. 7-9.) There are three specimens of Loaonema which have the surface too poorly preserved to permit of their being identified with certainty. The biggest one shows traces of spiral strize, which, together with its general form, cause it to resemble L. Grindrodz, but both it and the other two examples are more slender. This may arise, partly at any rate, from the manner of preservation; or, on the other hand, if may indicate that they belong to a distinct species. It hardly seems advisable to found a new species on specimens so imperfect, there- fore I refer them for the present with a query to L. Grindrodu. Dimensions.—The biggest example figured (Pl. XX XVII, fig. 7) consists of portions of five whorls in a length of 28°5 milli- metres; the width of the penultimate whorl=10 mm. ‘The specimen showing the aperture, and having only three whorls preserved, is 18 mm. long, and the penultimate whorl is 7-5 mm. wide. The smallest specimen figured (Pl. XXXVI, fig. 9) is 11 a mm. in length, and consists of about nine whorls. Horizon.—(63) Lower Ludlow, Aymestry lamesone included. Vol. 61.] THE SILURIAN ROCKS OF LLANGADOCK. 573 Family Trochonematip#, Ulrich. Genus Gyronema, Ulrich.’ Diagnosis.—Whorls ventricose ; aperture moderately oblique ; umbilicus small. Ornamentation consisting of spiral ridges, two of which often form a more or less distinctly-marked peripheral band, the ridges being most numerous on the base. Ty pe.—Gyronema pulchellum, Ulrich.? Remarks and Resemblances.—This genus was created for the reception of shells intermediate in character between Trocho- nema, Salter, and Cyclonema, Hall. The open umbilicus, as well as a vertical peripheral band, connects it with T’rochonema. It is dis- tinguished from that genus by the more elevated spire, less oblique aperture, and also by the peripheral band not being quite so distinctly marked, and there is frequently a submedian keel on it. The elevated spire causes it to bear some resemblance to Cyclonema, but it differs in having an open umbilicus. Gyronema Octavia (d’Orb.). (Pl. XXXVII, figs. 10-15.) Turbo carinatus, J. de C. Sowerby, 1839, in Murchison’s ‘ Silurian System’ p. 612’ & pl. v, fig. 28; non Turbo carinatus, Sow. ‘Mineral Conchology’ 1821, pl. cexl, fig.3; non Turbo carinatus, Honinghaus, 1830, Jahrb. f. Min. Geol. & Petrefkde. p. 230, which is identical with Helix carinatus, Sow. ‘Min. Conch.’ 1812, vol. i, p. 34 & pl. x. Turbo Octavia, A. d’Orbigny, 1850, ‘ Prodrome de Paléontologie stratigraphique ’ vol. i, p. 30. Cyclonema carinatum, G. Lindstrom, 1884, ‘Silurian Gastropoda & Pteropoda of Gotland’ Kongl. Svensk. Vet.-Akad. Handl. vol. xix, No. 6, p. 178 & pl. xviii, figs. 28-30. Diagnosis.—Shell turbinate, acute, having about six whorls. Whorls increasing somewhat rapidly, convex, ornamented by spiral keels. ‘The three or four upper keels are frequently stronger than the others ; the grooves between them vary in width, and the third groove generally forms a peripheral band. ‘There are additional keels on the body-whorl, which vary in number on different specimens, and there is always a strong ridge round the umbilicus. The lines of growth cross the keels rather obliquely, and some are so strong as to be almost lameliar. Umbilicus open. Aperture subovate; outer lip thin and sharp; inner lip reflected on the body-whorl, and partly covering the umbilicus. Remarks and Resemblances.—The type of Sowerby’s Turbo carinatus is stated to be from the Upper Ludlow of the Trewerne Hills, but unfortunately I have been unable to trace its existence anywhere. It is not in the Geological Society’s Collection, nor in the Museum of Practical Geology, London. I have enquired in several other Museums, but without result. His description and figure are hardly definite enough for a satisfactory comparison with other shells. There are numerous specimens in Prof, Groom’s 1 Final Rep. Geol. & Nat. Hist. Surv. Minnesota, vol. iii, pt. ii (1897) p. 1046. 2 Ibid. p. 1054 & pl. Ixxviii, figs. 19-21. 574 MISS J. DONALD ON GASTEROPODA FROM (Aug. 1905, collection which appear to agree with the few characteristics given, more especially with the nature of the ornamentation: the keels being three in number on the penultimate whorl, and more numerous and closer below on the body-whorl. Although Sowerby’s figure and description are so very incomplete, I nevertheless think it advisable to refer Prof. Groom’s specimens to this species, as they resemble it more than any other British-described species belonging to the genus. Also they agree very nearly with specimens that I have seen from the Upper Ludlow elsewhere, as well as from the Aymestry Limestone, Wenlock Limestone, and Wenlock Shale, which have been referred to this species. They also resemble those identified by Prof. Lindstrom with Turbo carinatus, Sow., the greater number coming near to his variety (Cyclonema) glabrum, which has fewer additional keels on the body-whorl. The name Turbo carinatus seems to have been pre-occupied when J. de C. Sowerby thus named this species in the ‘Silurian System,’ 1839 (p. 612 & pl. v, fig. 28), for J. Sowerby had named a Greensand fossil Turbo carinatus in the ‘Mineral Conchology’ vol. 111 (1821) pl. cexl, fig. 3, and Heliw carmatus, Sow., had been so called by Honinghaus in 1830 (in the Jahrbuch fur Min. Geol., &c. p. 230). } In 1850, A. @Orbigny, in his ‘ Prodrome de Paléontologie strati- graphique’ (vol. i, p. 30) enters this species as Z’wrbo Octavia, d’Orb., 1847. He gives no reason for the change of name; but it was probably changed in order to avoid confusion, on account of three different species having been called Turbo carimatus, and two (as has ‘been shown) previous to Sowerby’s description of the species under discussion. It therefore seems advisable to adopt d’Orbigny’s specific name Octavia, as several succeeding paleontologists have done. There is a certain amount of variation in the number and dis- position of the keels on different individuals, but all agree in having the wider spaces above. ‘Thus, there appear to be at least three, or perhaps four, well-marked varieties. The first, which seems to agree best with the type, has always two and sometimes three or more additional keels below on the body-whorl, as- well as the strong ridge round the umbilicus ; and there are three keels visible on the penultimate whorl besides the sutural keel, the second and third being closer than in the variety glabrum. In the Museum of Practical Geology, London, there is a specimen from the Upper Ludlow near Ludlow that might be referred here ; and there is also one in the Manchester Museum, Owens College, from the Upper Ludlow of Whiteliff. The second resembles this last variety so much, that it is some- times difficult to decide to which a form should be referred; but there is as a rule only one additional keel, or rarely two, on the body-whorl, and but two strong keels are seen on the penultimate whorl besides the sutural one. This is the most abundant variety among Prof. Groom’s specimens, there being about twelve examples, and it is probably the variety glabrum of Lindstrom. Here belong Wool, 61. | THE SILURIAN ROCKS OF LLANGADOOCK. 575 three specimens in the Museum of Practical Geology: from the Bone- Bed, Mocktree, from the Aymestry Limestone of Botoyle, Caer Caradoc, and from that of Shucknall Hill, Woolhope, respectively. Also one in the British Museum (Natural History) from the Wenlock Shale of Gaercoed. The third variety has a finer keel intercalated between tho second and third keels, and four additional fine keels below on the body-whorl. There are two specimens of this in Prof. Groom’s collection, and one in the Sedgwick Museum, Cambridge, from the Upper Ludlow Beds, Burton and Brockton. The fourth variety is very different from the type. The second and third keels are placed so close together as to give the appearance of a Pleurotomarian band, only the lines of growth pass obliquely over it ; and the base is much flattened, having two additional fine keels and two or three fine threads. There are two specimens of this in Prof. Groom’s collection, and one in the Sedgwick Museum greatly resembles it; but it has eight fine keels below instead of two : it is from the Upper Ludlow of Woolhope. For the third variety | would suggest the name interstriatum, and for the fourth fasccatwm; this last differs most from the type, and may possibly prove a distinct species, but interstriatum comes very near the var. glabrum, Lind. Dimensions.—tThe specimen figured in Pl. XXXVII, figs. 10 & 11, as possibly resembling the type, has the apex broken; the four existing whorls have a length of 12°5 millimetres, and the greatest width is 10 mm. The variety glabrum, Lindstrom, figured in Pl. XX XVII, figs. 12 & 18, consists of five whorls in a length of 15 millimetres, and the width is 11 mm. The best specimen of the ciel interstriatum has only one whorl preserved, and it is not wholly exposed: its height = about 7°5 millimetres, and its width = about 8°75 mm. (See Pl. XXXVII, fig. 14.) A smaller example has two whorls in a length of 6°5 millimetres. The biggest example of the variety fasccatum consists of about two whorls, which have a length of 9 millimetres, the greatest width being 12mm. (See Pl. XXXVII, fig. 15.) Horizon, —tThe typical form, as well as the varieties, occurs in (63) the Lower Ludlow, Aymestry Limestone included. ‘The variety glabrum also is found in (90) the Wenlock. Etheridge recorded this species as occurring in the Aymestry Limestone, Upper Ludlow, and doubtfully in the Wenlock Shale and Wenlock Limestone. According to Lindstrom, it is found in all the Silurian strata of Gothland, Family 'Tursinipm, Alder. Genus PoLyrRoPINa, nov. - Euomphalus (pars), J. Sowerby, 1814, ‘Min. Conch.’ vol. i, p. 118. Polytropis, Ll. G. de Koninck, 1881, ‘Faune du Calcaire Carbonifére de la Belgique’ pt. iii, Ann. Mus. Roy. W’Hist. Nat. de Belg. vol. vi, p. 107. load 5076 MISS J. DONALD ON GASTEROPODA FROM [ Aug. 1905, Oriostoma (pars), G. Lindstrém (non Munier-Chalmas), 1884, ‘ Silurian Gastropoda & Pteropoda of Gotland’ Kongl. Svensk. Vet.-Akad. Handl. vol. xix, No. 6, p. 156. Omphalotrochus, K. A. Zittel, 1896 (non Meek, 1864), ‘ Text-book of Paleeont- ology ’ translated by C. R. Eastman, vol. i, pt. i (1900) p. 447. Diagnosis.—Shell discoidal, or depressed conical ; spire short. Whorls convex, contiguous, ornamented by spiral keels and threads. Aperture subcircular; lips thin, generally continuous. Operculum thick, flat internally, conical externally. Umbilicus open, wide. Type, Polytropina discors (Sow.). Remarks and Resemblances.—In 1881 L. G. de Koninck gave the name Polytropis to a group hitherto included m Huom- phalus, taking EH. discors, Sow., as the type. It is distinguished from the typical Huomphalus by having no sinus in the outer lip. Unfortunately the name was preoccupied, for it had been given by C. L. F. Sandberger to a subgenus of Valvata in 1874) De Koninck considered Polytropis identical with Inachus, Hisinger, but this name had been previously used by Leach. I therefore suggest the name Polytropina for the genus. Lindstrom referred Huomphalus discors and other allied forms to Oriostoma, Munier-Chalmas;° but this genus, as described by Munier-Chalmas, is quite distinct, for the whorls of the spire and the umbilicus are disjoint, and the last whorl is very much larger than the others. Munier-Chalmas considered his genus to have affinity with certain species placed in Platyceras and Tuba. Zittel referred Huomphalus discors, Sow. and H. globosus (Schloth.) to Omphalotrochus, Meek,’ which genus he considered identical with Polytropis, de Kon. and Oriostoma, Lindstrom, but not with Oriostoma as originally defined by Munier-Chalmas. Huomphalus Whatneyr, the type of Omphalotrochus, appears to me quite distinct in its characters from either H. discors, Sow. or H. globosus (Schloth.), the whorls being ornamented by only two keels on the periphery, which give them a banded appearance; they are also flattened above and below, instead of being convex; the aperture is different; and the shell appears to have more in common with Trochonema. Solarium antiquum,* A. dOrbigny, the other species referred by Meek to his genus, seems to agree with Huomphalus Whitneyr, but is quite distinct from L. doscors and EH. globosus. Potyrropina eLoBosa (Schloth.). (Pl. XXXVII, fig. 16.) Trochilites globosus, Schlotheim, 1820, ‘ Die Petrefactenkunde’ p. 162. Euomphalus funatus, J. de C. Sowerby, 1823, ‘ Mineral Conchology’ vol. v, p. 71 & pl. ceccl, figs. 1-2. Diagnosis.—Shell conical ; spire somewhat depressed, of about 1 “Die Land- & Stisswasser-Conchylien der Vorwelt ’ p. 697. 2 Journal de Conchyliologie, vol. xxiv (1876) p. 103. ° ‘Geol. Surv. California: Paleontology’ vol. i (1864) p. 15 & pl. ii, figs. 8-8 a. * «Voyage dans l’Amérique Méridionale’ vol. iii, pt. iv, Paléontologie (1842) p. 42 & pl. iui, figs. 1-3. Quart. Journ Geol.Soc.Vol. LAL PL AXXVIL. Gaee sede F WMGchacl i. Bale & Damelsson L SILURIAN GASTEROPODA . t = G “imp. Vol. 61.] THE SILURIAN ROCKS OF LLANGADOCK. 577 five whorls. Whorls convex, ornamented above by four strong keels, the intervening spaces unequal in width. Lines of growth distinct and close together, crossing the keels obliquely. Aperture subcirecular. Umbilicus open, wide. Remarks and Resemblances.—There are two examples of this form, the wax-impression of only one of which shows the orna- mentation distinctly. The base of both is embedded in the matrix. On the body-whorl of the best-preserved specimen an additional keel is seen below the four, and there are traces of a fine thread in the middle of each of the two lower spaces. Sowerby’s actual type of this species is wanting in his Collection in the British Museum (Natural History); but there are two specimens in it from the Wenlock Limestone (43623), which are marked Huomphalus funatus and agree with his description. I have compared the wax- impressions with these examples, and they appear to agree with them as well as with Sowerby’s figures in the ‘ Mineral Conchology, and also with other specimens in the general collection. Some of these show the aperture to be circular, alsothe operculum ; the umbilicus is open and of moderate size, and there are at any rate four additional keels on the base; one or two specimens show also a fine inter- ealated thread between the keels. Lindstrom’ considered Huomphalus funatus, Sow. identical with Z'rochilites globosus, Schlotheim. I am guided by his opinion in this, as he had the opportunity of examin- ing Schlotheim’s type in the Museum of the University of Berlin, an opportunity which I have not had. Dimensions.—tThe length of the specimen figured(Pl. XX XVII, fig. 16) is 15°5 millimetres, and the width il mm. Horizon.—(90) Wenlock. Etheridge recorded Huomphalus funatus from the Upper Lland- overy, the Woolhope Limestone, the Wenlock Limestone, and the Aymestry Limestone. Lindstrém recorded this species from all the Silurian strata of Gothland. EXPLANATION OF PLATE XXXVII pars. Fig. 3. Plethospira (Ulrichospira) similis, sp. nov. X 3. (See p. 569.) 4, Bembexia (!) Groomii, sp. nov. X 6. (See pp. 569-70.) 5. Bembexia (1) sp. X 3. (See p. 570.) 6. Murchisonia (Goniostropha) Cambria, sp. nov. X 6. (See p. 571.) Fies. 7-9. Loxonema Grindrodii, Don.(?). Fig. 7. x2. Fig. 8, front view. wze Hien x4. (See p. O72.) Figs. 10 & 11. Gyronema Octavia (VOrd.). Fig. 10. x 3. Fig. 11, back view of base. xX 2. (See p. 575.) 12 & 13. Gyronema Octavia, var. glabrum, Lindstrom. Fig. 12, aperture. x 2. Fig. 18, back view. x 2. (See p. 5795.) Fig. 14. Gyronema Octavia, var. interstriatwm nov. X 2. (See p. 575.) 15, Gyronema Octavia, var. fasciatum nov. X 2. (See p. 575.) 16. Polytropina alobosa (Schloth.). x 2. (See p. 577.) 1 ‘Silurian Gastropoda & Pteropoda of Gotland’ Kongl. Svensk. Vet.-Akad. andl. vol. xix (1881-84) No. 6, p. 162. Q.J.G.S. No. 243. o3 578 SILURIAN GASTEROPODA FROM LLANGADOCK. [Aug. 1905, DiscussioN (ON THE [WO FOREGOING PAPERS). Prof. Groom said that students of Paleozoic stratigraphy con- stantly experienced difficulty in the determination of the imperfectly- known gasteropoda so abundant in many places, and they would be grateful to the Authoress for her useful contribution to the literature of the subject. It was true that the studies had been made on casts, and that casts were not so readily examined as fossils pre- served in their original condition; but the perfect retention of the external form and minute details of ornamentation not uncommon in such cases was an advantage. Vol. 61.] IGNEOUS ROCKS OF THE PEMBROKESHIRE COAST. 579 ® 28. On the Ianzous Rocks occurring between Sr. Daviv’s Heap and STRUMBLE Heap(PeMBROKESHIRE). By James Vincent Htspen, B.Sc., F.G.8. (Read May 24th, 1905.) [Puarzs XXXVIII-XL.] ConrTEnTs. Page Hee loa OGine Olina saciid saree aeeee wale ss Maer aemansmeaisas seek ote 579 II. The Contemporanecus Igneous Rocks .................. 580 III. The Intrusive Rocks of Strumble Head and the PAG OMMIMNE WDishriCtce see owen cMeads onus ince oiadendine <= a6 581 IV. The Intrusive Rocks of St. David’s Head and the EACH ONMINT DIS tC) po nya cisae ass Seana canis sanie sats 584 V. The Lime-Bostonite and Porphyrite-Intrusions of the Per case Vat mnyMDIStVICh a aceeey cats mae wooe seen 594 VI. Review of the Petrography of the Rock-types ......... 599 VII. Mutual Relations of the Magmas ..................0ee08- 603 NMS Summary amd Conclusions stcccec acts. <+2-6+0 dese sn sacs 605 I. Inrropvucrion. THE area with which this paper deals adjoins the strip of coast lying between St. David’s Head and Strumble Head in Pembroke- shire. No detailed account appears to have been given hitherto of the igneous rocks of the greater part of this district, but the Strumble-Head rocks have been described by Mr. F. R. Cowper Reed in his paper on the geology of the Fishguard District.’ Adjoining parts of the county have also received attention: Mr. John Parkinson has discussed the Prescelly area,’ and the district south of St. David’s, including Skomer Island, has been described by various writers in considerable detail.2 The granitic rock of St. David’s, of classic interest by reason of its disputed igneous origin, has been the subject of exhaustive discussion by Henry Hicks,‘ and has been described petrographically by Thomas Davies,’ E. B. Tawney,’ Prof. Bonney,’ Sir Archibald Geikie,’ the Rev. J. F. Blake,’ and Prof. C. Lloyd Morgan.” Murchison made some reference to the trap-rocks of Pembrokeshire in his well-known memoir,’ and these rocks were mapped on the l-inch scale by the 1 Quart. Journ. Geol. Soe. vol. li (1895) p. 149. 2 “Igneous Rocks in North Pembrokeshire’ Quart. Journ. Geol. Soc. vol. liii (1897) p. 465. 3 See F. Rutley, ‘The Felsitic Lavas of England & Wales’ Mem. Geol. Surv. (1885) pp. 16, 18; J.J. H. Teall, ‘ British Petrography’ 1888, pp. 222, 284, & 336 ; and F. T. ‘Howard & E. W. Small, Rep. Brit. Assoc. 1893 (Nottingham) p. 766. * Quart. Journ. Geol. Soc. vol. xxxi (1875) p. 167; vol. xxxiii (1877) p. 229; vol. xxxiv (1878) pp. 147, 153; and vol. xl (1884) p. 507. > Ibid. vol. xxxiii (1877) p. 231, footnote. ° Proc. Bristol Nat. Soc. n.s. vol. ii, pt. ii (1878) p. 112. * Quart. Journ. Geol. Soc. vol. xxxiv (1878) p. 155, footnote. 8 Ibid. vol. xxxix (1883) p. 315. 9 Ibid. vol. xl (1884) p. 302. 10 Ibid. vol. xlvi (1890) p. Poa, 11 «The Silurian System’ 1839, p. 401. 282 580 MR. J. V. ELSDEN ON THE IGNEOUS ROCKS _ [ Aug. 1905, Geological Survey in 1845, under the superintendence of Sir Henry de la Beche, the igneous rocks being re-surveyed in 1855-56 by W. T. Aveline. Of the stratigraphy of this portion of Pembrokeshire there is still much to learn. Hicks mapped the outcrops between St. David’s and Abereiddy Bay,’ and Mr. Cowper Reed has done the same for the neighbourhood of Fishguard.* These lines are approxi- mately shown in the accompanying sketch-map (Pl. XXXVIII). There is, however, a good deal of uncertainty with regard to the intervening area, and the scarcity of fossils increases the difficulty of any attempt to fill in the stratigraphical details necessary to complete the survey of this part of the county, although good exposures are not lacking, both in the fine coast-section and in numerous inland quarries. A prominent feature in the area under discussion is the fault running in a south-easterly direction from Pwll-Strodyr on the coast, about 1 mile east of Abercastle, and truneating a series of narrow sills. which strike east and west between Abercastle and Mathry. This fault, together with the great east-and-west fault extending from St. David’s to near St. Edren’s, isolates a triangular wedge of country from the adjoining district of Strumble Head on the one side, and the pre-Cambrian area of St. David’s on the other. In this triangle the Lingula-Flags, Tremadoc Beds, Arenig and Llandeilo Beds, form successive bands striking east and west. ‘There are other minor faults, which, however, do not need further descrip- tion for the purpose of this paper. The Upper Llandeilo strata, which the late Dr. Hicks recognized on the north of Abereiddy Bay, seem to extend over the district of Barry, but from this point northward to Strumble Head the sequence is obscure. Bala Beds probably occupy the greater part of the area between Trevine and Strumble Head, although the outcrops appear to have been con- siderably displaced by the Pwll-Strodyr Fault. — Il. THE Conremporaneous Ienrovus Rocks. The sequence of the volcanic rocks of North Pembrokeshire has been already established over a considerable part of the area under discussion, but to what extent Arenig lavas are represented is still imperfectly known. Mr. Parkinson was not able to establish definitely the age of the Prescelly lava-flows, which may possibly date from Arenig time, and several bands of contemporaneous volcanic rock are mapped, in strata presumably of this age, in the southern portion of the triangle mentioned above. I shall, however, at a later stage (p. 599), advance reasons for doubting the contempo- raneous character of some, at least, of these exposures in the neighbourhood of the Pwll-Strodyr Fault. The most conspicuous of the true lava-flows in this portion of the district are seen in the neighbourhood of Llanrian, where 1 Quart. Journ. Geol. Soc. vol. xxxi (1875) pp. 167 et seg. 2 Ibid, vol. li (1895) pp. 149 et segg. Vol. 61.| BETWEEN 8ST. DAVID’S HEAD AND STRUMBLE HEAD. 581 the lowest beds, exposed as tuffs on the south of Abereiddy Bay, were taken by Hicks as the base of the Llandeilo Series. These outbursts are, therefore, of the same age as the lowest volcanic series of Fishguard, as described by Mr. Cowper Reed. The higher Llanrian lavas correspond with those of Goodwick, and are of Upper Llandeilo and Bala age. Hxamination of these Llanrian lavas shows them to be thoroughly acid in character, and to resemble, in a general sense, those of the Fishguard and Prescelly areas. By the courtesy of Mr. Parkinson, I have been able to compare his slices of the Prescelly lavas with my own specimens from the Llanrian district, with which (except that I have not noticed very pronounced spherulitic structures at Llanrian) they agree fairly well. There does not seem to be any reason to doubt that, from a petrographical point of view, the eruptive rocks of the Prescelly, Fishguard, and Llanrian areas are of similar type. My Llanrian specimens may be briefly described as containing pheno- erysts of quartz and monoclinic felspar in a microfelsitic matrix ; but, in view of the very detailed descriptions of similar acid lava- flows given by Mr. Cowper Reed and Mr. Parkinson, I do not think it necessary, for the purpose of the present paper, to dwell further upon this portion of the subject. Higher in the Bala Series come the thin volcanic beds of Porth Sychan and Porth Melyn on Strumble Head, of which I have noticed no equivalents farther along the coast to the south-west. Some of the exposures mapped by the Geological Survey as contemporaneous lavas, in the neighbourhood of the Pwll-Strodyr Fault, are of a character totally different from these acid lava-flows. I allude to certain exposures in the neighbourhood of Mathry, to which reference will again be made in another section of this paper (p. 599). ILL. Tue Inrrvustve Rocks or StrumBLE HEAD AND THE Apgorntne District. An extensive series of intrusive basic rocks breaks through both the lavas and sedimentary rocks of the Fishguard district. These are described in Mr. Cowper Reed’s paper, and very similar rocks are described by Mr. Parkinson from the Prescelly area. I need not, therefore, enter into details of these rocks, more than is necessary to illustrate their relation to the intrusive rocks of the district farther to the south-west. The prevailing type is a normal diabase, more or less ophitic, without olivine, and with an abundance of chlorite and epidote. They are moderately-basic rocks, and my observations tend to confirm Mr. Cowper Reed’s statement that the felspars generally belong to the oligoclase-andesine series. Very often, however, they are too much altered for optical determination. A typical development of this rock occurs at Llanwnda, near Goodwick, where an extremely coarse-grained variety of the gabbro-type is capriciously intermingled with the ordinary type. I shall refer to the general type of these basic intrusives as the Llanwnda type, in which I include both the Fishguard and the Prescelly rocks. 982 MR. J. V. ELSDEN ON THE IGNEOUS ROCKS [Aug. 1905, The large mass lying along the northern coast of Strumble Head differs from this type in being a uniformly fine-grained basaltic rock, distinctly columnar at Pen Anglas, and in places tachylytic. Along the southern margin, from Penrhiw, near Good- wick, to Porth Melyn, it is amygdaloidal or vesicular, and often it closely simulates a true surface-flow. Atits western end it has been considerably sheared, as may be seen at Trevishec and at Rhos-yn-wen. On the Geological-Survey map this rock is merged in the Llanwnda rock, but I saw no actual junction in the field, nor any sign of the passage of this fine-grained basalt into the very coarse Llanwnda type: Mr. Cowper Reed, in fact, refers it to a later period. We may now proceed to trace a variation in the basic type, referred to above, which appears to possess considerable interest in view of the character of the intrusive rocks occurring farther south. For this purpose, it will be convenient to describe in more detail the group of intrusions lying immediately to the west of Llanwnda, between Pont Tago and Porth Melyn. This group forms a well- defined range of hills rising into the conspicuous summits of Y Garn, Garn Bolch, Garn Gilfach, Garn Fechan, and Garn Fawr. If we begin the examination of this ridge at Y Garn near Pont lago, we find that the rock, although microscopically indistinguish- able from the medium-grained Llanwnda type, shows under the microscope the gradual appearance of a rhombic pyroxene. The ophitic augites also give place to a more pronounced idiomorphic type. Some of the crystals of augite appear to be of earlier con- solidation than the felspar; and a later generation, penetrated by felspar-laths, includes remnants of a rhombic pyroxene, some of which is intergrown with the earlier generation of augite. The rhombic pyroxene has undergone the usual bastite-alteration, and includes numerous granules of brown sphene. At Garn Bolch a rock of coarser grain shows, in addition to the above-described characters, zoned felspars, and also felspars of a later generation with a lower refractive index. These rocks, which approximate to enstatite-diabase in character,’ are penetrated by dykes of a finer-grained rock, with granular augite, no enstatite, and a considerable proportion of magnetite, the last-named mineral being replaced in the main mass by ilmenite. Proceeding to Garn Gilfach we find a typical dolerite, with ilmenite, magnetite, and phenocrysts of felspar and augite, the groundmass containing square sections of untwinned felspar, augite, and an abundance of magnetite. This rock bears a close resem- blance to the dykes which penetrate Garn Bolch. We now come to Garn Fechan, where the dominant rock is the variolite, so fully described by Mr. Cowper Reed. It is important * The term enstatite is used in a general sense, to denote both the unaltered and the altered forms of this mineral, and to include also the more ferriferous varieties, known generally as bronzite and hypersthene. . Vol. 61.] BETWEEN ST, DAVID'S HEAD AND STRUMBLE HEAD. 583 | to note, however, that this mass contains an enstatite-bearing rock, with quartz and micropegmatite, the relation of which to the variolite is not very clear. Finally, at Garn Fawr the base of the hill is a coarse-grained doleritic rock with two generations of both felspar and augite, no rhombic pyroxene, and differing from the rock of Garn Gilfach only in the scarcity of magnetite. The summit of the hillis crowned by a tachylytic rock (described by Mr. Cowper Reed), which, from its pronounced columnar structure, seems to be intrusive in the main mass, or, at any rate, subsequent to the coarse rock at the base of Garn Fawr. The above-described facts seem to point to the conclusion that this ridge is a composite intrusion. Mr.Cowper Reed explains the occurrence of the granophyric enstatite-bearing rock of Garn Fechan, as due to the incorporation of the acid lava which it penetrates. The analyses tabulated by him! show so low a percentage of magnesia in the acid lavas, that it is difficult to understand, upon chemical grounds, how its incorporation could lead to the development of enstatite in a rock which carries no olivine in its normal state. On the other hand, the experimental work of Prof. Vogt has demonstrated that an ordinary non-olivine- bearing diabase-magma might be expected to develop enstatite if enriched by silica and magnesia.” I am inclined, therefore, to associate this occurrence with that of the enstatite-diabase of Garn Bolch and Y Garn, and will leave its interpretation to a later stage. The point which I wish to emphasize at present is the occurrence, in this ridge, of rocks differing from the Llanwnda type, and marked by the incoming of a rhombic pyroxene. Proceeding next to the St. Nicholas district, a large intrusion is observed on the coast at Llech Dafad.. The rock here varies much in grain. ‘The coarsest variety forms irregular streaks and patches in a finer-grained matrix. The coarse rock is paler in colour, owing to a scarcity of ilmenite and other dark minerals, which, as in most of the specimens hereafter to be described, is not confined to the minerals of first consolidation. Enstatite occurs in all the slices to a variable degree, and it always precedes augite in order of crystal- lization. ‘The rock does not differ greatly from that of Garn Bolch, but apatite is more conspicuous. It is an enstatite-diabase. At Tresseysilt, close by, is another intrusion of a more variable character. A conspicuous variety recalls the coarse-grained Llanwnda type, but the felspars are more resistant to atmospheric weathering, and stand out in bold relief on the exposed surface. Under the microscope, enstatite can be recognized in all varieties, in some cases as bastite-pseudomorphs, in other cases altered to an * Quart. Journ. Geol. Soc. vol. li (1895) p. 177. > ‘Die Silicatschmelzlosungen’ pt. i, pl. i (Christiania, 1903). 584 MR. J. V, ELSDEN ON THE IGNEOUS Rocks [| Aug. 1905, almost isotropic substance with pyroxene-cleavages, and sometimes still retaining the usual pleochroism of ferriferous varieties of this mineral. The felspars are mainly of a more acid species than those found in the Llanwnda type. They commonly have a lower refractive index than balsam, are often untwinned, occurring in broad rectangular plates, and a little microcline is sometimes recognizable. The augite does not differ from the normal type. Quartz and apatite are conspicuous in the more acid types. Differ- entiation in situ seems to have taken place to a considerable extent, with corresponding variations in mineralogical characters. The rock is not sufficiently well exposed to establish any progressive change from margins to centre, although probably this is the case. Secondary changes have often obscured the original character of the rock, leading to extensive developments of chlorite, epidote, and zeolitic substances. The rock seems, on the whole, to vary from an enstatite-diorite to an enstatite-diabase. As we proceed eastward to Trellys, the character of the rock is seen again to pass into the normal Llanwnda type, which is pre- served through Panteg to Manorowen. So far as the Strumble-Head district is concerned, I have confined myself to an endeavour to show that the diabases of Fishguard and Prescelly (although remarkably uniform in character in those areas), when traced westward show local variations, characterized by a tendency to greater acidity and a development of enstatite. These changes, which are most pronounced in Garn Bolch, Garn Fechan, Llech Dafad, and Tresseysilt, are of such a nature as to suggest the intrusion at these localities of a magma of different composition from the typical diabase-magma of the eastern intrusions. It will now be necessary to describe the intrusions on the south- west side of the Pwll-Strodyr Fault; and, as it seems to conduce to greater clearness to attack this region from the extreme south- western end, I will next discuss the St. David’s-Head rocks, which lie about 12 miles from the above-mentioned fault. LY. Tae Inrrvustve Rocks or Str. Davip’s HEAD AND THE Apgsornine Districz. The existence of a quartz-gabbro with rhombic pyroxene at St. David’s Head has long been known, but no very detailed account of it has yet been published. Mr. Harker, speaking of a specimen from this district, calls attention to its identity with the rock of Carrock Fell, with the exception that the highly-basic modification found in the latter district had not then been noted in the St. David’s- Head rock." The most basic variety in my specimens from this 1 © Petrology for Studeits’ 1895, p. 4C. Vol. 61.| BETWEEN ST. DAVID'S HEAD AND STRUMBLE HEAD. 585 area were taken from the western extremity of Carn Llidi. The dominant rock is holocrystalline, of medium grain, and showing considerable variation in colour, according to the proportions of felspars and ferro-magnesian minerals present. The specific gravity of the dark variety was ascertained to be 2°98. Under the microscope, the rock is seen to consist mainly of felspar, pyroxene, biotite, and iron-ores. The ielspars give extinctions corresponding to a composition varying from Ab,An, to Ab,An,, and are of a thoroughly-basic species. Pyroxene is present, in both rhombic and monoclinic forms. The rhombic pyroxene is a fibrous, brownish, bastite-modification of enstatite. It is sometimes of earlier, and at other times of later, consolidation than the augite, with which it is also occasionally intergrown. The augite is brown, granular, and sometimes rather uralitized. It possesses the basal striation so often seen in this class of rock, and twins of the ordinary type, sometimes showing ‘herring-bone’ structure, are common. Biotite is moderately abundant, and crystallized after the felspar. The iron-ore is ilmenite, now largely converted into opaque leucoxene and sphene. Quartz is very sparingly present, and seems to be wanting in some varieties. Apatite, also, is apparently absent. The basic character of this rock and the abundance of rhombic pyroxene seem to place it among the norites, using that term as defined by Prof. Zirkel.! (See Pl. XXXIX, fig. 1.) Along the ridge towards the eastern shoulder of Carn Llidi the rock becomes less basic. Quartz-areas begin to appear, and, although my specimens do not here show any micropegmatite, the quartz-areas are invariably associated with rectangular untwinned felspars, having a lower index of refraction than quartz. These appear to be orthoclase. The long laths, on the other hand, which penetrate the pyroxenes, seem to be of a basic kind. The rock exhibits in a marked degree a tendency to the aggregation of enstatite in one portion of the slide and augite in another. A similar peculiarity in hypersthene-rocks has been remarked by other observers.” Both fibrous enstatite and augite occur in large plates, interpenetrated by felspar-laths (see Pl. XXXIX, fig. 2). The augite also occurs in more idiomorphic forms, which are nearly always twinned. Biotite gradually disappears with increas- ing acidity, and apatite becomes very plentiful. The norite here passes into a quartz-norite or, as some would describe it, an enstatite-diorite. Following the outcrop of this ridge to Carnedd Givian, a similar character is observed. Quartz-areas are associated with broad rectangles of untwinned felspar showing a low refractive index, 1 Dr. Teall, in describing the Galloway granites, prefers the term hy perite for basic, holocrystalline rocks containing both rhombic and monoclinic pyroxene. a ‘The Silurian Rocks of Britain’ Mem. Geol. Surv. vol. i (1899) p. 615. 21. H. Holland, ‘The Charnockite-Series’ Mem. Geol. Surv. India, vol. xxvii (1909) p.152; also F. H, Hatch, Quart. Journ. Geol. Soc. vol. xlv (1889) p. 344. 086 _ MR, J. VY. ELSDEN ON THE IGNEOUS ROCKS [| Aug. 1905, but there is still an absence of micropegmatite, and the augite retains a pronounced basal striation. ‘There is also an apparent absence of original hornblende in the slices examined. From St. David’s Head a ridge extends along the coast, parallel to that of Carn Llidi. Specimens taken at intervals along this ridge show considerable variations in texture. A very coarse- grained variety, recalling in the field the coarse rocks of Llanwnda and Tresseysilt, seems to be capriciously intermixed with varieties of finer texture. All these varieties exhibit more or less micro- pegmatite, which is often very conspicuous. Associated with the micropegmatite and quartz are untwinned felspars, with a lower refractive index than quartz or balsam. Plagioclase with albite- striation is also present, and the extinctions point to a species of andesine. Rhombic pyroxene is abundant, generally in large plates, often intergrown with augite and penetrated by felspar-laths. The relative proportions of rhombic and monoclinic pyroxenes are very variable, one or the other variety preponderating in different slides, or in different portions of the same slide. The rhombic pyroxene is invariably fibrous, and is occasionally brown and slightly pleochroic, but never approaches the character of typical hypersthene. ‘The augite is commonly twinned in simple binary combinations, but more complex twinning is also occasionally seen, the twinning-plane being then oblique to the trace of the vertical cleavage. Basal striation is still conspicuous in some slides. Biotite is absent from all the slices, but a little original, compact, green hornblende may be recognized in some of the specimens from the more easterly portions of the mass. Apatite is present, often in conspicuous quantity, and the iron-ore is invariably ilmenite, sometimes showing good crystalline outlines, with rhombohedral faces, but generally altered to leucoxene or sphene. On the whole, the changes noticeable along this ridge in a north-easterly direction seem to indicate a gradual increase in acidity, with the incoming of hornblende in addition to the rhombic and monoclinic pyroxenes. It differs, also, from the Carn-Llidi intrusion in the abundant develop- ment of micropegmatite and an increased proportion of an acid fel- spar, which appears to be orthoclase. The rocks, therefore, would ap- pear to graduate towards the class of enstatite-diorites, although there is still a preponderance in places of a rhombic pyroxene. East of Carn Llidi, at a distance cf about half a mile, is another ridge, about a mile in length, which rises into the rocky eminences of Carnedd Lleithr, Carn Perfedd, Carn Ffald, and Carn Trelwyd. Here the rock is of finer grain, and macroscopically very uniform, looking much like a grey granite. At Carnedd Lleithr, a specimen from the south-western corner shows under the microscope a considerable amount of quartz and micropegmatite, the latter often framing the felspar-crystals in the typical manner. The felspars projecting into the quartz-areas all have a lower refractive index than quartz, and are generally Vol. 61.] BETWEEN ST. DAVIDS HEAD AND SfRUMBLE HEAD. 587 untwinned. These appear to be orthoclase. Some of the sections show an outer zone of more acid composition than the interior. Both augite and enstatite are much reduced in quantity, and the chief ferromagnesian mineral is a strongly-pleochroic brownish hornblende. The scheme of pleochroism is: a, pale brownish-yellow; (, light-brown; y, dark greenish-brown ; y>S6 >a. The extinction-angle is about 15° on clinopinacoid sections. Augite occurs very sparingly, and the enstatite seems to be rather more ferriferous, distinctly pleochroic, and sometimes altered into a fibrous amphibole on the margins. All the dark minerals seem to have preceded the felspars in order of consolidation. The latter apparently grew more acid, until finally the eutectic point of orthoclase and quartz was reached. The iron-ores are represented by ilmenite, rather altered. Apatite is abundant, and there is some secondary epidote. In another specimen, of finer grain, the order of consolidation is apparently different, felspar preceding both enstatite and augite ; with hornblende, reduced in quantity, imme- diately preceding the quartz and micropegmatite. (See Pl. XX XIX, fig. 5.) At Carn Ffald the rock is very similar, but there is less quartz and micropegmatite; and at Carn Perfedd the latter structure appears to be absent, but neighbouring interstitial quartz-areas extinguish simultaneously, and are penetrated by a felspar having the appearance of orthoclase. This character is still more pro- nounced at Carn Trelwyd, where orthoclase seems to be more plentiful, both simple and in Carlsbad twins. The earlier felspars are polysynthetic, with extinctions corresponding to andesine. Some augite preceded the felspars, which enclose it in peecilitic fashion. Augite also occurs in good octagonal sections. Enstatite is about equal in quantity to the augite, and occurs in small fibrous pseudomorphs, slightly pleochroic. Hornblende is rather plentiful, and has an idiomorphic habit which becomes more pronounced in the quartz-areas. JImenite is scarcer than usual, but apatite is very abundant. Quartz-areas are associated with orthoclase, the latter in idiomorphic crystals, but there is no micropegmatite visible in the specimens examined. The rocks in this ridge appear to belong generally to the class of enstatite-diorites. The apparent abundance of orthoclase in the Carn-Trelwyd rock almost suggests a monzonite, and I determined the alkalies in this rock, with a view to the estimation of the relative amounts of orthoclase and plagioclase present. The following was the . result :— Per- Molecular centage. proportion. Na, O29 7.26) vane eseaneeees ‘060 TOO! = 20 Ory na tenssinasest ‘022 The orthoclase caleulated from these data would thus form 12-232 per cent. of the rock, which is scarcely high enough to 588 MR. J. V. ELSDEN ON THE IGNEOUS Rocks [ Aug. 1905, warrant the placing of this rock among the monzonites ; but, as the felspars are rather altered, only surface-exposures being accessible, it is possible that some alkali has disappeared. From a general point of view, I think it may be stated that the rocks in this ridge vary from quartz-enstatite diorite towards quartz-enstatite monzonite, and typical examples of the latter rock might be expected to occur locally. There is certainly a marked difference between the intrusions along this ridge and the biotite-norites of Carn Llidi. The prominence of hornblende also differentiates them from the rocks of St. David’s Head, in which hornblende seems to occur only sparingly towards the eastern extremity. Rhombic pyroxene, however, continues to be a characteristic and abundant component of the rock. We come next to Penberry Hill, which is an isolated boss-like intrusion, lying in direct line with, and about a mile to the north-east of, the Carn-Trelwyd ridge. Under the microscope this rock bears some resemblance to that of Carn Trelwyd, but it is evidently of a more basic type, containing less quartz and orthoclase, and only a very insignificant amount of hornblende. The feature of this rock is the predominance of a bronzite-form of enstatite, which occurs in very numerous rectangular sections, with ill-defined terminations, sometimes showing rather indistinct blunt domes at one end. It is fibrous and slightly pleochroic, and seems to belong to an early period of consolidation—preceding, in fact, all the constituents except apatite (which is fairly plentiful) and some of the ilmenite. It closely resembles the enstatites above described, and has a tendency to enclose sphene-granules. The next mineral to crystal- lize was felspar, which seems to be a not very-basic plagioclase, but is rather too turbid for accurate determination. ‘This was followed by a pale augite in subordinate amount, sometimes twinned and rather granular. There seems to be some orthoclase, with occasional Carlsbad twinning; and quartz with a very little micropegmatite were the last minerals to crystallize. (See Pl. XXXIX, fig. 3.) I made a chemical analysis of this rock with the following results :— Molecular Percentage. proportion. hoy | CTE ene Aner erienars AAD AA ORE RADA Gs 4.52 54:42 902 SDA CA CIE) an sec ece en arent aon 0-72 ‘009 JAcliirainnae 252 95s Sores ee 15°34 "151 Tronesesquiloxide 2.5.6.5 tost onsen soe 0°67 004 rom=mionoxidle gs. =. 45-22 gr ce eecereee 517 ‘071 Mameaimese-Oxtdle wae nee sete eee ee trace Destine; 20 255 eae Se re need cme ene aoe 8:30 148 Maenesia aie cmecie ss Eee ees 6°69 "166 Potasli ssscan te Ge asoncrseenecce meee 101 ‘010 Doda. ‘in.;sue. aetna teat ae oo eee Aal ‘068 Phosphoric acid costae eee 0-57 ‘004 Water expelled at 110° Centigr....... 0:47 Waiter: (comilinech) = en -eeeeerre tee eeeree 2°60 @arbonm: dioxide]... 2500.4. fe. eee trace 100-17 Vol. 61.] BETWEEN SI. DAVID’S HEAD AND STRUMBLE HEAD. 589 The felspars are rather turbid, and the rock is evidently some- what altered, but the analysis corresponds approximately to the following percentage mineral-composition, omitting water :— (C\)nE TE 2a a ine ee ee ae aN 1-740 Orxthoclasel s/s tsk ate 5560 SMart + : = Constituting an oligo- ane be AE GRC ae i Aa ee \ Pen a ee es = uM Peete seen eons serene ; eee is { position Ab. An ; PBASGALIEC: ica accidace ds cGemasecdmo LT O28ie ao. Ze Hornblende and augite ...... 16-716 Ilmenite and magnetite ...... 2296 PND ALIE CRS wre wreciiaes coves ces Voaeass ve 1240 97-726 In arriving at the foregoing result there is, of course, the usual difficulty with regard to the composition of the pyroxenes and amphiboles, which I have calculated as diopside, with the addition of a small proportion of Tschermak’s molecule CaO. A1,O, .Si0,. As, however, some soda-molecules should probably be included, the albite is, in consequence, too high, and the quartz too low. It 1s interesting to compare the percentage composition of this rock with some quartz-enstatite rocks of this and other countries :— I. eee iat, IV. me VI. SIIUIGE 33 A asega nese tana 54:42 58:45 5350 50°71 54:03 56°72 PRANETATIVE, Fess oop alevnis ce oie 15°34 17-08 2220 1478 1671 16:90 HEMI OME 2 kc 8.) .adiosiejne a 0-67 0-76 3°60 Boe 1:37 4-14 MEEFOUS OKIE ih. yo.sSee.os-- 517 = =461 2°64 8:95 G00 6:28 IVI CMS Iai ones fst cv seca veness 6°69 5:15 2°00 5°90 5°66 4-62 LLARSES Seay a am a nee eee 8°30 7-60 9°45 8:21 Sse 629 SO APE Gils sacs cnje aves 4°21 4:25 4-26 2°76 2:99 4°65 IEG ae ocak eae ee 1-01 102 0°61 1:39 0-67 0°63 Water at 110° Centigr.... O47 0-12 a oa 0-14 oe Water (ignition) ............ 2°60 0:95 1:50 1-78 0°53 075 AMIGA ACI... ee nscen soos. 0°72 n.d. 0°45 1-92 0-84 ss Phosphoric acid’ -.........-- 0:57 n.d. sie are 013 10017 99°99 100-21 99:92 99:61 101-94 I. Quartz-norite of Penberry Hill. Author’s analysis. Il. Enstatite-diorite, Penmaenmawr. Analysis by J. A. Phillips, Quart. Journ. Geol. Soc. vol. xxxiii (1877) p. 424. III. Gabbro of Carrock Fell. Analysis by G. Barrow, Quart. Journ. Geol. Soe. vol. 1 (1894) p. 323. IV. Enstatite-diabase, Whin Sill. Analysis by J. J. H. Teall, Quart. Journ. Geol. Soe. vol. xl (1884) p. 654. V. Hypersthene-gabbro, Pennsylvania. Analysis by W. F. Hillebrand, U.S. Geol. Surv. Bull. No. 228 (1904) p. 48. VI. Hypersthene-norite, Oberhofen (Tyrol). Analysis by F. Teller & C. von John, Jahrb. d. k.-k. Geol. Reichsanst. vol. xxxii (1882) p. 647. The close agreement which this Penberry-Hill rock exhibits with that of Penmaenmawr is evident from a comparison of the analyses. This is graphically represented in the accompanying diagram (fig. 1, p. 590) drawn upon Brogger’s familiar plan. The Penmaenmawr rock, however, has no hornblende, and a little biotite is occasionally 590 MR. J. V. ELSDEN ON THE IGNEOUS ROCKS [Avie 1905, present. The agreement would have been still closer, if the alumina of the Penmaenmawr rock had been diminished by the determination of titanic and phosphoric acids, especially if allowance be made for the water of hydration in the Penberry-Hill sample. The Carrock-Fell hypersthene-gabbro has considerably less rhombic pyroxene, and Be Al Penmaenmawr and Penberry Mill, O Fig. 1.— Diagram illustrating the difference in composition between the rocks of O3 [The continuous line represents the Penmaenmawr rock, and the broken line the Penberry-Hill rock. | there is a corresponding deficiency in magnesia. The Whin-Sill rock contains more iron and a smaller percentage of alkalies and silica. On the whole, the composition of the Penberry-Hill rock seems to entitle it to a place among the quartz-norites, described by Vol. 61.| BETWEEN ST. DAVID’S HEAD AND STRUMBLE HEAD. O91 F. Teller and C. von John.’ It seems advisable to retain this term, for the sake of clearness of description, in order to distinguish rocks which appear to occupy a place between the normal diorites and the norites. Examples of similar gradations from true norites into quartz-bearing rhombic pyroxene-rocks have been described from other localities in addition to the Tyrol; as, for example, in the Charnockite Series of India,” at Ekersund in Norway,’ and elsewhere. The nomenclature of enstatite-bearing rocks of this type has been a widely-felt difficulty, and has been much discussed by writers on rock-classification.t It appears desirable to adopt the term quartz-norite, to include the enstatite-bearing equiva- lent of the quartz-gabbros, in preference to the introduction of a new name, as has been proposed by Mr. J. E. Spurr in describing the sc- ealled belugite (or norite-diorite) of Alaska.’ The need for a class- name of this sort is especially felt in cases like the present, in which rocks rich in enstatite are associated with normal diorites wherein rhombic pyroxene becomes distinctly subordinate to hornblende. Near the northern flank of Penberry Hill a long, irregular, narrow intrusion extends from Trwyndiallt in an east-north-easterly direction to near Llanvirn. Specimens from this intrusion, taken at Pen Clegyr, show very similar characters to the eastern portion of the Carn-Llidi mass, of which it may possibly be a continuation. In the neighbourhood of Portheiddy Common are several thin intrusions, which have a distinctly more basic character. The felspars are in large rectangles, penetrating ophitically now augite, now enstatite. In some parts the latter mineral predominates and occurs in various stages of alteration from an almost unaltered yellowish or colourless variety to the usual fibrous form, but always preceding augite in order of crystallization. Chlorite is fairly abundant. Quartz is practically absent, and apatite is very sparingly represented. The iron-ore is ilmenite, which is not much altered. It would seem that we have here an enstatite- diabase with a tendency to a predominance of enstatite, and differing only from a norite in its ophitic tendency. On ascending the hill north of Abereiddy Bay, several other basic dykes are seen along the edge of the cliff. Specimens from these exposures possess very much the same character as those above described, but do not form very satisfactory objects for micro- scopic examination, on account of the large quantity of secondary alteration-products. Despite the confused structure, however, the 1 “Geologisch-petrographische Beitrage zur Kenntniss der dioritischen Gesteine von Klausen in Sudtirol’ Jahrb. d. k.-k. Geol. Reichsanst. vol. xxxii (1882) pp. 589 e¢ seqq. 2 Mem. Geol. Surv. India, vol. xxviii (1900) pp. 125 e¢ segq. 3 J. H. L. Vogt, Zeitschr. fir prakt. Geol. vol. i (1893) p. 4. 4 See F. Loewinson-Lessing, ‘ Kritische Beitrage zur Systematik der Eruptiv gesteine’ T'schermak’s Min. & Petr. Mitth. n. s. vol. xxi (1902) p. 311. ° * American Geologist’ vol. xxv (1900) p. 238. 592 MR, J. V. ELSDEN ON THE IGNEOUS ROCKS [Aug. 1905, presence of enstatite 1s :learly established, and the rocks can be assigned to the class uf enstatite-diabases. At Penclegyr, to the east of Porth Gain, is a large boss-like intrusion which has been extensively quarried. The rock is bluish- grey and of a more compact character than that of Penberry Hill. Slices from different parts of this mass show two principal modifications. In the first variety, which is the rock exposed in the quarry on the northern face of the cliff, there is a close resem- blance to the rock of Penberry Hill. The minerals present are apatite, ilmenite, augite, felspar, rhombic pyroxene, and quartz. Apatite is abundant. The augite clearly precedes both the felspar _and the rhombic pyroxene. It is granular, and is included in, or moulds, both the last-named minerals. Rhombic pyroxene, however, crystallized later than the felspar, by which it is penetrated. It occurs in rather ragged rectangular sections, and is faintly pleochroic. A large portion of the felspar has rather a low refractive index and a symmetrical extinction of nearly 20° in twins on the albite-plan: it is, therefore, probably albite. A little orthoclase of later crystallization appears to be present. Quartz is fairly abun- dantin small interstitial grains, clusters of which extinguish simul- taneously, but there is no micropegmatite. From its greater acidity this rock may therefore be classed asa quartz-enstatite diorite. In another variety of the rock augite is completely wanting, and quartz seems to be present in reduced amount. The bulk of the rock consists of plagioclase and a pale yellow pseudomorph after enstatite. The felspar resembles the species above mentioned, and probably is mainly albite, but a little orthoclase is doubtfully recognizable. It preceded the enstatite, which is interstitial to it. Apatite is moderately abundant, and there is some opaque iron-ore in rather irregular patches. I made a partial chemical analysis of this rock, with the following results :— Per cent. SULTGias iy ee. Acne Sa hearers area 61°45 ANUoaoU ary, THEOL, SUOy “ Ragesens-cas 24°80 AGNI Cr) az scl soc eee Ree ene Sak eee EEEE 0-85 MAGMESTON 2. cccs osu eeeen ses 2°91 (The specific gravity of the rock is 2°68.) The summation leaves about 10 per cent. for alkalies and water. The small proportion of lime is significant, and explains the absence -of augite in this variety, as well as the character of the bulk of the felspar. Taken in conjunction with the fact, that in the main mass the augite crystallized before the felspar, the explanation might be that this portion of the magma has been derived by a process of liquation from another portion in which augite had already crys- tallized ; or, perhaps, it may represent a magma from which augite- crystals had been removed by gravitation toa lower stratum. I am at a loss for a class-name for this albite-enstatite rock, which seems to be of rather an abnormal type. (See Pi. XXXIX, fig. 4.) Vol. 61.] BETWEEN ST. DAVID’ HEAD AND STRUMBLE HEAD. 593 We pass now to the series of thin parallel intrusions in the neigh- bourhood of Trevine, several of which emerge on the shore at Aberfelin. One of these, near the footpath leading to the beach, bears a close resemblance to the variety described above. The bulk of the rock consists of felspar, which, however, is associated with a rather abundant groundmass of micropegmatite and quartz. The extinctions and refractive index again point to albite as the dominant species, the orthoclase being confined to the micro- pegmatite. Some enstatite in rather fragmentary, much altered shreds seems to be present, and there are irregular strings of ilmenite and leucoxene, with a few specks of pyrites. Apatite is still fairly abundant. Secondary patches of calcite are present, and a little vermicular chlorite resembling the species which has been described as helminth.’ Augite again seems to be wanting. It is possible that this may be an “offshoot from the Porth-Gain | aS: the last-described variety of which it much resembles. The other intrusions, all of which seem to be narrow sills, have a totally-different character, so far as I have been able to examine them. They are distinctly more basic in composition. The felspars have a higher refractive index than balsam, and the symmetrical extinctions of twins on the albite-type correspond to a basic oligoclase or andesine, in some cases approaching that of labra- dorite, Ab,An,. There is much pale-brown augite, more or less ophitic, and a few relics of scarcely-recognizable enstatite, although some of the rather abundant chlorite may represent it. Quartz is scarce, except where the felspars are much decomposed, and apatite is absent or very rare. JIron-ores in the form of ilmenite, more or less altered, and pyrites occur. ‘These rocks would be called diabase; but, as enstatite undoubtedly occurs, I am inclined to associate them both with the St. David’s-Head intrusions and with the typical diabase of the Llanwnda type. It is highly probable that they represent a mixture of the two types. I was unable to confirm the colouring on the Geological-Survey maps to the east of Trevine, as the conditions did not permit of my tracing the continuity of these sills into the Abercastle-Mathry area, on account of the unfavourable time of year, much of the country | being inaccessible owing to growing crops of corn. So far as my observations went, however, these diabase-sills seem to be absent from the neighbourhood of the fault. Ynys-y-Castell is a small islet lying off the north of Abercastle Bay, only accessible at low water. It consists of an igneous in- trusion of fine grain and bluish-grey colour. In the hand-specimen this bears a close resemblance to the rock of Porth-Gain Quarry, but under the microscope it appears to be of a distinctly-basic character 1 Otto Meyer, Zeitschr. d. Deutsch. Geol. Gesellsch. vol. xxx cole p.2l ; and EK. Hussak, Tscherm. Min. & Petrogr. Mitth. n. s. vol. i (1878) p. 2 Q.J.G.8. No. 243. aT 094 MR. J. V. ELSDEN ON THE IGNEOUS Rocks [Aug. 1905, the majority of the felspars being more highly refractive and the small quantity of quartz being most probably secondary. The felspars are generally too turbid for determination. IJlmenite, as usual in all the rocks described, continued to separate after the felspars. It is considerably altered to sphene, very little inter- mediate leucoxene remaining. Augite is present, sometimes in rather idiomorphic crystals, but in other cases penetrated by felspar-prisms. That some augite preceded felspar is proved by its occasional in- clusion in the latter mineral. Rhombic pyroxene seems to have been present in considerable quantity, but is now almost entirely altered. Chlorite is abundant, and a little hornblende, associated with augite, may be secondary. Apatite is moderately abundant. There are numerous calcite-areas, and a considerable amount of fibrous secondary mineral resembling tremolite. The rock may be described as a somewhat granular type of enstatite- diabase. I have now traced upwards, from St. David’s Head to the Pwll- Strodyr Fault, a series of enstatite-bearing rocks which seem to merge into those previously described south of Strumble Head, and afford an explanation of the types of rock occurring at Llech Dafad, Tresseysilt (see Pl. XX XIX, fig. 6), Garn Bolch, and the granophyric rock of Garn Fechan. Certain rocks of an entirely-different character, which occupy a small area west of the above-mentioned fault, in the Mathry district, remain to be described. V. Tue Lime-Bostonite anp PoRPHYRITE-INTRUSIONS OF THE ABERCASTLE-Matury District. I will first call attention to the broad strip of igneous rock ex- tending from Pwll Whiting, through Abercastle to the Pwll-Strodyr Fault. This is coloured in the Geological-Survey map as greenstone on the west of Abercastle, and as intrusive felstone on the east. It is, however, the same throughout, so far as my specimens, and ex- amination in the field, enable me to judge. The rock is clearly intrusive, and alters the shales on the north side in the direction of the dip, thatis, on its upper margin. The rock decomposes rather easily, and shows a tendency to present a vesicular appearance from the weathering-out of irregular elongated cavities formerly occupied by a dark material, resembling chloritic matter, which spots the unweathered portion of the rock. A few felspar-phenocrysts and some calcite-areas are visible. The general appearance is that of a greenish-grey trachytic rock. Under the microscope, it is seen to consist almost entirely of felspar, chiefly in the form of laths, but some larger crystals are also present. The dark material mentioned above is seen to consist of irregular greenish patches, nearly isotropic, but often associated with a fibrous, feebly-polarizing substance resembling chlorite, and Vol. 61.] BETWEEN ST. DAVID’s HEAD AND STRUMBLE HEAD. 595 possibly due to the hydration of an original glass, forming a kind of palagonite, in the manner suggested by Prof. Bonney in expla- nation of a somewhat similar occurrence in the Prescelly lavas.’ Some of these patches have minute spherulites round the margin, showing a distinct cross between crossed nicols. Quartz occurs sparingly, usually in thin streaks and patches, and may be of secondary origin. xcept a little granular opaque matter, pro- bably a decomposed titaniferous iron-ore, no dark minerals are seen. Patches of calcite are visible in places, but neither these nor the other secondary material appear to replace pre-existing crystals. (See Pl. XL, fig. 1.) The felspars are nearly all plagioclase. The laths are rather ragged, and extinguish nearly parallel to their length. The refrac- tive index is lower than quartz. In some cases the symmetrical extinction on each side of the trace of the twinning-plane of albite- twins reaches 10°. Flow-structure is commonly visible, and the felspars are often bent. The porphyritic felspars are apparently more basic than the laths. I determined the chemical composition of this rock, selecting the least-weathered specimen obtainable, which, however, was by no means fresh. The following results were obtained :— Molecular Percentage. proportions, Silent See cite: Pieter un hence 55°38 "923 PA roman eaas eae tivkrors eco 18°34 181 HeETRIG OXIME! Lhe csehonconsesecns. 1:13 ‘007 Ferrous oxide ..... Ua MAAN Ne 5°86 O81 T DINERS, “Sa Eye a ae oe a 325 058 WMlayaraersis © 2 ochs Sbdapeebecsoeeoaue 347 ‘086 WOtASH es cheeses acecs Pe patie Oe 0:22 ‘002 SOGIE BEAN tweet OE Re in seicnag age 712 “115 AMAT CLACIO a htaccigssaracieiee neds 0:90 7010 hes pMOrie ACO: Nae scaee sess trace Warbonie’aciG’ “sic..).sceccee nsec 2:00 Water (at 110° Centigr.) ....-. 0:48 Water (ignition) ............... 2°39 MTG Geller on aha raieieresteisinieo's 100°54 Calculating the albite- and anorthite-percentages from the soda and lime, we get which would together amount to 76:38 of a plagioclase, of composi- tion between Ab,An, and Ab,An,, corresponding to an acid oligoclase of low extinction, of which a large portion of this rock 1 J, Parkinson, ‘Igneous Rocks in North Pembrokeshire’ Quart. Journ. Geol. Soc. vol. liii (1897) p. 468. 7% T 596 |. MR, J. Y. ELSDEN ON THE IGNEOUS Rocks [Aug. 1905, consists. I found its specific gravity to be 2°73. Below are given for comparison some analyses of similar rocks from other areas. IL II. JUOL, IV. Silli@ariey neuer sae 55°38 56°50 52:00 77°29 PANNA NIUE cet teen oa cae 18°34 1814 18:06 14°62 enric oxide! So. ..2ds.0 1:18 3°12 218 \ nel Ferrous oxide ............ 5°86 2°86 5:14 af IMC tt ae... Sake e eaten 3°25 3°38 4:59 trace Miaigmesiajsce epee sereae. 347 1-22 2:84. 0:38 | OUASIA enters Sac aenw se 0°22 1-60 4:68 0-16 Soda ine e ay en eres 12 5:28 3°78 7:60 ANNO GVONG| Gaeboendose. 65 0-90 0:85 0:98 meds Phosphoniega cide. se trace Lie ae n.d. @arhomic acide ses ee 2:00 o11 3°59 ae Water (at 110° Centigr.) 0-48 | 5 re Water (ignition) ......... 2°39 | = aoe es Manganese-oxide ...... oe Ss 0°25 : 100°54 99:3205 99-95 100°62 T.=Intrusive rock, Abercastle, Author’s analysis. Il.=Lime-bostonite of Mena. W. C. Brogger, ‘Die Eruptivgesteine des Kristianiagebietes, III: Das Gang-Gefolge des Laurdalits’ Christiania, 1898, p. 207 ; also ‘ Basic Eruptive Rocks of Gran’ Quart. Journ. Geol. Soc. vol. 1 (1894) p. 26. III.=Bostonite, Onston Ness, Orkney Is. J.S. Flett, Trans. Roy. Soc. Edin. vol. xxxix (1900) p. 873. Y'V.=Keratcphyre, Wicklow. F. H. Hatch, Geol. Mag. 1889, p. 72. In some respects this rock is strongly suggestive of a bostonite. Mr. Cowper Reed’s description of the smaller intrusives of Foilna- neena Cove (County Waterford),’ would apply almost perfectly to the Abercastle rock. Mr. Cowper Reed was kind enough to send me a slide of the Waterford bostonite-like rock for comparison, and I find the resemblance very close. At the same time, the chemical analysis does not altogether corroborate this view, since typical bostonite not only exhibits a more completely-holocrystalline. structure, but has also the proportions of potash and soda approxi- mately equal. There is, however, a very close resemblance between bostonites and certain keratophyres, and the chemical composition of the Abercastle rock is so similar to that of a rock described by Prof. Brogger as lime-bostonite from Mena, Gran, Christiania,” that I am inclined to refer the Abercastle rock to that type. The accompanying diagram (fig. 2, p. 598) represents graphically this comparison. It is interesting to note that the lime-bostonites of Meena are associated with a porphyritic variety, called by Brogger meenite-porphyrite: this is the oligoclase-porphyry of 1 “Toneous Rocks of the Waterford Coast’ Quart. Journ. Geol. Soc. vol. lvi (1900) pp. 677, 683. 2 «Die Hruptivgesteine des Kristianiagebietes, III: Das Gang-Gefolge des Laurdalits’ Christiania, 1898, p. 207; also ‘ Basic Hruptive Rocks of Gran” Quart. Journ. Geol. Soc. vol. 1 (1894) pp. 23 e¢ seqq. Vol. 61.] BETWEEN ST. DAVID’S HEAD AND STRUMBLE HEAD. 597 Kjerulf. Some specimens of the Abercastle rock show a similar porphyritic tendency. With the exception of the occurrence. in Ireland, noted above, the only locality from which bostonite has hitherto been described in this country is in the Orkney Islands,’ the analysis of which (as given by Dr. Flett), however, so far as the alkalies are concerned, differs materially from that of the Abercastle rock. It is notable that the latter rock resembles the bostonites in its marked tendency to decomposition, as is seen in the presence of a considerable proportion of carbonic acid and combined water. I have appended, for purposes of comparison, an analysis by Dr. Hatch of a keratophyre from Wicklow, which, although closely agreeing in the proportions -of soda and potash, is i other respects a ey different type of rock. To the north of Abercastle, on the coast opposite Ynys-y-Castell, is another igneous exposure. From its position, this might be taken for a part ot the Ynys-y-Castell diabase-intrusion. A specimen, however, taken from the top of the cliff about midway between Abercastle Bay and Porth Gwynion, looks very like a coarse -agglomerate, such as is commonly seen in the Goodwick volcanic series. It contains angular greenish-grey fragments in a darker matrix. Differential Senilncrice results in the removal of the angular fragments, leaving hollow spaces separated by walls of the more resistant matrix, a feature which may have some bearing upon the interpretation of the origin of this rock. Under the microscope, the angular fragments are seen to consist of the bostonite-like rock, described above. The matrix is a finely- granular material, through which small bostonite-fragments are scattered. No fragments of other rocks are recognizable, and I am inclined to think that this is a brecciated, tuff-like intrusion some- what similar to those which Messrs. Kilroe & McHenry have described in the South-Hast of Ireland.? Microscopic examination tends to support this view (see Pl. XL, fig. 5). The extreme angularity of the fragments, the thin shreds of uncrushed rock which occur in the matrix, and the small proportion of the matrix compared with that of the coarser fragments, tend to confirm the theory that this rock has been crushed in situ. If this be the case, the greater resistance of the matrix to weathering can only be explained by some secondary process which has indurated the powdered rock. lt may be noted that I found a precisely-similar brecciated rock, with the:same microscopic structure (Pl. XL, fig. 6), in a small exposure at Priskilly Fawr, about + miles south-east of Abercastle, and not far from the Pwll-Strodyr line of fault. The exposure is very small, consisting of a patch only a few square yards in . J.8. Flett, ‘The Trap-Dykes of the Orkneys’ Trans. Roy. Soc. Edin. VOl. Xxxix (1900) p. 873. 2 «Tntrusive, Tuff-like, Igneous Rocks & Breccias in Ireland’ Quart. Journ. Geol. Soe. vol. lvii (1901) p. 479. 598 MR. J. V. ELSDEN ON THE IGNEOUS Rocks [{ Aug. 1905, area, protruding in a marshy field about half a mile west of the farmhouse. I believe that the rock is in situ, and its occurrence at this horizon would then tend to confirm its intrusive origin. It is possible that these brecciated intrusions have been produced by earth- movements, in a man- ner somewhat similar to those described by Mr. Lamplugh in the Manx Volcanic Series,* a conclusion which is strengthened by the fact that a good deal of folding is noticeable in the cliff- sections near Abercastle. Several of the paral- lel sills lying between Abercastleand Mathry are of the same type as the Pwll-Whiting- Abercastle intrusion. Specimens from Car- nachen Wen (Pl. XL, fig. 2) and from an exposure in the Aber- castle road, about a mile from Mathry (Pl. XL, fig. 4), are petrographically iden- tical with the lime- bostonite of Aber- castle, with the excep- tion of a greater pro- portion of porphyritic felspars. I noticed no sign of brecciation, however, in these areas. A somewhat dif- ferent type occurs at Cwm-y-Graig, near the south-eastern ex- tremity of Mathry Hill, where a conspicuous boss of pale-blue compact rock is quarried for road-metal. Micro- scopically, this rock differs from the type described above, in having lume-hostonite of Mena. [The continuous line represents the Meena rock, and the broken line the Abercastle rock. | Vig. 2.--Diagram illustrating the comparison between the Abercastle rock and the 1 “On some Effects of Harth-Movement on Carboniferous Volcanic Rocks of the Isle of Man’ Quart. Journ. Geol. Soc. vol. lvi (1900) p. 20. Vol. 61,] BETWEEN ST. DAVID’S HEAD AND STRUMBLE HEAD. 599 frequently a banded structure, owing tothe presence of lines of opaque white spots. It has then the appearance of a banded spherulitic felsite. Under the microscope, however,:these white patches are seen to be merely circular spots of incipient decomposition, the banded structure being apparently due to shearing or fluxion- structure. There is no trace of any spherulitic structure. Shearing has largely confused the original character of the rock, but it seems to belong to the same type of rock as that described above, with the exception that phenocrysts of a ferromagnesian mineral are represented to a limited degree. This is a pale pyroxene, very fibrous, and looking very much like an altered rhombic form. Some doubtful monoclinic pyroxene is seen, and the rock may, perhaps, be designated an augite- or enstatite-porphyrite. (See Pl. XL, fig. 3.) It is mapped by the officers of the Geological Survey as a contemporaneous lava. I think, however, that it is intrusive, and is a modification of the lime-bostonite series described above. For reasons already mentioneds (p.593), I was not able to examine all the exposures in the Mathry district, but among my specimens from that area there is not a single indication of the Llanrian lava- series. The appearance rather suggests aseries of thin parallel sills of lime-bostonite or porphyrite, which is the typical form that such intrusions take in some other localities. I was equally unable to trace the continuity of the enstatite-diabase sills of Trevine east- wards to the Pwll-Strodyr Fault, all my specimens from this area belonging either to the lime-bostonite type of Abercastle or to the porphyrite-type. Much remains to be done, however, in accurately mapping this area, and as the igneous exposures may belong to any of the above-described varieties (which, in the field, are not always easy to distinguish), considerable care will be necessary, not only in separating the lime-bostonites and porphyrites from the contem- poraneous flows, but also in ascertaining the exact limits of the enstatite-diabase-intrusions, It is probable, also, that other exposures of this type occur beyond the Mathry district. In the Geological-Survey collection of rock- slices from this part of Pembrokeshire are two specimens, one from the Tremynydd range, and the other from the Carn-Lhdi area, which closely resemble this type; but their exact localities are not quite certain. VI. Review or tor PetRoGRAPHY OF THE RocK-TYPEs. Under this head attention is drawn to certain points of petro- graphical or mineralogical interest, which have come under obser- vation in the examination of a large series of rocks from the areas dealt with in the foregoing pages. These I will now proceed to describe. 609 MR. J. V. ELSDEN ON THE IGNEOUS ROCKS [Aug. 1905, Apatite.—This mineral is a very prominent constituent of certain of the rock-types, but in others it is rare or absent. It 1s, for example, extremely rare in the Fishguard and Prescelly diabases, and in the more basic variety of the enstatite-diabases of the Llan- rian and Trevine areas; but in the quartz-enstatite-rocks it is often abundant, and always present to some extent. This distribution ot apatite is very noticeable at Carn Llidi. The basic norite of the western extremity of this mass apparently contains no apatite, but towards the east, where the rock passes into quartz-norite, apatite becomes conspicuous. In the lime-bostonite series it seems to be wanting. Tron-ores.—Magnetite seems to be confined almost entirely to — some of the fine-grained rocks of Strumble Head, the dolerite of Carn Gilfach, and the fine-grained intrusions of Y Garn. In all the other types the only recognized species of iron-ore is ilmenite, often in good rhombohedral forms. The usual decomposition- products, leucoxene and sphene, are present. Pyrites is often, present, but is apparently not confined to any particular groups of rock. Rhombic pyroxene.—The rhombic pyroxene occurs in various forms, and exhibits very different degrees of alteration. The least-altered forms occur in some of the diabases, and show no fibrous structure. Only the pinacoidal cleavages are recognizable. These possess marked pleochroism: rays vibrating parallel to the y axis are green, those vibrating parallel to the 6 axis being yellow. In no case is the brownish-red colour, characteristic of the brachy- diagonal vibrations (a) in typical hypersthene, visible. These characters would seem to point to a bronzite-variety of enstatite. Various degrees of hydration lead to the development of the fibrous forms, diaclasite and bastite, with a corresponding loss of pleo- chroism; while, in other cases, the mineral passes into a kind of chloritic pseudomorph. In the diorite-series the prevailing form of the enstatite is in prisms terminated at one extremity by rather rounded domes. The crystals frequently are elongated in the direction of the ¢ axis. They are always fibrous and generally faintly pleochroic, the latter quality being sometimes confined to patches only. Lastly, in the norite-series we find the rhombic pyroxene in broad plates, often changed to a colourless fibrous substance with high double refraction and nearly-straight extinction. This may be an amphibole.t At other times the ordinary bastite-alteration is present. All the varieties include sphene-granules. Interesting variations occur in the order of separation of the rhombic pyroxene. In the diabases it seems always to have preceded : This change has been noted in other cases; see O. H. Erdmannsdorffer, Die devonischen Eruptivgesteine & Tuffe bei Harzburg, &c.’ Jahrb. der k, Preuss. Geol. Landesanst. & Bergakad. vol. xxv (1904) pt. i, p. 47. Vol. 61.] BETWEEN ST, DAVID’S. HEAD AND SIRUMBLE HEAD. 601 augite, in which it is often included. In the other groups it is frequently intergrown with augite, and in some cases even encloses the latter mineral. Similar reversals of order with regard to felspar may also be noticed. Sometimes it precedes the latter, and at other times is penetrated ophitically by it. : Monoclinic pyroxene.—In the diabases augite usually occurs in typical ophitic plates; but granular augite, tending to idiomorphic development, is not wanting in certain types—as, for example, Garn Fawr, Trellys, Llanwnda, and other localities. In the enstatite- bearing rocks idiomorphic forms are, on the whole, more common, and are often polysomatic. ‘Twinning on the usual plan, that is, simple binary twins, the twinning-plane being parallel to the ortho- pinacoid, is an exceedingly-common feature of the granular augites ; and the so-called sahlite-striation, parallel to the basal plane, with typical herring-bone twins, occurs usually in the norite-group. Pleochroism is not distinguishable, and the colour is generally a very pale brown. In many of the rocks there appear to be two distinct generations of augite. In a specimen from Garn Fawr the earlier generation has a higher cy extiuction-angle than the later form. The maximum extinction of the most ferriferous variety is about 43°. A characteristic feature in all the rock-types is the freshness of the augite. Uralite-alteration is comparatively rare, and the polarization-tints are usually very uniform. Hornblende.—The distribution of this mineral is well-defined. In the Carn-Llidi ridge it is wanting or very scarce. In the St. David’s-Head ridge it begins to come in towards the east; but in the Carnedd-Lleithr Carn-Trelwyd ridge it is prominent, and if oceurs also at Penberry Hill, after which it was only noticed at Ynys-y-Castell, where, however, it is present in small amount, and may be secondary. In some slides it appears as an outgrowth on augite, and seems generally to be associated with the later stages of consolidation, being more noticeable in the neighbourhood of quartz-areas. It is pale-brown in colour, with normal pleochroism. Biotite.—This mineral has only been noticed in the basic norite-type of the western end of Carn Llidi and St. David’s Head. It presents normal characteristics. Felspars.—The felspars generally are not of a very basic kind, even in the diabases ; but the norites appear to contain labradorite oi composition Ab,An,. In the diabases the usual type is andesine, but in the quartz-bearing rocks there are frequently at least two generations of felspar, the earlier being the more basic. Orthoclase is apparently present in many of the dioritic types, and is also a constituent of the micropegmatite. Albite characterizes the quartz- albite-enstatite-rock of Porth Gain, and the lime-bostonites have a 602 MR. J. V. ELSDEN ON THE IGNHOUS RocKS [ Aug. 1905, rather acid _.oligoclase. The twinning is normal in nearly all the specimens examined, the pericline-type, although occasionally seen, being uncommon, In a variety from Tresseysilt a somewhat un- usual ‘ window-shaped’ twinning occurs, in which four rather square parallelograms have a nearly-parallel simultaneous extinction, and are surrounded by a framework, extinguishing at 10° to its length. In the 45° position all trace of the twin-structure disappears. The accurate determination of the felspars in many of the rocks is rendered difficult by their turbidity. Secondary products.—Among secondary products sphene and leucoxene are everywhere present, but call for no further notice, with the exception of the marked tendency of the enstatite- pseudomorphs to include little aggregations of sphene-granules. Epidote is very abundant in the diabases, but is not so notice- able in the other types. Granular epidote often shows a marked tendency to develop round the margins of chlorite-areas in the gabbro- and diabase-types, and, beginning thus, gradually spreads over the whole area. In quantity, it generally bears a direct proportion to the amount of alteration exhibited by the felspars. In the enstatite-bearing rocks, in which the felspars are of a more acid type, this feature is not noticed, a character which agrees with Prof. Zirkel’s statement that saussuritization is not usually conspicuous in the norites.! An interesting occurrence in several of the latter is that of a colourless uniaxial mineral of tetragonal form, with rather high double refraction, and rectangular cleavages. The refractive index is higher than quartz. I refer this to one of the scapolites. Prof. Judd has explained the conversion of plagioclase-felspar into scapolite,* and it is a significant fact that the rock of Oodegaarden, Norway, in which this conversion is described, is a gabbro containing rhombic pyroxene. Similar occurrences have been noted in the diabase-dykes of Lake Champ- lain,? and in the diabase of the Pyrenees.* In Canada, also, Prof. F. D. Adams and Prof. A. C. Lawson have noted the occur- rence of scapolite in an enstatite-diorite.? In the present case, the scapolite has been noted in a few examples only in the St. David’s- Head rocks; it has all the appearance of being of secondary origin, and not, as considered by Mr. J. KE. Spurr, in the case of some Alaskan rocks, a primary constituent.° Of other secondary products chlorite is an abundant con- stituent of the Strumble-Head diabases, but is less prominent in the quartz-norites of the St. David’s-Head district. In a few instances vermicular chlorite (helminth) is noticeable in these varieties. In the enstatite-diabases there is evidence of a gradual passage of 1 «Lehrbuch der Petrographie’ 2nd ed. vol. ii (1894) p. 776. 2 Min. Mag. vol. viii (1888-89) p. 186. 3 J. F. Kemp & V. F. Marsters, Bull. U.S. Geol. Surv. no. 107 (1893). 4 A. Lacroix, Comptes Rendus Acad. Sci. Paris, vol. ex (1890) p. 1011. > «On some Canadian Rocks containing Scapolite, &c. Canad. Rec. Sci. vol. ili (1888-89) p. 189. ° *Scapolite-Rocks from Alaska’ Am. Journ. Sci. ser. 4, vol. x (1900) p. 310. Vol. 61.] BETWEEN ST. DAVID’S HEAD AND STRUMBLE HEAD. 603 enstatite into chlorite, and examples occur in which the chlorite- patches contain nuclei of enstatite. The chloritic substance in the lime-bostonites has already been mentioned. Less frequently are found brightly-polarizing, radially-aggregated zeolitic species. Sericite and opaque amorphous granular matter are common alteration-products of the felspars in the southern area. I noticed also that the Llanwnda type develops asbestiform shear-planes locally, a phenomenon which I never observed in the rocks between St. Nicholas and St. David’s Head. VII. Murvat Retations oF tHE Macmas. I have endeavoured to show that there is evidence in this area of three distinct types of intrusion, namely: (1) the gabbro- type, including the diabase of Fishguard and Prescelly, which I have designated the Llanwnda type; (2) the norite and enstatite- diorite type of St. David’s Head; and (3) the lime-bostonite type of the Abercastle-Mathry district. We may consider what evidence there is as to the age of these intrusions, and whether they may be regarded as the result of differentiation from an original magma or the product of distinct intrusions from different deep-seated sources. Prof. Brogger’s explanation of the origin of the bostonites and camptonites of Gran,’ which he regards as complementary dykes resulting from the differentiation of an olivine-gabbro-diabase magma, can scarcely be applied to the present case, in the absence of a larger series of chemical analyses. In the case of the lime-bostonite series of Abercastle, however, the evidence seems to point to the conclusion that these are of earlier date and quite distinct from either of the other types. In the first place, they were evidently intruded before the main faulting of the district took place, since these narrow sills are abruptly truncated by the Pwll-Strodyr Fault. Moreover, they are sharply distinguished from any other intrusions in this area, and do not show, so far as I have observed, any gradual passage into, or admixture with, either the quartz-norites on the one hand, or the diabase-group on the other. Mr. Cowper Reed brings forward evidence to show that the Waterford intrusions are later than the first post-Ordovician folding and earlier than the pre- Upper Old-Red-Sandstone denudation.* Messrs. Kilroe & McHenry assign the intrusive tuff-like rocks of the south-eastern corner of Ireland to the Old-Red-Sandstone age.* The evidence for these conclusions seems to be fairly complete. I have no acquaintance with the Waterford district personally, but the lime-bostonites and porphyrites of Abercastle so strongly resemble some of these Irish * ‘Basic Eruptive Rocks of Gran’ Quart. Journ. Geol. Soc. vol. 1 (1894) p. 26. 2 *Tgneous Rocks of the Coast of County Waterford’ Quart. Journ. Geol. Soe. vol. lvi (1900) p. 690. 3 ‘Intrusive, Tuff-like, Igneous Rocks & Breccias in Ireland’ Quart. Journ. Geol. Soc. vol. lvii (1901) p. 488. 604 MR. J. V. BLSDEN ON THE IGNEOUS ROCKS [Aug. 1905, intrusions, that it seems reasonable to refer them to the same period. It is, at least, certain that they are earlier than the period during which the Pwll-Strodyr faulting took place. In the case of the quartz-norite intrusions the evidence is more obseure. I have not been able to find any section in which they are actually seen in contact with the lime-bostonite sills. At Ynys-y- Castell they occur very near together, and here the lime-bostonite is brecciated and tuff-like. It may, therefore, perhaps be inferred that the brecciation is connected with the later intrusion of the Ynys-y- Castell rock, although such an explanation does not necessarily hoid Le R Diagram showing the Relation of the Abercastle Intrusions to those of the South-East of Ireland. in the case of the similar brecciation at Priskilly Fawr. Itis perhaps more probable that the brecciation in each case is connected with the period of faulting, the exposures lying comparatively near to the line of the Pwll-Strodyr displacement. My evidence as to the relation of the Pwll-Strodyr Fault to the quartz-norite intrusions is admittedly imperfect ; but, so far as it goes, it seems to support the view that the quartz-norites were intruded later than the main period of faulting. This view is supported by the apparent absence of any signs of brecciation or shearing in any of the rocks of this type which have come under my notice. With some hesitation, therefore, 1 ascribe the quartz-norites to a later period than the lime-bostonites. Vol. 61.] BETWEEN ST. DAVID’S HEAD AND STRUMBLE HEAD. 605 Coming next to the diabase-series, we have evidence that the Garn-Fawr Y-Garn intrusions are of a composite nature; and it appears to be certain that, between Strumble Head and St. David’s Head, there is an indefinite zone of enstatite-diabases, which seem to graduate south-westward into the quartz-norite rocks, and north-eastward into the Strumble-Head diabases, as if some amount of mixing of two magmas had taken place locally. This seems to be a sufficient explanation of the marked change which the gabbro- diabase magma of the Fishguard area undergoes as it approaches the norite-region, and, as mentioned above (p. 583), is quite in accord- ance with the experimental results obtained by Prof. Vogt. This phenomenon is noticeable around Trevine, in the St. Nicholas area, and at Y Garn and Garn Bolch. Ofcourse, such a result might equally be expected to occur in the case of a deep-seated magmatic differentiation, as explained by Prof. Brogger; but in either case it would imply an approximately-contemporaneous origin for these two types. There is need, however, of more detailed work on the Garn-Fawr Y-Garn complex before its structure can be properly understood. In the absence, therefore, of further evidence, I assume that at. a later period than that at which the lime-bostonites. were intruded, the strata were injected with more or less contemporaneous laccolitic intrusions of a diabase- magma from the Fishguard area, a norite-magma from the St. David’s area, and a mixed magma over an ill- defined intermediate zone. It might be possible to gene- ralize further, and to assume some connection between the enstatite- bearing rocks of this district with those of other localities, such as those of the Breidden Hills,‘ Carrock Fell,? Penmaenmawr,? and the Whin Sill*; but in the present state of our knowledge such a. conclusion would be merely speculative. With respect to evidences of differentiation in situ, [ am convinced that a more detailed examination of this area will afford interesting results, which, however, are beyond the scope of my present. researches. VIII. Summary anp ConcLusions. The observations recorded in the foregoing pages point to the following conclusions :— 1. The contemporaneous lavas of the Llanrian area agree generally in character with the eruptive rocks of apparently-Ordovician age in the Strumble-Head and Prescelly districts. These are all of an essentially-acid type. 1 W. W. Watts, Quart. Journ. Geol. Soe. vol. xli (1885) pp. 539 e¢ segg. 2 A. Harker, Quart. Journ. Geol. Soc. vol. 1 (1894) p. 317. 3 Id., ‘ Bala Voleanie Series of Caernarvonshire’ 1889, pp. 62 e¢ seqq. 4 J.J. H. Teall, Quart. Journ. Geol. Soe. vol. xl (1884) pp. 640 ez segg. 606 MR. J. V. ELSDEN ON THE IGNEOUS ROCKS [ Aug. 1905, 2. The intrusive rocks are of later date, and are of three distinct types, namely: (a) The gabbros and diabases of the Strumble-Head area. (6) The norites and associated rocks of St. David’s Head and the surrounding district. (c) The lime-bostonites and porphyrites of the Abercastle-Mathry district. 3. The lime-bostonite series is apparently older than the gabbros and norites, and seems to belong to the petrographical province of the South-East of Ireland. 4, The gabbros and norites were intruded approximately during the same interval, at a later period. ». The norites and associated rocks have spread north-eastward from St. David’s Head, and have penetrated the area of the Strumble-Head intrusions. 6. The gabbros and diabases have similarly spread to a limited extent south-westward into the norite-area. 7. The gabbro- and norite-provinces are separated by an ill-defined zone, in which some mixture of the magmas took place. 8. The latest phase of igneous activity was the formation of the Pen-Caer basaltic laccolite, with apophyses penetrating the Garn-Fawr Y-Garn intrusions. It is not, of course, necessary to assume that each of the several intrusions was confined to any one single stage of vulcanicity. The laceolites and bosses were probably the result of injections, extending over a prolonged interval, from co-existing magma-basins or from a single differentiated magma. There are clear evidences -of some further differentiation in situ, but the full extent to which this took place offers a large field for future investigation. In conclusion, I have to express my indebtedness to Mr. G. T. Holloway for placing his laboratory at my disposal, and thus greatly facilitating the chemical work connected with the preparation of ‘this paper. EXPLANATION OF PLATES XXXVIII-XL. Prats XXXVIII. ‘Geological sketch-map of the country between Fishguard and St. David’s Head, on the scale of 13 miles to the inch. PuaTeE XXXIX. Fig. 1. Biotite-norite from the western end of Carn Llidi, showing ‘ herring- bone’ twin of augite. The minerals represented are plagioclase, augite, rhombic pyroxene, and ilmenite. x 30 diams. (See p. 589.) 2. The same rock, showing large plates of rhombic pyroxene enclosing plagioclase and intergrown with augite. X 30diams. (See p. 585.) 3. Quartz-norite, Penberry Hill, with conspicuous bronzite. The felspars are cloudy, and the augite is granular. x 30 diams. (See p. 588.) 4. Albite-enstatite rock, Porth-Gain Quarry. The enstatite is much altered, and is interstitial to the felspar. x 30 diams. (See p. 592.) 5. Enstatite-diorite, with micropegmatite, Carnedd Lleithr. x 380 diams. (See p. 587.) . N ANGLAS IW, Usa nile and Porphyrtte ‘tan Lava-F lows nporaneous Tuffs etc. | S LRP $2 resents SP SSDS Quart. Journ. Geol. Soc. Vol. LXI, Pl. XXXVI. STRUMBLE HEAD GEOLOGICAL SKETCH-MAP of the country between FISHGUARD and Si. DAVID'S HEAD. ao Scale:-1 inch=14 miles. PEN ANGLAS x il Bostonile and Porfhyrite | Basallic Laccolite(Pen Caer))| Rhombic Pyroxene-Rocks Llanrian Lava-Flows » FISHGUARD Fe pede pe 3 Gabbro and Diabase LLECH DAFADS Llanwnda& Prescelly Type). *| Contemporancous Tuffs,etc. TRESSEYSILT ate SSS == = ===, = Sse =I A oe 2€9009 00 2354 hes=1 mile,] [For explanation, see fig. 2, below. | ‘oqo ‘op tA d.10 J-opusTq ULOFT JO SuOIsNAyUT = CG ‘oJLL[OT O1jIsapuy o41gdG Jo suoIsnajyuy = Fz ‘oylsopuy-suoyjsaod AFT FO suotsnaquy = e7 ‘Spog so1urysey,7 oy} JO Ssep pur syitg = Zz "‘spogq-v7/aNbuIT = Tz ‘Spoq-DuUny0gnInT = (i “purg~ $2.0299N92919)-S1Y24) = BT ‘Spoq-viNgI9g = SENOS Te0OU Ne al €1 Vi =| ———|- SSNS SSS esl Sa SoS SS Set ------ 9 SSS = ~~ a (J = = —S S — == —— z —— : oer ‘ IMEC ISP i popprkpy th Stet) shkinq3 q IA a0 ‘a's ‘osuq oy ye purg -nuvauohkjouy YM ‘speg Npp-yueyT = OT ‘SOV UOLOFT-Iey, = CT ‘saTRyg Ppouury == FT SSE aed ‘ssupyy queuéyq = Z ‘SoySV ShosivoreO UvTTUeTT = TT ‘sUOISOUUI'T JUOMAGE = OT ‘puvg-ysy Yi speg smesiyyiyZ = @ [O]IW T=Soy out F-:ayeIG] So08nin) useyy saennersevcsemnennnanaa-=~—5- Suess Ayoyepy JO sa}VIeMOTIS 7 “SIUIALY gO ees: woddq ‘wang brew Lo prumuns oy) 02 syunpfl wtajsam oy? sso.on WOyIg—G “SLT | ‘SoTeYG VpYTO “‘SIUOLY puv soysy aeMoryT "soTBYS IMVy1oV(T ‘saYSV Olisopey ploy "SaTISW OAISSB]AL ‘soysy orjpodqy "QUOJSAWIVT To} 1a(T ‘soley -sngdpubounsougy oa) m2 00 Hi Cor 612 MR. W. G. FEARNSIDES ON THE GEOLOGY oF [ Aug. 1905, { Amnodd or Shumardia-Shales. Tai-Herion or Asaphellus-Flags. | Nadel Nant-ddu or Bellerophon-Beds. | a 4 Dictyonema-Band. Niobe- and Psilocephalus-Beds. _ Peltura-Beds. i Black “Bend, Dolgelly. a: | CAMBRIAN iy). Orthis-lenticularis Band. J Parabolina-Beds. Lingulella-Beds. | Grits and Flags. | Ffestiniog. There are also important intrusions of andesites (almost identical with the Lower Ashes of Arenig), hornblende-porphyrites, and ophitic dolerites. The Ffestiniog Beds [22]. The oldest rocks of the district occur in the west and south-west, and belong to the shallow-water phase of the Lingula-Flags. They are a monotonous series of grits and flags with hardly any fossils, and determine a belt of most uninteresting, boggy, heather-covered, rolling moorland of only slight relief. Westward they rise to form the steep escarpment which locally determines the main watershed of Wales. Although usually dipping eastward or north-eastward at about 30°, they are so broken up by folds and faults of small amplitude, that, in the absence of any continuous exposure, it is impossible to form any exact estimate of their thickness ; but, as the outcrop is considerably more than a mile wide, that thickness must be considerable. The beds are best exposed in the valley of the Lliw, where also may be seen a fine large sill of hornblende-porphyrite, quite like the well-known sills which occur at about the same horizon at Dolgelly. The Lingulella-Beds [21]. Towards the top these grits and flags become much finer in texture, and in the highest 30 or 40 feet are crowded with specimens of Lingulella Davisu, M‘Coy, which, in places, become so abundant as to form the greater part of certain bands (4637).' These beds are exceedingly easy to recognize by their mode of weathering, for, from being bluish-grey, they become first quite rusty and brown and then increasingly paler, until finally they are almost white. A similar belt of fossiliferous flags occurs in the same relative position at Penmorfa (Portmadoc) and at Rhobell Fawr; hence it would seem that the division should be traceable all round the Harlech dome. ‘The beds are well exposed in the two westernmost. branches of the Trinant Valley. The Parabolina-Beds [20]. Passing upward, the Lingulella-Beds become finer-grained and less gritty, giving place gradually to the hard flaggy shales of the 1'The numerals in parentheses throughout the text of this paper refer to the numbers of the corresponding rock-specimens preserved in the Sedgwick Museum at Cambridge. Vol. 61.] ARENTG FAWR AND MOEL LLYFNAN'. 613 Parabolina-Beds. These are dark bluish-grey, and give a sonorous ring when struck ; they break with a curious, china-like, conchoidal fracture, and tend to fly before the hammer. They contain a certain amount of iron-pyrites, and coat themselves with ycllow rust in the early stages of weathering, although this afterwards disappears and the whole rock appears much darker. In the lower parts they are quite unfossiliferous, but about the middle certain bedding-planes yield indifferently-preserved examples of Parabolina spinulosa, Wahl., which becomes abundant in the higher beds. The Orthis-lenticularis Band [19]. Some 200 feet from the base of the Parabolina-Beds appears a band of darker and more earthy shale crowded with innumerable shells of Orthis lentecularis, Dalm. ‘This band is only some 4 or 5 feet thick, but is readily recognized at intervals all round the Harlech dome from Ogof-ddu near Criccieth to Dolgelly. It is best seen in the old Nant-y-Derbiniad slate-quarry, immediately north- west of the area mapped, but is also very evident in the western Trinant-stream section, about 100 yards south of the confluence with the eastern tributary. In both these places the Orthis is abundant enough to render the shale quite calcareous. The Peltura-Beds [18]. Above the Orthis-lenticularis Band begins the famous ‘ Black Band,’ distinguishable from all other beds in the district by the fact that when it is scratched with a hammer the streak produced is quite black. The coming-in of the black coloration is of course gradual, and, with practice, one can tell by the streak exactly with what bed one is dealing. Many have thought that the blackness of the beds is due to graphite or organic matter; but a study of the way in which the rock rusts in weathering leads me to think that it 1s rather due to the presence of finely-divided, slightly- decomposing iron-sulphides. When heated alone, the slates become slightly paler, and acids, which will dissolve iron-pyrites but have no action on graphite, completely bleach small pieces of it. The sediment composing the Black Band is finer than that of either the beds below or above it, and accordingly has, in places, taken on sufficient cleavage to tempt some persons to open trial~ holes for slate. The slates obtained are very soft and silky, but they rust and scale at so early a stage in the weathering that, although easy to work, they have not proved to possess any per- manent value, and all the trials are now abandoned. ‘The best- cleaved material contains abundant distorted fragments of Peltura scarabeordes, Wahl., and fine, large examples of Agnostus trisectus, Salt., are not uncommon. The lower layers near the Orthis-Band yield occasionally Spherophthalmus alatus, Boeck, and one or two specimens of Cienopyge pecten, Salt., have also been found there. 614 MR. W. G. FEARNSIDES ON THE GEOLOGY or [ Aug. 1905, Tbe best exposure in the district is the stream-section in the lower part of the Trinant Valley ; but that in the small stream which comes down from Moel Llyfnant to the Beudy-uchaf of Hendre Blacn-lliw is also quite good. The Drift south of Tai Herion, too, affords a good collecting-ground, and the specimens of Peltura which it contains in abundance are the only evidence for the completion of the Zingula-Flag succession to the east of the great North-and-South Fault. The Niobe-Beds [17]. Towards the top the beds of the Black Band lose their silky character, and become cleaved mudstones rather than slates. Pel- tura is no longer abundant, but occasional examples of Wzrobe Homfrayt, Salt., and Psilocephalus innotatus, Salt., take its place. Passing up, the amount of pyrites rapidly diminishes, and through dark-blue the sediments assume a rather light leaden-grey colour. Weathered and joint-surfaces are no longer thickly coated with scaly rust, but are merely filmed over with it, and often appear iridescent. The character of the sediment also alters, and the main mass of the Mobe-Beds is not unlike that of the lower part of the ~ Parabolina-Beds. The jointing, however, is quite different, and is rather like that of the well-known ‘needle-slate’ rocks of Port- madoc, which belong to the same horizon. Judging from casual specimens, obtained from washouts in the heather-covered moorland, the Niobe-Beds must occupy a good deal of ground on the north and west of Moel Llyfnant, but exposures are not encouraging. The best exposure is undoubtedly the stream-section along the eastern branch of the Trinant Valley, which runs along the strike of these beds for more than half a mile. This section well shows the relation between the beds and a series of sill-lke intrusions of granular andesite or dolerite, which characterize this horizon right across the district... Similar beds and intrusions are well seen in the old road-section west of Nant-ddu, in the railway-cutting north of Y Waun, which is east of the great North-and-South Fault, and again for about a mile to the west and north-west of Hendre Blaen-lliw. The Dictyonema-Band [16 pars]. Overlying the Niobe-Beds is the Dictyonema-Band, which (most unfortunately) is even more imperfectly exposed than they are. Dictyonema has been found abundantly in certain small boulders — in the Drift of the Tryweryn Valley and elsewhere, but is only seen in situ at one locality. Fortunately this spot, a few yards west of Nant-ddu, adjoins one of the few sections from which Mobe has been obtained, and it is perfectly clear that there, as ever in the Portmadoc district, the Dictyonema-Band overlies the Niobe-Beds, and has nothing whatever to do with the Black Band below. On this evidence, I would class the Welsh Mol. 61. | ARENIG FAWR AND MOEL LLYFNANT. 615 Dictyonema-Band as the lowest division of the Tre- madoc, and would place the Niobe-Beds as the highest member of the Dolgelly or Upper Lingula-Flags. Wherever found, Dictyonema is always enclosed in dark bluish- grey shale, which on inside joints is invariably filmed over with iridescent iron-oxide; also, it is always associated with spicules of some sponge like Protospongia. As above mentioned, the only good exposure of the Dictyonema-Band is the Old-Road section, a few yards west of Nant-ddu; but sponge-spicules a situ and Dictyonema in a loose block have been found close to the mountain- fence, about half a mile due west of the summit of Moel Llyfnant. The thickness of the band is quite small, and, as at Penmorfa, cannot much exceed 15 or 20 feet. The Nant-ddu or Bellerophon-Beds [16 pars]. Above the Dictyonema-Band is the most monotonous and un- interesting series in the district. This, in the absence of any more characteristic fossil, I have termed the Bellerophon-Beds. It consists of a series of hard, rather dark-grey, gritty shales, usually exhibiting a certain amount of incipient needle-cleavage; and, in the upper part; where the beds become softer, it has often been prospected for slates. At certain horizons the shales become quite calcareous, and flattened concretions of cone-in-cone chalybite up to a foot or two in diameter are almost characteristic (4638). The lower part of the series has yielded no trilobites, but occasionally contains a few oval Lingule, Acrotreta, and frequent, rather dis- torted, undeterminable Bellerophons. The best exposure is in the banks of the stream of Nant-ddu, and the entrance-cutting to the old manganese-mine which was worked in these beds there. Bellerophons are most abundant in the Afon Amnodd-bwll, about a quarter of a mile south of Yr Orsedd. A small trial-hole for slate, opened in higher beds close under the overlying Tai-Herion Flags in Nant Rhos-ddu, yields also examples of a broad form of Asaphellus Homfrayt, Salt., and a few distorted specimens of Olenus (Parabolinella) triarthrus, Call., and O. (P.) Salter, Call., which suggest a correlation with the lower fossiliferous horizon of Belswardine Brook, Sheinton (Shineton). The Tai-Herion or Asaphellus-Flags [15]. Immediately above these fossiliferous slates come the much coarser and more quartzose beds,'to which I have applied the name of Tai-Herion or Asaphellus-Flags. These are a well- marked series of hard, blue, shaly or slaty calcareous flags, and contain numerous worm-tracks and castings filled with white quartz-sand (4639). Certain beds among them also show remark- ably well a rather curious form of ripple-bedding. In these ‘ripple-bedded’ rocks, alternations of coarser and finer sediment take place laterally as well as vertically; and the rock appears 616 MR. W. G. FEARNSIDES ON THE GEOLOGY OF [| Aug. 1905, to be built up of flattened lenses of the coarser, closely set in a matrix of the finer material. Such rock, when compelled to break along the bedding, affords surfaces which are either nodular, or crossed somewhat irregularly by ripples of short wave- length. Curiously enough, such ripples always appear to have a trend which is almost parallel to the strike of the bedding-planes, which here makes a considerable angle with that of the cleavage. Apart from theripple-bedding, the Asaphellus-Flags are much more massive than any of the other divisions of the Tremadoc; and this character has so enabled them. to withstand the agents of denuda- tion, that they stand up as a visible feature right across the district. The same property has also caused them to be considerably quarried for wall-building by the makers of the roads. Fossils are not superabundant, but a good many very large specimens of Asaphellus Homfrayi, Salt., of broad type have been found in the alternations of the coarse and fine layers of the ripple-bedded flags; and it is noticeable that all such specimens are found with the dorsal side upwards, and are filled with coarser and covered by finer material. One or two enrolled specimens have heen found, and these too are filled with coarse, and embedded in fine, material. The best and most accessible exposure is that afforded by the road-side quarry immediately west of the Nant-Rhosddu bridge at Tai Herion. The waterfall just below that bridge is determined by the same beds, and the old quarries west of the Amnodd-wen road, near Hafotty Filltirgerig, are in similar though slightly- higher beds. Other sections are also seen at Yr Orsedd, and a curious piece of folding below Ceunant-y-gareg-ddu allows them to appear as inliers in the gorge there. The sections west of Moel Llyfnant are not so satisfactory, and have not proved to be very fossiliferous. The whole series is not more than 80 or 100 feet thick. It appears to correspond with the gritty shales of Penmorfa Post-Office, although unfortunately no Dikelocephalus has as yet been obtained here. The Amnodd or Shumardia-Shales [14]. Above the Asaphellus-Flags the beds gradually become much softer, and pass into a series of fossiliferous blue-grey mudstones. Except when baked by the intrusive dolerite-sills, which are common at this horizon, these beds are much softer than any of the other beds of the district; and so they usually occur in hollows and boggy places in the moors. Though sheared and considerably distorted, they rarely show any definite cleavage. Close to the dolerite-sills they are often much hardened, but break readily along a series of close-set quadrangular joints. In such places certain beds take on a very characteristic concretionary or shrinkage-jointing, and weather out into a mass of ovoidal lumps and curved splinters rather after the fashion of a massive basalt. When such con- eretions are broken across during the process of weathering, one finds the successive rings beautifully and differentially iron-stained, olor. | ARENIG FAWR AND MOEL LLYFNANT. G17 after the manner of the Moughton Whetstones of Yorkshire. Fossils are, as a rule, fairly abundant, the most characteristic of them being the beautiful little Shumardia. Slabs with ten or a dozen specimens of Asaphellus Homfrayi, Salt. (of narrow type) are nob uncommon, and Agnostus Siedenbladhi, Linn., and Macro- cystella Marie, Call., may also be obtained from most exposures. The fauna obtained is as follows :— Asaphellus Homfrayt, Salt. | Dikelocephalus. humardia salopiensis (Call.), ef. Cheirurus. alandica, Moberg. Conularia Homfrayt, Salt. Ogygia (Niobe) scutatriz, Salt. Theca operculata, Salt. Olenus(Parabolinella) triarthrus,Call. | Bellerophon multistriatus, Salt. Agnostus Siedenbladhi, Linn. Ctenodonta. Symphesurus Croftii, Call. Lingula ef. Nicholsont, Call. Remopleurides. | Acrotreta (Obolella) Sabrine, Call. Holometopus. | Protospongia-spicules. There are also abundant, branching, carbonaceous markings which are often regular enough to suggest graptolites, but are not sufficiently well preserved for identification. The best localities and collecting-grounds are the east-and-west stream-sections south of Amnodd-wen and north of Amnodd-bwll respectively. The latter is particularly good, and has yielded the best specimens of Shumardia and many beautiful slabs of Macro- cystella Marie, Call. The gorge known as Ceunant-y-gareg-ddu presents an excellent exposure of the lowest beds, and has yielded examples of all the fossils recorded, except Remopleurides. Remo- pleurides, indeed, seems to be exceedingly rare, and is only repre- sented by Mr. Williams’s one specimen, which came from Amnodd- wen. The best Asaphellus-slabs were obtained from the bed of the stream, which crosses the road about 250 yards south of Hafotty Filltirgerig. As will be seen from the foregoing list, the Shumardia-Shales may be exactly correlated with the main fossiliferous horizon of Sheinton, and with beds overlying the Post-Office Flags at Pen- morfa. The highest Shumardia-Beds of the latter locality, which are there exceedingly prolific, do not seem to be represented here, and the overlying «Kharga Oasis’ Egypt. Geol. Surv. Report (Cairo, 1900) p. 94. > Dr. Hume asks me to state that he has just found a rich fauna, identical with that characterizing the ‘ashen-grey clays’ of the oases, in the clays above the Pecten-Marls in the neighbourhood of Esna (eastern bank). The fossils, as in the Western Desert, are preserved in limonite. This discovery fully confirms my conclusions as to the age of Bed No. 4 in the Jebel-Awaina succession. —April, 1905. ~T Vol. 61. ] CRETACEOUS SYSTEMS OF THE NILE VALLEY. 67 Discussion, Capt. H. G. Lyons remarked on the interesting character of the area described by the Author, situated as it was at the end of the Nile-Valley faults. The more recent deposits referred to would probably, when worked out in detail, throw valuable light on many points connected with the history of the valley. The evidence of a conformity between the Cretaceous and the Eocene strata was most interesting, and would certainly necessitate some modification of the views hitherto held concerning the area lying to the north. Until further detailed examination had been made, he would prefer to suspend judgment on the point, whether this conformity continued as far as the Farafra Oasis, since in the Baharia Oasis, not 70 miles farther north, the unconformity was most strongly marked. Mr. R. Butten Newton wished to state his position with regard to the shell figured and described by himself in 1898, as Pecten Mayer-Eymari, which had been alluded to by the Author. This Kgyptian shell was obtained from Eastern Desert and Nile- Valley localities, being regarded by Messrs. Barron & Hume as of Lower Eocene age. As its facies seemed to support this horizon, it was so described. In 1900 Dr. Blanckenhorn, in his memoir on the Eocene of Egypt, noted the fact that Pecten Mayer-Eymari was synonymous with P. farafrensis of Zittel (1883), and belonged to Upper Cretaceous rocks. At this date Zittel’s shell was known only as a list-name, never having been figured or described ; and it was not until 1902 that Dr. Wanner published its details, and followed Dr. Blanckenhorn in placing P. Mayer-Hymari in its synonymy. A subsequent study of examples of the so-called P. farafrensis from the Libyan-Desert areas of Farafra and Baharia had convinced the speaker that, allowing fora somewhat variable shell, the two forms may be included under the same specific name, which, on account of priority, must now be known as P. Mayer-Eymarv, the old name suggested by Zittel not being retainable. A further paleontological investigation of the fauna associated with this shell confirmed in every way Dr. Blanckenhorn’s statement that it belongs to Upper Cretaceous rocks and ranges from the Campanian to the Danian : the Campanian forms being restricted to the Kastern Desert and Nile-Valley- localities, while the Danian are confined to the Libyan Desert. Moreover, the Author had eliminated the theory of an unconformity existing between these Pecten Mayer-Eymarv Beds and the rocks beneath, and so fully supported the view as to the Cretaceous age of these deposits. The Presipent said that he was glad to find that the Director of the Geological Survey of Egypt agreed with the main conclusions of the Author. With reference to an unconformity occurring at no great distance from an area where the beds were conformable, he thought that at least three such cases could be cited in the limited area of Great Britain. The AvurHor, in reply, observed that the President’s allusion to similar cases of rapid change from conformity to unconformity 18 EOCENE AND CRETACEOUS OF THE NILE VALLEY. [| Nov. 1905, had already met the point raised by Capt. Lyons. Unfortunately, for want of exposures in the intervening areas, it was almost impossible to follow the change from point to point. Mr. Bullen Newton had fully explained the reasons which led to the error in the determination of the Pectens in question. The field-notes accompanying the specimens seemed conclusive evidence that the latter were of Eocene, and not of Cretaceous, age. Moreover, as he - (the Author) had already mentioned, in some localities (notably near Ain Amur) the passage from Cretaceous to Eocene was so gradual that near the junction, fossils, typically characteristic of Cretaceous beds in other places, occurred side by side with forms having distinet Kocene affinities. Vol. 61.] THE GLACIAL CONGLOMERATE IN THF ‘TRANSVAAL. 679 32. A Conrrisurion to the Stupy of the Gractan (Dwyka) Con- GLOMERATE in the Transvaat. By Epwarp T. Metror, B.Sc., F.G.S. (Read June 21st, 1905.) Wire the exception of the gold-bearing conglomerates of the Witwatersrand, the Glacial or Dwyka Conglomerate at the base of the Karroo System has probably attracted more attention from geologists than any other rock occurring in South Africa. While, however, the rocks of the Rand derive their importance mainly from their economic value, the interest manifested in the Glacial Conglomerate over a period of fifty years * has depended entirely upon purely-geological considerations, The diversity of views which so long prevailed, as to the origin of the Dwyka Conglomerate, was no doubt largeiy due to the fact that these views were in many cases necessarily based upon the examination of hand- specimens. ‘The study of the rock in the field, however, can hardly be said to have resulted in any marked unanimity of opinion among local geologists, the majority of whom favoured an igneous origin for the rock in question; and, although the glacial view was stated by P. C. Sutherland’ as far back as 1868, and later supported by G. W. Stow,’ Mr.. E. J. Dunn,’ and Dr. A. Schenck,’ it is only quite recently that the accumulation of evidence in favour of the glacial origin of the rock can be said to have led to a general acceptance of this view. _ To South African geologists the Glacial Conglomerate affords the only common geological horizon as yet available for the various colonies, while its similarity to corresponding formations in India, Australia, and South America gives a wider interest to the investi- gation of the conditions under which the vast glacial deposits of South Africa were laid down. Recent Studies of the Glacial Conglomerate. A description of the Dwyka Conglomerate, as developed in the Vryheid district, now forming the northern portion of Natal, was given by Dr. G. A. F. Molengraaff in 1898,’ In the following year, 1 Communicated by permission of the Director of the Geological Survey of the Transvaal. 2 For references to the literature of the subject, see G. S. Corstorphine, Ann. Rep. Geol. Comm. Cape of Good Hope for 1899 (1900) pp. 4-17. 3 «On the Geology of Natal’ Pietermaritzburg, 1868. 4 On some Points in South-African Geology’ Quart. Journ. Geol. Soe. vol. xxvii (1871) pp. 497-548. § Geological Sketch-Map of South Africa” London, 1875. 6 «Die Geologische Entwickelung Siidafrikas’ Peterm. Mitth, vol. xxxiv (1888) p. 225, ‘ 7 «he Glacial Origin of the Dwyka Conglomerate’ Trans. Geol, Soc. S. A. vol, iv (1898) p. 103. DLiIs PRIN a 34 quently give good op- S ef ot portunities for study ; = za oi while the intervening Pe i q — areas of older rocks = \ /- < afford information as < | . = to the source of much "= /. 3s & of the material in- eS . = .» corporated |i jeme = : 2 . 5 GlacialConglomerate, l nM = ‘/ @&# . and having been de- is a ware. dQ & ances cone aa eo5 ne A /) > as le necemt of their a é.| e g a & conte of Karroo SoS Sy es OS < rocks, they preserve ST yz 4% €& approximately the FS as s, character and outline Sy 8 f of the land-surface TS j. si ¢ upon which the S.s “oe < glacial deposits were "Ss f ‘ AEN ot laid down. Round Sis ° ee & the margins of the 33 eStats ., Karroo outliers this eS i 2 r old land - surface, = i _; dating back as far as a _& Carboniferous time, 2s =] £ & still preserves aston- Ges 3“ ishingly-clear traces iS ion 2 | 8 & of ice-action, Se Si ail 5 From the southern ! : 3 =, and eastern margins = | sf = = of the main area S i g =~ occupied by Karroo = Bee. a Bi) capes woe in South Africa s 3 : i si wees: Re eee s 3! i & and western edges in S ) re *, the ‘Transvaal, the W i ee 2 Karroo System shows | a! ne a considerable dimi- N Qo nution in thickness ; 80 | and, while in Cape S.13°E. Pevols 61". | CONGLOMERATE IN THE TRANSVAAL. 683 averages not more than 400 or 500 feet, and it is not possible at present to recognize in these portions of the Transvaal the many divisions which the Karroo System presents in its fuller development in Cape Colony and Natal. So far as our present knowledge goes, the Karroo rocks in _ the Central and Northern Transvaal may be divided into an Upper Division, consisting of sedimentary rocks including conglomerates, grits, sandstones, and shales, associated with coal-seams, referred to by Dr. Molengraaff as the ‘High-Veld Series’; and a Lower Division, consisting of glacial deposits including the Glacial Con- glomerate (Dwyka) and the associated shales and sandstones. The general succession of the beds and their relationship to the underlying formations in most localities is usually similar to that shown in the section (fig. 2, p. 682). In the district here referred to, the Glacial Conglomerate varies considerably in thickness, averaging about 20 feet. In places, where it} has been deposited in depressions in the old land-surfaces, it may attain a thickness of 200 feet or more ; while, on the other hand, it may be locally absent altogether, the Upper Karroo rocks then resting directly upon the older formations. The following description of the Conglomerate is based upon that previously given by mein the Annual Report of the Geological Survey of the Transvaal for 1903. When exposed at the surface, the Glacial Conglomerate is light- yellow in colour, while specimens from shafts and boreholes are frequently greenish or grey. Owing to the rapid disintegration of the rock at the surface into abundant sandy material, outcrops are rarely met with. When they occur, they have very generally the hummocky appearance shown in fig. 3 (p. 684), which represents a very characteristic example. The matrix of the conglomerate is a sandy-looking material, consisting for the most part of sharply-angular fragments and grains of quartz, and of various rocks similar to those of which the boulders in the conglomerate are composed, including quartzites, hard shales, felsites, and granophyres occurring in the district. The fragments range in size from minute grains to pieces several inches in diameter. The proportion of quartzose material is usually ereat, and the rock weathers to sandy débris; but in some cases felspathic material is abundant, and the weathering of the matrix produces a whitish sandy clay. Scattered through the matrix occur abundant boulders and subangular rock-fragments. These show no definite arrangement or orientation, large and small fragments |ying confusedly together. The boulders and fragments measure generally from 1 to 3 feet in diameter, but may attain as much as 8 or 10 feet; they are usually facetted, and especially when composed of material not excessively hard and somewhat fine in grain, such as hard shales and weathered felsitic rocks, frequently show striations. The smalier pebbles are often traversed by a network of cracks, dividing them into a number of pieces which have been re-cemented into a whole. Q.J.G.S. No, 244. 3G ( qonasupuy, ) sont syunfyg puo spun ay, fo wonounl ay? LDIU ¢ 1MDbY S07, 20 220 e iawojpbuog 7n007.59 —" 6 old Vol.61.] THE GLACIAL CONGLOMERATE IN THE TRANSVAAL. 685 A group of boulders recently observed in the south-western corner of the farm known as Bosseman’s Kraal, near the Wilge River, and south of the Eastern Railway-line, included the following members :—One boulder of white Megaliesberg Quartzite, 8 feet in diameter; one of Waterberg Conglomerate, 5 feet; three of Waterberg Sandstone, each measuring about 2 feet; two of coarse red granite, measuring respectively 8 and 21 feet ; and one of red-banded felsite, identical with the felsites of Rhenoster Kop, measuring 18 inches. The greater number of boulders in the Conglomerate consist of rocks of local origin, which either immediately underlie any par- ticular portion of the Conglomerate or occur to the northward of it. In the area shown in the map (fig. 1, p. 680), the great majority of the boulders consist of hard red quartzites and conglomerates from the Waterberg Formation and of the Red Granite, both of which occupy large areas to the north of the Kastern Railway-line. South of the ridge which is formed by the eastward extension of the Megaliesberg Quartzite, this rock has furnished many boulders to the Glacial Conglomerate; while, farther south again, on the Kastern Rand, many boulders are found, derived from the hard quartzites and ‘ bankets’ of the Witwatersrand Series, together with abundant boulders of chert from the Dolomite to the north. True bedding-planes are rarely seen in the Glacial Conglomerate, and then appear to be quite local. Certain zones are, however, richer in boulders than others, and the rock is frequently traversed by ‘partings ’ which divide it into rude sheets, usually lenticular, with irregularly-undulating surfaces. With the upper portions of the Conglomerate are sometimes locally associated beds of massive sandstone, and lenticular patches of white and cream-coloured shales and mudstones, which appear to have been deposited in ‘ pockets’ in the Con- glomerate and to consist of the finest glacial mud. In a section exposed on the banks of the Bronkhorst Spruit, immediately south of the railway-line, a thickness of 6 feet of these fine white shales and mudstones occurs, consisting of a succession of extremely-regular lamine varying from a tenth of an inch to an inch and a half in thickness. The lamine are readily separated one from the other. Their surfaces are either perfectly smooth, and similar in appearance and colour to that of a lithographic stone, or are covered with very delicate ripple-markings, of which as many as forty may occur in the space of aninch. Other markings occur which appear to be due to trains of eddies, such as might be produced in a film of water moving over fine glacial mud, by bigger particles lying on the smooth and gently-sloping surface. I have not hitherto found anything in the nature of fossils among these finely-laminated mudstones, although they would be admirably adapted for the preservation of vegetable-remains, such as frequently occur in the shales and sandstones which succeed the glacial beds. 3c 2 ‘(povasupa Tz ) pouowmng fo ysam-yr1ou-yitou sap g “Mmaguofdyy yn aonfuns paynon9—'F “SUT Vol. 61. | THE GLACIAL CONGLOMERATE IN THE TRANSVAAL, 687 Evidence is plentiful that the Glacial Conglomerate was originally formed on a land-surface possessing considerable variety of feature. The denudation of the Conglomerate frequently exposes ancient escarpments of Waterberg Sandstone, the uppermost beds of which are often glaciated, while the Conglomerate on their southern slopes is as a rule especially rich in very big boulders. In other cases the Conglomerate fills old valleys, which are now in process of re-excayation, such as the valleys of the Wilge River and Bronkhorst Spruit. The Waterberg-Sandstone Formation, which consists of a suc- cession of conglomerates and sandy strata of extremely-various degrees of hardness—from soft sandstones to very resistant quartzites—almost invariably gives rise to landscapes of con- siderable diversity, including some of the most rugged and picturesque scenery in the Transvaal. In the district shown in the map (fig. 1, p. 680) between the Elands and the Wilge Rivers, however, where the removal of the overlying Karroo glacial deposits is still in progress, the Waterberg ridges continue to retain outlines characteristic of glaciated areas. | In the district here dealt with, the Glacial Conglomerate occurs at all levels within a range of about 350 feet, its lower limit varying with the contours of the underlying surface of older rocks. Its upper limit, marked by its junction with the horizontal beds of the Upper Karroo or High-Veld Series, occurs very regularly at an altitude of about 4900 feet above sea-level. Glaciated Rock-Surfaces. The surfaces of the older rocks underlying the Glacial Conglo- merate frequently present very clear evidence of glacial action.’ The outcrops of the hard quartzites of the Waterberg Formation or the Pretoria Series, which formed part of the land-surface upon which the Glacial Conglomerate was laid down, are frequently rounded-off, polished, and sometimes very clearly striated. The constant alternations of heat and cold to which all rocks are sub- jected in the South African climate leads to the rapid destruction of brittle rocks, such as quartzites. Consequently the glaciated surfaces are broken up on exposure, and are only found on the immediate margin of the patches of Glacial Conglomerate, where the underlying rocks have been exposed comparatively recently. A typical example of these glaciated surfaces is shown in fig. 4 (p. 686). Such glaciated surfaces have been found distributed over an area of some 300 square miles, as shown in the accompanying map (fig. 1, p. 680). It will be seen from the compass-readings tabulated on the following page, that the strie exhibit a remarkable constancy of direction. 1. T. Mellor, ‘On some Glaciated Land-Surfaces occurring in the District between Pretoria & Balmoral’ Trans. Geol. Soc. 8. A. vol. vii (1904) p. 18. 688 MR. E. T. MELLOR ON THE GLACIAL (DWYKA) [Nov. 1905, DrrectTion OF GLACIAL STRIA IN PORTIONS OF THE PRETORIA AND Mippevsure Districts (TRANSVAAL). | , Direction LIES Login: (true bearing). 1. | Rooikopjes, 209. 25 miles W. of Balmoral Station.| 8S. 18° EH. 2. | Henzamheid, 121. 2m. N.W. i fs S. 28° H. 3. | Spitzkop, 407. 3m. N.W. as af S. 33° E. 4. | Klipfontein, 346. 63 m. N.N.W. af a 8. 28° E. 5. | Schoongezicht, 316. 18 m. N.W. ” mi 8. 28° H. 6. | Hlandsfontein, 245. 22m. N- ‘ - S. 33° B. 7. | Vlakfontein, 570. 15 am, INANENVS 3 3 8. 43° E. 8. | Witpoort, 408. 9m. S.W. . a 8. 48° H. 9. | Bosseman’s Kraal, 531.| 103 m. S.W. zy ‘ee 8. 43° EH. 10. | Zorgvliet, 254. 16 m. S.W. + 2 S. 28° E. | In nearly all cases, the glaciated surfaces afford clear evidence that the direction of the ice-movement was from the north southwards; and their evidence is further confirmed by the composition and distribution of the boulders in the Glacial Conglomerate, a very striking feature being the predominance in any locality of boulders formed of rocks occurring most abundantly (or probably, in some cases, exclusively) to the northward of their present position. The constancy of direction shown by the glacial striations over wide areas, and the extensive development of the glacial deposits, point to the conclusion that in early Karroo times an ice-sheet of considerable magnitude existed as far north, at least, as the present position of the Northern Transvaal. In the Prieska district of Cape Colony, Messrs. A. W. Rogers & EK. H. L. Schwarz found the general trend of ice-movement to have been from north-north-east to south-south-west." The same direction is given by Dr. A. Schenck from a locality near the junction of the Orange and Vaal Rivers’; in the Vryheid district Dr. G. A. F. Molengraaff gives the direction of movement as from north-west to south-east*®; and in the examples cited above the general direction is from north-north-west to south-south-east. The direction of movement of the early Karroo ice-sheet in South Africa appears, therefore, to have been generally in a southerly direction, and its origin must be looked for to the north. The Northward Extension of the Glacial Conglomerate. During the field-work of 1904, outliers of the Karroo System, including the Glacial Conglomerate, were found considerably farther 1 «The Orange-River Ground-Moraine’ Trans. 8. A. Phil. Soc. vol. xi (1900) Teo ILA * ‘Ueber Glacialerscheinungen in Suid-Afrika’ Verhandl. des VIIIten Deutsch. Geographentages in Berlin, 1889, p. 153. ‘Geology of the Transvaal’ Johannesburg, 1904, p. 69, note. Vol. 61.] CONGLOMERATE IN THE TRANSVAAL. 689 north than any previously met with.’ These occur in the neigh- bourhood of the junction of the Elands and Olifants Rivers, about 90 miles north of the latitude of Johannesburg. In this locality, the Glacial Conglomerate rests directly upon the Red Granite, and varies in thickness from 30 feet downwards. It is usually succeeded by about 3 feet of pale-grey shaly mudstones, followed by a variable thickness of well-bedded horizontal sand- stones and coarse grits, which, however, probably nowhere exceed 50 feet. These sandstones and grits are exactly similar to those associated with the coal-seams of the High-Veld Series in the district farther south. The Karroo Beds appear to have been here deposited along an old valley in the Red Granite, corresponding nearly with the present course of the Elands River. ‘The Genesis & Matrix of the Diamond’ 1897, pp. 14-16.- Vol. 61. | MICROSCOPIC STRUCTURE OF SERPENTINE. 693 in the olivine nor found a minute fibrous hornblende in his own specimens so often as that excellent observer appears to have done. They contain, however, the two fibrous microliths which the latter refers to bastite,' though the dull-blue one is rare, and we doubt whether it is more than a local staining. ‘The olivine alters into a minutely-fibrous serpentine, generally rudely perpendicular to, but sometimes parallel with, the outer surface, which forms a sort of thin shell, the interior being converted (some olivine often remains) into colourless fibres or even narrow blades sometimes about one twenty-fifth of an inch long(1 mm.). Their polarization- tints are generally the dull bluish-whites of the first order, but rise occasionally to the clear- or the orange-yellow (both tints may occur in the same slice), the extinction being generally straight, but occasionally oblique up to about 20°. In some grains these flakes form divergent tufts, which may develop longitudinally until the group roughly resembles a feather, the pinnules on opposite sides making angles of 22° to 24° (Pl. XLV, fig. 1). In one or two cases we find broad irregular flakes giving low polarization-tints, and notice that, in elongated grains, the flakes of the interior tend to lie parallel with the longer sides. We may, we think, conclude that the olivines in this rock are generally poor in iron, and may perhaps attribute the differences in structural change between them and the olivines in peridotites to their occurrence as isolated grains in a rather permeable material. III. Ampurzors.” The less ferriferous members of this group, as is well known, change, though not so readily as olivine, into serpentine. In fact, as might be expected, the ferromagnesian silicates with lime alter less rapidly than those without it. As this particular meta- morphism has been rather fully discussed, we may pass briefly over it. The best-known instance is the serpentine of the Rauenthal, which in 1875 was asserted to have originated in great masses from an amphibolite, and this to exhibit a passage into a normal gneiss, One of us, in 1887, when publicity was given to that statement in an important English work, showed the former part of it to be only so far correct that the original rock (like some at the Lizard) had been a hornblende-peridotite.’ This was confirmed, and the second part of it disproved, by the other of us in 1897." The hornblende in the Rauenthal serpentine has been a slightly- ferriferous variety. Between its prismatic cleavages strings or blades of mineral serpentine (best examined in longitudinal sections) 1 «The Genesis & Matrix of the Diamond’ 1897, pp. 14, 21. 2 We have not been able to study the alteration ‘of the rhombic amphibole, anthophyllite. One of us has been allowed to examine the specimens in the British Museum cabinet of slices, but these are practically unaltered, and a slice in his own collection (given to him by the late Mr. Rutley) is not helpful for this purpose. 3 Tl’. G. Bonney, Geol. Mag. 1887, p + ©. A. Raisin, Quart. Journ. Geos Boe vol. liii (1897) p. 246. 694 PROF. T, G. BONNEY AND MISS C. RAISIN ON THE [ Nov. 1905, have apparently forced their way. Their structure is obscure, but they scem to be formed of fibres lying in the general direction of the cleavages. Their polarization-tints range from the white to the paler yellow of the first order, being perhaps a little lower than those of the strings in the altered olivine. We also find, at longer intervals, and with less regular direction, strings which probably mark the position of a very imperfect basal cleavage. The parts of the altered crystal between this network often show a minute fibrous structure, sometimes accentuated by interrupted lines of opacite. This yields low polarization-tints, but the most structure- less parts produce hardly any effect on polarized light. Certain of the Lizard serpentines—those from Lower Pradanack, from south of Mullion, from the pit above Carnbarrow, from the mass below Kildown-Point Quarry, and from the northernmost outcrops on the Helston road—have all a general resemblance to the Rauenthal rock, though the olivine is occasionally, and the hornblende generally, better preserved. In the last-named Cornish example, however, one or two specimens of the latter mineral correspond exactly with those in the Vosges rock. IV. OrrnorHomBic PYRoxENEs. These ferromagnesian silicates form a series resembling that of the olivines. ‘Tschermak distinguishes those in which the iron lies between 1 and rather more than 20 per cent., the magnesia generally ranging from 40 to 30 per cent., into enstatites and bronzites; and the remainder, in which the iron is above 30 per cent. and the magnesia correspondingly depressed, into hypersthenes and amblystegites. The first symptom of change, and it appears to be more readily developed in the former two, is the replacement of the usual cleavages parallel to the prism-faces by one parallel to a pinacoid. Varieties in which the percentage of silica is rather high and that of ferrous oxide is generally low have been called diaclasite, but in the absence of proof of chemical composition we shall apply the name bastite’ to all forms occurring in serpentines. Signs of this change in the cleavage may be perceived when the olivine in a slice looks quite fresh, but conversion into serpentine takes effect more rapidly in the latter mineral.” Enstatite also alters into talc, but apparently with less ease, the reason for which will be noticed below. The polarization-tints of enstatite (which usually are not so high as those of augite) are lowered by change through bastite to serpentine, and the cleavage-planes become, as it were, soldered together ; but traces of them can be seen under the microscope, which, with the different kind of serpentinization, generally enable The optic axial plane, it will be remembered, is parallel in enstatite to the plane of easy cleavage, in bastite perpendicular to it. : * To this rule I have found two or three exceptions—for example, a serpentine from Carn Sparnack (Lizard), in which the bastite is replaced by a kind of steatite, and yet there is a fair amount of residual olivine. [T.G. B.] Vol. 61. ] MICROSCOPIC STRUCTURE OF SERPENTINE. 695 us to identify the mineral. Where it originally contained a fairly- high percentage of iron, opacite (sometimes as belonites) is de- posited more or less interruptedly along these planes, and thus indicates their position, where but for this record that would have been indistinguishable; but, when the percentage is low, we find only a few chance black specks or none at all. Even then, however, the mineral, instead of being practically colourless, sometimes has a pale-green tint (indicating no doubt a small amount of iron). It may then show a slight pleochroism, pale green with vibrations parallel with the cleavage-planes, and pale buff perpendicular to them. The polarization-tints of serpentinized enstatite are gencrally the dull bluish-whites of the first order, rising occasionally to the pale yellow; grains cut nearly parallel to the cleavage-planes present a slight, but peculiar, wavy aspect, and with crossed nicols show glimmering patches of dull bluish-white on a dark ground— the result, no doubt, of some curvature in the structure. Occasionally, as observed by Carvill Lewis in the diamantiferous rock of South Africa,’ the enstatite (which contains 34-91 per cent. of magnesia and 4°99 of ferrous oxide, thus lying, according to Tschermak, on the border-line between enstatite and bronzite) alters into a fibrous bastite, one variety of which is a dark indigo-blue. In my slices of the diamantiferous rock the occurrence of this variety is doubtful, but it appears in a saxonite* (boulder) where the enstatite has a well-defined pinacoidal cleavage, but hardly any other signs of change.® At the same place a fragment of a coarse enstatite- rock was also found.’ In conclusion, we may mention one or two rather exceptional forms of change. In the altered bastite the fibrous structure may become more pronounced, or the mineral assume a slightly- pleochroic pale-brown instead of a green tint; or two species of it, a ferriferous and a non-ferriferous, may be present; or, very rarely, portions in a less advanced state may remain as small, slightly- interrupted prismatic rods (defined, of course, by the pinacoidal cleavage); or (as occurs in a dyke consisting practically of enstatite from south of Penrhyn Fadog, Anglesey’) the grains, slightly pleochroic, show polarization-tints ranging from the bluish-white to the pale yellow of the first order, are apt to be bent, and break up at the ends into a rather fibrous mass, of serpentinous aspect, which acts more feebly on polarized light, sometimes remaining dark between crossed nicols. A poikilitic enclosure of olivine, so far as our experience goes, is rare, unless the crystals exceed the ordinary size (that is, about a third of an inch in diameter). At the Lizard it is practically absent, one or two slices only showing traces of it on a sinall scale, 1 «The Genesis & Matrix of the Diamond’ 187, pp. 19-21. 2 Saxonite of Wadsworth, or harzburgite of Rosenbusch; that is, olivine- enstatite rock. 3 IT am doubtful whether the colour indicates more than a local staining due to the accidental presence of some mineral. [T. G. B.] 4 See Proc. Roy. Soc. vol. Ixv (1899) p. 231. 5 Coll. C. A. R., No. 661. 696 PROF, T. G. BONNEY AND MISS C. RAISIN ON THE [| Nov. 1905, as it is in altered saxonites and lherzolites from Ayrshire and Portsoy, from the Alps and the Apennines.’ It occurs.in Anglesey (exceptionally), in Aberdeenshire, and in the well-known rock of Baste in the Harz. In these cases, the enstatite seems to be rather readily changed into a whitish steatite, with a muddy brownish aspect under the microscope. The included olivine is usually a non-ferriferous variety.” V. Monoctinic PYRoxenss. These, when they are associated with the orthorhombic species, are much less readily converted into serpentine, and, as in it, the change is practically restricted to the varieties poor in iron (diopside and sahlite), apparently not occurring in the aluminous varieties (for example, ordinary augite). Specimens in our collections from Coverack in Cornwall, from one or two localities in the Alps, the Apennines, and the Vosges, retain the augite practically unaltered but the change is very well illustrated in the noted ‘ Kozoonal’ rocks of Canada, which are mainly composed of calcite or dolomite, and malacolite or sahlite passing into serpentine.* A description of one specimen (from a wood by a road approaching Cote St. Pierre) will serve to illustrate the general character of the change. Here nodules of a whitish augite, more or less converted into serpentine (light green), are scattered in a marble containing irregularly- distributed grains of augite or serpentine, which sometimes occur in fairly-marked bands. ‘The augite in aslice is present in more or less rounded grains, which form a continuous band at one end. It exhibits sometimes the characteristic, nearly-rectangular cleavage of an augite, but more often a single cleavage, not so close as in a diallage. At the edge of the band and in many detached grains it passes rapidly into serpentine. This occasionally forms along cracks (not always cleavage-planes) and its fibres are sometimes twisted as in a cord, but more frequently are growing at right angles to a surface or to an internal crack. These afford polarization-tints up to the yellow of the first order, but the inner part of the grains is occupied by a filmy mineral with very low tints, sometimes all but black between crossed nicols, which now and then is pierced by a ! These remarks, it must be understood, apply only to what I have myself seen and collected. [T. G. B.| ; * The fusion-point in olivine is higher than in enstatite, but the different amounts of iron and the presence of water may lead to variations. 3 Remarks founded on ten microscopic slices (coll. T. G. B.); see Geol. Mag. 1895, p. 292. As Mr. Coomaraswimy found forsterite with sahlite in the Tiree Marble (Quart. Journ. Geol. Soc. voi. lix, 1903, p. 91), and the two minerals (apart from cleavage) have a close resemblance, I wish to say that the possible occurrence of an olivine in these Canadian rocks has been present to my mind for several years (Geol. Mag. 1895, p. 297) and has not been forgotten on the present occasion. It is impossible to prove that forsterite may not have occurred or be represented by some residual granules; but I can say that, whenever these afford an edge from which extinction may be measured, this is oblique, and that bands of pyroxene with characteristic cleavage do pass rapidly into serpentine. ['T. G. B| Vol. 61. ] MICROSCOPIC STRUCTURE OF SERPENTINE. 697 brighter ‘thorn.’ The scattered grains exhibit various stages of serpentinization, which most affects the thinner streaks. The fibres or flakes occasionally tend to be rudely parallel, but rarely, if ever, recall by their arrangement the almost rectangular cleavages so characteristic of augite when cut parallel with a basai plane. As we purpose to refer to the chemical significance of these changes, we quote analyses by the late Dr. T. S. Hunt: (1) of the pyroxene, and (II) of the serpentine from Grenville, where similar rocks occur with the so-called Hozoon.' Th a0 SOs ere el 54-90 49-85 ISO Pee eed 16-76 41°68 CHO WES eek a: 27-67 BeOyebestiet cesta. - 0:67 TEL Ow ene dealt 0802 13:89 10013 99:09 Augite, as Miss Raisin found during her visits to the Vosges,* is not an unfrequent constituent of their serpentines. Certain of these, southward of the Rauenthal in the Central Vosges, are more than usually variable in composition. For instance, in one rather large mass to the north-east of Bonhomme, cropping out in craglets over a space of about 100 yards, the mineral structure varies from obscurely parallel to distinctly banded. In the latter case the bands, some- times made conspicuous by a peculiar weathering and jointing, are often 1 or 2 inches thick. They are dislocated by a few slight faults, but the rock affords no other sign of mechanical disturbance. Microscopic examination shows the chief constituents to be picotite (fairly abundant), olivine (almost wholly converted into serpentine),' enstatite (partly changed), and augite. The last mineral has some- times assumed the diallage-cleavage, and is often rather ‘ dusty’ ; cracks and cleavage-partings are occupied by very thin strings of serpentine, which often seems as if it had been formed by percolation from outside rather than by alteration of the adjacent mineral. Sometimes, however, the outer part of an augite-grain in contact with serpentine becomes rather fibrous, Curiously enough, the ‘interleaving ’ with films of the latter mineral is least conspicuous in those grains which exhibit the two nearly-rectangular’ cleavages. A slice (thin) from one of the bands (Pl. XLV, fig. 2) shows 1 Quart, Journ. Geol. Soc. vol. xxi (1865) p. 68. It is rather remarkable that, as so much lime (to say nothing of the silica) has been removed, the change from augite to serpentine has left no trace in the adjacent calcite (or dolomite) of my St. Pierre specimens. ['T. G. B.] * In this case called ‘ volatile matter.’ 3 Undertaken for the immediate purpose of studying the noted Rauenthal serpentine. See this Journal, vol. lili (1897) p. 246. * The structure is as described above, but the polarization-tints are rather bright ; the two slices, however, are a little thick. 5 In other words, those which are cut nearly parallel to the basal plane, and have not assumed the diallage-habit. 698 PROF, T. G. BONNEY AND MISS C. RAISIN ON THE | Nov. 1905, a granular structure, and consists of a pale augite (the more abundant), fairly clear, though setting up a diallage-cleavage, and a very clean serpentine which often produces little effect on polarized light, but sometimes gives low tints, revealing traces of a platy cleavage and generally extinguishing obliquely with it. This fact, the residual granules of augite in the serpentine, and the way in which the latter occasionally seems to soak like water into a erain of the former, justify us in regarding the one as an alteration- product of the other. Miss Raisin obtained a rather remarkable pyroxenic serpentine from the Felleringenkopf in the Southern Vosges. In the hand-specimen it appears to be a dark serpentine,’ mottled with a paler green (perhaps merely the thin edges of fractures), and spotted with fairly- numerous pale brass-yellow to whitish grains with an undulating platy cleavage. The microscope shows the following minerals :— (a) grains of an iron-oxide (not abundant) ; (b) grains with a rather wavy parallel cleavage, indicated by granules or short belonites of opacite; polarization-tints whitish to a distinct dull blue; extinction probably straight, but difficult to measure because of curvatures ; (c) a dusty-brown fibrous mineral, alternating in flakes with, and apparently passing into, the last one, and giving, when this can be seen, marked pleochroism and rather bright polarization-tints, with straight extinction ; (d) a colourless mineral associated with small grains of a granular, or fibrous granular, light honey-brown mineral, which is probably an augite, and seems to pass into an almost amorphous aggregate acting very feebly on polarized light. No structure characteristic of olivine occurs in the slice and, notwith- standing the megascopic aspect of the rock, two varieties of enstatite with some augite seem to be more probably its original constituents. Bent cleavages and other irregularities in this specimen suggest slight mechanical disturbance. A slice of another rock from the same locality contains augite in small grains or prisms parted by very narrow films of appa- rently-amorphous serpentine. These are obviously residues of larger grains, which occasionally suggest slight mechanical dis- turbance. We also find minute flecks scattered about the slice, with little granular fibrous and rather dirty-looking spots. These, when highly magnified, prove to be augite, and occur like islands in the serpentine which (with some opacite and grains of iron- oxide) occupies most of the slice, and produces no sensible effect on polarized light. Thus augite, which now is the only anhydrous silicate recognizable in the rock, seems to have been formerly very abundant. In a third specimen from this locality the greater part of the slice suggests, by the disposition of the opacite, the former presence of an olivine; the structure of the serpentine is minute and its action on polarized light rather feeble, but it seems locally to become irregularly fibrous. Here and there spots occur free from opacite, but containing numerous small fibrous flakes of a 1 Not unlike the biack serpentine of the Lizard, the Apennines, Corsica, ete, Vol. 6x. | MICROSCOPIC STRUCTURE OF SERPENTINE. 699 mineral with a higher refractive index than serpentine, and with whitish polarization-tints, which, as will be seen in the next section, has some resemblance to antigorite. A few of the flakes are slightly iron-stained, and they give brighter polarization-tints. These clear spots presumably indicate the former presence of some kind of pyroxene, but retain no trace of its original structure. VI. ANTIGORITE-SERPENTINE. Having thus described the forms of serpentine which can be shown to have been produced from olivine, hornblende, augite, and enstatite, we pass on to that called antigorite and the circum- stances of its occurrence. It was named from the Val Antigorio in Piedmont, but it has been described in considerable detail by Dr. Hussak* from Sprechenstein on the Brenner. He, however, had not visited the locality, but received his specimens from a friend. The district was examined by Miss Raisin in the summer of 1904, so that, though one of us has seen the Val-Antigorio rock, we will deal more particularly with that from the Tyrol. Antigorite is defined * as a light-green mineral, occurring in scales with a perfect cleavage of the mica-type. Sections at right angles to this perfect cleavage are lath-shaped. They give straight extinction, and are distinctly pleochroic ; leek-green when the short axis of the nicol is parallel to the cleavage-cracks, colourless when the short axis is at right angles to these cracks. The double refraction of this mineral is slight and negative, the negative bisectrix agreeing with the vertical axis. Cleavage-flakes show, in convergent light, the optic picture of a biaxial crystal with small axial angle. ‘The dispersion is well marked. The following analyses are quoted: (I) of the Sprechenstein mineral; (II) of that from the Val Antigorio, in which apparently a little iron-oxide still remained ; (III) of the schistose serpentine (bulk), and (IV) of the massive serpentine (bulk)—both from Sprechenstein. I. IL. III IV SOU eth. Gina 41-14 41:58 40:55 40:90 Orr Svcs 3-01 722 10-40 7:68 i ae 3:82 2:60 2-70 2:08 C0). aay Oy eee 4-40 0:30 TON i a vce, 39:16 36 80 33:59 37°45 HIGOR Hie Ae check 11:85 12°67 9:32 12:15 99:38 100°87 10096 100-56 The two mineral analyses, so far as they differ from that of a perfectly-typical serpentine (Si0,=44'1, Mg0=43-0, H,O =12:9) probably do this in consequence of the replacement of magnesia by 1 Tschermak’s Min. & Petrogr. Mitth. n. s. vol. v (1883) p. 61. 2 Quoted in substance from the excellent summary of the original paper in Dr. J. J. H. Teall’s ‘ British Petrography’ 1888, pp. 112-15. Oud- Ges: No, 244. 3D \o 700 PROF. T. G. BONNEY AND MISS C. RAISIN ON THE [Nov. 1905, ferrous oxide and the impossibility of getting the material quite pure. The bulk-analyses are not unfrequent among serpentines. Dr. Hussak also detected in the Sprechenstein serpentine residual grains of sablite, of a brownish diallage, tale (often associated with the latter), a green chlorite and staurolite (in small round grains, or, more rarely, as columnar crystals). He calls attention to slight differences between the compact and the schistose serpentines, pointing out that the former consist mainly of antigorite-scales, which are arranged in two sets of parallel planes meeting at an angle of 90°, so as to produce a netting-like (gestrickte) structure. ‘In short, the sahlite-grains are related to the antigorite-serpentine, exactly as the olivine-grains to normal serpentine, and the horn- blende-grains to the serpentine with lattice-structure.’ So ‘ three definite types of structure of genetic importance are now recog- nized,’ one of them being serpentine with netting-like structure (gestrickte struktur) or augite (antigorite)-serpentine. One of us has, more than once, put on record his doubts of the validity of this induction.’ Dr. Teall himself expressed a suspicion that the author had not made sufficient allowance for the effect of mechanical disturbances. Prof. Rosenbusch? intimated in 1898 that the above generalization required some limitation, and Prof. G. A.J.Cole *® in 1902 cautioned the student against hasty recognition of this netting-structure. The British-Museum. Collection of minerals contains a specimen of antigorite from the Val Antigorio, a slice from which, by the kindness of the authorities, has been cut for examination. It was so ‘flaky’ that the section had to be made parallel to the cleavage, on which surface spots with a faint metallic gleam were discernible, like the ghosts of enstatite. These could be distin- guished under the microscope by a slight difference in structure from the rest of the groundmass, which consisted of very minute irregular flakes, with the usual bluish-white polarization-tints and a slightly ‘thorn-like’ aspect. No pleochroism is perceptible, and this mineral (antigorite) is much less characteristic than in the specimens from Sprechenstein. The most conspicuous objects in the slice are a few little tufts of a fibrous mineral, like actinolite, but with an extinction-angle ranging up to 35° (? wollastonite). Three points are noteworthy in this type-specimen: one, the extreme minuteness of the antigorite*; another, that the rock has been greatly affected by pressure; and the third that it originally con- tained, certainly enstatite, and so probably more olivine than augite.’ 1 Quart. Journ. Geol. Soc. vol. lii (1896) p. 453 & ibid. vol. lix (1908) p. 59. 2 «Hlemente der Gesteinslehre’ 1898, p. 525. 3 « Aids in Practical Geology’ 4th ed. (1902) pp. 149 & 180. 4 To this I can find a parallel in more than one specimen from other localities in my collection. [T. G. B.| ° F. Becke, in Tschermak’s Min. & Petrogr. Mitth. n. s. vol. xiv (1894-95) p. 271, describes the formation of antigorite in a rock which was substantially a dunite, occurring near Windisch Matrei in the Stubachthal, and calls attention to the frequent occurrence of the mineral in pressure-modified serpentines. Vol. 61.] MICROSCOPIC STRUCTURE OF SERPENTINE. 701 Quite recently two closely-allied minerals—pseudo-regular anti- gorites, to use his phrase—have been described by Axel Hamberg.* One, from Persberg in Wermland, occurs with magnetite, chlorite, and calcite, in cubic form, measuring from 2 to 5 millimetres along the edge, with cleavage in three directions, one strong; greenish- white in colour, and pearly in lustre; not harder than gypsum. The other from Kograbe, Nordmark, is a hexagonal, easily-cleaving mineral, yellow-brown in colour, only slightly pearly, with a larger axial angle and more transparent than the other. Analyses are given as follows :— SIO iodrtucunaeesisas 43°68 42-90 AUEO. ee ete: eae 0°34 0°51 Mig ON er een a 38°94 39°19 | EEO ik Wet 65 Rae 4-18 3°90 VE Ok yet cance i trace trace TUE Orn octet sb 12:03 12°30 1 EI ARR Eae A Ne 3A ae pal 0:97 99°17 99°77 ar He remarks that these are practically analyses of an ordinary serpentine (H,Mg,Si,0,) with some replacement of MgO by FeO, and that this mineral seems to fall into two groups—one fibrous, typified by chrysotile; the other leafy, by antigorite. That, as will be seen, quite accords with our own conclusions, but we doubt whether a hard-and-fast line can be drawn between them. VII. Tur SPRECHENSTEIN SERPENTINES. Sprechenstein is near the town of Sterzing, on the Brenner road. ‘The serpentine can be traced obliquely up the steep wooded slopes east of the Hisack Valley, the largest mass exposed being in a crag which forms a slightly-convex projection at the foot of the hill, while smaller outcrops are visible higher up. This crag is largely composed of a hard, rather tough, harsh-feeling serpentine, pale green on fresh fractures, weathering to a dark green, some- times purplish on smooth surfaces. The rock is compact, often rather regularly jointed, so as to form big rectangular blocks. Not a little, however, especially at the northern part, is con- spicuously schistose, and the imperfect wavy cleavage-planes often enclose lenticles of the more compact serpentine. The schistose parts are generally not quite so hard or rough to the touch as the compact, are less granular-looking, and a little more mottled with lighter-coloured spots. They are frequently patched or veined with a whitish mineral. A much-crushed gneiss crops out to the north, separated from the serpentine-crag by an interval of the wooded slope. A mass of vein-stuff about 4 feet thick, a description of which is reserved for the present, borders the serpentine, which for the first 20 feet is conspicuously schistose. It then becomes a ' Geol. Féren. Stockholm Forh. vol. xxvi (1904) pp. 67-88. OD 2 702 PROF, T. G. BONNEY AND MISS C, RAISIN ON THE [ Noy. 1905, massive and jointed rock, extending (partly within a fence) for about 100 yards. A slice cut from the edge of the serpentine, adjacent to the vein- stuff, proves to be mainly composed of a mica-like mineral in slightly- irregular flakes, from about :01 inch downwards, all but colourless and without perceptible pleochroism, giving low polarization-tints (bluish-whites of the first order) and straight extinction; little streaks or patches being occasionally replaced by a carbonate allied to dolomite. Here and there are a few fibres with higher tints, and extinguishing obliquely, probably actinolite. The mica-like minerals sometimes exhibit an approach to foliation, sometimes to rectangular arrangement; but closer examination shows this, where it is not illusory, to affect the whole slice and to have no relation to any original mineral structure (Pl. XLV, fig. 3).' Iron-oxide occurs in clustered or trailing granules, and this occasionally includes or is pierced by the mica-like mineral, giving a minute ‘ ophitic’ structure (fig. 1). The rock has unquestionably been modified by pressure. Fig. 1.—Antigorite, showing ‘ ophitic’ structure in magnetite (from a Riffelhorn specomen). aps [Magnified 30 diameters. | Two slices have been cut from specimens taken farther in the schistose zone. In these the flakes are sometimes very slightly 1 Hereafter, for brevity, we shall refer to this as ‘thorn-structure,’ a name which we gave it for purposes of reference. I first. came across it in a serpen- tine to the east of Andermatt, in 1878, and we found it occasionally in Anglesey. (eG asl Vol. 61. ] MICROSCOPIC STRUCTURE OF SERPENTINE. 708 larger, but there are no differences of any importance. A slice from the more massive serpentine only differs in not having the granular iron-oxide so much ‘trailed out,’ and in containing a number of minute granules, giving fairly-bright polarization-tints, which possibly represent residual augite. The hillside then slightly recedes for from 200 to 300 yards, and a path across it (leading up to the old castle) passes some serpen- tine, a craglet of which exhibits crushed zones and a bluish weathering. Another outcrop is obviously much crushed, but this may not be a sitw. Micaceous gneiss and schist also crop out on the slopes, the castle standing on a knoll of stronger gneiss. Miss Raisin made two other traverses across the serpentine, one about the level of the castle, and one higher up the slope. On the former she found the serpentine in bosses, near some small cottages, much crushed and including a crushed talc-schist; and on the upper she crossed an interesting vein about 33 feet long and 6 inches wide—showing, like the surrounding serpentine, much crumpling. The ‘crushed flaky mottled rock, by the path to the castle,’ exhibits a rather crumpled foliated structure, and consists of the following :—a colourless mica-like mineral; black iron-oxide in more or less irregular patches; and a fairly-large amount of slightly-greyish or brownish granules, sometimes forming thin streaks. The flakes of the first are commonly about ‘015 inch long, but occasionally almost double this, The polarization-tints belong to the first order, and rise to yellow or brownish orange, but smaller flakes of the bluish-white variety are associated with it ; though these are generally the smaller, we doubt whether the difference is due to size alone. ‘The slice also contains, though very locally, a third variety, the tints of which never rise above a very dull dark blue. The granular mineral is apparently residual augite, the crystals of which have been crushed almost to powder. The tale-schist collected on the lower traverse proves, on micro- scopic examination, to be a matted mass of that mineral, generally resembling those described from the Gorner Grat! and Anglesey,* but it contains a rather large amount of a carbonate (? magnesite) often with flecks of limonite deposited in its cleavages. ‘he crushed serpentine taken on the higher traverse shows the very faintest trace of pleochroism (straw-coloured to pale dull green), and consists of (@) the usual mica-like mineral, occasionally very minute: sometimes showing ‘ thorn-structure’ and sometimes a streaky foliation, indicative of erushing, in which the polarization- tints become slightly higher than usual; (6) the usual granules and grains of iron-oxide ; and (c) a fair number of granules or small fragments of crystals, which resemble residual augite, although their extinction-angles, so far as they can be measured, agree better with hornblende. The slice cutfrom the vein affords marked indications ' Geol. Mag. 1890, pp. 558, 540. 2 Quart. Journ. Geol. Soe. vol. xxxvii (1881) p. 44. 704 PROF. T, G. BONNEY AND MISS C. RAISIN on THE [ Noy. 1905, of crushing, and consists of calcite (the most abundant), a colour- less acicular hornblende (clearly secondary), some residual granules which may be augite, and flakes (not numerous) of the low-tinted serpentine. Turning now to the vein already mentioned, we find the matrix to be a dolomitic calcite, and the greyish material embedded in it to be a rather prismatic mineral, resembling an augite, granules of which are apparently enclosed, though these afford only low polarization-tints like the flaky serpentine and extinguish at small angles.’ This suggests that we have here an altered condition of the latter mineral, but that, owing to the absence of some necessary factor, it has not yet become antigorite. VIII. Tae Sarrensprrz District. The Sprechenstein outcrop, according to Dr. Hussak, is the westernmost of a zone which extends, with some interruption, from the Sattelspitz, at the head of the Sengesthal. Of this mountain Miss Raisin was not able to make more than a hasty examination, but she observed that the crags of green serpentine cropping out on the slopes of its broad combe exhibited a schistose structure, with a rough east-to-west strike. She collected specimens from the secrees and abundant débris below, six of which have been sliced. All show the usual flaky mineral (antigorite) with more or less of the ‘ thorn-structure,’ and occasional streaking along a line of erush. They differ only in the greater or less amount of ‘ ophitic structure’ and of residual augite. One slice contains this mineral in fair-sized grains of a pale brownish colour, which sometimes exhibit a well-marked diallage-cleavage. ‘The antigorite shows a slight tendeney to follow the latter, but none whatever in regard to any prismatic augite-cleavage. Beyond the Wilde Kreuzspitze (northward of the Sattelspitz) is the Burgumerthal (a tributary of the Pfitschthal, joing the Eisack just below Sterzing). On the sides of the valley serpentine crops out, apparently intrusive, among gneiss and schist. Speci- mens were collected from the screes below, near the Sterzinger Hutte, from which three slices have been cut. One consists of some crushed iron-oxide (occasionally showing the ophitie structure) and a little residual augite, but mainly of the clear, colourless, mica- like antigorite, with the usual low polarization-tints, the length of the flakes running up to about ‘03 inch. Foliation is con- spicuous, with here and there sharply-arched flexures (Pl. XLV, fig. 4). Another specimen contains a considerable amount of residual augite, and rather less of a dull-yellow granular mineral. The augite, which looks as if it had been somewhat affected by pressure, is slightly banded, and, where most abundant, forms 1-This abnormal extinction seems not unfrequent in the residual augite of these Alpine serpentines with antigorite, and is to some extent comparable with the well-known change of the former mineral into uralite. ee ee, a ee = 2 Vol. 61.| MICROSCOPIC STRUCLURE OF SERPENTINE. 705 about half of the rock; the flakes of the mica-like mineral are slightly shorter and stouter than is usual, and its low polarization- tints are of a more ‘chalky’ white. Its extinction sometimes appears slightly oblique, which, however, may be due to strain. It can hardly be anything but antigorite, but it occasionally resembles one variety of chlorite. The yellow mineral is perplexing: the granules have no regular outlines, though one or two seem slightly elongated. Their general aspect suggests a rather impure epidote, but they remain dark between crossed nicols.|_ We must be content with suggesting the possibility of perofskite. A third contains a rather fibrous mineral, associated with the antigorite, which, in polarization-tints, extinction, and general aspect, corresponds best with actinolite. There is also a vein occupied by calcite, probably rather dolomitic. A specimen collected from a block in the stream near Mauls, below the Sengesthal, is so very like the first of the three from near the Sterzinger Hiitte, that it is enough to say that the flakes of antigorite are slightly smaller and the folding is not quite so conspicuous. IX. Tas Marret SERPENTINE. Here, on the northern slope of the Brenner Pass, a much- crushed ophicalcite has been worked in a large quarry, on the steep hillside near the hamlet of Pfons. The specimen examined consists so largely of carbonates—calcite with some dolomite—that we are unable to draw any conclusion from it, the flaky mineral presenting more resemblance to an ordinary mica. The most interesting out- crop of serpentine is at the northern end of Matrei village. Here the river sweeps in a more than semicircular curve round the base of a crag crowned by a castle. On its southern face is serpentine, apparently intrusive in a muddy-looking limestone, the horizontal strata of which are displaced by slight faults. Difficulties of access interfered with close examination, and made it impossible to obtain a junction-specimen, but slices have been examined from the two rocks at the distance of a few yards and from other parts of the crag. Of the former, one is a very fine-grained dolomite, which might either come from the Trias or be a pulverized member of the cale-mica-schist group, to which several other specimens, though modified by pressure, probably belong. Miss Raisin found the serpentine to be blackish or invisible green in colour, with a resinous lustre; brittle, much jointed, almost crackled ; more compact and smooth-looking on a fresh fracture, and softer than the Sprechenstein rocks ; showing occasional small weathered enstatites, and altogether more like a ‘black’ serpentine from the Lizard. A specimen from behind a small shrine proves to be greatly crushed and altered, consisting of a minute fibrous mineral, resembling tale, but with duller polarization-tints, in which (as in the talc- ! Occasionally a small grain seems to produce some effect, but this may be due to the interposition of a flake of the mica-like mineral. 706 PROF. T. G. BONNEY AND MISS C. RAISIN ON THE [ Novy. igo5, schists of the Gorner Grat) we find a little of a flaky greener mineral, faintly pleochroic in that colour, and producing but small effect on polarized light. From the north of the castle comes a specimen, not much crushed, which has been an olivine-enstatite rock’; the serpentine replacing the former mineral produces more effect on polarized light in the ‘ strings’ than in the meshes, but it approaches once or twice the antigorite-‘ habit’: that replacing the enstatite needs no special description. Of four specimens from a crag and blocks near a waterfall: one, resembling the rock from near the shrine, but with brighter polarization-tints, is a variety of tale-schist ; another is rather banded; flakes producing dull white polarization-tints * dominating in one part, a very minute mineral— perhaps the same—in another, and in a third, a mineral affording rather bright polarization-tints, with apparently-straight extinction —perhaps a peculiar form of antigorite. The other specimens, which contain normal antigorite, do not call for any special remark— except that one is about as much crushed as some of the slaty serpentine described in the next section. Thus the serpentines of the Brenner district prove (a) the ex- istence of antigorite (including the variety with slightly-higher polarization-tints) in close association with augite, but without any relation to its prismatic cleavages ; (6) that pleochroism is not an essential property of antigorite, but probably depends on the acci- dental presence of some colouring-matter ; and (c) that we have failed to find any mineral resembling staurolite. X. Orner ALPINE SERPENTINES. The Alpine serpentines, as one of us has more than once pointed out, can be arranged in two fairly-distinct groups, namely, altered olivine-enstatite rocks, with or without some augite, and olivine- augite rocks often rich in the latter mineral. He has found the former in situ on the Col de Cristillan, the Col de Sestrieres, the Mont Genévre, in the Val d’Anniviers, and once or twice in the Central Pennines, near Davos, at more than one place between Tiefenkastell and the Julier Pass, and by the Silser See:* the 1 This difference in the parent-rock is noticed by Dr. Hussak, and in Zirkel’s ‘Lehrbuch der Petrographie’ 2nd ed. vol. iii (1894) p.895. We have, however, noted some residual augite in a second (less crushed) specimen from near the shrine. It also has contained olivine and perhaps enstatite. 2 This also, as in the specimen described above, is suggestive of a chlorite ; but, on the whole, I incline to regard it as an abnormal antigorite. A speci- men in Miss Raisin’s collection from Cerig Moelion, Anglesey, with much of this mineral, some altered enstatite, and residual diallage confirms this view. T. G. B.] ® But I found, south of the Bernina, at the junction of the glens from the Muretto and Canciano passes, a serpentine consisting largely of antigorite (polarization-tints up to yellow) with a fair amount of residual augite (some stained sienna-brown) and a little of a chlorite; the serpentine also above Lanzada (with ‘ asbestos’), on the west side of the latter pass, contains residual augite and antigorite in rather foliated flakes, sometimes ‘04 inch long, the polarization-tints ranging up to the pale yellow of the first order. [T.G. B.] Vol. 61. | MICROSCOPIC STRUCTURE OF SERPENTINE. 707 other is especially common in the Pennine Alps between the Col du Collon and the Simplon Pass, and occurs also near Cogne. Alpine serpentines are sometimes so much affected by pressure as to become perfectly slaty. Such he has found near the Col de Vallante (Viso), at Verrex in the Val d’Aosta, on the Gorner Grat and at the base of the Riffelhorn, where flakes can be obtained no thicker than a postcard. For the microscopic structure of the first group we may refer to descriptions already published.’ Except for occasional effects of pressure, they do not differ from serpentines of similar com- position from Scotland, Cornwall, and the Apennines. For the second group also, if that so abundant about the head-waters of the Visp be accepted as an example, we may refer, in most cases, to what is already in print. This serpentine is usually harder to scratch or to break,’ a little more granular to the eye, and rougher to the touch than that obtained at the Lizard, and very rarely, if ever, shows any trace of enstatite. Even when most compact, it breaks with less ease and with a less curd-like fracture than the other serpentine. But even then the microscope generally reveals some minute residual grains of augite, while the more granular kinds are rich in that mineral. Many of them are megascopically identical with specimens brought by Miss Raisin from Sprechenstein. We will first briefly notice five specimens, hitherto undescribed, from the upper part of the Saasthal. The first, from the smallest of the three well-known great boulders on the valley-floor above the Mattmark Hotel, must occur 7m setu, either on the eastern face of the Strahlhorn or in a spur running from it to the north-east. The microscope shows the rock to have suffered from pressure, to contain more than the usual amount of magnetite (with a little pyrite), much augite, both residual and in larger, dusty, brownish grains frequently showing diallage-cleavage—perhaps making up altogether one-fifth of the slice,— while the rest consists of the two varieties of the mica-like mineral (antigorite), as mentioned above, the one with bright tints, generally, but not always, the larger, perhaps a little less definitely cleaved, and certainly sometimes giving a slightly-oblique extinction up to about 10° or 12°. In t Quart. Journ. Geol. Soc. vol. xlv (L889) p. 81 & Geol. Mag. 1880, p. 538. 2 Its hardness is generally higher in the scale than that of the other variety, sometimes nearly a degree. As Miss Raisin observed in the Brenner district (p. 701) the more schistose specimens are less hard and rough than the others, [Since this paper was read I have again visited the Saasthal, and examined many boulders on the moraine of the Mee Glacier and in thevalley above Almagell (that is, representing another set of outcrops). ‘The waterworn blocks commonly haye a characteristic smooth, rather mottled surface (pale and dark green) ; they are much tougher than the ordinary serpentines, and feel so much harder and (commonly) ‘harsher’ in the hand, that I believe I could distinguish them blind- fold. IL failed to find any specimen of the ordinary (olivine-enstatite) serpentine. I may say that the work of the past two years has proved to me that augite has been, at any rate sometimes, a still more abundant constituent in this second group than I formerly supposed.—T. G. B.| 708 PROF. T. G. BONNEY AND MISS C, RAISIN ON THE [ Nov. 1905, one place the two varieties form a nest in the heart of a grain of diallage, piercing it in all directions irrespective of the cleavage. The second specimen, labelled in the field ‘ serpentine (streaky),’ came from a block on the right lateral moraine of the Fee Glacier, and is probably zn situ somewhere near the Hinter Allalinhorn.’ The rock has been somewhat affected by pressure; about four-fifths of it (Pl. XLV, fig. 5) is augite, clear to ‘ dusty,’* with only occasional traces of diallage-cleavage, and the remainder (besides iron-oxide) consists of the two mica-like minerals, the larger generally (though not always) affording the yellow polarization-tints ; both, so far as measured, giving straight extinction. They are intimately associated with the augite, but their general direction is obviously at right angles to that in which pressure has acted.’ There is one grain, about 06 inch long, which gives the dull but rich blue polarization- tints already mentioned. The third specimen, from the terminal moraine of the same glacier, may have come from either the above-named range or a spur running northwards from the Allalinhorn to the Langefluh. The rock is modified by pressure, and consists (besides iron-oxide) almost wholly of a rather confused mass* of colourless mica-like minerals, which afford both kinds of polarization-tints, the brighter on the whole dominating, and both giving, so far as measured, straight extinction. We find, however, some irregular patches of flakes, which have a slightly-stronger cleavage, show a tinge of brown with transmitted light, and are feebly pleochroic (very pale green with parallel vibrations, and rather straw-coloured with perpendicular). The fourth specimen (labelled ‘ rather crushed ’) is from the same moraine, and is found to be (apart from the iron-oxide) a mass of mica-like flakes, varying in length up to about °01 inch, and exhibiting the two usual polarization-tints of the first order, the yellow dominating. Parts of the slice, however, show an approach to “thorn-structure’; others streaky patches of flakes, arranged so as to produce a nearly-uniform colour and simultaneous extinction. Two grains, showing a cleavage like that of augite, but acting feebly on polarized light, may represent remnants of that mineral. The last specimen, ‘from the moraine of the Schwarzenberg Glacier,—-a very typical one of the rather lighter-green hard serpentine, though not very fissile in the hand-specimen, 1s shown by the powdered magnetite to have been much crushed. It is 1 The mountains from the Allalinhorn to the Egginerhorn are coloured as serpentine in the Swiss Geological-Survey map, but Griiner Schiefer also vecurs in the range. ['T. G. B.] * The apparent dust, under a high power, often resolves itself into minute clear films. * Each of these statements may be made of a schistose serpentine (rather richer in magnetite) but recently sliced. It was collected in 1889 from the old moraine on the left bank of the Findelen Glacier, where it was rather common. This leads me to suppose that it comes from the Gorner-Grat mass — probably from somewhere near its north-eastern end. [T. G. B.] + The confusion may be due to the accidental direction of the slice, which, as the rock showed no very definite structure, was cut to suit convenience. Vol. 6x, | MICROSCOPIC STRUCTURE OF SERPENTINE. 709 composed of flakes, rather irregular in outline, of the usual mineral, without any distinct orientation, which give the faintest possible trace of pleochroism (green to buff) and polarization-tints ranging through the first order, once or twice reaching the violet of the second order. Specimens of this kind of serpentine from the summit of the Riffelhorn have been already described,’ so it will suffice to repeat that they (and one from the moraine of the Gorner Glacier) contain the mica-like minerals with the lower and the higher polarization- tints, and though the latter are generally, they are not invariably, the larger. One slice includes only the dull-tinted, and all of these show residual augite, sometimes clear, sometimes dusty, occasionally with diallage-cleavage; in the flakes extinction 1s usually straight, but, as stated, there are exceptions which some- times at least may be actinolite, for they apparently have a slightly- higher refractive index. Magnetite, and occasionally awaruite, is present ; crushing, crumpling, and the ophitic structure have been noticed. Additional work has convinced the author of the original description that augite has been even more abundant in these rocks than he had supposed (for he fails to find any certain trace of other ferromagnesian minerals), and that it has frequently produced the above-mentioned flaky mineral. He pointed out (in 1896) its resemblance to antigorite, as then described, and has now no hesitation in assigning that name to at least the variety with low polarization-tints, between which and the other one he has not yet found any valid distinction.’ XI. Stary SERPENTINEsS. ‘These are so schistose, as to resemble green tiles or slates, the broken surface of which affurds no clue to the original composition of the rock. The least fissile of them comes from the Fee Alp, near Saas, where it forms a dyke in the cale-mica-schist series.* ‘lwo slices have been cut from it, one of which (a little thicker) shows a slightly-stronger tint of green with parallel than with perpendicular vibrations. They contain the usual iron-oxide (with occasional ophitic structure) and a streak of a granular mineral (? a carbonate), but are mainly composed of the two mica-like minerals, variable in size, though generally rather small, and with so marked a structure that the slice exhibits fairly-definite streaks of colour (generally pale yellow) where the former makes an angle of 45° with the vibration-planes of the crossed nicols. Here also size and thickness, 1K. Aston & I. G. Bonney, Quart. Journ. Geol. Soc. vol. lii (1896) p. 452. > A specimen collected in 1889 ‘from old moraine of Furggen Glacier’ (it might come from the Furggen Grat or the northern spur of the Matterhorn on the whole resembles a serpentine from olivine, but contains 10 certainly- recognizable bastite or other residual mineral, and is almost wholly composed of rather minute antigorite, with a structure ranging from ‘thorn’ to streaky. ’ The Alpine serpentines, indeed all that I have seen, very rarely form dykes. [T. G. B.] 710 PROF. T. G. BONNEY AND MISS C. RAISIN ON THE [ Nov. 1905, though favourable to the production of higher tints, do not appear to be the only factors. Extinction is generally straight. The slabby serpentine from the Gorner Grat has been so fully described,' that we need only repeat that it is a felted foliated mass of rather minute minerals like those already described, the highest polarization-tints being the clear yellow of the first order. ‘The author then (1890) suggested the possibility that part at least might be antigorite, and would now identify it without hesitation, for a very faint pleochroism is occasionally perceptible. Fig. 2.—Slaty serpentine from the Gorner G'rat, sliced generally parallel with the nucrofoliation. | Magnified 50 diameters. | (Geol. Mag. 1890, p. 537. We are indebted to the Hditor, Dr. Henry Woodward, F.R.S., for the use of the block. | As the augitic serpentine of the Riffelhorn is very abundant in that neighbourhood we should naturally suppose those slaty ser- pentines on the Gorner Grat to be modifications of it.? But one of us accidentally discovered the need of caution. Probably on his third visit (in 1860), certainly some years before he collected rocks 1 Geol. Mag. 1890, p. 538. Miss Raisin has specimens (not quite so slabby) from this locality and from near the Lower Théodule hut. Both consist almost wholly of antigorite (without residual augite): the former might have-come from Sprechenstein, in the latter the mineral is rather smaller. 2 They are also a little harder than ordinary serpentine. A slaty specimen from a small pit by the path from the Riffelalp Hotel to the Vindelen Glacier, contains narrow and thin blades, up to about three-quarters of an inch long, of a pale-green mineral which proves to be actinolite. ) . Vol. 61. | MICROSCOPIC STRUCTURE OF SERPENTINE. al except as mementos or samples of anything unusual, he brought away a bit not so big as his thumb from the Riffelhorn. He has forgotten the exact locality, but thinks that it probably came from rather low down on the northern face of the peak. A short time ago, aS it seemed a little different from his other specimens, he had it sliced, and found it to be not only practically unaffected by pres- sure, but also to exhibit most distinctly the peculiar mesh-structure of serpentine derived from olivine, and to contain a little altered enstatite. ‘'he replacing mineral in the ‘ strings ’ (clotted occasion- ally with black iron-oxide) affords low polarization-tints in the first order (rarely reaching palo yellow) and that in the interstices is almost inert, as it also is in the replaced enstatite. The occurrence of this saxonite, in such close association with an augitite, shows that at present we could not safely claim the latter rock as the in- variable parent of a fissile serpentine.' In a slaty serpentine collected ‘a short distance above Verrex, Val d’ Aosta,’ the iron-oxide indicates great crushing and the bulk of the slice consists of a felted foliated mass of the usual mica- like mineral with low polarization-tints, though it is large enough in places (about -025 inch long) to give the higher colours if they depended on size alone. The slice also contains a few small streaks (probably formed in cracks) of a rather mica-like colourless mineral in stoutish flakes (not exceeding :01 inch) which show pale-yellow (inclining to buff) polarization-tints and give straight extinction. A still more slaty serpentine (about a quarter of an inch thick) comes from near the Col de Vallante (Viso district).” It is a felted foliated mass (with slight ‘ rucking’ or ‘stepping’) of rather minute flakes, and a little crushed iron-oxide, which shows a faint tinge of the usual pleochroism, and affords, when placed at an angle of 45°, as mentioned above, fairly-bright polarization-tints occurring streakily —the clear yellow of the first order to the blue of the second, rather bright in one part. Some longer flakes occur, and a little patch of another mineral which gives straight extinction and low polarization- tints—a pale greyish-buff—(? a form of chlorite). A. less fissile specimen, from rather nearer the Col so far as the collector remembers, is a little hard, consists of ‘ antigorite’ of both tints, rather foliated, together with powdered magnetite and some flakes (pale green and very feebly pleochroic, having a little opacite between the cleavages) which reach the blue of the second order. 1 At the same time, after examining a rather numerous collection of fragments which Miss Raisin brought some years ago from this district, I think that the bulk of the rock, whether slaty or not, represents the augitic group. [T. G. B.] A specimen in Miss Raisin’s collection, sliced since these words were written, from a block on the right bank of the Zmutt Glacier, beneath the Matterhorn, also appears to consist of a serpentinized olivine (poor in iron) and a few grains of another mineral, probably once an enstatite, but now replaced by minute antigorite (cf. the specimen from Val Antigorio) which sometimes exhibits an approach to thorn-structure. ? This was collected (because of its curious look) so long ago as 1860. a2 PROF. T. G. BONNEY AND MISS C. RAISIN ON THE [| Noy. 1905, Several analyses of Alpine serpentines are tabulated by Dr. M. E. Wadsworth,’ and some by Miss E. Aston will be found in this Journal.” One of the latter contained an unusually-high percentage of nickel, but in other respects did not differ from the normal. The differences in these analyses (including the Sprechenstein specimens) seem insufficient as a basis for distinctions, and they all lie within the limits of variation due to the presence of this or that magnesian silicate or the conversion of them into serpentine. XII. SereentTines FRoM JAPAN. Through the kind offices of Prof. John Milne, F.R.S., one of us received, nearly twenty years ago, from Prof. Koté a number of specimens of serpentine (dull green) from Japan. As all were rather seriously affected by pressure, and he was then desirous of studying unaltered types, none of them were sliced until he began to put together the notes for this paper. Each of the eight specimens examined under the microscope shows signs of pressure, but this appears, as a rule, to have acted less definitely in one direction than it has done in the Alps. Two or three have contained enstatite ; one, much olivine with some augite; two others were probably peridotites; in one or two augite may have dominated, although this is not quite certain; in two the chlorite-like mineral, with dull-white polarization-tints, as already mentioned, is present, forming in one a rather distinct band. The serpentine generally occurs in fibrous flakes with low polarization-tints, but we find occasionally typical antigorite, and in part of one slice the rather bright-tinted variety with an oblique extinction at low angles. XIII. Caemicat CHaners. The chemical changes in the conversion of olivine and one or two ferromagnesian silicates into serpentines were discussed by J. Roth and have been explained by J.J. H. Teall. If we take (for sim- plicity) the non-ferriferous forms, their composition is as follows :— IH OMSLEMILE pebeseyscncheneees 2MgO + Si0,. ABmiStalater ceo ae ne ee MgO + Si0O,. Augite (diopside) se et (MaCa)O + SiO, ; SOM UELIUMI® toéocacdeosscacee 3MgO + 28i0, + 2H,0. RE CREO neces devas eve 3MgO + 4SiO, se Jel, °0. Thus the conversion of two molecules of forsterite (4MgO + 28i0,) into one of serpentine requires the removal of one molecule of magnesia and the addition of two of water—a slight increase of bulk. But ordinary olivine contains an appreciable quantity of iron which remains as an oxide, so the removal will be less and the 1 «TLithological Studies’ Mem. Mus. Comp. Zool. Harv. vol. xi (1884) pp. XXIV—XxVill. > Vol. lii (1896) pp. 454-56. ° «British Petrography ’ 1888, chapt. vi, p. 104. Vol. 61.] MICROSCOPIC STRUCTURE OF SERPENTINE. 713 increase greater.' We may, therefore, say that the ratio of the silica to the magnesia is practically unaltered. Two molecules of enstatite (2MgO + 28i0,) become one of ser- pentine by the addition of one molecule of magnesia and two of water, and if the enstatite be ferriferous still more magnesia must: be added; or, if the magnesia in the rock remain as before, some silica must be removed in adding water. If, for simplicity, we assume augite to contain equal amounts of magnesia and of lime, the conversion of two molecules of augite (MgO + CaO + 28i0,) into serpentine requires the addition of two molecules of magnesia and the same of water and the removal of one of lime —or, in other words (apart from the water), this signifies the removal of a large amount of silica and lime from the rock—obviously the greater change. So it is not surprising to find augite more persistent than the other two minerals; especially since, as we can see from a table of analyses of diopside and sahlite, the lime generally exceeds the magnesia in the approximate ratio of 17:13. The evident fact that pressure (leading to reduction of volume) is favourable to the conversion of augite into serpentine (antigorite) is significant. It also follows, that to convert forsterite into tale requires the removal of more than half the magnesia and the addition of a little water, but if any iron be present the loss is not quite so great. When enstatite is altered into talc, either a little silica must be added with the water, or a corresponding amount of magnesia removed— a less serious change. The conversion of serpentine into tale means either the addition of two molecules of silica and the removal of one of water, or the removal of half the magnesia and much of the water. In regard to this, the frequent presence of a magnesian carbonate where this change has occurred may be significant. XIV. GEnERAL Conciusions. These investigations, which we fear may have seemed rather prolix, into the production of serpentine from each of its parent minerals, and as a rock-constituent, justify, we trust, the following conclusions :— (1) That a tint and pleochroism are accidental rather than essential characteristics of the variety of the mineral serpentine named antigorite. (2) That, if low polarization-tints be regarded as an essential characteristic of antigorite, a closely-associated mineral must exist, which is distinguished only by greater brightness of these. If the minerals can be isolated and subjected to analysis (which we have not the means of applying), they may prove to be distinct; but the way in which, as described in the preceding pages, they seem to eraduate one into the other, leads us to believe that they are varicties 1 Tt is noteworthy that in gabbros where grains of olivine are converted into serpentine the neighbouring felspar is much cracked, as if by their swelling. Also, in regard to the chemical change, we may note the rather slow alteration of the non-ferriferous olivine in the diamantiferous breccia described above. 714 PROF. T. G. BONNEY AND MISS C. RAISIN ON THE [ Nov. 1905, of a single mineral—antigorite. Both forms usually afford straight extinction, but it is occasionally oblique, though the angle is small. Thus, either the mineral is dimorphous, or its optical characters have been affected by pressure, or it 1s really monoclinic. Flakes, however, do occur which, while extinguishing obliquely at low angles, have a slightly-higher index of refraction. ‘These probably represent a form of hornblende. (3) That it is doubtful whether any hard-and-fast line can be drawn between the rather fibrous forms of the mineral in the ordinary serpentine-rocks and the mica-like (antigorite) of certain others. (4) That the most typical antigorite occurs when the rock has been considerably affected by pressure, but that it becomes smaller and rather less typical when the pressure has been very great (that is, in the most slaty serpentines). (5) That the ‘gestrickte struktur’ of the antigorite, so far as it exists (and it is mostly subjective), has no connection with the nearly-rectangular prismatic original cleavage of augite ; the latter structure, curiously enough, being worse preserved than any other in the process of serpentinization. Typical antigorite, however, appears to be produced rather more readily from augite than from the allied ferromagnesian silicates, but its characteristic form is more directly a consequence of pressure! than of chemical com- position, or, in other words, when this has acted, the mineral serpentine occurs in mica-hke plates, instead of. in rather irregular or flame-like flakes. EXPLANATION OF PLATE XLV. Fig. 1. Diamantiferous breccia (‘Hard Blue’) from Kimberley (specimen obtained by Sir J. B. Stone in 1894). (@) unchanged olivine; (0) shell of serpentine; (c) feather-like growth of serpentine. (x 20, crossed nicols.) (See p. 693.) 2. Band ofalinost pure augite im a serpentine from north-east of Bonhomme, Vosges. (a) augite ; (0) serpentinized olivine (shaded). (x 20.) (Se pp. 697-98.) 3. Antigorite-serpentine, Sprechenstein, Brenner. From one of the less- erushed lenticles, about 7 feet from the edge of the mass, representing the so-called ‘thorn-structure.’ (XX 25, crossed niculs.) (See p. 702.) 4, Antigorite-serpentine with puckered foliation: (a) antigorite. Of the non-flaky materials, the very dark (0) are iron-oxide (mostly magnetite) and the dusky (¢) residual augite. (x 25, crossed nicols.) (See p. 704.) . Antigorite-serpentine, from a boulder with a slightly-streaky structure on the right moraine of the Fee Glacier, Saas Fee, consisting largely of augite. (a) antigorite; (0) augite, represented not only by the granular clear mineral, but also by much of the dusty part not showing a mica-like structure ; (c) magnetite. (x 25.) (See p. 708.) 6. Antigorite-serpentine, from the summit of the Riffelhorn, Zermatt. (a) antigorite; (4) residual augite; (c) magnetite. (x 25, crossed nicols.) (See p. 709.) Or | F. Becke called attention to the connection of antigorite with pressure (as already stated) in 1894; but our conclusions were formed independently, as one of us had noticed it some time before that date. Quart. Journ. Geol. Soc Vol LXLPLXLV. F.H.Michael del. et lath. ; Bale &Damelsson, Tt imp. Acoli AnD sOTeEe SERPEN TINGS. Vol. 6r.| MICROSCOPIC STRUCTURE OF SERPENTINE, WAS Discussion. The Presrpenr referred to the interest that the Fellows must feel in having a paper laid before them, in which, besides much original information, there was a summary of the history of the progress made in a group of rocks upon which one of the Authors had thrown light thirty years ago. Dr, Trkatt remarked that the President had, to some extent, anticipated what he was about to say on the importance of the communication which had just been laid before the meeting. He feared that he could not throw much additional light on the subject. The main point appeared to be that, in addition to the serpentines derived from peridotites, another important group existed, wherein the structure was not the same, that was, the antigorite-serpentine group. ‘This was of more widespread occurrence than had pre- viously been supposed, and was largely composed of altered augitie rocks. His own experience, so far as it went, confirmed the Authors’ conclusions. He would be glad to learn the Authors’ views as to the origin of such augitic rocks as those from Canada: was it possible that they represented altered siliceous dolomites or rocks of a similar type? Prof. Bonnny replied that he had meant to say that antigorite might come from olivine or enstatite (there was enstatite in the original Val-Antigorio rock), but that it came most readily from augite. The origin of the augitic rocks of Canada was tco long a subject for the present occasion, but he did not believe that they had been formed in the way suggested by Dr. Teall. Q.J.G.8. No. 244. 3B GENERAL INDEX THE QUARTERLY JOURNAL AND PROCEEDINGS OF THE GEOLOGICAL SOCIETY. Aalenian Lytoceratide, 142-47 figs. & pls. xv—xvi. Abbot’s Leigh (Somerset), Carb. Limest. of, 233. Abercastle- Mathry district (Pem- broke), lime-bostonite & porphyrite- intrusions in, 594-99 fig., w. chem. anals. & pl. xl; their extension into S.E. Ireland, 603-604 w. map. Abereiddy Bay (Pembroke), enstatite- diabases near, 591. Aberfelin (Pembroke), 593. Acceleration, relative, in development, 563. Acrophylium, 281. After-shock of Derby earthquake of July 3rd, 1904, 15-16 & map. Agglomerates of Arenig, 623-24. Agneash Grit, 360-61, 364 fig. Albite-enstatite-rock of Penelegyr, 592 & pl. xxxix. Aldwarke (Yorks), 339. Alectryonia cf. Martinsi, 166-67 & faunal pl, xx. Algz (?) in Tyrolese dolomites, 118 et seqq. Alocolytoceras defined, 144. dilucidwm, 145-46. Crermaini, 145 & fig. Pompeckji, nom. nov., 145. teniatum, 146 w. fig. & pl. xvi. Alpine serpentines, generally, 706-709 & pl. xlv. Alternate formation & cessation of deposit, Ixv—lxvi. Alum-Shale nr. Blea Wyke, &e., 443 et segq. Alveolites in Carb. Limest., range of, 243, 267. septosa, 267. Amadi (Congo Free State), 645, 646; eranite from, 656-57. Ambocelia carbonaria, sp. nov., 531— 32 & pl. xxxv. Amnodd Shales ef Arenig, 616-17. Amphibole, format. of serpentine from, 693-94; see also Horn- blende. Amphibolite from lLado Enclave, 662. Amphistegina from Somaliland, 176, 177. Amplexus in Carb. Limest., range of, 243, 269. ef. coralloides, 269. Analyses, chemical, of dolomites fr. 8. Tyrol, 103 e¢ segg. ; of igneous rocks fr. N. Pembrokeshire, &c., 588 e¢ seqgg.; of Keuper Marls, 433-34, 436. Andesites, granular, of Arenig, 632; hypersthenie, 2bzd., 628-30. Andesitie ashes of Arenig, 626; do- lerites thid., 680-31. Angba, Mt. (Congo Free State), iron~ ore of, 646. Anhydrite, &e., fr. Boultham Boring, Xev. Anniversary Address, xlvii—lxxxvi. Antigorite-serpentine, 699-701, 713- 14, w. chem. anals. & pl. xlv. Apatite in igneous rocks of N. Pem- brokeshire, 600. Aragonitic limestone of Sett Sass, 28. aE 2 a 118 GENERAL INDEX. Anzer, E. A. N., Lyell Geological Fund awarded ‘to, xlvi; on the Sporangium-like Organs of Glosso- pteris Browniana, Brongn., 3824-38 & pis. XXX—-XxXi. Archean (?) rocks fr. Congo Free State, 656 et seqq. Archeocidaris cf. A. vetusta & A. ben- burbensis, v, 529 & pl. xxxv, 547. Ardwick Series, correlation of, 315. Arebi (Congo Free State), 650-51 ; rocks from, 657-60 Arenig Fawr & Moel Llyfnant (Merio- neth), geology of, 608-40 w. sects. & pl. xli (map). Arnoup-Bemrose, H. H., 8,9; Wol- laston Donation-Fund awarded to, xlv; (& EH. T. Newron), on an Ossiferous Cavern of Pieistocene Age at Hoe-Grange Quarry, Long- cliffe, near Brassington (Derby- shire), 43-63 & pls. v-viii. Asaphellus-Flags of Arenig, 615-16. Asbestiform shear-planes, | 603. Ash Pit, see Slippery Lane. Ashes & Agglomerates (Lr.) of Arenig, 623-24; Upper do., 625-27. Ashgillian Series, Ixxxiv-Ixxxvi. Asio accipitrinus (at Longeliffe), 56. Assets, statement of, xxxviil. Aswan-Esna reach (Nile Valley), Hocene & Cretaceous of, 667-78 w. map & sect. Athyrids in Carb. Limest., range of, 245. Athyris ef. expansa, 558. cf. glabristria, 558. Auditors elected, iv. Augite, format. of serpentines from, 696-99, 712-13 ; see also Pyroxene. Auldyn, Glen (I. of Man), Schistose Breevia in, 361-62 fig. Aulophyllum-group defined, 286. Aust Cliff (Gloucest.), chem. anals, of Keuper Marl from. 434. Autoclastic rocks, definition of, 868- 70; examples of, 371. Avesury, Lord, on an Experiment in Mountain-Building: Pt. II, 345- 55 figs. Avicula-contorta Beds at Goldchff, &c., 376 et seqg. ; at Lavernock, &c., 389, 390 fig. e¢ segq. ; conditions of deposition of, 414-15 Avon (Bristol) sect. deser. & fig., 188- 203 & pl. xxvii. Avonian, defined, 264 Awaina, Jebel (Nile Valley}, Eocene, &e. ae 673, 674. Awards of medals & funds, xxxix— xlvi. [Nov. 1905, Axophyllum, genus defined, 281. 0, 282 & pl. xxiv. Aymestry Limestone, gasteropoda from, 566, 570 et seqq. Ayot (Herts), 42. Backwell-Wrington (Somerset), Carb. Limest. mass, 240-42. Bapuam, H. A., 430. Bala, use of stratigraphical term, Ibex. Balance-sheet for 1904, xxxiv-xxxy. Balmoral (Transvaal), sect. N. of, 682. Baltic basin, points in geology of, illustrated by exhibits, lxxxvii. Barker, T. V., Daniel- Pidgeon Fund awarded to, xcil. Bartow-JAmeson Fund, list of awards, xXx. Barnsley Seam, wash-out in, 339-42 figs. Barrule Slates deseribed, 359-60; distribution of, 8364-65. Barry (Glamorgan), Rheetic, &c. betw. Cowbridge and, 397-404. Barton Farm, see Upton Cheney. Basal Grit of Arenig Series, 618. Basaltic rock of Strumble Head, 582. Bassey-Mine Ironstone, 809, 310, 322, Bassus-subzone in Bristol area, 189- 90, 205; faunal characters of, 259-60. Bastite in serpentines, 694 et seqq. Bats, Miss D. M. A., v. Barunrr, F. A., 173; ‘exhibits Archeo- cidaris Git A. vetusta & A. benbur- bensis, v; also Clypeaster altus, var. portentosus, v; also new Spa- tangide, vi; also a series of Danish rocks, lxxxvii; [on the terms ‘mutation’ & ‘cireulus’], Ixxii—] xxiv. Baverman, H., elected Auditor, iv. Bay or Lady Coal, marine band, 499- 500. Beach, raised, in Great Northern Coalfield, 69-72 figs. Brapnew., H. J. L., on the Relations of the HWocene & Cretaceous Systems in the Esna-Aswan Reach of the Nile Valley, 667-78 w. nap & sect. Bebside (Northumberland), sect. to North Seaton, &4. Bexcugr, C. E., obituary of, xlix—l. Beigium, tectonic map presented, xey ; Carb. Limest. ae w. that of Bristol area, 255-5 Beiuamy, C. Ve, on ‘ae Geology of Cyprus (title. only), WV; presents geol. map of that island, xci. Vol. 61.] GENERAL INDEX. 719 Bellerophon-Beds (Carb. Limest.), 212 et segg., 217, 231; (Cambrian) of - Arenig, 615. Bembexia (?) Groomii, sp. nov., 569- 70 & pl. xxxvii. Lloydii (2), 571. (?), sp. nov., 570-71 & pl. xxxvii. Benthoal organisms & stratigraphy, Ixxiv—lxxv. Berbera (Somaliland), 163 e¢ segq. Berrow Hill (Worcest.), Rheetic at, 425-30 w. map & sects. Berry-Hill Colliery (N. Staffs.), marine band at, 5U5, 506. Berth Hill (Worcest.), sect. thro’ Gadbury Bank, 42:5. Bibliography of twin - earthquakes, 19; of Northumberland & Durham Coalfield [Drift-deposits, &c.], 94- 95; of the palxontology &e. of Somaliland, 158-60; of — spo- rangium-like orgins of Glossopteris, &¢, 336-37; of marine bands in Coal-Measures, 523-27; of the geology of the N.H. Territories of the Congo Free State, 664. Bifidus-Shales of Arenig, 622-23. BicsBy medallists, list of, xxx1. Billy Mill (Northumberland), sect. to -. Westoe, 78. Biloculina fr. Somaliland, 176, Bilsdale (Yorks), Dogger, &e. about head of, 405-56. Bima (Congo Free State), 645; rocks from, 656-57. Biotite-norite fr. Carn Llidi, 585, 601 a pl, Xxxix. Birchenwood Colliery (Staffs.), marine band, 506, 509. Bishpool (Mon), sect. deser., 382. Bishton (Mon.), sect. deser., 377- (ies Bison (at Longeliffe), 51-52. Blackband Group & its flora, 310 ed seqq. Black Shales, see Avicwla-contorta Beds. Blaize-Castle Wood (Gloucest.), Carb, Limest. at, 235. Bu Akg, Rev. J. F., on the Order of Suc- cession of the Manx Slates in their Northern Half, & its Bearing on the Origin of the Schistose Breccia associated therewith, 358-72 figs. Blea-Wyke Beds & Dogger in N.E. Yorks., 441-60 figs. Blown sand (?), im Dewlish aie arouit trench, 37. Blue Lodge, see Siston. _Bomokandi (Congo Free State), 645 ; B. River, 648. Bone-bed in Tea-Green Marls, 376-77; Rheetic, of Glamorgan, 392e¢ seqg. Bone-cave at Longcliffe, 43-63 & pls. v-vili. Bonnny, T. G. (& C. A. Rarsry), on the Microscopic Structure of Minerals forming Serpentine, & their Relations to its History, 690- 715 figs. & pl. xlv (microscop. sects.). Borings & sinkings in great Northern Coalfield, 64 et segq., 73 et seqq. Bos primigenius ? (at Longeliffe), 51- 52. Bostonites, see Lime-bostonites. Boulby Cliff (Yorks), Dogger, &c. of, 451-52 fig. Boulder-Clay, &c. of great Northern Coalfield, 65 e¢ seqggq. Boulders, distribution of, in great Northern Coalfield, 69; boulders in Glacial (Dwyka) Conglom., 689. Boultham Boring (Lines.), specims, from, xev. Bowman, H. L., Murchison Geological Fund awarded to, xlv. Brachiopods, ranges & maxima of, in Bristol area, 245-47 & pl. xxix ; see also Product us, &e. Bradford Colliery (Lancs.), list of fossil plantsfrom, 320, 321 ; B. Four- Foot Seam, 320, 321, 322 Bramble - Hall gravel-pit (Hssex), specims. from, xcv. Brass, Rev. H., obituary of, lvii. Brassington (Derbyshire), ossiferous eavern near, 43-63 & pls. v—vill. Breccia, ossiferous, in Longcliffe Cavern, 45, 46. Brecciated intrusive rocks of N. Pem- brokeshire, 597 & pl. xl. Brentry Hill (Gloucest.), Ca b. Limest. at, 235. Bridgend (Glamorgan), Rhietic, &c. at, 407. Bristol area, palzont. sequence of Carb. Limest. in, 181-307 figs. & pls. xxii-xxix. Bristow, —, 41. British Museum (Nat. Hist.), Ter- tiary fossils fr. Somaliland in, 155- 80, w. map & pls. xvili-xx1. Broukhorst Spruit (Transvaal), ripple- marked mudstones, &c. of, 685. Brownz, R. G. M., obituary of, lx. Bryozoa-Beds (Carb. Limest.) in Bristol area, 188, 189, 220, 229. -Buchenstein Beds, chem. anals. of siliceous, &c. limest. from, 108; -- origin of do., 114; 1iiinéral. strue- ture of do., 123, 125, & pl. xii. 720 Bucxmay, 8. S., on certain Genera & Species of Lytoceratide, 142-54 figs. & pls. xv—-xvi. Bufo vulgaris (at Longeliffe), 57. Bundukwa, Mt. (Congo Free Statc), gneiss of, 647—48, 661. Bur Dab (Somaliland), 162 ez seqq. Burt, F. P., 549. Buta (Congo Free State), rocks from, 655-56 & pl. xl. _ Buta Shales, 644. Bye-laws, alterations in, x. Cadbury Camp (Somerset), Carb. Limest. near, 231. Cadoxton (Glamorgan), Rueetic &e. at, 399, 400. Calanophyllia Aylmert, 174. Caleareous rocks, causes of variega- tion in, 431-39. Calcitice limestones of Marmolata, 128. Caledonian folds in relat. to earth- quakes, 33, 34; faults & folds in Arenig district, 633-34. Calymene-Ashes of Arenig, 619-20. Camarotechia mitcheldeanensis, sp. nov., 302-303 fig. & pl. xxvi. Cambrian of Arenig district, 612-17. Campanian of Nile Valiey, 671, 675. Campanile, remarks on genus, 160-61. ef. giganteus, vars. A & B, 161-63 & pl. xvii. somaliensis, sp. nov., 163 & pl. xviii. Campophylium in Carb. Limest., range of, 244; genus defined, 276. aff. Murchisoni, 276-77. Caninia in Carb. Limest., range of, 243: genus defined, 272. cylindrica, muts. y & 8,, 272-73 & pl. xxiii. ‘Caninia-Oolite,’ 193, 212, 552, 558. Caninia-zone in Bristol area, 193-95, 207-208 ; faunal characters of, 260— 61. Canis lupus (at Longcliffe), 49-50. Capreolus caprea (at Longcliffe), 54 & pl. viii. Caradocian Series, [xxxiii-lxxxiv. Carboniferous Limestone of Bristol area, palzontological sequence in, 181-307 figs. & pls. xxii-xxix ; C.L. of Weston-super-Mare district, 548- 63 figs. Cardiwm cloacinwm, 422-23 & pl. xxxiii. Carn Ffald, Carn Perfedd, & Carn Trelwyd (Pembroke), igneous rocks of, 586-88, _ Carn Llidi (Pembroke), igneous rocks of, 585 & pl. xxxix. GENERAL INDEX. [ Nov. 1905, Carnachen Wen (Pembroke), oligo- clase-porphyrite of, 598 & pl. xl. Carnedd Lleithr (Pembroke), enstatite- diorite of, 586-87 & pl. xxxix. Catalogue of Library, x, xiii. Cave-deposits of Derbyshire, chrono- logy of, 63. Cavern, ossiferous, at Hoe-Grange Quarry, 43-63 & pls. v—viii. Centenary record of Geol. Soe., x. Cervus dama, 52-54, 61 et seqg. & pl. vii; teeth-measurements of, 53. elaphus, 52 & pl. viii; teeth- measurements of, 53. giganteus, 52 & pl. viii. Chalk, Danian Kchinocorys-, of Nile Valley, 668-69, 675; Phosphatic, of Taplow, 461-94 figs. Chalybeate water, raddling of rocks attributed to, 437. Charnian folds in relat. to earth- quakes, 33, 34. Charnwood Forest, faults originating Leicester earthquakes, 7; MS. geol. map exhibited, iv. Chase Hill, Wickwar (Gloucest.), Rheetic, &e. at, 417. ’ Cheadle Coalfield (Staffs.), marine horizon in, 510-12. Cheddar (Somerset), Semminula-zone at, 560. Chell Colliery (N. Staffs.), marine band in, 500. Chemical & mineralogical evidence as to the origin of the Dolomites of S. Tyrol, 97-141 w. map & pls. x-xiv (microscop. sects.) ; chemical analy- ses, see Analyses. Chepstow area (Gloucest.) Carb. Limest. correlated w. that of Bristol, 251. Chert fr. N.H. Congo Free State, 663. Chipping-Norton Limestone, 440. Chipping Sodbury (Gloucest.), sect. in Carb. Limest. descr. & fig., 203-11 & pl. xxvii. Chlorite, vermicular, in Aberfelin rock, 593, 602. Chonetes cf. comoides, 294; aff. co- moides, 295 fig & pl. xxvi. cf. crassistria, 294 & pl. xxvi. cf. hardrensis, 293-94 & pl. xxvi. - ef. daquessiana, 294 & pl. xxvi; mut. 6, 530 & pl. xxxv. papilionacea, 294; aff. papilio- nacea, 295 & pl. xxvi. Churnet Valley (Staffs.), marine band Bes OLAS . ‘Cipit’-hmestone of Seiser Alp, &e., LOG, alee. Vol. 61.] Circulus, use of term, Ixxii-lxxiv, 183, 306-307. Clapton-in-Gordano (Somerset), Carb. Limest. of, 231-32. Classification of sedimentary rocks, Ixi-lxxxvi ; see also Correlation. Clathratus-subzone in Bristol area, 191-92, 206, 215, 220, 227, 229, oe 232, 233; faunal characters of, Cleavage of rocks in Arenig district, 632-33. Clee-Hill area (Salop), Carb. Limest. pee ted w. that of Bristol, 252- a crore in Carb. Limest., range of, 243. aff. geometrica, 268. Cleistopora-zone in Bristol area, 189- 90, 201, 204-205, 214-15, 220, 227, 230; faunal characters of, 259. Clevedon area (Somerset), Carb. Limest. of, 225-28. Clevedonian defined, 264. Climatic changes in geological time, Ixxviii-lxxix, Cliothyris Royssti, 297. glabristria & mut., 297 fig., 298. Clisiophyllids in Carb. Limest., range of, 244; diagnosis of, 280-81; evo- lutionary history of, 286-87. Clisiophyllum (Carcinophyllum) 0, 285 & pl. xxiv. eee y matter in dolomite-crystals, Clypeaster altus var. portentosus, v. Coal-Measures of N. Staffs,, marine beds of, 495-547 figs. & pls. xxxiv— xxxvi; C.-M. (Middle) of S. Yorks. wash-outs in, 339-44 w. map & sects. ; C.-M. (Upper), divisions & correlation, &c. of, 308-23. Coalbrookdale Coal-Measures, biblio- graphy of marine bands in, 525; list of marine fossils from, 543- 44, Coalescence of the two parts of twin- earthquakes, 21-22. Codrington (Gloucest.), White Lias, &e. of, 419. Coedyrallt Group, 314. Celonautilus cf. subsulcatus, 042. Cogan Hall (Glamorgan), Rhetic near, 397. Col Crepa (Tyrol), chem. anals. of dolomites from, 106; mineral. structure of do., 120-21. Colchester earthquakes of April 22nd, 1884, 18, 22, 29; map of. 30. Coldknap (Glamorgan), Rheetic, &e. at, 397-98. GENERAL INDEX. 721 Columnar basaltic rock of Strumble Head, &c., 582, 583. Combe, Mt. (Congo Free State), rocks from, 658, 659. Conglomerates (Rhetic) of Tregyff, 41)2; Glacial, in Transvaal, 679- 89; limonitic, in Congo Free State, 645 e¢ segg., 649-50. Congo Free State, geology & petrology of N.H. Territories, 641-66 figs. & pls. xlii—xliv. Contemporaneous erosion of Lias, 450 fig., 452; igneous rocks of Weston-super-Mare district, 9953, 558, 561; do. of N. Pembrokeshire, 580-81 ; vole. materials, accumulat. of, Ixviii—ixix. Conus (Hocene), fr. Somaliland, 166. Cora-subzone in Bristol area, 195-96 ; in Weston-super-Mare district, 049 et seqgq. Corals, ranges of Carb. Limest. in Bristol area, 243 e¢ segg., w. range- diagram, pl. xxviii; as zonal indices ibid., 184 e¢ seqgg.; in Tyrolese dolomites, 120 e¢ segg. ; list of, fr. Somaliland, 178. Coral-reef theory of origin of Tyrolese dolomites, 98 ez seqq. Corny Hill (Durham), sect. to West Boldon, 91. Correlation of Coal - Measures by means of marine horizons, 319- _ 22 w. vert. sects. on p. 518: by means of plant-remains, 308-23. Cortina (Tyrol), rock-succession at, 101; dolomites from, chem. anals. of, 106-107 ; origin of do., 113; mineral. structure of do., 120-21. Cotham Marble, equivalent, at Bishton, &e., 377 et seqg.. Council, report of, ix-xi; Council & Officers elected, xxi. Cowbridge (Glamorgan), Rhzetic betw. Pyle and, 406-10; betw. Barry and, 397-406. Crabtree Coal, marine horizons near, 512. Cretaceous & Eocene of Nile Valley, 667-78 w. map & sect.; see also Chalk. Crick, G. C., 474, 493. Cristallo, Mte. (Tyrol), chem. anal. of dolomite from, 107 ; mineral. struc- ture of do., 122. Cromer Forest-Bed, flint-scraper from, ie Cromhall district (Gloucest.), Carb. Limest. in, 239-40. Cross Farm (Glamorgan), Rhetic, &, at, 399-97. ) . GENERAL INDEX. Crush-conglomerate in I. of Man, origin of, 358, 361 ez seqgg., 368 et segq., 872-73. Ctenodonta levirostris, 536 & pl. xxxv. undulata, 537 & pl. xxxv. Cullinan diamond, lxxxix. Cuuuis, C. G., 421. Cwm-y-Graig (Pembroke), pyroxene- porphyrite from, 598-99 & pl. xl. Cwrt Colman (Glamorgan), 408. Cyathophyllum in Carb. Limest., range of, 244; evolut. & mutat. of, 276. Murchison, 275. regium, 275-76. —— 6, 274 & pl. xxii. —— 0, 274-1960 pl. xan. Cymatiophyllum-group defined, 285- 86. Cyprus, Clypeaster from, v; geol. map presented, xci. Cyrtina carbonaria, 301, 558. Cyrtostropha torquata (?), 572. Dachstein dolomites, chem. anals. of, 109; origin of, 115; mineral. structure of, 123-24. Daerfawr Shales of Arenig, 624-25. Danian of Nile Valley, 668-69, 675. Dantet-Prpgron Fund, list of awards from, XxVili. Danish rocks exhibited, lxxxvii. Darau (Nile Valley), sect. to Jebel Silsila, 670. Davison, C., on the Leicester Harth- quakes of August 4th, 1893, & June 2st, 1904, 1-7 fig. & pl. i (map); on the Derby Earthquakes of July 3rd, 1904, 8-17 fig. & pl. ii (map) ; on Twin-Harthquakes, 18-33 figs. ; requests co-operation of Fellows in obtaining earthquake-records pre- vious to 1891, 34. Denbighshire, Coal- Measure plants from, 314; C.-M. marine fossils from, 543-44. Dendracis sp. (Kocene), 175. Derby earthquakes of July 3rd, 1904, 8-17 fig. & pl. 11 (map). Derbyshire cave-deposits, chronology of, 63. Derfel Limestone of Arenig, 627- 28. Dewaraus, G., presents his tectonic map of Belgium, xcv. Dewlish (Dorset), Hlephas meridionalis at, 35-38 & pls. iii—iv. Diabases of Strumble-Head district, 581 et segg.; in Congo ree State, 645, 651, 659. [Nov. 1905, Diamantiferous breccia of S. Africa, microscop. characters of, 592-93 & pl. xlv. Diamond, the Cullinan, lxxxix. Dibunophyllum 0, 283-84 & pl. xxiv. —— ¢, 284 & pl. xxiv. wp, 284-85 & pl. xxiv. Dibunophyllum-group defined, 282- 83. Dibunophyllum-zone in Bristol area, 197-99, 202-203, 211, 218-19, 234, 235, 236-37, 242 ; faunal characters of, 261-62. Dicranograptus - Shales of Arenig, mOe Dictyonema-Band of Arenig, 614-15. Differences in characters of successive deposits, Ixvi—lxviil. Differential solution & dolomitization, 132 e¢ segg., 140-41. Differentiation of magmas in N. Pembrokeshire, 605 e¢ seqq. Dimorphoceras Gilbertsont, 5389 & pl. EXKV. Dinantian, use of designation dis- cussed, 264. Dinas Powis (Glamorgan), Rhzeetie, &e. near, 395-97. Discocylina fr. Somaliland, 176, 177. dispansa, 177. Divergence of isoseismal axes in twin- earthquakes, 26. Dixon, E., 253, 254 et seqq. Djabbir (Congo Free State), 645. Dobar Limestone, Tertiary age of, 157 ; foss. from, 167, 170. Dogger (& Blea-Wyke Beds) in N.E. Yorks., 441-60 figs. Dolerites of Strumble-Head district, 582, 583 ; andesitic, of Arenig, 630- 31. Dolgelly Beds of Arenig district, 613— 14 Dolomites of 8. Tyrol, origin of, 97-141, w. map & pls. x-xiv (micro- scop. sects.). Dolomitic Conglomerate, & its relats. to Carb. Limest. nr. Tytherington, 222-23. Dolomitization, causes, &e. of, 127 et seqq. Donan, Miss Jann, Observations on some of the Loxonematida, with Descriptions of two new Species, 564-66 & pl. xxxvil pars; on some Gasteropoda from the Silurian Rocks of Llangadock (Caermarthen- shire), 567-77 & pl. xxxvii pars. Dongorreh (Somaliland), 163 e¢ segq. Donors to Library, lists of, x- XVLIL. * ’ { a ee ee Wol. 6r.| Double earthquakes differentiated fr. twin-earthquakes, 18; double shocks in Leicester earthquakes of 1893 & 1904, 2, 4-5; in Derby earthquake of 1904, 11, 12; double slip originating Leicester earth- quakes, 7. Draycott Colliery (Cheadle), marine band at, 511. Drei Zinnen area (Tyrol), chem. anals. of dolomites from, 108; origin of do., 113; mineral. structure of do., 122. Druridge (Northumberland) pre-Gla- cial valley, 85-86 & map. Dungu (Congo Free State), rocks from, 660. Duyn, H.J.,Murchison Medalawarded to, xl—xli. Durdham Downs (Somerset), Carb. Limest. at, 283-384. Durham Coal-Measures, bibliography of marine bands in, 527; list of marine fossils from, 543-44; Dur- ham (& Northumberland) coalfield, superficial deposits & pre-Glacial valleys of, 64-96 & pl. ix (map). Durrenstein area (Tyrol), chem. anals. of dolomites trom, 107; origin of do., 113; mineral. structure of do., 122. Dwyka Conglomerate in Transvaal, 679-89 figs. Harth-movements, variation in nature of, Ixix-lxx ; (post-Carboniferous), in Glamorgan, &ec., 411-18, 414, 415, 421; in Arenig district, 632 e¢ seqq. Harthquakes in Derbyshire on July drd, 1904, 8-17 fig. & pl. ii (map) ; in Leicestershire in Aug. 1893 & June 1904, 1-7 fig. & pl. i (map); twin-earthquakes, 18-34 figs. Echinocorys-Chalk of Nile Valley, 668, 669, 674, 675. Echinoderm-spines in Tyrolese dolo- mites, 115, 125; echinoderms & _ rock-building, Ixxxvii. Eddy-marks (?) in mudstones, 685. Edfu (Nile Valley), sect. descr., 671- 72. Hl] Atwani, see Edfu. El Kab (Nile Valley), 672-73. Hlection of Fellows, i, ii, iii, iv, vii, PaEXVLly XC; XC XCM OL oor, Corresp., iv, Xcill. Elephas antiquus, 55, 59 & pl. vii. — meridionalis at Dewlish, 35-38 & pls. ilt-iv. GENERAL INDEX, 723 Exspen, J. V., on the Igneous Rocks occurring between St. David’s Head & Strumble Head (Pembrokeshire), 579-607 figs. & pls. xxxvili-xl (microscop. sects.). Enstatite, format. of serpentines from, 694-96, 712-13. Enstatite-diabase of Strumble-Head district, 582, 5838-84; fr. Portheiddy Common, &c., 591-92; of Ynys-y- Castell, 593-94; of Tresszysilt, 004 & pl. xxxix. Enstatite - diorite of St. David's - Head district, 585 e¢ segg. & pl. KIN, Eocene (& Cretaceous) of Nile Valley, 667-78 w. inap & sect.; Hoc. fossils fr. Somaliland, 155-80 w. map & pls. xvii-xxi. Eoliths, so-called, 38. Hphipptoceras costatwm, SAL. Epicentres of Leicester earthquakes Of 1SIS) &) N90E 2 ec scoge: (ot Derby earthquakes of 1903 & 1904, 10, 12; of twin-earthquakes, 28- 31. Epidote in igneous rocks of N. Pem- brokeshire, 602. Erithacus rubecula? (at Longecliffe), 56. Hrosion, contemporaneous, of Lias, 450 fig., 452. Erwent Limestone of Arenig, 62Z0- 21: Eskdaleside (Yorks), Lias, &c. of, 454, ' Eskers in Northumberland, 68. Esna-Aswan reach of Nile Valley, HKocene & Cretaceous in, 667-78 w. map & sect. Hsna Shales, 675, 676. Lstheria-Bed at Goldcliff, &c., 376 e seg. Estimates for 1905, xxxli-xxxiii. istuarine (Upper), of Lincolnshire, &c., 440; Estuarine of N.E. Yorks, 441, 447-48 et seqg. Ktruria-Marl Group & its flora, 310 et seqq. EHumetria spp., 301-802. Kuphemus ct. Urei, 538 & pl. xxxvi. Europe, Internat. Geol. Congress map of, xciv. Huspira cf. scalariformis, 164 & pl. Salixis ——- cf. hybrida, 164-65 & pl. xix. Evolution &involutionin cephalopoda, 142-43 et seqgq. Excentricity of isoseismals in twin- earthquakes, 24-25 fig. Extensus-Flags of Arenig, 619. 724 Failand district (Somerset), Carb. Limest. of, 211-19. Falling Foss (Yorks), Dogger, &c., of, 453. Farach (Congo Free State), 651; rocks from, 660. Fatira (Nile Valley), tufaceous lime- stone at, 668. Fault, hade of, within twin-foci, 32, 33; faults originating Derby earth- quakes of 1904, 17; originating Leicester earthquakes of 1893 & 1904, 6-7; growth of faults, 33, 34; faults in Weston-Worle ridge, 591; in Arenig district, 633-34 ; in St. David’s-Head district, 580. — Fayolia cf. grandis, i. Frarnsipes, W. G., on the Geology of Arenig Fawr & Mvel Llyfnant, 608-37 w. sects. & pl. xli (map); exhibits Llandovery-Tarannon grap- tolites fr. Llanystumdwy, v. Fedaja Pass, &c. (Tyrol), dolomites, &c. from, 104, 105, 117. Felis catus (at Longcliffe), 48-49 & pl. vil. leo (at Longeliffe), 49 & pl. vil. Fellows elected, i, ii, ili, iv, vii, lxxxvil, Ixxxvili, xc, xcl, xcii, xclii; names read out, xciv; number of, ix, xix— Sx Felspars in igneous rocks of N. Pem- brokeshire, 601-602. Fercuson, W., obituary of, vii. Ffestiniog Beds cf Arenig, 612. Fiiltirgerig Beds of Arenig, 621-22. Fimbria ct. lamellosa, 172-78 & pl. xxi. Financial Hepes XXX11-XXXViil. Fishes in N. Staffs. Coal-Measures, 528-29. Fish-bed (Rheetic) at Lavernock, 391- FisueEr, the Rev. O., on the Occurrence of Hiephas meridionalis at Dewlish (Dorset)—Second Communication : Human Agency suggested, 35-37 & pls. ili-iv. Flax Bourton, see Failand. Flint-implements found w. remains of elephant, rhinoceros, &c., 36; flint-scraper (?) fr. Cromer Forest- Bed, il. Flintshire Coal- Measures, fossils from, 543-44. Flora of the Upper Coal-Measures, 308 et seqq. Florence Colliery (N. Staffs.), sect. at, 505, 506. Florence marine bed, 503-504. Foci of twin-earthquakes, 22-24, 28- 32; foci of Leicester earthquakes marine GENERAL INDEX. [ Nov. 1905, of 1893 & 1904, 2 e¢ segg.; of Derby earthquakes of 1904, 12, 17. Foley Colliery (N. Staffs.), marine band at, 500. Foraminifera in Tyrolese dolomites, 123, 125; in Tertiary limest. of Somaliland, 175-77 ; in Taplow Chalk, 484. Fore-shock of Derby earthquake, 9. Foreign Correspondents elected, iv xcill; list of, xxiv. Foreign Members, list of, xxiti. Forest of Dean (Gloucester), faunal sequence in Carb. Limest, of, 251— 52. iHioreeta! submerged, in great Northern Coalfield, Tks Formenreihe (=genetic series), 147—- 48. Forsterite, format. of serpentine from, 712-13. Fossil-lists, compilation & interpreta-— tion of, Ixxvii, 182. Fostrr, Sir Ciement Le N., obituary of, lii—liv. Foveus, F. A., obituary of, xlvii—xlix. Four-Feet Coal, marine horizons near, 512. Fow ter, P., obituary of, Ix. Fox, W. Storrs, 44, 50. Fulwell Hill (Durham), sect. to Clea- don Hills, 66 ; raised beach on, 70- 71 figs. - Gadbury Bank (Worcest..), sects, to Berth Hill & Berrow Hill, 426. Gader Gorge (Tyrol), limest. &e. from, 108, 109, 114; mineral. structure of do., 123 & pl. xii. Gaima, Mt. (Congo Free State), 651 ; rocks from, 657-59. Garden Cliff (Gloucest.), sect. to La- vernock, +12. Garn Boleb, Garn Fawr, Garn Fechan, &Garn Gilfach (Pembroke), igneous rocks of, 582-83. Garrasgooi (Somaliland) 164 ez seqq. G-arwoop, E. J., exhibits lantern-slides illustrating the use of three-colour photography in demonstrating the microscopic characters of rock- forming minerals in polarized light, vil; elected Secretary, xxii. Gastrioceras carbonarium, 539-40 & pl. xxxvi. Listeri, 540. Gatheram Farm, see Wick. Gerxir, Sir Arcw1BALD, receives Lyell Medal for H. Reusch, xlii—xliii ; exhibits photographs & pebbles fr. Nan-t'ou, Xcl. Vol. 61. ] Gens or species-group defined, 183-84. Geograms defined, lxii. Geological Survey maps, &c. presented, MI IKXRVIll, Xe, XCIi, KCI, XCLV, XCV. Gerard’s Cross (Bucks), ancient swal- low-holes exposed at, 41. Giau Pass (Tyrol), chem. anal. of dolomite from, 107 ; mineral. struc- ture of do., 121 & pl. xiv. Greson, W., Lyell Geological Fund awarded to, xlvi. Gin-Mine Coal, marine band below, 500-501. Glacial (Dwyka) Conglomerate in Transvaal, 679-89 figs. ; glacial de- posits in great Northern Coalfield, 65 et segg.; Glacial Period, zbid. protracted duration of, 93. Glaciation of Arenig district, 635-36 ; of Pretoria & Middelburg districts, 687-88. Glaisdale (Yorks), Dogger, &ec. of, 454-55. Glamorgan, Rhaetic & contiguous deposits of, 385-424 figs. & pl. xxxiii (foss.); see also Gower, &e. Glen Auldyn, sce Auldyn, Glen. Globigerina fr. Somaliland, Livithe Glossopteris Browniana, sporangium- like organs of, 324-38 & pls. xxx— KI Glyphioceras micronotum, 538-39 & pl. xxxv. paucilobum, 539. —— Phillipsi (2), 538 & pl. xxxv. reticulatuim, 538 & pl. xxxv Gneisses, in Congo Free State, &c., 647, 648 e¢ segg., 660 et seqg. & pl. xliii. Goldcliff (Mon.), sect. deser. & fig., 374-77 & pl. xxxii; sect. to Laver- nock, 415. Goldsitch Colliery (Staffs.), marine band at, >12. Goniopora Parkinsoni, 174-75. Croniostropha Cambria, sp. nov., 571 & pl. xxxvii. Gornergrat (Switzerland), slaty ser- pentine from, 710 fig. Gower, W. (Glamorgan), Carb. Limest. of, 205. Granite in Conge Free State, &c., 644, 645 et seqqg., 656 et segg. Granular andesites of Arenig, 632, Graptolites, Llandovery-Tarannon, v. Great Barr, sce Hamstead. Grecory, J. W., Bigsby Medal awarded to, xliii—xliv. GRENFELL, W. H., 495. 176, GENERAL INDEX, 720 Grey Marls, so-called, 384; interpre- tation of, 386-87, 414, 480; in Glamorgan, 389 e¢ seqq. Grindon (Durham), esker near, 68. Groden Pass (Tyrol), dolomites from, 105, 118 & pl. x. Groom, T. T., communicates Miss Donald’s papers, 564, 567. Grovesend, see Tytherington. Growth of faults & folds, 33, 34. Gryphea Gregoryi, sp. nov., 167-68 & pls. xvil, xxi. sp. (Eocene), 168 & pl. xxi. Gubbin Ironstone, 322. Gurnny, Rev. H. P., obituary of, lix. Gyronema, genus diagnosed, 573. Octavia, & varr. fasciatum, glabrum, & interstriatum, 573-715 & pl. xxxvii. Hematite nr. Mt. Lingwa, 646; he- matite-band at Weston Sprink, 508 fig., 510; sce also Iron-ores. Hamstead Colliery (Warwick), list of fossil plants from, 318. Hand-refractometer exhibited, v—vi. ‘ Hard Blue,’ see Diamantiferous brec- cia. Harker, A., exhibits photographic views illustrating geol. structure & physical features of Skye, lxxxviii. Hasty Bank (Yorks), Dogger of, 456. Hatcn, F. H. [on the Cullinan dia- mond |, Ixxxix. Hatley Rocks (Somerset), 555, 556. Hawthorn Dene (Durham), viewof,92. Hayes- Wood Colliery (N. Statfs.), marine band at, 507, 509. Huarry, Miss M., Notes on Upper Jurassic Ammonites, with special reference to Specimens in the Uni- versity Museum, Oxford: II (title only), i. Helminth (?) in Aberfelin rock, 593. Henbury & Henbury Hill (Gloucest.), Carb. Limest. at, 235. Hendre (Glamorgan), Rheetic, &e. at, 406. Henllan Ashes of Arenig, 619—20. Herberts, the (Glamorgan), Rheztic near, 404. Herrizs, R. §., retires fr. Secretary- ship, xxi; exhibits Inferior-Oolite fossils fr. N.E. Yorks., xcii. ‘ Herring-bone’ structure in twinned augite, 989. ‘Heteropic’ character of dolomites of S. Tyrol, 98, 100. Hexenfels (Tyrol), chem. anal. of do- lomite from, 107; mineral. struc- ture of do., 121. Hill Series in I. of Man, 365. Hinp, W., Notes on the Paleontology [of the Marine Bands in the N. Staffs. Coal-Measures], 527-47 & pls. xxxv—xxxvi. Hirnant Limestone. horizon of, lxxxv. Hirundo-Beds of Arenig, 621-22. Hoe-Grange Quarry (Derby), ossi- ferous cavern at, 43-63 & pls. v-viii. Horrmann, J. I., presents his Wit- watersrand map, iii. Hognaston (Derby), 17. Houtanp, R., 175. Houuoway, G. T., 606. Homeeomorphy, importance of, Ixxv-- Ixxvi. Hornblende in igneous rocks of N. Pembrokeshire, 601; see also Am- phibole. Hornblende-porphyrites of Arenig, 612, 632. Horse, remains of, absent at Longcliffe _ Cavern, 59. How Mill (Glamorgan), Rheetic near, 404. Hows, J. A., Petrological Notes [on Rocks fr. N.B. Territories of Congo Free State, &c. | 655-66 & pls. xliii- xliv (microscop. sects.); commu- nicates G. F. J. Preumont’s paper, 641. Hugues, T. Mck., 609. Hungary, Geol. Surv. maps presented, Xcill. Hyena crocuta, 49. Hyde Heath (Bucks), greywethers at, 42. Hypersthene - andesites of Arenig, 628-30. Ibembo (Congo Free State), 644. Igneous rocks betw. St. David’s Head & Strumble Head, 579-607 figs. & pls. xxxvill-xl; see also Granite, gc. Ilkeston (Derby), Fayolia from, i. Inferior Oolite of Oxfordshire, 440; of Blea Wyke, &c., 441 et seqg. ‘ Insect- Limestone’ (Rheetic) at Wain- lode Oliff, 429. ‘Insoluble residue in limest., signifi- cance of absence or presence of, 100 et seqq. Intensity, relative. in twin-earth- quakes, 20, 26-28 & figs. International Geol. Congress map of Kurope, xciv. Interval between parts of twin-earth- quakes, mean duration of, 21. Intrusive rocks of Strumble- Head & St. David’s-Head districts, 581-94 ; of Arenig district, 628-82. GENERAL INDEX, Kinston, &., | [ Nov. 1905, Involution & evolution in- cephalo- poda, 142-43 et segg. Ireland (S.H.), intrusions correlated w. those of Abercastle-Mathry dis- trict, 6038-604 w. map, 607. Tron in Keuper Marls, 434. _ Jron-mountains of Uelle, 646. Tron-ores in igneous rocks of N. Pem- brokeshire, 600; in Congo Free State, 646 e¢ segg., 657 et seqq. ‘Tegmsiome Measures at. Priorsfield, 500. Isacoustic lines of Derby earthquake of 1904, 13-14. Isoseismals of Leicester earthquakes of 1893 & 1904, 1-2,3; of Derby earthquakes of 1904, 9-10, 15-16; of twin-earthquakes, 24-26. Itembiri River (Congo Free State), 644. Japan, serpentines from, 712. Jebel Awaina, &c.; see Awaina, Jebel, Se. Jockie’s Syke (Cumberland), Measure plants from, 315-16. Jones, O. T., 253. Jupp, J. W., 132; receives Murchison Medal for E. J. Dunn, xl-xhi. JuKns-Browne, A. J., 493; [Coutribu- tions to] the Geology of Cyprus (title only), v. Jurassic Lytoceratide, 142-54 figs. & pls. xv-xvi; see also Lias, &e. Jurense- & allied groups of Lytocera- tide, 142 e¢ seqg. Jurensis-zone at Blea Wyke, 443. Coal- Kaolin in Uelle district, 645. Karroo rocks, in Central & W. Trans- vaal, subdivision of, 683. Keele Group & its flora. 310 e¢ seqq. Keicuiny, Miss M., 450. Keisley Limestone, horizon of, Ixxxv— lxxxvi. Kettleness (Yorks), Dogger, &c. of, 451. Keuper (Upper) at Goldeliff, &¢., 377 et seqg.; in Glamorgan, 389 ef scqq. ; in Berrow-Hill district, 425 et seqq. ; at Wainlode Cliff, 429; K. Mar's, causes of variegation in, 431-39 w. chem. anals. on the Divisions & Correlation of the Upper Portion of the Coal-Measures, with special reference to their Development in the Midland Counties of aici 308-21. Vol. 6r.] Kidwellian defined, 264, 265. Kidwelly(Caermarthen), Carb. Limest. correlated w. that of Bristol, 254. Kirkmichael (I. of Man). interpreta- tion-section to Laxey, 367. Kitali (Congo Free State), mica-schist at, 646. Klipfontein (Transvaal), view showg. glaciated surface at, 686. Knypersley marine band, 512. Kom Ombo (Nile Valley), geology of, 667-70. Koninckophyllum, genus defined, 281. ——- 9, 228 & pl. xxiii. Kor6, Bunut1ré, elected For. Corresp., XCiil. Lado Enclave (Nile Territory), geo- logy of, 653-54; rocks from, 661- 62. Lady Coal, marine band above, 499- 500. Lamellibranch-shells in Tyrolese dolo- mites, 125, 126; see also Cardium, &e. Laminosa-dolomites, see I.-subzone. Laminosa-subzone in Bristol area, 227, 229, 230, 231, 234, 238, 239, 241; in Weston-super-Mare dis- trict, 551 et segg., 558. Lampe.uen, G. W., 358 et segg., 372. Lanarkian Series, name proposed, 319, 320; do. opposed, 322. Lancashire Coal-Measures correlated w. those of Yorks. & Midland Counties, 518-22; bibliograpby of marine bands in, 526; list of marine fossils from, 543-44. Langkofl (Tyrol), chem. anals. of, dolomites from, 104; origin of do., 112; mineral. structure of do., 116- ie Lavas of Spring Cove, &c., 553; of Llanrian, 580-81. Lavarella (Tyrol), chem. anals. of dolomites from, 105; mineral. struc- ture of do., 118-19. Lavernock (Glamorgan), Rheetic &c. at, 389-93 figs.; sects. to Garden Cliff, &e., 412, 415. Lavernock Shales, 393, 394. Laxey (I. of Man), interpretation- section to Kirkmichael, 367. Leafy Glacial Clay of great Northern Coalfield, 67. Txpoor, G. A., 64, 90, 94. Lacks, R.'G. E., 155 et segg. . _Leckwithbridge (Glamorgan) sect. deser., 393-94. Leicestershire earthquakes of August: 4th, 1893, & June 21st 1904, 1-7 GENERAL INDEX.. da Yond G24 fic. & pl. i (map); Leicestershire Coal - Measures, bibliography of marine bands in, 525; list of marine fossils from, 543-44. Leiopteria longirostris, 537 & pl. xxxv. Lemmus lemmus (22) at Longeliffe, 56. Leptena anaioga, 296. Lepus cuniculus (at Longcliffe), 55. sp. (at Longcliffe), 55. Leucoxene in igneous rocks of N. Pembrokeshire, 602. Ley-Hill Quarry, see Cromhall. Leycett Colliery (N. Staffs.), marine band at, 507, 509. Lias (Lr.) at Goldcliff, &c., 375-76 ct segg.; at Lavernock, 389, 392 e¢ seqgg.; at Berrow Hill, 427-28; Lias in N.E. Yorks., 441 et segq. Library, progress of new card-cata- logue, x, xiii; lists of donors, xiii— XViil. Library & Museum Commnittee, report of, Xi-Xxill. Libyan (Lr.)= Eocene pars, 674. Likati (Congo Free State, 645. Lima valoniensis, 425-24 & pl. xxxiii. Lime-bostonite & porphyrite-intru- sions‘in Abercastle-Mathry district, 594-99 fig., w. chem. anals. & Tolls ell. Limestones, see Carboniferous, Dolo- mites, gc. Limonitic conglomerates in Congo Free State, 645 et seqg., 649-50. Lincolnshire Limestones, 440. Lingula mytitoides, 529-30 & pl. xxxv. Lingula-Beds of Blea Wyke, 448, 444. Lingulella-Beds of Arenig, 612. Lingwa, Mt. (Congo Free State), iron- ore of, 646. Linthia (2), Eocene, 173. Lnotina somaliensis, sp. nov., 165-66 & pl. xix. Lipodongu Falls (Congo Free State), eranite at, 644, 656. Lis-Werry (Mon.), sect., descr., 382- 83. Lithological characters, their import- ance in stratigraphy, Ixvii et seqq. Lithophaga sp. (Kocene), 170 & pl. xxi. Lithostrotion in Carb. Limest., range of, 244; genus & its modifications defined, 277-78 ; mutations of, 280, 304 & pl. xxiii. —— basaltiforme, 279. arreguiare, 279. —— junceum, 279. '—_— Martini, 278. — Portlocki, 279. Littlebeck (Yorks.), Dogger, &c. of, 453-54, 428 Llandeilian Series, Ixxxiii. Llandovery - Tarannon _ graptolites exhibited, v; Llandovery Beds, gasteropoda from, 569. Llangadock (Caermarthen), Silurian gasteropoda from, 567-78 & pl. XXXVii. Lianmartin (Mon.), sect. descr. & fig., 379-80. Lianrian (Pembroke), lavas, 580-81. Lianwern (Mon.), sect. descr. & fig., 380-81. Lianwnda type of basic intrusive rocks defined, 581. ~ Llanystumdwy (Caernarvon), grapto- lites from, v. Llech Dafad (Pembroke), enstatite- diabase of, 583. Llyfnant Flags of Arenig, deser., 619. Lobes, superior lateral, in Lytocera- tide, comparison of, 151-53 figs. Lopes, H., 493. Lonan (& Niarbyl) Flags (I. of Man), position of, 566-68. Long Ashton (Somerset), Carb. Limest. at, 233. Longeliffe (Derby), ossiferous cavern at, 43-63 & pls. v-viil. Longton (Staffs.), Lady Coal near, 499. Longtou-Hall Colliery (Staffs.), marine _ band above Moss Coal, 504-505. Lonsdalia floriformis, 286. rugosa, 286. Lonsdalia-group defined, 286. Lonsdalia-subzone in Bristol area, 199, 203, 235, 236-37; faunal characters of, 262. Lorenzo, G. px, elected For. Corr., iv. Lort-Puriurs, Mrs., 163 et seqg. Loxonema, restriction of genus, 564. Loxonema acutum, 533 & pl. xxxv. Grindrodti, sp. nov., 565-66, 572 & pl. xxxvil. — pseudofasciatum, sp. nov., 566 & pl. xxxvil. sinuosum (?), 572. Loxonematidz, observations, on 564— 66 & pl. xxxvii pars; see also Loxo- nema. Lucina cf. gigantea, 170-71 & pl. xx. cf. Menardi, 172 & pl. xxi. ef. thebaica, 171-72 & pl. xx. Ludlow Beds, gasteropoda from, 566, 570 et seqq. Lyrtut Medallists, list of, xxix; Geolo- gical Fund, list of awards from, xxx. Lytoceras defined, 148. Lytoceras confusum, 150. Lytoceratide, certain genera & species of, 142-54 figs. & pls. xv—xvi. = GENERAL INDEX. [ Nov. 1905, McC eax, F., obituary of, lix—lx. McManon, C. A., obituary of, 1- hi. Meena (Norway), lime-bostonite com- pared w. that of Abercastle, 596, 598 fig. Magnesian Limestone in great North- ern Coalfield, pre-Glacial condition of, 91,94; concretions in Longcliffe Cavern, 47. Mahamid (Nile Valley), 672. Main Golis (Somaliland), 173, 175. Makassa Rapids (Congo Free State), rocks from, 660. Man, I. of, see Manx. Mandjana, Mt. (Congo Free State), iron-ore of, 646. Manseu-Puieypa1, J. C., 35. Manx Slates, order of succession of, & its bearing on the origin of the Schistose Breccia assoc. therewith, 308-73 figs. Map of Leicester earthquakes of June 21st, 1904, 4: of do. of August 4th, 1893, pl. i; of Derby earthquake of July 3rd, 1904, pl. ii; of aftershock of the same, 16; of Colchester earthquake of 1884, 30; of pre- Glacial ‘Sleekburn Valley,’ &c., 82-. of Druridge [pre-Glacial] Valley, 85; of Wear, ‘ Wash,’ & Tyne pre- Glacial Valleys, pl. ix; of part of S. Tyrol, 102; of British Somali- land, 156; showg. outcrop of Carb, Limest. in Bristol area, 187; illus- tratg. the Middle Coal-Measure wash-outs around Aldwarke & Thry- bergh, 339; (geol.) of the country around Berrow, 425; of the railway and canal-system of N. Staffs, showg. posit. of collieries where Marine Bands have been traced in the Coal-Measures, pl. xxxiv; (geol.) of the Weston-Worle ridge, 550; showing relations of Aber- castle & S.H. Irish intrusives, 604 ; (geol.) of country betw. Fishguard & St. David’s Head, pl. xxxviii; (geol.) of Arenig Fawr. & Moel Llyfnant, pl. xli; (geol.) of N.E. Territories of Congo Free State & Lado Enclave, pl. xlii; of River Nile fr. Aswan to Qena, 667; of district HE. ef Pretoria, 680. . Maps presented, ili, vili, xe, xci, xcii, XCill, XCiV, XCV. Marine Beds in Coal-Measures of N. Staffs., 495-547 figs. & pls. XXXIV—XXXVI. Marmolata (Tyrol), chem. anal. of dolomites from, 104; origin of do., Wolk Ox: | 112; mineral. structure of do., 117-18 &pl. x. Marmoree hemera, beds of, 393. Marr, J. B., 636 ; addresses to medal- lists and recipients of awards, xxxix et seqg.; obituaries of deceased Fellows, &c., xlvii e¢ segg.; on the Classification of the Sedimentary Rocks, lxi-Ixxxvi. Marsupites-Beds at Taplow, 478-80. Massive Ashes of Arenig, 626. Mathry - Abercastle district (Pem- broke), lime-bostonite & porphyrite- intrusions of, 594-99 fig., w. chem. anals, & pl.xl; their extension into S.E. Ireland, 603-604 w. map, 607. Matrei (Tyrol) serpentine, 705-706. Maughold Head (I. of Man), 364, 366. Maxima (& ranges) of Carb.- Limest. corals & brachiopods in Bristol area, 243-47 & pls, xxvili- eR Medals & Funds, award of, xxxix— xlvi. Megalytoceras, gen. nov., 150, 161. confusum, 150 w. figs. Meles taxus (at Longcliffe), 50. Menior, FE. T., on the Glacial (Dwyka) Conglomerate in the Transvaal, 679-89 figs. Menvity, E. H. V., Ixxxix; presents photogr. of Cullinan diamond, xci. Mendip area (Somerset) Carb. Limest. correlated w. that of Bristol, 248-50; see also Weston. Mendola (Tyrol) dolomite, chem. anals. of, 108; origin of, 114; mineral. structure of, 123, 125. Merch (Glamorgan), Rhetie near, 397. Mica abundant in Blea-Wyke Series, 446. Michelinia in Carb, Limest., range of, 243, 269. —— ef. favosa, 269. megastoma, 269. ef. tenuisepta, 269. Micraster cor-anguinum-Beds at Tap- low, 477-78, 489. Microcline-gneisses fr. Congo Free State, 658 ez segg. & pl. xiii. Microtus agrestis (?), 56. amphibius (2), 56. (Hvotomys) glareolus, 55-56. Middelburg & Pretoria districts (Transvaal), glaciation of, 687-88. Middle Hope, see Woodspring. Mipputeroy, F. E., on the Wash-outs in the Middle Coal-Measures of South Yorkshire, 339-44 w. map & sects. GENERAL INDEX, 729 Midland Counties, divisions & cor- relation of Up. Coal-Measures in, 308-23; coalfields correlated w. those of Yorks. & Lanes., 518-22. Miholina fr. Somaliland, 176. Milton (Mon.), sect. descr., 381-82. Milton Hill (Somerset), Carb. Limest. of, 549 et seqg. Minnie Pit (Staffs.), fossils fr., 509. Miocene Spatangide fr. Holstein, vi. Mitcheldean area (Gloucest.), Carb. Limest. correlated w. that of Bristol, 251-52. Mirtcueson, G. A., 504, 522. Moat-House (Somerset), Carb. Limest. of, 232. Modiola-zone in Bristol area, 188-89, 200-201, 204, 214, 219, 229; faunal characters of, 258-59. Moel Liyfnant (Merioneth), geology of Arenig Fawr and, 608-40 w. sects. & pl. xli (map). Monckton, H. W., elected Auditor, iv. Monmouthshire, Rheetie of, 374-84 & pl. xxxii (sect.). Monte Cristallo, see Cristallo. Monzonite (?) of Carn Trelwyd, 587- 88. Moopy, G.T., on the Causes of Varie- gation in Keuper Marls & in other Calcareous Rocks, 431-39 w. chem. anals. Moreay, C. L., 265. | Moss Cannel, marine bed, 505-506. Moss Coal, marine bed above the, 504-505. Mountain - building, experiments in, 345-57 figs. Moysnry, L., 1. Mudi (Upper Nile), sect. at, 653. Mudstones, ripplemarked, &c. of Bronkhorst Spruit, 685. Morcuison Medallists, list of, xxvii; Geological Fund, awards from, XXvVHi. Mus sylvaticus (?) at Longceliffe, 56. Muschelkalk (Lr.), Tyrol, chem. anal. of dolomite from, 109; origin of do., 114; mineral. structure of do, 123, 125. Museum, annual report on, xiii. Mutation, use of term, Ixxii-lxxiv, 184, 306-307 ; mutations & stratigraphy, Ixxyi. Myalina compressa, 5387 & pl. xxxv. Nan-t’ou Formation (China), xci, Nannolytoceras, gen. nov., 151. Nant-ddu Beds of Arenig, 615. Nap Hill (Bucks), 39, 42. 730 Naticopsis brevispira, 533 & pl. xxxv. Natural History Museum, Tertiary foss. fr. Somaliland in, 155-80, w map & pls. xvii—xxi. Ndoruma (Congo Free State), 647. Nekton & stratigraphy, Ixxv. Nerinea contrasted w. Campanile, 161. Nerinea-Bed at Blea Wyke, 442, 446-47. Netley Heath (Surrey), fossilif. ironst. fr. Phoe. sands of, xev. Netting - structure in 700, 714. Nettlebank & Speedwell marine bed, 501-503. Nettlebank Colliery (Staffs.), Archco- cidaris from, v, 529 & pl. xxxv, 547. Newbiggin (Northumberland), pre- Glacial gravel-deposit at, 68 fig. Newbridge Hill (Somerset), White Lias, &c. at, 420. Newcastle-under-Lyme Group & its flora, 310 et seqq. Newstead boring (Staffs.), list of fossil plants from, 312. Newton, E. T., exhibits specim. of Fayolia fr. Ikeston,i; (& H. H. AnnoLp-Brmrose) on an Ossiferous Cavern of Pleistocene Age at Hoe- Grange Quarry, Longceliffe, near Brassington (Derbyshire), 43-63 & pls. v—viil. Newton, R. B., on the Tertiary Fos- serpentines, sils of Somaliland, as represented - in the British Museum (Natural History), 155-80 w. map & pls. xvii-xxi; [on Pecten Mayer-Eymart], 677. Newton House (Yorks), Dogger, &c., near, 453. Niangara (Congo Free State), 646-47. Niarbyl (& Lonan) Flags (I. of Man), position of, 366-68. NicHousoy, Major, 43. Nieri, Mt. (Upper Nile), sect. at, 652 ; rocks from, 662. Nile Valley (Egypt), Eocene & Creta- ceous of Esna-Aswan reach, 667-78 w. map & sect.; see also Lado. Niobe-Beds of Arenig, 614. Nomenclature, triple, in classif. sedi- ment. rocks, Ixxx. ‘Norites fr. St. David’s-Head district, 585 & pl. xxxix. North Seaton (Northumberland) sect. to Bebside, 84. Northampton Sands, Lytoceratidz from, 142-47 figs. & pls. xv—xvi. Northumberland & Durham Coalfield, superficial deposits & pre-Glacial GENERAL INDEX. [ Nov. 1905, valleys of, 64-96 figs. & pl. ix (map); bibliography of marine bands in C.-M. of, 527. Norton Colliery (Staffs.), marine band at, 507, 509. Norway, Geol. Surv. map presented, xO. Nottinghamshire Coal-Measures, bib- liography of marine bands in, 526 ; list of marine fossils from, 543-44. Nubian Sandstones of Esna-Aswan reach, 669 e¢ seqq. Nucula gibbosa, 5386 & pl. xxxv. oblonga, 536 & pl. xxxv. Nuculana acuta, 536 & pl. xxxy. Sharmant, 536 & pl. xxxv. Number of Fellows, Gey 1x, Xi Xx Octoplicata-subzone in Bristol area, 190, 205, 215; faunal characters of, 260. Officers elected, xxii. Ogygia-Limestone of Hnenie, 620- 21. Olchfa Shales of Arenig, 622-23. Old Down, see Olveston. Oligoclase-porphyrite fr. Wen, 598 & pl. xl. Olivine, format. of serpentine from, 691-93 & pl. xlv. Olveston (Gloucest.), Carb. Limest. near, 239. Oolitic limestone fr. pl. xliv. Oolites (Jurassic) in Oxon., 440; in N.E. Yorks, 441 e¢ seqq. Operculina tr. Somaliland, 175 e¢ seqq. —-— complanata, 175, 176. Operculina-Limestone of Nile Valley, 669. Opposite relative intensity, areas of, in twin-earthquakes, 26-28 figs. Orbiculoidea nitida, 530 & pl. xxxv. Orbitolites (?) fr. Somaliland, 177. Ordovician system, classification of, Ixxxi et segg.; Ord. rocks of Arenig district, 609, 618-28. Oreton (Salop), Carb. Limest. of, 232-53. Organisnis included in strata, changes in nature of, lxx-]xxviii ; in limest. & dolomites of 8. Tyrol, a 24-27. Orthids in Carb. Limest., range of, 246. Orthis-lenticularis Band of Arenig, 613. Orthis-Limestone of Arenig, 627-28. Orthoceras spp. (Coal-Measures), 542. Orthoceras aff. asciculare, 542 & pl. XXXVI. Orthotetes crenistria (muts. Z & ©), 296. Carnachen Buta, 635-56 & Wol. 61. | Ossiferous cavern at Longcliffe, 43- 63 & pls. v—viil. Ostrea Bristovi, 422 & pl. xxxiii. Ostrea-Beds (Lr. Lias) at Lavernock, &e., 389 e¢ segg.; at Berrow Hill, 427-28. Overlap, Rhetic-Keuper, 384, 386, 414, 430. Oxfordshire, new Oolitic strata in, 440, Oyster -limestone (Campanian) in Nile region, 672, 673, 675. Pachylytoceras, gen. nov., 144. —— aalenianum, sp. nov., 146 w. fig. & pl. xv. phylloceratoides, sp. nov., 147 & pls. xv—xvi. Palzontological sequence in Carb. Limest. of Bristol area, 181-307 figs. & pls. xx1i-xx1x. Paper-Shales, 393. Parabolina-Beds of Arenig, 612-13. Paris, H, T., 384, 385, 421, 430. Parkgate Seam (Yorks.), wash-out in, 341-44 figs. Parkinson, H. B., 162 e seqgg. Peak Alum-Works (Yorks), Dogger at, 448-49; see also Ravenscar. Peak Fault, 441, 448, 457, 459. Pebble-Bed in Blea-Wyke Oolite (Yorks), 446, 449 et seqgq., 454. Pecten farafrensis, 674 et seqq. Mayer-Eymart, 674, 677. Pecten-beds at Lavernock, &c., 392 ée¢ segqg.; at Berrow Hill, 428. Pecten-mar|s (Cretaceous), 673 et segq. Peltwra-Beds of Arenig, 613-14. Pembrokeshire, igneous rocks of part of, 579-607 figs. & pls. xxxviii-xl. Penarth district (Glamorgan) Rheetic, &e. in, 388-97 figs. Penberry Hill (Pembroke), quartz- norite of, 588-91 fig. w. chem. anal. & pl. xxxix. Penclegyr (Pembroke), enstatite-rocks of, 592. Pencoed (Glamorgan), Rhetic near, 406. Pendoylan (Glamorgan), Rheetic of, 405. Penmaenmawr, (Caernaryon), ensta- tite-diorite compared w. Penberry- Hill rock, 589-91 fig. Pentre (Glamorgan), White Lias at, 403. Prrcevat, 8. G., 235. Permian, so-called, of Potteries Coal- field, 308, 312; do. of Derbyshire, 314. Q.J.G.S. No, 244. GENERAL INDEX. 731 Peterston (Glamorgan), Rhetic of, 405. Phosphatic Chalk of Taplow, 461-94 figs. Photography, three-colour, vil. Phyllite fr. Congo Free State, 659, 660. Phylloceratidze contrasted w. Lyto- ceratide; 142. Plankton & stratigraphy, Ixxv. Plant-remains, Coal-Measures corre- lated by means of, 308-23. Pleistocene cavern at Hoe-Grange Quarry, Longclitfe, 43-63 & pls. v— vili; Pleistoc. lake in Nile region, 668, 669, 672-73. ‘Pleurolytoceras defined, 144. Pleuronautilus costatus, sp. nov., d40- 41 & pl. xxxvi. pulcher, 541 & pl. xxxvi. Pleurotomariidxz, Palzxozoic, 568 e¢ seqq. Plicatula hettangiensis, 423 & pl. xxxiil. intus-striata, 423 & pl. xxxiil. Piummer, W. E., 12. Poko (Congo Free State), 645, 646; rocks from, 653-57. Polytropina, gen. nov., 575-76. —— globosa, 576-77 & pl, xxxvii. Porphyrite-intrusions of Abercastle- Mathry district, 594-99; horn- blendic, of Arenig. district, 632. Portheiddy Common (Pembroke), enstatite-diabase from, 591. Portishead (Somerset), Carb. Limest. of, 228-30. Posidoniella levis, 535 & pl. xxxv. —— sulcata, 585 & pl. xxxv. Postgate Hill (Yorks.), Dogger of, 455. Potteries Coalfield, flora of, 308 e¢ £egq.; marine horizons in, 5i3. Pre-Glaciai valleys (& superficial de- posits) of Northumberland & Dur- ham Coalfield, 64-96 figs. & pl. ix (map). Premier Mine (Transvaal), diamond from, exhibited, lxxxix. Presidential address, xivii-lxxxvi. Prustwicu bequest, x; medallist, XS Pretoria (Transvaal), map of district E. of, 680; & Middelburg districts, glaciation of, 687-88. Prevumont, G. F. J., Notes on the Geological Aspect of some of the N.E. Territories of the Congo Free State, 641-55 w. sects. & pl. xlii (map). Prionastrea sp. (Eocene), 174. OF 732 Priorsfield Ironstone-Measures, 500. Priskilly Fawr (Pembroke), br reveiated lime-bostonite from, 597 & pl. x1. Prismatic Glacial Clay of great Northern Coalfield, 66—67. Productids in Carb. Linest., range of, 246-47 ; adductor-impressions in convex valve of, 293 fig. Productus anthrax, sp. nov., pl. Xxuy. bassus, sp. nov., 287-88 & pl. OY. Cora, 290-91 & pl. xxv (muts. C &8,); muscular scars in convex valve of, 293 fig. giganteus, 198, 292. hemisphericus, 291-92 & pl. xxv. ef, Martini, 288 & pl. xxv. —— punctatus, 292. -— pustiulosus, 292. scabriculus, 292-93, 531 semireticulatus, 259; muscular scars in convex valve of, 293 fig. §, 289-90 & pl. xxv; muscular scars in convex valve of, 293 fig. sp., 031 & pl. xxxv. Pseudamusium fibrillosum, 5384 & pl. X¥XV. -Pseudo-breccia in Phosphatie Chalk, 471. Psiloceras planorbis, first appearance of, 3/9 Pteria, see Avicula. dbl & Pterinopecten carbonarius, 534-35 & pl. xxxv. papyraceus, S34 & pl. xxxv. Ptychoceras-limestone in Nile region, 673, 674, 675. Publication-Committee, x. Pwll-Strodyr (Pembroke) Fault, d81, 594. Pyle (Glamorgan), Rheetic betw. Cow- bridge and, 406-10. Pyroxenes, in igneous rocks of N. Pembrokeshire, 600-601; ortho- rhombic, format. of serpentine from, 694-96; monoclinic do., 696-99 & pl. xlv. Pyroxene-porphyrite from COwm-y- Craig, 598-99 & pl. xl. 580, Qena (Nile Valley) map, 667. Quaquaversal dip in Berrow-Hill district, 427. Quarella Quarry Cee Rhetic, &e. at, 407-408 Quartz - enstatite diorite Trelwyd, 587-88 ; 592. Quartz-gabbro of St. David's Head, 584-85 & pl. xxxix. of Carn of Penclegyr, GENERAL INDEX. [ Nov. 1905, Quartz-norite of Carn Llidi, 585; of Penberry Hill, 588-91 fig. w. chem. anal., & pl. xxxix. Quartz-schists fr. Congo Free State, 658, 662. Raddling of rocks attributed to action of chalybeate water, 439. Radstockian Series, name proposed, 319, 820; do. opposed, 323 Raghama (Nile Valley), 668, 669. Raibl Beds, chem. anals. of dolomites from, 109; origin of do., 114-115; mineral. structure of do., 124, 126. Raised beach in great Northern Coal- field, 69-72 figs. Rarsin, Miss C. A. (& T. G. Bonney), on the Microscopie Structure of Minerals forming Serpentine, & their Relation to its History, 690- T15 figs. & pl. xlv (microscop. sects.). Rana temporaria (at Longcliffe), 57. Range of organisms & stratigraphy, Ixxiv; ranges & maxima of Carb.- Limest. corais & brachiopods in Bristol area, 243-47 & pls. xxvili- - Xxix ; range-diagrams explained, 257-58. . Raphistoma radians, 582 & pl. xxxv. Rastauu, R. H., 636; on the Blea- Wyke Beds & the Dogger in N.E. Yorkshire, 441-60 figs. Ratzes Bad (Tyrol), Schlern Dolomite from, 103, 116, & pl. xiii. Rauenthal serpentine, 693-94. Ravenscar (Yorks), 441 e¢ seqq. Reading age of certain greywethers, Record, Centenary, of Geol. Soc., x. Redjaf (Lado Enclave), 654, 662. Redland (Glamorgan) Rheetic, &e. of, 399-400. Refractometer exhibited, v—vi. Residue, insoluble, in limest., signifi- cance of presence or absence of, 110 e¢ seggq. Resupinata-subzone in Bristol area, 192, 206, 215-16, 220, 227, 229, 230, 232, 233, 237-38, 240; in Woodspring ridge, 558-59; faunal characters of, 26U, 558-59. Reticularia att. lineata, 299. Retzids in Carb. Limest., 246. Revuscu, H., Lyell Medal awarded to, xlii—xlii. Reywnoups, 8. H., 265, 395, 549. Rhabdostropha, subgen. nov., 565. Rheetic of Monmouthshire, 374-84 & pl. xxx1i (vert. sect.) ; (& contiguous range of, ol. 61.] deposits) of Glamorganshire, 385- 424 fies. & pl. xxxii (foss.); at Berrow Hill, 425-30 w. map & sects. Rhinoceros leptorhinus (=hemitechus), 54-55, 57. Rhipidemella Michelini, 297. Rhiwlas Limestone, borizon of, Ixxxv. Rhynchonella sp. first recorded in Egypt, 675. Rhynchonellids in range of, 246. Rhyolitic Ashes of Arenig, 626-27. RicuarpDson, L., 266; on the Rheetic Rocks of Monmouthshire, 374-84 fies. & pl. xxxii (vert. sect.); on the Rhetic & Contiguous Deposits of Glamorganshire, 385-424 figs. & pl. xxxiii (foss.) ; on the Occurrence of Rhetic Rocks at Berrow Hill, 425-30 w. map & sects. Richthofen Reef (Tyrol), chem. anal. of dolomites from, 106; mineral. structure of do., 120. Ricxerrs, C., obituary of, lvii—lviil. Riddings Junction (Cumberland), Coal-Measure plants from, 314- 15. Ridge Way, see Olveston. Riffelhorn (Switzerland), &c., ser- pentines from, 709, fig. (on p. 702), & pi. xlv. Ripple-marked mudstones of Bronk- horst Spruit, 689. River-development in great Northern Coalfield, 89 e¢ seqq. Roserts, I., obituary of, lx. ‘Rock’ (=Clay-with-Klints), 40. Rosszihne (Tyrol), Schlern Dolomite from, 103-116. Rotaline fr. Somaliland, 176, 177. Rowr, A. W., 474, 493. Ruabon Marls, 314. Rubi Basin (Congo Free State), 644 ; rocks from, 655 eé seqg. & pl. xliv. Runton Gap (Norfolk), flint-scraper (?) from, il. Russian Geol. Surv. maps presented, Vili. Rut ey, F., obituary of, liv-lv. Carb. Limest., Saasthal (Switzerland), from, 707-708 & pl. xlv. Sabaia (Nile Valley), Cretaceous, &e. of, 673-74. Saltwick (Yorks), Dogger at, 449. St. Cassian district (Tyrol), chem. anals. of dolomites from, 105-106 ; origin of do., 118, 125 & pls. xi— ture of do., 118-20; mineral. struc- XIV. serpentines GENERAL INDEX. 733 St. David’s Head (Pembroke), igneous are of, 579-607 figs. & pls. xxxviil— xd; St. Fagans (Glamorgan), Rhetie of, 405-406. St. Hilary district (Glamorgan), Rhe- tic, &e. of, 403. St. Kew’s Steps (Somerset), 554, 559. St. Mary’s-Well Bay (Glamorgan), Rheetic, &c. at, 394-95. Saltation, use of term, Ixxiii. Saurer, A. E., exhibits specims. fr. Bramble-Hall gravel-pit, xev. Sandsend (Yorks), Dogger, &c. of, OL. SANGER-SNEPHERD process of three- - colour photography, vii. Sarsen-stones in a claypit, 39-42 & fig. Sattelspitz (Tyrol), serpentine from, 704-705. Scaldia minuta, 537 & pl. xxxv. Scapolite in igneous rocks of N., Pembrokeshire, 602. Schaalsee (Holstein), Miocene Spatan- gidee from, vi. Schistose Breecia (I. of Man), 361-63 figs., 865; characters & origin of, 368-72. Schizaster sp. (Hocene), 173. Schizodus antiquus, 537 & pl. xxxv. Schizophoria resupinata, 206-97. Schlern area (Tyrol), rock-succession in, 1O1; chem. anal. of dolomite from, 103-104; origin of do., 111- 12; mineral. structure of do., 115- 16 & pls. xi, xu. Schlern Dolomite, origin of, 98, 111- 12, 127; chem. anals. of, 103-108 ; mineral. structure of, 115-25 & pls. x-xiv. Scisst hemera, Lytoceratide of, 146 et segg. & pls. xv—-xvl. Sea-caves on Cleadon Hills, 69. Seaton (Devon), chem. anals. of Keuper Mar ls from, 433. Sedimentary rocks, classification of, Ixi-lxxxvi; see also Cambrian, Con- glomerate, ¢c. Seiser Alp (Tyrol), rock-succession at, 101 ; ‘ Cipit’-limest. of, 103, 114, 116; Wengen Limest. of, 122. Seismographic records in Derby earthquake of 1904, 12-18. Sella (Lyrol), chem. anal. of dolomites from, 105; origin of do., 112-13. mineral. structure of do., 118 & pl. x. Seminula defined, 298-99. Seminula ambigqua, 299. Jicoidea, 299. tot ‘ Seminula-Oclite,’ 212. Seminula-zone in Bristol area, 194-96, 202, 209-10, 214, 218, 222-23, 232, 233, 234, 235, 236, 239, 241; in Weston-super-Mare District, 551 e¢ segg.; faunal characters of, 261, Oo7.” Semireticulatus-subzone in Bristol area, 194-95, 222; in Weston- super-Mare istrict, 549 e¢ segq. Serpentine, microscopic structure of minerals forming, 690-715 figs. & pl. xlv. Serpula-Beds of Blea Wyke, 448, 444. Sett Sass (Tyrol), chem. anals. of dolomites from, 106; origin of do., 114; mineral. structure of do., 119- 20 & pls. xii -xiv. Seven-Feet Banbury Coal, marine bed over, 506-509. Seven Sisters’ Bay (Glamorgan), Rhetic, &e. of, 386. Suaw & Lovecrove, 43, 44. Sheikh, Upper (Sumaliland), 165 e seqq. Suersory, C. D., x, xiu. Suors, LT. W., obituary of, lvili-lix. Surussotn, O. A., exhibits flint- scraper (?) fr. Cromer Forest-Bed, aie Shumardia-Shales of Arenig, 616-17. Sipiy, I. F., 248, 251, 254, 266; on the Carboniferous Limestone of the Westou-super-Mare District, 548-— 561 figs. Silsila, Jebel (Nile Valley), Nubian Sandst., &e. of, 670-71; sect. to Darau, 670. Silurian gasteropoda fr. Llangadock, 67-78 & pl. xxxvii. Silverdale (Staffs.), marine band above Single T'wo-Feet Coal, 505-506. Silwa (Nile Valley), 671-72. Single Two-Feet Coal, marine band above, 505-506. Siston (Gloucest.), White Lias, &e. at, 418. Skeats, E. W., on the Chemical & Mineralogical Hyidence as to the Origin of the Dolomites of 8S. Tyrol, 97-141 w. map & pls. x—xiv (micro- scop. sects. ). Skiddavian Series, ]xxxi—lxxxiil. Skye (Hebrides), photographic views of, exhibited, Ixxxvili. Slaty serpentines, 709-12 & fig. Sleekburn pre-Glacial Valley (Nor- thumberland), 83-85 w. map & sect. Slips along faults originating earth- quakes, 7, 17. GENERAL INDEX, [ Nov. 19@5,". Slippery Lane (Staffs.), marine Coal- Measure fossils from, 503, 504. Suita, G. F. H., exhibits his bhand- refractometer, V—Vl. Smytug, J. A., 89, 94. Snaefell laminated slates deser., 360 ; distribution of, 364. Sneyd Colliery (Staffs.), marine bands at, 505, 507. Sodbury, see Chipping Sodbury. Solurium cf. canaliculatum, 165 & Tolle Sais Solenocheilus aff. cyclostoma, 542 & pl. xxxvi. Solenomya primeva, 537 & pl. xxxyv. Sottas, W. J., communicates Miss Healey’s paper, in. Somaliland, Tertiary foss. from, 155- 80, w. map & pls. xvil—xxi. Sorapis (Tyrol), chem. anal. of dolo- mite from, 107; mineral. structure of do., 121. Sound-phenomena of Leicester earth- quake of 1904, 5-6; of Derby earth- quakes of 1904, 18-15, 16 ; in twin- earthquakes, 22. South Wales, Carb. Limest. correlated w. that of Bristol area, 254-255; bibliography of marme bands in Coal- Measures, 525-26; list of marine fossils from do., 548-44, Southmead (Gloucest.), Carb. Limest. near, 234-35. : Spatangidee, Mioc., fr. Holstein, vi. Speedwell & Nettlebank marine bed, 501-503. Spence Works, sce Eskdaleside. Sphene in igneous rocks of N. Pem- brokeshire, 602, Spicer, the Rev. E. C., on Sarsen- Stones in a Claypit, 39-42 & fig. Spirifer aff. clathratus, 300 & pl. xxvi. —- glaber, 299. aff. grandicostatus, 300. aff. mosquensis, 300. Spiriferids in Carb. Limest., range of, 245. Spiriferina octoplicata, 800 & pl. xxvi. Spirorbis sp., 002 & pl. xxxvi. Spirorbis-Limestone, 309, 310, 516 e seqq. Spondylus egyptiacus, 169. somaliensis, sp. nov., 169-70 & pple xt Sporangium-like organs of Glossopteris Browniana, 324-38 & pls. xxx-xxxi. Spratton Ironstone-workings (North- ants), Lytoceratide from, 146-47 & pls. xv—xvi. Sprechenstein (Tyrol), serpentines from, 699, 701-704 & pl. xlv. Vol. 61.] Spring Cove (Somerset), lava of, 553. Staffordian Series, name propose, 319-320; do. opposed, 322-25. Staffordshire (N.), marine beds in Coal-Measures of, 495-547 figs. & pls. xxxXiv-xxxvi. Stalagmite in Longcliffe Cavern, 46. Stangeria paradoxa, microsporangia compared w. similar organs in Glossopteris, 331 & pl. xxxi. Stanniferous diabase (?) in Congo Free State, 645. Staurocephalus- Limestone, ]xxxvi. SrEBBING, W. P. D., exhibits specims. fr. Netley Heath, xcv. Srewart, C., 49. Stinking Coal, marine horizons near, 512. Sropss, J. T., on the Marine Beds in the Coal-Measures of N. Stafford- shire, 495-527 figs. & pl. xxxiv (map). Sroppart, W. W. [anal. of his paper on the Avon sect. |, 200-203. Stony Boulder-Clay of great Northern Coalfield, 65-66. Stormy Down (Glamorgan), Rheetic, &e. at, 408-10. Srorrig, J., 390, 421. Striz (glacial), directions of, in Pre- toria & Middelburg districts, 688. Striatulus-Shales at Blea Wyke, 443, 448. Strophomenids in Carb. Limest., range of, 246. Strumble Head (Pembroke), igneous rocks occurring betw. St. David's Head and, 579-607 figs. & pls. xxxvili-xl (microscop. sects. ). Submerged forests in great Northern Coalfield, 72. Subzonal (& zonal) indices in the Bristol area, 183, 184-88. Suiby Glen (I. of Man), Schistose Breecia, & in, 362-63 figs. Sully Beds (Glam.) 386- 87, 389 et segq., 410-14, 420-430; upper sur- face of, at Lavernock, 390 fig, Sun-Bed (White Lias) at Siston, &ec. 418. Superficial deposits (& pre-Glacial valleys) of Northumberland & Durham Coalfield, 64-96 figs. & pl. 1x (map). Suronga (Congo Free State), from, 662. Sus scrofa (at Longcliffe), 54. Swallow-holes in the Chalk (& sarsen- stones), 40, 41; swallow-hole at Longcliffe Cavern, 44, 46, 60, 61 e¢ sey. chert GENERAL INDEX, 739 Swallow-Wood Seam (Yorks.), 339- 41. Sweden, Geol. Surv. maps presented, XCiv. Syncyclonema carboniferum, 534 & pl. XXXV. Synkinetic band & line of twin-earth- quakes, 21 e¢ seqq. Syringopora in Carb. Limest., of, 243, 267. ef. distans, 267-68. -—— ef. geniculata, 268. —- cf. ramulosa, 268. cf. reticulata, 268. 9, 268 & pl. xxii. Syringothyri is aff. /aminosa, 800-<01. cuspidata, 301. Syringothyris-zone in Bristol area, 193-94, 202, 207-208, 216-18, 221, D2 230, 2ol, 2o4; im Hine Gite super-Mare district, "BBL et seqq. ; faunal characters of, 261, 556, 559. range Tachylytie rocks of Strumble-Head district, 582, 583. Tai-Herion Flags of Arenig, 615-16. Valk o’ th’ Hill Colliery _(Staffs.), marine fossils from, 509. Tambura (Congo Free State), gneiss at, 647. Taplow oe Phosphatic Chalk of, 461-94 figs. Tea-Green Marls, bone-bed in, 376-77 ; ¥.-G. M. at Bishton, &c , 378 et seqq.; disting. fr. Grey Marls, 386-87, 420; T.-G. M. at Lavernock, &c., 3089 et segg.; at Berrow Hill & Wainlode Oliff, 428, 429. Tuaur, J. J. H., Wollaston Medal awarded to, xxxix—xl, Lemnocheilus (¢), 541. Lemnocheilus carbonarius, 541 & ul XXXVI, concavus, 041-42. Tena, Mt. (Congo Free State), 648 e¢ segg.; sect. to the Uelle Kibali, 652. Tenby (Pembroke), Carb. Limest. cor- related w. that of Bristol, 255. Terebratula-Bed at Blea Wyke, 445, 446. Tertiary foss. fr. Somaliland in Brit. Mus., 155-80, w. map & pls. xvii- xxi; see also Eocene, &c. Tewkesbury (Gloucest.), Rhztie at Berrow Hill near, 425-30 w. map & sects. Teaxtularia from U7. Somaliland, 176, 736 Tuomas, H. H., 637. ‘Thorn - structure’ in serpentines, 702, 703 et seqg. Three-colour photography demon- strating microscopic chars. of rock- forming minerals, vii. Thrybergh (Yorks), 339. Thysanoceras defined, 148. LThysanoceras onychograpium, nov., 149. Orhignyi, nom. nov., 149. Thysanolytoceras, gen. nov., 149-50. Tiberi, Mt. (Congo Free State), micro- cline granite-gneiss from, 658. Tickenham (Somerset), Carb. Limest. of, 232. Time-relations of sound & shock in Derby earthquake of 1904, 14— 15. Toarcian (& Aalenian) Lytoceratide, 142 et seqq. Toits Kraal (Lransvaal), view showg. Glacial Conglom. at, 684. Tomes, R. F., obituary of, lv—lvi. Tournaisian of Bristol area, 186 e¢ seqg.; fauna disting. fr. Viséan do., 263-64. Traie Harkan (I. of Man), Agneash Grit at, 364 tig. Transition Series (Coal-Measures), 309, 310, 315, 319. Transvaal (S. Africa), Glacial (Dwyka) Conglom. in, 679-89 figs. Travernanzez Valley (Tyrol), chem. anal. of dolomite from,107 ; mineral. structure of do., 121. ‘Travertine’ nr. Llanmartin, 379. Tre Croci (Tyrol), rock-succession at, JOL; chem. anal. of dolomite from, 107; mineral. structure of do., 122: Treacuer, L., & Wurtz, H. J. O., on the Age & Relations of the Phos- phatie Chalk of Taplow, 461-93 figs. Trevyff (Glamorgan), Rheetic, Ke. at, 400-402. Tremadoc Beds of Arenig district, 614-17. Tresseysilt (Pembroke), enstatite - diabase, &e. of, 583-84, 594 & ple pce Trevine (Pembroke), intrusive rocks of, 593. Triple nomenclature in classif. sedi- ment. rocks, lxxx. Trophon (%) tr. Somaliland Eocene, 166. ‘True Coal-Measures, use of term, 546, 547. Trust-funds, XXXVI. nom. statement of, xxxvi- GENERAL INDEX, [ Nov. 1905, Tuff, submarine Schlern, 116. Tugby (Leicestershire), 2, 6, 7. Turbonellina formosa, 5382-33 & pl. XXXV. Turdus iliacus (at Longcliffe), 56. Turritella (Kocene) tr. Somaliland, 166. Turcusr, J. W., 154, 266, 421. Twin-earthquakes, 18-34 figs. ; twin- character of Leicester earthquakes, &e., 1-3; of Derby earthquakes, LU ét seqq. Twist Coal, marine band below, 500- 5OL. Ty-ganol (Glamorgan), 402. Tyne R., pre-Glacial valley of, 76, 79 figs. & pl. ix (map). Tyrol (8.), origin of dolomites of, 97- 141 w. map & pls. x—xiv (microscop. sects.). Tytberington area (Gloucest.), Carb. Lithest. of, 219-25. caleareous, fr. Uelle district (Congo Free State), 641; physical features of, 643-44 ; iron-mountains of, 646-48. Uintacrinus in Taplow Chalk, 470, 478 et seqq. Ulrichospira, subgen. nov., 569. similis, sp. noy., 569 & pl. xxxvii. Unconformity betw. Lias & Oolites in N.E. Yorks, 452; in Arenig district, 617-18; betw. Eocene & Cretaceous in parts of Egypt, 675-76, 677-78. Upton Cheney (Gloucest.), White Lias, &e. of, 419-20. Uradu Limestone, Tertiary age of, 157 ; Calamophylliafrom, 174. - Ursus horribilis (Y), 50 & pl. vii. Vallante, Col de (Piedmont), slaty serpentine of, 711. Valleys, pre-Glacial, of Northumber- land & Durham Coalfield, 64-96 figs. & pl. ix (map). Vary, R. H., obituary of, lvi-lvii. Vankerckhovenville (CongoFreeState), 651 ; rocks from, 659, 660 & pl. xl. Variation in the nature of earth- movements, Ixix-lxx; of relative intensity in twin-earthquakes, 26- 27 & fig. Variegation in Keuper Marls & other calcareous rocks, 431-389 w. chem. anals, Variolite of Garn Fechan, 582-83. Vauauan, A., on the Paleontological Sequence in the Carboniferous Limestone of the Bristol Area, Vol. 61. | 181-305 figs. & pls. xxli-xxix; [on Productus anthr ait], 531; commu- nicates I’. EF’. Sibly’s paper, 548. Vermicular chlorite in Aberfelin rock, 593. Verrex (Piedmont), slaty serpentine from, 711. Vertical sections (Geol. Surv.) pre- sented, Ixxxvili. Vespertilio (Plecotus) at Longcliffe, 50. Viséan of Bristol area, fauna disting. fr, 263-64. Volcanic phenomena & the deposition of limestones, 110, 111 e¢ segq.; vole. materials, contemporaneous, accumulat. of, xviii—lxix ; rocks of Weston-super-Mare district, 552, 553, 558, 561, 563; of Arenig do., 623-34. Vosges serpentines, 697-99 & pl. xlv. Vulpes alopex at Longcliffe, 50. Vulsella (¢) sp. (Hocene), 168-69 & pl. xxi. auritus (2), 186 et seqq. ; Tournaisian do., ‘Wad ’-deposit in Longcliffe Cavern, 47 Wainlode Cliff (Gloucest.), Rhezite, &e. at, 417, 429; chem. anals. of marls from, 433. Wainstones (Y orks), Dogger below, 456. Wales (South), see South Wales. Watrorp, E. A., on New Oolitic Strata in Oxfordshire, 440. Waker, W., 62. Walter’s Ash (Bucks), sarsen-stone embedded in clay at, 39 fig. Watton, G., 44. Warp, J., 43. ‘Wash’ pre-Glacial Valley (Dur- ham), 79-80 & pl. ix GQnap). Wash-outs in Middle Coal-Measures of 8. Yorks, 339-44 w. map & sects. WasuBourn, W., 427. Watchet (Somerset), equivalent of Sully Beds at, 389. Warts, W. W., 7, 38, 91, 94; ex- hibits MS. geol. map of Charn- wood- Forest district, iv; communi- cates G. T. Moody’s paper, 451. Wear R. (Upper) & tributaries, pre- Glacial valleys of, 8U-83 & map (pli). Wengen. Limestones, chem. anals. of, 108; origin of, 114; mineral. struc- ture of, 122, 120. West Boldon (Durham), sect. to Corny Hole On. GENERAL INDEX. Toe Westbury Park (Gloucest.), Carb. Limest. at, 234. Westoe (Durham), sect. to Billy Mill, 78. Weston Sprink (Staffs), marine bed at, 509-10; Coal-Measures at, 508 fig. een auner-Maie (Somerset), Carb. Limest. of, 548-63 figs. ; correlated w. that of Bristol area, 250-5]. Westphalian Series, name proposed, 319, 320; do. upposed, 322. Weruerred, EH. B. [on Tregyff-Conglo- merate specimens], 402. Wetley Moor (Staffs), marine band at, 512 Wuiraker, W., exhibits specims. fr. Boultham Boring, xcv. Whitby a Dogger, &c. near, 449-50 fig. Wurrs, H. J. O., & Treacner, L., the Age & Relations of the ibe platic Chalk of Taplow, 461-94 figs. White lias at Laverneck, &c., 390 fig., 393, 396, 398; W. L. of Glamor- gan, 415-20 fig., 421. Wick (Gloucest.), Carb. Limest. of, 236-37 ; Rheetic, &e. of, 418. Wickes, W. H., 230, 266. Wickwar (Gloucest.), Carb. Limest. of, 237-39. Wiirams, G. J., 609. Wiis, BAiLgy, xci. Windsor Castle, sarsen-stones used in building operations at, 40, 42. Wirksworth (Derby), 12, 17. Witwatersrand (Transvaal), map of HE. extension presented, ili. Wo.taston medallists, list of, xxv; Donation-Fund, list of awards, XXVi. Woodhouse Eaves (Leicester), 7. Woodspring ridge (Somerset), Carb. Limest. of, 558-59, 560 e¢ seqq. Woonpwarp, A. S., exhibits specim. of Glossopteris, viii, Woopwarp, H. B., x. Wootacorr, Di; on the Superficial Deposits & pre-Glacial Valleys of the Northumberland & Durham Coaldeld, 64-95 fiys. & pl. ix (map). Worle Hill (Somerset), figs. showg. overfold in Seminula-Beds, 504, 505; Worle- Weston ridge, Carb, Limest of, 549-51, 559-60. Worsley Four-Foot Seam, 322, 323. Wrexham Red Sandstones & Marls, 314. Wrington (Somerset), Carb. Limest. of, 240-42, ‘. A F) ) NA A wa JS hud 738 GENERAL INDEX. [Nov. 1905. ‘Writing-desk’ form in tectonics, 347. Wyre Forest Coal-Measures, biblio- graphy of marine bands in, 525. Y Garn (Pembroke), rocks of, 582. Yagu, Mt. (Congo Free State), 651, 658. Yambili, Mt. (Congo Free State), 648. Yellow Beds (Oolite) at Blea Wyke, 442, 445-46. Ynys-y-Castell (Pembroke), igneous rocks of, 593--94. Yorkshire, pre-Glacial valleys in, 95- 96; Yorks Coal-Measures correlated w. those of Lancs. & the Midland Counties, 518-22; bibliography of marine bands in C.-M., 526; list of marine fossils from do., 543-44; Yorks. (N.#.), Blea-Wyke Beds & Dogger in, 441-60 figs. ; (S.), wash- outs in Middle Coal-Measures of, 339-44 w. map & sects. Zaphrentis in Carb. Limest., range of, 243. Zaphrentis aff. cornucopie, 271-72 & pl. xxil. aff. Phillipsi, 269-71 fig. & pl. SOU Zaphrentis-zone in Bristol area, 190- 92, 202, 206-207, 215-16, 220, 227, 230, 231 et segg., 237-38, 239, 240 ; in Woodspring ridge, 558; faunal characters of, 260, 558—5Y. Zarrentin (Holstein), Mioc. Spatan- gide from, Vi. . Zobia (Congo Free State), 645. Zonal & subzonal indices in Bristol area, 183, 184-85. Zone, proper use of term, lxxxi ; zones of Taplow Chalk, 463, 480 ed segq.; of Carb. Limest. in Bristol area, 186; do. represented at Weston- super-Mare, 549. Zoning of dolomite-crystals, 129-30. END OF VOL. LXt. PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLENT STRUET. LLLP DIE OOOO 8 MDE Vol. L&I. FEBRUARY 28th, 1905. Wo. 2Al. Parr 1. , . ? | PAL PRPPRLILI LD DILD II I LII OI fIIOIIOI Fo /) y aw ’ Bage 1. Dr. Davison on the Leicester Earthquakes of August 4th, 1893, and June 2st, 1904., (Plate 2) cies lisensenecidercaes oak eeeetcenatiee ten 1 2. Dr. Davison on the Derby Earthquakes of July 3rd, 1904. (Plate II) ...... 8 . Dr. Davison-on Twin -Harthquales 2.0 ..cgc0.ccecs:sivseeccesons cule canteen ne aa 18 3 4. The Rev. O. Fisher on Elephas meridionalis at Dewlish. (Plates IIL & IV)... 35 5. The Rev. E. C. Spicer on Sarsen-Stones ina Claypit 4..2....:;.:0ssedeers pen suee 39 6 5. Messrs. Arnold-Bemrose & E. T. Newton on the Ossiferous Cavern at Longeliffe”” (Platés V-VIL)) oc rc ee he cat acu foun ges er 43 7. Dr. Woolacott on the Superficial Deposits & pre-Glacial Valleys of the Northumberland:& Durham Coalfield (Plate 1X}#.i2.\..).tee ee 64 8. Prof. Skeats on the Origin of the Dolomites of Southern Tyrol. (Plates X— RLV) ys sods cganoecdld os lease geouaade ass uasteee tee «ne crt tan Goede en 97 9. Mr. Buckman on Certain Genera & Species of Lytoceratide. 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Sire ANG OD) vo cvenasicsasedccescssessoavve 18 0 Mole Vale Bart 2ecccccsceedesceseucuecdsscoees 010 0 AO PIO APt 2) css ieesecsvecdoseaceeceseoes 0 4 0 Violo ValiePartiayn seavseeccacshvousesoncsanves 010 0 “6 AES Gites: ces coacods sas ceudacvasessseness 0 4 0 QUARTERLY JOURNAL. (Vols. III to LX, inclusive.) Price to Fellows, 13s. 6d. each (Vols. XV, XXIII, XXX, and XXXIV to LX, 16s. 6d.), in cloth. CLASSIFIED INDEX TO THE TRANSACTIONS, JOURNAL, &c., by G. W. Ormerop. New Hdition, to the end of 1868, with First, Second, and Third Supplements to the end of 1889, Price 8s. 6d. To Fellows, 5s.6d. [Postage 5d.|—The First, Second, and Third Supplements may be purchased separately. GENERAL INDEX TO THE FIRST FIFTY VOLUMES OF THE QUARTERLY JOURNAL (1845-1894). Part I (A-La). Part II (La-Z). Price 5s. each. To Fellows 3s. 9d. each. [Postage 3d.] CATALOGUE OF THE LIBRARY, 1880. (620 pages 8vo.) Price 8s. To Fellows 5s. [Postage 6d.] GEOLOGICAL LITERATURE added to the Geological Society’s Library during the years ended December 31st, 1894-1904. Price 2s. each. To Fellows ls. 6d. each. {Postage 23d. | LIST OF THE TYPE- AND FIGURED SPECIMENS RECOG- NIZED BY C. D. SHERBORN IN THE COLLECTION OF THE GEOLOGICAL SOCIETY, verified and arranged, with additions, by the Rey. J. F. Buaxe. 1902. Price 3s. 6d. (bound in cloth); 3s. Od. (in paper wrappers), To Fellows, 2s. 6d. and 2s. 0d. [Postage 3d.] ' HUTTON’S ‘THEORY OF THE EARTH,’ Vol. IIL, edited by Sir ArcuiBaLp Gurxrin, D.C.L., F.R.S. Price 5s.6d. To Fellows 2s. [Postage 4d.] THE GEOLOGY OF NEW ZEALAND. Translated by Dr. O. F. Fiscuzr, from the works of MM. Hocusterrzr & Perrruann. With an Atlas of Six Maps. Fellows may purchase One Copy of this book at 2s.; Additional Copies will be charged 4s. [Postage 5d. | CONTENTS, Pages Proceedings of the Geological Society, Session 1904-1905, including the i: 12. 13. 14. 15. 16. 17. Proceedings at the Annual General Meeting, the President's Anniversary Address, eb. 6.0. Pei ve en widens ee ceded a ack EO ree SU Rn ne er ix-xcli PAPERS READ. Page Dr. Vaughan on the Paleontological Sequence in the Carboniferous Limestone of the Bristol Area... (Plates XXIT—XXIX.) oie 0. .dossccdccc sas oeee pene ee 181 Mr. Kidston on the Divisions & Correlation of the Upper Portion of the Coal-' Measures. is i as0 i. o.c.05 dsc dagetencteestocdetoee ce vegh wees soni Ges agence aaa 308 Mr. Newell Arber on the Sporangium-like Organs of Glossopteris Browniana, Brongu:; (Plates XXX & XXKP) oe aieas es ae ce hn cce te oe ee 324 Mr. F. HE. Middleton on the Wash-outs in the Middle Coal-Measures of South. Yorkshire > (i322. .0..ce.c5 ces edeaseas cuve cues ences oonteanecceinie st =i= aan 339 The Rev. J. F. Blake on the Order of Succession of the Manx Slates in their Northern Half, and its Bearing on the Origin of the Schistose Breccia associated: therewith 0. 6c.cs.eececnscecneventasaet soccer ictey Ces sense tages tonne 358 » Mr. L. Richardson on the Rheetic Rocks of Monmouthshire. (Plate XXXII.) 374 -[No. 243 of the Quarterly Journal will be published next August. | [The Editor of the Quarterly Journal is directed to make it known to the Public that the Authors alone are responsible for the facts and opinions contained in their respective Papers. | *.* The Council request that all communications intended for publication by the Society shall be clearly and legibly written on one side of the paper only, with proper references, and in all respects in fit condition for being at once placed in the Printer’s hands. Unless this is done, it will be in the discretion of the Officers to returnthe communication to the Author for revision. The Library and Museum at the Apartments of the Society are open every Weekday from Ten o'clock until Five, except during the fortnight commencing on the first Monday in September, when the Library is closed for the purpose of cleaning; the Library is also closed on Saturdays at One p.m. during the months of August and September. It is open until Hight p.m. on the Days of Meeting for the loan of books, and from Hight p.m. until the close of each Meeting for conversational purposes only. Vol. LXI. AUGUST 31st, 1905. No. 243. Part 3, THE QUARTERLY JOURNAL OF THH HDITED BY THE ASSISTANT-SECRETARY. [With Twelve Plates, illustrating Papers by Mr. Richardson, Mr. Stobbs & Dr. W. Hind, Miss Donald, Mr. Elsden, Mr. Fearnsides, and Messrs. Preumont & Howe. | LONDON: LONGMANS, GREEN, AND CO. PARIS:—CHARLES KLINCKSIECK, 11 RUE DE LILLE. SOLD ALSO AT THE APARTMENTS OF THE SOCIETY, Price Five Shillings. BPP LDL_L_L_L_L_PI_IOOOOOOOOaOOOOoaOeeeeeeeeeeeeeeeeoovr 00020 00 202280080 82 GEOLOGICAL SOCIETY. LIST OF THE OFFICERS AND COUNCIL OF THE GEOLOGICAL SOCIETY OF LONDON. Elected February ‘ith, 1905. PrestVent. John Edward Marr, Sc.D., F.R.S. Wice-Presivents. Prof. Thomas George Bonney, Se.D.,LL.D., | Prof. Charles Lapworth, M.Sc., LL.D., E.R.S., F.S.A. - F.R.S Robert Stansfield Herries, M.A. Horace Bolingbroke Woodward, F.R.S8. Secretaries. Prof. William Whitehead Watts, M.A., | Prof. Edmund Johnstone Garwood, M.A. M.Sc., F.R.S. Poreiqu Secretary. Creagurer. Sir John Evans, K.C.B., D.C.L., LU.D., [ Vacant. | E.R.S., F.L.S. COUNCIL. Francis Arthur Bather, M.A., D.Sc. Richard Lydekker, B.A., F R.S. Prof. Thomas George Bonney, Sc.D., LL.D.,| Bedford McNeill, Assoc. R.S.M. F.R.S., F.S.A. John Edward Marr, Sce.D., F.R.S. Sir John Evans, K.0.B., D.O.L., LL.D.,) Prof. Henry Alexander Miers, M.A., F.RB.S. F.R.S. Horace Woollaston Monckton, F. Ti S. Prof. Edmund Johnstone Garwood, M.A. | Frederick William Rudler, I s. O. Sir Archibald Geikie, Sc.D., D.C.L., LL.D.,| Leonard James Spencer, M.A. Sec.R.8. Aubrey Strahan, M.A., F.R.S. Robert Stansfield Herries, M.A. Charles Fox Strangways. Prof. John W. Judd, C.B., LL.D., F.R.S.| Prof. William Whitehead Watts, M.A., Prof. Percy Fry Kendall. M.S&c., F.R.S. Philip Lake, M.A. The Rev. Henry Hoyte Winwood, M.A. Prof. Charles Lapworth, M.Sc., LL. Dy Horace Bolingbroke Woodward, F.R.S, E.R.S. : Assistant-Secretarp, Clerk, Librarian, anv Curator, L. L. Belinfante, M.Sc. Assistants in @ilice, Library, and Museum. W. Rupert Jones. Clyde H. Black. Alec Field. STANDING PUBLICATION COMMITTEE. Dr. J. E. Marr, President. Prof. W. W. Watts. ¢ . Prof. HE. J. Garwood. } ee sd Dr. F. A. Bather. Mr. R. Lydekker. Prof. T. G. Bonney. Prof. H. A. Miers. Sir Archibald Geikie. Mr. H. T. Newton. Mr. BR. 8S. Herries. Mr. A. C. Seward. Prof. J. W. Judd. Mr. H. B. Woodward. Prof. Charles Lapworth. EVENING MEETINGS OF THE GEOLOGICAL SOCIETY TO BE HELD AT BURLINGTON HOUSE. Sresston 1905-1906. 1905. 1906. Wednesday, November......... 8*—22* | Wednesday, March ........... . TF—21 Gs December ......... 6*—20 a Asorril:.’. <2 doseawprame 4* 95 © 1906. 49 May e\ojee'sieeiwieinlscejs\e 9*—23 Wednesday, January............ 10*—24* ” JUNE vesseeereeeee, lot—27* Pe Feb. (Anniversary, Friday, Feb. 16th) 7*—21* [Business will commence at Hight o’ Clock precisely each Evening. | The dates marked with an asterisk are those on which the Council will meet. _ ADMISSION AND PRIVILEGES. OF FELLOWS OF THE GEOLOGICAL SOCIETY oF LONDON. Every Candidate for admission as a Fellow must be proposed by three or more Fellows, who must sign a Certificate in his favour. The Proposer whose name stands first upon the Certificate must have a personal knowledge of the Candidate. year. The Annual Contribution may, at any time, be compounded for by a payment of Thirty-Five Pounds, The Fellows are entitled to receive gratuitously all the volumes or parts of volumes of the Quarterly Journal of the Society that may be published after their election, so long as their Annual Contributions are paid; and they may purchase any of the publications of the Society at a reduction of 25 per cent. under the selling-prices, The Library is open daily to the Fellows between the hours of 10 and 5 (except during the fortnight commencing on the first Monday in September ; see also next page), and on Meeting-NDays until 8 pa. Under certain restrictions, Fellows are allowed to borrow books from the Library. ee ea Publications to be had of the Geological Society, Burlington House. Reduced Price Reduced Price TRANSACTIONS. to the Telos: TRANSACTIONS. to the eas 8. d. 8. da. Sito: He SV il BCR ae ean 110 0 Ber Ti Volo V, Parti k cnet: ne 010 O Petaiignvole Ol, Part 2:00) ore 110 0 Ny Partie ie ame Ane 010 0 Wool UN PartO ce i ek 010 0 ss Part i vente acne 110 0 Pee Re etree oul vie e yc 2 010 0 Volta, Bart ly oh nes ee 110 0 ‘3 Part 3 (Supplement) 010 0 oa Pairtidi, coote cence 110 0 Woleet Eh PorPart ness cen. 010 0 VolinVill Part 4 accion a 010 0 os eur bea 010 0 Pe bart ou eee ic 010 0 QUARTERLY JOURNAL. (Vols. III to LX, inclusive.) Price to Fellows, 13s. 6d. each (Vols. XV, XXIII, XXX, and XXXIV to LX, 16s. 6d.), in cloth. CLASSIFIED INDEX TO THE TRANSACTIONS, JOURNAL, &e., by G. W. Ormerop. New Hdition, to the end of 1868, with First, Second, and Third Supplements to the end of 1889. Price 8s, 6d. To Fellows, 5s. 6d. [Postage 5d.|—The First, Second, and Third Supplements may be purchased separately, GENERAL INDEX TO THE FIRST FIFTY VOLUMES OF THE CUARTERLY JOURNAL (1845-1894). Part I (A-La). Part II (La-Z). Price 5s. each. To Fellows 3s, 9d. each. [ Postage 3d.] CATALOGUE OF THE LIBRARY, 1880. (620 pages 8vo.) Price 8s, To Fellows 5s. [Postage 6d.] GEOLOGICAL LITERATURE added to the Geological Society's Library during the years ended December 31st, 1894-1904, Price 2s. each. To Fellows ls. 6d. each. [Postage 24d. ] LIST OF THE TYPE- AND FIGURED SPECIMENS RECOG. NIZED BY C. D. SHERBORN IN THE COLLECTION OF THE GEOLOGICAL SOCIETY, verified and arranged, with additions, by the Rev. J. F. Brake. 1902. Price 3s. 6d. (bound in cloth); 3s. Od. (in paper wrappers), To Fellows, 2s. 6d. and 2s. Od, [Postage 3d.] HUTTON’S ‘THEORY OF THE EARTH,’ Vol. III., edited by Sir Arcuizatp Gurxm, D.C.L., F.R.S. Price 3s. 6d. To Fellows 2s. [Postage 4d,] THE GEOLOGY OF NEW ZEALAND. Translated by Dr. O. F, Fiscunr, from the works of MM. Hocusrerrer & PErernann. With an Atlas of Six Maps. Fellows may purchase One Copy of this book at 2s. ; Additional Copies will be charged 4s. [Postage 5d.] CONTENTS. Pages Proceedings of the Geological Society, Session 1904-1905...........sscescsseeees xciii-xcv PAPERS READ. Page 18. Mr. Richardson on the Rhetic and Contiguous Deposits of Glamorganshire. (Plate XXORTLD) oo scnSnmecienceth cat emes dinaienteccacdoeden collteccas dec co aiheenaiaeeetaet 385 19. Mr. Richardson on the Rhetic Rocks at Berrow Hill ............eesceeeeeeeeees 425 20. Dr. Moody on the Causes of Variegation in Keuper Marls, etc. .........00000 431 21. Mr. Walford on New Oolitic Strata in Oxfordshire. (Abstract) .........:..00 440 22. Mr. Rastall on the Blea-Wyke Beds and the Dogger in North-East Yorkshire 441 23. Messrs. H. J. O. White & L. Treacher on the Phosphatic Chalk of Taplow... 461 24, Mr. Stobbs on the Marine Beds in the Coal-Measures of North Staffordshire, with Notes on their Paleontology by Dr. Wheelton Hind. (Plates XXXIV- XOXOK TD) oe eran sec dhageosactardeossehes vac ace ocuencecres sce: cen ecete ee eta 495 25. Mr. Sibly on the Carboniferous ideatediay of the Weston-super-Mare DIStYICt per esd. oc ccos sen sgeta gute Mee a0 sinpdteghatie'ssssesiedeecuocs vans: aetee een 548 26. Miss Donald on Two New Species of Loxonema. (Plate XXXVII pars)...... 564 » 27. Miss Donald on Silurian Gasteropoda from Llangadock. (Plate XXX VII pars) 567 28. Mr. Elsden on the Igneous Rocks between St. David’s Head and Strumble Head iUlates XXX VILIXD) © 2B 579 29, Mr. Fearnsides on the Geology of Arenig Fawr and Moel Llyfnant. (Plate PGT) seen coc sas ok dese e uncle seaiupastNegws sadoe racunahceneres< sa (eh an 608 30. Mr. Preumont on the Grokey of Part of the Congo Free State, etc. With Petrological Notes by Mr. J. A. Howe. (Plates XLII-XLIV) [No. 244 of the Quarterly Journal will be published next November. | [The Hditor of the Quarterly Journal is directed to make it known to the Public that the Authors alone are responsible for the facts and opinions contained in their respective Papers. | *,* The Council request that all communications intended for publication by the Society shall be clearly and legibly written on one side of the paper only, with proper references, and in all respects in fit condition for being at once placed in the Printer’s hands. Unless this is done, it will be in the discretion of the Officers to returnthe communication to the Author for revision. The Library and Museum at the Apartments of the Society are open every Weekday from Ten o'clock until Five,except during the fortnight commencing on the first Monday in September, when the Library is closed for the purpose of cleaning; the Library is also closed on Saturdays” at One P.M. during the months of August and September. Itis open until Eight p.m. on the Days of Meeting for the loan of books, and from Hight P.M. until the close of each Meeting for conversational purposes only. ADMISSION AND PRIVILEGES OF FELLOWS OF THE GEOLOGICAL SOCIETY OF LONDON. Every Candidate for admission as a Fellow must be proposed by three or more Fellows, who must sign a Certificate in his favour. The Proposer whose name stands first upon the Certificate must have a personal knowledge of the Candidate. Fellows on election pay an Admission-Fee of Six Guineas. The Annual Contribu- tion paid by Fellows is Two Guineas, due on the Ist of January in every year, and payable in advance; but Fellows elected after the month of February are subject only to a proportionate part of the Contribution for the year in which they are elected, and Fellows elected in November or December pay no Contribution for the current year. ‘The Annual Contribution may, at any time, be compounded for by a payment of Thirty-Five Pounds. The Fellows are entitled to receive gratuitously all the volumes or parts of volumes of the Quarterly Journal of the Society that may be published after their election, so long as their Annual Contributions are paid; and they may purchase any of the publications of the Society at a reduction of 25 per cent. under the selling-prices. The Library is open daily to the Fellows between the hours of 10 and 5 (except during the fortnight commencing on the first Monday in September ; see also next page), and on Meeting-Days until 8 p.m. Under certain restrictions, Fellows are allowed to borrow books from the Library. Publications to be had of the Geological Society, Burlington House. Reduced Price Reduced Price TRANSACTIONS. tothe Blows TRANSACTIONS. to the Helens. 8. 8. d. DeVere Vlei escse tuck sashc ccd vss ssetenvies 110 0 Ser) Tis Voke Ve) Part ll was.ccscassteencs 010 0 Bere Viole 4 1, Part 2 iicsesccseccesse 110 0 a Partie: ese 010 0 Violen bart) 2i\ieigesnssccess see ON LOS O HH IPartisy ieee 110 0 3 1 Ee ono eenonae a bemeceeaen 010 O Vol. VI, Part 1 ........ 110 0 is Part 3 (Supplement) 0 10 0 oD Part 2iitescvcerstosseewss 110 0 Wo RED SRartulia.cisccerscsvscevs 010 0 Mol Valine Partia | s.c: orecune es 010 0 RS Asics sete aise aiecietsciss 010 0 a arb Sitccoteeccwses sues 010 0 QUARTERLY JOURNAL. (Vols. III to LXI, inclusive.) Price to Fellows, 13s. 6d. each (Vols. XV, XXIII, XXX, and XXXIV to LXI, 16s. 6d.), in cloth. CLASSIFIED INDEX TO THE TRANSACTIONS, JOURNAL, &c., by G. W. OrmErop. New Hdition, to the end of 1868, with First, Second, and Third Supplements to the end of 1889. Price 8s. 6d. To Fellows, 5s. 6d. [Postage 5d.|—The First, Second, and Third Supplements may be purchased separately. GENERAL INDEX TO THE FIRST FIFTY VOLUMES OF THE QUARTERLY JOURNAL (1845-1894). Part I (A-La). Part II (La-2Z). Price 5s, each. To Fellows 3s. 9d. each. [Postage 3d.] CATALOGUE OF THE LIBRARY, 1880. (620 pages 8vo.) Price 8s, To Fellows 5s. [Postage 6d.] GEOLOGICAL LITERATURE added to the Geological Society’s Library during the years ended December 31st, 1894-1904. Price 2s. each. To Fellows ls. 6d. each, [Postage 23d. ] LIST OF THE TYPE- AND FIGURED SPECIMENS RECOG- NIZED BY C. D. SHERBORN IN THE COLLECTION OF THE GEOLOGICAL SOCIETY, verified and arranged, with additions, by the Rey. J. F. Brake. 1902. Price 3s. 6d. (bound in cloth); 3s. Od. (in paper wrappers). To Fellows, 2s. 6d. and 2s. 0d. [Postage 3d.] HUTTON’S ‘THEORY OF THE EARTH,’ Vol. III., edited by Sir ARCHIBALD Guikiz, D.C.L., F.R.S. Price 3s. 6d. To Fellows 2s. [Postage 4d.] THE GEOLOGY OF NEW ZEALAND. Translated by Dr. O. F. Fiscunr, from the works of MM. Hocusterrur & Perermann. With an Atlas of Six Maps. Fellows may purchase One Copy of this book at 2s.; Additional Copies will be charged 4s. [Postage 5d.] CONTENTS, PAPERS READ. Page 31. Mr. Beadnell on the Relations of the Eocene and Cretaceous Systems in : the Hsna-Aswan Reach of the Nile Valley ...............cccceceuseuce ear vommmnemenc 667 32. Mr. E. T. Mellor on the Glacial (Dwyka) Conglomerate in the Transyaal...... 679 33. Prof. Bonney & Miss Raisin on the Microscopie’ Structure of Minerals forming Serpentine, and their Relation to its History. (Plate XLV) ...... 690 (TITLEPAGE, ConTEnTs, and Inpzx to Vol. LXI.) [No. 245 of the Quarterly Journal will be published next February. | [The Editor of the Quarterly Journal is directed to make it known to the Public that the Authors alone are responsible for the facts and opinions contained in their respective Papers. | *,* The Council request that all communications intended for publication by the Society shall be clearly and legibly written on one side of the paper only, with proper references, and in all respects in fit condition for being at once placed in the Printer’s hands. Unless this is done, it will be in the discretion of the Officers to returnthe communication to the Author for revision. The Library and Museum at the Apartments of the Society are open every Weekday from Ten o’clock until Five, except during the fortnight commencing on the first Monday in September, when the Library is closed for the purpose of cleaning; the Library is also closed on Saturdays at One p.m. during the months of August and September. It is open until Hight p.m. on the Days of Meeting for the loan of books, and from Hight p.m. until the close of each Meeting for conversational purposes only. Vol. LXI. NOVEMBER 30th, 1905. No. 244, : Part 4, Cot Whit. ~ QUARTERLY JOURNAL OF THER GEOLOGICAL SOCIETY. HDITED BY THE ASSISTANT-SECRETARY. [With One Plate, illustrating the Paper by Prof. Bonney & Miss Raisin. | LONDON : LONGMANS, GREEN, AND CO. PARIS:—CHARLES KLINCKSIECK, 11 RUE DE LILLE. SOLD ALSO AT THE APARTMENTS OF THE SOCIETY, Price Five Shillings. —PRIIIPIPIOFFOP PF GPLIIPSPLI I OT Se ee eee LIST OF THE OFFICERS AND COUNCIL OF THE GEOLOGICAL SOCIETY OF LONDON. ——2O— Elected February 17th, 1905. KA. ae ii DPE a aS Prestvent. John Hdward Marr, Sc.D., F.R.S. OiceePrestdents. Prof. Thomas George Bonney, Se.D.,LL.D., E.R.S., F.S.A. Robert Stansfield Herries, M.A. Prof. Charles Lapworth, M.Sc., LL.D., E.R.S. Horace Bolingbroke Woodward, F.R.S. Secretaries. Prof. William Whitehead Watts, M.A., M.Sce., F.R.S. Foreiqu Secretary. Sir John Evans, K.C.B., D.C.L., LL.D., E.R.S., F.L.S. | Prof. Edmund Johnstone Garwood, M.A. Creagurer. | Horace Woollaston Monckton, Treas.L.S. COUNCIL. Francis Arthur Bather, M.A., D.Sc. Prof. Thomas George Bonney, Sc.D., LL.D., E.R.S., F.S.A. Sir John Evans, E.RB.S. Prof. Edmund Johnstone Garwood, M.A. Sir Archibald Geikie, Sc.D., D.C.L., LL.D., Sec.R.S. Robert Stansfield Herries, M.A. K.C.B., D.O.L., LL.D., Prof. John W. Judd, C.B., LL.D., F.RB.S. Prof, Percy Fry Kendall. Philip Lake, M.A. Prof. Charles Lapworth, M.Sc., UL.D., E.R.S8. Richard Lydekker, B.A., F.R.S. Bedford McNeill, Assoc. R. S.M. John Hdward Marr, Sc.D., F.R.S. Prof. Henry Alexander Miers, M.A., FBS. Horace Woollaston Monckton, Treas, LS. Frederick William Rudler, 1.8.0. Leonard James Spencer, M.A. Aubrey Strahan, M.A., F.R.S. Charles Fox Strangways. Prof. William Whitehead Watts, M.A., M.8c., F.R.S. The Rev. Henry Hoyte Winwood, M.A. Horace Bolingbroke Woodward, ERS. Assistant-Secretarp, Clerk, Librarian, and Curator. L. L. Belinfante, M.Sc. Assistants tn @flice, Library, and Huseum. W. Rupert Jones. Clyde H. Black. Alec Field. STANDING PUBLICATION COMMITTEE. Dr. J. E. Marr, President. Prof. W. W. Watts. Prof. E. J. Garwood. Dr, F. A. Bather. Prof. T. G. Bonney. Sir Archibald Geikie. Mr. R. S. Herries. Prof. J. W. Judd. Mr. R. Lydekker. } Secretaries. Prof. H. A. Miers. Mr. H. T. Newton. Mr, A. C. Seward. Mr. L. J. Spencer. Mr. H. B. Woodward. EVENING MEETINGS OF THE GHOLOGICAL SOCIETY TO BE HELD AT BURLINGTON HOUSE. Sresston 1905- 1906. 1905. Wednesday, December ......... 6*—20 1906. Wednesday, January..... ...... 10*—24* 55 Feb. (Anniversary, de Friday, Feb. 16th) 7*—21* XS oe 14 4 Bea ~ 1906. Wednesday, March ............ T*—21 is Asprilicwc aoe 4* 25 % Malye 2." ces care 9* —23 i JUS, ee eee 13*—27* [Business will commence at Hight o’ Clock precisely each Evening.| ates marked with an asterisk are those on which the Council will meet. _ va . 3 9088 0