PfRIODiQUES 6590
MONOGRAPH OJK THE PAI.AFONTOGRAPIIICAL SOCIETY
ENGLISH CALLOVIAm ^ fe. (MIDDLE JURASSIC) PERISPHINCTID AMMONITES
B. M. COX
PART 1 Pages 1-54: Plaies 1-23
© THE PALAEONTOGRAPHICAL SOCIETY - LU.NDO.N February 1 m Tli«- PALarontogr;ip iir.: Scxir'v issues an inivi.il vnliirrci* of.«-ri;»1v iv.imbrnvi p.ihlir^:i
Publication No. 575. issued as pare of Volume: HI) for 1986
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ABSTRACT Ti. P;II 1 ;>r**virr.iv irsearrh. i.ir stracLi^r;iphy 0: the Eiigliil- Cdlnviiin (in |>,IIIKIIIM: :1;nsr hori/.nna i:i which ihc pccUphiociids ?.re most abunrnnii. ,irH ,i. Amwi<»m:rs PerisphincriHr's H11 (\il.i»vir:i iJur.LSsnpic :noycii; aa^lais I<*rc :«nnir RltSUMfi Dan * h. prcmftrc partfc. les recherche* anwercure*, ;u4ir4ii^rapriitc.uCii)iuvicn Prr-sph:ti<:i«N ! Ar.nnunilhn-.; des ui^liachco Callovs I Mr.tl^rrr Jwra). T< il I. 7USAMMEXTASS1ING In LVil I vrcrdcn M^ri'ttdc 1 IIUKCJ. crorlul: {a'l \»i-Lu-m Pui'>i:iu:tg. *b! Mja.i^j^.^li.i ACCYKlftCKtiQ K^.lOBOftCKKe (CpeaHRH Kjpw ) lirpiir;i|u/MK lM»AOHMr llMMOUH/M PE'iHlM K Bjicpuuii^afu?npI NEPMC £di:cd by J. K. M1.IT. P. I). I.AM, and K. M. OWENS ENGLISH CALLOVIAN (MIDDLE JURASSIC) PERISFHINCTID AMMOM I ES INTRODUCTION AND ACKNOWLEDOEMENTS In England. theCallowan Stagenfrhe Middle Jurassic is represented by marine arenaceous to argillaceous clastic. and carbonate sediments. lr contains a clivara* ammonite fauna compr ising die Boreal Kosmoccratidae Ktppirri!*A, SignU>u?a$. K&snwcaas) and (iardiocrraliriae (Cadoctras* PscudoicuhiCTos* LftyigWincfirtut rteoaw/w, ikteMitdtoww). and the Terhyati MacrocepludUidae {Mtzcmxphniitis). Pachyceratidae ; Erynwotwa*. P/iikyaru.*]. Oppehidao (/Vtf.VWw. W«:/irw>mv, Disiiihoaras). Reiner kcii RLPOSI I ORIES BGS: British Geological Survey, Koywonh, Nottingham; BM: British Museum (Natural History;, London; BSM: Baycrischc Staatssanmiluii^ fur Palaontologie usul hisiorische Geologic, Munich: CNIGR: CMGR Museum. VSKCKL Leningrad: DM: Devizes Museum, Wiltshire; DCM: Dorset County Museum. Dure Lester; ETII: Eidgenossisc he I'cchnischc Ilochsc huK Zurich: FSL: Department des Sciences de la I K:T<\ Faodte des Scicnccs de Lyon; FW: Private collection of Mr Felix YVhitham. Hull; GBV: Geologiscrhe Bundesan^Ull, Vienna; GPI: Geolopischpalaontologisrhrs lmtitut, Tubingen: GSI: Geological Survey of India. Calcutta; HU: Hull University: JKWs Private «>IUi:tiori of Dr. J. K. Wright, Chelsea College. Ixmdon; LIS: Services Gcologioo* de Portugal, Lisbon; LPP: Laboialoire de Paleontologie des Invern:bn:s% (Jiiivrrsiu* Pierce et Marie Curie, Pans: MM: Manchester Museum; MNHNP: Museum National d'llistoirr NsitiirHle* Paris, NMW: National Museum uf Wales, Cardiff; OUM: University Museum, Oxford; PM: Pavlov Museum, MCRI, Moscow: SM: Sedgwirk Museum. Cambridge; SMF: For*cJiungsinstiuK Scnckcnbire, Krankfur.-am-Majn: WMS: YVoodcnd Museum. Scarborough; YM: The Yorkshire Museum, York. ENCI.ISH CALI.OVLW PERISPHINCHI) AMMOXITKS HISTORY Ob RESEARCH Although most oJ the English (Jallovian ammonite fauna is well known ami has been used as tin: ha-us ol detailed biostratigraphical arc! rhioriostratigrapliical schemes* litcle systematic work has been published on the Pcrisplunctidac, which have liule primary slraligraphiral value in the Knglish sequence. In contrast, detailed descriptions of thi: abundant perisphirictids from the Bathouiari and the Coralliau Beds (Oxfordiari) were included in Arkelfs (1935-18; 19ol-58) monographs The first monographic treatment of the Perisphinetidae was by Sieiriir.'.dzki (1008) who placed Callovian forms in G'wsouvrio. Pa-uphiacUs, Prwerito and Cfwffetw. Together with "jBiplica" and AtQ*ioccr 1'AKi.ft: I. Gene r a and subgiuc.-a o: ihc Pcmpl;incrjdac published records in :hc Callovian <; Hamulisphinctes), and continued to use Buckman's Proplanulitidae for Propla7u1lit.es and related forms which stand aside as a distinct group. STRATIGRAPHY In England, rocks of Callovian age crop out in an almost continuous strip from Dorset to North Yorkshire, broken only in west Dorset and across the Market Weighton Block in Humber- side where they have been removed by erosion before deposition of late Cretaceous strata ( Text- figs 1-3). They underlie younger sediments over much of the land area to the east of the outcrop, with the exception of a large area beneath East Anglia and the Thames Valley, and a smaller area on the Market Weighton Block. Total thicknesses are difficult to establish because of inadequate or imprecise data in many areas, and only estimates can be given. Where complete at outcrop in southern and central England, the total thickness is c. 45 m on the Dorset coast, c. 50 m in Oxfordshire and c. 50-55 m in the East Midlands. The sequence is c. 50 m in parts of The Weald subcrop, but thins due to attenuation and later erosion as it approaches the London-Brabant Massif. In Humberside, the thickness is reduced to c. 15 m, but increases to as much as 40 m in North Yorkshire. LITHOSTRATIGRAPHY From Dorset to Humberside, Callovian strata arc included in three main lithostratigraphical STRATIGRAPHY 7 units -Upper Cornbraslu Kellaways Beds and Oxford (Hay (Lower and Middle)—which prob- ably represent an increasingly transgressive marine sequence of shallow water shell deposits ranging from thin limestones through silly clays and sands, to a relatively thick clay unit. Recent mapping by BGS in Lincolnshire and Humberside lias not differentiated the Oxford (!lay from the other Upper Jurassic clay formations recognized elsewhere; in I hat. area, the Oxford day is represented in the lower part, ol the so-called Ancholrric day Group. In North Yorkshire, the argillaceous aspect of I his succession is replaced by an almost completely arenaceous sequence, the Osgodbv Formation, representing a change to near shore marine environments. The Callo- vian is represented by lour main lithostratigraphieal units, the Cornbrash, Kellaways Rock, Langdale Beds and Hackness Rock (Text-fig. 4) 1 KX 1-1 l(.. Outcrop c»fC;illi»vi;m s(r;i(;i in mitral Kut;l;iii CaiRONOS I KA I KrKAiM I V The current standard Jurassic zones were established on the basis of particular ammonite faunas, and most fall broadly within the categories of assemblage or total-range biozones of current usage (Hoc! berg lc)7b: Holland^//. 1978). In the Callovian Stage all the M sub/ones of the six zones (largely based on and recognized by the Boreal kosinoeeraiid and cardioeeralid ammonites) now have type and reference sections (Duff?/* Cope etal. I WO, Table 2). '['lie Stage is divided into three subslages Lower, Middle and Upper—with two zones in each. Locally in the English sequence even finer chronoslraligraphical subdivisions (chronohorizons) may be distin- guished, such as the Cornptoni Bed and Acutistriatum Band. 6 KNCLISII CALLOVIAN"PERISPHINCTI D AMMONITES LOCALITIES Callovian strata arc exposed in coastal sections in Dorset and North Yorkshire, and in brickpits and quarries along the outcrop. In Dorset, a complete Callovian sequence is exposed along the shores of The Fleet behind Chesil Beach (at Abbotsbury Swannery, and between East Fleet and Tidrnoor Point) but generally in low, badly slipped and overgrown cliffs. The Lamberti Zone is again poorly exposed at the base of Ham Cliff to the E of Weymouth. On the North Yorkshire coast, there is a magnificent section through the Callovian at Red Cliff at the southern end ofCayton Bay, S of Scarborough, and these beds can also be seen farther S at Gristhorpe Cliff and Cunstone Nab (Wright 1968). The famous exposures of Callovian stata. at Castle Hill, Scarborough are now partly obscured and relatively inaccessible. Inland, there is a number of TEXT-FIG. 3. Outcrop of Callovian strata in northern England. exposures in small quarries and stream sections between Hackness and Newtondale (where the Kellaways Rock forms almost continuous crags for more than 3 km) and in the Tabular and Hambleton Hills (Wright 1968). Between Dorset and North Yorkshire, there are fine exposures of Oxford Clay in working pits of the London Brick Company at Calvert and Bletchley, Buckinghamshire; Bedford, Bedfordshire, and Peterborough, Cambridgeshire, where the work- ing faces show the Jason to Athleta Zones (Callomon 1968). Exposures of Kellaways Beds can be seen in the banks of the River Avon near Kellaways, Chippenham, Wiltshire, and in sandpits near South Cave, Humberside. The stratigraphical position of certain sections and localities referred to are shown in Text-fig. 4. STRATIGRAPHY 7 COKNKKASII The Cornbrash is traditionally divided into Lower and Upper divisions on the basis uf lirhologv, bur the two are more easily distinguished by their ammonite and brachiopod faunas (Douglas & Arkell 1928; 1932). The Lower Cornbrash, consisting of poorly bedded marly limestone with shell detritus, rubbly marl and massive beds of blue-hearted limestone, belongs to the Bathonian and the Upper Cornbrash, consisting of sandy limestone 01 ferruginous sandy marls with dogger-like limestone beds and occasional massive beds of limestone weathering into flags, belongs to the Callovian (Arkell 1933). Together they total only a few metres in thickness at most, and either division may be locally very thin or absent. -jir o< NORTH H ZONE DORSET TO HUM BERSIDE SECTIONS AND LOCALITIES in YORKSHIRE CD (local non sequences N. D not shown] Dorset Yorkshjp, f §!l ii I Lamberti HACKNfcSS 2o CC / • ROCK• LLI | CL CL O a1 1 i h- a^l Athleta < UJI I a D Corn brash only. The following notes may help to avoid confusion about (he provenance of specimens. Long Hon\d\borough, Oxjoukhhv: Perisphinctid material has been recorded from both the Lower and Upper Cornbrash. No specimen ha&> been traced 10 support Douglas & Arkell's (1928. ]>. 120) I Jppcr Cornbrash record (neither OL M nor SM). Material from the Lower Corn brash was recorded by Pringle (1926) and later described and figured by Arkell (1958) (BGS GSM37364, CSM83I40; OUM J1370;. There is othci undesciibed maierial, without""stratigraphical information (OIJM JSOOOa, b. J14010-1.J14016a, bj 14017J14254-3). Berkley. Somerset: Pcrisphinctids were recorded hum a cream-coloured sandy limestone in a shallow quarry at Berkley and assigned to the Upper Corn brash by Douglas & Arkell (1928, p. 143). Subsequently, reinterprcratinn ofthis section with reference to ones nearby at Frome showed that it belonged to the Lower Cornbrash (Arkell 1933, p. 330, l%4b, p. 120; 1958b, p. 218): (BGS GSM95035, 95039). ZONE suezoNt TYPF LOCALITY REFERENCE SECTION(S) Woodham brick pit ^ Buckinghamshire: Rivp' H'ora section.Sutherland: Haccally Sandstonelupocr Lamberti 1 oaril ond Cly-^elish Quart y.SutliHrl/inil C.lynpiish Quarry lamberti Lrniestono (Bed C} Sandetono Lamberti Woodham brickoit. Btjr.kiiujli#insliire: Foreshore section,south of Bioid HslitHiy, SuihmtancJ: Henrici 4 Pascal y Siltctonc \jddci parti 6 Faace'ly 5flnd3'.one ;ioy/«r Oxford Clay iBcd U2} aaril Wood ham brickpit Bucking ham shire: Foreshore section,j>ouir of Brora estudiv . Sutherland, Spinosum Oxford Clav '.Bed3 E-D1)4 rascally SillHiriiw lu|i|i«i par?} Calvort brickpit. Buckinghamshire: Fintfhliuu? suction ,south of Bro'a Ofilua^y, Sutherland: Athlota Proniee Oxford Clav !0eds 13a-hl4 Faacelly Sillatonc (niodlif iJdill Foroshoro KPction,south of U'ora octuary Suthorlond: Phocinum Calvert brickpit. Qucfcinohnmshiie Oxford Clav IBeds 10-121* Hrora 3nck Clay b Foacolly Siltatone {'ower niirtj Peterborough pits.Carnbridoeahirc! : Grossouvrci 4 Uxtord Clay IB«ds'l7a-22cl Coronatum Peterborough pits.Cambridgeshire: Obductum Uxtord Clav IBeds 14-16bl4 KidlinotonOxfordsliire: Peterborough oits. Cambridgeshire: Jason Oxford Clay IBeds 15 26}* Oxford C\*v (Beds 10-13I4 Jason Kidlington, Oxfordshire Peterborough pits.Cambridgeshire: Medea Oxford Clav TABLE 2. Callovian c.hronostratigraphic zones and subzones. with their type localities, rcfercncc sections and horizons. Slalbihige, Dorset: Pcrisphinctids have been recorded from the Upper Cnrnhrash ofStalbridge and the Lower Cornbrash of Stalbridge Weston. The specimen from t he Upper Cnrnhrash ofStalbridge (Douglas & Arkell p. 147) is OU.Vl J12767 (PI. 1, fig. 3); both Upper and Lower Cornbrash were present at the locality. Occurrences in the Lower Cornbrash ofStalbridge Weston (notably the type of I loinoeoplanidllvx fwitweomorphus Buckman) were discussed by Arkell (1958b, p. 226). Only Lower Cornbrash is thought to have been exposed in the quarry there, which was worked in the last century; (BGS GSM0654-5, SM J20354). ' Hot well. Dorset: There is some doubt about specimens from this locality. An ex situ specimen was recorded from the Upper Cornbrash by Douglas & Arkell (1928, p. 148). but no specimen has been traced (neither OU VI. SM nor DC M ). Arkell (1958b. pi. 32 fig. 1) figured a specimen {Ot'MJ 13002) which he inferred to be from the Lower Cor nbrash. 1 his was one of a number of specimens formerly held by the Sherborne School Museum. Much of the material displayed there (Torrens 1978) from the Cornbrash of Holwcll (including the Rev. H. Wood collection probably made between 1860 and 1880} has apparently been lost; only two ammonites (a Clvdoniceras and a Macrocephalites) are preserved in the material transferred to BM, and the DCM has none. There are two specimens (BM CI 1796, CI 1825; PI. 1, figs 1. 2) DE I ^ GHOLUGIP- IO; STRATIGRAPHY 9 collected by Blake {1905, p. 7) from the "Upper Beds" ar Holwell; he recorded 23 ft 9 in f 7-2 m | of strata, and the upper 2-9 m at least is apparently Kpprr Cornbrash (with Maaocephalitrs); the rest is Lower Cornbrash and 1 ores I Marble (Arkell 1958b. p 226). The former specimen was figured by lllake (1905. pi. 5 lig. 5, wrongly numbered 4 on plate) and discussed by Cox & Arkell (1950, p. 94, incorrectly numbered BM CI 1795). ' Corscombe, Doisd: The specimen from the Upper Cornbrash (associated wiih Macrocephnlitcs) recorded by Douglas & Arkell (1928, p. 152) from a temporary exposure at Corscombe, has not been traced (neither OL'M, SM nor DOM). Both Lower and Upper Cornbrash were quarried around this village. KELLAWAYS BIDS The Kellaways Beds of southern Britain, which belong to the Macrocephalus Zone (pars) and the Calloviense /one, are best known in Wiltshire (the type area; Cave & Cox 1975) and Gloucestershire. The majority of museum specimens come from these two areas, e.g. former brickpits at Siddington, Gloucestershire, railway cuttings at South Ccrncy, Gloucestershire, Bincombe Wood. Chippenham and Trowbridge, Wiltshire, and road cuttings on the M4 motor- way near Christian Malford, Wiltshire (Mantell 1850, Harker 1881, Woodward 1895, Reynolds & Vaughan 1902. Gallomon 1961, Barron 1972, Cave 1977). 1'he two-fold lithological division of Kellaways Clay below and Kellawavs Rock and/or Sand above, can be recognized southwards into Somerset and Dorset (Arkell 1932, 1947c, 1948b, Cope 1969, Cope & Cox 1969), and northwards into Oxfordshire (Arkell 1947d, Gallomon 1955) and the East Midlands (Callomon 1968) where they floor the extensive Oxford Clay brickpits. In Hurnberside, the Kellaways Beds comprise a thin Kellaways Clay overlain by arenaceous Kellaways Sand and Rock. The Calloviense Zone ammonite fauna, which occurs mainly in the Kellaways Rock, differs from that of this stratum in southern England and is assigned to a younger (Enodatum) Subzone (Callomon 1964, p. 275). These arenaceous strata are known from quarries at South Cave, South Newbald and Ketllethorpe, and from the railway cutting at Drewton (Keeping & Middlemiss 1883, De Boer, Neale & Penny 1958, Brasier & Brasier 1978). Kellaways Rock is also recognized within the completely arenaceous Callovian sequence of North Yorkshire and has yielded perisphinctids at the coastal localities of Cay toil Bay, Osgodby Nab, Cornelian Bay and at scattered localities between there and Newtondale (Wright 1968). OXFORD CLAY The Oxford Clay is a laterally rather uniform argillaceous sequence ranging in thickness from !j0 to 15Um. On the basis of gross lirhology and Fauna., it is divided into three—Lower, Middle and Upper. The Lower Oxford Glav is a sequence of bituminous shaly clays with crushed iridescent fossils often preserved in white aragonite. The following zones are represented: Calloviense (pan), Jason, Coronatuin and Athleta (pars). The Middle and Upper Oxford Clay are sequences of non- bituminous, pale grey calcareous clays. They are less fossiliferous than the Lower Oxford Clay and the ammonite fauna is preserved commonly as uncrushed pyritic inner whorls or nuclei. The Middle Oxford Clay belongs to the Athleta Zone (pars) and Lamberti Zone, but the Upper Oxford Clay is entirely Oxfordian (Mariae and Cordatuin zones) in age. The clays are or have been worked in a number of pits, fossils from which are well represented in museum collections, although the attractive small pyritized ammonites are rarely accompanied by detailed stratigraphical information. Museum collections also include material from coastal outcrops. These Callovian localities are listed below (from S to N). Tidmoor Point, Dorset; Lamberti and PMariae Zones (Spath 1933, p. ttoG, Arkell 1947c. p. 30). Wolvcreote and Summertown, Oxfordshire; Athleta Zone (Pringle 192(i, pp. 31, 30; Arkell 1939b. p. 207: 1947d, p. 70). Wood ham. Buckinghamshire; Athleta, Lamberti and Mariae Zones (Arkell 1939b, Callomon 1968, p. 288). St Ncots, Cambridgeshire,- Athleta Zone ( Roberts 1892. p. 11. Edmonds & Dinham 1965, p. 14). The ammonite fauna of the Lower and Middle (i.e. Callovian) Oxford Clay is dominated by Kosmoceras, which is used as the basis for the zonation. ft is accompanied by rarer cardioceratids (though these equal Kosmoceras in number by the end of the Callovian), oppeliids, perisphinctids, pachyceratids, reineckeiids and aspidoceratids. Perisphinctids are particularly common at three 10 KNCLISII CALLOVIAN"PERISPHINCTI D AMMONITES horizons which are widespread throughout southern and central England—the Comptoni Bed, the Acutistriatum Hand and the Lamberti Limestone. They also form a significant, pan of the assemblage in the basal shell-bed of the Jason Subzone, well-exposed in the brickpits at Calvert, Buckinghamshire, forming the base to which the pits are worked (Callomon 1968. p. 285). The Comptoni Bed is a thin (usually less than 0.3 m) shell-bed occurring at the top of the Coronation Zone in the Lower Oxford Clay. It is crowded with pcrisphinctids, accompanied by Erymnoceras, Hecticoceras and Kosmoceras, and may be associated with a band of hard calcareous shale or fissile limestone rich in nuculoid bivalves and Mele.agrinella., with locally-developed limestone lenses. The Acutistriatum Band is a highly calcareous mudstone or concretionary limestone at the base of the overlying Athleta Zone. The type locality is (Calvert, Buckinghamshire (Buckman 1025); but most museum collections arc from Christian Malford, Wiltshire, where the horizon was exposed during the construction of the Great Western Railway (Pratt 1841; Callomon 1968. p. 274). The Lamberti Limestone, at the top of the Middle Oxford Clay, is a thin (generally less than 0-3 m), pale grey, siltv. calcareous mudstone or marly limestone, packed with ammonites which are usually distorted and often fragmentary; they are preserved as internal clay moulds with a black or brown powdery coating of pyrite. This bed belongs to the upper part of the Lamberti Zone and is best developed in the Buckinghamshire area, where it was exposed at Woodham brickpit (Arkell 1939b). HACKNESS ROCK The I laekness Rock was identified and defined as a discrete unit within the so-called Kelloway Rock [ = Osgodby Formation, Text-fig. 4] of the North Yorkshire coast by Arkel I (1933, 1939b). 1 r is a thin (c. 2 0m) sequence of poorly sorted, sandy limestones and fine-grained calcareous sandstones, in both of which chamosite ooliths may be common, together with silts and marls (Wright 1968, Hemingway 1974); it belongs to the Athleta and Lamberti zones. When weathered, some beds have a distinctive purplish-red colour mottled with green. Its fossils were first described by Leckenbv (1859)1 including the type specimens of the pcrisphinctids Attigaticeras Buckman, 1923, Binatisphinctes Buckman, 1921, Hamulisphinctes Buckman, 1921 and Poculisphinctes Buckman, 1920. These occur with kosmoceratids, cardioccratids, oppeliids, aspidoccratids, pachyceratids and rcineckeiids. Care must be exercised in the examination of old museum collections because Hackness Rock specimens arc included in, and must be identified from amongst, material marked "Kelloway Rock". The Hackness Rock has yielded pcrisphinctids at the coastal localities ofCayton Bay, Cornelian Bay, Cunstone Nab, Gristhorpe Cliff. Osgodby Nab, and at Castle Hill, Scarborough and Hackness Quarry (Wright 1968). CRITERIA FOR CLASSIFICATION TAXA OF THE SPECIES GROUP Only in a few cases (e.g. Ilomoeoplanulites difficilis and Binatisphinctes comptoni) is material sufficiently plentiful, well-preserved and with sufficient stratigraphical control (and hence assumed to be isochronous) for biospecific assemblages to be mapped out with any confidence. In most cases, specific classification has to be based upon morphospecies, and it is probable that contemporaneous ones will probablv be merclv variants of a single biospecies (cf. Callomon 1981, p. 260). Many ammonite workers have used Arkell's (1936, p. x) introductory notes on general 'John T.eekenhy (1814—77) wa.s a hank manager in Scarborough and one time Treasurer of the Borough of Scarborough (Obituary in Proc. gtol Soc. Lonxt. 1878, 34, p 35}. He was a contemporary of William Bean (1787— I8t>6)—a local lossil collector of some renown. Bean himself did not publish many scientific papers describing the specimens which he collected but many new species were described by others, using his manuscript (often specimen label} names. Bean's own fossil collection was sold to the British Museum in 1859 for £500 (McMillan Green wuod 1972). The Leckenby Collection was purchased, following an appeal bv Professor Adam Sedgwick, by the University of Cambridge in 1871 for £800 {Nature, Dec. 1871, p. 151). CRITERIA FOR CLASSIFICATION 11 classification, particularly in the case of perisphinctids. Arkell (1951a, p. 23; 1958b) later added only a few qualifications to these. He considered four main criteria—shell dimensions, whorl shape and coiling, septal sutures, and ribbing; he (Arkell 1958b, p. 235) concluded that rib-style had proved to be the most valuable basis tor classification amongst perisphinctids. Since Arkcll's work on Bathonian and Oxfordian forms, there have been two other significant monographs (Enay I960; Mangold 1971 b), in both of which Arkcll's classification criteria were used as a basis. Mangold used further morphological features to deline the various ranks in the hierarchy of taxa: sutures and ornament on the early whorls for subfamilies, sequence of successive stages of ornament for genera and (in order of priority) mode ot division of primary ribs, average diameter for appearance of adult characters, strength and number of ribs, index of rib division, whorl section, and shell dimensions and coiling, for species. ArkelPs four main criteria are each discussed below in the light of more recent work, including the approach adopted in this monograph. The morphological terms are those used by Arkell (1935; 1957a, pp. L3, L81). Any qualifying remarks or additional terms, most of which reflect current common usage, are given where appropriate. Shell dimensions Species arc defined on the basis of complete adult individuals, the criteria for which are: (i) contraction of the body-chamber towards the aperture with uncoiling of the umbilical seam. (ii) modification of the shell form near the peristome (coarsening and regeneration or degenera- tion of ribbing, often with terminal constrictions, ventral collars, flares, horns, rostra, lateral lappets etc.). (iii) approximation and degeneration of last few septal sutures (Callomon 1963, p. 25). The maximum size of a pcrisphinctid species is a well-defined character, with a variability from the mean of c. 10% (Callomon 1955, p. 237; 1963, p. 26). In reasonably numerous assemblages, assumed to follow a normal distribution, the range between the smallest and largest individuals will usually encompass a range about the mean of plus or minus two standard deviations (Howarth in Callomon 1963, p. 28). A widely used convention for expressing shell dimensions is the formula of Buckman (1912, p. viii): (i) diamerer (d) in millimetres (h) whorl height (wh) as fraction of (i) (hi) whorl thickness (wt.) as fraction of (i) (iv) umbilical width (uw) as fraction of (i) to which mav be added (v) diameter at last septum in specimens with some or all of the body-chamber preserved (vi) length of body-chamber preserved, as fraction of a whorl. These parameters give some indication of size, whorl section and coiling (see below). Whorl thickness is a meaningless parameter in crushed specimens but diameter, whorl height and umbilical width may be only slightly distorted. In this monograph, parameters (i) to (iv) are given for figured specimens, bur (ii) to (iv) arc not expressed as fractions of (i). Whorl thickness may be measured between or on the ribs; the. difference in perisphinctids is usually only small, and the measurement is taken on the rib. Whorl height is measured in the plane of coiling, not obliquely. The known maximum diameter for a species and parameter (vi) arc given in cach species description. Whorl shape and coiling The whorl section (Text-fig. 5a) may be described as compressed (higher than wide) or depressed (or inflated) (wider than high) and expressed by the ratio: 12 KNCLISII CALLOVIAN"PERISPHINCTI D AMMONITES wh'f compressed TKXT-FU;. 5a (left) Description of whorl section as ratio of whorl height (wh) and whorl thickness fwt). 1'EXT-FIG. 5b (above) Coiling as ratio of whorl height (wh) and diameter (d). depressed (i) wh;wt (the greater the ratio, the more comprcssed the whorl) The style of coiling (Text-fig. 5b), is expressed by the following ratios: (ii) wh:d (the greater the ratio, the more involute the shell) (iii) uw:d (the smaller the ratio, the more involute the shell) (iv) d: number of whorls (the greater the ratio, the more evolute the shell) The terms involute and evolute are relative. All the Callovian perisphinctids are more or less evolute with wh:d ratios ranging from 20-30% (evolute) to 30-40% (moderately evolute). The Proplamliles fauna is the only involute group, with wh:d ratios ranging above 40%. Whorl sections (wh:wt ratios) range from compressed (140-150%)—moderately compressed (115-140%)— slightly compressed (105-115%)—rounded/squarish (95-105%)—slightly depressed (85-95%) to moderately depressed (60-85%). The combination of style of coiling and degree of compression may be described by terms such as planulate, platycone, serpenticone, and expressed by the ratio (v) uw: umbilical depth (ud) the greater the ratio, the more serpenticone-like the shell. Each of these five ratios can be shown graphically in a bivariatc plot. In the ideal case, such a plot would show a positive correlation represented by a straight line (perfect functional relation- ship) or an even curve. The wh;wt ratio in perisphinctids tends to increase during ontogeny (i.e. inner whorls tend to be more or less depressed and outer whorls tend to be more or less compressed), but it may decrease. Septal sutures The general form of the suture has been the basis of many ammonite classifications, e.g. Buc.kman (1909-30). As internal shell features, they were thought to be of more fundamental significance than external features such as ribbing that might be influenced by environmental conditions. Spath (1930, p. 7) considered the role of sutures in classification to be much overrated, CRITERIA FOR CLASSIFICATION 13 and many authors have followed Arkell's (1957b, p. 246) conclusion that they constitute only one of a number of at least equally significant morphological characters; he contended that the form of the suture was influenced strongly by the shape of the whorl and that variation within a species or an individual might be great. Although Arkell's views have been challenged, for example by Schindewolf (1957) and Westermann (1958), sutures have since assumed a less significant role in generic and specific classification. They are, however, fundamental criteria for recognizing the major (suborder) divisions of Palaeozoic and Mesozoic ammonoids (Wiedmann & Kullmann 1981). In this monograph, only a summary of sutural characters is given for each genus. Ribbing The ontogenetic development of rib style is generally useful for the definition of species and where possible that lor the inner, middle and outer whorls (including body-chamber) is described separately. All perisphinctids tend to have similar inner whorls and these are interpreted by- association with accompanying larger forms where available. Constrictions are more common in some groups than others and vary from broad and shallow to deep and narrow; they arc included as a feature of rib-style in the descriptions. As well as style, there are variations in rib number which Arkell and others thought also reflected specific differences. These are shown by plotting rib-density curves (diameter against number of ribs). Ideally, each species is thought to have its own characteristic cunt, but Arkell (1935, p. xviii ) emphasized that comparison of rib-density curves for identifying species should always be subordinate to a consideration of the shape and style of the individual ribs. A line enclosing all the points in a plot of as many specimens as possible from one population shows the extent of variation; overlap between species may be considerable. Estimated diameters, which will have only a small margin of error, can be used for perisphinctid inner whorl rib counts. Rib- density curves are given in the species descriptions only where a reasonable number of mature individuals are available. When rib counts are made, intercalatory ribs are included with the secondary ribs. Simple, unbranchcd ribs may be included in primary and secondary rib counts; in the latter case, the more accurate collective name 'ventral ribs' should be used. Strong, widely spaced, blunt ribs are called massive. The general style ofornament may be described as pcrisphinctoid, that is mainly regular bifurcate ribbing with constrictions. Dimorphism Dimorphism has been a major consideration in ammonite taxonomy since the idea was revived by Callomon (1963) and by Makowski (1963). Dimorphic pairs are designated mac.ro- conchs [M] and microconchs m] (Callomon 1955, p. 238). By analogy with living cephalopoda, and because it develops both ontogenctieally and phyletically (Callomon 1981, p. 260) in ammonites, this dimorphism is considered to be sexual. The Perisphinctaceae provides some of the most consistent and impressive examples of dimorphism (Callomon 1963, p. 37), particularly those from the Bathonian, Callovian and Oxfordian. Dimorphism in Bathonian pcrisphinctids was recognized by Arkell (1951 58). Hahn (1969) and Mangold (1971b). Arkell (1951, p. 2) drew attention to the presence of forms of large size (diameters greater than 400 mm without the body-chamber as in Procerit.es) and smaller forms (diameters of only 100 mm) with body-chambers bearing lappets such as Siemimdrkia. bur he did not formally recognize dimorphism in his classification which used well-established generic names for groups defined mainly on the basis of rib-style. However, he concluded that the persistence of the two main morphological types over a long period (Bathonian to Upper Oxfordian) lent attraction to the hypothesis of sexual dimorphism. An examination of phylogeny taking account ofmacroconch and microconch forms led Hahn (1969) to recognize a phylogenetic tree of paired dimorphic lineages evolving in parallel. He attempted to express this systematically by dividing each genus into a microconch subgenus and a macroconch subgenus. This approach was also adopted by Mangold (1971b) lor rhe Bathonian and Callovian perisphinctids of the 14 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES southern Jura. The dimorphic relationships amongst existing Callovian perisphinetid genera were outlined by Callomon (1963, p. 37). Similar dimorphic relationships within Oxfordian forms were recognized by Enay (1966). In Callovian perisphinctids dimorphism can be recognized ai most stratigraphical levels. Although it is generally believed that macroconchs are females and microconchs males, the standard zoological symbols are not used because we cannot be absolutely certain. However, in allowing that dimorphism is sexual, ii does lead TO a rationalization of the taxonomy. The large number ( TAX A OF THE GEM'S GROUP In a specific classification based on morphological differences, genera are merely well- established, traditionally used "supergroups'' into which morphologically similar species are collected, rather than phyletic units comprising a succession of biospecies. The subgenus is not used herein, because there is some ambiguity in its usage either as a taxon of infra-generic, supra- specific rank, or as Lhe nominal taxon for incorporating "the morphological manifestation of dimorphism" into a morphological classification (Callomon 1969, p. I 16). As most genera were established before the significance of dimorphism was appreciated widely, and recent studies have dealt with dimorphism at generic and subgeneric level, the procedure adopted here has meant that a number of generic and subgeneric names have become junior synonyms. These are discussed under the appropriate genus. TAXA OF THE FAMILY-GROUP The classification ofjurassic ammonites adopted in the second edition of the Treatise (Part L) favours the use of the subfamilies Pseudoperisphinctinae, Proplanulitinae and Perisphinctinac for the Callovian perisphinctids, thereby following Arkell (1957a) except that the Zigzagiceratinae are restricted to the Lower and Middle Bathonian (Donovan el al. 1981). This classification is followed herein, but Binalisphinclet> is included with the Pseudoperisphinctinae rather than with the Peltoceraunae <>1 the Aspidoceratidae. SYSTEMATIC DESCRIPTIONS Fa mil v PERISPHINCTIDAE Steinmann, 1890 Subfamilv PSEUDOPERISPHINCTINAE Schindewolf, 1925 Genus HOMOEOPLANULITES Buckman, 1922 (Synonyms. Anaplanulites Buckman, 1922 (type species A. difficiiis Buckman. 1922) [m], Parachoffatia Mangold, 1971b (type species Ammonites subbakeriae d'Orbignv, 1850) [M], ?Loboplanulites Buckman, 1925 (type species L. longilobatus Buckman, 1925)) Type spmes. Homoe.oplamlitf.s hamMommphus Buckman, 1922 [m Diagnosis. Moderately evolute to evolute, with compressed ink die-outer whorls (Text-fig. 6); lappered microconchs ribbed throughout with rather dense, recliradiate or prorsiradiate prim- aries. sometimes with rursiradiate aspect to secondaries (Text-fig. 7). Macroconchs moderately and progressively variocostate, with weakening of secondaries and finally loss of all ribbing towards aperture. Weak parabolic ribs or constrictions on inner-middle whorls. External suture has first lateral saddle with well-marked accessory lobe, atrifid, slightly asymmetrical lateral lobe about as deep as ventral lobe and a suspensive lobe with some well defined auxiliaries. Discussion. When Buckman (1922, pi. 328) created IIomoeoplanulit.es, he figured only one. HOMOKOPLANLI.ITKS If) specimen of the type species with a brief caption. He later (1924, pi. J15) figured an additional new species. II. stabilis. These figures show medium-sized (100-140 mm maximum diameter) evolute forms, ribbed to the aperture which bears lappets. The ribbing consists of fairly dense, long, slender, straight, rectiradiate or prorsiradiate primaries which split into two or three secondaries with intcrcalatorics, and there are shallow constrictions. As originally proposed, the genus thus accommodated microconch forms. Buckman included the genus in the oldest hernera of his Macrocephalitan age. which succeeded the Clvdoniceratan age, and thereby implied that it came from the Upper Cornbrash (Callovian) rather than the Lower Cornbrash (Bathonian). Arkell (1958. p. 225) believed that the holotypc of//, homoeomorphus was a stunted individual whose growth may have been inhibited by injury, and that the holotypc of II. stabilis was a more normal, fully-grown individual (with a diameter of c. 135 mm). Spath (1931, p. 353), Arkell TEXT-FIG. 6. Whorl sections of species Homoeoplamlites and Indospkincies: (a) BM CI 1825 at 110 mm; (B) BGS GSM /070 at (JO mm; (c) FW TNN528 at 66 mm; (d) FW TNN145 at 75 mm: (e: FW TN.Y173 at 87 mm; (f) BM CI 17% at 230 mm: (g) BGS GSM7680 at 136 mm; (h) FW TNN306 at 160 mm; fi) BGS /.t 167.5 at 10.5 mm: (j) GBV 1870/04/1 at 210 mm; (k) BGS 7682 at 65mm. (1958, p. 22J) and Mangold (1971 b, p. 61) synonymizcd these two species, and Homoeoplanufiles is now considered to include relatively large microconch forms of up to 150 mm diameter. The following 'species' are also included: aculicosta Roemer, aequalis Roemer, balinensis Ncurnavr, bugesiacus Doiriinjon. couxi Dominjon, furcula Ncumayr, leptns Cemmellaro, mangoldi Dominjon, pseudoannulum Lissajous, rambertensis Mangold andybbsensis Jusscn: they are all based on Euro- pean forms and are recorded from the Upper Bathonian and/or Lower Callovian. Both Arkell (1950b, p. 211) and Mangold (1971b, p. 49) included Buckman's other Lower Callovian perisphinctid genus Anaplunulites, based on an Knglish form, as a junior synonym. This latter genus has never really found acceptance and has also been included in Proplamtliles (Spath 1933; Arkell 1945) and Choffatia (Arkell 1957a). Buckman named only one species, A. difficilis, based on a single specimen (PL 1, fig. 6); discussion of the genus is therefore to a large extent a discussion of the species. Until Mangold's (1971b) work, Homoeoplanulitcs was considered a microconch partner and subgenus of Choffatia (Arkell 1957a, p. 317; 1958, p. 211; Callomon 1963, p. 37: Hahn 1969, p. 70). However. Mangold (1971b, p. 48) separated iUmocaplamdite.s as an independent genus in 16 KNCLISII CALLOVIAN" PERISPHINCTID AMMONITES which he also included die larger forms belonging to the group of subbakeriae d'Orbigny. He removed this latter group from its traditional place in Choffatia because of differences in ornament and suture, and introduced a new taxon, Parachojfatia, for these macroconch partners of the microconchs grouped in H amofoplamtliles s. s. As well a $ subbakeriae, Mangold based Pa/acfwfjatiaon Q[)[)vY s funalus and distinguished it from Proceriles by the more marked differentiation of primary and secondary ribs; also included were the species madam Spath and arisphinctoides Arkell. Mangold (197 I b, p. 73) likened ParachoffaUa to Buckman's (1925, pi. 596) genus Loboplanultle.s but concluded that (he type and only specimen of the type species of the latter, from the Cornbrash of Long I lanborough. ()xfbrdshire, was too fragmentary and worn to be properly interpreted. Latei (1971b, p. 15/), he regarded it, as did Elmi (1962), a junior synonym of Subgmssouvria (now Ti:x r-i-'iG. V. Ribbing ufsju-cics of Homotofilanvi'iHw and Indosbkinck.-.. HOMOEOPLANULITES 17 included in Choffatia). However. Callomon (pers. comm. 1901) believes LoboplanulUes is "almost certainly merely the inflated variant of Homoeoplanulites". The earliest known representatives of Homoeoplanulites are from the Bathonian, where it is thought to have originated from the dimorphic group ofProcerites [macroconchs] and Siemiradzkia [microconchsj. Mangold (1971b, p. 13) included Homoeoplanulites with these two genera in the Zigzagiceratinae. members of which arc characterized by the presence of a variable "zigzag" stage of ornament, resulting from a development of parabolic ribs and nodes with strengthening of the ribs in the early ontogenetic stages. Morphological intermediates in the Hodsoni and Orbis (olim Aspidoides) zones of the Upper Bathonian make the dividing-line between the Pseudo- perisphinctinae and the ancestral Zigzagiceratinae arbitrary, according to Callomon (pers. comm. 1985). Homoeoplanulites cf. subbakeriae (d'Orhigny, 1850) PI. 1. figs 1-3 Material. Three poorly-preserved fragments from the Upper Cornbrash (Macroccphalus Zone) ofStalbridge and Upper? Cornbrash of Holwell, Dorset. Discussion. Despite a number of records o \ H. suhhakeriae from the English Upper Cornbrash (Douglas & Arkell 1928), these are the only specimens that have been traced that can with any certainty be judged to have come from that horizon. They are too poorly preserved for detailed description and definitive determination, but appear to he from moderately cvolutc forms with the following characteristics; a maximum diameter of ?more than 250 mm (macroeoneh); moderately compressed whorl at least on middle and outer stages, with flat whorl sides and moderately broad venter. Ornament of rather dense and well-defined primaries dividing regularly into two or three secondaries with intercalatories which increase in number with growth and fade on the venter. Cox & Arkell (1950, p. 94) identified the specimen from Holwell, figured by Blake (1905) (see Introduction), as a fragment of an outer whorl of Choffatia cf. lungilubala Arkell, but later Arkell (1958, p. 217) thought it probably belonged with H. subbakeriae. although it was too small a fragment to be really identifiable. The former species, type of Lubup la nut ties, has stouter, rounded, circular or depressed whorls and more massive ribbing than the H. subbakeriae group (Arkell 1958, p. 212). Data for figured specimens. d wli wt uw primaries ventrals BM CI 1796 (PI. 1 fig. 1) est. 230 67 50 est. 85 (4) — BM CI 1825 (PI. 1 fig. 2) est. 110 c. 30 c. 20 est. 55 — (26) OUMJ12767 (PI. 1 fig. 3) est. 60 — — est. 30 est. 40 — Homoeoplanulites afT. balinensis (Neumayr, 1871) PI. 1, figs 4, 5 Material. Three specimens (two completely septate, and one incomplete but with some body- chamber), uncrushed (one in nodular cements tone), pinkish shell material partially preserved; presumed microconchs. From Kellaways Clay (Calloviense Zone, Koenigi Subzonc) of Trowbridge, Wiltshire and Siddington, Gloucestershire. Description. Maximum diameter seen 95 mm, apparently including c. 170° body-chamber which begins ate. 65 mm diameter. Five whorls visible. Moderately cvolutc (wh/d=c. 30-35%); whorl section squarish Lo slightly compressed on inner whorls, becoming more compressed (wh/wt=<120%) with flat sloping whorl sides and rather flat venter (Text-fig. 6); steeply sloping umbilical wall. Ribs (Text-fig. 7) gently prorsiradiate throughout becoming rcctiradiatc near venter; on inner whorls bifurcate with occasional intercalatories and rather dense; on middle and outer whorls, trifurcate with an associated intercalatory or bifurcate with two associated inter- calatories; primaries rather strong, sharp and regular throughout, generally splitting above or about the middle of the whorl side; ribs pass uninterrupted across venter. Occasional weak constrictions on inner and middle whorls. Aperture not seen. 18 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES Data for figured specimens. eh (septate to) wh wt uw primaries ventrals BGS GSM7676 (PI. 1, fig, 4) 66 (66) 22 20 27 34 c. 108 BGS GSM7679 (PI. 1, fig. 5) 47 (47) 17 — 20 40 est. 100 Remarks. The type specimen of H, balinensis comes from the richly fossiliferous Balin Oolite of Balin in southern Poland which provided material for a number of monographs in the last century (Neumayr 1871; Sicmiradzki 1894) and from which Teisseyre (1887; 1888; 1889) described Proplamdites. The holotypc is incomplete but shows that its body-chamber begins at c. 60 mm diameter (cast figured by Mangold 1971b, pi. 6 fig. 1). The present material is of comparable proportions but. assuming that the three specimens have been grouped together correctly, they show a rather coarser spacing of the primary ribs on the body-chamber (BGS Gcol. Soc. Coll. 3110) than generally accepted for this specics. However, with so little material it is not possible to assess how significant this difference is. 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85-89 90-95 diamete(inrrir | TEXT-FIG. Size distribution For adult microconch Homoeoplanulites difficilis ;S. S. Buckman) [29 specimens including Buckman's type], Homoeoplanulites difficilis (Buckman, 1922) PL l', fig. 6; PL 2, figs 1-6; PL 3, figs 1-3; PI. 4, fig.l; PL 5, fig. 2 1922 Anaplanulites difficilis. now; Buckman, pi. 229. 1933 Proptanuliles (Anaplanulites) difficilis. Buckman; Spath. p. 856. 1931 Proplamdites difficilis; [Spath], p III 1 945 Prnpl.anuf.itts difficilis (Buckman); Arkell, p. 341. 1950 Anaplanulites \= Homoeoplanulites] difficilis S. Buckman; Arkell, p. 211. 1971b Anaplanulites [=HomueoplurtulilesJ difficilis Buckman; Mangold, p. 52. Type specimen. Buckman's (1922, pi. 329) holotypc. from the Kellaways Rock of South Gave, Humberside is believed to have been kept at Hull Museum (Frank Petch collection) and is presumed to have been destroyed during the Second World War; however, there is no proof of this because the whole of the Hull Museum catalogue was lost at that time (P. Bovlan, pers. comm. 1976). In the present case, there is no "exceptional circumstance" that warrants the designation of a ncotype at this time (1.C.Z.N., Article 75); there are abundant topotypes. H O M O EG PL AN U1. II ES 19 Material. About 200 specimens, uncrushecl and generally undisiorted, including specimens that arc complete, with aperture, or nearly complete, with body-chamber and uncoiling; pre- served in ironshot oolite, usually as internal moulds. Microconchs and macroconchs. From Kellaways Rock (Calloviense Zone, Enodatum Subzone), South Cave and South Newbald, Humbcrsidc. Description. Microconchs (46 specimens); maximum diameter 95 mm, generally 75 to 80 mm (Text-fig. 8). Body-chamber 220° to 250°. Five whorls visible. Moderately evolute (wh/d = c.. 35-40% ); whorl section rounded on inner whorls, compressed (wh/wt = 140-150% ) on middle and outer whorls with flat whorl sides (Text-fig. 6); gently sloping and almost smooth umbilical wall; umbilicus c. 30 mm wide and up to 10 mm deep in adult. Ribs prorsiradiate though secondaries may develop slight rursiradiate aspect; on inner whorls, ribs rather fine and dense, rarely weakening to lirac, bifurcate with occasional simple ribs and parabolae; on middle whorls, ribs trifurcate or bifurcate with intercalatories and rare simple ribs, parabolae and rare weak constrictions; on outer whorls, long straight slender primaries which may be strengthened at umbilical edge, splitting above or about the middle of whorl side, where they may weaken, into usually three secondaries with some intercalatories (Text-fig. 7). Ribs pass across venter without interruption and persist to, though may weaken towards, aperture which bears lappets (up to c. 0-5X15 mm) (Text-fig. 9). primary Er simple ribs 40 TNN 476 TNN 475 TNN 446 30 FW TNN 473 TNN FW TNN 500 503 FW TNN • = start of body chamber 20 502 — i i i i i i i i 0 20 30 40 50 60 70 80 90 diametBr(mm) TEXT-KK;. 9. Rib density curves for adult mirrnronrh Hanwmplamdites (tijfialis (Buckman!. Macroconchs (33 specimens): maximum diameter 180 mm, generally 160 to 180 mm. Body- chamber 310° to 360°. AT least 5 whorls visible. Moderately evolute (wh/D=30-35%); whorl section rounded on inner whorls, compressed (wh/wt= 120-130%) on middle and outer whorls with flat whorl sides (Text-fig. 6): gently sloping to moderately steeply sloping and almost smooth umbilical wall; umbilicus 60 to 70 mm wide, and up to 25 mm deep in adult. Ribs prorsiradiate; on inner whorls, ribbing dense with parabolae (only primaries visible); on middle whorls, ribs trifurcate or bifurcate with intercalatories, rare strengthened simple ribs or weak constrictions, primaries generally straight, long arid slender; on outer whorls, primaries may be strengthened at the umbilical edge and gently prorsiradiate. splitting about middle of whorl side where they appear to weaken into usually three secondaries with some intercalatories; ribbing gradually weakens towards body-chamber which is almost completely smooth except for weak development of blunt primaries which may persist particularly at the umbilical edge (Text-fig. 7). Close to aperture, which is simple, these may be lost and growth lines may be visible. Ribs pass across the venter without interruption. 20 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES Data for figured specimens, t =type of H. spirorbis. (septate to) wh wt n w primaries ventrals Ilolotvpc (PI. 1, fig. 6) 85 (c. 55) 29 24 35 33 — FW TNN475 (PI. 2, fig. 1) 78 (c. 50) 26 18 30 33 108 FWTNN473 (PI. 2, fig. 2) 87 (c. 51) 30 22 33 31 e. 90 BGS Zkl439 (PI. 2. fig. 3) 80 (c. 50) 26 e. 23 31 27 6. 105 FW TNN527 (PI. 2. fig. 4) 72 {c. 45) 25 c. 19 27 33 c. 95 FW TNN528 (PI. 2. fig. 5) 66 (c. 42) 21 18 28 33 est. 85 FW TNN510 (PI. 2. fig. 6) 54 (c. 49) 18 est. 18 21 c. 45 — FWTNN521 (PI. 3. fig. 1) 02 (-) 35 25 30 25 — BGS GSM 117460 (PI. 3. fig. 2) c. 75 (-) 26 c. 18 29 180+ FW TNN508 (PI. 3, fig. 3) 180 (c. 95) c. 60 (40) 72 24 FW TNN506 (PL 4, fig. 1) 160 (c. 95) c. 55 46 64 24 t (PI. 5, fig. 1) c. 120 ( ) c. 43 c. 30 c. 40 26 est. 120 FW TNN516 (PL 5, fig. 2) 180 {c. 100) c. 55 45 70 21 Remarks. Buckman's (1922, pi. 229) original figure of this spccics showed a microconch with about five-eighths of a whorl of incomplete body-chamber, with an actual diamerer of85 mm, and an estimated maximum diameter of95 mm. The "perfect topotypc" (SM J 4 7365) of Arkell (1958, p. 211) is smaller (d=c. 75 mm), but compared with other topotypes seems to be the more normal size (Text-fig. 8). Arkell (1958b, p. 211) believed that, except for the smaller size of//, dijjicilis, there was little to distinguish it from H. homoeomorphus. Spath (1933) and Arkell (1945) compared the South Cave perisphinctids with P. scldosseri and P. comptoni figured by Krenkcl (1915) from Lithuania. However, there is no stratigraphical information or description to accompany Krcnkel's two figures and their stratigraphical position is doubtful. Most of the perisphinctids which Krenkel figured are true Binatisphinctes of the Athleta Zone (i.e. a much younger horizon than that of H. dijjicilis) (Arkell 1956b, p. 473). Spath (1933) and Arkell (1945) also thought that the difficilis fauna included "undescribed species allied to P.ferisphictes] spirorbis Neumayr". The type of the latter (Neumayr 1870, p. 148, pi. 7, fig. 2; BSM ASI838; cast figured herein PL 5 fig. 1), from the Marrocephalenschichten of southern Germany, is an incomplete macroconch which compares closely with some of the dijjicilis macroconchs, and apparently comes from a similar stratigraphical level. Mangold (1971b, p. 240) believed that spirorbis belonged in Indosphinct.es} but it has usually been assigned to Proplanulites in comparison with Ncumavr's (1871, pi. 11 fig. 4) figure. This smaller specimen, cf. spirorbis of Neumayr, from the Lower Callovian Balin Oolite of Poland, is a moderately involute compressed form with thickened short primaries, and is correctly placed in Proplanulites. Neumayr's two figured speci- mens arc not just microconch and macroconch of the same species, for the macroconchs of Proplanulites arc found in Crassiplanulit.es which also has characteristic thickened primary ribs, in contrast to those shown on Neumayr's type specimen of spirorbis, Krenkel's (1915, p. 244, pi. 23, figs 4, 9, 10) two inner whorl examples of P. spirorbis from Lithuania (probably from a younger stratigraphical horizon) and Corroy's (1932, p. 155) record ofincomplete examples from the Paris Basin, do not throw further light on the species; however, both these authors assigned it to Proplanulites and included Neumayr's second example in their synonymies. Specimens from Cutch (Waagen, 1875, pi. 41 (wrongly numbered 40 on plate), figs 1, 2) were excluded from P. spirorbis by Siemiradzki (1899, p. 323) and assigned to a new species P. indicus. Spath (1931, p. 333) confined the latter to VVaagen's fig. 1 and used the second figure as the type of a new species /. peregrinus) he included both species in Indosphinctes. The species spirorbis is thus clearly not well known and needs revision; Neumavr's type shows only one whorl. Therefore, until the German and Polish faunas are described and figured more- fully, H. dijjicilis is retained, although ultimately it may prove to be a synonym of spirorbis. H. dijjicilis shows some variability . Although usually preserved only as internal moulds, some INDOSPH1 NOTES 21 variation in the strength of ribbing on the body-chambers is apparent. PI. 2, fig. 6 (FW TNN510) is one of a small number of less compressed individuals which have a more rectiradiate rib style. The microconch figured in PI. 2, fig. 5 (FW TNN528) is slightly more cvolutc with rather delicate ribbing on the inner and middle whorls, and the secondaries have a marked rursiradiate aspect. Rursiradiate ribbing is characteristic of the microconch group of Elatmit.es Shevyrev. I960, which, with the macroconch group of Indosphinctes Spath, 1930, is believed to have evolved from Homoeoplanulites at the beginning of the Callovian (Mangold 1971b). As probably the youngest Homoeoplanulites, H. difficilis may show close affinities with Indosphinctes (e.g. the microconch nikitinoensis Sasonov, i%5, Middle Callovian of the Russian Platform). However, microconch Indosphinctes have a bolder rib style, particularly on their inner-middle whorls. Also, Mangold (1971b, p. 52) believed that their lappets were long compared with those of Homoeoplanulites and that Indosphinctes had a more marked development of parabolic ribbing particularly at the end of the phragmocone and beginning of the body-chamber. Compared with the other microconch Homoeoplanulites, H. difficilis is most like //. balmensis but the latter is more cvolutc. The macroconchs may also show similarities with certain Indosphinctes because the ornament on the outer whorls is usually lost, except for the primaries. However, in Indosphinctes the primary ribs arc typically thickened at the umbilical edge at all stages and are shorter than those of//, difficilis. The II. difficilis macroconchs are much smaller than the other described macroconch Home.oplanuliles such as H. subbakeriae and H. funalus (Oppel). Genus INDOSPHINCTES Spath, 1930 (Synonym: Elatmites Shevyrev, I960 (type species Perisphinct.es submutatus Nikitin) |m|) Type species. Ammonites calvus J. de C. Sowcrbv, subsequently designated by Roman (1938. p. 275); lcctotypc Spath 1931, pi. 52, fig. 1 (BM C52288) [M]. Diagnosis. Moderately cvolutc to cvolutc forms with compressed to rounded whorl section (Text-fig. 6); lappcted microconchs strongly ribbed throughout, usually with marked rursiradiate aspect to secondaries; macroconchs show weakening of secondaries and development of short, blunt primaries which fade towards aperture (Text-fig. 7). Inner/middle whorls may have weak constrictions; parabolic ribs/nodes (particularly near venter) not uncommon. External suture has first lateral saddle with well marked accessory lobe, a trifid. slightly asymmetrical lateral lobe slightly deeper than ventral lobe, and a suspensive lobe with some well defined auxiliaries. Remarks. Indosphinctes was proposed by Spa th (1930, p. 36) for a group of perisphinctids from the Callovian ofCutch, India. He included the species calvus ). deC. Sower by, indicus Sierniradzki, patina. Neumayr, abichi Neumayr &. I Ihlig, c.hoffdti Parona & Bonarelli and subpatina Petitclerc, and later (1931. p. 329) six new species, errans, nalmaris. patiniformis, peregrinus. mslicus and urbanus. He noted particularly the following characteristics: a tendency to irregular ribbing on the inner whorls with inconspicuous primary ribs, often bundled or confined to a blunt node at the umbilical edge; a subsequent loss of ribbing with growth and its return, in modified form, on the body-chamber; projection of the ribs on the venter, at least in later growth stages; and a highly- complex suture (Spath 1931, p. 32!)). Spath clearly considered the style and development of the ribbing to be an important generic character which he referred to as '"the Indosphinctes type of costation" (1931, p. 331). Many of Spath's described or figured specimens were incomplete, with diameters ranging generally from 115 to 150 mm; when complete, specimens had diameters of the order of 250 mm. From this description, it seems certain that, as originally defined, the genus accommodated macroconch forms. Indosphinctes was discussed by Mangold (1971b, p. 84) who included in the genus microconch forms previously assigned to Elalmites. He confined the macroconchs, including besavoensis Collig- non, brenoni Collignon, cesaredensis Mangold, lancharesi Elmi & Mangold, linaresi Elmi & Mangold. luceyensis Mangold, pseudopatina Parona & Bonarelli and roberti Petitclerc, to Indosphinctes s.s., and used Elalmites to accommodate the microconchs. 22 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES In proposing Elatmites, Shcvvrev (1960) discussed only ontogenetic development, particularly of the suture, of the type species {Perisphinctes submutatus Nikitin 1881b; lectotype (Nikitin's pi. 1. fig. 4) designated and rcfigured by Sasonov (1965, pi. 2, fig. 3) [CNIGR Nikitin coll. 6/1344]). A fuller diagnosis given by Sasonov (1965, p. 10) and subsequently used by Mangold (1971b, p. 110) is as follows: compressed forms with wide umbilicus and gently sloping umbilical wall; last whorl covering 25-30% of preceding whorl: whorl section circular in young, becoming oval in adult: size between 65 and 80 mm; ornament of primary and secondary ribs, the latter rursiradi- atc on phragmocone; primaries well developed and prorsiradiate on body-chamber, splitting at middle of whorl side into two or three secondaries, sometimes with intercalatories; mouth border with lappets. L'sing the second and new species nikitinoensis assigned to Elatmites by Sasonov (1965), Mangold (1971b, p. 110) pointed out additional characters, particularly the presence of simple ribs and parabolic tubcxcles (the latter being especially well developed at the end of the phragmocone and the beginning of the body-chamber); he explained the lack of parabolae on Sasonov's figure of the holotypc oCE. submutatus as being probably clue to preservation. There may also be weakening of the secondaries or a sulcus on the venter. As well as the two Russian species, Mangold (1971b) included in Elatmites the species arcicosta Petitclerc non VVaagen, calloviensis Loczy, cheyensis Petitclerc, atrvicosta Oppel, gr ados us Siemiradzki. lobatus Buckman, prahecquensis Mangold, revili Mangold, steinmanni Parona & Bonarelli and subrjasanensis Petitclerc, and Cariou (1974a) added revolt Petitclerc 1918. Spath (1931, p. 325) suggested that Indosphinctes was connected with the Bathonian genera Proce.ril.es |macroconchs| and Siemiradzkia [microconchs]. These have since been taken as the parent groups of Hom.aeoplanuli.tes from which genus Indosphinctes is now thought to have evolved at the beginning of the Callovian (Mangold 1971b, p. 85). The dividing line between Homoeoplamdites and Indosphinctes is arbitrary and likely to be drawn differently by different authors. Both genera persist into the Middle Callovian. Indosphinctes lobatus (Buckman. 1922) PI. 6, figs 1-3 1922 Proplanulites lobatus nov.; Buckman, pi. 330. 1958 Proplanulites lobatus Buckman; Arkell, p. 235. 1971b Indosphinctes {m. Elatmites) lohatns (Burkman); Mangold, p. 115, tig. 83. 1975 Choffatia sp.; Cave & Cox: p. 40. ' Holotype. BGS CSM7682, PI. 6, fig. 3, figured Buckman 1922, pi. 330. Microconch from "Oxford Clay" |Kellaways Clay], Calloviense Zone, Kocnigi Subzonc, Rampisham, Dorset. (Blake (1905, p. 7) described this locality as "a deserted quarry in Oxford Clay but any Cornbrash seen there would he available". Wilson el al. (1.958. p. 112) gave the horizon as Kellaways Clay). Uncrushed specimen in cementstone with pink shell material partially preserved. Material.. Two uncrushed macroconchs with white chalky body-chambers and pink shell material partially preserved. From Kellaways Clay (Calloviense Zone, Kocnigi Subzone) of Sutton Benger (M4 Motorway cutting), Wiltshire and Siddington, Gloucestershire. Description. One microconch: maximum diameter 65 mm. Body chamber 220°. Six whorls visible. Moderately evolute (wh/d=32%); at least outer whorl section moderately compressed (wh/wt=r. 125%) (Text-fig. 6); moderately steeply sloping and almost smooth umbilical wall; umbilicus 27 mm wide and 5 mm deep at 65 mm diameter. Ribs (Text-fig. 7) gently prorsiradiate with slight rursiradiate aspect, near venter, less so on body-chamber. Primaries strong and rather widely spaced throughout (Text-fig. 10) splitting about the middle of whorl side (nor seen on inner/middle whorls). Outer whorl has bifurcate ribs each with an associated intercalarory, or irregular trifurcate ribbing. Occasional weak constrictions on inner whorls. Ribs generally pass uninterrupted across venter, though weakened in part, arid continue to aperture which bears lappets (up to c. 4X 14 mm). Two macroconchs: maximum diameter c. 150 mm. Body-chamber at least 220°. At least five * (probably six) whorls visible. Moderately evolute to evolute (wh/d=30-35%); whorl section IX DOS PI 11NCTES (Text-fig. 6) rounded (wh/wt=100 115%) on inner whorls, becoming more compressed (wh/wt= 115-130%) on middle and outer whorls, with flat whorl sides converging on fairly broad and rather flat venrer; moderately steeply sloping and almost smooth umbilical wall; umbilicus c. 65 mm wide and c. 15 mm deep at 135 mm diameter. Ribs (Text-fig. 7) gently prorsiradiate throughout, sometimes becoming rectiradiate near venter; on middle and outer whorls, trifurcatc with an associated intercalatory, or bifurcate with two associated intercalatories; primaries rather strong, sharp and regular throughout generally splitting above or about the. middle of the whorl side where they weaken: on body-chamber, primaries shorter and more blunt; ribs pass across venter without interruption. Shallow, weak constrictions (maybe two per whorl) on inner and middle whorls. Aperture not seen. primary & simple ribs OUM J 309181ml 40 OUM J 30912 Iml OUM J 30911 OUM J 309131ml Im] K, —• K- 30 BGSGSM BGS /6821m OUM GSM 7680 1M1 J 30917 [ml 20 - start of horiy chnmbcr 10 20 30 40 50 60 70 80 90 diameter (mm) TEXT-FIG. 10. Rib-density curVR.S for /ndnsphi.Mlt'i lobatus (Buckman) [broken line] and I. patina (Neumayr) [solid line]. Data for figured specimens. d (septate to) wh wt uw primaries BGS GSM7680 (PL 6, fig. I) 136 (c. 100) 42 32 63 30 128 BGS Zi 1639 (PI. 6, fi^. 2) t. 115 (c. 100) est. 40 est. 35 c. 55 BGS GSM7682 (PI. 6, fig. 3) 65 {c. 40) 21 17 27 31 est. 85 Remarks. Mangold (1971b, p. 115) considered I. lobatus to be monotypic. He thought that the holotypc possessed all the characters ofElatmites, in particular the rursiradiate ribs on the end of the phragmocone, and that it was manifestly not a Proplanulites to which genus Buckman (1921) originally assigned it. Proplanulites was one of the genera for which Buckman gave some notes for each species to accompany the type figures, but perhaps significantly, P. lobatus was the one exception. No further microconch specimen has since been found, but the two additional specimens described here (PI. 6, figs I, 2) arc possibly the macroconchs. It is not certain how far from complete these mature specimens are (PI. 6, fig. 1 has at least 130° body-chamber missing), but they do not show any signs of loss of secondary ribbing on the bodv-chambcr which is normal for Indosphinctes; however, they arc here assigned to the genus on the basis of the microconch. The microconch lobatus appears close to Sasonov's (1965) probably slightly younger E. nikitinoensis from Yelat'ma, USSR (Zone of Cadoceras milaschevici and Kosmoceras jason). However, I. lobatus has more widely spaced primaries, at least on the last whorl of'the phragmocone, and appears to be more compressed. Mangold (1971b, p. 114) believed that his species I. revili, from the Koenigi- Patina Subzoncs of Mont du Chat in the French Jura, was very close to I. lobatus, but the former species was more involute and had a smaller whorl height, with less "important" spacing of the primaries on the body-chamber. 24 ENGLISH CALLOVIAN PKR1SPHINCTI1) AMMONI TES Indosphinctes patina (Neumayr, 1870) PI. 6, fig. 4; PI. 7, fig. 1; Pi. 8, figs 1-4 1870 PerisphincUspatina now sp.; Neumayr, j>. 140, pi. 8 fig. I. turn 1871 PerisphincUs patina Ncumavr: Neumayr, p. 41, pi. 13 figs 2a, b [=/. pseudopatina (Parona & Bonarelli)!. 1097 PerisphincUs patina Xcuni.; Farona & Bonarelli, p. 174. ?I897 PerisphincUs submutatus Nik., Parona & Bonarelli, pp. 181, 182; pi. 10 Iig. 2. 1898 PerisphincUs Comptoni Pratt; Siemiradzki. p. 135 \Jpars\ 1899 Perispkinctes Patina Neum.; Siemiradzki, p. 297. 1910 PerisphincUspatina Neum.; von See. p. 698. 191 1 PerisphincUs patina Xnim.; Till, p. 35, pi. 4 (8) fig. 11 [suture only]. ?1913 PerisphincUs patina Neum.; Lowe. p. 154. 1915 PerisphincUs patina Neum.; Loczy, p. 409. 1915 PerisphijuUs puiina .Ncuinayi', Pelitclcn;, p. 73. 1918 PerisphincUs arcicosta Waagen, sp.; Petitclerc, p. 23, pi. 18 (4), fig. 1; pi. 19 (5), fig. 14. 1930 Indosphinctes patina (Neumayr); Spath, p. 36. ?1931 Indosphinctespatina (Neumayr); Spath, p. 338, pi. 102, figs 3a, h. 1932 PerisphincUs patina Neumayr; florroy. p. 137, pi. 12. fie;. 3. ?1935 Choffatia patina Neum; Model & ICuhn. p. 473. I9i>b Grossouvria cf. comptoni (Pi all}; Callomon, p. 233. 1955 i Binatisphinctes cf. Jluciuosus ( Pratt}; Callomon. p. 233. ? 1961 PerisphincUs (Indosphinctes) gr.patina (Neumayr); Ruget-Perrot, pp. 38, 58, 101, 153. ? 1967 Indosphinctes patina; Elmi, p. 460. 1968 Choffatia (Elalmites) suhmutata Nikitin; Callomon, p. 286. 1968 Choffatia cf. patina (Neumayr); Callomon. p. 286. 1971b Indosphinctes (M Indosphinctes) patina (Neumayr); Mangold, p. 100, fig. 74; pi. 13, fig. 2 [XU'5]. 1971b Indosphinctes (m Etat mites) pruheiyuensis uuv. num.; Mangold, p. 121, tigs 91, 94; pi. 12, lig. 3. 1971 ChoJJutiu (Etuimiles) cf. suhmutata (Nikitin); Callomon & Cope, p. 168. Holotypc by monotvpy; GBV 1870/04/1, PI. lig. 1; PI. 7, lig. 1 (original of Neumayr 1870, pi. 8, lig. I which was reversed), from Macrocephalen-Kalk (Lower Gal lovian), Brielral. nearGosau. Salzkammergut, Austria. Macroconch. All previous authors have referred to Neumayr1?; original and only figure as "type" lor the species. Material. Nine crushed and mainly incomplete, pyritized microconchs and one macroconch uncrushed body-chamber in cemenrstone. Description. Microconchs: maximum diameter 90 mm. Body chamber c. 180°. Six whorls visible. Moderately evolute (wh/d=150-40%); whorl section rounded at least on middle whorls; umbilicus c. 25-30 trim at 50—b 5 mm diameter. Ribs (Text-fig. 7) gently prorsiradiate or rec- tiradiate with marked rursiradiate aspect near venter. Ribs on inner and middle whorls strong, blunt but not swollen, even, moderately dense (Text-fig. 10) with long primaries splitting into two rather high on whorl side, with occasional simple ribs and rare intercalatories; outer whorls develop trifurcate, or bifurcate with an associated intercalatory, ribbing which remains even and blunt to aperture which bears lappets. Occasional weak constrictions. Ribs apparently, though not certainly, pass uninterrupted across venter. Macroconch: maximum diameter 265 mm. Body-chamber 210°. Evolute (wh/d=24%); whorl section compressed on outer whorl (wh/wt=c. 100%) (Text-fig. G); ribbing (Text-fig. 7) on body-chamber reduced to short, blunt primaries developed at umbilical edge, evenly spread c. 10 mm apart, splitting low on whorl side into secondaries; all ribbing fades as simple aperture approached. Data for figured specimens. + = type of II. patina; *on body chamber. d (septate to) wh wt uw primaries ventrals OUM J30911 (PI. 8, fig. 2) 89 (c. 60) 28 — 35 c. 32 c. 84 OUM J30912 (PI. 8, fig. 4) 67 (—) c. 21 — 31 c. 40 est. 90 OUM J30918 (PL 8, fig. 3) est. 55 {—) est. 16 29 — BGS Ztl675 (PI. 8, fig. 1) 265 (—) 65 c. 40 c. 130 20* — t (PI. 6, fig. 4 & PI. 7, fig. 1) 210 (c. 145) c. 55 est. 36 110 ±32 — INDOSPHINCTES 25 Remarks. I. patina was amongst the species listed by Spath (1030) in his proposal of Indosphinctes. It has been widely recorded and the macroconch form is one of the best known Indosphinctes in Europe. In France, it is used as a subzonal index in the Lower Callovian Gracilis Zone. Specimens of macroconch I. patina were figured by Spath (1031, pi. 102, figs 3a, b), Corroy (1932, pi. 12, fig. 3) and Mangold (1971b, pi. 13, fig. 2). Spath's figure showed an immature example and his description was based on a specimen that is much larger than the lcetotypc. The assignment of these specimens to I. patina is open ro doubt a view shared by Mangold (1971 b, p. 101). Corroy's figure is one of the best illustrations. Parona & Konarelli (1897, p. 177) excluded Neumayr s second published figure of/, patina because ir showed more involute coiling and gently curved ribs compared with the straight ribs typical of the species. They assigned it to a new species I. pseudopatina, and this specific distinction has been accepted by all subsequent authors. No microconch species has previously been formally linked with the macroconch patina but, following Mangold (1971b), the former are believed to he found in the suhmutatus Nikitin, 1881 group. Mangold did not attempt to pair up individual macroconch and microconch species but Callomon (1968, p. 286), having used both species for microconchs and macroconchs from the basal shell bed of the Jason Subzone at Calvert, believed that suhmutatus (Nikitin)[m]—patina (Neumayr) [M] made a plausible pair (Callomon, pers. comm. 1975). The early Russian authors, including Nikitin (1881) assigned the macroconchs associated with suhmutatus xofunatus Oppel, 1857 and mutatus Trautschold, 1862. These records offunatus arc now included in Choffatiapseudofunata (Teisseyre, 1889) sensu Mangold 1971 b. p. 154. Trautschold (1862, p. 211, pi. 6, figs 1,2) figured two specimens of mutatus, the second and smaller of which was included by Nikitin (1881b) in his original proposal of submutalus. Trautschold's species was thereby restricted to his first figure and this usage has been followed by subsequent authors (e.g. Lahusen 1883; Nikitin 1885; Sicmiradzki 1899: Stoll 1934; Kuhn 1939). It is clearly a macroconch form (d—c. 240 mm) which is distinct from I. patina, particularly its more involute coiling. It is reasonable to suppose that suhmutatus (Nikitin)[m]—mutatus (Trautschold) [M] are a dimorphic pair and, assuming the microconchs of mutatus and patina are distinguish*!) e, the microconch of the latter must he sought elsewhere. Most earlier authors recorded or figured only macroconch patina, and without adequate figured examples and/or stratigraphical control, it is impossible to be certain if associated microconchs are present and, if they arc, under what name. They may have been included in suhmutatus (e.g. Parona & Konarelli 1897 recorded patina and submutalus from the same locality in the J ura), or they may have been confused with those of the younger Binatisphincles, particularly B. comptoni (e.g. Siemiradzki 1898; Callomon 1955). In the key to his figure of submulatus, Petitclerc (1915, pi. 5 fig. 3) explained that compared with B. comptoni. the species had a thicker whorl with a more oval section, more involute coiling, stronger ribbing and more obvious parabolic ribs in the ventral area (these are emphasized in Parona & Bonarellrs (1897) figure of submulatus); B. comptoni also has much finer and denser ribbing ai least on the inner-middle whorls. Corroy (1932) may also have included the microconchs in "Perisphmct.es Comptoni Pratt sp.'\ for he recorded this species from both Lower and Upper Callovian and from a Lower Callovian locality with I. patina. Von See's (1910) description of another microconch, Binatisphincles mosquensis, from the Lower Callovian, may also be a rnisidentilication which could be related to macroconch patina. A possible microconch to accompany Loezy's (1915) patina from Villany is his "Parkinsonia callovien- sis no v. sp." (1915, p. 379, pi. 4, fig. 11; pi. ft. fig. 11: text-fig. 88) which Mangold (1971b, p. 127) believed belonged to the submutalus group. Mangold's (1971 b, p. 121) speciesprahecquensis from Deux-Sevres, figured by Petitclerc (1915, pi. 18 (4) fig. 1) as Perisphinctes arcicosta VVaagen, is considered here to be the microconch partner of /. patina. It occurs at the same stratigraphical level in France, and the specimen of Mangold's additional figure (Mangold 1971b, pi. 12. fig. 3) from the French Jura compares well with the English microconch material figured herein (PL 8, figs 2—4). Mangold (1971b, p. 122) believed 28 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES prahecquensis to be close to suhmutatus, but distinguished from this and all other Elatmites by its large size (up to 100 mm diameter). Distribution. Oxford Clay (Jason Zone) of Calvert, Buckinghamshire; Witney. Oxfordshire and Warlingham Borehole, Surrey (Callomon & Cope 197L). Lower Callovian of France (Paris Basin, Poitou, Deux-Sevrcs, and Ardeche (Elmi 1967); Lower-Middle Callovian of Germany (Macrocephalenschichten of Saxony (Lowe 1913; von Sec 1910); Calloviense Zone-Middle Callovian ofFranconia (Model Genus CHOFFATIA Siemiradzki, 1898 (.Sy«0«yw.f. Grossouvria Siemiradzki, 1898 (rype species Ammonites sulciferus Oppel, 1857) [m], Poculisphinctes Buckman, 1920 (type species Ammonitespoculum Leckenby, 1859), Trinisphinctes Buckman, 1922 (type species T. trim Buckman. 1922), Subgwssoiwria Spath, 1924 (type specics Perisphinct.es aherrans Waagen, 1875) [M]). Type species. Perisphinctescobra Waagen, 1875, by subsequent designation of Buckman (1920, p. 29); Ilolotype (GSI Type no. 2056), cast figured herein PL 9 fig. 1 |M| (BGS GSM11744a). Diagnosis. Moderately evolute. forms with moderately compressed, rounded or depressed whorl section (Text-fig. 11); strongly ribbed, often with well developed constrictions and sometimes parabolic ribs and nodes (Text-fig. 12); ribbing usually rursiradiate near venter, particularly in microconchs, becoming coarse on later whorls of macroconch, where primaries may be distant and blunt; lappetcd microconchs. External suture has first lateral saddle with a well marked accessory lobe, a trifid slightly asymmetrical lateral lobe usually about as deep as the ventral lobe, and a more or less retracted suspensive lobe with some well defined auxiliaries. Remarks. Choffatia was described originally by Siemiradzki (1898. p. 79) as one of six subgenera within Perisphinctes. Lie gave the diagnostic features as a smooth protoconch, compressed form without any trace of lateral lappets, simple mouth border (like Perisphinctes mar tins i dOrbigny), lateral sculpture similar to the martiusi group and simple suture line. Siemiradzki's figure (1898, p. 327, Fig. 83) of the aperture of P. martiusi shows a typical macroconch form with a gently sinuous mouth-border. The group was thought to link rhe perisphinctids with Proplanulites and included a single lineage, that of Perisphinctes cobra. Waagen. Siemiradzki (1898, p. 334) described this species as having a thick, disc-shaped shell form (diameter 125 mm) with a wide, deep, funnel-shaped umbilicus and thick rounded whorl with coarse widely spaced ribs; these disappeared before reaching the venter which remained almost entirely smooth. The inner whorls were finely ribbed, the ribs usually bifurcate and constrictions were rare. Siemiradzki's definition of Choffatia thus accommodated macroconch forms. Choffatia. and its type species have been discussed by Spath (1931, p. 344) and Arkell (1958, p. 211). The larrer concluded that the typespecies belonged to a Lower and Middle Callovian group of large constricted forms with gradually modifying ribs and smoothing venter, and no lappet. Following Spath (1931, p. 325), he also included Ilonioeoplanulites Buckman as a microconch subgenus which like Choffatia s.s. ranged from the Upper Bathonian into the Callovian (Arkell 1957a, p. 317; 1958, p. 211). However, Mangold (1971b) removed Ilomoeoplanulites as a separate genus. Elmi (1962) included Spatlrs (1924) Subgrossouuria (based on Perisphinctes aberrans Waagen) as an additional macroconch subgenus, to accommodate forms with depressed or circular adult whorls and an ornament of coarse (massive) and distant primary ribs suddenly replacing closely spaced fine ribbing on the inner whorls (Spath 1931, p. 327). Both Elmi (1962) and Mangold (1971b) included the Bathonian based genus Loboplanulites Buckman as a junior synonym of Subgwssouvria. The associated microconchs of both Choffatia s.s. and Subgrossouuria have been included in Grossouvria (Callomon 1963, p. 37; Mangold 1971b) which is discussed below. CHOFFATIA 27 There has been confusion about The interpretation of the type species of G rosso uvria and its type specimen, following Buckman's (1920, p. 28) designation of Perisphinctes subtilis Neumayr, 1870 with Neumayr's (18/1) pi. 14fig. 3as lectorype (viz'. Spath 1931, p. 326; Arkell 1939, p. 157; Arkell 1958, p. 214; Mangold 1971b. p. 163). These authors have shown that Perisphinctes subtilis Neumayr, 1870 is a junior objective synonym of Ammonites sulciferus Oppel, 1857, which is therefore taken now as the type species of Grossouvria (I.C.Z.N. Article 67(e)). The figure designated by Buckman as lectotype (Neumayr 1871. pi. 14 fig. 3) and cited by Siemiradzki (1898) when he proposed the genus (see below), is considered to be distinct from Oppel's A. sulciferus. It is septate to the end and therefore incomplete (Spath 1931, p. 326); Spath considered that it might be the nucleus of a Choffatia species. He advocated that Grossouvria should be used for forms for which Oppel (1857, nun 1862) used the name sulciferus and for which Neumayr (1870, non 1871) used subtilis. This view was supported by Arkell (1958, p. 214) who designated Quenstcdt's (1849, pi. 13, fig. I) Ammonites convolutus orriati as type specimen (GPI unnumbered; cast figured ti sulci (era su In ifera TEXT-FIG. 1 I. Whorl sections ofChoffahci spccics: (a! IJGS GSM49454 ai 193 mm: (b) FW TNN537 at 90 mm; (c.) FW TNX322 at 57 mm: (d) GSI 20:>(> at 127 mm; (c) FW TNN507 at 91 mm; (f) FW TNN460 at 58 mm; (g) OUM J1203 at 60 mm; (h) OUM J 17870 at 19 mm: fi) OUM J2588 at 30 mm; (j) GPI (httlotypr) ar Til mm: fk) OUM J2255'J at 87 nun: ii) S\1 J3298 at 60 mm: (m) BGS GSM 6509 at no mm. herein, PI. 12, fig. 1). Mangold (1971b) also adopted this definition. Siemiradzki (1898) in proposing Grossouvria listed Perisphinctes sulciferus as characterizing on of its lineages. Its use as type species docs not conflict therefore with the original definition. Siemiradzki (1898, p. 76) diagnosed Grossouvria as a perisphinctid of small to medium size, mostly not exceeding 100 mm diameter; mouth-border with well-developed, more or less con- stricted, sword-like or tongue- or spoon-shaped lappets; strong parabolae recognizable, when the state of shell preservation allows, right up to the mouth border; bifurcate ribbing in the young, in older stages frequently three or more branches; ribbing extending to the end of the shell, which is never smooth; protoconch smooth; funnel-shaped umbilicus with rounded, strongly depressed whorl section; from the beginning of normal ribbing, firstly some occasional large folds, then hairline, forward sloping, bifurcate ribbing, with a somewhat backwards swing in the ventral region: normal ribbing occurs first at about 3 mm total diameter; suture line simple with few ramifications umbilical lobe extending only a little downwards, the auxiliary lobes weakly 28 KNCLISII CALLOVIAN"PERISPHINCTI D AMMONITES inner middle outer whorls— whorls whorls body chamber Chuff a tin cardor i m 1 wcll-deveh :>pcd. rather wide con strictions llml f([ffr Choffatia recuperoi moderat ely well- devel oped constr ictions WW** |FMI Choffatia yW 1 sulcifer a parabolic ribs & nodes weak to moderatel y strong constr ictions m Lm Choffatia aff. iahuseni 0T I shallow c onstriction «s m/rLi m Choffatia m ijL^r i /„/ pocutum nodes, HJ3flared ribs and weak c onstriction! mllr iMJr* Choffatia trina 112? fW moderate ily strono, i shallow cc>nstriction s llml TKXT-FIG. 12. Ribbing of Choffatia species. developed, the second lateral lobe always present although twice as small as the first, easily distinguishable from the auxiliary lobe by its straight position. Siemiradzki recognized several lineages within four different morphological types ("Mutationsrcihc") characterized respectively by Perisphinctes subtilis Neumayr. Perisphinctes alligatus Lcckcnby. Perisphinctes aurigerns Oppel and Perisphinctes euryptchus Neumayr. Grossouvria as defined by Siemiradzki thus accommodated micro- conch forms. Choffatia is used in preference to Grossouvria in accord with the recommendation of the I.C.Z.N. Article 24A. It includes the largest number (over 80) of described species of any Callovian perisphinetid, having been recorded from nearly all areas of ammonite-bearing Callo- vian strata (worldwide except for some of the most Boreal areas). 31 CHOFFATIA Choffatia is thought to have its origins in the Bathonian. Spath (1931, p. 325) and Arkell (1958, p. 211) both suggested, though not explicitly, that Choffatia [M]-Cr0W0tf»r/d[m] originated from Procerites[\i]-Siemiradzkia[m]. Mangold (1971b, p. 219) believed rather that the latter pair gave rise to Homoeoplanulites and Indosphinctes, and that together these belonged to quite another subfamily. He believed that the ancestors of Choffatia were to be found in Wagnericeras, full grown specimens of which were described by Arkell (1958, p. 176) as "massive smooth ammonites indistinguishable from Procerites". Choffatia cardoti (Petitclerc, 1915) PI. 9 figs 2-3; PI. 10 fig. 1 1915 Perisphinctes Cardoti nov. sp., nobis; Petitclerc, p. 04, pi. 5, lig. 2. cf. 1932 Perisphinctes cardoti Petitclerc; Corroy, p. 141, pi. 24, ligs 5. 6. non 1939 Grossouvria (Poculisphinctes) cardoti (Petitclerc); Arkell, p. 179 [ — C. poculum\. 1958 Grossouvria cardoti Petitclerc. sp.; Arkell, p. 222. 1971b P. cardoti PMilderc: Mangold, p. 162. 1974 Choffatia cardoti Petitcl ; Cariou, p. 307. Holotypc, by monotypy. Specimen thought to be in the Laboratoire de Paleonrologie des Invertebr<5s, Univcrsitc Pierre ct Marie Curie, Paris, but not traced (Pajaud, pers. comm. 1980). Originally figured Petitclerc. 1915, pi. 5, fig. 2. Lower Callovian (probably Koenigi Subzone Callomon, pers. comm.). quarry of Prahccq, Dcux-Sevres, Aquitaine, France. Macroconch. Material. Three unerushed and undistorted internal moulds preserved in coarse friable sandstone; well displayed sutures and siphnncles. Macroconchs, including one with body chamber. Description. Maximum diameter at least 200 mm. Body chamber at least 280°. More than five whorls visible. Kvolute (wh/d~c. 25%); whorl section rounded on inner and middle whorls becoming compressed (wh/wt< 150%); Hat whorl sides and rounded venter, broad on inner and middle whorls (Text-lig. 11); moderately to steeply sloping atid almost, smooth umbilical wall; umbilicus wide and moderately deep (up to 105 mm wide and 20 mm deep at 195 nun diameter). primary & simple ribs • = start of body chamber FW TNN 460 40- ImJ FW TNN 507 FW TNN 522 [Ml 30 FW TNN 512 BGS [ml GSM 49454 FW TNN 537 IMJ 20 JL 10 30 50 70 90 110 130 150 170 190 diameter (mm) TF.XT-FIG. 13. Rib-density curves for Choffatia cardoti {Petilclcrc) | broken line] and C. muperoi (Gemrnellaro) I solid line]. Ribs (Text-fig. 12) generally rcctiradiatc to gently prorsiradiate throughout, though where primaries more markedly prorsiradiate, secondaries may develop slight rursiradiate aspect. Primary ribs strongly developed and rather widely spaced throughout (Text-fig. 13), particularly on middle whorls where they are almost bulla.te; on outer whorls, primaries weaken bur. persist: on middle and outer whorls, primaries split into three, a little above middle of whorl side, maybe with an associated inrercalatory (sometimes this combination appears almost virgatotome); on inner 30 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES whorls (up to c. 40 mm diameter), some similar style ribbing but also some bifurcate ribs. Ribs pass across rounded venter without interruption. Well developed, rather wide constrictions on inner and middle whorls, maybe two per whorl. Data for figured specimens. d (septate to) wh wl uw primaries FW TNN536 (PI. 9 lig. 2) 64 (64) 6". 21 c. 21 — — FW TNN537 (PI. 9 fig. 3) c. 90 (—) 28 32 41 23 c. 62 BGS GSM49454 (PI. 10 fig. 1) 193 (c. 123) 49 6-. 32 105 est. 28 Remarks. The holotvpe was alleged (Petitclerc 1915) to be from the anceps Zone [ = Middle Callovian |. However, little stratigraphical information was given and it possibly came instead from the Lower Callovian, because in that area of France it has not always been possible to separate Lower and Middle Callovian faunas, which may occur in one unit (Couffon & Dollfus 1928, p. 406). Mangold (1971b, p. 162) believed C. cardoti belonged in the Lower Callovian. Corroy (1932) figured a specimen from the Haute Marne that appears to be less coarsely ribbed than the holorype. although he was clearly in no doubt about characteristic features of the latter. Unpublished work by Cariou on the type material from Aquitaine indicates that C. cardoti belongs to the Macrocephalus /one, Rehmarmi Sub/one which is equivalent to the Calloviense Zone, Koenigi Snhzone of Great Britain (Callomon, pers. comm. 1981). Specimens from the Lamberti Limestone ofWoodham (OUM J22375-7), identified by Arkell (1939, p. 1 79) as C. cardoti. and described by him as "like a very coarse-ribbed poculum" arc herein referred to C. poculum. The macroconch of this species appears to be more involute than C. cardoti, with blunter ribbing and only a weak development of constrictions; it also occurs at a younger horizon (Lamberti Zone). Later, Arkell (1958, p. 222) described C. cardoti as "almost a homoco- rriorph or perhaps a direct descendent" of Choffatia (Loboplanulites) cerealis of the Bathonian, but with a less inflated whorl section. Loboplanulites was subsequently taken by Elmi (1962) and Mangold (1971b, p. 157) as a junior synonym of Subgrossouvria. C. cardoti also appears to have affinites with Sub grossouvria euryptchus (Ncumavr, 1871) from the Balin Oolite of Poland (?Lower Callovian) (Spath 1931, p. 375; Gerard & Contaut 1936, p. 56 (although their record, without figure, is stratigraphically less appropriate)). Ncumavrs (1871, pi. 12 lig. I, wrongly given in the text (p. 38) as pi. 14) figure shows a generally more evenly ribbed form whose ribbing docs not become as coarse until a later stage, (cf. figure of S. euryptychus from Hungary: Loczy 1915, p. 403 fig. 119). However, without better illustrations of the type material, further comment cannot be made (see also Choffatia recuperoi below). Distribution. Kellaways Sand (Calloviense Zone, Calloviense Sub/one) of South New bald and South Cave, Humberside. Lower — ?Middle Callovian of France (l)eux Sevres. Aquitaine (Macrocephalus Zone; Cariou 1974) (see above) ?Haute Marne). Choffatia recuperoi (Gemmellaro. 1872) PI. 11, figs 1 4 aff. 1872 Perisphinctes Sciutoi Gemrn.; Genimellaiu, p. 25, pi. 4, ligs /-9. 1872 Perisphinctes Recuperoi Comm., Gemmellaro, p. 26.. pi. 5, ligs 9-11. nan 1875 Perisphinctes recuperoi Gemmellaro; Waagen, p. 172, pi. 43, fig., I \ = C. soorkaensis Spaih]. 1801 Perisphinctes Recuperoi. Comm.; Hang, p. 99. ? 1090b Per. Recuperoi Gemm,; Siemiradzki, p. 175. all". 1894 Perisphinctes etegans n. sp., Siemiradzki. p. 517, pi. 40. fig. aff. 1894 Perisphinctes crussus ci. sp., Siemiradzki, p. 518, pi. 40, fig. 5. 1894 Perisphinctes Recuperoi Gemmellaro: Siemiradzki, p. 525 pars. |~pars=C. soorkaensis]. non 1895 Perisphinctes Recuperoi Gemmellaro; Noeding, p. 20, pi. 13, lii». 4. 1897 Perisphinctes Recuperoi Gemm.; Parona & Bonarelli, p. 173. ff. 1898 Perisphinctes Sciutoi Gemm.; Siemiradzki. p. 128 pars \pars~C. soorkaensisJ. aff. 1898 Perisphinctes erassus Sic.rnir.; Siemirad'/.ki. p. 129 pars 1890 Perisphinctes Recuperoi Gemm.; Siemiradzki. p. 295, fig. 68pars [/tars— C. soorkaensis], all". 1913 Perisphinctes of. etegans Siem.; Lowe. p. 153. 1913 Perisphinctes Recuperoi Geniellaro Lowe. p. 15'1 pars CHOFFATIA 31 non 1915 Perisphinctes recuperoi Gcmmrllaro; Petitclerc, p. /'/, pi. 8, fig. 2 [— C. dumortieri Mangold & Elmi]. aff. 1915 Perisphinctes Sciutoi. Gemmellaro; Petit derc, p. 82. non 1915 Perisphinctes Recuperoi Gcmm.; Loczy, p. 420, pi. 13. fig. 8 | = C. dumortieri Mangold & Elmi]. 1919 Perisphinctes Recuperoi Gemmellaro; Coufion, p. 215, pi. 14, figs 2. 2a, 2b pars, non 1924 Perisphi/uiei Recuperoi Gemmellaro: Roman, p. 99. pi. 11. fig. 3 [ = C. dumortieri Mangold & Elmi]. non 1930 Perisphinctes Recuperoi Gemmellaro; Roman, p. 181 pi 18, fig. 1 f = C. dumortieri Mangold & Klriiij. 1930 Choffatia aff. recuperoi (Gemmellaro):. Spath. p. 38. pi. 4, fig. 13; pi. 5, lig. 6. aff. 1930 Grossouvria cf. elegant (Sicmiradski); Spath, p. 40. pi. 4, ligi. 4. 11; pi. 5, fig. 4. 1931 Choffatia aff. recuperoi (Gemmellaro); Spath, p. 358. aff. 1931 Perisphinctes sciutoi; Spath, p. 303. 1932 Perisphinctes Recuperoi Gemmdlaro; Corroy, p. 129. pi. 16. fig. 3 pars fpars=C. mark ante mis and C. dumortieri). aff. 1932 Perisphinctes Sciutoi Gemmdlaro; Corroy, p. 112, pi. 23.. fig. 9. all'. 1932 Perisphinctes Sciutoi Gemmellaro var. crassus Sicmiradski [sir]; Corroy. p 143, pi. 17. figs /, 0. non 1938 Choffatia Waageni (Teisseyrc) var. Recuperoi (Gemmellaro); Pfachler-Eialli, p. 15, pi. 4, figs 2a, b. [fide Mangold 1971b]. aff. 1939 Perisphinctes (Grossouvria) sciutoi Gemm.; Kuhri, p. 500, pi. 10, fig. 2. 1939 Perisphinctes recuperoi Gcmm., Kulin, p. 512, pi. 4. fig. 2. non 1952 Perisphinctes (Perisphinctes) recuperoi Gemellaro |«cj; Makowski, p. 33. pi. 9, fig. 3 [= C. dumortieri Mangold & Elmi]. 1958 Choffatia (Loboplanuiites) recuperoi (Gcmmo.lla ro); Arkell, p. 220, fig. 80. ?1961 Perisphinctes (Choffatia.) recuperoi (Quenst.); Rugct-Pcnot, p. 39. 1965 Subgrossouuria rf. recuperoi (Gemmellaro); Busnardo, Elmi & Mangold, p. 78. 1971b Choffatia (M Subgrossouma) ntuperoi (Gemmellaro); Mangold, p. 161. fig. 117. pi. 10 figs 2. 3. a IT. 1971b Choffatia (m Grossotwrm) sautoi [ Gemmellaro); Mangold, p. 181, figs 122. 3, pi 7, fig 7 P1971 Chojjuliu {Choffatia) cf. recuperoi (Gemmellaro); Hahn & Roomer, pi. I 1. all: 1974 Grossouvria sciutoi Gem.; Cariou, p. 307. all". 1974 G. crassa Siem.; Cariou, p. 307. Type specimens. Gemmellaro's (1872) specimens are thought to be either in the Museo di Geologia e Mineralogiadella R. Universita di Palermo or the Museo di Palaeontologia e geologia, Palermo, Sicily, but have not been traced. From the Rocea chi parra ('zone of Stephanoceras macrocephalum') Calatafimi, Trapani, Sicily. Macroconch. Material. Seven uncrushed and generally nndistorted specimens preserved in ironshot oolite, usually as internal moulds. Microconchs (complete with aperture) and macroconchs (incomplete); one pyriti&ed microconch. Description. Microconchs (three specimens): maximum diameter 60 mm. Body-chamber at least 220°. Six whorls visible. Moderately evolute (wh/d = 30-35%); whorl section rounded on inner and middle whorls, later becoming more compressed (wh/\vt= 110-130%) (Text-fig. 11); moderately steeply sloping and almost smooth umbilical wall; umbilicus c. 25 mm wide and up to 8 mm deep in adult. Primary ribs prorsiradiate, secondaries rnrsiradiate; inner whorls have bifurcate ribs with occasional intercalatories; middle and outer whorls have rather long, straight primaries splitting, sometimes irregularly and always with a backward swing, above the middle of the whorl side into two with an associated intercalatory to each pair, or more rarely into three (Text-fig. 12). Inner and middle whorls with moderately well developed constrictions. Ribs pass across venter without interruption. Body-chamber with terminal constriction; aperture bears lappets (up to c. 5X15 mm). Macroconchs (one wholly septate specimen): maximum diameter c. 90 mm. At least six whorls visible. Evolute (wh/d=c. 30%); whorl section rounded or slightly compresscd on inner and middle whorls, becoming slightly depressed on outer whorls (wh/wr=c. 85%) with rather flat whorl sides, gently arched towards moderately broad venter (Text-fig. 11); steeply sloping and almost smooth umbilical wall; umbilicus c. 40 mm wide and up to 12 mm deep at c. 90 mm diameter. Ribs (Text-fig. 12) gently prorsiradiate but on inner whorls, secondaries have rursiradi- ate aspect. Inner and middle whorls have bifurcate ribs with occasional intercalatories; outer whorls have trifurcate ribs and more rarely bifurcate with an associated intercalatory, primaries splitting at about rhe middle of the whorl side. Inner and middle whorls have moderately well developed constrictions (c. 2 per whorl). Ribs pass across rounded venter without interruption. 32 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES Rib density curves for figured specimens are given in Text-fig. 13. For any one individual, from at most 20 mm diameter, the number of primaries per whorl apparently varies remarkably little. Data for figured specimens. d (septate to) wh wt uw primaries vcntrals FW TNN507 (Pi. 1L fig. 1} 91 (91) e. 25 c. 29 40 33 est. 85 FW TNN 160 (PI. 11, lig. 2) 58 (c. 38) 19 17 24 38 90 FW TNN.512 (PI. 11, fig. 3) c. 60 (c. 35) 21 c. 20 24 27 c. 75 FW TNN.522 (PI. 11, fig. 4) 57 (c. 36) 19 14 26 32 est. 80 Remarks. Perisphinctes recuperoi was proposed by Gemmellaro (1872) for macroconch material from Sicily. Arkell (1956, p. 207) believed, on the basis of field evidence, thai it came from a condensed bed representing the Lower and possibly the lowest part of the Middle Callovian. It has since been widely used, particularly by French authors, for several species from various horizons in the Callovian. The records of Petitclerc (1915), Loczy (1915), Roman (1924; 1930) and Makowski (1952) from the Middle Callovian were separated by Mangold & Elmi (I960) (who saw most of the figured and cited material) into a new species Choffatia dumor fieri. This is distinguished from C. recuperoi by a less depressed whorl section and less thick primary ribs, but most noticeably by the straight and close ribbing of the inner whorls, which in C. recuperoi persists to a comparatively large diameter a feature already noted by Spath (1930, p. 38; 1931, p. 359). Spath retained Gcmmellaro's species for "the more doubtful serpcnticone Perisphinctids of the macrocephalus beds" ofCurch and based his new species C. soorkaensis on Waagen's (1875) main example of C. recuperoi which was distinguished from Sicilian specimens by the ( lose ribbing on the periphery of the earlier whorls and comparatively simple suture line (Spath 1931, p. 360). Siemiradzkrs (1891; 1898) records of the species included Waagen's example in their syn- onymies. Corroy?s (1932) record also included this form as well as specimens subsequently referred to C. dumortieri. He (1932, p. 130) gave the horizon as Upper Callovian, but in the key to his plate 16. attributed ir to the Lower Callovian; the stratigraphieal section agrees with the text. The division is also included in the Middle Callovian of current usage; the localities given by Corroy showed both Lower and Upper Callovian, and the record must therefore remain open to doubt. Other related forms are C. euryptychus (Neumayr) and C. cardoti (Petitclerc) (see above); compared with C. recuperoi, the former is rather more irregularly ribbed, and the latter is more strongly, sharply and irregularly ribbed. Both, but particularly C. cardoti, lose the straight and dense ribbing of the inner whorls at an earlier stage, and both have a less depressed whorl section. Spath (1930, p. 39) believed C. recuperoi was intermediate between Choffatia s.s. and Sub- grossouvria and more recently it has commonly been included in the latter (Busnardo, Elmi & Mangold 1965, p. 78; Mangold 1971b). Arkell (1958) included it in Loboplanulites, since taken as a junior synonym of Subgrossouvria (see above). The associated microconchs are tentatively recognized amongst and grouped with Gcm- mellaro's species Perisphinctes sciutoi: the type specimen (Gemmellaro 1872, pi. 4, figs 7-9) came from rhe same horizon and locality as C. recuperoi but it is much less well known. Mangold (1971b, p. 181) included it with the eve.xa-sulcifera group of Grossouvria (characterized by a regular style of ornament) which he used to accommodate microconchs associated with Subgrossouvria. Peri- sphinctes elegans Siemiradzki and Perisphinctes erassus w:ere also included. Siemiradzki himself (1898) placed P. etegans in the synonymy with P. sciutoi'; P. erassus is clearly closely related and Corroy (1932, p. 143) included it as a variety of P. sciutoi. Parona & Bonarelli's (1897) Perisphinctes cf. subtilis listed by Siemiradzki (1898, p. 129) in the synonymy of P. erassus, is not included. Perisphinctes gracilis is also excluded, although Siemiradzki (1898) subsequently grouped it, together with P. etegans, in P. sciutoi; Mangold (1971b, p. 185) believed it belonged to a younger horizon. P. gracilis is less compressed than the otherwise similar but slightly younger Grossouvria CHOFFATIA - . ^ 33 vurvkosla (Oppel)-kontkiewczi (Siemiradzki) of Pfaehler Krar.h (1938. pi. 1. figs -4a, h) and those figured herein are less strongly constricted, at least on the outer whorls, than some of the examples, including the types, mentioned above. Distribution. Kellaways Rock (Calloviense Zone, Knodatum Subzone) of South Newbald and South Gave. Humberside;• basal Oxford Clav/ (Knodatum Subzone)f of the Hast Midlands: Lower Callovian of Sicily; France (Haute Maine, Ardennes. Aquitaine (Gracilis /one; Cariou 1974a)); thejura; southern Spain (Andalusia); ^Portugal; Poland ("Eiserioolithe" of Balin and Rudniki); Kenya; India (Cutch); USSR (Lithuania; Siemiradzki 1890b); Macrocephalus Zone of Germany (Saxonv (Lowe 1913), Swabia (Halm & Koerner 1971) and Franconia (Kuhn 1939)); and Lower Callovian of the Alps (Haug 1891). Choffatia sulcifera (Oppel, 1857) PI. 12, ligs 1 (S 1840 Ammonites conuolutus ornati: Quenstedt, p. 169. pi. 13. fie:. 1857 Ammonites sulci ferns; Op pel. p. 555. non Ub8 Amnmonites convolutus vrnati; Qucn.s(ed(, p. 544, pi. 71. fig. 9. |=ef. Choffatia aff. lahusent] 1802 Ammonites sulcijerus; Oppel. p. 155, pi. 49, figs 4a, I), c. non 1932 Perisphinctes sulcijerus Oppel tip.; Corroy, p. 126. pi. 18., figs 8, 9. 1952 Perisphinctes (Grossouvreia) variabilis Lahusen; Maknw.ski, p. 32, pi. figs 4, 4a. 1956 Grossouvria aff. variabilis (I.ah ); Arkell, p. 482. 1957a Grossouvria (Grossouvria) sulcifera fOppel); Arkell, p. LI519, Fig. 44)5, 12a. b. 1958 Grossouvria sulcifera (Oppel); Aikell, p. 214. 1971b Choffatia (in. Grossouvria) sulcifera (Oppel); Mangold, p. 189. Holotype. By monotypy. Specimen figured Quenstedt 1849, pi. 13, fig. 1, GPI (unnumbered); from "Dogger zeta (Callovium)", Gammclshauscn, Wurttcmbcrg, W. Germanv. Cast, BGS GSM 117447, figured PI. 12, fig. 1. Material. Ten uncrushed or partially crushed specimens, small but nearly complete (adult) pyritized internal moulds, and one uncrushed incomplete specimen in a shelly calcareous dogger. Microconchs. Description. Microconchs: maximum diameter c. 40 mm. Body-chamber probably at least 250". At least 4 whorls visible. Moderately evolute (wh/cl=c. 35%); whorl section generally moderately compressed (wh/wt= 100-120%) with rather flat whorl sides and gently arched broad venter, but innermost whorls depressed (Text-fig. 11); umbilical wall steeply sloping and almost smooth; umbilicus shallow and wide (c. 15 mm wide and 3 mm deep at 37 mm diameter). Ribs (Text-fig. 12) generally prorsiradiate on umbilical edge and whorl sides, becoming rursiradi- ate, often markedly, towards venter. Innermost whorls smooth or with weak primaries only, and weak constrictions (maybe two per whorl). By 10 mm diameter, ribbing becomes bifurcate with primaries splitting into rwo on the outer part of the whorl side and generally passing uninter- rupted across venter; constrictions (maybe two per whorl), weak to moderately strong—par- ticularly the one marking end of phragmocone. Sometimes weak nodes on the ventro-latcral margin, particularly on the later whorls and body-chamber where ribbing bccomcs altogether less regular with parabolae and occasional simple ribs. Generally 30-10 primaries for diameters between 10 and 40 mm. Data for figured specimens. d (septate to) wh wt uw primaries ventrals Holotype (GPI, no number} (PI. 12, fig. 1) 31 (27) 9 9 1.5 29 est. 68 BGS GSM27932 (PI. 12. fig. 2) 32 (c. 24) 11 10 13 est . 35 OUM J2588 (PI. 12. fig. 3) 30 (18) 10 9 13 38 est. 66 JKW BH12G (PI. 12, fig. 4) c. 28 (—) 9 9 OUM J1218 (PI. 12, fig. 5) 37 (26) 13 (») 15 38 OUMJ2587 (PI. 12, fig. 6) 27 (27) c. 9 8 11 c. 42 est. 65 Remarks. Although C. sulcifera is the type species of (irassouvria and in that role has received 34 KNCLISII CALLOVIAN"PERISPHINCTI D AMMONITES considerable coverage in the literature (see above, under Choffatia), it is not particularly well known. The holotypc is a constricted form with prorsiradiate primary ribs throughout and a characteristic rursiradiate twist in the secondaries. There may be the vestige of a ventral sulcus and parabolae are confined to the body-chamber (PI. 12. figs la-d). The material described herein includes nearly complete adult (microconch) individuals comparable with the type material of de LorioPs (1808) species miranda which has been used previously to accommodate the small pyritized representatives of the 'mainstream1 perisphinctids (Choffatia-Grossouvria) of the Athleta to Gordatum zones. Spath (1931, p. 394) restricted miumia to de LorioPs figures 15 (lectotype. Arkell, 1939) and 15a. However, compared with the present material, miranda shows a more irregular rib style on the phragmocone with well developed parabolic ribs and nodes, but with fewer constrictions; the type also comes from a younger (Lower Oxfordian, Mariac Zone) horizon. Perisphinctes variabilis Lahusen (1883, pi. 10, fig. 4) is based on a complete Russian microconch from a condensed ironshot oolite possibly of late Callovian age (Lahusen 1883, p. 85) and inferred by Spath (1931, p. 328) and Mangold (1971b, p. 166) to come from the Lamberti Zone. Tt differs from most of the material described here in having more pronounced irregular ribbing on the phragmocone and no, or only a weak, development of constrictions. Makowski's (1952, pi. 8, figs 4a, h) figure of P. variabilis seems to fall within the range of variation here illustrated for C. sulci [era, and following Mangold (1971b), is included with it. Makowski's material from Poland (Upper Callovian, Lamberti Zone, fide Arkell 1956, p. 482) shows an a perl i i re heari ng lappets. 1 he A t hie la Zone material descri bed here occu rs wi t h A lligaticera.c rotifer (Brown) (see below). The few large pyritized, poorly preserved (incomplete or with pyrite overgrowths) specimens in old collections (e.g. OUM J1211. J26254), which come from similar stratigraphieal levels or localities might be the associated macroconchs of C. sutcifera. Distribution. Oxford Clay (Athleta Zone) of YVolvercotc and Summertown, Oxfordshire; Hackness Rock of Hackness, North Yorkshire (Bed 4 of Wright 1968; Athleta Zone): Athlela- Larnberti Zones of Swabia, southern Germany (Hahn & Kocrner 1971); Lamberti Zone of Lukow, Poland; Athleta Zone of the French Jura (Mangold 1971a, b) and north-west Aquitaine (Cariou 1974). Choffatia aff. lahuseni (Sasanov, 1965) PI. 12, figs 7, 8 Material. Two completely septate nncrushed pyritized internal moulds from the Oxford Clay (Athleta Zone) of Blctchley, Buckinghamshire (Bed 21 of Callomon 1968. p. 282) and Wolver- eote, Oxfordshire. Description, Maximum diameter seen c. 70 mm, completely septate; at least 4 whorls visible. Moderately evolute (wh/d~c. 30-35%); whorl section rounded or slightly depressed (wh/wt=85 95%) with gently rounded whorl sides and broad venter (Text-fig. 11); moderately steeply sloping and almost smooth umbilical wall. Ribs (Text-fig. 12) prorsiradiate throughout; bifurcate with occasional intercalatories on inner whorls (up tor. 30 mm diameter) with shallow constrictions: on middle whorls, this style persists but trifurcate ribs also common with some strengthened and flared primaries; ribs split about middle of whorl side and pass uninterrupted across venter; 25 30 primaries at i. 20 mm diameter. Outer whorls/body-chamber unknown. Data for figured specimens. d (septate to) wh wr uw primaries ventrals OUM J17870 (PL 12, fig. 7) 19(19) 7 8 7 30 — OUM J1203 (PI. 12, fig" 8) est. 68 (68) 21 22 est. 28 — — Remarks. The specimens are comparable with Neumayr's illustration of his species Perisphin ct.essubtilis (1871, pi. 14, fig. 3) (cast figured PI. 12. fig. 10). There has been confusion surrounding the interpretation of Choffatia lahuseni arising from Neumayr's (1870) original citation and his subsequent (1871) figure and description of Perisphinctes subtilis. This has been widely discussed and since resolved (see above), although his later (1871, pi. 14, fig. 3) P. subtilis' is distinct and requires a new name. Neumayr (1871, p. 38) made it clear that this specimen (from Balin) was CHOFFATIA 37 septate to the end and also noted that the species was "not rare" in the upper part of the "Ornatenthonen" of Wurttemberg (Franconia) (Upper Callovian). His specimens from Wiirt- tcmburg apparently showed body-chambers and had diameters up to 50 mm, but without illustration, further comparison is impossible. I favour the view that Neumayr's 'type' specimen is an incomplete microconch, which remains finely ribbed throughout; because of its incomplete nature and uncertain age, I refrain from giving a new specific name. The two specimens described herein (PI. 12, figs 7, 8) are comparable with Neumayr's specimen (cast figured herein, PI. 12, fig. 10), but arc more coarsely ribbed than this form at a comparable diameter which has c. 40 ribs at 20 mm diameter, the larger specimen (OUM J1203; PI. 12 fig. 8), an incomplete macroconch. is larger than any specimen previously referred to Neumayr's P. sub lilts, I.ahuserTs (1883) figured example of Perisphinctes sub til is from the Upper Callovian of the Russian Platform, Peltoceras athleta and Qitensledtoceras keyserlingi Zone (Sasonov 1961), was made the type oiOkaitespseudosubtilis Sasonov, 1965 (p. 24). However, in the same paper (p. 26) he used the same specimen as the type of Loriolites lahuseni. These two species arc therefore objective synonyms, and the latter name is favoured because Sasonov gave a full description. He alleged that it showed an interruption of the ribs on the venter, with a weakly developed sulcus. It is not possible to tell how significant or marked this feature is because Sasonov figured no additional material, and gave no synonymy. It is certainly not well defined on Lahusen's figure. Until more complete material becomes available, the English specimens are referred to Choffatia aff. lahuseni. Distribution. Possible records from Athleta Zone of the western Alps (Ilaug 1891), Swabia (Halm & Koerner 1971), Franconia (Neumayr 1871) and north-west Poland (Dayczak- Calikowska 1977). Choffatia poculum (Leckenby, 1859) PI. 12, figs 9, 11-16; PI. 13 figs 1-5; Text-fig. 14 1859 Ammonites pneubtm I.cckenby (Bean MS); Leckenby. p. 9, pi. 1. figs 4a-c. non 1878 Perisphinctes poculum Lock. ?cf. cumcostu Oppel; L'lilig. pp, 613, 649, pi. 16, fig. 2. 1920 Poculisphinctes poculum Bean-Ldckcnby sp.: Buekman, pi. 185. 1920 Pvidhpfunites auricularis no v.; Buckman, pi. 186. 1931 Poculisphinctes poculus (Bean-Leckenby); Spath, p. 383. 1931 Poculisphinctes auricularis S. Buekman; Spath. p .393. ?1933 Poculisphinctes aff. poculum (Rcan MS) Leckenby sp..; Spath, p. 859. ? 1933 Perisphinctes of. poculus Leek.; Djanelidze. pp. 3. i, 15. 1939 Gwssouvrta (.Poculisphinctes/ poculum (Leckenby); Arkell, pp. 158, 178, 202. 1939 Grossotwria (Potulisphinctes) auruulare Buckman: Arkell, p. 179. 1957a Poiuiisphinci.espoculum (Leek.); Arkell, p. 319. 1971 Orionoides (Poculisphinctes) poculum Leckenby; Cariou, pp. 455, 458 1971 ; Poculisphinctes" auricularis Buekman; Cariou, p. 459 1971 Grossouvria poculum (Lorkenby}: Callomon & Cope, p. 166. 197-1 Pocuf.isphin.ctes cf. poculum Leek.; Cariou, p. 310. Type specimens. Macroconch holotype, SM J3298, PL 12. fig. 9, designated Buckman 1920, pi. 185 (original of Leckenby 1859, pi. 1, fig. 4b). Microconch paratype^SM J3299, PI. 12, fig. 11, designated Buckman 1920, pi. 186 (original of Leckenby, 1859, pi. I, fig. 4a), — holotype of Poculisphinctes auricula Ruckman. Both specimens preserved in grey limestone from "Kelloway Rock" [blackness Roek|. near Cristhorpc Bay, North Yorkshire; probably Lamberti Zone (see Wright 1968, p. 390, fig. 6). Material. About 105 specimens: the type specimens and about 25 others, uncrushed but mostly incomplete or immature (preserved in sandy limestone with ooliths); about 80 specimens, partially crushed or otherwise distorted, some adults but mainly incomplete (many only whorl fragments) or immature (preserved in calcareous mudstone and marly limestone as internal clay moulds with thin black powdery pyritic coatings when fresh) and one specimen, uncrushed but incomplete pyritized internal mould. Microconchs and macroconchs. Description. Microconchs (62 specimens): maximum diameter 53 mm, generally 40-50 mm. Body chamber 230°-240°. Al least tour whorls visible. Moderately evolute (wh/d=30-35%); 36 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES whorl section generally rounded hut may be moderately compressed on outer whorls (wh/wt= 110-130%) with flat whorl sides (Text-fig. 11); gently sloping and almost smooth umbilical wall; umbilicus c. 20 mm wide and up to 8 mm deep in adult. Ribs (Text-fig. 12) rectiraditc to prorsiradiate but secondaries may have rursiradiate aspect, particularly on outer whorls; on inner whorls, weak, widely spaced prorsiradiate primaries (sometimes very weak or replaced by lirae). irregularly branching into two with intercalatories and occasional simple ribs; nodes and flared ribs; on middle and outer whorls, the primaries are stronger, rectiradiare or weakly prorsiradiate, splitting low on the upper part of the whorl side into three secondaries with an intcrcalatory or bundles of four, or more rarely bifurcate with two intercalatories; weak constrictions. Ribs pass across broad rounded venter without interruption. Aperture, with associated strengthened rib and terminal constriction, bears lappets (up to c. iX 10 mm). Macroconchs (46 specimens): maximum diameter 180 mm. Body-chamber 270°. At least six whorls visible (shown by completely septate type specimen). Moderately evolute (wh/d—30- 40%); whorl section generally rounded, but may be slightly depressed on inner whorls (wh/wt=80 100% and moderately compressed on outer whorls (wh/wt=l 10 130%) with flat whorl sides (Text-fig. II): steeply sloping and smooth umbilical wall; umbilicus c. 45 mm wide and up to 15 nun deep in adult (estimated). Ribs (Text-fig. 12) gently prorsiradiate to rectiradi- ate; on inner whorls (up to c. 40 mm diameter), primaries prorsiradiate and rather weakly or irregularly developed and w idely spaced, with some flared ribs; on middle whorls (from c. 40 mm to 80 mm diameter), the primaries strengthen and thicken, becoming blunt and widely spaced, splitting about the middle of the whorl side into bundles of rather slender secondaries (usually four with two intercalatories). The secondaries become coarser with growth until on the outer whorl(s) (more than 80 mm diameter), the number of secondaries decreases, usually to two with an inlercalatorv, or three, and the ribbing is generally coarse and rather irregular, with only 16 primaries on the last whorl. Ribs pass across rounded venter without interruption. Poor preservation makes it difficult to establish rib density curves for individual specimens and only a few general observations can be made; for macroconchs, the number of primaries ranges between 10 and 20 per whorl for diameters between 60 and 100 mm; for microconchs. the number of primaries ranges between 25 and 10 for diameters between 40 and 55 mm. Data for figured specimens. d (septate to) wh wt uw primaries ventrals SM J3298 (PI. 12, fig. 9) 60 (60) 22 21 21 12 c. 80 SM J3299 (PI. 12. fig. 11) •18 (c. 30) 15 14 20 c. 25 WMS J49 (PI. 12, fig. 12) 49 (c. 30) 15 est. 14 20 OUM J22362 (PL 12, fig. 13) 51 ( ) 16 est. 13 20 BGS FR1116 (PI. 12, fig. 141 11 ( ) 14 (8) 17 MM LL5664A (PL 12, fig. 15) 33 (33) OUM J22361 (PI. 12, fig. 16) 53 (c. 34) 16 14 21 est. 28 BGS Zt517 (PL 13, fig. 1) 80 ( ) 28 c. 25 33 16 c. 54 OUM J22553 (PL 13, fig. 2) 87 (87) 28 28 38 18 YVMSJ58 (PL 13, fig. 3) 95 (-) 30 38 40 18 ?c. 70 YM 606 (PL 13, fig. 4) 51 (54) 20 21 19 c. 65 OUM J22375 (PL 13, fig. 5) 101 (-) 30 23 45 18 c. 61 Text-fig. 14 180 (—) 16 Remarks. Lcckcnby's (1859, pi. 1, ligs 4a-c) figures of specimens from the Hackness Rock show a dimorphic pair—a microconch bearing lappets (fig. 4a) and the inner whorls of a larger (macroconch) form (fig. 4h). Buckman (1920) subsequently separated them on morphological grounds into two species, poculum and aurkularis, and assigned both to a new genus Poculisphinctes, with poculum as type species. The holotypc of/1, poculum (Lcckenby, 1859, lig. 4b) shows distant, blunt primaries associated with close secondaries and a deep umbilicus with high smooth walls: CHOFFATIA TEXT-FIC;. II. Chojfalia poculum (Leckenbv) fM|; Lambcrli Limestone; VVoodbam. Buckinghamshire; Lamberti Zone, Lamberti Sub/one; XI (J. II. Callomon collection and photoncgative). Spath (1931, p. 328) took these features to be characteristic of the genus and added (p. 383) a further species (Poculisphinctes kachhensis) based on a single completely septate specimen from the "athleta beds" of Clutch, India. Arkell (1939) included Poculisphinctes cardoti (Petitclerc, 1915) in the genus, thereby suggesting some similarity with Subgrossouvria (macroconch Poculisphinctes show, after a diameter ofc. 40 mm, a change to a coarse rib style (Spath 1931)) and also Poculisphinctes subpatina (Petitclerc. 1915). Poculisphinctes trina Buckman. 1922 (see below) and Poculisphinctes 38 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES fascisculptus (I.oczy, 1915) (based on Ammonites cotwolutus piicomaphalus Quenstedt, 1886) have also been included (Sparh 1931. p. 328; Cariou 1971, p. 454). Poculisphinctes poculum is herein assigned to Choffatia; the other species listed above can also be included either therein, or in other well- established genera such as lndosphincles. Uhlig's (1878) tentative determination of C. poculum from the northern Carpathian Moun- tains, Poland is excluded as the stratigraphical information is inadequate; Arkell (1956, p. 170) suggested that most of the ammonites figured from that area came from the Middle Callovian. Uhlig's figure shows a compressed form whose rib-style bears some resemblance to microconch poculum hut which, assuming the lithograph is accurate, is rather too strongly ribbed on the inner whorls. Djanelidzrs (1933) record from the Callovian of Georgia, USSR, based on two incomplete specimens and without figures, or precise stratigraphy, is open to serious doubt. Cariou (1971, p. 459) thought that poculum (based on Buck man's type figure) showed striking similarities with young Rugeticera-s and the middle growth stages of certain Orionoides such as 0. monestieri (Gerard & Contaut, 1936). He included it in Orionoides as a I.amberti Zone form and considered that the microconch auricularis belonged to quite another genus. Orionoides (Spath, 1931), based on Perisphinctes orion Waagen, 1875 [non Oppel, =indicu.s Spath] and Perisphinctes pseudorion Waagen, 1875 (type spccies)seems better restricted to involute, weakly constricted forms with ii regular ribbing (including parabolae) on the inner whorls, which do not show early thickening and bluntness of the primary ribs on the phragmocone and which develop macroconch body-chambers "like Pseudopeltoceras. but not tubcrculatc" (Arkell 1957a). In western France, C. poculum. although unfigurcd, is sufficiently well known to be used as a subzonal index in the lower part of the Lambcrti Zone. Distribution. Rare in Athleta Zone (Hackncss Rock of Hackncss, North Yorkshire and Oxford Clay of Wolvercote, Oxfordshire). Common in I.amberti Zone (Lamberti Limestone of Woodham, Buckinghamshire; Hackncss Rock of Cayton Bay, Cunstone Nab, Gristhorpe and Scarborough (Castle Hill), North Yorkshire; and ?Oxlbrd Clay of Tidmoor Point, Dorset (Spath 1933)). Recorded from Lambcrti Zone of Prance (north-west Aquitaine (Cariou 1974a), Poitou (Cariou 1971), Normandy (Arkell 1939, p. 203; Cariou 19/1)). Choffatia trina (Buckman, 1922) PI. 14, figs 1-5 1922 Trinisphinctex trims nov.; Buckman. pi. 332. 1931 T. trims; Spath, p 328. 1931 Poculisphinctes ("Trinisphtncfes') t.rinus S. Buckman; Spath, p. 383. 1939 Grossouvria fPoculisphinctes) tuna (Buckman); Arkclh pp. 159, 179, 203. 1947a Grossouvria (Poculisphinctes) trina (Buckman! (?); Arkell, p. 31 1971 Orionoides (Trinisphinctes) trim Buckman; Cariou. p. 455. 1971 Trinisphinctes tritius Buck.; Cariou, p. 310. Holotype. BGS GSM6509, PI. 14. fig. 1; completely septate, uncrushed limonitic cast from the Oxford Clay. Buckman (1922, pi. 332) gave the horizon and locality as Athleta Zone. Weymouth, Dorset, but Arkell (1939, p. 1 79; 1947a, p. 31) believed that the type of preservation indicared that it came from the Lamberti Zone, Tidmoor Point. Material. Apart from the type, 16 specimens, mostly incomplete (many only whorl fragments), partially crushed or otherwise distorted (preserved in calcareous mudstonc or marly limestone as internal clay moulds with thin black (when fresh), powdery pyritic coatings and partially pyritized inner whorls), and one completely pyritized specimen. Description. Maximum diameter (of macroconch) 110 mm. Body-chamber up to 360°. Al least five whorls visible. Moderately evolute (wh/d = 30-35%); whorl section moderately compressed (wh/wt= 100-130%), with flat whorl sides and gently rounded venter (Text-fig. 11); steeply- sloping and almost smooth umbilical wall. Umbilicus c. 20 mm wide and 7 mm deep at 55 mm diameter. Ribs (Text-fig. 12) prorsiradiate, though less so on inner whorls, which may show BINATISPHINCTLS 39 rursiradiate aspcct near venter. Iiuierrnosi whorls smooth or weakly ribbed, later developing bifurcate ribs with an associated inlercalalorv; middle whorls have trifurcatc ribs with inter- calatories, with rather long straight primaries splitting at, or a little above, middle of whorl side into bundles of slender secondaries; on later whorls, ribbing coarsens with primaries becoming more widely spaced and secondaries weakening. Moderately strong but shallow constrictions, following course of ribbing, particular ly on middle whorls. Ribs pass uninterrupted across venter. Poor preservation makes it difficult to establish rib density curves lor individual specimens, and only a few general observations can be made: from at most 10 mm diameter, the number of primaries per whorl ranges between c. 28 and 36, arid remains fairly constant for any one individual. Data for figured specimens. d (septate to) wh wt. uw primaries vent ra Is BGS CSM6509 (PI. 14. fig. 1) 55 (55) 18 17 21 35 c. 100 OUM J16729 (PI. 14, fi?. 2) 110 (c. 55) 29 21 49 28 est. 105 OUM J22368 (PI. 14, fig. 3) 87 (-) ' f. 23 18 42 36 c. 120 BGS Zr3766 (PI. 14. fig. 4) 74 (-) 24 20 31 OUM 122370 (PI. 14, fig. 5) 53 (-) 19 est. 16 21 Remarks. It is not certain whether the holotypc is a microconch or macroconch, because it is completely septate. Amongst the material described herein, there is no definite microconch, and it seems likely that most of the larger specimens are incomplete macroconchs; specimen OUM J16729 (PI. 14 fig. 2) is nearly complete. The possibility that microconchs of (J. trim have been included with those of C. poculum cannot be ruled out. Spath (1931) included C. trim in Poculisphinctes and believed that the holotype represented the inner whorls of one of the more finely ribbed (? and undescribcd) forms of that genus and compared with it his species Poculisphincteskachhensis (Spath, 1931) from Cutch, India, based on a single specimen which, like C. Irinus, was completely septate and finely ribbed. Cariou (1971) included the form with Orionoides, presumably partly following Spath (1931) and Arkell (1939. 1947a) and partly following his discussion of the species poculum. C. trim bears comparison with Prope risp h inctes pseudobe mens is Sasonov, 1965 from the Middle Callovian of the Russian Platform which, however, has a more rounded and depressed whorl (cf. particularly Sasonov 1965, pi. 18, figs 5a, b) and also with 4Grossouvria'peliklerct de Loiiol, 1898 from the Lower Oxfordian (Mariac Zone) of the Jura which is, as Arkell (1939) pointed out, more involute. Distribution. Lamberti Zone (Oxford Clay of Weymouth [Tidmoor Point), Dorset and ?Millbrook, Bedfordshire: Lamberti Limestone of Woodham, Buckinghamshire). Recorded from the Lamberti Zone of France. \W Aquitaine (Cariou 1974a), Poitou (Cariou 1971), Normandy (Arkell 1939). Genus BINATISPHINCTES Buckman, 1921 (Synonyms: Hamulisphinctes Buckman, 1921 (type species //. hamulatus Buckman, 1921) [m], Okait.es Sasonov, 1961 (type species Ammonites mosquensis Fischer, 1813) [m], ?Rugeticeras Tintanr, 1961 (type species R. cesaredense Choffat MS, Tintant in Rnget-Pcrrot el ai, 1961 [ MJ, pars Pse.udopeUoceras Spath, 1928 (type species Ammonites chauvinianus d'Orbigny, 1847) [M]). 'type species. Ammonites binatus (Bean MS) Leckenbv, 1859 Diagnosis. Evolute forms with rounded inner whorls and more compressed later whorls (Text- fig. 15). Inner and middle whorls with rather dense, mainly bifurcate and simple ribbing (Text- fig. 16). Weak parabolac and/or constrictions. Generally flattened venter with smooth band or 40 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES sulcus. During later growth stages, macroconchs develop strong, thick, widely spaced primary then simple non-Luberculate ribs. Lappeted microconchs. External suture has first lateral saddle with a well marked and quite deep accessor)- lobe, a trifid asymmetrical lateral lobe, generally deeper than the ventral lobe, and a more or less retracted suspensive lobe with some well defined auxiliaries. TF.XT-FIO. If). Whorl sections ofBinatisphinctesspecies: (a) J K W AC./Mat lit* nun: (b: SM J:530bat 75 mm; (r) Y\L 61 I at 70 mm; (d) S\1 J3304 al 82 mm: ;"e) SMJ3305 at 63 mm: (f) YM 61 J at 77 mm.' Remarks. As with many ofBuckman's genera published in Type Ammonites, no formal descrip- tion was given. Buckman used Binatisphinctes to accommodatc the species binatus "Bean- Leckenbv from the Castle Rock [Hackness Rock; Athlcta-Lamberti zones) of North Yorkshire. Jluctuusus Prat l and possibly comptoni Pratt, from the Oxford Clay | Aciitisrriatum Band; Athleta Zone] of Wiltshire. Buckman considered that B. comptoni could be placed only tentatively in the genus because its suture line was not available for study. Our understanding of the original meaning of Binatisphinctes must rely solely on Buckman'* four figures of these three species, with their cryptic dimension details (Buckman 1021, pi. 261 A, B (binatus): 1924. pi. 435 (comptoni); 1925, pi. 615 (JJucluosus)). His designated lcctotvpe of the type species is an incomplete, evolute inner middle outer whorls whorls whorls body chamber Binatisphinctes comptoni weak parabolae Binatisphinctes ham u fat us occasional weak constrictions Binatisphinctes binatus occasional weak constrictions parabolae and ventral nodes 1 EX'I'-HC. 16. Ribbing o[ Binulhphincles species. BINATISPHINCTLS 41 com pressed planulate with a ventral smoorh hand. Ribbing is dense with long straight primaries. The suture line on both figures has been painted in (usual Buckman practice), but not described. The inclusion of Pratt's B. ftuctuosus and B. comptoni means that (he genus as understood by Buckman, included both macroconch and microconch forms. The present definition and scope ol the genus was discussed by Mangold (1971 b, p. 198). He considered thai the B. binatus group was restricted to macroconch forms rela ted to the microconch group of Perisphinctes rjasanensis Teisseyre. This latter species, together with others from the Callovian of the Russian Platform and Poland (subaurigerus' I 'eisseyre and mosquensis Fischer) had already been associated with Binatisphinctes by Spath (1931, p. 327). Sasonov (1961, 1965) subsequently proposed Ohailes for the group of mosquensis and rjasanensis; Mangold (1971b) considered this a microconch subgenus of Binatisphinctes, and restricted Binatisphinctes s.s. to the associated macroconchs. The type specimen ofB. binatus cannot conclusively be recognized as a macroconch, and to use Binatisphinctes s.s. exclusively for macroconch forms with binatus as the type species is questionable. In accordance with the policy of associating macroconch and microconch forms at species level, the genus, without subgenera, is herein taken to include both forms, thereby following Buckman and avoiding the problem of the dimorphism of the type specimen of the type species. There is a number of other closely similar generic groups of approximately the same age as Binatisphinctes— Okaites Sasonov. 1961. Hamulisphinctes Buckman, 1921, Ruge tic eras Tintant, 1961, and Pseudo- peltoceras Spath, 1928. Other species assigned to Binatisphinctes include B. giganleus Gerard & Contaut, 1936, B. robauxi Gerard & Contaut. 1936 and B. welschi Gerard & Contaut, 1936 from the Athleta Zone of France, the Russian B. arlti (Krenkel. 1915) and the mainlv Russian B. rossicus (Siemiradzki, 1898). Binatisphinctes is thought to have evolved from Choffatia during the mid to late Callovian (Coronatnm-Aihleta zones). Some authors, e.g. Spath, thought the microconch of B. comptoni to he better placed in Grossouvria (=mieroconch Choffatia) and forms such as Quenstedt's (1886-7, pi. 81, figs 15 19) evexa arc certainly quite close. Mangold (1971 b, p. 186) designated Quenstedt's fig. 16 as leerotvpc of evexa and concluded that it was a form of the Coronatum Zone. The macroconch may be derived from Subgrossouvria [ = Choffatia] which has a characteristic sudden change in its ribbing style to strengthened and thickened primaries on the outer whorls (cf. Marigold 1971 b, p. 202). 11 shows affinities with Peltoceras which later in parts of the Athleta Zone becomes the predominant perisphinctaccan member of the English Callovian ammonite fauna. Notes on genera regarded as synonyms of Binatisphinctes. (i) Hamulisphinctes Buckman, 1921 This genus was published without formal description—only figures of three specimens of two new species (11. hamulatus and H. auricula) from the Castle Rock | Hackness RockJ of Yorkshire (Buckman 1921, pis 262A, B; 263). This material was included by Leckenbv (1859) in his species A. binatus. Buckman's figures show evolute forms, rather coarsely ribbed (ribs having rursiradiate aspect towards the venter at least on the outer whorls) with ventral weakening of the ribs or smooth band, and rounded whorl section. The type specimen of auricula is complete (diameter 66 mm) and its aperture bears lappets. Mangold (1971b. p. 208) restricted Hamulisphinctes to microconch forms related to the macroconch taxon Pseudopeltoceras (see below). No further species has been recognized within, or assigned to, the group, although Spath (1924. p. 13; 1931, p. 371) quoted another Bean manuscript species name (marifimus) attached to a specimen in the British Museum (Natural History) (no. 39530: PI. 18, fig. 5). Callomon (pers. comm. 1985) believes this specimen to be "an excellent [m| of Pseudopeltoceras. (ii) Okaites Sasonov, 1961 The original material of the type species was in the Fischer Collection, kept at the Pavlov Museum, Moscow. N. T. Sasonov reports that it is lost. He intends to select a neorype from material described by Lahusen (1883) (G. Sasonova. pers. comm. 1978). Sasonov included in 42 KNCLISII CALLOVIAN"PERISPHINCTI D AMMONITES Okaites regular, evolute forms with rounded inner whorls. flattened venter with smooth band or sulcus, straight ribs alternating simple and bifurcate, with parabolae, and a body-chamber occupying threequarters of a whorl and with lappets. Suture details were described by Sasonov (1965), and in translation by Mangold (1971 b. p. 200). As well as the type species, Sasonov (1961. p. 28) included Neumayr's species Perisphinctes scopinensis and Perisphinctes eurvptychus and later (Sasonov 1905, p. 22), added Teissevrc's (1881) suhauri.gerus and rjasauensis, sinzowi Nikolajcva & Rozhdesiwenskaya and C. lahuseni Sasonov. Mangold (1971b), who restricted the genus to microconch forms, included KrcnkcTs (1915) species popilanicus, bodeni and credneri and SieniiradzkTs polonicus. All these spccics arc based on Russian or Polish forms; the geographical distribution, according to Sasonov (1961), eenrres on the Russian Platform, northern Caucasus and Poland, and includes England and France. (iii) Rugeliceras Tintant (in Ruget-Pcrrot el al.), 19bI This genus was proposed to accommodate some 40 specimens of the species R. cesaredense from the Upper Callovian (Athleta Zone) of Portugal. It included evolute forms with a wide umbilicus; inner whorls with bifurcate ribs are followed by a stage with strong, spaced-out primaries each giving rise, on the upper half of the whorl side, to three or four secondaries often slightly rursiradiate and weakened or interrupted on the venter. Adult forms have lengthened, strengthened and spaced out primaries which become very strong, but never with tubercles, and the secondaries disappear totally. There is no constriction. Suture line incised with short ventral lobe, a much longer lateral lobe and an even, well developed suspensive lobe. Choffat described in manuscript cesaredense in 1910 and assigned it to "Peltoceras (Perisphinctes?)". He thus clearly thought that this spccics was transitional between the true perisphinctids and Peltoceras, which led Tintant in the subsequent published description to compare it with Pseudopeltoceras (see below). Without the inner and middle whorls on which there are some differences in ornament, Tintant concluded that distinction between Rugeliceras and Pseudopeltoceras was slight. He also pointed out the close similarity with Subgrossouuria; young examples of the two genera are dillicull to distin- guish, but Rugeliceras has no constriction at that stage and more marked tendency to have an interruption of the ribbing on the venter. In adult forms, Sub grossouvria has a much shorter (about a half whorl) stage of simple raised ribs; in Rugeliceras, it starts on the phragmocone and lasts for two whorls. 'Tintant believed that Choffatia, Subgrossouuria, Rugeliceras and Pseudopeltoceras con- stituted a continuous morphological series characterized by the progressive development on the adult of a "peltoceratoid" ornament of coarse, raised simple ribs and progressive disappearance of secondaries. 'The type species of Rugeliceras was thought to be closest to Pseudopeltoceras rollieri Jcannet. Binatisphinctes was not discussed, but it clearly belongs ro the same group. (iv) Pseudopeltoceras Spa ill, 1928 'This genus was proposed for offshoot forms from the main perisphinetid stock transitional to Peltoceras. Spath differentiated Pseudopeltoceras from Suhgrossouvria (see Choffatia) in the. gradual development of ventral tubercles on an inflated Nequeniceras like body-chamber (Spath 1931, p. 557). He referred to undescribed material from Monireuil ttellay (Fiance) and Scarborough, North Yorkshire (Hackncss Rock) including the unpublished Bean manuscript species famulus (figured Spath 193 L pi. 103, fig. 4; pi. 105, figs 6a, b) and le.ckenbyi (PI. 20, fig. 1). IIcdescribed the inner whorls leckenbyi as "closely costatc, perisphinctoid" showing a very gradual changc to the tuberculate simple ribbing of the body chambcr. His one new species Pseudopeltoceras retrorsum from the Callovian of Cutch has uniform simple and bifurcate rursiradiate ribs on the depressed and later rounded inner whorls; these ribs become more distant and thickened until the subquadrate- sectioned bodv-chambcr which narrows towards the aperture and has secondary ribs and intercalatories confined to the flat venter. The 'holotype1 of the type species (svntypc according to Callomon, pers. comm. 1985) was examined and re figured by Tintant (1961, p. 187, pi. 2 fig. 2). This shows that d'Orbigny's original illustration exaggerated the development of ventral tuber- cles. Nevertheless, the so-called "peltoceratoid" tuberculate ornament on subquadrate whorls was a generic character understood by Spath. Jeaimet (1951) added to the genus two new species. BINATISPHINCTLS 43 P. rollieri and P. zuberi from the Callovian of the Swissjura. Mangold (1971 h, p. 208) subsequently restricted Pseudopeltoceras to macroconch forms related to the microconch Hamulisphinctes. He described three successive stages of ornament: inner whorls with simple and bifurcate ribs, weakened or interrupted on the venter, parabolae and constrictions; followed by a middle stage with prorsiradiate primaries becoming more widely spaced, strong at their base, weakening on the whorl side high up on which they split into secondaries with intercalatories having rursiradi- ate aspect and with compressed whorls, constrictions but no parabolae: and then a final stage with widely spaced primary ribs thickened but without tubercles particularly in the ventrolateral area, and ventral ribs disappearing and being replaced by a broad ventral "cushion". Until Mangold associated Pseudopeltoceras with Hamulisphinctes, the former genus had been grouped exclusively with Pe.ltnce.ras in the subfamily Peltoceratinae. Specimens of' Pseudopellocers Jama turn Spath are not uncommon in the Hackness Rock (Athleta Zone) and two examples are figured (PI. 21, figs 3, 6). Spatlvs type specimen from the Hackness Rock of Scarborough which he figured is BM 39512 not 39312 {fide Phillips 1977, p. 156). Binatisphinctes comptoni (Pratt, 1841) PI. 14, figs 6. 7; PI. 15, (igs 1-8; PI. 16. fig. 1; PI. 17, figs 1, 2; PI. 18, fig. I 1041 Ammonites Comptoni; Pratt, p. 163, pi. 1 fig. 1. 1841 Ammonites jluctuosus; Pratt, p. 161, pi. 6 fig. 1 only. 1849 Ammonites Comptoni; Brown, p. 244, pi. <20*"fig. 7. 1849 Ammonites jluctuosus; Brown, p. 245, pi. 20**fig. I (J. 1898 Perisphinctes Comptoni Pratt; Siemiradzki, p. 13.0 pars 1808 Perisphinctes ftuctuosus Pratt, Siemiradzki, p. 293, mm pi. 25 fig. 13 pars non 1913 Perisphinctes Comptoni PraLL; Lowe, p. 152 J1915 Perisphinctes Comptoni Pratt; Krcnkel, pi. 23 fig. 5. 1924 Bmitisphiwtes? Comptoni, Pratt sp.; Buckman, pi 485 1925 Binatisphinctes jhictuosus. Pratt sp.; Rnckman, pi. 615. 1932 Perisphinctes comptoni Pratt sp.; Corroy, p. 127, pi. Hi figs 11, 12 pars non 1939 Perisphinctes (Grossouvria) comptoni Pratt: Kulin, p. 504. pi. 10 fig. 17 non 1939 Perisphinctes ftuctuosus Pratt; Kulm, p. 511 non 1955 Grossouvria cf. comptoni ! Pratt); Callomon, p. 233 [=/. patina [mj] non 1955 ?Binatisphirttles jluctuosus (Pratt}; Callomon. p. 233 (=/ patina fM|| I9G3 Am. jluctuosus Pratt [M] compUmi Prarr [mj; Callomon. p. >H. 1969 Binatisphinctes comptoni and B. jluctuosus; Smith in Cope, p. A42. 1971b Binatisphinctes (m. Okaites) comptoni [Pratt); Mangold, pp. 123, 199, 202, 220. 19711> Binatisphinctes (M. Binatisphinctes) jluctuosus (Piatt); Mangold, pp. 199. 202, 220. 1971 Binatisphinctes comptoni (Pratt) and B.jluctuosus (Pratt); Callomon in Callomon &. Cope, p. 167. Hololype. Bristol City Museum Ca7088; Oxford Clay [Acutistriatum Band, Athleta Zone], Christian Mai ford, Wiltshire. Figured Buckman 1924, pi. 485 (see Morley Davies 1924, p. 258). Microconch. Material. About 70 specimens, mainly adult and complete, but crushed almost flat in shale, with white aragonitic shells, some partially pyritized; 4 specimens (mainly fragments) partially crushed, in finegrained sandstone. Microconchs and macroconchs. Description. Microconchs (57 specimens): maximum diameter 102 mm (holotype), generally between 60 and 80 mm (Text-fig. 18). Body-chamber 180° to 220°. Six whorls visible. Evolute (wh/d —c. 30%); whorl section compressed at least on middle and adult stages; venter narrow with weakening of ribs and smooth band, at least in part. From at most 5 trim diameter, ribbing (Text-fig. 16) generally straight and dense, rectiradiate to prorsiradiate becoming slightly rursiradiate near the ventral margin. Primary ribs generally long and slender, splitting on the outer half of the whorl side into two or three secondaries with intercalatories, interspersed with simple ribs. Ribbing becomes more widely spaced on the body-chamber with increasing rur- siradiate aspect towards the aperture which bears long, narrow lappets (t. 5X30 trim). Weak development of parabolae on both inner and outer whorls. Number of primaries increases with growth up to a diameter of c. 30 mm (from c.. 30-50 at 10 mm. tor. 35-60 at 20 mm, toe. 40 65 at 44 KNCLISIICALLOVIAN "PERISPHINCTI D AMMONITES 30 mm), thereafter decreases regularly, though some rimes abruptly, to between 30 and 40 on the last whorl (Text-fig. 17). Macroconchs (18 specimens): maximum diameter 250 mm, generally between 200 and 235 mm. Body-chamber 180° to 210°. At least six whorls visible. Evolute (wh/d=c. 30%). On first four whorls, primary ribs generally long, straight and dense, recti radiate to prorsiradiate, Acutistriatum Hand Comptoni Bed 1 - BGS FR970 2 = BGSFR1320 3 = BGS FR1045 4 = BGS FR 938 5 = YM INN 887 BGS „ FR 1020 OUM J17889 BGS GSM BGS 30348 GSM — '30344 BGS^^. GSM YM607 30319 j -L 80 90 100 diameterimm) TKX I -MC;. 17. Rib-density curves: Ibraduh microconch Bmatisphindts rnmpkm.i (Pratt). splitting on the outer half of the whorl side into two or three secondaries which are scarcely visible; simple ribs and intercalatories also present with weak parabolae (Text-fig. 16). Primaries then becoming (by 80 mm diameter) increasingly strong and somewhat thickcncd until on the last two whorls, ribs are strong, simple, massive, widely spaced (20 to 25 per whorl); they apparently do not cross the venter which remains smooth. Aperture simple. Aptychi present. Data for figured specimens. d (septate to'l wh wt uw primaries ventrals BGS GSM30349 (PL 14, fig. 6) 77 (c. 52) 22 32 36 102 BGS PR 1233 (PI. 14. fig. 7) 70 (-) 22 30 HGS PR 1297 (PI. 15. fig. 1) 67 (c. 44) 23 30 r. 40 c. 210 BGS FR970 (PI. 15, fig. 2) 55 (c. 33) 18 — 24 37 70+ OUM J 17889 (PI. 15, fig. 3) 75 (c. 50) 24 — 33 c. 38 c. 100 YM 608 (PI. 15, fig. 4) 52 (c. 38) 15 24 34 c. 94 YM 607 (pi. 15, fig. 5) 87 (61) 30 — 34 31 116 BGS GSM30342 (PI. 15, fig. 6) 52 (59) 15 — 27 34 c. 85 BGS GSM3034j (PI. 15, fig. 7) 86 (59) 27 — 37 24+ 101 BGS FR 1020 (PL 15, fig. 8) 78 (50) 29 33 42 96 + DM 2143 (PL 10, fig. 1) 235 (—) 62 — 95 c. 26 OUM J30868 (PI. 17, fig. 1) c. 220 (—) 115 c. 22 BGS GSM30351 (PL 1 7, fig. 2) 133 (-) •10 — 60 24 BM 32343 (PL 10, fig. 1) 250 (-) 75 120 c. 20 Remarks. Although B. comptoni (microconch) and B. finetuosus (macroconch) were the only species apart from the type assigned to Binatisphinctes by Buckman, their position in this genus has been open to doubt. Spath (1931, p. 237) thought that the comptoni group connected Binatisphinctes with Choffatia and belonged to the assemblage for which Grossouvria Siemiradzki was mainly intended. He thought that Binatisphinctes should he retained for the group of evolute' Grossouvria' of the mosquensis group, which included B. binatus and Hamu/isphinctes. However, he stated (p. 392) BIXA'1 ISPIIINCTES 45 that "many. . . examples of Pratt's Amm. lomploui. . . are undoubtedly fiinalispbinctesoC the same \=z-rjasattensis'Vctescyre] group . . Callomon (1955, p. 233) also doubted the systematic position a\'comptoni and allied species, and thought they were probably assignable to (iro\\nu;;ria rather than to Binatisphinctes. Siemiradzki (1898) compared the species comptoni with mosquensis. rjasanensis a nd scop in ens is, all since recognized as typical microconch Binatisphincles and formerly grouped together in Okaites. There is no doubt that B. comptoni is correctly grouped with these Russian and Polish species, but the figured specimens of their type material are all incomplete and vvithoui examination of more complete material, a more explicit statement of similarity cannot be made, liven their recognition as definite microconchs must be considered speculative. Binatisphinctes comptoni I ml • - —I W - • | • • - ~ III M ILIA I • • M II • • I « ••• •• -*»• 40-44 45-49 50-54 55-59 60-64 65-69 /0 74 75-/9 80u4 h5 h9 90-94 95 99 100 104 did meter (mm) Comptoni Acutistriatum cumulative Bed Band totals TEXT l ie., 18. Size distribution lor adult microcoiidi BmatkfflwicM comptmi (Pratt' |")8 sped in ens including Pratt's typo]. Siemiradzki (1098) and some later authors (e.g. Corroy 1032, p. 127) wrongly included mbmutatus Nikitin, 1881 (now type species of 'Elalmites) with H. comptoni. The two species bear superficial resemblance because they are both based on lappeted microconchs of similar size, but the latter is an older form with a different rib pattern. Some records of B. comptoni most probably should be included with submutatus or its related species: for example Lowe's (1913) record from the Lower Callovian of Saxony (i4MacrocephaleittonenM) and Kuhn's (1939) record of comptoni and Jluctuosus from the Lower Callovian of southern Germany (Kranconia) Kuhn's figure of comptoni. showed only inner whorls and he equaled Jluctuosus with leptus Gemmellaro. now con- sidered to be a Homoeoplanulites (Mangold 1971 b, p. 184). Callomon's (1955) record ocomptoni and jluctuosus from the Jason Zone of Kidlington, Oxfordshire also probably belong with suhmulatus or its related spef ics. Siemiradzki (1898) also included jliuluosus in his monograph and assigned it to Perisphinctes s.s. His record from the Eisenoolilh (Lower Callovian) of Krakow, Poland is now exc luded from I he species. 48 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES Within the assemblages of B. comptoni from the Comptoni Bed and Acutistriatum Band, there appears to be a number of individuals that, although having similar inner whorls to a diameter of c. 30 mm (cf. rib curves in Text-fig. 17), mature earlier and consequently have a smaller adult diameter (40 (SO mm. generally 45-55 mm). However, forms intermediate in size between them and the 'normal' comptoni do occur and there appears to be no disparity in the stratigraphical distribution. At least 12 specimens of this smaller form have been identified, and three arc figured (PI. 15, figs 2, 4. b). There is insufficient macroconch material to detect any significant or comparable size variation therein. In general terms, forms from the Comptoni Bed arc smaller (mean diameter=65 mm) than those of the Acutistriatum Band (mean diamctcr=74 mm) but there is complete overlap in the variation from each bed (Text-fig. 18). A real difference between the two populations based on adult diameter is not proven by statistical methods. Compared with B. binatus, B. comptoni [m] is smaller, does not have constrictions, and has generally more finely ribbed inner whirls. Distribution. Oxford Clay (Acutistriatum Band (Athleta Zone) and Comptoni Bed (Cor- onatuni Zone)) of southern and central England; I.angdalc Beds (Coronation Zone) of Gristhorpe and Row Brow Quarry near Scarborough, North Yorkshire. Kopik (in karczewski 1970, p. 41) recorded the species from Poland, based on Sicmiradzki's (1898) record and Stoll's (1934) record of B. comptoni in the Middle Callovian of Pomerania. Binatisphinctes hamulatus (Buckman, 1921) PI. 18, figs 2-fi; PI. 19, fig. 1 1921 Hamrdisphwrits hamulatus, no v.; Buckman. pi. 262 A, B. 1921 Hamuli sph inctts auricula, nnv.; Ruckman, pi. 263. 1924 IlamulisphincUs sp. [A maritimus, Bean MS.); Spath, p. 13. 1931 Biriutisphirtctes { — ' Hamidisphindes') maritimus (Bean MS}: Spath, p. 371. 1931 Binatisphinctes (—' Hamulisphinites') hamulatus S. Buckman; Spath, p. 371 non 1931 Pseudopeltoceras leckenbyi (Bean MS}; Spath. pp. 557, 572 [sec below] a IT. 1936 Binatisphinctes Welschi nov. sp.: Gerard & Contain, p. 61, pi. 11, tigs 2. 3. 1936 Pseudopeltoceras leckenbyi Bean sp.; Gerard & Contain, p. 68. pi. 17. 1951 Pseudopeltoceras cf f.eckeubyi Bean ap.;Jcannet, p. 176. pi. 85, text-fig. 411. 1971b Itamuiisphinctes (m. Ilamulisphincles) hamulatus Buekman, 1921; Mangold, p. 211. fi^s 155, 6; 158. 9. 1971b Hamulisphirutes (M. Pseudopeltoceras) leckenbyi (Bean MS); Mangold, p. 214. tigs 153, 157. 1971 Ilamulisphincles hamulus [sicJ Buckman; Cariou, p. 453. Type specimens. Holotype. SM J3306, PI. 18, fig. 6, originally designated Buckman 1921, pi. 262A. Microconch with about 225° of body-chamber but without its aperture preserved. From Castle Rock Hackness Rock], PAthleta Zone, Scarborough, North Yorkshire. Preserved in sandstone wit i black ooliths. The paratype, SM J3307, PI. 18, fig. 3, is preserved in grey shelly limestone with rhvnchoncllids, comparable with the doggers of bed 4 (Athleta Zone) of Hackness Quarry (Wright I960, p. 392). Material. Eight microconchs including types, uncrushed. preserved in sandstone with chamosite ooliths, or limestone; one possible macroconch. Description. Microconchs: maximum diameter c. 90 mm. Body-chamber ar least 225°. Six whorls visible. Evolute (wh/d=c. 25-30%); whorl section generally rounded or slightly depressed (wh/wt = 90-100%) but may be more depressed on inner whorls (wh/wr >70%) (Text-fig. 15); umbilicus shallow and wide (c. 38 mm wide and 8 mm deep at 75 mm diameter) with steeply sloping umbilical walls, smooth on the outer whorl, ribbed to umbilical seam on the inner and middle whorls. On inner and middle whorls, ribbing (Text-lig. lb) mainly gently prorsiradiate becoming rursiradiate near ventral margin, bifurcate with intercalatories (prim- ary: sc co ndarv ratio of 1:2-5); simple ribs and weak constrictions may also occur; oil outer whorl, ribs become more widely spaced remaining mainly bifurcate, with intercalatories and t are simple ribs but developing rursiradiate aspect which may be marked. Ribs on venter almost invariably interrupted by smooth band. Aperture bears lappets. Number of primaries increases with growth up to c. 30 mm (from c. 30-35 at 10 mm, toe. 35 45 at 20-30 mm), thereafter decreases regularly to 25-35 on the last whorl. BINATISPHINCTLS 47 Possible macroconch: maximum diameter seen 225 mm.f with 70° body-chamber* . Evolute (wh/d= 1859 Ammonites binatus. Bran. MS; T.cc.kcnhy; p 10. 10/11 Rin/itisphindes binatus, Bean-Leckcnby sp.; Buckman, pis 261 A, B. 1931 Binatisphinctes' binatus (Bean MS) Leckenby sp., Spath. p. 327. 1935 Pnisphindes binatus Leek.; Model & Kuhn, pp. 478, 9, 481. 48 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES 1939 Grossouvria (Binatisphinctes) binata (Leckenbv); Arkell, p. 180pais 1957a B. binatus (Leek.); Arkell, p. 319, figs 405, 6a-c. 1971 Binatisphinctes (M. Binatisphinctes) binatus Buckman; Mangold, p. 198. Types. Lectotypes SMJ3304 (PL 21, fig. I), designated Buckman 1921, pi. 261 A. From Castle Rock | Hackness Rock], /Lamberti Zone. Scarborough. North Yorkshire. ?Microconch preserved in sparsely oolitic limestone with some pinkish shell material attached. Wholly septate paralcc- totype, SM J3305 (PL 21 fig. 2), preserved in reddish stained sandstone with black chamosite ooliths and Meleagrindla\ /Athleta Zone. Material. 'The type specimens and nine others, incomplete, mainly inner whorls or juveniles but generally uncrushed, preserved in sandy limestone usually with chamosite ooliths. One additional fragment of partially crushed internal clay mould. Microconchs. Description. Microconchs (eight specimens): maximum diameter amongst incomplete material c. 85 mm. Body-chamber at least 170°. Six whorls visible. Evolute (wh/d=c. 30-35%; for inner whorls 20-25%); whorl section rounded or slightly depressed (wh/wt=c. 90%) becoming more compressed on later whorls (wh/wt= 120-140%) and with flat whorl sides (Text-fig. 15); umbilicus shallow and wide (c. 35 mm wide and 6 mm deep at c. 75 mm diameter) with rather steeply sloping umbilical walls and ribs extending weakly down to the umbilical seam. On inner and middle whorls, ribbing (Text-fig. 16) gently prorsiradiate becoming rursiradiate near ventral margin, alternating bifurcate and simple with dense, long, slender, straight primaries; on outer whorls, ribs of similar aspect, but number of secondaries increases; primaries remain rather long and well defined, splitting into three, or two with intercalatories, on the outer half of whorl side; primaries become more widely spaced towards aperture which is not seen. Weakly developed constrictions and parabolic ribs, with nodes at ventral margin, sometimes occur. Venter becom- ing narrower with growth, with weakening of ribs and usually a ventral smooth band throughout. Number of primaries increases with growth up to a diameter of c.. 40 mm (from c. 35 45 at 10 mm, to c. 40-50 at 20 mm, to c. 45-55 at 30 mm, to c. 50-55 at 40 mm), thereafter decreases regularly, probably to between 30 and 40 on last whorl. Data for figured specimens. d (septate to) wh wt uw primaries ventrals SM J3304 (PL 21. fig. 1) est. 82 (—) c. 29 20 est. 35 SM J3305 (PL 21. fig. 2) 63 (63) 23 c. 18 25 WMS J-19-1 (PI. 21, fig. 4) 32 (—(—)) 7 8 17 45 YM 615 (PL 21, fig. 5) 77 (58)) 23 20 35 37 c. 103 Remarks. Despite being type species of Binatisphinctes, it is one of the least well known. It is unclear from Lcckenby's original description and Buckman's .subsequent. (1921) figures whether the type specimens are macroconch or microconch. The lectotype is incomplete and broken, but septate to at least 70 mm; the paralec.totypc is completely septate. Opinion has varied; Spath (1931, p. 327) considered them to be microconchs belonging with "the similar "Hamulisphinctes to Grossouvria of the mosquensis group. The latter was used subsequently as the type of the microconch 'genus' Okaites. Arkell (1957a p. 319) apparently considered Binatisphinctes, based on binatus, to be a macroconch group but included Haniulisphinc.tes, which accommodates microconch forms, in synonymy. Mangold (1971b, p. 199), following Gerard & Contaut (1936 p. 60), considered binatus to characterize a macroconch group, but I do not consider that his arguments justify this. Although no conclusive statement can be made, it seems more likely that the type specimens are microconchs. As type species ol Binatisphinctes. the matter is of some importance, particularly for those who incorporate dimorphism at subgeneric level. If one supposes that as defined by Buckman, Binatisphinctes included both macroconch and microconch, and one restricts Binatisphinctes s.s. (with binatus as type) to macroconchs and B. (Okaites) to microconchs. as done by Mangold (1971b), then a new name is required for the Hackness Rock microconchs; but this group) probably includes the type of binatus. ALLIGATICERAS 49 The microconch o[ B. binatus resembles most closely the microconch of B. comptoni, but it is probably slightly larger in size—up to 120 mm diameter, compared with 95 mm; Buckman thought that the lectotype of B. binatus would be 120 mm diameter if complete, and the paralec- totypc 110 mm. In addition, it has constrictions, albeit weak, whereas B. comptoni does not, and although the rib curves for the few available specimens fall within the range shown for B. comptoni (Text-fig. 1 7), B. binatus ribbing seems to be slightly coarser on the inner whorls relative to its later whorls. Xo macroconch is known from England. B. binatus, like B. comptoni belongs to the same group as the Russian and Polish species mosquensisrjasanensis and scop mens is but more detailed comparison with these forms is not possible (see above). Distribution. Hackncss Rock (Athlcta-Lamberti Zones) ofCayton, Gristhorpc, Hackness and Scarborough, North Yorkshire. Rare in Lambcrti Limestone (Lamberti Zone) of Wood ham, Buckinghamshire. Recorded from Normandv, France (Arkell 1939, p. 180) and southern Ger- many (Athleta Zone) (Model & Kuhn 1935,'p. 478). Subfamily Pr.Kt.sniiNCTiNALStcinmann. 1890 Genus ALLICATICERAS Buckman, 1923 Type species. Ammonites alligatus (Bean MS) Leckenby. 1859 Diagnosis. Evolute forms with squarish or rounded whorl section (Text-fig. 19); regular, often wiry, mainly bifurcate ribbing and strong constrictions (Text-fig. 20). Lappctcd microconchs. External suture has iirst lateral saddle with a well-marked and quite deep accessory lobe, a trifid slightly asymmetrical lateral lobe slightly deeper than the ventral lobe and a rather short slightly retracted suspensive lobe with some well defined auxiliaries. Remarks. Buckman (1923, p. 157) gave no formal description when he created the genus to accommodate the single species Ammonites alligatus described by Leckenby (1859, p. 9. pi. 2: figs 2a, b) from the 'Kelloway Rock' and 'Scarborough Castle Rock1 | Hackness Rock; Athlera- Lamberti zones] of North Yorkshire (Buckman 1921, pi. 212). Apart from this figure with its Orotifer TEXT-HI,. 19. Whorl sections of Alligaticcrasspecies, (a) SMJ3303at II mm; Arkell thought lappets would be present on complete adult individuals. It seems certain that Alligati.ee/as accommodated a microconch group. Aliigaticeras is taken to include microconch and macroconch forms; although Mangold (1971b, p. 221) did not describe the systematics of Aliigaticeras he suggested that at least some of its macroconchs had been included in Orionoides Spath, 1931. Collections from west-central France might provide an answer, because the stratigraphy is well known, and there are records of alligatum and associated forms, and published illustrations (cf. Gerard & Contaut 1936) which include forms assigned to Orionoides. Ccrard & Con tain's (1936) species O.piveleaui, 0. raguini and 0. termieri could be Alligatoceras macroconchs. inner middle outer whorls — whorls whorls body chamber occasional 1MI parabolae I Aliigaticeras alligatum deep constrictions Aliigaticeras rotifer deep constrictions Alligatfcoras aff. rotifer weak co istrictions TEXT no. 20. Ribbing of Alligathnos spccics. Aliigaticeras includes the Knglish species alligatum and rotifer of the Upper Callovian; in the Lower Oxfordian pseudograciosus Arkell, 1939 belongs to this group and forms identified as bemensis de Loriol, the type species of Hroperisphincles (Spath, 1931), must be very closely related (see PI. 23, fig. 8; Arkell 1936,.pp. xli-xlii), although this genus is based only on pyritic nuclei. Forms from India occurring at a similar horizon and assigned to the genus by Spath (1931) include A. jooraense (Waagen), A. nbliqueiplicatum (Waagen), A. polymorphum Spath and A. indicum Spath. Arkell (1936, p. xliii) added several other species from the Lower Oxfordian of the Jura including ,4. birmensdor- fen sis (Moesch), A. noellutgi (de Loriol) and .4. mairei (de Loriol). Callomon (pers. comm., 1985) considers A. bimensdorfemis to be from the Middle Oxfordian Transversarinm Zone, and not closely related to the others. Aliigaticeras is thought to have evolved from Choffatia during the late Callovian ( Athleta Zone); .4. rotifer shows transitional characters (cf. Choffatia poculum) and is probably an early form. The group persists into the Oxfordian where it is common amongst the perisphinctid fauna of the Lower Oxfordian in many sub-Boreal and more southerly areas. ALL IG ATI CE R A S Alligaticeras rotifer (Brown, 1849) PI. 22, figs 1-6, 8 1841 Ammonites rotifer (nob.); Williamson, p. PI7 [nom. nud.]. 1849 Ammonites rotifer; Brown, p. 246. pi. 20* figs 14, 15. 1918 Perisphinctes rotifer Williamson-Brown sp.; Buckman, pi 113, pp. 113b, c. ?1971 Grossouvria rotifer (Williamson); Ilahn & Koerner, pi. 12. Holotype. MM LI 1494 (PI. 22, fig. 1), designated Buckman 1918,pi. 113 from 'Kelloway Rock' [Hackness Rock: Athleta-Lamberti zones], Castle Hill, Scarborough, North Yorkshire. Pre- served in a highly calcareous oolitic sandstone; it almost certainlv comcs from the Athleta Zone (cf. Bed 3 at Castle Hill; Wright 1968). Material. The type specimen and about 18 others, uncrushed but incomplete or immature (completely septate), preserved in calcareous and/or oolitic sandstone or in shelly calcareous doggers; and about 35 specimens, mainly small, uncrushcd but completely septate (inner whorls), pyritized internal moulds. Description. Maximum diameter amongst incomplete material 90 mm. Body-chamber at least 180". At least four and more often five whorls visible. Moderately evolute (wh/d = 30-35%); whorl section moderately depressed (wh/wt=65-85%) with gently rounded whorl sides and broad venter ( Text-fig. 19); steeply sloping and almost smooth umbilical wall; umbilicus moderately shallow and wide (c. 2.5 mm wide and 8 mm deep at c. 55 mm diameter). Ribs (Text- fig. 20) generally prorsiradiate (though inner whorls may show slight rursiradiate aspect near the venter), bifurcate on inner whorls (up to 25 mm diameter), becoming bifurcate with intercala- tories and occasional simple ribs (up ro 35 to 40 mm diameter) and then (more than 40 mm diameter) trifurcate with intercalatories giving a primary to ventral ratio of up to 1:4. Ribs split high up on the whorl side (on the ventro-lateral shoulder of depressed whorls) and pass uninterrupted across the venter. Moderately strong arid deep constrictions are common on the inner and middle whorls (usually two per whorl). Number of primaries decreases with growth from 30-50 at 20-2J irun diameter, to 30-40 at 30-50 mm diameter, to c. 3J at 50-55 nun diameter, to c. 30 at 90 mm diameter. Data Jot figured specimens. d (septate to) wh wt uw primaries venirals MM LI 1494 (PI. 22, fig. 1) 53 (53) 14 22 24 35 fc\ 100 YM 613 (PI. 22. fig. 2) 88 (c. 65) 22 25 45 30 c. 75 OUM J1204 (PI. 22, fig. 3) <;. 40 (—) 13 c. 16 26 39 — OUM J1250 (PI. 22, fig, 4) 19 (19) 6 8 8 c. 36 c. 62 BGS Y2125 (PI. 22. fig. 5) 30 (-) 10 14 13 BGS Zt3495 (PI. 22. fig. 6) 57 (57) 18 22 24 OUM J26360 (PI. 22, fig. 8) 90 (-) (25) (16) 45 Discussion. Buckman (1918, pp. 113b, c) discussed A. rotifer in considerably more detail than any of his own species, quoting Williamson's (1841) original nominal citation (in a faunal list, without figure or description) and Brown's (1849) subsequent description. As published in the former, the name is a no men nudum, and the latter is the first valid publication. Brown (1849) made- no mention of Williamson, but as indicated by Buckman (1918, p. 113c) there is circumstantial evidence to suggest that Brown was describing Williamson's species. The available and valid name is therefore Ammonites rotifer (Williamson MS) Brown, 1049. Williamson (1841) gave its provenance as a 1-8 m thick hard ironstone [probably upper partj at Scarborough Castle Cliff, which Buckman concluded to be the "grey sandstone of [the] Athleta Zone". Buckman gave his own description based on an examination of the wholly septate holotype, but evidently could not relate it to any of the new generic groups that he rccognizcd amongst the Callovian perisphinctids, and so assigned it to Perisphinctes. Perhaps bceausc of this, the spccics has since tended to be overlooked. Callomon (pers. comm. 1985) believed that it was probably the oldest available name for many of the pyritized nuclei from the Brown Jura zcta (Athleta Zone) of southern Germany 52 ENGLISH CALLOVIAN PERISPIIINCTID AMMONITES "described in the past, originally as Amm. convolutus of one sort or another, then renamed starting with Amm. convolutusgigas Qu. 1047. pi. 13. fig. 6, . . . Amm. conv. dilalatus, Qu. 1887, pi. 81 . . ."; he concluded that "rotiferdeserves more currency than it has had, and there has been no excuse post- Buckman." The species rotifer is thought to belong in Aliigaticeras not least because of the presence of the characteristic strong deep constrictions, its more depressed whorl section and bundled rib-style suggest a position intermediate between Choffatia and the typical alligatum group Aliigaticeras. Its stratigraphieal position supports this interpretation. It differs from Choffatia poculum (but the adult microconchs seem very similar) in having the characteristic cleep constrictions and more Strongly ribbed inner whorls. Distribution. Hackness Rock of Hackness (including Bed 4 (Athleta Zone) of Wright 1968), Cay ton and Scarborough Castle, North Yorkshire; Oxford Clay, Athleta Zone of Summcrtown and Wolvcrcotc, Oxfordshire; Athleta Zone, Proniac Subzone of Milton Keynes A5 diversion, Buckinghamshire. Recorded from the Athleta—lower Lamberti zones of south-west Germany (Hahn & Kocrncr 1971). Aliigaticeras aff. rotifer (Williamson MS), Brown 1849 PI. 22, figs 7, 9; PL 23, figs 1, 2 1939 Perisphinctes (Proper isphificlei) tulitmgtiaius Noelling; Arkell, p. Hit), 195. pi. 9, ligs 3. 1969 Properisphwctes (?) sp.; Hudson & Palframan, p. 414. pi. 19. lit*, f. 1969 Properisphinctes sp.: Hudson & Palframan, p. 414, pi. 19, lig. h. Material. Three uncrushed, completely septate, pyritized specimens (presumed macro- conchs); 20 nuclei and inner whorls, similarly preserved and two similar specimens with outer whorls preserved as clay moulds. Microconchs and macroconchs. Description and discussion. The inner whorls are indistinguishable from those of .4. rotifer, but later whorls are less depressed (wh/wt=90-95%) (Text-fig. 19), more finely and densely ribbed, and constrictions arc less deep (Text-fig. 20). Microconch body-chamber (c. 55 mm diameter) with bundled ribs (primary:ventral ratio about 1:4) and lappets (up to c. 5x20 mm) resembles that of Choffatia poculum. Number of primaries decreases with growth from c. 40 at 20-50 mm diameter, to 30-35 at 65-75 mm diameter, to c. 35 at 90-110 mm diameter. Arkell's (1939, pp. 160, 161, 195) records (OUM J22503, 4 and possibly OUM J22L26, 7, Arkell 1939, pi. 9. figs 2. 3) of latilinguatus Noctling 1887, from the Athleta Zone of Woodham belong to this group. With their small diameter, they might equally well be assigned to .4. rotifer, but because of the associated more complete material from this horizon and locality, they are included herein with A. aff. rotifer. Noetling's material came from the Mariae Zone of Mount Hermon, Syria and the illustrations (Noet.Iing 1887. pi. 4, fig. 7 8c) show septate fragments and inner whorls only. Arkell (1938b) also used this species name for the pyritized perisphinctid fragments and nuclei (OUM J22837 collective) from the Lamberti Zone clays, exposed in the excavations for the Bodleian Library extension in Oxford; however, although these included forms of the rotifer-alligatum bemensis group, they are now considered to be indeterminate at specific level. The relationships of .4. aff. rotifer are. not clear; its more, compressed whorl section, finer ribbing and slightly younger stratigraphieal position compared with .4. rotifer, might indicate a position intermediate between .4. rotifer and .4. alligatum, but it has only a comparatively weak development of constrictions. Da ta fo r fig u red specim ens. d (septate to) wh Wt 11 w primaries ventrals OUM J29909 (PL 22. lig. 7) c. 53 (—) c. 17 — — BGS Z13703 (PL 22, fig. 9) 65 (65) 19 20 29 — OUM J29910 (PL 23, fig. 1) 110 (-) 33 — 47 c. 36 OUM J1206 (PL 23, fig. 2) 92 (-) 34 35 35 c. 36 Distribution. Oxford Clay ( Athleta Zone of Summerrown, Oxfordshire; Athleta Zone, Proniae AI.LICATICERAS 53 Subzone of Milton Keynes. Buckinghamshire; Athleta Zone. Spinosum Subzone ofWoodham, Buckinghamshire). Alligaticeras alligatum (Leckenby, 1859) PI. 23, figs 3-7 1059 Ammonites alligatus Leckenby (Bean MS); Leckenby. p. 0, pi. 9} fig.?, 2a, b. i'1897 Perisphinctes alligatus (Bean); Parona & Rnnarrlli, p 178. pi. 9, figs 1, la. 1898-9 Perisphinctes alligatus Leek.; Siemiradzki, p. 86. pi. 10. fig. 0, ?pl. 17, lit;. 58. 1921 Dichotomoceras alligatum, Bcan-Leckcnby sp.; Buckman, pi. 212. 1927 Alligaticeras alligatum, Bcan-Leckenby sp.: Buckma.il [corrigenda slip]. 1931 Alligaticeras alligatum (Bean MS) Leckenby sp.; Spath, p. -107. ?1933 Alligaticeras all", ulligutum (Bean MS) Leckenby sp.; Spath, p. 859. 1936 Perisphinctes (Alligaticeras) alligatus Leckenby; Arkell. p. xlii, pi 100. figs 4a—c. 1939 Perisphinctes {Alligaticeras) alligatus (Leckenby); Arkell, pp. 161, 100, 2(13. ? 1939 Perisphinctes bermnsis Lor.; Knhn, p. 509. 1957a Alligaticeras alligatum (Leckenby): Arkell, p. 319. lii>. 407. 1971 Alligaticeras alligatum Leckenby; Cariou, p. 453. 1971 Alligaticeras alligatum Leek.; (Janon. p. 309. Holotype. SM J3303 (PI. 23, fig. 3), designated Buckman 1921, pi. 212 from 'Castle Rock' [Hackness Rock; Athleta-Lambcrti zones], Scarborough, North Yorkshire. Microconch. The preservation of this specimen (limestone with pinkish shell material) strongly suggests that it comes from the Lambcrti Zone. Other specimens support this—they are associa ted with Qitensted- locems and/or come from Cunstone Nab (see Wright 1968). Material. The type specimen and about 10 others, uncrushed but mainly incomplete or immature (preserved in sandy limestone with ooliths) and about 30 specimens partially crushed or otherwise distorted, including at least two adults, otherwise incomplete or immature and all more ot less fragmentary (preserved in calcareous mudstonc or marly limestone as internal clay moulds with thin black (when fresh) powdery pyritic coatings). Microconchs and macroconchs. Description. Microconchs (29 specimens): maximum diameter c. 55 mm, generally 40-50 mm. Body-chamber at least 270". At least four whorls visible. Evolute (wh/d —25-30%); whorl section squarish (wh/wr~~80 100%) with flat whorl sides and broad rather flat or gently rounded venter (Text-fig. 19); inner whorls may be depressed; gently sloping and almost smooth umbilical wall; umbilicus shallow and wide (up to 25 mm wide and 5 mm deep in adult). Ribs (Text-fig. 20) mainly recliradiate but prorsiradiate on the inner whorls and gently prorsiradiate on the venter; apart from this change in trend, ribbing remains remarkably constant at all stages of growth with sharp regular primaries splitting very high on the whorl side, often at the ventro-lateral margin, into two secondaries; occasionally two (or more rarely one) simple ribs with an associated intercalatory. Strong deep constrictions common, usually two per whorl, and occasional nodes at the ventro-lateral margin. Ribs pass across broad venter usually without interruption but sometimes with vestige of weak smooth ventral band. Aperture, with associated strengthened rib and terminal constriction, bears lappets (apparently short). Macroconchs (six specimens): maximum diameter amongst incomplete material (no speci- men seen to aperture) c. 100 mm. Length of body-chamber unknown. At least four whorls visible. Evolute (wh/d = 25-30%); whorl section squarish (wh/wt=90-100%) with flat whorl sides and broad rather flat or gently rounded venter (Text-fig. 19); gently to moderately steeply sloping umbilical wall; umbilicus shallow and wide (estimated up to 50 mm wide and 10 mm deep in adult). Ribs (Text-fig. 20) mainly rectiradiate, becoming gently prorsiradite on the venter. As in the microconch, the ribbing style apparently remains remarkably constant with sharp regular primaries splitting very high on the whorl side, often at the ventro-lateral margin, into two secondaries; occasional simple ribs with an associated intercalatory; strong deep constrictions particularly on middle and probably inner whorls. Ribs pass across broad venter without interruption. For microconch and macroconch, the number of primaries increases with growth from 10-50 at 20-25 mm diameter, to (40)-60 al 30-35 mm diameter to (50)—65 at 70-75 mm diameter. 54 ENGLISH CALLOVIAN PERISPHINCTID AMMONI TES Data far figured specimens. d (septate to) wh wl uw primaries ventrals SM J3303 (PI. 23, fig. 3) 44 (29) 13 14 21 58 c. 112 OUM J258b (PI. 23, fig. 4) 19(-) 5 8 9 40 YVMS J46 (PI. 23, fig. 5) 91 (-) 23 f. 22 46 — BGS Zt5l6 (PI. 23, fig. 6) c. 70 (—) 6". 18 20 c. 33 c. 47 c. 90 OUM J22384 (PI. 23* lig. 7) 36 (-) 9 c. 10 18 50 c. 90 Discussion. A discussion of Aliigaticeras has almost always involved .4. alligatum and for this reason the microconch form, albeit based on the holotypc only, has become fairly well known. The macroconch is less well known, and no complete specimen is known from England. Most other records of the species are not supported by illustration or systematic description. A. alligatum is more compressed, with finer and more regular bifurcate ribbing than A. rotifer. Distribution. Lamberti Limestone (Lamberti Zone) ofWoodham, Buckinghamshire; Hackness Rock (Lamberti Zone and possibly Athleta Zone) of Cunstone Nab. Cayton, Hackness and Scarborough, North Yorkshire; ?Oxford Clay (Athleta Zone of Wolvercote, Oxfordshire; ?Lam- berli Zone of Tidmoor Point, Dorset (Spath 1933)). Recorded from France (Athlcta-Lambcrti zones of Calvados (specimen figured by Siemiradzki 1098, pi. 20 fig. 8), Poitou, northwest Aquitaine), the Jura, possibly as bernensis in the Athleta Zone of Franconia (Kuhn 1939) and doubtfully from the "Eisenoolithe" (Jason Zone) of Poland (Siemiradzki 1898). REFERENCES i REFERENCES (Part 1) ARKELL, W.J. 1932. An unknown Kcllavvavs locality in Dorset? [The West fleet near LangUm HerringJ. Geol. Mag.. 69, 4-1—5. 1933. The Jurassic System in Great Britain, xii+681 pp.. 41 pis. Oxford. 193 ">-1948. A monograph on the ammonites of the English Corallian Beds. Paiaeontogr. Soc. [Mon/igr.) (1), 1935, i- xxxii, 1 30, pis A-B, 1-6; (2), 1936, xxxiii-xlvi, 31-42, pUC-D, 7-10; (3), 1937, xlvii-liv, 43-67, pis F.-F, 11-13; (4), 1938. 60-104, pis 14-18; (5), 1939a.. 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Geology of the country around Rridpor! and Yeovil (explanation of sheets 327 and 312). Mem. geol. Sun. Gr Bt. xii+239 pp., 7 pis. REFERENCES v WOODWARD. H. B. 1895. The Jurassic rocks of Britain. Vol. V. The Middle and Cppcr Oolitic rocks of England (Yorkshire excepted). Mm. geol. Sum. Or Bt. xiv+409 pp. WRIGHT, J. K. 1968. I'he stratigraphy of the Callovian rocks between Xewtondale and the Scarborough coast, Yorkshire Proc. Geo!. Ass., 79," 363-99. PLATES Unless otherwise stated on the plate, the figures are reproduced at natural size; most specimens were coated with ammonium chloride before photo- graphy. Start of the body-chamber is marked (>) where visible. PLATE 1 Fig. Page Homoeoplanulites cf. subbakeriae (cTOrbigny, 1850) 17 la, b BM CI 1796 (J. F. Blake Collection); [M] body-chamber fragment; Upper? Cornbrash; Holwell, Dorset. 2a, b BM CI 1825 (J. F. Blake Collection); whorl fragment; Upper? Cornbrash; Holwell, Dorset. 3 OUM J12767; Upper Cornbrash; Stalbridge, Dorset; Macrocephalus Zone and Subzone. Homoeoplanulites aff. balinensis (Neumayr, 1871) 17 4a, b BGS GSM7676; completely septate; Kellaways Clay; Siddington, Gloucester- shire; Calloviense Zone, Koenigi Subzone. - 5 BGS GSM7679; completely septate; Kellaways Clay; Siddington, Gloucester- shire; Calloviense Zone, Koenigi Subzone. Homoeoplanulites difficilis (S. S. Buckman, 1922) 18 6a, b Holotype (presumed lost) as figured by S. S. Buckman (1922, pi. 329); [m]; Kellaways Rock; South Cave, Humberside; Calloviense Zone, Eno- datum Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate 1 PLATE 2 Fig. Page Hamoeaplanulites difficUu (S. S. Buckman, 1922) 18 I 3: 6a, b Topotypes; [m]; Kellaways Rock; South Cave Station Quarry. South Cave. Humbcrsidc; Calloviense Zone, Enodatuin Subzone. L FW TNN475; 2, FW TNN473; 3. IKiS Zkl439 fall complete adults with lappets); 6a. b, FWTNN510. 4a, b, 5a-c Complete adults (m) with lappets; Kellaways Rock; South Ncwhald Quarry, South Ncwhald, I I umherside; Calloviense Zone. Ivnodalum Subzone. 4. FW TNN527: 5, FW TNN528. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate j2 PLATE 3 Fig. Page Ilomoevplanulitesdifficilis (S. S. Buckman, 1922) IK I FW TNN521; [M]; Kellaways Rock: South Newbaid, Hiirabcrsicle; Callovi- ense Zone, Lnodatum Subzone. 2% 3 Topotypes; Kellaways Rock; South Cave Station Quarrv, South Cave, Hum- be rside; Calloviense Zone. Enodaium Sub/one. 2, BGS GSM 117460, [m]> septate inner whorls and pare of body-chamber; 3, FW TNN508, adult [M|. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY \ COX, Callovian perisphinctid ammonites Plate 3 PLATli 4 HomneopUiniilUes difficilis (S. S. Buckman, 1922) FW TNN506; topotype; adult [MJ: Kellaways Rock; South Cave Station Quarry, South Cave, Humberside: Calloviense Zone. Enodalum Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinetid ammonites Plate 4 PLATE 5 I'if?. Page Perisphinctesspirorbis Neumayr, IK'70 20 la. b Plaster cast of holotypc; BGS GSM 117448; according to Neumayr, last whorl almost all body-chamber with some mouth border bul no suture visible; Macrocephalcn-Schichten; Vogi&heim im Brcisgau, Baden> W. Germany; original specimen is BSM AS1838. HomoeopIanuMes difficilis (S. S. Buckman. 1922) 1X 2 FW TNN516; topotype; adult [MJ; Kellaways Rock; South Cave Station Quarry, South Cave, Humberside; Calloviense Zone, Lnodatum Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinetid ammonites Plate 5 PLATE 6 Fig. Page Indosphinctes lobatus (S. S. Buckman. 1922) 22 la. I> ItOS GSM7680] |M|; Kellaways Clay, Siddington, Gloucestershire; Callovi- ense Zone. Koenigi Subzone. 2 BGS Zrl639: [M]; Kellaways Clay; Sutton Benger (M4 motorway cutting), Wiltshire; Calloviense Zone, Koenigi Subzone. 3a, h BGS GSM7682; holotypc; complete adult [m] with lappets: Kellaways ('lay; Rampiskam, Dorset; Calloviense Zone. Koenigi Subzone. Indosphinctespaiina (Neumayr, 1870) 24 A GBV 1870/04/1; lectotype; original of Neumayr 1870, pi. 8, fig. I ; [M]; Macro- cephalen-Kalke; Rrictal, near Gosau, Salzkammcrgut, Austria; see PL 7, lig. 1 for lateral view. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinetid ammonites Plate 6 PLATE 7 Page Fig. Indosphinctes patina (Neumayr, 1870) 24 GBV 1870/04; 1: leclolypc; original of Neumayr 1870. pi. 8, lig. 1; (Ml; Macro- cephalcn-Kalke; Brictal, ne-tir Cosau. Salzkammergut, Austria: see PI. 6, fig. 4 for apertural view. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate j2 PLATE 8 Indosphinctes palifia (Neumayr. 1870) BGS Z1I675; [M] body-chambcr; Lower Oxford Clay; Witney. Oxfordshire; Jason Zone; lb, x 0-8. OUM J30911; adult [m| with broken lappet; Lower Oxford Clay; LUC pit, Calvert, Buckinghamshire; Jason Zone. Jason Subzone (Bed 2e of Callo- mon 1968). OUM J309I8; [mj; Lower Oxford Clay; LBC pit. Calvert, Buckinghamshire; Jason Zone. Jason Sub/one (Bed 2c of Callomon I96K). OUM J30912; [mj; Lower Oxford Clay; LBC pic, Calvert, Buckinghamshire; Jason Zone. Jason Subzone (Bed 2c of Callomon l%K). MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinetid ammonites Plate 8 PLATE 9 Fig. Page Choffatia cobra (Waagen, 1875) 26 la, b Plaster cast of holotype; BGS GSM 117449; |M|; 'Beds with Per. aneeps\ south of Bhooj. Cutclu India; original specimen is GS1 Type no. 2056. Choffatia cardoti (Petitclerc, 1915) 29 2a~e FW TNN536; completely septate; Kellaways Sand; South Newbald Quarry, South Newbald, Humberside; Calloviense Zone, Calloviense Subzone. 3a-c FW TNN537; no suture visible; Kellaways Sand; South Newbald Quarry, South Newbald. Ilunihersidc; Calloviense Zone, Calloviense Subzone. COX, Callovian perisphinctid ammonites Plate 9 PLATE 10 Choffatia cordon (Petitclerc. 1915) IKiS PLATE 11 Fig. Page Choffatia recuperoi (Gemmellaro, 1872) 30 la c FW TNN507; completely septate |MJ; Kellaways Rock; South Cave Station Quarry. South Cave, Humberside: Calloviense Zone. Enodatum Subzone. 2a-e FW TNN460; adult [m] with lappets; Kellaways Rock; South Cave Station Quarry, South Cave, Humberside; Calloviense Zone, Hnodatum Subzone. 3a c FW TNN512; adult [m]; Kellaways Rock: South Cave Station Quarry, South Cave, Humberside; Calloviense Zone, Hnodatum Subzone. 4a-c FW TNN522; adult [m]; Kellaways Rock; Soulh Newbald Quarry, South Newbald. Humberside: Calloviense Zone, Enodatum Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites PLATE 12 Fig. Page Choffatia sulcifera (<)ppcl, 1857) 33 la d Plaster cast of holotype; HC.S GSM 117447; [m]; Brown Jura zcta; Gammel- shauscn. Wurttetnberg, W. Germany; original specimen is GPI |no number] (Quenstedi 1X49, pi. 13, fig. I). 2 BCJS GSM27932; [in); Oxford Clay; Summer town, Oxfordshire; Athlcta Zone. 3fl-c OIJM J2588; [m]: Oxford Day; Wolvercote, Oxfordshire: Athlete Zone. 4 JKW BH/126; [mj; Ilacknesa Rock; Hackncss Quarry. Hackney North Yorkshire; Athlcta Zone (Bed 4 of Wright 1968). 5 OLM J1218; [mj; Oxford Clay; Wolvercote, Oxfordshire; Athlcta /one. 6 OUM J25X7; completely septate; Oxford Clay; Wolvercote* Oxfordshire; Athlela Zone. Chojj'utia alT. lahuseni (Sa.sonov, 1965) 34 7a, b OUM J17870; completely septate; Middle Oxford Clay; I.BC pit, Bletchlcy. Buckinghamshire: Athlela Zone, Proniac Subzone (Bed 21 of Callomon 1968). 8ath OUM J1203; completely septate: Oxford Clay; Wolvercote, Oxfordshire; Athlela /one. Choffatiapocutwn (Lcckcnby. 1859) 35 9a c SM J3298: holotype; completely septate | M); Hackneys Rock: near Gristhorpc Bay, North Yorkshire; Lamberti Zone. Ila? b SM J3299; para type; complete adult (mj with lappets; Hackncss Rock; near Gristhorpe Hay, North Yorkshire; Lamhcrl.i Zone. 12 WMS J49; [mj; Hackness Rock; Cunstone Nab. North Yorkshire; Lamberti Zone. 13 OUM .122362; complete adult (mj with lappets; Lamberti Limestone; Wood- ham, Buckinghamshire; Lamberti Zone, Lamberti Subzone. 14 BGS FR1116; complete adult [in] with lappei.s; Lamberti Limestone; Wood- ham, Buckinghamshire; Lamberti Zone. Lamberti Sub7one. 15 MM LL5664A; completely septate; Oxford Clay; Wolvercote, Oxfordshire; Athleta Zone. 16 OUM J22361; complete adult fm| with lappets; Lnmbcrii Limestone; Wood- ham, Buckinghamshire; Lamberti Zone, l amberti Subzone. Perisphinctes suhtilis Neumayr, 1871 35 10a, b Plaster cast of Neumayr 187K pi. 14, fig. 3a c; BOS GSM 117446; according to Neumayr, completely septate; 'oberer Dogger'; Balin, near Krakow, Poland; original specimen is BSM ASXXI2. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate j2 PLATE 13 Fig. Page Choffatia poculum (Locke n by, 1859) 35 1 IKiS Zt51? [M]; Lamberti Limestone; Wood ham, Buckinghamshire; Lam- berti Zone, l.ambcrti Subzone. 2a, b OUM J22553; completely septate [MJ; Lamberti Limestone; Woodham. Buckinghamshire; Lambcrli Zone. Lamberti Subzone. 3a. b WMS J53; [MJ; Hackncss Rock: Gristhorpe(7): North Yorkshire; Lamberti Zone. 4 YM 606; completely septate [M); Ilackness Rock: near Scarborough, North Yorkshire; Lamberti Zone. 5 OUM J223~5; [M]; Lamberti Limestone; Woodham, Buckinghamshire; Lam- berti Zone, Lamberti Subzone. PLATE 14 Fig. Choffatia trina (S. S. Buckman. 1922) 38 la c BGS GSM6509; holotype; completely septate; Oxford Clay; Fleet Bridge [? = Tidmoor Point]" Weymouth, Dorset; ?Lumberti Zone. 2 OUM .11 6729; complete adult [M] wilh one whorl body chamber; TWuodham, Buckinghamshire; Lamberti Zone. 3 OUM J22368; [MJ; Lamberti Limestone, Woodham, Buckinghamshire; Lam- berti Zone, Lamberti Subzone. 4 BGS Zr3766; 'Lamberti Limestone; Millbrouk, Bedfordshire: Lamberti Zone. 5 OUM J22370; Lamberti Limestone; Woodham. Buckinghamshire; Lamberti Zone. Lamberti Subzone. Binatisphinctes comptoni (Pratt, 1841) 43 6 BGS GSM30349; complete adult [m] with lappets; Oxford Clay [Acutistri- atum Bund]; Christian Mai ford: Wiltshire; Athleta Zone, Phaeinum Sub- zone. 7 BGS FR1233; adult [m] with lappds; Oxford Clay [Comptoni Bed]; LBC pit, Calvert, Buckinghamshire; Coronatum Zone. Grossouvrei Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY \ COX, Callovian perisphinctid ammonites Plate 14 PLATE 15 Fig. Page Binatisphinctes comptoni (Pr&ii^ 1841) 43 1 BGS FR1297; adult |m| with lappets: Oxford Clay (Acutistriatum Bond); LBC pit, Stewartby, Bedfordshire; Athleta /one, Phaeinum Subzone. 2 A small form; BGS FR970; adult |m) with lappets; Oxford Clav [Comptoni Bed); LBC pit. Calvert, Buckinghamshire; Coronatum Zone, Grossouvrei Subzone. 3 OUM J17889; adult |m|; Oxford Clay (Comptoni lied): LBC pit, Blctehley, Buckinghamshire; Coronatum Zone, Grossouvrei Subzone. 4. 6 A small form: adults [nij with lappets; Oxford Clay [Acutwtriatuiu Band]; Christian Mai ford, Wiltshire; Athleta Zone, Phaeinum Subzone; 4. YM 608; 6, BGS GSM30342. 5*7 AdulLs (m] with lappets: Oxford Clay [Aeulislriatum Band]; Christian Mal- ford, Wiltshire; Athleta Zone. Phaeinum Subzone: 5, YM 607; 7. BGS GSM 30345. 8 BGS TR1020; adult ("ml with lappeta; Oxford Clay [Comploni Bed]; LBC pit, Calvert, Buckinghamshire: Coronatum Zone. Grossouvrei Sub7one. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY \ 0 COX, Callovian perisphinctid ammonites Plate 15 A PLATE 16 Bimiisphincies lompfoni (Pratu 1841) DM 2143; [MJ: Oxford Clay [?Acuminatum Band]: ?\ViJtshirc; ?Athlcta Zone. Phacinum Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian pcrisphinctid ammonites Plate 16 PLATi: 17 Fig. Page Bimtisphincies comptoni (Pratt, 1841) 43 1 OUM J 30868; [MJ; Oxford Clay I Acuminatum Baud]; LBC pit: Blctchley, Buckinghamshire; Athleta Zone, Phaeinum Subzone. 2 BGS GSM30351; [M]; Ox lord Clay [AeuListriatum Hand]: Christian Mall'ord, Wiltshire; Athleta Zone, Phaeinum Subzone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate j2 PLATII IS Fig. Page Biaatisphincfrs comptoni (Pra 11, IH41) 43 i BM 32343; [M] with aptychi; Oxford Clay (Aeutislriatum Band]; Christian Malford. Wiltshire; Athleta Zone. Phacinum Subzone; xO-5. Bimithphhw/as hamulatiis (8. 5. Buckman, 1921) 46 2a. b, Topotvpcs; [mj; Hackncss Rock; Scarborough. North Yorkshire; Athlera 5a, b Zone; 2a. b. YM 614; 5a, b. BM 39530. 3a, b SM J3307; paratype; Hackncss Rock; Scarborough [?1 lackness], North York- shire; Athlcta Zone. 4a. b JKW AC/66: Hackncss Rock: Cornelian Bay, North Yorkshire; Athlela Zone. fta-e SM .13306; holotype; adult [m|; Hackney Rock; Scarborough. North York- shire: Athleta Zone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY \ PLATE 19 Fig. Page ?Bina(isph'tncteshwnuUttus (S. S. Buekmun, 1921) 46 la, b BM C107X; adult [MJ; Hackncss Rock; Scarborough, North Yorkshire; Alhlcla Zone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate 19 PLATE 20 Fig. Pa?S Pseudopeltoceras tecktwbyi Spath. 1931 47 la. b BM -'16516; holotypc; adult |MJ; Hackncss Rock; Scarborough. North York- shire: Athleta Zone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY \ COX, Callovian pcrisphinctid ammonites Plate 20 ^RS PI.ATE 21 Fig. Page Binatisphinctes binatus {Leckenby, 1X59) 47 la, b SM J33G4; lcctotypc; ?[m]; Hackness Rock; Scarborough, North Yorkshire; ?Lamberti Zone. 2n c SM J3305: paralectotype; completely septate; Hackncss Rock; Scarborough. North Yorkshire; YAthlcta Zone. 4a, b W.MS J-19-J; Hackncaa Rock; [?Casile Hill, Scarborough]; North Yorkshire; ?AthIeta Zone. 5a-c YM 615: Hackness Rock: Scarborough. Norlh Yorkshire; ?Athlcta Zone. Psetuiopefloceras famulwn Spath, 1931 43 3a, b YM 612: Hacknc^s Rock; Scarborough NorLh Yorkshire; Athleta Zone. 6a, b WMS J4S; Hackncss Rock; [?Castle Hill, Scarborough], North Yorkshire; Athleta Zone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY \ COX, Callovian perisphinctid ammonites Plate 21 J PLATE 22 Fig. Page Alligaticeras rotifer (Brown, 1849) 51 la, b MM LI 1494; holotype;completely septate; Hackness Rock; Castle Hill. Scar- borough, North Yorkshire; Athlela Zone. 2a. b YM 613; [M]; Ilackne&s Rock; Scarborough, North Yorkshire; Athlcta Zone. 3a, b OUM .112 COX, Callovian perisphinctid ammonites Plate 22 PLATE 23 Fig. Page Alligatkeras aft. rotifer (Brown. 1849} 52 1 OUM .129910; | M|; Middle Oxford Clay: Woodham, Buckinghamshire: AlhleUi Zone. Spinosuni fvuhznne. 2 OUM .11206; [MJ; Oxford Clay: ?Suramerto\vn1 Oxfordshire: Athleta Zone. Aliigaticeras alligatum (I.eckenby, 1 &59) 53 3a c SM .13303; holotype; [ml; Hackness Rock; Scarborough, North Yorkshire; Lamberti Zone. 4a-c OUM J2586; <>xford Clay; Wolvcrcotc. Oxfordshire; Athleta Zone. 5a, b WMS J-M>; [M]; Hackness Rock; Can stone Nab, North Yorkshire; Lamberu Zone. 6a c BGS 7,1516; [MJ; Lamberti Limestone; Woodham, Buckinghamshire; Lam- berti Zone, Lamberti Subzone. 7 OUM .I223K4; complete adult [m] with lappets; Lamberti Limestone; Wood- hum, Buckinghamshire; Lamberti Zone, Lamberti Subzone. Propmsphinctes bernensis (de Loriol, I89K) 50 8a-c MM L6251A; Oxford Clay; St. Ives, Cambridgeshire; Lower Oxfordian, Mariae Zone. MONOGRAPH OF THE PALAEONTOGRAPHICAL SOCIETY COX, Callovian perisphinctid ammonites Plate 23