Sl.fll vt« Hi/, /*" BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY VOL. VII 1962-1963 X R U S T E E S OF THE BRITISH MUSEUM (NATURAL HISTORY) LONDON : 1964 DATES OF PUBLICATION OF THE PARTS No. i. isth May ...... 1962 No. 2. 1 5th May .... . 1962 No. 3. 1 4th August ...... 1962 No. 4. i4th August ...... 1962 No. 5. 1 4th August ...... 1962 No. 6. jth December ..... 1962 No. 7. 7th December ..... 1962 No. 8. 8th February ..... 1963 No. 9. gth July ...... 1963 PRINTED IN GREAT BRITAIN BY THOMAS DE LA RUE & COMPANY LIMITED LONDON 2 0 CONTENTS GEOLOGY VOLUME VII PAGE No. i. A new Eocene Primate Genus, Cantius, and a Revision of some allied European Lemuroids. E. L. SIMONS i No. 2. The Brachiopod Genus Cyclothyris, E. F. OWEN 37 No. 3. The Trilobites of the Caradoc Series in the Cross Fell Inlier of Northern England. W. T. DEAN 65 No. 4. Fossil Flora of the Drybrook Sandstone in the Forest of Dean, Gloucestershire. K. M. LELE & J. WALTON 135 No. 5. Fossil Insects from the Lower Lias of Charmouth, Dorset. F. E. ZEUNER 153 No. 6. The English Cretaceous Turritellidae and Mathildidae (Gastropoda). H. L. ABBASS 173 No. 7. The Morphology of Tubicaulis africanus sp. nov. a fossil fern from Tanganyika. H. S. HOLDEN & W. N. CROFT 197 No. 8. The Ordovician Trilobite Faunas of South Shropshire, III. W. T. DEAN 213 No. 9. The Gastropod Genus Thatcheria and its Relationships. A. J. CHARIG 255 Index to Volume VII 299 7V, /t, V. A NEW EOCENE PRIMATE GENUS, CANTIUS, AND A REVISION OF SOME ALLIED EUROPEAN LEMUROIDS E. L. SIMONS BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vo1- 7 No. i LONDON : 1962 A NEW EOCENE PRIMATE GENUS, CANTIUS, AND A REVISION OF SOME ALLIED EUROPEAN LEMUROIDS BY ELWYN L. SIMONS Peabody Museum and Department of Geology, Yale University, New Haven, Conn. Pp. 1-36 ; Pis. 1-3 ; 4 Text-figures BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. i LONDON: 1962 THE BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY), instituted in 1949, is issued in five series corresponding to the Departments of the Museum, and an Historical series. Parts will appear at irregular intervals as they become ready. Volumes will contain about three or four hundred pages, and will not necessarily be completed within one calendar year. This paper is Vol. 7, No. i of the Geological (Palaeontological) series. Trustees of the British Museum 1962 PRINTED BY ORDER OF THE TRUSTEES OF THE BRITISH MUSEUM Issued May, 1962 Price Fifteen Shillings A NEW EOCENE PRIMATE GENUS, CANTIUS, AND A REVISION OF SOME ALLIED EUROPEAN LEMUROIDS By ELWYN L. SIMONS CONTENTS Page I. A NEW EUROPEAN OMOMYID Cantius ...... 3 Taxonomic Revision ........ 5 II. REVISION OF THE SPECIES OF Protoadapis Lemoine ... 8 III. NOTES ON Pronycticebus gaudryi GRANDIDIER .... 14 IV. THE TAXONOMIC POSITION OF Anchomomys STEHLIN . . .21 V. RELATIONSHIPS OF EARLY TERTIARY LEMUR-LIKE PRIMATES . 23 VI. CLASSIFICATION OF EUROPEAN EOCENE PRIMATES ... 27 VII. CONCLUSIONS .......... 34 VIII. ACKNOWLEDGEMENTS ......... 34 IX. REFERENCES .......... 34 SYNOPSIS Cantius, a new European early Eocene lemur-like Primate genus, is described and additions to knowledge of anatomy and affinities for three Eocene lemuroid genera, Protoadapis, Pronyc- ticebus and Anchomomys are made. The significance of the terms " tarsioid " and " lemuroid " is discussed as these concepts bear on a consideration of the relationships of early Cenozoic European and American lemur-like Primates to each other and to contemporary tarsier-like prosimians. The classification of European Eocene Primates is revised from Simpson (1945) and the conclusions drawn that some European Eocene lemuroids may relate closely to subse- quent stocks as well as to American prosimian families contemporary with them. ABBREVIATIONS A.M.N.H. — American Museum of Natural History, New York. B.M.N.H.— British Museum (Natural History). G.P.I.H. — Geological and Paleontological Institute, University of Halle /Wittenburg. M.C.Z. — Museum of Comparative Zoology, Harvard. P.U. — Princeton University. S.M.G.C. — Sedgwick Museum of Geology, Cambridge. I. A NEW EUROPEAN OMOMYID CANTIUS A RECENT examination of fossil mammals from the London Clay at the British Museum (Natural History) resulted in the discovery of an undescribed upper and two partial lower dentitions of Protoadapis eppsi Cooper (1932). The specimens belong to a new genus which can be assigned to the prosimian family Omomyidae. Gazin (1958 : 47) proposed family status for the Omomyinae, which have previously been ranked as a subfamily of Anaptomorphidae. The latter taxon is now understood to be a separate stock primarily characterized by reduced dental formula and much GEOL. 7, i. i§ 4 A NEW EOCENE PRIMATE GENUS, CANTIUS enlarged third and fourth premolars. There are at least two European primate species, Cantius eppsi (described below) and Teilhardina belgica, which can best be assigned to the Omomyidae, although each presents some features of difference from typical omomyids. One might establish a new family or subfamily for these European species, but until they are better known such a procedure has little to recommend it.1 Higher categories among early Cenozoic Primates have already been too much multiplied. This may be due principally to the difficulties of grouping species which are usually known only from dentitions, on rare occasions associated with fragmen- tary skeletal materials, and to the emotional element involved in the study of human relatives and ancestors, deservedly criticized by Simpson (1945 : 181) and elsewhere, and which, apparently, has even pervaded some discussions of fossil prosimians. Both Cantius and Teilhardina come from deposits containing Sparnacian (early Eocene) faunas and consequently represent some of the oldest Old World Primates. They are the earliest, in fact, that could possibly be near the basal stock or ancestry of any of the surviving European, Asian, or African members of the order. Evidence as to whether or not Eocene omomyids were more lemur-like or more tarsier-like is scanty, for skull parts, other than maxillae, are practically unknown in this group. Hiirzeler (1948) appears to be correct in stressing dental similarities between the early Eocene primate Teilhardina, from Belgium, and the much better known necrolemurines. This view is shared by the writer and is also implied by Gazin (1958 : 92). The Necrolemurinae are quite definitely tarsier-like, and close correspondence between premolar and molar cusp patterns in unspecialized necro- lemurines and omomyids reinforces the idea that Omomys and its allies are nearer to true tarsioids than to such distinctly lemuriform Primates as Adapis or Pronycticebus. There is a reasonable probability that necrolemurines, North American omomyids, and even Old World Anthropoidea were derived from a form like the generalized prototarsioid Teilhardina, which has a lower dental formula of 2.1.4.3., and which lacks specializations in known parts that could rule out this possibility. Of course, Teilhardina itself, of Sparnacian Eocene provincial age, occurs too late in time to have such a position. A skull fragment of an omomyid, Hemiacodon, discussed and illustrated by Gazin (1958 : 55, pi. 4, fig. 4) indicates some expansion of the dorso-frontal area in at least one member of this family — together with reasonably large orbits. Between the orbital apertures the rostrum, however, is relatively broader than in the probably omomyid derived genus Necrolemur, being about as in Microchoerus (S.M.G.C. 9669). In degree of forward rotation the orbits of Hemiacodon appear to be intermediate between these latter two necrolemurines. Simpson (1940 : 190-197) discussed a pelvis, some vertebrae, and some elements of the hind limb which probably belong to Hemiacodon (A.M.N.H. 12613) and con- cluded that the " skeleton of Hemiacodon, as far as known, is at least as lemuroid as tarsioid, probably more ". Such judgements ultimately depend on how these two 1 It also seems possible that Periconodon, Lushius and Hoanghonius represent three other Old World omomyids. Together with broad similarities in known parts, both of these Primates possess an un- usual cusp on the antero-internal base of the protocone which has been called a pericone. This struc- ture often occurs in Omomys but is known in very few other members of the order. For discussion of Luchius, see Chow (1961). A NEW EOCENE PRIMATE GENUS, CANTIUS 5 concepts are defined. It seems unlikely that the features of the postcranial skeleton in any Eocene primate would be closely similar to those in a highly specialized modern form like Tarsius. The earliest tarsioid postcranial distinctions remain elusive. Segregating out osteological characters of value in determining earlier radiations of higher categories, or in indicating phyletic relationships, is always difficult and uncer- tain. Nevertheless, an attempt to do so can be made for Tarsius. In the class of late and unusual specializations (of uncertain value in determining tarsioid phylogeny) may be the following characters : (i) Much enlarged orbits with flaring bony rims. (Occurring also, in a somewhat less exaggerated form, among other primarily nocturnal animals, such as Nycticebus, Aotes, owls, etc.) (2) Greatly elongated cal- caneum and astragalus. (This specialization is seen elsewhere in galagos and in an analogous way in anurans.) (3) Fused tibia and fibula. (Such fusion occurs in a variety of hopping tetrapods including many rodents, lagomorphs, in some marsupials and insectivorans, as well as among Aves. See Barnett & Napier (1953 : 12) for further discussion of the adaptive significance of this feature.) Should these charac- ters be relatively recent acquisitions among tarsiines, even the direct Eocene ancestor of Tarsius, in lacking them, would be difficult to distinguish from lemuroids post- cranially. In view of this possibility, evidence provided by the postcranial bones of Hemiacodon appears to be equivocal in relating the animal either to Tarsiiformes or Lemuriformes. What would help to indicate the affinities of such omomyids would be knowledge of such features as the size and shape of component parts of the brain (their size relative to each other), extent of facial shortening, proportions of palate and skull vault, amount of forward shifting of the foramen magnum, and various other characters of the basicranium, particularly degree of inflation of the auditory bullae and mastoid region, and situation or relationships of entocarotid circulation, of the ectotympanic pterygoid alae, and of cranial foramina. Although for omomyids these cranial features are not known they can be observed in Necrolemur, which in most of these areas closely resembles Tarsius, and which dentally (at least) shows affinity with Omomyidae. As knowledge of the earliest Primates grows with new finds, taxonomic separation, at all grades of classification, can be expected to become more arbitrary. In this respect, some European Primates, particularly Cantius, evidence a closer relationship between Notharctidae and Omomyidae than has previously been documented ; although this possibility was briefly considered by Gazin (1958 : 47). Perhaps both of these families, assuming the two groups deserve separate family status, are not far removed from a common late Paleocene ancestry. TAXONOMIC REVISION Genus CANTIUS1 nov. (PI. i) TYPE SPECIES. Protoadapis eppsi Cooper, 1932. GENERIC CHARACTERS. As for the species. 1 From the Latin for County Kent, England (Cantium, Cantia) in which all specimens of this primate have been discovered and in analogy with such related forms as Washakius, from the North American Eocene. 6 A NEW EOCENE PRIMATE GENUS, CANTIUS DISCUSSION. Size : Cantius is a large omomyid, intermediate in size between Hemiacodon and Ourayia, but distinctly smaller than any of the species of Protoadapis, and may have been about the size of the living African Giant Galago, Galago crassi- caudatus. The discovery of a right maxilla with P3-M3 of this species (PL la) from the early Eocene deposits at Abbey Wood, Kent (since Cooper's original description) confirms that the species belongs to a genus distinct from Protoadapis, a conclusion which can also be demonstrated by features of the lower dentition of Cantius eppsi (B.M.N.H., M-I3773) originally reported on by Cooper (1932), and by two other partial lower dentitions found subsequently (PI. ib). Indeed, Cooper himself suggested the possi- bility that the British species belonged to a distinct genus. Re-examination of all available specimens of Protoadapis indicates that this is so. Some differences between Cantius and Protoadapis (in the lower dentition) are that the former is somewhat smaller, has paraconids on P4, Mx, M2, a much longer and more complex M3 talonid, and a considerably smaller and lower P3. A charac- teristic feature of Protoadapis, sometimes seen in species of the North American genus Pelycodus as well, is that the P3 stands noticibly higher than P4. In Proto- adapis the paraconid decreases in expression posteriorly in the molar series but not in the same way as in Cantius where the paraconid and metaconid are increasingly drawn together in the series M-^g, compare Pis. ib and 3/. Throughout the lower molar series of Protoadapis the paraconid remains widely separated from the meta- conid and in M3 is represented only by a slight crest — still considerably removed from the metaconid. In Cantius paraconids are clearly delimited in all three molars and are nearly as high as metaconids.1 In this progressive alteration of trigonid elements posteriorly Protoadapis resembles closely Notharctus, while Cantius is much more like some specimens of Omomys in which, although a distinct paraconid is retained throughout the lower molars, the paraconid is closer to the metaconid in M^_3 than in Mg. Cantius, in its enlarged and complex M3 talonid, also agrees well with the elaboration of this element in omomyids. Yet another distinction in the lower dentition between Cantius and Protoadapis is that in Cantius a clearly defined paraconid cusp is present in the P4, a structure which never occurs in Protoadapis (see PL 3/, and Stehlin, 1912 : 1282). Recognition of the Abbey Wood species as generically distinct from Protoadapis was delayed, in part, because of the scarcity of comparative material in European museums. The total number of good specimens belonging to all species of both of these genera is probably less than ten. Nevertheless, the significance of the facts that Cantius, an omomyid, and Protoadapis, a notharctid-like adapid, occur in the European Eocene should be stressed. Knowledge of such ranges gives added import to the more extensively known North American Primates of the omomyid-notharctid type because it indicates that forms closely affined to them were present in the early Tertiary of the Old World. The possiblity is thus strengthened that some North 1 Paraconid and metaconid of the M3 in the holotype of C. eppsi cannot be distinguished, either because of wear or because they are coalesced. In B.M.N.H., M-i^i^ja, b, however, these M3 cusps are separate but closely approximated. A NEW EOCENE PRIMATE GENUS, CANTIUS 7 American species may approximate morphological, or even linear stages in the ances- try of Old World Primates. The upper dentition from the Abbey Wood locality (PI. la ; B.M.N.H., M-I5I45)— quite apart from its occluding well with the type lower dentition of Cantius eppsi (both are of the right side) — shows definite omomyid affinities to about the same degree as do the lower teeth. Hence there is little reason to doubt that it can be assigned to Cantius eppsi. Taken as a whole, this upper dentition is close to that of Omomys and of Teilhardina but is one-half larger than that of either of these small Primates. P3 and P4 are rather simple teeth with a constriction between the inner and outer cusps and are similar in conformation to those of Omomys, Teilhardina and Hemiacodon. P3 has but a single outer and inner cusp and is smaller relative to P4 than in some specimens of Omomys. Both P3 and P4 are less crenulate than in Hemiacodon, but exhibit slight enamel wrinkling, particularly on the median slope of P4 protocone. P4 carries a small cuspule on the anterior slope of the outer cusp which occurs also in Hemiacodon and Washakius, but apparently not in typical Omomys. The anterior, median and posterior protocone crests of the P4 of Cantius are situated about as in Washakius (see Gazin 1958, pi. 9, No. i). An interesting similarity of Cantius to necrolemurines (and to Tetonius as well) is that the posterior protocone crest of M1 and M2 turns down toward the posterolingual part of the basal protocone cingulum, thus breaking the ridge running toward the metaconule. This forms a so-called " nannopithex-fold ". There is, however, practic- ally no indication of an incipient hypocone element, other than a slight thickening of the posterolingual part of the basal protocone cingulum. As in other omomyids the para- and metaconules are distinct on all three upper molars. These elements are usually less well denned in notharctids. Also unlike notharctids Cantius lacks any suggestion of an upper molar mesostyle. Molar para- and metacones are connected by straight crests on their facing slopes, much as in Omomys and Washakius. Nearly continuous lingual and labial basal molar cingula in Cantius are also quite like those of Omomys. Another resemblance to Omomys, to Teilhardina, to some of the more generalized late Paleocene Primates particularly Navajovius, and also to Tetonius is the small size of the M3 compared to M1"2. Para- and metastyle elements are present, as in most omomyids, except on M3 metacone. The recent identification of an upper dentition of Protoadapis in the collections of the Geological Institute of the University of Halle /Wittenburg makes possible further comparative remarks about it and Cantius. Protoadapis, unlike Cantius, shows no indication in the upper molars of a nannopithex-fold, and the internal cingulum is typically pronounced and continuous around the lingual base of the protocone, the hypocone is large, and there is no indication of a metaconule on any of the upper molars, see PL 3. In these differences from Cantius, Protoadapis more closely resembles the notharctid Pelycodus. In conclusion, Cantius has not been found to exhibit any features of resemblance to notharctids or adapids not occurring in the North American Omomyidae, and in view of numerous similarities to Omomys and Hemiacodon it is assigned to the latter family. The dental formula of Cantius is apparently more reduced than in Teilhardina, but evidence regarding the exact number of antemolar teeth remains inadequate. 8 A NEW EOCENE PRIMATE GENUS, CANTIUS Cantius eppsi (Cooper) (PL i) 1932. Protoadapis eppsi Cooper, p. 461, pi. n, figs. 2, 3. HOLOTYPE. Right ramus of mandible with P3-M3 and partial alveolar borders of I3-P2, B.M.N.H., M-I3773. MATERIAL. B.M.N.H., M-I3773 (Holotype), B.M.N.H., M-I5I45, maxilla with P3-M3; B.M.N.H., M-i5i47#, mandibular fragment with Mj-Mg ; and B.M.N.H., M-I5I47&, mandibular fragment with M2_3. HORIZON AND LOCALITY. Blackheath Beds (Sparnacian) ; Abbey Wood, one and three-quarter miles east of Woolwich, Kent.1 DESCRIPTION. Lower dentition: Dental formula: 2(?).i.3(?).3. One small incisor alveolus, followed by a much larger canine alveolus, narrow anteroposteriorly and broad buccolingually. If only one premolar was present anterior to P3 it may have been two-rooted. Two-rooted P3 with crown lower than P4 and lacking distinct para- and metaconids. Para- and metaconids well developed on P4, connected to protoconid by crests ; well-defined central crest on talonid, running posteriorly along mid-line of tooth from protoconid and with small posterior cuspule ; P4 not molar- ized. Trigonid of Mx large, with three well-separated cusps ; paraconid and metaconid joined to protoconid by low ridges ; talonid much larger than trigonid with distinct ento- and hypoconid, small hypoconulid present on slope of posterior crest of hypo- conid. Outline of M2 (crown view) more nearly circular than that of Mx, as in Ourayia, Hoanghonius, etc. Mg trigonid broad transversely, narrower anteroposteriorly, with more closely approximated paraconid and metaconid than Mj. Paraconid and metaconid of M3 trigonid either coalesced as a single cusp (M-I3773) or closely approximated (M-i5i47# and 6). Upper dentition : B.M.N.H., M-I5I45 : P3~4 with slight constriction between protocone and outer cusp. P4 with small anterior cuspule, as in Hemiacodon. M2, M1, M3 ; no mesostyle or distinct hypocone on upper molars ; antero-internal base of molar protocone projecting most mesiad ; nannopithex-fold present on posterior slope of M1 and M2 ; paraconule and metaconule present on M1"3. II. REVISION OF THE SPECIES OF PROTOADAPIS LEMOINE History of Study Preparation of the foregoing section on the British early Eocene primate Cantius necessitated investigation of all the available material of Protoadapis. It soon became clear that species of this genus were much in need of revision. Unfortunately Stehlin's discussion of members of Protoadapis (1912 : 1284-1286) intruded some taxonomic confusion, as well as a misspelling of the generic name ; this was largely corrected by Teilhard (1921 : 66, 67, 88-91) but Stehlin's views, and additional misconceptions of dating quoted by Osborn (1890 : 55) have continued to 1 Dr. G. G. Simpson of Harvard University has suggested in a personal communication that the species of Hyracotherium from Abbey Wood indicate an earliest Eocene age for this fauna. This is also indicated by an M3 of Coryphodon from the same locality figured by Cooper (1932 : 459). A NEW EOCENE PRIMATE GENUS, CANTIUS Measurements (in mm.) of Cantius eppsi (Cooper) (All specimens in the British Museum of Natural History) Mandible : Depth of jaw beneath M2 Anteroposterior length of P3-M3 Anteroposterior length of Mx_3 Anteroposterior length of M2~3 Anteroposterior diameter of P3 Transverse diameter (trigonid) (talonid) M2 M, M2 M3 M! M2 M, Maxilla : M-I5I45 Anteroposterior diameter of P3 Anteroposterior diameter of P3 P4 M1 M2 M3 M-I3773 6-7 17-2 11-4 8-1 2-8 3'3 3-6 3-6 4'5 1-8 2-3 2-5 3'3 3'0 2-8 3'i 2-4 15-0 3-6 3'7 8-0 3-6 3'7 4'3 2-3 3-0 2-9 2-8 3'0 2'4 (Transverse diameter) 3'2 3-8 4'7 5'4 4'3 3-8 4'4 affect the literature on this primate. These errors were largely reproduced by Hill (1953 : 482-487). Further complications derive from the observation, made during a recent visit to the Halle /Wittenburg Geological and Paleontological Institute, that the holotypes of two Eocene Primates, " Europolemur " klatti and " Megatarsius obeli " described by Weigelt (1933) can be assigned with confidence to Protoadapis. As it was not possible for Weigelt (1933) to make direct comparisons with previously described fossil Primates some specific and generic assignments which might have been recog- nized for the Geiseltal species were not noted by him. In fact, at that time Weigelt probably could not have determined his two new genera as upper dentitions and skulls of Protoadapis, since the associated upper and lower dentition, G.P.I.H. 4310, discussed below, had not then been discovered. The assumption that species of this genus occur in the French Paleocene of Cernay and Rilly dates from an erroneous citation in Lemoine & Aumonier (1880 : 611) as stated by Teilhard (1921). * However, this misapprehension was repeated in Hill 1 Lemoine & Aumonier list a species of this genus, P. copei, as occurring in the Cernay Paleocene. It was not figured or described and is now lost, probably because Lemoine later referred the specimen to a different genus and species, not Protoadapis. io A NEW EOCENE PRIMATE GENUS, CANTIUS (1953 : 483). Lemoine later stated (1891 : 28) that this genus is restricted to the Eocene. D. E. Russell who is currently revising the French Paleocene faunas, informs me that it does not occur at Cernay. The recognition of several specimens of Protoadapis from the Middle Eocene Brown Coals of the Geiseltal, Germany, now in the collections at Halle, serves to date the earlier members of this genus better than the rather scanty and poorly associated Cuisian fauna with which the French specimens of Protoadapis curvicuspidens and " Protoadapis recticuspidens " were recovered. A further error in the literature on this genus is its recorded occurrence in the Belgian Eocene deposits (Hill, 1953:483). There is no real evidence for such a record, but a specimen of Protoadapis from the Quercy phosphorites of south-central France was, at the time of Teilhard's writing, in a private collection at Louvain and his reference to it may have led to this confusion of range. All the materials of this genus discussed by Lemoine, Stehlin, and Teilhard, as well as the specimens at Halle, belong (after the removal of " Protoadapis " eppsi) to no more than three species. Protoadapis recticuspidens Lemoine, 1878, is based (in spite of published remarks to the contrary) on a single specimen in which the teeth are so worn that only a few characters of M3 can be determined. This tooth, and the mandible, now in the Paris Museum, are distinctly smaller than are those of Protoadapis curvicuspidens (here designated as the type species of the genus) and it may not belong to Protoadapis. I would prefer to regard Protoadapis recticuspidens as a nomen vanum. As Teilhard stressed, the specimen called Protiadapis recticuspidens by Stehlin (1912, fig. 278) is actually P. curvicuspidens, the holotype of which is now in the Museum National d'Histoire Naturelle in Paris. It is on the basis of this specimen that the genus Protoadapis was first defined. TAXONOMIC REVISION Genus PROTOADAPIS Lemoine (Text-fig, i) TYPE SPECIES. Protoadapis curvicuspidens Lemoine (1878). (Unnumbered holo- type and two other specimens in National Museum of Natural History, Paris.) AMENDED DIAGNOSIS. Size : somewhat larger than Adapis parisiensis ; lower dental formula : i?.i.3.3. incisors missing in type but one or more alveoli appear to be present in other specimens ; canine large (alveolus) ; Pt absent, replaced by diastema ; P2 short with single pointed cusp, and with two obliquely situated roots, the anterior located more buccally. P3 distinctly larger, much higher and more pointed than P2 with nearly vertical anterior margin, no distinct paraconid or metaconid ; P4 lower than P3 (unlike Cantius) lacking paraconid, but with well-defined metaconid and talonid possessing central ridge ; molar paraconids reduced, but extending much more lingually than in Adapis, less so than in Cantius. Mj and M^ with small hypoconulid on posterior hypoconid crest ; M3 hypoconulid making up a distinct lobe ; length from P4 to M3 — 22 mm., depth of horizontal ramus beneath M2 from io to 12 mm. A NEW EOCENE PRIMATE GENUS, CANTIUS n DISCUSSION. Two French species of this genus are accepted here as valid, Proto- adapis curvicuspidens collected in Paris Basin deposits, perhaps of Cuisian age, and Protoadapis angustidens (Filhol, 1888) from the Quercy phosphorites (see Text-fig, i). Protoadapis brachyrhynchus Stehlin (1912) is clearly a synonym of the latter species, as Teilhard (1921 : 97) concluded. A third species, Protoadapis raabi, from the Middle Eocene Brown Coals of the Geiseltal, Germany, is slightly smaller than COMPARISONS OF MANDIBLES OF Protoadapis species A (ALL X 2 APPROX., INTERNAL ASPECT) Diagram of Protoadapis angustidens from ilhard (1921, pl.4. fig. 12 reversed) Protoadapis curvicuspidens from Teilhard (1921, pl.3, fig.5) GEOL. 7, I. Protoadapis curvicuspidens from Stehlin (1912, fig. 288) FIG. i. Species of Protoadapis Lemoine from French deposits. i§§ 12 A NEW EOCENE PRIMATE GENUS, CANTIUS P. curvicuspidens but does not differ greatly from it otherwise, in so far as these two species can be compared. Better materials may prove that the latter two " species " intergrade but pending such an eventuality, it is advisable to retain a separate species for the Geiseltal finds. SPECIFIC DIAGNOSES. Teilhard (1921) has published full descriptions of the two species of this genus from the French Eocene and consequently they will not be separately diagnosed here.1 Protoadapis klatti (Weigelt) (Pis. 2, 3) 1933. Europolemur klatti Weigelt, p. 123, pi. 4, fig. 5 ; pi. 6, fig. 4. 1933. Megatarsius obeli Weigelt, p. 141, pi. 4, fig. 4 ; pi. 6, figs. 1-3. MATERIAL. In addition to the holotypes of " Europolemur " klatti and " Mega- tarsius obeli " (No. 4234) ; numbers 4238, 4258, 4280, 4292 and 4310 of the collections of the Geological and Paleontological Institute of the University of Halle /Wittenburg are referable to this species. Some of these specimens were regarded by Heller (1930) as belonging to Adapis, but this genus does not occur in the Geiseltal fauna. DIAGNOSIS. A medium-sized primate — apparently about the size of Pronycticebus 2 . 1 . "3 . "3 or the Recent Potto, Perodicticus. Dental formula : .r-1— — '- — ; anterior lower incisor ?l. 1.3.3 not known (if present), I3 procumbent and spatulate ; C long and pointed with slightly developed posterior shelf — appearance about as in Notharctus, £ followed by diastema ; P2 two-rooted with simple pointed crown and posterior heel, lacking metaconid and protoconid ; P3 much higher than P2 and P4 and lacking protoconid ; P4-M3 as in Protoadapis curvicuspidens but smaller, Mx and M2 with distinct hypo- conulid on posterior slope of hypocone, M3 hypoconulid and entoconid large. I2 larger than I3, spatulate with crown anteromedially directed and somewhat procumbent ; I3 small and simple, may be separated from C by a diastema ; C much larger and longer than in Adapis, furrowed along its external face by anterior and posterior vertical grooves and followed by a diastema ; P2 less than half as large as P3, and with small protocone (two rooted) ; P3 and P4 with single ectoloph and large protocone ; M1 lacking mesostyle and metaconule, but with distinct para- conule and prominent internal and external cingula, internal cingulum with large hypocone, basal cingulum sometimes incomplete across internal face of protocone ; M2 slightly larger than M1 with more continuous lingual cingulum and larger hypo- cone ; M3 smaller than JVF-M2, lacking a distinct hypocone, but with pronounced internal cingulum. DISCUSSION. " Two " undescribed specimens in the Halle collection form a valuable basis for the clarification of the dental structure of Protoadapis. One of these G.P.I.H. 4310, from the Leonhardt Coal Mine (the locality of " Europolemur ") includes the left P4 through M3, the right M3 an associated right lower canine and M1"3 (M1"2 somewhat damaged) see PI. ^e,f. The second specimen, G.P.I.H. 4258 (PI. 2), crushed facial region with attached lower jaw fragment of the left side with I2 through P3 1 Protoadapis angustidens is larger and occurs later in time than P. curvicuspidens. A NEW EOCENE PRIMATE GENUS, CANTIUS 13 and I3 through P3 was also collected from Leonhardt Mine. The specimen card of No. 4310 states that these teeth probably belong to the same individual as No. 4258, and this association is reinforced by similarity of colour, wear, matrix, and the fact that the two specimens do not share any overlapping parts, which would rule out such a possibility. In any event, both are referable to Protoadapis and together they preserve almost the entire dentition intact. Dental comparisons indicate that the skull of " Europolemur " klatti belongs to the same species as the foregoing specimens and is therefore a synonym of Protoadapis. The holotype of " E." klatti (apparently lost during the last war) has upper molars of the same size and conforma- tion as those of G.P.I.H. 4310 (judging from Weigelt's published information) and in so far as these two finds can be compared, there is no basis for a specific distinction. Teilhard (1921, pi. 3, fig. 6) illustrated an upper left molar which he suggested might be of P. curvicuspidens ; this is confirmed by the Halle specimens. Because of crush- ing, measurements on Brown Coal fossil Primates, other than on teeth, are not very reliable and thus have reduced value when drawing taxonomic distinctions. However, the length of P4-M3 series of Protoadapis klatti is about 15 mm. in the type and the length of P4-M3 in G.P.I.H. 4310 is about 17*2 mm. Similar measurements for Cantius eppsi are 14' 2 and 15*1 mm. respectively. Regarding the teeth of " Megatarsius obeli " from the Cecilia Coal Mine (locality Leichenfeld II), as Weigelt noted (1933 : 142) : " die Beschaffenheit der Kronen 1st eigenartig stumpf , als wenn die oberste Schimelzchicht fehlte . . . ". There is no doubt that this condition is due to post-mortem chemical absorption of the enamel and some of the dentine of the canine and P4 through M3 of the right side (all of the dentition that remains in " Megatarsius "). This sort of erosion of fossil teeth is quite common in early Cenozoic mammals. Neither Heller (1930) J nor Weigelt (1933) appear to have taken into account the fact that many of the Geiseltal Primates have lost almost all significant dental characters in this way. Such erosion also explains the extraordinary appearance of the canine of " Megatarsius " figured by Weigelt (1933, pi. 6, fig. i). In this tooth, the enamel and much of the dentine of the crown has been removed and there has also been erosion around the base of the tooth. The odd basal cingulum and the whole appearance of the tooth is unreal misleading. In " Megatarsius ", G.P.I.H. 4234, the upper dental formula is the same as in G.P.I.H. 4258-5310, Protoadapis. Furthermore, the eroded crowns of M1 and M2 show metaconule and mesostyle absent, but paraconule present, and allowing for the reduction in size caused by enamel erosion, M1"3 of " Megatarsius " are of appropriate size for Protoadapis klatti. For the writer, no doubt remains that " Megatarsius " is referable to P. klatti. In any case, G.P.I.H. 4234 is not adequate as a type specimen, and if not Protoadapis would be a nomen vanum. Weigelt's discussion of the skulls of " Europolemur " and " Megatarsius " describes adequately these much damaged specimens. In overall morphology the skull of Protoadapis is more like that of Pronycticebus than of Adapis. With Pronycticebus, 1 Heller's holotype of Adapis minimus is an indeterminate specimen for the same reason, all of the enamel having been removed by chemical solution. i4 A NEW EOCENE PRIMATE GENUS, CANTIUS it shares a comparatively shorter rostrum, larger orbits, more slender zygoma, P4 with a single outer cusp and two-rooted P2, but differs in having lost P i/i. " Mega- tarsius " has a broad interorbital septum about i cm. wide and resembles that of Pronycticebus in the disposition of the medial end of the supraorbital margin. On the antero-dorsal face of this skull between the temporal crests is a broad and slightly depressed area. The temporal ridges converge to the mid-line about 2 '25 cm. behind the posterior end of the nasals. Conformation and extent of the nasals can be deter- mined in G.P.I. H. 4234. These bones are slightly expanded posteriorly as in Pronycti- cebus. The orbital region is much crushed and, consequently, the lacrymal foramen cannot be located, but fragments suggest that the post-orbital bar was more slender than in Adapis. Relationships of Protoadapis Now that both the upper and lower dentitions and something of the skull are known in Protoadapis, it takes a more significant position in early Primate history. Placement of this genus as a typical lemuroid primate seems beyond doubt, and in fact it is the only Old World early Cenozoic form which has the same dental formula as any of the living lemuroids, although it lacks the specialized tooth comb below which is typical of the latter taxon. Being older, and yet having a more reduced dental formula, it cannot be near the lines which gave rise to such Eocene lemuroids as Adapis, Pronycticebus and Notharctus. Perhaps its greatest similarities are with Pelycodus and Pronycticebus which, however, retain P I/I. In Pelycodus the manner of hypocone formation may also be different. Some specimens of Pelycodus, for instance A.M.N.H. 15022 (see Gregory, 1920, pi. 35), appear to have an incipient hypocone on the basal cingulum and at the same time another " pseudohypocone " developing from the nannopithex-fold on the posterior slope of the protocone. In the line leading to Notharctus the hypocone derived from the basal cingulum is suppressed, while in Protoadapis the nannopithex-fold is absent. The nearest known upper molar morphology that could give rise to both these patterns is that of Cantius but this form is too late to be ancestral to Pelycodus and its dentition too generalized for classification with the adapids. As suggested by Teilhard (1921), Simpson (1940), and others, Protoadapis shares with the North American notharctids many of the features which distinguish the latter group from the Adapidae. The upper dentitions and the anterior teeth preserved at Halle add somewhat to this conclusion, but in several respects this primate tends to link adapids and notharctids as Cantius links the omomyids with the latter families. In view of dental similarities with Caenopithecus and Pronycticebus, together with its European provenance, Protoadapis is here referred to the Adapidae. III. NOTES ON PRONYCTICEBUS GAUDRYI GRANDIDIER (Text-fig. 2) The unique skull and mandibular fragment of Pronycticebus was discovered in 1893 and reported, in the original studies of Grandidier (1904, 1905), to be of Bar- tonian, late Eocene age, from Memerlein-le-Quercy in south-central France. The Abbe Rene Lavocat has suggested in a personal communication to the writer that A NEW EOCENE PRIMATE GENUS, CANTIUS 15 judging from his studies of mammals of Oligocene provenance, there is a similarity in the colour of bone and matrix of this specimen to those of the European Oligocene. This interesting observation implies, at least, that Pronycticebus may be from the latest levels of the Quercy caves. If so, it could be of Stampian Oligocene provincial age. Pronycticebus has long been a difficult form to assess taxonomically, due in part to the lack of specialization of the teeth and the presumed absence of a post-orbital bar. Grandidier originally suggested affinities with the living lorisiform Primate Nycticebus, hence its generic name. This view has some merit. Subsequently Gregory (1920) and others held that the species has tarsioid affinities. This conclusion appears to have been based largely on the brachycephaly of the skull (considerably more pro- nounced that in Adapis or Notharctus) and which, at the time of Gregory's writing, was rivalled in degree, among Eocene Primates, only by Necrolemur skulls (also from Quercy) and by a fragmentary skull, lacking dentition, from the Middle Eocene of North America described by Granger & Gregory (1917) as " Aphanolemur gibbosus ". Gazin, in a revision of the Middle and Upper Eocene Primates of North America (1958), has shown that Aphanolemur is a synonym of Smilodectes. Several specimens figured by him indicate that expansion of the brain case in the latter primate (appar- ently closely related to Notharctus) has reached about the same level as in Pronycti- cebus. Skulls of Smilodectes, and to a lesser extent of Notharctus, demonstrate, therefore, that the degree of brain expansion which occurred in Pronycticebus was not unique among Eocene lemuroids. Protoadapis, judging from the crushed skulls at Halle, also had a rather large brain. On other grounds, Le Gros Clark's careful study (1934) of the cranial anatomy of Pronycticebus has already demonstrated that this genus is not a tarsioid, a position recently re-affirmed by Piveteau (1957 : 55, 56). Re-examination of the Evidence Orbital Region It is, perhaps, an amusing commentary on the nature of appraisal of fossil speci- mens that the zygomatic arch of the one known skull of Pronycticebus can be said to have been " evolving " almost continuously since Grandidier 's original studies on this primate in 1904 and 1905. Apparently some time before the original description, the zygomatic arch was buried in a thick layer of plaster of Paris, which closely resembles the colour of the original bone. In 1934 Le Gros Clark remarked that the zygoma was not quite as broad as is indicated in Grandidier's illustrations and figured a narrower arch. Piveteau's plate (1957 : 61) shows a still more slender arch. In the same year, the writer was able to remove most of the remaining plaster which exposed a yet more gracile arch and the very distinct base of a post-orbital process (Text-fig. 2). Furthermore, the region of the frontal attachment of the post-orbital bar shows distinct fractures on both sides of the skull, where the bar has been broken off. The cross-sectional extent of this area is shown by hatching in Text-fig. 2. One can clearly distinguish the broken surface, and although this area of attachment is not very extensive in the vertical dimension, this correlates well the slender zygoma, 16 A NEW EOCENE PRIMATE GENUS, CANTIUS FIG. 2. Dorsal and lateral views of the skull of Pronycticebus gaudryi (Holotype), Hatching indicates broken surfaces, stipple missing parts. In dorsal view, right side restored from left. A NEW EOCENE PRIMATE GENUS, CANTIUS 17 found under the plaster, and with the much enlarged orbit indicated by the remaining median part of the orbital margin.1 Living and fossil Primates with comparatively large orbits often have a slender post-orbital bar and a thin and flaring zygoma, as in Galago and Necrolemur. In fact, in some Galago species, the temporal base of the post-orbital bar in cross-sectional area is less extensive (when compared to total skull size) than is this area in Pronycticebus. In view of the observed presence in Pronycticebus of both a frontal and a zygomatic base for the post-orbital bar, the large brain compared to Adapis, the complete absence of any evidence that other primates of the grade of advance seen in Pronycti- cebus lack the post-orbital bar, and the suggestion that enlarged orbits do sometimes correlate with relatively small frontal areas of attachment for the bar, no basis now remains for thinking that the bar was not continuous. Text-fig. 2 presents a conjec- tural restoration of its position. Le Gros Clark (1934 : 20-27) noted most of the observable characters in the skull of Pronycticebus and discussed occurrences of many of these features in other Primates. The numerous new fossil primate specimens, which have been discovered or restudied since that time justify further comparison of some of these structures. Contrary to the current assumption Pronycticebus gaudryi is not a conservative form. With existence of a post-orbital bar in this species established, little remains to be seen in it that is particularly primitive for an Eocene primate. In fact, the expansion of the brain case, the large, forward-directed eyes and the short rostrum are all features that have been considered " advanced ". Location of the lachrymal foramen, together with part of the lachrymal bone, outside the orbit in Pronycticebus was suggested as a difference from Adapis by Le Gros Clark (1934). However, a specimen of Adapis magnus, P U. 11481, indicates that in this species the position of the foramen and forward extension of the lachrymal may sometimes be about as in Pronycticebus. In Malagasy lemurs the lachrymal foramen typically lies further outside the orbit than in the foregoing, while in living lorisines, and the potto in particular, the position of foramen and lachrymal is about as in Pronycticebus, except for the smaller size of the lachrymal itself. Necrolemur (M.C.Z. 1179) and Tarsius have also a facial location of this foramen, but in Smilodectes , Notharctus and most platyrrhines this foramen clearly lies within the anterior orbital margin, as in pongids and man. In this character it would seem that Adapis and Pronycticebus approach more closely the living lemuroids than they do members of the Notharctidae and Anthropoidea. Forsyth Major (1901 : 151) concluded that the primitive condition for Primates is to lack a great facial expansion of the lachrymal. Shape and position of the foramen and lachrymal in Pronycticebus appear to be equivocal in relating it either to living lemurids or lorisids. Rostrum The comparatively foreshortened face of this primate is evident from the parts preserved. A vertical position of the premaxillo-maxillary suture (as well as the anterior recurving of the alveolar border around the canines) indicates that the missing 1Relative to skull size Pronycticebus has larger orbits than most, if not all, other early Tertiary Primates. This may indicate nocturnal habits. i8 A NEW EOCENE PRIMATE GENUS, CANTIUS anterior tip of the skull can hardly have been much longer than the conjectural reconstruction shown in Text-fig. 2. The sharp constriction in transverse diameter of the rostrum immediately posterior to the canines in Pronycticebus is not as distinct in living lemurs and is absent in Adapis. However, this feature can be seen in Loris and Nycticebus, and is one of the reasons why this skull is reminiscent of that of Nycticebus coucang. Dorsal Aspect of Skull Cleaning of the skull has revealed sutures on the top of the brain case more clearly, and allows further comparison of this aspect of the skull in Pronycticebus with that of Adapis. Unlike Adapis, in Pronycticebus the posterior margins of the f rentals extend on to the anterior part of the brain case. A sinus canal, near the posterior extremity of the parietal, is single in Pronycticebus, but in Adapis parisiensis it is multiple, as noted by Le Gros Clark (1934 : 22) and indicated by Stehlin's figures (1912). A large size for this canal has been said to be a primitive feature. After cleaning, sutures can be determined in Pronycticebus delimiting paired interparietals and (posterior to the sinus canal) small accessory ossicles (see Text-fig. 2). These bones have not been reported as occurring in Adapis. Taken as a whole the dorsal aspect of the brain case of Adapis does not closely resemble that of Pronycticebus. Such distinctions suggest that by the Middle or Late Eocene (the exact time range for both forms is uncertain) these two lemuroids had already diverged considerably. Such an assumption is reinforced by distinctions in other skull components, discussed above, such as the different shape of the muzzle, divergent character of the dentition, and difference in position and size of the orbits in these two Primates of the Quercy phosphorites. At present, it is probably better to retain them in the same family, as has been done by Hill (1953) and Piveteau (1957). Nevertheless, Pronycticebus and Adapis are as distinct morphologically as forms from the North American Eocene currently placed in different families, for example the notharctid, Pelycodus, and omomyid, Ourayia see Simons (1961^:5). Apart from the construction of the inside of the auditory bulla the basicranium of Pronycticebus was fully described by Le Gros Clark (1934). It will not be reconsidered in detail here. A possible alternative for an identification made by him (1934 : fig. 3) is that the foramen indicated as the hypoglossal canal may be the inferior petrous sinus. On obtaining permission to examine the interior of the auditory bulla it was determined that the ectotympanic is not tubular, thus completely confirming, in this regard, Le Gros Clark's thesis that this primate is not a tarsioid. It is noteworthy that the annulus lies very near the external auditory meatus and, unless it has been displaced, appears to be fused with the bulla wall in its posterior third, just internal to the posterior rim of the external meatus. From this point the annulus arches inward and downward, so that its ascending anterior limb lies some distance from the antero-lateral wall of the bulla. Near the ventral extremity of the ring (and external to it) is a shelf on the lateral bulla wall for the support of the annulus membrane. Compared to that of Adapis this shelf is quite small. Hill (1953 : 113) figures a dissection of the auditory bulla of Loris tardigradus which indicates only A NEW EOCENE PRIMATE GENUS, CANTIUS 19 slightly greater reduction of the annulus. The position of the tympanic ring in Pronycticebus, close to the external meatus, is an additional indication that Grandidier may have been nearer the truth than has sometimes been thought, when he suggested an affinity between this species and the modern lorises. Dentition It was principally because of the somewhat enlarged brain and generalized charac- ters of the dentition (resembling teeth of Anchomomys a supposed tarsioid), that such students as Stehlin (1916 : 1422), Gregory (1922) and Abel (1931 : 186) referred this primate to the tarsioids. Founding his conclusions principally on characters of the skull Le Gros Clark demonstrated that this primate cannot be considered a tarsioid. However, it may not have been sufficiently stressed that the dentition also, although unspecialized, is not Tarsius-like. Some principal reasons why this dentition does not indicate tarsioid relationships are as follows : The cross-sectional area of the upper canine base is considerably greater relative to adjacent teeth than it is in Tarsius while in necrolemurines the upper canine is even smaller proportionately than in Tarsius. Tarsiids, with the possible exception of Nannopithex, lack the P1 present in Pronycticebus. The latter primate, like Adapis, Protoadapis, Anchomomys and Progalago, has two-rooted second premolars above and below, while in tarsiines, these teeth are always single-rooted. In configuration of the remaining teeth Pronycticebus closely resembles Protoadapis, but differs from it dentally in having a less well-developed lingual cingulum on the upper molar protocone, and a more reduced M2_3 paraconid. However, these are rather slight distinctions, known to be variable in other primate species.1 Otherwise, these two forms agree in such features as the absence of mesostyles, and of a distinct hypocone on M3 (although it is well developed on M1 and M2). Also, they are closely similar in proportion and size. It is just possible that better specimens might even show that species of these two types of Primates are not separable generically. Unlike tarsioids, Pronycticebus has, as Simpson (1940 : 202) remarks (with reference to Caenopithecus) " open trigonids and the peculiar mode of paraconid reduction so characteristic of Adapis and its close allies and unknown among any forms of really probable tarsioid affinities ". Cranial Proportions A logarithm of ratio diagram (Text-fig. 3) indicates graphically the close similarity in linear proportions between Pronycticebus and Nycticebus and in contrast to those of an early Cenozoic lemuroid species Adapis magnus? and a Recent Malagasy lemur.2 1 Even in Protoadapis, as is indicated by isolated upper molars from the Geiseltal coals at Halle, the lingual protocone cingulum of the upper molars is sometimes incomplete, as it also is in Pronycticebus. 2 Measurements indicated in Text-fig. 4 are as follows : (i) Transverse diameter from mid-line of skull to greatest flare of zygomatic arch. (2) Length of skull, from posterior margin of canine to anterior margin of foramen magnum. (3) Length of skull from posterior margin of canine to posterior extremity of skull. (4) Length of dentition from anterior face of canine to posterior edge of M3. (5) Greatest transverse width of dentition. (6) Greatest transverse diameter of the cranium. (7) Least post-orbital diameter of skull. (8) Length from posterior margin of the canine to end of hard palate. (9) Length from anterior margin of canine to point of least post-orbital diameter. (10) Length from point of least post-orbital diameter to posterior tip of skull, (n) Greatest diameter of orbit from base of post-orbital bar to opposite rostral orbital margin. (12) Greatest transverse diameter across auditory bullae. (13) Greatest transverse diameter across canines. (14) Least transverse diameter of muzzle across upper second premolars. 20 A NEW EOCENE PRIMATE GENUS, CANTIUS The major differences between Nycticebus and Pronycticebus are in plots 4, 7, and 8. Measurement number 4, the length of the upper teeth might be expected to be less in Nycticebus as its dental formula is more reduced, and the same would apply to measurement number 8, the approximate length ol the hard palate. Measurement Pronycticebus Nycticebus 2 3 4 5 6 7 8 9 10 II 12 13 14 L -.40 Ada pis (standard) fLemur \ \ v *"^"**^w& \. I I I I I I I I I I — I — I — I — I — I — I — I -.35 -.30 -.25 r20 -.15 -,IO-:05 0 +.05 +.10 +.15 +.20 +.25 +.30 +.35 +.40 +.45 FIG. 3. Logarithm of ratio diagram comparing cranial proportions in four prosimians ; Adapis (standard). Mean, and extremes of range are indicated for a sample of ten Nycticebus coucang. number 7, the least post-orbital diameter of the skull (much smaller in Pronycticebus) is a primitive feature, correlated with a comparatively unexpanded brain, and is common to all Eocene lemuroids. In the remaining measurements Pronycticebus falls within (or very close to) the range of size variation of a small sample of the living lorisid Nycticebus coucang (10 individuals) . CONCLUSIONS Perhaps all the above-mentioned similarities are due to parallelism produced by similar adaptations in Pronycticebus and lorises, but such a view appears to be rather A NEW EOCENE PRIMATE GENUS, CANTIUS 21 strained. A more likely conclusion is that Pronycticebus does have some relationship to the radiation which produced extant Lorisiformes. Nevertheless, because of many primitive structures also shared with the contemporary Adapis and Protoadapis it seems best not to remove this genus from the Adapidae, at present. IV. THE TAXONOMIC POSITION OF ANCHOMOMYS STEHLIN (1916) (Text-fig. 4) This rather small primate, originally described by Stehlin (1916) occurs in deposits ranging from early Lutetian to early Ludian age in Europe. Four species have been proposed, differing little in known parts except for size. Taxonomic placement of this genus has varied considerably. Abel (1931 : 175) and others considered it a tarsioid, but Simpson (1940 : 202) quite correctly pointed out that such an assignment was most improbable. Of European Eocene lemuriforms the closest dental resemblances to Anchomomys are to be seen in Pronycticebus and Caenopithecus, but because of a common simplicity in cusp pattern their similarities can, perhaps, be over-emphasized. In some respects these three genera also resemble Adapis, particularly in type of paraconid reduction, but all three differ from Adapis in having M3 hypoconulid much more distinctly set off as a separate lobe from the hypoconid. They also lack the bicusped ectoloph of P4 and continuous lingual upper molar cingula seen in Adapis. For Anchomomys the closest dental resemblances appear to be with a Miocene lorisiform of Kenya, Progalago. In fact, in spite of the differences in time and place of occurrence of the species belonging to these two genera, some of the European Eocene forms, particularly Anchomomys quercyi, can hardly be distinguished generic- cally, on the basis of parts preserved, from Progalago dome. Species of these genera also overlap as far as size is concerned and similarities in the lower molars are particu- larly striking. Both exhibit reduced paraconids, well-developed entoconids, a large M3 hypoconulid, with remaining molar cusps of closely corresponding shape and situation relative to one another. Both these prosimians also display in the major molar cusps a fairly distinctive angular or pyramidal form. The upper molars of Anchomomys are quite like those of Progalago although in some, but not all, species of Anchomomys the paraconule and metaconule are more distinctly developed. In Progalago dorae and Anchomomys quercyi the latter two cusps are absent, see Text-fig. 4. These two species are alike in having a subquadrate M1 with large hypocone, more triangular M2 with smaller hypocone and lack a distinct M3 hypocone, see Text-fig. 4 ; Le Gros Clark (1956, pi. i) and Stehlin (1916, figs. 327, 328, 332). Moreover, at least one specimen of Progalago dorae (Le Gros Clark & Thomas, 1952, pi. 3, fig. 9) shows that in this species the P2 was a much elongated and two-rooted tooth. If the same applies to the maxilla of Anchomomys quercyi figured by Stehlin, and shape of the anterior alveoli strongly indicates this possibility, then the upper dental formulae of both species are identical, at least from the canine posteriorly. Perhaps the best preserved skull of Anchomomys is that of the unnumbered holotype of Anchomomys latidens (now in Paris) described by Teilhard (1921 : 13} 22 A NEW EOCENE PRIMATE GENUS, CANTIUS from the Quercy phosphorites and identified as " Rossignol Collection 1893 : n ". The specimen is much broken and distorted, but careful preparation could probably expose more of the cranial anatomy. As in Pronycticebus and Progalago there is a single large infra-orbital foramen above P4. The anterior root of the zygoma appears to arise about M2, and through this anterior root opens to the rear a relatively large posterior infra-orbital canal. On the antero-dorsal surface posteriorly converging FIG. 4. — Comparison of upper dentition in Anchomomys and Progalago. A. Progalago sp.. [Diagram after Le Gros Clark, 1956, pi. 4, fig. i.] Right maxilla, reversed, xy-5 approx. B. Anchomomys quercyi. [After Stehlin, 1916, fig. 332.] XJ'5 approx. temporal ridges are evident, but the dorsal insertion of the post-orbital bar cannot be distinguished. Between these temporal ridges, there is a broad depression, appear- ing rather as does this area in Pronycticebus. An apparently distinctive feature of Anchomomys latidens is the character of the surface of the temporal bone which is covered by numerous minute foramina, a condition certainly not to be seen (to this extent, if at all) in Adapis or Necrolemur. At the back of this skull are well- developed nuchal crests. These are typical of Eocene Primates and their presence is consistent with the retention of similar strong ridges in this position in Progalago. A NEW EOCENE PRIMATE GENUS, CANTIUS 23 Taxonomic Position Stehlin (1912 : 1426) tended to favour the idea that Pronycticebus and Anchomomys have about the same relationship to the Galagidae [" Nycticebiden "] as Adapis has to the lemuriform lemurs, but remarked that until the position of the carotid foramen and situation of the extotympanic was revealed for one of these Primates their taxonomic position would remain uncertain. Now that the annulus of Pronycti- cebus is known to show a possible foreshadowing of the condition seen in lorisiform Primates, Stehlin's analysis is strengthened. The subsequent placement of these two genera among the tarsioids, proposed for Anchomomys by Teilhard (1921),, and for both Pronycticebus and Anchomomys by Gregory (1922) and Abel (1931) can now be seen to have marked a step backward in determination of their relation- ship to other prosimians. Teilhard, although stressing tarsioid relationships for Anchomomys latidens, did however remark (1921 : 16) : " Tout au plus pourrait-on le rapprocher des Galago pour le developpment de 1'hypocone et la tendance a la molarisation de P 4 . . . ". This observation is important taxonomically because the fourth upper premolar in species of the genera Anchomomys, Progalago and Galago has an interesting similarity in basic plan, in addition to the other features of resemblance between these genera mentioned above. The view that these forms were tarsioids was rejected by Simpson (1940) after Le Gros Clark's study of the cranial anatomy of Pronycticebus, but since then their position among the non-tarsioid Prosimii has remained uncertain. The very close dental relationship between Anchomomys and Progalago, and the similarities which the latter in turn has with living lorisoids reinforce the idea that this phylum can now be traced back with a fair degree of accuracy as far as the European Middle Eocene. V. RELATIONSHIPS OF EARLY TERTIARY LEMUROID PRIMATES The Concept of " Lemur vid " Primates One objective of the research reported here and in Simons (1961) has been to determine whether tarsier-like and lemur-like Primates can be distinguished in the early Cenozoic. For at least one subfamily of this period, Necrolemurinae, a definite relationship with Tarsius is indicated. Most remaining Paleocene and Eocene Primates have (or should have) been termed " lemuroid " in the past. A great many fossil genera have consistently been classified as tarsioid when there is no basis, in known parts, for so doing. If one examines the better known lemuroid Primates they seem to be of four general kinds, as follows : (i) Species on the border-line between Primates and Insectivora as these orders are currently understood, of the families : Amphilemuridae Microsyopidae Apatemyidae 24 A NEW EOCENE PRIMATE GENUS, CANTIUS (2) Specialized Primates of early extinction. Forms too specialized dentally to be near ancestral lines of later stocks : Families : Plesiadapidae Carpolestidae Anaptomorphidae [in part] Paromomyidae [ — Phenacolemuridae, in part] (3) Relatively generalized groups that could be near the ancestry of some living families, but which show no convincing evidence of having reached a tarsioid, or higher, grade of advance. Families : Adapidae Notharctidae (4) Generalized Primates, possibly close to the stocks which gave rise to living groups, but which are not well enough known to indicate their grade of advance. Omomyidae perhaps some [paromomyids and anaptomorphids] Past usage has roughly equated the term lemuroid with at least some members of each of the four groups of extinct families listed above. Such usage implies, however, that all these types can be assigned to the Lemuridae, which is not the case. On the other hand, it is surely valid to assume that the ancestral stocks of all the groups which have advanced beyond the lemur-like state (represented today by tupaiids and lemurids) went through such a level of advancement, and consequently their ancestors of the early Cenozoic can correctly be called lemuroid or lemur-like. Obviously then, among fossil forms that are distinctly lemuroid may be found ancestors of the more advanced Primates : tarsioids, and anthropoids. Some members of the above families do foreshadow tarsioids. For instance, Navajovius of the Tiff an- ian Paleocene of Colorado and Teilhardina of the Sparnacian Eocene of Belgium, both exhibit interesting dental resemblances to the European Middle Eocene tarsiid, Nannopithex, while the only skull with advanced (or tarsioid) features ever discovered in North America (Tetonius ; A.M.N.H. 4194) also possesses upper molars that, together with a general similarity of detail, share with those of Nannopithex an unusual feature, the nannopithex-fold. At present these four genera are assigned to three different families, viz. Navajovius and Teilhardina . Omomyidae (Simpson, 1940 : 208) Nannopithex .... Tarsiidae (Simons, 1961 : 61) Tetonius . . . . Anaptomorphidae (Gazin, 1958 : 73) Dental variation among these primates is not as great as their assignment to different families implies, being in most ways far less than seen in the Malagasy family Lemuridae. Yet, until better cranial remains are known for some omomyids, paro- momyids and anaptomorphids it will remain difficult to judge whether or not these A NEW EOCENE PRIMATE GENUS, CANTIUS 25 groups show the same definite indications of tarsioid relationships in their osteology than they do in their dental anatomy. All these most interesting Primates fall within the fourth group listed on p. 24. In regard to the first three groups primatolo- gists are on safer ground, for they are either so primitive dentally that tarsioid relationships cannot be considered or they are known from skulls that show no convincing tarsioid features. In the broadest sense it appears reasonable to call these forms lemuroid, and it is with them that the following paragraphs will be concerned. Border-line Primates A mphilemuridae This family, proposed by Heller (1935) for the reception of Amphilemur eocaenicus from the Middle Eocene deposits of the Geiseltal, has recently been assigned to the Erinaceoidea (Insectivora) by McKenna (1960 : 58). To this subfamily McKenna also assigns, among others, the following North American Paleocene and Eocene genera : Entomolestes , Macrocranion and Sespedectes. As far as Primate classification is concerned, this procedure is not likely to improve the taxonomy of the genera involved, for the type of Amphilemur cannot be located at Halle, and if lost makes an unsatisfactory choice as the type genus of a subfamily known otherwise only in the New World, and to which it may not belong. Both Simpson (1945) and Hill (1953) refer Amphilemur to the Adapidae, incertae sedis. In its poorly-known state, now entirely dependent on Heller's text and figures, there is little basis for placing it elsewhere. In Adapis parisiensis the lower canine is often very small and otherwise the antemolar teeth exhibit gradual and nearly unbroken size-decreases from back to front, which is not unlike the size sequence of these lower teeth in Amphilemur and which shows that the same general kind of tooth proportions seen in Amphilermir can occur in a primate. Microsyopidae McKenna (1960 : 76) has re-defined this family so as to include the following genera : Microsyops, Craeseops and Cynodontomys. His view, that this family belongs among the Primates appears to have sound justification. He is of the opinion that the nearest affinities of the Microsyopidae, as re-defined by him, are with the more primitive plesiadapids of North America. Moreover, he remarks (1960 : 78, 79) while discussing Microsyopidae : " Recently Hiirzeler (1948^, pp. 343-356) has described a new genus and species, Alsaticopithecus leemanni, from the Lutetian of Alsace, based on excellent dental material. The animal was placed in the Primates incertae sedis. Alsaticopithecus appears to me to be a microsyopid ... As Hiirzeler notes, the genus is indeed primatelike. Thus Alsaticopithecus has a bearing on the problem of microsyopid origins. The genus is an interesting extension of the known statigraphic and geographic range of microsyopids." In view of this assignment of Alsaticopithecus, taken together with what is now known of microsyopid anatomy, including cranial material, soon to be reported on 26 A NEW EOCENE PRIMATE GENUS, CANTIUS by McKenna, Hiirzeler's conjecture that this form has significant dental resemblances to Anthropoidea is no longer tenable. Apatemyidae The series of genera now assigned to this family were first clearly distinguished from plesiadapids by Jepsen (1934). Although they are retained provisionally in the order Primates by Gazin (1958), research on the basicranium reported by Hiirzeler (1949 : 485) indicates that this group is almost certainly not to be referred to the Primates, as the order is now defined. Notwithstanding this, the apatemyids may have had their origin in the same eutherian stock from which the Primates arose — a conclusion which is indicated principally by molar-pattern resemblances. They certainly have no close connection with Paleocene- Recent Primates and will not be considered further here. Specialized Lines of Early Extinction A number of divisions of the order of family and subfamily status, which became extinct before the end of the Eocene, exhibit such pronounced dental specializations that it is clear they could not be near the ancestry of any living Primate species. Of these, the carpolestids are the least well understood, but conformation of the fourth lower premolar alone (elongate and saw-like) removes them from consideration as ancestral to surviving lines. The same applies to plesiadapids, and to Phenacolemur1 because of the marked reduction of their anterior dentition. Even so, Plesiadapis is of interest because of its geographical distribution. Species of this genus are known from the late Paleocene of both Europe and North America. This occurrence demon- strates that climatic conditions as well as the requisite land-bridges, allowing not only other mammals but prosimians to communicate between these two continents then existed, and helps to explain the presence of omomyids, microsyopids and possi- bly other primate families, in both continents in the early Eocene.2 Among the plesiadapids, carpolestids, and paromomyids the cranial and post- cranial anatomy is poorly known except in two species of Plesiadapis. The limb bones of Plesiadapis studied by Simpson (and greatly amplified by undescribed specimens recently collected by Russell in the Cernay Paleocene deposits near Rheims in central France) are primitive, but can be spoken of as lemur-like. Russell (1960) briefly reported on a remarkably well-preserved skull of Plesiadapis from the Cernay region. This is the oldest primate skull yet to be described. The skull of Plesiadapis is very broad, flat, with a small brain-case, while the premaxillaries are enormously expanded and make up most of the muzzle. Elsewhere, among Primates such expanded premaxillaries occur only in the Madagascan lemur Daubentonia. However, a relationship with the latter is excluded by the presence in Plesiadapis, but not in Daubentonia, of a tubular ectotympanic element. Finally, it is clear that in Plesiadapis there is no post-orbital bar, nor any indication of post-orbital processes. 1 Here regarded as a paromomyid, following McKenna (1960 : 70). 2 Basically all living prosimians are tropical forest dwellers. Uniformitarian reasoning would suggest that their early Cenozoic forerunners were also warm-climate animals. A NEW EOCENE PRIMATE GENUS, CANTIUS 27 From this feature of the Cernay Plesiadapis skull it must be concluded that the basal stock of the order lacked the post-orbital bar, although it occurs in all other undoubted Primates (for which this part of the skull is known) with the single exception of Anagale from the Oligocene of Mongolia. The families Anaptomorphidae and Paromomyidae are known only from North America. In terms of present knowledge, they include the most likely candidates for a relationship with the rise of tarsioids and of surviving higher Primates, possibly by way of containing forms ancestral to the omomyids. Regrettably members of these families, with the exception of Tetonius, are known only from dentitions, and consequently, little can be said as to whether they are lemur-like or tarsier-like. The same is true for omomyids. Nevertheless, dental analogies suggest that some of the species referred to these families were at least transitional to the tarsioid grade and such an assumption is further indicated by the large, forward-directed orbits and expanded brain of Tetonius. VI. REVISED CLASSIFICATION OF EUROPEAN EOCENE PRIMATES Revisions included here, in Simons (1961), and in a number of other works published since Simpson (1945) now make it possible to assign taxonomically certain European early Cenozoic Primates formerly listed by Simpson as incertae sedis, as well as to transfer others for which a better placement can be supported. The most recent extensive treatment of these forms is by Hill (1953, 1955), but Hill's taxonomy is clearly synoptic and no revision of fossil prosimians is included in these works. The following section, therefore, attempts to bring the classification of the fossil Primates of Europe up to date. Genera to be considered here are listed in Simpson (1945) as follows : Plesiadapidae : Megachiromyoides Weigelt, 1933. M. Eoc.; Germany. Adapidae incertae sedis : Caenopithecus Riitimeyer, 1862. M. Eoc.; Switzerland. (?) PROSIMII of uncertain infraorder or family : Ceciliolemur Weigelt, 1933. M. Eoc.; Germany. Europolemur Weigelt, 1933. M. Eoc.; Germany. Megatarsius Weigelt, 1933. M. Eoc.; Germany. Microtarsioides Weigelt, 1933. M. Eoc.; Germany. Two additional Eocene Primates from Europe described by Hiirzeler (1946, 1947) are also discussed in the following pages. Gesneropithex peyeri Hiirzeler, 1946. M. Eoc.; Switzerland. Alsaticopithecus leemanni Hiirzeler, 1947. M. Eoc.; Alsace. Inasmuch as the European plesiadapids, and a specimen from the Walbeck Paleocene of Germany, referred to Phenacolemur by Weigelt (1947) but of uncertain generic and familial assignment are currently under study by others they are not discussed here in detail. These groups are, however, indicated in Text-chart I, in 28 A NEW EOCENE PRIMATE GENUS, CANTIUS PALEOCENE EOCENE PROVINCIAL AGE THANETIAN SPARNACIAN INCL. EARLY YPRESIAN CUISIAN EQUALS LATE YPRESIAN LUTETIAN BARTONIAN LUOIAN EARLY LATE EARLY LATE _,^- Necrolemur Necrolemur Necrolemur ^" "-- Microchoerus Microchoerus X ,,---' ftilhordino ,'- Nannopithex Nannopithe* Pseudolor/s Gesneropithex Anchomomys Adapts Protoadapis Adopis Periconodon > OMOMY DAE - Cantius Anchomomys — Adapts Caenopithecus Anchomomys Adapts Protoadapis Anchomomys Adapts Protoadapis Pronycticebus \ X V Chiromyoides ^•* ^ Protoadapis ^ > N *\_ Plesiadopis Plesiadapis * • PLESIAC JAPIOAE \ \ N X. Plalychoerops ^ Phenacolemur ">PAROMO MYIDAE \ \ X ***•. J Alsoticopithec us > MICRO J SYOPIDAE CHART I Temporal occurrence of early Cenozoic European primate genera indicating approximcte interrelationships. (* Occurrence in this horizon dubious.) CHART i. A NEW EOCENE PRIMATE GENUS, CANTIUS 29 which temporal occurrences and approximate interrelationships of all European early Tertiary Primates are shown. Megachiromyoides Since Megachiromyoides is frequently referred to in the literature as a primate, it should be emphasized that Stehlin & Schaub (1951 : 21) stated that it is a rodent, assignable to the genus Aeluravus. A recent examination, by the writer, of the holo- type of " Megachiromyoides " from the Geiseltal Brown Coals (described by Weigelt, 1933) has confirmed the view that this form cannot possibly be a plesiadapid. Caenopithecus This interesting primate from Middle Eocene (Lutetian) deposits near Egerkingen, Switzerland was originally described by Rutimeyer (1862). Stehlin (1916) discussed the species further and figured a mandible which shows only one incisor alveolus on either side. He stated that his material indicated the same lower dental formula as in Tarsius, and noted other advanced features including the loss of the first upper and lower premolars, and a short rostrum. Corroboration of Simpson's placement (1940) of this primate among adapidscan be drawn from its similarities with the Lutetian species Protoadapis klatti. Principally Caenopithecus differs from Protoadapis in showing more reduced molar paraconids, in the possession of distinct mesostyles and in having less well-developed upper molar lingual cingulum. Protoadapis also exhibits a more distinct P3 protocone. In spite of these generic differences, however, Caenopithecus and Protoadapis are, in upper and lower dental conformation, in dental formula and in what is known of the skull, much closer to each other than either is to Adapis, but (in different ways) both exhibit some features of resemblance to a species of the latter genus. Stehlin (1916 : 1319) remarked that knowledge then available of Caenopithecus lemuroides indicated affinities with Protoadapis and Pelycodus and this view has been strengthened by the better material of Protoadapis klatti now known. Protoadapis and Caenopithecus agree in possessing the following features, some of which are unknown among other European Eocene Primates : Long and large canines (above and below) — not very procumbent ; PI/I absent and replaced by diastema ; P3 higher than P4 ; metaconule of upper molars lacking but distinct paraconule present ; well-developed hypocones on M1"2 only ; upper molar cingula (labial and lingual) well defined and in some individuals continuous across lingual base of protocones ; similar proportions in lower molars. Common possesssion of pronounced upper molar cingula, absence of a distinct Pa protocone and near identity in overall proportions of the lower molars between Caenopithecus and Adapis parisiensis, tend to link species of these two genera as well. Weigelt noted a slight mesostyle on the M2 of Protoadapis klatti (also in agree- ment with Caenopithecus} and expressed the view that his Brown Coal species was closer to Caenopithecus than to Adapis. Moreover, his illustration of the skull of P. klatti (1933, pi. 6, fig. 4) indicates a vertically deepened anterior base for the zygomatic arch, as in Caenopithecus lemuroides. One further similarity between 30 A NEW EOCENE PRIMATE GENUS, CANTIUS these two types of Primates is the possible loss (reported for species of both genera) of all but one pair of lower incisors. Because of the low angle at which the anterior alveolar border of the mandible of Caenopithecus (Basel Eh. 733) from which this was deduced, is broken off, the possibility remains that there were more incisors below. In some specimens of Adapis parisiensis in the Paris Museum, where this margin is broken off in a similar way, the incisor alvoli are entirely missing. If these were the only known specimens of A . parisiensis its lower incisor formula would be equally uncertain. The exact number of lower incisor pairs in given Eocene primate species can seldom be stated categorically. Both Caenopithecus and Protoadapis could have had two pairs of these teeth, but present evidence is not adequate to prove that they did. A further note of some interest regarding Caenopithecus , and the nature of true hypocones and pseudohypocones, is provided by a specimen of this primate at Basel (Eh. 727) which shows both kinds of hypocone formation in one individual. The retention of both of these patterns in this dentition suggests that a latency for producing pseudohypocones, as in the line leading to Notharctus as well as for true hypocone production in Adapis, probably existed in the ancestral adapid-notharctid stock. Periconodon The genus Periconodon was established by Stehlin (1916) for a species " helveticus " which had been assigned by Riitimeyer (1891 : 115) to the North American genus Pelycodus. Like most Caenopithecus materials the type of Periconodon helveticus came from Middle Eocene deposits near Egerkingen, Switzerland. Apparently no additional specimens referable to this genus have been discovered since Stehlin's discussion.1 The individual illustrated by Stehlin (1916, pi. 22 fig. 3), which preserves P3 and M1"2 shows a distinctive pericone on the antero-internal base of M1"2 proto- cones. Since a pericone sometimes occurs here in Omonys (see Gazin, 1958, pi. 6, figs. 3 4) but not elsewhere among early Tertiary Primates, and because omomyids are known to have been present in the European Eocene fauna, the provisional reference of Periconodon to this family seems advisable. Furthermore, the small size of the species and general conformation of the teeth does not suggest adapid or notharctid affinities. Ceciliolemur and Microtarsioides Ceciliolemur is now considered by Matthes (1957), and by others, to be an insecti- vore, primarily because it seems to have had dermal spines. Recent examination of the holotypes of Ceciliolemur, G.P.I.H. 4237, and of Microtarsioides, G.P.I.H. 4235, both from the Geiseltal Brown Coals of Cecilia mine, locality Leichenfeld II, indicates strongly that they belong to the same species. Cheek teeth do not survive in either specimen, so dental formula and affinities cannot be determined. Moreover, the 1 Heller (1930) and Weigelt (1933) both mention the presence of isolated upper molars of this Primate in the Geiseltal Brown Coals. These teeth do not belong to Periconodon, but are those of a larger Primate from which the enamel has been resorbed. What remains of the cusp bases suggests their reference to Protoadapis klatti. A NEW EOCENE PRIMATE GENUS, CANTIUS 31 condition of bones and of eruption of lower teeth indicate that both are very young individuals, perhaps pre-natal. No basis remains for referring either of these speci- mens to the Primates. It is a remarkable accident of fossilization that either of these very delicate specimens were preserved, considering that the body excluding the tail, in both cases, is only about 4 cm. long. Locality data indicates recovery from the same place, and possibly they are from the same " litter ". Europolemur and Megatarsius As discussed above (pp. 13, 14) these primate genera are junior synonyms of Protoadapis. A Isaticopithecus The species A Isaticopithecus leemanni Hiirzeler (1947) can be assigned to the family Microsyopidae, as re-defined by McKenna (1960 : 76), see p. 25. Gesneropithex Gesneropithex peyeri Hiirzeler (1946) is based on a lower jaw containing P4_M2and one second upper molar collected in Ludian deposits near Bosgen, Switzerland. The lower teeth differ from Alsaticopithecus and resemble such adapids as Anchomo- mys, in that M1_2 lack distinct hypoconulids. Moreover, conformation of the upper second molar is within the general range of variability of species now assigned to the Adapidae. M2 is most similar in size and cusp pattern to those of Anchomomys latidens, but wear obscures some of its features. Anchomomys and Gesneropithex also agree in one rather unusual feature of M2 ; both have a strong anterior crest running from the metaconule to the metacone. Presence of an upper molar mesostyle in Gesnero- pithex is in agreement with Caenopithecus. It seems reasonable to assume that Gesneropithex peyeri can be referred to the Adapidae (s.s.). REVISED CLASSIFICATION1 Order PRIMATES Suborder PROSIMII Family TARSIIDAE Gray, 1870 Subfamily NECROLEMURINAE Simpson, 1933 MICROCHOERUS Wood, 1844 Synonyms — Microchaerus Forbes, 1894 Necrolemur : Filhol, 1880 (in part) Microchoerus erinaceus Wood, 1844 Microchoerus edwardsi (Filhol, 1880) Synonym — Necrolemur edwardsi Filhol, 1880 Microchoerus ornatus Stehlin, 1916 1 Since a revision of the European plesiadapids is currently being undertaken by Russell at the Paris Museum they have been omitted from this classification. 32 A NEW EOCENE PRIMATE GENUS, CANTIUS NECROLEMUR Filhol, 1873 Necrolemur antiquus Filhol, 1873 Necrolemur zitteli Schlosser, 1887 NANNOPITHEX Stehlin, 1916 Synonyms — Necrolemur Chantre & Gaillard, 1897 Pseudoloris : Weigelt, 1933 Nannopithex filholi (Chantre & Gaillard, 1897) Synonyms — Necrolemur filholi Chantre & Gaillard, 1897 Nannopithex pollicaris Stehlin, 1916 Nannopithex raabi (Heller, 1930) Synonyms — Pseudoloris abderhaldini Weigelt, 1933 Necrolemur raabi Heller, 1930 PSEUDOLORIS Stehlin, 1916 Synonym — Necrolemur : Filhil, 1889 Pseudoloris parvulus (Filhol, 1889) Synonym — Necrolemur parvulus Filhol, 1889 Family OMOMYIDAE Gazin, 1958 TEILHARDINA Simpson, 1940 Synonym — Omomys Teilhard, 1927 Teilhardina belgica (Teilhard, 1927) Synonym — Omomys belgicus Teilhard, 1927 CANTIUS nov. gen. Synonym — Protoadapis : Cooper, 1932 Cantius eppsi (Cooper, 1932) Synonym — Protoadapis eppsi Cooper, 1932 PERICONODON Stehlin, 1916 Synonym — Pelycodus Riitimeyer, 1891 Periconodon helveticus (Riitimeyer, 1891) Synonym — Pelycodus helveticus Riitimeyer, 1891 Family ADAPIDAE Trouessart, 1879 ADAPTS Cuvier, 1822 Synonyms — Aphelotherium Gervais, 1848 Leptadapis Gervais, 1852 Palaeolemur Delfortrie, 1873 A NEW EOCENE PRIMATE GENUS, CANTIUS 33 Adapts parisiensis Blainville, I84I1 Adapts magnus Filhol, 1874 A da pis rutimeyeri Stehlin, 1912 Adapis prisons Stehlin, 1916 Adapis sciureus Stehlin, 1916 PROTOADAPIS Lemoine, 1891 Synonyms — Plesiadapis : Lemoine, 1878 (in part) Protadapis : Stehlin, 1912 Megatarsius Weigelt, 1933 Europolemur Weigelt, 1933 Protoadapis curvicuspidens2 Lemoine, 1878 Synonym — Protadapis recticuspidens : Stehlin 1912 (in part) Protoadapis angustidens (Filhol, 1888) Synonyms — Adapis angustidens Filhol, 1888 Protadapis brachyrhynchus Stehlin, 1912 Protoadapis klatti (Weigelt, 1933) Synonyms — Europolemur klatti Weigelt, 1933 Megatarsius obeli Weigelt, 1933 CAENOPITHECUS Riitimeyer, 1862 Caenopithecus lemur oides Riitimeyer, 1862 PRONYCTICEBUS Grandidier, 1904 Pronycticebus gaudryi Grandidier, 1904 ANCHOMOMYS Stehlin, 1916 Synonym — Caenopithecus : Riitimeyer, 1891 Anchomomys Pygmaeus (Riitimeyer, 1891) Anchomomys gaillardi Stehlin, 1916 Anchomomys quercyi Stehlin, 1916 Anchomomys latidens Teilhard, 1916 GESNEROPITHEX Hiirzeler, 1946 Gesneropithex peyeri Hiirzeler, 1946 Family MICROSYOPIDAE new sense, McKenna (1960) ALSATICOPITHECUS Hiirzeler, 1947 Alsaticopithecus leemanni Hiirzeler, 1947 ? Primates incertae sedis AMPHILEMUR Heller, 1935 Amphilemur eocaenicus Heller, 1935 1 For numerous synonyms of the various species of Adapis, see Stehlin (1912, 1916). 2 Here designated as the type species of Protoadapis. 34 A NEW EOCENE PRIMATE GENUS, CANTIUS VII. CONCLUSIONS ' The occurrence of a new omomyid prosimian genus, Cantius, from the English Sparnacian is reported on and its distinctions from the Middle Eocene genus Proto- adapis outlined. Assignment of this form to the Omomyidae reinforces the extension of the range of this family into the Old World suggested by a few previously described forms. Although additional resemblances to North American notharctids are noted for Protoadapis, it is referred to the Adapidae on the basis of its greater similarities with Caenopithecus and Pronycticebus. Preliminary evidence suggests that Notharctidae and Adapidae, as denned by Gazin (1958) may not actually be distinguishable, but solution of this problem requires additional comparative study. Certain loris-like features of the genus Pronycticebus are pointed out. Just possibly, these can be interpreted as indicating the differentiation of the lorisiform prosimians from the general stock of the Adapidae (s.l.) . A high degree of dental similarity between an undoubted lorisoid prosimian, Progalago, of the early Miocene of Kenya, and the late Eocene European primate Anchomomys is stressed. These findings are in contrast to the widespread opinion that no close relationship of early Cenozoic with Recent prosimian families can be demonstrated, but is in line with the vertical taxonomic association of necrolemurines and tarsiines proposed by Simons (1961). However, zoogeographical and morphological considerations alone are sufficient to indicate that it would be unwise to regard any such relationships direct ancestor-descendant lineages. A number of species previously regarded as incertae sedis are here re-assigned or removed from the order and the taxonomy of European Eocene Primates revised. VIII. ACKNOWLEDGEMENTS I should like to thank Dr. K. P. Oakley of the British Museum (Natural History), Dr. J.-P. Lehman of the National Museum of Natural History, Paris, and Drs. H.-W. Matthes and G. Krumbiegel of the Geological and Paleontological Institute of the Martin Luther University of Halle/Wittenburg for the opportunity to study and report on Eocene Primates in their respective collections. Thanks are also due to Dr. G. L. Jepsen of Princeton University, Sir Wilfrid Le Gros Clark, and to many others with whom this subject has been discussed. Figures were prepared by Miss Christine Court of Oxford University and Mrs. Margaret E. Freeman of New Haven, and early completion of the work facilitated by a grant from the Wenner-Gren Foundation for Anthropological Research. IX. REFERENCES ABEL, O. 1931. Die Stellung des Menschen im Rahmen der Wirbeltiere. 398 pp. Jena. BARNETT, C. H. & NAPIER, J. R. 1953. The rotatory mobility of the fibula in eutherian mammals. /. Anat. Lond., 87 : 11-21. CHOW, MIN-CHEN. 1961. A New Tarsioid Primate from the Lushi Eocene, Honan. Verte- brata Palasiatica, Peking, 5 : 1-5, 3 figs. CLARK, W. E. LE GROS. 1934. On tne skull structure of Pronycticebus gaudryi. Proc. Zool. Soc. Lond., 1934 : 19-27, 3 figs. — 1956. A Miocene lemuroid skull from East Africa. Fossil Mammals of Africa, 9, 6 pp. i pi. British Museum (Nat. Hist.), London. A NEW EOCENE PRIMATE GENUS, CANTIUS 35 CLARK, W. E. LE GROS & THOMAS, D. P. 1952. The Miocene Lemuroids of East Africa. Fossil Mammals of Africa, 5, 20 pp., 3 pis. British Museum (Nat. Hist.), London. COOPER, C. FORSTER. 1932. On some mammalian remains from the Lower Eocene of the London Clay. Ann. Mag. Nat. Hist., London (10) 9 : 458-467, pis. 11-12. FILHOL, H. 1888. Description d'une nouvelle espece d'Adapis. Bull. Soc. philom. Paris, 7, 12 : 10-12. FORSYTH MAJOR, C. I. 1901. On some characters of the skull in the lemurs and monkeys Proc. Zool. Soc. Land., 1901 : 129-153, pis. 11-13. GAZIN, C. L. 1958. A review of the Middle and Upper Eocene Primates of North America. Smithson Misc. Coll., Washington, 126 : 1-112, pis. 1-14. GRANDIDIER, G. 1904. Un noveau Lemurien fossile de France, le Pronycticebus Gaudryi. Bull. Mus. Hist. nat. Paris, 10 : 9-13, 3 figs. 1905. Les lemuriens disparus. Nouv. Arch. Mus. Hist. nat. Paris (4) 7 : 1-42. GREGORY, W. K. 1920. On the structure and relations of Notharctus, an American Eocene primate. Mem. Amer. Mus. Nat. Hist., New York (n.s.) 3 : 49-243, pis. 23-59. 1922. The origin and evolution of the human dentition, xviii + 548 pp., 14 pis. Baltimore. GRANGER, W. & GREGORY, W. K. 1917. A revision of the Eocene Primates of the genus Notharctus. Bull. Amer. Mus. Nat. Hist., New York, 37 : 841-859, pis. 103-107. HELLER, F. 1930. Die Saugetier fauna der mitteleozanen Braunkohle des Geiseltals bei Halle. Jb. hallesch. Verb. Erf. mitteldtsch. Bodensch., Halle (n.f.) 9 : 13-41, pis. 1-5. — 1935. Amphilemur eocaenicus n. g. et n. sp., ein primitiver Primate aus dem Mitteleozan des Geiseltales bei Halle a. S. Nova Acta Leop. Carol., Halle a. S. (n.s.) 2 : 293-300. HILL, W. C. O. 1953. Primates. Comparative Anatomy and Taxonomy. I. Strepsirhini. xxiv + 798 pp., 34 pis. Edinburgh. 1955- Primates. Comparative Anatomy and Taxonomy. II. Haplorhini : Tarsioidea. 347 pp., 14 pis. Edinburgh. HURZELER, J. 1946. Gesneropithex Peyeri nov. gen. nov. spec, von Gosgen (Solothurn). Eel. geol. Helv., Lausanne, 39, 2 : 354-361, 4 figs. — 1947. Alsaticopithecus Leemanni nov. gen. nov. spec., ein neuer Primate aus dem unteren Lutetien von Buchsweiler im Unterelsass. Eel. geol. Helv., Lausanne, 40 : 343- 356, 12 figs. — 1948. Zur Stammesgeschichte der Necrolemuriden. Abh. schweiz. palaont. Ges., Zurich, 66 : 1-46, 41 figs. 1950. liber die europaischen Apatemyiden. Eel. geol. Helv., Lausanne, 42, 2 : 485. JEPSEN, G. L. 1934. A revision of the American Apatemyidae and the description of a new genus, Sinclair ella, from the White River Oligocene of South Dakota. Proc. Amer. Phil. Soc., Philadelphia, 74 : 287-305, pis. 1-3. LEMOINE, V. 1878. Communication sur les ossements fossiles des terrains tertiares inferieurs des environs de Reims. Bull. Soc. Hist. nat. Reims, 1878 : 90-113, pis. 1-5. 1891. Etude d'ensemble sur les dents des mammiferes fossiles des environs de Reims. Bull. Soc. geol. Fr., Paris (3) 19 : 263-290, pis. 10, n. LEMOINE, V. & AUMONIER, M. 1880. Terrains tertiaires des environs de Reims. Ass. Franc. Avanc. Sci., Paris, 9 : 605-619, pi. 5. MATTHES, H. W. 1957- Die mitteleozane Saugerfauna des Geiseltales and ihre verwand- schaftlichen Beziehungen. Wiss. Z. Univ. Halle, Math. Nat., 7 : 37-62, 22 figs. MCKENNA, M. C. 1960. Fossil mammalia from the early Wasatchian Four Mile fauna, Eocene of northwest Colorado. Bull. Dep. Geol. Univ. Calif., Berkeley, 37 : 1-130, 64 figs. OSBORN, H. F. 1891. A review of the Cernaysian Mammalia. Proc. Acad. Nat. Sci. Philad., 1890 : 51-62, 6 figs. PIVETEAU, J. 1957. Primates, paleontologie humain. Traite de Paleont., Paris, 7 : 1-675. RUSSELL, D. E. 1960. Le crane de Plesiadapis. Bull. Soc. geol. Fr., Paris, 7 : 312-314, pi. 18. 36 A NEW EOCENE PRIMATE GENUS, CANTIUS RUTIMEYER, L. 1862. Eocane Saugethiere aus dem Gebiete des schweizerischen Jura. Denkschr. schweiz. Ges. Naturw., Zurich, 19 : 1-248, pis. 1-6. — 1891. Die Eocane Saugethier-welt von Egerkingen. Abh. schweiz. palaont. Ges., Zurich, 18 : 1-153, pls- T~8- SIMONS, E. L. 1961. Notes on Eocene Tarsioids and a revision of some Necrolemurinae. Bull. Brit. Mus. (Nat. Hist.) Geol., London, 5 : 43-69, pis. 12-14. - 19610. The dentition of Ourayia : — its bearing on relationships of omomyid prosimians. Postilla, Yale Peabody Mus., New Haven, Conn., 54 : 1-20, 3 figs. SIMONS, E. L. & RUSSELL, D. E. 1960. Notes on the cranial anatomy of Necrolemur. Breviora Mus. Comp. Zool. Harv., Cambridge, Mass., 127 : 1-14, 3 figs. SIMPSON, G. G. 1940. Studies on the earliest primates. Bull. Amer. Mus. Nat. Hist., New York, 77 : 185-212, 8 figs. 1945- The principles of classification and a classification of mammals. Bull. Amer. Mus. Nat. Hist., New York, 85 : 1-350. - 1955. The Phenacolemuridae, new family of early primates. Bull. Amer. Mus. Nat. Hist., New York, 105 : 415-441, pis. 30-35. STEHLIN, H. G. 1912. Die Saugetiere des schweizerischen Eocaens. Abh. schweiz. palaont. Ges., Zurich, 38 : 1165-1298, figs, 244-288. 1916. Die Saugetiere des schweizerischen Eocaens. Abh. schweiz. palaont. Ges., Zurich, 41 : 1299-1552, pis. 21-22. STEHLIN, H. G. & SCHAUB, S. 1951. Die trigonodontie der simplicidentaten nager. Abh. schweiz palaont. Ges., Zurich, 67 : 1-385, 620 figs. TEILHARD DE CHARDIN, P. 1921. Les mammiferes de 1'Eocene inferieur Fran9ais et leurs gisements. Ann. Paleont., Paris, 10 : 171-176 ; 11 : 9-116, 42 figs. WEIGELT, J. 1933. Neue Primaten aus der mitteleozanen (oberluteitischen) Braunkohle des Geiseltals. Nova Acta Leop. Carol., Halle (n.f.) 1 : 97-156, pis. i-u. PLATE i Cantius eppsi (Cooper) A. Right maxilla, B.M.N.H., M 15145, with P3-M2. B. Right mandible, B.M.N.H., M 13773 (Type), with P3-M3. x 6-0 approx. Bull. B.M. (N.H.) Geol. 7, i PLATE i A \ PLATE 2 Protoadapis klatti (Weigelt) Anterior dentition, G.P.I. H. 4258. xya approx. Bull. B.M. (N.H.) Geol. 7, t PLATE 2 PLATE 3 Protoadapis klatti (Weigelt) Specimens of Protoadapis at Halle. A. Right M3, G.P.I.H. 7325 ; B. Right M1, G.P.I. H. 4292 ; c. Right M2, cf. Protoadapis, G.P.I.H. 4238 ; D. Left M3, G.P I H 4292 • E Left M2-3, Left P4_M8, G.P.I.H. 4310. All x 8 -o approx. (Photographs slightly retouched.) Bull. B.M. (N.H.) Geol. 7, i PLATE 3 A B PRINTED IN GREAT BRITAIN BY ADLARD AND SON, LIMITED BARTHOLOMEW PRESS DORKING THE BRACHIOPOD GENUS CYCLOTHYRIS E. F. OWEN BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. 2 LONDON: 1962 THE BRACHIOPOD GENUS CYCLOTHYRIS BY ELLIS FREDERIC OWEN Pp- 37-63 ; •?&• 4. 5 ; 10 Text-figures BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. z LONDON: 1962 THE BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY), instituted in 1949, is issued in Jive series, corresponding to the Departments of the Museum, and an Historical series. Parts will appear at irregular intervals as they become ready. Volumes will contain about three or four hundred pages, and will not necessarily be completed within one calendar year. This paper is Vol. 7 No. 2 of the Geological (Palaeontologicai) series. Trustees of the British Museum, 1962 PRINTED BY ORDER OF THE TRUSTEES OF THE BRITISH MUSEUM Issued May, 1962 Price Fourteen Shillings THE BRACHIOPOD GENUS CYCLOTHYRIS By ELLIS FREDERIC OWEN SYNOPSIS A revision of M'Coy's genus Cyclothyris from the Upper Aptian is made and serial sections of the type-species presented for the first time. In addition eight other species of Cyclothyris are described, two of these are new species. The subfamily Cyclothyrinae of Makridin is emended and discussed. A comparison is made between Cyclothyris from the Lower Greensand and the Upper Chalk genus Cretirhynchia. A new generic name is proposed for five Lower Cretaceous Rhynchonellidae. INTRODUCTION THE name Cyclothyris was first used by M'Coy (1844 : 103) to indicate a group of brachiopods which he called "... those curious species in which the deltidium completely surrounds the foramen ". No geological age was mentioned nor was any species named. M'Coy did, however, figure a specimen (p. 150, fig. 29) which is probably lost. From the beak characters of Mesozoic and Palaeozoic Rhynchonellidae it seems likely that M'Coy was referring to an early Cretaceous genus and, from the arrange- ment of the costae, shell outline, growth-marks and interarea as seen in his fig. 29, it is probable that M'Coy had selected a specimen of Aptian age. FIG. i. Copy of M'Coy's (1844) original illustration of fig. 29, p. 150. Previously, J. de C. Sowerby (1825 : 165, pi. 502, fig. i) had described and figured a rhynchonellid from the Upper Aptian, Sponge Gravel of Faringdon, Berkshire under the name Terebratula lata. He subsequently changed this specific name to T. latissima in the index to the Mineral Conchology published in 1829, having realized that his father J. Sowerby (1815 : 227) had already used the name T. lata for a brachiopod from the Drift of Lowestoft, Suffolk. The outline, arrangement of costae and growth-lines of J. de C. Sowerby's figured specimen of Terebratula latissima (pi. 502, fig. i) agree with the figure of M'Coy's genus Cyclothyris. This similarity was certainly noted by Davidson (1855 : 93) who included Cyclothyris in his synonymy of Fischer's genus Rhynchonella and quoted C. latissima in brackets after the generic name, probably as a typical species of Cyclothyris. GEOL. 7, 2. 2 4o THE BRACHIOPOD GENUS CYCLOTHYRIS Buckman (1906 : 326) was the first to designate T. latissima J. de C. Sowerby as the type species of Cyclothyris and subsequent authors have followed Buckman. The genus was not further investigated nor adequately defined until Hertlein & Grant (1944 : 61) published a full synonymy in their work on Caenozoic Brachiopoda from western North America. Stratigraphically the genus ranges from the Upper Aptian to the Upper Cenomanian and was probably developed from such a middle European form as Lepidorhynchia which Burn (1956 : 689) described from the Neocomian, Lower Barremian, of Dm B SP FIG. 2. Four drawings illustrating some of the internal characters of Cyclothyris. A. Pedicle valve showing subquadrate hinge-teeth (Ht) and large pear-shaped diductor muscle-scars (Dm). B. Subparallel dental lameleae in pedicle valve (Dl). c. Brachial valve showing ventral surface of the crura (Cr). D. Brachial valve showing the dorsal concave surface of the crura (Cr) and deep crenulated dental sockets (Ts) and short septum (Sp). Switzerland. Cyclothyris appears to have been confined chiefly to the European continent, although a notable exception to this is C. americana described and figured by Cooper (1955 : 3, pi. i) from the Aptian of Arizona. Examples of this species have not yet been examined by the writer but to judge from the figure on Cooper's pi. i it may well belong to this genus. Other species referred to Cyclothyris by Hertlein & Grant (1944 : 63) are probably not referable to the genus, but careful examination including the use of serial sections is necessary before any conclusions can be drawn. Another species from the American continent referred to this genus is Cyclothyris ? subtrigonalis Imlay from the Lower Neocomian of Mexico. This is shown in serial section (Imlay, 1937 : 571) to have a persistent septum in the brachial THE BRACHIOPOD GENUS CYCLOTHYRIS 41 valve and a large septalium, both characters which do not appear in serial sections of the type species C. latissima (J. de C. Sowerby). In the English Aptian the genus is represented by at least four species namely, C. latissima, C. depressa (J. de C. Sowerby), C. antidichotoma (Buvignier) and C. lepida sp. n., but there may be others not yet investigated. The rhynchonelloid species " R." nuciformis described from the Upper Aptian of Faringdon by J. de C. Sowerby (1825 : 166), and often erroneously referred to Cydothyris, is probably related to a species described by the writer (Owen, 1960 : 253) as Lamellaerhynchia larwoodi from the Upper Aptian of Upware, Cambridge. B D FIG. 3. Diagram illustrating different types of anterior commissure found in Cydothyris. A. Broadly arcuate. B. Trapezoidal, c. Asymmetrical. D. High arcuate. Some of these Upper Aptian species are recognizable as passage forms in the Lower Albian deposits at Leighton Buzzard, Bedfordshire. Middlemiss (1959 : 138) regards the Shenley Limestone fauna as essentially of an Albian-Cenomanian type. While possibly true of the terebratuloid fauna it is certainly not of the rhynchonelloids. With the possible exception of two species the fauna is distinctly Albian, having close affinities with Upper Aptian faunas at Brickhill and Upware in this country and Lower Albian faunas at Grandpre, Haute-Savoie and Haute-Saone, France. Two Lower Albian species of Cydothyris are described here from the Leymeriella tardefurcata Zone of the Shenley Limestone of Leighton Buzzard, Bedfordshire. One is the widely quoted C. antidichotoma (Buvignier), which also occurs in the Upper Aptian, and C. levis sp. n. By far the commonest Cenomanian species of Cydothyris is C. difformis (Valen- ciennes in Lamarck) which ranges from the Lower to Middle Cenomanian. It has 42 THE BRACHIOPOD GENUS CYCLOTHYRIS been recorded from Wiltshire, Devon and Dorset in England and from Normandy in France, Tournai in Belgium, and Essen in North Germany. Examples of this species with its many varieties are to be found in the general collections of the British Museum (Natural History). Apart from C. difformis, other Cenomanian species here described include C. scaldi- sensis (d'Archiac) from the Tourtia of Belgium, and C. schloenbachi (Davidson), a common fossil in the Lower Cenomanian of Somerset and Devon. The generic name Burrirhynchia is proposed for " Rhynchonella " leightonensis Walker from the Lower Albian, L. tardefurcata Zone of Shenley Hill, Leighton Buzzard, Bedfordshire. This genus is also represented in the Upper Aptian, P. nut- fieldensis Zone, of Upware, Cambridge and Brickhill, Buckinghamshire by the species " R." cantabrigensis Davidson. An emended description of " R." leightonensis together with serial sections were published by the writer (Owen, 1956 : 166, 167) and these may be compared with serial sections of Burrirhynchia cantabrigensis (Davidson) figured here as Text-fig. 10. TERMINOLOGY The terms used in the systematic descriptions here are according to Thomson (1927), Muir-Wood (1934) and Muir-Wood & Cooper (1960). Cyclothyrid. As applied to the deltidial plates was proposed by the writer (Owen, 1956 : 165) to replace the term " auriculate " which was used by Buckman (1918 : 18) to describe the encirclement of the foramen by the deltidial plates. Sulcus. The term sinus has often been used by authors to describe the median sulcation of a valve. Muir-Wood & Cooper (1960 : 8) pointed out that the term for this condition should be sulcus. Their definition was in connection with productoids, but the term is equally applicable to the rhynchonelloids and is quoted as " Sulcus. — A major depression in either valve usually median in position, which helps channel the outgoing stream in feeding. A median fold is usually opposite a median sulcus in the productoids." The term sulcus, therefore, as defined by Muir-Wood & Cooper is used throughout the following systematic descriptions. In the same publication Muir-Wood & Cooper (1960 : 14) redefined the following terms : Capillae. Fine radial, elevated lines (with more than 25 in 10 mm.). Costellae. Radial lines coarser than capillae (about 15-25 in 10 mm.). In the following systematic descriptions the measurement of 10 mm. is taken to indicate a position 10 mm. wide at a distance 10 mm. anterior to the umbo on the brachial valve. These terms have been used as above in the descriptions of C. anti- dichotoma, C. lepida sp. n. and C. levis sp. n. Dimensions of Cyclothyris specimens are given in millimetres but are defined generally as : Small, measuring up to 15 mm. long, 20 mm. wide. Medium, 16-28 mm. long, 21-38 mm. wide. Large, 29-35 mm. long, 39-45 mm. wide. THE BRACHIOPOD GENUS CYCLOTHYRIS 43 SYSTEMATIC DESCRIPTIONS Superfamily RHYNCHONELLACEA Schuchert, 1896 Family RHYNCHONELLIDAE Gray, 1848 Rzhonitskaya (1959), in an attempt to reclassify the rhynchonelloids, cited the subfamily Cyclothyrinae which was proposed by Makridin (1955) for certain rhyn- chonelloid genera ranging from the Trias to the Cretaceous. Makridin's definition quoted by Rzhonitskaya is translated by Mrs. G. A. Cooper, Washington, U.S.A. as : " Ribbed or plicate rhynchonellids without a septalium ; septa may be developed or be absent, hinge-plate divided." This very broad definition included such genera as Stolmorhynchia Buckman, 1914 and Lacunosella Wisniewska, 1932 which, unlike most of the other genera included, are known to possess falcifer crura and are quite distinct from those genera bearing radulifer crura. The following emended definition of Makridin's subfamily Cyclothyrinae is there- fore proposed : Costate, costellate, capillate or plicate rhynchonelloids without a septalium ; sep- tum developed or absent, hinge-plates divided, crura radulifer, foramen hypothyrid. This would include the following genera : Cyclothyris M'Coy, 1844. Cretirhynchia Pettitt, 1950. Sulcirhynchia Burri, 1953. Lamellaerhynchia Burri, 1953. Plicarostrum Burri, 1953. Lepidorhynchia Burri, 1956. Burrirhynchia nov. RANGE. Cretaceous. Subfamily CYCLOTHYRINAE Makridin, 1955 emended Genus CYCLOTHYRIS M'Coy, 1844 1844 Cyclothyris M'Coy, p. 103, 150, fig. 29. 1852 Cyclothyris Davidson, p. 93. 1877 Cyclothyris Dall, p. 24. 1906 Cyclothyris Buckman, p. 18. 1913 Cyclothyris Schuchert in Zittel, p. 398. 1918 Cyclothyris Buckman, pi. 14, fig. ia. TYPE-SPECIES (by subsequent designation, Buckman, 1906). Terebmtula latissima J. de C. Sowerby. EMENDED DIAGNOSIS. Medium to large biconvex rhynchonellidae, oval to subtri- angular in outline. Shell multicostate, costae sharp, coarse to fine, subangular to rounded. Growth-lines lamellar to step-like. Anterior commissure uniplicate. Beak-ridges usually distinct, interarea well defined. Foramen medium to large, circular. Deltidial plates conjunct, cyclothyrid. 44 THE BRACHIOPOD GENUS CYCLOTHYRIS Internal characters. Umbonal cavities oval in cross-section. Denticulae well developed. Teeth large, deeply inserted. Dental lamellae strong, subparallel. Hinge-plates broad, slightly arched in transverse section, divided terminally. Crura anteriorly concave. DESCRIPTION. Cyclothyris comprises a very variable group of medium to large rhynchonellidae. With the exception of perhaps one or two species, the outline is distinctly transversely oval. A fold and sulcus develop late and there is usually considerable lateral and anterior thickening of the margins in the gerontic stage. The ornament consists chiefly of strong costae with marked growth-lines sometimes becoming lamellar. The type and position on the valves of the growth-lines is regarded as a specific character and can be linked with type of costation when group- ing the species. The members of the latissima group, for instance, have numerous subangular or rounded radiating costae with fairly distinct growth-lines at about one-third the distance from the umbo, and approximately three to five at about two-thirds the distance from the umbo. They tend to be closer together or more lamellar and less prominent at the anterior margin. Bifurcation of the costae in adult forms is rare. In some species, notably C. antidichotoma (Buvignier), the ornament shows con- siderable deviation from the typical. Davidson (1851, pi. 14) in the species Capil- lirhynchia urighti (Davidson) from the Inferior Oolite, and Ager (1958 : 69) in Furcirhynchia furcata Buckman from the Lias illustrated a similar kind of ornament. In the genus Cyclothyris this type of ornament is regarded as a specific character. Marked uniplication of the anterior margin is a strong feature but some species show a tendency to produce an asymmetrical commissure. These aberrant forms are noticeable throughout the generic range and particularly in the Cenomanian species C. difformis. Some species, for instance C. scaldisensis (d'Archiac), are characterized by their large circular foramen. This is a common feature of the latissima group. Internal characters Pedicle valve. The umbonal cavity is roughly oval in cross-section, a pedicle collar being developed within the first 4 mm. The cyclothyrid deltidium is seen in transverse section as two outwardly curving plates, one on either side of the foramen. The crenulated hinge-teeth are thick, quadrate and deeply inserted, expanding dorsally. The diductor muscle-scars are large and triangular. The adductor muscle- scars are too faint for adequate description. Brachial valve. No cardinal process is developed. The hinge-plates are slender and gently arched ventrally. Inner and outer socket-ridges are well defined. The median septum is short and does not support the hinge-plates. Radulifer crura originate from the distal parts of the hinge-plates and curve ventrally. Each terminates in a Y-shaped fork which may be slightly deflected dorsally or remains almost horizontal to the sides of the valve. DISCUSSION. The chief distinguishing characters of Cyclothyris, apart from its general outline, are the extensive interarea, absence of bifurcation and intercalation THE BRACHIOPOD GENUS CYCLOTHYRIS 45 of costae in adult forms, large circular foramen and incipient fold in the brachial valve. The arched and divided or forked hinge-plates, as seen in transverse section, distinguish it from other Cretaceous rhynchonellid genera. It is readily distinguished from Orbirhynchia (Pettitt, 1954) in possessing radulifer crura. The stratigraphical zones quoted for species of Cyclothyris from the Lower Green- sand are according to Casey (1961). Cyclothyris latissima (]. de C. Sowerby) (PI. 4, figs. 7, 8 ; Text-fig. 4) 1825 Terebratula lata J. de C. Sowerby (non T. lata J. Sowerby), p. 165, pi. 502, fig. i. 1829 Terebratula latissima J. de C. Sowerby, Index. 1852 Rhynchonella latissima (J. de C. Sowerby) : Davidson, p. 82, pi. n, figs. 15—22. 1918 Cyclothyris latissima (J. de C. Sowerby) : Buckman, p. 14, pi. 14, fig. ia. 1950 Cyclothyris latissima (J. de C. Sowerby) : Pettitt, pi. i, figs. 14, 15. 1956 Cyclothyris latissima (J. de C. Sowerby) : Owen, pi. 3, fig. 6. EMENDED DIAGNOSIS. Medium sized Cyclothyris approximately 21 mm. long, 24 mm. wide and 13 mm. thick. Transversely oval to subtriangular in outline, lenticular in anterior contour. Brachial valve convex, with broad, flat almost imperceptible median fold. Pedicle valve less convex, with broad shallow sulcus. Anterior commissure broadly arcuate. Umbo short, thick, slightly incurved. Fora- men large. Deltidial plates well exposed. Each valve ornamented by about 60 rounded or subangular costellae (23 per 10 mm.) with approximately 13 on the fold and a corresponding number in the sulcus. LECTOTYPE. In the original description of the species J. de C. Sowerby (1825 : 165) quotes three localities, Faringdon, Sidmouth, and Devizes Canal. The species is represented in the Sowerby Collection, British Museum (Natural History) by three specimens from the above localities. Of these, the specimen from Faringdon was selected and figured as lectotype of the species by Pettitt (1950, pi. i). It is registered in the British Museum (Natural History) collections as 6.61499. Of the two remain- ing syntypes, one is recognizable as a young C. difformis (Valenciennes in Lamarck) from the Cenomanian of Sidmouth, Devon, while the other is crushed and too badly damaged for identification. DESCRIPTION. Although C. latissima does not seem to show the same range of variation as other species of Cyclothyris, a marked variant occurs at Faringdon, Berkshire and at Brickhill, Buckinghamshire and reaches dimensions considerably larger than the typical form, measuring approximately 25 mm. long, 34 mm. wide and 18 mm. thick. The dimensions of the lectotype are 21 mm. long, 28 mm. wide and 12 mm. thick. A fine series of specimens illustrating the above variant are to be found in the collections of the Sedgwick Museum, Cambridge numbered SM. 6.25682-6.25708. The outline of the shell of C. latissima remains oval to subtriangular with a broad flat fold on the brachial valve. The ornament consists of approximately 60 costellae on each valve, which are characteristically subangular or rounded and interrupted by step-like or fairly steep concentric growth-lines at about one-third the distance GEOL. 7, 2. 2§ 46 THE BRACHIOPOD GENUS CYCLOTHYR1S from the umbo and again at about two-thirds the distance from the umbo. Growth- lines at the anterior margin tend to be more numerous, usually about 3 to 5 and are lamellar. Internal structure. As for genus. Text-fig. 4. Cyclothyris latissima can be distinguished from other Aptian species of Cydothyris by its more acutely triangular outline, more extensive interarea, less marked anterior fold and more prominent growth-lines. It differs from C. depressa (J. de C. Sowerby) FIG. 4. A series of fifteen transverse serial sections through the umbonal part of a specimen of Cyclothyris latissima (J. de C. Sowerby) from the type locality, Faringdon, Berkshire. BM. 66.5482. X2. in its less produced beak, larger dimensions, less angular costellae and more arcuate anterior commissure. It is less convex than other Cyclothyris species with the excep- tion of C. scaldisensis (d'Archiac) from the Tourtia of Belgium which it resembles, but can be distinguished from this species by its smaller dimensions, more prominent growth-lines and less well-developed interarea and beak-ridges. DISTRIBUTION. Apart from the type locality at Faringdon, Berkshire, where it occurs in the Tropaeum subarcticum subzone of the Parahoplites nutfieldensis Zone, C. latissima has also been found in the P. nutfieldensis Zone at Upware, Cambridge and from the junction of the Hythe and Sandgate Beds on the foreshore just west of Folkestone Harbour, Kent. THE BRACHIOPOD GENUS CYCLOTHYRIS 47 Cyclothyris antidichotoma (Buvignier) (PI. 4, figs. 3^6 ; Text-figs. 5, 6) 1842 Terebratula antidichotoma Buvignier, p. 533, pi. 4 fig. 8. 1847 Rhynchonella antidichotoma (Buvignier) d'Orbigny, p. 31, pi. 500, figs. 1-5. 1847 Rhynchonella antidichotoma (Buvignier) : Pictet & Roux, p. 534, pi. 50, figs. $a-g. 1872 Rhynchonella antidichotoma (Buvignier) : Pictet, p. 41, pi. 199, figs. 13-176. 1874 Terebratula antidichotoma Buvignier : Davidson, p. 65, pi. 8, figs. 19-21. 1903 Rhynchonella lineolata var. mirabilis Walker, p. 261, pi. 18, figs. ja-c. EMENDED DIAGNOSIS. Medium to large biconvex Cyclothyris approximately 31 mm. long, 36 mm. wide and 15 mm. thick. Transversely oval to subcircular in outline. Brachial valve with broad, faintly developed median fold. Pedicle valve with wide, shallow sulcus, anteriorly developed. Anterior commissure broadly arcuate to trapezoidal. Umbo massive to sharp, slightly produced. Foramen large. Deltidial plates well exposed. Beak-ridges distinct, interarea extensive. Each valve ornamented with between 15 and 30 fine rounded costellae posteriorly and a few strong angular costae anteriorly. TYPE SPECIMEN. The original specimen figured by Buvignier (1842, pi. 4, fig. 8) cannot be traced and is presumed lost. It is not proposed to erect a neotype of this species until more material from the type locality has been examined. The only available specimen said to be from the area of the type locality examined by the writer is in the d'Orbigny Collection, Museum Nationale d'Histoire Naturelle, Paris and is registered in the d'Orbigny catalogue as 6014. This specimen, stated to be from the Albian of Saulce, Ardennes, does not resemble Buvignier's figured specimen in general outline although the ornament is similar. Instead it resembles one of the more robust forms commonly found in England at Brickhill and Upware and regarded as an extreme variant. D'Orbigny (1847, pi. 500) figured two specimens both of which resemble the one figured by Buvignier (1842, pi. 4, fig. 8). Neither of these specimens is in the d'Orbigny Collection and their whereabouts cannot be ascer- tained. DESCRIPTION. Buvignier's figure shows a large Cyclothyris measuring approximately 32 mm. long and 42 mm. wide, with a sharp beak, large foramen and ornament of fine costellae and strong costae which are the main distinguishing features. Specimens possessing similar features have been examined by the writer from Upware, Cam- bridgeshire, Brickhill, Buckinghamshire and Potton and Leighton Buzzard, Bed- fordshire. In addition collections of specimens also bearing these features from Albian localities in France and Switzerland have been studied in the Museum d'Histoire Naturelle, Geneva. It is probable that the original specimen described by Buvignier came from the Gault of Grandpre, although specimens of other species from this locality are usually preserved as internal casts in phosphatized sandy clay. Buvignier's specimen, however, has a well-preserved shell and may have come from the beds below the phosphate workings which are known to be of Upper Aptian age. In England, the Upper Aptian forms occurring at Brickhill and Upware differ from Buvignier's figured specimen in their more circular general outline and more 48 THE BRACHIOPOD GENUS CYCLOTHYRIS convex valves, although variants approaching the typical form have been found. The Lower Albian forms from Leighton Buzzard, while agreeing in general outline and proportions with Buvignier's figure, have a less acute apical angle, less produced beak and smaller interarea and are much nearer a form which occurs at Goudiniere, Grand St. Bernard and at Mont Saxonet, Savoie, France. This form is represented o .0 0-2 FIG. 5. Eighteen transverse serial sections through the umbonal part of Cyclothyris antidichotoma (Buvignier) from the Upper Aptian, Upware, Cambridge. BM. 6.25753. X 2. in the Davidson Collection, British Museum (Natural History) by three specimens from Goudiniere registered as 66.41485-87. Another specimen showing a marked resemblance to the Leighton Buzzard form comes from the Albian of Vergys, Upper Savoie and is registered as BM. 6.35284. Young forms of this species were thought to belong to a new variety by Walker (1903 : 261) who described them as Rhynchonella lineolata var. mirabilis. They are THE BRACHIOPOD GENUS CYCLOTHYRIS 49 usually more triangular in outline than the adult forms, with marked anterior sulca- tion of both valves. The large marginal costae are less numerous at this stage and the median fold in the brachial valve is not developed. Examples of this juvenile stage were figured by Pictet & Roux (1847, pi. 50) and by Pictet (1872, pi. 919) as R. anti- dichotoma (Buvignier) . The ornament of fine costellae and coarse costae running into one another is characteristic of the species but, as already stated, authors have described a similar 0-2 FIG. 6. Fourteen transverse serial sections through the umbonal part of Cyclothyris antidichotoma (Buvignier) from the Lower Albian, Shenley Hill, Leighton Buzzard, Bedfordshire. BM. 66.17561. x 2. feature on species in the Jurassic, and less notably, on Upper Cretaceous species such as Cretirhynchia octoplicata (J. Sowerby) as figured by Davidson (1852, pi. 10, figs, i-n). Although there may be sufficient grounds both morphologically and stratigraphic- ally for separating the Upper Aptian forms from those in the Lower Albian of this country, the writer proposes to leave this extremely well-known species as it is at present interpreted until more material from Grandpre, or at least from the French Ardennes, is available and the limits of variation are possible to define. DISTRIBUTION. C. antidichotoma as at present interpreted is a common fossil in 50 THE BRACHIOPOD GENUS CYCLOTHYRIS the Upper Aptian, P. nutfieldensis Zone, at Upware, Cambridge and Brickhill, Buckinghamshire and occurs, though not commonly, in the Lower Albian, Leymeriella tardefurcata Zone at Leighton Buzzard, Bedfordshire. It has also been collected from the Albian of Mont Saxonet and Goudiniere and from the Ardennes, France. Cyclothyris depressa (J. de C. Sowerby) (PI. 4, fig- ii) 1825 Terebratula depressa J. de C. Sowerby, p. 165, pi. 502, fig. 3. 1852 Rhynchonella depressa (J. de C. Sowerby) Davidson, p. 89, pi. n, figs. 28-32. EMENDED DIAGNOSIS. Small Cyclothyris about 9 mm. long, n mm. wide and 8 mm. thick. Elongate-triangular in outline. Brachial valve convex with moderately well-developed median fold. Pedicle valve less convex with shallow sulcus. Anterior commissure uniplicate with trapezoidal linguiform extension. Beak suberect, apical angle acute. Foramen large. Deltidial plates well exposed. Shell ornamented by about 25-28 sharp, angular, radiating costae originating from the umbones, with 6 on fold and 7-8 in sulcus. LECTOTYPE. In the original description of the species J. de C. Sowerby (1825) figured two specimens as fig. 3 on his pi. 502. Of these the larger of the two specimens is shown in dorsal and ventral views. This specimen is here selected as lectotype of the species. It is in the Sowerby Collection, British Museum (Natural History) No. 6.61468, together with the second figured specimen (6.61469) and three other syntypes (6.61470-72) which are also referable to C. depressa. DESCRIPTION. Apart from its small dimensions, the distinctive characters of this species are those of the beak, which is slightly produced, sharp and suberect. The large circular foramen shows the cyclothyrid deltidial plates to advantage. The pedicle valve has a marked trapezoidal linguiform extension. The sharp, angular costae show no signs of bifurcation or intercalation. They are interrupted only by a faint growth-line which appears at about two-thirds the distance from the umbo to anterior margin. Internal structure. As for genus. REMARKS. C. depressa has been grouped with C. schloenbachi (Davidson) since the two species have much in common. Their general outline and profile is roughly the same with a well-defined fold and sulcus. The linguiform extension is trapezoidal in shape. Both species are relatively small and seem to show the same extremes of variation with fine and coarse costation. C. depressa, however, is distinguished from C. schloenbachi by its more acutely triangular outline, slightly produced beak and shallower sulcus in the pedicle valve and well-developed fold on the brachial valve. It differs from C. latissima in its general triangular outline, angular costation, pro- duced beak, smaller dimensions and trapezoidal linguiform extension. DISTRIBUTION. C. depressa is commonly found in association with C. latissima in the Upper Aptian (P. nutfieldensis Zone) of Faringdon, Berkshire and also at the same horizon at Brickhill, Buckinghamshire. THE BRACHIOPOD GENUS CYCLOTHYRIS 51 Cyclothyris difformis (Valenciennes in Lamarck) (PI. 5, figs. 1-7 ; Text-figs. 7, 8) 1819 Terebratula difformis Valenciennes in Lamarck, p. 255, fig. indicated Encycl. Meth., 1789, pi. 242, fig. 5. Terebratula dimidiata J. Sowerby, p. 138, pi. 277, fig. 5. Terebratula gallina Brongniart, p. 84, pi. 9, fig. 2. Terebratula deformis Lamarck : Defrance, p. 160, pi. 5, fig. 3. Rhynchonella compressa (Lamarck) : d'Orbigny, p. 35, pi. 497, figs. 1-5. Terebratula difformis Lamarck : Davidson, p. 433, pi. 15, fig. 48. Terebratula compressa Lamarck : Davidson, p. 80, pi. n, figs. 4, 5. Terebratula difformis Lamarck : Quenstedt, p. 696, pi. 54, fig. 2. 1900 Rhynchonella difformis (Lamarck) Jukes-Browne, p. 65, figs. 41, 42. 1918 Terebratula difformis Valenciennes in Lamarck : Clerc & Favre, pi. 15, fig. 84. EMENDED DIAGNOSIS. Medium-sized Cyclothyris approximately 23 mm. long, 31 mm. wide and 17 mm. thick. Shell biconvex, fold low, indistinct, oval to sub- triangular in outline. Anterior commissure with well-marked uniplication. Umbo short, massive, slightly incurved. Foramen fairly large. Deltidial plates conjunct, well exposed. Beak-ridges distinct. Interarea extensive. About 40-45 costae on either valve (14 per 10 mm.) with 9 on fold and 10-11 in sulcus. LECTOTYPE. Owing to Lamarck's blindness the brachiopods in his " Animaux sans Vertebres " (vol. 6, 1819) were described by his pupil A. Valenciennes from specimens in Lamarck's own collection. In the description of Terebratula difformis (p. 255) Valenciennes indicated a specimen illustrated in Encyclopedic Methodique (1789, pi. 242, fig. 5) quoting the localities " near Le Mans, and also at Cap la Heve, near Le Havre " both Cenomanian localities. No type specimen was named or indicated and the whereabouts of the figured specimen is not known. Davidson (1850 : 433) in a description of Lamarck's species states that he bor- rowed the ten specimens used by Valenciennes in his original description and figured one of them as T. difformis (pi. 15, fig. 48). This would have served as lectotype of the species had the specimen not been subsequently lost or mislaid. A further specimen figured by Clerc & Favre (1918, pi. 15, figs. 8^a-d) has therefore been selected as lectotype of the species. This specimen is one of eight to be found under the name Terebratula difformis in the Lamarck Collection at the Museum d'Histoire Naturelle, Geneva and is registered as No. 48 in the Lamarck catalogue. From the mode of preservation and adhering matrix it was almost certainly collected from the Lower Cenomanian of the Normandy coast. The other seven specimens are probably of Jurassic age. The dimensions of the lectotype are : 23 mm. long, 31 mm. wide and 17 mm. thick. DESCRIPTION. C. difformis is an extremely variable species ranging in outline from subcircular to transversely oval to subtriangular. The ornament usually consists of about 45 coarse to relatively fine costae originating from the umbo of each valve and becoming more elevated towards the anterolateral margins. These costae are usually interrupted by one or two step-like growth-lines situated at about one-half to two- thirds the distance from the umbo to the anterior margin. The umbo varies from short to massive to slightly produced. An extensive interarea 52 THE BRACHIOPOD GENUS CYCLOTHYRIS with distinct beak-ridges is seen throughout the range of variation. The median fold on the brachial valve remains indistinct while the broad, shallow sulcus in the pedicle valve is late in development. The linguiform extension varies from broadly arcuate to trapezoidal but asymmetry of the anterior commissure is a notable character. Variants worthy of special note occur at Wilmington, south Devon and at Cap la Heve, Normandy. One of the Wilmington varieties departs from the typical in having more convex valves, shorter umbo, smaller foramen and more acutely arched FIG. 7. Diagram illustrating thirteen variants of Cyclothyris difformis (Valenciennes in Lamarck) from Wiltshire, south Devonshire, and Normandy. anterior commissure. The variety usually found on the Normandy coast, on the other hand, has a slightly produced beak, less convex valves and commonly exhibits an asymmetrical anterior commissure. Another notable variant occurs in the Lower Cenomanian, Tourtia, Belgium. Six well-preserved specimens in the British Museum (Natural History) are numbered 66.41475-80. The same variety occurs in the Lower Cenomanian deposits of Essen, North Germany and is represented in the same museum by a single specimen (BB. 4I473)- The specimen figured and described as Terebratula dimidiata by J. Sowerby (1821 : 138, pi. 277, fig. 5) from Halldown near Chudleigh, south-east Devon, is a large, almost sphaeroidal rhynchonellid with coarse costae, sharp, produced beak and THE BRACHIOPOD GENUS CYCLOTHYRIS 53 asymmetrical anterior commissure. This is either an extreme variant of C. difformis or a pathological form. A form somewhat resembling the outline of Sowerby's T. dimidiata but with finer costae, is figured by d'Orbigny (1847, pi- 49$, figs. 6-9) from the Charentes as Rhynchonella difformis. Some authors have followed d'Orbigny 's interpretation of Lamarck's species and Mile G. Fage (1935 : 433, pi. n), in a description of some Upper Cretaceous rhynchonellids from the Charentes, illustrated an evolutionary development from R. difformis d'Orbigny to a variety R. globata Fage. Her figured specimen of R. difformis is stated to have been collected from the Coniacian. A specimen figured by J. de C. Sowerby (1836, pi. 18, fig. 2) as T. dilatata was stated in the explanation of the plates to have been collected from Blackdown, south Dorset. FIG. 8. A series of twelve transverse serial sections through the umbonal part of Cyclo- thyris difformis (Valenciennes in Lamarck) from the lower Cenomanian, Cap la Heve, near Le Havre, Normandy. BM. 6.35224. x 2. This figure shows a remarkable similarity to a specimen figured by Schloenbach (1867, pi. 23, fig. 2) as C. difformis from the Lower Cenomanian of Essen, Germany. DISTRIBUTION. C. difformis ranges from the Lower to Middle Cenomanian of the west of England, Normandy and North Germany. In the type area of the Normandy coast it occurs in the remanie bed at the base of the Cenomanian, is abundant in the Lower Cenomanian and is less common, but still well represented in the Middle Cenomanian. In England the species is almost unrepresented in the Middle Cenomanian though rare examples have been found in the Middle Cenomanian basement beds of west Dorset. It is abundant, however, in the Lower Cenomanian, occurring in Wiltshire (Warminster Greensand) and the Devon coast, as well as in the Isle of Wight. A well-marked variant is the commonest brachiopod in the sandy Lower Cenomanian 54 THE BRACHIOPOD GENUS CYCLOTHYRIS of Wilmington, south Devon. It is said to occur in the dispar Zone at Punfield Cove, south Dorset but specimens of this species are more likely to have been collected from the bottom Cenomanian beds. Its occurrence below this level is uncertain. Cyclothyris compressa (Valenciennes in Lamarck) (PL 5, ng. 8) 1819 Terebratula compressa Valenciennes in Lamarck, p. 256, No. 54. 1850 Terebratula compressa Lamarck : Davidson, p. 455, pi. 15, fig. 54. 1918 Terebratula compressa Valenciennes in Lamarck : Clerc & Favre, pi. 19, figs. 117, 119. EMENDED DIAGNOSIS. Cyclothyris, about 28 mm. long, 32 mm. wide and 14 mm. thick. Distinctly subtriangular in general outline ; brachial valve convex with faint median fold. Pedicle valve posteriorly convex with broad, shallow median sulcus. Both valves ornamented by about 40 strong, acutely angular, radiating costae, (8 per 10 mm.) with 8 on fold and a corresponding number in sulcus. Concentric growth-lines very faint. Beak short, slender, slightly incurved. Beak-ridges distinct, interarea small. Deltidial plates triangular, foramen small. LECTOTYPE. The specimen here selected as lectotype of the species is one of four syntypes in the Lamarck Collection at the Museum d'Histoire Naturelle, Geneva and is numbered in the Lamarck Catalogue as No. 54. The specimen was figured by Davidson (1850, pi. 15, fig. 54) and by Clerc & Favre (1918, pi. 19, fig. 117). It was collected from the Upper Cenomanian of Coulaines near Le Mans in the Sarthe, south-west of the Paris basin. The dimensions of the lectotype are : 29 mm. long, 35 mm. wide and 14 mm. thick. DESCRIPTION. C. compressa is one of the most distinctive species of Cyclothyris. It is characterized by its acutely subtriangular outline and strong angular costae. It can be distinguished by its low, faintly developed median fold, trapezoidal lingui- form extension, and marginal thickening of the valves. It is probable that this species is a direct development of C. difformis. A specimen from the Tourtia of Belgium, showing characters of both species is in the British Museum (Natural History) numbered BM. 6.1889. Another specimen figured by Davidson (1852, pi. n, figs. 4, 5) as C. compressa and figured here on PL 5, fig. 8 as C. difformis shows the general outline of C. difformis with the anterior and lateral contours and sharp angular costae of C. compressa but without the marginal thickening of the valves. DISTRIBUTION. The species, originally described from Coulaines near Le Mans in the Sarthe, France is confined to the sandy Cenomanian of the south-west Paris basin. The typical form is characteristic of the Upper Cenomanian, Sables du Perche, where it is the only rhynchonellid present. Related but not identical forms occur in the beds above (Marnes a Ostrea biauriculata) and below (Sables et Gres du Mans). Varieties, stated to belong to this species, were described by Cayeux (1949) from Le Havre but were not accompanied by any adequate description or illustration, nor were any type-specimens indicated. THE BRACHIOPOD GENUS CYCLOTHYRIS 55 Cyclothyris schloenbachi (Davidson) (PI. 4, figs. 12, 13) 1852 Rhynchonella depressa vars. A and B, Davidson, p. 92, pi. 12, figs. 28-30. 1874 Rhynchonella schloenbachi Davidson, p. 59. EMENDED DIAGNOSIS. Small Cyclothyris about n mm. long, 15 mm. wide and 13 mm thick. Shell outline oval, brachial valve convex, slightly inflated, with well-defined median fold. Pedicle valve less convex with shallow sulcus broadening anteriorly. Foramen medium sized to small. Beak-ridges distinct, interarea fairly long. Orna- ment varying from fine to coarse costae. LECTOTYPE. C. schloenbachi was first described by Davidson (1874 : 59) who included three specimens which he had previously described and figured (1852 : 92, pi. 12, figs. 28-30) as varieties A and B of Rhynchonella depressa (]. de C. Sowerby), an Upper Aptian species. Two of these specimens (figs. 28, 29) were collected from the Cenomanian of Chardstock, Somerset, BM. 6.8215, and the third (fig. 30) from the Cenomanian of Shaftesbury, Wiltshire. Of these syntypes, the specimen from Shaftesbury (BM. 6.8216), figured by Davidson (1852, pi. 12, fig. 30) is here selected as lectotype of the species. DESCRIPTION. Cyclothyris schloenbachi is a common fossil is the Lower Cenomanian beds of south Devon, Somerset, south Wiltshire, and Dorset. As can be seen from Davidson's original figures (1852, pi. 12, figs. 28-30) the ornament varies from fine, subangular to strong, coarse costae. Davidson himself (1874 : 59) noted this varia- tion and stated that intermediate forms were commonly found with the extreme forms. The median fold is better developed or more distinct on specimens with finer costae and is often replaced in the coarser costate forms by a slight sulcation of the brachial valve. Bifurcation of the costae is a fairly common feature of the young coarsely costate forms. Both variants occur with intermediate forms in the same beds at Chardstock in Somerset, Beer Head, Devon, and Pinhay Cliff, Dorset. Because of its comparatively small dimensions C. schloenbachi cannot easily be confused with other known Cyclothyris species. It is distinguished from the somewhat similar C. depressa. by its oval outline, less produced beak, smaller foramen and better developed or deeper sulcus in the pedicle valve. DISTRIBUTION. In England, C. schloenbachi appears to be confined to the Lower Cenomanian beds of south Devon, Dorset, Somerset and Wiltshire. A slightly larger form of the same species occurs in the Lower Cenomanian beds of Vivautier in the department of Orne, France and is represented in the Davidson Collection, British Museum (Natural History) by fifteen specimens numbered 6.11917. These specimens show variations identical with those of the English forms. Cyclothyris lepida sp. n. (PI. 4, fig. 10) DIAGNOSIS. Cyclothyris about 22 mm. long, 32 mm. wide and 16 mm. thick. Shell biconvex, transversely oval in outline. Brachial valve with poorly developed median 56 THE BRACHIOPOD GENUS CYCLOTHYRIS fold. Pedicle valve with broad shallow sulcus. Both valves ornamented by about 60-65 fine rounded costellae (21 per 10 mm.) with 20 on the fold and about 22 in the sulcus. Anterior contour lenticular. Linguiform extension trapezoidal, moderately developed. Beak prominent with large foramen. HOLOTYPE. SM. 6.25683 from the Upper Aptian, Brickhill, Buckinghamshire in the collections of the Sedgwick Museum, Cambridge. Dimensions of holotype. 26 mm. long, 33 mm. wide and 16 mm. thick. PARATYPES. Twenty-two specimens from the type locality in the Sedgwick Museum SM. 6.25682, 6.25684-87, 6.25689-702, 6.25706-08. Also 40 specimens from the same locality and horizon in the 6ritish Museum (Natural History), 6.25546, 6.25547, 5.25549. DESCRIPTION. C. lepida is a medium-sized Cyclothyris with a characteristic orna- ment of fine radiating costellae originating from the umbones of each valve. The absence of any prominent growth-lines gives the species a neat appearance. The beak is strong and slightly incurved. An extensive interarea is bounded by distinct beak-ridges. The foramen is large and the deltidial plates well exposed. Internal characters. As for genus. REMARKS. This species can be distinguished from others of Cyclothyris mainly by its distinctly oval outline, fine costellae, regular anterior commissure, moderately developed but well-marked median fold on the brachial valve, trapezoidal linguiform extension and absence of marked growth-lines. It occurs with C. antidichotoma (6uvignier) at 6rickhill but its ornament shows none of the characteristics of this species. It is probably the species referred to by authors as Rhynchonella lata d'Orbigny (1847 : 21) from the Neocomian of France. 6ecause if its regular outline, well-marked median fold and absence of prominent growth-lines, C. lepida is grouped with C. depressa and C. schloenbachi. DISTRIBUTION. C. lepida appears to be confined to the Upper Aptian of 6rickhill, 6uckinghamshire. Cyclothyris levis sp. n. (PI. 4, fig- 9) DIAGNOSIS. Cyclothyris about 20 mm. long, 24 mm. wide and 12 mm. thick. Shell biconvex, distinctly subtriangular in outline. No median fold developed on brachial valve. Shallow, broad sulcus developed anteriorly in pedicle valve. 6oth valves covered by about 100 very fine capillae (48 per 10 mm.). 6eak short, massive, foramen small. 6eak-ridges distinct. Interarea small. Deltidial plates not well exposed. HOLOTYPE. 66.41493 in 6ritish Museum (Natural History) from the Lower Albian (L. tardefurcata Zone) of the Shenley Limestone, Leighton 6uzzard, 6edford- shire. Dimensions of holotype are : 22 mm. long, 27 mm. wide and 14 mm. thick. PARATYPES. Sixty-one specimens in 6ritish Museum (Natural History) registered Nos. 6.26541, 6.26542, 6.26595. . DESCRIPTION. In general outline this species resembles C. latissima but has a much more inflated brachial valve. A broad, shallow sulcus develops late in the THE BRACHIOPOD GENUS CYCLOTHYRIS 57 pedicle valve giving rise to a low broadly arcuate anterior commissure. The short, slightly incurved beak is sharp and massive with a small circular foramen. Distinct beak-ridges define a small interarea. Faint concentric growth-lines are seen on both valves and appear more distinct towards the anterolateral margins. Internal characters. As for genus. REMARKS. C. levis is distinguished from other Cyclothyris species by its extremely fine, rounded capillae, short massive beak, absence of median fold in the brachial valve and poorly developed sulcus in the pedicle valve. It can be distinguished from C. lepida sp. n. mainly by its general subtriangular outline, fine capillae, absence of median fold, shorter more massive beak, less extensive interarea, poorly exposed deltidial plates and broad arcuate anterior commissure. Although resembling C. latissima in general outline it can be distinguished from this species by its less extensive interarea, less produced beak, finer ornament of capillae, less marked growth-lines and broader arcuate anterior commissure. DISTRIBUTION. Cyclothyris levis is confined to the Lower Albian and is a common fossil in the limestone lenticles (L. tardefurcata Zone) at Leighton Buzzard, Bedford- shire. Cyclothyris scaldisensis (d'Archiac) (PI. 4 fig. i) 1846 Terebratula scaldisensis d'Archiac, p. 330, pi. 21, fig. n. EMENDED DIAGNOSIS. Cyclothyris about 24 mm. long, 32 mm. wide and 16 mm. thick. Shell biconvex, oval to subtriangular in outline, brachial valve with broad incipient median fold. Broad flattened median sulcus in pedicle valve. Umbo short, massive, slightly incurved. Foramen large, circular. Deltidial plates well exposed. Costae fine, rounded, numbering about 68 on each valve (12 per 10 mm.) with 15-18 on the fold and a corresponding number in the sulcus. HOLOTYPE. The specimen used by d'Archiac in his description of the species was stated to have been collected from the Tourtia of Belgium. It is not certain whether this specimen is still extant and enquiries are still being made. Several well-preserved specimens from the Tourtia of Belgium are to be found in the Davidson Collection and in the general collections of the British Museum (Natural History). Two good examples of this species are from Tournai and are registered 6.1889, 66.41492. Another specimen, larger than the dimensions given for the typical form, is figured here on PI. 4, fig. i. DESCRIPTION. C. scaldisensis is medium sized, characteristically oval to broadly subtriangular in outline. The brachial valve is convex and slightly inflated posteriorly with a very faintly developed median fold. The pedicle valve is convex in the umbonal region but develops a shallow sulcus which broadens anteriorly. The linguiform extension is moderately developed giving rise to a low broad, arcuate anterior commissure. Both valves are ornamented by about 65-68 fairly fine, rounded costae radiating from the umbones. Faint lamellar growth-lines are seen at about half and again at two-thirds the distance from the beak to the anterior margin. They tend to become more prominent anteriorly. The short umbo is massive with a large circular 58 THE BRACHIOPOD GENUS CYCLOTHYRIS foramen and well-exposed deltidial plates. The beak-ridges are distinct and define a faintly concave extensive interarea. This is probably the least variable of all species of Cyclothyris. Its characteristically fine, rounded costae and faint concentric growth-lines make it easily distinguishable from C. difformis, with which it is often associated. It differs from C. latissima, from which it was most probably developed, by its less prominent growth-lines, longer or more extensive interarea and less incurved beak. FIG. 9. Fourteen transverse serial sections through the umbonal part of Cretirhynchia norvicensis Pettitt from the Upper Chalk (mucronata Zone), Mousehold Pit, Norwich. BM. 6.25079. x 2. DISTRIBUTION. Apart from the area of its original description in the Lower Ceno- manian, Tourtia, of Belgium, the species is recorded from the Lower Cenomanian of Honfleur, Cap la Heve and Fecamp, Normandy and from a similar horizon in the Munster basin at Essen, Germany. It also occurs, though not commonly, in the Lower Cenomanian beds of Wiltshire, and the south Devon coast. Genus BURRIRHYNCHIA nov. DIAGNOSIS. Small to medium biconvex rhynchonellidae. Usually elongate- triangular in general outline. Umbo massive, suberect ; beak-ridges rounded. THE BRACHIOPOD GENUS CYCLOTHYRIS 59 Foramen small, circular, hypothyrid. Deltidial plates disjunct, cyclothyrid. Anterior commissure with broad trapezoidal linguiform extension Faint fold on brachial valve. Hinge plates narrow, ventrally arched. Median septum strong, persistent. Ornament of fine, rounded costellae (more than 50 on each valve). TYPE SPECIES. " Rhynchonella " leightonensis Walker, 1903. HOLOTYPE. From Lower Albian (L. tardefurcata Zone), Shenley Hill, Leighton Buzzard, Bedfordshire, No. GSM. 51279 in the Geological Survey Museum. FIG. 10. A series of thirteen serial sections through the umbonal part of Burrirhynchia cantabrigensis (Davidson) from the Upper Aptian of Upware, Cambridge. B.M. B.2574Q. x 2. REMARKS. The genus differs from Cyclothyris in its more elongate-triangular outline, strong persistent median septum, small foramen, rounded beak-ridges, and narrow hinge-plates which are not terminally divided. In transverse outline it resembles Sulcirhynchia Burri (1953) from the Swiss Neocomian, from which it may have been developed. It can be distinguished from this genus, however, by its stronger, more persistent, median septum, narrower, less acutely ventrally deflected hinge-plates, shorter, less deeply inserted hinge-teeth and more clearly defined inner and outer socket-ridges. Burrirhynchia almost certainly gave rise to Cretirhynchia Pettitt, 1950, from the Upper Chalk but is distinguished from it by its subparallel dental lamellae, disjunct 60 THE BRACHIOPOD GENUS CYCLOTHYRIS deltidial plates, poorly defined interarea and absence of bifurcation of costellae and thicker, less clearly defined hinge-plates. RANGE. Upper Aptian to Lower Albian. SPECIES ASSIGNED. " R." leightonensis Walker, " R." cantabrigensis Davidson, " R." gibbsiana (]. de C. Sowerby), " R." bertheloti d'Orbigny. " R." tripartita Pictet. MATERIAL AND LOCALITIES. One hundred and sixty specimens of B. leightonensis (Walker) from the Lower Albian (L. tardefurcata Zone), Shenley Hill, Leighton Buzzard, Bedfordshire (6.26524-28, 6.26595), 57 specimens of B. cantabrigensis (Davidson) from the Upper Aptian, of Upware, Cambridge and 85 specimens of the same species from Brickhill, Buckinghamshire and one specimen of " R" gibbsiana (J. de C. Sow.) from Folkestone, Kent, all in the British Museum (Natural History). CONCLUSION Although, externally, Cyclothyris shows considerable variation both in size, outline and ornament, internally it remains fairly constant. Within certain limits internal variation can be confined to the development of the hinge-plates, dental lamellae and the septum in the brachial valve. In the typical form from the Upper Aptian the dental lamellae are postero-anteriorly shorter than those of the Albian and Cenomanian forms and the hinge-plates in the Upper Aptian and Albian forms tend to be more acutely deflected towards the ventral valve than in the Cenomanian species, though this may be a variable character. Some authors, such as Makridin (1955) and Dacque (1934) have suggested that the genus ranges from the Upper Jurassic to Cretaceous. Their definition of the genus is most probably based on Central European material which may have con- tained early ancestral forms. The Neocomian genus Lepidorhynchia Burri (1956) certainly has both external and internal characters in common with Cyclothyris. The cyclothyrid deltidial plates are already evident and the ornament of subangular costae shows a tendency to marginal dichotomy, a character observed in very young specimens of C. latissima from Faringdon. Also, in Lepidorhynchia, are seen the ventrally curved and termin- ally divided hinge-plates which, when further developed in Cyclothyris, form the main distinguishing characters allowing the genus to be separated from Sulcirhynchia and Lamellaerhynchia. Both these genera, however, have a great deal in common with Cyclothyris and have obviously been developed from the same original stock. It was at first thought that Cyclothyris gave rise to the Upper Cretaceous genus Cretirhynchia but, in the light of present knowledge, this theory is no longer tenable. In his description of the genus Cretirhynchia, Pettitt (1950) remarked on the differences between his genus from the Upper Chalk, and the Lower Cretaceous genus Cyclothyris. In the same work (p. n, text-fig. 4) he figured a series of serial sections of the type- species C. plicatilis (J. Sowerby) from Northfleet, Kent showing the strong converging dental lamellae, short hinge-plates persistent septum and broad radulifer crura. Recently, the writer, has prepared several serial sections of other species of Cretirhyn- chia from Norfolk and Kent which compare favourably with Pettitt's illustrations. These sections show quite clearly that Cretirhynchia is not a direct development of THE BRACHIOPOD GENUS CYCLOTHYRIS 61 Cyclothyris but is closely related to early Cretaceous forms represented by the species " Rhynchonella " cantabrigensis Davidson from Upware and Brickhill and " R." leightonensis Walker from the Shenley Limestone. Both these species are here referred to Burrirhynchia gen. nov. A comparison between the serial sections of Burrirhynchia cantabrigensis from Upware (Text-fig. 10) and Cretirhynchia norvicensis Pettitt from Norfolk (Text-fig. 9) shows that the two have much in common. Neither species has a pedicle collar ; the outline in transverse section is similar ; both have narrow thickened hinge-plates. The median septum in the brachial valve of both forms persists for well over one half the length of the shell. In addition the broad radulifer crura are given off dorsally from similarly shaped crural bases. Externally also the two forms are much alike. Both have a short, massive umbo with small foramen and ornament of fine, rounded costae. Neither species shows any of the distinguishing characters of Cyclothyris nor is there any tendency to asymmetry of the anterior margin, a common feature of some Cyclothyris species. It is probable, therefore, that Cretirhynchia developed from such early Cretaceous forms as Burrirhynchia cantabrigensis and B. leightonensis which marked the beginning or early stages and C. norvicensis the last or later stages of its evolution. Both B. cantabrigensis and B. leightonensis are closely related to Sulcirhynchia Burri, from the Neocomian of Switzerland. Cyclothyris probably died out in the Upper Cenomanian with C. compressa (Valen- ciennes in Lamarck), though Turonian species such as " Rhynchonella " vespertilio (Brocchi) which may have been developed from C. compressa and " R." elegans Hanstein, from the Ciply Chalk, have still to be investigated. ACKNOWLEDGMENTS I am greatly indebted to Dr. E. I. White, F.R.S., Keeper of Palaeontology, British Museum (Natural History) for permission to work on the collections in his department and to Dr. H. M. Muir-Wood for her kind help and encouragement, and for reading the manuscript. My thanks are also due to Dr. F. Burri, Basel ; to Mme. A. Schnorf, Musee Geolo- gique, Lausanne, Switzerland ; to Mr. A. G. Brighton and Dr. Colin Forbes, Sedgwick Museum, Cambridge ; to Mr. K. J. Evans, King's College, London and to Dr. VV. T. Dean and Mr. F. M. Wonnacott, British Museum (Natural History), London. REFERENCES ACER, D. V. 1958. A Monograph of the British Liassic Rhynchonellidae , 2 : 51-84, pis. 1-3. [Mon. Palaeont. Soc., London.] D'ARCHIAC, A. 1847. Rapport sur les fossiles du Tourtia. Mem. Soc. geol. Fr., Paris (2) 2 : 291-351, pis. 13-25. BARROIS, C. 1875. Sur le Gault et sur les couches entre lesquelles il est compris dans le bassin de Paris. Ann. Soc. geol. Nord, Lille, 2 : 1-63. BROCCHI, G. 1814. Conchiologia fossile subapennina, 2 : 241-712, pis. 1-16. Milan. BRONGNIART, A. 1822. In Cuvier, G. & Brongniart, A. Description geologique des environs de Paris, iv + 428 pp., n pis. Paris. 62 THE BRACHIOPOD GENUS CYCLOTHYRIS BUCKMAN, S. S. 1906. Brachiopod Nomenclature. Ann. Mag. Nat. Hist., London (7) 18 : 32-327- — 1918. Brachiopoda of the Namyau Beds, Northern Shan States, Burma. Palaeont. Indica, Calcutta (N.S.) 3, 2 : 1-299, pis. 1-21. BURRI, F. 1956. Die Rhynchonelliden der Unteren Kreide (Valanginien-Barremien) im westschweizerischen Juragebirge. Eel. geol. Helv., Lausanne, 49 : 600-701, pis. 1-15. CASEY, R. 1961. The stratigraphical palaeontology of the Lower Greensand. Palaeontology, London, 3 : 487-621, pis. 77-84. CAYEUX, L. 1949. Essai de classification des mollusques brachiopodes de 1'etage cenomanien de la region. Bull. Soc. geol. Normandie, Le Havre (N.S.) 3 : 1-4. CLERC, M. & FAVRE, J. 1918. Catalogue illusive de la collection Lamarck, Part I. 117 pis. Paris. COOPER, G. A. 1955. New Cretaceous Brachiopoda from Arizona. Smithson. Misc. Coll., Washington, 131, 4 : 1-18, pis. 1-4. CORROY, G. 1925. Le Neocomien de la bordure orientale du Bassin de Paris. Bull. Soc. Sci nat. Nancy (4) 2 : 1-171. DACQUE, E. 1934. Wirbellose des Jura. In Gurich, G. Leitfossilien, 7 : 582 pp., 24 pis. Berlin. DALL, W. H. 1877. Index to the names which have been applied to subdivisions of the Class Brachiopoda. Bull. U.S. Nat. Mus., Washington, 8 : 1-87. DAVIDSON, T. 1852-54. A Monograph of British Cretaceous Brachiopoda, 2. 117 pp., 12 pis. [Mon. Palaeont. Soc., London.] — 1874. A Monograph of the British Fossil Brachiopoda, 4, i. Supplement to the Recent, Tertiary, and Cretaceous Species. 72 pp., 8 pis. [Mon. Palaeont. Soc., London.] DEFRANCE, M. J. L. 1828. Terebratula deformis Lamk. Diet. Sci. nat., Paris, 53 : 160. FACE, G. 1935. Rhynchonelles du Cretace Superieur des Charentes. Bull. Soc. geol. Fr.t Paris (5) 4:433-441, pi. i. FITTON, J. 1836. Observations on some of the strata between the Chalk and the Oxford Oolite in south-east of England. Trans. Geol. Soc. Lond. (2) 4 : 335-349, pis. 11-23. GEINITZ, H. B. 1872. Das Elthalgebirge in Sachsen. Palaeontographica, Stuttgart, 20 : 147-207, pis. 36-45. HANSTEIN, R. VON. 1879. Brachiopoden der oberen Kreide von Ciply. 58 pp. Bonn. HERTLEIN, L. G. & GRANT, U. S. 1944. The Cenozoic Brachiopoda of Western North America. Univ. Calif. Publ. Math. Phys. Sci., Berkeley, 3. vi + 236 pp., 21 pis. IMLAY, R. 1937. Lower Neocomian fossils from the Miquihuana region, Mexico. /. Paleont., Menasha, 11 : 552-574, pis. 1-13. JUKES-BROWNE, A. J. 1900. Cretaceous Rocks of Britain, i. Gault and Upper Greensand of England, x + 499 Pp- [Mem. Geol. Surv. U.K.] London. - & HILL, W. 1896. A Delimitation of the Cenomanian ; being a comparison of the corresponding Beds of South-Western England and Western France. Quart. J. Geol. Soc., Lond., 52 : 99-177. LAMARCK, J. P. B. 1819. Histoire naturelle des animaux sans vertebres, 6, i : 1-343. Paris. MAKRIDIN, V. P. 1955. Some Jurassic Rhynchonellids of the European part of USSR. Zap. Geol. Fak. Kharkov State Univ., 12 : 81-91. [In Russian]. M'Cov, F. 1844. A synopsis of the characters of the Carboniferous Limestone fossils of Ireland. viii + 207 pp., 29 pis. Dublin. MEYER, C. J. A. 1874. On Cretaceous rocks of Beer Head and adjoining cliff-sections, and on the relative horizons therein of the the Warminster and Blackdown fossiliferous deposits. Quart. J. Geol. Soc. Lond., 30 : 369-393. MIDDLEMISS, F. A. 1959. English Aptian Terebratulidae. Palaeontology, London, 2 : 94-142, pis. 15-18. MuiR-WooD, H. M. 1934. On the internal structure of some Mesozoic Brachiopoda. Philos. Trans., London (B) 223 no. 505 : 511-567, pis. i, 2. THE BRACHIOPOD GENUS CYCLOTHYRIS 63 MuiR-WooD, H. M. 1955. A History of the Classification of the Phylum Brachiopoda. 124 pp. British Museum (Nat. Hist.), London. — & COOPER, G. A. 1960. Morphology, Classification and life habits of the Productoidea (Brachiopoda). Mem. Geol. Soc. Amer., Rochester, N.Y., 81 : xi -f- 447 pp., 135 pis. OWEN, E. F. 1955. The use of sugar solution in the differentiation of the internal structures of Upper Chalk Brachiopods. Proc. Geol. Ass. Lond., 66 : 369-370. 1956. The Lower Cretaceous Brachiopods " Rhynchonella " gibbsiana (J. de C. Sowerby) and Sulcirhynchia hythensis sp. nov. Ann. Mag. Nat. Hist., London (12) 9 : 164-172, pi. i. — 1960. A Note on " Rhynchonella " sulcata (Parkinson) from the Lower Cretaceous of Great Britain. Ann. Mag. Nat. Hist., London (13) 2 : 248-256, pi. i. ORBIGNY, A. D'. 1848-51. Terrains cretaces. Paleontologie francaise, 4: 1-390, pis. 490-599. Paris. PETTITT, N. E. 1950. Rhynchonellidae of the British Chalk, I. 26 pp., 2 pis. [Mon. Palaeont. Soc., London.] - 1954. Rhynchonellidae of the British Chalk, II. 26 pp, i pi. [Mon. Palaeont. Soc., London] . PICTET, F. J. 1872. Description des fossiles du terrain cretac6 des environs de Sainte-Croix, 5. Mater. Paleont. suisse, Geneve (6) 1 : 1-158, pis. 195-208. — & Roux, W. 1847-53. Mollusques fossiles des gres verts de Geneve. 558 pp., 51 pis. Geneve. QUENSTEDT, F. A. 1882. Handbuch der Petrefactenkunde. viii -f 1239 pp., Tubingen (esp. p. 696). RZHONITSKAYA, M. A. 1959- Systematics of the Rhynchonellids. Pal. J. Akad. Nauk. SSSR., 1 : 25-36. [In Russian]. SCHLOENBACH, U. 1867. Uber die Brachiopoden der norddeutschen Cenoman-Bildungen. Geogn. Paldont. Beitr. (E. W. Benecke), Miinchen, 1 : 399-506, pis. 21-23. SCHUCHERT, C. 1913. Brachiopoda. In Zittel, K. A. von, edited by Eastman, C. R. Textbook of Palaeontology, 1 : 355-420, figs. 526-636. 2nd edit. London. SHARPE, D. 1854. On the age of the fossiliferous sands and gravels of Farringdon and its neighbourhood. Quart. J. Geol. Soc. Lond., 10 : 176-198, pis. i, 2. SOWERBY, J. 1812-15. Mineral Conchology of Great Britain, 1. vii + 234 pp., 102 pis. London. — 1818-21. Mineral Conchology of Great Britain, 3. 184 pp., pis. 204-306. London. SOWERBY, J. DE C. 1836. In Fitton, J. Observations on some of the strata between the Chalk and the Oxford Oolite in the south-east of England. Trans. Geol. Soc. Lond. (2) 4 : 335-349, pis. 11-23. SPATH, L. F. 1926. On the zones of the Cenomanian and Uppermost Albian. Proc. Geol. Ass. Lond., 37 : 420-432. THOMSON, J. A. 1927. Brachiopod morphology and genera (Recent and Tertiary). N.Z. Board Sci. Art. Manual, 7 : vi + 338 pp., 2 pis. Dominion Museum, Wellington. WRIGHT, C. W. & E. V. 1951. A survey of the fossil cephalopoda of the Chalk of Great Britain. 41 pp. [Mon. Palaeont. Soc., London.] PLATE 4 FIGS. ia-c. Cyclothyris scaldisensis (d'Archiac). Tourtia, Gussignies, Belgium. BM. B.I 1965. FIGS. za-c. Cyclothyris dimidiata (J. Sowerby) = C. difformis. Cenomanian, Halldown, south-east Devon. BM. 6.61466. FIGS. 3«-c. Cyclothyris antidichotoma (Buvignier). Lower Albian, Shenley Hill, Leigh ton Buzzard, Bedfordshire. BM. 66.41495. FIGS. ^a-c. Cyclothyris antidichotoma (Buvignier). Lower Albian, Goudiniere, Grand St. Bernard, Savoie, France. BM. 66.41486. FIGS. $a-c. Cyclothyris antidichotoma (6uvignier). Upper Aptian, 6rickhill, 6uckingham- shire. 6M. 66.41490. FIGS. 6a-c. Cyclothyris antidichotoma (6uvignier). Upper Aptian, Upware, Cambridge. 6M. 6.27264. FIGS. ja-c. Cyclothyris latissima (J. de C. Sowerby). Upper Aptian, Faringdon, 6erkshire. 8M. 66. 41494. FIGS. Sa-c. Cyclothyris latissi ma (J. deC. Sowerby). Lectotype. Upper Aptian, Faringdon, 6erkshire. 6M. 6.61499. FIGS. ga-c. Cyclothyris levis sp. n. Holotype. Lower Albian, Shenley Hill, Leigh ton 6uzzard, 6edfordshire. 6M. 66.41493. FIGS. ioa-c. Cyclothyris lepida sp. n. Holotype. Upper Aptian, 6rickhill, 6uckingham- shire. Sedgwick Museum Coll. 6.25683. FIGS. na-c. Cyclothyris depressa (J. de C. Sowerby). Lectotype. Upper Aptian, Faring- don, 6erkshire. 6M. 6.61468. FIGS. I2a-c. Cyclothyris schloenbachi (Davidson). Lectotype. Lower Cenomanian, Shaftes- bury, Wiltshire. 6M. 6.8216. FIGS. i$a-c. Cyclothyris schloenbachi (Davidson). Coarsely costate variant from Chard- stock, Somerset. 6M. 6. 8215. All figures at natural size unless otherwise stated. 6M. — 6ritish Museum (Natural History). 4 JUN196? Bull. B.M. (N.H.) Geol. 7, 2 PLATE 4 6a PLATE 5 FIGS. la-c. Cyclothyris difformis (Valenciennes in Lamarck). Cenomanian, Warminster, Wiltshire. Typical form. B.M. no. 45336. FIGS. 2a-c. Cyclothyris difformis (Valenciennes in Lamarck) . Lower Cenomanian, Wilming- ton, south Devon. BM. 36.41433. FIGS. 3«-c. Cyclothyris difformis (Valenciennes in Lamarck). Lower Cenomanian, Cap le Heve, near Le Havre, Normandy BM. 6.82754. FIGS. 4«-c. Cyclothyris difformis (Valenciennes in Lamarck). Lower Cenomanian, Wilming- ton, south Devon. BM. 66.15292. FIGS. 5a— c. Cyclothyris difformis (Valenciennes in Lamarck). Tourtia, Tournai, Belgium. BM. 66.41476. FIGS. 6a-c. Cyclothyris difformis (Valenciennes in Lamarck). Cenomanian, Essen, Germany. Similar variant to fig. 5 from Belgium. 6M. 66.41473. FIGS. ja-c. Cyclothyris difformis (Valenciennes in Lamarck). Lower Cenomanian, War- minster, Wiltshire. 6M. 6.8301. FIGS. Sa-c. Cyclothyris compressa (Valenciennes in Lamarck). Upper Cenomanian, Le Mans, Sarthe, France. BM. 66.41489. Bull. B.M. (N.H.) Geol. 7, 2 PLATE 5 la Ic 2c 2a 8c THE TRILOBITES OF THE CARADOC SERIES IN THE CROSS FELL INLIER OF NORTHERN ENGLAND W. T. DEAN BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. 3 LONDON: 1962 THE TRILOBITES OF THE CARADOC SERIES IN THE CROSS FELL INLIER OF NORTHERN ENGLAND BY WILLIAM THORNTON DEAN Pp. 65-134 ; Pis. 6-1 8 ; 5 Text-figures BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. 3 LONDON: 1962 THE BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY), instituted in 1949, is issued in five series corresponding to the Departments of the Museum, and an Historical Series. Parts will appear at irregular intervals as they become ready. Volumes will contain about three or four hundred pages, and will not necessarily be completed within one calendar year. This paper is Vol. 7, No. 3 of the Geological (Palaeontologicai) series. Trustees of the British Museum 1962 PRINTED BY ORDER OF THE TRUSTEES OF THE BRITISH MUSEUM Issued August 1962 Price Forty-two Shillings THE TRILOBITES OF THE CARADOC SERIES IN THE CROSS FELL INLIER OF NORTHERN ENGLAND By WILLIAM THORNTON DEAN Page I. INTRODUCTION AND ACKNOWLEDGMENTS ...... 69 II. STRATIGRAPHICAL SUMMARY ........ 69 III. SYSTEMATIC DESCRIPTIONS ........ 72 Family Raphiophoridae Angelin . . . . . .72 Lonchodomas swindalensis sp. nov. ..... 72 Lonchodomas pennatus (La louche) ..... 78 Family Trinucleidae Hawle & Corda ..... 79 Subfamily Cryptolithinae Angelin ...... 79 Broeggerolithus nicholsoni (Reed) ..... 79 Broeggerolithus melmerbiensis sp. nov. . . . . .81 Broeggerolithus cf. transiens (Bancroft) .... 82 Broeggerolithus sp. . . . . . . .83 Onnia gracilis (Bancroft) ....... 84 Onnia superba (Bancroft) pusgillensis Dean .... 84 Subfamily Tretaspidinae Whittington ..... 85 Tretaspis cf. ceriodes donsi St0rmer ..... 85 Tretaspis convergens Dean . . . . . . .85 Tretaspis kiaeri St0rmer radialis Lament .... 86 Tretaspis kiaeri St0rmer duftonensis Dean . . . .86 Family Cheiruridae Salter ....... 86 Subfamily Cyrtometopinae Opik ...... 86 Pseudosphaerexochus cf. octolobatus (M'Coy) .... 87 Family Encrinuridae Angelin ....... 88 Subfamily Encrinurinae Angelin ...... 88 Encrinurus sp. ........ 88 Subfamily Dindymeninae Pfibyl ...... 89 Dindymene duftonensis sp. nov. ...... 89 Dindymene sp. ......... 90 Subfamily Cybelinae Holliday . . . . . .91 Atractopyge scabra sp. nov. . . . . . .91 Atractopyge? sp. ........ 93 Paracybeloides cf. girvanensis (Reed) ..... 94 Paracybeloides sp. ........ 95 Family Dalmanitidae Reed ....... 95 Subfamily Dalmanitinae Reed ...... 95 Dalmanitina mucronata (Brongniart) matutina subsp. nov. . 95 Subfamily Acastinae Delo . . . . . . -97 Kloucekia (Phacopidina) apiculata (M'Coy) ... 97 Duftonia lacunosa Dean ....... 97 GEOL. 7, 3. 3 68 THE TRILOBITES OF THE CARADOC SERIES Page Family Pterygometopidae Reed ...... 98 Subfamily Pterygometopinae Reed ..... 98 Calyptaulax planiformis sp. nov. ..... 98 Estoniops alifrons (M'Coy) ...... 100 Subfamily Chasmopsinae Pillet . . . . . .104 Chasmops cf. extensa (Boeck) . . . . . .104 Chasmops aff. maxima (Schmidt) ..... 105 Chasmops sp. ......... 105 Family Homalonotidae Chapman . ; . . . . .106 Brongniartella minor (Salter) . . . . . .106 Brongniartella ascripta (Reed) . . . . . .106 Brongniartella bisulcata (M'Coy) . ' . . . . . 108 Brongniartella depressa sp. nov. ...... 108 Brongniartella aff. platynota (Dalman) . . . .no Family Calymenidae Burmeister . . . . . .in Flexicalymene cf. caractaci (Salter) . . . . .114 Onnicalymene onniensis (Shirley) . . . . .115 Onnicalymene laticeps (Bancroft) . . . . .115 Diacalymene cf. marginata Shirley . . . . .116 Gravicalymene jugifera sp. nov. . . . . . .116 Family Dimeropygidae Hupe . . . . . . .118 Toernquistia aff. reedi Thorslund . . . . .118 Family Illaenidae Hawle & Corda . . . . . .120 Stenopareia? sp. . . . . . . . .120 Family Lichidae Hawle & Corda . . . . . .120 Subfamily Homolichinae Phleger . . . . . .120 Conolichas melmerbiensis (Reed) . . . . .120 Platylichas cf. laxatus (M'Coy) . . . . . .121 Family Odontopleuridae Burmeister . . . . . .122 Primaspis semievoluta (Reed) ...... 122 Odontopleurid gen. et sp. ind. ...... 123 Family Otarionidae R. &. E. Richter . . . . .123 Otarion sp. ......... 123 Family Proetidae Salter . . . . . . . .124 Subfamily Proetidellinae Hupe . . . . . .124 Proetidella? marri sp. nov. ...... 124 Family Remopleurididae Hawle & Corda . . . . .127 Remopleurides spp. ........ 127 IV. STRATIGRAPHICAL DISTRIBUTION AND RELATIONSHIPS OF THE TRILOBITES 128 V. REFERENCES .......... 130 SYNOPSIS The trilobites known from the Caradoc Series in the Cross Fell Inlier are described and figured, many of them for the first time. They comprise fifty species and subspecies, assigned to twenty-eight genera and fifteen families. The relationships of the trilobites to those of other successions is reviewed. In the Longvillian and Marshbrookian Stages the fauna is of Anglo- Welsh type with occasional Baltic elements, but in subsequent stages the affinities with corres- ponding Norwegian and Swedish faunas becomes marked, reaching a maximum in the Pusgillian Stage. THE TRILOBITES OF THE CARADOC SERIES 69 I. INTRODUCTION AND ACKNOWLEDGMENTS THE name Cross Fell Inlier is applied by geologists to the elongated area of Lower Palaeozoic rocks, a few miles north of Appleby, Westmorland, which extends in a south-south-easterly direction between the Carboniferous strata of the Pennines and the Permo-Trias of the Vale of Eden. The geological structure of the area is of great complexity and has been described by Shotton (1935). The disposition of the principal outcrops of Caradoc strata is shown in Text-fig, i. Although the first detailed stratigraphical accounts, accompanied by faunal lists, of the Caradoc Series in the Inlier were given during the last century by Harkness & Nicholson (1878), and Nicholson & Marr (1891), it was not until 1907 and 1910 that any figures and descriptions of trilobites were published. In those years Reed described four new species, Lichas melmerbiensis , Acidaspis semievoluta, Homa- lonotus ascriptus and Trinudeus nicholsoni, from strata which he called Dufton Shales at the road-section near Melmerby, as well as listing several other species from the same locality. Bancroft (1933) listed a few Shropshire species of trilobites and brachiopods from the Inlier but it was not until 1936 that another trilobite was illustrated, when Shirley figured a specimen of Flexicalymene onniensis, a south Shropshire species, from an unspecified locality and horizon within the Dufton Shales of Pus Gill, near Dufton. In 1948 Bancroft's manuscript notes on the Cross Fell succession, in- cluding locality maps of Swindale Beck and part of Pus Gill, were published posthumously by Lament, who added photographs of certain Shropshire specimens but figured none from the Inlier. Since then a new genus, Duftonia, has been described from the Dufton Shales by the writer (Dean, 1959) who, in a later paper (19590;), discussed the detailed strati- graphy of the area and gave faunal lists. More recently some of the Trinucleidae occurring in the upper part of the succession have been described and figured (Dean, 1961). The present work aims at describing and figuring all the trilobites listed and discussed in the foregoing papers. Extensive collections of trilobites have been made during field-work financed in part by grants from the Gloyne Fund of the Geological Society of London, and I am grateful to the Council of the Society for their assistance. All the material is housed in the British Museum (Natural History), London. I wish to thank the Council of the Yorkshire Geological Society for permission to reproduce the sketch-map shown in Text-fig. 4. I am indebted to Mr. A. G. Brighton for the loan of type-specimens from the Sedgwick Museum, Cambridge, to my wife for her important share of the collecting, and to Professor W. F. Whittard who has kindly read and criticized the manuscript. II. STRATIGRAPHICAL SUMMARY The following table represents the subdivisions of the Caradoc Series which are generally recognized today in the main portion of the Inlier, together with the equivalent faunal zones as established in the type-area of south Shropshire. The subdivision of the strata into Corona Beds and Dufton Shales is made on lithological grounds, the former including maroon and grey mudstones and shales 7o THE TRILOBITES OF THE CARADOC SERIES SKETCH-MAP SHOWING THE DISTRIBUTION OF CARADOC OUTCROPS IN THE CROSS FELL INLIER [AFTER SHOTTON. 1935] ASHGILL SERIES CARADOC SERIES A. ALSTON ROAD B. KNOCK-DUFTON DISTRICT C. HILTON BECK D. ROMAN FELL D.- FIG. i. THE TRILOBITES OF THE CARADOC SERIES Stage PUSGILLIAN ONNIAN ACTONIAN MARSHBROOKIAN U . Broeggerolithus longiceps LONGVILLIAN I Zonal TrUobite Onnia superba Onnia gracilis Onnia ? cobboldi Platylichas laxatus Broeggerolithus transiens Broeggerolithus globiceps Zonal Brachiopod Onniella broeggeri Onniella inconstans Cryptothyris paracyclica Onniella reuschi Dalmanella unguis Dalmanella wattsi Kjaerina typa Kjaerina bipartita Bancroftina typa Dalmanella indica and D. lepta Dalmanella horderleyensis ? Lithological Subdivision DUFTON SHALES CORONA BEDS with occasional limestone bands, whilst the latter comprise essentially a rather monotonous series of dark-grey mudstones and shales with bands of nodular and impure limestone which often weather to a rotten-stone or " gingerbread " rock. The Corona Beds are shown in the table to coincide with the limits of the Lower Longvillian Substage, but in fact the zone of Dalmanella indica and D. lepta is the lowest faunal horizon definitely recognized, though the underlying zone may well be represented. The topmost zone of the Lower Longvillian is represented in the highest Corona Beds and it seems likely that there is a transition to the overlying Dufton Shales, but owing to extensive faulting the lowest zone of the Upper Longvillian has not been detected throughout the greater part of the Inlier. The remainder of the succeeding Caradoc strata as found in the Shropshire type-area are, for the most part, represented in the Cross Fell Inlier, with the addition of the Pusgillian Stage. This subdivision is held to constitute the topmost part of the Caradoc Series and to pre-date any known Ashgill strata. In Swindale Beck, near Knock, the Pusgillian is followed in the succession by the Staurocephalus or Swindale Lime- stone. The junction of the two has often been assumed to be conformable, but the writer believes there is a marked stratigraphical break above the Pusgillian, and that the Limestone represents a relatively high Ashgill horizon, as it is followed at Swindale Beck by Ashgill Shales with Hirnantia sagittifera (M'Coy). South-east of Dufton the Pusgillian outcrop is separated from that of the Swindale Limestone by a small thickness of strata, equated with part of the Diacalymene Beds of Cautley, which are probably overstepped by the Limestone. The northernmost outcrops of Caradoc strata within the Inlier occur only in the vicinity of the village of Melmerby, after which they are known as the Melmerby Beds. The rocks have been divided into an upper and lower series ; the Upper 72 THE TRILOBITES OF THE CARADOC SERIES Melmerby Beds contain a fauna indicative of the lower zone of the Upper Long- villian Substage, an horizon which, as stated earlier, is not yet known elsewhere in the Inlier. In the field, the Lower Melmerby Beds appear to underlie the upper beds stratigraphically and are considered to be of Lower Longvillian age ; they contain abundant evidence of a Longvillian age but the zonal brachiopods of the Shropshire succession have not yet been detected and may be absent owing to the unsuitability of the environment. The rocks are mainly dark-green or maroon, blocky mudstones with occasional impure, nodular limestones. Their fauna includes a conspicuously large number of trinucleid trilobites, accompanied by common Kloucekia apiculata (M'Coy), features which readily distinguish them from the equivalent strata farther south in the Inlier, and which are more suggestive of corresponding North Welsh faunas. No useful evidence has yet been obtained from the region to elaborate on the cor- relation between the shelly and graptolitic successions already put forward for south Shropshire (Dean, 1958 : 226). The Pusgillian, from its position above the Onnian (believed to represent the topmost Dicranograptus dingani Zone) , is equated approxi- mately with the Pleurograptus linearis Zone, and the shelly fauna suggests a correlation with Etage 4ca of southern Norway, an horizon which is itself correlated with that graptolite zone. The fossil localities cited in the following descriptions are shown in Text-figs. 2-5. Text-fig 3 covers the well-known section of Swindale Beck, just north-east of the village of Knock ; Text-fig 2 shows Pus Gill, north-east of Dufton ; Text-fig. 4 covers the large area of east of Dufton, with the important sections of Dufton Town Sike, Billy's Beck and Harthwaite Sike ; Text-fig. 5 shows the small, isolated outcrop of the Melmerby Beds north-east of Melmerby, near the northern end of the Inlier. III. SYSTEMATIC DESCRIPTIONS Family RAPHIOPHORIDAE Angelin, 1854 Genus LONCHODOMAS Angelin, 1854 TYPE-SPECIES. Ampyx rostratus Sars, 1835 by subsequent designation of Bassler (1915 : 41). Lonchodomas swindalensis sp. nov. (PL 6, figs. 2, 6, 8) 19590. Lonchodomas aff. rostratus (Sars) Dean, pp. 194, 207. DIAGNOSIS. Lonchodomas with glabella projecting only short distance in front of fixigenae. Pygidium semi-elliptical with four pairs of pleural furrows, the first pair being the most sharply defined. DESCRIPTION. The material is fragmentary for the most part but includes two almost whole cranidia and one small, well-preserved pygidium. Excluding the THE TRILOBITES OF THE CARADOC SERIES 73 74 THE TRILOBITES OF THE CARADOC SERIES FOSSIL LOCALITIES IN SWINDALE BECK NEAR KNOCK FIG. 3. THE TRILOBITES OF THE CARADOC SERIES 75 o £ 76 THE TRILOBITES OF THE CARADOC SERIES FOSSIL LOCALITIES 71 ON THE ALSTON ROAD, NEAR XMELMERBY / / + + lT?'xTkiJ 1+ + • ^ '* ' * i v- o _±_ _+ + +'+/+ + + -»£ + + + * + + +S--*- ~~-r ~+-+ "_£**+• — ^ /+ + + + \C + + + + + + >^+ i^^1? + + T k=^± ± ± * +t + + + + + jr + >^+ + + + + + + + + +V + + + + +/* + yf + + + + + + + + + + +r . r . — -S . r r^ C C \ \ \ C i i ,i ' j~ —A. FOSSIL LOCALITY / FAULTS DELIMITING CARADOC OUTCROP FIG. 5. THE TRILOBITES OF THE CARADOC SERIES 77 frontal spine, the dimensions of the cranidia, numbered respectively In. 49946 and In. 49968, are as follows : length, 5 mm., breadth, 9 mm. ; length, u mm. ; breadth, 16 mm. Dimensions of the pygidium, In. 49967, are : length, 1-5 mm., breadth, 4-5 mm. The cranidium is roughly rhomboidal in plan, produced anteriorly into a long, frontal spine, the surface of which bears fine, longitudinal striae. The glabella attains its greatest breadth at its mid-point and is bounded by almost straight axial furrows containing slot-like hypostomal pits, situated frontally. One cranidium (PI. 6, fig. 2) shows a faint median ridge extending from near the occipital furrow to the base of the frontal spine, where it is replaced by a groove ; similar grooves occur on the sides and undersurface of the frontal spine as in other species of Lonchodomas , giving rise to the fluted, quadrate cross-section characteristic of the genus. The posterior margin of the cranidium, and the pleuroccipital furrows are parallel, transversely straight except medially where, owing to a small extension of the glabella, they are convex backwards. The pygidium is semi-elliptical in outline with a strongly-curved, steeply-declined, posterior border which carries fine, parallel terrace lines, though the latter are not visible in the photograph (PI. 6, fig. 6). The anterior margin is straight medially but curves forwards a little anterolaterally. There are four pairs of pleural furrows, the first pair being the most deeply impressed ; all are deepest anterolaterally becoming faint at, or near, the shallow axial furrows. No axial rings are visible. HORIZON AND LOCALITIES. All the known specimens have been collected from Dufton Shales belonging to the upper half of the Upper Longvillian Substage in Swindale Beck. There they occur in association with Kjaerina geniculata Bancroft, Reuschella sp. nov. and Dolerorthis sp. The figured specimens are from localities B. 5 and B. 6, but the same form has been found also at B. 10 (see Text-fig. 3). These are the only records of Lonchodomas from the Upper Longvillian of the Anglo- Welsh area. HOLOTYPE. In. 49968 (PI. 6, fig. 2). PARATYPES. In. 49946 (PI. 6, fig. 8) ; In. 49967 (PI. 6, fig. 6). DISCUSSION. The Swindale Beck species bears an obvious relationship to Lonchodomas rostratus (Sars) which has been refigured by St0rmer (1940 : 128, pi. 2, figs. 1-4). The latter species has, however, a smaller proportion of the glabella projecting in front of the fixigenae, and the pygidium of the Norwegian form, the type-specimens of which were obtained from the Ampyx Limestone (zone of Nemagraptus gracilis) near Oslo, differs also in having only one pair of well-defined, distally situated, pleural furrows, which die out before attaining the axial furrows. Lonchodomas politus (Raymond, 1925 : 39, pi. 2, figs. 8, 9 ; Cooper, 1953 : 18, pi. 6, figs, i, 2, 5-10), from the " Upper Lenoir Limestone " of Black River age in Tennessee, has a conspicuously punctate test and a pygidium bearing seven or eight pairs of furrows, only the first of which is deeply impressed, but otherwise much resembles the Cross Fell species. The stratigraphically younger species Lonchodomas pennatus (La Touche), discussed elsewhere in the present paper, has a relatively larger proportion of the glabella projecting in front of the fixigenae, whilst the pygidium has a less well- differentiated axis than that of L. swindalensis , and only one pair of pleural furrows. 78 THE TRILOBITES OF THE CARADOC SERIES Lonchodomas pennatus (La Touche) (PI. 6, figs, i, 3-5, 9, 12) 1884. Ampyx pennatus La Touche, p. 57, pi. 3, fig. 56. 1891. Ampyx tetragonus Angelin : Nicholson & Marr, p. 511. 1932. Ampyx (Lonchodomas) pennatus La Touche : Reed, p. 205, pi. n, figs. 5-7. 1949. Lonchodomas pennatus (La Touche) Bancroft, p. 299, pi. 10, fig. 17. 1958. Lonchodomas pennatus (La Touche) : Dean, pp. 213, 224. 19590. Lonchodomas pennatus (La Touche) : Dean, pp. 200, 207. 1960. Lonchodomas pennatus (La Touche) : Dean, p. 82, pi. u, figs. 2, 5, 8-12. Several cranidia agreeing in all essentials with La Touche's species have been collected from the Dufton Shales. The often indifferent preservation renders precise measurement difficult , most of the specimens being compressed vertically, but the proportions are close to those of similarly preserved Shropshire material, the length of the cranidium, measured from the base of the frontal spine to the posterior margin of the occipital ring, being slightly more or less than three-quarters of the maximum breadth. A feature not previously seen in L. pennatus but now preserved in one specimen (PL 6, fig. i) is the retrousse form of the prismatic frontal spine, which curves forwards and gently upwards from the glabella : a similar curvature is seen also in Ampyx salteri Hicks and Ampyx linleyensis (Whittard, 1955, pi. i, fig. 17 ; pi. 2, fig. 6). A few individuals have traces of a slight median ridge or carina on the glabella, and this may be either accentuated by lateral com- pression or absent altogether. A similar ridge occurs in some Shropshire specimens, but its presence varies with the state of preservation. Two probably immature pygidia from Cross Fell (PI. 6, fig. 5) are proportionately broader than the forma typica, their length : breadth radio being i : 3, but in mature pygidia this changes to about i : 2, that is to say, generally comparable with the Shropshire material. HORIZON AND LOCALITIES. In the Knock-Dufton district Lonchodomas pennatus appears for the first time in the Onnian Stage, Onnia gracilis Zone, of Pus Gill, at localities A. 8, 9, 12 and 14. It has been found less commonly in the overlying Onnia superba Zone of Pus Gill, at localities A. 5 and 16. The ensuing Pusgillian Stage has yielded specimens at both Pus Gill, localities A. 6, 18 and 28, and Swindale Beck, locality B. 25. DISCUSSION. La Touche's holotype was obtained from the Onnian Stage, Onnia superba Zone, in the Onny Valley of south Shropshire, in which district Lonchodomas pennatus ranges upwards from the Actonian Stage (Dean, 1960 : 83). The discoveries in the Pusgillian Stage of the Cross Fell Inlier increase the known vertical range of the species, but there is no information yet regarding its relationship to still younger forms, though there is a general resemblance to certain species of Ashgill age, for example that figured by Reed (1905 : 97, pi. 4, fig. 2) as Ampyx (Lonchodomas) cf. rostratus Sars from the Slade Beds of Haverfordwest. Elsewhere, a small cranidium of Lonchodomas which may be conspecific with L. pennatus has been figured by Stermer (1945, pi. 2, fig. 10) as Lonchodomas aff. rostratus (Sars) from the Tretaspis Shales of Hadeland, a horizon approximately equivalent to the Pusgillian Stage. Lonchodomas carinatus (Cooper, 1953 : 17, pi. 7, THE TRILOBITES OF THE CARADOC SERIES 79 figs. 12-17, 19-23) from the Black River Stage of Tennessee bears a strong resem- blance to L. pennatus but possesses an irregularly punctate test, and the glabella projects less far forwards in front of the fixigenae. The pygidium of L. carinatus differs in having at least four discernible axial rings. Family TRINUCLEIDAE Hawle & Corda, 1847 Subfamily CRYPTOLITHINAE Angelin, 1854 Genus BROEGGEROLITHUS Lamont, 1935 TYPE SPECIES. Cryptolithus broeggeri Bancroft, 1929 by original designation. Broeggerolithus nicholsoni (Reed) (PL 6, figs. 7, ii?, 14? ; PL 7, figs. 1-12) 1891. Trinucleus goldfussi Barrande ?, Nicholson & Marr, p. 509. 1891. Trinucleus seticornis Hisinger ?, Nicholson & Marr, p. 509. 1910. Tinucleus nicholsoni Reed, p. 212, pi. 16, figs. 1-9. 1912. Trinucleus nicholsoni Reed : Reed, pi. 18, fig. 6 ; pi. 19, figs. 4, 4^. 1914. Trinucleus gibbifrons M'Coy : Reed, p. 356, pi. 29, fig. 6. 1914. Trinucleus nicholsoni Reed : Reed, p. 357. 1927. Cryptolithus nicholsoni (Reed) Stetson, p. 88. 1940. Broeggerolithus nicholsoni (Reed) Whittington, p. 245. 1948. Broeggerolithus nicholsoni (Reed) : Bancroft in Lamont, p. 416. I959& Broeggerolithus nicholsoni (Reed) : Dean, pp. 212, 214, 220. 1960. Broeggerolithus sp. (? nov.) Dean, p. 119, pi. 17, fig. 12. 1960. Broeggerolithus simplex Dean, p. 120, pi. 17, fig. 14. DESCRIPTION. The cephalon is sub-semicircular in outline, broader than long, the maximum breadth of the syntypes ranging from 14 mm. to about 22 mm. The glabella is of moderate breadth, equal to about two-thirds of the total length, and often carries a small, apical ocellus just forward of centre. A pair of small, basal, glabellar furrows with apodemes is located immediately in front of a second pair of apodemes situated at the distal ends of the occipital furrow. The glabella is separated from the convex cheek-lobes by moderately-deep, almost straight, axial furrows. The occipital ring is small, strongly convex transversely, produced backwards and upwards to form a broadly-based occipital spine. The cephalic fringe is moderately declined, both frontally and laterally, though this may not always be apparent owing to compression of the specimen within a shaly matrix. The upper surface of the fringe is generally smooth and there is no development of raised interradial ridges such as are found in some earlier species of Broeggerolithus, for example B. broeggeri (Bancroft). One or two specimens show suggestions of such ridges, but these are almost certainly due to crushing and are not of constant form. There are four concentric rows of fringe-pits in front of the glabella, where the breadth (sag.) of the fringe contracts slightly so as to accommodate the frontal lobe of the glabella. There is a strong radial arrangement of pits frontally, and this 8o THE TRILOBITES OF THE CARADOC SERIES persists laterally. The concentric arrangement is also marked, and the variation and norm of the four outer rows of pits is as follows : E2 = 19-24 (22), Ex = 21-23 (21), Ix = 21-22 (22), I2 = 20-22 (21). Up to three pits of E2 may be missing at the genal angle, and in certain rare instances an occasional pit of E2 may be absent laterally or anterolaterally. There is a notable lack of auxiliary E2 pits such as are found laterally in certain related species of Broeggerolithus. There is little marked differentiation in the size of pits, but those of Ij and I2 are slightly larger than the others, especially towards the posterior margin of the fringe. E2 and Ej are sited close together, but Ex and Ix are separated by a smooth, narrow, concentric " band " corresponding in position with a conspicuous girder on the underside of the fringe. A similar band of equal breadth separates I1 and I2, marking the position of a second less well developed pseudo-girder. There are seven to nine, most commonly eight, pits along the posterior margin of the fringe. I3 usually comprises fourteen or fifteen small pits, and is developed from Rn or thereabouts. The posterior margins of the fringe run slightly backwards, delimiting small genal prolongations, towards the genal angles which are produced to form librigenal spines ; the latter curve gently outwards and backwards, and their length is at least equal to that of the cephalon. One of the syntypes, A. 29607, retains only five thoracic segments of typical trinucleid form. The axis of each is narrow (tr.) and bears a pair of apodemes situated just above the axial furrows. On each pleura, a moderately-deep pleural furrow, situated just forwards of centre, runs obliquely backwards from the axial furrow to the pleural point. A complete topotype thorax (PI. 7, fig. 4) exhibits the customary complement of six thoracic segments. The syntype pygidium, A. 29615 (PL 7, fig. 2), is preserved as an internal mould and few details can be seen. The axis has three clearly defined axial rings, and three or four more are less well defined. The pleural lobes have three, or perhaps four, segments, separated by faint pleural furrows and widening (exsag.) towards the lateral margins. HORIZON AND LOCALITIES. All Reed's syntypes were described by him as having been collected solely from the Alston Road cutting near Melmerby, but the state of preservation of most of the specimens indicates that they came from what are known as the Lower Melmerby Beds, and the probable type-locality is believed to be that shown in the present paper as locality J (see Text-fig. 5). One syntype, Sedg. Mus. A. 29614, is preserved differently from the rest and the matrix suggests a probable origin in the Upper Longvillian strata such as are found at Alston Road, locality H. All the other localities, from A to G, along the Alston Road have yielded Broeggerolithus nicholsoni, but the specimens are, in general, smaller than the syn- types. Although trinucleid trilobites are so abundant almost everywhere at the Alston Road outcrop, elsewhere in the Inlier they are almost unknown from strata of Longvillian age. An uncommon exception is locality E. 3 at Harthwaite Sike where rare fragments, referred to B. cf. nicholsoni (see PL i, figs, n, 14), occur with an assemblage indicating the Bancroftina typa Zone of the Lower Longvillian. LECTOTYPE, here chosen. Sedg. Mus. A. 29613 (PL 7, figs. 6, 9). THE TRILOBITES OF THE CARADOC SERIES 81 PARATYPES. Sedg. Mus. A. 29607 ; A. 29608 ; A. 29609 (PI. 7, figs, i, 7) ; A. 29610 (PI. 7, fig. 10) ; A. 29611 (PI. 7, fig. 5) ; A. 29612 (PI. 7, fig. 8) ; A. 29614 (PI. 7, fig. ii) ; A. 29615 (PL 7, fig. 2). DISCUSSION. In a recent account of trinucleid trilobites in south Shropshire (Dean, 1960 : 103) the species assigned to the genus Broeggerolithus were divided into three groups on the basis of small but significant differences in the structure of the cephalic fringe. B. longiceps (Bancroft) and B. transiens (Bancroft) were placed together in Group 3, whilst B. simplex Dean was placed doubtfully in Group 2. The last-named species is here regarded as a synonym of B. nicholsoni and may also be placed in Group 3. B. simplex was founded on a small cranidium from the Lower Longvillian of the Onny Valley and was at that time believed to be distinct. The pit count, however, falls within the limits of variation now established for B. nicholsoni, and additional material from Shropshire tends to confirm the identity of the two species The fringe of Broeggerolithus transiens closely resembles that of the Melmerby species but its pit-count for the four outermost rows is noticeably smaller, and there are a few auxiliary pits situated anterolaterally in E2. Broeggerolithus longiceps is remarkably similar to B. nicholsoni. The former species is, unfortunately, known from only a comparatively small population sample in south Shropshire, but as far as can be ascertained the pit-count falls within the limits of that for B. nicholsoni. Like B. transiens, however, B. longiceps generally possesses a few auxiliary pits in E2, though situated posterolaterally, and these have not been found in B. nicholsoni. It is not known whether this is an invariable characteristic of B. longiceps, but if this should not prove to be the case then there is no other valid reason for regarding the species as distinct from B. nicholsoni. Certain well-preserved Shropshire speci- mens of B. longiceps have reticulate cheek-lobes, a feature not seen on any of the syntypes of B. nicholsoni but found on several specimens of the latter species from the Upper Melmerby Beds of the Alston Road cutting. Outside the Cross Fell Inlier Broeggerolithus nicholsoni probably occurs at several localities in North Wales, associated with faunas of Longvillian age. Broeggerolithus melmerbiensis sp. nov. (PI. 6, figs. 10, 13) 1959a- Broeggerolithus aff. nicholsoni (Reed) pars, Dean, p. 214. DIAGNOSIS. Large Broeggerolithus generally similar to B. nicholsoni but with large number of fringe-pits, about one hundred, in four outermost concentric rows. Both Ex and E2 extend to the genal angles. DESCRIPTION. One well-preserved specimen collected from the Alston Road cutting appears to resemble Broeggerolithus nicholsoni in most respects, but possesses a number of fringe-pits much larger than the norm for that species. The specimen has a closely similar radial and concentric arrangement of pits, but particularly noticeable is the manner in which rows E2 and Ex are placed close together, whilst rows E! and Ix are separated from each other by a wide, concentric " band " which GEOL. 7, 3. 4 82 THE TRILOBITES OF THE CARADOC SERIES coincides with the girder on the underside of the fringe. Ix and I2 are similarly separated from each other, and the pits composing these two rows become larger in size towards the posterior margin of the fringe. A conspicuous feature is the way in which both Ex and E2 are developed as far as the genal angles. Both I3 and I4 consist essentially of pits which are comparatively small, though increasing slightly in size posteriorly, and the two rows are developed respectively from Ri3 and Rig. The pit count for the specimen is as follows : £2 = 24 pits, Ei = 25 pits, Ii = 26 pits, 12 = about 25 pits. There are four continuous concentric rows of pits in front of the glabella, and seven pits are situated along each posterior margin of the fringe. The total number of pits in rows E2 to 12 inclusive is about one hundred, compared with an average of about eighty-five in Broeggerolithus nicholsoni (s. s.). The single available cranidium possesses four attached thoracic segments of typical Broeggerolithus aspect, but the total number originally present is unknown, as is the pygidium. HORIZON AND LOCALITY. The holotype was collected from a loose nodule of impure limestone immediately below locality A in the Alston Road cutting, three- quarters of a mile north-east of Melmerby (see Text-fig. 5). It is almost certain that the specimen did, in fact, derive from this locality. The horizon is in the Long- villian Stage, and the strata at this point are believed to be the Upper Melmerby Beds, of Upper Longvillian age (Dean, 1959*1 : 213). The associated fauna includes Broeggerolithus nicholsoni, Brongniartella and FlexicaLymene. HOLOTYPE. BM. In. 52558. DISCUSSION. Although bearing a general resemblance to certain other species of Broeggerolithus such as B. nicholsoni, B. longiceps and B. transiens, the new form is unlikely to be confused with them on account of its much higher pit-count for the four outer rows, whilst no other species exhibits a comparable development of E2 to the genal angles. Broeggerolithus cf. transiens (Bancroft) (PI. 8, figs, i, 3, 4, 6, 8, ii) 1929. Cryptolithus transiens Bancroft, p. 90, pi. 2, fig. 5. i959«. Broeggerolithus transiens (Bancroft) Dean, pp. 196-8, 207. 1960. Broeggerolithus transiens (Bancroft) : Dean, p. 123, pi. 18, figs. 2, 3, 7, 8, ii, 14. This reference contains a list of all other synonyms. Numerous cephala and cranidia have been found, agreeing in all essentials with the description of the species from the type-area of south Shropshire (Dean, 1960 : 123). The pit count for the various rows of the cephalic fringe falls within the limits of variation of the Shropshire specimens, but instead of having one or two pits of Ej marginal at the genal angle, the Cross Fell specimens commonly have three pits so situated, though the number has been found to vary from one to four. Generally there are up to two auxiliary pits in the outermost concentric row, E2, of the Shrop- shire specimens, and these may sometimes be absent from the Cross Fell examples. This casts some doubt on the validity of such a feature as a means of separating closely-related species, but too few complete cranidia are available from either THE TRILOBITES OF THE CARADOC SERIES 83 Shropshire or Cross Fell to give reliable statistics for the variation in E2. An analogous situation has already been noted with regard to Broeggerolithus nicholsoni and B. longiceps. The species is more abundant in the mudstones of the Cross Fell Inlier than in the corresponding coarser sediments of south Shropshire, and individuals frequently attain a larger size, the largest-known cephalon having a breadth of about 25 mm. HORIZON AND LOCALITIES. In the Knock-Dufton district Broeggerolithus cf. tran- sient is fairly common in Dufton Shales of the Marshbrookian Stage at Swindale Beck. There it occurs in small numbers in strata thought to belong to the middle portion of the stage (locality B 12), but becomes more abundant in higher strata (localities B. n, 14, 16) which contain Kjerulfina cf. polycyma Bancroft and are considered to be equivalent to the Onniella reuschi Zone of south Shropshire. B. cf. transiens occurs also in Harthwaite Sike, east-south-east of Dufton (see Text-fig. 4) at localities E. 7, 8, 9?, 10-12, but the fauna there is sparse, composed in the main of smaller individuals. Broeggerolithus sp. (PI. 8, %. 2) 19590. Broeggerolithus sp. (pars.) Dean, p. 207. Among the numerous trinucleid trilobites found in the Marshbrookian rocks of Swindale Beck is one individual quite different from all the rest. The specimen comprises a fragmentary cranidium preserved as a limonitic external mould in a dark-grey, cleaved mudstone. The estimated length and breadth of the original cephalon are respectively 12 mm. (approx.) and 26 mm. Its most distinctive feature is the manner in which the two outermost concentric rows of pits, E2 and Ex, end abruptly without extending to, or even near, the genal angle as is customary in normal forms of Broeggerolithus. E2 extends only to the anterolateral angle, leaving three pits of Ex external to the margin. Ex stops far short of the genal angle, leaving five pits of Ix external to the margin, though separated from it by a smooth band which is equal in breadth to one row of pits. Such an arrangement results in the somewhat unusual, indented form of the cephalic margin in front of the genal angle, and the obliquely truncated shape of the anterolateral angle. The estimated number of pits originally present is as follows : E2 + e2 = 12, Ex + et = 15, Ix + ix = 19, I2 -f i2 = 19, I3 -f i3 = 10. There is a small triangular group of eight pits situated between I2 and I3 near the posterior margin of the fringe, and seven pits are aligned parallel to the latter. The pits of Ex and 1^ are of roughly equal size, larger than those of E2 and I3. The last four pits of I2 nearest the posterior margin are of particularly large size. HORIZON AND LOCALITY. Found in mudstones of the Dufton Shales which contain Broeggerolithus cf. transiens (Bancroft) and Kjerulfina cf. polycyma (Bancroft), and belong to the topmost part of the Marshbrookian Stage, at locality B. 16 in Swindale Beck. DISCUSSION. It is not unusual for specimens of Broeggerolithus to have a de- ficiency in the number of E2 pits near the genal angle, and in such forms as B. 84 THE TRILOBITES OF THE CARADOC SERIES soudleyensis (Bancroft) and B. globiceps (Bancroft) some E2 pits may be absent frontally, but no known species compares in any way with the excessive loss of pits in the specimen now figured. In view of the large number of specimens of normal Broeggerolithus cf . tmnsiens associated with the cranidium it seems likely that the specimen represents a rare mutation or pathological form. Consequently it is not proposed to erect a new specific name, at least until further material is available. Genus ONNIA Bancroft, 1933 TYPE SPECIES. Cryptolithus superbus Bancroft, 1929 by original designation of Bancroft (1933 : 2). Onnia gracilis (Bancroft) (PI. 8, figs. 12, 13) 1929. Cryptolithus gracilis Bancroft, p. 94, pi. 2, figs. 8, 9. JQSQtf- Onnia gracilis (Bancroft) Dean, p. 207. 1960. Onnia gracilis (Bancroft) : Dean, p. 130, pi. 19, figs. 2, 7. This reference contains a comprehensive synonymy of the species. This species has recently been redescribed in detail by the writer (Dean, 1960 : 130) who gave the following figures for the range in variation of the number of pits present in the outermost four rows of the fringe. E2 + e2 = 31-37 (34), £!+€! = 21-25 (22), Ij + ij = 21-25 (23), I2 + ia = 21-25 (23) The figure in brackets represents the mode. Insufficient well-preserved material is available from the Cross Fell Inlier to give authentic figures for the corresponding variation, but the available material has yielded the following results: E2 + e2 = 32-37, Ej -f- ^ = 20-23, Ix + it = 20-22, I2 + i2 = 21-22. It is therefore apparent that the speci- mens fall within, or are very close to, the permissible variation for the species in its type-area. HORIZON AND LOCALITIES. As in south Shropshire Onnia gracilis characterizes the middle portion of the Onnian Stage. It has been found in some abundance in black mudstones of the Dufton Shales at Pus Gill, localities A. 8, 9, u, 12, 13, 14 and 15. Again, as in Shropshire, the species is accompanied by a fauna which includes Onnicalymene onniensis (Shirley), Lonchodomas pennatus (La Touche), Chonetoidea sp. and Onniella broeggeri Bancroft. Onnia superba (Bancroft) pusgillensis Dean (PL 8, figs. 5, 7, 9, 10) 1961. Onnia superba pusgillensis Dean, p. 120, pi. 7, figs. 1-6. Includes full synonymy. Onnia superba (Bancroft), the zone fossil of the topmost subdivision of the Onnian Stage in south Shropshire, has not been found in the Cross Fell Inlier, but is thought to be represented by a distinct, and possibly local, subspecies 0. superba pusgil- lensis. Although resembling 0. superba in almost all respects the Cross Fell form may easily be distinguished by the continuous development of I2 in front of the THE TRILOBITES OF THE CARADOC SERIES 85 glabella, and by the greater development of I3 and I4, respectively from R$ or R4, and Ry. HOLOTYPE. BM. In. 55707. PARATYPES. BM. In. 50005 (PL 8, fig. 9) ; In. 50008 (PI. 8, fig. 5) ; In. 50049 ; In. 55704 ; In. 55705 ; In. 55706 ; In. 55708. HORIZON AND LOCALITIES. Dufton Shales, Onnian Stage, Onnia superba Zone, Pus Gill, localities A. 5 and A. 16. Subfamily TRETASPIDINAE Whittington, 1941 Genus TRETASPIS M'Coy, 1849 TYPE SPECIES. Asaphus seticornis Hisinger, 1840 by subsequent designation of Bassler (1915 : 1285). Tretaspis cf. ceriodes (Angelin) donsi Stermer (PL 10, figs. 4, 6, 8) 1945. Tretaspis ceriodes (Angelin) var. donsi Stormer, p. 405, pi. i, fig. 8. !959<*- Tretaspis cf. ceriodes (Angelin) : Dean, p. 207. 1961. Tretaspis cf. ceriodes donsi St0rmer : Dean, p. 129, pi. 9, figs. 7-9. In southern Norway, Tretaspis ceriodes donsi has been shown by Stermer (1945 : 404) to be restricted to the upper part of the Upper Chasmops Limestone, 4b#. The earliest-known occurrence of Tretaspis in the Cross Fell Inlier is at Pus Gill, locality A. 13, in Dufton Shales belonging to the Onnia gracilis Zone of the Onnian Stage, and the evidence at this point, though fragmentary, suggests a comparison with the Norwegian subspecies. Additional, better-preserved material from the Onnia superba Zone at Pus Gill, locality A. 5, is too incomplete for detailed comparison, but shows all the principal features of T. ceriodes donsi. The horizon of the Cross Fell specimens corresponds fairly closely with that of the Norwegian material. Tretaspis convergens Dean (PL 10, figs, i, 3, 5) 1961. Tretaspis convergens Dean, p. 127, pi. 9, figs. 1-6. A detailed description of this species has already been given (Dean, 1961 : 127) to which nothing need be added here. T. convergens is a distinctive form, its closest relationships being with the species-group typified by Tretaspis seticornis (Hisinger), particularly T. seticornis var. anderssoni Stermer (1945 : 402, pi. i, fig. 2). T. convergens has so far been found at only one locality in the Cross Fell Inlier, namely B. 25 in Swindale Beck. There it occurs in the highest part of the Dufton Shales, belonging to the Pusgillian Stage, so that it is generally contemporaneous with Tretaspis seticornis anderssoni and allied forms as found in Etage 4ca of southern Norway. HOLOTYPE. BM. In. 50059^, b (PL 10, figs, i, 3, 5). Paratypes. In. 50030 ; In. 50037 (PL 10, fig. 2) ; In. 500580, b. 86 THE TRILOBITES OF THE CARADOC SERIES Tretaspis kiaeri St0rmer radialis Lament (PL 9, figs. 2-4) 1941. Tretaspis kjaeri mut. radialis Lament, 1941, p. 456, figs. 5, 6. 1961. Tretaspis kiaeri radialis Lament : Dean, p. 122, pi. 7, figs. 7-9, pi. 8, figs, i, 3-5. Includes full synonymy of the subspecies. The majority of the abundant specimens of Tretaspis collected from the Dufton Shales of the Cross Fell Inlier can be referred to this subspecies. T. kiaeri radialis was founded originally on two fragmentary specimens from the Portrane Limestone of Eire, but the description has since been supplemented, using material from the Dufton Shales (Dean, loc. cit.}, and the affinities with other species discussed. HORIZON AND LOCALITIES. All the known specimens are from Dufton Shales belonging to the Pusgillian Stage. The exact distribution within the Pusgillian is not clear, owing to the predominance of successions affected by strike-faulting, but the subspecies appears to occur throughout most of the stage. Localities include the following : Pus Gill, A. 6, A. 18, A. 21, A. 24 to A. 30 ; Swindale Beck, B. 18, B. 22 to B. 26, B. 28, B. 33, B. 34 ; Dufton Town Sike, C. I to C. 6 ; Billy's Beck, D. i ; also the section at Hurning Lane, one mile north of Dufton. Tretaspis kiaeri St0rmer duftonensis Dean (PL 9, figs, i, 5-7) 1961. Tretaspis kiaeri duftonensis Dean, p. 125, pi. 8, figs. 2, 6-8. The subspecies was described from a single, well-preserved specimen collected from Dufton Shales belonging to the Pusgillian Stage at Pus Gill, locality A. 27. Its closest relationship would appear to be with T. kiaeri radialis, from which it differs in having a conspicuously larger pit-count for Ej.2, a less well-developed concentric arrangement of I2_4 posterolaterally, as well as a larger, triangular area of irregularly arranged pits on the genal prolongations of the fringe. T. kiaeri duftonensis is not known with certainty outside the type-locality, though fragments of fringe suggest that it may occur elsewhere at Pus Gill, but identification is difficult in the absence of better-preserved material. HOLOTYPE. BM. In. 5oo2oa, b. Family CHEIRURIDAE Salter, 1864 Subfamily CYRTOMETOPINAE Opik, 1937 Genus PSEUDOSPHAEREXOCHUS Schmidt, 1881 TYPE SPECIES. Sphaerexochus hemicranium Kutorga, 1854 by subsequent designation of Reed (18960 : 119). THE TRILOBITES OF THE CARADOC SERIES 87 Pseudosphaerexochus cf. octolobatus (M'Coy) (PI. 10, figs. 7, 9-12) ?i8gi. Youngia trispinosa Nicholson & Etheridge : Nicholson & Marr, p. 511. I959« Pseudosphaerexochus sp. nov., Dean, pp. 204, 208. DESCRIPTION. The cephalon is known only from the cranidium. The glabella is strongly convex both longitudinally and transversely, subovate in plan, its maxi- mum breadth about, or slightly greater than, three-quarters of the sagittal length. It is bounded by deep, evenly-curved axial furrows, strongly convex abaxially, with deep, hypostomal pits. The frontal lobe is small, rather less than one-quarter of the glabellar length, and there are three pairs of equispaced glabellar furrows. The first and second pairs are parallel, extending inwards about one-quarter of the glabellar breadth ; they intersect the axial furrows at right-angles, but curve thence adaxially backwards, at the same time becoming rapidly shallower. The first and second pairs of glabellar lobes are identical in size and form, their convexity in line with the remainder of the glabella. The third glabellar furrows are deeper than, and parallel to, the first and second pairs, but curve backwards without reaching the occipital furrow and become shallower proximally. The occipital ring is small, narrow (tr.), strongly convex transversely, separated from the glabella by a moder- ately deep occipital furrow. The fixigenae are small, convex, and steeply declined abaxially. The pleuroccipital segment becomes slightly longer (exsag.) laterally, ending posterolaterally in a pair of short, broad, blunt fixigenal spines set a short distance inwards from the lateral margins. The pleuroccipital furrow is transversely straight for the most part, becoming shallower distally where it curves forwards towards, though without reaching, the lateral margins. The eyes have not been found preserved. The palpebral lobes are narrow, moderately convex abaxially, strongly arched longitudinally, and slightly divergent backwards ; they are defined proximally by palpebral furrows of moderate depth which die out quickly to both front and back. The anterior branches of the facial suture extend forwards from the eyes, parallel to the axial furrows, to cut the anterior border, whilst the posterior branches curve backwards distally to intersect the lateral margins just in front of the line of the pleuroccipital furrow. The librigenae have not been found. The surface of the glabella is covered with fine, evenly distributed granules, whilst all the furrows are smooth. The surface of the fixigenae is covered with large, dispersed pits, the intervening spaces, together with the surface of the pleuroc- cipital segment, being covered with smaller punctae which are apparent only on the external mould. The internal mould of the glabella is ornamented with closely- grouped, small, prickly granules, probably representing the infillings of canals in the original test. The hypostoma and thorax are not known. An incomplete pygidium, which must have been more than twice as broad as long, is the only specimen that has been found (PI. 10, fig. 7). It is made up of four segments which are produced backwards to form four pairs of strong, tapering spines ; the latter are separated from one another by well-defined notches, and their tips are stepped backwards slightly en echelon from first to fourth. Only three 88 THE TRILOBITES OF THE CARADOC SERIES axial segments are visible, the first two well defined by deep ring furrows, and the third poorly defined by two shallow transverse notches near the bases of the fourth pair of pleural spines. The axial furrows comprise broad, shallow grooves, moderately convergent backwards. Excluding the furrows, the surface of the pygidium is granulate on the internal mould, but finely pitted on the external mould. HORIZON AND LOCALITIES. The earliest-known occurrence of the species in the Cross Fell Inlier is in the Dufton Shales, Onnian Stage, Onnia superba Zone of Pus Gill, locality A. 5. Most of the available specimens are, however, from Dufton Shales belonging to the Pusgillian Stage at Swindale Beck, locality B. 25. Other localities, all in Pusgillian strata, are at Pus Gill, localities A. 6 and A. 30, and at Dufton Town Sike, locality C. 6, east of Dufton. DISCUSSION. The specific name Pseudosphaerexochus octolobatus has been used to cover forms of the genus occurring in British Ordovician strata of various ages. The holotype, described and figured by M'Coy (1849 : 4°7 » *» Sedgwick & M'Coy, 1851, pi. IG, fig. 10) as Ceraurus octolobatus, is a pygidium, Sedg. Mus. A. 11606, from the Rhiwlas Limestone, of Ashgill age, near Bala, and the species must be redescribed in detail before satisfactory comparisons can be made. Specimens from the Ashgill Series, Drummuck Group, of Girvan were assigned by Reed (1906 : 141, pi. 18, figs. 8-n) to Cheimrus (Cyrtometopus] octolobatus, and these appear to be identical with the Cross Fell specimens, at least as far as the cephalon is concerned. Pseudosphaerexochus has been recorded from the Onnian Stage of the Onny Valley in south Shropshire (Dean, 19610 : 316), but the material there is too fragmentary for comparison with that from Cross Fell. Family ENCRINURIDAE Angelin, 1854 Subfamily ENCRINURINAE Angelin, 1854 Genus ENCRINURUS Emmrich, 1844 TYPE SPECIES. Entomostracites punctatus Wahlenberg, 1821 by original designa- tion of Emmrich (1844 : 16). Encrinurus sp. (PI. n, figs, i, 4) 19590. Encrimtrus sp., Dean, p. 214. Only one specimen has been collected, a pygidium about 5 mm. long and 4-5 mm. broad frontally, preserved as an internal mould with part of the corresponding external mould. Frontally the axis occupies about one-quarter of the maximum breadth ; it is delimited by deep, smooth axial furrows and tapers backwards to a narrow tip. There are eight pairs of pleural ribs which terminate laterally in small free points ; the pleurae of the eighth pair almost coalesce with the terminal piece of the axis, from which they are separated by a pair of shallow grooves. The axis as far as the eighth pair of pleurae carries fifteen axial rings, but beyond this position is apparently smooth. The ring furrows, apart from the first three or four, become THE TRILOBITES OF THE CARADOC SERIES 89 shallower medially and there are traces of small median nodes on the third, fifth and eighth axial rings. The remainder of the dorsal surface is smooth. HORIZON AND LOCALITY. Locality H (see Text-fig. 5) beside the Alston Road, three-quarters of a mile north-east of Melmerby. The strata, the Upper Melmerby Beds, contain fossils indicating the lower part of the Upper LongvilHan Substage, the equivalent of the Kjaerina bipartita Zone or Alternata Limestone in south Shropshire. DISCUSSION. Few Caradoc species of Encrinurus are available for comparison. Encrinurus sp. (? nov.) from the Marshbrookian Stage of Shropshire (Dean, 1961^, pi. 49, figs. 10, 12) has a similar number of ribs but a larger number of axial rings, at least seventeen. The Alston Road specimen may well prove to represent a new species. Subfamily DINDYMENINAE Pfibyl, 1953 Genus DINDYMENE Hawle & Corda, 1847 TYPE SPECIES. Dindymene fridericiaugusti Hawle & Corde, 1847 by subsequent designation of Barrande (1852 : 816). Dindymene duftonensis sp. nov. (PL n, fig. 13) 19591*. Dindymene sp. nov., Dean, pp. 198, 207. The holotype is an incomplete cranidium of estimated breadth 4 to 5 mm., ex- cluding fixigenal spines, the maximum breadth being roughly twice the length. The glabella is strongly convex, both longitudinally and transversely, narrow posteriorly but expanding forwards until equal to rather more than one-third of the cephalic breadth. The axial furrows are deep and narrow posteriorly, but widen forwards where they curve distally to join the lateral border furrow which skirts the plump fixigenae. The occipital furrow is shallow and broad (sag.) medially, deepen- ing laterally where a pair of deep apodemal pits is situated ; the occipital ring is small, curving forwards abaxially to form a pair of occipital lobes. The pleuroc- cipital segment is uniformly narrow (exsag.), transversely straight, separated from the fixigenae by a parallel, moderately-deep, pleuroccipital furrow. The external mould shows that the narrow (tr.) lateral borders meet the pleuroccipital segment at the genal angles which are produced to form a pair of fixigenal spines, long, slender, slightly curved, convex side forwards, and broadly splayed backwards. The surface of the fixigenal spines, lateral border and pleuroccipital segment is uniformly and finely granulate, appearing almost smooth. The surface of each fixigena is covered with fine wrinkles, which contain numerous small pits, and carries seven large tubercles ; three of the latter are situated anterolaterally in a row parallel to the lateral border furrow, one is situated medially just in front of the pleuroccipital furrow, and the remainder are arranged more or less sporadically over the fixigena. The surface of the glabella, though incomplete, is estimated to have carried about twenty tubercles of moderate size. Three of these form a median, longitudinal row 9o THE TRILOBITES OF THE CARADOC SERIES extending half-way from the occipital furrow to the front of the glabella and are flanked by two pairs of tubercles situated a short distance adaxially from the axial furrows. The remaining tubercles are grouped more closely together across the frontal lobe, and the intermediate spaces are finely granulate. These figures apply to the partially preserved holotype, and the material available is insufficient to decide whether there is any variation in the disposition of the tubercles. The remainder of the exoskeleton is unknown. HORIZON AND LOCALITY. Dufton Shales belonging to the Marshbrookian Stage, probably the middle or upper third, at locality E. 12 (see Text-fig. 4) in Harthwaite Sike, east-south-east of Dufton. HOLOTYPE. BM. In. 546520, b, the latter, an external mould, being figured here in the form of a latex cast. DISCUSSION. The known species of Dindymene were reviewed recently by Kielan (1959 : 146 et seq.). Of them, the species with which D. duftonensis may best be grouped are D. ornate, Linnarsson, of Ashgill age, and D. plasi (Kielan, 1959 : 151, pi. 29, figs. 1-3) from the Llanvirn Series of Bohemia. Like them it is equipped with genal spines directed posterolaterally, but those of the Cross Fell species are notably longer. Both the extra-British species differ from D. duftonensis in having a particu- larly large tubercle, almost a cephalic spine, sited medially, one-third of the distance from the occipital furrow to the front of the glabella ; in this respect they somewhat resemble the more extreme development of a cephalic spine seen in the recently described Cornovica, from the Lower Llanvirn of west Shropshire (Whittard, 1960 : 122), a genus which possesses, however, glabellar furrows and eleven thoracic seg- ments. The fixigenae of D. duftonensis carry a similar number of large tubercles to those of D. plasi and D. ornata : the glabella, however, has a greater number of tubercles than that of D, ornata but fewer than that of D. plasi. As with D. ornata the space between the glabellar tubercles is finely granulate, a feature apparently not found in D. plasi. Harper's (1956 : 389) record of Dindymene cf . ornata from Upper Longvillian strata at Llanystwmdwy, Carnarvonshire, suggests that D. duftonensis may possibly be represented in the North Welsh faunas. Dindymene sp. (PL n, fig. 6) i959 n§s- 9a> b) nas been shown to be a cephalon of Chasmops extensa (Boeck) and the other syntype (Murchi- son, 1839, pi. 23, fig. gc) has been chosen as lectotype (Dean & Dineley, 1961 : 374). The latter specimen is a flattened, large pygidium with six attached thoracic seg- ments, preserved as an external mould and refigured here as a vinyl plastic cast (PL 41, fig. 2). The pygidium is large, with frontal breadth 85 mm. and median length 52 mm., though it has been both vertically compressed and slightly sheared sinistrally. The anterior margin is gently convex forwards, whilst the remainder of the outline is broadly subparabolic. The axis is triangular in plan, though this has undoubtedly been exaggerated by crushing, bounded laterally by poorly-defined, straight, axial furrows which are hardly more than broad, shallow depressions. Frontally the axis occupies roughly one-third of the total glabellar breadth, and its anterior third carries traces of three large axial rings : beyond these the axis is virtually smooth, and ends in a slightly better-defined terminal piece, separated from the margin by a long (sag.) posterior border. The pleural lobes also have a broad, gently concave, smooth border, inside which the pleural fields are slightly convex dorsally with seven pairs of shallow, poorly-defined pleural furrows becoming progressively fainter posteriorly, the furrowed area extending only for about two- thirds of the length of the axis. Each pleural lobe has a large, steeply downturned, anterolateral facet ; on the lectotype, only the left facet is preserved, slightly distorted by crushing. GEOL. 7, 8 17 230 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III The thorax of the lectotype retains only six thoracic segments. Each axial ring is relatively long (sag.), transversely straight as far as the poorly-defined axial furrows. What appears, superficially, to be another pair of longitudinal furrows is found on the lectotype (PL 41, fig. 2), extending along the thorax and intersecting each axial ring at the points where it is curved backwards. This inner pair of " furrows " is not present on uncrushed specimens assigned to the species, although it is known from individuals which have undergone distortion, and is believed to be of tectonic origin. The thoracic pleurae are directed only slightly backwards distally, and end in blunt tips ; the latter are not preserved on the lectotype, but on other specimens each can be seen to form a small, spine-like posterolateral process which, presumably, functioned as a stop during enrollment. There is a well-defined pleural furrow on each pleura, running from the anterior margin at the axial furrow towards, but not reaching, the posterolateral part of the pleural tip. Immediately in front of this furrow is a paraUel ridge which reaches the tip, though in a diminished form, and beyond the ridge the anterior band of the pleura is turned down antero- laterally, again a feature which was probably functional in enrollment. No topotype cephalon is yet available, and the following description is founded on a cranidium from Pontesford, east Shropshire, which retains the full asaphid complement of eight thoracic segments, and has one associated librigena (PL 41, fig. i). This individual shows the cranidium to be of depressed form, only gently convex both longitudinally and transversely, with straight posterior margin. The glabella is longer than broad in the ratio 4 : 3 and, although the frontal glabellar lobe is moderately well defined anteriorly but with no incised preglabellar furrow, the remainder of the glabella is poorly defined, particularly posteriorly, where it is continuous with the fixigenae and occipital ring. There are no glabellar furrows and the axial furrows are practically obsolete, apart from poorly defined depressions delimiting the lateral margins of the frontal glabellar lobe. The anterior border forms a brim-like structure, its anterior margin moderately convex forwards and its dorsal surface smooth, flattened or slightly concave. The palpebral lobes are strongly curved, placed opposite the middle of the glabella, their dorsal surface flat and continuous with that of the glabella. The anterior branches of the facial suture diverge forwards from the eyes for about half their length, but then curve strongly and evenly inwards to cut the anterior border at an acute angle, longitudinally in- line with the palpebral lobes. The posterior branches are moderately curved back- wards from the eyes, and cut the posterior margin of the cephalon midway between the axial furrows and the lateral margins. One displaced librigena has been found in association with the cranidium (PL 41, fig. i), though the visual surface of the eye is too badly damaged for examination. There is a broad, flat platform circum- scribing the eye, and from this the remaining dorsal surface of the librigena declines gently to the margin, which is slightly concave, though there is no marginal furrow. The librigena is produced posterolaterally to form a stout, sharp, librigenal spine which extended originally as far as the mid-point of the thorax. None of the available specimens shows any ornamentation of the surface of the test, with the exception of the distal portions of the thoracic pleurae which carry terrace-lines between the pleural tips and the fulcrum. There is no trace of a median tubercle on the glabella, ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 231 though the exoskeleton has always been found damaged at the point where such a tubercle might be expected to occur. No hypostoma has yet been recorded from the type-locality, nor has one been found in association with undoubted specimens of Parabasilicus powisi. However, a specimen, assigned doubtfully to the species, is figured here from the middle Costonian of the Coston district (PL 40, fig. 2). It is preserved as an internal mould, lacks the anterior wings, and is longer than broad in the ratio 6:5. The median body is gently convex both longitudinally and transversely, sub-ovate in plan, longer than broad, with a pair of well-defined maculae sited posteriorly, a short distance either side of the axial line. The posterior border is indented by a deep, parabolic notch which extends forwards as far as the median body and is flanked posterolaterally by a pair of broad points. From these points the flattened lateral border runs forwards in a curve, at first expanding and then contracting to meet the sides of the median body just in front of centre. LECTOTYPE. GSM. 6841 (PL 41, fig. 2). HORIZONS AND LOCALITIES. The lectotype of Parabasilicus powisi was obtained from Trilobite Dingle (= Bron-y-Buckley Wood), Welshpool, and is therefore almost certainly of Harnagian age ; this tends to be confirmed by the state of preservation, which resembles that of the so-called Trilobite Dingle Shales. In south Shropshire, the earliest example of the species is from the Costonian Stage of the Evenwood district (PL 40, fig. i) ; this is a smaller specimen than the lectotype, but shows all the specific characters, as far as can be judged, and closely resembles a specimen figured by Salter (1866, pi. 23, fig. 5) from an unspecified horizon at Waterloo Bridge, Conway. Asaphid remains are uncommon in the Harnagian strata of south Shrop- shire, but a fragmentary cranidium (PL 42, fig. 9) and pygidium, B.M. In. 55371, from the Reuscholithus reuschi Zone of Smeathen Wood, Horderley, can probably be assigned to P. powisi, as also can a relatively small cranidium and pygidium from the same horizon at Coundmoor Brook, Harnage (PL 40, figs. 4, 5). The species Asaphus (Basilicus) marstoni was founded by Salter (1866 : 156, pi. 23, figs. la, b) on a small damaged dorsal shield preserved as an internal mould, together with the damaged right librigena of a slightly larger specimen, both from the "Shales of Horderly ". The syntypes are refigured here (PL 42, figs, i, 6, 8). Although Reed (1931 : 470) claimed that the species was better referred to the genus Proetus, there can be little doubt that it is, as Salter believed, an asaphid. Reed's assertion that the specimen represents an immature individual with less than the usual proetid quota of thoracic segments seems to be incorrect, as the eight segments present are typically asaphid in both form and number. The cephalon is damaged but shows nevertheless a general resemblance to that of Parabasilicus Powisi, as do the pleural lobes of the thorax, though the thoracic axis is more convergent posteriorly than that of the latter species. The pygidium resembles that of P. powisi in outline but the axis is better defined and the pleural fields of the pleural lobes are more strongly convex, with at least six pairs of moderately defined pleural furrows, though the number of both these, and the axial rings, present is obscured by abrasion and crushing. In the absence of additional material it seems advisable, for the present, to restrict the name Parabasilicus ? marstoni to the type- 232 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III specimens. The preservation of the type-material matches that of the Smeathen Wood Beds, belonging to the Harnagian Stage, of the Onny Valley near Horderley. The only other asaphids known from these strata are probably referable to Para- basilicus powisi, and P.? marstoni may well prove to be a synonym of the former species. The apparent differences could well be explained by variations in preserva- tion or in the stage of development, and the more distinct furrowing of the pygidium of P.? marstoni may have disappeared by the time the adult stage was attained. Evidence of P. powisi from the Lower Soudleyan, Broeggerolithus broeggeri Zone, is scanty, but includes a large pygidium and thorax from Glenburrell Farm (PL 40, fig. 3) as well as the cephalon and thorax already described from Habberley Brook, Pontesford. In the succeeding Upper Soudleyan and Lower Longvillian strata, asaphid fragments, especially pygidia, are not uncommon. The pygidium and hypostoma from " Horderley ", figured by Salter (1866, pi. 23, figs. 4, 6) as Asaphus (Basilicas) Powisi, are probably from the Horderley Sandstone. The hypostoma, now refigured (PI. 42, fig. 2), is proportionately narrower than the Costonian specimen questionably referred here to P. powisi (PL 40, fig. 2), though bearing a general resemblance to the latter. None of the pygidia from these younger horizons may be satisfactorily matched with that of P. Powisi, and they (PL 40, fig. 6 ; PL 42, fig. 5), together with the hypostoma mentioned, are merely referred, with some uncertainty, to Parabasilicus. In general, the Longvillian pygidia, as well as being of slightly different outline, tend to exhibit more ring and pleural furrows than P. powisi ; in this respect they resemble the pygidium of Parabasilicus ? marstoni, already dis- cussed, but until more satisfactory material becomes available specific identification is virtually impossible. The only evidence of asaphid trilobites from the Upper Longvillian of Shropshire is an unidentifiable fragment from the Alternata Lime- stone, and the family is unknown from all the succeeding strata. The distribution of Parabasilicus powisi and allied forms in the south of Shropshire is of particular interest in that the genus is found most commonly elsewhere in the Chikunsan Beds of South Korea, from which area the type species was described by Kobayashi (1934 : 475). However, another asaphid genus, Basilicus, though best known from the Llandeilo Series of Wales, occurs also in Korea (Kobayashi, 1934 : 465). Elsewhere, trilobites assigned to Parabasilicus are recorded from both Bolivia and Virginia (Kobayashi, 1937 : 503 ; Raymond, 1925 : 85-86), though the former record has been questioned by Harrington and Leanza (1957 : 36), who tentatively report the genus from Argentina. Most of the Shropshire occurrences of P. powisi are in strata correlated with the Diplograptus multidens Zone, though known from the top of the preceding Nemagraptus gracilis Zone, and extending upwards at least a little way into the succeeding Dicranograptus clingani Zone. According to Kobayashi (1934 : 336) the Chikunsan Beds are of Llandeilo age, but as they contain Diplograptus (Amplexograptus) perexcavatus Lapworth, a species said to be common in the Llandeilo and early Caradoc Series of Great Britain (Elles & Wood, 1914 : 521), both they and the Korean species of Parabasilicus may be of an age comparable to those of Shropshire. The form most resembling P. powisi, as noted by Kobayashi (1934 : 480) is that described by him as Parabasilicus shirakii ; the differences between the two are small, the thoracic axis of P. shirakii being the ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 233 narrower, whilst the palpebral lobes are sited farther forwards than in P. powisi. Although several specific names were erected by Kobayashi for the material of Parabasilicus from Korea, it seems likely that only one or two species are, in fact, present, most of the apparent differences being the result of tectonic distortion or intraspecific variation. The asaphid trilobite from the Richmond Formation of Ohio described by Foerste (1919 : 65, pis. 14, I4A, 15, especially 15) as Isotelus brachycephalus is a large form resembling Parabasilicus in some respects, including the anterior facial suture, the shape of the librigenae, the thorax, and the pygidial outline. However, the eyes are situated farther forwards, and the axial and pleural furrows of the pygidium are even less well defined than in the British species. Family ILLAENIDAE Hawle & Corda, 1847 Genus ILLAENUS Dalman, 1827 TYPE SPECIES. Entomostracites crassicauda Wahlenberg, 1821 by subsequent designation of Miller (1889 : 550). Illaenus cf. fallax Holm (PL 42, figs. 3, 4, 12) 1958. Illaenus sp., Dean, pp. 211-213, 224- Several fragments of illaenid trilobites have been recovered from strata of Actonian and Onnian age in south Shropshire. They are often damaged and distorted, but a few of the best preserved are now figured. No undamaged cranidium has been found, and it has not proved possible to make a firm identification of most of those found (PI. 42, figs. 7, 10, n). Two pygidia, however, are undistorted and show certain distinctive features (PL 42, figs. 3, 4). The outline is well rounded, subpara- bolic, the median length about three-quarters of the maximum breadth, attained just behind the anterior margin. The axis, occupying about one-quarter of the frontal breadth, is triangular in outline, scarcely defined by faint axial furrows which converge backwards at 50 degrees to meet just in front of centre of the pygidium, and continue back as a single faint furrow for about half the distance to the posterior margin, finally being replaced by an extremely low, thin, median ridge which runs almost to the margin. The dorsal surface of the axis, which bears traces of four or five axial rings, is slightly depressed or level, whilst the surface of the pygidium outside the axial furrows is at first level and then declines fairly steeply towards the margins. The front of the axis is marked by a moderately deep, transversely straight, articulating furrow which turns backwards slightly as it crosses the axial furrows, and then becomes both deeper and markedly broader (exsag.), finally terminating at about the proximal margin of the doublure. Immediately in front of this furrow each pleural lobe carries a pronounced, broad (exsag.) ridge, bordered frontally by a large, steeply downturned, anterolateral facet. Illaenus fallax was described by Holm (1882 : 82, pi. 2, figs. 11-20, pi. 5, figs. 15- 24) using a number of syntypes stated to be from the " Chasmopskalk " of Sweden ; 234 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III several localities are mentioned in his account, and two or more horizons are almost certainly involved. One Shropshire cranidium (PL 42, fig. 12) is generally similar to that of I. fallax, whilst pygidia figured here bear a remarkably close resemblance to one figured by Holm (1882, PL 2, fig. 17) from Gullerasen, a specimen which possesses also the characteristic axial outline, followed by a median groove and ridge. Thorslund (1940 : 140-141) recorded Illaenus fallax from different localities and horizons in Sweden, but he stated that the species occurs most abundantly in the Kullsberg Limestone of Dalecarlia, an horizon generally contemporaneous with those containing the Shropshire specimens. Although Illaenus fallax has been supposed by Jaanusson (1954 : 574) to belong to what he calls the " Parillaenus-Gruppe " of Illaenus s.s., some of the specimens which have been assigned to the species bear a certain resemblance to the genus Stenopareia Holm, 1886, and Stenopareia camladica has recently been described from the Soudleyan Stage of the Shelve Inlier by Whittard (1961 : 216, pi. 30, figs. 10-13). HORIZONS AND LOCALITIES. Specimens of Actonian age have been found beside the River Onny, in the vicinity of the junction of the river with Batch Gutter ; at various exposures in and around the village of Acton Scott ; and at Gretton Quarry (now filled in), near Cardington. Localities in Onnian strata include the north bank of the River Onny about 63 yards east of its junction with Batch Gutter (Onnia ? cobboldi Zone) ; and the river bank 100 yards east of the same junction (Onnia gracilis Zone). Family LICHIDAE Hawle & Corda, 1847 Subfamily LICHINAE Hawle & Corda, 1847 Genus METOPOLICHAS Gurich, 1901 TYPE SPECIES. Metopias huebneri Eichwald, 1842 by subsequent designation of Reed (1902 : 62). Metopolichas? sp. (PL 43, figs. 3, 4, 6, 7) 1938. Lichas aff. verrucosa (Eichwald), Stubblefield in Pocock et al., p. 255. 1958. Metopolichas ? aff. verrucosa (Eichwald) Dean, p. 218. Two fragmentary cranidia from the Costonian Stage may tentatively be referred to Metopoliches. They are too incomplete to provide a detailed description of the species, but bear a general resemblance to Metopolichas patriarchus (Wyatt-Edgell), recently redescribed by Whittard (1961 : 194, pi. 25, figs. 14-17) from west Shrop- shire. As far as the state of preservation permits, the fragments differ from M. patriarchus in having a greater convexity, smaller basal lateral lobes, and straighter longitudinal furrows. Such differences may, however, be nothing more than the consequence of a different mode of preservation, and a full description of the south Shropshire form must await additional material. M. patriarchus, although originally described from the Llanvirn Series of Wales, has been found by Whittard in the ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 235 Llandeilo Series of the Shelve Inlier, an horizon not appreciably earlier than the Costonian Stage. HORIZON AND LOCALITIES. Zone of Harknessella subquadrata, Stevenshill Quarry, by the south-eastern side of the brook, 1,500 yards south-west of Harnage Farm, Harnage. Zone of Costonia ultima, the old quarry, now filled in, 650 yards west of Woolston House, Woolston. Both horizons constitute the highest subdivision of the Costonian Stage in, respectively, the northern and southern parts of the Caradoc district. Subfamily HOMOLICHINAE Phleger, 1936 Genus PLATYLICHAS Gurich, 1901 TYPE SPECIES. Lichas margaritifer Nieszkowski, 1857 by original designation of Gurich (1901 : 522). Platylichas laxatus (M'Coy) (PI. 43, figs, i, 2, 5, 8-12) 1846. Lichas laxatus M'Coy, p. 51, pi. 4, fig. 9. ?i846. Calymene (?) forcipata M'Coy, p. 48, pi. 4, fig. 14 (Pygidium only). 1848. Lichas laxatus M'Coy : Salter in Phillips & Salter, p. 340, pi. 8, fig. 6. 1851. Trochurus nodulosus M'Coy in Sedgwick & M'Coy, p. 151, pi. i, F, fig. 16. 1852. Lichas nodulosus (M'Coy) Salter, p. iv. 1854. Lichas sexspinus Angelin, p. 74, pi. 38, figs. j-8a. 1854. Lichas aculeatus Angelin, p. 75, pi. 38, figs, n, na. 1854. Lichas laxatus M'Coy : Murchison, p. 201, fig. 29, 5. 1859. Lichas laxatus M'Coy : Murchison, p. 223, fig. 44, 5. 1866. Lichas laxatus M'Coy : Salter, p. 324, pi. 19, figs. 1—3. 1866. Lichas segmentatus Linnarsson, p. 18, pi. 2, fig. 4. 1867. Lichas laxatus M'Coy : Murchison, p. 204, fig. 46, 5. 1872. Lichas laxatus M'Coy : Murchison, p. 204, fig. 46, 5. 1884. Lichas laxatus M'Coy : La louche, pi. 3, fig. 63. 1885. Lichas laxata M'Coy : Schmidt, p. 125, pi. 6, fig. 24. 1906. Lichas laxatus M'Coy : Olin, p. 53, pi. i, figs. 27, 28. 1908. Lichas laxatus M'Coy : Wiman, p. 133, pi. 8, fig. 23. 1937. Platylichas laxatus (M'Coy) 1938. Platylichas laxatus (M'Coy) pars : Stubblefield, p. 34. JQ39- Platylichas laxatus (M'Coy) 1945. Platylichas laxatus (M'Coy) 1945. Platylichas laxatus (M'Coy) 1958. Platylichas laxatus (M'Coy) 1958. Platylichas laxatus (M'Coy) Phleger, p. 1090. Warburg, p. 118, pi. 12, figs. 1-4, 6, 7, 9-12. St0rmer, p. 417, pi. 4, fig. 15. Bancroft, p. 183. Dean, p. 224. Tripp, p. 579, pi. 85, figs. 3-5. This oft-quoted Ordovician trilobite species was founded on a single, incomplete, slightly compressed cranidium, preserved in a dark-grey, shaly mudstone. The specimen is in the M'Coy Collection at the National Museum of Ireland, and is refigured here for the first time since M'Coy's original publication (PL 43, fig. 10). The outline of the central glabellar lobe is clavate, narrowing posteriorly to a minimum breadth opposite the posterior portions of the bicomposite lateral lobes, which themselves converge backwards at roughly 70 degrees. The central glabellar lobe expands both frontally, constituting the maximum length of the glabella, and 236 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III transversely, so that it is level with the distal margins of the bicomposite lateral lobes. The short (sag.), flattened, anterior border forms a rim which is separated from the central lobe by a shallow, narrow (sag.) furrow containing a pair of hypo- stomal pits opposite the intersection of the axial and longitudinal furrows. The right palpebral lobe is almost completely preserved ; its length is half that of the bicomposite lateral lobe, and carries a conspicuous palpebral furrow. The longi- tudinal furrows are moderately deep, curved, converging backwards for most of their length, and then diverge to circumscribe the bicomposite lateral lobes. At this point the holotype is broken, but Tripp (1958, pi. 85, fig. 4) has figured a more complete topotype cranidium showing most of the essential features. Platylichas laxatus was described in considerable detail by Warburg (1939 : 118) on the basis of Norwegian and Swedish material, which she considered to be specifi- cally identical with that from Ireland. There can be no doubt that, at least as far as the cranidium of P. laxatus is concerned, there are no significant differences between Irish, Welsh, English and Scandinavian specimens. The pygidium and hypostoma of the south Shropshire and Scandinavian forms are, for all practical purposes, identical but the hypostoma, thorax and pygidium of P. laxatus have not yet been described from topotype material. Until this has been done, it seems preferable to follow Warburg's interpretation of the species, though it may eventually prove necessary to recognize several different species or subspecies. Under the name Calymene forcipata, M'Coy (1846, pi. 40, fig. 14) figured from the " Silurian " of " Slieveroe, Rathdrum ", Ireland, a cranidium and pygidium, of which the latter has been generally supposed to represent Platylichas laxatus. In order to stabilize the nomenclature of Calymene forcipata, the cranidium figured by M'Coy, now housed in the National Museum of Ireland, is here chosen as lectotype, and may be referred to the genus Flexicalymene. The pygidium figured by M'Coy is refigured in the present paper (PI. 43, fig. 9). The specimen is unusually long, but this is due in part to mechanical deformation. Excluding the pleural spines, of which only the third pair is preserved intact, the outline is roughly semi-elliptical. The axis occupies about one- third of the total breadth, and half the length of the pygidium ; it is mainly parallel-sided, but posteriorly becomes tapered and increasingly convex, whilst the terminal piece is poorly defined. Frontally the axial furrows are well defined and almost parallel, but become convergent near the terminal piece of the axis ; beyond the latter they diverge slightly and terminate at the inner margin of the doublure, about halfway to the posterior margin. The axis has two well-defined axial rings with traces of an additional two. The pleural lobes carry three pairs of pleurae, each of which has a pair of well-defined pleural furrows and terminates laterally in a pair of backwardly-directed pleural spines, though the last-named are only partly preserved. It seems advisable to refer this specimen merely to Platylichas sp. until further material is available from the original locality. HOLOTYPE. M'Coy Collection, National Museum of Ireland (PL 43, fig. 10). HORIZON AND LOCALITIES. Platichas laxatus has been found at several localities in south Shropshire, almost all of them comprising strata of the Actonian Stage. They include the bed and banks of the River Onny immediately east and west of ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 237 its junction with Batch Gutter ; the section in the upper part of Batch Gutter itself; several points in and around the village of Acton Scott ; exposures near Plaish, north-east of Church Stretton ; and Gretton Quarry (now filled in), north- east of Cardington. The species has not been found higher than the Onnia ? cobbolcti Zone of the Onnian Stage in Shropshire, at which horizon it occurs at the exposure in the north bank of the Onny, 63 yards east-south-east of its junction with Batch Gutter. Outside Shropshire, P. cf. laxatus has been recorded from the Pusgillian Stage and highest Onnian of the Cross Fell Inlier. Family ODONTOPLEURIDAE Burmeister, 1843 Subfamily ODONTOPLEURINAE Burmeister, 1843 Genus PRIMASPIS R. & E. Richter, 1917 TYPE SPECIES. Acidaspis primordialis Barrande, 1852 by original designation of R. & E. Richter (1917 : 466). Primaspis harnagensis (Bancroft) (PI. 44, figs, i, 4, 6, 8) 1949. Acidaspis harnagensis Bancroft, p. 301, pi. 10, figs. 21, 22. 1958. Primaspis harnagensis (Bancroft) Dean, p. 201. 1962. Primaspis harnagensis (Bancroft) : Dean, p. 122. DESCRIPTION. The exoskeleton is known only from a few disarticulated cranidia, together with a single, detached librigena and pygidium. The glabella is subparabolic in plan, strongly convex, its upper surface declined frontally, with median length slightly greater than the maximum breadth, measured across the basal glabellar lobes. The frontal glabellar lobe is small, less than one-fifth of the length of the glabella, and bluntly pointed. There are three pairs of glabellar lobes, those of the third pair being the largest, almost oval in plan, slightly divergent forwards, and just over one-third the length of the glabella. The second glabellar lobes are subcircular in plan, about half the size of the third lobes. Both pairs of lobes are defined by deep second and third glabellar furrows which run backwards, and apparently continue, though shallower, so as to circumscribe the second and third lobes. This last feature is known only from internal moulds preserved in mudstones or shales, and may have been exaggerated by crushing. First glabellar lobes are represented by small, tubercle-like projections, delimited frontally by shallow, straight, first glabellar furrows directed only slightly backwards. The axial furrows are curved, strongly convex abaxially, shallowest just behind the line of the second glabellar furrows and then deepening both anteriorly and posteriorly. The anterior border, though incompletely known, is apparently of typical odontopleurid type, narrowest (sag.} medially but broadening abaxially, and delimited posteriorly by a poorly- defined furrow. The occipital ring is strongly convex transversely, with straight upper surface ; it is longest (sag.) medially, almost one-quarter the length of the glabella, but shortens markedly abaxially, at the same time turning sharply forwards anterolaterally to form a pair of distinct occipital lobes. The glabella and occipital 238 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III ring are separated by a straight, broad (sag.), occipital furrow which deepens distally. The fixigenae are strongly convex, standing highest posteriorly, where they are slightly narrower than the basal glabellar lobes, and decline steeply forwards to end opposite the first glabellar lobes. The palpebral lobes, though poorly known, are apparently strongly convex abaxially, with well-defined palpebral furrows and palpebral rims which are continued forwards as eye ridges to join the frontal glabellar lobe. The ocular surface of the eyes is not known. The anterior branches of the facial suture are convergent forwards, and apparently cut the cephalic margin opposite the anterior ends of the axial furrows, though this part of the exoskeleton has not been found well preserved. As far as can be judged from the available material, the posterior branches run from the palpebral lobes, a little in front of the pleuroccipital furrow, backwards to cut the posterior border at the base of the librigenal spines. The single available librigena (PL 44, fig. 8) is of typical odonto- pleurid form, steeply declined distally from the eye towards the raised marginal rim, the latter defined proximally by a deep marginal furrow which ends at the pleuroccipital furrow. The marginal rim is continued posterolaterally to form a librigenal spine, the length of which is at least equal to that of the remainder of the librigena. There are at least thirteen, slender, marginal spines, transversely straight or directed slightly backwards, and increasing in length (tr.) towards the genal angle. The hypostoma and thorax are not known. The pygidium, excluding marginal spines, is transversely semielliptical in plan, between three and four times as broad (tr.) as long. The axis, occupying frontally one- quarter of the maximum breadth, narrows backwards slightly at first, but ends in a small, bluntly pointed terminal piece which reaches the margin. There are three axial rings, the first well defined, the second and third less so. The axial furrows are moderately deep except frontally, where the first axial ring is produced postero- laterally as a pair of strong raised ridges which cross the flat pleural regions and continue beyond the posterior margin as the fifth and largest of seven pairs of spines distributed evenly along the margin. The first four pairs of spines increase in size from small to only slightly shorter than the conspicuous, stout, fifth pair. The sixth and seventh pairs are slender and subparallel backwards. The surface of the cephalon, excluding most of the furrows, is covered with closely- set granules of small, almost uniform, size. Similar granules ornament the entire dorsal surface of the librigena, including the librigenal spine, but the marginal spines are smooth. The axis and pleural lobes of the pygidium are covered with slightly coarser granules, but the furrows and pleural spines are apparently smooth. LECTOTYPE, here chosen. BM. In. 42086. PARATYPE. BM. In. 42087 (PI. 44, fig. 6). HORIZON AND LOCALITIES. The type-locality is the Smeathen Wood Beds, Harnagian Stage, Reuscholithus reuschi Zone, at the cart-way section near the southern end of Smeathen Wood, Horderley. A single cranidium has also been collected from the same horizon in the north bank of Coundmoor Brook, 1,300 yards south-west of Harnage Farm, Harnage. DISCUSSION. For convenience the discussion of Primaspis hamagensis is grouped with that of P, caractaci, ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 239 Primaspis caractaci (Salter) (PL 44, figs. 3, 7, 9, n, 13, 14) 1853. Acidaspis caractaci Salter, p. 7. 1857. Acidaspis caractaci Salter : Salter, p. 211, pi. 6, figs. 15-17. 1949. Acidaspis caractaci Salter : Bancroft, p. 303. 1958. Primaspis caractaci (Salter) Dean, pp. 211, 223, 224. 1962. Primaspis caractaci (Salter) : Dean, p. 122. DESCRIPTION. The dorsal exoskeleton, excluding pleural and pygidial spines, is roughly oval in plan, longer than broad approximately in the ratio 3 : 2. The cephalon is transversely semielliptical in plan, more than twice as broad as long. The glabella is steeply declined forwards, almost as broad as long, attaining its maximum breadth just in front of the occipital furrow, whence it narrows markedly to the subparabolic frontal glabellar lobe. There are three pairs of glabellar lobes, those of the basal pair being suboval in plan, moderately divergent forwards, and of large size, about one-third of the glabellar length. The second glabellar lobes are just over half the length of the basal lobes and slightly oval in plan, with long axes parallel to those of the succeeding pair. First glabellar lobes, originally stated by Salter (1857 : 211) to be obsolete, are poorly represented by a pair of small tubercles, the sudden diminution in size between the second and first pair of lobes resulting in a break in the glabellar outline. The second and third glabellar furrows are parallel to one another, deep, bifurcating, and circumscribe the second and third glabellar lobes, which are thus separated from the almost paraUel-sided central glabellar lobe. The axial furrows are narrow and curved, convex abaxially, deepening both frontally and posteriorly but becoming shallower mediaUy, opposite the third glabellar furrows. The anterior border is narrow (sag.), moderately inclined forwards, broadening laterally, and separated from the glabella by a furrow which increases in depth abaxially. The occipital ring is relatively long (sag.), becoming shorter laterally where it forms two distinct occipital lobes and extends forwards to join with the fixigenae ; it is delimited frontally by a broad (sag.), transversely straight, occipital furrow which deepens laterally. Each librigena is quadrant-shaped, and its upper surface declines steeply from the eye to a moderately-deep marginal furrow which ends posterolaterally at its intersection with the pleuroccipital furrow. The lateral margin is thickened, ridge-like, produced posterolaterally at the genal angle to form a stout, librigenal spine, the length of which is at least equal to that of the cephalon. The lateral margin carries thirteen, or occasionally fourteen, short (tr.) border spines, the hindmost of them almost transversely straight, becoming pro- gressively less divergent forwards. The hypostoma is not known. The thorax comprises ten segments. The axis is moderately convex transversely and the pleural lobes are flat as far as the bases of the pleural spines. Each pleura is divided into two bands by a pleural furrow which runs gently backwards distally from the anterior margin of the pleura at its junction with the axial furrow. The anterior pleural band is narrow (exsag.), moderately convex, the tip produced laterally into a short (tr.) pleural spine. The posterior pleural band is broader (exsag.), more convex, ridge-like, produced posterolaterally to give a posterior 24o ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III pleural spine of length almost equal to that (tr.) of the pleura itself. The posterior pleural spines become progressively more strongly directed backwards from front to rear of the thorax. The pygidium, excluding marginal spines, is transversely semielliptical in plan, with straight anterior margin. The axis occupies about one-quarter of the maximum breadth of the pygidium, and its anterior portion is strongly convex dorsally ; the remainder of the axis declines posteriorly and fails to reach the margin, apparently ending in-line with the inner limit of the doublure. There is evidence of at least two axial rings. The first of these is produced, in the form of a pair of large raised ridges, posterolaterally to the margin, beyond which it continues as a pair of stout spines, slightly divergent backwards. In front of these large spines are situated two pairs of small, slender, parallel spines, whilst the posterior margin of the pygidium carries a further three pairs of small spines of similar size and form, parallel to one another and directed straight backwards. One of the syntypes of P. caractaci (PI. 44, fig. 13) shows the exoskeleton in what may have been the position of rest of the animal on the sea-floor. The occipital ring and pleuroccipital segment are in the same vertical plane, and in this posture the glabella is steeply declined forwards. At the same time the cephalic margins rest on the border spines of the librigenae, the progressive increase in length of the spines posterolaterally assisting in maintaining the position of the cephalon. The thorax is flexed downwards slightly at its midpoint, rising again towards the pygi- dium which is, in turn, turned down. A comparable condition is known from other groups of trilobites, for example, the Trinucleidae and Calymenidae, and may be posthumous. The dorsal surface of the glabella, proximal parts of the librigenae, thorax and pygidium, excluding furrows, is mostly covered with coarse granules, the intervening space between the latter being ornamented with granules of smaller size. The glabellar furrows are smooth, but there is a tendency for the smaller granules to persist across the occipital furrow (PI. 44, fig. 7). Both the lateral border furrow and the lateral border of the cephalon are finely granulate, the granulation extending over part of the border spines, as far as can be judged. HORIZONS AND LOCALITIES. The earliest specimen of Primaspis caractaci known from south Shropshire is a single librigena from the Onniella reuschi Zone of the Marshbrookian Stage, just south of Marsh Wood Quarry, Marshbrook. The species becomes much more abundant, however, in the succeeding Actonian Stage, particu- larly in the more arenaceous facies, though it is rare in the grey mudstone succession of the Onny Valley. Localities include the stream section just south of the waterfall at the western end of Chuney Pool, Acton Scott ; the old quarry 210 yards east of Acton Scott Church ; the stream section by the east side of the road-bridge about 350 yards west-south-west of Hatton ; and the old quarry, now filled in, at Quarry Field, Cardington. The last-named locality yielded the type-specimens of P. caractaci, together with numerous other specimens of the species. SYNTYPES. GSM. 5214 (PI. 44, fig. 9) ; GSM. 35473 (PI. 44, fig. 13). DISCUSSION. The cranidium is of generally similar form in both Primaspis harnagensis and P. caractaci, but the former species may be distinguished by its ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 241 shorter occipital ring, narrower glabella and, perhaps, longer basal glabellar lobes. The pygidia of these forms may be separated more easily, that of P. harnagensis having two posterior and four anterior pairs of small marginal spines in addition to the single large pair, whilst the pygidium of P. caractaci has three posterior and only two anterior pairs of small spines. The only other species of Primaspis described from the Caradoc Series of the Anglo-Welsh area, P. semievoluta (Reed, 1910 : 214, pi. 17, figs. 1-3 ; Dean, 1962) from the Longvillian Stage of the Cross Fell Inlier, has a pygidium with two posterior and two anterior pairs of small marginal spines separated by a single pair of large spines. The pygidium is also slightly longer proportionately than that of the two Shropshire species. The cranidium of Primaspis ascitus (Whittington, 1956 : 199, pis. I, 2), from the Middle Ordovician of Virginia, is relatively broader than that of P. harnagensis and bears a remarkably close resemblance to that of P. caractaci though the anterior border of the last-named is slightly longer (sag.). The pygidium of P. ascitus is more easily distinguished and carries, in addition to the largest pair of margin spines, a further five pairs of small spines, three pairs situated anteriorly and the remaining two pairs posteriorly. An unusual feature common to the pygidia of P. ascitus and P. caractaci is the manner in which the basal part of each of the large pair of spines is expanded so as to merge with the proximal half of the first succeeding small, marginal spine (PL 44, fig. 9 ; see also Whittington, 1956, pi. I, figs. 9, 10). In a recent paper Whittard (1961 : 203, pi. 27, fig. 12 ; pi. 27, fig. 13) has figured what he calls Primaspis cf. harnagensis (Bancroft) and P. cf. caractaci (Salter) from the Spy Wood Grit of the Shelve district, an horizon approximately contemporaneous with the early Harnagian Stage of south Shropshire. The specimens are too frag- mentary for certain indentification but appear to be distinct from either of the south Shropshire forms and may represent a new species. Family OLENIDAE Burmeister, 1843 Subfamily TRIARTHRINAE Ulrich, 1930 Genus TRIARTHRUS Green, 1832 TYPE SPECIES. Triarthrus becki Green, by monotypy (Green, 1832 : 86-87). Triarthrus cf. Hnnarssoni Thorslund (PL 44, figs. 2, 5, 10, 12) 1940. Triarthrus Hnnarssoni Thorslund, p. 128, pi. 12, figs. 4-12. 1945. Triarthrus sp., Bancroft, p. 183. 1949. Triarthrus sp. Bancroft, map on p. 302. 1958. Triarthrus sp., Dean, pp. 213, 225. 1960. Triarthrus cf. Hnnarssoni Thorslund : Dean, p. 86. Three cranidia in varying degrees of completeness, and a single, small, incomplete pygidium, have been examined, all from one locality in south Shropshire. They 242 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III match the material described by Thorslund (1940 : 128) in both the shape and proportions of the cranidium and in the position of the palpebral lobes. Librigenae of the Shropshire form have not yet been discovered. The pygidium (PL 44, fig. 2) has a broad axis occupying almost half the total breadth, though this proportion may have been exaggerated by crushing, and taper- ing backwards only slightly, its junction with the posterior margin being indistinct. There are two well-defined axial rings, with a third ring less well defined. The pleural lobes carry at least two, and possibly three, pleural furrows which extend from the axial furrows to the margin, the ribs so defined curving backwards strongly in the same direction. The pygidium of T. linnarssoni has not yet been described, and comparison is therefore impossible. HORIZON AND LOCALITY. Onnia Beds, Onnian Stage, Onnia superba Zone, at the " Cliff Section " in the north bank of the River Onny, 720 yards west-south-west of Wistanstow Church. DISCUSSION. Thorslund's type-specimens came from Vastergotland and Jemtland, Central Sweden, where the species occurs in both the Upper Chasmops beds and shales of the corresponding Dicranograptus clingani Zone. As has been pointed out elsewhere (Dean, 1960 : 85-86), the trilobite assemblage of these Swedish strata is closely comparable with that of the highest Ordovician rocks of the south Shropshire succession. Family OTARIONIDAE R. & E. Richter, 1926 Genus OTARION Zenker, 1833 TYPE SPECIES. Otarion diffractum Zenker, 1833 by subsequent designation of R. & E. Richter (1926 : 95). Otarion sp. (PL 45, ng. i) 1958. Otarion sp., Dean, p. 223. Trilobites which can be assigned broadly to this genus are uncommon in south Shropshire. A few specimens have been found in the middle and upper Marshbrookian and in the Actonian, one of the best preserved, an incomplete cranidium about 2-5 mm. long, being figured here. The glabella is subparabolic in outline, occupies just over two-thirds of the median length, and is strongly inflated, particularly frontally. There is one pair of basal glabellar lobes, in length about two-fifths that of the glabella, from which they are separated by a pair of deep, curved, basal glabellar furrows. The preglabellar field is convex, steeply declined frontally, separated by a broad (sag.), well-defined, anterior border furrow from the thick, slightly flattened, anterior border. Both preglabellar field and anterior border are of equal breadth (sag.). The fixigenae are only partly preserved but apparently stand highest opposite the anterior part of the basal glabellar lobes, and are declined frontally, where they are continuous with the preglabellar field. The occipital ring, delimited anteriorly by a deep, transversely straight, occipital furrow, is strongly convex transversely, becoming thicker medially where it is directed upwards and slightly backwards. ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 243 The surface of the glabella, fixigenae and preglabellar field, excluding the furrows, which are smooth, is covered with conspicuous, coarse tubercles, but that of the anterior border is finely granulate. HORIZONS AND LOCALITIES. Specimens belonging, apparently, to the same species have been found in the Marshbrookian Stage both at and near Marsh Wood Quarry, Marshbrook ; in the stream-section 550 yards south-south-west of Common Farm, Wallsbank ; and by the track 2,900 feet north-west of the Methodist Chapel, Cardington. The highest record is from the middle Actonian at the old quarry 210 yards east of St. Margaret's Church, Acton Scott. Family PROETIDAE Burmeister, 1843 Subfamily PROETIDELLINAE Hupe, 1953 Genus PROETIDELLA Bancroft, 1949 ? Ogmocnemis Kielan, 1959. TYPE SPECIES. Proetidella fearnsidesi by original designation of Bancroft (1949 : 304). Proetidella fearnsidesi Bancroft (PL 45, figs. 3-8, 12, 14) 1949. Proetidella fearnsidesi Bancroft, p. 304, pi. 10, fig. 23. 1953. Decoroproetus fearnsidesi (Bancroft) Pfibyl, p. 60. 1958. Decoroproetus fearnsidesi (Bancroft) : Dean, pp. 201, 219. ?i96i. Ogmocnemis calvus Whittard, p. 186, pi. 24, fig. 15. 1962. Proetidella fearnsidesi Bancroft : Dean, p. 126. DESCRIPTION. The dorsal exoskeleton of the holotype, the most complete specimen known, is oval in plan, longer than broad in the ratio 9:7. The roughly semi- circular cephalon occupies one-third the median length of the holotype, with the glabella equal to one-third the cephalic breadth. The holotype is a flattened specimen, preserved in shaly mudstone, and its appearance and proportions are consequently distorted, but in the case of a specimen preserved in sandy limestones of late Costonian age (PI. 45, figs. 6, 7) the cephalon is convex both longitudinally and transversely, with the glabella occupying half the cephalic breadth. The glabella of the holotype, including occipital ring, is as long as broad ; however, the specimen is not only compressed but damaged, and its apparently irregular outline, narrowing forwards to a blunt point, is misleading, though it has been illustrated by Struve (in Moore, 1959 ; fig. 301, i). The uncrushed glabellar outline is subparabolic, well rounded frontally, and occasionally the anterior half is slightly constricted. Flat- tened topotype cranidia tend to appear broader, though with the same general outline, and there is some variation in the ratio of length to breadth (PI. 45, figs. 12, 14). Most of the known cranidia have no glabellar furrows, though one or two bear traces of a basal pair ; the conspicuous basal furrows shown in Struve's illustration (in Moore, 1959, fig. 301, i) are the result of crushing. The glabella is circumscribed laterally and frontally by a narrow, moderately-deep furrow representing the con- joined axial and preglabellar furrows. The glabella is preceded by a preglabellar 244 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III field and anterior border of somewhat variable form. The preglabellar field is flat, varying in length from one-sixth to one-eighth that of the glabella. The line of demarcation between preglabellar field and anterior border is generally poorly defined in topotype material, with no distinct anterior border furrow (PI. 45, figs. 3, 12, 14), but specimens in a more arenaceous matrix (see, for example, PL 45, fig. 5) tend to have a better defined, more steeply upturned, anterior border. The occipital furrow is well defined and moderately deep, flexing forwards a little both medially and laterally. The occipital ring follows a similar course, ending laterally in poorly defined occipital lobes ; its median length is about one-fifth that of the glabella, and in certain rare instances (PL 45, fig. 14) there is a small median tubercle. The eyes, the visual surface of which is not known, are elongated, semielliptical in plan, and slightly convergent forwards, equal in length to just over half that of the glabella. They are each delimited laterally by a moderately defined eye platform, and extend forwards from points sited just outside the axial furrows and opposite the occipital furrow. The combined palpebral lobes and fixigenae are thus small and narrow, becoming almost obsolete both anteriorly, immediately in front of the eyes, and posteriorly, where they reach a minimum opposite the pleuroccipital furrow and then expand suddenly to form part of the pleuroccipital segment (PL 45, fig. 4). The anterior branches of the facial suture extend only a very short distance forwards from the eyes, parallel to the axial furrows, before becoming suddenly and markedly divergent almost as far as the anterolateral margin where they turn adaxially through a right-angle and cut the margin at points longitudinally in line with the hindmost parts of the axial furrows. The posterior branches run backwards from the eyes, just outside and parallel to the axial furrows, as far as the pleuroccipital furrows ; there they change direction suddenly, running straight outwards and back to cut the posterior margin of the cephalon at points about mid-way between the axial furrows and the lateral margins. The librigenae thus formed are of relatively large size, produced posterolaterally to form long, broad-based librigenal spines, the points of which end in-line with the mid-point of the thorax, between the fifth and sixth thoracic segments. The hypostoma is unknown. The thorax of the flattened holotype comprises ten segments, and is divided into three longitudinal lobes of approximately equal breadth by narrow, deep, axial furrows which are parallel from the first to fifth axial rings, beyond which they converge backwards until the breadth (tr.) of the tenth axial ring is little more than half that of the first. The axial rings are of the same general shape as the occipital ring, though perhaps a little shorter (sag.) . The pleurae are transversely straight for the most part, but beyond the fulcra become directed backwards and end in short pleural spines. Each pleura is divided into two bands of unequal breadth (exsag.), of which the anterior band is the narrower, by a sharply defined pleural furrow ; each pleural furrow runs slightly backwards distally from the axial furrow, but turns backwards sharply at the fulcrum towards the pleural spine, at the same time becoming markedly shallower. The pygidium is broadly subparabolic in plan with margin entire, the breadth about two-and-a-half times the median length in the case of the holotype. The ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 245 tapering axis occupies just over three-quarters of the median length, carries six well-defined axial rings, and ends in a terminal piece of moderate length, with a small postaxial ridge extending to the margin. The doublure is of even breadth, extending inwards from the posterior margin as far as the tip of the axis. Each side-lobe carries four deeply impressed pleural furrows which curve backwards evenly to intersect the lateral margins ; there are, in addition, one or two further pairs of only poorly denned pleural furrows. The pleural ribs so formed carry faintly impressed rib furrows which are not parallel to the pleural furrows, but run back- wards only slightly for about three-quarters of their length and then turn sharply back to the margin. Each rib is thus divided into two bands, of which the anterior is the narrower (exsag.). Excluding all furrows the entire dorsal surface of the exoskeleton is ornamented with a series of thin, raised, anastomosing ridges so as to form a Bertillon pattern which is particularly conspicuous on the glabella. HORIZONS AND LOCALITIES. The holotype is from shaly mudstones of the basal Harnagian, Reuscholithus reuschi Zone, in the old cartway near the south end of Smeathen Wood, Horderley, and a few other specimens have been recovered from this locality. Proetidella fearnsidesi occurs also, and in small numbers, at the same horizon as exposed 550 yards north-west of Woolston House, Woolston. In the northern part of the Ordovician outcrop in south Shropshire the same species may be found occasionally in the topmost subdivision, the Harknessella subquadrata Beds, of the Costonian Stage. HOLOTYPE. BM. In. 42083 (PI. 45, fig. 3). DISCUSSION. It has recently been suggested by Dean (1962) that Ogmocnemis calvus, described by Whittard (1961 : 186) from the Lower Soudleyan of the Shelve Inlier, may prove to be synonymous with P. fearnsidesi. 0. calvus was founded on a single specimen, so there is no information concerning variation within the species. The preglabellar field and anterior border are apparently fairly well differentiated, but this may not be of specific significance, particularly in view of the variation in Harnagian specimens of P. fearnsidesi, and the two species are regarded here as being probably synonymous. Specimens of Proetidella are figured in the present paper from the Upper and, probably, Lower Soudleyan of south Shropshire (PL 45, figs. 9-11). They show small differences from P. fearnsidesi in glabellar outline and degree of differentiation of the anterior border, but owing to lack of material it has been impossible to demonstrate whether or not these are more than an expression of a different environment and lithology. The specimens, which are closely similar to the holotype of Ogmocnemis calvus, are therefore only compared with P. fearn- sidesi. There are in the old collections of the Geological Survey & Museum certain specimens, numbered 35614-35616 and 35618-35620, which are labelled Proetus ovatus, a manuscript name attributed to Salter. The specimens are typical Proetidella fearnsidesi, and the state of preservation suggests that they originated from the Smeathen Wood Beds of the Horderley district. The Norwegian species Proetus asellus (Esmark), from metamorphosed shales of probable Llanvirn age, has been redescribed and figured by St0rmer (1940 : 122, GEOL. 7, 8 18 246 ORDOVTCIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III pi. I, fig. i). The glabella is of more uniform breadth than that of Proetidella fearn- sidesi, and the anterior border is apparently better differentiated from the long (sag.) preglabellar field, though the importance of the latter feature may not be great. However, the general resemblance of the two forms is enough to suggest that Proetidella-like trilobites existed earlier than the Caradoc Series, though the group is inadequately known. Proetidella? sp. (PI. 45, fig. 13) 1958. Proetus (s.l.) sp., Dean, p. 223. A single proetid cranidium has been recovered from the Upper Cheney Longville Flags, west of the village of Hatton. The glabellar outline is relatively broad, especially posteriorly, becoming broadly convergent frontally towards the well- rounded frontal glabellar lobe after constricting noticeably at about its mid-point. There is a suggestion of a pair of basal glabellar furrows, but as the specimen is somewhat damaged this feature may have been exaggerated by crushing. The anterior border is bluntly pointed medially, gently inclined forwards, separated from the broad (sag.), preglabellar field by a shallow, anterior border furrow. The glabella is circumscribed by a conspicuous preglabellar furrow, continuous laterally with deep axial furrows which become shallower medially. Part of the right occipital lobe remains, showing it to be generally similar to that of Proetidella fearnsidesi, though perhaps a little broader and situated slightly farther from the axial furrow. There is insufficient material for the erection of a new species, though the specimen is probably specifically distinct from P. fearnsidesi. HORIZON AND LOCALITY. Marshbrookian Stage, Dalmanella unguis Zone, about 350 yards north-west of the road bridge situated 350 yards south-west of Hatton, near Acton Scott. Family REMOPLEURIDIDAE Hawle & Corda, 1847 Genus REMOPLEURIDES Portlock, 1843 TYPE SPECIES. Remopleurides colbii Portlock by subsequent designation of Miller (1889 : 565-566). Remopleurides warburgae sp. nov. (PL 46, figs, i, 2) 1958. Remopleurides sp. nov., Dean, p. 224. DIAGNOSIS. Glabella slightly broader than long, broadest posteriorly, narrowing frontally. Glabellar tongue strongly convex, steeply downturned, equal to about half breadth of glabella. Palpebral lobes flattened, narrowing frontally. Three pairs of equispaced glabellar furrows show through test as black lines. Test mainly smooth. DESCRIPTION. The glabella is moderately convex longitudinally and transversely, almost as long as broad, its greatest breadth occurring to the rear of centre of the main body. The anterior portion of the glabella is convex, including the glabellar tongue, which is strongly arched downwards. The glabellar tongue is about twice ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 247 as broad as long, its breadth half that of the glabella, and the lateral margins con- verge slightly towards the almost straight anterior margin. Strong palpebral furrows delimit the palpebral lobes, which narrow frontally and continue forwards as narrow rims to the anterolateral angles of the glabellar tongue. Three pairs of equidistant, parallel, glabellar furrows are present, their position indicated by poorly visible black lines showing through the test ; the first pair is shorter (tr.) than the second and third pairs, which are of almost equal length. The glabellar furrows curve gently backwards from near the palpebral furrows so as to leave an unfurrowed band extending along the axis of the glabella and occupying about one-fifth of the maximum breadth. The occipital furrow is deeply incised and transversely straight. The occipital ring is moderately convex both longitudinally and transversely, but in the holotype the distal parts are not wholly preserved. The surface of the cranidium is smooth except for the occipital ring, palpebral lobes and anterior portion of the glabellar tongue, all of which are ornamented with fine, slightly-raised, anastomosing ridges, sometimes forming a Bertillon pattern. The hypostoma, thorax and pygidium are not known (but see later). HORIZON AND LOCALITIES. The type-material was collected from grey mudstones in the uppermost third of the Actonian Stage in the north bank of the River Onny, 87 feet east of the junction of the river with Batch Gutter. The same species occurs also in the Actonian Stage at Acton Scott, and, perhaps, near Hatton. HOLOTYPE. BM. In. 49751 (PI. 46, figs, i, 2). DISCUSSION. In plan the glabella of Remopleurides warburgae most resembles R. dalecarlicus Holm MS., described and figured by Warburg (1925 : 88, pi. i, figs. 7, 8) from the Upper Leptaena Limestone of Sweden and therefore younger than the Shropshire species ; the Swedish form also has a smooth test but possesses a narrower, more convex, glabellar tongue. Remopleurides latus Olin onniensis subsp. nov. (PL 46, figs. 4, 5) DIAGNOSIS. Glabella broader than long, with main body transversely ovate in plan. Glabellar tongue equal in breadth to half that of glabella, strongly declined frontally, its anterior margin transversely truncated and indented medially. Palpebral lobes narrow forwards, forming rim along sides of anterior glabellar tongue. Three pairs glabellar furrows visible through test as dark lines. DESCRIPTION. The glabella is moderately convex both longitudinally and trans- versely, its length (sag.} equal to three-quarters the maximum breadth, which occurs midway between the occipital furrow and the base of the glabellar tongue. The latter is longitudinally convex, less so transversely, and strongly arched down frontally, its breadth half that of the glabella. Apart from a small median indentation the anterior margin of the glabellar tongue is transversely straight, meeting the anterolateral margins at right-angles. Three pairs of equidistant glabellar furrows are present, showing through the test as poorly-discernible dark lines, and not impressed upon the outer surface of the test. The first pair is shorter (tr.} than the second and third pairs which extend distally almost to the palpebral furrows ; the 248 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III third pair curves backwards a little more strongly than the first and second pairs, which are almost parallel to one another. All three pairs of furrows curve gently backwards and extend adaxially from the lateral margins so as to leave an unmarked band, running down the centre of the glabella and about one-fifth the breadth of the latter. The palpebral lobes, which narrow frontally and are separated from the main body of the glabella by deeply-incised palpebral furrows, continue forwards in the form of a much attenuated rim as far as the anterolateral angles of the glabellar tongue. The occipital ring is only slightly convex longitudinally, and becomes shorter (exsag.) laterally. The surface of the test of the glabellar tongue and occipital ring is ornamented with fine, anastomosing, raised ridges arranged parallel to the anterior margin, but the remainder of the test is smooth. The hypostoma, thorax and pygidium are not known (but see later). HORIZON AND LOCALITIES. The uppermost third of the Actonian Stage, exposed in the north bank of the River Onny, 87 feet east of the junction of the river with Batch Gutter. The type-material was found in a band of shelly debris, about 3 inches thick, containing also Remopleurides warburgae, Tretaspis, Chasmops, Sampo and Onniella. The species is not known with certainty elsewhere, but fragments possibly belonging to it have been found in the Actonian Stage at Acton Scott. HOLOTYPE. BM. In. 49750 (PI. 46, figs. 4, 5). PARATYPE. BM. In. 49762. DISCUSSION. The new subspecies is generally similar to Remopleurides lotus (Olin, 1906, pi. 2, figs. 50, b) from the Chasmops Series of Scania, particularly in the form of the posterior half of the glabella, but the convexity of the glabella is greater and the glabellar tongue is both longer and broader. R. latus kullsbergensis (Warburg, 1925 : 83, pi. i, figs. 1-6) has more distinct glabellar furrows as well as a smaller, narrower glabellar tongue than the Shropshire subspecies, though the two are probably of generally similar age, whilst R. latus var. granensis (St0rmer, 1945 : 408, pi. 4, fig. 4), from a slightly higher horizon, differs in possessing a narrower glabellar tongue, and a test which is described as having a completely smooth surface. R. validus (Thorslund, 1940, pi. 7, figs. 1-9), from the Lower Chasmops Limestone, shows a glabella of generally similar outline to that of the new subspecies but the glabellar tongue is both narrower and less well differentiated from the main body of the glabella. R. wimani (Thorslund, 1940 : 135, pi. 7, fig. 10), though of an age generally comparable to that of R. latus onniensis, exhibits a much narrower glabellar tongue and the main body of the glabella is both narrower and more convergent forwards. Remopleurides sp. (PI. 46, figs. 3, 7) At the type-locality of Remopleurides warburgae and R. latus onniensis, isolated fragments of Remopleurides have been found in abundance in a fossiliferous band of shelly mudstone about 3 inches thick. There appears to have been some sorting of the trilobite remains and although librigenae and thoracic segments are not uncom- mon, no pygidium has yet been found. Two typical specimens are figured here, but it has not yet been possible to assign either to a definite species. ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 249 The main part of the librigena is subtriangular in outline (PI. 46, fig. 3), slightly convex, and arched down laterally. A long, stout spine is developed, the whole of which is not preserved ; as in the case of Remopleurides latus kullsbergensis (Warburg, 1925 : 84, fig. 15), this is not developed from the true genal angle but arises from a position just in front of it. The posterior portion of the librigena stands at a some- what lower level than the remainder, from which it is separated by a strong transverse furrow. This part of the librigena terminates posterolaterally in a short, blunt, librigenal spine, separated by a well-defined notch from the long anterior spine, but the proximal end is marked by a rounded, flange-like notch, the function of which is to provide articulation with the fulcral process of the first thoracic segment. The surface of the test is ornamented with several well-developed, anastomosing ridges, subparallel to the distal margin of the librigena as far as the genal angle, but transverse in direction near the fulcral notch. The librigena strongly resembles that of R. latus kullsbergensis and may belong to the allied R. latus onniensis. It also recalls, but is shorter and broader than, one figured by Thorslund (1940, pi. 7, fig. 16) and referred by him to R. cf. latus Olin. In addition to numerous isolated thoracic segments, a group of six articulated segments has been found (PL 46, fig. 7). The axial rings are gently convex longi- tudinally and transversely, the breadth at least four times the length (sag.) , excluding the articulating half-ring. Apart from a small, central portion the posterior margin of each axial ring is serrated, particularly distally, up to six tooth-like spines being visible on the lateral half of each ring ; similar structures are developed on the axial rings of Remopleurides colbii Portlock (Whittington, 1950, pi. 70, figs. I, 4). The side-lobes are narrow, with flattened pleurae terminating in short (exsag.), broad, backwardly-directed pleural points. The pleural furrows are curved, deep, directed distally towards, but not attaining, the pleural points. Just outside the axial furrow the anterior margin of each pleura is thickened markedly to form a conspicuous, tooth-like, fulcra! process, the posterior margin being indented to give a corresponding, flange-like, articulating socket. The test is ornamented with fine raised ridges distributed more or less parallel to the margins of each segment and tending to converge at the pleural points. HORIZON AND LOCALITY. Actonian Stage, north bank of the River Onny, 87 feet east of its junction with Batch Gutter. Genus REMOPLEURELLA nov. DIAGNOSIS. Cranidium of typical remopleuridid outline, the main body only gently convex, both longitudinally and transversely, with three pairs of deeply- incised glabellar furrows, those of the first pair noticeably shorter (tr.) than those of the other two pairs. Surface of test with conspicuous pattern of subconcentric, thin, raised lines. Librigenae narrow with librigenal spines arising from the genal angles ; posterior margin entire. Hypostoma as long as, or slightly longer than, broad, with transversely straight anterior and posterior borders. Median body suboval, gently convex, with pair of oval areas converging backwards medially ; small anterior lobe, sometimes produced to form short spine, delimited by broad, 250 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III curved median furrow, convex backwards. Thorax incompletely known. Pygidium unknown. Robergiella, type-species R. sagittalis, from the Edinburg Limestone of Virginia (Whittington, 1959 : 431, pi. 6, figs. 16-33), may be related to Remopleurella, which it resembles in the depressed glabellar form, with three incised pairs of glabellar furrows. Robergiella differs, however, in having a larger glabellar tongue which expands forwards, as well as considerably broader librigenae, each of which carries a pronounced notch at the base of the librigenal spine. TYPE SPECIES. Remopleurides burmeisteri Bancroft, 1949. DISTRIBUTION. Known with certainty from the Onnian Stage of the type Caradoc Series in south Shropshire. Probably occurs also in the higher Caradoc strata of southern Norway. Remopleurella burmeisteri (Bancroft) (PI. 45, fig. 2 ; PI. 46, figs. 6, 8, 9, n, 12) 1945. Remopleurides (? Caphyra) sp., Lament, p. 118. 1949. Remopleurides burmeisteri Bancroft, p. 300, pi. 10, figs. 19, 20. 1958. Remopleurides burneisteri Bancroft : Dean, pp. 213, 225. Bancroft's original description covered the cranidium, librigenae and thorax (pars), and little need be added. Most known cranidia, including one of the syntypes, are slightly flattened with the glabellar tongue apparently arched down only slightly, but occasional specimens show that the plane of the tongue is, in fact, steeply declined frontally, almost at right-angles to the remainder of the glabella. Most of the known specimens are preserved in decalcified mudstones in which the glabellar test is not seen, but one specimen, BM. In. 54772, from the unweathered underlying strata shows the test to have been thin, its dorsal surface, apart from the smooth, deeply-incised glabellar furrows, ornamented by thin, raised, anastomosing ridges forming a Bertillon pattern. A hypostoma presumed to belong to this species occurs in association with the paratype thorax, and a slightly smaller specimen has recently been collected by Mr. S. F. Morris. The entire hypostoma is as long as, or slightly longer than, wide. The gently convex median body is generally ovate in outline with bluntly terminated anterior and posterior margins, and is circumscribed by a moderately-deep border furrow. The posterior border is apparently continuous with the narrow (tr.) lateral border, which is, in turn, continuous with the anterior border. The last-named is transversely straight produced distally to form a pair of anterior wings, separated by rounded lateral notches from the lateral borders. The median body is divided into two unequal parts by a curved median furrow, concave forwards, deepest medially, and shallowing distally. The anterior lobe is small, convex, and specimen In. 56800 shows it thickened medially to produce a small spine. The posterior lobe, occupying about three-quarters of the length of the median body, is traversed longitudinally by a faint groove, a continuation of the median furrow, which narrows backwards and ends at the posterior border. The posterior lobe is thus divided so as to form what Whittington (1950 : 541) has described as two oval ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 251 areas, their long axes convergent backwards. Fragments of the test show it to be thin, its lower surface covered by subconcentric, thin, raised ridges. LECTOTYPE, here chosen. BM. In. 42106 (PL 46, fig. n). PARATYPES. BM. In. 42098 (PL 46, fig. 6) ; BM. In. 49561 (PL 46, figs. 8, 12). HORIZONS AND LOCALITIES. The earliest known occurrence of the species is a single cranidium, BM. In. 54772, from the Onnian Stage, Onnia gracilis Zone, by the north bank of the River Onny about 100 yards east of the junction of the river with Batch Gutter. All the other known specimens, including the types, are from the Onnia superba Zone in the north bank of the Onny, 720 yards west-south-west of Wistanstow Church. DISCUSSION. Remopleurella burmeisteri appears to belong to a group of remo- pleuridid trilobites which, although they have received little attention, are not uncommon in at least the Upper Chasmops Limestone, Stage fod, of southern Norway, and probably occur also in parts of Sweden. Several such are housed in the Paleontologisk Institut, Oslo, where some have been labelled as ' Remopleurides cf. radians ", the type-species of Amphitryon Hawle & Corda, but they cannot be assigned to the latter genus and probably belong to Remopleurella. Family THYSANOPELTIDAE Hawle & Corda, 1847 Genus EOBRONTEUS Reed, 1928 TYPE SPECIES. Entomostracites laticauda Wahlenberg, 1818 by original designation of Reed (1928 : 58, 75). Eobronteus? sp. (Plate 46, fig. 10) 1958. Eobronteus ? sp., Dean, p. 224. Three fragmentary specimens housed in the Sedgwick Museum are the only representatives of this trilobite family found in south Shropshire, and the best preserved of these is now figured. The specimen comprises an almost complete thorax, the full number of thoracic segments not being visible, together with a fragmentary cephalon, which partly obscures the thorax, and an incomplete pygidium. The genus Eobronteus has been examined in detail by Sinclair (1949) who has figured or noted all the known species. None of these agrees wholly with the Shropshire species, which may be new, but a detailed description must await the collection of better-preserved material. HORIZON AND LOCALITY. Onnian Stage, Onnia superba Zone, north bank of the River Onny, 720 yards west-south-west of Wistanstow Church. REFERENCES ANGELIN, N. F. 1854. Palaeontologia Scandinavica. ix + 92 pp., 42 pis. Lund. BANCROFT, B. B. 1945. The brachiopod zonal indices of the Stages Costonian to Onnian in Britain. /. Paleont., Tulsa, 19 : 181-252, pis. 22-38. 1949. Upper Ordovician trilobites of zonal value in south-east Shropshire. Proc. Roy. Soc., London (B) 136 : 291-315, pis. 9-11. (Edited by A. Lamont). 252 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III BARRANDE, J. 1852. Systeme silurien du centre de la Boheme. i ere partie. Recherches paleonto- logiques. xxx + 935 pp., atlas, 51 pis. Prague & Paris. DEAN, W. T. 1958. The faunal succession in the Caradoc Series of south Shropshire. Bull. Brit. Mus. (Nat. Hist.) Geol., London, 3 : 191-231, pis. 24-26. 1959- The stratigraphy of the Caradoc Series in the Cross Fell Inlier. Proc. Yorks. Geol. Soc., Hull, 32 : 185-228, 6 figs. 1960. The use of shelly faunas in a correlation of the Caradoc Series in England, Wales and parts of Scandinavia. Proc. Int. Geol. Congr., list Session, Copenhagen, 7 : 82-87. 1960^. The Ordovician rocks of the Chatwall district, Shropshire. Geol. Mag., Lond., 97 : 163-171, 2 figs. 1962. The trilobite faunas of the Caradoc Series in the Cross Fell Inlier of Northern Eng- land. Bull. Brit. Mus. (Nat. Hist.), Geol., London, 7 : 65-134, pis. 6-18. DEAN, W. T. & DINELEY, D. L., 1961. The Ordovician and associated Pre-Cambrian rocks of the Pontesford district, Shropshire. Geol. Mag., Lond., 98 : 367-376, pi. 20. ELLES, G. L. & WOOD, E. M. R. 1914. A Monograph of British Graptolites, 10 : 487-526, pis. 50-52. Palaeontogr. Soc. [Monogr.~\, London. FOERSTE, A F. 1919. Notes on Isotelus, Acrolichas, Calymene and Encrinurus. Bull. Sci. Labs. Denison Univ., Granville, Ohio, 19 : 65-81, pis. 14-18. GREEN, J. 1832. A Monograph of the Trilobites of North America : with coloured models of the species. 93 pp., i pi. Philadelphia. GURICH, G. 1901. tJber eine neue Lichas-Art aus dem Devon von Neu Siid- Wales und iiber die Gattung Lichas uberhaupt. N. Jb. Min. Geol. Palaont., Stuttgart, 14 : 519-539, pis. 18-20. HARPER, J. C. 1947. The Caradoc fauna of Ynys Galed, Caernarvonshire. Ann. Mag. Nat. Hist., London (n) 14 : 153-175, pis. 6, 7. HARRINGTON, H. J. & LEANZA, A. F. 1957. Ordovician trilobites of Argentina. Dept. Geol. Univ. Kansas, Spec. Pub., Lawrence, 1 : 1-276, 140 figs. HAWLE, I. & CORDA, A. J. C. 1847. Prodrom einer Monographie der bohmischen Trilobiien. 176 pp., 7 pis. Prague. (Published also 1848, Abh. K. bohm. Ges. Wiss., Prague, 5 : 117-292, pis. 1-7). HOLM, G. 1882. De Svenska arterna af Trilobitslagtet Illaenus (Dalman). K. svenska Vetensk- Akad. Handl., Stockholm, 7 : xiv +136 pp., 6 pis. JAANUSSON, V. 1954. Zur Morphologic und Taxonomie der Illaeniden. Ark. Min. Geol., Stockholm, 1 (20) : 545-583, pis. 1-3. KOBAYASHI, T. 1934. The Cambro-Ordovician formations and faunas of South Chosen, Part I : Middle Ordovician faunas. /. Fac. Sci. Univ. Tokyo (2) 3 : 329-519, pis. 1-44. 1937- The Cambro-Ordovician shelly faunas of South America. /. Fac. Sci. Univ. Tokyo (2) 4 : 369-522, pis. 1-8. LAMONT, A. 1945. Excursion to Onny River, Shropshire. Quarry Manager's J., Mexborough, 29 : 118-119, i fig. LA TOUCHE, J. D. 1884. A Handbook of the Geology of Shropshire. 99 pp., 22 pis. London & Shrewsbury. LINNARSSON, J. G. O. 1866. Om de Siluriska Bildningarne i Mellersta Westergotland. I. 23 pp. 2 pis. Stockholm. M'CoY, F. 1846. A synopsis of the Silurian fossils of Ireland. 68 pp., 4 pis. Dublin. MILLER, S. A. 1889. North American geology and paleontology. 795 pp., 1457 figs. Cincinnati. MILLER, A. K., YOUNGQUIST, W. & COLLINSON, C. 1954. Ordovician Cephalopod fauna of Baffin Island. Mem. Geol. Soc. Amer., Baltimore, 62 : 1-234, P^s- J-^S- MOORE, R. C. 1959. Treatise on Invertebrate Paleontology. Part O. Arthropoda i. xix + 560 pp., 415 figs. Lawrence & Meriden. MURCHISON, R. I. 1839. The Silurian System, founded on geological researches in the counties of Salop, Hereford, Radnor, Montgomery, Caermarthen, Brecon, Pembroke, Monmouth, Gloucester, Worcester and Stafford ; with descriptions of the coal-fields and overlying formations, xxxii + 768 pp., 40 pis., London, ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III 253 MURCHISON, R. I. 1854. Siluria. xv -f 523 pp., 37 pis. London. 1859. Siluria. 3rd edit, xix + 592 pp., 41 pis. London. 1867. Siluria. 4th edit, xvii + 566 pp., 41 pis. London. 1872. Siluria. 5th edit, xvii + 566 pp., 41 pis. London. OLIN, E. 1906. Om de chasmopskalken och trinucleusskiffern motsvarande bildningarna i Skane. Lund. Univ. Arsskr. (N.F., 2), 2 : 1-79, pis. 1-4. PHLEGER, F. B. 1937. Species and geographic distribution of the Lichadacea. Amer. Midi. Nat., Notre Dame, 18 : 1085-1092. PHILLIPS, J. & SALTER, J. W. 1848. Palaeontological Appendix to Professor John Phillips' Memoir on the Malvern Hills, compared with the Palaeozoic Districts of Abberley, &c. Mem. Geol. Surv. Gt. Britain, London, 2, i : 331-386, pis. 4-30. POCOCK, R. W., WHITEHEAD, T. H., WEDD, C. B. & ROBERTSON, T. 1938. Shrewsbury District, including the Hanwood Coalfield (One-inch Geological Sheet 152 New Series). xii + 297 pp., 8 pis. Mem. Geol. Surv. Gt. Britain, London. PRIBYL, A. 1953. Seznam ceskych trilobitovych rodil (Index of trilobite genera in Bohemia). Knihovna Ustr. ust. geol., Prague, 25 : 1-80. (In Czech, Russian and English). RAYMOND, P. E. 1925. Some trilobites of the lower Middle Ordovician of eastern North America. Bull. Mus. Comp. Zool. Harv., Cambridge, Mass., 67 : 1-180, pis. i-io. REED, F. R. C. 1902. Notes on the genus Lichas. Quart. J. Geol. Soc. Lond., 58 : 59-82, 19 figs. 1906. The Lower Palaeozoic Trilobites of the Girvan District, Ayrshire. 3 : 97-186, pis. 14-20. Palaeontogr. Soc. \_Monogr.~], London. 1910. New fossils from the Dufton Shales. Geol. Mag. Lond. (5) 7 : 211-220, 294-299, pis. 16, 17, 23, 24. 1928. Notes on the Bronteidae [= Goldiidae]. Ann. Mag. Nat. Hist., London (10) 1 : 49-78. 1931- A review of the British species of the Asaphidae. Ann. Mag. Nat. Hist., London (10) 7 : 441-472. 1935- The Lower Palaeozoic Trilobites of Girvan, Supplement No. 3 : 1-64, pis. 1-4. Palaeontogr. Soc., [MonogrJ], London. RICHTER, R. & E. 1917. Uber die Einteilung der Familie Acidaspidae und iiber einige ihrer devonischen Vertreter. Zbl. Miner., Stuttgart, 1917 : 462-472, 10 figs. 1926. Beitrage zur Kenntnis devonischer Trilobiten, IV. Die Trilobiten des Oberdevons. Abh. preuss. geol. Landesanst., BerlinJ(N.F.) 99 : 1-314, pis. 1-12. SALTER, J. W. 1852. A systematic description of Palaeozoic fossils in the Geological Museum of the University of Cambridge. Appendix A. Description of a few species from Wales and Westmorland referred to in the foregoing work. Appendix to Sedgwick & M'Coy, 1851 : i-viii. 1853. Figures and descriptions illustrative of British organic remains. Mem. Geol. Surv. U.K., London, Dec. 7 : 1-78, pis. i-io. 1857. On two Silurian species of Acidaspis from Shropshire. Quart. J. Geol. Soc. Lond., 13 : 210-211, pi. 6. 1865. On the fossils of North Wales. Appendix to Ramsay, A. C., The geology of North Wales. Mem. Geol. Surv. Gt. Britain, London, 3 : 239-363, pis. 1-26. 18650. A Monograph of the British Trilobites from the Cambrian, Silurian, and Devonian formations, 2 : 81-128, pis. 7-14. Palaeontogr. Soc. \Monogr.~\, London. 1866. A Monograph of the British Trilobites from the Cambrian, Silurian and Devonian formations, 3 : 129-176, pis. 15-25. Palaeontogr. Soc. [MonogrJ], London. SCHMIDT, F. 1885. Revision der ostbaltischen silurischen trilobiten nebst geognostischer iibersicht des ostbaltischen Silurgebiets, II. Acidaspiden und Lichiden. Mem. A cad. Imp, Sci. St. Petersb. (7) 33 : 1-127, Pls- I~^>- SEDGWICK, A. & M'CoY, F. 1851. A synopsis of the classification of the British Palaeozoic rocks, with a systematic description of the British Palaeozoic fossils in the geological museum of the University of Cambridge, I. iv -f- 184 pp., n pis. London & Cambridge. 254 ORDOVICIAN TRILOBITE FAUNAS OF SOUTH SHROPSHIRE, III SHIRLEY, J. 1931. A redescription of the known British Ordovician species of Calymene (s.l.}. Mem. Proc. Manchr. Lit. Phil. Soc., 75 : 1-35, pis. i, 2. — 1936. Some British trilobites of the Family Calymenidae. Quart. J. Geol. Soc. Lond., 92 : 384-422, pis. 29-31. — 1938. The fauna of the Baton River Beds (Devonian), New Zealand. Quart. J. Geol. Soc. Lond., 94 : 459-505, pis. 40-44. SINCLAIR, G. W. 1949. The Ordovician trilobite Eobronteus. J. Paleont., Menasha, 23 : 45-56, pis. 12-14. ST0RMER, L. 1940. Early descriptions of Norwegian trilobites. The type specimens of C. Boeck, M. Sars and M. Esmark. Norsk, geol. Tidsskr., Oslo, 20 : 113-151, pis. 1-3. 1945. Remarks on the Tretaspis (Trinucleus) Shales of Hadeland, with descriptions of trilobite faunas. Norsk, geol. Tidsskr., Oslo, 25 : 379-426, pis. 1-4. STUBBLEFIELD, C. J. 1938. The types and figured specimens in Phillips and Salter's Palaeon- tological Appendix to John Phillips' memoir on " The Malvern Hills compared with the Palaeozoic districts of Abberley, etc." (Mem. Geol. Surv., Volume II, Part I, June 1848). Summ. Progr. Geol. Surv., London for 1936, Pt. II : 27-51. THORSLUND, P. 1940. On the Chasmops Series of Jemtland and Sodermanland (Tvaren). Sverig. geol. Under s. Afh., Stockholm (C) 436 : 1-191, pis. 1-15. TRIPP, R. P. 1958. Stratigraphical and geographic distribution of the named species of the trilobite Superfamily Lichacea. J. Paleont., Tulsa, 32 : 574-582. pi. 85. WARBURG, E. 1925. The trilobites of the Leptaena Limestone in Dalarne, with a discussion of the zoological position and the classification of the Trilobita. Bull. geol. Instn. Univ. Uppsala, 17 : i-viii, 1-446, pis. i-n. - 1939. The Swedish Ordovician and Lower Silurian Lichidae. K. svenska VetenskAkad. Handl., Stockholm, 17, 4 : 1-162, pis. 1-14. WHITTARD, W. F. 1960. The Ordovician trilobites of the Shelve Inlier, West Shropshire, 4 : 117-162, pis. 16-21. Palaeontogr. Soc. [Monogr.], London. 1961. The Ordovician trilobites of the Shelve Inlier, West Shropshire, 5 : 163-196, pis. 22-25. Palaeontogr. Soc. [Monogr.'], London. WHITTINGTON, H. B. 1950. Sixteen Ordovician genotype trilobites. /. Paleont., Tulsa, 24 : 531-565, Pis. 68-75. 1956. Silicified Middle Ordovician trilobites : the Odontopleuridae. Bull. Mus. Comp. Zool. Harv., Cambridge, Mass., 114 : 155-288, pis. 1-24. — 1959. Silicified Middle Ordovician trilobites : Remopleurididae, Trinucleidae, Raphio- phoridae, Endymionidae. Bull. Mus. Comp. Zool. Harv., Cambridge, Mass., 121 : 371-496, pis. 1-36. WIMAN, G. 1908. Studien iiber das Nordbaltische Silurgebiete. Bull. Geol. Instn. Univ. Uppsala., 8 : 73-168, pis. 5-8. PLATES Specimens whitened with ammonium chloride before photographing. Numbers with prefixes BM. In., GSM., and A. are housed respectively in the British Museum (Natural History), London, the Geological Survey & Museum, London, and the Sedgwick Museum, Cambridge. Other figured specimens are in the Shrewsbury Museum and the National Museum of Ireland, Dublin. PLATE 37 Flexicalymene acantha Bancroft . . . . p. 216 Harnagian Stage, zone of Reuscholithus reeuschi, section in old cartway, near southern end of Smeathen Wood, near Horderley. FIG. i. Internal mould of cephalon with incomplete thorax. BM. In. 50635. x 2. FIG. 3. Lectotype, an immature cranidium preserved as an internal mould. BM. In. 42091. X3- FIG. 4. Paratype pygidium, an internal mould. BM. In. 49592. x 3. FIGS. 5, 6. Latex cast from external mould of adult cranidium. BM. In. 50622. x 2. FIG. 14. Latex cast from external mould of damaged, almost whole, dorsal exoskeleton. BM. In. 50623. X2'5. Flexicalymene cf. acantha Bancroft . . . . p. 217 Costonian Stage, zone of Costonia ultima, old quarry about 500 feet south of Coston Farm, i mile east of Clunbury. FIG. 7. Internal mould of cranidium showing glabellar outline. BM. In. 51694. X2. FIG. 10. Cranidium illustrating variation in glabellar outline. BM. In. 52226. x 2. FIG. 13. Internal mould of pygidium, with axis broadened by crushing. BM. In. 52227. X2. Flexicalymene (Reacalymene} horderleyensis sp. nov. . . p. 221 Lower Longvillian Substage, zone of Dalmanella indica and D. lepta, south-eastern corner of Rookery Wood, south-east of Horderley. FIGS. 2, 8. Latex cast of holotype, an external mould. BM. In. 50656. X2. Flexicalymene planimarginata (Reed) . . . p. 217 Lower Longvillian Substage, zone of Dalmanella horderleyensis, Long Lane Quarry, f mile north-west of Craven Arms. FIG. 15. Internal mould of pygidium. BM. In. 52104. x 2*3. Flexicalymene (Reacalymene} pusulosa (Shirley) . . p. 220 Costonian Stage, probably zone of Harknessella subquadrata, quarry near eastern end of Black Dick's Coppice, Evenwood. FIGS. 9, ii. Holotype cranidium with test preserved. BM. In. 50780. X2*5. Horizon as for Fig. 9. Old quarry in north-western part of Round Nursery, south of Harnage Grange. FIG. 12. Pygidium showing granulate surface. BM. In. 54868. x 3. Flexicalymene (Reacalymene) cf. limba (Shirley) . . p. 221 Soudleyan Stage, probably zone of Broeggerolithus broeggeri, road-side quarry 150 yards north-east of Chatwall Farm, Chatwall. FIG. 16. Internal mould of incomplete cranidium. BM. In. 54320. x 2-5. FIGS. 2, 5, 6, 8 and 14 by Mr. E. W. Seavill, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 3? 14 FLEXICALYMENE. FLEXICALYMENE (REACAI YMENF) PLATE 38 Flexicalymene cobboldi sp. nov. . . . p. 218 Marshbrookian Stage, zone of Dalmanella unguis, Marshwood Quarry, \ mile south of Marsh- brook Station. FIG. i. Internal mould of cranidium, associated with that of Otarion sp. BM. In. 50762. X2. Upper Longvillian Substage. zone of Kjaerina bipartita (=Alternata Limestone), south-eastern side of Horderley-Marshbrook road, 420 yards north-east of Crosspipes, about 2 miles north-east of Horderley Station. FIG. 3. Holotype, internal mould of cranidium. BM. In. 55448. x 2*3. Flexicalymene caractaci (Salter) . . . . p. 217 Marshbrookian Stage, zone of Onniella reuschi, well-sinking at " first house along road south from The Corner", near Wistanstow. FIG. 2. Internal mould of incomplete cranidium. BM. In. 52820. xi'Q. Horizon and locality as for Fig. i. FIGS. 4, 5. Internal moulds of cranidium, thorax and pygidium, associated on same hand- specimen. Syntypes of Flexicalymene trigonoceps Bancroft (1949, pi. n, fig. 32). BM. In. 42102. Fig. 4, X2'4; Fig. 5, x 2. Marshbrookian Stage, zone of Dalmanella wattsi, " Acton Scott Lodge ", near Acton Scott. FIG. 6. Lectotype, an internal mould. GSM. 47698. x 1*5. Horizon as for Fig. 2. West side of track in Marsh Wood, just south of the quarry. FIGS. 8, ii. Internal mould of cranidium illustrating inclined anterior border. BM. In. 50735. Fig. 8, X2; Fig. n, X2'5. Horizon as for Fig. 6, south-eastern side of Horderley road, 520 yards west-south-west of Marshbrook Station. FIG. 12. Internal mould of incomplete cranidium. BM. In. 55446. X2. Onnicalymene laticeps (Bancroft) . . . p. 224 Actonian Stage, north end of wood west of Rose Villa, Marshbrook. FIG. 7. Holotype cranidium, an internal mould. BM. In. 42103. X2. Uppermost Actonian Stage, north bank of River Onny, 62 feet east of junction with Batch Gutter. FIGS. 10, 14, 15. Uncrushed cranidium with test preserved. BM. In. 50723. x 2*5. Onnicalymene salteri (Bancroft) . . . p. 224 Horizon and locality as for Fig. 7. FIG. 9. Holotype cranidium, an internal mould. BM. In. 42100. X2. Horizon as for Fig. 7, south bank of River Onny, 80 yards west of junction with Batch Gutter. FIG. 13. Incomplete cranidium with test preserved. BM. In. 50736. xi'8. Fig. i by Mr. E. W. Seavill, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 38 FLEXICALYMENE, ONNICALYMENE PLATE 39 Gravicalymene praecox (Bancroft) . . . p. 225 Harnagian Stage, zone of Reuscholithus reuschi, section in old cart-way near south end of Smeathen Wood, near Horderley. FIG. i. Slightly crushed internal mould of large cranidium. BM. In. 50523. xi'8. FIGS. 3, 9. Internal mould of large, incomplete cranidium showing glabellar outline and form of anterior border and axial furrows. BM. In. 50522. x 2. FIG. 12. Internal mould of incomplete cranidium showing palpebral lobe and undistorted axial furrows. BM. In. 50657. xi'8. FIGS. 13, 14. Holotype, the internal mould of an immature cranidium, the glabella bearing the impression of an ostracod, Tallinella scripta (Harper). BM. In. 42090. X3'5- Gravicalymene cf. praecox (Bancroft) . . . p. 225 Onnian Stage, zone of Onnia gracilis, north bank of River Onny, 100 yards east of junction with Batch Gutter. FIG. 4. Cranidium with test preserved. BM. In. 50654. Xi'5- FIGS. 5, 8. Thorax and pygidium associated with, and believed to belong, to same individual as Fig. 4. BM In. 50655. Xi'5- Actonian Stage, site of old quarry, Quarry Field, Gretton, near Cardington. FIG. 7. Internal mould of incomplete cranidium. BM. In. 50648. xi'5- Gravicalymene inflata sp. nov. . . . p. 227 Horizon and locality as for Fig. 4. FIG. 6. Holotype, an incomplete cranidium with the test preserved. BM. In. 50653. x 1*5. Onnicalymene onniensis (Shirley) . . . p. 223 Horizon and locality as for Fig. 4. FIG. 2. Thorax and pygidium with test preserved. BM. In. 52092. x 2. Horizon and locality probably as for Fig. 4. FIGS. 10, ii. Holotype cranidium. GSM. RR 1940. X2. Figs. 4-8 by Mr. E. W. Seavill, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 39 •-.u-*i &%&&m 12 GRAVICAT .YMFMF OMMTPAT YUFMF GEOL. 7, 8 PLATE 40 Parabasilicus powisi (Murchison) . . . p. 229 Costonian Stage, probably zone of Harknessella, subquadrata, old quarry just west of Round Nursery, south-east of Harnage Grange. FIG. i. Internal mould of pygidium and fragment of thorax. BM. In. 52197. x i'3. Soudleyan Stage, zone of Broeggerolithus broeggeri, exposure behind Glenburrell farmhouse, Horderley. FIG. 3. Internal mould of pygidium and thorax. BM. In. 52186. xi'i. Harnagian Stage, zone of Reuscholithus reuschi, south bank of Coundmoor Brook, 1340 yards south-west of Harnage Farm, Harnage. FIG. 4. Internal mould of cranidium with fragments of test, showing course of facial suture. BM. In. 54237. xi'5. FIG. 5. Internal mould of slightly distorted pygidium showing anterolateral facets. BM. In. 54238. X2'2. Parabasilicus powisi (Murchison) ? . . p. 231 Middle Costonian Stage, Harknessella Beds, north side of cartway 50 yards east of Coston Farmhouse, i mile east of Clunbury. FIG. 2. Internal mould of hypostoma lacking anterior wings. BM. In. 50621. xi'6. Parabasilicus ? sp. . . . . p. 232 Lower Longvillian Substage, zone of Dalmanella indica and D. lepta, top of western end of Rookery Wood, south-east of Horderley. FIG. 6. Internal mould of pygidium. BM. In. 50741. X 1*5. Flexicalymene (Reacalymene) horderleyensis sp. nov. . . p. 221 Horizon as for Fig. 6, old quarry just west of western end of Rookery Wood, south-east of Horderley. FIGS. 7, 8. Internal mould of incomplete cranidium. BM. In. 52103. X2. Onnicalymene onniensis (Shirley) . . . p. 223 Onnian Stage, zone of Onnia superba, north bank of River Onny 720 yards west-south-west of Wistanstow Church. FIG. 9. Internal mould of cranidium. BM. In. 50711. X2. Fig. 9 by Mr. E. W. Seavill, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 40 FLEXICAT.YMFNF mFAHAT YMFNF\ OMMIPAT YUFMF PAR ARA9TT in TQ PLATE 41 Parabasilious powisi (Murchison) . . . p. 229 Soudleyan Stage, zone of Broeggerolithus broeggeri, eastern bank of Habberley Brook, 500 yards north of The Lyd Hole, near Pontesford, Shropshire. FIG. i. Internal mould of cranidium, left librigena (displaced), and thorax. BM. In. 54305. Xi'i. Probably Harnagian Stage, Bron-y-buckley Wood (=Trilobite Dingle), Welshpool, Mont- gomeryshire. FIG. 2. Vinyl plastic cast of lectotype, an external mould of pygidium and incomplete thorax GSM. 6841. xn. Fig. i by the writer, Fig. 2 by Mr. J. Brown. Bull. B.M. (N.H.) GeoL 7, 8 PLATE 41 PARABASILICUS PLATE 42 Parabasilicus ? marstoni (Salter) . ,. . . p. 231 Horizon probably Smeathen Wood Beds, Harnagian Stage pars, of the Horderley district. Exact locality unknown. FIGS, i , 6. Syntype, internal mould of an almost complete dorsal exoskeleton with damaged cephalon. GSM. 12817. X 4- Fidg. Salter, 1866, pi. 23, figs, i, \a. FIG. 8. Syntype, internal part external mould of right librigena. GSM. 12818. X2'5. Figd. Salter, 1865, pi. 23, fig. ib. Parabasilicus ? sp. . . . . p. 232 Probably from the Horderley Sandstone, Lower Longvillian Substage, of the Horderley district. FIG. 2. Internal mould of hypostoma. GSM. 12830. x 2. Figd. Salter, 1866, pi. 23, fig. 6. Lower Longvillian Substage, zone of Dalmanella horderleyensis, quarry by north side of road, 300 yards south-east of Glenburrell Farm, Horderley. FIG. 5. Internal mould of pygidium. BM. In. 51459. X2. Parabasilicus powisi (Murchison) . . . p. 229 Harnagian Stage, zone of Reuscholithus reuschi, section in old cart-way near southern end of Smeathen Wood, near Horderley. FIG. 9. Latex cast from external mould of frontal portion of cranidium. BM. In. 51462. X2. Illaenus cf. fallax Holm ..... p. 233 Onnian Stage, zone of Onnia ? cobboldi, north bank of River Onny, about 70 yards east of junction with Batch Gutter. FIG. 3. Internal mould of pygidium. BM. In. 50760. xi'9- Onnian Stage, zone of Onnia gracilis, north bank of River Onny, 100 yards east of junction with Batch Gutter. FIG. 4. Internal mould of pygidium. BM. In. 50515. x 1*9. FIG. 12. Cranidium with most of test preserved. BM. In. 50759. x i'3- Illaenus sp. . . . . p. 233 Actonian Stage, site of old quarry, Quarry Field, Gretton, near Cardington. FIGS. 7, 10. Internal mould of cranidium. BM. In. 50576. x i'6. FIG. IT. Internal mould of immature cranidium. BM. In. 50755. x 2-3. Figs. 7, 10 by Mr. E. W. Seavill, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 42 PARABASILICUS, ILLAENUS PLATE 43 Metopolichas ? sp. . . . . p. 234 Costonian Stage, zone of Harknessella subquadrata, old quarry by south-eastern side of brook, 1500 yards south-west of Harnage Farm, Harnage. FIGS. 3, 6, 7. Internal mould of incomplete, slightly distorted cranidium. BM. In. 46455. Figs. 3, 6, xi'4; Fig. 7, X2. Costonian Stage, zone of Costonia ultima, old quarry 650 yards west of Woolston House, Woolston. FIG. 4. Internal mould of fragmentary cranidium. GSM. RR 2140. X2. Plaiylichas laxatus (M'Coy) . . . p. 235 Actonian Stage, site of old quarry, Quarry Field, Gretton, near Cardington. FIG. i. Latex cast from external mould of large pygidium. BM. In. 49558. x 1*4. FIG. 8. Internal mould of incomplete cranidium. BM. In. 50749. Xi'5- FIG. 12. Internal mould of hypostoma. BM. In. 50524. xi'7- Horizon as for Fig. i, south bank of River Onny, 80 yards west of junction with Batch Gutter. FIG. 2. Incomplete cranidium showing surface of test. BM. In. 50747. x 2. Horizon as for Fig. i, old quarry 1400 feet west-south-west of St. Margaret's Church, Acton Scott. FIG. 5. Internal and partly external mould of pygidium, showing impression of terrace-lines on doublure. BM. In 50754. x 2*4. Caradoc Series, Slieveroe, Rathdrum, Ireland. FIG. 10. Holotype, a fragmentary cranidium. National Museum of Ireland Collection, x 2. Horizon as for Fig. i, locality as for Fig. 2. FIG. ii. Almost complete cranidium. BM. In. 46440. x 1*4. Platylichas sp. ..... p. 236 FIG. 9. Internal mould of pygidium, figured by M'Coy, 1846, pi. 4, fig. 14, as Calymene forcipata. National Museum of Ireland Collection, x i'75- Caradoc Series, Ballygarvan Bridge, New Ross, Ireland. Figs. 2,9, 10 by Mr. E. W. Seavill, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 43 LICHAS?. PLATYLICHAS PLATE 44 Primaspis harnagensis (Bancroft) . . . p. 237 Harnagian Stage, zone of Reuscholithus reuschi, section in old cart-way near southern end of Smeathen Wood, near Horderley. FIG. i. Internal mould of cranidium. BM. In. 50802. x 9. FIG. 6. Paratype pygidium, an internal mould. BM. In. 42087. X2'5. FIG. 8. Latex cast from external mould of librigena. BM. In. 50803. x 4. Horizon as for Fig. i. By north bank of Coundmoor Brook, 1300 yards south-west of Harnage Farm, Harnage. FIG. 4. Internal mould of cranidium, slightly distorted. BM. In. 52829. x 8. Primaspis caractaci (Salter) . . . . p. 239 Actonian Stage, site of old quarry, Quarry Field, Gretton, near Cardington. FIG. 3. Internal mould of cranidium. BM. In 50805. x 4. FIG. 9. Syn type thorax. GSM. 5214. X5- FIG. 13. Syntype, internal mould of almost complete dorsal eivoskeleton. GSM. 35473. X4- Horizon as for Fig. 3. Bank of stream by east side of bridge c. 1000 feet west-south-west of Hatton. FIG. 7. Two incomplete cranidia with test preserved. BM. In. 50510. x 3*5. Horizon as for Fig. 3. Old quarry by road almost opposite Church Farm, Acton Scott. FIG. ii. Latex cast from external mould of librigena. BM. In. 50801. X4- Marshbrookian Stage, zone of Onniella reuschi, west side of track just south of quarry in Marsh Wood, near Marshbrook. FIG. 14. Poorly-preserved librigena. BM. In. 50799. x 3. Triarthrus cf. linnarssoni Thorslund . . . p. 241 Onnian Stage, zone of Onnia superba, north bank of River Onny, 720 yards west-south-west of Wistanstow Church. FIG. 2. Internal mould of immature pygidium. BM. In. 49320. x 10. FIG. 5. Incomplete immature cranidium showing position of palpebral lobe. BM. In. 51528. X5'5- FIGS. 10,12. Internal mould of cranidium. Shrewsbury Museum 374. X4- Figs, i, 3, 8, 10-12 by Mr. E. W. Seavill, Fig. 2 by Mr. J. Brown, remainder by the writer. Bull. B.M. (N.H.) Geol. 7, 8 PLATE 44 PRIMASPIS, TRIARTHRUS PLATE 45 Otarion sp. . . . . . p. 242 Marshbrookian Stage, zone of Dalmanella unguis, west side of track, 70 yards south of entrance to quarry, Marsh Wood, near Marshbrook. FIG. i. Latex cast of cranidium. BM. In. 50618. X4'5. Remopleurella burmeisteri (Bancroft) . . . p. 250 Onnian Stage, zone of Onnia superba, north bank of River Onny, 720 yards west-south-west of Wistanstow Church. FIG. 2. Internal mould of hypostoma. BM. In. 56800^. x 7. Proetidella fearnsidesi Bancroft . . . p. 243 Harnagian Stage, zone of Reuscholithus reuschi, section in old cartway near southern end of Smeathen Wood, near Horderley. FIG. 3. Latex cast from the holotype, an external mould. BM. In. 42083. x 3'4- FIG. 8. Internal mould of immature thorax. BM. In. 51454. X2-g. FIGS. 12, 14. Internal moulds of cranidia, showing variation in outline of glabella. Fig. 12, BM. In. 55449, X 3-4. Fig. 14, BM. In. 51522, x 3-25. Horizon as for Fig. 3. Exposure in field, 550 yards north-west of Woolston House, Woolston. FIG. 4. Internal mould of cephalon showing palpebral lobe and facial suture. BM. In. 50616. X3- FIG. 5. Internal mould of immature cranidium. BM. In. 51455. X3'5- Costonian Stage, zone of Harknessella subquadrata, old quarry just west of western end of Round Nursery, south of Harnage Grange. FIGS. 6,7. Internal mould of nearly whole dorsal exoskeleton. BM. In. 51152. X3- Proetidella cf. fearnsidesi Bancroft . . p. 245 Soudleyan Stage, ? zone of Broeggerolithus broeggeri, road-side quarry 150 yards north-east of Chatwall Farm, Chatwall. FIG. 9. Internal mould of cranidium. BM. In. 34326. x 4. FIG. ii. Internal mould of left librigena. BM. In. 34325. X 3'25- Soudleyan Stage, zone of Broeggerolithus soudlevensis , road-side quarry 100 yards south-east of Glenburrell Farm, Horderley. FIG. 10. Internal mould of cranidium. BM. In. 51456. X2. Proetidella ? sp. . . . . p. 246 Marshbrookian Stage, zone of Dalmanella unguis, stream bank about 350 yards north-west of road bridge, 350 yards south-west of Hatton, near Acton Scott. FIG. 13. Internal mould of cranidium. BM. In. 50617. x 4. Photographs by the writer. Bull B.M. (N.H.) Geol 7, 8 PLATE 45 OTARION, PROETIDELLA, REMOPLEURELLA PLATE 46 Remopleurides warburgae sp. nov. . . . p. 246 Highest beds of Actonian Stage, north bank of River Onny, 30 yards east of junction with Batch Gutter. FIGS. 1,2. Holotype cranidium with test preserved. BM. In. 49751. X 2-5. Remopleurides latus Olin onniensis subsp. nov. . . . p. 247 Horizon and locality as for Fig. i. FIGS. 4, 5. Holotype cranidium. BM. In. 49750. X2'5. Remopleurides sp. . . . . . p. 248 Horizon and locality as for Fig. i. FIG. 3. Almost complete left librigena. BM. In. 49752. X2'5_ FIG. 7. Incomplete thorax showing serrated axial rings and shape of pleurae. BM. In. 49753. X3- Remopleurella burmeisteri (Bancroft) . . . . p. 250 Onnian Stage, zone of Onnia superba, north bank of River Onny, 720 yards west-south-west of Wistanstow Church. FIG. 6. Paratype, internal mould of librigena. BM. In. 42098. x 2-5. FIGS. 8, 12. Paratype, incomplete, disarticulated exoskeleton preserved as internal mould. BM. In. 49561. Fig. 8, X2'5. Fig. 12, hypostoma, In. 49561^, x 6. FIG. 9. Internal mould of cranidium showing palpebral lobes. BM. In. 49748. X5'25. FIG. ii. Lectotype, internal mould of cranidium. BM. In. 42106. x 275. Eobronteus ? sp. . . . . p. 251 Horizon and locality as for Fig. 6. FIG. 10. Internal mould of incomplete dorsal exoskeleton. Sedg. Mus. A. 43833. x 2. FIGS, i -5, by Mr. E. W. Seavill, Fig. 10 by Mr. J. Brown, remainder by the writer. Bull. B.M. (N.H.) GeoL 7, 8 PLATE 46 EOBRONTEUS?, REMOPLEURELLA, REMOPLEURIDES PRINTED IN GREAT BRITAIN BY ADLARD AND SON, LIMITED, BARTHOLOMEW PRESS, DORKING THE GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS A. J. CHARIG BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. 9 LONDON: 1963 THE GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS BY ALAN JACK CHARIG Pp. 255-297 ; Plate 47 ; 10 Text-figures BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY) GEOLOGY Vol. 7 No. 9 LONDON : 1963 THE BULLETIN OF THE BRITISH MUSEUM (NATURAL HISTORY), instituted in 1949, is issued in five series corresponding to the Departments of the Museum, and an Historical series. Parts will appear at irregular intervals as they become ready. Volumes will contain about three or four hundred pages, and will not necessarily be completed within one calendar year. This paper is Vol. 7, No. 9 of the Geological (Palaeontological] series. Trustees of the British Museum 1963 PRINTED BY ORDER OF THE TRUSTEES OF THE BRITISH MUSEUM Issued July 1963 Price Sixteen Shillings THE GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS By A. J. CHARIG CONTENTS Page I. INTRODUCTION .......... 258 II. HISTORY OF Thatcheria AND OF THE VIEWS ON ITS RELATIONSHIPS 258 III. NOTES ON Thatcheria mirabilis ANGAS ...... 268 Identification of the holotype ....... 268 Additional material in the British Museum (Natural History) . 269 Supplementary description ....... 269 IV. NOTES ON Clinura ......... 271 Material studied . . . . . . . . .271 Posterior sinus ......... 272 Protoconch .......... 274 Transverse sculpture . . . . . . . .274 V. NOTES ON Waitara livatula POWELL . . . . . . 275 Protoconch .......... 275 Transverse sculpture . . . . . . . .276 VI. SYSTEMATICS .......... 276 General principles . . . . . . . . .276 The Clinura-Thatcheria group . . . . . . .278 Division into genera . . . . . . . .281 Interspecific differentiation in Thatcheria . . . . .283 Evolution in the Clinura-Thatcheria group .... 286 Systematic position of the Clinura-Thatcheria group . . . 288 Formal classification . . . . . . . .291 VII. A NEW SPECIES OF Thatcheria FROM THE PLIOCENE OF FIJI . 292 VIII. ACKNOWLEDGMENTS ......... 294 IX. REFERENCES .......... 295 SYNOPSIS The literature on the subject is reviewed with particular reference to the systematics of the genera concerned. A Recent gastropod shell, Brit. Mus. (Nat. Hist.) no. 1960.154, is identified as the holotype of the type-species of Thatcheria (T. mirabilis from off Japan) . The description is amplified. The form of the posterior sinus in Clinura has been generally misunderstood. The proto- conch, hitherto unknown in the genus, is described in the type-species and in one other. The protoconch of Waitara liratula is re-examined. The systematics of the genera concerned are reconsidered. Clinura is restricted to a few species from the Neogene of Europe and of the Western Pacific. Clinura, Waitara and Thatcheria are closely related to each other but not to Surculites. Fourteen species in those three genera are reclassified into two genera, Clinura (mainly Miocene) and Thatcheria (Upper Miocene to Recent, mainly Pliocene) ; Thatcheria is confined to the Western Pacific. The two genera constitute a sub-family of the Turridae, the Thatcheriinae, which has affinities with the Daphnellinae. Thatcheria vitiensis sp. nov. is described and figured from one specimen of probable Lower Pliocene age from Fiji. GEOL. 7, 9 20 258 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS I. INTRODUCTION THE discovery of a new fossil gastropod which resembles Thatcheria and Waitara has led to a re-examination of this little-known group of genera. The conclusions reached have been based upon all the relevant literature and upon a few shell characters hitherto unknown or imperfectly understood. Some of the earlier descriptions and illustrations of the gastropods in question were inadequate or misleading (especially with reference to the form of the posterior sinus and of the consequent growth-lines, the taxonomic significance of which had not then been appreciated). One drawing in particular, upon which some later workers relied for their knowledge of a type-species, is also quite different in that respect from the less accessible description and figures of the original author. The extreme scarcity of actual material obliged most later workers to rely very largely upon these earlier descriptions and figures, and misunderstandings therefore arose. Language difficulties appear to have exacerbated the situation. Finally, it is also evident that certain important works on the Thatcheria-Waitara group of gastropods were written in ignorance of the existence of some of the others. But this was sometimes unavoidable ; for example, two of the most important were written and published at about the same time during the Second World War, one in New Zealand and the other in the German-occupied Netherlands. Thus, while the known members of the group are few in number, both as species and as individuals, their systematics are confused. Although only two named species (Thatcheria mirabilis and T. gradata) have been referred to the genus That- cheria itself, those two species have already been placed by various authors in ten different prosobranch taxa of the genus-group (excluding synonyms). They have been considered, at least implicitly, as belonging to eight different prosobranch families, five of which possess alternative names. Indeed, one author alone (Wenz, 1943) has referred the two forms concerned and the closely related genus Waitara to three separate families. It has also been suggested that T. mirabilis is an opistho- branch, and elsewhere stated quite dogmatically that it is a " scalariform mon- strosity ". In all, in connexion with T. mirabilis and T. gradata, sixteen family names are involved. However, it is now generally accepted that these molluscs are so closely related as to form a natural group. The group might be either a sub-family within the Turridae or, as has been suggested, a separate family with strong affinities therewith. The status and relationships of the group require careful consideration, and the systematics within the group are in need of revision. II. HISTORY OF THATCHERIA AND OF THE VIEWS ON ITS RELATIONSHIPS Thatcheria mirabilis gen. et sp. nov. was described and figured by Angas (1877 : 529, pi. 54, figs. la, b}. His material consisted of one fairly large pagodiform shell believed to be unique ; it had been brought from Japan not long before by Mr. Charles Thatcher, and its occurrence could be localised no more accurately than " Seas of Japan ". No indication was given as to where the shell was deposited. GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 259 Of its systematic position, Angas wrote : " Without a knowledge of the operculum, its exact generic position cannot be determined ; but at present I regard it as belonging to the subfamily Fusinae " (i.e. in the family then called Fusidae, now either called Fusinidae or regarded as part of the Fasciolariidae). The next reference to the specimen is by G. B. Sowerby (1880 : 105, pi. 422, figs. 45, 46), who wrote that it " has been thought to exhibit, in the arched sinus of the outer lip above the angle, a peculiarity of generic value." He nevertheless referred the species to the genus Pyrula. (The " Thesaurus Conchy liorum " does not place genera in families, but the genus Pyrula Lamarck 1799, which should be replaced by the older synonym Ficus Roding 1798, is now referred to its own family Pyrulidae or Ficidae). Sowerby also considered Angas' type to be immature, and mentioned that it was " in the collection of Mrs. Deburch ". Tryon (1881 : 98, 112, pi. 44, figs. 238, 239) retained Angas' genus Thatcheria and referred it to the sub-family Melongeninae or Melongeniinae of the family Buc- cinidae ; but his arrangement might indicate that he considered Thatcheria to be synonymous with the older genus Hemifusus Swainson. Further, he opined that Angas' specimen did not represent the normal form of the genus, for he wrote " That this shell is a scalariform monstrosity cannot be doubted ". Later (1883 : 135, pi. 49, fig. 5) he gave an exact repetition of his earlier text. Fischer (1884 : 623) reported Tryon as considering Thatcheria to be a scalariform monstrosity of " Semifusus Swainson em. 1840 (Hemifusus}." In fact, Semifusus Agassiz 1846 is an invalid emendation of Hemifusus Swainson 1840. Fischer placed this genus in the sub-family Melongeninae of the family Turbinellidae (sometimes called Xancidae or Vasidae) ; the sub-family in question is now generally regarded as a separate family, the Melongenidae. Cossmann was at first (1889 : 162) unable to agree with Tryon on this matter ; the form of the sinus, as indicated by the growth-lines on the ramp, led him to believe that Thatcheria could well be a junior synonym of Mayeria Bellardi 1873. Mayeria, in any case, seemed to be close to " Semifusus " , for Cossmann placed them both together (in the same family and sub-family as Fischer had done). Later, however (1901 : 62, 93, 94), Cossmann decided that the canal of Thatcheria dis- tinguished it from Mayeria, and that Tryon was correct after all in supposing Thatcheria to be but a monstrosity of " Semifusus ". Meanwhile Pilsbry (1895 : 28) had reverted to Tryon 's classification and had listed Thatcheria mirabilis in the Buccinidae. No further mention of Thatcheria has been discovered earlier than Tomlin's editorial notes (1919 : 66), in which he stated that the de Burgh Collection was offered for sale and that it included Thatcheria mirabilis, frequently considered to be a monstrosity of Fusus. (Presumably Tomlin intended this to refer to the genus Fusinus Rafinesque 1815 emend, pro Fusus Lamarck 1799, non Helbling 1779). Yokoyama (1928 : 338, pi. 66, figs. 3, 4) described and figured two specimens from the Pliocene of Japan as Cochlioconus gradatus gen. et sp. nov. The new genus was not explicitly referred to any family, but it was described as " C onus-like " and Yokoyama stated that " The presence of a deep sutural notch reminds us of the genus Conus." Pilsbry saw this paper and wrote to Yokoyama, drawing his attention GEOL. 7, 9 20§ 260 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS to the similarity between Cochlioconus and Thatcheria. Yokoyama then stated in a subsequent paper (1930) that he regarded Thatcheria (T. mirabilis} and Cochlioconus (C. gradatus] as congeneric, though not conspecific, the Pliocene species being more Conus-like in appearance than the Recent form. He did not, however, change his views on the systematic position of the genus, for he wrote (p. 406) " I think I am right in placing it near Conus. This opinion seems to be also shared by Mr. Pilsbry as is evident from his communication." He also stated, probably wrongly, that Angas' specimen of T. mirabilis " may be the only one now existing [i.e., in a col- lection] in the whole world." Thiele (1929 : 320) considered Thatcheria to be a synonym of the sub-genus (" sectio ") Semifusus sensu stricto, which he placed in the family Galeodidae. The proper family name is in fact Melongenidae, the name of the type-genus Galeodes being a junior homonym (Roding 1798 non Olivier 1791). Thiele, who was con- cerned only with Recent molluscs, did not mention Cochlioconus. S. Hirase (1934 : 104, pi. 1286, fig. 3) figured a specimen of " Thatcheria mirabilis Angas (= Semifusus m.?} ", which is appreciably longer and more slender than Angas' type. The illustration is of interest in that it showed, for the first time, that more than one individual of the species had been found. This point was emphasised in 1937 at an Ordinary Meeting of the Malacological Society of London, at which Tomlin exhibited two shells of the species, both from Japan. Hopwood wrote in the Proceedings (1937 : 158) that " Tryon's dictum [that Thatcheria is a scalariform monstrosity] has been confuted recently by the discovery of several examples, but where it should be placed systematically is as great a problem as ever. Discussion elicited suggestions that it was a prosobranch to be placed in Turridae and that it was an opisthobranch allied to Akera." The suggestion that it was a turrid had not been made before. The first recorded find of the soft parts of Thatcheria was made at about this time ; Tomlin had obtained from a Japanese fisherman the anterior portion of a male ani- mal, which was described and figured by Eales (1938). Unfortunately the specimen had lost the radula. Eales concluded, however (p. 16), that its characters " show that the specimen belongs to the Toxoglossa." A comparison of the creature with various members of the Turridae (e.g., Turricula javana) and of the Conidae (e.g., Conus quercinus] showed a very close resemblance to the former and none whatever to the latter ; and an X-ray photograph of the shell of T. mirabilis, which " shows a typical columella similar to that of the Turrids, not resorbed as in the Cones ", confirmed Eales' opinion (p. 17) that " As far as it is possible to judge . . . Thatcheria mirabilis should be placed with the Turrids." The next paper to mention Thatcheria was that of Powell (1942), in which he suggested a close affinity between Thatcheria and the fossil Waitara. At this point it is necessary to digress a little upon the latter genus. All the species mentioned immediately below and referred to Waitara are from New Zealand. Marwick (1926 : 324, pi. 74, fig. 9) had described a specimen from the Upper Miocene under the new specific name waitaraensis, referring it to the genus Turricula ; but he also wrote (p. 326) that " the generic location of the Turridae described above is quite provisional. New genera seem to be required ". Later GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 261 (1931 : 149) he erected the new genus Waitara upon this species, and referred thereto another new Miocene species, W. generosa (pi. 18, fig. 339). Powell (1942 : 168) considered W. generosa to be of Lower Miocene age. Powell also described two more species of Waitara in the same work — W. pagodula (p. 168, pi. 14, fig. 7) from the Upper Miocene or Lower Pliocene and W. liratula (p. 169, pi. 14, fig. 8) from the Lower Pliocene — and mentioned yet another Lower Pliocene species (p. 168), repre- sented by a single specimen too poorly preserved for description or illustration but said to be " somewhat similar [to W. pagodula] but narrower ". The Waitara liratula material included the protoconch illustrated in his text-fig. 63 (p. 38). The paper gave a key to the four named species of Waitara (p. 168). Powell's systematic conclusions were important. He wrote (p. 167) " It is possible that Waitara may yet prove to be identical with Thatcheria . . . and Cochlioconus ... In any case all three are closely allied and represent a discordant Turrid-like group that cannot be satisfactorily placed in any of the nine sub-families adopted in this bulletin. . . . Cochlioconus is almost certainly a synonym [of Thatcheria], although its author made no reference to Thatcheria, but compared his genus with the Cones. Anyone acquainted with Thatcheria would scarcely have overlooked the need for some comparison." Evidently Powell did not know of Yokoyama's second paper on this subject ; nor, indeed, does he seem to have been aware of Eales' work. He sought to differentiate Waitara from Thatcheria, at least provisionally, because its sinus " although very similar to that of Thatcheria, does differ at its point of origin, in being narrowly concave before swinging forward, whereas the sinus in Thatcheria swings forward immediately." He also described the form of the sinus in all these genera as " deep Conid-like." Finally, after discussing the relationship of the genera in question to certain sub-families of the Turridae (the Daphnellinae and the Cochlespirinae) and to the Conidae, Powell came to the following conclusions (p. 168) : " In order not to prejudice the status of the other Turrid subfamilies by forcing in such an aberrant group, it seems advisable to consider Thatcheria and its allies as representative of a new family, closely akin or parallel to the Turridae, for it seems to have arisen from the Conidae, but probably much later and independent of the early Conid-like Turrid divergent stock as represented by the Conorbiinae." He called this new family the Thatcheriidae ; and, in the same work (p. 170), he wrote " The former [i.e. the Thatcheriidae] in having marked Conid affinity in respect to its sinus is indicated as a late Tertiary offshoot from the Conidae . . . Wenz (1943) evidently saw no connexion between Thatcheria, Cochlioconus and Waitara, for he placed all three in different families. He considered Thatcheria (p. 1215) to be a synonym of the sub-genus Hemifusus of the genus Pugilina Schu- macher 1817, family Galeodidae. Cochlioconus (mis-spelt " Cochliconus " in the text on p. 1470 and in the index on p. 1604, though correct in the legend to fig. 4154) he regarded as a sub-genus of Conus Linnaeus 1758, family Conidae. And he classi- fied Waitara (p. 1390, fig. 3929) as a genus of the sub-family Clavatulinae, family Turridae ; he wrongly cited W. generosa Marwick as the type-species, wrongly quoted its horizon as Upper Miocene and gave the stratigraphical range of the genus as Oligocene to Miocene, although no Oligocene species of Waitara has ever been 262 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS recorded. (The Pliocene species of Waitara described by Powell (1942) were, of course, unknown to Wenz because of the Second World War.) The genus Clinura Bellardi 1875 (see below) was also included by Wenz (p. 1390, fig. 3928) in the Clavatulinae, as a sub-genus of Surculites Conrad 1865. Beets (i943# : 296) described as Surculites (Clinura) bituminatus a new species of gastropod from the asphalt deposits of the island of Buton, off Celebes ; the deposits were at that time believed to be of Upper Oligocene age. Like Wenz, Beets re- garded Clinura as a sub-genus of Surculites and considered these forms to be turrids. In his description of S. (C.) bituminatus he placed Cochlioconus in the synonymy of Clinura ; but, when doing so, he knew nothing of Thatcheria, for it was not until later that Yokoyama's second paper (1930) drew his attention towards that genus. Perhaps the most important work of all on this group of gastropods was a second article by Beets (19436). He suggested that Thatcheria (including, ywfc Yokoyama, 1930, Cochlioconus}, Clinuropsis Vincent 1913 (non Thiele " 1931 " [should be 1929]) and Nekewis Stewart " 1926 " [should be 1927] should all be regarded as junior synonyms of the sub-genus Clinura. In this paper Beets discussed a large number of species — of Clinura, of Clinuropsis, and of other genera such as Cryptoconus, Surculites, " Pseudotoma ", " Surcula ", " Pleurotoma " and "Turricula " — in order to ascertain whether they might properly be included in Clinura ; and, since he considered their great variations in form (especially that of the posterior sinus) to fall within the range of the "fur die so schwierigen Turridae ' normalen Variabilitat '", his decision was usually affirmative. He concluded (p. 365) : " Clinura ist jetzt mit Gewissheit bekannt aus dem Eocan bis Miocan der atlantischen [surely that should be " pazifischen "?] Kiistenregionen Nordamerikas . . . , aus dem Montien bis Pliocan Europas und dem Oligocan des ostindischen Archipels ; in Japan tritt sie erst ins Pliocan auf und lebt dort mit einer einzigen, extremen rezenten Art fort. Vielleicht (?) ist Clinura auch noch bekannt aus dem Eocan S.W. Afrikas und des Congos, hochstens mit zwei Arten." At this point it may be useful to give a short account of Clinura and of its author. The genus was erected by Aloysius Bellardi (1875 : 20) in a paper written entirely in Latin ; although "A. Bellardi " and " L. Bellardi " (Luigi) are sometimes listed separately in bibliographies (e.g., Wenz, 1944 : 1513), there are several reasons which make it seem certain that " Aloysius " was merely a latinisation of " Luigi " and not the name of another author. First, both " Aloysius " and Luigi were Professors of Natural History, living at the same time in the same country and writing on the same subject ; indeed, not only " Aloysius " but also Luigi published works concerned with Clinura, including the one mentioned below in which Luigi quoted verbatim (but without acknowledgment) the generic diagnosis given by " Aloysius " and then designated a type-species. Secondly, both " Aloysius " and Luigi published in the Bullettino delta Societa Malacologica Italiana ; and authors of works in that journal were generally members of the society in question, yet only Luigi's name is to be found in the list of members for 1875. Thirdly, " Aloysius " (unlike Luigi) published nothing except this one paper. Fourthly, neither " Aloy- sius " nor Luigi, when referring to names proposed by a Bellardi or to previous publications by a Bellardi, was in the habit of distinguishing himself from the other GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 263 by the use of an initial. Fifthly, a paper in French by " Louis " Bellardi (1841) is clearly the work of Luigi ; it is therefore evident that Luigi was in the habit of altering his Christian name to conform with the style of the language in use. Finally, an obituary of Bellardi by his fellow malacologist Sacco (1889) gives a list of the " Publications scientifiques de M. Louis Bellardi " ; this includes all the works of " Aloysius ", Luigi and " Louis ", and thus provides conclusive proof of their identity. The 1875 paper designated no type-species for Clinura but assigned two species to the new genus, C. calliope (Brocchi, 1814 : 436, pi. 9, figs. 150, b) [Murex] and C. elegantissima (Foresti, 1868 : 598, pi. 2, figs. 10-13) [Pleurotoma] ; Bellardi placed Clinura in his new sub-family Pseudotominae, family Pleurotomidae. A far more complete account of the genus, published a few years later in Italian by Luigi Bellardi (1877 : 204-209), included five species therein ; Clinura calliope, from the Upper Miocene of Italy, was clearly designated as the type (p. 204). Other fossil species were subsequently referred to the genus, at first only from the Neogene of Europe, e.g., R. Homes & Auinger, 1891 : 362 ; Friedberg, 1912 : 210) ; later, however, species from rocks as old as the Eocene and as far away as California and Celebes were also placed in Clinura (e.g., Grant & Gale, 1931 : 494 ; Beets, 1943^, I943&, as indicated above). Meanwhile two Recent deep-sea gastropod species had also been referred to Clinura, C. monochorda Ball (1908 : 292, pi. 13, fig. i) and C. peruviana Dall (1908 : 293, pi. 13, fig. 2). Since these are the only Recent species ever referred to the genus, they are also the only species mentioned by Thiele (1929 : 371), whose work did not deal with fossil forms. Thiele wrote of Ball's species, however, that " doch diirften sie mit dieser [Clinura} kaum verwandt sein ", without giving any reason for this statement, and he proposed that these two species should constitute a new section Clinuropsis of the genus Pleurotomella Verrill 1873, with P. (C.} monochorda (Ball 1908) as the type-species. But, by the time he wrote his " Nachtrage und Berichti- gungen " to the same work, published in 1934, Thiele had learnt that the name Clinuropsis had already been used by Vincent in 1913 ; he therefore proposed (p. 1002) the new name Anticlinura to replace it. Wenz (1943 : 1460) treated the supposed Recent species of Clinura exactly as Thiele had done. Beets (19436 : 364) also agreed with Thiele (1929) in the matter, Ball's species being two of the few which he chose to exclude from the genus Clinura ; unlike Thiele, he gave reasons (such as the presence of lattice-like sculpture on Ball's species) for so doing. Further, Beets appears to have noted Vincent's preoccupation of the name Clinuropsis but not Thiele's subsequent correction and proposal of Anticlinura nom. nov. to replace Clinuropsis Thiele ; for he himself, with the same intention, proposed Clinuromella nom. nov. Thus Clinuromella Beets 19436 is an objective junior synonym of Anticlinura Thiele 1934, both being new names for Clinuropsis Thiele 1929 (non Vincent 1913). In conclusion, it would seem that Ball's two species should continue to be placed under the sub-generic name Anti- clinura (of which monochorda is the type-species) in the genus Pleurotomella. No author has ever disputed the position of Clinura in the Turridae (Pleuroto- midae). Cossmann (1896) and Friedberg (1912) both regarded the taxon as a sub- 264 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS genus of Surcula H. & A. Adams 1853 ; but Grant & Gale (1931) considered it to be a sub-genus of Surculites, in which opinion, as recorded above, they were followed by Wenz (1943) and Beets (19430 ; 19436). Wrigley (1939), however, while not denying the turrid (or at least toxoglossan) nature of Clinura, believed that Surculites was not a turrid and therefore not related to Clinura. Thus the connexion of Thatcheria with Clinura was suggested and firmly established in 1943. The rest of this historical account will deal also with papers referring to Clinura, even though they make no mention of Thatcheria. Though complete in most respects, Beets' paper (19436) had not considered Waitara. Powell's bulletin on the Turridae, published in New Zealand in 1942, drew attention to the relationship between Waitara and Thatcheria, but had not been seen by Beets working in that same year in the German-occupied Netherlands ; nor could he have seen Wenz's treatise (1943) which placed Waitara immediately next to Clinura. In 1949, however, Beets obtained access to Powell's bulletin ; and in 1951 he published yet another paper, one part of which was concerned with " Waitara and its relationships to Surculites-Clinura-Thatcheria." The main object of this work was to establish Waitara as part of " the species group Clinura . . . (taken in a broad sense) " ; the three taxa Clinura, Waitara and Thatcheria, hitherto related only as three different pairs by three different authors, were to be brought together. Beets recognised, however, that Wenz's conclusions regarding the taxonomic proximity of Waitara and Clinura had been based entirely on Marwick's original Miocene species of the former genus, while the affinities of that genus to Thatcheria depended more on the characters of the younger species described by Powell (1942). One noteworthy point from Beets' 1951 paper is that, whereas he had earlier (19436) considered Thatcheria to be a synonym of the sub-genus Clinura, he now regarded Clinura, Waitara and Thatcheria as three separate (but closely related) sub-genera, still in the genus Surculites. He gave no reason for this change. In- cidentally, this work of Beets contains three minor errors. First, he stated (p. 14) that Turricula waitaraensis Marwick became the type-species of Waitara by Powell's subsequent designation in 1942 ; it was, in fact, the type-species by Marwick's original designation (1931). Secondly, he appeared to claim (p. 15) that he himself was the first to refer Thatcheria to the Turridae (19426, cited in the present work as 19436) ; he was, of course, preceded in this by Eales (1938). Thirdly, he quoted Powell (p. 16) as describing the posterior sinus of Waitara as " first narrowly convex " ; that should read " concave ". Beets (1951) also gives a small, semi-schematical figure (pi. i, fig. 6) of " Thatcheria spec. nov. ; a portion of a specimen from the Pliocene of East-Borneo ". The fragment was mentioned only briefly in the text (p. 16) and has not yet been des- cribed. It appears to consist of two whorls from a pagodiform spire which must indeed have been remarkably like that of T. mirabilis, with a similar type of sinuosity in the growth-lines on the ramp. The asphalt deposits of Buton (which, according to Beets (19430 ; 19436), con- tained two species of Clinura) were supposed to be of Upper Oligocene age. In 1953, however, Beets showed (p. 239) that the age of the moUuscan fauna was most GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 265 likely Mio-Pliocene ; there is no evidence to support the suggestion that the molluscs might be a mixture derived from different stratigraphical horizons, but the possibility cannot be entirely excluded. He also reported Reinhold as concluding that the diatoms in the deposits indicate a probable Upper Miocene age. S. Hirase's posthumous handbook of Japanese shells (1951), which was in effect his catalogue of 1934 revised and enlarged by Taki, reproduced the figure of Thatcheria mirabilis which had appeared in the earlier work (pi. 1286, fig. 3, in both). The later work, however, no longer suggests that Thatcheria might be a synonym of " Semifusus " ; and the second edition (1954) is provided with a systematic index to the plates which, on p. 88, classifies Thatcheria as a genus of the Turridae. Thatcheria was also listed among the Turridae by Kuroda & Habe (1952 : 10). On p. 90 of the same work they indicated that the geographical range of T. mirabilis was off the Pacific coast of Japan, between 33° and 35° of latitude. Hatai & Nisiyama (1952 : 191) listed Yokoyama's two syntypes of Cochlioconus gradatus with full details of locality and horizon ; the latter was given as Takajo Formation, believed to be of Lower Pliocene age. It was noted that both specimens were in the collections of the Geological Institute of the Faculty of Science of Tokyo University. The specimen illustrated in Yokoyama's fig. 3 (1928, pi. 66) was designated as lectotype (" holotype ") by these authors, who evidently regarded C. gradatus as a junior synonym of Thatcheria mirabilis. Kuroda & Habe (1954 : 80) published important new information on Thatcheria mirabilis ; this was obtained from three individuals of different ages, each with soft parts. They were able to describe and figure the radula (text-fig. 2) and the proto- conch (text-fig. I, showing also the early nepionic whorls) ; the operculum was reported lost in all the specimens. The peculiar shape of the radula and the obliquely reticulated sculpture of the protoconch led them to suggest that Thatcheria was a member of, or had a close affinity with, the Daphnellinae. Unfortunately they had misinterpreted both Eales' and Powell's papers. First, they thought that Eales' observation, " No traces of proboscis or radula are present ", indicated the natural lack of a radula in the species ; but, in fact, the lack of a radula was clearly accidental in the specimen which constituted the whole of Eales' material, " the body being torn away immediately posterior to the mouth tube." Secondly, they believed that Powell had established the family Thatcheriidae to include, not only Thatcheria mirabilis and some fossil species, but also some other, related Recent groups (but no others are known) ; and further, that Powell had done this because of the " nature of its radula quite rudimentary " in Thatcheria (also unknown at that time). Habe (1955) devoted two short articles to " Thatcheria mirabilis Angas (Turridae) ". The first is in English ; it consists only of a direct quotation of Angas' description, reproductions of the figures of the early whorls and the radula (from Kuroda & Habe 1954), references to the works of Angas, Eales, Powell, and Kuroda & Habe, and the comment " This strange species seems better to locate under the sub- family Daphnellinae in having the reticulated protoconch and the dart shaped radula." The other article is in Japanese but is not the same ; it reproduces the illustrations to Angas' paper, cites the dimensions of three new specimens of T. mirabilis and mentions the fossil Cochlioconus. 266 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS Kira (1955 : 71, pi. 35, fig. 19) also placed Thatcheria mirabilis in the Turridae. Rossi Ronchetti (1951-56) included Murex calliope, the type-species of Clinura (see p. 263), among the species dealt with in her review of Brocchi's types ; she selected, figured and carefully described a neotype (1955 : 305, fig. 163) because Brocchi's holotype was no longer preserved. The species appears, however, under the name Pleurotomella (Clinuropsis) calliope, presumably for the following reasons : The introduction to Rossi Ronchetti's review stated (1951 : n) that the revision of the generic names would be based partly upon the works of Wenz (1938-44) and Schilder (1932), partly upon the works of Thiele (1929-31, 1934-35). Schilder, of course, dealt only with Cypraeacea. In this particular instance Rossi Ronchetti could not have used Wenz (or Thiele's " Nachtrage und Berichtigungen ") as the basis for her classification ; had she done so, she would then have known— as she clearly did not know — that Thiele had later proposed Anticlinura as a new name to replace his own Clinuropsis. It therefore appears likely that she based her classifica- tion only upon Thiele's main work. Noting that Ball's species of Clinura, the only supposed representatives of that genus mentioned by Thiele, had been transferred by the latter author to Pleurotomella (sectio Clinuropsis), Rossi Ronchetti did the same with Clinura calliope — probably without considering the possibility that Ball's species had no real connexion with Clinura. Although other authors may not agree that calliope Brocchi and monochorda Ball are co-sub-generic, or even congeneric, Rossi Ronchetti is nevertheless entitled to her opinion that they are. In that case she was correct in using for both species the oldest generic name available — Pleurotomella Verrill 1873. But, for the sub- genus, she should then have used the oldest generic name previously applied to any included species — and this was Clinura Bellardi 1875, not Clinuropsis Thiele 1929 (which, in any case, was preoccupied). Moreover, according to Grant & Gale (1931 : 510), Pleurotomella Verrill 1873 (type-species P. packardii Verrill 1873) is a sub- jective junior synonym of Pleurotomoides Bronn 1831 (type-species Defrancia pagoda Millet 1826). With respect to Clinura, Eames (1957 : 51) adopted the classification of Grant & Gale, Wenz, and Beets, in which Clinura appears as a sub-genus of Surculites in the Turridae. But he referred the Eocene species Surcula ingens (Mayer-Eymar 1896) [Pleurotoma] to Clinura, although Beets (1943^ : 363) had clearly expressed the opinion that it was not related thereto and represented an altogether different group. The Fiji Geological Survey Bepartment, in its Annual Report for the year 1958 (1959), mentioned on p. 15 the collection of an unusual fossil shell from the island of Vanua Levu, identified by the present writer as a new species of Thatcheria. The Report also quoted his observation (in litt.) " ... as far as I am aware, the genus has never been recorded as a fossil." Several gastropod species represented in the collections of the Institut Royal des Sciences Naturelles de Belgique were listed by Glibert (1960 : 25) under the generic name Clinura. They are all from the Tortonian or Plaisancian of Italy or the Vienna Basin. Glibert classified Clinura as a genus of the sub-family Cochles- pirinae (family Turridae). GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 267 TABLE I. — SUMMARY OF VIEWS ON SYSTEMATIC POSITION OF THATCHERIA (i.e., of the only two named species hitherto referred to that genus) Author Sp. Sub-genus Genus Sub-family Family Sowerby, 1880 m . Pyrula (juvenile) [Pyrulidae ( = Ficus} (— Ficidae)] Tryon, 1 88 1, 1883 . m Thatcheria, a . Melongeninae, "* scalariform Melongeniinae monstrosity listed ^ Buccinidae under Hemifusus Pilsbry, 1895 m . Thatcheria Thiele, 1929 . m Semifusus s.s. . Semifusus (= Hemifusus s.s.) (= Hemifusus} Galeodidae Wenz, 1943 . m . Hemifusus . Pugilina (= Melongen (Pchelintsev & m . Hemifusus dae) Korobkov, 1960 Fischer, 1884 \ Cossmann, 1901 j m A scalariform monstrosity of Semifusus Melongeninae Turbinellidae ( —Hemifusus) Cossmann, 1889 m . Mayeria J Angas, 1877 . m . Thatcheria . Fusinae "1 (= Fusi- Tomlin, 1919 m ninae) J . A monstrosity of . [Fusinae [ Fusus (= Fusi- '| [Fusidae (— Fusinidae ( = Fusinus} ninae)] J Hopwood, 1937 m . Thatcheria ? Turridae Eales, 1938 . ~\ Kuroda&Habe, 1952 \ . Thatcheria Hirase & Taki, 1954 \ Kira, 1955 >• . Turridae Beets, 19430 . g . Clinura . Surculites Beets, 19436 . m g . Clinura . Surculites Beets, 1951 m g . Thatcheria . Surculites Kuroda & Habe, m . Thatcheria . Daphnellinae . [Turridae] 1954 Habe, 1955 . m g . Thatcheria . Daphnellinae Turridae Powell, 1942 . \ MacNeil, 1960 J m g . Thatcheria Thatcheriidae Yokoyama, 1928 Yokoyama, 1930 g m g . Cochlioconus \ . Thatcheria f [Conidae] Wenz, 1943 . "1 Pchelintsev & > g . Cochliconus . Conus Conidae Korobkov, 1960 J (= Cochlioconus} Hopwood, 1937 m . Thatcheria ? [Akeridae] Charig, 1963 . me . Thatcheria . Thatcheriinae Turridae Note: m indicates application to mirabilis Angas. g indicates application to gradata Yokoyama. Square brackets [ ] denote implicit references. Where an author has used a junior synonym or homonym, or family name derived therefrom, the nan considered here to be correct is also given— in parentheses. GEOL. 7, 9 20§§ 268 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS The Osnovy Paleontologii (1960), edited by Pchelintsev & Korobkov, adopts a very conservative arrangement which seems to be based on that of Wenz ; the important works of Eales, Powell, Beets, and Kuroda & Habe are all ignored. Thatcheria (p. 222) is given as a synonym of the genus Hemifusus, family Galeodidae ; Cochlioconus (p. 241), again mis-spelt " Cochliconus ", appears as a sub-genus of Conus, family Conidae ; Waitara (p. 240) is cited as a genus incertae sedis in the Pleurotomidae ; and, in that same family, Clinura (p. 239) is still considered to be a sub-genus of Surcula. MacNeil (1960 : 120, pi. 15, figs, u, 12) described two shells from the Neogene of Okinawa, now in the United States National Museum, as Thatcheria cf. T. gradata (Yokoyama) ; he retained Powell's family Thatcheriidae for the genus. The figured specimen was from the Pliocene ; the other was from rocks which might be a little older, perhaps of either [Lower] Pliocene or [Upper] Miocene age. Both were compared with T. gradata rather than with T. mirabilis because of their plane to slightly concave ramp (the ramp in T. mirabilis is " definitely depressed with the periphery slightly upturned "), the coarser sculpture, the lack of crowded spirals just below the periphery, and (presumably) the less pagodiform spire. The excellent preservation of the Okinawan specimen figured by MacNeil, with the sculpture preserved nearly to the protoconch stage, shows that " The early sculpture is strongly turrid, the periphery being ornamented with well defined blunt denticulations, about 9 or 10 visible from an angle, and the denticulations themselves are crossed by fine spiral lines " ; in this respect comparison with Yokoyama's material is impossible, for the early whorls are not preserved in either of the Japanese specimens. Nor, for that matter, are they preserved in MacNeil's other Okinawan (possibly Miocene) specimen. MacNeil also expressed some slight doubt as to whether the young shell figured by Kuroda [& Habe] (1954) was really a Thatcheria, pointing out that the first nepionic whorl is quite different from that of the Okinawan form. The figured specimen from Okinawa, however, lacks more of the apex than is represented by the whole of Kuroda & Habe's figure, and therefore a proper comparison cannot be made. III. NOTES ON THATCHERIA MIRABILIS ANGAS Identification of the holotype It was suspected that the holotype of the species might be a shell in the collection of the Department of Zoology of the British Museum (Natural History), recently registered under the number 1960.154. The only available information pertaining to this specimen is that it formed part of the de Burgh Collection. As mentioned above (p. 258), Angas gave no indication as to where his unique shell was deposited. But Sowerby wrote that it was " in the collection of Mrs. Deburch " ; and a copy of Angas' original paper, now in the possession of Mr. S. P. Dance, bears the annotation " de Burgh Coll." in Fulton's handwriting. Finally, as also mentioned above, the de Burgh Collection was offered for sale in 1919 and GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 269 included material of T. mirabilis. Although it was not stated explicitly that there was only one specimen, there is nothing to suggest that there was more than one ; indeed, it was not until the nineteen-thirties that it became apparent that T. mirabilis was not just a unique monstrosity. The British Museum specimen referred to has therefore been compared with Angas' description and illustrations. Its dimensions and individual peculiarities, especially the form of the mended break in the outer lip, show that, while the draw- ings (which bear the indication " G. Sowerby lith.") are not wholly accurate, the common peculiarities are so many that they cannot be merely fortuitous. It may therefore be presumed that the B.M. specimen, registered number 1960. 154, is the holotype of Thatcheria mirabilis Angas. Additional material in the British Museum (1) The incomplete soft parts described by Eales (1938) (B.M. regd. no. 1937-12- 16 . i) . This specimen was obtained at Kii, Japan, and was presented to the Museum by Tomlin in 1937. The shell is missing, but it must be presumed that one was originally associated with these soft parts, for the latter could not otherwise have been identified ; it may have been one of the two exhibited by Tomlin in 1937 at a meeting of the Malacological Society of London. (Tomlin's collection, lodged in the National Museum of Wales, Cardiff, includes two uncatalogued shells of Thatcheria mirabilis from Kii, and it seems likely that these are the same two.) Dr. Eales has no information on the subject. (2) The shell of which an X-ray photograph was given in Eales' (1938) paper. This photograph was of " a specimen in Mr. Winckworth's collection ". Winck- worth's entire collection was later bought by the British Museum ; the shell shown in the photograph may therefore be in the Museum's possession, but it cannot be found at present. (3) Another shell (B.M. regd. no. 1937-7-9.40). This specimen is considerably smaller than the holotype (length 76 mm. as against 87 mm.). It too was obtained at Kii, Japan, and was bought from H. C. Fulton in 1937. It is certainly not the X-rayed specimen. Supplementary description Angas (1877) described Thatcheria mirabilis as having an " outer lip with a broad excavated sinus extending from its juncture with the body-whorl to the extremity of the last keel " ; he gave no more precise indication of its form. His fig. la of the shell in apical view shows the margin of the posterior sinus (and all the collabral growth-lines parallel thereto) intersecting the edge of the preceding whorl more or less at right angles ; as the margin passes outwards from that point it at once curves smoothly forward and then runs obliquely to meet the carina at an acute angle. His fig. i b of the same shell in apertural view gives no more information on this matter. 270 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS It is nevertheless obvious that, since each whorl is much wider at the carina than at the abapical suture, it will hide the inner part of the ramp of the following whorl when viewed from the direction of the apex ; thus, in Angas' figure, the line which seems to terminate the margin of the sinus at its inner end is the carina of the pre- ceding whorl. The margin of the sinus must in fact pass further adaxially beneath the carina to meet the (hidden) adapical suture. But what is the precise form of this inner part of the sinus margin? Except for one drawing by Beets (19436, referred to below), the work of subsequent authors has done nothing to make known the form of the posterior sinus in Thatcheria mirabilis ; sometimes, indeed, the form of the sinus has been completely misunder- stood. The holotype will therefore be briefly re-described, with particular reference to that feature. The form of the sinus is clearly shown in Plate 47, fig. 3. The margin of the sinus does not pass perpendicularly outwards from its point of origin on the adapical suture, but extends obliquely outwards and backwards for a short distance ; as it does so it curves right round until it is running obliquely forwards to meet the carina at an acute angle. The outer limb of this arch is much longer than the inner, so that any given growth-line meets the carina at a point which is much further forward than its point of origin, and the vertex or base of the sinus lies much nearer to the suture than to the carina — at about a quarter of the distance across the ramp. This type of sinus may be described as deep and juxtasutural, its depth being largely due to the for- ward extension of the outer lip. Powell (1942 : 167) was entirely misled by Angas' figure. He wrote that " That- cheria has ... a very deep sutural sinus " ; but, as mentioned above, he noted that Thatcheria seemed to differ from Waitara in that its sinus swung forward immediately from its point of origin. Beets, on the other hand, seemed to understand the true nature of this sinus. In his drawing of T. mirabilis in apical view (19436, pi. 36, fig. 2) the position of the suture, hidden by the projecting carina of the preceding whorl, is marked with a broken line ; also marked are the whole of the margin of the sinus and of one growth- line, rightly showing the hidden parts next to the suture passing backwards in an arc. However, he paradoxically wrote (p. 361) : " Der Sinus der Aussenlippe ist vollkommen vergleichbar jenem der (anderen) C/wwa-Arten ". Now this is true. But, as shown below, his conception of the form of the posterior sinus in Clinura was itself completely wrong ; it was based on the misleading illustrations of other authors, so that he believed the sinus to be quite shallow. Further, he cited (Beets, 1951 : 1 6) Powell's observations on the Thatcheria sinus, yet at the same time was puzzled by the apparent fact that the sinuses of Cochlioconus and Waitara, while similar to each other, differed from that of Thatcheria in that they were first narrowly concave. The superficial ornament of the shell is another feature of T. mirabilis that has not been adequately described. Angas (1877) wrote of his holotype : " above the keels finely arcuately striate [i.e. with collabral growth-lines parallel to the margin of the posterior sinus], below irregularly more or less crenately concentrically ridged ". Beets (19436 : 361) included this description of the superficial ornament of T. GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 271 mirabilis : " der Kiel 1st glatt, auch der obere Windungsabschnitt ; vor der Kante sind die Umgange wieder fein spiralig gefurcht." There are, in fact, three distinct categories of superficial ornament. These are spiral ornament, running in the direction of growth of the helicocone ; transverse ornament, running across (more or less) the direction of growth of the helicocone ; and collabral ornament (growth-lines), parallel to the outer lip throughout the length of the latter. Transverse ornament, of course, is usually collabral, but is not necessarily so (Cox, 1955 : 198). In Thatcheria mirabilis there are indeed many distinct spiral furrows on the outer face, often arranged in pairs (PL 47, fig. i). On the lower part of the outer face of the last whorl, within the inner lip, the furrows are soon obliterated by the forward growth of the edge of the mantle ; thus each spiral furrow, if traced backwards and inwards for a few millimetres beyond the inner lip, disappears beneath a shining white layer of callus. The carina of the shell is smooth. Very weak spiral striations are present on the ramp, except on its innermost part next to the adapical suture. Transverse ornament is entirely lacking in T. mirabilis. As for collabral lines, the form of the outer lip which produces them is simple and slightly convex between the anterior canal and the carina. On the ramp the outer lip delimits the posterior sinus, of which the form has already been described. A final point to mention is that consideration of the length of all the nine measured shells of T. mirabilis recorded in the literature and in this present work leads to the conclusion that the holotype is an adult shell of average size. The measured lengths are 18 mm., 33 mm., 76 mm., 77 mm., 87 mm. (holotype), 89 mm., 94 mm., 97 mm. and 98-5 mm. Three other shells have been mentioned but without measurements ; they are the third specimen of Kuroda & Habe (1954), which is presumed not to be the same as any of the three referred to by Habe (1955), and Tomlin's two shells in the National Museum of Wales. Thus, in all, twelve shells have been mentioned hitherto. There is at least one more shell in a private collection in England, there are probably several in the United States, and it is likely that there are further specimens in Japan and elsewhere. Indeed, Thatcheria mirabilis, once thought to be a unique monstrosity, is no longer even a great rarity. IV. NOTES ON CLINURA Material studied The British Museum collections contain two well preserved specimens of Clinura ; one of these belongs to the type-species C. calliope. The determinations were verified by detailed comparisons with the descriptions and figures of the original authors. Particulars of the specimens are as follows : (1) Clinura calliope (Brocchi 1814) [Murex]. Brit. Mus. (Nat. Hist.) regd. no. G. 79439- From the Plaisancian (Lower Pliocene) of Biot, near Antibes, Alpes Maritimes, France. (2) Clinura trochlearis (M. Homes 1854) [Pleurotoma]. Brit. Mus. (Nat. Hist.) regd. no. GG. 2185. (This specimen was formerly in the Wrigley Collection.) 272 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS From the Zweite Mediterran-Stufe (Middle or Upper Miocene) of Walbersdorf, Burgenland, Austria. This material was studied in order to ascertain the generic characters of Clinura rather than the specific characters of C. calliope or C. trochlearis. Since the former is the type-species, the latter was considered only in so far as it afforded additional evidence of those generic characters. Posterior sinus It is evident from Plate 47 that the posterior sinus of Clinura calliope (fig. n) was exactly like that of Thatcheria mirabilis (fig. 3). But, just as in T. mirabilis, the form of the posterior sinus is not so readily apparent from the descriptions and has often been misunderstood — though in an entirely different way. In these fossil suture shallow sinus $ outer lip drawn forwards carina outer face FIGS, i and 2. — Alternative ways of describing the posterior sinus of Clinura and Thatcheria. gastropods the outer lip with its sinus is usually broken away, and the form of the sinus must therefore be inferred from the form of the collabral growth-lines. Some of the earlier figures (and hence later ones copied from them) either did not show the growth-lines or else depicted them inaccurately ; and it is unfortunate that later workers have sometimes ignored descriptions in foreign languages. Finally, the posterior sinus of Clinura has been variously described as " deep " or " shallow ", even by the same author ; this point requires explanation. Confusion has probably arisen over the depth of the posterior sinus for the following reason. Some workers (including the present writer) define the posterior sinus as including the whole of the notch between the outer lip and the suture (Text-fig, i). Others, however, have considered it to end anteriorly (with respect to the direction of growth of the helicocone) at the level of the junction of its margin with the suture (Text-fig. 2) ; in which case the sinus of Clinura must be regarded as shallow, but it is then necessary to mention that there is also a well developed forward extension of the outer lip. The original author (Brocchi, 1814, pi. 9) gave two figures of Murex calliope which GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 273 were repeated in the later edition of his work (1843). His fig. 150, in apertural view, shows nothing of the growth-lines on the ramp ; but fig. 156, in abapertural view, shows them fairly well. All that Brocchi wrote in this connexion (p. 436) was " ... si osservano alcune finissime rugosita obblique ed arcuate che sono le tracce dell'antico margine di quella sinuosita, che hanno tutte le pleurotome nel labbro destro, e ch'e il carattere del genere." Bellardi (1847, P^ T> fi&- 9) depicted Pleurotoma calliope with strongly curved growth-lines in which both limbs of the arch appeared to be of about the same length ; that is, the sinus would have been deep but symmetrical. The same author (1875 : 20), proposing the new genus Clinura, gave only a generic diagnosis in Latin. This included two phrases which he later reproduced more grammatically (Bellardi, 1877 : 204) as " Sinus posticus labri sinistri valde profundus, arcuatus ; labrum sinistrum antice valde productum, aliforme ". But he also wrote on p. 204 : "I caratteri principal! di questo genere sono [inter alia] : 3° labbro sinistro sinuoso posteriormente ; 4° seno molto largo e poco profondo, foggiato ad arco, il quale parte direttamente dalla sutura posteriore ; 5° labbro sinistro protratto a guisa di ala ". It is not easy to reconcile " sinus . . . valde profundus " with " seno . . . poco profondo"! Incidentally, it should be noted that the outer lip is the "labbro destro " of Brocchi but the " labbro sinistro " of Bellardi. In Bellardi's figure (1877, pi. 7, fig. i) the little that can be seen of the growth-lines makes the sinus appear shallow. Cossmann (1896 : 74) described the sinus of Clinura as " largement arrondi en quart de cercle incompletement ferine et aboutissant presque perpendiculairement a la suture ". His pi. 5, fig. 19 shows nothing whatever of the growth-lines. It is evident that Grant & Gale (1931 : 494) based their idea of the form of the sinus in Clinura upon these works of Bellardi (1877) and Cossmann (1896), for they referred specifically to the figures of C. calliope therein. Thus they were led to write of the genus " posterior notch very wide and shallow, rounded ". They also transferred to Clinura certain American species which, in fact, differ widely from Clinura in the form of their sinus. Of modern authors, only Wrigley (1939 : 283) seems to have been aware of the true form of the posterior sinus in Clinura ; for he wrote of that genus, " the growth lines sweep back over the rear slope four or five times as far as those of Surculites " . This character was not illustrated in his paper. Wrigley was wrong, however, in stating that Nekewis io (Gabb), from the Eocene of California, was much like Clinura ; for Stewart's figure of that species (1927, pi. 30, fig. n) shows a fairly shallow, symmetrical sinus. Beets (19436 : 359) cited the figures of Brocchi, Bellardi and Cossmann mentioned above, and then wrote : " Wie die Aussenlippe vor der Kante verlauft, ist nicht aus Bellardi's Abbildung abzulesen, wohl aber aus den anderen zitierten Figuren." His semi-diagrammatical drawing (19436, pi. 36, fig. 8, pi. 37, fig. 23 ; 1951, pi. i, fig. 3) is nevertheless based upon Bellardi's figure, to which has been added a growth- 274 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS line evidently consequent upon a very shallow sinus. Thus Beets too had been misled. Rossi Ronchetti (1955 : 306) was not informative on this point. She wrote of " Pleurotomella " calliope that " la maggior parte della superficie [della porzione posteriore ... e] percorsa solo da strie di accrescimento alquanto arcuate." Her fig. 163 shows but the faintest trace of growth-lines, and then only the part nearest to the adapical suture. As for Clinura trochlearis , examination of the material in the British Museum shows that its posterior sinus is just like that of C. calliope. Indeed, the form of the sinus in C. trochlearis was depicted very clearly by M. Homes in the figures to his original description (1854 : 363, pi. 39, figs. 140, b, 150, b) [Pleurotoma] ; it has never been subject to misunderstanding. Protoconch No protoconch has yet been described in any species of Clinura ; it may be that the apex of the shell was missing in all the material available to those working on the genus. But the two specimens in the British Museum, of which details have been given above, both possess a protoconch. The protoconch of C. calliope (PI. 47, fig. 12 ; Text-fig. 3) is well preserved, though probably incomplete above ; two whorls remain. It is entirely covered with very distinct oblique cancellation, each thread being slightly concave towards the anterior side. The protoconch of C. trochlearis (Text-fig. 4), of which two and a half whorls are preserved, is rather abraded. The upper and lower parts of each whorl are obliquely cancellate, just like the protoconch of the type-species, but the central, thickest part is worn smooth in places. Transverse sculpture The presence of transverse sculpture is well known in Clinura calliope. It consists of prominent tubercles on the carina ; according to Rossi Ronchetti there are eighteen per whorl, but in fact the number increases with the size of the helicocone from not more than ten to at least twenty. Further, on the early whorls of the teleoconch each tubercle is continued abapically as a short, broad, slightly opistho- cline rib running down the outer face (see PI. 47, fig. 12). There is no record of any comparable sculpture in C. trochlearis ; indeed, Homes (1854 : 364) described his new species as having " nicht eine Spur von Spitzen oder Dornen an dem Kiele, selbst an den obersten Windungen ". This is certainly true of all the larger whorls. But the British Museum specimen shows that, just as in C. calliope, the first two and a half whorls of the teleoconch bear small nodules on the carina, about twelve on the first whorl and sixteen on the next ; each has a small rib beneath it. As the helicocone grows these successively diminish in relative size and eventually disappear. GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 5 67 FIGS. 3-7. — Protoconchs : 3. Clinura calliope (Brocchi) ; original drawing by D. L. F. Sealy, based on a photograph of specimen no. G. 79439 in the British Museum (Natural History). 4. Clinura trochlearis (M. Homes) ; original drawing by D. L. F. Sealy, based on a photograph of specimen no. GG. 2185 in the British Museum (Natural History). 5. Waitara liratula Powell ; after Powell. 6. Thatcheria mirabilis Angas ; after Kuroda & Habe. 7. Cryptodaphne pseudodrillia Powell ; after Powell. V. NOTES ON WAITARA LIRATULA POWELL Protoconch Powell (1942) was the first to postulate a close affinity between Waitara and Thatcheria. He mentioned that comparative studies of the protoconchs had yet to be made ; for, in any of the genera with which this work is concerned, the only protoconch known at the time was that of W. liratula described by Powell himself. Since then the protoconch of Thatcheria mirabilis has been described and figured by Kuroda & Habe (1954) from a beautiful specimen showing very distinct oblique reticulate ornament, and the remarkably similar protoconchs of two species of Clinura have now been described in the preceding section of the present work. If Clinura, Waitara and Thatcheria are indeed closely akin, it would be expected that the protoconchs also would be alike ; this expectation is rendered even more prob- able by the Clinura-like tuberculation of the carina on the first few whorls of the W. liratula teleoconch, noted below. But, according to Powell (1942 : 169), W. liratula has a " dome-shaped protoconch of two whorls bearing weak protractively arcuate axial growth threads " ; and his drawing (text-fig. 63 on p. 38 ; Text-fig. 5 in the present work) shows no ornament other than faint, slightly sinuate, slightly opisthocline striations, with no indication of others running across them. Might not this appearance have been caused by abrasion? 276 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS It was felt that the protoconch of Waitara liratula should be looked at again. According to Fleming (in litt.), " The paratype figured by Powell (pi. 14, fig. 8) is apparently the same specimen on which he based his text-fig. 63 ... The holotype and other paratypes are still more deficient in protoconch. . . . We have no evidence whether the protoconch was damaged after Powell's figure was made." The figured paratype (PI. 47, fig. 7) was therefore sent to London and examined with great care. Unfortunately the specimen does seem to have been damaged since Powell described it twenty years ago, for, whatever its condition before, the protoconch is now in such a poor state of preservation that it is difficult to compare it with Powell's drawing and impossible to see any traces of its original ornament. Indeed, the protoconch is far too worn and damaged to afford positive evidence of any significant difference between Waitara and Thatcheria in this taxono- mically important character. A close relationship between Waitara and Thatcheria, as originally suggested by Powell himself, is therefore still quite possible. Transverse sculpture During the examination of the figured paratype of Waitara liratula it was noticed that the first two or three whorls of the teleoconch bore unmistakable indications of nodules on the carina, arranged with an appearance of regularity. The angular distance between consecutive nodules was estimated at about 20° of arc ; thus, originally, there would have been about eighteen nodules per whorl. Beneath some of these there were traces of a short, broad and markedly opisthocline rib running down the outer face of the whorl. After the first few whorls, however, the carina became smooth. This character has not previously been recorded in W. liratula. The Neogene shells from Okinawa which MacNeil (1960 ; see above, p. 268) described as Thatcheria cf . gradata seem to have a close affinity with W. liratula, even though it must be admitted that comparisons are difficult when they have to be made from one illustration of a single incomplete specimen of each species. The early whorls of the teleoconch of the figured specimen from Okinawa are far better preserved than in Powell's specimen and bear distinct nodules on the carina, exactly like those of Clinura calliope ; these gradually become less distinct and eventually disappear at a point where the transverse diameter of the shell (measured across the carina) is about 4 mm. Marwick (1931 : 149) reported that the early whorls of W. gtnerosa bore about twelve low, rounded axial costae extending downwards from the keel and forming weak tubercles at their intersection with the shoulder-angle. VI. SYSTEMATICS General principles The classification of the gastropods discussed in this work, except that of the Recent Thatcheria mirabilis, is necessarily based entirely upon their shell characters. It has been generally believed that the most fundamental of these are the position and form of the posterior sinus, indicated in incomplete specimens by the position GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 277 and form of the collabral growth-lines ; this feature is considered to be the most useful of those by which a turrid may be distinguished from other Toxoglossa and assigned to a sub-family within the Turridae. But the posterior sinus is not in- fallibly diagnostic in these matters. In the Conidae, which are without doubt close relatives of the Turridae, the form of the posterior sinus varies not only from species to species but even within a species, and it is sometimes just like that of certain Turridae. For example, the collections of the British Museum (Natural History) include a series of shells of the Recent Conus pennaceus Born 1780, all characterised by a particular colour pattern. One of these, however, has a posterior sinus which resembles that figured by Powell (1942, text-fig. F28) as belonging to the Recent turrid Asperdaphne versivestita (Hedley 1912) [Daphnella} ; another has the " reversed L " sinus more typical of the Daphnellinae (as found in Daphnella cancellata Hutton 1878) ; in a third specimen the sinus is similar to that of Clinura or Thatcheria ; and in a fourth it is virtually absent. In other individuals it is yet again quite different from any of these. Thus there can be no such thing as a sinus typical of the Conidae, although Powell (1942 : 167), who mentioned the " deep Conid-like " sinus of his Thatcheriidae, clearly implied that there was. Again, Powell (p. 28) wrote of the Turridae that " Position and style of sinus is the best guide to subfamily grouping." Experience may indeed have shown that there is no better, but the guidance afforded by the posterior sinus provides no simple key to this problem ; its form, if not its position, may vary widely within a given sub- family. In short, the posterior sinus appears to be of systematic value only when the taxonomic placing indicated thereby is confirmed by other distinctive characters with which it has no connexion. It was therefore necessary to bear other characters in mind when considering whether or not the molluscs in question should be referred to the Turridae and, if so, to which particular sub-family thereof. Those characters were the nature of the protoconch and the absence of a tendency towards the resorption of the columella and early internal walls. Further, when a series of shells was thus referred to a given grouping, their possession of a common suite of less distinctive characters (such as a pagodiform spire, a certain distribution of spiral ornament, and a certain type of columella) offered additional confirmation of their relationship. Generic and specific separation were effected primarily upon the presence or absence of transverse sculpture and tubercles, and secondarily upon a number of other characters — the position of the carina on the whorl, the degree of develop- ment and precise nature of the spiral ornament, the degree of " pagodiformity ", the spire angle, and the height of the spire relative to that of the last whorl and aperture. In living Toxoglossa the soft anatomy (where known) affords more evidence of the animal's affinities. The morphology of the radula is important in this connexion. The presence or absence of an operculum, and, when present, its structure, are also characters which are generally of taxonomic value only in Recent forms. Fossil gastropods are rarely associated with opercula, even where they are known to have possessed them, and the seeming absence of an operculum in a little-known form is thus without significance. 278 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS The Clinura-Thatcheria group As mentioned above (p. 262), it was suggested by Beets (19436) that Clinuropsis, Clinura and Thatcheria formed a closely related group. He regarded Cochlioconus as part of Thatcheria, and did not consider Waitara at all. But Powell (1942) had already recognised a relationship between Waitara and Thatcheria ; and Wenz (1943) placed Waitara (at that time known to him only by its Miocene species) near Clinura, although he thought that Thatcheria and Cochlioconus had no affinities with either, or even with each other. Beets, therefore, in a later paper (1951), added Waitara to his group. This suggested grouping has evoked no mention or comment elsewhere. The forms in question certainly seemed to possess some characters in common and no fundamental differences ; in particular, the shell was always more or less pagodiform, with a juxtasutural posterior sinus (admittedly of variable depth) having its vertex close to the suture. All the species seemed to be extremely rare, and were probably abyssal in habit. More conclusive evidence of this supposed relationship is now available, although the extent of the group requires limitation. Beets' conception of the taxon Clinura was a very wide one, even in the more restricted sense in which he used it in 1951. His misunderstanding of the true form of the posterior sinus in the type-species, C. calliope (Brocchi), had led him to believe that the depth of the sinus, since it appeared to vary greatly in species which were otherwise similar, was subject to " normal " variation within the group ; yet, in the same work (19436 : 364), he stated that the form of the sinus was " ein Merkmal von hochster Bedeutung in der Sys- tematik der Turridae". It has now been made quite clear (see p. 272] that the posterior sinus of the type-species is very deep ; and it is also apparent (see PI. 47, figs. 3, 6, 8, n) that its exact shape as found in C. calliope is a constant character of Thatcheria (including Cochlioconus) , of Waitara, and of certain other species referred to Clinura itself, but not of the remaining species hitherto referred to Clinura and not of Clinuropsis. It is therefore suggested, in accord with Powell and Beets, that the highly distinctive type of sinus found so consistently in these genera is indeed of taxonomic value, notwithstanding what has been written above concerning the variable position and form of the posterior sinus in the Toxoglossa in general. (This, of course, would not be true if a sinus like that of Thatcheria could be clearly shown to have developed as a result of parallel evolution in an entirely different group.) It is further suggested that any alleged species of Clinura without this deep sinus have been wrongly placed in that genus. An examination of the original descrip- tions and figures of most of the species mentioned by Cossmann (1896 : 75) ; Grant & Gale (1931 : 494) ; Beets (19430 : 296, 297 ; 19436 : 358-64) ; Eames (1957 : 51) and Glibert (1960 : 25, 26) indicates that this exclusion from Clinura should apply to all the species from North America (Eocene to Miocene), Africa (Palaeocene and Eocene), and the Palaeocene and Eocene of Europe, and to most of those from the Neogene of Europe ; thus it is not possible to agree with Beets that the genera Clinuropsis Vincent 1913 (non Thiele 1929) and Nekewis Stewart 1927 should be placed in the synonymy of Clinura. Indeed, the only true species of Clinura (using GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 279 the name in Beets' narrower sense, thus also excluding Waitara, Cochlioconus and Thatcheria) seem to be the type-species and a few others from the Neogene of Europe, together with the two species from the Neogene of Buton (Celebes). It is noteworthy that the only species (other than C. calliope) mentioned by Bellardi when proposing the genus Clinura was C. elegantissima (Foresti 1868) [Pleurotoma}, which, by the form of its growth-lines, is clearly not a Clinura. Its complex spiral ornament is also very distinctive. On the other hand, a good example of a European species accepted here as a Clinura is C. trochlearis (M. Homes 1854) [Pleurotoma]. In the present work, the decision to retain this species within the genus Clinura was originally based upon Homes' description and figures, with particular reference to the form of the posterior sinus ; only later did this decision receive powerful support from the discovery that an individual of C. trochlearis in the collections of the British Museum (see p. 274) showed a diagonally cancellate protoconch, just as in C. calliope, and transverse, slightly opisthocline costae on the juvenile whorls of the teleoconch. Another species which may be assigned to Clinura with a high degree of probability is C. controversa (Bellardi 1847) [Pleuro- toma] ; Bellardi, incidentally, ascribed this new specific name to Jan 1845 " in litt. et specim." (p. 64). More doubtful cases, where it would probably be difficult to make a definite decision on the correct systematic position of the species without handling the actual type-material, include C. sopronensis (Wolf 1870) [Pleurotoma], C. subtrochlearis (Friedberg 1912) [Surcula], and C. sabatiorum Bellardi 1878. But it is felt that a full examination of every species attributed to Clinura by one author or another, often without justification, is beyond the scope of the present review. The species excluded would form such a large and varied assemblage, with such a wide geo- graphical distribution and such a long stratigraphical range, that they would doubt- less represent several distinct genera. The available genera to which they might be referred would include those listed by Grant & Gale (1931) and by Beets (19436) as synonyms of Clinura, other than Thatcheria and Cochlioconus : namely, Clinuropsis Vincent 1913 (non Thiele 1929) and Nekewis Stewart 1927. It is possible, how- ever, that not all species might be referred to those or to other existing genera, in which case new genera would be needed. The Butonese species of Clinura are C. carinata (Martin 1933) [Cryptoconus] and C. bituminata (Beets 19430) [Surculites]. If the genus Clinura be limited as suggested above, which to me seems perfectly reasonable, then the reasons for postulating a close relationship with Waitara and Thatcheria (including Cochlioconus) are much more convincing. But there are no grounds for supposing these forms to be related just as closely to the genus Clinuropsis. Confirmation of this affinity is given by the protoconchs. Until a few years ago that of Waitara was the only one described (Powell, 1942). Now, however, the protoconchs of the type-species of Clinura and Thatcheria have been made known (see p. 274 above; and Kuroda & Habe, 1954) ; both show the same type of diagonal reticulation, and this suggests a relationship between those two genera. On the other hand, the Waitara protoconch described by Powell gives no indication of 280 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS diagonal cancellation ; but, as stated above, its condition is so unsatisfactory that the nature of its original ornament cannot be ascertained. At least it affords no evidence to refute the suggestion, based on other conchological evidence, that Waitara is related to Clinura and Thatcheria. In any case, the species in question (Waitara liratula} is not the type-species of Waitara. Other common characters of the shells, which might be of little taxonomic value on their own, together reinforce the evidence already cited for the relationship of the three genera. They include the pagodiform habit, the distribution of the spiral ornament on the outer surface of the teleoconch, and the smooth, very slightly twisted nature of the columella. The distribution of the spiral ornament cannot always be ascertained very easily from the published descriptions and illustrations ; but the ornament is typically confined to the outer face of each whorl, except in that there are comparatively weak striations on the outer edge of the ramp (next to and parallel with the carina). This type of distribution is certainly found in Clinura calliope, C. trochlearis, C. bituminata, Waitara pagodula, W. liratula, and in the new species of Thatcheria from Fiji described below. In the Recent Thatcheria mira- bilis, of which the material is of course in a far better state of preservation, the spiral ornament on the ramp extends further towards the adapical suture, but it is altogether fainter than in the other species and is in no way comparable with the much stronger striation of the outer face. The value of Beets' eventual conclusion, that Clinuropsis, Clinura, Waitara and Thatcheria (including Cochlioconus) form a closely related group, may therefore be assessed as follows. His suggestion was based at the time on inadequate evidence ; but a more restricted conception of the genus Clinura, coupled with better under- standing of the form of the posterior sinus in that genus and with new knowledge of the form of the protoconchs in Clinura and Thatcheria, now indicates that it is perfectly reasonable in so far as Clinura, Waitara and Thatcheria are concerned. Clinuropsis, however, does not form part of this group. Further, it cannot be agreed that the similarities between the three named taxa in the group are sufficiently close to justify placing them all in synonymy (senior synonym Clinura, ranked as a sub-genus of Surculites in Beets, 19436), or even to warrant their being considered as three separate sub-genera of Surculites (in Beets, 1951). In the following argu- ment they are regarded initially as three distinct genera. In any case, close affinity with Surculites is denied in the present work ; the matter is discussed more fully below (p. 289), where the external relationships of the Clinura-Thatcheria group are considered in detail. At present, then, this group appears to include at least the following species : Clinura calliope Waitara waitaraensis Thatcheria mirabilis C. trochlearis W. generosa T. gradata C. controversa W. pagodula Thatcheria sp. nov. Beets C. bituminata Waitara sp. nov. Powell I95I C. carinata J942 aff. pagodula W. liratula GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 281 Division into genera The species referred to Waitara seem, in general, to be intermediate in character between Clinura and Thatcheria. This division of the group into three genera, however, appears rather unsatisfactory : like species are separated (C. carinata and W. pagodula, W. liratula and T. mirabilis} and unlike species placed together (C. bituminata and C. carinata, W. generosa and W. liratula). A careful consideration of all the species involved has led to the following conclusions. All three species listed as Thatcheria are correctly regarded as congeneric with each other. But several other species listed above (Clinura carinata, Waitara pagodula, Waitara sp. nov. Powell 1942 aff. pagodula, W. liratula} and the new species from Fiji described below as Thatcheria vitiensis are all very similar to the three species of Thatcheria listed ; they resemble them in having the carina generally high on the larger whorls and only weak spiral ornament, and in being entirely free of transverse ribbing or tubercles at every stage of development (except, in three cases, for minute vestigial nodules on the very youngest whorls of the teleoconch), while they differ from them chiefly in being less pagodiform. Indeed, there is little more than the variable degree of pagodiformity to distinguish any of these eight species from each other. It is therefore suggested that they should all be placed in the genus Thatcheria. The geographical distribution of the genus as thus enlarged remains entirely within the area of the Western Pacific. Its stratigraphical range extends from Upper Miocene to Recent, but it is predominantly Pliocene. Powell (1942), of course, recognised the affinity of Waitara and Thatcheria (see pp. 260,261), " probably basing his opinion mainly on the features of two species of Waitara newly described by him " (Beets, 1951 : 16). But, because he had mis- interpreted the form of the posterior sinus of T. mirabilis from the growth-lines shown in Angas' rather misleading figure, he doubtfully retained Waitara as a separate genus " for New Zealand usage ". Beets (1951 : 16) pointed out that the sinus in T. gradata [Cochlioconus] " is almost similar to that in Waitara ", but he failed to realise Powell's mistake in the matter of the T. mirabilis sinus, even though he him- self had earlier figured it correctly (19436, pi. 36, fig. 2). However, this misinter- pretation has now been explained (pp. 269, 270) ; and Powell's younger species of Waitara (though not Marwick's two older species, one of which is the type-species) have been referred to Thatcheria. On the other hand, if it should later transpire that the protoconch of T. liratula and its allies (known in only the one specimen of T. liratula, which seems to have been subsequently damaged) is, as appears from Powell's description and figure, essentially different from that of Thatcheria, then it would be necessary to erect a new genus for those forms. If the younger species formerly ascribed to Waitara are transferred to Thatcheria, then the only species remaining in the former genus are the type-species waitaraensis, from the Upper Miocene of New Zealand, and generosa, from the Lower Miocene of the same country. Marwick's fairly detailed generic diagnosis of Waitara ap- pears to be based equally upon waitaraensis and generosa, so that, as mentioned above (p. 261), Wenz (1943) was misled into believing that generosa was the type-species 282 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS of the genus. But, as far as can be judged from Marwick's descriptions of these two species, only one individual is known of each. The holotype of waitaraensis in particular is very incomplete and seems to have suffered distortion ; there are no highly distinctive characters, either positive or negative. It therefore seems that the genus Waitara, denned objectively by reference to this single specimen, cannot be denned very clearly. It is nevertheless obvious from Marwick's descriptions and figures that, unlike W. pagodula and W. liratula, neither W. waitaraensis nor W. generosa can be referred to Thatcheria. Neither species is much less pagodiform than is T. liratula or the new Fijian species T. vitiensis — indeed, they are probably more pagodiform than is T. pagodula — but their whorls have an entirely different aspect. On the other hand, Beets wrote (1951 : 16) that " there are also relationships between Waitara in its former sense (i.e., as based upon W. generosa and W. waitara- ensis) and Clinura " . This appears to be true at least of W. generosa, which has both the characteristic attributes of a Clinura : the first few whorls of the teleoconch are ribbed, with tubercles on the carina, and the carina is low on the larger whorls (that is, the ramp slopes steeply downwards). These show its affinity with the European species of Clinura (including the type-species, C. calliope] and with the Butonese C. bituminata. It is therefore proposed that W. generosa be transferred to the genus Clinura. As for W. waitaraensis, the incomplete and distorted nature of the specimen prevents its giving any information on these characters ; but, since Marwick (who handled the material) believed it to be congeneric with W. generosa, it may also be transferred — albeit provisionally — to Clinura, thus making Waitara a subjective junior synonym of Clinura. If better material later showed that this transfer, though correct for W. generosa, was not justified in the case of W. waitara- ensis, the generic name Waitara would still be available for the latter species. The genus Clinura, as listed above, has now lost C. carinata to Thatcheria but has gained the species waitaraensis and generosa from Waitara ; i.e., it includes the species calliope, trochlearis, controversa, bituminata, generosa, perhaps waitaraensis, and possibly others from Europe. The geographical distribution of the genus in this new sense is thus restricted to Europe (the Mediterranean Basin), the East Indies and New Zealand. The European species are all of Miocene age, although some (such as C. calliope itself) persist into the Lower Pliocene (Plaisancian) ; the Butonese species is of Neogene age, very probably Upper Miocene ; and the two New Zealand species, as mentioned above, are from the Lower and Upper Miocene respectively. It may therefore be said that the stratigraphical range of Clinura is from the Lower Miocene to the Lower Pliocene, but that the genus occurs mainly in the Middle and Upper Miocene. The stratigraphical range of Clinura contrasts with that of Thatcheria, essentially Pliocene to Recent. This shows that the most natural break in the Clinura- Thatcheria group occurs between the earlier and the later species of " Waitara " at about the level of the Miocene-Pliocene boundary. It seems, however, that there is a certain amount of overlap on either side of that boundary. In one direction C. calliope survives into the Plaisancian, as do other possible species of the genus (see Gilbert, 1960 : 25, 26) ; in the other, rocks which are probably no younger than GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 283 Upper Miocene already contain T. carinata, and T. pagodula may likewise be of Upper Miocene age. The genus Clinura, even in the restricted sense used here, cannot be denned very easily ; it is essentially a rather variable assemblage of species, of wide distribution and of predominantly Miocene age. Thatcheria, on the other hand, even in the present broad interpretation, is a fairly homogeneous group of species and may be denned quite clearly. It seems that it originated from Clinura towards the end of the Miocene, became widespread in the Western Pacific area during the Pliocene, and survives to the present day as the one rather " extreme " form living in deep waters off the Japanese coast. T. mirabilis may in fact occur more widely than is known at present, " off Japan " ; for a rare abyssal form is far more likely to be recovered in the Kii region, off the south coasts of Honshu and Shikoku, than anywhere else in the Pacific. Not only is the Pacific Ocean almost at its deepest off Japan, but in few places are there such deep waters so near to a large area of land. Indeed, they are nowhere else so close to a heavily populated shore-line from which intensive fishing is carried out. Interspecific differentiation in Thatcheria The eight species referred in this work to the genus Thatcheria seem to differ from each other in little more than in certain characters of the spire : in its degree of pagodiformity, in its acuteness, and in its size relative to that of the last whorl and the aperture. In general, the various species seem to form an evolutionary series in which the degree of pagodiformity increases with time ; and, as it increases, the spire appears less acute. It is very difficult, if not impossible, to define " pagodiformity " objectively. Several numerical properties of pagodiform shells were examined as possible indices but rejected for various reasons ; they are shown in Text-fig. 8. Measurement of the spire angle proved more useful, for this, in a shell of the type under consideration, can be measured in two different ways (Text-fig. 9). The term " internal spire angle " may be introduced for the angle between the two lines which, on either side of the spire, connect the intersections of the suture with the lateral profile. It is obvious that only an approximate value can be obtained for this, for the lines are unlikely to be straight ; it is not even likely that smooth continuous curves can be drawn to pass exactly through all the points, and the best that can be obtained will nearly always be a slightly concave curve passing close to most of them. The " external spire angle " is measured in a similar manner but is based on the inter- sections of the carina with the lateral profile ; it is, of course, larger than the internal spire angle. Of the eight species of Thatcheria in which such measurements were possible (including T. vitiensis sp. nov. described below), seven gave a value for the internal spire angle which was remarkably constant, lying always between 38° and 46° ; exact measurements would not be especially significant, for, even in different indi- viduals of one species (the Recent T. mirabilis), the angle varied between 38° and 44°. Only T. pagodula gave a significantly different value, 57°. 284 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS c FIG. 8. — Plane projection of the spire of an idealised pagodiform shell, to illustrate the numerical properties examined as possible indices of pagodiformity but rejected for various reasons. They are : (a) The projection of the carina, expressed as the ratio of its perpendicular distance from the shell axis (AB) to the distance of that perpendicular from the apex (BC). This is the tangent of half the external spire angle (e). (b) The angle (r) between the profile of the ramp and the shell axis. (c) The height of the carina on the whorl, expressed as the ratio of its axial distance from the lower suture (YZ) to the axial distance between the sutures (XZ). On the other hand, the external spire angle varied greatly, from 50° in the earliest species T. carinata to 82° in the holotype of the Recent T. mirabilis. It seemed to show a fairly steady increase with the passage of time ; but T. pagodula was once again the exception, with an external spire angle of 71°. This higher value, however, is consistent with the higher value for the internal spire angle. In fact, the ratio of the external spire angle to the internal, which might be called the " index of pagodiformity ", is the same in T. pagodula as in the much slimmer T. carinata (the only other species of possibly Miocene age) — namely, 1.25. To sum up, then, the situation seems to be that there are two species of Thatcheria of possibly Miocene age. One of these (T. carinata} has an internal spire angle of GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 285 FIG. 9. Note -Plane projection of the spire of an idealised pagodiform shell, to illustrate : i — the internal spire angle, e — the external spire angle, ds — the angle of declination of the suture, and dc — the angle of declination of the carina. (a) ds is greater than dc in a pagodiform shell, for the suture descends in a tighter (and therefore steeper) spiral than does the carina. (£>) Both dc and ds are smaller than they appear in the plane projection. This is because, in the plane projection, both carina and suture appear to descend from one side of the shell to the other in a straight line ; whereas, in fact, they do so on the surface of a cone and therefore less steeply. tan ds tan e/2 (c) — — should be equal to . tan dc tan t/2 40°, the other (T. pagodula) has a much broader spire (internal spire angle 57°) ; but both have exactly the same index of pagodiformity (1-25). All the later species have an internal spire angle which is much the same as in T. carinata ; but the index of pagodiformity, like the external spire angle, shows an increase with the passage of time — to 1-50 in the two supposed Lower Pliocene species (T. liratula, T, vitiensis), to 1-58-1-62 in the two species described simply as " Pliocene " (T. 286 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS gradata, Thatcheria sp. nov. Beets 1951), and to 175-2-05 in the Recent T. mirabilis. It seems likely that the index of pagodiformity will prove to be more constant and characteristic for a given species than either the internal or external spire angle ; for the two spire angles, though they may vary considerably between individuals, seem to do so together. Use of the index, though liable to considerable error, may afford a rough indication of the course of evolution. Of course, the position of a species on the evolutionary scale (and hence its approxi- mate geological age) should not be assessed on any one character alone. The various characters probably evolved at different rates in different lineages. Evolution in the Clinura-Thatcheria group Clinura calliope, type-species of the genus Clinura, ranged from Upper Miocene to Lower Pliocene. Clinura, however, was already well diversified at the beginning of that time ; thus the type-species occurred too late to occupy any central position in the phylogeny of the genus as defined in the present work. Moreover, in one prominent feature C. calliope differs from the other species which are considered here to constitute that genus : the entire carina is furnished with well developed tubercles. A better claim to a central position may be made on behalf of C. trochlearis (from the Middle Miocene1 of Europe). Unlike every other species referred to Clinura, C. trochlearis may be placed in that genus with absolute certainty. Except for the poorly known, rather peculiar C. generosa in the Lower Miocene, it is probably the oldest species of Clinura. It is somewhat variable in form, especially with regard to the acuteness of the spire and the position of the carina on the whorl. And it is also the most " central " in form ; for it could well be ancestral, by a late Miocene radiation, to all the Upper Miocene species of Clinura and to Thatcheria. Of those species in the Upper Miocene, C. waitaraensis is rather like C. bituminata in the general aspect of its whorls, which, where undamaged, seem to have a steeply inclined ramp and a low carina ; further, both those species are very similar to C. trochlearis. C. bituminata and C. waitaraensis could be derived from a common ancestor which, in turn, had evolved from C. trochlearis with little change in form. Migration from Europe to the south-western Pacific would have occurred at the onset of this hypothetical evolution. Another species in the Upper Miocene of the south-western Pacific which also is similar to Clinura trochlearis is Thatcheria carinata ; the flatter ramp and higher carina distinguish it from C. bituminata and C. waitaraensis. Like those two species, T. carinata may have been derived from a migrating descendant of Clinura trochlearis. From Thatcheria carinata a line of evolution to the Recent T. mirabilis may be envisaged ; it has been shown above that, with passage of time, the internal spire angle remained more or less constant while the external spire angle (and hence the index of pagodiformity) gradually increased. Only T. pagodula, with its generally much stouter spire, would necessarily have formed a distinct Upper Mio- cene offshoot from this series. It also seems that the evolution of Thatcheria from 1 Some authorities now prefer to regard the Zweite Mediterran-Stufe (Suess, 1866) of the Vienna Basin as Tortonian in age, i.e. Upper Miocene, rather than Helvetian. But C. trochlearis occurs also in the Middle Miocene of Italy (Bellardi, 1877 : 206). GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 287 FIG. 10. — A very tentative evolutionary tree of the Thatcheriinae. the Miocene onwards has been accompanied by a northward movement of the popula- tion towards its present home in the north-western Pacific. The only other species in the Upper Miocene which have definitely been referred to Clinura are both from the Mediterranean region, C. calliope (the type-species, per- sisting into the Lower Pliocene) and C. controversa. A list of characters distinguish- 288 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS ing these two species (at that time referred to Pleurotoma) was drawn up by Bellardi (1847 : 64) i in fact» it was largely by means of this comparison with P. calliope that he described his new species P. controversa. Once again C. trochlearis may be regarded as a possible ancestor — of C. calliope, C. controversa, or both, — but in this case there is no need to postulate a distant migration of the stock. The tendency towards the development of transverse sculpture on the first few whorls of the teleo- conch, manifested in C. trochlearis and in other early species of the group, might have led to the evolution of C. calliope by affecting the whole shell ; and, in similar fashion, C. controversa might have evolved through the development of a notched carina. As for Clinura generosa in the Lower Miocene, this species has a somewhat different appearance ; it is difficult to imagine it as a direct ancestor of C. trochlearis and of all the other species mentioned. But it has the typical posterior sinus of the Clinura-Thatcheria group, together with the tubercles on the early whorls of the teleoconch. It must therefore be retained within the group, in the genus Clinura, and placed on a sterile side-branch of the evolutionary tree. All these suggestions are summarised in Text-fig. 10. Systematic position of the Clinura-Thatcheria group Serious consideration of Thatcheria and its relatives has led most modern authors to place them in the Turridae (Eales, 1938 ; Beets, 19436, 1951 ; Kuroda & Habe, 1954, implicitly ; Habe, 1955). There have been only two important exceptions. Yokoyama (1928, 1930), though he did not explicitly refer Thatcheria [Cochlio- conus] to the Conidae, thought it had affinities therewith ; while Powell (1942) regarded Waitara, Cochlioconus and Thatcheria as constituting a new family, the Thatcheriidae, distinct from the Turridae (though parallel to them) and more closely related to the Conidae. Preference is given here to the view that this group of gastropods is best placed in the Turridae. The posterior sinuses of Clinura and Thatcheria may indeed be compared with those of certain Conidae (e.g., Conus araneosus Solander 1768) ; although, in general, the outer lip is drawn further forward in Clinura and Thatcheria before it crosses the line of the carina. On the other hand, their posterior sinuses also resemble those of certain turrids ; the diagonaUy cancellate ornament on the protoconchs of Clinura and Thatcheria is a turrid character ; and neither genus is known to show any manifestation of the tendency, typical of the Conidae, to resorb the columella and early internal walls. Further, the form of the radula in Thatcheria mirabilis and other characters of that Recent species confirm the opinion that the group should be referred to the Turridae, particular significance being attached to Eales' work upon the soft anatomy. There would seem to be little or no justification for the erection of a separate family to accommodate Clinura and Thatcheria, even if that family should be considered as having turrid rather than conid affinities. Clinura, of course, had been placed in the Turridae (Pleurotomidae) from the very date of its establishment in 1875, long before Eales (1938) wrote her paper on Thatcheria and long before it was first suggested that the two genera were related. A brief history of the more exact classification of Clinura has already been given above (pp. 263-268) ; sufficient here to note that, of recent years (since 1931), the taxon has GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 289 been generally regarded as a sub-genus of Surculites. Grant & Gale wrote (1931 : 494) •' " Clinura is closely related to Turricula, and might be considered a variational extreme in the opposite direction from Pleurofusia. It can, however, be distin- guished generically by its shorter form and broad, shallow notch. It is even more closely related to Surculites proper, Pseudotoma, and Megasurcula, sharing with them the broad conical shape and wide shallow notch, so that it is here not separated from them generically. ... It probably was derived from Turricula, perhaps indirectly, and later gave rise to, or is a branch of the stock that gave rise to, Pseudotoma and Megasurcula. The intergradations between it and the last named are evident in the California and Washington Tertiary. Clinura and typical Surculites are both well represented in the Eocene of the Pacific coast, . . . Clinura lived on into the Miocene, where it is represented by [Megasurcula] keepi (Arnold), ... " It is clear from this, however, that Grant & Gale were basing their arguments largely upon the characters of the species in the Eocene of North America which they had referred to Clinura ; and those species, as pointed out above, do not possess the deep posterior sinus which is considered here to be the most essential character of the genus. Their opinions, therefore, do not apply to Clinura in its proper sense. But, in any case, Wrigley (1939 : 282, 283) recognised quite correctly that the genus Surculites was not a turrid, having no true sinus or notch like that of the typical members of the family. He concluded that " The sinuous growth lines [of Surculites] here considered are not an unequivocal mark of the Turridae, they may occur in other families, linked with and proportionate to whorl-carination. Surculites is long extinct, we have no guidance from the animal anatomy and, in the light of the foregoing comparisons, it seems best to place the genus in a not too determinate position between the Fusinidae and the Buccinidae . . . On the other hand, he also noted that " Surculites has some resemblance, especially in general form, to Clinura Bellardi, but in that genus the growth lines sweep back over the rear slope four or five times as far as those of Surculites, here showing a Turrid character, or rather, a contour often seen in the Conidae." Thus, if the species properly referred to Clinura have no affinity with Surculites, then Clinura may be a turrid even though Surculites is not. Further, this means that Clinura cannot be regarded as a sub- genus of Surculites (in which classification Grant & Gale (1931) were followed by Beets (1943^, 19436, 1951)), nor can Thatcheria be considered as part of the latter genus (as in Beets, 19436, 1951). The true characters of Clinura and Thatcheria not only link those genera with the Turridae but with a particular sub-family thereof, the Daphnellinae. Of all the turrid sub-families listed by Powell (1942 : 29), only the Daphnellinae have (some- times) a diagonally cancellate protoconch (see Text-fig. 7) ; only the Daphnellinae possess a juxtasutural posterior sinus ; only the Daphnellinae and the Mangeliinae, together with a few genera in other sub-families, lack an operculum ; and the radula of the Daphnellinae, which has marginal teeth only, is very similar to that of Thatcheria. Indeed, Kuroda & Habe wrote of Thatcheria mirabilis (1954 : 81) that the protoconch " shows the obliquely reticulated texture of sculpture, suggest- ing that it is also of a Daphnelloid ", and (p. 80) that the species has a radula, " whose 2QO GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS peculiar shape shows that it has a close affinity with the Daphnellinae". But Powell (1942 : 167) had two objections to the location of Thatcheria and its allies in the Daphnellinae, " the lack of a typical Daphnellid apex . . . and the actual form of the sinus ". It has already been shown that the only Thatcheria protoconch known at that time, that of T. liratula [Waitara], was so badly abraded as to be useless ; but Powell was correct in supposing that the form of the Thatcheria sinus (either as he wrongly believed it to be in T. mirabilis, having been misled by Sowerby's figure to Angas' description, or as he actually observed it in T. liratula} was not quite like that of the Daphnellinae. The other differences between the Daphnellinae on the one hand and Clinura and Thatcheria on the other (listed below in Table II) cannot preclude the possibility that the Clinura-Thatcheria group originated from the Daphnellinae in the Upper Oligocene or Lower Miocene by the development of a larger, pagodiform shell ; even the protoconchs of Clinura and Thatcheria, now known from one good specimen of each of three species (C. calliope, C. trochlearis, T. mirabilis}, agree with such a theory. But, from the taxono- mic viewpoint, the consistent difference between the groups in the form of the Form of posterior sinus (juxtasutural) Protoconch (see Text-figs. 3-7) Spire .... Whole shell Earliest known occurrence . Present trend TABLE II Daphnellinae Typically a " reversed L " Generally diagonally cancel- late ; but never exactly like that of Clinura and Thatcheria Rarely pagodiform, if ever Generally small Oligocene, perhaps even Cre- taceous Still increasing Clinura and Thatcheria Smoothly arcuate, with outer lip drawn far forward Diagonally cancellate (where adequately known) Always more or less pagodi- form Always fairly large Lower Miocene Seemingly tending towards extinction posterior sinus is more fundamental. All things considered, it seems that, while Clinura and Thatcheria should be placed in the Turridae and may well have evolved from the Daphnellinae, they form a group which is so distinctive that it is best not to regard it as part of the Daphnellinae. The only logical alternative is to erect for them a special sub-family within the Turridae, the Thatcheriinae; i.e., it is proposed that the family Thatcheriidae Powell should be reduced in rank and the name of the taxon amended accordingly. The Thatcheriinae have a particularly close relationship with the Daphnellinae. The pagodiform habit, so characteristic of the former sub-family (especially its later mem- bers), has been evolved in a very similar manner in other sub-families of the Turridae, e.g. in the Cochlespirinae (compare Leucosyrinx (Aforia} circinata minatoensis Otuka 1949, pi. 13, fig. n, from the Pliocene of Japan) ; but the Thatcheriinae may be easily distinguished from such parallel developments by the form of the posterior sinus. GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 291 Formal classification Family TURRIDAE Sub-family THATCHERIINAE Powell 1942 nom. transl. herein Shell generally fairly large. Spire short relative to size of last whorl, very slightly coeloconoid, more or less pagodiform with deep suture and well developed carina. Posterior sinus on ramp of last whorl, juxtasutural, rounded, with vertex close to suture and deepened by forward extension of outer lip ; outer lip simple and slightly convex between carina and anterior canal ; distinct collabral growth-lines developed accordingly on ramp and outer face of whole teleoconch. Protoconch diagonally cancellate. Spiral ornament on outer face of teleoconch, and usually on outer edge of ramp next to carina ; transverse sculpture may be present on juvenile whorls of teleoconch (sometimes also on adult whorls), generally leading to formation of tubercles or notches on carina, but, alternatively, it may be entirely absent. Columella smooth, very slightly twisted. Operculum unknown and probably absent ; soft anatomy of the only Recent species typically turrid ; radula of that species like that of the Daphnellinae, with one pair of marginal teeth and no others. OCCURRENCE. Lower Miocene to Recent ; Mediterranean Basin and Western Pacific. Genus CLINURA Bellardi 1875 ?[i93i. Waitara Marwick, p. 149.] DIAGNOSIS. Spire slightly or moderately pagodiform with carina generally nearer to abapical suture ; juvenile whorls of teleoconch (sometimes also adult whorls) bear transverse sculpture, generally leading to formation of tubercles or notches on carina ; spiral ornament usually well developed. TYPE-SPECIES. Murex calliope Brocchi 1814 by subsequent designation of Bellardi, 1877. Upper Miocene to Lower Pliocene ; Italy and Southern France. RANGE. Lower Miocene to Lower Pliocene (mainly Middle and Upper Miocene) ; Europe, East Indies, New Zealand. REFERRED SPECIES. C. generosa (Marwick 1931) [Waitara} ; Lower Miocene, New Zealand. C. trochlearis (M. Homes 1854) [Pleurotoma] ; Middle Miocene, Vienna Basin and Italy. C. controversa (Bellardi 1847) [Pleurotoma] ; Upper Miocene, Italy. C. bituminata (Beets 1943) [Surculites] ; Upper Miocene, Buton (Celebes). SPECIES REFERRED PROVISIONALLY. C. waitaraensis (Marwick 1926) [Turricula] ; Upper Miocene, New Zealand. (May still represent distinct genus Waitara Marwick [Clinura may also include : C. sopronensis (Wolf 1870) [Pleurotoma} ; Upper Miocene, Vienna Basin. C. subtrochlearis (Friedberg 1912) [Surcula] ; Upper Miocene, Poland, C. sabatiorum Bellardi 1877 ; Lower Pliocene, Italy. Other species from the Miocene and Lower Pliocene of Europe.] 292 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS Genus THATCHERIA Angas 1877 1928. Cochlioconus Yokoyama, p. 338. DIAGNOSIS. Spire moderately to extremely pagodiform, with carina generally nearer to adapical suture ; no transverse ribbing, no tubercles or notches on carina (except for minute nodules on apical whorls of teleoconch in earlier forms) ; spiral ornament usually weak. TYPE-SPECIES. Thatcheria miraUlis Angas 1877 by monotypy. Recent ; off Japan. RANGE. Upper Miocene to Recent (mainly Pliocene) ; Western Pacific (New Zealand, Fiji, East Indies, Japan). REFERRED SPECIES. T. carinata (Martin 1933) [Ciyptoconus] ; Upper Miocene, Buton (Celebes). T. pagodula (Powell 1942) [Waitara] ; Upper Miocene or Lower Pliocene, New Zealand. Thatcheria sp. nov. aff. pagodula (Powell 1942) [Waitara] ; Lower Pliocene, New Zealand. T. liratula (Powell 1942) [Waitara] ; Lower Pliocene, New Zealand. T. vitiensis sp. nov. (see below) ; Lower Pliocene, Fiji. Thatcheria sp. nov. Beets 1951 ; Pliocene, East Borneo. T. gradata (Yokoyama 1928) [Cochlioconus] ; Pliocene, Japan. T. cf. gradata (Yokoyama 1928) MacNeil 1960 ; Pliocene (and Upper Miocene?), Okinawa. VII. A NEW SPECIES OF THATCHERIA FROM THE PLIOCENE OF FIJI Thatcheria vitiensis sp. nov. PL 47, figs. 4-6 DERIVATION OF NAME. Viti — the Fijian name for Fiji. DIAGNOSIS. A species of Thatcheria with a fairly thick shell, a relatively long and slender spire and a moderately projecting carina. The whorls bear dense, distinct spiral ornament on the outer face and a few weaker spiral striations on the outer part of the ramp. The first few whorls of the teleoconch bear minute nodules on the carina. HOLOTYPE. The unique specimen, Brit. Mus. (Nat. Hist.) Palaeont. Dept. no. G. 91124 (collector's field number VL . i) ; it lacks the extreme apex of the spire, the outer lip and the anterior canal. OCCURRENCE. In tuffaceous marls of the Vanua Levu Formation, of probable Lower Pliocene age. On the new south coast road near Savusavu, Eastern Vanua Levu, Fiji ; a large breast-cut 4 miles east of Salt Lake point where the road crosses higher ground north of Naweni. DESCRIPTION. [Note, (i) The protoconch is entirely lacking, and the condition of the early whorls is poor. (2) Although the whole of the outer lip has been broken off, the ramp of the last whorl is preserved up to its end. Had it extended further, it GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 293 would surely have left some indication of its attachment to the outer face ; and, in any case, the end of the suture is coincident with the adapical end of the last striation marking the limit of growth of the inner part of the mantle. (3) The abapi- cal end of the shell is also missing, but may be reconstructed with a fair degree of probability by reference to T. mirabilis. (4) The surface of the shell is abraded, but only very slightly.] MEASUREMENTS. Length as preserved ......... 45 mm. Estimated total length . . . . . . . . .51 mm. Height of spire as preserved . . . . . . . .22 mm. Estimated total height of spire . . . . . . -23 mm. Estimated height of last whorl . . . . . . . -34 mm. Maximum diameter (from end of carina to point diametrically opposite on carina of last whorl) . . . . . . . .26 mm. Internal spire angle . . . . . . . . .38° External spire angle . . . . . . . . -57° Angle of declination of suture (from plane perpendicular to shell axis) (see Text-fig. 9) .......... 14° Angle of declination of carina (see Text-fig. 9) . . . .8° This species shows a less extreme development of the characteristic form of the type-species (T. mirabilis). The shell is rather thick and solid ; this applies especially to the carina, the outer part of the ramp adjacent thereto, the columella, and the outer lip in the region of the anterior canal. The internal spire angle is a little less than in other species of the genus, the external spire angle much less than in any other species except the Miocene T. carinata ; the index of pagodiformity is greater than in T. carinata or the much stouter T. pagodula, about the same as in the slightly stouter T. limtula, and less than in the other species. The height of the spire is about 80% of the estimated height of the aperture ; the corresponding figure for T. liratula is about 50% (fide Powell) and for T. mirabilis 57%. The whorl profile shows that the carina projects rather acutely ; in the younger whorls both the outer face and the ramp are appreciably concave, the outer face being directed steeply downwards. On the penultimate and last whorls, however, the outer face shows a more or less straight profile ; and the ramp of the last whorl has a very marked angular concavity, the angle lying rather nearer to the suture than to the carina. The spiral ornament is very much like that of T. liratula and is clearly shown in Plate 47, figs. 4-6 ; the striations pass further into the interior of the last whorl, beyond the inner lip, than they do in T. mirabilis. There are very faint indications of minute nodules on the carina of the earliest whorls, just as in T. liratula. The growth-lines are also like those of T. liratula, the parts on the ramp showing that the characteristic posterior sinus of the Thatcheriinae was present ; the parts on the outer face, however, are inclined much less obliquely to the shell axis than they are in the New Zealand species. One peculiarity of the holotype, if not of the species, is the series of undulating striations on the inner lip which mark the limit of growth of the inner part of the mantle. 294 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS REMARKS. This species is closely related to Thatcheria liratula (Powell), to which it has an especial resemblance in its degree of pagodiformity, in the type and distri- bution of the spiral ornament, and in the presence of minute nodules on the first few whorls of the teleoconch. It may be distinguished from T. liratula, however, by its more acute spire, which is much longer relative to the aperture ; by the less oblique growth-lines on the outer face ; and by the fact that its carina is rather more acute, with the result that both the ramp and the outer face of each whorl generally appear a little more concave. T. liratula is from the Opoitian (Lower Pliocene) of New Zealand. The resem- blance of T. vitiensis to T. liratula rather than to any other species tends to confirm the suspected Lower Pliocene age of the marls from which T. vitiensis was collected. T. vitiensis is also like the Okinawan form which MacNeil (1960) described as T. cf. gradata, and which, as pointed out above, seems to have a close affinity with T. liratula. The Okinawan shell, however, differs from the Fijian species in certain details. The carina appears to be rather higher on the whorl and to project further, producing an almost flat ramp and a more pagodiform spire (just as in T. gradata itself, from Japan) ; while the nodules on the carina of the early whorls of the teleo- conch, if not better developed, are at least much better preserved than in T. vitiensis. ASSOCIATED FAUNA. Four other shells (three gastropods and one lamellibranch) were found in the Vanua Levu Formation with Thatcheria vitiensis. They will be described elsewhere. VIII. ACKNOWLEDGMENTS The specimen described above as the holotype of Thatcheria vitiensis sp. nov. was collected by Mr. R. W. Bartholomew of the Fiji Geological Survey Department, and was sent to London for examination by permission of Dr. N. J. Guest, Chief Geo- logist. Their interest and encouragement are gratefully acknowledged. My especial gratitude is due to Dr. L. R. Cox, F.R.S., for all the help he so patiently gave me. Among the many others who kindly offered useful information, sugges- tions and criticism were Dr. C. Beets, Mr. S. P. Dance, Dr. N. B. Eales, Mr. C. Matheson, Prof. J. E. Morton, Mr. C. P. Nuttall, Dr. A. W. B. PoweU, Mr. E. P. Smith, Mr. F. M. Wonnacott, and, in particular, Mr. D. L. F. Sealy. Dr. C. A. Fleming, Chief Palaeontologist to the New Zealand Geological Survey, allowed me to borrow the figured paratype of Waitara liratula Powell. Thanks are also due to Dr. G. Archey, Director of the Auckland Institute and Museum, for permission to reproduce Powell's text-figures of the protoconchs of Waitara liratula and Cryptodaphne pseudodrillia ; to Drs. T. Kuroda and T. Habe, of Kyoto University, for permission to reproduce their text-figure of the protoconch of Thatcheria mirabilis ; to Mr. D. L. F. Sealy, who copied those text-figures and made the original drawings of the protoconchs of Clinura calliope and C. trochlearis ; and to Mr. N. P. G. Tanti, who took some of the photographs. GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 295 IX. REFERENCES ANGAS, G. F. 1877. Descriptions of a new genus of gasteropodous Mollusca from Japan, and of a new species of Bullia from Kurrachi. Proc. zool. Soc. Lond., 1877 : 529-530, pi. 54. BEETS, C. 1943*1. Beitrage zur Kenntnis der angeblich Oberoligocanen Mollusken-Fauna der Insel Buton, Niederlandisch-Ostindien. Leid. geol. Meded., 13 : 256-328, pis. 27-30. 19436. Notizen fiber Thatcheria Angas, Clinura Bellardi und Clinuropsis Vincent. Leid. geol. Meded., 13 : 356-367, pis. 36, 37. 1951. On some genera of the family Turridae described from New Zealand. Basteria, Lisse, 15 : 14-25, pis. i, 2. 1953- Reconsideration of the so-called Oligocene fauna in the asphaltic deposits of Buton (Malay Archipelago). Leid. geol. Meded., 17 : 237-258, pi. i. BELLARDI, L. 1841. Descriptions des Cancellaires fossiles des terrains tertiaires du Pie"mont. Mem. R. Accad. Torino (2) 3 : 1-42, pis. 1-4. (Paginated 225-264 in whole volume.) 1847. Monografia delle Pleurotome fossili del Piemonte. Mem. R. Accad. Torino (2) 9 : 1-122, pis. 1-4. (Whole volume published in 1848, with this article paginated 531-650.) 1875. Novae Pleurotomidarum Pedemontii et Liguriae fossilium, dispositionis prodromus. Boll. Soc. malacol. ital., Pisa, 1 : 16-24. 1877. I molluschi dei terreni terziari del Piemonte e della Liguria, II. Gasteropoda (Pleurotomidae) . Mem. R. Accad. Torino (2) 29 : 1-364, pis. 1-9. (Whole volume published in 1878.) BROCCHI, G. B. 1814. Conchiologia fossile subapennina con osservazioni geologiche sugli Apennini e sul suolo adiacente, 2 : 241-712, 16 pis. Milano. 1843. 2nd edition of the same work : 1-556, 16 pis. Milano. COSSMANN, M. 1889. Catalogue illustre' des coquilles fossiles de 1'Eocene des environs de Paris, faisant suite aux travaux pale"ontologiques de G.-P. Deshayes. 4eme fascicule. Ann. Soc. malac. Belg., Bruxelles, 24 : 3-381, pis. 1-12. 1896. Essais de paleoconchologie comparee, 2 : 1-179, 8 pis. Paris. 1901. Essais de paleoconchologie comparee, 4 : 1-293, IO pis- Paris. Cox, L. R. 1955. Observations on gastropod descriptive terminology. Proc. malac. Soc. Lond., 31 : 190-202, figs. 1-9. DALL, W. H. 1908. The Mollusca and the Brachiopoda. Bull. Mus. comp. Zool. Haw., Cambridge, Mass., 43 : 205-487, pis. 1-22. EALES, N. B. 1938. On the affinities of Thatcheria mirabilis Angas. Proc. malac. Soc. Lond., 23 : 15-17, figs, i, 2. EAMES, F. E. 1957. Eocene Mollusca from Nigeria : a revision. Bull. Brit. Mus. (nat. Hist.}, London (geol.) 3 : 23-70, pis. 5-10. FISCHER, P. 1880-1887. Manuel de conchyliologie et de paleontologie conchy iiologique. xxii + 1369 pp., 24 pis. Paris. FORESTI, L. 1868. Catalogo dei molluschi fossili Pliocenici delle Colline Bolognesi. Mem. R. Accad. Bologna (2) 7 : 541-638, pis. i, 2. FRIEDBERG, W. 1912. Mieczaki miocenskie ziem polskich (Mollusca miocenica Poloniae), II. Wydaw. Muz. Dzieduszyck., Lwow, 14 : 113-240, pis. 6-14. GLIBERT, M. 1960. Les Conacea fossiles du C6nozoique Stranger des collections de Flnstitut Royal des Sciences Naturelles de Belgique. Mem. Inst. Sci. nat. Belg., Bruxelles (2) 64 : 1-132. GRANT, U. S. & GALE, H. R. 1931. Catalogue of the marine Pliocene and Pleistocene Mollusca of California and adjacent regions. Mem. S. Diego Soc. nat. Hist., 1 : 1-1036, pis. 1-32. HABE, T. 1955. Thatcheria mirabilis Angas (Turridae). Illustrated catalogue of Japanese shells (B), Nos. i6a, i6b : 2 pp., 3 figs. HATAI, K. & NISIYAMA, S. 1952. Check list of Japanese Tertiary marine Mollusca. Sci. Rep. Tohoku Univ., Sendai (2) special vol. 3 : 1-464. HIRASE, S. 1934. 4. collection of Japanese shells with illustrations in natural colours, xvi + 217 pp., 130 pis. Tokyo. GEOL 7, 9 21 2g6 GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS HIRASE, S. & TAKI, I. 1954. -An illustrated handbook of shells in natural colors from the Japanese Islands and adjacent territory (2nd edition), xxiv + 124 pp., 134 pis. Tokyo. HOPWOOD, A. T. 1937. Report of Ordinary Meeting of the Malacological Society of London held on Friday 8th January 1937. Proc. malac. Soc. Lond., 22 : 158-159. HORNES, M. 1851-1856. Die fossilen Mollusken des Tertiaer-Beckens von Wien. Abh. geol. Reichsanst., Wien, 3 : 1-736, atlas 52 pis. HORNES, R. & AUINGER, M. 1891. Die Gasteropoden der Meeres-Ablagerungen der ersten und zweiten miocdnen Mediterran-Stufe in der osterreichisch-ungarischen Monarchie, 8 : 331-382, pis. 43-50. Wien. KIRA, T. 1955. Coloured illustrations of the shells of Japan. 8 + 204 pp., 67 pis. Osaka. KURODA, T. & HABE, T. 1952. Check list and bibliography of the Recent marine Mollusca of Japan. 210 pp., 2 maps. Tokyo. KURODA, T. & HABE, T. 1954. Notes on three remarkable species of Japanese gastropods. Venus, Kyoto, 18 : 79-84, figs. 1-4. MACNEIL, F. S. 1960. Tertiary and Quaternary Gastropoda of Okinawa. Prof. Pap. U.S. geol. Surv., Washington, 339 : i-iv, 1-148, 21 pis. MARTIN, K. 1933. Eine neue tertiare Molluskenfauna aus dem Indischen Archipel. Leid. geol. Meded., 6 : 7-32, pis. 1-5. MARWICK, J. 1926. New Tertiary Mollusca from North Taranaki. Trans. AT.Z. Inst., Wellington, 56 : 317-331, pis. 73-75. - 1931. The Tertiary Mollusca of the Gisborne district. Palaeont. Bull. N ,Z., Wellington, 13 : 1-177, pis. 1-18. MAYER-EYMAR, C. 1896. Descriptions de coquilles fossiles des terrains tertiaires inferieurs (suite). /. Conchyliol., Paris, 43 (1895) : 40-54, pis. 2-4. MILLET, P.-A. 1826. Sur un nouveau genre de coquilles de la famille des Zoophages. Mem. Soc. linn. Paris, 5 (1827) : 437-441, pi. 9. OTUKA, Y. 1949. Fossil Mollusca and rocks of the Kiyosumi Group exposed at Minato-machi, Chiba Prefecture, and its environs (ist paper). Jap. J. Geol. Geogr., Tokyo, 21 : 295-313, pi. 13- PCHELINTSEV, V. F. & KoROBKOV, I. A. 1960. Gastropods. Osnovy paleontologii. 360 pp., 28 pis. Moskva. PILSBRY, H. A. 1895. Catalogue of the marine mollusks of Japan, with descriptions of new species and notes on others collected by Frederick Stearns, i-viii, 1-196, n pis. Detroit. POWELL, A. W. B. 1942. The New Zealand Recent and fossil Mollusca of the family Turridae, with general notes on Turrid nomenclature and systematics. Bull. Auckland Inst., 2 : 1-188, pis. 1-14. Rossi RONCHETTI, C. 1951-1956. I tipi della " Conchiologia fossile subapennina " di G. Brocchi. Supplement to Riv. ital. Paleont., Parma, 57-62 : 1-343 and indices, figs. 1-185. SACCO, F. 1889. Louis Bellardi : notice biographique et bibliographique. Ann. Soc. malac. Belg., Bruxelles, 24 : v-vij. SCHILDER, F. A. 1932. Cypraeacea. In Quenstedt, W., Fossilium Catalogus, 55 : 276 pp. Berlin. SOWERBY, G. B. 1870-1880. Thesaurus conchyliorum, or Monographs of genera of shells, 4: 260 pp., 137 pis. London. STEWART, R. B. 1927. Gabb's California fossil type gastropods. Proc. Acad. nat. Sci. Philad., 78 (1926) : 287-447, Pls- 20-32. THIELE, J. 1929-1931. Loricata, Gastropoda. Handbuch der systematischen Weichtierkunde, 1 : i-vi, 1-778, figs. 1-783. Jena. 1934-1935. Scaphopoda, Bivalvia, Cephalopoda [mit Nachtragen und Berichtigungen zum i. Band] ; vergleichende Morphologic, usw. Handbuch der systematischen Weichtier- kunde, 2 : i-v, 779-1154, figs. 784-897. Jena. TOMLIN, J. R. LE B. 1919. Editorial notes. /. Conch., London & Leeds, 16 : 66-67. TRYON, G. W. 1881. Tritonidae, Fusidae, Buccinidae. Manual of Conchology, structural and systematic, 3 : 1-310, pis. 1-87. Philadelphia. GASTROPOD GENUS THATCHERIA AND ITS RELATIONSHIPS 297 TRYON, G. W. 1883. Structural and systematic conchology : an introduction to the study of the Mollusca. 2 : 1-430, pis. 23-91. Philadelphia. VINCENT, E. 1913. Contribution a la paleontologie des falaises de Landana (Bas-Congo) : Mollusques. In Vincent, E., Dollo, L. & Leriche, M., La faune paleocene de Landana. Ann. Mus. Congo beige ^to, Bruxelles, A (3) 1 : 1-92, pis. i-io. WENZ, W. 1938-1944. Gastropoda : allgemeiner Teil und Prosobranchia. In Schindewolf, O. H., Handbuch der Paldozoologie, 6 : xii + 1639 pp., 4211 figs. Berlin. WOLF, H. 1870. Die Stadt Oedenburg und ihre Umgebung. Jb. geol. Reichsanst., Wien, 20 : 15-64, pi. 3. WRIGLEY, A. 1939. English Eocene Surculites. Proc. malac. Soc. Lond., 23 : 277-284, pi. 18. YOKOYAMA, M. 1928. Pliocene shells from Hyuga. /. Fac. Sci. Tokyo Univ. (2) 2 : 331-350, pis. 66, 67. 1930. On a univalve called Cochlioconus gradatus Yokoyama. /. Fac. Sci. Tokyo Univ. (2) 2 : 405-406, i fig. PLATE 47 Thatcheria mirabilis Angas Holotype : British Museum (Nat. Hist.), no. 1960.154. Recent ; off Japan. FIG. i. — Apertural view, x i. FIG. 2. — Apical view, x i. FIG. 3. — Oblique view of ramp to show growth-lines, x 2. Thatcheria vitiensis sp. nov. Holotype : British Museum (Nat. Hist.), no. G. 91124. Lower Pliocene ? (marls of Vanua Levu Formation) ; near Savusavu, Eastern Vanua Levu, Fiji. FIG. 4. — Apertural view, x i£. FIG. 5. — Apical view, x i. FIG. 6. — Oblique view of ramp to show growth-lines, x 2. Thatcheria livatula (Powell) Paratype : New Zealand Geological Survey, no. TM. 2864. Lower Pliocene (Opoitian) ; N.Z.G.S. loc. 1543, mudstone and argillaceous sandstone beds, Mangawhero Stream, Taramarama (S.W.) S.D., Wairoa, New Zealand. FIG. 7. — Lateral view of spire, x 2^. FIG. 8. — Oblique view of ramp to show growth-lines, x 6. Clinura calliope (Brocchi) British Museum (Nat. Hist.), no. G. 79439. Lower Pliocene (Plaisancian) ; Biot, near Antibes, Alpes Maritimes, France. FIG. 9. — Apertural view. X about ij. FIG. 10. — Abapertural view, x about i£. FIG. ii. — Oblique view of ramp to show growth-lines. X5- FIG. 12. — Protoconch and early whorls of teleoconch. x 125. Bull. B.M. (N.H.) Geol. 7, 9 PLATE 47 12 INDEX TO VOLUME VII New taxonomic names and the page numbers of the principal references are printed in Bold type. An asterisk (*) indicates a figure ABBASS, H. L. 173-196 Abbey Wood, Kent 6, 8 A caste alifrons 100, 103 exilis 100 Acastinae 97 Acidaspis caractaci 239 harnagensis 237 magnospina 123 primordialis 122, 237 semievoluta 69, 122 sp. 123 Actaletes neptuni 156 Adapidae 14, 21, 24, 25, 27, 31, 32, 34 Adapis 4, 10, 12-15, 17-23, 30, 32 angustidens 33 magnus 17, 19, 33 minimus 13 parisiensis 10, 18, 25, 29, 30, 33 priscus 33 rutimeyeri 33 sciwrews 33 Aeluravus 29 Aeschna 163 liassina 164 Akera 260 Akeridae 267 Alsaticopithecus 25, 31, 33 leemanni 25, 27, 31, 33 Alternata limestone 219 Amphilemur 25, 33 eocaenicus 25, 33 Amphilemuridae 23, 25 Amphitryon 251 radians 220 Amplexograptus perexcavatus 232 Ampyx linleyensis 78 pennatus 78 restrains 76, 78 salteri 78 tetragonus 78 Anachoropteris 208 involuta 208 Anagale 27 Anaptomorphidae 3, 24, 27 Anchomomys 3, 19, 21, 23, 31, 33, 34 fi 33 ^4 nchomomys — contd. latidens 21-23, 31, 33 pygmaeus 33 quercyi 21, 22*, 33 Anisozygoptera 155, 160 Anthropoidea 17 Anticlinura 263, 266 Anulatisporites anulatus 147 ; PI. 22, figs. 70, 71 sp. 148; PI. 22, fig. 72 Aotes 5 Apatemyidae 23, 26 Aphanolemur 15 gibbosus 15 Aphelotherium 32 Apiculatisporites 150 Apotropteris 208 Apterygota 156 Archaeopteridium 142 tschermaki 142 ; PI. 21, fig. 22 Archimediella 178 Architemidae 164 Arcotia 179 Asaphidae 229 Asaphinae 229 Asaphus marstoni 231 powisi 229, 232 seticornis 85 Asperdaphne versvestita 277 Asplenium 207 Asteroceras obtusum 155, 161 Atractopyge 91, 93, 130 aspera 91 atractopyge 93 michelli 93 scabra 91, 92, 93 ; PI. n, figs. 2, 3, 10 sp. 93, 94, ; PI. n, figs. 5, 8 Auckland Institute & Museum 294 Aurelia aurita 156 A zonotriletes 150 Balanus improvisus 156 Bancroftina typa 71 Zone 80, 93, 107, 125 Basilicus 229 marstoni 229 powisi 229, 232 3°° INDEX Birbal'Sahni Institute 151 Birmingham University 137, 151 Blattodea 158 Bourguetia saemanni 194 striata 194 Bothrodendron tenerrimum 139 Broeggerolithus 79-82, 129 broeggeri 79 Zone 221, 232 globiceps 71, 84 longiceps 71, 81-83 melmerbiensis 81 ; PI. 6, figs. 10, 13 nicholsoni 79, 80-83, I29 .' PI- 6> ngs. 7, n ; PL 7, figs. 1-12 simplex 79, 8 1 soudleyensis 84 sp. 79, 83 ; PI. 8, fig. 2 transiens 81, 82, 83, 84, 129, 218 ; PI. 8, figs. i, 3, 4, 6, 8, n Brongniartella 82, 106, 129 ascripta 106, 107, 108, no ; PI. 15, figs, i, 2, 5, 8, ii ; PL 16, fig. 14 bisulcata 107, 108, 109, no, 129 ; PL 16, fig. 8 depressa 108, 109, no ; PL 16, figs, i, 7, 10, 13 minor 106, 107 ; PL 15, fig. 4, ; PL 16, fig. 11 subcarinata 107, no parva 106 platynota 110 rwrfis 107 sp. 108 Buccinidae 259, 267, 289 Burrirhynchia 42, 43, 58, 59 cantabrigensis 42, 59*, 60, 61 leightonensis 59, 60, 61 Caenopithecus 14, 19, 21, 27, 29, 30, 31, 33, 34 lemuroides 29, 33 Calamospora 144, 150 mutabilis 144, PL 22, fig. 44 sp. 144 ; PL 22, fig. 44 Calathiops sp. 143 ; PL 21, figs. 27-29 Calliops brongniarti 104 jukesi 100 var. vicina 104 Calymene in aldonensis 113 bigener 113 blumenbachii var. caractaci 114, 216, 217, 225 brevicapitata 223 callicephala 111 caractaci in, 217 diademata 116 fatua 219 forcipata 235, 236 grayae 113 incerta 219 meeki in 104 planimarginata Calymene — contd. pulchra 220 quadrata 113, 227 senaria in verrucosa 91 Calymenidae 111, 215, 216 Calyptaulax 98, 130 actonensis 100 altumi 99, 100 compressa 100 glabella 98, 100 norvegicus 98, 99 planiformis 98, 99, 100 ; PL 13, figs. 1-5 schucherti 100 sp. 98, 99 Camptotriletes sp. 146 ; PL 22, fig. 58 Cantius 3, 4, 5, 6, 8, 10, 14, 22, 34 e^si 4, 6, 7, 8, 9, 32 ; PL i Capillae 42 Capillirhynchia wrighti 44 Cardium edule 156 Carpolestidae 24 Ceciliolemur 27, 30 Ceratopogon 156 Ceraurus octolobatus 88 Cerithiacea 180 Cerithium turritellatum 183 unicarinatum 182 CHARIG, A. J. 255-297 Charmouth, Dorset 155 Chasmops 104, 129, 248 conicophthalma 106 extensa 104, 106, 115, 229 ; PL 13, fig. 8 jukesi 100 maxima 105 ; PL 13, fig. 6 sp. 105 ; PL 13, fig. 12 Chasmopsinae 104 Cheiruridae 86 Cheirurus octolobatus 88 Chironomus 156, 157 Chomatopyge 119 Chondrites plumosus 150 Chondrosteus sp. 155 Chonetoidea 115 sp. 84 Cibotium barometz 205 regale 205, 206 Cirratriradites 150 sp. 148 ; PL 23, fig. 74 Clavatulinae 262 Clinura 257, 262-264, 2^6, 268, 270, 271, 272*, 273, 277-283, 286-289, 291 bituminata 262, 279-282, 286, 291 calliope 263, 266, 271-274, 275*, 276, 278-280 282, 286-288, 290, 294 carinata 279-282 controversa 279, 280, 287, 288, 291 elegantissima 263, 279 generosa 286, 288, 291 monochorda 263 INDEX 301 Clinura — contd. peruviana 263 sabatiorum 279, 291 sopronensis 279, 291 subtrochlearis 291, 279 Thatcheria group 278, 286, 288 trochlearis 271, 272, 274, 275*, 279, 280, 288, 290, 291, 294 waitaraensis 286, 291 Clinuromella 263 Clinuropsis 262, 263, 266, 278-280 calliope 266 monochorda 263 Cochlespirinae 261, 266, 290 Cochlioconus 260-262, 265, 267, 268, 270, 278 288, 292 gradatus 259, 260, 265 Coenopterideae 210 Coleoptera 159, 167 Colpocoryphe aldonensis 113 Colposigma 179 Conidae 261, 267, 268, 277, 288, 289 Conolichas 120, 129 melmerbiensis 120, 121 ; PI. 17, figs. 14, PI. 1 8, figs. 1-4 Conorbiinae 261 Conularia 150 Conus 259-261, 267, 268 araneosus 288 pennaceus 277 quercinus 260 Convolutispora sp. 146 ; 1*1. 22, fig. 59 tessellata 146 Coryphodon 8 Costellae 42 Costonia ultima Zone 235 Craeseops 25 Craiginia 179 Cretaceous Gastropoda 173-196 Cretirhynchia 39, 43, 59-61 norvicensis 58*, 61 octoplicata 49 plicatilis 60 Cristatisporites 150 CROFT, W. N. 197-211 Cryptoconus 262, 279, 292 Cryptodaphne pseudodrillia 275*, 294 Cryptolithinae 79 Cryptolithus broeggeri 79 gracilis 84 nicholsoni 79 transiens 82 Cryptothyris paracydica 71 Cupedidae 167, 169 Cupes 167 capitatus 167 Cybele loveni 94 var. girvanensis 94 iwrwcosa 91, 93 Cybelinae 91 Cyclogranisporites 150 amplus 145 ; PI. 22, figs. 49-51 orbicularis 145 sp. 145 ; PI. 22. fig. 52 Cy do stigma 138 Cyclothyrid 42 286, Cyclothyrinae 39, 43 Cydothyris 39*, 40*, 41*, 42, 43 americana 40 antidichotoma 41, 42, 44, 47, 48*, 49*, 56 ; PI. 4. figs. 3-6 compressa 54, 61 ; PI. 5, fig. 8 depressa 41, 50, 56 ; PI. 4, fig. n difformis 41, 42, 44, 45, 51, 52*, 53*, 54, 58 ; -280, PI. 5, figs. 1-7 latissima 39, 41, 45, 46*, 50, 56-58, 60 ; PI. 4, figs. 7, 8 lepida 41, 42, 55, 56, 57 ; PI. 4, fig. 10 levis 41, 42, 56, 57 ; PI. 4, fig. 9 plicatilis 60 scaldisensis 42, 44, 46, 57 ; PI. 4, fig. i schloenbachi 42, 50, 55, 56 ; PI. 4, figs. 12, 13 subtrigonalis 40 1 6 ; Cynodontomys 25 Cyphaspis jamesoni 126 megalops 123 nicholsoni 118 Cypraeacea 266 Cyrtometopinae 86 Dalmanella horderleyensis 71 Zone 217, 223 indica 71 Zone 222 /e/>ta 71, Zone 222 unguis 71, Zone 218, 219, 246 wattsi 71, Zone 218 Dalmania socialis 95 Dalmanitidae 95 Dalmanitina 95 mucronata 95, 96 matutina 95, 96 ; PI. 12, figs, i, 5, 6, 9, 12 Dalmanitinae 95 Dapedium granulatum 155 sp- 155 Daphnella 277 cancellata 277 Daphnellinae 257, 261, 265, 267, 277, 289-291 Daubentonia 26 DEAN, W. T. 65-134, 213-254 Decoroproetus 126 fearnsidesi 243 Defrancia pagoda 266 Densosporites 150 sp. 148 ; PI. 23, fig. 73 Diacalymene 113, 114, 116 bigener 113 diademata 113, 114 marginata 116, 227 ; PI. 13, fig. 13 ; PI- 14, fig. ii 302 INDEX Diacalymene — contd . praecox 113, 225, 227 Diastatomma liassina 164 Diastatommites 164 liassina 161, 164 ; PI. 27, fig. 3 Dicranograptus clingani Zone 72, 226, 232, 242 Dictyotriletes sp. 147 ; PI. 22, fig. 64 Didymograptus superstes Shales 113 Dimeropyge 119 Dimeropygidae 118, 119 Dindymene 89 duftonensis 89, 90 ; PI. n, fig. 13 fridericiaugusti 89 ornata 90 plasi go sp. 89, 90 ; PI. ii, fig. 6 Dindymeninae 89 Diplograptus multidens Zone 129, 226, 232 perexcavatus 232 Diplopteridium 140-143 holdeni 137, 140, 142 ; PI. 20, figs. 8-15 teilianum 141, 143 Diptera 156, 158 Dolerorthis sp. 77 Dry brook Sandstone 137, 149 Duftonia 69, 97, 103 lacunosa 97 Elcanidae 158, 159 Encrinuridae 88 Encrinurinae 88 Encrinurus 88, 89 sp. 88 ; PI. n, figs, i, 4 Endosporites sp. 148 ; PL 23, fig. 75 Ensifera 165 Entomolestes 25 Entomostracites crassicauda 233 laticauda 251 punctatus 88 Eobronteus 251 sp. 251 ; PI. 46, fig. 10 Erinaceoidea 25 Estoniops 100, 103 alifrons 100, 101-104, I29 > PI- I2> nSs- 2' 4> 7, 8, 10, 13 exilis 103 jukesi 101 Europolemur 12, 13, 27, 31, 33 £/a#i 9, 12, 13, 33 Ficidae 259, 267 Ficus 259, 267 Fiji Geological Survey 294 Filicales 201 Flexicalymene 82, in, 112, 113, 114, 118, 216, 219, 236 acantha 112, 216, 217, 219, 220, 225 ; PI. 37, figs, i, 3-6, 14 brevicapitata 112, 220 cambrensis 112, 219 Flexicalymene- — contd. caractaci 112, 114, 217, 218-220 ; PI. 13, fig. 10 ; PI. 38, figs. 2, 4-6, 8, ii, 12 cobboldi 218, 220 ; PI. 38, figs, i, 3 croneisi 223 declinata 112, 220 forcipata 112 horderleyensis 221, 223 ; PI. 37, figs. 2, 8 ; PI. 40, figs. 7, 8 incerta 220 laticeps 115, 224 limba 113, 221, 223 ; PI. 37, fig. 16 onniensis 69, 112, 115, 223 ; PI. 13, fig. 7 ; PI. 14, figs, i, 2, 7, 10 planimarginata 112, 114, 217, 219, 220 ; PI. 37, ng- 15 pusulosa 113, 217, 220, 221, 223 ; PI. 37, figs. 9, ii, 12 salteri 224 senaria 112 shirley i 112 sp. 221, 223 trigonoceps 217, 218 Fucus sp. 156 Furcirkynchia furcata 44 Fusidae 267 Fusinae 267 Fusinidae 267, 289 Fusininae 267 Fusinus 259, 267 Fusus 259, 267 Galago 17, 23 crassicaudatus 6 Galeodidae 261, 267, 268 Galigidae 23 Gastropoda 175, 180 Geological Society, London 69 Geological Survey & Museum 59, 102, 103, 187, 224, 225, 240, 245 GesneropithexSl, 33 peyerizi, 31. 33 Glasgow University 137 Glyptocrinus Flags 221 Grammatopteris 208 baldaufi 209, 201 rigolloti 209 Granulatisporites 1 50 orbiculus 145 ; PI. 22, figs. 47, 48 sp. 145 ; PI. 22, figs. 47, 48 tenuis 144 ; PL 22, figs. 45, 46 Gravicalymene 112, 113, 114, 117, 225 convolva 116, 118, 225, 225 inflata 227 ; PL 39, fig. 6 jugifera 116, 118, 226 ; PL 13, figs. 9, ii ; PL 14, figs. 3, 4, 8, 9 praecox 112, 216, 225, 226-228 ; PL 39, figs, i, 3,9, 12-14 sp. 227 Gryllacrididae 155,166 INDEX 3°3 Hagla 165, 166 Haglinae 165 Halle University 12, 34 Harknessella subquadrata Zone 220, 235, 245 Harpalideous Carabidae 168, 170 Harpalus schlotheimi 168 Haustator 178, 184, 187, 191 granulata 183, 184 granulatoides 183, 184 Hemiacodon 4-8 Hemifusus 259, 261, 267, 268 Heterophlebia westwoodi 161 Heterorthis alternata 219 Hirnantia sagittifera 71 Hoanghonius 4 Holcoelytrum 155, 167 giebeli 167, 168, 170, 171 ; PI. 27, figs. 6-8 schlotheimi 168, 170, 171 ; PI. 27, fig. 5 Holcoptera 168 HOLDEN, H. S. 197-211 Homalonotidae 106 Homalonotus ascriptus 69 bisculatus 106, 108 var. minor 106 rudis 107 Homalops altumi 99, 100 Homolichas melmerbiensis 120 Homolochinae 120, 235 Hydrobia 157 Hydrophilidae 157 Hymenoptera 159 Hyracotherium 8 Illaenidae 120, 233 Illaenus 129, 233 bowmani 120 fallax 233, 234 linnarssoni 120 sp. 233 Imperial College of Science, London 175 Inoceramus 155 Insectivora 25 Ireland National Museum 235, 236 Isotelinea 229 Isotelus brachycephalus 233 Isotelus powisi 229 Jurassobatea gryllacroides 166 King's College, London 61 Kingston Technical College 137, 151 Kjaerina bipartita Zone 71, 89, 219 geniculata 77, 91 typa Zone 71, 91, 218 Kjerulfina polycyma 83 Kloucekia 97 apiculata 72, 97, 129 ; PI. 12, fig. n Knoxisporites 147 Kyoto University 294 Lacunosella 43 Lamellaerhynchia 43, 60 larwoodi 41 Leiotriletes sphaerotriangulans 143 ; PI. 21, figs. 3°. 31 LELE, K. M. 135-152 Lemuridae 24 Lemuriformes 5 Lemuroid Primates, Concept of 23 Lepidophyllum fimbriatum 137, 138, 139, 140, 150 ; PI. 20, figs. 18-20 Lepidorhynchia 43, 60 Lepidosigillaria whitei 140 Lepidostrobophyllum fimbriatum 138 Leptadapis 32 Leptocolpus 179 Leucosyrinx circinata minatoensis 290 Leymeriella tardefurcata Zone 41, 42, 50, 56, 57, 59,6o Liassocupes 167 parvus 167 ; PI. 27, fig. 4 Liassophlebia 161 gigantea 163 ; PI. 27, fig. 2 jacksoni 162, 163, 164, ; PI. 25 magnified 161, 162, 163, 164 ; PI. 27, fig. i sp. 164 wither si 164 Liassophlebiidae 160 Lichas aculeatus 235 aequiloba 120 laxata 121, 235 margaritifer 121, 235 melmerbiensis 69, 120 nodulosus 121, 235 segmentatus 235 sexspinus 235 verrucosa 234 Lichidae 120, 234 Lichinae 234 Lipura maritima 156 Lonchodomus 72, 77, 78 carinatus 78, 79 pennatus 77, 78, 79, 84, 129 ; PI. 6, figs. 1,3-5, 9, 12 politus 77 rostratus 72, 77 swindalensis 72, 77 ; PI. 6, figs. 2, 6, 8 London Clay 3 Lophotriletes 150 Loris 1 8 tardigradus 18 Lushius 4 Lycospora 150 bracteola 147 ; PI. 22, fig. 65 granulata 147 spp. 147 ; PI. 22, figs. 66-69 Macrocranion 25 Manchester Museum 140, 150 INDEX Mangeliinae 289 Mathilda 179, 191 ahmadi 175, 177, 178, 181*, 193 ; PI. 32, fig. 24 coxi 175, 177-179, 181*, 191, 192, 193 ; PI. 32, fig. 23 douvillei 192 faucignyana 192 quadricarinata 192 Mathildidae 175, 191 Matonia pectinata 205 Mayeria 259, 267 Mecoptera 158 Megachiromy aides 27, 29 M egasurcula 289 keepi 289 Megatarsius 13, 14, 27, 31, 33 a&eftg, 12, 13,33 Melongenidae 259, 267 Melongeninae 259, 267 Menocephalus nicholsoni 119 Mesalia 178 Mesotaphraspis 119 Metacupes harrisi 167 huebneri 234 M etopolichas 234 patriarchus 234 sp. 234 ; PI. 43, figs. 3, 4, 6, 7 verrucas a 234 Microchoerus 4, 31 edwardsi 3 1 erinaceus 3 1 ornatus 31 Microreticulatisporites 150 cribellarius 146 ; PI. 22, figs. 60, 61 spp. 146 ; PL 22, figs. 62, 63 Microsyopidae 23, 25, 33 Microsyops 25 Microtarsioides 27, 30 Mwre.r 263, 271 calliope 266, 272, 291 Nannopithex 19, 24, 32 filholi 32 pollicaris 32 raa&i 32 Navajovius j, 24 Necrolemur 4, 5, 15, 17, 22, 31, 32 antiquus 32 edwardsi 31 filholi 32 parvulus 32 raabi 32 zitteli 32 Necrolemurinae 4, 23, 31 Nekewis 262, 279 io 273 Nemagraptus gracilis Zone 77, 113, 129, 226, 232 Nereis diversicolor 156 Nerinaea unicarinata 182 Neuroptera 158 New Zealand Geological Survey 294 Notharctidae 5, 17, 24, 34 Notharctus 6, 12, 14, 15, 17, 30 Notopamphagopsis bolivari 166 Nycticebus 5, 15, 18-20 cougang 1 8, 20 Odonata 156, 158, 160 Odontopleuridae 122, 237 Odontopleurinae 237 Ogmocnemis 126, 243 calvus 126, 243, 245 Olenidae 241 Omomyidae 3-5, 7, 24, 32, 34 Omomyinae 3 Omowrys 4, 6, 7, 30, 32 belgicus 32 Onnia 84, 1 30 cobboldi Zone 71, 224, 234, 237 gracilis 84, 129 ; PI. 8, figs. 12, 13 Zone 71, 78, 85, 92, 95, 99, 115, 122, 128, 223, 224, 226, 228, 234 ornata 220 superba 129 pusgillensis 84, 130 ; PI. 8, figs. 5, 7, 9, 10 Zone 71, 78, 84, 85, 88, 92, 95, 99, 115, 128, 224, 242, 251 Onnicalymene 104, 112, 113, 115, 129, 223 jemtlandica 113 laticeps 113, 115, 224 ; PI. 14, figs. 5, 6; PI. 38 figs. 7, 10, 14, 15 salteri 113, 224 ; PI. 38, figs. 9, 13 onniensis 84, 113, 115, 129, 223, 224 ; PI. 39, figs. 2, 10, ii ; PI. 40, fig. 9 Onniella 104, 115, 248 broeggeri 71, 84 inconstans 71 reuschi Zone 71, 83, 218, 240 Orbirhynchia 45 Ordovician trilobites 215 Orimops 1 1 1 Orthophlebia 158 Orthophlebiidae 158 Orthoptera Saltatoria 158, 165 Osmundaceae 210 Otarion 123, 242 diffractum 123, 242 isoplates 124 planifrons 123, 124 sp. 123, 242 ; PI. 17, figs. 4, 12 ; PI. 45, fig. i Otarionidae 123, 242 Ourayia 6, 18 OWEN, E. F. 37-63 Palaeolemur 32 Parabasilicus 229 marstoni 231, 232 powisi 229, 230-233 ; PI. 40, figs, i, 3-5 ; PI. 41, figs, i, 2 ; PI. 42, fig. 9 INDEX 305 Parabasilicus — contd. shirakii 232 typicalis 229 Paracybeloides 94, 129 girvanensis 94, 95, 96 ; PI. n, figs. 7, 9, 12, 14, 15 sp. 95, 103 ; PI. ii, fig. ii Parahoplites nutfieldensis Zone 42, 46, 50 Pareora 189 Paromomyidae 24, 27 Pelycodus 6, 7, 14, 18, 29, 30, 32 helveticus 32 Periconodon 4, 30, 32 helveticus 30, 32 Perodicticus 12 Petrophlebia 160, 161 anglicana 160, 161 anglicanopsis 159, 160, 161 ; PI. 24, figs, i, 2 Phacopidina 97 apiculata97 ; PI. 12, fig. ii harnagensis 97 Phacops alifrons 100,103 apiculatus 97 brongniarti 98 jukesi 100-103 var. vicina 104 panderi 103 phillipsi 97 Phaneropterinae 166 Pharostoma pulchrum 220 Phenacolemur 26, 27 Phenacolemuridae 24 Pholidophorus sp. 155 Planisporites 150 delucidus 145 granifer 146 ; PI. 22, fig. 56 minimus 145 ; PI. 22, figs. 53—55 sp. 146 ; PI. 22, fig. 56 Platycalymene 1 1 1 Platylichas 121, 122, 235 laxatus 71, 121, 122, 235, 236, 237 ; PI. 43, figs, i, 2, 5, 8-12 melmerbiensis 120, 121 sp. 122 Plesiadapidae 24, 27 Plesiadapis 26, 27, 33 Pleurofusia 289 Pleurograptus linearis Zone 72, 100, 226 Pleurotoma 262, 263, 271, 274, 279, 288, 291 calliope 273, 288 controversa 288 Pleurotomella 263 calliope 266, 274 monochorda 263 packardii 266 Pleurotomidae 263, 268, 288 Pleurotomoides 266 Plicarostrum 43 Portlockia apiculata 97 POWELL, A. W. B. 294 Primaspis 122, 237 ascitus 241 caractaci 122, 238, 239, 240, 241 ; PI. 44, figs. 3. 7-9- ii, 13, M harnagensis 122, 237, 238, 241 ; PI. 44, figs. 1,4,6,8 semievoluta 122, 123, 241 ; PI. 17, figs. 3, 10, ii, 13, 15 Princeton University 34 Proetidae 124, 243 Proetidella 124, 126, 129, 243, 245 fearnsidesi 124, 126, 243, 245, 246 ; PI. 45, figs. 3-8, 12, 14 marri 124, 126 ; PI. 16, figs. 4, 6, 9 ; PL 17, figs. 5, 6, 8, 9 sp. 246 ; PI. 45, fig. 13 Proetidellinae 124, 243 Proetus 231 asellus 245 decorus 126 girvanensis 126 ovatus 245 sp. 246 Progalago 19, 21-23, 34 dorae 2 1 sp. 22* Progonophlebia 162 Promi croceras planicosta 155 Pronycticebus 3, 4, 12-15, 17-23, 33, 34 gaudryi 14, 16*, 17, 33 Prophalangopsidae 155, 158, 165, 166 Prophalangopsis 166 Prosimii 27, 31 Prosobranchia 180 Protoadapis 3, 6, 7, 8, 9, 10, 12, 13, 14, 15, 19, 21, 29-34 angustidens ii*, 12, 33 brachyrhynchus ii, 33 copei 9 curvicuspidens 10, ii*, 12, 13, 33 eppsi 3, 5, 8, 10, 32 klatti 12, 13, 29, 30, 33 ; Pis. 2, 3 recticuspidens 10, 33 Protohagla 165, 166 langi 158, 165, 166 ; PI. 26 Psalixylon 208 Pseudoloris 32 abderhaldini 32 parvulus 32 Pseudomelaniidae 194 Pseudospkaerexochus86, 130 octolobatus 87, 88 ; PI. 10, figs. 7, 9-12 Pseudotoma 262, 289 Pseudotominae 263 Pteronemobius 158 Pterygometopidae 98 Pterygometopinae 98 Pterygometopus 100 grayae 113 jukesi 101-103 306 INDEX Pterygometopus — conid. pander i 103 sclerops 103 sp. 97 trigonocephala 103 Pugilina 261, 267 Punctatisporites 150 debilis 144 minutus 143, 144 ; PI. 21, figs. 32-37 spp. 144 ; PI. 21, fig. 43 subobesus 144 ; PI. 21, figs 38-42 Pyrula 259, 267 Pyrulidae 259, 267 Raphiophoridae 72 Reacalymene 112, 219, 220 croneisi 223 holtedahli 226 horderleyensis 221, 223 ; PI. 37, figs. 2, 8 ; PI. 40, figs. 7, 8 limba 113, 220, 221 ; PI. 37, fig. 16 pusulosa 112, 113, 220, 221, 223 ; PI. 37, figs. 9, II, 12 Sp. 221 Remopleurella 215, 249, 250, 251 burmeisteri 250, 251 ; PI. 45, fig. 2 ; PI. 46, figs. 6, 8, 9, ii, 12 Remopleurides 104, 115, 127, 129, 246 biaculeatus 127 burmeisteri 128 colbii 127, 128, 246, 249 dalecarlicus 246 latus 248 var. granensis 248 kullsbergensis 128, 248, 249 onniensis 247, 248, 249 ; PI. 46, figs. 4, 5 radians 220, 251 spp. 127, 128, 246, 248 ; PL 18, figs. 5-13 ; PL 46, figs. 3, 7 validus 128, 248 warburgae 246, 247, 248 ; PL 46, figs, i, 2 wimani 248 Remopleurididae 127, 246 Remysporites 149, 150 drybrookensis 148 ; PL 23, figs. 76-81 sp. 149 ; PL 23, fig. 82 Reticulatisporites 147, 150 Reuschella sp. 77 Reuscholithus reuschi Zone 217, 226, 231, 238, 245 Rhacopteris geikiei 141 petiolata 141 Rhodea 141 Rhynchonella 39 antidichotoma 47 bertheloti 60 cantabrigensis 42, 60, 61 compressa 51 depressa 50, 55 difformis 51, 53 elegans 61 Rhynchonella — contd. gibsiana 60 globata 53 /ate 56 latissima 45 leightonensis 42, 59—61 lineolata var. mirabilis 47, 48 nuciformis 41 schloenbachi 55 tripartita 60 vespertilio 61 Rhynchonellacea 43 Rhynchonellidae 39, 43 Rhynchota 158 Robergiella 250 sagittalis 250 Saccoloma elegans 205 Saltatoria 158 Ensifera 166 Sampo 248 Scutellocladus 138 variabilis 137, 138, 139 ; PL 19, figs. 1-6 Sechuritella 1 79 Sedgwick Museum, Cambridge 45, 56, 61, 69, 80, 81, loi, 107, 121-123, I75> ^5, 188, 191, 193 Semifusus 259, 260, 265, 267 Sespedectes 25 Shrewsbury Museum 221 Sigmesalia 189 SIMONS, E. L. 1-36 Smilodectes 15, 17 SMITH, E. P. 294 Sowerbyella 115 Spathulopteris 141 Sphaerexochus hemicranium 86 Sphenopteridium 141 Sphenopteris 141 affinis 143 bifidum 143 cuneolata 142 ; PL 21, fig. 21 obfalcata 141 ; PL 20, figs. 16, 17 Sporae dispersae 143 Staurocephalus 71, 123 Stenopareia 120, 234 camladica 120, 234 sp. i 20 Stigmaria 140 ; PL 19, fig. 7 Stolmorhynchia 43 Sulcirhynchia 43, 59-61 Sulcus 42 Surcula 262, 264, 268, 279, 291 ingens 266 Surculites 257, 262, 264, 266, 267, 273, 279, 280, 289, 291 biluminatus 262 Tanganyika 199 Tarsiidae 24, 31 Tarsiiformes 5 INDEX 307 Tarsius 5, 17, 19, 23, 29 Tarsophlebia 161 Teilhardina 4, 7, 24, 32 belgica 4, 32 Telangium 143 sp. 142, 143 ; PI. 21, figs. 23-26 Tenebrio molitor 169 Terebratula antidichotoma 47 compressa 54 deformis 51 depressa 50 difformis 5 1 dilatata 53 dimidiata 51-53 gallina 5 1 /a/a 39, 45 latissima 39, 40, 43, 45 scaldisensis 57 Tetonius 7, 24, 27 Tetralichas melmerbiensis 120 Tettigonia 166 viridissima 165 Tettigoniidae 166 Thatcheria 257, 258, 259, 283, 292 carinata 283-286, 292, 293 gradata 258, 268, 276, 280, 281, 292, 294 liratula 282, 285, 290, 292-294 mirabilis 257, 258, 260, 264-267, 268, 269-272 275*, 276, 280, 281, 283, 284, 286, 288-290, 292-294 pagodula 282-286, 292, 293 vitiensis 257, 281-283, 285, 292, 294 ; PI. 47, figs. 4-6 Thatcheriidae 261, 265, 267, 268, 277, 290 Thatcheriinae 257, 267, 290, 291 Thysanopeltidae 251 Toernquistia 118, 119, 129 nicholsoni 118, 119 reedi 118, 119 ; PI. 16, figs. 2, 3 translata 119 Tomiodendron ostrogianum 139 Torquesia 179, 182, 184, 187 faizai 175, 177, 178, 181*, 188 ; PI. 30, fig. 15 granulata 177-179, 181*, 182, 183, 189-191 ; PL 30, figs. 10-14 granulosa 184 hassani 175, 177, 178, 181*, 188, 189 ; PI. 28, fig. 2 ; PI. 29, fig. 9 tamra 175, 177, 178, 181*, 185 ; PI. 28, fig. i vibrayeana 177, 178, 181*, 185-i87 ; PI. 31, figs. 17-22 wagihi 175, 177, 178, 181*, 187 ; PI. 29, fig. 6 Tretaspidinae 85 Tretaspis 85, 130, 248 ceriodes 85 donsi 85 ; PI. 10, figs. 4, 6, 8 convergens 85 ; PI. 10, figs, i, 3, 5 granulata 220 kiaeri duftonensis 86 ; PI. 9, figs, i, 5, 7 radialis 86 ; PI. 9, figs. 2-4 Tretaspis — contd seticornis 85 var. anderssoni 85 Triarthrinae 241 Triarthrus 241 becki 241 linnarssoni 241, 242 ; PI. 44, figs. 2, 5, 10, 12 sp. 241 Trichoptera 156 Tridactylidae 158 Trinucleidae 69, 79, 129 Trinucleus bucklandi 220 gibbifrons 79 goldfussi 79 nicholsoni 69, 79 ornatus 220 seticornis 79 Trochurus nodulosus 235 Tropaeum subarcticum 46 Tubicaulis 201 africanus 199, 200*, 201, 202*, 204*, 205*, 207-209 ; Pis. 33-36 berthieri 203, 206, 208 multiscalanformis 207, 208 scandens 206—209 solenites 201, 206—209 steward 207, 208 sutcliffii 207, 208 Turbinellidae 259 Turbo quadricarinatus 191 terebra 180 Turricula 262, 289, 291 javana 260 waitaraensis 260, 264 Turridae 257, 260, 261, 263-267, 277, 278, 288, 290, 291 Turritella 178, 180 ageri 175, 177, 178, 181*, 190, 191 ; PL 32, fig- 25 cenomanensis 191 dzWeyi 177, 178, 180, 181* ; PL 29, figs. 7, 8 faizai 175, 177, 178, 181*, 188 ; PL 30, fig. 15 granulata 177—179, 181*, 182, 183, 184, 189-191 ; PL 30, figs. 10-14 granulatoides 183, 184 hassani 175, 177, 178, 181*, 188, 189 ; PL 28, fig. 2 ; PL 29, fig. 9 imbricataria 184 multistriata 191 rigida 186 sherborni 175, 177, 178, 181*, 190, 191 ; PL 30, fig. 1 6 tamra 175, 177, 178, 181*, 185 ; PL 28, fig. i tolenasensis 187 turbinata 177, 178, 181*, 193, 194 ; PL 32, figs. 26, 27 unicarinata 178, 180, 181*, 182 ; PL 28, figs- 3-5 vibrayeana 177, 178, 181*, 185, 186, 187 ; PL 31, figs. 17-22 308 INDEX Turritella — contd. Wattsellahorderleyensis 121 wagihi 175, 177, 178, 181*, 187 ; PI. 29, fig. 6 WENNER-GREN FOUNDATION 34 Turritellidae 175, 179*, 180 Xancidac 259 asi ae 259 Xipheroceras dudressieri 155 Verrucostspontes sp. 146 ; PI. 22, fig. 57 257, 258, 260-262, 264, 268, 270, 275, 278-281, 288, 291, 292 Yorkshire Geological Society 69 generosa 261, 276, 280-282 Youngia trispinosa 87 liratula 257, 261, 275*, 276, 280-282, 294 pagodula 261, 280-282 Zaria 178 waitaraensis 280-282 ZEUNER, F. E. 153—171 WALTON, J. 135-152 Zeuneriasp. 166 , 7 Zonales 150 PRINTED IN GREAT BRITAIN BY ADLARD AND SON, LIMITED, BARTHOLOMEW PRESS, DORKING