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LAO Vv oN » ®¥ \s gs ~ Vi Swi | & he, \ A RAS >» Ne wh Wow’ ¥ Pa) . Bey. ~~ wr. eo - A MONOGRAPH CRETACEOUS LAMELLIBRANCHIA ENGLAND. HENRY WOODS, M.A VOL. I. ae 80! | TN (ene eas | Aetion | Museu® A LONDON: PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY 1899—1903. PRINTED BY ADLARD AND SON, LONDON AND DORKING. PALAJONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVH. LONDON: MONOGRAPH OF THE CRETACEOUS LAMELLIBRANCHIA OF ENGLAND. VOLE ORDER OF BINDING AND DATES OF PUBLICA SUED EINETOTE PAGES PLATES ISSUED IN VOI FOR YEAR General Title-page, Contents, Introduction, = 1903 and Bibliography, i—xliii 1—72 I—XIV 1899 73—112 XV—XIX 1900 113—144. XX—XXVI 1901 145—196 XXVII-XXXVIII | 1902 197—232 XXXIX—XLII | 1903 TEOINE PUBLISHED December, 1903 December, 1899 December, 1900 December, 1901 December, 1902 December, 1903 Introduction Bibliography Description of species Nuculana Nucula ... Anomia ,. Arca Barbatia Grammatodon Trigonoarca Cucullea Tsoarca Pectunculus Limopsis Trigonia Mytilus ... Modiola Crenella Lithodomus Septifer Dreissensia Myoconcha Spondylus Plicatula Pecten (Syneyclonema) ,, (Camptonectes) (Chlamys) » (Aiquipecten) » (Neithea) Velopecten Hinnites Additions and corrections ... Index CONTENTS. PAGE INTRODUCTION: Derrattep accounts of three families only of English Cretaceous Lamellibranchs have hitherto been given, namely, the Trigoniidx by Lycett, and the Nuculidee and Nuculanide by Gardner. Numerous species, however, belongmg to various families, were described and figured by J. and J. de C. Sowerby in the ‘ Mineral Conchology,’ and a few also by Parkinson im his ‘ Organic Remains of a Former World. A number of works, dealing primarily with the stratigraphy of the Cretaceous beds, also contain descriptions and illustrations of Cretaceous Lamelh- branchs from certain districts or from special horizons. One of the earliest of these is ‘The Fossils of the South Downs; or, Illustrations of the Geology of Sussex,’ by Gideon Mantell (1822), in which a number of Lamellibranchs from the Gault and Chalk of the south-east of England are described and figured; but unfortunately the figures are not very satisfactory, and in many cases the type- specimens are now missing; nevertheless, with the aid of other examples collected from the same localities, it is usually possible to discover the characters of Mantell’s species. Another early work dealing with a special district is the ‘ Illustrations of the Geology of Yorkshire,’ by John Phillips (1829), in which a few Lamellibranchs from the Speeton Clay are figured and others recorded. In ‘An Outline of the Geology of Norfolk,’ by 8S. Woodward (1833), the more important species from the Norwich Chalk are illustrated, but descriptions are not given. In Fitton’s great memoir (1836) on ‘The Strata between the Chalk and the Oxford Oolite in the south-east of England,’ many species of Lamellhbranchs, chiefly from Blackdown, are excellently figured and briefly described by J. de C. Sowerby; and most of the type-specimens are now preserved in the Bristol Museum. An account of the more important Lamellibranchs from the Lower Greensand of the Isle of Wight and of the Weald is given by Edward Forbes (1845) in a paper entitled ‘Catalogue of Lower Greensand Fossils in the Museum of the Geological Society,’ Part I. Most of the specimens therein described may still be seen in the Society’s Museum. Dealing with almost the same area as Mantell’s work is the later publication of vil CRETACEOUS LAMELLIBRANCHIA. F. Dixon on ‘The Geology and Fossils of the Tertiary and Cretaceous Forma- tions of Sussex’ (1850 or 1852). This contains excellent figures of some Chalk Lamellibranchs by J. de C. Sowerby, but the descriptions of the species are very brief, or in some cases even omitted; moreover, the type-specimens appear to have been lost, and in many instances their original locality is not stated. The latest work on the Lower Cretaceous Lamellibranchs of England is that by W. Keeping on ‘The Fossils and Paleontological Affinities of the Neocomian Deposits of Upware and Brickhill’ (1883). Most of the original specimens described in that memoir are preserved in the Cambridge Museum. A few papers have been published from time to time on the Lamellibranchs of special horizons, such as those of the Cambridge Greensand by Seeley (1861) and by Jukes-Browne (1875, 1877); those of the Farmgdon Greensand by Sharpe (1853); those of the Chalk of Cambridge by Etheridge (1881); and those of the Chalk Rock by myself (1897). Various papers dealing with Cretaceous strati- eraphy give brief notes on some of the species of Lamellibranchs. The distribution of the Cretaceous Lamellibranchs of England is indicated in many books and papers on stratigraphical and local geology. The more important of those dealing with the Lower Cretaceous deposits are :—(1i) on the Isle of Wight by Fitton (1847), and by Bristow, Reid, and Strahan (1889); (11) on the Weald by Topley (1875); (i) on Farmgdon by Phillips (1871) ; Keepimg (1882) and others; (v) on Speeton by Lamplugh The distribution of Lamellibranchs in the Gault is given in great detail by Price (1879); in the Upper Greensand of Blackdown and Haldon by Downes (1882), in that of Warminster by Jukes-Browne (1896), and in the Upper Green- sand and Chloritic Marl of Maiden Bradley by Jukes-Browne and Scanes (1901). Amongst the more important works dealing with the zonal distribution in the Chalk are those by Barrois (1876), Meyer (1874), Jukes-Browne and Hill (1886-96), Griffith (1891), and Rowe (1900, 1901, 1903). The distribution of Cretaceous Lamellibranchs in different districts is also iv) on Lincolnshire by 1889, 1896). — indicated in numerous memoirs issued by the Geological Survey other than those above referred to; and revised lists showing the general distribution of the species in the Upper Cretaceous rocks are given in the memoir on ‘ The Cretaceous Rocks of Britain,’ by Jukes-Browne, vol. 1, 1900, pp. 453—487, and vol. i (in the press). The following monograph deals with the Lamellibranchs of all the Cretaceous deposits of England, with the exception of the Wealden formation, which, it is thought, will be more satisfactorily studied in connection with Mollusca of the Purbeck Beds. The species found in the lowest part of the Speeton Series in Lincolnshire and Yorkshire are, as a matter of convenience, included in this work, although they may possibly prove to be of Upper Jurassic age. The families are here considered generally in the order given in Pelseneer’s classification. INTRODUCTION. ix Some of the disadvantages of taking such a great range of formations are obvious. For example, it is almost impossible to collect personally from such an extensive series of beds, or to become sufficiently familiar with their stratigraphical details and foreign equivalents. The first of these objections is to a large extent removed by the magnificent collections which have been made by many enthusiastic and careful workers in the Cretaceous rocks. Some of these collections are still in private hands; many are now preserved in private museums; but all have been placed freely at my disposal. Although works dealing with the fossils of limited horizons are often of great service to stratigraphical geologists and collectors, yet, from a paleontological standpoint, such works are apt to be somewhat unsatisfactory, since, owing to the want of sufficient material for comparison from other horizons, the importance of slight differences is hable to be overrated, and a proper idea of the variability of the species can scarcely be obtained. Further, some of the differences between forms from different beds and successive horizons are found to be due merely to dissimilar preservation, or are connected, just as is the case at the present day, with the varying conditions under which the forms lived. Moreover, the knowledge of a genus obtained from the study of a number of species from various horizons is obviously much more thorough than when only a few forms from one horizon are being considered. From a biological standpomt the most satisfactory method would be to study a small group, such as a genus or family, and trace it through all formations from its earhest appearance to the present day or to the period of its extinction; and further, not to limit oneself, as is usually done, to a single country, but to study the representatives found in all parts of the world. The difficulties of obtaining specimens and of undertaking such extensive travel as that method of work would involve are very great; but quite as great, in the case of Lamellibranchs, is the difficulty of becoming familiar with the enormous literature which exists on this group of molluscs from every geological system. Consequently this method can scarcely be attempted until monographs on the Lamellibranchs found in all the geological systems of most countries have appeared. Moreover, such monographs are urgently needed in stratigraphical investigations. So that, great as is the labour involved in the preparation of a monograph on the Lamellibranchs of any geological system, it can scarcely be regarded as more than a necessary preliminary to the work which will be carried out in the future on many interesting problems in phylogeny and stratigraphy. Amongst the collections which have been studied in the course of this work are those in the British Museum, the Museum of Practical Geology, and the Geological Society of London; the Museums of Bath, Bristol, Brighton, Cambridge, Exeter, Norwich, and York. In all cases help has been freely given by those b x CRETACEOUS LAMELLIBRANCHIA. officially connected with the institutions named, and in this respect I desire to express my sincere thanks to Mr. H. A. Allen, Mr. H. Bolton, Mr. W. Rupert Jones, Mr. F. Leney, Mr. E. T. Newton, Mr. R. B. Newton, Mr. H. M. Platnauer, Mr. F. R. Rowley, and Dr. A. Smith Woodward. Iam also greatly indebted to several geologists for the loan of specimens from their collections, especially to Dr. H. P. Blackmore, Mr. R. M. Brydone, Mr. G. E. Dibley, Mr. R. Fortin, My. C. Griffith, Mr. A. de Grossouvre, Professor E. Holzapfel, Mr. A. J. Jukes-Browne, Mr. G. W. Lamplugh, Mr. J. P. J. Ravn, Mr. C. Reid, Dr. A. W. Rowe, Mr. J. Scanes, Mr. J. W. Stather, Mr. J. F. Walker, and Dr. A. Wollemann. I must likewise thank Mr. Jukes-Browne and Dr. F. L. Kitchin for thei kindness im reading the proofs and for other valuable assistance, whilst in bibliographical difficulties I owe much to the ever-ready help and unrivalled knowledge of Mr. C. Davies Sherborn. A portion of the travelling expenses involved in the preparation of this work and a part of the cost of the drawings have been defrayed from two grants made to me by the Government Grant Committee of the Royal Society. Every facility for carrying on this work in the Woodwardian Museum has been given me by Professor T. MeKenny Hughes, whose kindness I gladly take this opportunity of eratefully acknowledging. BIBLIOGRAPHY OF THE CRETACEOUS LAMELLIBRANCHIA. [This Bibliography does not include Stratigraphical Memoirs which give only lists of Cretaceous Lamellibranchs. | Acassiz, L. Ktudes critiques sur les Mollusques fossiles. Neuchatel, 1840-45. Part I, 1840; Part II, 1842; Part III, 1842; Part IV, 1845. Avessanpri, G. dE. Fossili cretacei della Lombardia. Paleont. Ital., vol. iv (1898), p- 169. [Lamellibranchs, pp. 180—189, 191—200. | — Nuovi Fossili de Senoniano Lombardo. Rendiconti R. Inst. Lombardo di Sci. e Lett., ser. 2, vol. xxxiv (1901), p. 183. [Lamellibranchs, pp. 192—197. | Arn, A. Geognostisch-palaeontologische Beschreibung der niichsten Umgebung von Lemberg. Huaidinger’s Naturwiss. Abhandl., vol. in, pt. 11 (1850), p. 171. [Lamellibranchs, pp. 227—255. | Antiuna, D. J. Ueber die Kreidefossilien des Kaukasus, mit emem allgemeinen Uberblick iiber die Entwicklung der Sedimentirbildungen des Kaukasus. Beitr. z. Paldont. u. Geol. Osterr.-Ungarns wu. d. Orients, vol. xii, pts. 2, 3, Vienna (1899), p. 55. [Lamellibranchs, pp. 71—91.] — On the Middle Neocomian of Tzernovatz. Ann. géol. Pénin. Balkan, vol. vi (1903), p. 6. [Lamellibranchs, pp. 54—62. | Arcurac, A. dD’. Mémoire sur la Formation Crétacé du sud-ouest de la France. Mém. Soc. géol. de France, vol. ii (1837), p. 157. [Lamellibranchs, pp. 181—189. ] — Rapport sur les Fossiles du Tourtia. Jbid., ser. 2, vol. 11 (1847), p. 291. | Lamellibranchs, pp. 300—313. | — Coupe eéologique des environs des Bais de Rennes (Aude), suivie de la Lair pete) | ae ? x description de quelques fossiles dé cette localité. Bull. Soc. géol. de France, ser. 2, vol. xi (1854), p. 185. [Lamellibranchs, pp. 208—216. | Arnaup, H. Position des Hippurites dilatatus et Hippurites bioculatus dans la série crétacée. Bull. Soc. géol. de France, ser. 3, vol. xu (1883), p. 138. Batty, W.H. Descriptions of some Cretaceous Fossils from South Africa. Quart. Journ. Geol. Soe., vol. xi (1855), p. 454. [ Lamellibranchs, pp. 460—465. | xi BIBLIOGRAPHY OF THE Barros, C. Mémoire sur le Terrain Crétacé des Ardennes et des Régions voisines. Annal. Soe. qéol. dw Nord, vol. v (1878), p. 227. [| Lamellibranchs, pp. 390, 391, 405—408, 419, 420, 474—479. ] —— Sur quelques especes nouvelles ou peu connues du Terrain Crétacé du Nord de la France. Ibid., vol. vi (1879), p. 449. [Lamellibranchs, pp. 452—456. | Baye, E. Observations sur la structure des coquilles de Hippurites, suivies de quelques remarques sur les Radiolites. Bull. Soe. géol. de France, ser. 2, vol. xii (1855), p. 772. —— Observations sur le Radiolites Jouanneti. Ibid., ser. 2, vol. xii (1855), p. 102. _—_ Observations sur le Radiolites cornu-pastoris. Ibid., ser. 2, vol. xin (1855), palag: —— Observations sur le Spherulites foliaceus. Ibid., ser. 2, vol. xin (1859), joe (ls ___ Nouvelles observations sur quelques espéces de Rudistes. Ibid., ser. 2 vol. xiv (1857), p. 647. — Sur les Rudistes découverts dans la craie de Maéstricht. Ilid., ser. 2 vol. xv (1858), p. 210, pl. im. __ Explication de la carte eéologique de France. Vol. iv, Atlas, pt. 1. Fossiles . . =) . — . = a . 2 eee principaux des Terrains. Paris, 1878. [Lamellibranchs, pls. e1i— exlviii. | —— and Coguann, H. Mémoire sur les fossiles secondaires recueillis dans le Chili. Mém. Soc. géol. de France, ser. 2, vol. iv (1851), p. 1. [Lamelli- branchs, pp. 37, 38. | Beurenvsen, O. Zur Geologie des Ostabhanges der argentinischen Cordillere. Zeitschr. d. deutsch. geol. Gesellsch., vol. xhu (1891), p. 369. [Lamelh- branchs, pp. 417—419. | Beuruns, G. Ueber die Kreideablagerungen auf der Insel Wollin. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxx (1878), p. 229. [Lamellibranchs, pp. 256—260. | Buainvinir, H. M.D. pe. Manuel de Malacologie et de Conchyliologie. Text 1825. Plates 1827. Paris. [Lamellibranchs, pp. 508—481. ] ——— Dictionnaire des Sciences naturelles. Planches. Conchyliologie et Malacologie. Paris, 1816-30. BuancKennorn, M. Beitriige zur Geologie Syriens: Die Entwickelung des Kreide- systems in Mittel- und Nord-Syrien. Eime geognostisch-paliiontologische Monographie. Cassel, 1890. [Lamellibranchs, pp. 71—97. | Boru, G. Beitriige zur Kenntniss der Hilsmulde. Zeitschir. d. deutsch. geol. Gesellsch., vol. xxix (1877), p. 215. [Lamellibranchs, pp. 281—242. ] —— Ooralliochama. Zeitschr. d. deutsch. geol. Gesellsch., vol. xliv (1892), p. 560. —— Ueber Cornucaprina. Neues Jahrb. fiir Min., etc. (1893), vol. u, p. 129. CRETACEOUS LAMELLIBRANCHIA. XU Boru, G. Beitrag zur Kenntniss der Kreide in den Sudalpen. Paleontographica. vol. xli (1895), p. 81. [Lamellibranchs, pp. 96—132, 137—142. | —— Beitrag zur Gliederune der Kreide in den Venetianer Alpen. Zeitschr. d deutsch. geol. Gesellsch., vol. xlix (1897), p. 160. [Lamellibranchs, pp- 172—178. | Ueber Caprinidenkalke aus Mexico. Ibid., vol. 1 (1898), p. 323. [Lamelli- branchs, pp. 324—330. | —— Beitrige zur aa mexicanischer Capridenkalke. an und Lenk’ s Beitr. 2. Geol. uw. Pal. d. Republ. Mexico, pt. 2 (1899), . 148. { Lamelli- branchs, pp. 161 51.] Boum, J. Der Griinsand von Aachen und seine Mollusken-Fauna. ee des naturhist. Vereines der preussisch. Rheinl., vol. xlii (1885), p. 1. [Lamelh- branchs, pp. 75—147. | —— Die Kreidebildungen des Fiirberes und Sulzbergs bei Siegsdorf in Ober- bayern. Palxontographica, vol. xxxviii (1891), Dek. | Lamellibranchs, pp. 70—93. | —— Ueber cretaceische Gastropoden vom ea und vom Karmel. Zeitsehi. 1. deutsch. geol. Gesellsch., vol. lii (1900), p. 189. [Lamelhibranchs, p. 218. | Boristax, A. Sur les Aucelles du Crétacé eae de la Crimée. Bull. Coii. géol. St. Pétersbourg, vol. xx (1901), p. 275 Bosquet, J. Fossiele Fauna en Flora van het Krijt van Limburg. In W. Carre Staring’ s Natuurlijke Historie van Nederland. De Bodem van Nederland, vol. ii (1860). Haarlem. [Lamellibranchs, pp. 8376—388. | Bourz, M. Note sur les Fossiles rapportés de Madagascar par M. KE. Gautier. Bull. Mus. @ Hist. nat., vol. 1 (1895), p. 181. -[ Lamellibranchs, pp. 182, 185, 186. ] Boyiz, C. B. A Catalogue eae Bibliography of North American Mesozoic Inverte- brata. Bull. U.S. Geol. Survey, Washington, No. 102 (1893). Part I, Bibliography ; ae II, Alphabetical List of Species. Brauns, D. Die senonen Mergel des Salzberges bei Quedlinburg und ihre orga- nischen Einschiliisse. Voit if dle gesainnt. Naturwissensch., vol. xlvi (1876), p. 325. [Lamellibranchs, pp. 357—395. | , Buiarr, A., and Cornet, F. L. Description minéralogique, géologique, et paléonto- logique de la Meule de Bracquegmes. Mém. couron. et Meém. des savaits étrang. Acad. Roy. Belg., vol. xxxiv (1868). [Lamellibranchs, pp. 45—8+4. | Brom, F. Ueber die Fauna der Orbitolinen fithrenden Schichten der untersten Kreide in der Krim. | 2) Vol. i. Espéces nouvelles ou peu connues. Ser. 3. Mollusques du Séno- nien & facies fluvio-marin. [Lamellibranchs, pp. 96—104.] Ser. 4 Hspéces diverses. [Lamellibranchs, pp. 1832—168.] 1901-2 Cottor, L. Description du Terrain crétacé dans une partie de la Basse-Provence. Bull. Soc. géol. de France, ser. 3, vol. xviii (1890), p. 49. [Brief Notes on Lamellibranchs, pp. 60, 61, 100—102. } —— Sur les Trigonies byssiféres. Jbid., ser. 3, vol. xxvii (1899), p. 224. Conrad, T. A. Notes on Shells, with descriptions of New Species. Proc. Acad. Nat. Set. Philad., vol. vi (1852), p. 199. [Lamellibranchs, p. 200.] son Shells. Jbid., p. 320. —— Descriptions of New Fossil eae of the United States. Journ. Acad. Nat. Sci. Philad., ser. 2, vol. ii, pt. 3 (1853), pp. 273—276. Ibid., pt. 4 (1854), pp. 299, 300. CRETACEOUS LAMELLIBRANCHIA. XV Conran, T. A. Descriptions of Eighteen New Cretaceous and Tertiary Fossils, ete. Proc. Acad. Nat. Sci. Philad., vol. vii (1855), p. 265. [Lamellibranchs, p- 266. ] —— Descriptions of One Tertiary and Eight New Cretaceous Fossils from Texas. Ihid., p. 268. —— Descriptions of Cretaceous and Tertiary Fossils. ep. U. S. and Mexican Boundary Survey, vol. i, pt. 2 (1857), p. 141. {Lamellibranchs, pp. 147 —157. —— Observations on a Group of Cretaceous Fossil Shells found in Tippah County, Miss., with descriptions of fifty-six new species. Journ. Acad. Nat. Sci. Philad., ser. 2, vol. iii (1858), p. 823. [Lamellibranchs, pp. 324—330. | —— Description of New Species of Cretaceous and Eocene Fossils of Mississippi and Alabama. Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. iv, pt. 11 (1860), p. 275. [Lamellibranchs, pp. 276—283. | ~ Descriptions of New Species of Cretaceous Fossils. [bid., p. 299. [Lamelh- branchs, pp. 302—305. | —— Descriptions of New Species of Tertiary, Cretaceous, and Recent Shells. American Journ. Conch., vol. 1 (1866), pp. 104, 105. —— Descriptions of and References to Miocene Shells of the Atlantic Slope, and descriptions of two new supposed Cretaceous species. Ibid., vol. iv (1868), p. 278. —— Descriptions of New Fossil Mollusca, principally Cretaceous. Lbid., vol. v (1870), pp. 96—105. —— Descriptions of New Genera and Species of Fossil Shells of North Carolina in the State Cabinet at Raleigh. Appendix to W. C. Keri’s Report Geol. Surv. N. Carolina, vol. i (1875), Raleigh. {Lamelhbranchs, pp. 2—11. | —— Synopsis of the Cretaceous Mollusca of North Carolina. [bid., p. 13. [Lamellibranchs, pp. 13—16. | Coorer, J. G. On some New Cretaceous (and Eocene ?) Mollusca of California. Proc. Californ. Acad. Sei., ser. 2, vol. vi (1896), p. 3380, pls. xlvii, xlvini. Coquann, H. Notice sur les richesses paléontologiques de la province de Con- stantine. Journ. de Conchyl., vol. tii (1852), p. 418. [Lamellibranchs, pp. 433, 434. | —— Synopsis des animaux et des végétaux fossiles observés dans la formation erétacée du sud-ouest de la France. Bull. Soc. géol. de France, ser. 2, vol. xvi (1859), p. 945. [Lamellibranchs, pp. 957—962, 969, 970, 975, 976, 982—985, 909—1008, 1017, 1018. } — Description physique, eéologique, paléontologique, et minéralogique du départe- ment de la Charente, 2 vols. Vol. I. Besancon, 1858. Vol. II. Marseille, 1860. [Lamellibranchs, vol. ii, pp. 102—109, 119—121, 123—125, 128—131, 140—145, 164—177. — Géologie et Paléontologie de la Région sud de la Province de Constantine. With Atlas, 1862. [Lamellibranchs, pp. 189—235, pls. vi—xxiii. | XvV1 BIBLIOGRAPHY OF THE Coauanp, H. Monographie de P’Etage Aptien de Espagne. Marseille, 1865. [Lamellibranchs, pp. 87—170. | —— Monographie du genre Ostrea. Marseille, 1869. Corrrau, G. Etudes sur les Mollusques Fossiles du département delYonne. Bull. Soc. Sci. Yonne, vols. vi—xi, 1852-57. [Lamelhibranchs (in vol. ix), pp. 48—124, 1855. ] Craciy, F. W. Contributions to the Paleontology of the Plains, No. 1. Ball: Washburn Coll. Lab., vol. ii, No. 10 (1889), p. 65. [| Lamellibranchs, pp. 67, 68. | Crepner, H. Die Kreide von New Jersey. Zeitschr. d. deutsch. geol. Gesellsch., vol. xx (1870), p. LOL. [ Lamellibranchs, pp. 225—237. | Cuvier, G., and A. Broneniart. Description géologique des couches des environs de Paris, ete., in Cuvirr, Recherches sur les Ossemens Fossiles, vol. u, pt. 2 (June, 1822). Paris. [Lamellibranchs, pp. 597—604, 608, 609. ] Dainenit, G. Appunti geologici sulla parte meridionale de Capo di Leuca. Boll. Soe. geol. Italiana, vol. Xx (1901), p. 616. | Lamellibranchs, pp. 642—651. | Daintree, R., see R. Eruertpce. Dames, W. Ueber Ptychomya. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxv (1873), p. 374. —— Ueber Diluvialgeschiebe cenomanen Alters. /bid., vol. xxvi (1874), p. 76. [| Lamellibranchs, pp. 762-6. Derrance, M. J. L. Dictionnaire des Sciences naturelles . . . par plusieurs Professeurs du Jardin du Roi, et des principales Ecoles de Paris. Strasbourg and Paris, 61 vols., 1816-45. Dricke, H. Beitrage zur geognostischen und paliiontologischen Beschaffenheit der unteren Ruhrgesend. Erster Beitrag: Die Tourtia in der Umgegend von Miitlheim a. d. Ruhr (Beilage zum 23 Jahresberichte der Realschule I. Ordnung zu Miilheim an dev Ruhr), 1876. | Lamellibranchs, pp. 25— 29. ] Drsnayrs, G. P. Traité Elémentaire | co Conchyliologie, avec les Applications de cette science ala Geologie. 2 vols. Paris, 1839-53. ——"and Mitne-Epwarps, H., see Lamarcr. Dierutarair, L. = Position de VP Ostrea Couloni dans le Néocomien du sud-est de la France. Bull. Soc. géol. de France, ser. 2, vol. xxvii (1870), p. 431. Dixon, F., see J. pk C. SowErsy. Doncrnux, L. Monographie eéologique et ee ee des Corbiéres Orientales. ‘Annal. de P Univers. de Lyon, n. 8., fascic. 11 (1903). [Lamellibranchs, pp. 307—310. | Dovuvittk, H. Essai sur la Morphologie des Rudistes. Bull. Soc. géol. de France, ser. 3, vol. xiv (1886), p. 389. CRETACEOUS LAMELLIBRANCHIA. xvi Dovvit.t, H. Sur quelques formes peu connues de la famille des Chamide. Ibid., ser. 3, vol. xv (1887), p. 756. —— Etudes sur les Caprines. Jbid., ser. 3, vol. xvi (1888), p. 699, —— Sur quelques Rudistes du terrain erétacé inférieur de Pyrénées. Ibid., ser. 3, vol. xvii (1889), p. 627. —— Etudes sur les Rudistes. Révision des principales esptces d’Hippurites. Mém. Soe. géol. de France, Paléont., vol. i, no. 6 (1890), pls. xv—xvii. —— Sur les caractéres internes des Sauvagesia. Bull. Soc. géol. de France, ser. 3, vol, sax (1891),;p. 669. —— Etudes sur les Rudistes. V. Sur les Rudistes du Gault supérieur du Portugal. Jbid., ser. 3, vol. xxvi (1898), p. 140. 5 ’ > | —— Sur les Couches a Rudistes du Texas. Jbid., ser. 3, vol. xxvi (1898), p. 387. —— Sur quelques Rudistes américains. /bid., ser. 3, vol. xxviii (1900), p. 205. — Sur la distribution géographique des Rudistes, des Orbitolines et des Orbi- toides. Ibid. (1900), p. 222. —— Classification des Radiolites. Ibid., ser. 4, vol. 11 (1902), p. 461, pl. xv. —— Sur un nouveau genre de Radiolites. Ibid. (1902), p. 478, pl. xv. —— Sur le genre Chondrodonta, Stanton. Ibid. (1902), p. 314 Drescuer, R. Ueber die Kreide-Bildungen der Gegend von Lowenberg. Zeitschr. d. deutsch. geol. Gesellsch., vol. XV (1863), p- 291. [Lamellibranchs, pp. 341—357. | Drovet, C. Sur un nouveau genre de coquille [ Neithea] de la famille des Arcacées, et description d’une nouy a eu de Modiole fossile. Mém. Soc. Linn. de Paris, vol. i (1824), p. 183, pl. vii. Dusarpiy, F. Mémoire sur les couches du Sol en Touraine, et description des coquilles de la Craie des Faluns. Mém. Soe. géol. de France, vol. i (1837), p. 211. [Lamellibranchs, pp. 223—230. | Kicuwatp, E. v. Ueber die Neocomschichten Russlands. JZeitschi. d. deutsch. geol. Gesellsch., vol. xviii (1866), p. 245. [Lamellibranchs, pp. 259—263, 270 — 273: ] — Lethxa Rossica ou Paléontologie de la Russie. Vol. ii (Période moyenne). With Atlas. Stuttgart, 1866-9 (pp. 1—224, 1866; 225—832, 1868; 833 —1304, 1869). [Lamellibranchs, pp. 355—797. | Kirert, J. Das untere Angoumien in den Osningbergketten des Teutoburger Waldes. Verh. nat. Ver. d. preussisch. Rheinl., etc., vol. viii (1902), p- 77. [Lamellibranchs, pp. 108—112. ] Krueripce, R. Description of the Paleozoic and Mesozoic Fossils of Queensland. [ Appendix I to ht. Daintree’s Notes on the Geology of the Colony of Queensland.| Quart. Journ. Geol. Soc., vol. xxviii (1872), p. 317. [ Lamellibranchs, pp. 338—34. | xvii BIBLIOGRAPHY OF THE Erseripce, R. In Penninc, W. H., and Juxes-Browne, A. J. The Geology of the Neighbourhood of Cambridge. With a Palzontological Appendix by R. Etheridge. Mem. Geol. Survey, 1881. [Lamellibranchs, pp. 141— 147. ] Hraeriper, R., jun. A Catalogue of Australian Fossils (including Tasmania and the Island of Timor). “Cambr idge, 1878. [Lamellibranchs, pp. 106—113. ] — The Cretaceous Mollusca of South Australia and the Northern Territory. Mem. Roy. Soc. South Australia, vol. ii, pt. i (1902). [Lamellibranchs, pp. 8—39. ] ———— See JACK, Iv. Ju: Eupes-Drstonascuames, J. A. Essai sur les Plicatules fossiles des Terrains du Calvados, et sur quelques autres genres voisins ou démembrés de ces coquilles. Mém. Soc. Linn. de Normand., vol. xi (1858), p. 1. Evans, J., and Saumarp, B. F. On some New Species of Fossils from the Cretaceous Formation of Nebraska Territory. Trans. Acad. Sci. St. Louis, vol. i (1857), p. 38. [Lamellibranchs, pp. 38—40. ] Ewatp, J. Ueber die Grenze zwischen Neocomien und Gault. Zeitschr. d. deutsch. geol. Gesellsch., vol. 11 (1850), p. 440, [Lamellibranchs, pp. 469-71. | —— Heogyra columba. Ibid., vol. ix (1857), p. 12. — Ueber die Fossile Fauna des unteren Gault bei Ahaus in Westphalen. Monatsberichte d. k. preuss. Ahad. d. Wissensch. zw Berlin, 1860 (1861), p. 332. [Lamellibranchs, pp. 344—346. | Fausas-Saint-Fonp, B. Histoire naturelle de la Montagne de Saint-Pierre de Maestricht. Paris, 1779. Favre, E. Description des Mollusques fossiles de la Craie des Environs de Lem- berg en Galicie. Genéve et Bale, 1869. [Lamellibranchs, pp. 102—163. | Fenix, J. Verstemerungen aus der mexicanischen Jura- und Kreide-Formation. Paleontographica, vol. xxxvii (1891). Usual sieeiaelns, pp. 165—168. ] Also published in Felix and Lenk’s Beitr. z. Geol. u. Pal. Republ. d. Mevico, pt. 3 (1891), p. 140. Firron, W. H., see J. pg C. SowERBY. Forbes, KE. Report on the Fossils from Santa Fé de Bogota, presented to the Geological Society by Evan Hopkins. Quart. Journ. Geol. Soc., vol. i (1845), p. 174. [Lamellibranchs, p. 179. ] —— On the Fossil Shells collected by Mr. Lyell from the Cretaceous Formations of New Jersey. Jbid., vol. i (1845), p. 61. —— Catalogue of Lower Greensand Fossils in the Museum of the Deelnical Society. Part I. Acephala Lamellibranchiata. Ibid., vol. i (1845), p. 237. —— Report on the Fossil Invertebrata from Southern India, collected by Mr. Kaye and Mr. Cunliffe. Trans. Geol. Soc., ser. 2, vol. vii, pt. : (1846), p. 97. [Lamellibranchs, pp. 139—157. | CRETACEOUS LAMELLIBRANCHIA. a D.< Fraas, O. Geologisches aus dem Orient. Jahresh. Ver. vat. Naturk. in Wiirtt., vol. xxiii (1867), p. 145. [Lamellibranchs, pp. 229—239. ] — Geologisches aus dem Libanon. Jbid., vol. xxxiv (1878), p. 257. { Lamelli- branchs, pp. 299—302, 326—328. | —— Aus dem Orient. I. Geologische Beobachtungen am Nil, auf der Sinai- Halbinsel und in Syrien. Stuttgart, 1867. [Lamellibranchs, pp. 86—9%5. | II. Geologische Beobachtungen am Libanon. Stuttgart, 1878. (A re- print of the two preceding papers.) ; Francuis, F. pr. Molluschi della Creta media del Lecesse. Boll. Soc. géol. Ital., vol. xxii (1903), p. 147. [Lamellibranchs, pp. 155—164. | Frecu, F. Die Verstemerungen der unter-senonen Thonlager zwischen Suderode und Quedlinburg. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxxix (1887), p. 141. [Lamellibranchs, pp. 151—174. | ——- Ueber Gervilleia. Centralbl. f. Min., etc. (1902), p. 609. Frirscu, A. Studien im Gebiete der bbhmischen Kreideformation. II. Die Weis- senberger und Malnitzer Schichten. (Archiv f. d. naturwiss. Landes- durchforschung von Béhmen (Prag), vol. iv, 1877.) [Lamellibranchs, pp. 112—143. | —— Ibid. III. Die Iserschichten. (dbid., vol. v, 1883.) [Lamellibranchs, pp. 97—122. | —— Ibid. 1V. Die Teplitzer Schichten. (Ibid., vol. vii, 1889.) [Lamellibranchs, pp. 75—87. | — Ibid. V. Priesener Schichten. (Jbid., vol. ix, 1893.) [Lamellibranchs, pp. 91—102. | —— Ibid. VI. Die Chlomeker Schichten. (Jbid., vol. x, 1897.) [ Lamellibranchs, pp- 50—68. | —— and Bayer, E. Jbid. VII. Perucer Schichten. (/bid., vol. xi, 1901.) [ Lamellibranchs, p. 165. | Forrerer, K. Die Oberen Kreidebildungen der Umgebung des Lago di Santa Croce in den Venetianer Alpen. Palxont. Abhandl., vol. vi (1892). g Aad a [Lamellibranchs, pp. 77—106. | —— Ueber einige Versteinerungen aus der Kreideformation der Karnischen Voralpen. Ibid., vol. vi (1896), pp. 10—22, 25—28. Gass, W. M. Descriptions of some New Species of Cretaceous Fossils. Journ. Acad. Nat. Sci. Philad., ser. 2, vol. iv (1860), p. 299. [Lamellibranchs, pp. 303—305. | —— Descriptions of New Species of American Tertiary and Cretaceous Fos Ibid., ser. 2, vol. iv, pt. iv (1860), p. 375. [Lamellibranchs, pp. 39 398, 403. ] —— Synopsis of the Mollusca of the Cretaceous Formation, including the Geographical and Stratigraphical Range and Synonymy. Proc. Amer. Phil. Soc., vol. viii (1861), p. 57. [Lamellibranchs, pp. 150—245. | > sils. DOE BIBLIOGRAPHY OF THE Gasp, W. M. Descriptions of New Species of Cretaceous Fossils from New Jersey, Alabama, and Mississippi. Proc. Acad. Nat. Sci. Philad., vol. v (1861) p. 318, [Lamellibranchs, pp. 3283—329. ] —— Notes on Cretaceous Fossils, with descriptions of a few additional new species. Tbid., p. 363. { Lamellibranchs, pp. 364—367. | — Geological Survey of California. Paleontology. Vol. I, sect. iv. Description of the Cretaceous Fossils (1864), p. 57. [Lamellibranchs, pp. 145—217. | Vol. II, sect. ii. Cretaceous Fossils (1869). [Lamellibranchs, pp. 175— 203, 233—253. — sect. iii. Cretaceous Fossils from Mexico (1869). [| Lamelli- branchs, pp. 265—275. | —— Notice of a Collection of Cretaceous Fossils from Chihuahua, Mexico. Proe. Acad. Nat. Sci. Philad., vol. v (1872), p. 263. [Lamellibranchs, p. 264. ] —— Notes on American Fossils, with descriptions of some new species. Ibid., vol. vi (1876), p. 276. [Lamellibranchs, pp. 304—323. ] — Description of a Collection of Fossils made by Dr. Antonio Raimondi in Peru. Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. vin, pt. 3 (1877), p- 263. [Lamellibranchs, pp. 282—298. | GaceL, C., and Kaunnowen, F. Ueber ein Vorkommen von Senonen Kreide in Ostpreussen. Jahrb. d.k. preussisch. geol. Landesanst. fiir 1899 (1900), p- 227. [Lamellibranchs, pp. 229—233. | Garpner, J. S. British Cretaceous Nuculide. Quart. Journ. Geol. Soc., vol. xl (1884), p. 120. Gaupry, A. Sur la découverte de l’Ostrea Leymerii & Wissant. Bull. Soc. géol. de France, ser. 2, vol. xvii (1860), p. 30. Getnitz, H. B. Charakteristik der Schichten und Petrefacten des siichsischen Kreidegebirges. Pt. 1. Dresden and Leipzig (1839). [Lamellibranchs, pp. 17—28. | — Ibid. Pt. 2 (1840). [Lamellibranchs, pp. 49—60. | — Charakteristik der Schichten und Petrefacten des siachsisch-béhmischen Kreidegebirges. Pt. 3. Dresden and Leipzig (1842). [| Lamellibranchs, pp. 75—85. | —— Die Versteinerungen von Kieslingswalda und Nachtrag zur Charakteristik des siichsisch-béhmischen Kreidegebirges. Dresden and Leipzig (1843). [Lamellibranchs, pp. 11—17. } —— Grundriss der Versteinerungskunde. Dresden and Leipzig, 1845-46. [Lamellibranchs, pp. 391—488. ] — Das Quadersandsteingebirge oder Kreidegebirge in Deutschland. Freiburg, 1849-50. Pp. 1—96, pls. i—vi, 1849; 97—end, pls. vii—xii, 1850. —— Das Elbthalgebirge in Sachsen. Paleontographica, vol. xx, pt. 1, pp. 169— ie (1872) ; 207—236 (1873); pt. 1, pp. 29—52 (1872); 53—72 873). CRETACEOUS LAMELLIBRANCHIA. oe Gernitz, H. B. Uber Inoceramen der Kreideformation. Neues Jahrb. fiir Min., etc. (1873), p. 7. Gernarpt, K. Beitrige zur Geologie und Paleontologie von Siidamerika. V. Beitrag zur Kenntniss der Kreideformation in Venezuela und Pern. Ibid. Beilage-Band xi (1897), pp. 96—116. VI. Beitrag zur Kenntniss der Kreideformation i in Colambien. Ibid., pp. 161—163, 175—189, 201. Ginset, C. G. Deutschlands Petrefacten. Hin systematisches Verzeichniss aller in Deutschland und der angrenzenden Liindern vorkommenden Petre- facten nebst Angabe der Synonyme und Fundorte. Leipzig, 1852. { Lamellibranchs, pp. 329 —441. | — Beitriige zur Paliiontologie. Berlin, 1853. II. Beitrag zur Paliiontologie des texanischen Kreidegebirges, p. 72. {Lamellibranchs, pp. 79—86. | (Reprinted from Jahresber. naturwiss. Vereines in Halle, vol. v.) Goutpruss, A. Petrefacta Germaniw. 3 vols. Dusseldorf, 1827-44. — [ Lamell- branchs, vol. 1, pp. 1—68 (1833); 69—140 (1836); 141—224 (1837) ; 225—312 (1840). | GossELE?, J. Esquisse géologique du Nord de la France, ete. Fase. 2, pls. xiv— xoak Ine, iste GRANGE, J. See pd’ ORBIGNY. Gras, A. Catalogue des Corps organisés fossiles dans le département de l’Isére. Bull. Soe. Statist. Iséve, ser. 2, vol. ii, 1852. [Lamellibranchs, pp. 30— 32, 33, 39, 42, 43, 44, 50. | Gray, J. E. On a Peculiar Structure in Shells; with some elerers on the Shell in Spherulites. Mag. Zool. and Bot., vol. 11 (1838), p. 228, pl. vi. GRIEPENKERL, O. Die Versteinerungen der Senonen Kreide von Kénigslutter im Herzogthum Braunschweig. Paleont. Abhandl., vol. iv (1889). [ Lamel- libranchs, pp: 33—70. | GriespacH, C. L. On the Geology of Natal in South Africa. Quart. Journ. Geol. Soc., vol. xxvii (1871), p. 53. [Lamellibranchs, pp. 65—67. | GronwaLt, K. A Sliktet Dimyodon i Danmarks krita. Meddel. fra Dansk geol. Foren., No. 6 (1900), p. 73. Grossouvre, A. DE. Sur le Terrain Crétacé dans le sud-ouest du bassin de Paris. Bull. Soe. géol. de France, ser. 3, vol. xvi (1889), p. 475. Lamelli- Y AS ’ p) i branchs, pp. 522—524, pl. xi. | Gufrancer, E. Album Paléontologique du département de la Sarthe. Le Mans. 1867. {Lamelhbranchs, pls. xv—xxv. | Guérin-Menevittz, F. EK. Iconographie du Régne Animal de Cuvier, vol. 1, pt. 3, plates xxiv—xxxiil; vol. in, Mollusques, pp. 40—52. 1829-43, Guiscarpl, G. Sur le Spherulites Tenoreana. Bull. Soc. géol. de France, ser. 2, vol. xix (1862), p. 1031. Studii sulla famiglia della Rudiste. Rendiconto d. Accad. Sct. Fis. e Math. (Soc. R. Napoli), vol. 1 (1863), p. 282. XXll BIBLIOGRAPHY OF THE Giprt, C. W. Geognostische Beschreibung der Kénigreichs Bayern, vol. Gotha (1868), pp. 764—769. Haentuin, C.v. Ueber gefurchte Cripsii-Formen in subhereynischen Untersenon. Schrift. Naturwiss. Vereins des Harzes in We ernigerode, vol. x (1895), p- 116. Hacenow, F.v. Monographie der Riigen’schen Kreide-Versteinerungen. III. Mol- haga. Neues Jahrb. fiir “‘Min., etc. (1842), p. 528. [ Lamellibranchs, 563. | Hatt, J., and Mrex, F. B. Descriptions of New Species of Fossils from the Cretaceous of Nebraska. Mem. Amer. Acad. Arts and Sci. (Camb. and Boston, 1855), p. 379. [ Lamellibranchs, pp. 3880—388. | pp. 045 Hamu, C. E. Results of an Examination of Syrian Molluscan Fossils, chiefly from Mount Lebanon. Mem. Mus. Comp. Zool., vol. x, No. 3 (1884). [Lamellibranchs, pp. 388—64. | Harris, G. D. The Lignitic Stage. I. Stratigraphy and Pelecypoda. Bull. Amer. Pal, vol. ii, No. 9 (1897). [Lamellibranchs, pp. 37—74, pls i—x1v. | Haver, F. v. Ueber Caprina Partschii eime neue Bivalve aus dem Gosauschichten der ésterreichschen Alpen. Haidinger’s Naturwiss. Abhandl., vol. 1 (1847), p. 109. Hépert, KE. Note sur les caractéres paléontologiques de la craie de Meudon. Pull. Soc. géol. de France, ser. 2, vol. xvi (1859), p. 148. [Notes on Lamelli- branchs. | — Remarques sur quelques Fossiles de la Craie du Nord de PEurope. bid., ser. 3, vol. vi (1879), p. 817. [Lamellibranchs, p. 318. | et Toucas, A. Matériaux pour servir a la description du Terrain Crétacé supérieur en France. Description du Bassin d’Uchaux. Ann. Set. géol., vol. vi (1875), No. 2. [Lamellibranchs, pp. 118—122 Huirrin, A. The Geology and Paleontology of the Cretaceous Deposits of Mexico. Proc. Acad. Nat. Sci. Philadelphia, 1890 (1891), p. 445, pls. xii—xiv. | Notes on Lamellibranchs. | Hennig, A. Om Ahussandstenen. Geol. Foren. i Stockholm Férhandl., vol. xvi (1894), p. 492. [Lamellibranchs, pp. 518—525. | — Revision af Lamellibranchiaterna i Nilsson’s “ Petrificata Suecana Forma- tionis Cretaces.” Kon. Fysiogr. Sdllsk. i Lund. Handl., N. F., vol. vin (1897). —— Faunan i Skines Ynere Krita. II. Lamellibranchiaterna. Bih. K. Svenska Vet. Akad. Handl., vol. xxiv, No. 7 (1899). Hiuter, V. Pironxa slavonica. Jahrb. d. k. k. geol. Reichsanst. (Wien), vol. li (1901), p. 169. —— Fossilen der Kainacher Gosau. Jhid., vol. li (1903), p. 277. [Lamelli- branchs, pp. 280—283. | CRETACEOUS LAMELLIBRANCHIA. XXiil Hitt, R.T. Paleontology of the Cretaceous Formations of Texas. Part I. (Univ. of Tewas School of Geol.) 1889. [Lamellibranchs, pl. 1. | —— Ibid. The Invertebrate Paleontology of the Trinity Division. Proc. Biol. Soc. Washington, vol. vin (1893 3), p. 9. [Lamellibranchs, pp. 22—32. | —— Ibid. The Invertebrate Fossils of the Caprinaw Limestone Beds. Proc. Biol. Soe. Washington, vol. viii (1893), p. 97. [Lamellibranchs, pp. 105—108. } — Geography and Geology of the Black and Grand Prairies, Texas. 21s? Ann. Rep. U. S. Geol. Suwrv., pt. vii (1901). [Lamellibranchs, Disa xx eval, xls Klivs, xiv, xvi. — and Vavenan, T. W. The Lower Cretaceous Gryphzas of the Texas Region. Bull. U. 8. Geol. Survey, No. 151 (1898), pls. i—xxx. Histncer, W. Lethza Suecica seu Petrificata Sueciz iconibus et characteribus ze F ~ i = illustrata. Holmiez, 1837. [Lamellibranchs, pp. 46—68. | Harness, R. Chondrodonta (Ostrea) Joanne, Choffat, in den Schiosischichten von Gorz, Istrien, Dalmatien, und der Hercegovina. Sitz. d. hk. Akad. d. Wissensch. Wien, Math.-nat. Cl., vol. exi (1902), p. 667. Houck, A. The Paleontology of the Cretaceous Formation on Staten Island. Trans. New York Acad. Sci., vol. xi (1892), p.96. [Lamellibranchs, pl. i.] Horzarret, E. Die Mollusken der Aachener Kreide. III. Lamellibranchiata. Palxontographica, vol. xxxv (1889), pp. 139—263. Hompres-Firmas, L. A. p’. Recueil de mémoires et d’observations de Physique, cle Vee d’ Agriculture, et d’Histoire naturelle (1838), p. 169. | Mémoire sur ‘les Hippurites et ee Sphér ulites du département du Gard. | Also Bull. Soc. géol. France, vol. ix (1838), p. 190. Hommatrre DE Heri, X., see D’ORBIGNY. Huptestoy, W. H. Notes on some Mollusca from South Australia, obtamed near Mount Hamilton and the Peak Station. (#eol. Mag. (1884), p. 339 (2 Cretaceous). [Lamellibranchs, pp. 340—342. ] —— Further Notes on some Mollusca from South Australia. bid. (1890), p. 241 (? Cretaceous). [Lamellibranchs, pp. 244—246. | Ivcetter, H. Die Kreidebildungen und ihre Fauna am Stallauer Eek und Enzenauer Kopf bei Volz. Paleontographica, vol. xlviii (1901), p. [ Lamellibranchs, pp. 30—4s8. | Jack, R. L., and R. Eraeripcr, jun. The Geology and Paleontology of Queens- > Mh) =) j land and New Guinea. Brisbane and London (1892). [Cretaceous Lamellibranchs, pp. 445—483, 561—573. | Jind, K. Beitrige zur Kenntniss der Fauna der Kreideformation von Hokkaido. Palzxont. Abhandl., vol. vi (1894), pp. 42—44. XXIV BIBLIOGRAPHY OF THE Jounson, C. W. New Cretaceous Fossils from an Artesian Well-boring at Mount Laurel, N.J. Proc. Acad. Nat. Sci. Philad., 1898 (1899), p. 461. [Lamellibranchs, p. 464. | Juxes-Brownz, A. J. On the Relations of the Cambridge Gault and Greensand. Quart. Journ. Geol. Soc. vol. xxxi (1875), p. 256. [Lamellibranchs, pp- 295—300. } —— Supplementary Notes on the Fauna of the Cambridge Greensand. Ibid., vol. xxxiii (1877), p. 485. [Lamellibranchs, pp. 500—503. | —— Ona Collection of Fossils from the Upper Greensand in the Dorset County Museum. Proc. Dorset Nat. Hist. and Antiq. Field Club, vol. xvii (1896), p. 96. [Lamellibranchs, pp. 105, 106. ] —— The Cretaceous Rocks of Britain. Vol. I. The Gault and Upper Greensand of England. (Mem. Geol. Survey, 1900.) [| Lamellibranchs, pp. 448—452. | Vol. III. The Upper Chalk (in the Press) [Lamellibranchs, pp. 448— 455, — and Hitr, W. A Delimitation of the Cenomanian; being a Comparison of the Corresponding Beds in South-western Hngland and Western France. Quart. Journ. Geol. Soc., vol. li (1896), p. 99. [Notes on Lamelhibranchs, pp. 149—155. ] —— and Minne, J. On the Cretaceous Fossils found at Moreseat, Aberdeenshire. Geol. Mag. (1898), p. 21. [Lamellibranchs, p. 29. | Karsten, H. Ueber die Geognostischen Verhiltnisse des Westlichen Columbien, der heutigen Republiken New-Granada und Equador. l I Vol. iii. Terreno Mesozoico (Creticeo inférior). Bolet. Com. Mapa geol. de Espaiia, vol. xiv (1887). [Lamellibranchs, pp. 80—141. | Mantett, G. The Fossils of the South Downs; or, [lustrations of the Geology of Sussex. London, 1822. [Lamellibranchs, pp. 73, 74, 94—96, 126—130, 201—208, 211—220. | Marti, K. Ueber das Vorkommen einer Rudisten fuehrenden Kreideformation im suedoestlichen Borneo. Sammlung. geol. Reichs-Museums in Leiden, vol. iv (1889), p. 117. xxvill BIBLIOGRAPHY OF THE Martin, K. Die Fauna der Kreideformation von Martapoera. Jbid., p. 126. { Lamellibranchs, pp. 151—178. | Marneron, P. Catalogue méthodique et descriptif des Corps organisés fossiles du Département des Bouches-du-Rhone et lieux circonvoisins. épertoire des travaue de la Soc. statist. de Marseille, vol. vi. Marseille, 1842. — Recherches paléontologiques dans le midi de la France. Marseille, 1878-S0. [ Cretaceous Lamellibranchs, pt. ii, pls. C i—iv, C viii—xiv, C xvi; pt. vi, pls. F xxu, xi xis) bs val, ole Gey) Mayer-Eymar, C. Ueber Neocomian-Verstemerungen aus dem Somaliland. Vier- teljahrschr. d. nat. Gesellsch. Zurich, vol. xxxvii (18938), p. 249. [| Lamel- libranchs, pp. 253, 254, 263. ] __— L’apparition dés le Campanien (Senonien) de Ostrea (Giryphea) angulata. Helogae geol. Helvet., vol. vi (1900), p. 121. —— Sur la distribution stratigraphique de V Ostrea (Gryphea) vesicularis. Ibid., vol. vi (1900), p. 121. Maver-Ermar, F. Systematisches Verzeichniss der Kreide- und Tertiir-Versteine- rungen der Umgegend von Thun. Beitr. %. geol. Karte der Schweiz, vol. xxiv (2) (1887). [Lamellibranchs, pp. 3—6. ] Merk, F. B. Description of New Organic Remains from the Cretaceous Rocks of Vancouver's Island. Trans. Albany Instit., vol. iv (1858), p. 37. [Lamelli- branchs, pp. 39—44. | —— Descriptions of new Fossil Remains collected in Nebraska and Utah by the Exploring Expeditions under the command of Capt. J. H. Simpson. Proc. Acad. Nat. Sci. Philad., vol. iv (1860), p. 308. [| Lamellibranchs, pp. 311, 312. ] —— Description of new Cretaceous Fossils collected by the North-Western Boundary Commission on Vancouver and Sucia Islands. Jbid., ser. 2, vol. v (1861), p. 314. [Lamellibranchs, pp. 315, 316. ] —— Check List of the Invertebrate Fossils of North America. Cretaceous and Jurassic. Smithson. Miscell. Coll., 177. Washington, 1864. [| Lamelh- branchs, pp. 5—16, 31—34. | —— Preliminary List of the Fossils collected by Dr. Hayden’s Exploring Expedi- tion of 1871 in Utah and Wyoming Territories, with descriptions of a few New Species. Hayden's Prelim. Rep. U.S. Geol. Surv. Montana, ete., 1871 (1872), p. 873. [Lamellibranchs, pp. 375, 376. ] —— A Report on the Cretaceous Fossils contained in the Collections brought from New Mexico. Rep. Luplor. Exped. from Santa Fé to the Grand and Green Rivers, etc., in 1859, under Capt. J. N. Macomb. With Geological Report by J. S. Newberry. Washington (1876), p. 121. [Lamellibranchs, pp. 123—129.] —— A Report on the Invertebrate, Cretaceous and Tertiary Fossils of the Upper Missouri Country. United States Geol. Surv. Territories, vol. ix. Washington (1876). [Lamellibranchs, pp. 10—265. | CRETACEOUS LAMELLIBRANCHIA. xx1x Merk, F. B., and Haypen, F. V. Descriptions of twenty-eight new species of Acephala and one Gasteropod, from the Cretaceous Formations of Nebraska Territory. Proc. Acad. Nut. Sci. Philad., vol. viii (1856), p. 81. Descriptions of new Fossil Species of Mollusca collected in Nebraska, ete. Ibid., p. 265. [Lamellibranchs, pp. 270—277, 283—286. | —— —— Descriptions of new species and genera of Fossils, collected by Dr. F. V. Hayden in Nebraska Territory. . . [bid., ser. 2, vol. i, 1857 (1858), p. 117. [Lamellibranchs, pp. 1 19 14:7. ] —— ——— Descriptions of new Organic Remains from the Tertiary, Cretaceous, and Jurassic Rocks of Nebraska. Jbid., ser. 2, vol. iv, 1860 (1861), p. 175. [Lamellibranchs, pp. 178—182. | — —— Synonymic Catalogue of Jurassic, Cretaceous, and Tertiary Fossils collected in Nebraska. Ibid., p. 417. [Lamellibranchs, pp. 424—429. | --— -—— Descriptions of new Cretaceous Fossils from Nebraska Territory. .. . Ibid., ser. 2, vol. vi, 1862 (1863), p. 21. [Lamellibranchs, pp. 26—28. ] Meu, R. Sulle Chamactée e sulle Rudiste del Monte Affilano presso Subiaco nel circondario di Roma. Boll. Soc. geol. Ital., vol. xx (1901), p. 149. Mercey, N. pe. Description de lInoceramus Mantelli. Mém. Soc. Linn. Nord de la France, vol. iv (1877), p. 324, pls. 1, 1. Micuagt, R. Cenoman und Turon in der Gegend von Cudowa in NSchlesien. Zeitschr, d. deutsch. geol. Gesellsch., vol. xlv (1893), p. 195. [Lamelli- branchs, pp. 232—239, 241—243. | — Ueber Kreidefossilien von der Insel Sachalin. Jahrb. d. k. preuss. geol. Landes- anst., vol. xix, 1898 (1899), p. 153. [Lamellibranchs, pp. 156—164. | Micuetin, H. Note sur un Argile dépendant du Gault observée au Gaty, Com- mune de Gérodot, Département de l’Aube. Mém. Soc. géol. de France, vol. ili (1838), p. 97. [Lamellibranchs, pp. 102, 103. | Morscu, C, Monographie der Pholadomyen. Abhandl. schweizer. paldont. Gesellsch., vol. i, 1874. [Cretaceous, pp. 82—115.] Moorr, C. Australian Mesozoic Geology and Paleontology. Quart. Journ. Geol. Soc., vol. xxvi (1870), p. 226. [Lamellibranchs, pp. 245—255. | Morickr, W. Die Gastropoden und Bivalven der Quiriquina-Schichten [in G. STEINMANN’S Beitriige zur Geologie und Paliiontologie von Siidamerika, ij. Neues Jahrb. “fiir Min., ctc., Beil. Bd. x (1895), ps [Lamelli- branchs, pp. 100—106. | Morris, J. A Catalocue of British Fossils. Second Edition. London, 1854. ? D Morton, 8. G. Synopsis of the Organic Remains of the Ferrugious Sand Forma- tion of the United States ; with geological remarks. Amer. Jowrn. Sci. and Arts, vol. xvii (1829), p. 274. [Lamellibranchs, pp. 283—286.] ee vol. xviii (1830), p. 245. Organic Remains of the Cretaceous Group of the United Site "Philadel his 1834. [Lamellibranchs, pp. 50—69. | exeX: BIBLIOGRAPHY OF THE Morton, 8. G. Two new species of Fossils from the Lower Cretaceous Strata of New Jersey. Proc. Acad. Nat. Sci. Philad., vol. 1 (1841), p. 182. — Description of some new species of Organic Remains of the Cretaceous Group of the United States, ete. Journ. Acad. Nat. Sci. Philad., ser. 1, vol. vili (1842), p. 207. [Lamellibranchs, p. 214.] Mounins, C. Des. Essai sur les Spherulites, . . . . . et considérations sur la famille i laquelle ces fossiles appartiennent. Bull. @hist. nat. Soc. Linn. de Bordeaua, etc., vol. 1, 1826. Mitier, G. Beitrag zur Kenntniss der oberen Kreide am nérdlichen Harzrande. Jahrb. d. k. preussisch. geol. Landesaust. fiir 1887 (1888), p. 372. [ Lamellibranchs, pp. 400—437. | — Die Molluskenfauna des Untersenon yon Braunschweig und _ Ilsede. I. Lamellibranchiaten und Glossophoren. Affinities. —This species is relatively shorter, more rounded posteriorly, and has its lunule less distinctly limited than N. planata, Deshayes. It is relatively higher in the umbonal region and tapers more anteriorly than N. ovata, Mantell. Types.—In Mr. Lamplugh’s Collection. Distribution.—Speeton Clay (D 4) of Speeton. Nucua, sp. Plate II, figs. 20 a—d. 1884. Nuvcuna simpiex, J. S. Gardner. Quart. Journ. Geol. Soc., vol. x], p. 129, pl. v, figs. 11—13. Description.—Shell small, triangular, smooth, somewhat compressed. Um- bones small. Apical angle small. Lunule distinet. Posterior part of shell very 1 «Mém. Soe. Geol. de Franc, vol. vy (1842), pl. ix, fig. 5, p. 7. D’Orbigny, ‘ Pal. Frang. Terr. Crét.,’ vol. iii (1843), p- 166, pl. cee, figs. 11—15. Pictet and Campiche,“ Foss. du Terr. Crét. de Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 4), pt. iii, p. 407. Non Gardner, ‘ Quart. Journ. Geol. Soc.,’ vol. x] (1884), p. 129, pl. v, figs. 11—13. NUCULA. 15 short. Anterior extremity rounded. Antero-dorsal margin slightly curved. Postero-dorsal margin short, nearly straight. Ventral margin gently curved. Measurements : Leneth ; , : : 7 mm Height . ; é : : 5'D A Thickness Red Mees Remaris—There are a few specimens of this small species in the British Museum and one or two in Mr. Meyer’s Collection. One in the British Museum was figured by Gardner as N. simplex, Deshayes, but it seems to me to be distinct from that form—it is smaller, much more triangular, and has a smaller apical angle. Until a larger series of specimens has been obtained I do not feel justified in giving this form a distinctive name. Distribution.—Lower Greensand of Atherfield and Shanklin. Nocuta Meyert, Gardner, 1884. Plate IT, figs. 21 a—e. 1884. Noucura Mrvert, J. 8. Gardner. Quart. Journ. Geol. Soc., vol. xl, p. 130, pl. v, figs. 14—16. Remarks.—This form is at present very imperfectly known. It is small, triangular, and high; with lines of growth, and a large lunule. Gardner states that “it is most nearly allied to N. impressa of Blackdown,” but it seems to be almost indistinguishable from N. antiquata, Sowerby. Measurements : () (2) Length : : 8:5 : : 8°5 mm, Height : 2 8 : : le hes 1 is the type specimen ; 2 is from Redeliff. Types.—In the British Museum. Distribution.—Lower Greensand of Atherfield; Perna-bed of Redeliff. 16 Nucuna pectinata, Sowerby, 1818. 1818. 1822. 1838. 1844. 1850. 1852. 1854, 1855. 1862. 1866. 1884. 1897. Non 1846. — ?1868. — 1872. CRETACEOUS LAMELLIBRANCHIA. 2. Gault and Upper Greensand Species. Plate IT, figs. 22, 23 a—c, 24—26, 27 a—c; Plate ITI, figs. 13 a, b. Nucuta pectinata, J. Sowerby. Min. Conch., vol. ii, p. 209, pl. exci, figs. 6, 7. G. Mantell. Foss. 8. Downs, p. 94, pl. xix, figs. 5, G29) H. Michelin. Mém. Soe. Géol. de France, vol. iii, p. 102. A. d’Orbigny. Pal. Frang. Terr. Crét., vol. ii, p. 177, pl. ecciil, figs. 8—14. — Prodr. de Pal., vol. 11, p. 188. F. J. Pictet and W. Roux. Moll. foss. des Grés verts de Geneve, p. 472, pl. xxxix, fig. 3. J. Morris. Cat. Brit. Foss., ed. 2, p. 217. G. Cotteau. Moll. Foss. de l’Yonne, p. 84. PortLanpia pectTinata, J. G. Chenu. Man. de Conchyl., &e., vol. ii, p. 180, fig. 907, Noucvta prectinata, Ff, J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Mater. Pal. Suisse, ser. 4), pt. 3, pp. 418, 418, pl. exxix, fig. 13. J. 8. Gardner. Quart. Journ. Geol. Soe., vol. xl, p. 132, pl. iti, figs. 15, 16. Rk. B. Newton. Proce. Dorset Nat. Hist. and Antiq. Field Club, yol. xviii, p. 90. A. H. Reuss. Die Verstein, der bohm Kreideformat., pt. 2, p. 5, pl. xxxiv, figs. 1—5. H. B. Geinitz. Das Quadersandstgeb. oder Kreidegeb. in Deutschland, p. 160. A. Alth. Geog.-pal. Beschrieb. der nichst. Umgeb. von Lemberg. Haidinger’s Naturw. Ab- handl., vol. 111, pt. 2, p. 171. HE. EKichwald. Letha Rossica, vol. 11, p. 586, pl. xxii, fig. 17. F. Schmidt. Resultate du Mammuthexpedition.! Mém. de l’Acad. Imp. des Sci. de St. Petersb., ser. 7, vol. xviii, No. 1, p. 152, pl. ii, fig. 6. H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palzonto- graphica, vol. xx), pt. 2, p. 57, pl. xvii, figs. 3—5, A. Fritsch. Stud. im Geb. der bohm Kreideformat. ii. Die Weissenberg. und Malnitz. Schichten, p. 117, fig. 79. NUCULA. iv ? Non 1852. Nucuta pectinara, R. Kner. Denkschr. d. k. Akad. Wissensch. Math.- nat. C]., vol. iii, p. 312. — 1885. — _~ F. Notling. Die Fauna der baltisch. Cenomange- schiebe (Paleont. Abhandl., vol. ii, pt. 4), p. 27, pl. iv, fig. 12. — 1889. -— — A. Fritsch. Stud. im Geb. der béhm. Kreideformat. ili. Die Teplitzer Schichten, p. 78. — 1893. — — — Ibid. y. Priesener Schichten, p. 91. — 1897. — — A. Hennig. Revis. af Lamellibr. i Nilsson’s ‘ Petrif. Suecana,’ p. 58, pl. ii, fig. 30. Deseription.—Shell thick, triangular or somewhat rhomboidal ; convex, slightly compressed anteriorly ; antero-dorsal border long, slightly convex; postero-dorsal much shorter and concave; ventral margin curved, the are of the curve often increasing towards the anterior extremity. Posterior extremity angular; anterior rounded or slightly angular. Umbones prominent, curved inwards and posteriorly ; usually placed rather near the posterior end of the shell. Lunule deeply depressed, broad, cordate, flattened, smooth except for growth-lines ; escutcheon long, nearly smooth except for growth-lines. Surface ornamented with numerous (usually 50 to 52) radiating and rounded ribs, separated by narrower grooves; the grooves, and sometimes also the ribs (especially on the earlier portion of the shell), are crossed by numerous growth-lines. ‘There are often also a few distant concentric depressions. A small rib is placed in the grooves of some of the larger specimens. ‘Teeth: anterior about 22, posterior about 9. Adductor impressions deep, near the margins; the anterior a little larger than the posterior. Margins of valves rather coarsely crenulated. Measurements : (1) (2) (3) (4) (5) Length . . ; : . 29 3 20 in. F203" 2 20s es ee caumea Postero-dorsal margin. Bn ADO eo lot ee PR trae (2) Antero-dorsal margin. aye =~ 20% 9 tL A li ees Height . : ; : . 18 OAGE so, AU Oe ss- eel Sr teng Vie, Thickness. : : co § Soe ib el iS eae Affinities. —This species is distinguished from N, tenera, Miller,’ and N, pul- villus, Miiller,” of the Aachen Greensand by its coarser ornamentation, its greater length, broader lunule, &. From N. arduennensis, d’Orbigny, it is said to differ in the deep lunule and the strong ribs. Remarks.—The specimens from the Plinerkalk of Hundorf, &c., and the Plinermergel of Luschitz, &c., which are referred to this species by Reuss, are relatively shorter, and the umbones more acute; the examples figured by that 1 J. Miiller, ‘Mon. der Petrefact. der Aachen Kreidef.,’ pt. i (1847), p. 17, pl. ii, fig. 1. E. Holzapfel, “ Moll. der Aachen Kreide” (‘ Paleontographica,’ xxxv, 1889), p. 200, pl. xxi, figs. 9—12. 2 Miller, ibid., Supplement (1859), p. 11, pl. vii, fig. 11. Holzapfel, ibid., p. 201, pl. xxi, figs. 7, 8. 3 18 CRETACEOUS LAMELLIBRANCHIA. author are apparently all casts, so that an exact comparison cannot be made. Geinitz considers that specimens which he obtained from the Plinerkalk of Strehlen and Weinbéhla, and from the Plinermergel of Walkmiihle near Pirna, belong to N. pectinata ; but they appear to differ from the English specimens in that the posterior part of the shell is rounded and relatively longer. The variations seen in different examples of this species are chiefly in the proportions of length and breadth, and in the form of the curve of the ventral margin, the latter giving to the shell a triangular or a rhomboidal outline. N. striatula, Rémer,' N. truncata, Nilsson,’ and N. Blochmanni, Geinitz,> have been regarded by Geinitz and Reuss as identical with N. pectinata, Sowerby. Types.—The types, now in the British Museum, are labelled “ Sussex.’ The Specimens figured by Mantell (except fig. 5) and those figured by Gardner are likewise preserved in the British Museum. Distribution.—Through all the zones of the Gault at Folkestone; Gault of Burham, Aylesford, Black Ven, Devizes, Campton (Hast Bedfordshire), Ely and Haddenham (Cambs.); Marls with Bel. minimus at Speeton; Upper Greensand of Warminster (cast only seen). Nocuza pxotinata, Sowerby, var. crnrm, Gardner, 1884. Plate III, figs. 14a, b, 15. 1884. Nucuna pecrrnata, var. creTa, J. S. Gardner. Quart. Journ. Geol. Soe., vol. xl, p. 182. Remarks.—This form appears to differ from N. pectinata, Sowerby, only in being proportionately shorter. The surface of the shell, in the two specimens which I have seen, is somewhat abraded, but I do not think that the ornamentation differs from that of N. pectinata. Without more examples I am unable to say whether this form is really distinct from N, pectinata. Measurements : Length . : : . ; 3 15 mm. Height . , ; k 5 ; ‘ 1 oe Thickness. ON. Types.—In the Museum of Practical Geology (Nos. 6449, 6450). Distribution.—Blackdown Greensand.! * “Die Verstein. der norddeutsch. Kreidegeb.’ (1841), p. 68, pl. viii, fig. 26 (the type comes from the Plinerkalk of Strehlen). ? «Petrif. Suecana’ (1827), p. 16, pl. v, fig. 6. 3 *Char. der Schicht. u. Petref. d. sachs. Kreidegeb.,’ pt. 1i (1840), p. 50, pl. x, fig. 8. + Erroneously stated by Gardner to come from the Grey Chalk of Devon. NUCULA. 19 Sub-genus—Aciia, H. and A, Adams, 1858. (‘ Genera of Recent Mollusca,’ vol. ii, p. 545.) Nvcuna (Acina) Brvircata, Sowerby, 1836. Plate III, figs. 1, 2a—e, 3, 4, 5a—e, 6—12. 1836. Nuvcvta pivineata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, p- 335, pl. xi, fig. 8. 1844. — ~~ A. @Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 176. pl. eceiil, figs. 1—7. 1844. — ORNATISSIMA, d’Orbigny. Ibid., p. 175, pl. eccii, figs. JI—12. 1854. — BivinGata, J. Morris. Cat. Brit. Foss., ed. 2, p. 217. 1854. _ ORNATISSIMA, Morris. Ibid., p. 217. 1855. — BIVIRGATA, G. Cotteau. Moll. Foss. de l’Yonne, p. 84. 1866. — -- F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 418. 1866, _- oRNATISSIMA, Pictet and Campiche. Ibid., p. 418. 1875. — BIVIRGATA, A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol. XXXxi, p. 299, pl. xv, figs. 4—8. 1884. — — J. 8. Gardner. Quart. Journ. Geol. Soe., vol. x1, p. 182, pl. iii, figs. 12—14.; pl. iv, figs. 20—22. Description.—Shell oval, convex, angular posteriorly, rounded anteriorly. Antero-dorsal margin slightly convex, postero-dorsal concave. Ventral margin evenly curved. Lunule cordate, depressed, ornamented with transverse ribs; central part elevated. Escutcheon narrow, elongate, not sharply limited, orna- mented with ribs. Surface of shell ornamented with numerous fine radiating ribs crossed by delicate lamelle; the ribs diverge at an acute angle from a line extending from the umbo in an antero-ventral direction. In some cases the ribs diverge from two lines near together, forming an inverted W, thus M. New ribs may become intercalated between the others, especially near the margins of the valves of larger specimens. Margins of valves crenulated. Teeth: posterior about six, anterior about twelve. Adductor impressions distinct, rounded, near the margins; the anterior larger than the posterior. Measurements : GQ @) (@) @ (5) (6) (7) Length : F . 19 16 14 215 18°5 23 18 mm. Height : : oat elo LOM AZ 13 16°5:" 13) 4; Antero-dorsal margnm . 16 14 11 115 16 20 Le Postero-dorsal margin . 9 8 7 7 8 11 tate oh Thickness : : LS 11 — 195) 20 CRETACEOUS LAMELLIBRANCHIA. 6 and 7 are Gardner’s figured specimens of N. ornatissima and N. bivirgata respectively. Affinities —The forms in which the ribs diverge from two lines (thus M) were regarded by d’Orbigny as constituting a distinct species—. ornatissima ; the only difference being in the form of the ornamentation, and this feature is not constant: in some cases the ribs on the earlier part of the shell diverge from one line, whereas on the later part they diverge from two lines, or the reverse may be the case. The adductor impressions are not so deep in N. bivirgata as they are in N., pectinata. N. Dewalquei, Briart and Cornet,’ from the Meule de Bracquegnies, is very closely related to N. bivirgata, but in the former the line from which the ribs diverge is directed more anteriorly than it is in the latter species. N. Dewalquei is stated by the writers mentioned to be longer in proportion to its width than N. bivirgata; I have seen no examples of the former. N. picturata, Yokoyama,’ from the Upper Cretaceous of Poronai (Japan), is also allied to N. bivirgata ; I have seen no specimen of that form, and the figures do not enable me to make an exact comparison. Remarks.—The variation in the proportions of length and breadth is fairly considerable. In some cases the line from which the two sets of ribs diverge cuts the ventral border of the valve near its middle point, but in others more anteriorly, the position varying in different examples. Types.—1 have not seen the type; it is apparently lost. The specimens figured by Gardner (except figs. 20—22) are in the British Museum; one of those figured by Jukes-Browne (fig. 6) is in the Woodwardian Museum, Cambridge. Distribution.—Lower Gault (zones v and vi) of Folkestone; also, perhaps, Upper Gault, according to Gardner (?). Gault of Black Ven. Cambridge Greensand. 1“ Descript. Min., Géol., et Paléont. de la Meule de Bracquegnies”’ (‘Mém. couron. et Mém. des Say. étrang. Acad. Roy. Belg.,’ vol. xxiv, 1868), p. 62, pl. v, figs. 26—28. 2 “WVerstein. aus der japanisch. Kreide,’’ ‘ Paleontographica,’ vol. xxxvi (1889), p. 18, pl. xxv, figs. 1, 2. NUCULA. 21 Nucuta ovata, Mantell, 1822. Plate III, figs. 16—18, 19 a, b, 20, 21a, b; Plate IV, figs. 1 a, b. 1822. Nucuta ovata, G. Muntell. Foss. S. Downs, p. 94, pl. xix, figs. 26, 27. 1838. = cAapszrorMis, H. Michelin. Mém. Soc. Géol. de France, vol. iii, pl. xii, fig. 8, p. 102. 1844. — ovata, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 173, pl. cecil, figs. 1—3. 1850. — — — Prodr. de Pal., vol. ii, p. 137. 1852. = — FJ. Pictet and W. Roux. Moll. foss. des Grés verts de Geneve, p. 473, pl. xxxix, fig. 4. L854. = a J. Morris. Cat. Brit. Foss., ed. 2, p. 217. 1866. — — FE. J. Pictet and G. Campiche. Foss. du Yerr. Crét. des Envir. de Ste. Croix (Matér. Pal. Suisse , ser. 4), pt. 3 pp. 409, 417, pl. exxix, fig. 9. 1874. — Derancet, F. G. H. Price. Quart. Journ. Geol. Soc., vol. xxx, p. 358, pl. xxv, fig. 7. 1874. — ovata, Price. bid., p. 357, pl. xxv, fig. 6. ? 1878. — — OO. Fraas. Aus dem Orient, pt. ii, p. 81. 1884, = — J.S8. Gardner. Quart. Journ. Geol. Soe., vol. x], p. 125, pl. i, figs. 1—3; pl. iv, figs. 28—30. 1884. _ CAPSEFORMIS, Gardner. Ibid., p. 127, pl. iii, figs. 4, 5. Non 1827. Nucuua ovata, 8. Nilsson. Petrif. Suecana, p. 16, pl. v, fig. 5. = Als HA): = — od. Phillips. Geol. Yorks., pt. 1, pl. ii, fig. 10, p. 122. — 1837; = — W. Hisinger. Lethea Suecica, p. 59, pl. xviii, fig, 7. — 1846. — — A. #. Reuss. Die Verstein. der béhmn. Kreideformat., pt. 2, p. 8, pl. xxxiv, fig. 25. — 1889. — — O. Griepenkerl. Die Verstein. der Senon. Kreide von Konigslutter (Paleont. -Abhandl., vol. iv), p. 56. — 1898. — — A. Fritsch. Stud. im Geb. der bohm. Kreideformat. v. Priesener Schichten, p. 92, fig. 103. — IE — — A. Hennig. Revision af Lamellibr. i Nilsson’s ‘ Petrifacta Suecana,’ p. 63, pl. iii, fig. 21. Deseription.—Shell oblong or ovate-oblong, short posteriorly, compressed, with a slight constriction near the margin opposite the umbo; central part of the ventral margin straight and nearly parallel to the dorsal; anterior margin rounded, forming an obtuse angle with the dorsal; posterior margin slightly angular, but sometimes somewhat rounded. Umbones not much curved. A slight depression usually extends from near the umbo to just below the posterior angle, giving a slight sinuosity to the margin at that point. Lunule ovate, not much depressed, sometimes ill-defined. Surface smooth, but with lines of growth ; and in a few cases faint indications of radial ribs, seen chiefly near the middle of the valve. Margins smooth. Adductor impressions shallow. 22 CRETACEOUS LAMELLIBRANCHIA. Measurements : (1) (2) (8) (4) (5) (6) (7) (8) Length : : - dd 29 27 26 22° 21 19 18 mm. Height : ; > 2k 20 17 a> 1S 7 1d) heb Ae Thickness . 5 ». 4 12 — — — I 9 95 29 Affinities.—The larger forms of this species, described by Michelin as N. capsxformis, and subsequently named N. Derancei by Price, have been regarded by some authors as distinct from Mantell’s N. ovata, but practically the only difference is in size: in France a perfect gradation has been traced between these two types; and a similar passage, although it is stated by Gardner not to exist, can be seen in English specimens. In England the larger forms are recorded by Price from zones i and ii only of the Lower Gault. N. ovata is related to N. obtusa, Sowerby; the points which distinguish the two are given on p. 23, Remarks.—Vhe variations in the relative proportions of the length, height, and thickness are fairly great, as will be seen from the table of measurements. The antero-dorsal border may be parallel to the ventral, or may slope more or less obliquely to it. The posterior extremity is commonly somewhat angular, but may be rounded. Types.—I have not been able to trace Mantell’s specimens. ‘The examples figured by Gardner and referred to above (except, perhaps, figs. 28 to 30) are in the British Museum. Distribution.—Through all the zones (except vii) of the Gault at Folkestone ; Gault of Black Ven; Cambridge Greensand (derived) ; Upper Greensand of Devizes. Nvucuta oprusa, Sowerby, 1836. Plate IV, figs. 2a, b, 3, 4a—d. 1836. Nucuna oprusa, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, p. 342, pl. xvu, fig. 11. 1850. — — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 163. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 217. ? 1866. — — F. J. Pietet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, pp. 415, 418, pl. exxix, fig. 15. 1884. — — J.8. Gardner. Quart. Journ. Geol. Soc., vol. xl, p. 126, pl. iv, figs. 1, 2. Non 1844. — _ A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 163, pl. ece, figs. 1—5 (named MW. planata on pl. cece). NUCULA. 23 Description.—Shell oval or ovate-oblong, moderately convex, rounded an- teriorly and posteriorly ; ventral margin evenly curved. Umbones not prominent, placed posteriorly. Lunule indistinctly defined. Surface smooth, but with growth- lines. Hinge with numerous small teeth about eighteen on the anterior part, and nine on the posterior,—the two parts forming an obtuse angle (about 133°). Measurements : (1) (2) Length . : ‘ . 21 . . 20mm. Height. ‘ : . td ; i Vda. Thickness : 13 5 . : } = Affinities.—N. obtusa is closely allied to N. ovata, Mantell; it differs from the latter (1) in being more oval, (2) in having the ventral margin more regularly curved, (3) in the umbones being usually placed more posteriorly, (4) in the absence of a constriction near the ventral margin, and (5) in the indistinct lunule. Types.—The type is in the Bristol Museum. The specimen figured by Gardner is in the Museum of Practical Geology, Jermyn Street. Distribution.—Blackdown Greensand (zones vil to x); Greensand of Haldon (fide Downes); Upper Greensand of Devizes and Warminster. > Nucvua impressa, Sowerby, 1824. Plate IV, figs. 5, 6a—-c, 7, ?8 a, b. 1824. Nucuna mpressa, J. de C. Sowerby. Min. Conch., vol. v, p. 118, pl. ececlxxvy, fig. 3. ? 1836. = ApicuLaTa, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, p. 342, pl. xvii, fig. 10. 1850. — Impressa, d. d’Orbigny. Prodr. de Pal., vol. ii, p. 163. 1854. -- -— J. Morris. Cat. Brit. Foss., ed. 2, p. 217. 21854. — ApicuLata, Morris. Ibid., p. 217. 1866. — IMPRESSA, F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 418, pl. exxix, fig. 16. 1884. — — J. S. Gardner. Quart. Journ. Geol. Soe., vol. xl p. 128, pl. iv, figs. 9—12. Non 1846. Nucura mpressa, 4. E. Reuss. Die Verstein. der béhm. Kreideformat., pt. 2, p. 6, pl. xxxiv, figs. 6, 7. — 1867. = — £. Guéranger. Album Paléont. du Dép. de la Sarthe, ; p. 15, pl. xx, fig. 16. — 1897. — — A. Fritsch. Stud. im Gebiete der bbhm. Kreideformat. vi. Die Chlomeker Schichten, p. 56, fig. 61. Description.—Shell oval, rounded anteriorly, angular posteriorly ; ventral margin evenly curved, postero-dorsal margin slightly concave. Umbones placed 24 CRETACEOUS LAMELLIBRANCHIA. very near the posterior end. Lunule elongate, much depressed, sharply limited. Surface with lines of growth. Margins entire. Anterior part of hinge-line with about eighteen teeth, posterior part with seven. Measurements : (1) (2) (3) (4) (5) Length . : slash 7 0 =) 29) sma. Height . : 5 tO) 3) CCH 5 nue Ys ag 10 wags Thickness. —— : == 5 wey 5 27s) 5 Zire) op Affinities.—This species is distinguished from N. obtusa, Sowerby, and N. ovata, Mantell, by the sharply defined lunule and the angular posterior extremity ; it is also a smaller form. N. apiculata, Sowerby (Plate IV, fig. 8), from Blackdown, appears to me to be only a variety of N. dimpressa ; it is somewhat shorter in proportion to its height than the ordinary forms of N. impressa, and consequently has a more rounded outline. Sowerby’s diagnosis of N. apiculata is ** Convex, smooth, trans- versely obovate; posterior extremity pointed.” A specimen in the Museum of the Geological Society of London (No. 1564, Fitton Collection) is, 1 believe, the type, but is a little smaller than Sowerby’s figure. The only other example known to me is in Mr. Meyer’s Collection. The late Rev. W. Downes’ considered JN. apiculata to be a synonym of N. antiquata, Sowerby; but that species is more triangular in outline, the valves are much more convex, and the umbones more prominent. Types.—One of the types (Sowerby’s lower figure) is in the British Museum. One of the specimens figured by Gardner (fig. 12) is in the Bristol Museum; I have not seen the others; they are stated to be in the Rev. W. Downes’ Collection, now in the Exeter Museum. Distribution.—Blackdown Greensand. Nucuta aLBensis, d’Orbigny, 1844. Plate IV, figs. 9a, b, 10, 11, 12 a, b, 13 a, b, TAG nb. Va, Oy liGsse aid. 1844. Nucuta atpensts, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 172, pl. ccci, figs. 16—17. 1850. — — — Prodr. de Pal., vol. ii, p. 187. 1866. — — F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, pp. 411, 417, pl. exxix, fig. 11. 1884. — — J.S. Gardner. Quart. Journ. Geol. Soc., vol. x], p. 128, pl. in, figs. 6—8 ; pl. iv, figs. 24, 25. 1 «Trans. Dey. Assoc.,’ vol. xii (1880), p. 436; and ‘Quart. Journ. Geol. Soe.,’ vol. xxxviii (1882), p. 88. NUCULA. nw or Description.—Shell subtriangular or more or less oval, compressed ; posterior part very short and somewhat angular; anterior part usually tapering rapidly, with the extremity rounded. Ventral margin curved evenly. Antero-dorsal margin curved ; postero-dorsal nearly straight or slightly concave. Umbones not prominent, curved. Lunule shallow, cordate, often not sharply defined. Anterior area limited by a faint ridge. Surface smooth, but with lines of growth. Margin smooth. Adductor impressions shallow. Measurements : (1) (2) (3) (4) (5) Length . ; Meee, «teen. l4d. 0 A mme Height. : Pwiowee eta . LS fo, 10 « ODE e Thickness : — i. Ow FO — ; : 7 Affinities. —N. Timotheana, Pictet and Roux,’ is shorter, and apparently more compressed than is N. albensis; N. ovata, Mantell, is less compressed and more rounded in outline; N. dimpressa, Sowerby, is more oval, and has a more depressed and better defined lunule. Remarls—This species varies considerably in the proportions of length and height—the shorter examples being more triangular, the longer more oval in out- line. A form found in the Blackdown Greensand (Plate IV, fig. 17), of which I have seen only a few specimens, approaches very closely the shorter types of N. albensis, but I have not sufficient material to allow me to speak of its affinities with certainty. Types.—I have not seen the type; it appears to be missing from the d’Orbigny Collection in the Museum of Natural History, Paris. Some of the specimens figured by Gardner (figs. 6—8) are in the British Museum. Distribution.—Lower Gault (zone vi) of Folkestone; Gault of Black Ven; Cambridge Greensand (derived). ? Grey Chalk (jide Gardner). Noucuna GauLrina, Gardner, 1884. Plate IV, figs. 18 a—c, 19, 20, 21 a—e. 1884. Nucuna gavtrina, J. S. Gardner. Quart. Journ. Geol. Soe., vol. xl, p. 184, pl. iii, figs. 9—11, 26, 27. Description.—Shell small, triangular, rather convex; pointed anteriorly and posteriorly. Ventral and antero-dorsal margins gently curved ; postero-dorsal margin slightly concave. Umbones pointed, curved, placed very posteriorly. Lunule cordate, sharply defined. Anterior area bounded by a ridge passing from the umbo to the anterior extremity. Surface nearly smooth, but with lines of ' Moll. Foss. Gres verts de Genéve (1852), p. 476, pl. xxvix, fi r ¢ o° ‘. 26 CRETACEOUS LAMELLIBRANCHIA. growth, crossed by very indistinct radial ribs. Margin crenulate. Hinge and adductor impressions not seen. Measurements : (1) (2) (3) Length . : 7 MO : 9 : 8 mm. Height . ; : 8 : 7 ‘ i Affinities. —This species is distinguished from N. impressa, Sowerby, by its more triangular outline and larger lunule. It is less convex and proportionately longer than N. antiquata, Sowerby, and has less prominent umbones. It is smaller, more pointed at the extremities, and has a deeper and more sharply limited lunule than N. albensis, d’Orbigny. Types.—In the British Museum. Distribution.—Lower Gault (zones y, vi, and vi) of Folkestone. Nucua anriquata, Sowerby, 1824. Plate IV, figs. 22 a—c, 23a, b, 24a, b, 25, 26. 1824. Nucuna antiquatra, J. de C. Sowerby. Min. Conch., vol. v, p. 118, pl. cecelxxy, fig. 4. 1854. -- — J. Morris. Cat. Brit. Foss., ed. 2, p. 217. 1866. — — F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 418. i884. — — J. S. Gardner, Quart. Journ. Geol. Soe., vol. xl, p. 184, pl. iv, figs. 3—S. Description.—Shell very convex, triangular, posterior angle rounded, anterior somewhat pointed ; ventral margin curved. Umbones prominent, curved, placed very posteriorly. Lunule very broad, cordate, smooth, depressed, sharply defined. An anterior area is cut off by a ridge passing from the umbones to the anterior margin. Surface ornamented with fine, slight, radiating ribs crossed by well-marked concentric growth-lines. Margins crenulate. Anterior part of the hinge-line has about twenty teeth, and is bent almost at right angles to the posterior part, which has about nine teeth; the anterior part is more than twice the length of the posterior part. Adductor impressions rounded, the anterior being the larger. Measurements : (1) (2) (3) (4) Length . . ; ee ge Us IK) eb aang Antero-dorsal margin 5 lee SO, OR Las Postero-dorsal margn . 6 . 45. 45 . O ,, Height. : ; a Ss Sh BO Se CY Thickness ; F SD ES —- .-— , ANOMIA. 27 Affinities —This species is distinguished by the convexity and triangular form of the valves, and by the broad and deep lunule. NV. apiculata, Sowerby, was regarded by the late Rev. W. Downes as a synonym of N. antiquata (see p. 24). Types.—In the British Museum. The specimens figured by Gardner (except fi. 6, which is in the Downes Collection) are in the Bristol Museum. Distribution.— Blackdown Greensand (zones vii to x). 3. Chalk Species. Nucuta, sp. Plate IV, figs. 27, 28. 1897. Nucvura, sp., H. Woods. Quart. Journ. Geol. Soe., vol. li, p. 378, pl. xxvii, figs. 1, 2. Remarks.—A species of Nucula is represented in the Montagu Smith Collection (Woodwardian Museum, Cambridge) by eleven specimens ; it approaches closely in form d’Orbigny’s N. Renauviana’ found in the Turonian of Uchaux, but unfortunately all the specimens are internal casts, so that an exact determination is impossible. Measurements : Length ; ; . 2 ; 13 mm. Height ; a Omeres Distribution.—Chalk Rock (Reussianum-zone) of Cuckhamsley. Family—ANOMIIDAS, Gray. Genus—ANomMIA, Linneus, 1758. (‘Syst. Nat.,’ ed. 10, p. 700.) 1. Lower Cretaceous Species. ANOMIA PSEUDORADIATA, @’Orbigny, 1850. Plate V, figs. 1 a—e, 2, 3. 1836. Anomia RAvIATA, J. de C. Sowerby (non Risso). Trans. Geol. Soc., ser. 2, vol. iv, p. 338, pl. xiv, fig. 5. 1 «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 179, pl. eeciv, figs. 7—9. This is regarded by Pictet and Campiche (‘ Foss. Terr. Crét. Ste. Croix,’ pt. iii [1866], p. 418) as a synonym of NV. impressa, Sowerby. 28 CRETACEOUS LAMELLIBRANCHIA. 1850. Anomia PsEUDORADIATA, A. d’Orbigny. Prodr. de Pal., vol. 11, p. 84. 1854. — RaDiaTa, J. Morris. Cat. Brit. Foss., ed. 2, p. 161. Non ? 1846. — — A. E. Reuss. Die Verstein. der bohm. Kreideformat., pt. ii, p. 45. = Sere — — ?4A. Fritsch. Stud. im Gebiete der béhm. Kriedef. ii. Die Weissenb. und Malnitz. Schichten, p. 142, fig. 142. Description.—Shell oval, a little irregular, higher than long. Left valve moderately convex, ornamented with numerous radial ribs, which on the adult shell are more distinct and more wavy than on the younger part of the shell, and of two sizes, the larger being distinctly granular. The radial ribs are some- times crossed by concentric growth-lines. Umbo near the margin. Measurements : (1) (2) (3) Length . ’ 20 » A). 5 PAL srowaat, Height . 23°. 1 2208 ea Affinities—This species appears to be similar to A. subtruncata, d’Orbigny,’ from the Plinerkalk of Strehlen, &c., but in that form the shell is much more regularly oval than in A. pseudoradiata. Types.—In the Museum of the Geological Society (No. 2029), from the Hythe Beds, near Sandgate. Distribution —Crackers, &c., of Atherfield; Ferruginous Sands (upper beds) of Shanklin; Hythe Beds, near Sandgate; Atherfield Beds of East Shalford, Sevenoaks, and Redhill. Anomia, sp. Plate V, figs. 4, 5 a, b. Description.—Shell more or less orbicular or oval, and rather inequilateral. Left valve moderately convex with a rather prominent umbo at the margin ; ornamented with radial ribs, which are slender, widely separated, only a little elevated, and rather irregular. Measurements : () (2) Length ; ; ; RZ; ; ; ) mm. Height i 5 ; 16 5 ; 8°5 56 Affinities. —In A. costulata, Romer,’ the umbo is not at the margin and is somewhat spiral, and the ribs are more numerous; the last is also the case in | ‘A. truncata, Geinitz (non Linneus), ‘Char. d. Schicht. und Petref. sichs.-bohm. Kreidegeb.,’ pt. iii (1842), p. 87, pl. xix, figs. 4, 5; and “Das Elbtlalgeb. in Sachsen” (‘ Paleontographica, vol. xx), pt. 2 (1872), p. 30, pl. viii, figs. 22,23. A. subtruncata, A. d’Orbigny, ‘ Prodr. de Pal.,’ vol. ii (1850), p. 171. 2 «Die Verstein. Nord-deutsch. Ool-geb. Nachtrag’ (1839), p. 24, pl. xvir, fig. 5, ANOMIA. 29 A. intercostata, Zittel.!| The ornamentation in this form resembles that of A. sub- radiata, Reuss,” but in that species the shell appears to be less inequilateral. Remarks.—I have seen only two examples of this form; it appears to be quite distinct from the other English species, and to resemble most A. subradiata, Reuss, from the Plinermergel of Luschitz. Distribution.—Crackers of Atherfield. ANoMIA L&vIGATA, Sowerby, 1836. Plate V, figs. 6, 7 a, b, 8a, b, 9. 1836. ANomiIA Levicata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, p- 338, pl. xiv, figs. 6a, b. ? 1847. — — A. d'Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 755, pl. ceeelxxxix, figs. 4—6. 1850. — — -— Prodr. de Pal., vol. 1i, p. 84. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 161. Description.—Shell regular, nearly orbicular ; surface smooth except for lines of growth. Left valve moderately convex; umbo small, at or near the margin. Measurements : (1) (2) (3) Length . 36 : 22 ; . 14mm. Height 4 : 32 F 21 tomes Types.—One of the types (PJ. V, fig. 6, and Sowerby’s fig. 6a), from the Hythe Beds of Lympne, is in the Museum of Practical Geology (No. 6414) ; I have not seen the other. Distribution.—Ferruginous Sands (upper beds) of Shanklin; Atherfield Beds of Peasmarsh; Hythe Beds of Lympne; Lower Greensand of Punfield. Anomia convexa, Sowerby, 1836. Plate V, figs. 10a, b. 1836. Anomia convexa, J. de C. Sowerby. Trans. Geol. Soe., ser. 2, vol. iv, p. 338, pl. xiv, fig. 7. 1854. — -—- J. Morris. Cat. Brit. Foss., ed. 2, p. 161. Description.—Shell rather small, more or less orbicular or quadrate ; surface smooth, or with fine ribs. Left valve very much inflated, with a rather prominent umbo. 1 «Die Bivalven der Gosaugeb.,’ pt. ii (1866), p. 51, pl. xix, fig. 10. 9 2 «Die Verstein. der bohm. Kreideformat.,’ pt. ii (1846), p. 45, pl. xxxi, figs. 18, 19. 30 CRETACEOUS LAMELLIBRANCHIA. Measurements : Length : : : , . 14mm. Height : ‘ ; : Mee sie ae Remarks.—This species is imperfectly known at present. The only specimens I have seen are in the Museum of the Geological Society, and in Mr. Meyer’s Collection. With regard to the type specimen, Sowerby remarks, ‘ The furrows are produced by a Terebratula [? Rhynchonella| to which this specimen was attached, and to which it consequently bears a great resemblance.” Types.—The type, from the Lower Greensand of Shanklin, is in the Museum of the Geological Society (No. 2032). Distribution.—Lower Greensand of Redhill (Reigate) and Atherfield; Ferru- ginous Sands (upper beds) of Shanklin. 2. Gault and Upper Greensand Species. ANOMIA, sp.; cf. PsEUDORADIATA, d’Orbigny. Plate V, figs. 11 a, b. Remarks.—This form appears to differ from A. pseudoradiata, d’Orbigny, only in having finer and less distinct ribs; the difference may perhaps be due to the mode of preservation. At present I have seen only two specimens. Distribution.—Gault of Black Ven (Museum of Practical Geology, No. 6440) and Folkestone. ANOMIA, spp. In the Museum of Practical Geology, Jermyn Street, there are several speci- mens from the Upper Greensand of Devizes and Warminster ; some appear to be closely related to A. levigata, Sowerby, others to A. pseudoradiata, d’Orbigny, but they are not sufficiently well preserved to allow of exact determination. 3. Chalk Species. ANOMIA ? TRANSVERSA, Seeley, 1861. Plate V, figs. 12a, b. 1861. Anomia? TraNsveRsA, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vil, p. 123, pl. vi, fig. 8. Description.—* Shell ovate, elongated, inflated. Umbo large, prominent, inclining to the posterior end rather than central” (Seeley). ANOMIA. 31 Measurements : Length 2 ; : , & 7 mom. Height : ; : ‘ Ete eGs Remarks.—This form may perhaps be related to A. papyracea, d’Orbigny, but without better specimens I am unable to make any definite statement con- cerning it. Types.—I have not seen the specimen figured by Seeley, but other examples to which he refers are preserved in the Woodwardian Museum, Cambridge. Distribution. —Cambridge Greensand. Anomia papyracea, d’Orbigny, 1847. Plate V, figs. 13—16. 1847. ANomta Papyracea, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 755, pl. eeeelxxxix, figs. 7—10. 1850. Anomya paprracea, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 171. 1881. Awnomta papyracea, A. d’Orbigny, var. BURWELLENSIS, Ft. Etheridge. In Penning and Jukes-Browne, Geol. Neighbourhood of Cambridge (Mem. Geol. Survey), p. 145, pl. i, figs. 3, 4. Description.—Shell more or less oval, longer than high, nearly smooth, but sometimes with faintly marked concentric ribs. Left valve slightly convex ; umbo small, near the margin. Right valve flat or shehtly concave. Measurements : () 2) (3) Length . : 3: 35 28 mm. Height : ; aR : ; DAD) : Qe, Affinities.—This species is distinguished from 4d. levigata, Sowerby, by its oval form and lesser convexity. Types.—The type is not in the d’Orbigny Collection. The specimens figured by Etheridge are in the Woodwardian Museum, Cambridge. Distribution.—Totternhoe Stone (zone of Holaster subglobosus) of Burwell and Reach. 32 CRETACEOUS LAMELLIBRANCHIA. Family—ARCIDA, Lamarck. Genus—Anca, Linneus, 1758 (sensu stricto). (‘ Syst. Nat.,’ ed. 10, p. 693.) 1. Lower Cretaceous Species. Arca Dupryrana, d’Orbigny, 1844. Plate VI, figs. 1a, b, 2, 3. 1844. Arca Dupintana, dA. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 207, pl. ecex, figs. 9, 10. 1845. — _ E. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 246. 1850. — — A.d’Orbigny. Prodr. de Pal., vol. ii, p. 80. 1854 -- — J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 1855 — — G. Cotteau. Moll. Foss. de l’Yonne, p. 86. 1866 _— — F. J. Pictet and G. Campiche. Foss. du Terr. Crét, Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, pp. 438, 468. 1867. — — P. de Loriol. In A. Favre, Recherch. géol. dans Savoie, &e., vol. i, p. 381. 1871. — — F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. iii, p. 842 (Barbatia). Description.—Shell elongate, very inequilateral, convex. Anterior margin rounded. Ventral margin sinuous, roughly parallel to the hinge-line. Posterior margin very oblique, nearly straight, forming sharply marked obtuse and acute angles with the dorsal and ventral margins respectively. Umbones prominent, moderately distant, with a prominent toothed carina extending to the postero- ventral angle, and cutting off a depressed postero-dorsal area. Hinge-line long. Hinge-area rather large. Ornamentation consists of numerous fine radial ribs— more prominent at the anterior end—crossed by concentric growth-lines. Pos- tero-dorsal area with four strong radial ribs which project posteriorly, giving a toothed margin. Teeth numerous, small, transverse, the terminal teeth slightly oblique. Measurements : Leneth . p : ; , , : ‘ » 25) mm, SH Dar Height . : , ; : . : : . diosa. Thickness , . : ; ; . ‘ > I ARCA. 33 Affinities. —This species is distinguished by its prominent toothed carina and strong postero-dorsal ribs. Its forrm is somewhat similar to that of A. Sancte- Crucis, Pictet and Campiche (see p. 34), but its posterior margin is more oblique. It also appears to be related to Arca Dufrenoyi, d’Archiac,’ but in that form the antero-dorsal extremity is rectangular. The hinge of A. Dufrenoyi seems to be unknown. Types.—I have not seen the type; it came from the Neocomian of Marolles (Aube). Distribution.—Perna-bed of Atherfield; Atherfield Beds of East Shalford and Peasmarsh; Ferruginous Sands (upper beds) of Shanklin. Arca Carteront, d’Orbigny, 1844. Plate VI, figs. 4a—e, 5 a—e. 1844. Arca Carreront, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 202, pl. eecix, figs. 4—8. 1845. — — E. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 246. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 1866. — — F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 38, pp. 436, 468, pl. exxx, fig. 9. 1853. — -- W. Keeping. Foss., &c., of Neoc. of Upware and Brick- hill, p. 114, pl. v, fig. 7. Description.—Shell oblong, very elongate and thick. Dorsal and ventral margins straight and nearly parallel. Hinge-line extends to the most anterior part of the shell, and forms with the anterior margin a right angle; the anterior margin curves ventrally from the hinge-line. Posterior margin a little oblique. Umbones of moderate size, widely separated, only slightly curved, with a low rounded carina extending to the postero-ventral angle; between the carina and the hinge-line is a second indistinct carina. Hinge-area very broad and large, lozenge-shaped, with several (about seven) ligament-grooves. Ornamentation consists of fine radial ribs. Hinge: the teeth near the umbo are small and transverse, but towards the extremities they become more oblique and longer. Measurements : (1) (2) Length . : . 40 ; . 28mm. Height . : é PG ; a8 Glows Thickness : : 20) ; i (1) From Upware. (2) From East Shalford. 1 * Bull. Soe. Géol. de France,’ ser. 2, vol. xi (1854), p. 214, pl. iii, fig. 9. 5 34. CRETACEOUS LAMELLIBRANCHIA. Affinities.—See A, Sancte-Crucis (below). The external teeth are more oblique in this than in most forms of Avea, in which respect it may be compared with A. equidens, Tate.’ Distribution.—Lower Greensand of Upware. Atherfield Beds of East Shalford and Peasmarsh. ? Perna-bed of Redcliff. Arca Sanora-Cructs, Pictet and Campiche, 1866. Plate VI, figs. 6 a—c, 7 a—e. 1866. Arca Sancrz-Cructs, #. J. Pictet and G. Campiche. Foss. du Terr. Cret. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 487, pl. exxx, figs. 10, 11. Description.—Shell elongate, very convex in the umbonal region; wedge-like posteriorly. Anterior margin rounded, more or less perpendicular to the hinge- line. Ventral margin a little sinuous, more or less parallel to the dorsal. Poste- rior margin nearly straight, and either at right angles or slightly oblique to the hinge-line. Umbones prominent, incurved, placed near the anterior third of the shell. Carina rounded; postero-dorsal area depressed, sometimes slightly con- cave, with one or two faint broad ridges. Hinge-area long and broad. Orna- mentation consists of numerous fine radial ribs crossed by lines of growth. Interior not seen. Measurements : Q) (2) Length . : : ool : . 205 mm. Height . : : eli, , 2) LA Thickness : : Gro 15 » (1) aud (2) are from Upware. Affinities.—This form agrees in many respects with A. Carteroni, d’Orbigny, and it is hkely that a large series of specimens would show a passage between the two. At present I have seen only three or four examples of each. Arca Sancte-Crucis appears to differ from A. Carteroni in being proportionately shorter, in having the ventral margin sinuous and less parallel to the dorsal, and in the umbones being more prominent and incurved. It also appears to be similar to Arca autissiodorensis, Cotteau,’ but seems to be less inflated and to have the posterior margin less oblique. 1 «Trans. Roy. Soc. S. Australia,’ vol. viii (1886), p. 189, pl. xi, fig. 9; G. F. Harris, ‘Cat. Tert. Mollusca’ (Brit. Mus.), part i (1897), p. 331. * «Moll. Foss. de ’Yonne’ (1855), p. 86; de Loriol and Cotteau, ‘Mon, Pal. Géol. de Port- landien de l’Yonne’ (1868), p. 179, pl. x, figs. 6, 7. BARBATIA. 35 Type.—From the Valangian of Sainte Croix. Distribution.—Lower Greensand of Upware. Atherfield Beds of East Shal- ford. 2. Upper Cretaceous Species. Arca PHOLADIFORMIS, d’Orbigny, 1844. 1844, Arca pHonapirorais, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 219, pl. ecexv, figs. 1—3. L850, — — — Prodr. de Pal., vol. ii, p. 164. 1866. — -- F. J. Pictet and G. Campiche. Foss. du Terr. Crét. Ste. Croix (Mater. Pal. Suisse, ser. 4), pt. 3, p. 473. 1867. — — E. Guéranger. Album Paléont. Sarthe, p. 16, pl. xxi, ffgs. 5, 11. 171.0 — ~ F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vel. iii, p. 343. P?1883. — ef. — A. Fritsch. Stud. im Geb. der bébm. Kreide- format. iii. Die Iser Schichten, p. 104, fig. 69. Remaris.—An internal mould of a right valve from the Upper Greensand of Devizes, which almost certainly belongs to this species, is preserved in the Museum of Practical Geology (No. 6454); its length is 28 mm., and its height 11 mm. I have seen no other specimen. The hinge is apparently unknown. Genus—Barpatia, J. H. Gray, 1847. [‘Syn. Brit. Mus.,’ 1840, p. 151 (nom. nud.) ; ‘Proc. Zool. Soc.,’ 1847, p. 197.] 1. Lower Cretaceous Species. Barpatta aptiensis (Pictet and Campiche), 1866. Plate VI, figs. 8 a—e, 9a, b. 1845. Arca Ravuini, FE. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 245 (partim). 1850. — — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 80 (partim). 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 1857. — — F. J. Pictet and E. Renevier. Foss. du Terr. Aptien (Matér. Pal. Suisse, ser. 1), p. 106, pl. xv, figs. 1—3. £1865. — crymopocr, H. Coguand. Mon. de l’étage Aptien de 1'’Espagne, p- 140, pl. xii, figs. 7. 8, 36 CRETACEOUS LAMELLIBRANCHIA. 1866. Anca apriensis, F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 8, pp. 454, 471. 171. — — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ii, p. 343 (Trigonoarca?). 21871. — cymopoce, Stoliczka. Ibid., p. 345. P1ss4. — Ravrtni, O. Weerth. Die Fauna Neocom. Teutoburg. Walde. (Paleont. Abhand., vol. ii), p. 47. Description.—Shell oblong, a little higher near the posterior part of the hinge- line than elsewhere, very inequilateral. Anterior margin forming a sharp angle (often about 90°) with the hinge-line, and curving evenly to join the ventral margin, which is slightly curved, and has a general slope posteriorly. Posterior margin oblique, shghtly convex, forming obtuse and acute angles with the dorsal and ventral margins respectively—the acute angle being somewhat rounded. Umbones not prominent, close together, with a rounded carina extending in a double curve to the postero-ventral angle, and cutting off a concave triangular area. Shell compressed in front of the umbones. MHinge-line about three quarters of the length of the shell. Hinge-area narrow, elongate. Ornamenta- tion consists of well-marked concentric ribs, and numerous fine radial ribs. On the anterior part of the shell, at intervals, some of the radial ribs become more prominent, and curve anteriorly. On the postero-dorsal area, and also near the carina, at intervals, some of the radial ribs are more elevated than the others, and here the concentric ribs are less distinct than elsewhere. Central teeth small and transverse, lateral teeth oblique.’ Measurements : () (2) Length . : : ; : 5 aS : . 37 mm, Height . : : : : . 14 ; a ed Thickness. : : — Gis Affinities —By most authors this species has been referred to Cucullexa Raulini, Leymerie,” to which it is certainly closely related; in fact, a larger collection of French specimens than I have been able to examine might well show the two forms to be identical. I have not seen the type of B. Raulini, nor the original of VOrbigny’s figures, but other specimens in the d’Orbigny Collection and the Heole des Mines, Paris. Stoliczka remarks on the difference between Leymerie’s and d’Orbigny’s figures of that species, and suggests that either one figure is incorrect or that they represent two distinct species. I think that the two figures ' The characters of the teeth are given on the authority of Pictet and Campiche. 4 «Mém., Soe. Géol. de France,’ vol. v (1842), pl. x, fig. 1, p. 7; d’Orbigny, ‘Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 204, pl. ecex, figs. 1,2; Pictet and Campiche, “ Foss. du Terr. Crét. de Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 4), pt. 3, pp. 440, 469. BARBATIA. 37 represent the same form, but that Leymerie’s specimen was imperfect in the postero-dorsal region. B. aptiensis appears to differ from B. Raulini in the greater height of the posterior part of the shell and consequent greater obliquity and curvature of the ventral margin, and in the presence of a few radial ribs, stronger than the others, on the anterior part of the shell. The average size of the English form appears to be greater than that of the French. B. aptiensis is also very similar to A. neocomiensis, VOrbigny. Judging from the figure the latter seems to differ chiefly in having the posterior extremity pointed instead of obliquely truncate. Arca cymodoce, Coquand, is perhaps identical with this form, but its area appears to be shorter. Types.—From the Crackers of Atherfield and the Aptian of the Perte-du-Rhéne and Presta. Distribution. —Perna-bed, Atherfield Clay, and Crackers of Atherfield; Ferru- ginous Sands of Sandown; Atherfield Beds of Haslemere, East Shalford, and Sevenoaks. Sub-genus—Scarnvra, Benson, 1834. [‘ Proc. Zool. Soe.,’ pt. ii, p. 91.] BarBatia (ScapHuta ?) Austeni (Forbes), 1845. Plate VII, figs. 1a, b, 2, 3. 1845. Carprum (Hemrcarpium) ? Ausrent, E. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 244, pl. iii, fig. 3. 1850. Arca AusTENI, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 118. 1854, Carprum Avstent, J. Morris. Cat. Brit. Foss., ed. 2, p. 192. 1866. Arca Avsrent, F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 471. Description.—Shell oval, very oblique and inequilateral. Anterior margin rounded, passing gradually into the curved and oblique ventral margin. Posterior margin a little convex, oblique, forming an acute angle with the ventral margin. Umbones of moderate size, incurved, with a very sharp carina extending to the postero-ventral angle; postero-dorsal area sharply depressed. Hinge-line short. Hinge-area small, triangular, with several ligament-grooves. Ornamentation consists of slightly elevated radial ribs crossed by faintly marked lines of growth ; the radial ribs are sometimes indistinct, but on the postero-dorsal area they are more prominent than elsewhere. Interior not seen. 38 CRETACEOUS LAMELLIBRANCHIA. Measurements : (1) (2) Length ? ; 5 ; 35 : . 21mm. Height ‘ : F : : 21 ; xe ot Ae oe Umbo to postero-ventral angle. 47 {) “i lO. (1) Perna-bed, Atherfield. (2) Crackers, Atherfield. Affinities—This differs from all other Cretaceous species with which I am acquainted. The form of the shell and the character of its ornamentation agree closely with the recent Scaphula, but since in our species the interior is unknown, I refer it with considerable doubt to that sub-genus. Type.—In the Museum of the Geological Society (No. 2152), from Peasmarsh. Distribution.—Atherfield Beds of Sevenoaks, Peasmarsh, East Shalford, and Redcliff (Isle of Wight). Crackers and Perna-bed of Atherfield. 2. Upper and Lower Cretaceous Species. BaRBATIA MARULLENSIS (@’Orbigny), 1844. Plate VII, figs. 4, 5 a—d, 6 a, 4, 7. 1844. Anca Marutiensis, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 205, pl. cecx, figs. 8—5. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 85 — G. Cotteau. Moll. Foss. de l’Yonne, p. 87. 1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. de Ste. Croix (Mater. Pal. Suisse, ser. 4), pt. 3, pp. 432, 468, pl. exxx, figs. l—4. 1867. — — P. de Loriol. In A. Favre, Recherch. géol. dans Savoie, &c., vol. i, p. 382. 1869. — — P. de Loriol and V. Gilliéron. Mon. pal. et strat. de Vétage Urgon. inf. du Landeron (Mém. Soc. Helvét. des Sci. Nat., vol. xxiii), p. 16, pl.i, fig. 13. 1871. — — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. i, p. 842 (Barbatia). 1883. — — W. Keeping. Foss., &c., Neoc. Upware and Brickhill, p. 114. Non 1850. Byssoarca MarkvuLuENsis, J. de C. Sowerby. In F. Diwon, Geol. Sussex, p. 3855, pl. xxviii, fig. 11. — 1878. — — Sowerby. Ibid., ed. 2, p. 385, pl. xxviii, fig. 11. Deseription.—Shell oblong, inequilateral, rather compressed. Anterior and posterior margins rounded, the postero-dorsal somewhat oblique ; ventral margin parallel to the dorsal. Umbones not prominent, rather close; carina near the BARBATIA. 39 umbones only, not well-marked. Postero-dorsal part of the shell sharply com- pressed. Hinge-area narrow, depressed, with close-set ligament-grooves. Orna- mentation consists of many equal-sized radial ribs, separated by narrow grooves, and crossed by less distinct concentric grooves. Occasionally smaller ribs (radial) appear in the grooves. On the postero-dorsal area the radial ribs are broader and more flattened. Measurements : (1) (2) (3) (4) Length. ; : . 255 . 31 . 80 . 15 mm. Height : . : : 15 me 28a Or ee Oli Thickness : : aoeeelel . ll. . — ,, (1) is. from Upware; (2)—(4) are from Folkestone. Affinities.—The shell is more rounded at the extremities and the umbones are less anterior than in Barbatia Raulini (d’Orbigny). B, marullensis is very similar to Arca Baudoniana, Cotteau;' the latter is of larger size, and may be only an older example of the former. It is also related to A. aubersonensis, Pictet and Campiche.? Arca Hugardiana, VOrbigny, differs in the ventral margin being oblique, and in having coarser radial ribs and less distinct concentric ornament. In Arca Galli- ennei, d’Orbigny, the umbones are more anterior (see p. 41). Remarks.—I have seen only two examples from the Lower Greensand, both from Upware, but the species has been recorded from Faringdon; it is not common in the Gault. The concentric ornament is not distinctly seen in the Upware specimens, but that is probably due to the somewhat worn nature of the shell. Types.—Specimens which agree well with the figures are in the d’Orbigny Collection, but I could not identify the type with certainty. Distribution. —Lower Greensand of Upware, and (fide Morris) of Faringdon. Gault (zones ili, vil, x, xi) of Folkestone. ? Cambridge Greensand (internal moulds only). 1 «Moll. Foss. de ’Yonne’ (1855), p. 86; Pictet and Campiche, “Foss. Terr. Crét. de Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 4), pt. 3, p. 482, pl. exxx, fig. 5. ? Tbid., p. 433, pl. exxx, fig. 6. 40 CRETACEOUS LAMELLIBRANCHIA. 3. Upper Cretaceous Species. Barsatia Hucarpiana (d’Orbigny), 1844. 1844. Anca Huaarpiana, A. d’Orligny. Pal. Frarg. Terr. Crét., vol. iii, p. 216, pl. ceexii, figs. 4—6. 1850. — — — Prodr. de Pal., vol. ii, p. 188. 1852, — —— F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Geneve, p. 457, pl. xxxvi, fig. 1. 1866. — _ F. J. Pictet and G. Campiche. Yoss. du Crét. de Ste. Croix (Matér, Pal. Suisse, ser. 4), pt. 3, p. 460. 1s7l. — _ F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. 1, p. 843 (Barbatia). 1875. — -- A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi, p. 299 (? partim). Some internal casts from the Cambridge Greensand (derived) may perhaps belong to this species. BarBaTiA RoTUNDATA (Sowerby), 1836. Plate VII, figs. 8 a—e. 18386. Arca rotunpata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, p- 342, pl. xvii, fig. 8. 1848. — rorunpira, H. P. Nyst. Tableau des Espéces vivant et foss. des Arcacées (Mém. Acad. Roy. Belgique, vol. xxii), p. 64. 1854. — rotunpata, J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 1866. — i F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 1, p. 473. 1871. — — F. Stoliczka, Paleont. Indica, Cret. Fauna S. India, vol. iil, p. 843 (Barbatia). Description. —Shell moderately convex, oblong, inequilateral, highest pos- teriorly. Anterior and posterior margins rounded; ventral oblique to the hinge- line, sinuous at the middle. Umbones close together, with an ill-defined posterior carina. Shell much compressed postero-dorsally; also slightly compressed ventral to the umbones. Ornamentation consists of numerous fine radial ribs separated by narrow grooves, and crossed by a few distant concentric growth- lines. Interior not seen. Measurements : Length . ; : : : : : 5 . 26mm. Height (approximate) . : : 2 ; 5 1S) be) BARBATIA, 41 Affinities.—Barbatia rotundata appears to be closely related to d’Orbigny’s! Arca Raspailli, but without seeing specimens of the latter, and with only one example of the former before me, I am unable to determine their relationship. B. rotundata is much smaller than the figured forms of A. Raspailli, and seems to be proportionately more convex. B. Hugardiana (a Orbigny) is proportionately longer and more coarsely ribbed. B. Galliennei (V Orbigny) is not so high posteriorly. T'ype.—Bristol Museum, This is the only specimen I have seen. Distribution.—Blackdown Greensand. BARBATIA VENDINENSIS (d’Orbigny), 1844. 1844, ARCA VENDINENSIS, A. d'’Orbigny. Pal. Frang. ‘err. Crét., vol. iii, p. 220, 1850. 1866. 1871. ? 1897. pl. ecexv, figs. 4—7. — Prodr. de Pal., vol. ii, p. 164. F. J. Pictet and G. Campiche. Foss. du Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 474. F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. iil, p. 843 (Barbatia). A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. vi, Die Chlomeker Schichten, p. 57, fig. 63. An imperfect right valve from the Chalk Marl (Meyer’s Bed 10) of Dunscombe, in Mr. Meyer’s Collection, probably belongs to this species. BarpatiA GALLIENNEI (d’Orbigny), 1844. Plate VII, figs. 9 a, b. 1844, Anca GaLLIENNEI, A. d'Orbigny. Pal. Franc. Terr. Crét., vol. ili, p. 218, 1850. 1866. 1867, 1871. 1873. 1895. pl. ecexiv. — Prodr. de Pal., vol. ii, p. 164. FE. J. Pictet and G. Campiche. Foss. Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 478. BE. Guéranger. Album Pal., p. 16, pl. xxi, fig. 4. FE. Stoliezka. Palwont. Indica, Cret. Fauna S. India, vol. ili, p. 843 (Barbatia). H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palewon- tographica, vol. xx), pt. 1, p. 220, pl. xlviii, figs. 20—22. E, Tiessen. Zeitsch. d. deutsch. geol. Gesellsch., vol. xlvii, p. 482. - 1% Pal. Frane. Terr. Crét.,’ vol. iii (1847), p. 766 (nom. mut.) ; ibid. (as A. Reguieniana), p. 239, pl. ceexxvi, figs. 1, 2; ‘ Prodr, de Pal.,’ vol. ii (1850), p. 196, No. 187. 6 42 CRETACEOUS LAMELLIBRANCHIA. Remarks.—I have seen only a few specimens—all internal casts—of this species. Distribution.—Base of the Chalk Marl (zone of Schlanbachia varians) of Lyme Regis, and Titherleigh, near Chard. Barat, sp., cf. Gernirzt (Reuss), 1844. Plate VII, figs. 10a, b, 11. Cf. 1842. Arca rapiata, H. B. Geinitz (non Goldfuss). Char. der Schicht. und Petref. sichs-bohm. Kreidegeb., pt. 3, p. 78, pl. xx, figs. 13, 14. — 1844. — Gernirzai, A. H. Reuss. Geogn. Skizzen, vol. ii, p. 192. — 1846. — _ — Die Verstein. der bohm. Kreideformat., pt. 2, p. 11, pl. xxxiv, fig. 31. — 1852, — — ? R. Kner. Denkschr. d. k. Akad. Wissensch. Math-nat. Cl., vol. iii, p. 314, pl. xvi, fig. 27. — 1869. — — E. Favre. Moll. Foss. de la Craie des Envir. de Lemberg, p. 125, pl. xii, figs. 15, 16. — 1873. — — 4H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palzonto- graphica, vol. xx), pt. 2, p. 55, pl. xvi, figs. 7, 8. — 1889. — — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. iv. Die Teplitzer Schichten, p. 79, fig. 63. 1897. — (Barparta), sp., cf. Gernrrzt, H. Woods. Quart. Journ. Geol. Soc., vol. liii, p. 878, pl. xxvii, figs. 5, 6. Measurements : Length (approximate) d : : : : . 23 mm. Height z ee en er at hae eee Remarks.—A specimen consisting of an internal and part of an external mould appears to agree with A. Geinitzi in form, but seems to differ in possessing rather finer ribs. It is, perhaps, the form figured by J. de C. Sowerby as Byssoarca marullensis,' from the Chalk of Kent. Distribution.—Chalk Rock (zone of Heteroceras Reussianum) of Cuckhamsley. Barzatia, sp. Plate VII, figs. 12 a, 6. Arca, sp. ef. Gatt1ennet, H. Woods. Quart. Journ. Geol. Soc., vol. lil, p. 378, pl. xxvii, fig. 38. 1 Sowerby (non d’Orbigny), in F. Dixon’s ‘ Geol. Sussex’ (1850), p. 355, pl. xxvili, fig. 11. I have not been able to find the original of Sowerby’s figure. BARBATIA., 43 Measurements : Length . ; . ‘ ; : ; : . 33 mm. Height. : F : : . : ; EAD. gs Remarks.—There are two internal casts of left valves from Cuckhamsley in the Montagu Smith Collection, Woodwardian Museum, which, in general form, agree with A. Galliennei, d’Orbigny, except that they are proportionately shorter. Distribution.—Chalk Rock (zone of Heteroceras Reussianuwm) of Cuckhamsley. Barzatia? sp. Plate VII, figs. 13 a, b. 1897. Arca, sp., H. Woods. Quart. Journ. Geol. Soe., vol. li, p. 379, pl. xxvu, fig. 4. Description.—Shell elongate, oblique, very inequilateral. Anterior margin forming an angle with the hinge-line, and curving ventrally to join the ventral margin, which is nearly straight, but has a considerable slope posteriorly. Posterior margin oblique, somewhat rounded. Umbones apparently sharp, pointing anteriorly ; shell compressed dorsal to a line between the umbo and the postero-ventral extremity. Surface with well-marked lines of growth; radial ribs extend from the umbo posteriorly, and perhaps occur also on other parts of the shell. Measurements : Length . : ; ; : ‘ . : . 13mm. Height . : : . , : : : ; 6.5 Remarks.— This form is at present known by one specimen only, an internal cast, but showing indications of ornament. It resembles Arca strehlensis, Geinitz,! from the Pliner-Kalk of Strehlen (Dresden), but in that species the shell is less oblique, and the surface is generally smooth except on the anterior part, which is marked with radial ribs. Distribution —Chalk Rock (zone of Heteroceras Reussianum) of Cuckhamsley. 1“ Das Elbthalgeb. in Sachsen”’ (‘ Paleontographica,’ vol. xx), pt. 2, 1873, p. 56, pl. xvi, fig. 5. 44 CRETACEOUS LAMELLIBRANCHIA. Genus—Graumatovon, Meek and Hayden (1860), 1864." [‘ Proc. Acad, Nat. Sci. Philad.,’ 1860, p. 419 (list name) ; “ Paleontology of the Upper Missouri,” ‘Smithsonian Contrib. to Knowledge,’ vol. xiv, No. 172, 1864, p. 89, pl. ii, fig. 9.] Grammatopon sucuris (Leymerie), 1842. Plate VII, figs. 14a, b, 15a, b; Plate WII, figs 2: 1829. Cucurima, J. Phillips. Geol. Yorks., pt. 1, p. 186, pl. ii, fig. 16. 1842. — sEcuURIS, A. Leymerie. Mém. Soc. Géol. France, vol. v, p. 6, pl. vii, figs. 6, 7. 1844. Anca securis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 208, pl. eecix, figs. 9, 10. 1845. — — E. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 246. 1850. — — A, d’Orbigny. Prodr. de Pal., vol. 11, p. 80. 11854 — = J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 1855. — _ G. Cotteau. Moll. Foss. de l’Yonne, p. 87. 1861. — - P. de Loriol. Anim. Invert. Foss. du Mont Saléve, p. 86, pl. x, fig. 8. 1866. — _ F. J. Pictet and G. Campiche. Foss. Terr. Crét. de Ste. Croix (Mater. Pal. Suisse, ser. 4), pt. 3, pp. 443, 469. 1875. Cucunima secunrts, J. Phillips. Geol. Yorks., pt. 1, ed. 3, p. 328, pl. ii, fig. 16. 1896. Arca sEcurIs, A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlviii, p. 845. Measurements : Length : : ; : . : : - ail mm: Height : : . : 5 : : 2 lt Thickness . ; : 5 RS ; f . é Affinities —This form, as was pointed out by de Loriol, is very similar to Grammatodon carinatus (Sowerby) (see p. 45), and I think it is possible that they may prove to be identical, but until more specimens have been obtained I shall regard the two as distinct. In G. secwris the area appears to be broader than in G. carinata ; and also on the left valve of the former the ribs are more widely separated than in the latter, and there are small ribs in the interspaces. Cucullea Schiisteri, Roemer,’ is perhaps an allied form, but I have seen no speci- men of it. Remarks.—The specimen figured by d’Orbigny is proportionately longer than 1 For the synonymy of this genus see Woods, ‘Ann. Mag. Nat. Hist.,’ ser. vii, vol. iii (1899), p. 47. To the names there given should be added Beushausenia, Cossmann, ‘ Rev. crit. Paléozool.’ (1897), p. 93. 2 «Die Verstein des nord-deutsch. Kreidegeb.’ (1841), p. 70, pl. ix, fig. 3. GRAMMATODON. 45 the English forms, but other examples in the d’Orbigny Collection do not differ from ours. Types.—I have not seen the types; they are stated to have come from Dienville. The specimen from Speeton figured by Phillips (vide supra) is in the York Museum. Distribution.—Speeton Clay (B. zone of Bel. brunsvicensis) of Speeton. ? Sandgate Beds of Sevenoaks. GRAMMATODON CARINATUS (Sowerby), 1813. Plate VIII, figs. 3 a—d, 4a—c, 5, 6, 1813. 21895. 1897. 7a, b, 8. Arca carinata, J. Sowerby. Min. Conch., vol. i, p. 96, pl. xliv (lower figure). CucuLi#a cosreLLata, J. de C. Sowerby. Ibid., vol. v, p. 67, pl. eecexlvii, fig. 2. — STRIATELLA, H. Michelin. Mém. Soc. Géol. de France, vol. iii, p- 102, pl. xii, fig. 11. Arca caRiInaTa, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 214, pl. ceexiii, figs. 1—3. — (Cucunima) costertata, A. HE. Reuss. Die Verstein. d. bohm. Kreideformat., pt. 2, p. 11. — cartnata, A. d’Orbigny. Prod. de Pal., vol. ii, pp. 188, 164. a= _— F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Genéve, p. 462, pl. xxxvii, fig. 1. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 185. Cucurt#sa cosreLnata, J. Morris. Ibid, p. 197 (not from locality given). Arca caRata, G. Cotteau. Moll. Foss. de |’Yonne, p. 87. — F. J. Pictet and G. Campiche. Foss. du Terr. Creét. de Ste. Croix (Mater. Pal. Suisse, ser. 4), pt. 3, pp. 463, 472. — cosTELLata, Pictet and Campiche. Ibid., p. 471. — carinata, A. Briart and F. L. Cornet. Descript. de la Meule de Bracquegnies (Mém. cour. et Mém. des Savants étrang., Acad. Roy. Belg., vol. xxxiii), p. 56, pl. v, figs. 15, 16. — — and A. cosTeLLAta, F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ili, p. 8343 (? Grammatodon). — — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx), pt. 1, p. 228 (?), pl. xlix, figs. 5 (?), 6 (from the Upper Greensand, Isle of Wight). — J. Kiesow. Schrift. nat. Gesellsch. Danzig, N. F., vol. y, p- 239. = E. Tiessen. Zeitsch. d. deutsch. geol. Gesell., vol. xlvii, p. 482. Cucuriza cantnata, R. B. Newton. Proc. Dorset Nat. Hist. and Antiq. Field Club, vol. xviii, pp. 72, 84, pl. ii, fig. 6. 46 CRETACEOUS LAMELLIBRANCHIA. Non 1837. Anca carinara, A. Goldfuss. Petref. Germ., vol. il, p. 150, pl. exxiv, fig. 2. -—— 18387. — — F.C. L. Koch and W. Dunker, Norddeutsch. Oolithgeb., p. 32, pl. ii, fig. 14. Description.—Shell elongate, trapezoidal, inflated, inequilateral, rather short anteriorly. Dorsal and ventral margins nearly parallel. Anterior margin joming the ventral in a gradual and regular curve, but forming with the hinge-line a sharp angle, which constitutes the anterior extremity of the valve. Posterior margin oblique, more or less sinuous ventrally, and forming sharply-marked obtuse and acute angles with the dorsal and ventral margins respectively. Umbones rather prominent, much incurved, with a sharp, finely crenulate carina, which extends in a double curve to the postero-ventral angle, and thus cuts off from the rest of the shell a deeply concave postero-dorsal area. Hinge-line nearly or quite equal to the length of the shell. Hinge-area fairly broad, with a varying number (often six or more) ligament-grooves. Surface of shell ornamented with numerous, distinct, rather flattened radial ribs, separated by narrower grooves, and sometimes crossed by concentric striz#. On the anterior part of the shell the radial ribs become narrower, much more elevated, more widely separated, and are crossed by distinct ridges; smaller ribs may be seen in the grooves. In most specimens well-marked growth-lines may be seen at rather distant intervals. On the postero-dorsal area the ribs are narrow and separated by wider depressions ; these ribs are more or less crenulate, and are cut by fine concentric ribs, giving a cancellated appearance ; a central, and sometimes also two other inner radial ribs, are more elevated than the others. Teeth finely striated, curving obliquely outwards from under the umbo; antero-laterals oblique; postero-laterals long and parallel to the hinge-line. Posterior adductor impression without projecting edge. Margins faintly crenulate.’ Measurements : GQ) (@) ©) (5) (6) Length . F : ; . 29 45 22 21 245 30 mm. Height . : : : BGS 2 90 e226 sail. ese ee Thickness : j F ._—- — — 12 15 PANO ecy (1) is from the Upper Greensand of Devizes; (2) and (3) are from the Gault of Folkestone ; (4—6) are from the Blackdown Greensand. Affinities —This species is closely related to Cucullaa securis, Leymerie (vide supra). Remarks.—The form described by Sowerby as Arca carinata came from the Upper Greensand of Devizes Canal; it has been regarded by d’Orbigny and some other authors as identical with Cucullea costellata, Sowerby, from the Blackdown ? Seen only in a few well-preserved specimens. TRIGONOARCA. 47 Greensand, the apparent differences between the two forms being explained by the imperfect state of preservation of the specimens from the Upper Greensand of Devizes. A comparison of a number of examples from these and other localities confirms the view of d’Orbigny. The specimens from the Gault are, on the average, of larger size than those from the Blackdown Greensand, and, owing to their different mode of preserva- tion, differ a little in appearance from the latter. The record of this species from the Lower Greensand of Kent, given by Morris, is apparently erroneous. Types.—The types of both Arca carinata and Cucullea costellata are in the British Museum. Distribution.—Greensand of Blackdown (zones viii to xii, especially x) and Haldon. Upper Greensand of Devizes and Ventnor. Gault of Black Ven. Zones of Acanthoceras mammilatum and Hoplites interruptus at Okeford Fitzpaine. Gault (zones 1, 11, vili—x) of Folkestone. Chalk Marl (zone of Schlenhachia varians) of Ventnor and Folkestone. Genus—Triconoaroa, 7. A. Conrad, 1863. [‘ Proc. Acad. Nat. Sci. Philad.’ (1862), 1863, p. 289; ibid., 1872, p. 54; ‘Amer. Journ. Conch.,’ vol. iii (1867), p. 9; Appendix to W. C. Kerr’s ‘Rep. Geol. Surv. N. Carolina, vol. i, 1875 (Raleigh) ; figured, ‘Journ. Acad. Nat. Sci. Philad.,’ ser. 2, vol. iv (1860), p. 281, pl. xlvii, fig. 20.] Triconoarca Passyana (d’Orbigny), 1844. Plate VIII, figs. 9 a—c, 10a, b. 1832. CucunLea cartnata, A. Passy (non Sowerby). Descript. Géolog. de la Seine-Infér., p. 8 (of expl. of plates), pl. xiv, fies. 11, 12. 1844. Anca Passyana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 241, pl. eeexxvii, figs. 1, 2. 1850. — — = Prodr. de Pal., vol. ii, p. 164. 1866. — _ F. J. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 38, p. 475. 1871. — _- F. Stoliczka. Palwont. Indica, Cret. Fauna S. India, vol. ii, p. 843 (Zrigonoarca). 1896. — _ tLicertensis, A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soce., vol. lii, p. 153 (from Chard). 21897. Cucutnrma Passyana, R. Leonhard. Die Fauna der Kreidef. in Ober- schles. (Paleeontographica, vol. xliv), p. 51. Description.—Shell oblong, more or less elongate, convex, inequilateral, rather short anteriorly. Ventral margin nearly straight, placed a little obliquely ; 48 CRETACEOUS LAMELLIBRANCHIA. anterior margin rounded ; posterior nearly straight and very oblique, forming an acute angle with the ventral margin. Umbones rather prominent, with a carina which extends to the postero-ventral angle, and cuts off a depressed postero- dorsal area. Ornamentation consists of very fine radial ribs. Hinge a little curved; teeth numerous, gradually becoming larger and more oblique toward the extremities. Measurements : () (2) (3) (4 (5) (6) Length : ‘ ; : . 58 50 37 57 62 48mm. Height ; : : : PPADS TSC 20 1399439 35), Thickness. : 48 35 — 39 39 30 ,, (1) From the Chloritie Marl, Warminster. (2) From the base of the Chalk Marl, Chard. (3) From the Upper Greensand, Kingskerswell, (4—6) From the Cenomanian, Rouen. Affinities.—This species is very similar to U'rigonoarca ligeriensis (d’Orbigny),’ with which it may prove to be identical; that form is said to be distinguished by its greater convexity and more widely separated umbones. Jt appears also to be related to d’Orbigny’s Arca royana,’ but that form is only known by its cast. Remarks.—This species was founded on internal casts from the Cenomanian of Rouen. The only specimen I have seen with the shell preserved is a silicified example from the Greensand of Kingskerswell (British Museum, No. L. 1853); an internal mould from the same locality and collection shows the character of the hinge. The internal casts from various localities agree perfectly with specimens obtained from Rouen. Types.—Some specimens from Rouen, but apparently not the type, are in the d’Orbigny Collection. Distribution.—Base of the Lower Chalk (zone of Schlenbachia varians) of Chard. Chloritie Marl of Maiden Bradley, Urchfont (near Devizes) and War- minster. Upper Greensand of Kingskerswell. 1 «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 227, pl. ceexvii, figs. 1—3 (not 4, 5). 2 Tbid., p. 243, pl. ecexxvii, figs. 3, 4. CUCULLAMA. 49 Genus—CucutLma, Lamarck, 1801. [‘Syst. Anim. sans Vert.,’ p. 116.] 1. Lower Cretaceous Species. Cucutuma Forpesi (Pictet and Campiche), 1866. Plate IX. 1845. Arca ExaLrara (?), #. Forbes (non Nilsson). Quart. Journ. Geol. Soc., vol. i, p. 245, pl. ii, fig. 5. 1850. — _ Gasrirtis, 4. d'Orbigny. Prodr. de Pal., vol. ii, p. 80 (partim). 1854. CucuLn®a easrietis, J. Morris. Cat. Brit. Foss., ed. 2, p. 197. 1866. Anca Forest, F. J. Pictet and G. Campiche. Foss. Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 471. Description.—Shell stout, much inflated, regularly convex, trapezoidal, in- equilateral. Anterior margin shorter than the posterior, and forming with the hinge-line about a right angle. Ventral margin slightly curved, or in part nearly straight, sloping posteriorly. Posterior margin nearly straight, oblique, forming with the hinge-line an obtuse angle, and with the ventral margin a rounded acute angle, which is usually the most ventral part of the shell. Umbones prominent, incurved, pointed, widely separated, with a sharply defined carina extending to the postero-ventral angle, and cutting off a flattened postero-dorsal area, which is sharply bent with regard to the rest of the valve. Hinge-area very large, with numerous close-set ligament-grooves; margins curved, bounded by a ridge. Ornamentation consists of many slender, sharp, radial ribs, separated by rela- tively broad and shallow grooves, which are crossed at regular intervals by fine concentric ribs. On the anterior part of the shell the radial ribs become more prominent and less numerous. On the postero-dorsal area, except near the umbo, the radial ribs are much less distinet than elsewhere, but numerous radial striae crossed by lines of growth are seen. Hinge-line long, sometimes five-sixths of the length of the shell. Central teeth numerous, perpendicular ; lateral teeth few, and parallel to the hinge-margin. Measurements : (1) (2) (3) (4) (5) Length . . : : . 8&6 79 72 65 63 mm. Height . : ; : A Lt 76 60 65 5G a Thickness. : : sO 95 fil 70 COL sy ( 50 CRETACEOUS LAMELLIBRANCHIA. Affinities.—Cucullea Forbesi is closely related to OC. Gabrielis, Leymerie,' but differs from it in the presence of strong radial ribs on the adult shell. In C. Gabrielis (of which I have seen three or four very perfect specimens) these ribs are found on the young parts only, and are but faintly marked. Cucullea tumida, Matheron, is perhaps related to C. Forbesi; it was founded on an internal cast. C. Forbesi is distinguished from Arca Moreana, d’Orbigny,’ by its strong carina and more widely separated umbones. The form figured by Coquand® as Arca dilatata (from the Aptian of Obon, Arcaine, &c.) is very near to C. Forbesi; but the shell is longer posteriorly, and the radial ribs are not seen. A. Gresslyi, de Loriol,* is, perhaps, closely allied to CO. Forbesi, but is at present imperfectly known. Types.—From Atherfield. I have not seen the original of Forbes’ figure (1845). Distribution.—Perna-bed of Atherfield. Also, according to Fitton, in Beds iii, vi, ix, and xiii of Atherfield. Cucunnma Cornvettana (d’Orbigny), 1844. Plate VIII, figs. 11—13; Plate X, figs. 1 a—e, 2a, b, 3. 1844, Arca Cornvetiana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. ii, p. 208, pl. ceexi, figs. 1—3. 1845. — _— E. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 246. 1850. — — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 80. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 185. 1855. — _ G. Cotteau. Moll. Foss. de l'Yonne, p. 86. 186]. — —_ P. de Loriol. Anim. Invert. Foss. du Mont Saléve, p. 86, pl. x, fig. 7. 1866. — _— F. J. Pictet and G. Campiche. Foss. Terr. Cret. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, pp- 445, 469. 1867. — - P. de Loriol. In A. Favre, Recherch. géol. dans Savoie, &e., vol. i, p. 380, pl. ¢, fig. 9 1871. — -- F. Stoliczka. Palwont. Indica, Cret. Fauna 8. India, vol. il, p. 842 (? Trigonoarca). 21883. Cucunnma suBNANA, W. Keeping. Foss., &c., Upware and Brickhill, p.115 pl. v, fig. 10. 1«Mém. Soe. Géol. de France,’ vol. v (1842), p- 6, pl. vii, fig. 5; d’ One Pal. Frang. Terr, Crét.,’ vol. iii (1844), p. 198, pl. ceeviii. 2 D’Orbigny, ibid., p. 200, pl. eecix, figs. 1—3. 5 Mon. de l’étage Aptien de l’Rspagne ’ (1865), p. 189, pl. xxii, figs. 1, 2. 4 Anim. Invert. foss. Néoc. du Mt. Saléve’ (1861), p. 87, pl. xi, figs. 1—8. CUCULL AA. al 1898. CucuLitza (IponEarca) Cornveviana, EF. G. Skeat and V. Madsen. Dan- marks geol. Undersog., vol. 11, p. 167, pl. vi, fig. 5. ? Non 1846. Anca (CucuLLz,) Cornuetrtana, A. FE. Reuss. Die Verstein. der bohm. Kreidetormat., pt. 2, p. 13. Description.—Shell more or less oblong, convex, a little inequilateral. Anterior border forming an angle (90° or more) with the hinge-line, gradually curving toward the ventral border. Ventral border curved. Posterior border nearly straight, oblique, forming a rounded angle with the curved ventral border. Umbones of moderate size, close together; no distinct carina, but the shell is sharply bent along a line passing from the umbo to the postero-ventral angle ; this flattened part is divided into two nearly equal parts by a narrow carina passing from the umbo posteriorly; on the right valve the carina is thread-like and crenulated; on the left valve it is less sharply defined. Area small, narrow. Ornamentation consists of numerous fine concentric ribs or striw, and radial ribs usually less distinct than the concentric, but well marked anteriorly. Hinge- line relatively long. Central teeth transverse; lateral teeth parallel to the hinge- margin, striated. Measurements : (1) (2) (3) (4) Length . , : ; : fDi, 20°5 38 28 mm. Heicht . y ; : ; . 22 21 32 25) «,, Thickness. : : : . 19 20 — — , Afjinities.—This species is closely related to C. glabra, Parkinson (see p. 57), but it never attains such large size, and its average is much smaller. It varies considerably in the proportion of length to height ; in some eases the valves are only a little longer than high—in this respect differing from the type. Many forms are proportionately longer than is ever the case with C. glabra. The umbones are less prominent and less pointed than in the latter species. Arca Robinuldina, d’Orbigny, differs from this species in possessing a sharply defined carina, &e. I am inclined to think that the three specimens from Upware (preserved in the Woodwardian Museum), which were referred by W. Keeping (vide supra) to C. subnana, Pictet and Roux, belong to C. Cornueliana. Types.—I did not find the types in the d’Orbigny Collection. Distribution.—Crackers and Lower Crioceras Group of Atherfield. Bed xiv of Blackgang Chine (fide Fitton). Atherfield Beds of East Shalford. ? Lower Greensand of Upware. Or we CRETACEOUS LAMELLIBRANCHIA. SucuLLmA Frrront (Pictet and Campiche), 1866. Plate X, figs. 4 a—d, 5—7. 1857. Arca Ropinanpina, FF. J. Pictet and HB. Renevier (non d’Orbigny). Foss. Terr. Aptien, &v. (Matér. Pal. Suisse, ser. 1), p. 105, pl. xv, fig. 4. 1866. — Frrront, #. J. Pictet and G. Campiche. Foss. Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 8, pp. 455, 471. 1871. — — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ill, p. 843 (? Drigonoarca). Description.--Shell more or less oblong, rather inflated, equilateral or shghtly inequilateral. Anterior margin evenly rounded, passing gradually into the ventral, which is parallel to the dorsal margin, but curves toward the postero-ventral angle. Posterior margin nearly straight, oblique. Umbones moderately large, nearly median, separated by only a small space, with a very sharp carina, curved, and passing to the postero-ventral angle. The postero-dorsal area is sharply de- pressed, and near its ventral third bears another carina. Hinge-line rather short ; area small, with many ligament-grooves. Ornamentation consists of many fine concentric grooves, and on the antero-dorsal part of the shell of a few radial ribs ; postero-dorsal area with many radial ribs. Central teeth (about ten) transverse ; lateral teeth longitudinal. Interior not seen. Measurements : (1) (2) Length . é 5 19°5 : : 14. mm. Height . : : 15 ; a eee Thickness : : 12°5 ; g BPSY 55 Affinities —This form is probably only a local variety of Arca Kobinaldina, dOrbieny ; it differs from that in being less elongate posteriorly. In d’Orbigny’s figure of A. Robinaldina the ventral margin has a greater curvature than in any of the specimens which I have seen in the Paris museums. Arca Cornueliana, VOrbigny, is distinguished from C. Fittont by the absence of the sharp carina. Arca xquilateralis, Briart and Cornet, is very similar to C. Fittoni, but it appears to be proportionately shorter, and to have the anterior margin less curved. Distribution.—Crackers of Atherfield. Atherfield Beds of East Shalford. CucULLaA vaGANs, Keeping, 1883. Plate X, figs. 8—10. 1883. Cucunnma vaaans, W. Keeping. Foss., &c., Neoc. Upware and Brickhill, p. 151, pl. vi, fig. 8. 1883. — ERRANS, Keeping. Ibid., pp. 38, 34, 86, 65 (nom. nud.). CUCULLAA. 53 Deseription.—Shell rather stout, rounded, nearly equilateral. Anterior margin rounded; posterior a little truncated ; ventral curved. Umbones promi- nent, incurved. Hinge-area relatively broad. Posterior part of shell sharply bent. Ornamentation consists of strong, equal, regular ribs, separated by broader grooves; the grooves are crossed at regular intervals by fine concentric ribs. Central teeth transverse; lateral parallel to the hinge-line. Margins of valves coarsely toothed. Measurements : Length . : ; : , : : , - 20cm: Height . F : ; : ' : ‘ : iStees Remarks.—This form, which at present is only known by a few rather imperfect specimens, appears to be clearly distinguished by the character of its ornamentation. Cucullexa errans, Keeping, nom. nud., I think undoubtedly refers to this species; the name was used in the earlier part of Keeping’s work (vide supra), and the remarks there made concerning it agree perfectly with those given later in connection with C. vagans. This view is further supported by the fact that on the back of the tablet which bears the type-specimens of C. vagans there is written in Keeping’s handwriting ‘‘ C. errans, W. K.”’ Types.—In the Woodwardian Museum, Cambridge. Distribution —Lower Greensand (black grit nodules) of Upware. ? Spilsby Sandstone of Spilsby. Sub-genus—DIcraNnovonta, s.-g. nov. Shell stout, subquadrate or rounded, Hinge-area broad. Hinge-plate large, curved; central teeth transverse; lateral teeth long, parallel, often bifurcating. No posterior adductor plate. Type.—Cucullea donningtonensis, Keeping (Pl. X, figs. 11—14; Pl. XI, fig. 1). Claxby Ironstone. curved ventrally, nearly The form described by Keyserling,' and by F. Schmidt,’ as Pectunculus petschore probably belongs to this sub-genus. The latter author was inclined to regard it as the type of a new genus. 1 «Reise in das Petschora-land’ (1846), p. 306, pl. xvii, figs. 5, 6. “ Resultate der Mammuthexpedit.,” ‘ Mém. Acad. Imp. Sci. St. Pétersbourg,’ ser. 7, vol. xviii, No. 1 (1872), p. 151, pl. i, fig. 14; pl. iiia, fig. 17. no 54 CRETACEOUS LAMELLIBRANCHIA. CucuLima (DicRANODONTA) DONNINGIONENSIS, Keeping, 1883. Plate X, figs. 11 a—e, 12—14; Plate XI, figs. la, b, 2. 18838. CuctuLnL®a ponninetonrnsis, W. Keeping. Foss., &c., Neoc. Upware and Brickhill, p. 152, pl. vii, fig. 9. Description.—Shell stout, subquadrate, rounded, a little equilateral, rather convex. Anterior margin rounded, uniting with the ventral in a regular curve. Ventral margin nearly parallel to the dorsal. Posterior truncated, slightly oblique, more or less curved, and forming with the ventral border a rounded angle usually a little less than a right angle. Umbones prominent, pointed, well separated; no distinct carina, but behind a line drawn from the umbo to the postero-ventral angle the shell is sharply compressed. Anteriorly the shell is gently compressed. Hinge-area broad, shorter than the length of the shell, usually three-fifths to four-fifths of the latter; ligament-grooves numerous, close-set, very regular. Ornamentation consists of well-marked but slightly elevated radial ribs, which are less distinct on the posterior slope of the shell; between these ribs are from two to five smaller ribs; lines of growth, usually faintly marked, occur at intervals. Hinge-plate large, extending ventrally along the anterior and posterior margins of the shell; central teeth small, transverse, becoming a little oblique laterally ; lateral teeth long, usually three or four at each end, curved ventrally oO? so as to be nearly parallel to the tmner border of the hinge-plate, and usually bifureating. No posterior adductor plate. Margins coarsely crenulate. Measurements-: @ (2) @) @ ©) © Length 3 : : : . 92 51 48 41 385 19 mm. Height : é : : . 49 49 45 38 30 16 ,; Thickness. : : : . 48 42 36 32 25 12 ,, Affinities.—This species appears to be closely allied to Arca Sablieri,’ Coquand, from the Aptian of Josa, bon, and Arcaine (Spain), but that form, so far as I am able to tell froin the figures and description, differs in the shell being higher and shorter, and in having a trellis-like ornamentation. Coquand refers the specimen figured by Vilanova® as Arca fibrosa, VOrbigny, to A. Sablieri, but Vilanova’s figure appears to represent quite a different form. Remarks.—This species was founded by Keeping on an external mould in a black grit nodule from the Lower Greensand of Upware, and that author con- 1 «Mon. de l’étage Aptien de l’Espagne’ (1865), p. 187, pl. xiv, figs. 7, 8. 2 J. Vilanova y Piera, ‘ Mem. geog.-ayric. de Castellon’ (1858), pl. ii, fig. 13. CUCULLAA. 55 sidered that the form which is abundant at Donnington! was distinct. After a _ eareful comparison of a larger series of the latter with the type-specimen I am unable to see any real difference. The figure given by Keeping is not quite accurate in outline, and is drawn from a gutta-percha cast; the mould itself is not perfect at the anterior and ventral margins, and near the umbo a portion of the shell remains in it. Types.—In the Woodwardian Museum, Cambridge, from Upware. Distribution.—Lower Greensand (black grit nodules) of Upware. Claxby Ironstone (zone of Bel. lateralis) of Benniworth Haven, near Donnington. Spilsby Sandstone of Donnington. Cucutnma (Dickanoponra ?) oBLiqua (Keeping), 1883. Plate XI, figs. 3 a—e, 4. 1883. ProruncuLus opiiguus, W. Keeping. Foss., &c., Neoc. Upware and Brick- hill, p. 116, pl. vi, fig. 1. Non 1826. —_ _— Defrance. Dict. Sci. Nat., vol. xxxix, p. 224. — 1883. — obxieua, J. Lea. Contrib. Geol., p. 78, pl. iii, fig. 57. — 18385. — oBLiquus, G. Miinster. Neues Jahrb. fiir Min., &c., p. 488. — 1843. — — LI. Reeve. Conch. Icon., vol. i, pl. vi, fig. 33. Description.—Shell stout, ovate-oblong, inequilateral, moderately convex but flattened centrally. Anterior border rounded, ventral slightly curved, posterior oblique and slightly curved—forming with the ventral a blunt angle. Shell com- pressed dorsal to a line from the umbo to the postero-ventral angle. Umbones small, rather close together. Hinge-line short. Hinge-area narrow, with many ligament-grooves. Surface of shell with fine radial striz and a few fairly well- marked lines of growth. Central teeth few, small; the laterals (two or three) long, the first parallel to the hinge-margin, but the last curving ventrally. Measurements : (1) (2) : Length. : : ; : eG : 20 mm. Height. : : : : ey als eee DVemouss Thickness : : oe LO : ao “i Affinities —This form was referred by Keeping to Pectunculus, but the character of the teeth show that it cannot be placed in that genus. The concluding remark of the author mentioned (“It approaches nearest to some Jurassic species from the Great Oohte and Coral Rag”’) seems to show that he was really thinking of Cucullea rather than Pectunculus. The fact that the lateral teeth (or some of 1 Erroneously spelt Doddington by Keeping (‘ Foss. Upware,’ &e.), p. 158. 56 CRETACEOUS LAMELLIBRANCHIA. them) curve ventrally, and also the form of the shell, seem to connect this species with C. donningtonensis, Keeping (vide supra, p. 54). Remari:s.—The specific name given by Keeping is preoccupied as shown above, but, since the species is now removed from Pectunculus, the specific name can be retained. Types.—The only specimens seen are the types (three in number) from Upware, preserved in the Woodwardian Museum, Cambridge. Distribution.—Lower Greensand of Upware. 2. Upper Cretaceous Species. CucuLLma venusta, Nyst, 1848. Plate XI, figs. 5 a—c, 6a, b, 7a, b. 1836. CucuLtnma Formosa, J. de C. Sowerby. Trans. Geol. Soe., ser. 2, vol. iv, p. 342, pl. xvii, fig. 7. 1848. Arca (CucunL®a) venusta, H. P. Nyst. Tableau des Espéces vivant et foss. des Arcacées (Mém. Acad. Roy. Belg., vol. xxil), p. 76 (nom. mut.). 1850. — suBrorMosa, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 164 (nom. mut.). 1854. CucuLttma Formosa, J. Morris. Cat. Brit. Foss., ed. 2, p. 197. 1866. Arca (Cucunnma) Formosa, F. J. Pictet and G. Campiche. Foss, Terr. Creét. Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. ii, p. 473. 21868. — susrormosa, A. Briart and F. L. Cornet. Descript. de la Meule de Bracquegnies (Mém. Cour. et des Sav. étrangers, Acad. Roy. Belg., vol. xxxiv), p. 54, pl. v, figs. 11, 12. 1871. — Formosa, F. Stoliczka. Palwont. Indica, Cret. Fauna 8S. India, vol. ill, p. 843 (? ZLrigonoarca). Non 1833. Cucutima Formosa, G. B. Sowerby. Proc. Zool. Soe., pt.1, p.20. (Figured Reeve, Conch. Icon.. vol. 11, 1844, pl. ii, fig. 10.) Measurements : (1) (2) (3) Length , ; : > 8 : 7 é 4 min. Height. 5 3 sien 020 : 5b : Oe ast Remarls.—I have seen only five specimens of this form—three in the Bristol Museum and two belongmg to Mr. Meyer. The shell is not well preserved in any case. In form, and the character of the concentric ornamentation, it is near to QO. Fittoni (see p. 52), but all five specimens are much smaller. C. venusta appears to differ from C. Mittoni in beg more convex; in having the ventral margin less curved posteriorly—so that the postero-ventral angle is CUCULLAA. 5 ~ more acute; and the carina is perhaps less sharp. The inner carina and also the anterior radial ribs seem to be wanting in (. venusta. The specimen figured by Briart and Cornet from the Meule de Bracquegnies is much more pointed posteriorly than the Blackdown examples. Type.—Bristol Museum, Distribution.—Blackdown Greensand. CucuLLmHA GLABRA, Parkinson, 1811. Plate XI, figs. 8a—c, 9a, b, 10—12; Plate Non 1832. — 1882. P?— 1837. ?— 1840. AIL, figs. 1a, b, 2.:3'0, b)4). 5: Cucutima G@tasra, J. Parkinson. Org. Remains, vol. iii, p. 171. = — J. Sowerby. Min. Conch., vol. i, pl. lxvii, p. 151. os FIBROSA, Sowerby. Ibid., vol. iii, p. 9, pl. eevii, fig. 2. — CARINATA, Sowerby. Ibid., vol. iii, p. 9, pl. cevil, fig. 1. ARCA GLABRA, A. Goldfuss. Petref. Germ., vol. ii, p. 149 (partim), pl. exxiv, figs. La, b (? Le). — Fiprosa, A. d'Orbigny. Pal. Franc. Terr. Crét., vol. ili, p. 212, pl. ecexii. = — — Prodr. de Pal., vol. ii, p. 188. = —_ F. J. Pictet and W. Rouw. Moll. Foss. Gres Verts de Genéve, p. 463, pl. xxxvii, fig. 2. CucuLLza GLABRA, J. Morris. Cat. Brit. Foss., ed. 2, p. 197. — FipRosa, Morris. Ibid., p. 197. Arca FiBrosa, G. Cotteau. Moll. Foss. de Yonne, p. 838. — avasra, FF. J. Pictet and E. Renevier. Foss. du Terr. Aptien de la Perte du Rhone, &e. (Mater. Pal. Suisse, ser. 1), p. 104. Iponrarca FrBrosa, 7. A. Conrad. Proc. Acad. Nat. Sci. Philad. for 1863, p. 289. Arca GuaBRa, F. J. Pictet and G. Campiche. Yoss. Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 8, pp. 456, 473. = = A. Briart and F. L. Cornet. Descript. de la Meule de Bracquegnies (Mém. Cour. et Mém. des Sav. etrangers, Acad. Roy. Belg., vol. xxxiv), p. 55, pl. v, figs. 1—6. Iponearca @buaBra et J. rrprosa, 7. A. Conrad. Proc. Acad. Nat. Sci. Philad., p. 54. Arca @tapra, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palwonto- graphica, vol. xx), pt. 2, pl. xlix, fig. 2 (mon figs. 1, 3). CucuLn#a Gtabra, A. Passy. Descript. géol. de Ja Seine-Inférieure, p. 8 (of explanation of plates), pl. xiv, fig. 10. —— caRINATA, Passy. Ibid., p. 8, pl. xiv, figs. 11, 12. Anca carinata, A. Goldfuss. Petref. Germ., vol. ii, p. 150, pl. exxiv, fig. 2. Cuountma ataBra, H. B. Geinitz. Char. der Schichten und Petrefacten des sachsisch. Kreidegeb., pt. 2, p. 49. 8 58 CRETACEOUS LAMELLIBRANCHIA. Non 1842. Cucunn#a @uasra, P. Matheron. Catal. méthod. et descript. des Corps foss. du Bouches-du-Rhone, p. 161. — 1843. — — 4H. B. Geinitz. Die Verstein. von Keislingswalda, p. 14, pl. iii, figs. 4—7. ?— 1846. Arca (Cucunn#a) ataBra, A. FE. Reuss. Die Verstein. der bohm. Kreide- format., pt. 2, p. 18, pl. xxxiv, fig. 44; pl. xxxv, figs. 1, 2. — 1847. — Guapra, J. Miller. Petref. der Aachen. Kriedeformat., pt. 1, p. 18. — 1847, Cucunima evapra, Miller. Ibid., p. 19. — 1858. Arca rrBrosa, J. Vilanova y Piera. Mem. geog.-agric. de Castillon, pl. ii, fig. 13. ?— 1863. CucuLtma anaBra, R. Drescher. Zeit. d. deutsch. geol. Gesellsch., vol. xv, p. 349. ?— 1875. Anca etapra, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx), pt. 1, p. 221, pl. xlix, figs. 1, 3. ?— 1881. — _ Frprosa, J. Kiesow. Schrift. d. nat. Gesellsch. Danzig, N. F., vol. v, p. 410. ?— 1885. Cucunrnma cGuaBra, F. Nétling. Die Fauna der baltisch. Cenoman- geschiebe (Palwont. Abhandl., vol. ii), p. 25. P— 1897. — (Iponvarca) @naBRa, R. Leonhard. Die Fauna der Kreide- format. in Oberschlesien. (Paleonto- graphica, vol. xliv), pp. 21, 51. Deseription.—Shell subrhomboidal or more or less oval, a little inequilateral and oblique; high, convex. Anterior margin curved, passing gradually into the ventral margin, and joining the hinge-line at a slightly obtuse angle. Posterior margin nearly straight, oblique, forming with the hinge-line an obtuse angle, and with the ventral margin an acute angle more or less rounded. Umbones large, with a rounded but usually well-marked carina extending from each to the postero-ventral angle of the valves. Sometimes a thread-like ridge, crenulated, passes from the umbo of the right valve to the middle of the posterior margin. Hinge-area long, but com paratively narrow ; with three or four, sometimes more, ligament-grooves on each side. Ornamentation consists of numerous radial ribs, sometimes raised and somewhat granular, crossed by concentric growth-lines. Hinge-line long, with from five to eight central transverse teeth, and three or four long lateral teeth, placed parallel or nearly parallel to the hinge-line, and striated. Posterior adductor plate large. Anterior adductor impression smaller. Margins of valves entire. Measurements: @ @2 ©& ©® (5) (6) = (7) Length . F : ~ eh ey 4 0) SX 22 21 mm. Height . 5 ‘ 61 Voll) 743525 30%o 2 ail Thickness j ; . 62 46 40 28 31 PL UG Hinge-line ‘ . 60 44 35 27 2025 7a Ge ess Ajinities—The forms described by Sowerby under the names Cucullea glabra CUCULLAA. 59 and C, fibrosa have been considered by Briart and Cornet, Pictet and Campiche, Pictet and Renevier, Downes, and others, to belong to the same species. Sowerby’s glabra was a more rhomboidal example than his jibrosa, but a large series of specimens shows that there is no essential difference between the two. One of the specimens figured by Goldfuss (fig. le) as Area glabra (Sowerby) was regarded by d’Orbigny as distinct from the others (figs. 1 a, b, d), and named! by him Area subglabra. This name has been since generally adopted for the form found in the Aachen Greensand (Senonian). Goldfuss does not state from whence his figured specimens came, but gives in the text, as localities of the species, Quedlinburg, Coesfeld, Aachen, Kelheim, and Blackdown. J. Béhm? found, in the Museum of the Schloss Popplesdorf, examples labelled ‘“* England” which agree well with Goldfuss’ figures, and he believes that the figured specimens really came from Blackdown, and are the true Cucullea glabra, Sowerby. Briart and Cornet® also regard Goldfuss’ glabra as identical with Sowerby’s. The Blackdown specimens of (. glabra, Sowerby, certainly agree closely with the figures of Goldfuss (except fig. 1 c, in which the lateral teeth are not parallel to the hinge-margin, but this may have been a worn specimen) ; speci- mens and figures both differ considerably from the figures of the undoubted Aachen form given by Holzapfel;* the last-named author, however, does not appear to accept Bohm’s view, but takes the glabra of Goldfuss as the type of Area subglabra, @ Orbigny. Judging from MHolzapfel’s figures and description, Cucullea subglabra of the Aachen Greensand differs from C. glabra, Sowerby, in the shell being more convex and relatively higher; the hinge-line relatively shorter; the lateral teeth shorter, somewhat curved and not quite parallel to the hinge-line; the absence or indistinct nature of the radial ribs; and perhaps also in the less distinct carina. The arrangement of the teeth in C. glabra is similar to that in C. Miilleri, Holzapfel,’ from the Aachen Greensand; but in that form the shell is more rounded than in C. glabra, it is without a keel, the area is smaller, the hinge-line shorter, &e. C. Mailleana (d’Orbigny) (see p. 63) is relatively longer, more oblique—owing to the greater proportionate length of the posterior margin, and is ornamented with well-marked concentric grooves, the radial ribs being absent or indistinct. 1 ¢ Prodr. de Pal.,’ vol. ii (1850), p. 244. * “Der Griinsand von Aachen und seine Molluskenfauna,” ‘ Verhand!. des naturh. Vereines der preussisch. Rheinl.,’ &., vol. xliv (1885), p. 92. 3“ Descript. de la Meule de Bracquegnies,’’ ‘Mém. Cour. et Mém. des Sav. ¢trangers, Acad. Roy. Belg.,’ vol. xxxiv (1868), p. 55. * “« Die Mollusken der Aachener Kreide ” (‘ Paleeontographica,’ vol. xxxv, 1889), p. 206, pl. xxii, figs. 3, 5. 5 Tbid., vol. xxv (1889), p. 209, pl. xxiii, fig. 1. 60 CRETACEOUS LAMELLIBRANCHIA. C. Marceana (d’Orbigny), from the Cenomanian of Mans, is more oval in outline, the area and hinge-line are relatively shorter, and the surface of the shell is smoother than in C. glabra, Sowerby. According to Geinitz C. glabra occurs in the Lower Quadersandstone (Ceno- manian) of Koschiitz, Neiderschéna, and Goldenen Hohe (Saxony). All the specimens obtained are apparently internal casts, so that comparison is very difficult, but they appear to be relatively longer and more oblique than C, glabra, Sowerby, and the umbo is sharper than in wax casts taken from Blackdown specimens. ‘The same remarks apply to the Bohemian form referred by Reuss to this species. Cucullea (Idonearca) Shumardi, Meek and Hayden,’ from the Fox Hill Group of Upper Missouri, appears to be very closely related to C. glabra, but without seeing specimens I am unable to state whether it is really distinct or not. Remarks.—This is one of the commonest fossils in the Blackdown Greensand. In old specimens the radial ribs usually become obliterated, and the shell is then nearly smooth save for lines of growth. The appearance of the ornamenta- tion varies considerably according to the state of preservation of the shell. In old forms the shell becomes, as a rule, relatively longer, more convex, and more oblique. Before the adult state is reached the lateral teeth are placed obliquely to the hinge-line (Pl. XI, figs. 10,11). Two forms of this ‘‘species” may be recognised :—(i) in which the shell is rhomboidal in outline, rather compressed, and with a sharp carina (Pl. XII, figs. 3, 4); (i) in which the shell is of more rounded outline, more inflated, and has only an indistinct carina (Pl. XI, fig. 8). These two types can be seen in various stages of growth, but there are also some examples which seem to be intermediate in character. Types.—\ have not seen the type, but the specimens figured by Sowerby as C. glabra, C. fibrosa, and CO. carinata (all from Blackdown) are in the British Museum. Distribution.—Blackdown Greensand (especially zone x). Gault of Folkestone. 1 «Proe. Acad. Nat. Sci. Philad.,’ vol. viii (1856), p. 86; Meek, ‘Invert. Cret. and Tert. Foss. U. Missouri’ (‘Rep. U.S. Geol. Surv. Territ.,’ vol. ix, 1876), p. 86, pl. xxviii, figs. 15 a—g; pl. xxix, fig. 4. CUCULLAA. 61 CucutLma opesa (Pictet and Roux), 1852. Plate XII, figs. 6, 7a, b, 8a, b. 1852. Arca opuysa, F. J. Pictet and W. Roux (non Sowerby). Moll. Foss, Gres verts de Geneve, p. 464, pl. xxxviii, figs. 1, 2. 1866. — — FJ. Pictet and G. Campiche. Foss. du Terr. Creét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 459. 1871. — — F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. in, p- 343 (TLrigonoarca ?). Non 1833. Arca opesa, G. B. Sowerby. Proc. Zool. Soe., pt. 1, p. 21 (figured Reeve, Conch. Iconiea, vol. ii, 1848, pl. i, fig. 3). Descrviption.—Shell subrhomboidal, rounded, a little inequilateral and oblique, much inflated. Posterior border slightly convex, forming an obtuse angle with the hinge-line, and joining the ventral border at an acute but rounded angle. Umbones prominent, well separated except in young forms. A prominent but rounded carina extends from the umbo to the postero-ventral angle. Hinge-area long, of moderate breadth, with numerous (often thirteen to eighteen) closely-set ligament-grooves. Ornamentation consists of faintly marked radial ribs crossed by lines of growth. Hinge with some central transverse teeth, and lateral teeth which are parallel or nearly parallel to the hinge-line. Posterior adductor plate well marked. Measurements : (1) (2) (3) (4) (5) Length . : ‘ . 98 47 43 28 22 mm. Height . : : . 48 42°5 40 25°5 LS) 35 Thickness ; ; Seri 44, 37 21 iW fameee Hinge-line ' : 39 31 26 15 14 ,, Affinities. —This is related to C. glabra, Sowerby, but can be distinguished from that by its more inflated form, more prominent umbones, more rounded outline; the ventral margin is placed more obliquely with regard to the hinge- line ; the hinge-line is relatively shorter and the ligament-grooves more numerous ; the radial ribs are less distinctly marked. Remarks.—The name Arca obesa was pre-occupied by Sowerby for a recent species dredged near the coast of West Columbia ; but since the fossil form is now referred to the genus Cucullea the specific name may be retained. Types.—The types are from the Gault of the Perte du Rhone. Distribution.—Gault of Folkestone (zones viii, ix); and Aylesford. Cambridge Greensand (derived). Chloritic Marl of the Isle of Wight and Warminster. Upper Greensand of Devizes. 62 CRETACEOUS LAMELLIBRANCHIA. CucutLmA NANA, Leymerie, 1842. Plate XIII, figs. 1 a—e, 2, 3. 1842. CuctLnma nana, A, Leymerie. Mém. Soe. Géol. de France, vol. v, p. 7, pl. ix, figs. 1 a—d. 1844, Arca nana, 4. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 210, pl. ecexi, figs. S—12. 1850. — — _ Prodr. de Pal., vol. ii, p. 188. 1866. — — FJ. Pictet and G. Campiche. Foss. du Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 3, p. 472. Description.—Shell rhomboidal, inflated, inequilateral. Anterior margin forming about a right angle with the dorsal, and curving ventrally. Ventral margin nearly parallel to the dorsal, slightly curved. Posterior margin slightly convex or sinuous, a little oblique. Umbones of moderate size, curving forwards, more or less well separated, placed near the anterior third, with a carina extending to the postero-ventral angle; postero-dorsal area concave, but slightly raised near the middle. Hinge-area long, broadest just in front of the umbones ; inner part raised in front, with a parallel-sided groove and ridge on each side; ligament- grooves numerous. Ornamentation consists of numerous slightly elevated concentric ribs, crossed by narrower radial ribs; at the anterior end of the shell some of the radial ribs at intervals are more elevated and serrate. Hinge not seen. Measurements : (1) (2) (3) (4) Length : : ; 15 12°5 12 975 mm. Height . 3 : ; il 9 9 G27Dy lee Thickness. 5 , 11°5 8 9 G - Affinities.—This species is closely allied to Cucullza subnana, Pictet and Roux, but appears to differ in the form of the area, which is widest just in front of the umbones, and tapers much more rapidly anteriorly than posteriorly. Remarks.—In many English specimens the area is wider and the umbones more distant than in the example figured by d’Orbigny; but others agree exactly with his figure, and a series of specimens shows a gradual transition from forms with a comparatively narrow area to those with a wide area. Types.—Specimens, but probably not those figured, are in the d’Orbigny collection. Distribution.—Gault (zones ii, vii, viii, ix, and x) of Folkestone. Cambridge Greensand (derived). CUCULLAA. 63 Cucuttma Maitieana (d’Orbigny), 1844. Plate XIII, figs. 4a—e, 5a, b. 1832, CucuLL@a Guapra, A. Passy (non Sowerby). Géol. de la Seine-Infér., p. 8 (of expl. of plates), pl. xiv, fig. 10. 1844, Anca Marrneana, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 229, pl. ecexviii, figs. 3—7. 1850. — -— — Prodr. de Pal., vol. ii, p. 164. P1852, — — Rk. Kner. Denkschr. d. k. Akad. Wissensch, Math.-nat. Se., vol. iii, p. 313, pl. xvii, fig. 25. 1866. —- _ F. J. Pictet and G. Campiche. Foss. Terr. Crét. de Ste. Croix (Matér. Pal. Suisse, ser. 4), pt. 8, p. 475. 1871. — -- . F. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ili, p. 8343 (Zrigonoarca). Description.—Shell oval or rhomboidal, convex, oblique, highest posteriorly. Anterior margin gently curved, relatively short. Posterior margin rather long, oblique, slightly curved. Ventral margin with a considerable slope posteriorly, forming an acute, but rounded, angle with the posterior margin. Umbones rather small, with a carina extending to the postero-ventral angle. A curved ridge passes from the umbo to just above the middle of the posterior side. Hinge- area rather narrow. Ornamentation consists of well-marked concentric grooves, with faint radial ribs on the posterior and anterior portions of the shell. Lateral teeth parailel to the hinge-line. Measurements : (1) (2) Length ; : : 26 : . 25mm Height : : : 22°5 ; eeeetaily 55 Thickness. . ; 18°5 : se alicia Affinities. —This species can be distinguished from C. glabra, Sowerby, by the great obliquity of the ventral margin of the shell, the shorter area, and the much less distinct radial, and better-marked concentric, ornamentation. The larger forms of CU. obesa are readily distinguished from C, Mailleana ; in the smaller the outline of the shell is more rounded, the posterior angle is less sharp, the carina more rounded, and the concentric grooves less distinct than in Mailleana. D’Orbigny compares this species with C. Cornueliana, but in that form the ventral margin is more nearly parallel to the hinge-line. In form, some examples of C. Mailleana resemble Arca Dumortieri, d’ Archiac,} but the character of the ornamentation appears to be different. 1 «Bull. Soc. Géol. de France,’ ser. 2, vol. xi (1854), p. 213, pl. xi, figs. 8, 8 a—d. 64 CRETACEOUS LAMELLIBRANCHIA. Remarks.—Most of the English specimens have only a portion of the shell preserved. I have collected examples from the Cenomanian of St. Catherine, near Rouen (the locality of the types), which agree exactly with English specimens. Types.—Specimens from Rouen, but not the types, are in the d’Orbigny Collection at the Museum of Natural History, Paris. Distribution.—Chalk Marl of Pinhay Cliff, Lyme Regis. Base of Chalk Marl (zone of WNSchlenbachia varians) of Chard, Maiden Newton, Eggardon Hill, and Titherleigh near Chard. Chloritic Marl of Maiden Bradley. Rye Hill Sand of Warminster. Upper Greensand of Plush. CucuLtza, sp. Plate XIII, figs. 6a, d, ¢. Cf. 1844. Arca Gurraneert, A. d’Orbigny. Pal. Frang. Terr. Cret., vol. iii, p. 228, pl. eeexviii, figs. 1, 2. — 1850. — — — Prodr. de Pal., vol. ii, p. 164. — 1866. — — F J. Pictet and G. Campiche. Foss. du Terr. Crét. Ste. Croix (Mater. Pal. Suisse, ser. 4), pt. 3, p. 474. — 1871. — — F.. Stoliczka. Palwxont. Indica, Cret. Fauna 8S. India, vol. iii, p. 848 (ZLrigonoarca). Description.—Shell oval or rhomboidal, high, convex. Anterior and ventral margins curved. Posterior margin oblique; postero-ventral angle rounded ; antero-dorsal angle sharp. Umbones rather small, close together, placed near the anterior third of the shell. Carina rounded. Hinge-area narrow. Orna- mentation consists of very fine radial ribs crossed by lines of growth. Measurements : Length . . . : : : : , 2) oo mm. Height . ; : ; , : : : <) Al =; Remarks.—The only example I have seen of this is a right valve in Mr. Meyer's collection. It is similar to Arca Guerangeri, d’Orbigny, but is less inflated. Only a small part of the hinge is seen. Distribution.—Chalk Marl (Meyer’s Bed 10) of Dunscombe, ISOARCA. 65 Genus—Isoarca, G. Minster, 1842. [‘ Neues Jahrb. fiir Min., &.,’ 1842, p. 98; ‘ Beitr. zur Petrefact.,’ pt. vi, 1843, p. 81.] Tsoarca AGassizi1, Pictet and Rouv, 1852. Plate XIII, figs. 7a, b. 1842, Crromya crassicornis, L. Agassiz. Et. Crit. Moll. Foss., p. 36 (partim), pl. vii f, figs. l—4 (non 5—10). 1850. Isocarpra crassrcornis, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 187 (partin). 1852. Isoarca AGassizu, F&F. J. Pictet and W. Roux. Moll. Foss. Grés Verts de Geneve, p. 466, pl. xxxviii, fig. 3. 1866. — _— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 3), p. 422. 1875. —_— _ A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol. xxxi, p. 200, pl. xv, figs. L—3. 1879. — canrapricienstis [H. G. Seeley, MS.], # G. H. Price. The Gault, p. 60 (nom. nud.). The only examples which I have seen of this species are a few internal moulds found in the Cambridge Greensand (derived), Isoarca opesa (d’Orbigny), 1844. Plate XIII, figs. 8 a—c. 1844, NucuLa opesa, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 180, pl. ecciv, figs. 10—14. 1846. Isocarpra Orpianyana, 4. d’Archiac.. Mem. Soc. Géol. France, ser. 2, vol. li, p. 305, pl. xv, fig. 1. 1847. Nvucuna rnoromacGensis, d’Orbigny. Pal. Frang. Terr. Crét., vol. ili, p. 766. 1848. Arca 1socarprzForMis, H. P. Nyst. Tableau Espéces vivant et foss. des Arcaces, p. 38. 1850. Isoarca opesa, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 168. 1866 _ — F.J. Pictet and G. Campiche. Voss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 3), p. 423. Non 1837. Nucwuna ovesa, A. Gold/uss. Petref. Germ., vol. il, p. 150, pl. exxiv, fig. 4. Description.—Shell oval or slightly subquadrate, rounded, length greater than height, much inflated, short anteriorly, long posteriorly; ventral margin slightly curved. Umbones large, anterior, close together, curved forward. Hinge-line about two-thirds the length of the shell. Hinge-area indistinctly limited, short anteriorly, elongate posteriorly. Ornamentation consists of numerous, very regular, closely-set, concentric grooves, with broader, flattish interspaces ; and radial grooves which are less distinct than the concentric; the 9 66 CRETACEOUS LAMELLIBRANCHIA. whole forms a rectangular network, with pits at the intersection of the grooves. Teeth numerous. Margins of valves smooth. Measurements : (1) (2) (3) Length . 25 20) 15°5 mm Height . : 21-5 i8 : : 13 ss Thickness 21 Ws ~~ ; Wi (1) and (8) from Ball Wood. (2) from Maiden Bradley. T'ypes.—From the Cenomanian of Rouen. Distribution.—Chloritie Marl of Ball Wood, near Plush, and of Maiden Bradley. Base of Chalk Marl (zone of Schlanbachia varians) of Cerne, near Chard. Genus—PerctuncuLus, Lamarck, 1799. [‘Mém. Soe. Hist. Nat. Paris,’ p. 87.] 1. Lower Cretaceous Species. PECTUNCULUS MARULLENSIS, Leymerie, 1842. Plate XIII, figs. 9a—e, 10. 1842. PEcruncULUS MARULLENSIS, A. Leymerie. Mém. Soe. Géol. de France, vol. v, p. 7, pl. ix, fig. 2. 1844. --- -- A.d’Orbigny. Pal. Frang. Terr. Crét., vol. in, p- 187, pl. ecevi, figs. 1—6. 1848. a= MAROLLENSIS, H. G. Bronn. Index Paleont., vol. i, p. 938. 1850. — MARULLENSIS, A. d’Orbigny. Prodr. de Pal., vol. 11, p. 80. P P1882. = — W. Keeping. Foss., &c., Upware and Brick- hill, p. 116, pl. v, fig. 11. Description.— Shell of moderate size, suboval or nearly orbicular, longer than high, rather convex, compressed antero-dorsally and postero-dorsally. Anterior margin rounded, posterior slightly subtruncate. Umbones of moderate size, close together, nearly median. Hinge-area small. Hinge with from four to six oblique teeth on each side. Ornamentation consists of numerous radial ribs, which bear finer ribs, and are crossed by fine concentric ribs. Measurements : (1) (2) Length ; : : 1105) 2 k 11 mn. Height : ; 2 1 : : 9°D),, (1) and (2) from Shanklin. 1 Dall considers that the name Glycimeris, Da Costa, should be adopted in place of Pectunculus or Avinea. Until the necessity for this change has been definitely shown, I prefer to retain the name which has been in general use for the last hundred years. Dall, ‘Trans. Wagner Free Inst. Sci. Philadelphia,’ vol. ii, pt. iv (1898), pp. 571, 607. Cossman, ‘ Rey. Crit. Paléozool.’ (1899), p. 66. PECTUNCULUS. 67 Affinities. —This is similar to P. sublevis, Sowerby, but is smaller, proportion- ately less convex, and with less prominent umbones. Remarks.—Three specimens from the Lower Greensand of Upware, which were referred by Keeping (vide supra) to Pectunculus marullensis (and are preserved in the Woodwardian Museum), seem to differ from that species in having a subquadrate outline and more prominent umbones; the surface of the shell in those specimens is worn, and it is consequently impossible to compare satisfactorily the ornamentation. One example shows the hinge, but, unfortu- nately, very indistinctly ; so far as I can see, the lateral teeth appear to be like those of Cucullxa rather than Pectuinculus. Types.—From the Neocomian of Marolles. Distribution.—Ferruginous Sands (upper beds) of Shanklin. 2. Upper Cretaceous Species. PrcrunxcuLus susLzvis, Sowerby, 1824. Plate XIV, figs. la—c, 2a, b, 3a—d, 4 a—e, 5 a—e, 6, 7. 1824. Prcruncutus susL«£vis, J. de C. Sowerby. Min. Conch., vol. v, p. 112, pl. eceelxxii, fig. 4. 1850. -- — A, d’ Orbigny, Prodr. de Pal., vol. ii, p. 163 (partim). 1854. _— — J. Morris. Cat. Brit. Foss., ed. 2, p. 220. 1868. -= — A, Briart and F. L. Cornet. Descript. de la Meule de Bracquegnies (Mém. Cour. et Mém. des Sav. étrangers, Acad. Roy. Belg. (vol. xxxiv), p. 61, pl. v, figs. 21—23. P? 1883. —- _ W. Keeping. Foss., &c., Upware and Brickhill, p. 115, pl. v, fig. 9. Non 1837. — _ A. Goldfuss. Petref. Germ., vol. ii, p. 160, pl. exxvi, fig. 3. — 1813. = -- H. B. Geinitz. Die Verstein. ven Kieslingswalda, p. 14, pl. ii, figs. 19—21. — 1846. — — A. £. Reuss. Die Verstein. der bohm. Kreide- format., pt. il, p. 9, pl. xxxv, figs. 10, 11. — 1847. -= —- J. Miller. Mon. Petr. der Aachen. Kreidef., pun ds: pi Lvs ?— 1883. — = FI. Schrider. Zeitschr. der Deutsch. geol. Gesellsch., vol. xxxiv, p. 274. Description.—Shell stout, convex, longer anteriorly than posteriorly, but sometimes nearly equilateral; outline rounded or somewhat subquadrate ; usually a little longer than high. Antero-dorsal part compressed, with a rounded 68 CRETACEOUS LAMELLIBRANCHIA. anterior border; posterior border subtruncate, dorsal part of it nearly straight ; posterior extremity slightly angular. Umbones of moderate size. Hinge-line long. Hinge-area moderately broad, with many ligament-grooves. Ornamenta- tion consists of broad radial ribs separated by narrow grooves—the main ribs bearing smaller ribs; this ornamentation is less distinctly marked antero-dorsally and postero-dorsally, the change in passing to the former area being gradual, to the latter rather sudden. At distant intervals there are lines of growth. Hinge- plate stout, with two or three small transverse teeth ; and oblique, moderately long lateral teeth (usually six to nine). Adductor impressions well marked; the anterior subtrigonal, the posterior smaller and oval. Margins strongly crenu- lated. Measurements : (5) Average of : (1) (2) (3) (4) 29 specimens. Length . 24 . 22 6s S25) ee e883 Oman: Elcie hte ss22cote #2 ee een LON ses eels ar UUSHOUT (1—5) from Blackdown. Affinities —A species from the Aachen Greensand was described and ficured by Goldfuss as P. sublevis, Sowerby; but it has been shown by later authors to be distinct from the latter; Romer! and also Brauns,” have referred it to P. lens, Nilsson,* but the characters of that form are knowu only from internal casts. Bohm* has named the Aachen form P. dux, but Holzapfel,’ in a later work, refers it to P. Geinitzi, d’Orbigny,° the type of which is P. sublexvis, Geinitz,’ non Sowerby, from Kieslingswald. The Aachen species is rather variable, but a comparison of several specimens and of the good series of figures given by Holzapfel, shows that it generally differs from P. sublevis, Sowerby, in the following features : (1) The average size of the adults is considerably larger, and the valves are less inflated than in P. sublevis. (2) The hinge-area is smaller and the external teeth shorter. (5) The shell is more quadrate in form, and, as a rule, a little higher than long. (4) The ribs are more flattened and are separated by striz. 1 *Die Verstein. des norddeutsch. Kreidegeb.’ (1841), p. 68. 9 NT 2 “ Die senon Mergel des Salzberges., &e.,”’ ‘ Zeitsch. f. d. gesammt. Naturwiss.,’ vol. xlvi (1876), 3 « Petrif. Suecana’ (1827), p. 15, pl. v, fig. 4; Hennig, ‘ Revis. af Lamellibr. 1 Nilsson’s “ Petrif: Suecana,” ‘ Kongl. Fysiogr. i Lund Hanadl.,’ vol. viii (1897), p. 63. * «Verhandl. des naturhist. Vereines der preuss. Rheinl., &e.,’ vol. xlii (1885), p. 93. ° “Die Mollusk. der Aachen. Kreide.,”’ ‘ Paleontographica,’ vol. xxxv (1889), p. 210, pl. xxiii, figs. 11, 12; pl. xxiv, figs. 1—10. 6 «Prodr. de Pal.,’ vol. ii (1850), p. 196. 7 «Die Verstein. von Kieslingswalda’ (1843), p. 14, pl. ii, figs. 19—21. PECTUNCULUS. 69 In P. obsoletus, Goldfuss,' the shell is oblique, and more oval and rounded in form than in P. sub/evis. P. subpulvinatus, V Archiae,’ from the Tourtia of Tournay, is also more oblique and has the posterior border more rounded. For the relation of this species to P. winbonatus, Sowerby, see p. 70. The two examples described by Keeping (vide supra) from the Lower Green- sand of Upware appear to differ from P. sublevis in being less inflated and in having a higher area, but the specimens are not sufficiently perfect to allow me to give a definite opinion on their affinities. Types.—From Blackdown ; in the British Museum. Distribution.—Greensand of Blackdown (zones xi and xii); Lower Gault (zone vi) of Folkestone (fide Price), PECTUNCULUS UmMBONATUS (Sowerby), 1817. Plate XIV, figs. 8 a—c, 9a—e, 10 a—e, iets 1817. Carprum umBonatum, J. Sowerby. Min. Conch., vol. ii, p. 128, pi. elvi, figs. 2—4, 1824. Precruncunus umBonarus, J. de C. Sowerby. Ibid., vol. v, p. 113, pl. eeelxxii, fig. 3. 1854. = -- J. Morris. Cat. Brit. Foss., ed. 2, p. 220. 1868. — — A. Briart and F. L. Cornet. Descript. de la Meule de Braequegnies (Mém. Cour. et Mém. des Say. étranvers, Acad. Roy. Belg., vol. xxxiv), p. 61, pl. v, figs. 19, 20 ? Non 1837. -- — A. Goldfuss. Petref. Germ., vol. il, p. 160, pl. exxvi, fig. 2. ?— S41. -— -— F. A. Rémer. Die Verstein. des norddeutsch. Kreideformat., p. 68. — 1846. — _ A. E. Reuss. Die Verstein. der béhm. Kreide- format., pt. ii, p. 9, pl. xli, fig. 20. — 1857. -- _ J. W. Salter. Quart. Journ. Geol. Sov., vol. xiii, p. $6. (Por remarks on this form see Jukes-Browne, Geol. Mag., 1898, p. 29.) Description.—Shell rather inflated and more or less circular or slightly sub- quadrate, usually a little higher than long, nearly equilateral. Anterior margin 3? 1 *Petref. Germ.,’ vol. ii (1837), p. 160, pl. exxvi, fig. 4; Geinitz, “ Das Elbthalgeb. in Sachsen” ‘ Paleontographica,’ vol. xx, pt. i (1873), p. 228, pl. xlix, figs. 7—11. 2 «Mém. Soc. Géol. de France,’ ser. 2, vol. xii (1846), p. 306, pl. xv, fig. 2. 70 CRETACEOUS LAMELLIBRANCHIA. generally evenly rounded, sometimes forming an obtuse but rounded angle with the hinge-margin. Posterior extremity slghtly angular; dorsal part of the posterior margin subtruncate, straight or slightly curved. Hinge-line long. Umbones prominent, pointed; valves compressed in the postero-dorsal region. Hinge-area broad, with several ligament-grooves. Ornamentation consists of broad radial ribs bearing finer ribs, and separated by narrow grooves ; the ribs are crossed by lines of growth and by faintly marked concentric ridges." On the anterior and posterior parts of the valves the radial ribs are less distinct. Central teeth (two to four) small, transverse ; lateral teeth (eight to ten) long and oblique. Anterior adductor impression large, subtrigonal; posterior adductor a little smaller and rounded. Margins of valves strongly crenulate. Measurements : (4) Average of (1) (2) (3) 27 specimens. Length . 18 ; 17 : 15 : 18°851 mm. Height . 20 : 19 ‘ 16 : 19:924 ,, (1—4) from Blackdown. Afjiivities—This species differs from P. sublevis, Sowerby, in the shell being less stout, more inflated, and usually higher than long; also in having a broader hinge-area, more prominent umbones, and fewer ribs. It resembles P. woricus, Zittel, in general form, but that species appears to be usually larger, with rather less prominent umbones, fewer ribs, and less oblique lateral teeth. 2, which was referred by Goldfuss (vide supra) to this species, has been regarded as distinct by Rémer,’ The form from the Senonian of Coesfeld and Quedlinbur and named P. decussatus; a fuller description, but without figures, is given by Brauns.* I have seen no examples of that form. The name was changed by d’Orbigny ° to subdecussatus, since decussatus had been used previously (1813) by Sowerby for an Hocene species. Types.—From Blackdown; in the British Museum. Distribution.—Blackdown Greensand (zone vii, and occasionally beneath it). Lower Gault (zones vi and vii) of Folkestone (fide Price). Folkestone Beds of Copt Point, Folkestone.° 1 Seen in only a few specimens. 2 “ Die Bivaly. der Gosaugeb.,” pt. i, ‘ Denkschr. der k. Akad. der Wissensch. Math.-nat. Cl.,’ vol. axiv (1865), p. 167, pl. ix, fig. 9. 3 *Die Verstein. des norddeutsch. Kreidegeb.’ (1841), p. 69. 4 «Die senon. Mergel des Salzberges, &c.,” ‘ Zeitsch. f. d. gesammt. Naturwiss.,’ vol. xlvi (1876), p- 383. 5 *Prodr. de Pal.,’ vol. ii (1850), p. 243. ® There are three specimens from this horizon in the Woodwardian Museum; the surface of the shell is not perfectly preserved, but I have very little doubt that they are referable to this species. LIMOPSIS. ~ — PECTUNCULUS EUGLYPHUS, sp. nov. Plate XIV, figs. 13 a—e. Description.—Shell inflated, nearly equilateral, outline rounded, length and height nearly equal; posterior border (especially its dorsal part) less curved than the anterior. Umbones large. Hinge-line moderately long. Ornamentation con- sists (1) on the anterior part of the valves of numerous fine, rounded, radial ribs, crossed by very faint concentric ridges and a few distant growth-lines ; the radial ribs are separated by well-marked but narrow grooves with puncta; (2) on the posterior part of the valves of broader, flatter radial ribs, crossed in a regular manner by fine, rather closely-set concentric ridges. Measurements : Length . : : , ; ; : 22 mm. Height . ; : : ; 22 Affinities.—Pectunculus subpulvinatus, @ Archiac, from the Tourtia of Tournay, be] apparently differs from this species in the obliquity and greater convexity of the valves, and in the ornamentation being somewhat coarser and of the same type on the anterior and posterior parts of the shell. P. euglyphus is more inflated than P. sublevis, and also differs in the character of the ornamentation. Types.— Three specimens in Mr. Meyer’s collection. Distribution.—Chalk Marl (Meyer’s Bed 11) of Dunscombe. Genus—Linopsis, A. Sasso, 1827. [‘ Giornale Ligustico di Scienze,’ i, p. 476.] LIMopsIs ALBIENSIS, sp. nov. Plate XV, figs. 1 a—d, 2—4. 1874. Precruncuuvs, sp., F. G. H. Price. Quart. Journ. Geol. Soc., vol. xxx, p- 360 (in list from Bed ii). 1879. -- — (= Lvcrya orsicuraris ?), Price. The Gault, p. 62. Description.—Shell small, oval, shorter than high, somewhat inequilateral and oblique, of moderate convexity, compressed postero-dorsally. Anterior and ventral margins evenly rounded, posterior less curved and forming a blunt angle with the hinge-line. Umbones of moderate size, pointed. Hinge-line long, more extended posteriorly than anteriorly. Hinge-area long. Ornamentation consists of broad, flattened concentric ridges, separated by sharp, narrow grooves. Radial 72 CRETACEOUS LAMELLIBRANCHIA. ribs slender, faintly marked, sometimes indistinct in part, better marked near the umbones and on the postero-dorsal region than elsewhere. Anterior teeth (about five) short and nearly perpendicular; posterior (about six) more oblique, the external being nearly horizontal. Margins entire. Measurements : (1) (2) (3) Length . 5:5 : ; 4°25 : ; 3:70. mm, Height g 6-0 a : Ae 5 ; : Are Affinities.—This appears to be similar to the form described as Pectunculus insculptus, Reuss, from the Priesen Beds of Bohemia, but since the figures’ of that form show casts only it is difficult to determine its affinities. The hinge-line in P. insculptus seems to be much more curved, forming a fairly sharp angle at the umbo, and the teeth are also more numerous than in L. albiensis. In P. reticulatus, Reuss,’ the radial ribs are much better marked than in L. albiensis. Types.—In the Museum of Practical Geology. Distribution.—Lower Gault (zones ii, 11, and vu) of Folkestone. Limoprsis, sp. Plate XV, figs. 5a—c, 6a—c. 1897. Lraopsis, sp., H. Woods. Quart. Journ. Geol. Soc., vol. li, p. 379, pl. xxvii, figs. 7, 8. Description.—Shell small, oval, convex, a little oblique, higher than long; margins of valves not crenulate. Casts show fine radial striae, sometimes crossed by a few shallow concentric furrows. Measurements : Length . , : j : : : 8S mm. Height. : : ; ; : Remarks.—At present this species is known only from internal casts, so that “I 99 a complete description cannot be given; it seems, however, to be distinet from other forms.’ I have not been able to make out satisfactorily the hinge 1 Geinitz, ‘Char. der Schicht. u. Petref. d. sachs.-bobm. Kreidegeb.,’ pt. 11 (1842), p. 78, pl. xx, fig. 17; Reuss, ‘Die Verstein. der bohm. Kreidef.,’ pt. ii (1846), p. 8, pl. xxxv, fig. 5; Fritsch, ‘Stud. im gebiete der bohm. Kreidef.,’ v. Priesener Schichten (1893), p. 98, fig. 106. 2 Reuss, ibid., p. 8, pl. xxxv, figs. 7, 8. $ Compare with the following, most of which are known as casts only : (i) LZ. calvus, Sowerby, ‘Trans. Geol. Soc.,’ ser. 2, vol. ii (1832), p. 417, pl. xxxviii, fig. 2; Zittel, ‘‘ Die Bivalv. der Gosaugeb.,’’ ‘ Denkschr. d. k. Ak. d. Wissensch. Wien. Math.-nat. Cl.,’ vol. xxiv (1865), p. 165, pl. ix, fig. 8. (i) L. rhomboidalis, Alth, ‘Haidinger’s Naturwiss. Abhandl.,’ vol. ii, pt. 2 (1850), p. 238, pl. xu, fig. 17; Favre, ‘ Moll. Foss. Craie de Lemberg’ (1869), p. 121, pl. xii, figs. 11, 12. PALAONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVIL. VOLUME FOR 1900. LONDON: mopcece, A MONOGRAPH OF THt CRETACEOUS LAMELLIBRANCHIA OF ENGLAND. BY HENRY WOODS, M.A., UNIVERSITY LECTURER IN PALZXZOZOOLOGY, CAMBRIDGE. PART II. TRIGONIIDA, MYTILIDA, axnp DREISSENSIIDA. Paces 73—112; Pirates XV—XIX. LONDON : PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY L900, PRINTED BY ADLARD AND SON, ‘BARTHOLOMEW CLOSE, E.C., AND 20, HANOVER SQUARE, W. TRIGONTA, ~I je) and hinge-area; it is therefore possible that this form may belong to Pectun- culus. Distribution —Chalk Rock (zone of Heteroceras Reussianwir) of Cuckhamsley. Family—TRIGONIIDAS, Lamarck. Genus—Triconia, Bruguiere, 1789. (‘Encye. Méth. Vers.,’ vol. i, p. xiv; Lamarck, ‘ Syst. Anim. sans Vert.,’ 1801, p. 116.) The British forms of this genus have already been considered in detail by Mr. Lycett in his ‘Monograph of the British Fossil Trigoniw,’ published by the Palaontographical Society in 1872-9 ; it will therefore not be necessary, in the present work, to do more than enumerate the Cretaceous species, and to give some additional notes on their affinities, synonymy, etc. Section 1.—ScAPHOIDES. TRIGONIA SCAPHA, Agassiz, 1840. Plate XX, figs. 1, 2. Additional Synonymy. 1861. Triconta HuNsTANTONENSIs, H. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii, p. 123, pl. vi, fig. 9. 1877. — scapHa, Lycett, p. 183, pl. xxxviil, fig. 6. 1884. — —- O. Weerth. Die Fauna Neocom. im Teutoburg. Walde (Palxont. Abhandl., vol. ii), p. 45. 1896. — — A. Wollemann. Zeitschr. d. deutschr. geol. Gesellsch., vol. xlvili, p. 846. 1900. —- — _- Die Biv. u. Gastrop. d. deutsch. u. hollind. Neocoms. (Abhandl. d. k. preussisch. geol. Land, N. F., pt. 31), p. 92. (iii) Z. radiata. Alth, ibid., p. 284, pl. xii, fig. 19; Favre, ibid., p. 122, pl. mii, fig. 18. (iv) LZ. plana. Romer, ‘ Die Verstein. des norddeutsch. Kreidegeb.’ (1841), p. 69, pl. vill, fig. 24 ; Griepenkerl, “Senon. Kreide von Kénigslutter,’’ ‘ Paleont. Abhandl.,’ vol. iv (1889), p. 56. In this form the valves appear to be flatter and the umbones less prominent than in the English species described above. (v) Pectunculus? insculptus, Reuss, ‘ Die Verstein. der bohm. Kreideformat.,’ pt. ii (1846), p. 8, pl. xxxv, fig. 5; Fritsch, ‘Stud. im Gebiete der bohm. Kreideformat., vy. Priesener Schichten’ (18938), p. 98, fig. 106, 10 ie: CRETACEOUS LAMELLIBRANCHIA. Remarks.—From Agassiz’ figures alone it would be difficult to feel sure of the identity of the English form, described by Seeley as 7. hunstantonensis, with T. scapha, Agassiz; but the figures of Pictet and Campiche give a much better idea of the characters of the species. Seeley’s figure is more accurate than Lycett’s, but the arrangement of the tubercles is not satisfactorily shown. Types.—The type of 7. scapha is from the Neocomian near Neuchatel. The type of 7. hunstantonensis is in the Woodwardian Museum ; it was at first stated to come from the Red Chalk, but the matrix differs entirely from the Red Chalk, and the specimen in all probability is from the Snettisham Ironstone nodules! (Lower Greensand), West Norfolk. Distribution.—Snettisham Ironstone of Sandringham Warren and Wolferton Station. Snettisham Clay of Heacham and Snettisham. The records of this species from the Red Chalk of Hunstanton are probably erroneous. TRIGONIA EXALTATA, Lycett, 1877. 1877. Lycett, p. 184, pl. xxxviii, fig. 2. Type.—In the British Museum. listribution.—Lower Greensand of West Norfolk. Triconta Roprnanpina ? @ Orbigny, 1844. 1844. Triconia Rosinaupina, 4. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 189, pl. cexcix, figs. 1, 2. 1850. — — — Prodr. de Pal., vol. ii, p. 78. 1866. F. J. Pictet and G. Campiche. Foss. Terr. Crt. Ste. Croix (Matcér. Pal. Suisse, ser. 4), p. 385. An internal cast from the Tealby Limestone (zone of Bel. brunsvicensis) of Claxby, now in the Woodwardian Museum, probably belongs to this species. ' See Lamplugh, in Whitaker and Jukes-Browne, ‘“ Geol. Borders of the Wash” (‘Mem. Geol. Survey,’ 1899), p. 16, ete. TRIGONTA. “J Or Section 2.—CiLAVELLAT®. TRIGONTA INGENS, Lycett, 1872. 18 Lycett, p. 24, pl. viii, figs. 1—3. 18 72. 77-9. Ibid., p. 207, pl. xxxvi, figs. 5, 6. 1877. Triconta Keeprnatr, Lycett. Tbid., p. 196, pl. xxxv, figs. 1, 2. Remarks.—Maas' states that his 7. roelligiana, from the Gault of Wilhelmshéhe, near Langenstein, is related to 7. cagens ; but it seems to be clearly distinguished by the greater curvature of the ribs near the carina and the indistinctness or absence of tubercles. TL. Keepingi, Lycett, is known only by the two type specimens from the Spilsby Sandstone. I have carefully compared these with a large series of 7. ingens from the Claxby Ironstone—the chief horizon for that species, and find that the curvature and number of the coste and the size of the tubercles vary considerably in different specimens of 7’. ingens; some forms possessing smaller and more numerous tubercles agree perfectly, im these respects, with 7. Keepingi. The plications on the area of the smaller specimen of 7’. Keeping? are quite similar to those on 7’. ingens ; but on the larger specimen they are less distinct than usual ; this, I think, is accounted for by imperfect preservation. In comparing the form of the shell in the larger example of 7. Keepingi with that of 7. ingens it is important to note that that specimen is larger than usual, and that the whole of the marginal parts posterior to the umbo are very imperfect, so that a false idea may at first be taken of the height of the shell. Lycett’s figures, although giving a good idea of the character of the shell, are not accurate in either outline or size. Types.—T. ingens, from the Carstone of Downham, was formerly in the museum at Lynn, but cannot now be found. Specimens figured on Lycett’s plate xxxvi, from the Claxby Ironstone, are in the Museum of Practical Geology; and also a gutta-percha cast of the original of plate vin, fig. 1. 1’. Keepingi, from the Spilsby Sandstone, in the Woodwardian Museum. Distribution—Spilsby Sandstone (zone of Pel. lateralis) of Claxby and Donnington. Claxby Ironstone (zone of Bel. lateralis) of Benniworth Haven. Carstone of Downham, Norfolk. The specimens named 1. Keeping’ are from the Spilsby Sandstone (zone of Bel. lateralis) of Claxby and Tealby. 1 «Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xlvii (1895), p. 282, pl. ix, fig. 7. 76 CRETACEOUS LAMELLIBRANCHIA. Section 3.—GLABRA. TRIGONIA ECCENTRICA, Parkinson, 1811. 1811. Triaonta eccenrrica, J. Parkinson. Org. Remains, vol. iii, p. 175, pl. xii, fie. 5. 1811. — stnvaTa, Parkinson. Ibid., p. 177, pl. xii, fig. 18. 1818. — EcceNnTRICA, J. Sowerby. Min. Conch., vol. iii, p. 11, pl. ceviii, fies; 1512: 1828. -- pxcEnTRICA, Defrance. Dict. Sciences nat., vol. lv, p. 296. 1837. = — G. G. Pusch. Polens Paliont., p. 61. 1837. — stnuATA, Pusch. Ibid., p. 61. 1840. — ExcentTRICA, L. Agassiz. tudes crit. Moll. Foss. (Trigon.), Dae: 1848. Lyrtopon stnvatus, H. G. Bronn. Index Palxont., vol. i, p. 688 (partim), 1848. -- EXCENTRICUS, Bronn. Ibid., p. 686 (partim). 1850. TRriconta ExcentTRICA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 162. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 228. 1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 387. 1866. — sInuATA, Pictet and Campiche. Ibid., p. 387 (partim). 1875. — EXCENTRICA, Lycett, p. 94 (partim), pl. xx, fig. 6 (not 5); pl. xxi, fig. 6; pl. xxii, fig. 5; pl. xxviii, figs. 6, 9, 10. Non 1837. Lyropon excentricum, A. (Goldfuss. Petref. Germ., vol. ii, p. 208, pl. exxxvu, fig. 8 (= Trigonia Micheloti, de Loriol). — 1847. Triconta pxcrntrica, J. Miiller. Petref. Aachen. Kreideformat., pt. 1, p. 16. — 1847. — sinuata, A. d’Orbiqny. Voy. Astrol. Paléont., pl. iv, figs. 29, 30. Reimarks.—This is distinguished from 7. affinis, Sowerby, by being proportion- ately longer, more produced posteriorly, less ovoid in outline, and in having the cost near the antero-ventral margin less regularly concentric (except in small specimens). T'ypes.—I have not seen Parkinson’s types. The specimen figured by Sowerby is in the British Museum. Specimens figured by Lycett are in the Museum of Practical Geology (pl. xxi, fig. 6; pl. xxu, fig. 5), and in Mr. Vicary’s collection (pl. xx, fig. 6; pl. xxviu, figs. 6,9, 10). The original of pl. xx, fig. 5, stated by Lycett to be from Blackdown, is in the British Museum (No. 32596); it is really from the Cenomanian of Le Mans, and is an example of 7’. siiuata, @Orbigny (non Parkinson)—see 7’. affinis. Distribution—Greensand of Blackdown (Zone xi), Haldon, and Kingskerswell. TRIGONTA. “NI “I TRIGONIA LavIuscuLA, Lycett, 1875. 1875. Lycett, p. 96, pl. xxii, fig. 6. Remarks.—I doubt whether this can be regarded as more than a variety of T. eecentrica, Parkinson. The only specimens I have seen are those referred to by Lycett. More material is needed to allow of a definite opinion being given. Type.—From the Greensand of Cullompton; in Mr. Vicary’s collection. Distribution —Blackdown Greensand of Collumpton. Lycett states that this species was obtained by Mr. Meyer from the Cenomanian of Dunscombe, but the specimens do not appear to be in Mr. Mejer’s collection. TRIGONTA ArriInts, Sowerby, 1818. 1818. Triconra arrinis, J. Sowerby (ex Miller, MS.). Min. Conch., vol. iii, p- Ll, pl. ceviii, fig. 3. 1828. — — Defrance. Dict. Sciences nat., vol. lv, p. 297. 184.0. — — L. Agassiz. Etudes crit. Moll. Foss. (Trigon.), p. 9. 1844. — stnuava, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 147, pl. cexciii. 1848. Lyrropon stnvatus, H. G. Bronn. Index Paleont., vol. i, p. 688 (partim). 1850, Trraonra stnuara, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 161. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 229. ? 1867. — — &. Guéranger. Album Paldont. de la Sarthe, p. 14, pl. xix, fig. 4. 1875. — ExcENTRICA, Lycetl, pl. xx, fig. 5 (from Le Mans). 1877. — AFFINIS, Lycett, p. 187, pl. xxi, fig. 7; pl. xl, fig. 2 (from Le Mans). 1896. -- — A.J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. lii, p. 153. Remarks.—I have compared examples of this species with 7’. sinuata, d@ Orbigny (non Parkinson), from the Cenomanian of Le Mans, and consider that, as maintained by d’Orbigny, the two are identical. ‘Two specimens from Le Mans were accidentally figured by Lycett as English examples (see below). Types.—The type is in the Bristol Museum. One of the specimens figured by Lycett (pl. xl, fig. 2) is in Mr. Vicary’s collection ; the other (pl. xxi, fig. 7), stated to be from Blackdown, is in the British Museum (No. 32396), and was really obtained from the Cenomanian of Le Mans; the original of pl. xx, fig. 5 (figured as 7’. excentrica), is also from the same locality, and is in the British Museum, Casts of these two specimens, labelled 7’. stiuata by Lycett, are in the Scarborough Museum. Distribution. —Greensand of Blackdown and Haldon. ? Cenomanian of Axmouth Meyer collection, 78 CRETACEOUS LAMELLIBRANCHIA. TRIGONIA DUNSCOMBENSIS, Ivycett, 1877. Plate XIX, figs. 12 a, b. e co} 1877. Lycett, p. 188, pl. xl, figs. 5, 6; pl. xh, fig. 14. 1896. A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soc., vol. lii, p. 153. Remarks.—Messrs. Jukes-Browne and Hill consider that 7. dunscombensis is probably identical with 7. sinwata, @Orbigny (non Parkinson) which I regard as a synonym of 1’ affinis (see p. 77). Small forms (85 mm. long) seem to be inseparable, unless it is by the somewhat greater convexity of 7. dunscombensis, but the larger examples of the latter (e.g. Lycett’s fig. 5) seem to differ in having a less ovoid outline and fewer ribs. More specimens of 7’. duiscombensis are needed before its affinities can be definitely settled. Types.—Figs. 5 and 6, from near Sidmouth, are in Mr. Meyer's collection. The original of pl. xh, fig. 14, from Dunscombe, is in the Museum of Practical Geology. Distribution—Cenomanian (Beds 10, 11, and 12 of Meyer) of Dunscombe, Branscombe, Whitecliff, and Pinhay; Bed 11 of Humble Point, Lyme Regis. Base of Chalk Marl (zone of Schlaenbachia varians) of Titherleigh. TRIGONIA DEBILIS, Lycett, 1877. 1877. Lycett, p. 189, pl. xl, fig. 8; pl. xi, fig. 5. 1896. A.J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soc., vol. li, p. 154. Types.—In Mr. Me¥er’s collection (fig. 8), and in the Museum of Practical Geology (fig. 5). Distribution —Cenomanian (Bed 10) of Dunscombe. Section 4.—QUADRATR. TRIGONIA NoposA, Sowerby, 1826. oy J? 1822. TrRIGoNIA CLAVELLATA, G. Mantell (non Sowerby). Foss. 8. Downs, p. 73. 1826. _ noposa, J. de OC. Sowerby. Min. Conch., vol. vi, p. 7, pl. dvi, fiom, P1840. — crnora, L. Agassiz. Etudes crit. Moll. Foss. (Trigon.), p. 27, pl. vii, figs. 21, 28; pl. viii, figs. 2—4. 1844, — rupIs, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. ii, p. 187, pl. eelxxxix, TRIGONTA. 79 1850. Triconta rupis, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 78 (? partim). 1854. — novosa, J. Morris. Cat. Brit. Foss., ed. 2, p. 229. ? 1855. — RUDIS, Gr. Cotteau. Moll. Foss. de l’Youne, p. 76. 1857. — DADALEA, I’. J. Pictet and TL. Renevier. Foss. Terr. Aptien (Mater. Pal. Suisse, ser. 1), p. 92, plexi, fig. 1. 1857. — noposa, Pictet and Renevier. Ibid., p. 94, pl. xii, fig. 2. 1865. — — H. Coquand. Mon. Aptien de l Espagne, p. 133. 1866. = — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 385. 1875. — — Lycett, p. 106, pl. xxv, figs. 1, 2; pl. xxxvii, figs. 5, 6. 1875. — — var. Orpienyana, Lycett. Ibid., p. 107, pl. xxiv, figs. 1—3. 1896. — — A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlviii, p. 846, 1900. _ — — Die Biv. u. Gastrop. d. deutsch. u. hol- lind. Neoc. (Abhandl. d. k. preus- sisch. geol. Land., N. F., pt. 81), p- 90, pl. iv, fig. 8. Non 1852. — — F.J. Pictet and W. Roux. Moll. Foss. Grés verts de Gentve, p. 454, pl. xxxv, fig. 5. Remarks.——There appears to be a perfect passage from the typical 7’. nodosa to the variety named by Lycett Orbignyana. Lycett regarded 1’ cineta, Agassiz, as a synonym of 7’. nodosa; I have seen no examples of the former, but its area appears to be proportionately larger, while the ribs seem to be more nearly perpendicular to the carina and more nearly parallel to the ventral margin than in the English specimens. Types.—I have not found the type; it came from the Hythe Beds of Hythe. The specimens figured by Lycett are in the Museum of Practical Geology. Distribution.—Hythe Beds of Hythe and Lympne. Crackers of Atherfield. Perna-bed of Atherfield and Redcliff. Folkestone Beds near Copt Point, Folke- stone. Claxby Ironstone of Tealby (fide Lycett). TRIGONIA TEALBYENSIS, Lycett, 1875. 1875. Lycett, p. 114, pl. xxviii, fig. 7. Type.—In the Woodwardian Museum, Cambridge. Distribution.—Spilsby Sandstone (zone of Bel. lateralis) of Claxby. 80 CRETACEOUS LAMELLIBRANCHIA. TRIGONIA DEDALEA, Parkinson, 1811. Additional Synonymy. 1828. Triconia papaLua, Defrance. Dict. Sciences nat., vol. ly, p. 294. 8 — — A. Briart and F. L. Cornet. Descript. Mineralog. Géol. et Pal. de la Meule de Bracquegnies (Mém. cour. et Mem. des Sav. etrangers, vol. xxxiv), p- 64, pl. vi, figs. 1—3. 1875. — — Lycett, p. 100, pl. xxii, figs. 7, 8; pl. xxiii, figs. 2, 3; pl. xxviu, fig. 8. 1875. — — var. conrusa, Lycett, p. 102, pl. xxiii, fig. 1. Non 1819. — DHDALEA, Lamarck. Anim. sans Vert., vol. vi, p. 63 (ed. 2, 1835, p. 516), from Le Mans. — 1866. — — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 371. Remarks. Lycett regarded 7. palmata, Deshayes,' as a variety of 1’. dedalea ; but it should be noted that the former occurs at a distinctly lower horizon than the latter, namely, in the Middle Neocomian of the Aube. I have seen no example of T. palmata. Types.—I have not found the type. The specimens figured by Sowerby are in the British Museum; those figured by Lycett are in the Museum of Practical Geology, except the type of the variety confusa, which is in Mr. Vicary’s collection. The type of 7. quadrata, Sowerby, is in the Bristol Museum. Distribution Greensand of Blackdown (Zone xii) and Haldon. TRIGONIA sprcraBitis, Sowerby, 1826. 1875. Lycett, p. 112, pl. xxxvi, figs. 1—4. Remarks.—I do not think that Lycett’s view of the identity of the species figured by Pictet and Roux’ as 7. nodosa with T. spectabilis can be maintained. In the former the area is smaller, the posterior extremity more produced and rounded, the tubercles smaller and more rounded and not forming such distinct rows as in 7’. spectabilis. 1 «Mém. Soe. géol. France,’ vol. v (1842), p. 7, pl. viii, fig. 5. 9 * «Moll. Foss. Grés verts de Gentve’ (1852), p. 454, pl. xxxv, fig. 5. TRIGONIA. 81 Types.—I have not found the type. The specimens figured by Lycett are in the Museum of Practical Geology (figs. 1—3), and in Mr. Vicary’s collection (fig. 4). Distribution —Blackdown Greensand (Zone x). Section 5.—Scapra. Triconta Erxeripcet, Lycett, 1875. 1875, Lycett, p. 127, pl. xxvii, figs. 1—3. Types.—In the Museum of Practical Geology. Distribution.—Perna-bed of Atherfield. TRIGONIA CAUDATA, Agassiz, 1840. Additional Synonymy. ¢1852. Triconia auirormis, I. J. Pictet and W. Roux. Moll. Foss. Grés verts de Geneve, pl. xxxv, fig. 1 (not fig. 2), p. 450. 1866. _— caupara, Ff. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mat¢r. Pal. Suisse, ser. 4), p. 374. 1869. — — P. de Loriol and V. Gilliéron. Mon. Urgonien Infér. du Landeron (Mém. Soc. helvét. Sci. nat., vol. xxii), p. 15. 1875. _ — Lycett, p. 129, pl. xxvi, figs. 5—7, 1895. — — G. Maas. Geitschr., der deutsch. geol. Gesellsch., vol. xlvil, p. 264. 1900. — _ A, Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hollind. Neoc. (Abhandl. d. k. preussisch. geol. Land., N. F., pt. 31), p. 89. Types—From the Neocomian of Neuchatel. The specimens figured by Lycett are in the Museum of Practical Geology. Distribution.—Crackers of Atherfield. Recorded by Topley (1875) from several localities in the Weald—lI have not seen the specimens ; 1t is probable that some of them are examples of 7, vectiana. 11 82 CRETACEOUS LAMELLIBRANCHIA. TrigoniA scapricota, Lycett, 1875. 1875. Lycett, p. 130, pl. xxvu, figs. 4, 5. Remarks.—This form is very closely connected with 1. caudata from the Lower Greensand—indeed, some specimens appear to be almost inseparable from that species; but the majority of the Upper Greensand examples have rather more numerous and closer ribs towards the umbo, the shell less produced posteriorly, and its height somewhat greater in proportion. It should, however, be noted that a specimen from the Aptian of the Perte-du-Rhéne, figured by Pictet and Renevier,' agrees perfectly with examples of 7. scabricola from Blackdown and Haldon. Types.—From Blackdown, in the Museum of Practical Geology. Distribution.—Greensand of Blackdown, Haldon, and Devizes. Triconia crenutirena, Lycett, 1877. 1877. Lycett, p. 189, pl. xl, figs. 1, 7, 9. 1896. A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. li, p. 154. Remarks.—The more prominent and fewer coste, and the greater slope of the area and escutcheon, which Lycett regarded as features distinguishing this from 1’. crenulatu, @Orbigny, vary considerably in different specimens, as may be seen by comparing Lycett’s figures 1 and 9. In one example of 7. crenulata in the British Museum, from Le Mans, the coste are actually fewer than in a form of T. crenulifera of the same size. The costellee on the area, however, seem to separate 1’. crenulifera from T’. crenulata; in the latter they appear to be found only near the anterior end of the area. Types.—In Mr. Me¥er’s collection (figs. 1 and 7), and in the Museum of Practical Geology (fig. 9). Distribution.—Cenomanian (Beds 10 and 11), near Beer Head, Dunscombe, and Pinhay Cliff. TRIGONIA CRENULATA, Lamarck, 1819. Plate XIX, fie. 14. 1819. Trigonia crenutata, Lamarck. Anim. sans vert., vol. vi, p. 63. 1828. = = Defrance. Dict. Sciences nat., vol. lv, p. 294. «Foss. Aptien de la Perte du Rhone” (‘ Matér, Pal. Suisse,’ ser. 1, 1857), pl. sail, fig. 1. TRIGONTA. 83 1835. TrIGcontA cRENULATA, Lamarck. Ibid., ed. 2, vol. vi, p. 515. 1840. -- —- L. Agassiz. tudes crit. Moll. Foss. (Trigon.), p. 32, pl. vi, figs. 4—6. 1844, — — A. @Orbigny. Pal. Frane. Terr. Crét., vol. iii, p. 151, pl. cexev. 1848. Lyrropon crenuxatus, H. G. Bronn. Index Palxont., vol. i, p. 186. 1850. ‘T'rrconta crenunata, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 161. 1866. -— — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 388. 1867. -= — I. Guéranger. Album Paléont. de la Sarthe, p. 14, pl. xviii, figs. 3, 4. ? 1878. —- —_ O. Fraas. Aus dem Orient., vol. ii, Geol. Beobacht. Libanon, p. 70. 1896. — — A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. lii, p. 154. Remarl:s.—I have seen only one English example of this. The surface is not quite perfectly preserved, so that the rugose character of the costze is not well seen. T'ype-—From the Cenomanian of Le Mans. Distribution —Cenomanian (Meyer's Bed 10) of Dunscombe. Tricgonta antrormis, Parkinson, 1811. Additional Synonymy. 1828. Trriconra ALEForMIS, Defrance. Dict. Sciences nat., vol. lv, p. 297. 1850. — ALIFormis, G. P. Deshayes. Traité Elément. Couch., vol. ii, p. 258, pl. xxxii, fig. 3. ? 1865. _ _ H. Coquand. Mon. Aptien de l’Espagne, p. 134. ¥ 1866. “= — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), pp. 377, 386, pl. cxxviul, fig. 9. 1875. — — Lycett, p. 116, pl. xxv, figs. 83—6 ; pl. xxviii, fig. 5. 1897. = — R. B. Newton. Proce. Dorset Nat. Hist. and Antiq. Field Club, vol. xviii, p. 95, pl. 1, fig. 14. Non 1841. — AL@Formis, FI’. A. Riimer. Die Verstein. des nord-deutsch. Kreidegeb., p. 68. = 1848" == — H. B. Geinitz. Die Verstein. von Kieslingswalda, p. 14, pl. ii, figs. 15, 16. — ?1846. — — A. FE. Reuss. Die Verstein. der bohm. Kreide- format., pt. 2, p. 5. — 1847. — J. Miller. Mon. Petref. der Aachen. Kreideformat., pt. 1, p. 15. — 1863, — ALIForMis, R. Drescher. Zeitschr. d. deutsch. geol. Gesellsch., vol. xv, p. 348. 84. CRETACEOUS LAMELLIBRANCHIA. Non 1873. ‘Trtconra attrormis, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleon- ; toegraphica, vol. xx), pt. 2, p. 58. — 1897. — ALmFormis, A. Fritsch. Stud. im Gebiete der bohm. Kreide- format. vi. Die Chlomeker Schichten, p. 55, fig. 60. Types.—From Blackdown. I have not been able to trace the type. Sowerby’s specimens are in the British Museum, except the original of fig. 3, which is in the Bristol Museum. The specimens figured by Lycett are in the Museum of Practical Geology (figs. 3—6), and in Mr. Vicary’s collection (pl. xxvin, fig. 5). The specimen figured by Newton is m the British Museum. Distribution.—Greensand of Blackdown (Zones iv to vi) and Devizes. Stated by Lycett to occur at Haldon, but not recorded by Downes (1882); I have seen no example from that locality. Zone of Hoplites interruptus of Okeford Fitzpaine. The variety attenuata is found in the Upper Greensand of Niton, Ventnor, and Warminster. Agassiz’’ record of this form from the Greensand near Cambridge is erroneous. ? Folkestone Beds of Copt Point, Folkestone. TricontA Mnyert, Lycett, 1875. 1875. Lycett, p. 125, pl. xxiii, fig. 6; pl. xli, figs. 15, 16. 1896. A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. lii, p. 154. Types.—In the Museum of Practical Geology—from near Sidmouth and Duns- combe. Distribution —Cenomanian (Meyer's Beds 10, 11, 12) of Dunscombe, Culver Hole (Devon), west of Pinhay, ete. Base of Chalk Marl (zone of Schlanbachia varians) of Titherleigh, near Chard. Triconta Vucttana, Lycett, 1875. 5 eK Additional Synonymy. 1818. Triconra aLHrormis, J. Sowerby. Min. Conch., vol. iii, p. 27 (parti), pl. cexv, fig. 2 (not 1, 3, 4 ). 1875. = Vecriana, Lycett, p. 128, pl. xxiv, figs. 10, 11; pl. xxv, fig. 7. Types.—Museum of Practical Geology—from the Perna-bed of Atherfield. Distribution.—Perna-bed and Bed 45 (Fitton) of Atherfield. Perna-bed of 1 «tudes crit. Moll. Foss.,’ Trigon. (1840), p. 31. TRIGONIA. &5 Redcliff, near Sandown. Ferruginous Sands of Shanklin. Hythe Beds of Hythe, etc. Atherfield Beds of Sevenoaks. Lower Greensand of Seend (side Lycett). Sandgate Beds of Parham Park. Triconta ornata, @’ Orbigny, 1844. Plate XIX, fig. 13. Additional Synonymy. £1855. Trreonta ornara, G. Cotteau. Moll. Foss. de ’Youne, p. 76. ? 1858. — — J. Vilanova-y-Piera. Mém. Geogr.-agric. de Castellon, pl. ii, fig. 14. P1865. —_— — H. Coquand. Mon. Aptien de l’Espagne, p. 137. 1866. —~ —_ F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matcér. Pal. Suisse, ser. 4), pp. 373, 385. 1867. oo — PP. de Loriol. In A. Favre, Rech. géol. dans Savoie, etc., vol. i, p. 379, pl. c, fig. 8. ? 1871. _ — W. A. Ooster and C. v. Fischer-Ooster. Protoz. Helvet., vol. ii, p. 101, pl. xv, fig. 18. 1875. — — Lycett, p. 139, pl. xxiv, figs. 6, 7. 1884. -- sp. indet. (2nd), O. Weerth. Die Fauna Neocom. im Teuto- burg. Walde (Paleont. Abhandl., vol. ii), pp: 45, 46, 1896. -= ornata, A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlviii, p. 847. 21899. — — G. Maas. Ibid., vol. li, p. 248. 1900. — — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holland. Neoe. (Abhandl. d. k. preussisch. geol. - Land., N. F., pt. 31), p. 88. Remarks.—The English specimens agree better with the example figured by Pictet and Renevier than with the type, in which the coste are less numerous. A specimen from Lympne (Plate XIX, fig. 15) possesses fewer cost than the exam- ples found at Atherfield, and in this character, as also in general shape, it approaches more nearly the foreign examples. The specimen from Shorncliffe, figured by Sowerby’ as 7. spinosa, var., has been regarded by several authors as 7. Archiaciana, @Orbigny ; but I think it is more likely to be an example of 7. ornata. I have not been able to trace the specimen. T'ypes.—The specimens figured by Lycett are in the Museum of Practical Geology. Distribution —Perna-bed of Atherfield. Ferruginous Sands of Shanklin. Hythe Beds of Hythe, Lympne, and near Maidstone. 1 «Trans. Geol. Soc.,’ ser. 2, vol. iv (1836), pp. 131, 338, pl. xiii, fig. 3. 86 CRETACEOUS LAMELLIBRANCHIA. TRIGONIA UPWARENSIS, Lycett, 1875. 1875. Triconra UpwaRENsIs, Lycett, p. 143, pl. xxiii, figs. 8, 9; pl. xxxix, fig. 4. 83 — — W. Keeping. Foss., ete., Neoc. Upware and Brick- hill, p. 118. Remarks.—This species is allied to 7. Archiaciana, @Orbigny, but the coste are more numerous and have greater curvature near the anterior border. ‘The costelle on the area appear to be generally more numerous and more nearly perpendicular to the carina. The outline of the larger specimens appears to be more rounded than in 17’. Archiaciana. Types.—In the Museum of Practical Geology. The specimen figured on Lycett’s pl. xxxix is in the collection of Mr. J. F. Walker. Distribution.—Lower Greensand of Upware. TriGontaA ARCHIACIANA, @ Orbigny, 1844. Additional Synonymy. 1866. Trraonta Arcuractana, #. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matdér. Pal. Suisse, ser. 4), p. 380. 5. — _— Lycett, pp. 140, 202 (partim), not the figures. —_ oO “NI Remarks.—It seems doubtful whether this species occurs in England; I have seen two specimens from the Peria-bed of Atherfield and Sandown, which may perhaps belong to it; but they are not sufficiently perfect for exact determination. The surface of the specimen from the Gault of Okeford Fitzpaine, figured by Newton,} has perished, so that I am unable to give any opinion as to its affinities. Triconta spinosa, Parkinson, 1811. Additional Synonymy. 1875. Triconta spinosa, Lycett, p. 136, pl. xxiii, fig. 10; pl. xxiv, figs. 8, 9; pl. xxviii, figs. 1, 2. P1881. — — J. Kiesow. Schrift. d. nat. Gesellsch. in Danzig, vol. v, p. 413. 1 «Proc, Dorset Nat, Hist, and Antiq. Field Club.,’ vol, xviii (1897), p. 96, pl. iui, fig. 16. TRIGONTA. 87 21885. Triconta spinosa, EF’. Notling. Die Fauna d. baltisch. Cenoman. (Palont. Abhandl., vol. 11), p. 27, pl. iv, figs. 16, 17. F Non 1837, — — F. Dujardin. Mém. Soe. géol. France, vol. ii, p. 224. — 1844. — — A. @Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 154, pl. cexevii, figs. 1—5. — 1850. _— o POrbigny. Prodr. de Pal., vol. ii, p. 161. Types.—The type, from Blackdown, and the specimen figured by Sowerby, are in the British Museum. The originals of Lycett’s pl. xxi, fig. 10, and pl. xxviii, fig. 1, 2, are in the Museum of Practical Geology; of pl. xxiv, fig. 8,in the Wiltshire Collection, Wood- wardian Museum; of pl. xxiv, fig. 9, in the Williamson Collection, Manchester Musewn. Distribution.—Greensand of Blackdown. Triconia Vicaryana, Lycett, 1875. 1844. Tricon1a spinosa, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 154, pl. cexevil, figs. 1—5 (non 1. spinosa, Park.). 1850. —_ ms @’ Orbigny. Prodr. de Pal., vol. ii, p. 161. 1867. — — E. Guéranger. Album Paléont. de la Sarthe, p. 14, pl. xviii, fig. 2. 1875. = Vicaryana, Lycett, pp. 141, 203, pl. xxiii, fig. 7; pl. xxv, figs. 8, 9; pl. xxviii, fig. 4; pl. xl, figs. 3, 4. ? 1882. psEuDospinosa, P. de Loriol. Gault de Cosne (Mém. Soe. Pal. Suisse, vol. ix), p. 99, pl. xii, figs. 12 —14. 1896. _— Vicaryana, A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. li, p. 154. Remarks.—This is relatively higher and shorter than 7, Arehiaciana, dV Orbigny, T. upwarensis, Lycett, and 7’. ornatu, VOrbigny. The costelle on the area are more oblique to the carina than in 7. upiwarensis. The costee are more numerous than in 1’, ornata. 1. Ludovice, Briart and Cornet,’ from Bracquegnies, is more produced pos- teriorly, it has fewer ribs anteriorly, and closer ribs posteriorly, than T. Viewryana. De Loriol figures a form from the Gault of Cosne, which he regards as 7. spinosa, VOrbigny, ow Sowerby, and names 7. pseudospinosu, but it seems to possess fewer and stronger costelle on the area than 7’. spinosa, d’Orbigny, which is here considered to be identical with 7) Viewryana, Lycett. Types.—F rom the Greensand near Sidmouth and Haldon; in the Museum of Practical Geology (Lycett’s pl. xxv, fig. 8), and Mr. Vicary’s collection (fig. 9). ' «Descript. de la Meule de Bracquegnies’ (1868), p. 65, pl. vi, figs. 6, 7. 88 CRETACEOUS LAMELLIBRANCHIA. Other figured specimens are in Mr. Vicary’s collection (pl. xxiii, fig. 7—from Haldon, not Blackdown as stated by Lycett; and pl. xxvii, fig. 4), and in Mr. Me¥er’s collec- tion (pl. xl, figs. 3, 4). Distribution —Greensand of Haldon, Kingskerswell, and near Weymouth. Cenomanian of Dunscombe, Branscombe, and Beer Head (Mever’s Beds 10, 11 and 12); and of Pinhay (Bed 10). Base of Chalk Marl (zone of Sehlaubachia varias) of Eggardon Hill, Chard, Chardstock, and Titherleigh (near Chard). Triconia Frrront, Deshayes, 1842. Additional Synonymy. 1866. Triconta Frrroni, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), pp. 381, 386, pl. exxvui, fig. 10. 1875. _— — Lycett, p. 132, pl. xxiii, figs. 4, 5. 1897. — a R. B. Newton. Proc. Dorset Nat. Hist. and Antiq. Field Club, vol. xvii, p. 96, pl. iii, fig. 15. T'ypes.—In the Ecole des Mines, Paris, from the Albian of Le Gaty, Hpothémont, ete. (Aube). The specimens figured by Lycett are in the Museum of Practical Geology, and in the Wiltshire Collection, Woodwardian Museum. The example fieured by Newton is in the British Museum. Distribution.—Gault (zone i) of Folkestone. Zone of Hoplites interruptus of Okeford Fitzpaine. Triconia costicERA, Lycett, 1879. 1879. Lycett, p. 205, pl. xh, fig. 17. Type.—In the Museum of Practical Geology. his is the only specimen seen ; it is very imperfectly preserved. Distribution.—Cenomanian (Meyer's Bed 10) of Dunscombe. TRIGONIA PENNATA, Sowerby, 1819. _ 1 Additional Synonymy. 1828. Triconia peNNATA, Defrance. Dict. Sciences nat., vol. lv, p. 297. 1866. _ _ F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 387. 1875. —- — Lycett, p. 133, pl. xxiv, figs. 4, 5; pl. xxxvui, fig. 4. TRIGONIA. 89 Types.—In the British Museum—from near Teignmouth. The specimens figured by Lycett are in Mr. Vicary’s Collection, and in the British Museum (Cunnington Collection). Distribution.—Cenomanian (Me¥er’s Beds 10 and 11) of Dunscombe. Greensand of Haldon, Teignmouth, and Kingskerswell. TRIGONIA SULCATARIA, Lamarck. Additional Synonymy. ?1840. Triconia suncataria, H. B. Geinitz. Char. d. Schicht. u. Petref. sich- sisch. Kreidegeb., pt. 2, pp. 54, x, pl. xxi, fig. 3. ? 1846. — = Geinitz. Grundriss der Verstein., p. 444. ? 1846. ae — A. E. Reuss. Die Verstein der béhm. Kreideformat., pt. 2, p. 5. 1850. — -- H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 158. 1850. _ = G. P. Deshayes. Traité Elém. de Conchyl., vol. ii, p. 259, pl. xxxiii, fig. 10. 1866. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 387. 1867. — — E. Guéranger. Album Paldont. de la Sarthe, p. 14, pl. xviii, fig. 6. 21873. - — H. B. Geinitz. Das Elbthalgeb. in Sachsen. (Paleontographica, vol. xx), pt. 1, p. 224, pl. xlix, figs. 13, 14. 1875. _ _— Lycett, p. 135, pl. xxvi, fig. 8; pl. xxviii, fig. 3. Remarks.—T. maudeusis, Whiteaves,' 7’. diversicostata, Whiteaves, and 7. Buchi, Geinitz,’ are allied forms; and so also is probably 7’. subovalis, Jimbo.! Types—The specimens figured by Lycett are in Mr. Vicary’s Collection. Distribution.—Cenomanian of Dunscombe. Greensand of Haldon and Kings- kerswell. ‘ «Mesozoic Fossils,’ vol. i, pt. 3 (Geol. and Nat. Hist. Survey Canada,’ 1884), p. 230, pl. xxxi, fig. 2. 2 Tbid., pt. 1 (1876), p. 68, pl. x, fig. 1. % «Das Elbthalgeb. in Sachsen,’ pt. 1 (1873), p. 225, pl. xlix, figs. 15, 16. + “ Kreideformat. von Hokkaido” (‘ Paleont. Abhandl.,’ vol. vi, 1894), p. 42, pl. viii, fig. 5. 12 90 CRETACEOUS LAMELLIBRANCHIA. Triconta Cunnincront, Lycett, 1875. 1875. Lycett, p. 146, pl. xxi, fig. 11. Type.—British Museum (Cunnington Collection). Distribution —Upper Greensand of Devizes. TRIGONIA CARINATA, 1858. 1861. 1865. 1866. 1877. 1896. 1900. Section 6.—BYSsIFERm. Agassiz, 1840. Additional Synonymy. Tricgonra caRiINATA, J. Vilanova-y-Piera. Mém. Geog.-agric. de Castellon, pl. iii, fig. 19. —- oa P. de Loriol. Invert. Foss. du Mt. Saleve, p. 74. — — H. Coquand. Mon. Aptien de |’Espagne, p. 135. — ~~ F. J. Pictet and G. Campiche. Foss. Terr. Crct. Ste. Croix (Matcr. Pal. Suisse, ser. 4), p. 365. a Lycett, p. 179, pl. xxxv, figs. 3—6. — — A. Wollemann. Geitschr. d. deutsch. geol. Gesellsch., vol. xlviii, p. 846. a — = Die Biv. und Gastrop. deutsch. u. holland. Neoc. (Abhandl. d. k. preussisch, geol. Land. N. F., pt. 31), p. 86, pl. iv, figs. 6, 7. Remarks.—T. subcarinata, Ebray,' (= T. Heva, Dollfuss) is an allied form, but with fewer coste. Types.—From the Neocomian of Hauterive. The specimens figured by Lycett are in the Museum of Practical Geology. Distribution.—Perna-bed of Atherfield and Sandown. Hythe Beds of Hythe, Lympne, and Maidstone. Upper Greensand of Ventnor, Blackdown, Melbury (near Shaftesbury), and Potterne. 1 «Btudes géol. sur le départ. de la Nitvre’ (1858), p. 200; Dollfuss, ‘ Bull. Soc. géol. France,’ ser. 2, vol. xx (1863), p. 220, pl. ii; De Loriol, ‘Gault de Cosne’ (1882), p. 97, pl. xu, figs. 8—10. MYTILUS. 9] Family—Myrition, Lamarek. Genus—Myritts, Linneus, 1758. (‘ Syst. Nat., ed. 10, p. 704.’) MYTILUS INRQUIVALVIS, Sowerby, 1836. Plate XV, figs. 7 a—d. 1836. Myriztus InmQuivatvis, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp. 241, 342, pl. xvii, fig. 16 (non Deshayes, 1838). 1854. = == J. Morris. Cat. Brit. Foss., ed. 2, p. 215. Description.—Shell slightly inequivalve, compressed, triangular, expanded and rounded posteriorly; edges sharp except at the anterior part of the ventral margin. Dorsal margin slightly curved, ventral nearly straight. Umbones slightly curved, pointed; no carina; greatest convexity between the umbones and the postero-ventral extremity. Surface smooth except for faintly marked growth- lines. Measurements : (1) (2) Umbo to postero-ventral extremity —. : 42 : 31mm. Height (at right angles to greatest length) . 24 : LOR Thickness ; . ; ; : ~. MBS F ia ees (1), the Type; (2), in the British Museum. Affinities—This species seems to approach M. Crallicnnei, d’Orbigny,! but is more compressed near the postero-ventral edge, less regular in outline, and without ornamentation near the ventral border. Type.—In the Bristol Museum. The only other specimen seen is in the British Museum. Distribution —Blackdown Greensand. Myritus, sp., ef. tornacensis, @’ Archiac, 1847. 1847. Myrinus tornacensis, A. d’Archiac. Mém. Soc. géol. France, ser. 2 vol. ii, p. 307, pl. xv, fig. 3. 1847. — HAINOENSIS, P. de Ryckholt. Elucubrat. paléont. (not seen). i 1 «Pal. Franc. Terr. Crét.,’ vol. ii (1844), p. 273, pl. ceexxxix, figs. 1, 2. See also Geinitz, ‘‘ Das Elbthalgeb, in Sachsen” (‘ Paleontographica,’ vol. xx), pt. 1 (1873), p. 213, pl. xlviii, figs. 1—3, 92 CRETACEOUS LAMELLIBRANCHIA. 1852. Myrinus rornacensis, P. de Ryckholt. Mélanges Paldéont., pt. 1 (Mém. cour. et Mém. des Sav. é¢trangers vol. xxiv), p. 150, pl. ix, fig. 7. 1871. — — F. Stoliczka. Palewont. Indica, Cret. Fauna S. India vol, ili, p. 374. 1883. Moprona, sp. nov., W. Keeping. Foss., &c., Neoc., Upware and Brickhill, p. 118. Remarks.—A single specimen described, but not named, by W. Keeping agrees closely with M. tornacensis, @Archiac. The greater part of the shell has unfortu- nately disappeared except ventrally to the carina, where the characteristic crimp- like ornamentation is seen, but is rather finer than in Belgian specimens. D’Orbigny' and some other authors have considered M. tornacensis to be identical with M. Galliennei, dOrbigny, but the two forms seem to me quite distinct. The former (of which I have one specimen from 'Tournay, sent me by M. Piret, and also figures of a specimen in the Brussels Museum, kindly made by M. Rutot) is distinguished from the latter by (1) the more prominent, ridge-like, regular growth- lines ;* (2) the presence of the crimp-lke ornamentation near the dorsal margin as well as ventrally; (3) the less pointed umbonal region; (4) the curvature of the carina. [am doubtful whether this species should be referred to Mytilus. Type.—From the Tourtia of Tournay. Distribution.—Lower Greensand of Upware. Genus—Moptona, Lamarck, 1799. (‘Mém. Soc. Hist. Nat. Paris,’ p. 87.) Moptona mquaris, Sowerby, 1818. Plate XV, figs. 8a—e, 9—14. 1818. Moprona mauatts, J. Sowerby. Min. Conch., vol. iii, p. 18, pl. cex, fig. 2. ? 1842. — Brpartira, A. Leymerie. Mém. Soc. géol. France, vol. v, p. 26, pl. ix, fig. 8 (non bipartita, Sowerby). 1844. Myrinus mquauts, A. d’Orbigny. Pal. Frane. Terr. Crét., vol. ui, p. 265, pl. ecexxxvii, figs. 3, 4. 1845. — (Moprouvs) mauauis, FE. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 248. 1850. —_ mQuarts, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 81. 1854. Moprona mquauis, J. Morris. Cat. Brit. Foss., ed. 2, p. 210. 1855. Myritus mquauis, G. Cotteauw. Moll. Foss. de lYonne, p. 93. 1 «Prod. de Pal.,’ vol. ii (1850), p. 165. * In this respect d’Archiac’s fig. 3 is not satisfactory; it was probably drawn from a worn specimen, MODIOLA. 93 1858. Mytrnus mauauis, F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér. Pal. Suisse, ser. 1), p. 116, pl. xvi. fig. 2. 1865. — — H. Coquand. Mon. Aptien de l’Espagne, p. 143. 1868. — — BE. Bichwald. Lethzea Rossica vol. ii, p. 531. 1867. -= -- FP. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), pp. 496, 507. 1883. Moprona oprsa, W. Keeping. Foss., &c., Neoc. Upware and Brickhill, p. 117, pl. vi, fig. 3. y Non 1846, — #quaris, A. B. Reuss. Die Verstein. der bihm. Kreideformat., pt. 2, p. 15, pl. xxxiii, fig. 10. — 1866, —— —_ K. A. Zittel. Die Bivalv. der Gosaugeb , pt. 2 (Denkschr. d.k. Akad. Wissen. Math.-nat. Cl. Wien, vol. xxv), p. 80 (p. 4 of reprint), pl. xi, fig. 4. — 1882. — — J. Kiesow. Schrift. der nat. Gesell. in Danzig, vol. vy, p. 240. P— 1885. — - F. Nétling. Die Fauna der baltisch. Cenom. (Palewont. Abhandl., vol. ii), p. 24, pl. iv, fig. 1. Description.—Shell ovate-oblong, rather short, rounded at the ends, convex, compressed posteriorly. Dorsal and ventral margins usually nearly parallel. Umbones obtuse, not terminal. Carina absent or very indistinct; greatest con- vexity of valve between the umbo and the postero-ventral extremity. 20 28 27 22:5. 22 2] 15 mm. Height . : s Paes: Loi 12 2 oles Ot oa, Thickness. oe ees 15 14 Lhe 10 9257 eT (1—7) all from the Crackers of Atherfield. Affinities —The young forms of M. reversa, Sowerby, are distinguished from this species by the greater obliquity of their ventral margins. M. Fitton’, dOrbigny,' appears to differ from M. xqualis in the presence of a distinct carina with radial striz in front of it, and also in its greater length. Forbes and Morris considered that M. Archiaci, Leymerie,? and M. bipartita, Leymerie, on Sowerby, were identical with MM. equalis. Some of our specimens agree very closely with Leymerie’s figures of the latter, but with the former the agreement is not quite so satisfactory; the figures given by d’Orbigny,® and by 1 «Prodr. de Pal.,’ vol. 11 (1850), p. 81. * *Mém. Soe. géol. France,’ vol. v (1842), p. 8, pl. x, fig. 2. 3 «Pal. Franc. Terr. Crét.,’ vol. iii (1845), p. 291, pl. ecexliv, figs. 1O—12. 94 CRETACEOUS LAMELLIBRANCHIA. Pictet and Campiche,' show a more elongate shell; the species is referred by these authors to Lithodomus. M. culter, Wollemann,’ from the Hils-conglomerate of Brunswick, is closely allied; it appears to differ chiefly in having a more angular outline and a distinct carina. Young specimens of M. equalis are similar in form to M. matronensis, d’Orbigny,’ but apparently somewhat longer. I am unable to distinguish M. obesa, Keeping (from Upware), from M. xqualis ; its somewhat greater inflation is, I think, due to crushing. Types.—In the British Museum—internal casts from the Sandgate Beds of Parham Park. The type of MW. obesa, Keeping, is in the Woodwardian Museum. Distribution.— Perna-bed, Crackers, and Beds 35 and 36 (Fitton) of Atherfield. Perna-bed of Redchff. Ferrugimous Sands of Shanklin. Atherfield Beds of Seven- oaks and Peasmarsh. Hythe Beds of Maidstone. Sandgate Beds of Parham Park. Lower Greensand of Upware. Moprora reveErRsA, Sowerby, 1836. Plate XV, figs. 15, 16, 17 a, b, 18 a Plate XVI, figs. 1, 2.a, b, 3. C5 1836. Moprona reversa, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp. 241, 342, pl. xvii, fig. 13. ? 1842. — L&HVIGATA, H. B. Geinitz. Char. der Schicht. und Petref. des siichs.-béhm. Kreidegeb., pt. 3, p. 78, pl. xx, fig. 35. ? 1843. = REVERSA, H. B. Geinitz. Die Verstei. von Kieslingswalda, p. 15, pl. ii, fig. 11. 1844, Myrrnus semirapiatus, A. d’Orbigny. Pal. Frane. Terr. Crét., vol. ii, p. 277, pl. ccexlhi, figs. 1, 2. 1850. Moprona reversa, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 168 (partim). 1850. Mrrytus reversus, A. d’Orbiyny. Prodr. de Pal., vol. 11, p. 165. 1854. Moprona reversa, J. Morris. Cat. Brit. Foss., ed. 2, p. 211. 1867. Myrinus (Mopiota) reversvs, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 510. 1868. — rEVERSUS, A. Briart and F. L. Cornet. Descript. Min. géol. et Pal. de la Meule de Bracquegnies (Mém. cour. et Mém. des Sav. étrangers, vol. xxxiv), p. 53, pl. iv, figs. 9, 10. 1 «Boss. Terr. Crét. Ste. Croix” (‘ Mater. Pal. Suisse,’ ser. 3, 1866), pp. 517, 524, pl. exxxiv tig. 8. 2 «Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xlviii (1896), p. 843, pl. xxi, f. 4; and ‘Die Biv. u, Gastrop. d. deutsch. u. hollind. Neoc.’ (1900), p. 65. 8 «Pal. Franc. Terr, Crét., vol. ii (1844), p. 269, pl. ccexxxvil, figs. 14—16. MODIOLA. 95 ?1873. Moproua reversA, var., H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleontographica, vol. xx), pt. 1, p. 216, pl. xlviii, fig. 9. Non 1844. Myrinus reversus, A. d’Orbigny. Pal. Franc. Terr. Cret., vol. iii, p. 264, pl. ccexxxvil, figs. 1, 2. 21846. MoproLa reversa, A. FE. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2, p. 15, pl. xxxii, fig. 9. Description.—Shell elongate-oval, extremities rounded; median part of shell— from the umbo to the posterior extremity—inflated and slightly curved; dorsal part compressed and somewhat extended. Ventral to the inflated part is a shallow depression. Hinge margin forms an obtuse angle with the oblique and slightly convex posterior margin. Ventral border sinuous. Umbones obtuse; no carina. Ornamentation consists of concentric ridges, often sharply marked, sometimes dis- continuous and rather irregular; between these are seen, in some specimens, much finer ridges. A bundle of fine radial ribs extends from the umbo to the ventral sinuosity and occupies the greater part of the shallow depression ; occasionally fine close-set radial Imes are seen on other parts of the shell. Measurements : @) (2) (3) ©) ) (6) Length . ; : ; . 71 70 58 54 34 21 mm. Greatest diameter perpendicular to length ; 5 x 29» “30 (26% 2oee ope si omeee Thickness. ; 27 — 22 21 — — (1—6) all from Blackdown. Affinities—The form figured by d’Orbigny as M. reversus (Sowerby), but after- wards separated as M. Fiitoni, VOrbigny,' appears to differ from Sowerby’s species in the possession of a distinct carina, and in having the umbones placed less anteriorly. M. typica (Forbes),’ especially as represented by the forms from Gosau, is closely allied to M. reversua. M. albensis (VOrbigny)’ is very near to M. reversa, but is perhaps distinguished by the somewhat longer and less curved anterior margin. For the relation of this form to M. ligeriensis (d’Orbigny) see below. Type.—In the Bristol Museum, from Blackdown. 1 For the synonymy of this species see Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (Matér. Pal. Suisse, ser. 4, 1867), p. 495. * «Trans. Geol. Soc.,’ ser. 2, vol. vii (1846), p. 152, pl. xiv, fig. 4; Zittel, “ Die Bivaly. der Gosaugeb.” (‘Denkschr. d. k. Akad. Wissensch. Math.-nat. Classe,’ vol. xxv, 1866), pt. 2, p. 78 (p. 2 of reprint), pl. x1, fig. 5; Stoliczka, ‘Cret. Fauna 8. India,’ vol. iii (1871), p. 377, pl. xxiii, figs. 12—15. 5 Pictet and Campiche, op. cit., p. 504, pl. exxxiy, fig. 1. 96 CRETACEOUS LAMELLIBRANCHIA. Distribution —Greensand of Blackdown. Greensand (chert beds) of Woodlands Covert, Great Haldon. Upper Greensand of Black Ven and Devizes. Cenomanian (Me¥er’s Bed 12) of Dunscombe. + Gault of Black Ven. Mopio.a Lickrimnsis (2 Orbigqny), 1844. Plate XVI, figs. 4a, b, 5a, b, 6. 1844. Myrinus LiceriEensts, A. d’Orbiyny. Pal. Franc. Terr. Crét., vol. iii, p. 274, pl. cccxl, figs. 1, 2. 1850. — = = Prodr. de Pal., vol. ii, p. 165. 1867. — = EL. Gueranger. Album Paléont. de la Sarthe, p. 17, pl. xxu, figs. 2—4. 1867. Moprona LicERriEeNsIs, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matcér. Pal. Suisse, ser. 4), p. 509. ? 1876. — — D. Brauns. Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi, p. 874. ? 1883. — ypica, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat., MOQ ii. Die Iserschichten, p. 106, fig. 73. ? Non 1846. Myrinus (Moproua) ticeriensis, A. EH. Reuss. Die Verstein. der béhm. Kveideformat., pt. 2, p. 16, pl. xxxiii, fig. 3. Measurements : (1) (2) Length , ; : ‘ : 89 . : 60 mm. Greatest height (perpendicular to length) . : ; ; : 40 ; : DAS). pp Thickness. F ; : ; 34. : : 24 (1) and (2) from the Perna-bed of Athertfield. Afjinities.—This species agrees with M. reversa, Sowerby, and seems to be distinguished only by the crimp-like ornament in the spaces between the ribs; this is usually best developed on the dorsal and postero-ventral parts of the valves, and seems always to be absent on the anterior region. The specimens of M. reversa from Blackdown do not show that ornament,’ and its absence can scarcely be explamed by imperfect preservation, since other finer ornament is clearly shown on some specimens. On the other hand, the possibility of the two species being identical is supported by the great variability in the development of the crimp-like ornament in M,. ligeriensis. On some specimens from the Cenomanian of Orbiquet it is very faint, but on one from Le Mans (preserved in the Ecole des Mines, Paris) the crimp-ornament is stronger and more continuous than the concentric ornament. ' One specimen seems to show a very faint trace of it near the hinge-margin. MODIOLA. 97 Distribution.—Perna-bed of Atherfield. Upper Greensand of Potterne. Chlo- ritic Marl of Warminster. ? Cenomanian of Wilmington (fragment only seen). Mopriona ruGosa, Mémer, 1836. 1836. 1841. 1850. 1867. 1896. 1900. Moproua ruGosa, I’, A. Rimer. Die Verstein. nord-deutsch. Oolithengeb., p- 93, pl. v, f£. 10. — _ -- Die Verstein. nord-deutsch. Kreidegeb., p. 67. Miry.us susruaosus, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 81. Myritus (Mopiota) ruaosus, Ff. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 508. Moptoua ruGosa, A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlviui, p. 845. a _- = Die Biv. u. Gastrop. d. deutsch. u. hollind. Neoc. (Abhandl. d. k. preuss. geol. Land., N. F., pt. 31), p. 64. Remarks.—A specimen 45 mm. long, with the umbones broken, is in the Leckenby Collection (Woodwardian Museum), and belongs, I think, to this species. Type. From the Hilsthon of the Eligser Brink. Distribution.—Crackers of Atherfield. Moptona sussimpeiex (d’Orbigny), 1850. Plate XVI, figs. 7, 8, 9a, b, 10a, b. Moprota simpLex, G. P. Deshayes. In A. Leymerie, Mém. Soe. géol France, vol. v, pp. 8, 26, pl. vii, fig. 8 (non Mytilus simplex, Detrance, 1824; Passy, 1832). Myritus — A. @Orbigny. Pal. Franc. Terr. Crét., vol. in, p. 269, gny g if pl. ccexxxviii, figs. 1—4. Myriivus (Moptouus) stmpex, EF. Forbes. uart. Journ. Geol. Soc., vol. i, > p. 248. Miry.us sussimpxex, A. d’Orbiqny. Prodr. de Pal., vol. ii, p. 81. Myrixus curairis, F. J. Pictet and W. Rouw. Moll. Foss. Grés verts de Gentve, pp. 481, 551, pl. xl, fig. 2. Mopioua simPLex, J. Morris. Cat. Brit. Foss., ed. 2, p. 211. Myrinus subsImMPLEX, G. Cotteau. Moll. Foss. de l’Yonne, p. 94. Je ~ = — F. J. Pictet and HE. Renevier. Foss. Terr. Aptien (Matér. Pal. Suisse, ser. 1), p. 114, pl. xvi, fig. 3. — = P. de Loriol. Anim. Invert. Foss. Mt. Saltve, p. 92, pl. xi, fig. 9. 13 98 CRETACEOUS LAMELLIBRANCHIA. 1865. Myrinus sussimpLex, H. Coquand. Mon. Aptien de | Espagne, p. 145. 1867. — -- F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mat¢r. Pal. Suisse, ser. 4), pp. 493, 507. 1882. Moptona sus-simpLex, P. de Loriol. Gault de Cosne (Mém. Soc. Pal. Suisse, vol. ix), p. 81, pl. ix, fig. 17. 1884. Myrrius stmpiex, O. Weerth. Die Fauna d. Neoc. im Teutoburg. Walde (Paleont. Abhandl., vol. 11), p. 47. 1895. — — G. Maas. Zeitschr. der deutsch. geol. Gesellsch., vol. xlvii, p. 266. 1896. Moprona stmpLex, A. Wollemann. Zeitschr. der deutsch. geol. Gesellsch., vol. xlvii, p. 844. 1897. Mytinus — R. B. Newton. Proce. Dorset Nat. Hist. and Antiq. Field Club, vol. xviii, p. 89, pl. in, fig. 13. 1900. Moproua susstmpLex, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holland. Neocoms. (Abhandl. d. k. preussisch. geol Land., N. F., pt. 31), p. 62.3 Description.—Shell elongate, straight or curved, somewhat compressed. _Ante- rior extremity narrow ; posterior part somewhat expanded. Hinge-margin straight, long; posterior margin relatively short, curved, oblique; ventral margin concave. A rounded ridge extends from the umbo to the postero-ventral extremity ; i front of this is a shallow depression. Surface smooth except for faint growth-lines. Measurements : (1) (2) (3) (4) ( Length (greatest). Ol 6 SASS es Ade 340% 8 0Gmm. Height (at right angles to greatest length) 3 pe Oe ho oo al eel mle Thickness : ‘ : ete ee CD25 ee) a OO Spee ore (1)—(5) all from the Crackers of Atherfield. Affinities —This species is very near to, and perhaps identical with, M. siliqua, Mathéron ;’ but the latter is said to have the anterior extremity more obtuse. M. semiornatus, @Orbigny, has the concentric ornament more pronounced on the dorsal part of the shell. M. rectior, Wollemann,’ from the Hails-conglomerate of Brunswick, is very ' «Catal. Foss. Bouches-du-Rhone’ (1842), p. 178, pl. xxviii, figs. 5, 6; d’Orbigny, ‘Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 274, pl. cccexxxix, figs. 3, 4; and ‘Prodr. de Pal.’ (1850), p. 165; Geinitz, ‘Quadersandst. in Deutschland’ (1850), p. 168, pl. x, fig. 14; Zittel, ‘Die Bivalv. der Gosaugeb.,’ pt. 2 (1866), p. 81 (p. 5 reprint), pl. xi, fig. 3; Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix (1867), p. 510; Geinitz, ‘Das Elbthalgeb. in Sachsen,’ pt. 1 (1873), p. 215, pl. xlvii, fig. 3, pt. 2, pl. xv, fig. 4; Bohm, “ Kreidebild. Fiirbergs,” etc. (‘Paleontographica,’ vol. xxxviii, 1891), p. 81, pl. iu, fig. 29; Miller, “ Mollusk. Untersen, Braunschweig und Isede ” (‘ Abhandl. d. k. preuss. geol. Land.,’ N. F., pt. 25, 1898), p. 46, pl. v, fig. 14. * *Zeitschr, d. deutsch, geol, Gesellsch.,’ vol. xlviii (1896), p. 844, pl. xxi, f. 6; and ‘Die Biv. u. Gastrop. d. deutsch. u. hollind. Neoc,’ (1900), p. 63. MODIOLA. 99 closely related to M. subsimplex, but seems to differ in being less convex between the umbo and the posterior extremity, and in having the ventral margin straighter and the posterior more rounded. Types.—The type comes from the Neocomian of Ville-sur-Terre. The specimen referred to by Forbes is in the Museum of the Geological Society. The specimen figured by Newton is in the British Museum. Distribution.—Perna-bed and Crackers of Atherfield. Atherfield Beds of Seven- oaks. Upper Greensand of Devizes. Gault of Folkestone, Black Ven. and Okeford Fitzpaine. ? Greensand of Blackdown. Moprona FLAGELLIFERA, Forbes, 1846. Plate XVII, figs. 1, 2. ? 1842. Inocreramus srtiqua, P. Mathéron. Catal. Foss. Bouches-du-Rhone, p. 174, pl. xxv, fig. 6. 1846. Myrinus (Moprouvs) FLAGELLIFERUS. E. Forbes. Trans. Geol. Soc., ser. 2, vol. vii, p. 152, pl. xvi, fig. 9. 1850. Mrrynus FLAGELLiFERvs, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 247. ? 1863. Myrinus (Moprotus) FLaceniirervs, D. Stur. Jahrb. d. k.-k. geol. Reichsanst., vol. xili, p. 55. 1866. Moprona ruaceniirera, K. A. Zittel. Die Bivaly. d. Gosaugeb. (Denkschr. d. k. Akad. der Wissensch. Math-nat. Classe, vol. xxv), pt. 2, p. 82 (p. 6 of reprint), pl. xii, fir, 2. 1867, — FLAGELLIFERUS, I’, J. Pictet and G. Campiche. Foss. Terr, Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 513. 1871. _ FLAGELLIFERA, F. Stoliczka. Pal. Indica, Cret. Fauna S. India, p. 379, pl. xxiv, figs. 1, 2. ? 1873. Myriius (Moprona) FrraGELLirera. H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palwontographica, vol. xx), pt. 2, p. 55, pl. xv, fig. 5. 1897. Moprona FLAGELLIFERA, A. Fritsch. Stud. im Geb. der béhm. Kreidef. vi, Die Chlomek. Schicht., p. 59, fig. 69. Description.—Shell very elongate, slightly curved, compressed, with knife-like edges; somewhat enlarged posteriorly. Dorsal margin almost straight, and nearly parallel with the slightly concave ventral margin. Umbones obtuse, nearly terminal, with a faintly marked oblique carina extending to the postero-ventral extremity. Ornamentation consists of flagelliform ribs, which are broad near the dorsal margin, and are directed obliquely backwards. At about half their length they curve rapidly, diminish in size, bifurcate, and often have smaller ribs intercalated: the ribs taper at the carina, ventral to which the shell is marked with growth-lines only, or is nearly smooth, 100 CRETACEOUS LAMELLIBRANCHIA. Measurements : (1) (2) Leneth . A ; 5 : ; : 3. @¢ 102mm, Height . ; : F ; : ' 5 2) Pg (1) and (2) from Devizes. Affinities —This species belongs to a section of Modiola characteristic of the Jurassic rocks, of which M. Somwerbiana (dOrbigny) [= M. plicata, Sowerby ], M. perplicata (Etallon), M. Medus (VOrbigny), and M. icawnensis (de Loriol) are well-known representatives. I have seen only three English examples, and these, although in the form of in- ternal casts, seem to agree perfectly with the types of MW. flagellifera, Forbes (from Pondicherry), with which I have compared them. Zittel has referred to this species a form found in the Gosau Beds, of which I have seen one specimen collected by Mr. H. Kynaston from Finstergraben, and now preserved in the Woodwardian Museum; this also agrees with the Forbes’ types. The specimen figured by Mathéron as Inoceramus siliqua is probably an imper- fect example of this species. Modiola Gillieroni (Pictet and Campiche),’ from the Valangian of Presle (near Bienne) and Cinquétral, appears to differ from M. jlagel- lifera in having fewer ribs dorsally, and in the general absence of bifurcation as they curve on approaching the carina. M. Baini, Sharpe,’ from Sunday River (South Africa), apparently differs from M. flagelliferau m haying the ribs continued ventral to the carina, and perhaps also in having a more elongate shell. M. Ebrayi, de Loriol,’ is probably another related form, but at present is im- perfectly known. Types.—From the Valudayoor Group of Pondicherry, preserved in the Museum of the Geological Society of London (No. 10631); these are also figured by Stoliczka. Distribution —Upper Greensand of Devizes and Black Ven. Mopiona unputata (Forbes). Plate XVII, fig. 3. 1845. CypricarpiA? unpuata, H. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 242, pl. ii, fig. 1. 1848. Cypricarpia unpuLaATA, H. G. Bronn. Index Paleont., vol. i, p. 387. 1 “oss. Terr. Crét. Ste. Croix” (‘Mater. Pal. Suisse,’ ser. 4), 1867, p. 503, pl. cxxniil, figs. 9, 10. 2 «Trans. Geol. Soc.,’ ser. 2, vol. vii (1856), p. 193, pl. xxii, figs. 2, 3. % “Paune du Gault de Cosne”’ (‘Mém. Soe. Pal. Suisse,’ vol. ix, 1882), p. 80, pl. ix, figs. 18—20 (especially fig. 20). MODIOLA. 101 1850. Muiryius unpuxarvs, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 119. 1854. Cypricarpia unpuLata, J. Morris. Cat. Brit. Foss., ed. 2, p. 199. 1867. Myrinus (Mopioia) unpuxnatus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 508. 1871. Moprona unputata, I. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. iii, p. 372. Description.—Shell moderately elongate, compressed, enlarged posteriorly. Dorsal margin nearly straight; ventral oblique ; anterior rounded. Umbones not terminal, with a sharply marked curving carina extending to the postero-ventral extremity. From the dorsal margin broad ribs start and are directed posteriorly, afterwards curving to join the cara, where they end. Ventral to the carina the shell is marked by fine lines only. Measurements : Leneth . ; ' , é ; : ; 33 mm. Height (at the posterior end). F : : se Mlle ene Affinities —This is distinguished from M. flugellifera, Forbes, and M. Gillicroni (Pictet and Campiche) by the shorter shell, the carma, the small curvature of the ribs, and the absence of bifurcation in them. The generic position of this species cannot be stated with certainty, since the type specimen is the only example seen and the interior is unknown. T'ype.—In the Museum of the Geological Society of London (No. 2088). Distribution.—Atherfield Clay of Atherfield. Sub-genus—Bracuypontes, Swainson, 1840. (‘ Treatise on Malacology,’ p. 384.) Mopiota (Bracuyponres) Guerancert ? (’Orligny), 1844. Plate XVIT, figs. 4, a a—e. 1844. Myrinus Gurrancert, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 282, pl. ecexli, figs. 7—9. 1850. Miryius — @’Orbigny. Prodr. de Pal., vol. ii, p. 166. 1862. Bracnypontes Gurrancert, J. G. Chenu. Manuel de Conchyl., vol. ii, p. 154, fig. 762. 1867. Myrinus Guerancert, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 509. 1867. — — EB. Guéranger. Album Paldont. de la Sarthe, p. 17, pl. xxii, fig. 3. 1871. Moproua GuErancenrt, I’ Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. iii, p. 373 (Brachydontes). 102 CRETACEOUS LAMELLIBRANCHIA. Remarks.—Two incomplete specimens in Mr. Me¥er’s collection agree with M. (Brachydontes) Guerangeri, from the Cenomanian of Le Mans, except in having finer ribs. Not having seen the type or other French specimens of M. Guerangeri 1 am unable to refer these examples definitely to that species. The ribbing on the ventral surface is clearly shown, and separates this form from M. divaricata, VOrbigny.' A specimen from the Greensand of Haldon, in Mr. Vicary’s collection (pl. xvii, fig. 4), agrees with M. Guerangeri, especially with the example figured by Guéranger, except in the absence of the fine ribbing on the ventral surface; this difference may be due to imperfect preservation. The shell tapers more rapidly toward the umbones than in M, divaricata. Distribution.—Greensand of Haldon. Cenomanian (Me¥er’s Beds 10 and 12) of Dunscombe. Moprona (BRACHYDONTES) VECTIENSIS, sp. nov. Plate XVII, figs. 6 a, b, 7 a—e, 8. Deseviption.—Shell small, rather short, inflated, expanded, and compressed posteriorly, extremities rounded. Ventral margin with a sinus produced by a mesial depression. Umbones obtuse, not terminal. Ornamentation consists of many strong and somewhat irregular ribs, which cover the entire surface and generally bifurcate toward the margin of the valve. Measurements : (1) (2) (3) (4) (4) Length . : : ; . 14 147 3:5 1225) 9mm. Height . : : : on 8, 8S oe Thickness ; : ude XG —- —- — —, (1), (5) from the Crackers, Atherfield. (2) from the Perna-bed, Redcliff. (3) from the Atherfield Beds, Littleton Pit, near Guildford, (4) from the Atherfield Beds, East Shalford. Affinities.—The smaller forms of this species resemble M. striato-costata (VOrbigny), but possess stronger and less regular ribs, and are without the con- centric ribs. M. morinicus’ (de Loriol) is also similar, but has more regular ribs, which do not bifureate, and some parts of the shell are without ribs. 1 «Pal. Frang. Terr. Crét.,’ vol. iii (1844), p. 275, pl. ecexl, figs. 3, 4; ‘Prodr. de Pal.,’ vol. ii (1850), p. 246; Pictet and Campiche, ‘ Foss. Terr. Crét. Ste. Croix’ (1867), p. 511. * De Loriol and Pellat, ‘ Portlandien de Boulogne-sur-Mer’ (‘ Mem. Soe. Phys. et d’Hist. Nat. de Genéve,’ vol, xix, 1866), p. 91, pl. ix, fig. 4, MODIOLA. 103 M. pedernalis, Romer,! is a larger species with finer ribs, and the anterior part of the shell nearly smooth. Distribution.—Perna-bed of Redcliff. Crackers of Atherfield. Atherfield Beds of Kast Shalford, Peasmarsh, Sevenoaks, and (ferruginous nodules) Littleton Pit, near Guildford. Moptota (Bracuyponves) srriavto-cosrara (@’ Orbigny), 1844. Plate XVIL, fies. 9a, b, 10a, b, 11 w—e. 1844. Myrinus srrraro-cosratus, A. d’Orbigny. Pal. Franc. Terr. Crét , vol. iii, p. 281, pl. ccexlii, figs. 4—6. 1848. Moproua srriaro cosrara, H. G. Bronn. Index Paleont., vol. i, p. 739. 1850. Mrryuus srrraro-cosratus, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 166. 1867. Moproua srrraro-cosratus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 510. 1871. ~- stRIATO-cosTavTA, E. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. i, p. 373. Description.—Shell small, oblong or ovate-oblong, short, inflated, somewhat expanded, and also rounded and compressed posteriorly, ventral margin slightly sinuous. Umbones not quite terminal. No carina; dorsal and ventral to a line between the umbones and the posterior extremity the valves are sharply com- pressed. Ornamentation consists of numerous fine radial ribs separated by narrow grooves and covering the entire surface; the ribs curve toward the dorsal margin. The radial ribs are crossed at tervals by concentric ridges. Measurements : (1) (2) (3) (4) (9) Leneth . ; ; an) 8 8 7 5°) mm. Height . : F cad 5 es) 25 Ba eee Thickness ; ; ._— I ve) 5 — ,, (1) to (5) from Blackdown. Affinities.—The relation of this species to M. vectiensis is given above. It seems to approach closely the form described by Pictet and Campiche* as Litho- domus prestensis. Distribution —Blackdown Greensand. ' «Tie Kreidebild. von Texas’ (1852), p. 58, pl. vii, fig. 11. 2 « Boss, Terr. Crét. Ste. Croix” (‘ Matcér. Pal. Suisse,’ ser. 4, 1867), p. 522, pl. exxxvi, figs. 2—4. 104. CRETACEOUS LAMELLIBRANCHIA. Mopiota, sp. 1883. MopioLa PEDERNALIS (?), W. Keeping. Foss., ete., Neoc. Upware and Brickhill, p. 117, pl. vi, fig. 2. A portion of a left valve with the surface abraded, from the Lower Greensand of Upware, was regarded by Keeping as probably M. pedernalis, Romer. The imperfect character of the specimen makes this reference very doubtful. The shell also resembles M. autissiodorensis, Cotteau, from the Portlandian.’ Genus—CreENELLA, Brown, 1827. (‘Illust. Conch. Great Britain and Ireland,’ pl. xxxi, figs. 12—14.; ed. 2 (1844), p. 75, pl. xxiii, figs. 12—14.) CRENELLA BELLA (Sowerby), 1836. Plate XVII, figs. 12 a, b, 13 a—d. 1836. Moprota seuua, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp. 118, 158, 336, pl. xi, fig. 9. 1844. Myrinus Cornuguianus, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. in, p. 268, pl. ecexxxvu, figs. 1O—13. 1845. — (Moprotus) Bexuus, EH. Forbes. Quart. Journ Geol. Soc, vol. i, p. 248. 1850. Mrryius Cornuexianus, A. d’Orbigny. Prodr. de Pal., vol. 1, p. 81. 1850. — BELLA, @’ Orbigny. Ibid., p. 138. 1854. Moproua Bexua, J. Morris. Cat. Brit. Foss., ed. 2, p. 210. 1855. Myrrius Cornuetianus, G. Cotteau. Moll Foss. de l’Yonne, p. 93. 1858. — BELLUS, F. J. Pictet and EH. Renevier. Foss. Terr. Aptien (Mat¢r. Pal. Suisse, ser. 1), p. 118, pl. xv, fig. 10. 1867. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matcr. Pal. Suisse, ser. 4), p. 502. 1869. — — P.de Loriol and V. Gilliéron. Mon. de ? Etage Urgonien Infér. du Landeron (Mém. Soc. Helvet. Sci. Nat., vol. xxiii), p. 17, pl. i, fig. 15. 1871. Mopiona BELLA, F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. ili, p. 372 (7 Crenella). 1895. Myriius Cornvetrianus, G. Maas. Zeitschr. der deutsch. geol. Gesellsch., vol. xlvu, p. 266. 1896. Mopioura Cornurniana, A. Wollemann. Zeitschr. der deutsch. geol. Gesellsch., vol. xlvin, p. 844. 1900. — BELLA, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holland. Neocoms. (Abhandl. d. k. preuss. geol. Land., N. F., pt. 31), p. 69. 1 De Loriol and Cotteau, ‘Mon. l’Etage Portlandien de Yonne’ (1868), p. 189, pl. xu, fig. 8. CRENELLA. 105 Description.—Shell subquadrate or oval, short, inflated—especially anteriorly and between the umbo and the postero-ventral extremity ; on each side of this line the shell is compressed, and on the ventral side it is flattened. Hinge-margin relatively short; posterior margin curved, oblique; ventral long, nearly straight. Postero-ventral angle rounded. Umbo prominent, extending beyond the short anterior margin. Ornamentation consists of numerous fine regular radial ribs, crossed by finer concentric ribs, which are best marked on the dorsal part of the valves; also at intervals a few well-marked growth-lines. Measurements : (1) (2) (3) Length , : . 16 : 14 : 15) mm. Height : : ; ita : 9 2 85 ,, Thickness. - : 135. 1225): IL (1—3) all from Atherfield. Affinities —This is distinguished from the other Cretaceous species’ by its more quadrate outline. It may, perhaps, belong to the sub-genus Ihomboidella, Monterosato. T'ypes.—I have not seen the type; it came from the Hythe Beds, near Hythe. Distribution. —Perna-bed of Atherfield and Redcliff. Crackers of Atherfield. Hythe Beds near Hythe, and near Maidstone. Genus—LirHopomus, Cuvier, 1817. (‘Le Régne Animal,’ vol. ii, p. 471.) LirHopomus ruGosus? d@’Orbigny, 1845. Plate XVII, figs. 14a, b. 1845. Lirgopomus ruaosus, A. d’Orbigny. Pal. Franc. Terr. Crct., vol. ii, p. 294, pl. ecexlvi, figs. 1—3. 1850. _ — —_ Prod. de Pal., vol. ii, p. 166. 1867. — — E. Guéranger. Album Paléont. de la Sarthe, p. 18, pl. xxiii, figs. 18—20. 1873. — —— H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleon- tographica, vol. xx), pt. 1, p. 219, pl. hi, figs. 24.—26. Deseription.—Shell elongate, oval, subcylindrical, dorsal and ventral margins nearly parallel, extremities rounded. Surface with strongly marked erowth-lines. Umbones not terminal. 1 C. concentrica, Gabb; C. elegantula, Meek and Hayden; C. sericea, Conrad; C. granulato- cancellata (Rimer); C. inflata (Mill.). 14 106 CRETACEOUS LAMELLIBRANCHIA. Measurements : Length . . . ; : ; ; ; : 28 mm. Height . : : : : : : : ‘ ee Affinities—This species approaches L. oblongus, @Orbigny, and L. alpinus, Zittel. Remarks.—The three specimens seen are imperfectly preserved, and the radial ornament, described by @Orbigny as occurring on the antero-ventral part of the valves, 1s not shown. Distribution.—Cenomanian (Me¥er’s Bed 10) of Dunscombe. Family—DREISSENSIIDA, Gray. Genus—Suptiver, C. A. Récluz, 1848. (‘ Rev. Zool.,’ p. 275.) SEPTIFER LINEATUS (Sowerby), 1836. Plate XVIII, figs. 1—12. ? 1820. Pinnrres uneunatus, H. F. Schlotheim. Die Petrefactenkunde, p. 304. 1836. Moprona tineata, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, pp- 129, 338, pl. xiv, fig. 2 (non Mytilus lineatus, Gmelin, 1789). 1839. — AnausTA, F. A. Romer. Die Verstein. norddeutsch. Oolithen- geb. Nachtrag, p. 33, pl. xviii, fig. 36 (non M. angusta, Deshayes, 1824). P 1840. — Corts, H. B. Geinitz. Char. d. Schicht. u. Petref. des sichs Kreidegeb., pt. 2, p. 56, pl. x, fig. 5. 1841. — anousta, ’. A. Romer. Die Verstein. norddeutsch. Kreidegeb., p. 66. ? 1841. Myrinus Corra, Rimer. Ibid., p. 66, pl. viii, fig. 18. 1842. — Cuviert, P. Mathéron. Cat. Foss. des Bouches-du-Rhone, p. 179, pl. xxviii, figs. 9, 10. ? 1843. — Corra, H. B. Geinitz. Die Verstein. von Kieslingswalda, p. 15. 1844. _ LInEATUS, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p. 266, pl. ccexxxvii, figs. 7—9. ? 1844. Moprota aranutosa, V. Potiez and A. Michaud. Galerie des Moll., vol. 1, p. 182, pl. liv, fig. 10. 1845. Myrinus (Mopronus) asprer, LH. Forbes (non Sowerby). Quart. Journ. Geol. Soc., vol. i, p. 248. ? 1846. a Corrs, A. EH. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2, p. 14, pl. xxxiii, fig. 4. 1848. Monprona tinzata, H. G. Bronn. Index Palaeont., vol. i, p. 737. 1850. Mrryius susuingatus, A. d’Orbigny. Prodr. de Pal., vol. ii, pp. 81, 119. 2, — susaneustus, d’Orbigny. Ibid., p. 81. 1861. 1864. 1865. 1867. 1867. 1869. SEPTIFER. 107 Mityius pereGRINvs, d'Orbigny. Ibid., p. 165. — Cuvrert, d’Orbigny. ITbid., p. 246. — Corrs, dL’ Orbigny. Thid., p. 246. Moprona Quaprata, J. de C. Sowerby. In F. Dixon, Geol. Sussex, p. 347 [p. 382 of ed. 2], pl. xxviii, fig. 13. Myriuvus Corrm, P. de Ryckholt. Mélanges Paldont., pt. 1 (Mém. cour. et Mém. des Sav. étrangers, vol. xxiv), p. 147. _ crpLyAnus, de Ryckholt. Tbid., p. 152, pl. ix, figs. 12, 13. Moprona tineata, C. G. Giebel. Deutschl. Petref., p. 379 (partim). -- — J. Morris. Cat. Brit. Foss., ed. 2, p. 210. Myritus Orsianyanus, I. J. Pictet and W. Roux. Moll. Foss. Gris verts de Genive, p. 479, pl. xxxix, fig. 9. — SUBLINEATUS, (Gr. Cotteau. Moll. Foss. de l’Yonne, p. 93. _ — F. J. Pictet and EB. Renevier. Foss. Terr. Aptien de la Perte du Rhone (Matér. Pal. Suisse, ser. 1), p. 111, pl. xv, figs. 8, 9. — ~- P. de Loriol. Anim. Invert. Foss. du Mt. Saltve, p. 92. — spaTHuLaTus, H. Seeley. The Geologist, vol. vii, p. 53. — Cuvirri, H. Coquand. Mon. Aptien de l’Espagne, p. 142. — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mat¢r. Pal. Suisse, ser. 4), p. 491. — Corrm, Pictet and Campiche. Tbid., p. 511. -- Cuviert, P. de Loriol and V. Gilliéron. Mon. de l Etage Urgon. inf. de Landeron (Mém. Soc. Helvet. Sci. Nat., vol. xxiii), p. 16, pl. i, fig. 14. Moprona, ef. ninEata, F. Rimer. Geol. von Oberschles., p. 333. Mytitus Corrs, F. Stoliczka. Paleont. Indica, Cret. Fauna 8S. India, vol. ili, p. 373, No. 56 (Septifer 7). Mopro1ra Corrs, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palexonto- graphica, vol. xx), pt. 1, p. 214, pl. xlviii, figs. 4—8. -- (Septrrer?) Corre, D. Brauns. Die Senon. Mergel des Salz- berges (Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi), p. 375. Stud. im Geb. der bihm Kreidef. iv. Die Teplitzer Schicht., p. 79, fig. 66. Zeitschr. der deutsch. geol. Gesellsch., Mytizvus Cortra, A. Fritsch. Mopiona anausta, A. Wollemann. vol. xlvili, p. 844. — Corrm, R. Leonhard. Die Fauna der Kreidef. von Oberschles. (Paleontographica, vol. xJiv), p. 27. = — H. Woods. Quart. Journ. Geol. Soc., vol. liii, p. 380, pl. xxvii, figs. 9—12. Myvitus (SepTiFeR) Lineatus, A. Fritsch. Stud. im Geb. der bohm. Kreidef. vi. Die Chlomeker Schichten, p- 57, fig. 65. SepriFeR LinEatus, G. Miller. Die Mollusk. Untersen. von Braunschweig und Ilsede, pt. 1 (Abh. d. k. preuss. geol. Land., N.F,, pt. 25), p. 48, pl. vii, fig. 2. 108 CRETACEOUS LAMELLIBRANCHIA. 1899. Moproua Corrm, A. Hennig. Bihang till k. Svenska Vet.-Akad. Handl., vol. xxiv, p. 13, pl. 1, figs. 16—19. 1900. — Cuvrerr, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hollind. Neoe, (Abhandl. d. k. preuss. geol. Land., N. F.,, pt. 31), p. 68. Non 1847. Myrinus tineatus, J. Miller. Petref. Aachen. Kreidef., pt. 1, p. 34. — 1889. Seprrrer tineatus, LH. Holzapfel. Die Mollusk. Aachen. Kreide (Palxon- tographica, vol. xxxv), p. 216, pl. xxv, figs. 10—138 (these figures are enlarged three times). Description.—Shell thin, ovate-oblong, inflated, regularly convex from the umbo to the posterior extremity, more or less compressed at right angles to its greatest length (dorso-ventrally) ; shghtly curved or occasionally straight. Dorsal margin slightly convex. Posterior extremity well rounded, a little expanded. Antero- ventral margin slightly concave, sometimes straight. Umbones small, curved, terminal. Carina faintly marked near the umbo, absent elsewhere. Antero-ventral face of the shell flattened or concave, postero-dorsal part regularly convex. Ornamentation consists of fine but well-marked radial ribs, crossed by rather less distinct concentric ribs, giving a cancellate appearance; the radial ribs are serrate or granular where crossed by the concentric ribs. At intervals fairly strong erowth-lines occur. An oval area below the umbones is without radial ribs, and shows only lines of growth. Measurements : Umbo to posterior qa) (2) (3) (4) (5) (6) (7) (8) (9) (40) extremity . . 49 42 42 4) 37 34 32 29 36 28 mm. Greatest diameter at right angles to pre- ceding . : . 18 15 14 145 14 12 12 Thickness : . 29 25 23 26 22 20° 15 (1—3, 6) from the Hythe Beds, Lympne. (4) - Chalk Marl, Chardstock. bo 1 i 1 16 | vr Or 29 (5) > - Kempstone Rocks. (7) ” ») Dunscombe. (8) » 9 Titherleigh, (9, 10) Chalk Rock, Cuckhamsley. Affinities —The specimens figured by Geinitz as M. Cotte in ‘Das Elbthalge- birge in Sachsen’ agree perfectly with our examples from the Cenomanian. The figures of M. Cotte given by earlier authors appear to represent imperfect or crushed specimens, and I follow Geinitz, who was probably acquainted with the originals, in regarding them as the examples of M. Cotte. Modiola angusta, Romer, is considered by Wollemann to be identical with M. lineata ; 1 have seen no examples of it. SEPTIFER. 109 Modiola quadrata, Sowerby, from the Upper Chalk, is, I believe, only a somewhat crushed example of this species, similar to the one figured on our Pi VLE. tio. 12: Holzapfel considers that the forms from the Aachen Greensand, originally described by Miiller as Mytilus lineatus and M. sealavis, should be referred to M. lineatus, Sowerby. The Aachen species is very variable, and [ am greatly indebted to Prof. Holzapfel for the loan of six specimens which vary in their greatest length from 95 to 15 mm.' The Aachen shell is clearly distinct from our species ; it is more curved, more irregular, smaller, and with the radial ribs more strongly marked and not crossed by concentric ribs, so that the cancellate appearance is not seen. The form figured as Mytilus ciplyanus by de Ryckholt,? from Ciply and Maestricht, is perhaps a small example of S. lineatus (Sow.). M. xquatoralis, Mayer-Eymar,® from Somaliland, is perhaps an allied form, but is imperfectly known at present. Remarks.—The variations in this species consist chiefly in the amount of inflation and curvature of the valves, and in the flattening of the antero-ventral surface. The examples from the Hythe Beds are usually larger, rather more inflated, and have the antero-ventral surface more flattened than those found in the Upper Greensand and Cenomanian. But all the different forms which the shell takes may be seen at all horizons, and from the examination of a large series of specimens | am convinced that the Lower Cretaceous forms cannot be separated from those of the Upper Cretaceous. The relative proportions of the valves of course change as age increases. On account of the thinness of the shell the form of the valves has often become somewhat altered by pressure, and the shell itself—especially in specimens from the Hythe Beds—has often partly disappeared. None of the specimens I have seen show the interior of the valves, but some of the internal casts give indications of the presence of an umbonal plate. The name M. Cottx, Romer, is adopted by Geinitz (1873) for this species, and M. Cuvieri, Mathéron, by Pictet and Campiche (1867), since the name Mytilus lineatus had been used by Gmelin in 1789 for another form, and Modiola angusta was also preoccupied by Deshayes (1824). D’Orbigny in 1850 substituted the name sublineatus for lineatus, Sow. If Sowerby’s species be referred to Septifer, then his specific name may be retained. ' It should be noticed that Holzapfel’s figures of this species are enlarged three times. 2 “Mélanges Paldont.,” pt. 1 (¢ Mém. cour. et Mém. des Say. étrangers,’ vol. xxiv, 1852), p. 152, pl. ix, figs. 12, 13. 3 *Vierteljahrs. nat. Gesellsch. Zitrich,’ vol. xxxviii (1893), p. 254, pl. i, figs. 7, 8. 110 CRETACEOUS LAMELLIBRANCHIA. Types.—I have not seen the types; they were obtained from the Hythe Beds, near Hythe. The type of M. spathulatus, Seeley, from the Barnwell Gravel (derived from the Chalk), is in the Woodwardian Museum, Cambridge. Distribution.—Hythe Beds of Hythe and Lympne. Lower Greensand of Faringdon and Seend. Upper Greensand of Chilfrome (Dorset), and near Weymouth. Greensand of Haldon. Chloritie Marl of Maiden Bradley. Ceno- manian (Me¥er’s Bed 12) of Dunscombe and Kempstone Rocks (Sidmouth). Chalk Marl of Chardstock. Basement Bed of Chalk Marl of Cerne Abbas. Cenomanian Sands of Wilmington. Lower Chalk of Burwell and Stoke Ferry. Chalk Rock of Winchester, Cuckhamsley, Luton cutting, and Underwood Hall (Dullingham). Upper Chalk of Northfleet. Flint gravel (derived from Upper Chalk) near Ventnor. Zone of Bel. quadrata of Winchester and Salisbury. Zone of Bel. mucronata of Salisbury and Norwich. fenus—DREISsENsIA, P. van Beneden, 1835. (Ann. Sci. Nat.,’ ser. 2, vol. iii, p. 198, pl. viii. Emend. P. Fischer, ‘Man. de Conch.,’ 1886, p. 972.) DREISSENSIA LANCEOLATA (Sowerby), 1823. Plate XVIII, figs. 13—15; Plate XIX, figs. 1—11. 1823. Myrinus mpentunus, J. de CO. Sowerby. Min. Conch., vol. v, p. 55, pl. cecexxxix, fig. 1. 1828. — LANCEOLATUS, Sowerby. Ibid., fig. 2. 1836. — TRIDENS, J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. iv, p. 342, pl. xvii, fig. 14. 1836. — PRHELONGUS, Sowerby. Tbid., p. 342, pl. xvii, fig. 15. 1844. — LANcEoLatus, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iu, p. 270, pl. ecexxxviii, figs. 5, 6. 1844. — raucatus, d’Orbigny. Ibid., p. 280, pl. ecexli, figs. 11—13. 1845. — LANCEOLATUS, var. EDENTULUS, E. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 248. ? 1846. — = A. E. Reuss. Die Verstein. der bohm. Kreide- format., pt. 2, p. 15, pl. xxxvii, fig. 5. 1848. — — H. G. Bronn. Tndex Palaeont., vol. i, p. 773. 1850. Muirytus asruptus, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 107. 1850. — suBFALCATUS, d’Orbigny. ITbid., p. 166. 1850. — LANCEOLATUS, @’Orbigny. Ibid., p. 166. 1854. Myriivus epentuuus, J. Morris. Cat. Brit. Foss., ed. 2, p. 215. 1854. — LANcEOLATUS, Morris. Ibid., p. 215. 1854, — prmHLonevs, Morris, Ibid., p. 215, DREISSENSIA. 1 1854. Myrinus rripens, Morris. Ibid., p. 215. 1858. — LANCEOLATUS, I’. J. Pictet and EB. Renevier. Foss. Terr. Aptien de la Perte du Rhone (Mat¢r. Pal. Suisse, ser. 1), p: L110; pl. xv; fig: 7: r 1861. — Gaviiennel, H. Trautschold. Bull. Soc. Imp. Nat. de Moscou, 1867. -- LANCEOLATUS, Ff’. J. Pictet and G. Campiche. Foss. Terr. Crct. Ste. Croix (Matcr. Pal. Suisse, ser. 4), p. 485. 1868. oa — A, Briart and F. L. Cornet. Descript. Meule de Bracquegnies (Mém. cour. et Mém. Sav. ¢étrangers, vol. xxxiv), p. 52, pl. iv, figs. 11, 12. vol. xxxiv, pt. 2, p. 433, pl. xii, fig. 4. ? 1868. Moprona susraucara, L. Vichwald. Lethea Rossica, p. 533, pl. xxi, fig. 14. 1871. Myrintus tancrouatus, J. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ili, p. 372. 1872. _ _- EF’. Schmidt. Mammuthexpéd. (Mcém. de Acad. Imp. Sci. de St. Pétersb., vol. xvii, No. 1), p. 154, pl. ii, fig. 7; pl. iii, fig. 12. y 1884. _ a J. F. Whiteaves. Geol. and Nat. Hist. Survey of Canada: Mesozoic Fossils, vol. i, pt. 3, p. 236, pl. xxxi, fig. 7. Non 1868. Moprona Lancronara, HL. Kichwald. Lethea Rossica, p. 532, pl. xxii, fig. 5. Description.—Shell stout, convex; outline subtrapezoidal, or sometimes sub- triangular. Hinge-margin slightly convex, sometimes straight, usually nearly half the length of the antero-ventral margin; the latter is slightly concave. Posterior margin convex, often roughly parallel to the antero-ventral margin, and curving gradually at the posterior extremity of the valve. Umbones sharp, terminal ; apical angle varying from 47° to 53°—average 513°. Carina sharp, but rather more rounded on the older parts of the shell; usually close to the margin except in the umbonal region. The shell m front of the carina is vertical, or nearly vertical, to the plane of the valves, except near the umbones, where it slopes outward. Behind the carina the shell slopes gradually to the posterior and dorsal margins. Ornamentation: the greater part of the shell is usually nearly smooth except for growth-lines, but concentric ribs are seen on the earlier parts and near the cara ; sometimes also cn the antero-ventral margin. Interior not seen except at the umbonal region; wmbonal septum present ; teeth absent or rudimentary. 112 CRETACEOUS LAMELLIBRANCHIA. Measurements : (1) (2) (8) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) Antero-ventral margm 47 45 42 40 38 35 35 34 33 30 26 26 25 24 22mm. Hinge-margin . » 20) 22 2420-20) 20 16 20 18916 13s 12515) 15 2am Diameter from the middle of the carina (perpendicular) — to posterior margin . 16 19 19 18 18 17 14 17 15 13 12 11 18 — 10mm. Thickness . : Bly PAL Aiksy sy UG} TS) sy UG ls ass” 1} 11) kes}. 0) ald semen 1, 3, 4, 5, 7, 8, 10, 14 from the Crackers, Atherfield. 2 * Perna-bed, Atherfield. 6, 9, 11, 12, 13, 15 from Blackdown. Affinities —The presence of an umbonal plate shows that this species should be referred to the Dreissensiide. In the few specimens showing the interior I have found no trace of the anterior myophore (for the byssal muscle) which distinguishes Congeria from Dreissensia'—but further specimens to confirm the absence of this structure are desirable. From the Upper Eocene of the Paris basin, associated with marine fossils, M. Cossmann” has already described two species of Dreissensia, and that author confirms my reference of this Cretaceous species to the Dreissenstidee. This species may be allied to Mytilus tornacensis, d’Archiac, from the Tourtia of Tournay, of which I have seen one specimen, sent me by M. Piret (see p. 91). That species, however, appears to differ from ours in having the carina at a greater distance from the antero-ventral border, also in the presence of more distinct and regular growth-lines with ridges or grooves at right angles to them, the ridges being best marked on the antero-ventral face of the shell. I do not know whether it possesses an umbonal plate or not. M. subfalcatus, VOrbigny, from the Cenomanian, appears to have the concentric ribs more distinct on the carina than is usual in M. lanceolatus, but since this feature is seen in some specimens of the latter, and is generally present on the earlier parts of the shell, it can hardly be regarded as distinctive. D’Orbieny considered that his Mytilus Galliennei,®? which in outline is similar to the larger examples of M. lanceolatus, was identical with M. tornacens/s, @ Arch. The forms from the Aachen Greensand described by Miler as MM. tegulatus, Mill., M. lanceolatus, Sow., and M. falcatus, @’Orb., whilst referred by Holzapfel * ! P. Oppenheim, ‘ Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. li (1891), p. 923, pl. hi. > © Cat. Il. Coq. Foss. Hoc. de Paris,’ fascic. 2 (1887), p. 151. 8 «Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 278, pl. ccexxxix, figs. 1, 2; ‘ Prodr. de Pal.,’ vol. ii (1850), p. 165. + “Die Mollusk, Aachen. Kreide” (‘Paleontographica,’ vol. xxxv, 1889), p. 218, pl. xxv, figs. 1—9. It should be noted that these figures are enlarged twice. THE PALAONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVII. VOLUME FOR 1901. LONDON: Mbccccl. . + ae) oe A MONOGRAPH OF THE CRETACKOUS LAMELLIBRANCHIA OF ENGLAND. BY HENRY WOODS, M.A., UNIVERSITY LECTURER IN PALZOZOOLOGY, CAMBRIDGE. PART III. MODIOLOPSIDA AND SPONDYLIDA. Paces 113—144; Phares XX—XXVI. LONDON: PRINTED FOR THE PALZONTOGRAPHICAL SOCIETY. 1901. PRINTED BY ADLARD AND SON, BARTHOLOMEW CLOSE, E.C., AND 20, HANOVER SQUARE, W. DREISSENSIA. 113 to Septifer tegulatus, are regarded by him as probably identical with Sowerby’s species. I believe that view is probably correct, but without a larger series of specimens it is difficult to speak with confidence on the subject. The Aachen form is smaller and more variable in outline than the English species. I am indebted to Professor Holzapfel for the loan of several specimens. M. subarcuatus, Meek and Hayden, from the Fox Hills group, is considered by Meek? to be near M. lanecolatus, but is only known from an internal cast. Although it is possible for small fluviatile Lamellibranchs to be carried out to sea by currents and become entombed in marine deposits, such does not appear to have been the case with the species we are now considering, because (1) all the associated fossils are marine ; (2) the lithological evidence is not in favour of the strata having been deposited near a shore-line; (3) the species occurs at several horizons and in more or less widely separated localities ; and (4) some specimens have the two valves still united. [f, then, this species be truly marine, it might be urged that it is unlikely to belong to the genus Dreissensia, which at the present day is found in brackish and fresh waters only. That it does not belong to the genus Septifer is shown by the entire absence of radial sculpture, which characterises all the known species of that genus; in this feature, and also in the form of the shell, it agrees with living species of Dreissensia, differing only in the very young stages when (as shown by erowth-lines on adult specimens) the shell was rather more elongate pro- portionately. We have therefore apparently only two views to choose from concerning the generic position of the species here described as Dreissensia lanceolata :—(i) That it is an early marine form of Dreissensia ; or (ii) that, although possessing the characters of Dreissensia, yet it has no direct genetic connection with that genus, but is an instance of heterogenetic homceomorphy. If the latter view be taken, then this species must be regarded as the type of a new genus. The former view seems more likely to be correct, unless it can be shown that the Tertiary Dreissensix have no connection with this species, but have descended from some other generic type. That Dreissensia may have been marine at no very remote geological period seems possible from the fact that living forms occur in the brackish waters of the Aralo-Caspian area, etc.; that it probably was marine is supported by a study of its development,’ which differs from that of other fresh-water Lamellibranchs, and agrees closely with that of certain marine forms. It is further noteworthy 1 “Tnvert. Cret. and Tert. Foss. Missouri” (‘U.S. Geol. Surv. Territ.,’ vol. ix, 1876), p. 69, pl. xxxviii, fig. 2. 2 A detailed account of the development of Dreissensia polymorpha, with a full bibliography, has been recently given by J. Meisenheimer, ‘ Zeitschr. fiir wissensch. Zool.,’ vol. xix (1901), pp. 1—137, pls. i—xiii. 15 114 CRETACEOUS LAMELLIBRANCHIA. that whilst a number of living genera of fresh-water mollusks occur in pre-Tertiary rocks, Dreissensia has not yet been found associated with them.' Remarks.—Four examples from the Blackdown Greensand were described by Sowerby as distinct species under the names edentulus, lancevlatus, tridens, prelongus. Most later authors (d’Orbigny, Forbes, Bronn, Pictet and Renevier, Pictet and Campiche, Briart and Cornet, Stoliczka, Whiteaves, etc.) have considered these forms to be mseparable, and have united them under the name lanceolatus, but that view was not shared by Morris. An examination of all the available specimens leads me to agree with the opinion generally held. In 1850 d@Orbigny regarded the Lower Cretaceous examples as distinct from those found m the Blackdown Greensand, and named them Mytilus abruptus. Pictet and Campiche did not uphold this separation. The only difference that I can detect is that, on the average, the examples found in the earlier beds reach a larger size than those in the later. T'ypes.—From the Blackdown Greensand: M. edentulus is m the British Museum; M. tridens and M. prelongus are in the Bristol Museum. I have not been able to trace the type of M. lanceolatus. Distribution. —Perna-bed, Crackers, and Fitton’s Beds 32 and 45, of Atherfield. Perna-bed of Sandown. Atherfield Beds of East Shalford and Peasmarsh. Ferruginous Sands of Shanklin. Sandgate Beds of Parham Park. Blackdown Greensand (zones x and xv). Greensand of Haldon. Upper Greensand of Shaftesbury. Family—MODIOLOPSIDA, Fischer. Genus—Myoconcua, J. de OC. Sowerby, 1824. (Min. Conch., vol. v, p. 103, pl. cecelxvii.) Myoconona creracka, A. @Orbigny, 1844. Plate XX, figs. 3a, b. 21832. Myrinus srmpiex, A. Passy. Géol. de la Seine-infér., p. 6 (expl. of plates), pl. xiii, figs. 4, 5. (Non M. simplex, Defrance, 1824.) 1 W. J. Sollas, “On the Origin of Fresh-water Faunas,” ‘Scient. Trans. Roy. Dublin Soc.,’ ser. 2, vol. iii (1884), p. 106; C. A. White, ‘Third Aun. Rep. U.S. Geol. Survey’ (1883), p. 428. It has been suggested that Mytilus membranaceus, Dunker, from the North German Wealden of Obern- kirchen, Egestorf, Oesede, etc., and the Purbeck beds of Nienstedt and Linden, may belong to the Dreissensiide, but the characters of the interior of the shell are at present unknown; the same may be said of Mytilus Lyelli, Sowerby, from the English Purbeck and Wealden. See Dunker, ‘ Mon. Norddeutsch. Weald.’ (1846), p. 25, pl. xi, f. 10, 11; C. Struckmann, ‘ Die Wealden-Bildungen von Hannover’ (1880), p. 68, pl. i, f. 11, 12; P. Oppenheim, ‘Zeitschr. der deutsch. geol. Gesellsch..,’ vol. xliii (1891), p. 944. MYOCONCHA. 115 1844. Myoconcua cretacea, A. d’Orbigny. Pal. Franc. Terr. Crcét, vol. iii, p. 260, pl. ceexxxy. ? 1847, -- — A. d’Archiac. Mém. Soe. géol. France, ser. 2, vol. 11, p. 307. 1850. — — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 165. 1854. = —= J. Morris. Cat. Brit. Foss., ed. 2, p. 214. 1862. -— -- J. G. Chenu. Manuel de Conch., vol. ii, p. 155, fig. 766. 1866. — — F. J. Pictet and G. Campiche. Moll. Foss. Terr Crét. Ste. Croix (Matér. Pal. Suisse, ser. 4), p. 344. ? 1868. — — E. Kichwald. Lethea Rossica, vol. ii, p. 588, pl. xxii, fig. 10. Description.—Shell subtriangular, or more or less oblong, gradually increasing in height posteriorly. Anterior end blunt, rounded ; posterior border rounded, somewhat oblique; ventral border nearly straight. Valves flattened, gradually compressed posteriorly, more sharply compressed towards the ventral margin. Ornamentation consists of slender, equidistant, slightly curving, radial ribs, which are absent near the dorsal margin ; the most dorsal rib is stronger than the others. The radial ribs are crossed regularly by numerous slender concentric ribs which are parallel to the growth-lines. Measurements : Length. : : : : : ; : . 74mm. Height . : ; , : ‘ ; . EOC: Thickness . ; : : . : + a2 Saae Affinities. —M. Requieniana, Mathéron,' is less expanded posteriorly, and more concave ventrally. Myoconcha, n. sp., Miller,’ may be an allied form, but is known only by internal moulds. T'ypes.—From the Cenomanian of Saintes, Angouléme, Rouen, ete. Distribution.—Basement bed of Chalk Marl (zone of Schloenbachia variais) of Chard, Maiden Newton, and Evershot. Chloritie Marl of Maiden Bradley, Wool- combe, and Toller Fratrum.* * *Cat. Foss. Bouches-du-Rhone’ (1842), p. 177, pl. xxvii, figs. 3, 4. D’Orbigny, ‘ Prodr. de Pal.,’ vol. it (1850), p. 196. 2 «Die Mollusk. d. Untersen. v. Braunschweig u. Ilsede” (‘ Abhandl. d. k. preuss. geol. Land.,’ n. F., pt. 25, 1898), p. 48, pl. vii, fig. 3. * Casts of Myoconcha, from the Lower Greensand of Seend, are preserved in the Museum of Practical Geology, but the species cannot, at present, be determined. 116 CRETACEOUS LAMELLIBRANCHIA. Family—S PONDYLIDA, Gray. Grenus—Sponpyius, Linnewus, 1758. (‘Syst. Nat.,’ ed. 10, p. 690.) SronpyLus Rormeri, Deshayes, 1842. Plate XX, figs. 4 a—d. 1841. Sponpynus Rapratus, Ff. A. Rimer (non Goldfuss). Die Verstein. d. nord- deutsch. Kreidegeb., p. 60. 1842. — Latus, G. P. Deshayes (non Sowerby), in A. Leymerie. Mém. Soe. géol. de France, vol. v, pp. 10, 27, pl. vi, fig. 7. — — Roemert, Deshayes. Ibid., pp. 10, 27, pl. vi, figs. 8—10. 1847, _ — A. @Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 655, pl. ecccli, figs. 1—6. 1850. _ — @Orbigny. Prodr. de Pal., vol. ii, p. 83. 1855. _ — G. Cotteau. Moll. Foss. de ?Yonne, p. 118. 1861. — — P. de Loriol. Anim. Invert. Foss. du Mt. Saléve, p. 107, pl. xiv, figs. 4, 5. 1870. _ — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matcr. Pal. Suisse, ser. 5), pp. 256, 260. 2 187i: _- — W. A. Ooster. Pteropodenschicht Schweizer-Alpen (Protozoe Helvetica, 2), pp. 126, 141, pl. xvii, figs. 8—10. 1883. — — W. Keeping. Foss., etc., Neoc. Upware and Brickhill, p- 113. 1896. — — A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvili, p. 834. 1900. = — Wollemann. Die Biv. u. Gastrop. d. deutsch. u. holland. Neoc. (Abhandl. d. k. preuss. geo). Land., n. F., pt. 31), p. 20. Description.—Shell oval in outline, the proportion of length to height variable, more or less oblique. Right valve flattened, with numerous radial ribs, usually faintly marked, and strong concentric lamellze. Left valve convex, with numerous slightly unequal ribs, separated by grooves of the same width; the larger ribs occur at regular intervals, and bear spines mostly directed ventrally : between the larger ribs are two or three smaller ribs, either smooth or with small spies. Ears of both valves apparently smooth. SPONDYLUS. 117 Measurements : Length . : : : : : Poo anim: Height. , F : : ; : : 1 a0 a Thickness . 5 : : : : : h LeD 95 Affinities. —This species appears to be closely allied to S. gibbosus, VOrbigny, but the ribs are more spiny and rather coarser, and the valves less convex in pro- portion to their size. It seems to differ from S. striato-costatus, d’Orbigny, in having more numerous and more slender ribs. Liemarks.—Deshayes’ ficures of this species appear to represent worn specimens, and consequently do not show the real characters of the ornamentation. In the absence of other specimens from the locality of the types one is obliged to rely on the figures and descriptions by d’Orbigny as giving the specific characters of S. Roemer. This species appears to be very rare in England. The examples from Brickhill are rather water-worn, but the stumps of the spines remain on some of the ribs. Types.—From the Neocomian of Fouchéres, in the Ecole des Mines, Paris. Distribution —Perna-bed of Atherfield. Lower Greensand of Brickhill.’ SponpyLus Gipposus, d’Orbigny, 1847. Plate XX, figs. 5, 6 a—e, 7 a—e,8 u, b, 9 a, b, 10, 11. 1847. Sponpyius eipposus, A. d’Orbigny. Pal. France. Terr. Crét., vol. i, p. 658, pl. ceeclii, figs. 1—6. 1850. — = @ Orbigny. Prodr. de Pal., vol. 11, p. 189. 1853. _- Brunnert, F. J. Pictet and W. Roux. Moll. Foss. Gres verts de Genéve, p. 514, pl. xlvii, fig. 1 (? 2). 1858. — — F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matcér, Pal. Suisse, ser. 1), p. 156. 1866, — arpposus, H. G. Seeley. Ann, Mag. Nat, Hist., ser. 3, vol. xvii, ined WAC 1870. -- — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 257, pl. elxxxii, figs, 1—4. 1875. -- — A, J. Jukes-Browne. Quart, Journ. Geol. Soc., vol. xxxi, p. 297. — - DuremMPLEANUS? Jukes-Browne. Ibid., p. 297. — — = J. Phillips. Geol. Yorks., ed. 3, pt. 1, p. 245. 1 Dianchora ? guttata, Sharpe, from the Lower Greensand of Faringdon, is probably a Spondylus, but I have not succeeded in finding the type or any other specimens. Sharpe, ‘ Quart. Journ. Geol. Soc.,’ vol. x (1853), p. 197, pl. vi, fig. 3. 118 CRETACEOUS LAMELLIBRANCHIA. Deseviption.—Shell oval, oblique, higher than long. Right valve variable, flattened when attached by its entire surface, more convex when attached by a part only, the umbonal part sometimes much produced and talon-like. The attached part with concentric lamelle, the free part with many radial ribs without spines. Left valve moderately convex; umbo more or less produced; ribs numerous, unequal: the stronger occur at regular intervals, and are separated by two or three (rarely one only, or more than three) smaller ribs ; the stronger ribs bear numerous spiny processes, the smaller ribs are usually without spines.’ Measurements of left valve: (1) (2) (8) (4) (5) (6) (7) (8) (9) (20) (11) (12) (18) Length 5 BL Bul BHO) Xe), DY) Bes ys) BAL Ges) Bs} Wil as) LS} seawan, Height 5 Bio) Bi) ov! BY) Bil BS) By Bey Ws) Bs) Wes Wes) 1G) (1—9) Cambridge Greensand. (10—13) Red Limestone, Hunstanton. Affinities. —For the relation of S. gibbosus to S. Roemeri see p. 117. In 8S. Dutempleanus the shell is less oblique than in S. gibbosus ; the spines on the left valve are generally more irregular and more nearly vertical than in the latter (judging from the figure of Pictet and Campiche). The stronger ribs which occur at regular intervals in S. giblosus are never so distinctly marked in WN. Dutempleanus. Remarks.—The specimens figured by d’Orbigny, as pointed out by Pictet and Campiche, are worn examples with the shell imperfect. The specimens found in the Cambridge Greensand vary considerably ; a gradual passage can be traced from forms in which the right valve is flat (fig. 9 b) to others in which it is much pro- duced and talon-like (fig. 11); in the mght valve the appearance of the surface depends largely on the amount of wearing the shell has undergone,—one specimen, in which the ribs appear almost equal and without spines, agrees perfectly with d’Orbigny’s fig. 2; in most cases, however, the stronger ribs occurring at regular intervals are distinctly seen (fig. 6 a). Only the bases of the spines remain ; they are generally regularly developed on the stronger ribs, but occasionally occur more irregularly (fig. 8 a). The specimens found in the Red Limestone of Hunstanton and Speeton are, on the average, smaller than those im the Cambridge Greensand, and the spies, probably owing to the hardness of the matrix and consequent difficulty of extraction, are usually wanting or indistinct, but one specimen in the British Museum shows them clearly. 1 The specimen figured by Pictet and Campiche shows spines on the small ribs. The general absence of small spines on our specimens is probably due to the worn nature of the shell. SPONDYLUS. 119 Sn o7Anai : F : : ieee ele : . l';pes.—D’Orbigny’s specimens came from the Albian of Novion and Machéro- ménil (Ardennes). Mistribution—Cambridge Greensand (derived from the Gault), Cambridge. Red Limestone of Hunstanton and Speeton. SPONDYLUS STRIATUS (Sowerby), 1815. Plate XX1, fies. 1a, b):2,.3°a.h. ae 5, 1815. Drancnora srrrara, J. Sowerby. Min. Conch., vol. i, p. 183, pl. Ixxx, fig. 1. 1819. — — Defrance. Dict. Scien. nat., vol. xiii, Dooly pl. Ixxviii, fig. 1. 1833. Sponpynus srriatus, A. Goldfuss. Petref. Germ., vol. ii, p: 98; pl. cv; fig. 5. 1829-40. Drancuora srriata, F. E. Guérin-Méneville. Icon. du Réegne Anim. Moll., p. 42, pl. xxv, fig. 4. 1837. Sponpyius srriatus, H. G. Bronn. TLethea Geog., p. 687 (ed. 3, pt. 5, p- 283), pl. xxxii, fig. 4. 1840, _- a H. B. Geinitz. Char. a. Schicht. u. Petref. des sichsisch. Kreidegeb., pt. 2, p. 58. 1841. _ — F. A. Roimer. Die Verstein. d. nord-deutsch. Kreidegeb., p. 59. ? 1846. — — A. EF. Reuss. Die Verstein. d. bbhm. Kreideformat., pt. 2, p. 37, pl. xl, figs. 5, 10, 11. 1847. -—— CAPILLATUS, A. d’Archiac. Mém. Soc. géol. de France, ser. 2, vol. ii, p. 311, pl. xvii, fig. 1. = — striatus, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 660, pl. ceeeliii. ? 1850. —- ?, BR. Kner. Kreidemerg. von Lemberg, ete. (Haidinger’s Naturwiss. Abhandl., vol. iii, pt. 2), p. 30. > — — — ?, A. Alth. Geogn.-pal. Beschreib. Umgeb. von Lemberg (Haidinger’s Naturwiss. Abhandl., vol. iii, pt. 2), p. 251. = — — A. @Orbigny. Prodr. de Pal., vol. ii, p. 170. -- — — H. B. Geinitz. Das Quadersandst. oder Kreidegeb, in Deutschland, p. 194. -— CAPILLATUS, Geinitz. Ibid., p. 194, pl. xi, figs. 2, 3. ? 1852. — sTRIATUS ?, R. Kner. Denkschr. d. k. Akad. d. Wissensch. Wien. Math.-nat. Classe, vol. iii, pt. 1, p. 318, pl. xvii, fig. 8. 1854. - — J. Morris. Cat. Brit. Foss., ed. 2, p. 182. 1858. _ — J. A, Eudes-Deslongchamps. Mém. Soc. Linn. de Normand., vol. xi, p. 134, pl. xx, figs. 24—26. ? 1866. — a K. A, Zittel. Die Biv. der Gosaugeb. (Denkschr. d. k. Akad. d. Wissensch. Math.-nat. Classe, vol. xxv), p. 118 (p. 42 of reprint), pl. xviii, fig. 7b, ¢ (? fig. 7a). 120 CRETACEOUS LAMELLIBRANCHIA. ? 1868. Sponpytus striatus, H. Hichwald. Lethza Rossica, vol. ii, p. 422. 1870. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mater. Pal. Suisse, ser. 5), p. 261. 1872. — — A. B. Geinitz. Das Elbthalgeb. in Sachsen (Palie- ontographica, vol. xx), pt. 1, p. 186, pl. xlu, figs. 1—3. P 1877. — — A, Fritsch. Stud. im Gebiete der bohm. Kreidef. : IT, Die Weissenberg. u. Malnitz. Schicht., p. 138. 1878. — -- G. Behrens. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxx, p. 259. 1893. — —- R. Michael. Ibid., vol. xlv, p. 237. 1895. — — E. Tiessen. Ibid., vol. xlvii, p. 475. 1897. — -- R. Leonhard. Die Kreidef. in Oberschles. (Palaon- tographica, vol. xliv), p. 50. Non 1822. Popopsis striata, A. Brongniart. Descript. géol. des Envir. de Paris. In Cuvier, Ossem. foss., ed. 2, vol. ii, pp. 319, 604, pl. v, fig. 3. — 1870. Sponpyxus striatus, F. Romer. Geol. von. Oberschles., p. 315, pl. xxxvii, figs. 3, 4. Descrviption.—Shell large, obliquely ovate, high; anterior and ventral margins regularly rounded; posterior margin slightly concave or nearly straight. Right valve usually more inflated than the left, and generally attached by the larger part of its surface ; free part with radial ribs, separated by shallow grooves, and crossed by numerous very fine concentric lamelle. Left valve moderately convex, umbonal part prominent and produced; surface sometimes undulating; ribs numerous, equal, smooth, flattened, separated by deep grooves except on the later formed parts of the valve, where the grooves become shallow and the ribs less distinct. The grooves and ribs are crossed by concentric lamellee, like those on the right valve. Ears smooth except for growth-lines. Measurements of left valve : (1) (2) (3) (4) Length F : . : 56 52 50 4.0 min. Height : ; ' ; WY 65 ~ 58 AS ,, (1—4) from Warminster. Affinities.—For the relation of this species to 8. latus, Sowerby, see p. 123. S. hystrix, @Orbigny (? Goldfuss) is distinguished from this species by the left valve being less convex, the umbo less produced, the narrower and more widely separated ribs, and the spines on the earlier part of the valve. S. capillatus, @’Archiac, from the Tourtia of Tournay, has been regarded by Geinitz, d’Orbigny, and other authors as a synonym of XW, striatus ; specimens SPONDYLUS. 12] which I have obtained from Tournay agree perfectly with the Engish examples, but the example figured by d’Archiac appears to differ in having the umbo of the left valve less produced. S. subcostulatus, Stoliczka,' appears to be a closely allied form, and was indeed regarded by Geinitz as identical with S. striatus. S. complanatus, @Orbigny, is imperfectly known, but may be closely allied to, or identical with, S. striatus ; it is recorded by Morris from the Lower Greensand of Folkestone. Remarks.—This species is known chiefly from specimens found at Warminster. An example from that locality m Mr. J. F. Walker’s collection shows the interior of the right valve. The size of the attached surface varies considerably in different specimens. Specimens showing the interiors of fixed valves, resembling SY. gibbosus and S. latus, occur in the Blackdown Greensand and the Gault of Folkestone, but I am unable to determine the species without more specimens. Type.—From Chute Farm, Warminster, in the British Museum. Distribution —Lower Greensand of Faringdon. Rye Hill Sand of Warminster. Upper Greensand, Longleat. Cenomanian Sandstone of Wilmington. Base of Chalk Marl of Maiden Newton. Cenomanian (Bed 11) of Branscombe. SPONDYLUS LaTUS (Sowerby), 1815. Plate XXII, figs. la, b, 2a, b, 3, 4a, b, 5—7, 8 a—, 9; 10 a, hb, 1815. Drancuora tara, J. Sowerby. Min. Conch., vol. i, p. 184, pl. Ixxx, fig. 2. 1822. — — G. Mantell. Foss. 8. Downs, p. 205, pl. xxvi, fig. 21. — — oBLiqua, Mantell. Ibid., p. 206, pls. xxv, fig. 1; xxvi, fig. 12. 1836. SponpyLus tineatus, A. Goldfuss. Petref. Germ., vol. ii, p. 97, pl. evi, 1839. — — H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs. Kreidegeb., pt. 1, p. 25 pl. xx, fig. 39. 1841. — — F. A. Rimer. Die Verstein. des nord-deutsch. Kreidegeb., p. 59. 5 , — — LAtus, Romer, Ibid., p. 59. ? — — oBiiquus, Rimer. Ibid., p. 60. 1842. — Latus, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.- bohm. Kreidegeb., pt. 3, p. 82. ' «Paleontologia Indica,” ‘Cret. Fauna S. India,’ vol. iii (1871), p. 449, pl. xxviii, fig. 8 ; pl. xxxiv, fig. 2. ao S 16 122 ib) ? 1868. ? 1869. 1870. CRETACEOUS LAMELLIBRANCHIA. SponpYLus oBLiquus, Geinitz. Char. d. Schicht. u. Petref. des sachs.- bohm. Kreidegeb., pt. 3, p. 82. (D1iancHora) opriquus, A. H. Reuss. Die Verstein. d. bohm. Kreideformat., pt. 2, p. 36, pl. xl, fig. 4. — LINEATUS, Reuss. LIbid., p. 36, pl. xl, figs. 7—9. — — J. Miller. Petref. der Aachen. Kreidef., pt. 1, p. 34, Lingatus, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschl., p. 194 (partim). oBLIQuUS, Geinitz. Ibid., p. 194 (partim). Lingatus, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 254. Latus, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 356 (p. 386, ed. 2), pl. xxviii, figs. 30, 31. LIngatus, A. Alth. Geogn.-pal. Beschreib. von Lemberg (Haidinger’s Naturwiss. Abhandl., vol. iui, pt. 2), p. 250. Latus, J. Morris. Cat. Brit. Foss., ed. 2, p. 182. opLiquus, Morris. Ibid., p. 182. LINEATUS, . Hichwald. Lethxa Rossica, vol. 11, p. 421. — E. Favre. Moll. Foss. de la Craie des Envir. de Lemberg, p. 158. striatus, F. Rimer. Geol. von Oberschles., p. 315, pl. xxxvil, fies. 3, 4. Latus, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleon- tographica, vol. xx), pt. 1, p. 187, pl. xii, figs. 4-6; pt. 2, p. 32, pl. viii, figs. 18—21. — A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. II, Die Weissenberg. u. Malnitz. Schicht., p. 139. mguicostatus, R. Etheridge, in W. H. Penning and A. J. Jukes-Browne. Geol. Cambridge (Mem. Geol. Survey), p. 145, pl uy, fig. 5. Larus, H. Schrider. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxxiv, p. 262. ef. narus, B. Lundgren. Spondylus-art. i Sveriges Kritsyst. (Sver. Geol. Undersok., ser. C, No. 69), p. 12, pl. ii, fig. 28. tatus, A. Fritsch. Stud. im Gebiete} der bihm. Kreidef. IV, Die Teplitz. Schicht., p. 86, fig. 82. ef. ninEATUS, O. Griepenkerl. Senon. von Kénigslutter (Pale- ont. Abhandl., vol. iv), p. 39. Latus, E. Holzapfel. Die Mollusk. d. Aachen. Kreide. (Paleontoeraphica, vol. xxxv), p. 244, pl. xxvii, figs. 11, 14. — E. Stolley. Die Kreide Schleswig-Holsteims (Mitth. a. d. Min. Institut der Univ. Kiel, vol. i), p. 236. — R. Leonhard. Die Kreidef. in Oberschles. (Paleonto- eraphica, vol. xliv), p. 50. — H. Woods. Quart. Journ. Geol. Soe., vol. li, p. 387. SPONDYLUS. 123 Non 1842. Sponpytus tatrus, A. Leymerie. Mém. Soe. géol. de France, vol. v, p. 10, pl. vi, fig. 10. Description.—Shell oval, rounded, more or less oblique, but sometimes nearly equilateral, of moderate size or small, height and length nearly equal. Right valve usually attached by its entire surface, and bearing concentric spiny lamelle ; when part of the valve is not attached it is ornamented with numerous radial ribs; the whole of the interior also shows numerous small radial ribs. Left valve inflated, sometimes with undulating surface; growth-lines few and not strongly marked; the radial ribs are numerous, small, regular, flattened or rounded, without spines, and of equal size, except when new ribs are occasionally introduced ; the ribs are separated by grooves of the same or less width, and in these are seen very faintly marked transverse ribs, which sometimes pass on to the radial ribs. Umbo small, pomted. Near the umbo some of the radial ribs, at regular intervals, are stronger than the others, and bear short spiny processes. Ears smooth. Measurements : (1) (2) (8) (4) (5) (6) (7) (8) (9) (0) Length . : . 25 25 24 23 21 26 34 40 43 23 mm. Height . . . 26 25 24 23 20 27 36 37 39 23 ,, (1—4) zone of A. quadratus, East Harnham, Salisbury. (5) 33 West Harnham, Salisbury. (6, 7) zone of M. cor-anguinum, Gravesend. (8, 9) zone of H. subglobosus, Cherry Hinton; (8) is the type of S. equicostatus, Eth. (10) Lower Chalk, Fulbourn Asylum. Affinities —The numerous smooth ribs serve to distinguish this species. SN. striatus, Sowerby, from the Warminster Greensand, etc., is a much larger form, shorter in proportion to its height, and with the umbonal region more produced. The form from the Lower Chalk, described by Etheridge as 8. xquicostatus, cannot, I think, be separated from this species; the type (Pl. XXII, fig. 1) appears to differ somewhat from NS, /atus, but this is on account of its being an old individual; other smaller examples found on the same horizon are inseparable from S. latus found in higher zones of the Chalk. The Lower Chalk forms are in several cases somewhat larger than any that I have seen in the Middle or Upper Chalk. Two specimens from the Chalk Marl of Dover and Folkestone probably belong to this species, but more examples are needed before a definite determination ean be made. Types.—The type, from the Chalk of Lewes, and the specimen figured by Dixon, are in the British Museum. I have not seen the types of Dianchora obliqua, Mantell, which came from Lewes and Brighton; nor his figured specimen of S. latus. The type of S. equicostatus, Etheridge, is in the Woodwardian Museum. 124 CRETACEOUS LAMELLIBRANCHIA. Distribution : (i) Lower Chalk: Fulbourn Asylum. Zone of H. subglobosus of Shelford, Cherry Hinton, and cutting east of South Cave Station. (ii) Middle Chalk: Lewes. Melbourn Rock near Hitchin. Zone of fh. Cuvieri of Dover. Zone of Terebratulina gracilis of Dowlands (near Rousdon), the Dorset coast, Dover, the Sussex coast, Whyteleaf (Warlingham), St. Giles’ Hill (Winchester), Hitchin, Worsted Lodge, and Mutlow Hill (Cambs). Zone of Holaster planus of Chapel Rock (Pinhay), Dover, the Sussex coast, Cheveley, and Linton. Chalk Rock (Iewssianwm-zone) of Brixton, Winchester, Cuckhamsley, Thickthorn Hill, and Boxmoor. (iii) Upper Chalk: Zone of M. cor-testudinarium of Dover, the Sussex coast, and Balsham. Zone of M. cor-anguinum of Thanet, St. Margaret’s, the Sussex coast, Charlton, Gravesend, Strood, Northfleet, and near Hitchin. Zone of Marsupites of Thanet and the Sussex coast. Zone of A. quadratus of Henstmg Farm, Marwell Road, and Hensley Lane (all near Winchester), Hast and West Harnham (near Salisbury), and the Sussex coast. Zone of B. mucronata of the Dorset coast. SPONDYLUS SERRATUS, sp. nov. Plate XXI, figs. 6 a—c, 7 a—e. Description.—Shell rounded, outline rather irregular, slightly mequilateral ; height and length nearly equal. Right valve flattened or slightly concave, with numerous parallel, concentric, and spiny laminge and faint radial ribs. Left valve moderately convex, except in small forms ; ornamented with numerous small ribs, which are of equal size except on the earlier parts of the shell, where new ribs are being introduced ; all the ribs bear many small spines, placed regularly, but on the old parts of the shell the ribs may be nearly smooth. The grooves are broader than the ribs, moderately deep, and crossed by well-marked but somewhat irregular, transverse, thread-like ribs. Ears with four or five ribs. Measurements : (1) (2) (3) Length . , > XO) : 5 OB ; . o2mm. Height. 5 2 AGES : . 23 : > 29° 55 (1) Upper Chalk (Uintacrinus-bed), Devizes Road, Salisbury. (2) Upper Chalk, locality unknown. (8) Upper Chalk (Uintacrinus-bed), Newgate, Thanet. Affinities. —This is similar in form to S. latus, but is distinguished by the small and regular spines, and the broader grooves between the ribs. S. Royanus, SPONDYLUS. 125 d’Orbigny,' differs from this species in having stronger ribs at regular intervals, and in being proportionately higher. S. asper, Goldfuss,’ is similar in form, but the spines are coarser, fewer, and less regular. S. occultus, Geinitz,* is a very small (7 mm.) form, which may be closely related to S. serratus, but the ribs appear to be more unequal and to bear tubercles which are in contact, instead of spiny processes distinctly separated from one another. Remarks.—This is a very rare species; I have seen only five examples which could be definitely referred to it. Distribution.—Marsupites-zone (Uintacrinus-bed) of Devizes Road, near Salis- bury, and the Thanet coast. SponpyLus DurempLeanus, @’ Orbigny, 1847. Plate XXII, figs. 11a, b, 12a, b, 13, 14; Plate XXIII, figs. 1—5. 1833. Drancnora sprnosa, S. Woodward. Geol. Norfolk, p. 48, pl. vy, fig. 24. 1847. Sponpytus Durempreanus, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p- 672, pl. eccelx, figs. 6—11. 1850. — — — Prodr. de Pal., vol. ii, p. 254. 1869. — _ Hi. Favre. Moll. Foss. de la Craie de Lemberg, p. 159, pl. xiii, figs. 14, 15. 1870. - - F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 262. 1887. -- Durempe!, A. Peron. Hist. du Terr. de Craie (Bull. Soc. Sci. hist. et nat. de ’Yonne, ser. 3, vol. xii), p. 166. 1889. —- Durempueanus, FE. Holzapfel. Die Mollusk. d. Aachen. Kreide. (Paleontographica, vol. xxxv), p. 244, pl. xxvii, figs. 8—10. 1891. — — J. Bohm. Die Kreidebild. des Firbergs, etc. (Paleontographica, vol. xxxviii), p. 88. 1892. — — EB. Stolley. Die Kreide Schleswig-Holsteins (Mitth. a. d. Min. Inst. Kiel, vol. i), p. 236. Non 1875. os a= ?, A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi, p. 297. Description.—Shell oval, shghtly oblique, usually inflated, rounded ventrally, pointed and produced in the umbonal region. Right valve sometimes with greater, 1 «Pal. Franc. Terr. Crét.,’ vol. iii (1847), p. 671, pl. cecclx, figs. 1—5. 2 * Petref. Germ.,’ vol. ii (1836), p. 96, pl. evi, fig. 1. 3 “Das Elbthalgeb. in Sachsen” (‘ Paleeontographica,’ vol. xx, pt. 1), p. 207, pl. xlvi, fig. 1. (N.B.—Enlarged about three times.) 126 CRETACEOUS LAMELLIBRANCHIA. sometimes less inflation than the left; the attached part bears concentric toothed lamella; the free surface has numerous regular, nearly equal radial ribs, separated by narrow grooves; in some cases the ribs carry short spines placed rather irregularly, and sometimes slender transverse ribs are seen. Left valve usually regularly convex, with numerous slightly unequal ribs, which are occasionally a little wavy. The ribs are separated by grooves, generally of greater, but sometimes of the same width. The spines on the ribs are hollow, usually short, sometimes perpendicular to the surface, sometimes sloping ventrally ; they may be developed rather irregularly, or larger spmes may be borne on slightly stronger ribs at regular intervals; between these ribs are three or two slightly smaller ribs, with sometimes smaller spines. Faintly marked transverse ribs occur in the grooves, and sometimes extend on to the ribs. Kars smooth, except for erowth-lnes. Measurements of left valve : (1) (2) (3) (4) (5) (6) (7) (8) (9) Length . 20 22°5 23 28 26 17 22 27 24 mm. Height . 23 25 250 26:0 30) 19: 5a 20 BONE, (1—5) zone of A. quadratus, East Harnham. (6—8) 39 x West Harnham. (9) Chalk of Trimingham. Affinities. —S. Omalii, d’Avchiac,’ appears to be a more oblique form with fewer ribs. The form referred by d’Orbigny”® to S. hystri# is larger than S. Dutempleanus, and has the spines confined to the neighbourhood of the umbo. Specimens from the Cenomanian of Devon and Orbiquet (Normandy) agree with the Turonian and Senonian examples, except that the ribs are a little more widely separated. Similar Cenomanian forms from St. Fargeau (Yonne) and St. Sauveur (Yonne) have also been referred to S. Dutempleanus by @Orbigny and by Peron. S. fimbriatus, Goldfuss,’ is very similar to S. Dutempleanus ; jadgmg from the fivures alone, the only difference appears to be in the fewer spies on the ribs. A specimen, described and figured by Sowerby * as Lima? spinosa, is perhaps an example of S. Dutempleanus. I have not been able to find the original, and the locality is not stated. Remarks.—In the majority of specimens seen the spines have been more or less completely broken in the process of clearing away the matrix. Examples from 1 «Mem. Soe. géol. de France,’ vol. ii (1847), p. 312, pl. xv, fig. 11. ‘Pal. Franc. Terr. Crét.,’ vol. iii (1847), pl. ecccliv, figs. 1—9. 3 « Petref. Germ.,’ vol. ii (1836), p. 97, pl. evi, fig. 2. A specimen was referred to this species by Dixon (‘ Geol. Sussex,’ p. 356, pl. xxviu, fig. 34). + F. Dixon, ‘ Geol. Sussex’ (1850), p. 347, pl. xxviii, fig. 33; p. 382 of ed. 2. 1 SPONDYLUS. 127 the Trimingham Chalk appear to have the spines placed more closely together than in other zones. The convexity of the valves varies considerably. The largest examples seen came from the B. iweronata zone of Norwich and Shering- ham. — — striatus, Defrance. Ibid., p. 207. 1827. Puacrosroma sprnosum, S. Nilsson. Petrif. Suecana, p. 25. 1835 — — S. Woodward. Geol. Norfolk, p. 40, pl. v, fig. 25 (? young). 1836. Sponpyius sprnosus, A. Goldfuss. Petref. Germ., vol. ii, p. 95, pl. ev, fig. 5. — —_ pupLicatus, A. Goldfuss. Ibid., vel. ii, p. 95, pl. ev, fig. 6. 1837. Pxiaciosroma sprnosum, W. HMisinger. Lethea Suecica, p. 54, pl. av, fig. 4. — Sponpyuus srinosus, H. G. Bronn. Lethwa Geog., p. 684 (ed. 2), p. 280 (vol. ii, pt. 5, ed. 3), pl. xxxil, fig. 6. CRETACEOUS LAMELLIBRANCHIA. 1839. Sponpyuus sprnosus, H. B. Geinitz. Char. d. Schicht. u. Petref. das siichs. Kreidegeb., pt. 1, p. 24. = = puPLIcATUS, Geimitz. Ibid., p. 25. 1841. _— sprnosus, F. A. Rémer. Die Verstein. des norddeutsch. Kreidegeb., p. 58. — ~- puPLIcATUS, Fdmer. LTbid., p. 58. 1842. Lima BRIGHTONIENSIS, F. v. Hagenow. Riigen’schen Kreideverstein. Neues Jahrb. fiir Min., ete., 1842, p. 556. 1846. Sponpyxius sprnosus, H. B. Geinitz. Grundr. der Verstein., p. 474. — -- (Pacuytos) sprnosus, A. EZ. Reuss. Die Verstein. der bohm. Kveideformat., pt. 2, p. 36. 1847. — spinosus, A. d’Orbigny. Pal. Franc. Verr. Crét., vol. iii, p. 673, pl. cecelxi, figs. 1—4. 1848. _ — 4H.G. Bronn. Index Paleont., vol. i, p. 1189. 1850. — _ H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 196. — = — A.d’Orbigny. Prodr. de Pal., vol. ii, p. 264. — — — A. Alth. Geog.-pal. Beschreib. der Umgeb. von Lem- berg (Haidinger’s Naturwiss. Abhandl., vol. ili, pt. 2), p. 250. 1852. — a R. Kner. Denkschr. d. k. Akad. d. Wissensch. Math.- nat. Cl., vol. i, p. 318. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 182. — — BRIGHTONIENSIS, Morris. Ibid., p. 182. 1855 — spinosus, G. Cotteau. Moll. Foss. de lYoune, p. 118. 1859. — mQuauis, LH. Hébert. Bull. Soc. géol. de France, ser. 2, vol. xvi, p. 149. 1860. — susspinosus, H. Coquand. Descript. Départ. de la Charente, vol. ui, p.142. (Non d’Archiac, 1848.) 1868. — sprnosus, HE. Hichwald. Lethzea Rossica, vol. 11, p. 420. ? 1869. — — E. Favre. Moll. Foss. de la Craie de Lemberg, p- 158. 1870. _- — F. Rémer. Geol. von Oberschles., p. 315, pl. xxxiv, fig. 11. 1871. — suPERBUS, H. Willett. Cat. Cret. Foss. Brighton Mus., p. 35. 1872 — spinosus, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pale- ontographica, vol. xx, pt. li), p. 31, pl. ix, figs. 1—3. 1876. — — D. Brawns. Die Senon. des Salzberges (Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi), p. 391. 1877. — — var. DuPLIcATUS, A. Fritsch. Stud. im Geb. der bohm. Kreidef. IT. Die Weissen- berg. u. Malnitz. Schicht, p. 138, fig, 132. 1881. Lrma sprnosa, R. Etheridge. In Penning and Jukes-Browne’s Geol. Cam- bridge (Mem. Geol. Survey), pp. 65, 69, 72. 1882. Sponpyius meuauis, B. Lundgren. Bull. Soc. géol. de France, ser. 3, vol. x, p. 458. SPONDYLUS. 129 1885. SponpyLtus xQuatis, Lundgren. Spondylusart. i Sverig. Kritsyst. (Sverig Geol. Undersoék., ser. C, No. 69), p. 5, pl. i, figs. 1—3. 1889. — — O. Griepenkerl. Senon von Kénigslutter (Paleont. Abhandl., vol. iv), p. 38. — — spinosus, . Holzapfel. Die Mollusk. Aachen. Kreide (Paleon- tographica, vol. xxxv), p. 248, pl. xxvii, figs. 12, 13. — — — A, Fritsch. Stud. im Gebiete der béhm. Kreide- format. IV. Die Teplitzer Schicht, p- 85, fig. 81. 1897. = — H. Woods. Quart. Journ. Geol. Soe., vol. liii, p. 385. — — —- R. Leonhard. Kreideformat. in Oberschles. (Paleon- tographica, vol. xliv), p. 50. - — mQquauis, A. Hennig. Revis. Lamell. i Nilsson’s ‘ Petrif. Suecana’ (Kon. Fysiogr. Sillsk. 1 Lund. Handl.,N. F., vol. viii), p. 25. 1898. — sprnosus, G. Muller. Mollusk. Untersen. von Braunschweig u. Ilsede (Abhandl. d. k. preuss. geol. Land.,n. F., pt. 25), p. 23, pl. iv, fig. 4. Description.—Shell regular, ovate, slightly imequilateral, rounded ventrally, more or less pointed and produced in the umbonal region, where the margins are only slightly curved. Valves sometimes equally convex, but the right usually flattened ; convexity greatest in the median line, towards the umbo. Right valve a little larger than the left, with the dorsal part of the posterior border longer than the corresponding part of the anterior border. Ribs stronger than those of the left valve, separated by deep narrow grooves; the grooves are crossed by rather irregular linear ridges. In some specimens almost every rib is divided into two parts by a narrow median furrow—the furrows starting, in different specimens, at varying distances from the umbo; in others only a few ribs (often near the centre of the valve or near the anterior and posterior borders) are so divided; or all the ribs may be undivided. Long shghtly curving spines, with a groove on their upper surfaces, are borne at intervals by some of the ribs— frequently by eight, and grow out radially, those near the margin of the valve extending outwards in all directions roughly parallel to the plane of the valves; the spines near the anterior and posterior margins are the strongest. The ribs bearing spines are often not divided by a groove. Left valve with from 26 to 51 regular, rounded ribs, occasionally bearing short spines ; the grooves between the ribs may be wider or narrower than the ribs, and are crossed by many rather irregular linear ridges, which sometimes extend on to the ribs. The ribs may be (1) all of uniform size, separated by broader grooves, and are then relatively few in number and stout; or (2) the stronger ribs may alternate regularly with smaller ribs introduced in the grooves at varying distances ilr¢ 130 CRETACEOUS LAMELLIBRANCHIA. from the umbo, thus increasing the total number of ribs at the margin of the valve; or (3) only afew smaller ribs occur here and there between the larger. The first is associated with undivided ribs on the right valve; the second with all the ribs divided; the third with a few ribs divided—the divided ribs of the right valve corresponding in position with the small intercalated rib of the left valve. Rarely one or two ribs on the left valve may be divided. In old specimens rather strong growth-lines placed near together occur near the margin of the valve, giving it a frilled appearance. Near the umbones the ribs sometimes have a serrated appear- ance, due to the presence of short, close-set, spiny processes. Ears on both valves with growth-lines only or with faintly marked radial ribs also near the umbones; at the inner border the ear is limited by a ridge (often indistinct on the left valve), and between this and the commencement of the regular series of radial ribs on the valve is a smooth area. Measurements of the left valve. Zone of T. gracilis. Zone of H,. planus. Length (in millimetres) . . 49 48 47 47 35 34 ... 57 53 49 47 46 45 44 42 42 41 40 38 33 30 Height __,, 6 : . 53 50 5149 38 39 ... 59 59 57 52 49 48 46 48 49 44 43 39 34 31 Number of main ribs ‘ . 83 43 27 80 38 27 ... 34 33 338 29 33 28 81 34 28 30 33 30 31 82 Number of small intermediate ribs 9 8 811 5 8...1410 922361418 910 8 6 06 1 Chalk Rock. Zone of M. cor-testudinarium. Zone of M. cor-anguinum. Length : j : > SI 46037 Be 52041 4138355840... (2062 Sb sols ol o0R47 Height : 9 : . 6250 41 ... 55 47 45 43 388 36 ... 83 69 57 56 55 60 53 Number of main ribs 5 » 80) 38726 4 80126 25.25) 25028). SOkooN 4a Zone adecD Number of small intermediate ribs 1111 8 ... 1014141012 2... 41715 0 814 7 Zone of Marsupites testudinarius. Length : j 5 . 53 58 58 47 47 47 45 44 48 48 438 42 40 37 385 Height ; : F . 60 59 56 50 47 52 51 49 54 49 46 47 44 40 41 Number of main ribs : . 30: 29 31 29 29 37 28 28 29 28 26 26° 27 27 35 Number of small intermediate ribs 4 619 0 012 0 0 0 0 1 1 0 8 18 Zone of A. quadratus. Zone of B.mucronata, Trimingham Chalk. Length : é é . 55 40 33 29 27 26 005 52 ass 36 31 Height : 6 : . 65 42 36 31 30 28 ae 56 sas 40 32 Number of main ribs ; . 85 28 27 27 31 29 000 32 a8 30 27 Number of small intermediate ribs 1316 0 4 2 11 aan 0 sis 4 0 Remarks.—The amount of convexity of the two valves together, and also the relative conyexities of right and left valves, varies considerably in different examples, and is to some extent associated with differences in the ribbmg. On the right valve the variation in the ribs consists (1) im the presence or absence of a narrow furrow on the rib—giving the appearance of a split rib,—and (2) in the period at which this furrow is introduced. Coincident with the beginning of SPONDYLUS. 131 the furrow on this valve is the introduction of a small intermediate rib between two main ribs on the left valve, so placed that at the margin of the valve the small furrow of the right valve fits into the small rib of the left valve. The number of the small intermediate ribs and the period at which they are introduced vary considerably in different specimens; in some cases they are quite absent, in others only a few occur, or they may appear in almost every groove. When these inter- mediate ribs are absent, the other ribs appear to be stronger and are equal in size, and separated by broad and deep grooves; the form named S. wqualis by Hébert belongs, I believe, to this group. Another form, with many intermediate ribs, was named S. duplicatus by Goldfuss ; this, however, has been regarded by most later writers (Geinitz, Reuss, d’Orbigny, Brauns, etc.) as inseparable from S. spiiosus. In the cases where the intermediate ribs are introduced at an early period, they become towards the margin of the shell almost or quite as large as the other ribs, so that the shell appears to bear a large number of rather small ribs, and differs greatly in appearance from the forms with no intermediate ribs. Between these different varieties every transition seems to occur, but certain types, as noted below, are more abundant in some zones than in others. The form described by Hébert as S. equalis' was found in the B. mucronata Chalk of Meudon. It was stated to differ from 8. spinosus, Sowerby, in haying (1) equal ribs (7. e. no intermediate ribs) on the left valve, and undivided ribs on the right valve; (2) the two valves of equal convexity; (8) spines on both valves. Hébert gave no figures, but Lundgren has figured specimens from Kopinge, which, however, do not show the spines. I believe that S. xqualis is only one of the varieties of S. spinosus. Forms found in the Upper Chalk of England (especially in the B. mucronata and Marsupites zones) agree in the first and second of the features above mentioned, and also in rare cases show spines on the left valve, although never so well developed as those on the right. This form, as already stated, passes into the one with many intermediate small ribs, It will, however, probably be convenient to refer to the two extremes as the xquualis-type and the duplicatus-type respectively. Plagiostoma brightoniensis, Mantell, seems to be an old individual belonging to the xqualis-type; it occurs chiefly in the M, cor-anguinum zone. Near the margin of the left valve intermediate ribs are introduced, and at this part on both valves growth-lines are well marked and close together, giving something of a frilled appearance. S. obesus, d’Orbigny,’ from the Senonian, appears to be only a variety of ' It is recorded by Barrois from the B. mucronata zone of Studland Bay and Norwich. See «Rech. Terr. Crét. Supér.’ (1876), pp. 103, 163. 9 ? «Pal. Frang. Terr. Crét.,’ vol. iii (1847), p. 675, pl. eccelxi, figs, 5—7. 132 CRETACEOUS LAMELLIBRANCHIA. N. spinosus, having the valves rather more convex than usual and the ribs on the ears a little more distinct. Two small specimens in Dr. Blackmore’s collection from the A. quadratus zone of Hast Harnham (length 6 mm.), and the B. mucronata zone of Clarendon (length 65 mm.), are probably young individuals of S. spinosus. S. superbus, Willett, MS., is an example of the equalis-type from the Upper Chalk (probably Marsupites zone) of Seaford. The inner layer of the shell, and also the area and teeth, have been removed by solution from the specimens of S. spinosus and other species of Spondylus found in the Chalk of England.' A large number of good specimens of S. spinosus are preserved in most museums and collections, but unfortunately, in the majority of cases, the zones from which they were obtained are not definitely known, and consequently, in order to determine whether any of the varieties are characteristic of particular zones, I have had to rely mainly on the collections kindly lent me by Drs. Black- more and Rowe, and Messrs. Jukes-Browne, W. Hill, G. HE. Dibley, and J. Scanes, and on my own collecting. Similarly, in selectmg specimens for figuring, I have chosen those of which the exact horizon is known even when finer examples of the same type, but of uncertain zone, were at hand. In order to work out satisfactorily the zonal characters of S. spinosus, a much larger number of carefully collected specimens than I have had at my disposal would be required, and the following notes on the forms found in successive zones must, therefore, be regarded as of a preliminary nature only. T. gracilis-zone-—The common forms (Pl. XXIII, fig. 6) have the valves flattened. Ribs on the left valve are generally slender and separated by broad erooves; intermediate (small) ribs are seen in all cases, and, as a rule, are moderately numerous. Forms with the left valve more convex occur rather rarely (PIS XT fies 7): H. planus-zone and Chalk Rock.—Valves, especially the left, are more convex than in the preceding zone; ribs rather stouter (Pl. XXIII, figs. 8—10). Some forms having few or no intermediate ribs occur (Pl. XXIII, fig. 8). M. cor-testudinarium-zone.-—Commonly the left valve is very convex, and the intermediate ribs are introduced early and become nearly as large as the others (Pl. XXITI, fig. 11). Less common are forms with only a few intermediate ribs. M. cor-anguinum-zone.—Convexity of the two valves is generally more nearly equal. Intermediate ribs are generally small and not numerous, and the main ribs stout (Pl. XXIV, fies. 1, 2). The old individuals of this type, named Plagiostoma 1 For a more detailed account of this, with references to previous writers on the subject, see Woods, ‘ Quart. Journ. Geol. Soe.,’ vol. lui (1897), p. 386. SPONDYLUS. 133 brightoniensis by Mantell, occur chiefly in this zone, but occasionally in the previous zone (Pl. XXIV, fig. 3). Marsupites-zone. Two types occur : (1) with few or no intermediate ribs and the valves of nearly equal convexity (Pl. XXIV, figs. 4, 6); (ii) with many inter- mediate ribs of nearly the same size as the main ribs, and valves of nearly equal convexity : this is not so common as the first type (Pl. XXIV, fig. 5). A. quadratus-zone.—The same two types occur. Only a few examples have been seen, the average size being apparently less (Pl. XXIV, fig. 7). B. mucronata-zone.—No intermediate ribs in the examples seen (similar to Pl. XXIV, fig. 4). Trimingham Chalk.—Two rather small examples are in Mr. A. C. Savin’s collection, one without intermediate ribs, and the other haying four. Another specimen is in Mr. R. M. Brydone’s collection. Types.—Sowerby’s types from Brighton and Northfleet are in the British Museum. I have not seen the specimen figured by Mantell as Plagiostoma spinosa, nor the type of P. brightoniensis. S. superbus, Willett, MS., is in the Brighton Museum. The types of S. duplicatus, Goldfuss, came from the Senonian of Quedlinbure and Coesfeld. Distribution.—S. spinosus ranges from the zone of Rhynchonella Cuvieri to zone of B. mucronata. A few of the localities are given below. i. Zone of R. Cuviert.—Dover. iu. Zone of Terebratulina gracilis—Dowlands (near Rousdon). Whitecliff (Seaton). Hooken (near Beer Head). St. Giles’s Hill and Twyford Down (Win- chester). East Knoyle (Wilts). The Sussex coast. Dover. Whyteleaf (War- lingham). Dunton Green. Preston (Hitchin). Luton. iii. Zone of Holaster planus.—Chapel Rock (Pinhay). St. Giles’s Hill (Win- chester). The Sussex coast. Dover. Cuxton. Borstal. Cheveley (Newmarket). Three quarters of a mile north-west of West Wratting (Cambs). iv. Chalk Rock.—West Wycombe. Princes Risborough. Cuckhamsley. Box- moor. Luton. Clothall (Herts). Quickwood (Herts). Reed and Newsells (Royston). Underwood Hall (Dullingham). Barkway. Great Chesterford. v. Zone of Micraster cor-testudinarium.—West of Beer Harbour. North of Alton Line Junction. The Sussex coast. Dover. Chatham. Purley. Balsham. vi. Zone of Micraster cor-anguinum.—Hungry Down, Blandford. Mitcheldever (upper part of zone). Eaton Lane and Winnal Road (Winchester). The Sussex coast. St. Margaret’s. Thanet. Gravesend. vii. Zone of Marsupites testudinarius—Witherington, near Salisbury (lower part of zone). Devizes Road, near Salisbury (Uintacrinus-band). The Sussex and Thanet coasts. Margate. vii. Zone of Actinocamax quadratus—The Dorset coast. East and West 154 Harnham (Salisbury). coast. CRETACEOUS LAMELLIBRANCHIA. Hursley. Hensting Farm (Winchester). The Sussex ix. Zone of Belemnitella mucronata.—Studland Bay. ? Winchester. Norwich. Sheringham. x. Trimingham Chalk. Genus—PuicatuLa, Lamarck, 1801. (‘ Syst. Anim. sans Vert.,’ p. 132.) PLicaTULA PLACUNEA, Lamarck, 1819. Plate XXV, figs. 1—4. 1819, Puicatruta pLacunEA, Lamarck. Anim. sans Vert., vol. vi, p. 186. 1822. 1826. 1842. Sponpyuus? srricitis, A. Brongniart. Deseript. géol. Envir. de Paris. In Cuvier, Ossem. foss., ed. 2, vol. ii, pp. 833, 613, pl. ix, fig, 6. PuricatuLa pLacunata, Defrance. Dict. Sciences nat., vol. xli, p. 400. pLacunma, A, Leymerie. Mém. Soc. géol. de France, vol. v, pp. 16, 27, pl. xiii, fig. 2. _— P. Mathéron. Catal. Foss. des Bouches-du-Rhone, prls9: — EH. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 249. piacuneA, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 682, pl. ceeelxii, figs. 11—18. a @ Orbigny. Prodr. de Pal., vol. ii, pp. 84, 119. — Ewald. Zeitschr. d. deutsch. geol. Gesellsch., vol. 11, p. 470. — F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Genétve, p. 518, pl. xlvii, fig. 5. _ J. Morris. Cat. Brit. Foss., ed. 2, p. 180. pLAcuNmA, G. Cotteau. Moll. Foss. de l’Yonne, p. 118. pLacungEA, F’. J. Pictet and E. Renevier. Foss. Aptien de la Perte du Rhéne, ete. (Matér. Pal. Suisse, ser. 2), p. 136. — J. A. Eudes-Deslongchamps. Les Plicat. du Calvados (Mém. Soe. Linn. Norm., vol. xi), p. 102, pl. xvii, figs. 1, 2. — J. Vilanova-y-Piera. Mém. géog.-agric. de Castellon, pl. ui, fig. 16. —_ H. Coquand. Aptien de Espagne, p. 158. a E. Eichwald. Zeitschr. d. deutsch. geol. Gesellsch., vol. xvii, p. 271. = — Lethzea Rossica, vol. ii, p. 414. — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), pp. 268, 271. PLICATULA. 135 1875. Purcaruta pLacunea, J. Phillips. Geol. Yorks., ed. 3, pt. 1, p. 244. 1900. — — A. Wollemann. Die Biv. u. Gastrop. des deutsch. u. hollind. Kreide. (Abhandl. d. k. preuss. geo]. Land., n. F., pt. 31), p. 23. Deseription.—Shell very oblique, oval, projecting and pointed at the umbones ; length greater than height. Left valve flat or slightly concave; right valve convex. Both valves ornamented with strong angular ribs, usually eight to ten in number, bearing tubular overlapping spines; between these large ribs smaller ones are introduced, and bear spiny processes. Near the margin of the shell, in old individuals, the two sets of ribs may become of nearly equal size. The ribs are crossed by concentric, usually faintly marked lamelle, and at intervals by well- marked growth-lines. Measurements : (1) (2) (3) (4) Length . 36 27 25 19 mm. Height ! : 33 24. 2405 P40 ep (1—4) from Hythe. Affinities —This is distinguished from P. inflata, Sowerby, and P. Carteroniana, d’Orbigny, by greater development of spines and the presence of the smaller ribs. Distribution—Hythe Beds of Hythe, Lympne, St. Martha’s (Hast Shalford), Sevenoaks, and Maidstone. ? Ferruginous Sands of Shanklin. ? Speeton Clay. Recorded by Fitton (1847) from the Perna-bed of Atherfield.’ Pricaruta CarterontAna, d’Orbigny, 1847. Plate XXV, figs. 5a, b, 6a, b, 7—12. 1847, PuicaruLa Carreroniana, A. d’Orbigny. Pal. France. Terr. Crét., vol. ii, p. 680, pl. eecexlii, figs. 5—7. 1850. _ — d’ Orbigny. Prodr. de Pal., vol. ii, p. 83. 1854. — — J. Morris. Cat. Brit. Foss., ed. 2, p. 180. 1871. _— Carteront, F. J. Pictet and G. Campiche. Foss. Terr. Crét, Ste. Croix (Mat¢r. Pal. Suisse, ser. 5), pp. 265, 271, pl. clxxxii, figs. 3, 4. 1883. — — W. Keeping. Foss., etc., Neoc. Upware and Brick- hill, p. 110, pl. v, fig. 4. 1896. — CarTERONIANA, A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlviii, p. 835. 1 Measured obliquely from the umbo to the middle of the ventral margin. 2 I have not been able to find the type or other specimens of Plicatula inwquidens, Sharpe, from the Lower Greensand of Faringdon, ‘ Quart. Journ. Geol. Soc.,’ vol. x (1853), p. 197, pl. vi, fig. 4. 156 CRETACEOUS LAMELLIBRANCHIA. 1900. Puricatuta CarTERONIANA, Wollemann. Die Biv..u. Gastr. d. deutsch. u. holliind. Neoc. (Abhandl. d. k. preuss. geol. Land., n. F., pt. 31), p. 22. Description.—Shell oval, somewhat triangular, oblique; height greater than length. Right valve much inflated, ornamented with usually eight to ten sharp, prominent ribs, which are slightly curved, bear short spiny processes, and are separated by broad furrows; well-marked growth-lines occur at intervals. Left valve flat or slightly concave; ribs less prominent, more rounded, and broader than on the right valve, separated by narrow furrows. Measurements : (1) (2) (3) Length ie 15 11 mm. Height’. ; 2 ; 2] 16 Wah. (1—3) from Upware. Types.—From the Neocomian of Maisons, near the Ecorces (Doubs). The specimen figured by Keeping is in the Woodwardian Museum. Distribution—Hythe Beds of Hythe and (Bargate Stone) of St. Catherine’s Hill (Guildford). Sandgate Beds of Sevenoaks. Lower Greensand of Brickhill, Potton, and Upware. PLicaTuLA mQuicostata, Keeping, 1883. 1883. PuicaruLta mquicostata, W. Keeping. Foss., etc., Upware and Brickhill, yee LILIES alle iz ails GE Deseription.—Shell small, ovate, oblique, high, very inequivalve, margins rounded. Right valve much inflated, umbonal part prominent, with a small area for attachment ; ornamented with numerous (about fifty) small, regular, rounded ribs, which curve slightly, are of nearly equal size, and are separated by narrow grooves; these ribs are crossed by small concentric lamelle, and occasionally by ‘stronger growth-lines. Left valve flat or slightly concave, with similar ornamenta- tion, but the ribs apparently fewer and broader. Measurements : (1) (2) Length . : : ; : : iy) 16. mm. Height . : : 3 : : 14. NgPsy Thickness ‘ ; : : : 8'°5 ili + (1, 2) from Upware. (1) the type. ' Measured obliquely. PLICATULA. 137 Affinities.—This species appears to be closely allied to P. imbricata, Koch and Dunker,! from the Hilsthon of the Elligser Brink, but is distinguished by the left valve being flat or concave. The shell is also very similar in form to P. Carteroniana, and may even prove to be only a worn example of that species. Remarks.—The only undoubted specimens which I have seen are the three rather imperfectly preserved examples on which the species was founded. Types.—In the Woodwardian Museum. Distribution—Lower Greensand of Upware. PricaTuLa Gureitis, Pictet and Roux, 1853. Plate XXV, figs. 13a, b, 14—21. 1823. Pricaruna pectinorpes, J. de C. Sowerby (non Lamarck). Min. Conch., vol. v, p. 5, pl. ecccix, fig. 1. 1847. — rapioua, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p. 683 (partim), pl. eccelxiii, figs. 6, 7 (non 1—5). 1850. — — = Prod. de Pal., vol. ii, p. 139 (partim). 1853. — curaitis, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Gentve, p. 517, pl. xlvii, fig. 4. 1854. — PECTINOIDES, J. Morris. Cat. Brit. Foss., ed. 2, p. 180. ? 1855. — RADIOLA, G. Cotteau. Moll. Foss. de l’Yonne, p. 118. 1871. — auraitis, F’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 272. 1875. — pectinorpEs, A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi, p. 297. Non 1846. Puicatruta PEctinoiIpEs, A. EL. Reuss. Die Verstein. d. bdhm. Kreidef., pt. ii, p. 37, pl. xxxi, figs. 16, 17 (= P. Barroisi, Peron). —_- — — — J. de C. Sowerby. Trans. Geol. Soc., ser. 2, vol. v, p. 328, pl. xxii, figs. 6, 9 ( = P. peregrina, VOrbigny). Description—Shell oval, more or less triangular, umbonal part generally produced; margins rounded, the postero-dorsal being often concave. Inequivalve : right valve sometimes only slightly, but generally very convex, somewhat flattened near the umbones; left valve concave, sometimes flat. Right valve ornamented with numerous narrow, sharp, radial ribs, curving and slightly irregular, separated by broad spaces. The ribs bear many spines, having usually a roughly concentric arrangement, and being longest near the margins of the valves. Concentric ' «Norddeutsch. Oolithgeb.’ (1837), p. 50, pl. vi, fig. 3; G. Bohm, ‘ Zeitschr. der deutsch. geol. Gesellsch.,’ vol. xxix (1877), p. 236; A. Wollemann, ‘‘ Die Biv. u. Gastrop. des deutsch. u. holliind. Neoce.”’ (‘Abhandl. d. k. preussisch geol. Landesanst.,’ n. F., part 31, 1900), p. 28. 18 138 CRETACEOUS LAMELLIBRANCHIA. lamella and well-marked growth-lines are present. The ribs vary in number considerably in different specimens, but are always more numerous near the ventral margin than near the umbo, owing to the imtercalation of new ribs. Left valve ornamented with similar but usually broader and more rounded ribs, crossed by numerous concentric lamellee. Measurements : ad) @) @) @ © ©) (7 (8) (8) G0) QI) (2) Length . . 53 48 47 39 36 38 31 30 25 22 22 17 mm. Height’ . . 48 44 46 51 40 38 28 36 28 30 29 20 Number of ribs 33 at margin of right valve . 39 34 25 29 23 19 19 24 24 26 28 11 (1—7, 11, 12) from the Gault of Folkestone ; (8—10) from the Gault near Cambridge. Affinities —See P. inflata (p. 140). Remarks.—This species was described by Sowerby as Plicatula pectinoides (Lamarck). The type of Lamarck’s species came from the Lias of Metz,? and is quite distinct from the Cretaceous species; the latter must, therefore, be known as P. gurgitis, Pictet and Roux. Types.—The types of P. pectinoides, Sowerby, from the Gault near Cambridge, appear to have been lost. Distribution—Gault of Folkestone (zones i—ili, vi, vill, x, xi), of Ford (near Aylesbury), and of Barnwell (Cambridge). Cambridge Greensand (derived from the Gault). Red Limestone of Hunstanton. Upper Greensand of the Isle of Wight. PricaTuLa minuta, Seeley, 1866. Plate XXV, figs. 22—25. 1866. Puricatuta minuta, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. xvii, p. 176. Remarks.—The ornamentation of this small form is of the same type as that of P. gurgitis, but the ribs are perhaps more numerous than at the umbo of that species. Comparison, however, is difficult, since the umbo of P. gurgitis is seldom well preserved. It seems probable that P. minuta is only the young form of P. gurgitis, but since the smallest known example of the latter is very much larger 1 Measured obliquely from the umbo to the middle of the ventral margin. 2 Placuna pectinoides, Lamarck, ‘ Anim. sans Vert.,’ vol. vi (1819), p. 224. Plicatula pectinoides, Defrance, ‘Dict. Sciences nat.,’ vol. xli (1826), p. 400; Deshayes and Milne Edwards, Lamarck’s ‘Anim. sans Vert.,’ ed. 2, vol. vii (1836), p. 178; d’Orbigny, ‘Prodr. de Pal.,’ vol. 1 (1849), p. 238. PLICATULA. 139 than the largest of the former, it is at present impossible to trace a passage from one to the other. Types.—From the Red Limestone of Hunstanton, in the Woodwardian Museum. Distribution —Cambridge Greensand. Red Limestone of Hunstanton and Speeton. PricaTuLa INFLata, Sowerby, 1823. Plate XXVI, figs. 1—11. 1819. PuicaTULA RADIOLA, Lamarck. Anim. sans. Vert., vol. vi, p. 185 (? partim). spinosa, G. Mantell. Foss. S. Downs, p. 129, pl. xxvi, figs. 13, 16, 17 (non spinosa, Sowerby). INFLATA, J. de C. Sowerby. Min. Conch., vol. v, p. 6, pl. ececix, fig. 2. A, Goldfuss. Petref. Germ., vol. ii, p. 102, pl. evil, fig. 6. RADIOLA, Lamarck. Anim. sans Vert.,ed. 2 (by Deshayes and Milne Edwards), vol. vii, p. 177 (? partim). tnFLAta, A. EH. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2, p. 37. rapioLa, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. ii, p. 683 (partim), pl. eecelxiii, figs. 1—5 (non 6, 7). spinosa, d’Orbigny. Ibid., p. 685, pl. cecelsiii, figs. 8—10. RADIOLA, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 120. — R. Kner. Denkschr. d. k. Akad. d. Wissensch. Math.-nat. Cl., vol. iii, p. 319, pl. xvui, fig. 9. — F. J. Pictet and W. Roux. Moll. Foss. Gres verts de Genéve, p. 516, pl. xlvii, fig. 3. INFLATA, J. Morris. Cat. Brit. Foss., ed. 2, p. 180. RADIOLA, G. Cotteau. Moll. Foss. de l’Yonne, p. 118. — ?, J. A. Eudes-Deslongchamps. Mém. Soc. Linn. de Normand., vol. xi, p. 103, pl. xvii, figs. 3—8. INFLATA ?, Ludes-Deslongchamps. Ibid., p. 100, pl. xvi, figs. 31—33. — F. J. Pictet and E. Renevier. Foss. Terr. Aptien (Matér. Pal. Suisse, ser. 1), p. 137. — A. v. Strombeck. Zeitschr. der deutsch. geol. Gesellsch., vol. xi, p. 37. — — Ibid., vol. xv, p. 109. — 4H. Coquand. Mon. Aptien de l’Espagne, p. 159. — FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 269. — R. Windmiller. Jahrb. a. k. geol. preussisch Geol. Landesanst.’ (1881), p. 21. 140 CRETACEOUS LAMELLIBRANCHIA. 1882. Puicaruna spinosa, J. Kiesow. Schrift der Nat. Gesellsch. in Danzig, n. F., vol. v, p. 241. 1885. = inFuata, F. Nothing. Die Fauna d. baltisch. Cenoman. (Pale- ont. AbhandL, vol. ii), p. 15, pl. ii, fig. 3. 1887. — — A. Peron. Hist. du Terr. de Craie (Bull. Soc. Sci. Hist. et Nat. de l’Yonne, ser. 3, vol. xii), p. 169, pl. ii, fig. 3. 1889. — _— A. Fritsch. Stud. im Gebiete der bohm. Kreide- format. IV. Die Teplitz. Schicht, p- 86, fig. 84. 1895. — — E. Tiessen. Zeitschr. der deutsch. geol. Gesellsch., vol. xlvii, p. 477. ? 1897. — — A. Fritsch. Stud. im Gebiete der bohm. Kreide- format. VI. Die Chlomeker Schicht, p. 68, fig. 88. Description.—Shell oval or somewhat triangular—more distinctly oval in large specimens; very oblique, margins rounded. Right valve moderately convex, the convexity increasing considerably with age, so that in old specimens the later part of the valve curves considerably from the less convex earlier part. Left valve flat or concave. Right valve ornamented with regular, radial, slightly curved ribs, which are usually few in number, and bear short recumbent spines, which are longer at the anterior and posterior margins; a few new ribs may be introduced between the older ones. Left valve with similar ribs and spines. Measuremeits : qd) (2) (8) (4 () Length . 18 22 238 24 25 Height’ . 22 28 21 26 28 (2) from the Lower Chalk, Ventnor. (8) from the Chalk Marl, Haslingfield. (9) from the H. swhglobosus zone, Cherry Hinton. Others from the Totternhoe Stone, Burwell. 6 = (7) (8) (9) (10) (11) 98 37 45 45 49mm. 3088 Ae Ao” bo bo ~I~1~ b 6 +} Affinities —From a comparison of specimens of P. radiola, @Orbigny, from the Aptian, with specimens of P. inflata, Sowerby, from the English Cenomanian, Pictet, Renevier, and Campiche came to the conclusion that the two forms could not be regarded as distinct species. My own observations lead me to endorse the opinion of those writers—that examples of the same size are inseparable. In the Cenomanian, however, the specimens often reach a larger size than any I have seen from the Lower Cretaceous; in such cases the ventral part of the valve is nearly smooth, or has only indistinct ribs. Figures of a large and also a small form from the Chalk are given by Goldfuss, and good figures of an Aptian speci- men by Pictet and Roux. Peron has named some very small forms from the Cenomanian P. Cotteawi, and considers that P. spinosa, @Orbigny, is an example 1 Measured obliquely from the umbo to the middle of the ventral margin. PLICATULA. 14] of the same. He admits, however, that P. Cotteaui is practically inseparable from P. radiola, d’Orbigny, and gives the name chiefly because it occurs on a different horizon. Peron considers that P. Cotteaui is distinct from P. inflata: after the examination of a large series of specimens of different ages I am unable to accept that view, especially in consideration of the large amount of variation which occurs in the very closely allied species P. gurgitis. P. inflata is distinguished from P. gurgitis by the fewer and more regular ribs and the fewer spines ; also by the ribs being absent or indistinct on the ventral part of the valves in large specimens. Some specimens of P. inflata, with more numerous ribs, approximate to certain examples of P. gurgitis which have fewer ribs than usual; this is more particularly seen in some examples from the Upper Greensand. Remarks——The number and strength of the ribs vary in different examples ; large specimens are sometimes almost smooth (e.g. Pl. XXVI, fig. 9). Since two forms were included by Lamarck under the name P. radiola, and since uncertainty exists as to which of them his name should be applied to, I follow Pictet, Renevier, and Campiche in retaining the name inflata given by Sowerby. Types.—P. inflata is from the Cenomanian near Cambridge ; the specimens cannot now be found. The type of P. spinosa, Mantell, is in the British Museum. Distribution.—Upper Greensand near Nursted and (Chert Series) of the Isle of Wight. Rye Hill Sand of Warminster. Chloritic Marl of Maiden Bradley and the Isle of Wight. Grey Chalk of Folkestone. Chalk Marl of Ventnor, Folkestone, Reach, Burwell, Haslingfield, Harlton, Speeton, ete. Zone of Holaster subglobosus of Hitchin, Totternhoe, Arlsey, Isleham, Burwell, Cherry Hinton, Fulbourn, Shelford, Louth, Witheall, Speeton, ete. I have seen no examples from the English Lower Cretaceous which could be definitely referred to this species, but Topley (1875) has recorded P. inflata from the Hythe and the Sandgate Beds. Pricatuta Barrorst, Peron, 1887. Plate XXVI, figs. 12—18. 1846. Purcaruna pecrinorpes, A. BE. Reuss (non Sowerby). Die Verstein. der béhm. Kreideformat., pt. ii, p. 37, pl. xxxi, figs. 16, 17. 1850, — noposa, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 254 (partin). 1872. _ — H#.B. Geinitz. Das Elbthalgeb. in Sachsen (Palzon- tographica, vol. xx), pt. i, p. 32, pl. ix, fig. 5. 1878. — — ©. Barrois. Terr. Crét. des Ardennes (Ann. Soc. géol. Nord, vol. v), p. 391. 142 CRETACEOUS LAMELLIBRANCHIA. 1887. Puicarura Barrorsi, A. Peron. Hist. du Terr. de Craie (Bull. Soc. Sci. Hist. Nat. de l’Yonne, ser. 3, vol. xii), p. 167, pl. ui, figs. 5—7. 1889. — noposa, A. Fritsch. Stud. im Gebiete der bdhm. Kreideformat. IV. Die Teplitz. Schicht, p. 86, fig. 83. 1895. — ef. Noposa, B. Lundgren. Mollusk. i Mammitll.-och Mucron- zonerna i nordéstra Skane (K. Svenska Vet.- Akad. Handl., n. s., vol. xxvi, No. 6), p. 41. 1897. = Barroisi, H. Woods. Quart. Journ. Geol. Soc., vol. li, p. 388, pl. xxvii, figs. 18, 19. Deseription.—Shell small, ovate, rounded, alittle oblique. Right valve inflated, with the apical part truncated by the attached surface, which is often fairly large. Left. valve flattened or slightly concave, often with a subcircular opening near the umbo. Both valves ornamented with more or less numerous, strong, nearly smooth and rounded ribs, separated by deep and well-marked grooves; the ribs may bifurcate near the margins of the valves, and new ribs may be intercalated. Strongly marked growth-lines occur at intervals, and also concentric lamelle, the latter being most distinct on the left valve. Measurements : (1) (2) (3) (4) Length . : : : 575 ay) 50 4-5 mim. Height . F : ; 6:0 6:0 Bra) BB) op (1—4) from the Chalk Rock, near Winchester. Remarks.—This species was described and figured by Reuss as P. pectinoides, Sowerby, but it differs greatly from Sowerby’s species. D’Orbigny referred it to P. nodosa, Dujardin ;' Geinitz and Fritsch followed the same course. Barrois, although using the name P. nodosa, stated that Dujardin’s figure was very incomplete, and consequently his specimens could not be identified as belonging definitely to that species. Peron subsequently pointed out that the species under consideration differs considerably from P. nodosa, Dujardin; the latter bemg about four times larger, more elevated, and ornamented with large, simple, widely separated ribs. He therefore described and figured it as a new species— P. Barvroist. T'ypes.—Reuss’s specimens came from the Pliner-Kalk and Pyrope Sand of Trziblitz, and from the Pliner-Mergel of Weberschan. Peron’s figured specimens came from the Upper Turonian of Valmy. Distribution.—Zone of R. Cuviert of the Devon coast. Zone of VT. gracilis of the Devon coast and Dover. Zone of H. planus of Dover, the Sussex coast, Twyford (Winchester), ete. Chalk Rock of Winchester, etc. Zone of M. cor- 1 «Mém. Soe. gdol. de France,’ vol. 11 (1837), p. 228, pl. xv, fig. 14. PLICATULA. 143 testudinariwm of Dover and the Sussex coast. Zone of M. cor-anguinum of the Thanet coast, the North Foreland, St. Margaret’s, and the Sussex coast. Uintacrinus band of Kingsgate. Marsupites zone of the Sussex and Thanet coasts. Zone of B. mucronata of Clarendon, near Salisbury. PLICATULA SIGILLINA, Woodward, 1864. Plate XXVI, figs. 19—22. 2? 1852. Sponpyius picnoromus, A. Buvignier. Statist. géol., ete., de la Meuse, Atlas, p. 25, pl. xix, figs. 16, 17. 1864. Puicarua starnyina, 8S. P. Woodward. Geol. Mag., vol. i, p. 112, pl. v, figs. 1—5. Description.—Shell small, semi-oval or semicircular in outline, a little oblique. Hinge margin long. Right valve attached by nearly the whole of its surface ; interior with slightly raised radial ribs, somewhat irregular, becoming more numerous at the sharp raised margin; beyond this margin is a broad smooth sloping border bounded by a raised edge, outside which are, in some cases, radial ribs. Left valve slightiy convex, ornamented with well-marked concentric lamelle. Measurements : ® 2 8 ® © © @ © @ ~ «@o) Lencth 4 lo 8s 65 11. 16 9) 17 18) 2mm: Height’. 12 15 17 6 10 12 9 516" diGe sols: 5, (1—3) M. cor-testudinarium zone, Chatham. (4—6) M. cor-anguinum zone, Gravesend. (7—10) B. mucronata zone, Hartford Bridge, Norwich. Affinities—The form from the Gault of Clermont and Les Islettes (Argonne, Meuse), described by Buvignier as Spondylus dichotomus, is probably identical with this species; it is especially like examples of P. sigillina from the Cambridge Greensand and the Gault of Folkestone. P. sigillina differs from the other Cretaceous Plicatulz here described in bemg attached by almost the entire surface of the right valve, and in the absence of radial ribs or folds on the left valve ; in these respects it resembles the completely fixed forms of the recent species P. philippinarum, Hanley. Remarls.—This species occurs attached to Hchinocorys, Inoceramus, Belemnitella, and other fossils. The fixed valve is common in the Norwich Chalk and the Cambridge Greensand. The left valve is much less frequently found than the right, and at present appears to be known only from the Upper Chalk and the H. planus zone. The inner layer of the shell has undoubtedly disappeared, and ! Measured obliquely. 144 CRETACEOUS LAMELLIBRANCHIA. consequently the character of the hmge and the adductor impression cannot be seen. A small oyster, as noted by Dr. 8. P. Woodward, is often found in the Chalk attached to echinoids, etc., and is similar in general appearance to Plicatula siyillina ; but it is easily distinguished by its triangular ligament-pit and clearly marked adductor impression, by the absence of ribs from the interior of the attached valve, and by the more porous structure of the shell. Types.—One of the types (Woodward’s fig. 1) from Grays is in the British Museum. The others, from the Upper Chalk of Norwich and Grays, I have not seen. Distribution—Upper Gault (zones x and xi) of Folkestone. Cambridge Greensand. Grey Chalk of Dover. Zones of R. Cuvieri, T. gracilis, and H. planus of Dover and the Sussex coast. Zone of M. cor-testudinariwm of Chatham, Dover, and the Sussex coast. Zone of M. cor-anguinum of Gravesend, the Thanet coast, Kingsgate Castle, St. Margaret’s, and the Sussex coast. Zone of Marsupites of the Thanet and Sussex coasts. Uintacrinus-band of Devizes Road (near Salisbury). Zone of A. quadratus of the Dorset and Sussex coasts. Zone of LB. mucronata of the Dorset coast, Hartford Bridge, ete. (near Norwich). THE PALAONTOGRAPHICAL SOCIETY. INSTITUTED MDCCCXLVIL. VOLUME FOR 1902. LONDON: A MONOGRAPH CRETACEOUS LAMELLIBRANCHIA INGLAND. HENRY WOODS, M.A., UNIVERSITY LECTURER IN PAL EFOZOOLOGY, CAMBRIDGE. PART IV. PECTINID A. Paces 145—196; Puarzrs XXVII—XXXVIII. LONDON: PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY. 1902, PRINTED BY ADLARD AND SON, BARTHOLOMEW CLOSE, E.C.; 20, HANOVER SQUARE, W.; AND DORKING. PECTEN. 145 Family—PECTINIDA,! Lamarck. Genus—Prcrren, Miller, 1776. (‘ Prodr. Zool. Dan.,’ p. 248.) Sub-genus—Syneyctonema, I’. B, Meek, 1864. (‘Check List of Invert. Foss. N. America, Cret. and Jur.,’ Smithson, Misc. Coll. 177, pp. 7, 31.) Syncyclonema should probably be united with Entolium, as has been suggested by Philippi, since in the former the concentric ornamentation of the right valve is sometimes incompletely developed, and the ears have, in some cases, a more or less well-marked dorsal prolongation ; on the other hand, in some forms of Hitolium the dorsal prolongation of the ears is insignificant. Syneyclonema is the earlier of the two names. The type of Mntolium’ is Pecten demissus, Phillips ; this has also been taken by Verrill? as the type of Protamusium. PEcTEN (SyNCYCLONEMA) orBICULARIS, Sowerby, 1817. Plate XXVII; and Text- fig, LE: 1817. Prcren orpicunaris, J. Sowerby. Min. Conch., vol. ii, p. 193, pl. elxxxvi. 1819. = sa Lamarck. Anim. sans Vert., vol. vi, pt. 1, p. 182. 1822. — LAMINOSUS, G. Mantell. Foss. 8S. Downs, p. 128, pl. xxvi, figs, 8, 22. 1825. — ORBICULARIS, Defrance. Dict. Sci. nat., vol. xxxviii, p. 252. 1 Recent accounts of the classification of the Pectinida have been given by—aA. E. Verrill, “ A Study of the Pectinid, with a Revision of the Genera and Sub-genera,” ‘Trans. Connecticut Acad.,’ vol. x (1897), p. 41. F. Sacco, “ Molluschi dei Terreni Terziarii del Piemonte e della Liguria ;”’ pt. 24, “ Pectinide,’ 1897. W. H. Dall, ‘Tertiary Fauna of Florida,” ‘Trans. Wagner Free Inst. of Philadelphia,’ vol. iii, pt. 4 (1898), pp. 689—758. E. Philippi, “ Beitriige zur Morphologie und Phylogenie der Lamellibranchier:” (1) “ Hinnites und Velopecten,” ‘ Zeitschr. der deutsch. geol. Gesellsch.,’ vol. 1 (1898), p. 597; (2) “ Zur Stammesgeschichte der Pectiniden,” ibid., vol. lii (1900), p. 64, A. Loeard, ‘ Faune Malacologique Francaise,” xi, ‘‘ Monographie des Esptces appartenant au Genre Pecten,” ‘Ann. Soc. Linn. de Lyon,’ vol. xxxiv (1888), p. 133. C. Depéret and F. Roman, “Monographie des Pectinides néogtnes de l'Europe et des régions voisines,” ‘Mem. Soe. géol. de France (Paléont.),’ vol. x, pt. 1 (1902). * Meek, “Geol. Survey of California,” ‘ Geology,’ vol. 1, Appendix B (1865), pp. 478, 479. 8 «Trans. Connect. Acad.,’ vol. x (1897), p. 71. 19 146 P 1845. 1846. 1847. 1854. 1855. 1863. 1868. 1874. CRETACEOUS LAMELLIBRANCHIA. Pecren Ltaminosus, A. Gold/uss. Petref. Germ., vol.ii, p. 76, pl. xeix, fig - oF Anim. sans Vert. (ed. 2, by Deshayes and g.- ORBICULARIS, Lamarck. Milne-Edwards), vol. vii, p. 159. tAminosus, H. B. Geinitz. Char. d. Schicht. u. Petref. des sichs. 9 23. Kreidegeb., pt. 1, p. CIRCULARIS, Geinitz. Ibid., p. 28. orprcuLaRris, I’. A. Rémer. Die Verstein. nord-deutsch. Kreidegeb., p. 49. LAMINOSUS, Romer. Ibid., p. 49. orprcuLARis, H. B. Geinitz. Die Verstein. von Kieslingswalda, pe LG: — A. @Orbiqny. In X. Hommaire de Hell, Les Steppes de la Mer Caspienne, vol. iii, p. 459, pl. vi, figs. 18—20, _ E. Forbes. Quart. Journ. Geol. Soc., vol. 1, p. 249. -- A. HE. Reuss. De Verstein. der bbhm. Kreideformat., pt. 2, p. 27, pl. xli, figs. 18, 19. LAMINOoSUS, Reuss. ITbid., p. 27, pl. xxxix, fig. 5. ORBICULARIS, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iui, p. 597, pl. cecexxxii, figs. 14—16. LAmiInosus, J. Miller. Petref. Aachen. Kreideformat., pt. 1, p. 31. orBIcuLARIS, H. G. Bronn. Index Paleont., vol. i, p. 928. — H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 180. — A. dOrbigny. Prodr. de Pal., vol. ii, p. 169. — R. Kner. Denkschr. d. k. Akad. d. Wissensch. Math.-nat. Classe, vol. in, p. 515. == J. Morris. Cat. Brit. Foss., ed. 2, p. 177. — G. Cotteau. Moll. Foss. de ?Yonne, p. 116. — A. yv. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch., vol. xv, p. 108. = H. Bichwald. Lethsea Rossica, vol. 11, p. 423, pl. xx, fig. 4. suBLAMINOsUS, EH. Favre. Moll. Foss. Craie de Lemberg, p. 143, pl. xin, fig. 1. GRBICULARIS, I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 206. — W. A. Ooster. Protoz. Helvet., vol. ii, p. 57. (SYNCYCLONEMA) ORBICULARIS, F'. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. in, p. 428. taminosus, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx, pt. 1), p. 192, pl. xliii, fig. 14. opERcULARIS, W. Dames. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxv, p. 68; ibid, vol. xxvi, p. 763 (foot-note). (Amusium) orBicutaRts, Dames. Ibid., vol. xxvi, p. 763. 1881. 1882. 1883. 1885. ? 1889. 1893. ? 1894. 1895. 1896. 1897. 1900. Non 1827. — 1846. Description. Sl ereater than leneth PECTEN. 147 Prcren LAmrnosus, Dames. Ibid., p. 764. H. Deicke. Die Tourtia von Miilheim a. d. Ruhr, p. 26. A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. : II, Die Weissenberg. und Malnitz. Schicht., p. 156, fig. 126. Zeitschr. d. vol. xxix, p. 233. Schrift. d. nat. Gesellsch. in Danzig, N. F., vol. v, p. 415. Windndller. —— ORBICULARIS, G. Boehm. deutsch. geol. Gesellsch , — J. Kiesow. Jahrb. d. k. preussisch. geol. Landesanst. fiir 1881], p 20. Foss., ete., Neve. Upware — cf. oRBICULARIS, R. — ORBICULARIS, var. MAGNUS, W. Keeping. and Brickhill, p. 106, pl. v, fig. 1. - (SyncycLonema) orpicuanis, I’, Nitling. Die Fauna d. baltisch. Cenoman. (Palaeont Abhandl., vol. ii), p. 19, pl. iii, figs. 4, 5. Tbid., p. 19, pl. iii, fig. 3. Verhandl. des = : LAmINosus, Notling. SYNCYCLONEMA SUBLAMINOSA, J. Bihm. tat. Vereins d. preussisch. Rheinl., vol. xlii, p. 83. PecreN Laminosus, FE. Holzapfel. Die Mollusk. Aachen. Kreide (Pale- ontographica, vol. xxxv), p. 231, Zeitschr. d. vol. xlv, p- 256. -— oRBIcULARIS, R. Michael. deutsch. geol. Gesellsch., = LAMINOSUS, Michael. Ibid, p. 235. — orxicuLAnis, A. Hennig. Geol. Foren. i Stockholn Forbandl., vol. xvi, p. 519. — Corratpinus, G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvii, p. 269. — ORBICULARIS, var. LoHMANNI, A. Wollemann. Ibid., vol. xviii, p- 839, pl. xxi, fig. 1. Geognost. Jahreshefte, N. J. (1896), p. 40, pl. iv, fig. 8. Proc. Dorset Nat. Hist. and Antiq. Field Club, vol. xviii, p. 84, pl. iii, fig. 9. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hollind. Neocoms (Abhandl. 4. k. preussisch. geol. Land., N. F., pt. 31), p. 41, pl. viii, figs. 13—19. U. Sochle. SYNCYCLONEMA ORBICULARIS, R. B. Newton. Precrren Germanicus, A. Precren orpicunaris, S. Nilsson. Petrif. Suecana, p. 23, pl. x, fig. 12 (= P. Nilssoni, Goldf.). ?, H. Forbes. Trans. Geol. Soc., ser. 2, vol. vii, p. 154 , i (= Amusium sulcatellum, Stol.). iell ovate or nearly orbicular, nearly equilateral; height a little ; margins on each side of the umbo straightened, that on the posterior side being slightly longer than the corresponding anterior part. Valves 148 CRETACEOUS LAMELLIBRANCHIA. flattened, compressed near the straight margins; the left valve sometimes rather more convex than the right. Kars rather small, nearly equal, the anterior shghtly larger than the posterior, both often shghtly produced dorsally ; external margins usually curving, sometimes nearly straight ; those of the posterior ears somewhat more oblique than those of the anterior. Surface of ears smooth or with growth- lines, and occasionally radial striw. Umbones sharp; apical angle varying from 99° to 115°, average 106°. No byssal sinus. Hinge similar to Amusiwm. Right valve ornamented with broad and usually well-marked concentric ridges and furrows, varying in number. Ridges flat, and, in well-preserved specimens, with a ventral laminar portion projecting over the next furrow; the furrows are narrower or absent near the antero- and postero-dorsal margins. he ridges are ornamented with fine concentric grooves, and with finer radial striz, the latter bemg seen best near the antero- and postero-dorsal margins. Left valve appears almost or quite smooth to the naked eye, but with a lens is seen to be ornamented with numerous fine concentric grooves, and sometimes with fine radial strize. Measurements : (5) (6) (7) (8) (9) (40) (11) (12) (18) (14) (15) (16) (17) (18) (29) (20) (21) (22) (23) Length . 2% lé 13°5 21:5 31 47 40 395 55 30 26 24 155 44 73 22 13 69 34 31 23mm Height .275 26 2517 155 25 3450438 42 56 33 28 26 17 47 76 23 14 70 36 33° 26 eS (1—4) Tealby Limestone. | (14—16) Gault, Folkestone. (5) Folkestone Beds, Folkestone. (17—19) Chalk Marl, Folkestone. (6, 7) Greensand (Chert Beds), Haldon. (20, 21) Chalk Marl, Burwell. (8—11) Upper Greensand, Ventnor. 22, 23) ‘Totternhoe Stone, Burwell. (12, 18) - - Warminster. Affinities —P. germanicus, Wollemann, from the Neocomian of Brunswick, appears to be inseparable from this species. The characters regarded as distinctive by Dr. Wollemann, such as the fine concentric striz on the left valve, the more laminar character of the concentric ribs on the right, and their radial strive, are also found in many specimens of P. orbicularis ; their presence and distinctness depend mainly on the state of preservation of the specimens. Dr. Wollemann has examined a specimen from the Tealby Limestone (similar to Pl. XX VII, figs. 1, 2), and informs me that it is undoubtedly identical with his 2. germanicus ; he has also kindly sent me specimens of the latter from near Brunswick, and they seem to be quite inseparable from P. orbicularis. The difference im horizon is mentioned by Dr. Wollemann as giving some support to lis view that the Neocomian form is distinct, but since P. orbicularis ranges, without a break, from the zone of LB. brunsvicensis to the zone of Holaster subglobosus, we must rather regard the con- tinuous distribution as favourable to the identity of the earler and later forms. P. orbicularis, var. magnus, Keeping, from Upware, is a large variety of this species, and is similar to a form found in the Chalk Marl (Text-fig. 1). In the PECTEN. 149 specimens which [ have seen, the concentric ornament on the right valve is indis- tinct, owing to the imperfect preservation of the surface of the shell, but in several cases the fine concentric grooves are clearly shown on the left valve. Pecten Darius, V@Orbigny,' from the Albian, is a closely allied form, but at present is known only by the brief description in the * Prodrome.’ The form from the Gault of Cosne, described by De Loriol® as P. Darius, appears to differ from P, orbicularis in the inequality of its ears; the figures do not show the character of the ornamentation satisfactorily. Amusium suleatellum, Stoliezka,” and P. concentrice-sulcatus, Miller,! appear to be closely allied to P. orbicularis. The Senonian specimens described by Goldfuss, Holzapfel, ete., as P. laminosus, Goldfuss, and by Favre and Bohm as P. sublaminosus, seem to agree with those forms of P. orbicularis which have more numerous ribs than usual, and particularly with some examples from the Warminster Greensand and the Chloritic Marl of Maiden Bradley. Professor Holzapfel has kindly sent me eight specimens from the Aachen Greensand, but it is difficult to compare them satisfactorily with English examples owing to their different mode of preservation. There does not, however, appear to be sufficient reason to regard them as distinct from the Cenomanian forms of P.orbicularis. The ears in the example figured by Goldfuss are larger than is usual in P. orbieularis. P. membranaceus, Nilsson,’ is similar in form to P. orbicularis, but has the con- centric ornamentation very fine, so that the shell appears to be almost smooth. P, Nilssoni, Goldfuss,’ is also distinguished by being nearly smooth, and (judging from Goldfuss’ fig. 8/) is still further separated from this group by its deep byssal sinus. P. nummularis,’ Fischer de Waldheim,’ is a closely allied form, but without seeing a series of specimens I am unable to make a comparison. P. (Amusium) balticus, Dames,° is probably identical with P. orbicularis. 1 «Pyodr. de Pal.,’ vol. ii (1850), p. 139. * « Faune du Gault de Cosne,” ‘Mém. Soc. Pal. Suisse,’ vol. ix, 1882, p. 84, pl. x, fig. 6. 3 «Paleont. Indica, Cret. Fauna 8. India,’ vol. iii (1871), p. 136, pl. xxxi, figs. 12, 17. (ar > * Petrif. Suec.’ (1827), p. 23, pl. ix, fig. 16 (lower figure). See also Hennig, Holzapfel, Zittel, Geinitz, Goldfuss, ete. 5 *Petref. Germ.,’ vol. ii (1836), p. 76, pl. xcix, fig. 8. 7 Fischer de Waldheim, ‘Bull. Soc. Imp. Nat. de Moscou,’ vol. xvi (1843), p. 135, pl. v, fig. 4; WVOrbigny, in Murchison, de Verneuil, and Keyserling, ‘ Géol. de la Russie,’ vol. ii (1845), p. 475, pl. xli, figs. 20—23, and figs. 16—19 (P. demissus) ; d’Orbigny, ‘ Prodr. de Pal.,’ vol. i (1849), p. 373; Trautschold, ‘ Bull. Soc. Imp. Nat. de Moscou,’ vol. xxxviii (1865), p. 23, pl. iii, fig. 2; Nikitin, “ Les Vestiges de la Période Crét. dans la Russ. Centrale,’ ‘Mem. Com. Géol.,’ vol. vy, 1888, p. 73; P. demissus, Trautschold, * Bull. Soc. Imp. Nat. de Moscou,’ vol. xxxiv (1861), p. 268, pl. vii, fig. 4. 8 *Zeitschr. d. deutsch, geol. Gesellsch.,’ vol. xxvi (1874), p. 762, pl. xxi, fig. 1. Notling, 5 * *Mollusk. Untersenon von Braunschweig u. Ilsede’ (1898), p. 34, pl. v, fi ‘* Baltischen Cenoman.,” * Palaeont. Abhandl.,’ vol. ii, p. 17, pl. ui, fig. 7. 150 CRETACEOUS LAMELLIBRANCHIA. Remarks.—The appearance of the shell differs considerably according to the state of preservation; the fine concentric grooves on the might valve are seen chiefly when the outermost layer of the shell has been removed; when a thicker layer has disappeared this valve may become almost smooth. This is one of the commonest and most widely distributed of the Cretaceous Pectens; it varies considerably in size, m proportions, in the number of con- centric ribs, and also to some extent in convexity. Some of the varieties are more abundant at certain horizons than elsewhere, but are seldom, if ever, limited to one level, and are doubtless accounted for by the varying conditions under which the deposits were laid down. Some of these varieties are here briefly noticed. 1. Tealby Limestone (zone of Bel. brunsvicensis).—The forms found at this horizon never reach a large size (Pl. XXVII, figs. 1, 2), and on the average are smaller than those found in the Cenomanian; they are also shghtly higher im proportion to their length, and often rather more convex. The number of con- centric ribs is not so great as in many Upper Greensand and Cenomanian forms. Near the umbo there is usually seen a fairly large, smooth portion of the shell without ribs, which at first sight appears to be a distinguishing feature of the forms from this horizon. But the examination of a large series of specimens shows that this is due to imperfect preservation ; the same feature has been noticed by Dr. Wollemann in Brunswick specimens. The size of this smooth area varies very considerably in different specimens, and occasionally nearly all the concentric ribs have disappeared; moreover, an identical smooth portion is Sometimes seen in specimens from the Gault and Chalk Marl. 2. Folkestone Beds—Forms very similar to those from the Tealby Limestone and of about the same size occur in the Folkestone Beds of Folkestone, but do not appear to be numerous. The number of ribs is sometimes greater, sometimes less than in the Tealby specimens. 3. Gault——The forms in the Gault (Pl. XXVII, fig. 3) are, on the average, of about the same size as the Tealby specimens, but some larger examples also occur; they sometimes possess rather more numerous ribs, and in some cases the valves are quite as convex as in the Tealby forms, but usually rather less. {. Upper Greensand.—The forms from Ventnor are noteworthy for the large size which they reach; the number of concentric ribs is variable, and on the largest specimens the later part of the valve (Pl. XXVII, fig. 77) is smooth and without ribs, and in the ribbed part two distinct stages may sometimes be noticed, an earlier with close-set ribs, a later with more widely separated ribs (Pl. XX VII, figs. 8,9). Sometimes the grooves are widely spaced and the ribs broad (fig. 9a). DP. orbicularis seems to be rare at Blackdown, and the forms seen are rather small, with numerous ribs. The examples from the Chert Beds of Haldon (PL XXVII, fig. 4), of which there is a good series in the Hxeter Museum, have the PECTEN. 151 ears much larger than usual, also a smaller apical angle, and straight antero- and postero-dorsal margins; the shell is rather high in proportion, and the ribs are numerous. Since all the Haldon specimens agree in these respects, and are readily distinguishable from those found elsewhere, they may be regarded as a local variety, and named P. orbicularis, var. haldonensis : this variety resembles the form from the Cenomanian of Bavaria figured by Séhle (1897). The forms found in the Upper Greensand of Warminster are rather larger than most of those in the Gault and Lower Cretaceous, and often have numerous ribs. 5, Cenomanian.—Small forms, with a variable number of ribs, occur commonly in the Chalk Marl, and rarely also a very large variety, sometimes reaching 76 mm. in height (Text-fig. 1). In the H. subglobosus zone the average size is rather Fia. 1.—Pecten (Syncyclonema) orbicularis, Sow. Chalk Marl, Folkestone. Woodwardian Museum. Natural size. larger than in Gault and Lower Cretaceous, but no forms as large as those in the Upper Greensand mentioned above have been seen. The number of ribs is variable. Lypes.—The type, from the Upper Greensand of Devizes, appears to have been lost, and the same is the case with the types of P. laiinosus from the Chalk Marl of Hamsey and Stoneham. Distribution.—Folkestone Beds of Folkestone. Lower Greensand of Upware. Spilsby Sandstone of Donnington and Spilsby. Claxby Ironstone of Benniworth Haven. ‘Tealby Limestone (zone of LB. brunsvicensis) of North Willingham and Claxby. Speeton Series (same zone) of Speeton (fide Lamplugh). Also recorded in the Geological Survey Memoirs from the Perna-bed of Ather- 152 CRETACEOUS LAMELLIBRANCHIA. field and Sandown; the Ferruginous Sands of Shanklin; the Carstone of Bon- church, etc.; the Hythe Beds of Hythe, Maidstone, Godalming, and Pulborough ; and the Sandgate Beds of Sandgate and Parham. I have not seen the specimens on which these records are based. Gault of Folkestone (zones i—ili, ix—xi), and Black Ven. Zone of H. inter- ruptus of Okeford Fitzpaine. Recorded by the Geological Survey from the Gault of Compton Bay, Culver, Blackgang, Niton, and Bonchurech, and from the Red Limestone of Hunstanton. Cambridge Greensand (derived from the Gault). Upper Greensand (zone of Schlenbachia rostrata) of Blackdown, Devizes, Ventnor, Selborne, and the Devon coast. Upper Greensand (zone of Peeten asper) of Haldon, Warminster, Ventnor, and Niton. Chloritic Marl of Maiden Bradley and Ventnor. Chalk Marl of Folkestone, Hamsey, Blue Bell Hill (Burham), Burwell, Madingley, and Hauxton. Ceno- manian of Wilmington. Lower Chalk (? Chalk Marl) of Stoke Ferry. Totternhoe Stone of Cherry Hinton, Fulbourn, and Burwell. Zone of //. subglobosus of Cherry Hinton. Prcren, sp., cf. Nitssont, Goldfuss, 1836. ’ ] 0) ’ 4 ’ A species, apparently belonging to this group, has been found by Mr. R. M. Brydone in the Chalk of Trimingham; it has a smooth, or nearly smooth, thin shell, with nearly equal ears, and seems to agree with P. Nilssoni, Goldfuss,! but I am unable to say whether it possesses a byssal sinus as is shown in the figures of Goldfuss and Ravn. It also resembles P. membranaceus, Nilsson (see p. 149), but appears to have been proportionately longer, and has consequently a larger apical angle and smaller ears. Only three incomplete specimens have been seen, the lareest having a leneth of about 55 mm. to} (oI to) Sub-genus—Campronncres (Agassiz MS.), F. B. Meek, 1864. (‘Check List of Invert. Foss. N. America, Cret. and Jur.,’ Smithson, Mise. Coll. 177, pp. 28, 39.) Proren (Campronecres) cinetus, Sowerby, 1822. Plate XXVIIT; and Text-fig. 2. 1822. Prcren crncrus, J. Sowerby, Min. Conch., vol. iv, p. 96, pl. ecelxxi. 1825. — — Defrance. Dict. Sci. nat., vol. xxxvili, p. 254. 1 Miiller (1827), p. 23, pl. x, fig. 12. Goldfuss, vol. ii (1836), p. 76, pl. xcix, fig. 8. Hennig (1897), p. 45, pl. iii, figs. 18, 19. Vogel (1895), p. 21, pl. i, fig. 17. Ravn (1902), p. 9, pl. ii, figs. 8—5. Bee also Romer (1841), Reuss (1846), Favre (1869), Geinitz (1872), Brauns (1876), Fritsch (1877-97), Behrens (1878), Griepenkerl (1889), Stolley (1892), Leonhard (1897). PECTEN. 153 1839. Prcren crassiresta, F. A. Rémer, Verstein. nord-deutsch. Oolith.-geb. Nachtrag, p. 27. 1841. — cinctus, F. A. Rimer. Die Verstein. nord-deutsch. Kreidegeb., p. 50. 1846. — nperraris, A. Keyserling. Petschoraland, p. 295, pl. xv. 1847. — crassrresta, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 584, pl. eeeexxx, figs. 1—3. ? 1854. — crxetus, J. Morris. Cat. Brit. Foss., ed. 2, p. 176 (not from the locality and horizon given). — — orassirest., Morris. Ibid., p. 176. 1868. = —_— FE. Bichwald. ethaa Rossica, vol. ii, p. 427. 1870. — = FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p- 212. 1871. — (Pseupamustum) crassrtesta, F. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. iii, p. 428. 1884. — crassirEsta, O. Weerth. Die Fauna des Neocom. im Teutoburg. Walde (Palaeont. Abhandl., vol. ii}, p. 53. _— — Roemert, Weerth. Ibid., p. 54. 1895. — (Syncyctonema) crassrresta, F’, Vogel. Hollind. Kreide, p. 54. — — crassirEsta, G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvii, p. 299. 1896. = — A. Wollemann. Ibid., vol. xlviii, p. 838. 1899. — — G. Maas. Ibid., vol. li, p. 249. 1900. -- — A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hollind. Neocoms (Abhandl. d. k. preussisch. geol. Land., N. F., pt. 51), p. 39. Description.—Shell very large, stout, rather convex, oval or nearly circular, almost equilateral, length sometimes a little greater than height, sometimes a little less. Umbo pointed, with the margins on each side straight or slightly concave. Apical angle from 133° to 144° in the longer forms; from 120° to 127° in the shorter and higher forms. Ears long and low, unequal. Right valve moderately convex, with a nearly smooth surface; ornamented with very regular concentric linear grooves between which are flat interspaces, the ventral edges of which are sometimes produced as laminz over the grooves. The interspaces are crossed by numerous radial striz, which sometimes extend only part of the distance from one concentric groove to the next; also faint concentric ridges are sometimes seen. Anterior ear larger than posterior, with a well-marked byssal sinus, ornamented with close-set sinuous ridges. Posterior ear with the outer angle rectangular or slightly obtuse, ornamented with ridges crossed by radial strix. Left valve more convex than the right, with similar ornamentation, but having the concentric grooves more distinct, the laminze often more prominent, and the 20 154 CRETACEOUS LAMELLIBRANCHIA. radial strize usually less distinct and sometimes absent except near the umbo. Ears slightly unequal, with ridges and radial grooves. Measurements : A B () (2) (8) (4) (5) (6) (1) (2) (8) (4) (5) (6) (7) Leneth . 57 118 118 120 132 191 ... 52 150 191 195 204 212 231 mm. Height . 62 125 129 127 145 207 ... 52 145 179 184 192 201 226 ,, A. The higher and shorter forms. (1) Tealby Limestone: (2—-6) Claxby Ironstone. b. The lower and longer forms. (1) ‘Tealby Limestone: (2—7) Claxby Ironstone. Ajfinities—Goldfuss’ P. circularis' was regarded by Rémer and Bronn as identical with P. crassitesta, Romer; subsequently both were considered by Rémer as synonyms of P. cinctus, Sowerby. The example figured by Goldfuss is stated by him to have come from the Greensand of Dorsetshire ; but no species of this type appears to have been found in the Greensand of that district, whereas the similar forny P. lamellosus, Sowerby, from the Portlandian, is common there, and Goldfuss’ ficure agrees more closely with that than with P. cinctus : this view was evidently held by Morris, since he gives P. circularis as a synonym of P. lamellosus. P. lamellosus, Sowerby,’ is undoubtedly closely allied to P. cinctus ; the ornamenta- tion 1s practically identical in both, for although the radial striz on the former are usually less distinct in specimens from the Portland Limestone, they are quite as well-marked in specimens from the Portland Clay as in P. cinctus. P. lamellosus may, however, be distinguished by its greater obliquity, smaller apical angle, and proportionately higher ears (especially the anterior). The shell never attains the same size as P. cinctus, its average being much less; the height appears to be nearly always greater than the length. Remarks.—There are two forms of this species which differ in the proportions of leneth and height, as will be seen from the figures, and from the measurements (A and B) given above. In one (a) the height is greater than the length, and the valves are oval in outline, with a smaller apical angle and more elevated ears (Text-fig. 2). The right valve is rather more convex than in the other form. This form (A) was figured by Sowerby as P. cinctus. In the other form (8) the leneth is greater than the height, and the valves are more nearly circular in outline, with a larger apical angle and lower ears. The convexity of the valves is jess, and the anterior and posterior parts are more compressed (Pl. XXVIII). This form was figured by @Orbigny as P. crassitesta. Since the forms a and B agree in all the details of ornamentation, and also 1 «Petref. Germ.,’ vol. ii (1836), p. 76, pl. xcix, fig. 10. 2 «Min. Conch.,’ vol. iii (1819), p. 67, pl. cexxxix. See also de Loriol and Pellat, ‘‘ Mon. de l’étage Portlandien de Boulogne-sur-Mer” (‘Mém. Soe. Phys. et d’Hist. nat. de Gentve,’ vol. xix, 1866), p. 103, pl. x, fig. 4. PECTEN. 155 occur on the same geological horizons, and since each shows some variation in the proportions of length and height, there seems no reason to regard them as more than varieties of one species. The concentric grooves are generally more widely separated in the specimens from the Speeton Clay than in those which come from the Claxby Ironstone. This species has usually been known on the Continent as P. crassttesta, owing, no doubt, to the fact that the type of P. cinctus came from the Drift, and its true horizon was for some time thought to be Middle Jurassic; also to the fact of its Fig. 2.—Pecten (Camptonectes) cinctus, Sow. Claxby Ironstone, Claxby. Woodwardian Museum, The higher and shorter form of the species. x j. being the form with a higher shell, which is rather less common than the other variety. T'ype.—In the British Museum; from the Drift—probably derived from the Claxby Ironstone. Distribution.—Claxby Tronstone (zone of Bel. lateralis) of Claxby, North Willingham, Tealby, Donnington. Tealby Limestone (zone of Bel. brunsvicensis) of Claxby. Speeton Series (zone of Bel. jaculum, D1, D 4, D 5) of Speeton. 156 CRETACEOUS LAMELLIBRANCHIA. Pecren (Camprongcres) Corraupinus, @’Orbigny, 1847. Plate XXIX, figs, 1, 2 a, b, 3 tt, b. 1845. Prcren crrcunaRris, H. Forbes. Quart. Journ. Geol. Soc., vol. i, p. 249 (non Goldfuss). 1847. — Corranpinus, A. d@’Orbigny. Pal. Franc. Terr. Crét., vol. in, p- 590, pl. eceexxxi, figs. 7—11. 1850. ~- — — Prodr. de Pal., vol. 11, p. 85. 1855. —_— — G. Cotteaw. Moll. Foss. de ’Yonne, p. 115. 1861. — — P. de Loriol. Anim. Invert. Foss. Mt. Salve, p. 108, pl. xii, fig. 3. 1868. — — F. J. Piclet. Mélanges Paldont., pt. 4, p. 261, pl. x1, figs. 6, 7. — -- — EF. Hichwald. ethea Rossica, vol. 11, p. 451. 1870 — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér, Pal. Suisse, ser. 5), pp. 197, 212, pl. elxvii, fig. 3. ? 1871. — = W. A. Ooster. Protozoe Helvetica, vol. 11, pp. 105, 125, 141. ~- — (SyneycLtonema) Corrauprnus, F’. Stoliczka. Palseont. Indica, Cret. Fauna 8. India, vol. i, p. 428. 1900. a Corraupinus, G. Miller. Verstein. d. Jura u. d. Kreide. In W. Bornhardt, Zar Oberflachen u. Geol. Deutsch - Afrikas (Deutsch - Ost- Afrika, vol. vir), p. 551. Non 1895. —_ _ G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvii, p. 269. Description—Shell ovate, rather higher than long, inequilateral; antero-dorsal margin slightly concave, and longer than the postero-dorsal, which is slightly convex. Convexity of valves.small. Ears very unequal. Right valve shehtly convex ; surface almost smooth, ornamented with numerous fine, regular, concentric grooves, which become more closely placed in passing from the umbo to the margin of the valve. The interspaces are flat and sometimes produced as slightly projecting lamine next the concentric grooves. Near the umbo the interspaces are crossed by very fine, close-set radial striae. Anterior ear large, produced, with a very deep byssal sinus, and a sulcus near the junction of the ear and valve; surface with many concentric narrow ridges. Posterior ear small, triangular, outer angle slightly obtuse, with concentric ornament. PECTEN. 157 Left valve moderately convex, with ornamentation similar to that of the right, but the concentric grooves are rather more distinct and not so close together; the radial striz are more distinct and cover a larger part! of the valve. Anterior ear large, triangular, outer angle about 90°, height nearly or quite equal to length, with concentric ridges and radial striz. Posterior ear much smaller and lower. Measurements : (1) (2) (3) (4) (5) (6) Leneth , BOD ae AO ae hoe es Di ee Oman Height ; 37 « AQ 2. 54 5, 56 5. “60° 8 78ides, Oo > (1—5) Perna-bed of Atherfield. (6) Lower Greensand of Whale Chine. Ajjinities—This species is allied to P. cinetus, but differs in being less convex, higher than long, distinctly inequilateral, smaller, in having the concentric grooves, and usually also the radial striz closer together, the ears more unequal, and the byssal sinus deeper. Remarks—A few small specimens (10 to 17 mm. long) from the Atherfield Beds of Kast Shalford, in the Me¥er Collection, may be young examples of P. Cottaldinus, but they also closely resemble P. Greppini, Pictet and Renevier.? Types.—D Orbigny’s specimens came from the Neocomian of Auxerre, ete. The specimen referred to 2. circularis by Forbes is in the Museum of the Geological Society (No. 2030). Distribution.—Perna-bed of Atherfield. Lower Greensand (either Scaphites or Lower Crioceras Groups of Fitton) of Whale Chine. Recorded by Topley (1875) from the Atherfield Beds of Peasmarsh and Shalford. Prcoren (CAMPYONECTES) STRIATO-PUNCTATUS, Ldmer, 1839. Plate XXIX, figs. 4a,b, 5, 6. 1839. Prcren srriaro-puncratus, . A. Rimer. Die Verstein. d. nord-deutsch. Oolith.-geb. Nachtrag., p. 27. 1841. = = — Die Verstein. d. nord-deutsch. Kreidegeb., p. 50. 1847. : = A. d'Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 592, pl. cceexxyii, figs. 4—7_ 1850. — — — Prodr. de. Pal., vol. ii, pp. 83, 119. 1 Perhaps the whole in perfectly preserved specimens. 2 «Poss. Terr. Aptien de la Perte du Rhone, ete.’ (1858), p. 154, pl. xix, fig. 4. Pictet and Cam- piche, ‘ Terr. Crét. de Ste. Croix’ (1870), p. 198. 158 CRETACEOUS LAMELLIBRANCHIA. 1854. Prormn srriato-puncratus, J. Morris. Cat. Brit. Foss., ed. 2, p. 177. 8 1868. — arzigrrEnsis, P. de Loriol. Valangien d’Arzier, p. 47. pl. iv, figs. 3—5. 1870. — srriaro-puncratus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), pp. 196, 211, pl. clxxi, figs. 4, 5. = — ARZIERENSIS, Pictet and Campiche. Ibid., pp. 195, 211, pl. elxxi, fig. 3. 1871. — (CAMPTONECTES) stTRIATO-puNcTATUS, IF. Stoliczka. Palont. Indica, Cret. Fauna 8. India, vol. iu, p, 428. 1877. — strrIAto-puncratus, G. Bohm. Zeitschy. d. deutsch. geol. Gesellsch., vol. xxix, p. 253. 188-4. _ — O. Weerth. Die Fauna des Neocom. im Teuto- burg. Walde (Palaeont. Abhand1., vol. 11), p. 53. 1888. — arziprensis, 8. Nikitin. Les Vest. de la Pér. Crét. dans la Russ. centrale (Mém. Com. Geéol., vol. v), p. 73, pl. ii, fig. 12. 1889. — LENs, var. Morini, G. W. Lamplugh. Quart. Journ. Geol. Soc., vol. xlv, p. 615. 1895. — (Casmpronecres) striaro-puncratus, F. Vogel. Hollind. Kreide., p. 04. 1896. — srRrato-puncratus, A. Wollemann. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvii, p. 840. 1900. — -- — Die Biv. u. Gastrop. d. deutsch. u. hollind. Neocoms (Ab- handl. d. k. preussisch. geol. Land., N. F., pt. 31), p. 49. ? 1900. — G. Miller. Verstein. d. Jura u. d. Kreide. In W. Bornhardt, Zur Oberflichen u. Geol. Deutsch-Afrikas (Deutsch- Ost-Afrika, vol. vii), p. 550, pl. xxiv, fig. 7. Description.—Shell ovate, a little higher than long, nearly equilateral, convexity small, margins rounded, dorsal portion pointed. Kars unequal. Right valve flattened, anterior ear with a deep sinus. Left valve rather more conyex, anterior ear with the outer angle nearly rectangular, posterior ear with obtuse outer angle. Both valves ornamented with numerous flattened radial ribs, which curve out- wards from the median part of the valves, and sometimes bifurcate, or have new ribs intercalated. Ribs separated by narrow, sharply marked punctate grooves. At intervals a few distinct growth-lines occur. Ears with radial ribs crossed by concentric growth-ridges. PECTEN. 159 Measurements : (1) (2) (3) (4) Leneth f 36 : 25 : 22 : 15 mm. Height ——. a) 27 : 26 ie (1) B. lateralis zone, Speeton. (2,3) B. jaculum zone, Speeton. (4) Claxby Ironstone, Benniworth Haven. ‘These measurements are approximate only, on account of the imperfection of the specimens. Considerably larger examples than (4) occur in the Claxby Tronstone. Affinities —I have seen only a few specimens of this species, and most of them are very imperfect, consequently [ am unable to make a detailed comparison with allied forms. The species which appears to approach most nearly P. striato- punctatus is P. Morini, de Loriol;! it is found in the Portlandian of Swindon, Hartwell, etc., and seems to differ from I. striato-punctatus in being less equilateral, owing to the greater proportionate leneth and inward curvature of the antero- dorsal margin; the ribs are also, on the average, more numerous and closer together, but vary somewhat in this respect. P. virgatus, Nilsson, and P. curvatus, Geinitz (see below), are also related to I. striato-punctatus. Remarks.—Romer figured no examples of this species, but erroneously referred to Goldfuss’ figure of a Jurassic form (P. lens). A small form found rarely in the Gault of Folkestone is perhaps referable to P. striato-punctatus. T'ypes.—From the Hils-conglomerate and Hils-clay of Schandelah, Schoppen- stedt, and Elhigser Brink. D’Orbigny’s specimens were obtained from the Aptian of St. Dizier (Haute Marne). Distribution.—Speeton Clay (zones of DB. lateralis, D1, and of B. jaculwm, C 11) of Speeton. Claxby Ironstone (zone of Pel. lateralis) of Benniworth Haven. ? Upper Gault (zone viii) of Folkestone. Recorded by Topley (1875) from the Atherfield Beds of Peasmarsh and East Shalford, and from the Folkestone Beds of Folkestone. Recorded by Morris from the Lower Greensand of Folkestone. Prcren (Campronectes) curvatus, Geinitz, 1843. Plate XXIX, figs. 7a, b; Plate XXXVII, fig. 16. 1833. Prcren arcuatus, A. Goldfuss. Petref. Germ., vol. ii, p. 50, pl. xci, fig. 6 (non Nilsson). ? 1841. — — F. A. Rimer. Die Verstein. d. nord-deutsch, Kreidegeb., p. 51. 1 De Loriol and Pellat, “ Portlandien de Boulogne-sur-Mer’”’ (‘ Mém. Soe. Phys. et d’Hist. nat. Geneve,’ vol. xix, 1866), p. 107, pl. x, fig. 6. 160 1842. ae) — lee) “I “NI CRETACEOUS LAMELLIBRANCHIA. Prcten strtato-punctatus, H. B. Geinitz. Char. d. Schicht. u. Petref. des sichs.-bohm. Kreidegeb., pt. 3, p. 83. curvatus, H. B. Geinitz. Die Verstein. von Kieslingswalda, p. 16, pl. ii, fig. 13. pivaricatus, A. FH. Reuss. Die Verstein. der bbhm. Kreideformat., pt. 2, p. 28, pl. xxxix, fig. 6. arcuatus, Reuss. Ibid., p. 27, pl. xxxix, fig. 7. curvaTus, H. B. Geinitz. Grundr. der Verstein., p. 468. Arcuatus, J. Miller. Petref. der Aachen. Kreidef., pt. 1, p. 32. vireatus, A, @Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 602, pl. cccexxxiv, figs. 7—10. curvatus, H. G. Bronn. Index Paleont., vol. i, p. 922. vireatus et curvatus, H. B. Geinitz. Das Quadersandst. oder Kreidegeb in Deutschland, p. 180. curvatus, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 197. pivaricatus, A. d’Orbigny. Ibid, p. 252. vireatus, F. Rimer. Geol. von Oberschles., p. 333. curvarus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 217. — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx, pt. 1), p. 193, pl. xli, fig. 15.; pt.2, p. 33, pl. x, fig. J. (CaMPTONECTES) cuRVATUS, D. Brauns. Zeitschr. f. d. gesammt. Naturwissensch., vol. xlvi, p. 390. curvatus, A. Irritsch. Stud. im Gebiete der bohm. Kreideformat. : II, Die Weissenbere. und Malnitz. Schicht., p. 136, fig. 127. viraatus, H. Schrider. Zeitschr. d. deutsch. goel. Gesellsch., vol. XXxlv, p. 270. curvatus, A. Fritsch. Stud. im Gebiete der bohm. Kreideformat. : III, Die Iserschicht., p. 116. (CampronectEs) Divaricatus, I. Notling. Die Fauna d. baltisch. Cenoman. (Palaeont. Abhandl., vol. 11), p. 17, pl. ui, fig. 6. CampronecteEs curvaAtTus, J. Bohm. Verhandl. des naturhist. Vereins d. Rheinl., vol. xlu, p. 78. Prcren (Campronectes) curvatus, F. Frech. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxxix, p. 155, pl. xix, fig. 18. vineatus, TZ. Holzapfel. Die Mollusk. Aachen. Kreide (Paleeonto- eraphica, vol. xxxv), p. 229, pl. xxvi, figs. 7—9. (CAMPTONECTES) virGatus, O. Griepenkerl. Die Verstein. der. Senon. von Kénigslutter (Palaeont. Abhandl., vol. iv), p. 46. curvatus, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat. IV, Die Teplitz. Schicht., p. 85. PECTEN. 161 1892. Percren vireatus, F. Vogel. Verhandl. nat. Vereins d. preussisch. Rheinl., vol. xlix, p. 55. ? 1893. — of. curvatus, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlv, p. 236. Pp — — curvatus, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat. : V, Priesen. Schicht., p. 100. ? 1895. — (Campronectes) vireatus, F. Vogel. Hollindisch. Kreide, p. 23. ? 1897. — curvatus, A. Fritsch. Stud. im Gebiete der béhm. Kreideformat. : VI, Die Chlomek. Schicht., p. 68. PP — — vireatus, A. Rutot. Bull. Soc. Belge Géol., etc., vol. x, p. 30. yo — —- R. Leonhard. Die Kreideformat. in Oberschles. (Pale- ontographieca, vol. xliv), p. 26. ? 1900. —_ — C. Gagel and F. Kaunhowen. Jahrb. d. k. preussisch. geo). Landesanst. u. Bergakad. fiir 1899, p. 231. Non 1827. — arxcuatus, S. Nilsson. Petrif. Suecana, p. 22, pl. ix, fig. 4. ==" == — vireatus, Nilsson. Ibid., p. 22, pl. ix, fig. 15, S37. — “= W. Hisinger. Letheea Suecica, p. 52, pl. xvii, fig. 3. — — arcuatus, Hisinger. Ibid., p. 52, pl. xvii, fig. 2. oe —— 1846: — vireatus, H. Forbes. Trans. Geol. Soc., vol. vii, p. 154, pl. xv, fig. 22. ? — 1852. — — F. Rimer. Die Kreidebild. von Texas, p. 66, pl. viii, fig. 5. — 1866. — -- K. A. Zittel. Die Biv. der Gosaugeb. IT (Denkschr. d. k. Akad. Wissensch. Math.-nat. Cl. Wien, vol. xxv, pt. 2), p. 109 (33 of reprint), pl. xvii, fig. 8. ? — 1871. — (CampronecteEs) curvatus, F'. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. ii, p. 433, pl. xxxi, figs. 15, 16; pl. xli, figs. 4—6. 2? — 1884. Campronecrss curvatus, J. F. Whiteaves. Mesozoic Fossils, vol. i, pt. 3 (Geol. and N. H. Survey, Canada), p. 242, pl. xxxii, fig. 4. — 1897. Prcren vireatus, A. Hennig. Revis. Lamellibr. i Nilsson’s * Petrif. Suec.’ (Kon. Fysiogr. Sillsk. Lund. Handl., N. F., vol. viii), p. 41, pl. ii, figs. 28, 33; pl. iii, figs. 32, 33. Remarks.—This species closely resembles P. striato-punctatus, Romer, but generally possesses fewer ribs, and is, on the average, of smaller size. I have seen only two English specimens. One is aright valve from Great Haldon, 10 mm. in length and 11 mm. in height, with well-marked radial ribs on the ears crossed by much smaller concentric ribs. Another example, from the Chloritic Marl of Kastbourne, is 9 mm. in length and also in height. Without more English speci- mens, and without the opportunity of comparing them with collections of the foreign forms described as P. virgatus, ete., it is useless to attempt to discuss the relation of this to other Upper Cretaceous species. = 162 CRETACEOUS LAMELLIBRANCHIA. Distribution.—Upper Greensand of Great Haldon. Chloritie Marl of Kast- bourne. Prcren (CAMPTONECTES) DUBRISIENSIS, sp. nov. Plate XXIX, figs. 8 a—e. Deseription.—Shell ovate, height a httle greater than length, almost equilateral, margins evenly rounded. Umbones pointed. Apical angle about 117°. Kars rather large, unequal. Right valve flattened, nearly smooth, with a few radial ribs near the antero- dorsal border, and oceasional fine curving radial ornamentation like that on the left valve. Antero-dorsal margin slightly concave. Anterior ear long, with a deep byssal sinus, very sinuous growth-lines, and well-marked growth-ridges. — Posterior ear triangular, with radial ribs and grooves. Left valve moderately convex —the convexity greatest in the dorsal third, the ventral portions more compressed. Greater part of the surface smooth or nearly smooth ; a few faintly marked growth-lines. Ornamentation seen on the sides of the umbonal region, also at the ventral edge, and for a short distance on the inner margin of some of the growth-lines; it consists of faintly marked outwardly curving ribs, separated by very marrow grooves, which are somewhat irregular and (in well- preserved specimens) punctate. Anterior ear large, not sharply separated from the rest of the valve, ornamented by a continuation of the radial ribs and grooves of the umbo, some of which cut the dorsal margin obliquely; the ribs are crossed by faint growth-ridges. Posterior ear smaller with similar ornamentation. Measurements : (1) (2) (3) (4) Length : 58 : 58 ; 2 : 32 mm. Height . 63 . 59-5 AG : BH) ss (1) Totternhoe Stone, Cherry Hinton. (2) Chalk Marl, Burham. (3) Totternhoe Stone, Burwell. (4) H. subglobosus zone, Hitchin. Affinities —The ornamentation is much less developed than in P. striato- punetatus ; the shell is also larger, with a wider apical angle, less elevated ears, and with the left anterior ear indistinctly limited. Remarks.—This is a comparatively rare form, which appears to be confined to the Chalk Marl and the zone of H. subglobosus. Type.—Chalk Marl of Dover, British Museum, No. 38243. Distribution.—Chalk Marl of Dover and Blue Bell Hill, Burham. Totternhoe PECTEN. 163 Stone of Cherry Hinton and Burwell. Zone of H. subglobosus of Hitchin. Lower Chalk of West Row near Mildenhall, and Stoke Ferry. Precten (CAMPTONECTES ?) GAULTINUS, sp. nov. Plate XXX, figs. la, b, 2. Description —Shell small, oval, a little higher than long, convexity small ; somewhat inequilateral, the antero-dorsal border slightly concave and longer than the postero-dorsal, which is shghtly convex. Kars very unequal. Apical angle from 95° to 100°. Right valve flattened, nearly smooth, with faintly marked, nearly straight radial ribs near the anterior and posterior borders, separated by narrow punctate grooves ; ribs and grooves absent or indistinct on the middle of the valve, except near the umbo. Anterior ear long, with a deep sinus, and three or four radial ribs crossed by growth-ridges. Posterior ear small, with its outer angle obtuse. Left valve rather more convex, with similar ornamentation. Measurements : (1) (2) (3) (4) Leneth ‘ 22 15 14 : 17 mm. Height : 19 ily : 16 : ik? ee (1—3) Gault, Black Ven. (4) Gault, Folkestone. Remarks.—This species differs from the typical Camptonectes m having the punctate grooves nearly straight instead of curving outwardly. Types—In the Woodwardian Museum, Cambridge. Distribution.—Gault of Folkestone and Black Ven. Sub-genus—Curamys, J. I’. Bolten, 1798. (¢‘ Museum Boltenianum,’ p. 165.) Prorun (Cutamys) risstcosra, Mtheridge, 1881. Plate XXX, figs. 3, 4, 5a, b, 6 a—e, 7, 8. 1881. Prcren risstcosta, Rh. Etheridge. In W. H. Penning and A. J. Jukes- Browne, Geol. of Cambridge (Mem. Geol. Survey), p. 141, pl. ii, fig. 1; pl. in, fig. 1. 164 CRETACEOUS LAMELLIBRANCHIA. Description.—Shell ovate, shehtly inequiateral ; height greater than leneth, the difference increasing with age, usually in the proportion of 9:7 or 9:8, but im small specimens of 5:4°5. Valves compressed, the right flatter than the left; antero- and postero-dorsal margins nearly straight, the remainder regularly rounded and with corrugated edges. Apical angle about 90°, but larger (sometimes 100°) in small specimens. Hars unequal. tight valve ornamented with strong, rounded, radial ribs, usually from sixteen to eighteen in number, but sometimes fewer or more (twelve to twenty-three). The ribs are separated by rather deep, rounded furrows, which are rather narrower than the ribs. At a distance from the margin of the valve, which varies in different specimens, some of the ribs are usually divided by a narrow groove, some- times median, sometimes on one side; towards the umbo this groove becomes relatively more important, and divides the maim mb into two equal and narrow ribs; and at the same time another similar rib may appear in the main furrow, ceiving the appearance of numerous slender ribs. All these ribs seem to die out before reaching the umbo, where the shell (to a length of about 5 mm.) is apparently smooth.’ At distant intervals well-marked growth-ridges are seen, and also (in some cases) very fine concentric lines. The surface of both ribs and furrows (but especially the latter) is covered by close-set radial striee, which at the middle of the valve are parallel with the main ribs, but, in passing to the anterior and posterior margins, become more and more oblique to the main ribs, and also more irregular and less continuous. Anterior ear large, produced, with a deep byssal sinus; surface with sinuous growth-lines (some strong), and two or three faintly marked radial ribs at the middle of the ear near its apex. Posterior ear smaller, not produced, triangular, with from seven to nine faintly marked radial ribs and growth-lines (two or three beimg strong); on the ventral part of the ear the fine striz of the rest of the shell are continued, and cut the ribs obliquely. Left valve with ribs similar to those of the right, but rather narrower, and separated by broader furrows. The ribs are sometimes divided by a small groove, which may reach the margin of the valve. In the main furrows there is frequently asmall radial rib, which often ends at varying distances from the margin, but some- times is continued, becoming stronger. Close-set radial striz, like those on the right valve, occur on both ribs and grooves. Fine concentric ribs occur in places, especially on the earlier parts of the valve, and also, at intervals, strong growth- ridges. ars triangular; the anterior larger, and with radial ribs and growth-lines ; the posterior nearly smooth and with faint ribs. 1 This may, however, be due to imperfect preservation. PECTEN. 165 Measurements : (1) (2) (3) (4) (5) (6) (7) Leneth . 45 . 40 . 36 . 06 . 35 . 27 . 26 mm. Height . 52 . 47 . 445 . 44 . 42 . 31 . 29 (1) Totternhoe Stone, Cherry Hinton. (2—7) 5 5 surwell. 29 Affinities. —P. fissicosta is readily distinguished from the other species with strong ribs by its numerous radial striae and by the fission of some of the main ribs. P. landeronensis, De Loriol,! resembles this species in form, but possesses a strongly marked concentric ornamentation. The radial striae of I’. fissicosta resemble those of Camptonectes as well as those seen in [’. Robinaldinus, ete. The varieties, with few and undivided ribs (Pl. XXX, fig. 7), approach P. decencostatus, Goldfuss (references on p. 167), but the valves are higher. T'ypes.—F rom the Totternhoe Stone, Burwell; in the Woodwardian Museum. Distribution.—Chloritic Marl of Ventnor. Chalk Marl of Egeardon Hill (Dorset), Folkestone, and Blue Bell Hill, Burham. Totternhoe Stone of Arlesey, Cherry Hinton, Burwell, Orwell, and Stoke Ferry. Zone of H. subglobosus of Cherry Hinton. Precren (Cutamys) Puzosianus, Matheron, 1842. Plate XXX, figs. 9a, b, 10a, b, lesion 1842. Prcren Puzostanus, P. Matheron. Catal. Foss. des Bouches-du-Rhone, p. 185, pl. xxx, figs. 1—3. 1847. — — A. @Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 610, pl. ceeexxxvii, figs. 1—4. 1850. — _ — Prodr. de Pal., vol. ii, p. 197. 1870. — — PF. J. Pictet and G, Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 215. 1896. — ef. Puzostanus, A. J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. ii, p. 151. Deseription.—Shell ovate, higher than long, nearly equilateral and equivalve, dorsal portion pointed; antero- and postero-dorsal margins long. Convexity small, valves bent near the antero- and postero-dorsal margins. Apical angle about 90°. Kars large, unequal. Right valve shghtly convex, with numerous narrow ribs, which on the mid- dorsal parts of the valve are alternately large and small, but elsewhere become ‘ De Loriol and Gilliéron, ‘ Urgon. Infér. de Landeron’ (1869), p. 22, pl. i, fig. 19; Pictet and Campiche, “Terr. Crét. de Ste. Croix”’ (‘ Mater. Pal. Suisse,’ ser. 5, 1870), p. 187, pl. elxix, figs. 6, 7. 166 CRETACEOUS LAMELLIBRANCHIA. more nearly equal in size. Surface with concentric ridges or orowth-lines, which sometimes develop into small spiny projections where they cross the ribs. Anterior ear large, rising dorsally, with a deep byssal sinus. Left valve rather more convex, with usually from thirty-eight to forty-four ribs at the margin, where they are separated by very narrow grooves. Most of the ribs are of nearly equal size, but occasionally smaller ones occur ; they are rounded on the early parts of the valve, but become flattened and broader ventrally, and also anteriorly and posteriorly. Secondary ribs are introduced at a short distance from the umbo. The grooves become narrow ventrally. Surface of ribs and erooves with close-set, concentric, linear ribs, which are better marked near the umbo than elsewhere. The bent antero- and postero-dorsal margins are without ribs, but have numerous radial striz; these striae appear on some of the ribs also. Anterior ear more elevated and larger than the posterior; both with a few broad radial ribs. Measurements : (1) (2) (3) Length ; AD, , 39 . 35 min. Height 50 . 49 : A, +) ” (1) Cenomanian (Bed 11), Dunscombe. (2) Cenomanian, Wilmington. (3) Cenomanian (A. Mantelli zone), Beer Head. Afjinities.—The ribs in this species are more numerous as a rule, and the concentric ornamentation much less well-developed than in P. Hspaillaci, VOrbigny. The ribs are much more numerous than in P, fissicosta, Etheridge, and the radiating strix much less developed, being apparently confined to the anterior and posterior part of the valves. Remarks.—The English specimens are smaller than those figured by Matheron and d’Orbigny, and, as pointed out by Jukes-Browne, agree better with the figures than with the descriptions given by those authors, but specimens obtained from France leaye no doubt as to the identity of the English form with Matheron’s species. I have not seen the arrangement of the ribs shown in Matheron’s section (fig. 3), but there is sometimes an alternation of large and small ribs. T'ypes.—Cenomanian (Chert Beds) of Les Martigues, Uchaux, and Mornas Sault. Distribution.—Cenomanian of Wilmington. Cenomanian (Beds 10, 11) of Beer Head, and (Bed 11) of Dunscombe. Chloritic Marl of Melbury (Dorset) and Maiden Bradley. PECTEN. 167 Prcoten (CHLAMYS) BRITANNICUS, sp. nov. Plate XXXI, figs. 1a, b, 2a, b. Description.—Shell thick, ovate, flattened, with even margins, slightly inequi- lateral, antero-dorsal margin a little longer than the postero-dorsal, apical angle about 9O°. Left valve with sixteen or more (sometimes probably thirty) strong, rounded, radial ribs, separated by deep grooves, which are frequently as broad as or broader than the ribs. The ribs merge into the smooth margin of the shell; they do not bifureate, and only rarely is a new rib introduced between two others. Both ribs and grooves are marked by concentric, linear ridges, which are more distinct in the grooves than on the ribs, and are placed close together at regular intervals; the ridges imbricate upwards. Anterior ear moderately large, with the outer angle nearly rectangular, and one or two radial ribs. Posterior ear not seen. Right valve not seen. Measurements : Length ; : ; : : ° : ; 26°0 mm. Height : : . ; ; ; : . 98°5 ,, From M. cor-anguinum zone, South Croydon. A ffinities—This species resembles P. Hspaillaci, @Orbigny,' from the Senonian of Dordogne and Charente-Inférieure, but it differs from the French form in possessing fewer ribs, with a stouter shell and thick margin (instead of a sharp and corrugated edge); also in the concentric ridges imbricating upwards, instead of downwards. 2 2 207594159. 12) 5 anme Height . 32 . 295 . 24 Wp 5 ley gE) gg (1—6) All from Blackdown. ' «Foss. S. Downs’ (1822), p. 203, pl. xxv, fig. 6. PECTEN. 169 Remarks.—The right valve is less common than the left. he state of preser- vation of the shell, and consequently the appearance of the ornamentation, varies a good deal. Type.—From Blackdown ; in the Bristol Museum. Distribution.—Blackdown Greensand (Bed 10). Recorded by Downes (1882) from Haldon, and by Jukes-Browne (1900) from the Upper Greensand of Lulworth and Warminster. Prcren (Cutamys) susacutus, Lamarck, 1819. Plate XXXI, figs. 7 a,b, 8a—e, 9. 1819. Prcren susacurus, Lamarck. Anim. sans Vert., vol. vi, p. 181. 1836. _— — Ibid., ed. 2 (by Deshayes and Milne- Edwards), vol. vii, p. 158. 1847. — = A. d'Orbiqny. Pal. Frang. Terr. Crét., vol. ii, p. 605, pl. ceeexxxv, figs. 5—10. i= = Broneniarti, A, d’Archiac. Mém. Soc. géol. de France, ser. 2, vol. ii, p. 310, pl. xvi, fig. 4. 1850. - — H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 183. 1870. — susacurus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste Croix (Matér. Pal. Suisse, ser. 5), pp. 214, 218. 1872. — — HW. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx, pt. 1), p. 195, pl. xliv, fig. 5. 1877. a — A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol. xxxil, p. 501. 1896. _ -- -- and W. Hill. Ibid, vol. lui, p. 151. Description.—Shell ovate, pointed dorsally, much higher than long, nearly equi- lateral, convexity small. Apical angle about 80°. Right valve with about twenty-three strong ribs, which are straight or slightly curved, and haye usually sharp summits, but are sometimes rounded; the grooves separating the ribs are broad, with rounded or angular bases. Near the anterior and posterior margins the ribs are rather smaller; near the umbo they are often more rounded than elsewhere. Both ribs and grooves are crossed by numerous, fine, close-set, wavy, laminar ridges, which are more regular and distinct near the umbo than ventrally. The ribs usually bear along their summits many scaly knobs or short spines, which are often distributed at fairly regular intervals ; sometimes these scaly spies are absent over part or almost the entire shell. Anterior ear large, with a deep sinus ; growth-ridges well-marked, radial ribs indistinct. Posterior ear much smaller, triangular, with radial ribs. 170 CRETACEOUS LAMELLIBRANCHIA. Left valve a little more convex, with similar ornamentation; ears shehtly unequal. Measurements : (a) (2) (3) Leneth : 37 : 34 : 24 mm. Height : AY 43 Sie (1) Greensand, Haldon. (2,3) Chalk Marl (Bed 11), Dunscomhe. Affinities. —P. acuminatus, Geinitz,’ resembles closely this species, but seems to differ from it in having few or no scaly spines on the ribs, and also m having the concentric ornament somewhat coarser; the ribs, as a rule, are also less sharp and somewhat less numerous. The state of preservation of the spines in 1’. subacutus varies a good deal in different specimens; in some cases (as in fig. 8) they are absent from the greater part of the surface. It seems probable, therefore, that the comparison of good series of specimens might show P. aeuminatus and P. subacutus to be identical. The form from the Cambridge Greensand, referred to this species by Jukes- Browne, possesses the characteristic concentric ornamentation, but has rather more numerous ribs; only three specimens have been seen, and since they are rather imperfectly preserved, the determination of the species cannot be regarded as quite certain. T'ype.—From the Cenomanian of Le Mans. Distribution.—Cenomanian :—Bed 10 of Hooken, Beds 11 and 12 of Dunscombe, Bed 12 of Branscombe. Greensand of Haldon. ? Cambridge Greensand. Prcren (Cutamys) ELoNGATUS, Lamarck, 1819. Plate XXXI, figs. 10, 11 a,b, 12,6, 13; Plate XXXII, figs. Lazb; Pony 83 Gly 1819. Precren eLoneatus, Lamarck. Anim. sans Vert., vol. vi, p. 181. 1822. — osxiquus, J. de C. Sowerby. Min. Conch., vol. iv, p. 95, pl. ccelxx, fig. 2. 1 Geinitz, ‘Char. d. Schicht. u. Petref. des sichs-bohm. Kreidegel.,’ pt. 3 (1842), p, 84, pl. xxi, fiz. 6; Reuss, ‘Die Verstein. der bohm. Kreidvformat.,’ pt. 2 (1846), p. 29, pl. xxxix, figs. 20, 21; VArchiac, ‘Mém. Soe. géol. de France,’ ser. 2, vol. 11 (1847), p. 309, pl. xvi, fig. 8; Kunth, ‘Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xv (1863), p. 725; Michael, ibid., vol. xlv (1895), p. 285; Romer, ‘Geol. v. Oberschles.’ (1870), p. 833, pl. xxvi, fig. 3; Geinitz, “ Das Elbthalgeb. in Sachsen” (‘ Paleeonto- eraphica,’ vol. xx, pt. 1, 1872), p. 194, pl. xliii, fig. 16; pl. xliv, fig. 1; Fritsch, ‘ Bohm. Kreideformat. III. Iserschicht.’ (1883), p. 116, fig. 89; Notling, “ Die Fauna d. baltisch. Cenoman.” (‘ Palaeont. Abhandl., vol. ii, 1885), p. 19, pl. iii, fig. 2; Leonhard, “ Die Kreideformat. in Oberschles.” (‘ Palaonto- graphica,’ vol xliv, 1897), p. 26. 1825. 1833. ? 1847, 1850. 1853. PECTEN. 171 Pecten ELonaatus, Defrance. Dict. Sci. nat., vol. xxxviil, p. 265. cretosus, A. Goldfuss (non Defrance). Petref. Germ., vol. ii, p- 58, pl. xciv, fig. 2. ELONGATUS, Lamarck. Anim. sans Vert., ed. 2 (by G. D. Deshayes and H. M. Edwards), vol. vii, p. 158. crevrosus, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs. Kreidegeb., pt. 1, p. 22. crispus, F. A. Riimer. Die Verstein. d. nord-deutsch. Kreidegeb., p. ol. comans, Rimer. Tbid., p. 51, pl. viii, fig. 6. Fausast, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs.- bihm. Kreidegeb., pt. 3, p. 83. cCOMANS, Geinitz. Ibid., p. 83. rAuJAsI, H. B. Geinitz. Grundriss der Verstein., p. 468. crispus, A. #. Reuss. Die Verstein. der bbhm. Kreideformat., pt. 2, p. 30. ELONGATUS, A. d’Orbiqny. Pal. Franc. Terr. Cret., vol. ii, p. 607, pl. eceeexxxvi, figs. 1—4. Ravuuinranus, d’Orbigny. Ibid., p. 595, pl. ececxxxiii, figs. 6-9. ELONGATUS, d'Orbigny. Prodr. de Pal., vol. ii, p. 169. crispus, d’Orbigny. Ibid., p. 169. Ravurnianvs, d’Orbigny. Ibid., p. 139. gELonGcatusS, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 182. comaAns, Geinitz. Ibid., p. 180. Ravurnianus, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Genéve, p. 510, pl. xlvi, fig. 2. ELonGaATuS, J. Morris. Cat. Brit. Foss., ed. 2, p. 176. Marrorianus, Morris (non d’Orbigny). Tbid., p. 176. Ravuuintanus, Morris. Ibid., p. 177. opiiguus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mater. Pal. Suisse, ser. 5), p. 214. ELONGATUS, Pictet and Campiche. Ibid, pp. 214, 218. Rauintanus, Pictet and Campiche. Jhid., pp. 202, 213, pl. elxxii, figs. 5—7. ELonGatus, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palwonto- graphica, vol. xx, pt. 1), p. 195, pl. xliv, figs, 2—4. crispus, H. Deicke. Div 'Tourtia von Miilheim a. d. Ruhr, p. 26. Ravuprnianus?, A. J. Jukes-Browne. Quart. Journ. Geol. Soe., vol. xxxiii, p. 501, ELoNGATUS, C. Barrois. Ann. Soc. géol. du Nord, vol. vy, p. 318 (foot-note 4). ef. eLonGatuS, J. Kiesow. Schrift. der naturf. Gesellsch. in Danzig, vol. v, p. 415, fig. 11. Ravurnranus, W. Keeping. Foss., etc., Neoe. Upware and Brick- hill, p. LO4, 172 CRETACEOUS LAMELLIBRANCHIA. 2? 1885. Preren ELonGatus, Ff. Nitling. Die Fauna d. baltisch. Cenoman. (Palae- ont. Abhandl., vol. ii), p. 20, pl. in, fio. 6. 1887. — — A. Peron. Hist. du Terr. de Craie (Bull. Soe. Sci. hist. et nat. de ’Yonne, ser. 3, vol. xii), p- 163. 1893. _— = R. Michael. Zeitschr. d. deutsch. geol. Gesellsch , vol. xly, p. 235. 1895. os (Cutamys) ELonGATUS, FH. Tiessen. Ibid., vol. xlvii, p. 468. 1896. —_ pLonaatus, A. J. Jukes-Browne and W. Hill. Quart. Journ, Geol. Soe., vol. li, p. 151. 1900. = — Jukes-Browne. Cret. Rocks of Britain (Mem. Geol. Survey), vol. i, p. 451. Non 1833. —— — A. Goldfuss. Petref. Germ., vol. 1, p. 59, pl. xciv, Hee, Oe — 1844. = = F. M‘Coy. Carb, Limest. Foss. Ireland, p. 92, pl. xvi, fig. 9. — 1846. — comans, A. H. Reuss. Die Verstein. der bohm. Kreideformat., pt. 2, p. 29, pl. xxxix, fig. 13. 2. 18. ete., p. 441, pl. xvii, a — oBpLiquus, Reuss. Ibid., p. 29, pl. xxxix, fi —— heyy l. — mLoneatus, J. Phillips. Geol. Oxford, fio. 19. Description.—Shell ovate, pomted dorsally, higher than long, of little convexity, nearly equilateral. Ears rather large, very unequal. Apical angle from 78° to about 90°. Right valve flattened or shehtly convex, ornamented with numerous ribs, which are frequently grouped in triplets—a larger central rib with a smaller on each side—but sometimes occur in pairs or singly. The smaller ribs appear at varying distances from the umbo in different specimens. Each rib bears many lappet-like scaly projections placed transversely; these are sometimes close together and arranged very regularly, but may be more distant and somewhat irregular. In places fine growth-ridges are present. The grooves between the ribs are rather narrow and rounded. Narrow portions of the valves at the antero- and postero- dorsal margins are without ribs, but are covered by numerous fine grooves placed nearly perpendicularly to the plane of junction of the valves. Ears with radial ribs, which are often indistinct, and with well-marked growth-lines ; on the posterior ear strize (like those on the margin of the valve) are sometimes seen crossing the ribs ; anterior ear large with a deep sinus, posterior ear smaller, triangular. Left valve of moderate convexity with ornamentation similar to that of the right valve. Kars triangular, with many spiny ribs; the anterior larger than the posterior. ] PECTEN. 17: Measurements : (Ly (2) (8) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) Length . 43 41 37 33 20 35 56 60 56 40 38 285 13 36 50 60 35 55 mm. Height .53 51 47 41:5 25 44 65 73 66 50 49 34 17 47 58 74 45 65 (1—5) Gault, Folkestone. (9-13) Grey Chalk, Dover. (6) Upper Greensand, Warminster. (14) Chalk Marl, Ventnor. (7) s Ventnor. (15—17) Lower Chalk, Burwell. (8) Malmstone, Wilton. | (18) Totternhoe Stone, Arlesey. Affinities. —The examples from the Gault (usually named P. Raulinianus) have been regarded as distinct from those found in the Upper Greensand and Chalk (21’. elongatus); in the former the ribs usually appear to be more prominent owing to the longer and more pointed scales, and generally the triple arrangement of the ribs is not so well-marked as in the latter. The first difference is, I think, readily explained by the less perfect preservation of the spiny scales im specimens from the pervious beds of the Upper Greensand and Chalk ; the triple arrangement of the ribs varies considerably in different specimens of P. elougatus from the Chalk and Greensand, and some forms with less regular triplets seem to be quite inseparable from the examples found in the Gault; on the other hand, a few Gault specimens have the triplets well and regularly developed. Ma. Jukes-Browne and Dr. IF. L. Kitchin have examined carefully a number of specimens, and agree with me in considering that the differences between P. clongatus and P. Raulinianus are not of specifie value. P. Marrotianus, VOrbigny,' from the Upper Senomian of Dordogne, resembles P. elongatus, but is apparently distinguished by the ears bemg less unequal, and by the anterior left ear having fewer and more distinct ribs ; also the scales on the ribs of the valve are closer together and more numerous, and in the grooves between the triplets of ribs there are, in the adult, two small ribs. P. Faujasi, Defrance, from the 2B. mucronata Chalk of Maestricht, approaches very closely those forms of 1. elongatus which have the triple arrangement of the ribs well developed, but appears to differ in having fewer ribs. Remarks. The specimens figured as 2. Raulinianus by Pictet and Roux, and by Pictet and Campiche, seem to differ from the English forms in having fewer ribs; in this respect, however, the figures of those writers do not agree with their descriptions. But since Pictet and Campiche obtained specimens from Folkestone for comparison it is probable that their determination is correct. The example 1 «Pal. Frane. Terr. Crét.,’ vol. iii (1847), p. 612, pl. cecexxxviii, figs. 1—6. 2 Faujas-St.-Fond, ‘ Hist. Nat. de la Mont. de St. Pierre de Maestricht’ (1799), p. 153, pl. xxiv, fig. 5; Defrance, ‘ Dict. Sci. nat.,’ vol. xxxviii (1825), p. 265; Goldfuss, ‘Petref. Germ.,’ vol. 11 (1833), p. 57, pl. xciii, fig 7; ? Reuss, ‘ Verstein. bohm. Kreideformat.,’ pt. 2 (1846), p. 30; Schroder, ‘Ze'tschr. d. deutsch. geol. Gesellsch.,’ vol. xxxiv (1882), p. 265; Vogel, ‘ Verhandl. nat. Vereins d preussisch. Rheinl.,’ vol. xlix (1892), p. 59, and ‘ Hollandisch. Kreide’ (1895), p. 24, pl. i, fig. 22. 174 CRETACEOUS LAMELLIBRANCHIA. ficured as P. elongatus by @Orbigny appears to belong to another species. P. obliquus, Sowerby, is probably identical with P. elongatus ; the type, however, is missing, and the figures do not show the character of the ornamentation satis- factorily, but it is clear from the description that the ribs were in triplets and covered with numerous scales. This is a moderately common species in the Upper Greensand and Lower Chalk. In a specimen from the Chalk Marl of Ventnor (Pl. XXXI, fig. 12) the shell is proportionately higher, and has a smaller apical angle than usual ; it is near to the form figured by Geimitz (1872, pl. xliv, figs. 2, 3). Other specimens connect this high form with those of normal proportions. A few specimens from the Lower Greensand of Upware—now in the Woodwardian Museum, and in Mr. J. F. Walker’s collection, were referred by W. Keeping to P. Raulinianus ; their state of preservation is less satisfactory than that of Upper Cretaceous examples, but they approach closely some forms of P. elongatus from the Upper Greensand and Chalk, and are probably correctly referred to that species. Types.—The type of P. elongatus came from the Cenomanian of Le Mans. The type of P. obliquus from the Upper Greensand (? Devizes) cannot be found in the Sowerby collection. The types of P. Raulinianus came from the Albian of Grand Pré and Machéroménil (Meuse). Distribution—Gault of Folkestone (zones vill and xi of Price). Cambridge Greensand. Upper Greensand of Ventnor. Malmstone of Alton. Chloritic Marl of Maiden Bradley. Rye Hill Sand of Warminster. Chalk Marl of Ventnor, Folkestone, and Burwell. Totternhoe Stone (//. subglobosus zone) of Arlesey and &< Burwell. Lower Greensand of Upware (see ‘ Remarks” above). Precren (Cutamys) crerosus, Defrance, 1822. Plate XXXII, figs. 4 a—ua, 5 a,b, 6 a—c; Plate XXXITI. 1822. Prcren crerosus, Defrance. A. Brongniart. Descript. géol. Envir. de Paris (in Cuvier’s Ossem. foss., vol. 11), pp. 251, 598, pl. in, fig. 7. — — aracunorpes, Defrance. Brongniart. Tbid., pp. 251, 599, pl. i, fie. 8. — — witipa, G. Mantell. Foss. S. Downs, p. 202, pl. xxvi, figs. 4, 9 (? fig. 1). 1823. — nitipus, J. de C. Sowerby. Min. Conch., vol. iv, p. 120, pl. ecexeiv, home 1825. — cretosus, Defrance. Dict. Sci. nat., vol. xxxviii, p. 267. — — ARACHNOIDES, De/rance. Ibid., p. 266. “a5 1841. 1845. ISk6. 1847. 1848. 1850. 1869. 1870. PECTEN. 175 Pecren nivipus, F. A. Rimer. Die Verstein. nord-deutsch. Kreideg: b., p- 52. unpuLatus, A. d’Orbigny. In Murchison, de-~Verneuil, and de Keyserling’s Géol. Russ. d’ Europe, vol. ii, p. 490, pl. xliii, figs. 8—10. nitipus, A. EH. Reuss. Die Verstein. der bihm. Kreideformat., pt. 2, p. 28. cretosus, A. d’Orbigny. Pal. Frane. Terr. Crét., vol. iii, p. 617, pl. cecexl, figs. 1—7. nitipus, H. G. Bronn. Index Palwont., vol. i, p. 927. crerosus, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 182. A. dOrbigny. Prodr. de Pal., vol. ii, p 251. niripus, A. @Orbigny. Ubid., p. 252. Zvisnert, A. Alth. Geog.-pal. Beschreib. der niichst. Umgeb. von Lemberg (Haidinger’s Naturwiss. Abhandl., vol. 11, pt. 11), p. 249, pl. xii, fig. 36. Ancuatus, Alth (non Sowerby). Ibid., p. 245, pl. xii, fig. 29. suBINtERSTRIATUS, HF, Divon (non d’ Archiac). Geol. Sussex, p. 356, pl. xxviu, fig. 19. nitipus, J. Morris. Cat. Brit. Foss., ed. 2, p. 176. crerosus, Morris. Ibid., p. 176. — K. A. Zittel. Die Biv. der Gosaugeb. (Deukschr. d. k. Akad. Wissensch. Math.-nat. Classe, vol. xxv), p. 112 (56 of reprint), pl. xviii, fig. 2. AZvisnert, 2. Favre. Moll. Foss. de Lemberg, p. 146, pl. xiii, fig. 2. crevosus, F. Rimer. Geol. Oberschles., p. 316, pl. xxxvii, fig. 6. — I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), pp. 215, 218. _ PF’. Stoliczka. Palwont. Indica, Cret. Fauna 8. India, vol. i, p. 428. niripus, Stoliczka. Vbid., p. 428. crerosus, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx, pt. ii), p. 34, pl. x, figs. 5, 6. ~- I. Schréder. Geitschr. d. deutsch. geol. Gesellsch., vol. XxXxiv, p. 265. var. nitipa, Schrider. bid., p. 266. 1887. 1889. —- A. Peron. WHist. Terr. de Craie (Bull. Soc. Sci. hist. et nat. de l’Yonne, ser. 3, vol. xii), p. 164. — O. Griepenkerl. Senon. von Konigslutter (Pala2ont. Ab- handl., vol. iv), p. 41 (not the synonymy). — A. Fritsch. Stud. im Gebiete der béhm. Kreideformat. : IV, Die Teplitz. Schicht., p. 85. (Cunamys) crerosus, HL. Stolley. Die Kreide Schleswig-Holsteins (Mitth. Min. Inst. Kiel, vol. i), p. 2389. crerosus, R. Leonhard. Wreideformat. in Oberschles. (Paleonto- graphica, vol. xliv), p. 45. 176 CRETACEOUS LAMELLIBRANCHIA. ? 1897. PrcrEen creETosvs, var. nrTIpA, A. Hennig. Revis. af Lamell. i Nilsson’s ‘ Petrif. Suecana’ (Kon. Fysiogr. Siillsk. i Lund. Handl., N. F., vol. viii), p. 49. 1898. ~- — G. Miller. Mollusk. d. Untersenon v. Braunschweig, ete. (Abhand. d. k. preussisch. geol. Lande- sanst., N. F., Heft 25), p. 31, pl. v, fig. 1. 1900. -- —- var. ZEISNERI, C. Gagel and F. Kaunhowen. Jahrb. d. k. preussisch. geol. Landesanst. u. Bergak. fiir 1899, p. 229. A, Wollemann. Die Fauna Senons von Biewende (abid., 1900), p. 16. 1902. — -- J. P. J. Ravn. Mollusk. i Danmarks Kridtafl. — I. Lamellibr. (KK. Danske Vid. Skrift. 6 Raekke, nat. math. Afd., vol. xi), p. 88, pl. 1, figs. 11, 18. = SK == var. NitIpA, Ravn. Ibid., p. 88, pl. 1, figs. 12, 18, 21. 5 Non 1833. == —= A. Goldfuss. Petref. Germ., vol. ii, p. 58, pl. xeiv, fig. 2 ( = ecrispus, Romer, and elongatus, Lamarck). Description. —Shell thin, ovate, higher than long, shehtly inequilateral, rounded ventrally, antero-dorsal margin shehtly concave, postero-dorsal marein straight or slightly convex. Valves of sheht convexity. Apical angle varying from 90° to 105°. Kars moderately large, unequal. Right valve flattened or shehtly convex, with numerous narrow ribs which may be very slender or moderately strong; the imterspaces are sometimes broader than the ribs, but narrower when the ribs are more numerous. In the interspaces are numerous regularly placed, linear, concentric ridges, which may be confined to the neighbourhood of the umbo, or may cover a larger part, or even the entire surface of the valve; these ridges are usually closer together ventrally than near the umbo. At some distance from the umbo, in a few or in many of the inter- spaces, new ribs appear, and sometimes remain throughout smaller than the primary ribs, but in other cases rapidly become of the same size as the primaries. Near the antero- and postero-dorsal edges of the valve the radial ribs are absent, and numerous fine striz are placed nearly perpendicular to the edge. The ribs bear numerous spiny processes, which are usually scale-lke and placed transversely, but may be more pointed or rounded and nodular; these processes may occur over the entire surface or be confined to parts, and they vary in size on different specimens. Anterior ear long, with a deep sinus; dorsal portion smooth, but between that and the sinus are from three to five spiny ribs, which are usually rather indistinct. Posterior ear smaller, triangular, with the outer angle slightly obtuse ; with seven or eight radial mbs bearing scaly or nodular processes, and sometimes crossed by concentric ridges. PECTEN. 177 Left valve rather more convex than the right, and with similar ornamentation, but the ribs usually rather stronger, and sometimes more numerous; the concentric ridges are often less distinct, except near the umbo; ventrally, they are often placed very close together. Anterior ear with the outer edge convex, and eight to eleven radial ribs which are slightly spiny; the dorsal margin without ribs. Posterior ear smaller, with the outer angle obtuse, and with eight or nine ribs which are shghtly spiny. Measurements : M. cor-anguinum Marsupites zone. zone. A. quadratus zone. B. mucronata zone. (1) (2) (3) (4) (5) (6) (7) (8). (9) (10) (11) (12) (13) (14) (15) (16) (17) (18) (19) (20) (21) (22) (23) (24) (25) Length 31 32 34 28...27 36... 24 2727-5 32 33:5 35 38 41 42 43 49...23 24 25 25 28 36 37 41mm. Height 38 37 38 33... 285 42... 28 3233 3639 40 42 47 48 48 55...27 28 30 31 33 42 44 48 (1) M. cor-anguinum zone, Porton, Salisbury. (2, 3) a3 » Gravesend. (4) o Fr Northfleet. (5, 6) Marsupites zone, Witherington, Salisbury. (7-17) A. quadratus zone, East Harnham, Salisbury. (18—25) B. mucronata zone, Norwich. Remaris.——This species varies greatly in the details of its ornamentation, and to some extent also in the proportions of height and length. ‘The number, close- ness, and strength of the ribs differ considerably ; near the ventral margin of the valves they may be of equal size, or alternately large and small, owing to the later ribs still remaining smaller than the earlier ones. When the ribs are relatively few in number the flat interspaces are broader than the ribs, as in the form named P. arachnoides, Defrance; when the ribs are more numerous the interspaces are narrower than the ribs. For a short distance ventrally to a strong growth-line the ribs are sometimes deflected to one side. The narrow concentric ridges are usually distinct near the umbo, and may be absent or indistinct on the rest of the shell, or they may extend to varying distances from the umbo, and in some cases cover the entire shell. Usually the concentric ridges are well-spaced near the umbo, and become closer together ventrally, but sometimes they are equally distant all over the shell, or even become more widely separated ventrally. Spimes are usually present near the umbo, and may be absent from all the rest of the shell, or may recur at the ventral border only; often they extend to about one-third of the distance from the umbo, or even cover the entire surface. In some cases alternat- ing spiny and smooth concentric bands occur, the change taking place at well- marked growth-lines, ¢. g. spines near the umbo, in the middle of the valve and at the ventral border, separated by two smooth bands. In other cases the spines may be absent from the greater part of the valve. The “spies” vary in form, being usually scaly, but sometimes more pointed or nodular ; in some cases they are 99 =v 178 CRETACEOUS LAMELLIBRANCHIA. rather irregularly developed, but in others they are placed at yery regular intervals, and are of very uniform size. The differences in the spies are in some cases connected with the state of preservation of the specimens. Nothing less than a large series of micro-photographs would illustrate adequately all the differences im the ornamentation of this species. A few large specimens (length 67 mm., height 72 mm ), from the Bb. mucronata zone of Norwich, appear at first sight to differ greatly from this species, on account of the greater part of the valves being nearly smooth, or marked with linear radial grooves separating flat mterspaces; these forms agree perfectly im outline and in the form of the ears with some of the large examples of P. cretosus, and I believe they are only large and much-worn examples of that species, since the characteristic ornamentation sometimes occurs in the neighbourhood of the umbo for a distance of about 10 mm. (Norwich Museum, No. 2189), or, in other cases, just below well-marked growth-lines near the ventral border of the valve, where the shell has undergone less wearing (Norwich Museum, No. 2188). In this variable species the extremes differ to such an extent im their orna- mentation that, when considered separately, they appear as distinct species, but on examining a large series of specimens! a complete gradation is found to exist between the different forms, which we must therefore regard as merely modifications of one species.” The different forms, moreoyer, are not confined to one horizon or one locality, and it seems therefore hardly necessary to give them distinct names ; but from the same zone and the same spot (¢. g. Hast Harnham and Norwich) extreme forms and connecting links may sometimes be found. Moreover, in some cases two types of ornamentation appear on different parts of the same shell. The form with numerous strong ribs agrees with the type of P. cretosus, Defrance. 1’. arachnoides, of the same author, is the variety with relatively few and narrow ribs, with the spines poorly developed, and with regularly-placed concentric ridges. A variety with very slender and numerous ribs (found at Trimingham, ete.) agrees with the example figured as 1’. undulatus by Holzapfel. Another form with numerous well-developed, regularly placed, spiny scales on the fairly numerous radial ribs approaches P. serratus. It is very difficult to decide which of the two names, crelosus or nitidus, has the priority, since the exact dates of publication of the works of Cuvier and Mantell cannot be determined at present. Mantell’s preface is dated May Ist, 1822, and the work was received by the Geological Society before the end of June of that year. Mr. C. D. Sherborn informs me that the work of Cuvier was noticed as ' T have had the opportunity of studying over 200 examples. * Dr. Blackmore, who has made a very large collection of P. cretosus, has independently come to the same conclusion—that all are forms of one species. PECTEN. 179 published in the * Bibliographie dela France’ for June 8th, 1822, and he is inclined to think that it appeared somewhat earlier than Mantell’s book. Affinities. —P. undulatus, Nilsson,’ and I. serratus, Nilsson, are very closely allied to P. eretosus, but the examination of a large series of specimens could alone enable us to determine their exact relationships. Types.—The types of P. nitidus (from Lewes and Brighton) cannot be found, but the specimen from Gravesend figured by Sowerby is in the British Museum. The types of P. eretosus and P. arachnoides came from the Upper Senonian of Meudon. [have not seen the types, but specimens from the same locality are in the Wiltshire Collection, and another has been sent to me by M. A. de Grossouvre. Distribution.—R. Cuvieri zone of Dover. T. gracilis zone of the Dorset coast and Dover. HH. planus zone of the Sussex coast and Dover. M. cor-testudinariwm zone of the Sussex coast, Dover, Purley, and Hitchin. M. cor-anguinum zone of the Dorset coast, Winchester, Porton (Salisbury), the Sussex coast, St. Margaret’s, Thanet, Northfleet, Purley, Haling Pit (South Croydon), Bromley. Marsupites zone of the Dorset coast, Winchester, Witherington, the Sussex coast, and Thanet. A. quadratus zone of the Dorset coast, Winchester, East Harnham (Salisbury), and the Sussex coast. LB. mucronata zone of the Dorset coast, Clarendon and Alderbury (Salisbury), and Norwich. Chalk of Trimmgham. Proven (Cunamys) Manreniianus, @’Orbigny, 1847. Plate XXXIV, figs. 1 a,b, 9 » 7 J 2, 5a—c, 4—6. 1833. Prcren concentricus, S. Woodward. Geol. Norfolk, p. 48, pl. v, figs. 27, 28. 1847. — Manreviuianus, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 619, pl. cecexl, figs. 8—11. 1850. — ~ — Prodr. de Pal., vol. i, p- 251. 1854. — concentricus, J. Morris. Cat. Brit. Foss., ed. 2, p. 176. 1870. — Manvreuuianus, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 215. 1 * Petrif. Suecana’ (1827), p. 21, pl. ix, fig. 10 ; Holzapfel, “‘ Mollusk. Aachen. Kvreide” (‘ Palaon- tographica,’ vol. xxxv, 1889), p. 235, pl. xxvi, figs. 1, 2; Hennig, Revision af Lamell. i Nilsson's ‘ Petrif. Suecana’ (1897), p. 48, pl. iii, figs. 9—11; Strombeck, ‘ Zeitschr. d. deutsch. geol. Gesellsch..,’ vol. xv (1863), p. 154; Schroder, ibid., vol. xxxiv (1882), p. 266. > Op. cit. (1827), p. 20, pl. ix, fig. 9; Holzapfel, op. cit. (1889), p. 236, pl. xxvi, fig. 16; Hennig, op. cit. (1897), p. 50, pl. iii, fig. 15; Stolley, ‘Die Kreide Schleswig-Holsteins’ (1892), p. 288; Ravn, ‘Mollusk. i Danmarks Kridtafl.’ (1902), p. 89. 180 CRETACEOUS LAMELLIBRANCHIA. 1871. Prcren Manrenianus (= concenrricus), Ff. Stoliczka. Paleont. Indica, Cret. Fauna 8. India, vol. 11, p. 428. 1879. “— cf. concentricus, C. Barrois. Ann. Soc. géol. du Nord, vol. vi, p. 452, pl. xu, fig. 4. 1889. — Manrexut, 2. Holzapfel. Die Mollusk. Aachen. Kreide (Palaonto- eraphica, vol. xxxv), p. 235, pl. xxvi, fig. 6. 1892. — (Cuiamys) Manrennranus, EH. Stolley. Die Kreide Schleswig- Holsteins (Mittheil. Min. Inst. Kiel, vel. i), p. 287. Non 1822. — concentricus, 7. Say. Journ. Acad. Nat. Sci. Philadelphia, vol. li, pt. 2, p. 259. — 1825. — — Defrance. Dict. Sci, nat., vol. xxxviui, p. 253. — 1887. -- — F.C. L. Koch and W. Dunker. Beitr nord-deutsch. Oolithgeb., p. 43, pl. v, fig. 8. Description.—Shell rather small, thin, ovate, dorsal third pointed ; inequilateral, higher than long; postero-dorsal margin straight or shghtly convex, and longer than the antero-dorsal, which is straight or shghtly concave. Apical angle from 86° to 90°. Ears moderately large, rather high, unequal. Right valve flat, with several (usually from three to five) strong growth-ridges separated by considerable intervals, and fine radial and concentric ornament, which is often indistinct or absent on the later parts of the valve. Radial ornament con- sists of about eleven very slightly elevated ridges or folds, which become indistinct ventrally; on the summits of the ridges there are usually two fine linear ribs, and others (two or three) of the same kind in the shallow furrows; near the anterior and posterior margins the radial ridges are replaced by ribs. Concentric ornament consists of fine, close-set, regular, linear ridges, which bear minute pointed granules where they cross the radial ribs. Anterior ear considerably larger than the posterior, and shghtly produced dorsally, with a distinct, but not deep, sinus ; surface with growth-lines, which become sinuous near the valve—above the sinuous part there are faintly marked radial ribs. Posterior ear with an outer angle of about 90°, and with well-marked growth-lines. Left valve convex, with several strong growth-ridges at intervals. Ornamenta- tion consists of seventeen or eighteen main ribs, which are narrow and but little raised ; they are separated by broad, very shallow furrows. In the middle of each furrow is a similar but smaller rib, which, near the ventral border, sometimes be- comes almost as large as the main rib. At some distance from the umbo other smaller linear ribs (two to five) are introduced. In some cases all the radial ribs become indistinct near the ventral border, where the shell is then smooth, except for concentric ornament. The concentric ornament consists of regularly-placed, fine, linear ribs, which are more widely spaced near the umbo than elsewhere, and form PECTEN. 181 a pointed granule where they cross the radial ribs; near the ventral border the ribs are often very closely placed. Ears triangular, with a few growth-lines; the anterior with granular ribs and nearly rectangular outer angle, the posterior smaller and with obtuse outer angle. Measurements : (1) (2) (3) (4) (5) (6) (7) (8) Length « 39 :; 38 . 33.5... 32 . 30 .. 28 . 26 |..20 mm. Height . 45 . 44 . 37 . 35 . 35 . 31 . 81 . 28 (1—8) B. mucronata zone, near Norwich. 39 Affinities—In form, and in the possession of similar radial and concentric ornamentation, this species resembles some of the varieties of P. eretosus, but is easily distinguishable by the stronger radial ridges, ete. Remarks.—The differences in the appearance of the ornamentation in this species seem to depend mainly on the state of preservation; in some cases the right valve is almost smooth. Frequently in the larger specimens the later part of the valve is almost without ornament. By far the larger number of specimens which I have seen were obtained from the neighbourhood of Norwich, where it is a characteristic fossil. Type.—Vhe type of P. concentricus, Woodward, came from the Chalk of Norwich, but cannot now be found. ‘The types of P. Mautellianus, @Orbigny, came from the Senonian of Chavot (Marne). Distribution —M. cor-anguinum zone of South Croydon (Haling Pit). B. mucronata zone of Clarendon (near Salisbury), of Hartford Bridge and various other localities near Norwich. Upper Chalk of Sussex. Peormn (Cutamys) Ropinanpinus, @Orbigny, 1847. Plate XXXIV, figs. 7 a,b, 8 a,b, 9 a,b, 10 a,h, hil 12 a—c; Plate XXXV, fics, 1—TL0! co) 1842. Pecoren wvrersrriatus, A. Leymeric. Mém. Soc. géol. de France, vol. vy, p- 10, pl. xiii, fig. 1 (non inter- striatus, Minster). 1845. -— oBLiguus, EF. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 249 (non obliquus, Sowerby ). 1847. — Rosrnarpinus, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p- 587, pl. cecexxxi, figs. 1—4. yo — intersrriatus, d’Orbigny. Tbid., p. 594, pl. eccexxniii, figs. 1—5. 1850. — apriensis, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 119. 182 CRETACEOUS LAMELLIBRANCHIA. 1852. Prcten aptrensis, Ff. J. Pictet and W. Rouz. Moll. Foss. Gres verts de Genéve, p. 511, pl. xvi, fig. 3. 1854. — INTERSTRIATUS, J. Morris. Cat. Brit. Foss., ed. 2, p. 176. ? 1861. — Rosrinatpinus, P. de Loriol. Anim. Invert. Foss. Mt. Saléve, p: LOM ppl isan fics. Oh 0: — = Barrerti, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii, p- 118, pl. vi, fig. 1. ? 1869. — LOBINALDINUS, P. de Loriol and V. Gilliéron. Urgon. Inf. de Landeron (Mém. Soc. helvét. Sei. nat., vol. xxiii), p. 22. 1870. — —— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matcr. Pal. Suisse, ser. 5), p. 188, pl. elxx, figs 1—5. 1877. — apriensis, A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxiu, p. 500. — = Barrer, Jukes-Browne. Ibid., p. 500. ? 1883. — Dvremeret, W. Keeping. Foss., etc., Neoc. Upware and Brickhill, p. 105. 1884. — Roptnaupinus, 0. Weerth. Die Fauna des Neocom. im Teutoburg. Walde (Palaeont. Abhandl., vol. ii), p. 53. 1895. <= — G. Maas. Zeitschr. d. deutsch. geol. Gesellsci., vol. xlvii, p. 269. 1896. = — A. Wollemann. Ibid., vol. xlviii, p. 840. — — GALLIENNEI, PAssyt, et SUBINTERSTRIATUS, A.J. Jukes-Browne and W. Hill. Quart. Journ. Geol. Soe., vol. lu, p. 150. 1900. — Rosinaxpinus, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hollind, Neocoms (Abhandl. d. k. preussisch. geol. Land., N. F., pt. 31), p. 47. r 1900. — cf. Roprnanpinus, G. Miller. Ji W. Bornhardt, Zur Oberflachen u. Geol. Deutsch-Afrikas (Deutsch - Ost-Afrika, vol. vii), p. 551. Description—Shell ovoid, pointed dorsally, higher than long, shghtly imequi- lateral, of moderate convexity. Apical angle from 80° to 85°. Ears rather large, unequal. Right valve ornamented with numerous narrow, slightly raised ribs, which are sometimes wavy, and are separated by flattened spaces, often of greater width than the ribs. The ribs bear numerous small, scaly spines, which are placed transversely and are generally close together, but sometimes more widely and regularly sepa- rated. Spaces between the ribs covered by numerous striz, which in the middle of the valye are more or less parallel with the ribs, but become more and more oblique in passing towards the anterior and posterior borders. Anterior ear large, with a large sinus, well-marked growth-lines, and fait radial ribs. Posterior ear PECTEN. 183 much smaller, triangular, outer angle obtuse, marked with radial striz lke those on the valve. Left valve rather more convex, ornamented with similar but fewer ribs, bearing scaly spines which are often placed at fairly regular intervals. Interspaces with striz as on the right valve. Ribs generally of nearly uniform size; but im some sases smaller ribs are intercalated at some distance from the umbo, so that alternat- ing larger and smaller ribs are clearly seen. Narrow concentric ridges, placed at regular intervals, are sometimes present near the umbo. Anterior ear large, with a few radial ribs—usually near the valve only, leaving the upper part smooth; ribs crossed by oblique striz. Posterior ear small, with outer angle obtuse, and marked with striz. Remarks.—This species varies greatly ; the number of ribs on the left valve ranges from 35 to 57, and consequently the width of the interspaces also varies. Sometimes smaller ribs are intercalated between some of the others. The spines on the ribs may be close together and numerous, or fewer and more widely sepa- rated, and sometimes they have a fairly distinct concentric arrangement ; im some rases the ribs on part of a valve, or on almost the entire surface, are without spines. Such smooth or nearly smooth forms occur in the Hythe Beds of Hythe, the Chloritic Marl of Maiden Bradley, the Rye Hill Sand of Warminster, the Cenomanian (Bed 12) of Beer Head, ete. The sharpness of the spines varies in different specimens, and is partly dependent on the nature of the enclosing rock. Some examples from Faringdon and also some from the Upper Greensand (Pl. XXXV, fig. 3) have ribs over the whole of the anterior left ear, and the ribs on the valve are numerous with the spines irregularly placed; I have not sufficient specimens to determine whether these are distinct from the other forms, or merely a variety. Some forms (Pl. XXXYV, fig. 1) with few and strong ribs, and well-developed scales, also appear at first sight to be distinct, but it is difficult to draw a line between them and the normal form.’ A much larger series of specimens is required to determine whether these forms are really distinct, or merely varieties. Mr. Jukes-Browne now agrees with me in regarding the forms which he named ' A form similar to this, but having more numerous ribs and with the spines usually more pointed and erect, obtained from the Cenomanian Sandstone of Wilmington, ete. (Pl. XXXV, fig. 10) has been referred by Jukes-Browne to P. hispidus, Goldfuss. The state of preservation of the specimens is not sufficiently good to enable me to decide as to their affinities, but Iam inclined to regard them as constituting only a variety of P. Robinaldinus. In some examples of the latter the spines are almost, if not quite, as large as in the former. hey agree better with the figures of Geinitz than of Goldfuss, but the ribbing appears to vary considerably. Goldfuss, * Petref. Germ.,’ vol. ii (1833), p. 59, pl. xciv, fig. 4; Pictet and Campiche, ‘Foss. Terr. Crét. Ste. Croix’ (1870), p. 215; Geinitz, ‘Das Elbthalgeb. in Sachsen’ (‘ Paleontographica,’ vol. xx, pt. 1, 1872), p. 197, pl. xliv, figs. 9, 10; Jukes-Browne, ‘ Cret, Rocks of Britain” vol, 1 (1900), p. 452. 184 CRETACEOUS LAMELLIBRANCHIA. (in 1897, see synonymy) Gallienne?, Passyi, and subinterstriatus as identical with P. Robinaldinus. The larger number of the specimens seen were obtained from the Perna-bed of Atherfield, the Rye Hill Sand of Warminster, the Chloritic Marl of Maiden Bradley, and the Cenomanian of the Devon coast. Affinities —This species is closely related to (and probably identical with) several forms described by @Orbigny, d’Archiac, ete. Pecten Passyi, @ Archiac,'’ from the Tourtia (Cenomanian) of Tournay, varies considerably, but is perhaps distinguished from P. Robinaldinus by the smaller intercalated ribs being more numerous and more distinct; in some cases (as in the type specimen) spines are absent from most of the ribs, but in other examples from Tournay, which I have seen, they are as numerous as in most specimens of P. Robinaldinus. P. subinterstriatus, @ Archiac,’ from the same horizon, appears to differ only in having very numerous ribs. P. Dutemplei, VOrbigny,? from the Gault, seems to be indistinguishable from P. Robinaldinus, except perhaps (as suggested by Pictet and Campiche) by the occurrence in P. Dutemplei of about fifteen ribs distributed over the whole surface of the anterior left ear, whereas (according to the same writers) in P. Robinaldinus seven or eight ribs only occur, and are confined to the lower part of the ear. But it 1s doubtful whether these characters are constant: im Leymerie’s figure the ribs seem to be distributed over the whole ear; while in d’Orbigny’s figure of P. Robinal- dinus the ribs, although only six in number, are also distributed over the entire ear. P. Galliennei, VOrbigny,* is probably only a variety with rather fewer ribs on the valve, and with four or five ribs distributed over the anterior left ear. It is recorded by Pictet and Campiche from the Upper Greensand of Ventnor. P. rhotomagenis, VOrbigny,’ from the Cenomanian of Rouen, is another similar form with numerous ribs. P. Oosteri, de Loriol,’ is likewise closely related to P. Robinaldinus. The form figured by @’Orbigny as P. interstriatus, Leymerie, 1s probably only a variety, but it possesses fewer ribs than any English form which I have seen. It approaches, however, some examples found in the Upper Greensand. The name aptiensis was proposed by @Orbigny (1850) for the interstriatus of 1 .) 109 cam. Hohtueemol me oo; 1 LOLs 1060 9dr. NOD sg (1, 2) Chalk Marl, Folkestone. (3) Pp ». Meldreth. (4, 5) Totternhoe Stone, Burwell. (6) H. subglobosus zone, Cherry Hinton. Affinities. —I?. depressus, Goldfuss, seems to be scarcely distinguishable from l’. Beaveri. The specimen figured by Goldfuss as 2. Beaver does not show the 190 CRETACEOUS LAMELLIBRANCHIA. small ribs on the sides of the main ribs, and may perhaps be distinct, but this can be determined only by an examination of specimens. T'ypes.—The type was obtained from Lower Chalk of Childrey, near Wantage, and is said to be in the Oxford Museum. The type of P. jugosus is missing, and the locality from which it was obtained is not given by Sowerby. Mantell’s figured specimen, from the Chalk Marl of Hamsey, also appears to have been lost. Distribution.—Upper Gault (zone x) of Folkestone. Red Limestone of Hunstanton (fide Survey Memoirs). Chloritic Marl of Blackgang and Niton. Chalk Marl of Ventnor, Folkestone, Meldreth, Hunstanton, Stoke Ferry, ete. Totternhoe Stone of Cherry Hinton, Burwell, Dersingham, and Hunstanton. H. subglobosus zone of Blue Bell Hill (Burham), Shelford, and Cherry Hinton. Precren (AMQUIPECTEN) PEXATUS, Sp. nov. Plate XXXVI, figs. 5 a,b, 6, 7 a,b. 2? 1850. Proren Dusarprnt, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 356, pl. xxviii, fig. 4 (? locality). 1897. Curamys rernata, H. Woods. Quart. Journ. Geol. Soc., vol. li, p. 382 (not the synonymy). Description.—Shell small, ovate or nearly circular, pointed dorsally, equi- lateral, and almost equivalve; of slight convexity. Length usually a little less than height. Apical angle about 104°. Kars fairly large. Both valves have radial folds, of slight elevation, and usually eleven in number. The entire surface is ornamented with numerous narrow, elevated, and sharply limited ribs, which are placed regularly, are of shghtly unequal size, and bear many short, hollow spines, which are generally directed ventrally, but are sometimes nearly perpendicular. At the summit of each fold is a rib rather larger than the others, and bearing longer spines; other ribs occur on the sides of the folds, and are introduced at different distances from the umbo, the latest rib bemg the smallest. On each side of a fold, near the margin of the valve, there are generally three, but sometimes more ribs. Ears slightly unequal, ornamented with four or more radial spiny ribs, and with a row of spines at the dorsal edge ; byssal sinus moderately deep. Measurements : (1) (2) (3) (4) Length s DA : 20, : 16:0 , 11:0 mm. Height : 25 : 20°5 : 16°75 ; ile gn (1, 3) H. planus zone, Cheveley. (2) Upper Chalk, near Salisbury. (4) A. quadratus zone, Kast Harnham. PECTEN. 19] Affinities.—This species resembles P. asper (see p. 186), but is much smaller, less convex, with fewer folds (or main ribs), and, in specimens of the same size, with more numerous and more closely placed ribs. When describing the Mollusca of the Chalk Rock (1897), I referred this species to P. ternatus, Goldfuss, which was founded on a cast from the Quader Sandstone of Schandau (Saxony), and appears to be the form usually known as 2. Dujardini. On further examination this determination did not seem altogether satisfactory, and I have recently, through the kindness of M. Raoul Fortin and M. A. de Grossouvre, received specimens of P. Dujardini from France; Professor Deich- miller has also sent me casts of Geinitz’ figured specimens. I am now able to say that P. Dujardini differs from P. pevatus in haying much stronger and more distinctly separated folds, with less distinct ribs and spines, and in having closely- placed concentric lamellz; in specimens larger than those figured by d’Orbigny the ventral margins of the valves are sharply bent. ‘Two of the specimens figured by Geinitz' (figs. 10, 11) may belong to P. pevatus, but they show the interior of the valves only. P. Dujardini appears to be more nearly related to P. septem- plicatus, Nilsson, than to P. pevatus. Distribution.—Zone of T. gracilis of Hooken (Devon). Zone of H. planus of Cheveley (Newmarket). Chalk Rock of Winchester and Clothall (Baldock). Uintacrinus zone of Devizes Road (Salisbury). Zone of A. quadratus of Kast Harnham. Zone of 2. mucronata of Clarendon (Salisbury), and of Shute-end Pit, Alderbury. Prcren (ANQUIPECTEN), sp. Plate XXXVI, figs. 8 a,b. Description.—Shell small, flattened, ornamented with from ten to thirteen narrow, elevated ribs, which are separated by broad, flat interspaces. Ribs with hollow, curving spines, placed at regular and fairly distant intervals. Remarks.—This form, of which I have seen three specimens only, appears to be distinguished from P. asellus, Sowerby,’ by the spines on the ribs. It differs from P. rarispinus, Reuss,* in the absence of radial folds. Distribution —Chalk Rock of Winchester. A. quadratus zone of East Harnham (Salisbury) and near Winchester. 1 «Das Elbthalgeb. in Sachsen’ (1872), pt. 2, pl. x, figs. 10, 11. * J. de C. Sowerby, in F. Dixon, ‘ Geol. Sussex’ (1850), p. 348 (p. 683, ed. 2), pl. xxviii, fig. 5. The locality and horizon of P. asellus are not given by Dixon, and the type cannot now be found. I have seen no example which could be referred to this species. 3 «Die Verstein. der bohm. Kreideformat.’ (1846), pt. 2, p. 31, pl. xxxix, fig. 15; Geinitz, “ Das Elbthalgeb. in Sachsen” (‘ Palasontographica,’ 1872, vol, xx, pt. 2), p. 36, pl. x, fig. 13. 192 CRETACEOUS LAMELLIBRANCHIA. PEcTEN (AVQUIPECTEN) SARUMENSIS, sp. nov. Plate XXXVII, figs. 1, 24,0, 3. Deseription—Shell small, shehtly inequilateral, height and length nearly equal, outline rounded, convexity small. Apical angle 107° to 111°. Ears rather large. Right valve ornamented with very numerous (fifty to sixty) narrow, well- marked, radial ribs, which are separated by deep, narrow grooves. The ribs are often slightly unequal, sometimes alternately, the smaller ribs beimg imtroduced later than the larger. The ribs bear numerous small, similar, spiny scales, placed either vertically or sloping, and sometimes having a roughly concentric arrangement ; near the umbo concentric lamelle occur. Postero-dorsal margin with fine oblique strie. Anterior ear long, with a deep sinus and four radial ribs with spines. Posterior ear much shorter, with three or four radial, spiny ribs. Left valve not seen. Measurements : (1) (2) (3) (4) Leneth ; 8°5 : 70 . 6 d 5°25 mm. Height : 8:0 ; 6275 ’ 6 y 5:0 e (1—4) A. quadratus zone, East Harnham, Salisbury. Affinities —In form this species resembles P. campaniensis, but is easily distinguished by the much larger number of ribs. The ornamentation resembles that of P. pewatus, but the shell is without radial folds, the ribs are fewer, and the apical angle larger. Radial folds occur on even the smallest specimens of P. pexatus. Types.—In Dr. Blackmore’s collection. Distribution.—A. quadratus zone of East Harnham (Salisbury). B. mucronata zone of Clarendon (Salisbury). PEcTEN (AEQUIPECTEN) CAMPANIENSIS, @’ Orbigny, 1847. Plate XX XVII, figs. 4—8. 1847. Proren cAmpantrensis, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. i, p. 620, pl. ccecexl, figs. 12—16. 1850. — = — Prodr. de Pal., vol. ii, p. 251. 1870. — — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 215. 1887. oo _- A. Peron. Hist. Terr. Craie 8.E. du Bassin Anglo- Parisien (Bull. Soe. Sci. hist. et nat. de l’Yonne, ser. 3, vol. xii), p. 163. 1889, — -= O. Griepenkerl. Senon von Kénigslutter (Palaeont. Abhandl., vol. iv), p. 44. PECTEN. 193 Description.—Shell small, nearly equilateral, nearly circular, length equal to, or slightly greater than the height. Antero- and postero-dorsal margins straightened. Convexity small. Apical angle about 106°. Ears moderately large, unequal. Right valve with about twenty-four strong, rounded ribs at the margin, some of which may be formed by bifurcation at some distance from the umbo. The ribs may be all of nearly equal size, or those formed by bifurcation may be somewhat smaller and closer together. Grooves between the ribs are deep, but rather narrower than the ribs. Both grooves and ribs are crossed by concentric lamellar ridges, which are especially distinct near the umbo, and may be absent or indistinct ventrally; these ridges are continuous, and placed at regular intervals. Anterior ear long, with a deep sinus, and two or three serrate ribs radiating from its apex and crossed by fine concentric ridges. Posterior ear smaller, triangular, nearly smooth. Left valve with similar ornamentation, but rather narrower ribs, some of which do not reach the neighbourhood of the umbo. Anterior ear rather long, with three or four well-marked radial ribs crossed by concentric ridges. Posterior ear smaller, with rather less distinct radial ribs and concentric ridges. Measurements : (1) (2) (3) (4) (5) (6) Henoth) >. lis". 9:0 @ ( 692 0.0) mm: ei hteee LICOW Onion. fs TORO): ge Oamemmeiommes (1,2) B. mucronata zone, Norwich. (3, 6) am re Clarendon, Salisbury. (4) Uintacrinus zone, Devizes Road, Salisbury. (5) A. quadratus zone, East Harnham, Salisbury. Affinities—This species resembles both P. acute-plicatus, Alth,’ and P. leopo- liensis, Alth,? but is distinguished from both by its more numerous ribs, the narrower furrows, and concentric ridges. Remarks.—This appears to be a rather rare species; I have seen only about a dozen specimens. Type.—F rom the Senonian of Chayot (Marne). Distribution.—Uintacrinus zone of Devizes Road, one mile west of Salisbury. Marsupites zone near Winchester. A. quadratus zone of East Harnham near Salisbury, and Winchester. 2. mucronata zone of Clarendon near Salisbury, and of Norwich. Upper Chalk of Guildford. Chalk of Trimingham. 1 Haidinger’s ‘Naturwiss. Abhand.,’ vol. iii, pt. 2 (1850), p. 248, pl. xii, fig. 34; Favre, ‘ Moll. Foss. Craie de Lemberg’ (1869), p. 148, pl. xiii, figs. 3, 4. 2 Op. cit., p. 247, pl. xii, fig. 33; Favre, op. cit., p. 149, pl. xiii, fig. 5. b> wr 194 CRETACEOUS LAMELLIBRANCHIA. PecTEN (AUQUIPECTEN) ARLESIENSIS, sp. nov. Plate XXXVII, figs. 9—11. Description.—Shell small, nearly circular, pointed dorsally, height and length nearly equal; nearly equilateral; convexity moderate. Apical angle about iOS Ears very unequal. Right valve with fifteen or sixteen strong, rounded, radial ribs, which are undivided, and of nearly equal size, but somewhat smaller anteriorly and poste- riorly. Ribs separated by strong, rounded grooves, a little narrower than the ribs. Fine, regularly-placed, concentric ridges cross both ribs and grooves, and are best marked near the umbo; on the ribs they develop into rather prominent, projecting scales. Near the posterior border of the valve the grooves are marked obliquely by closely set striz. Anterior ear very long, with a deep sinus, and two or three radial ribs bearing scales or tubercles. Posterior ear much shorter, the outer angle approximately rectangular. Left valve with similar ornamentation, but the ribs rather narrower and the scales somewhat more widely separated. Measurements : (1) (2 (3) (4) Length : 22 : 9-5 7 6 mm. Height : 23 : 975 i 6a (1, 3, 4) Totternhoe Stone, Arlesey. (2) Chalk Marl, Folkestone. Affinities —This species resembles the form referred by Geinitz (from the Turonian), and by Fritsch, to P. pulchellus, Nilsson (see p. 196), but it differs in having fewer and more widely separated ribs. These characters, as well as the scales on the ribs, also separate P. arlesiensis from P. campaniensis, d’Orbieny. T'ypes.—From the Chalk Marl of Folkestone. Distribution.—Chalk Marl of Folkestone, and from a deep boring in the axis of the Winchester anticline. Totternhoe Stone (H. subglobosus zone) of Arlesey. PECcTEN (ANQUIPECTEN) PULCHELLUS, Nilsson, 1827. Plate XXXVII, figs. 12a—e, Ss TAGs. lb: 1827. Prctren putcHenuus, S. Nilsson. Petrific. Suecana, p. 22, pl. ix, fig. 12. — — rneatus, Nilsson. Ibid., p. 22, pl. ix, fig. 13. 1833. — spurtus, A. Goldfuss. Petref. Germ., vol. ii, p. 51, pl. xei, fig. 10. _ — PULCHELLUS, Goldfuss. Ibid., p. 51, pl. xci, fig. 9. 1900. 1902. PECTEN. 195 PEcTEN PULCHELLUS, W. Hisinger. Lethea Suecica, p. 51, pl. xvi, fig. 9. LINEATUS, Hisinger. Ibid., p. 51, pl. xvii, fig. 1. PULCHELLUS, F. A. Rimer. Die Verstein. d. nord-deutsch. Kreide- geb., p. 52. spurius, Rimer. Ibid., p. 52. PULCHELLUS, Fv. Hagenow. Neues Jahrb. fiir Min., ete., p. 550. = J. Miller. Petref. der Aachen. Kreidef., pt. 1, p. 33. — H.G. Bronn. Index Paleont., vol. i, p. 929. — A. d’Orbigny. Prodr. de Pal., vol. ii, p. 252. SUBPULCHELLUS, d'Orbigny. Tbid., p. 252. PULCHELLUS, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 184 (partim). Staszycr, A. Alth. Beschreib. der Umgebung von Lemberg (Haidinger’s Naturwiss. Abhandl., vol. iii, pt. 2), p. 248, pl. xii, fig. 35. _ R. Kner. Denkschr. d. k. Akad. Wissensch. Math.-nat. Classe, vol. iii, p. 316, pl. xvii, fig. 2. PULCHELLUS, A. v. Strombeck. Zeitschr. d. deutsch. geol. Gesellsch., vol. xv, p. 154. —- E. Favre. Moll. Foss. de la Craie de Lemberg, p- 145. mx C. Schliter. Neues Jahrb. fiir Min., ete., p- 951. — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mater. Pal. Suisse, ser. 5), p. 219. — I’. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ili, p. 428. — E. Holzapfel. Die Mollusk. Aachen. Kreide (Pale- ontographica, vol. xxxv), p. 234, pl. xxvi, figs. LO—13. — O. Griepenkerl. Senon. von Kinigslutter (Palaeont. Abhandl., vol. iv), p. 45. LINEATUS, Griepenkerl. Ibid., p. 44. (CHLAMYs) PULCHELLUS, FE. Stolley. Die Kreide Schleswig- Holsteins (Mittheil. Min. Institut. Univers. Kiel, vol. i), p. 240. PULCHELLUS, I’. Vogel. Holliindisch. Kreide, p. 23. spurius, Vogel. Ibid., p. 22, pl. i, figs. 20, 21. PULCHELLUS, A. Hennig. Revis. Lamell. i Nilsson’s ‘ Petrif. Sue- cana’ (Kon. Fysiogr. Siillsk. i Lund. Handl., N. F., vol. viii), p. 33, pl. ii, figs. 27, 29—32; pl. iii, figs. 1, 2. (iquipecreN) puLcHELLus, FL. Philippi. Zeitschr. d. deutsch. eeol. Gesellsch., vol. lii, p- 101, fig. 18. PULCHELLUS, J. P. J. Ravn. Mollusk. i Danmarks Kridtafl. I. Lamellibr. (Kgl. Danske Vid. Selsk. Skrift. 6 Rekke, nat. math. Afd., vol. xi), p. 82, pl. i, fig. 8. 196 CRETACEOUS LAMELLIBRANCHIA. Non 1842. Precren putcuenyius, P. Matheron. Cat. Foss. du Bouches-du-Rhéne, p. 186, pl. xxx, figs. 4—6. == 1 Weysy33, — — L. Reeve. Conch. Iconica, vol. viii, pl. xxxii, fig. 142. 1872 -- — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Palaon- tographica, vol. xx, pt. 2), p. 33, pl. x, figs. 2—4. — 1877. a _ A. Fritsch. Stud. im Gebiete der bohm. Kreide- format.: II, Die Weissenberg. u. Malnitz. Schicht., p. 136, fig. 130. — 1893. -— — R. Michael. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlv, p. 243. Deseription.—Shell small, oval, rounded, height equal to, or shghtly greater than the length; nearly equilateral, the postero-dorsal margin a little longer than the antero-dorsal. Convexity of valves small. Apical angle about 103°. Ears of moderate size, unequal. Right valve with a variable number (twenty-three to forty-four at the margin) of broad, flattened, radial ribs, separated by much narrower, shallow grooves ; in approaching the umbo some of the ribs become united in pairs. Near the anterior and posterior borders ribs are small or absent. Both ribs and grooves are marked by numerous fine radial strize, which, in the middle of the valve, are parallel with the ribs, but cut them more and more obliquely in passing toward the anterior and posterior margins, which they meet at acute angles. Anterior ear longer than high, with the outer margin rounded and a rather small sinus; posterior ear smaller, triangular, higher than long, outer angle obtuse; both ears with radial strie lke those on the valve, and the anterior ear sometimes with a few concentric ridges also. Left valve with narrow, elevated, sharply-limited ribs, some of which (often alternate ones) do not reach the neighbourhood of the umbo. Ribs small or absent near the anterior and posterior margins. Grooves between the ribs broad and deep, marked by radial striz like those on the right valve. Summits of ribs slightly serrate. Ears triangular, the posterior a little smaller than the anterior and with the outer angle obtuse; both ears with radial strie. Measurements : (1) (2) (3) (4) Length : 20°5 : 15:0 : 12°5 ‘ 10°5 mm. Height ; 20°5 : 16:0 : 13-0 : GIO aes (1—4) from Trimingham. Afjinities.—P. lineatus, Nilsson, is a left valve of P. pulchellus. P. spurius, Goldfuss, from Haldem, of which the type is in the Munich Museum, has been shown by Hennig to be identical with P. pulchellus. The form from the Planer- kalk of Strehlen referred by Geinitz to P. pulchellus is regarded by Schliiter, PALASONTOGRAPHICAL INSTITUTED MDCCCXLVIL. VOLUME FOR 1908. LONDON: MDCCCCHI. SOCIETY. A MONOGRAPH OF THE CRETACKOUS LAMELLIBRANCHITA ENGLAND. BY HENRY WOODS, M.A., UNIVERSITY LECTURER IN PALZOZOOLOGY, CAMBRIDGE. PART V. PECTINIDA (continued). INTRODUCTION, BIBLIOGRAPHY, INDEX, AND TITLE-PAGE TO VOL. I. Paces 197—232, i—xliii; Phares XXXIX—XLII. LONDON: PRINTED FOR THE PALHONTOGRAPHICAL SOCIETY. 1903. : p | PRINTED BY ADLARD AND SON, LONDON AND DORKING. - 7 - = Po - _ - |—(G PECTEN. 197 Holzapfel, Vogel, and Hennig as another species; it appears to differ in having sealy ribs, a larger anterior ear, anda larger apical angle. Goldfuss’ pulehellus was thought by @Orbieny to differ from Nilsson’s species, and was named subpulchellus “ce P in the rodrome.” P. miscellus, Goldfuss,' appears to be very near to P. pulchellus, and was regarded by d’Orbigny as identical with it. P. subaratus, Nilsson,’ although similar in form, is easily distinguished by its more numerous ribs, ete. Type.—Nilsson’s specimens came from Képinge, etc. Distribution.—Chalk of Trimingham. Sub-genus—Neirnba, Drouet, 1824. (‘Mém. Soc. Linn. de Paris,’ vol. iii, p. 186.) Precren (Neiruéa) atavus, Pémer, 1839. Plate XXXIX, figs. 1—d. 1839. Preren avavus, I’. A. Rimer. Die Verstein. nord-deutsch. Oolithen-geb. Ein Nachtrag, p. 29, pl. xviii, fig. 21. 1841. — — _ Die Verstein. d. nord-deutsch. Kreidegeb., p. 54. 1847. Janrra atava, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. i, p. 627, pl. eecexlii, figs. 1—3, 5. -—- — neocomiensis, d'Orbigny. Tbid., p. 629, pl. eecexhi, figs. 4, 6—9. 1850. — AtAvA, d’Orbigny. Prodr, de Pal., vol. ii, p. 83. — — weocomrensts, d’Orbigny. Ibid., p. 83. 1854. Prcren atavus, J. Morris. Cat. Brit. Foss., ed. 2, p. 175 (partim). 1855. Janrra arava, G. Cotteau. Moll. Foss. de ?Yonne, p. 117. — — NeEocomtensis, Cotteau. Ibid,, p. 117. ? 1859. — arava, J. Vilanova y Piera. Mem. geogn.-agric. de Castellon, pl. iii, fig. 21. 1861. —_ — P.de Loriol. Anim. Invert. Foss. Mt. Saléve, p. 105, pl. xiv, fie. 1. nrocomtensts, de Loriol. Tbid., p. 104, pl. xiv, figs. 2, 3. 1868. avava, de Loriol. Valangien d’Arzicr (Matér. Pal. Suisse, ser. 4), p. 48. 1870. -—- — F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p- 237, pl. elxxx. — wrocomrensts, Pictet and Campiche. Ibid., pp. 240, 251. (Nerruea) ornirHorus, W. Keeping. Foss., ete., Neoc. Upware and Brickhill, p. 107, pl. iv, fig. 5. 1 + Petref. Germ.,’ vol. ii (1833), p. 51, pl. xei, fig. 8. 2 *Petrif. Suecana’ (1827), p. 21, pl. ix, fig. 11; Hennig, ‘ Revision Lamell. i Nilsson’s Petrif. Suecana ’ (1897), p. 46, pl. iii, figs. 14, 16, 17. OG CRETACEOUS LAMELLIBRANCHIA. — oO 1884. Janrra atava, O. Weerth. Die Fauna des Neocom. im Teutoburg. Walde (Paleont. Abhandl., vol. ii), p. 54. 1887. = —- Ii. Mallada. Sinops. Espec. Fés. en Espana, vol. i, Cret. infer. (Bolet. Com. Mapa geol. Espana, vol. xiv), p. 129. — — wneocomtenstis, Mallada. Ibid., p. 130. 1891. — apava, J. Felix. Verstein. mexican. Jura- u. Kreide- Format. (Paleontographica, vol. xxxvii), p. 171. 1895. - -- G. Maas. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlvu, p. 269. 1896. — — A, Wollemann. Ihbid., vol. xlvin, p. 841. 1899. Vora (Jantra) atava, D. J. Anthula. Kreidefoss. d. Kaukasus (Beitr. z. Palwont. u. Geol. Osterr.-Ungarns u. d. Orients, vol. xii), p. 71. 1900. Janrra atava, A. Wollemann. Die Biv. u. Gastrop. d. deutsch. u. hol- lind. Neocoms (Abhandl. d. k. preus- sisch. geol. Land., N. F., pt. 31), p. 50. Po Vota atava, G. Miller. Verstem. des Jura und der Kreide (Deutsch- Ost-Afrika, vol. vii), p. 551, pl. xxiv, fig. 4. 2? Non 1883. Preren (Netruma) atava, W. Keeping. Foss., etc., Neoc. Upware and Brickhill, p. 107, pl. iv, fig. 6. Deseviption—Shell roughly triangular, often shghtly imequilateral; ventral marein very convex, with deep incisions between the main ribs; postero-dorsal margin concave, antero-dorsal nearly straight. Anterior ears long, triangular. Right valve convex, with the umbo considerably incurved and sharp. The six main ribs are prominent and rounded, and are separated by much broader inter- spaces, which are concaye or somewhat flattened. In the interspaces and on the sides of the main ribs, from three to twelve small, shghtly raised ribs usually occur, but are absent in some cases; the central ribs are rather stronger than the lateral. Numerous fine, equal, regularly placed, concentric ridges cross both ribs and interspaces ; they are parallel with the ventral margin of the valve, and con- sequently bend ventrally in crossing the main ribs, and curve dorsally m the inter- spaces. Similar concentric ridges are also present on the ears. Left valve flattened, sometimes shehtly convex or shghtly concave, with six main ribs, which are rounded and somewhat more prominent than those on the right valve. Interspaces broad and deep, with small ribs. Concentric ornamentation similar to that on the right valve. Measurements : (1) (2) (3) (4) (5) (6) (7) (8) (9) Length. 24 . 28 . 22 wn 5 BHO 5, BO 5 ts) . Wy . Bil waa, Height . 30 . 28 . 29 My 5 26 . By . Bo . 22. B87 x (1—8) Upware. (9) Faringdon, PECTEN. 199 Affinities —Whilst recognising the close resemblance which exists between P. atavus and P. neocomiensis, Pictet and Campiche thought that the latter could be distinguished from the former by the absence of ribs in the interspaces. Wollemann, however, by means of a much larger series of specimens, has shown (1896) that the differences which were supposed to separate the two forms are not constant. The form described by de Loriol' as Janira Matheroniana is very similar to P. atavus, and may prove to be identical with it. Janirva valangiensis, Pictet and Campiche,’ differs from Pecten atavus chiefly im the convexity of the left valve. Remarks—The English examples of this species are of rather small size, the average height being about 26 mm.; none of them reaches the size of the large forms figured by d’Orbigny and by Pictet and Campiche. Many of our examples are more or less inequilateral, but even in the large specimens from Ste. Croix this character is sometimes noticeable. The anterior ear is also distinctly larger than the posterior in most specimens. The large example from Upware, figured as P. (N.) atava by W. Keeping, is considerably worn, and the ribs in the interspaces are stronger than usual ; consequently Iam unable to regard it as belonging to P. atavus. It is probably only a worn specimen of P. (N.) quinquecostatus. On account of their inequilateral character the specimens from Upware were regarded by W. Keeping as belonging to a distinct species, which he named P. ornithopus ; but this form also occurs in Brunswick, and Wollemann has shown that it cannot be separated from P. atavus. Types.—Romer’s types came from the Hils-conglomerate of Schandelah and Schéppenstedt. Romer’s figure is not quite satisfactory, but any doubt which may formerly have existed as to the nature of his species has been removed by Wollemann, who has obtained other specimens from the same locality. D’Orbigny’s specimens of P. neocomiensis came from the Hauterivian near Neuchatel, ete. The specimen figured by Keeping as P. atavis is in the collection of Mr. J. F. Walker. The types of P. ornithopus are in the Woodwardian Museum. Distribution—Lower Greensand of Upware and Faringdon. Ferruginous Sands of Shanklin. 1 «Foss. Corall. Valang. et Urgon. de Mt. Saléve’ (1866), p. 65, pl. E, fig. 9. Also in A. Favre, ‘Rech. géol. dans Savoie,’ vol. 1 (1867), p. 390, pl. C, fig. 27. 2 «Boss. Terr. Crét. Ste. Croix’ (1870), p. 242, pl. clxxxi, figs. 1—3. 200 CRETACEOUS LAMELLIBRANCHIA. Prcren (Nurraea) compra (d’Orbigny), 1847. Plate XXXIX, figs. 6—10. 1847. Janina comets, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p. 640, pl. cccexlv, figs. 15—20. 1850. = = =— Prodr. de Pal., vol. ii, p. 170. 1868. — — A. Briart and F. L. Cornet. Descript. Mineralog. Géol. et Pal. de la Meule de Bracquegnies (Man. cour. et Mém. des Sav. ctrangers, vol. xxxiv), p. 50, pl. iv, figs. 23, 24. 1870. -- — F.J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 252. Description.—Shell small, subtriangular, much higher than long, nearly equi- lateral. Antero- and postero-dorsal margins long; ventral margin very convex, with deep incisions between the main ribs. Ears very unequal; the anterior very long, the posterior small. Right valve very convex, with a greatly incurved umbo, and five’ very prominent angular ribs, which are crossed by numerous fine concentric ridges. The main ribs are separated by broad, deep, rounded depressions in which from three to seven slightly raised radial ribs occur; these small ribs are flattened and separated by narrow grooves, and bear numerous fine ridges placed transversely. At distant intervals from two to four strong growth-ridges may occur. Left valve flattened, with five strong, rounded radial ribs separated by broad interspaces, both bemg crossed by fine concentric ridges. A few strong growth- ridges may occur. Measurements : Q) (2) (3) (4) (5) Length . , dé . Wey . Ilil > 10) TTL saan, Height . , ile , i® , dle). ay KGS, (1, 2) Cenomanian, Wilmington. (3, 4) Upper Greensand, Warminster. Ajjinities.—Vhis species is closely allied to Janira longicauda, d@Orbigny,’ but is distinguished from it by the main ribs being narrower and more angular. It 1s also nearly related to P. notabilis, Goldfuss,’ but differs in possessig five main ribs instead of six, and apparently also in being relatively higher. ' Occasionally a sixth rib, not quite so prominent as the others, occurs near the anterior margin. 2 «Pal. Franc. Terr. Crét.,’ vol. iii (1847), p. 639, pl. cccexlv, figs. 9—14. Geinitz, “ Das Elbthalgeb. in Sachsen” (‘ Paleontographica,’ vol. xx, pt. 1, 1872), p. 202, pl. xlv, figs. 16, 17. 3 *« Petref. Germ.,’ vol. ii (1833), p. 56, pl. xciii, fig. 3. Geinitz, ‘Das Elbthalgeb. in Sachsen ”’ (- Palexontographica,’ vol. xx, pt. 1, 1872), p. 202, pl. xlv, figs. 10-12. PECTEN. 20] It is difficult to separate Janira Johannis Bahmi, Tiessen,' from P. (N.) cometa, - since in the latter the symmetry (depending on the position of the middle rib) varies in different specimens. P. (Neithea) cometa also presents some resemblance to the smaller forms of P. (N.) atavus, but is distinguished by possessing five (imstead of six) main ribs, by being relatively higher, and by having the right valve more convex. Remarks.—This appears to be a relatively rare species. A specimen from the Cenomanian of Saint Jouin (Seine-Inférieure) has been sent me by M. Fortin, and agrees perfectly with the English examples. T'ypes.—D’ Orbigny’s specimens came from the Cenomanian of Villers (Calva- dos) and Le Havre (Seine-Inférieure). Distribution.—Upper Greensand (zone of Pecten asper) of the Isle of Wight, Maiden Bradley, Melcombe Bingham (Dorset), south-west of Armswell Farm (Dorset), and west of Melbury Hill (Dorset). Rye Hill Sands of Warminster. Chloritic Marl of Ventnor and Maiden Bradley. Cenomanian of Wilmington. Pecren (Nerruva) Morrist (Pictet and Renevier), 1858. Plate XXXIX, figs. lla—e, 12a, b, 15. ? 1841. Pecren Quinquecosratus, var. a, F. A. Rémer. Die Verstein. d. nord- deutsch. Kreidegeb., p. 54. 1845. — = E. Forbes. Quart. Journ. Geol. Soe., vol. i, p. 249 (partim). 1846. — versicostatus, A. Leymerie. Statist. géol. et min. du départ. de lAube, Atlas, p. 11, pl. vi, fig. 9. 1847. — QuINQUECosTaTUS, var., J. Morris. Quart. Journ. Geol. Soc., vol. 11, p. 295 (foot-note) 1853. Janrra quinquecosrata, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Gentve, p. 506, pl. xlv, figs. 3a, b (not c). 1858. — Morxrtsr, Ff’. J. Pictet and EB. Renevier. Foss. Terr. Aptien (Matcr. Pal. Suisse, ser. 1), p. 128, pl. xix, fig. 2. ? 1859. guinquecosrata, J. Vilanova y Piera. Mem. geogu.-agric. de Cas- tellon, pl. iii, fig. 23. 1865. — Morrisi, H. Coguand. Mon. Aptien de l’Espagne, p. 151. 1870. _— -- F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 244. 1887. -- — L. Mallada. Sinops. Espec. Fos. Espana, vol. ii, Cret. infer. (Bolet. Com. Mapa geol. Espana, vol. xiv), p. 130. ' « Zeitschr. d. deutsch. geol. Gesellsch.,’ vol. xlvii (1895), p. 473, pl. xvii, fig. 5. 202 CRETACEOUS LAMELLIBRANCHIA. 1901-2. Vora Morrist, P. Choffat. Faune Crét. du Portugal, vol. i, ser. 4, p. 147, pl. iii, figs. 5, 6. Non 1883. Prcren (Nerruea) Morris1, W. Keeping. Foss., ete., Neoc. Upware and Brickhill, p. 106 (= quin- quecostatus), Remarks.—The forms found in the lower part of the Lower Greensand are very closely related to Pecten (Neithea) quinquecostatus, but show, in general, certain small differences from the latter, so that it will, I think, be convenient to retain for them the name Morrisi, given by Pictet and Renevier. As a rule P. (N.) Morrisi is characterised by the relatively greater height of the shell (and consequently smaller apical angle), by the smaller convexity of the right valve, the rather stronger main ribs, with the ribs of the imterspaces rather more unequal in size, and lastly in having the areas,’ as a rule, without ribs. The concentric ornamentation agrees with that of P. CN.) quinguecostatus. Measurements : (1) (2) (3) (4) (5) (6) (7) Length. 28 eye, fe US ee Wa a ALYY , 28 , I snim, Height Biles CB GPR, «CIS) Cg CSS gC (1—4) Perna-bed, Atherfield. (5, 6) Hythe Beds, Lympne. (7) Crackers, Atherfield. Distribution —Perna-bed and Crackers of Atherfield. Hythe Beds of Lympne. Proven (Neiruua) Quinquecostatus, Sowerby, 1814. Plate XXXIX, figs. 14—17 ; Plate XL, figs. 1—5. 1814. Pxroren quinquecostara, J. Sowerby. Min. Conch., vol. i, p. 122, pl. lvi, figs, 4—8. 1819. — versicostatus, Lamarck. Anim. sans Vert., vol. vi. p. 181. 1822. — gQuinqurcostatus, A. Brongniart. Déscript. géol. envir. de Paris. In Cuvier’s Ossem. Foss., ed. 2, vol. ii, pp. 251, 320, 382, 600, pl. iv, fig. 1. —- — guinquecostata, G. Mantell. Foss. S. Downs, pp. 128, 201, pl. xxvi, figs. 14, 19, 20. 1824. Nerrrnka versicostata, C. Drowet. Mém. Soc. Linn. de Paris, vol. iii, p. 187, pl. vii, fig. 4. 1825. Pxrcren versitcosratus, Defrance. Dict. Sci. nat., vol. xxxviii, p. 254. 1827. — quinquecostarus, S. Nilsson. Petrif. Suecana, p 19, pl. ix, fig. 8; pl. x, fig. 7. ' This term in this sub-genus refers to the parts of the right valve between the outermost main ribs and the antero- and postero-dorsal margins. 1847. PECTEN. 203 Prcren versicostatus, Bruguicre. Hist. nat. des Vers et des Mollusques (Encye. méthod.), vol. iii, p. 727, pl. cexiv, fig. 10. — QurNnguEcostatus, A. Goldfuss. Petref. Germ., vol. ii, p. 55, pl. xeiii, fig. 1. —_ — S. G, Morton. Synops. Org. Remains Cret. U.S., p. 57, pl. xix, fig. 1. — versicostatus, Lamarck. Anim. sans Vert. (ed. 2 by Deshayes and Milne-Edwards), vol. vii, p. 158. — QuinquEcosratus, S. G. Morton. Amer. Journ. Sci., vol. xviii, p. 250, pl. iu, fig. 5. — versicostatus, F. Dujardin. Mém. Soc. géol. France, vol. ii, p. 227. — gQuringurcosratus, H. G. Bronn. TLethea Geogn., p. 678, pl. xxx, fics 17. — - W. Hisinger. Lethea Suecica, p. 50, pl. xvi, fig. 2. — — A. dArchiac. Mém. Soe. géol. de France, vol. i, p. 186. — H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs. Kreidegeb., pt. 1, p. 22. — = var. B, F. A. Rimer. Die Verstein. nord- deutsch. Kreidegeb., p. 54. = — FE. Forbes. Trans. Geol. Soc., ser. 2, vol. vii, p. 153. — — H. B. Geinitz. Grundy. der Verstein., p. 470. (Nerrnea) verstcosratus, A. 2. Reuss. Die Verstein. der béhm. Kreideformat., pt. 2, p. 31 (2 partim). JANIRA QuINQUECOsTATA, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iii, p-. 652, pl. eecexliv, figs. 1—5. Pecren (Nerrnra) Qurnquecosratus, J. Miller. Petref. Aachen. Kreide- format., pt. 1, p. 33. Jantra Fonranrert, A. d’Orbigny. Voy. au Pole Sud dans l’Ocdéanie sur les corvettes Astrolabe et la Zellée. Atlas, pl. vii, figs. 38—40. PEcTEN Quinquecostatus, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p- 356 (p. 386, ed. 2), pl. xxviii, figs. 1—3. JANIRA QuINQUECOsTATA, A. d’Orbigny. Prod. de Pal., vol. ii, p. 169. — Fowrantert, d’Orbigny. Thbid., p. 253. Pecren (Nerruea) Qurnquecosratus, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 186. Neirnea qurnguecostata, H. G. Broin. ethea Geogn., ed. 3, vol. ii, pt. 5, p. 275, pl. xxx, fig. 17. PEcTEN QuINQuECcostatTus, J. Morris. Cat. Brit. Foss., ed. 2, p. 177. — s#aquicostratus, Morris. Ibid., p. 177 (partim). 204 1863 1870. 1890. 1890-91, CRETACEOUS LAMELLIBRANCHIA. Precren qurinquecostratus, W. H. Baily. Quart. Journ. Geol. Soc., vol. xi, p. 462. JANIRA QuINQUECOosTATA, G. Cotteau. Moll. Foss. de ?Yonne, p. 117. Prcren Quinquscostatus, A. Kunth. Zeitschr. d. deutsch. geo). Gesellsch., vol. xv, p. 725. JANIRA QuInquercostaTa, F#. Romer. Geol. von Oberschles., p. 540. = — C. Schliiter. Neues Jahrb. fiir Min., ete., pp. 937, 951. — -— F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mater. Pal. Suisse, ser. 5), p. 246. Vora Qguinquecosrara, FI’. Stoliezka. Palwont. Indica, Cret. Fauna §. India, vol. ii, p. 457, pl. xxxi, figs. 1—6,; pl. xxxvii, figs. 4—9. — — HB. Geinilz, Das Elbthalgeb. in Sachsen (Pal- weontographica, vol. xx, pt. 1), p. 201), pl) xly,, figs. 8; 97 pb. 2; p. 36, pl. x, figs. 17, 18. — = A. Fritsch. Stud. im Gebiete der bohm. Kreide- format. : II, Die Weissenbere. und Malnitz. Schicht., p. 137. NeITHEA QuinquecostatTa, W. M. Gabb. Journ. Acad. Nat. Sci. Philad., ser. 2, vol. vin, pt. 3, p. 294. — FE. Bayle. Explic. Carte géol. France, vol. iv, Atlas, pt. i, pl. exxu, figs. 2, 3. Vora Qurnquecostata, H. Schrider. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxxiv, p. 271. Peoren (Nerruea) Morrist, W. Keeping. Foss., etc., Neoc. Upware and Brickhill, p. 106. = = atava, Keeping. Ibid., p. 107, pl. iv, fig. 6. Vota guinqurecostata, A. Fritsch. Stud. im Gebiete der bohm. Kreide- format.: III, Die Iserschicht., p. 116, fig. 90. JANIRA QuiINQquEcostata, F. Nétling. Die Fauna d. baltisch. Cenoman. (Paleont. Abhandl., vol. ii), p. 21. Vota gurnquecostata, K. Martin. Die Fauna der Kreideformat. vy. Mar- tapoera (Samml. Geol. Reichs-Museum in Leiden, vol. iv), p. 157, pl. xvi, figs. 10, 11. = = A. Fritsch. Stud. im Gebiete der béhm. Kreide- format.: IV, Die Teplitz. Schicht., p- 85. — ef. quinquecostara, LH. Holzapfel. Die Mollusk. Aachen. Kreide (Paleontographica, vol. xxxv), p. 238. — -- M. Blanckenhorn. Beitr. z. Geol. Syriens. Ent- wickel. d. Kreidesyst. in Mittel und Nord-Syrien, p. 77. Proven Quinquecostatus, A. Peron. Moll. Foss. Terr. Crét. de la Tunisie (Explor. Scient. de la Tunisie), pt. 2, p. 227. PECTEN. 205 1893. Janira (VoLA) quinquecosrara, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlv, p. 237. 1895. — Quinguecosrata, FH. Tiessen. Tbid., vol. xlvii, p. 471. 1896. Voxa quinquecostara, A, Rutot. Bull. Soc. Belge de Géol., ete., vol. x, p- 30. 1897. — —- U. Séhle. Geogn. Jahresh. (1896), p. 40. -- — — KR. Leonhard. Kreideformat. in Oberschles. (Pala- ontographica, vol. xliv), p. 46. — — — A. Hennig. Revis. af Lamellibr. i Nilsson’s ‘ Petrif. Suecana Form. Cret.’ (Kon. Fysiogr. Sallsk. i Lund. Handl., N. F., vol. viii), p. 52. ? 1900. — _— G. Miller. Verstein. des Jura u. d. Kreide. (Deutsch-Ost-Afrika, vol. vii), p. 565, pl. xxiv, fig. 1. 1901. — ~- H. Imkeller. Die Wreidebild. Stallauer Eck u. Enzenauer Kopf (Palonto- graphica, vol. xlviii), p. 32. 1901-2. — — P. Choffat. Faune Crét. Portugal, vol. i, ser. 4, p. 148, pl. iui, fig. 7. 1902. — — J.P. J. Ravn. Mollusk. i Danmarks Kridtafl. I. Lamellibr. (D. Kel. Danske vid. Selsk. Skrift. 6 Rekke, nat. og math., vol. xi), p. 95. Non 1850. Prcren quinquecosratus, &. Kner. Verstein. Kreidemerg. von Lemberg (Haidinger’s Naturwiss. Abhandl., vol. 111), p. 29 (? = striatocostatus). Description.—Shell ovate or somewhat triangular, nearly equilateral ; height sometimes equal or nearly equal to, but usually rather greater than, the length. Right valve moderately convex, with mcurved umbo, and strong, rounded, regular ribs. Six main ribs are rather larger than the others, and project at the margin of the valve, forming angles between which the parts of the margin are slightly concave; the anterior and posterior main ribs are not quite so strong as the others. ‘he interspaces between the main ribs are flattened or sometimes slightly concave; in the larger number of cases four ribs occur in each interspace, but occasionally there are three, five, or six ribs in one or more of the interspaces—not infrequently the interspace next the posterior area has five ribs. The two middle ribs of the interspaces are commonly rather stronger than one or both of the laterals; sometimes one lateral is very small. The grooves between the ribs are usually narrower than the ribs. Posterior area slightly larger than the anterior; both with ribs which are smaller than those on the rest of the shell ; the anterior usually with from four to eight, the posterior with from five to eight ribs. Both ribs and grooves are crossed by numerous fine, regular, concentric 7 al 206 CRETACEOUS LAMELLIBRANCHIA. ridges, which run parallel with the margin of the shell and with the erowth-ridges. Kars small or of moderate size, triangular, slightly unequal, with small radial ribs. Left valve slightly concave or nearly flat; length greater than height. Ribs narrow, rounded, separated by broader grooves; six of the latter (corresponding in position with the main ribs of the right valve) are broader than the others. The ribs vary in number from twenty-seven to thirty-five, with also a few very small ribs near the anterior and posterior margins. Concentric ornamentation similar to that on the right valve. Hars triangular, nearly equal, with faint radial ribs. Measurements : (@) (2) (3) () () (6) (7) (8) (9) (10) (11) (12) (18) (14) (15) (16) 17) (18) (19) (20) Length. 23 .30 21 15 11 35 17 82 22 17 19 17 48 33 30 26 22 2 21 20 Height. 27 34 26 19 13 85 19 35 26 20 22 19 52 37 35 .30 26 27 24 22°5 (21) (22) (23) (24) (25) (26) (27) (28) (29) (30) (31) (32) (33) (84) (85) (36) (37) gene thy se Lid 25) 239 19) 32) 28) (205927 sae 82s ee 31 32 17 34 39 39mm. Height. . 20 14 28 26 22 33 33 20530 385 35 ... 29 28 16 380 37 33 mm. (1—31) Right valves. (82—87) Left valves. (1, 2) Lower Greensand, Upware. (8—5) ,, . Faringdon. (6—12) Upper Greensand (zone of Pecten asper): (6, 7) Shaftesbury; (8) Warminster ; (9—11) Ventnor; (12) Haldon. (18—22) Cenomanian, Wilmington. (23—25) 3 Devon Coast (Dunscombe and Branscombe). (26) Upper Chalk (? M. cor-anguinum zone), Gravesend. (27) % » Brighton. (28) *) » (2 M. cor-anguinum zone), Gravesend. (29) 55 » (M. cor-anguinum zone), Charlton. (30), ” 99 » Gravesend. (GID). = » Lewes. (32) Upper Greensand, Warminster. (83) Upper Chalk (? M. cor-anguinwm zone), Gravesend. (34) Upper Greensand, Shaftesbury. (85—37) Upper Chalk (M. cor-anguinum zone), Gravesend, Ajjinities—See P. (N.) Morrist (p. 202), quadricostatus (p. 210), xquicostatus (p. 209), sexcostatus (p. 214). The specimens from the Lower Greensand of Upware, which were referred by W. Keeping to P. (N.) Morrisi (see p. 201), agree perfectly in form, in the regularity of the ribs, and in the occurrence of ribs on the areas with P. (N.) quinquecostatus and should, I think, be referred to that species. Remarks.—This species varies to some extent in the convexity of the right valve and in the relative proportions of length and height, but these variations seem to be connected with local conditions only. The specimens from the Upper PECTEN. 207 Greensand of Ventnor are rather more convex than usual; those from the Upper Greensand of Warminster are, as a rule, less convex and rather longer. Other modifications are seen in the strength of the main ribs, the flatness or slightly concave character of the interspaces, the number of ribs in the interspaces and the amount of their inequality, and the length of the hinge-line, which is corre- lated with the slope of the anterior and posterior areas. In some specimens from the Upper Chalk (Plate XL, fig. 2) the main ribs are rather stronger than usual, the intermediate ribs more unequal, and the hinge- line shorter; but such forms can be matched with some of those found in the Cenomanian of Devon and France, whilst other Upper Chalk specimens belong to the type which is common in the Upper Greensand of Warminster and the Cenomanian of the Devon coast and France. The specimens figured by Mantell were regarded by d’Orbigny as distinct from Pecten quinquecostatus, Sowerby, and were referred by him to Janira Dutemplei. Peron adopts the same view, and moreover refers the first two of Sowerby’s figures (figs. 4, 5) to P. Dutemplei, and regards the Upper Greensand form as distinct. An examination of a number of specimens from the Upper Chalk shows, however, that whilst there is some variation, yet they are inseparable from the Upper Greensand form, and that they differ from P. Dutemplei (see p. 216). Morris also appears to have regarded the Warminster specimens as distinct from those found in the Chalk; the latter he referred to P. quinquecostatus, and the former to P. xquicostatus ; but the Warminster form figured by Sowerby is certainly distinct from P. equicostatus, Lamarck. A typical form of P. quinquecostatus from the Cenomanian of Rouen is figured by Bayle, and similiar specimens from that and other French localities have been sent me by M. Raoul Fortin of Rouen. In some Cenomanian specimens the main ribs are not so strong as usual; such forms make some approach to P. equicostatus, but can be easily distinguished by their well- marked concentric ridges. Types —In the British Museum; figs. 4, 5, from the Chalk of Lewes; figs. 6—8 from the Rye Hill Sand of Chute Farm, Warminster. Mantell’s figured specimens appear to have been lost. Distribution—Lower Greensand of Farmgdon and Upware. Folkestone Beds of Folkestone. Upper Greensand (zone of Schlanbachia rostrata) of Blackdown; malmstone of Devizes and the Isle of Wight. Upper Greensand (zone of Pecten asper) of Haldon, Cheddington (Dorset), Ball Wood (Dorset), Shaftesbury, Warminster, Ventnor, and Niton. Rye Hill Sand of Warminster. Chloritic Marl of Maiden Bradley. Cenomanian (Meyer’s Beds 10 and 12) of Dunscombe and (Bed 11) of Branscombe and Whitecliff. Cenomanian Sandstone of Wilmington. 7’. gracilis zone of Dover 208 CRETACEOUS LAMELLIBRANCHIA. (fide Rowe). H. planus zone of Dover and the Sussex coast (fide Rowe). M. cor-testudinavium zone of Seaford, Chatham, and Purley. M. cor-anguinum zone of Mitcheldever (Hants), Broadstairs, Charlton, Northfleet, and Gravesend. Marsupites zone of Brighton and Margate. A. quadratus zone of Brighton, Pauls- erove (Hants), and West Harnham (Salisbury). Upper Chalk of Lewes. Prcren (Nerraea) mquicosratus, Lamarck, 1819. Plate XL, figs. 8 a, b, 9 a—c. 1819. Prcoren xQuicosrarus, Lamarck. Anim. sans Vert., vol. vi, p. 181. 1824. Nerruea pectinorpgs, C. Drowet. Mém. Soc. Linn. de Paris, vol. i, p- 186, pl. vii, figs. 1, 2. 1825. Prcoren maurcosratus, Defrance. Dict. Sci. nat., vol. xxviii, p. 255. > > 1833. — —- A, Goldfuss. Petref. Germ., vol. ii, p. 54, pl. xeii, fig. 6. 1836. — — Lamarck. Anim. sans Vert., ed. 2 (by Deshayes and Milne-Edwards), vol. vii, p. 158. 1839. — — H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs. Kreidegeb., pt. 1, p. 22. 1841. — a F. A. Romer. Verstein. nord-deutsch. Kreidegeb., p- 54. 1846. — — H. B. Geinitz. Grundr. der Verstein., p. 469. — A. E. Reuss. Die Verstein. der bihm. Kreideformat., pt. 2, p. 32, pl. xxxix, fig. 22; pl. xl, figs. 2, 3. 21847. Jantra maquicostata, A. d’Orbigny. Pal. Franc. Terr. Crét., vol. iu, p- 637, pl. cecexlv, figs. 1—4. 1850. — mQuicostata, d’Orbigny. Prodr. de Pal., vol. 11, p. 170. = Prcren mquicostatus, H. B. Geinitz. Das Quadersandst. oder Kreidegeb. in Deutschland, p. 186. 1854. = = J. Morris. Cat. Brit. Foss., ed. 2, p. 175 (partim). 1863. = —- A. Kunth. Zeitschr. d. deutsch. geol. Gesellsch., vol. xv, p. 725. 1868. Janrra mQuricostata, A. Briart and F. L. Cornet. Descript. Mineralog. Géol. et Pal. de la Meule de Brac- quegnies (Mcém. cour. et Mem. des Sav. ctrangers, vol. xxxiv), p. 49, pl. iv, figs. 25, 26. 1872. Vota mauicosrata, H. B. Geinitz. Das Elbthalgeb. in Sachsen (Paleonto- graphica, vol. xx, pt. 1), p. 200, pl. xlv, figs. 5—7. 21876. Prcren mQuicosTatus, var. Lonarcouuis, H. Deicke. Die Tourtia von Milheim a. d. Ruhr. (Beitr. z. geogn. u. pal. Beschaffenh. d. unt. Ruhrgegend. Beitr. I), p. 26. PECTEN. 209 1878. Nerruea mquicosrata, H. Bayle. Explic. de la Carte géol. de France, vol. iv, pt. 1 (Atlas), pl. exxii, fig. 4. 1882. Janina meuicosrata, P. de Loriol. Gault de Cosne (Mém. Soe. Pal., Suisse, vol. ix), p. 102, pl. xi, figs. 6—8. 1885. — —_ F. Nitling. Die Fauna d. baltisch. Cenoman. (Palwont. Abhandl., vol. ii), p. 21. 1893. — (Vora) meauicostara, R. Michael. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlv, p. 237. 1894. Vora xqurcostata, A. Hennig. Om Ahussandst. (Geol. Foren. i Stockholm Forhandl., vol. xvi), p. 520 1895. Janrra mquicostara, FH. Tiessen. Zeitschr. d. deutsch. geol. Gesellsch., vol. xlviul, p. 472. 1901-2. Vora mauicostata, P. Choffat. Faune Crét. Portugal, vol. 1, ser. 4, p. 152, pl. ii, fig. 10. ? Non 1847. Prcren mauicosratus, J. Miller. Petref. Aachen. Kreideformat., pt. 1, p. 33. Non 1850. — — J. de C. Sowerby. In F. Dizon's Geol. Sussex, p. 356, pl. xxvui, figs. 17, 18 = seavcostatus). Description.—Shell ovate, equilateral ; ventral margin very convex and rounded ; antero- and postero-dorsal margins slightly concave. Right valve very convex, with a prominent imeurved umbo, and with from thirty-four to fourty-four rather small, rounded ribs of nearly equal size, except those near the anterior and posterior margins, which are smaller. The ribs are separated by rounded furrows of about the same width as the ribs. Both ribs and furrows are smooth, or nearly smooth. Near the antero- and _ postero-dorsal margins are narrow, smooth areas without ribs, the anterior area being slightly smaller than the posterior. Ears of moderate size, triangular, nearly equal, smooth, or with fine concentric ridges. Left valve flat or shehtly concave, with ribs similar to those of the right valve. Measurements : (1) (2) (3) Length ; 14. : 10S 9 mm. Height : 16 ; 12 : Laas (1, 3) Upper Greensand (zone of Pecten asper), Haldon. (2) ” ro 1 3 » Worbarrow. Affinities.—This species is distinguished from P. (Veithea) quinquecostatus by the ribs being of equal size, and smooth or nearly smooth; also by the ventral margin of the shell being evenly rounded and by the areas being without ribs. D’Orbigny’s figure shows six more prominent ribs, but I have seen faint indications 210 CRETACEOUS LAMELLIBRANCHIA. of such ribs m only a few specimens. A typical form is figured by Bayle; it agrees perfectly with specimens from the Cenomanian of Rouen and Orbiquet which have been sent me by M. Fortin, and with others from the Cenomanian of Le Havre, sent by M. A. de Grossouvre. Remarks.—Morris referred the specimens from the Upper Greensand, which Sowerby figured as P. quinquecostatus (figs. G—8), to this species, but they are clearly distinguishable by the presence of six main ribs, and by the concentric ornamentation. T'ypes.—Lamarck’s types came from the Cenomamian of Le Mans, and from near Angers. Goldfuss’ specimens came from the Quader-sandstone near Dresden, and the Greensand of Regensburg. Distribution.—Upper Greensand (Chert Beds, zone of Pecten asper) of Haldon, of Worbarrow, and Warminster. Chloritic Marl of Maiden Bradley. Pucren (Nerrana) quapricostatus, Sowerby, 1814. Plate XL, figs. 6, 7. Text-figs. D. 9 (3) 1806. (Figure without name), J. Sowerby. British Mineralogy, vol. ii, p. 159, pl. elxxxiii. 1814. Prcren guapricostata, Sowerby. Min. Conch., vol. i, p. 122, pl. lvi, figs. 1, 2. 1833. — quapricostatus, A. Goldfuss. Petref. Germ., vol. ii, p. 54 (partim), pl. xeu, fig. 7. 1837. — quapricostata, H. G. Bronn. Lethea Geogn, p. 680, pl. xxx, fig. 16. 1839. — quapricostatus, H. B. Geinitz. Char. d. Schicht. u. Petref. des siichs. Kreidegeb., pt. 1, p. 22. 1841. -— — F. A. Rimer. Verstein. des nord-deutsch. Kreidegeb., p. 54. 1843. — — H. B. Geinitz. Die Verstein. von Mieslingswalda, p. 16, pl. iii, figs. 14, 15. 1846. — ~- Geinitz. Grundriss der Verstein., p. 469. a — versicostatus, A. H. Reuss. Die Verstein. der bohm. Kreide- format., pt. 2, p. 31 (? partim). 1850. Jantra Gurnirazn, A. d’Orbigny. Prodr. de Pal., vol. ii, p. 197. 1850-51. Nerruea Qquapricostatus, H. G. Bronn. Lethwa Geogn., ed. 3, vol. il, pt. 5, p. 277, pl. xxx, fig. 16. 1853. Janrra Faucranyana, F. J. Pictet and W. Roux. Moll. Foss. Gres verts de Genéve, p. 505, pl. xlv, fig. 2. 1854. Proren quapricosratvs, J. Morris. Cat. Brit. Foss., ed. 2, p. 177. 1863. — = A. Kunth. Zeitschr. d, deutsch. geol. Gesellsch., vol. xv, p. 725. 1870. ? 1881. ? 1882. —— 1895. P1397. Non 1847. — 1850. ?P— 1854. —- 1866. PECTEN. 211 JANIRA QuADRIcosrata, A. Briart and F. L. Cornet. Descript. Mineralog. Géol. et Pal. de la Meule de Brac- quegnies (Mém. cour. et Mém. des Sav. ¢trangers, vol. xxxiv), p. 48, pl. iv, figs. 21, 22. — ~- FJ. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), pp. 249, 251. Pecren quapricostatus, H. Credner. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxii, p. 252. Voua quapricosrata, I’. Stoliczka. Palwont. Indica, Cret. Fauna S. India, vol. iii, p. 430. — — H. B. Geinitz. Das Elbthalgeb. in Sachsen (Pali- ontographica, vol. xx, pt. 2), p- yf pl. x, figs. 14—16. Janira Quapricosrara, W. Dames. Zeitschr. d. deutsch. geol. Gesellsch., vol. xxvi, p. 765. — — J. Kiesow. Schrift. nat. Gesellsch. in Danzig, N. F., vol. v, p. 414. = — — Thid., vol. v, p. 240. == — P. de Loriol. Gault de Cosne (Mém. Soe. Pal. Suisse, vol. xii), p. 103, pl. xin, fig. 4. — — E. Tiessen. Yeitschr. d. deutsch. geol. Gesellsch., vol. xlvii, p. 472. Vo1a quapricostara, U. Séhle. Geogn. Jahresh. (1896), p. 39. Pecren quapricosratus, J. Miller. Petref. Aachen. Kreideformat , pt. le p- 33. JANIRA Quapricosrata, A. d’Orbigny. Pal. France. Terr. Crét., vol. iii, p. 644, pl. eecexlvii, figs. 1—7 (= Faujasi, Pict. and Camp.). — — A. Alth. Geog.-pal. Beschreib. von Lemberg (Haidinger’s Naturwiss. Abhandl., vol. iii), p. 249. —_— = A. d' Orbigny. Prodr. de Pal., vol. ii, p. 253. Prcren Quapricosratus, Ll’, Romer. Kreidebild. von Texas, p. 64, pl. viii, fig. 4. -- — R. Kner. Wreideverstein. von Ost-Galizien (Denkschr. d. k. Akad. Wissensch. Math.-nat. Classe, vol. iii), p. 317. — -~ A. dArchiac. Bull. Soe. géol. de France, ser. 2, vol. xii, p. 215, pl. in, fie. 10. Jana Quapnicosrata, K. A. Zittel. Die Biv. der Gosaugeb. (Denkschr. d. k. Akad. Wissensch. Math.-nat. Classe, vol. xxv), pt. 2, p. 115, pl. xviii, fig. 4. 212 CRETACEOUS LAMELLIBRANCHIA. Non. 1869. Janrra quapricostata, H. Favre. Moll. Foss. de la Craie de Lemberg, p. 155. — 1876. Voxa quapricosrara, D. Brauns. Senon. des Salzberges (Zeitschr. f. d. gesammt. Naturwiss., vol. xlvi), p. 388. — 1877. Janira quapricosrata, A. Peron. Bull. Soc. géol. de France, ser. 3, vol. v, p. 502. — 1889. Vota quapricostata, H, Holzapfel. Die Mollusk. Aachen. Kreide (Palzeon- tographica, vol. xxxv), p. 297, pl. xxvi, fig. 20. = = = = O. Griepenkerl. Senon. von Kénigslutter (Paleeont. Abhandl., vol. iv), p. 48. — 1892. Nurryea Quapricostara, K. Futterer. WKreidebild. des Lago di Santa Croce (Paleont. Abhandl., vol. vi), p. 80, pl. 1, fig. 6. — 1894. Vora quapricosrara, A. Hennig. Om Ahussandst. (Geol. Foren. i Stock- holm ForhandL., vol. xvi), p. 520. = = = — B. Lundgren. Mollusk-faunan i Mammillat. och Mucronata zonerna (IK. Svenska Vet.-Akad. Handl., N. F., vol. xxvi, No. 6), p. 44. — 1895. — a F. Vogel. Hollindisch. Kreide, p. 25. — 1896. = == A. Rutot. Bull. Soe. Belge de Géol., ete., vol. x, p- 00. — 1901. — — H. Imkeller. VWreidebild. am Stallauer Eck, ete. (Palwontographica, vol. xlvii), p. 31, pl. i, figs. 8, 9, Description—Shell large, ovate, rounded ventrally, more or less pointed dorsally, nearly equilateral; postero-dorsal a little longer than the antero-dorsal margin. Hinge-line long; ears large. Right valve convex. Umbo prominent, meurved. Length of valve either equal to or slightly less than its height; greatest length at about the middle of the valve. Usually with twenty-one (occasionally twenty-four) ribs, which curve shehtly outwards; all are strong and rounded, with slightly narrower furrows separating them. Six of the ribs are rather larger than the others, and project slightly at the ventral margin, forming angles, between which the margin of the valve is straight or shghtly concave. The interspaces between the six main ribs are flattened, and in each, three (rarely four) smaller ribs occur; these are of nearly equal size, but the middle is sometimes shghtly larger than the lateral. Occasionally this regularity im the ribs is partly lost owing to the stronger ribs being more numerous and the smaller ribs fewer than usual. Both ribs and furrows are crossed by numerous, very fine, regular concentric ridges, which are continued on to the areas. Antero- and postero-dorsal areas of fairly large size and sloping outwards—the former a little smaller than the latter. Antero- ¢ c PECTEN. 213 dorsal area with four small radial ribs; postero-dorsal area with four or five (sometimes fewer) very small ribs. Kars very large and long, convex, with fine concentric ridges; the anterior with a sinus; the posterior larger than the anterior, with the outer angle acute, and usually with six faint radial ribs. Left valve slightly concave or nearly flat, with a large apical angle; length greater than height, greatest length being above the middle line; usually with twenty-one rounded ribs of nearly equal size, separated by broader furrows, of which six—corresponding in position with the main ribs of the right valve—are Fia. 4. Fias. 3 anp 4.—Pecten (Neithea) quadricostatus, Sow. Upper Greensand, Warminster. Woodwardian Museum, Natural size. Fig. 3, right valve; Fig. 4, anterior view of the same. rather broader than the others. Antero- and postero-dorsal areas with small ribs. Ears very large, elongate, triangular, with very small radial ribs. Measurements : (1) (2) (3) «(4 «() «6(6)) SO(7)-—s (8)-—s (9)-—s (10) (11), (42) (18) (14) (15) = (16) Tength . 74 67 67 66 63 52) 78 7 56558." 57) 86. 71" 58.08.4908 83mm: Height . 77 70 68 66 65 52 75 67 56 58 57 36 66 51 41 30. ,, (1—12). Right valves: (1—6) Upper Greensand, Warminster. (7—9) Upper Greensand (zone of P. asper), Ventnor. (10—12) __,, (zone of Schlenb. rostrata), Blackdown. (18—16). Left valves: (183—15) Upper Greensand (zone of Schlenb. rostrata), Warminster. iS); 3 (zone of P. asper), Ventnor. Affinities—This species resembles DP. (Neithea) quinquecostatus, but is of larger size, with usually only three ribs in each interspace, and with relatively larger ears and longer hinge-line. A form found in the Senonian was deseribed and figured by d’Orbigny as 98 eit 214 CRETACEOUS LAMELLIBRANCHIA. Janiva quadricostata, and many later writers have followed d’Orbigny in referrin g that form to Sowerby’s species; but it was shown by Pictet and Campiche, and also by Briart and Cornet, that d’Orbigny’s species is distinct from Sowerby’s. The latter differs from the former in being of larger size, in having much larger ears and a longer hinge-line, in the anterior and posterior areas sloping outwards, in the larger apical angle (seen especially in the left valve), and in the greatest leneth of the left valve bemg above the middle line. The Senonian form figured by @Orbigny was named Jamra Faujasi by Pictet and Campiche,’ and is regarded by Choffat® as identical with regularis of Schlotheim. Fia. 5.—Pecten (Neithea) quadricostatus, Sow. Upper Greensand, Warminster. York Museum. Interior of left valve. Natural size. Types. The specimens figured by Sowerby are in the British Museum—fig. 1 is from the Upper Greensand of Haldon, fig. 2 from the Upper Greensand of Chute Farm, Warminster. The example figured in the ‘ British Mineralogy’ is from the Upper Greensand of Stourhead. Distribution.—Upper Greensand (zone of Schlenbachia rostrata) of Blackdown and the Isle of Wight; Upper Greensand (zone of Pecten asper) of Haldon, Cerne Abbas, Meleombe Bingham, Egeardon Hill, Maiden Newton, Ballard Down (Swanage), Warminster, and Ventnor. Prcotren (Nurrupa) sexcostatus, Woodward, 1833. Plate XL, figs. 10—15; Plate XUI, figs. 1—10. ? 1822. Proren quinquecosrata ?, G. Mantell. Foss. S. Downs, p. 128, pl. xxv, fig. 10. P — — TRIPLICATA, Mantell. Ibid., p. 128, pl. xxv, fig. 9. 1833. -- sEexcosratus, S. Woodward. Geol. Norfolk, p. 48, pl. v, fig. 29. 1 «Foss. Terr. Crét. Ste. Croix” (‘ Matér. Pal. Suisse,’ ser. 5, 1870), p- 253, * «Waune Crét. Portugal,’ vol. i, ser. 4 (1901-2), p. 149. PECTEN. 215 1847. Janira Duremp.et, A. d’Orbigny. Pal. Frang. Terr. Crét., vol. iii, p. 646, pl. cecexlvuy, figs. 8—11. 1850. — —_ — Prodr. de Pal., vol. 11, p. 253. — Percren xQuicosratus, J. de C. Sowerby, in F. Dizon. Geol. Sussex, p. 356 (p. 886, ed. 2), pl. xxviii, figs. 17, 18. 1854. _- sexcosratus, J. Morris. Cat. Brit. Foss., ed. 2, p. 177. 1870. Janrra Duvempcet, I’. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5), p. 253. 1877. — — A. Peron. Bull. Soe. géol. France, ser. 3, vol. v, p. 507, pl. vii, figs. 4, 4a. 1887. Vora (Janrra) Durempet, Peron. L’Hist. Terr. Craie (Bull. Soc. Sci. hist. et nat. de l’Yonne, ser. 3, vol. xii), p. 164. 1889. — Dvurempier, O. Griepenkerl. Senon. von Kénigslutter (Paleont. Abhandl., vol. iv), p. 48. 1891. - — J. Bihm. Die Kreidebild. des Fiirbergs u. Sulzbergs (Paleontographica, vol. xxxvill), p. 83, pl. i, fig. 33. 1896. — — ?, A. Rutot. Bull. Soc. Belge de Géol., ete., vol. x, p. 31, fig. 14. ?1901-2. — _ cf. Durempxes, P. Choffat. Faune Crét. Portugal, vol. i, ser. 4, p. 149, pl. iii, figs. 8, 9. Description.—Form (6 (from the Upper Chalk, figs. 1—5). Shell ovately triangular, considerably higher than long, nearly equilateral. Ventral margin nearly semicircular, but with concave incisions of moderate depth between the main ribs. Both valves show well-marked growth-ridges at fairly distinct intervals. Hinge-line relatively short. Right valve very convex, with six main ribs. Umbo greatly incurved and pro- jecting beyond the level of the left valve. Antero- and postero-dorsal areas usually sloping inwards and concave. The six main ribs are usually prominent, and are separated by broad, concave, more or less deep interspaces. In the inter- spaces there are from four to seven ' well-marked rounded ribs separated by furrows of about the same width; the central ribs are usually rather stronger than those at the sides (near the main ribs). The number of ribs in the interspaces varies in different specimens, and usually also in different imterspaces of the same speci- men; rarely four ribs are found in each interspace, less rarely five in each, but frequently five in four of the interspaces and six or seven in the remaining inter- space, or the numbers in different interspaces may be four, five and six, or five, six and seven. ‘The antero-dorsal area of this valve (7. e. the space between the anterior main rib and the anterior margin of the valve) bears from six to eight narrow ribs separated by broader furrows ; these ribs are smaller than those in the mterspaces 1 Occasionally three or four very much smaller ribs are also present. 216 CRETACEOUS LAMELLIBRANCHIA. of the main ribs. On the postero-dorsal area from eight to twelve small ribs occur. Numerous fine, concentric, regular ridges are present on all the ribs; but the ridges in the furrows are less numerous and more widely separated than on the ribs, giving a ladder-like appearance. Ears nearly equal, triangular, of moderate size, with small radial ribs; the anterior ear more sharply marked off from the valve than the posterior ear. Left valve flattened, sometimes slightly concave or slightly convex, with six main ribs which are less prominent than those on the right valve and are separated by shallow interspaces. At the summit of each main rib is a broad furrow. The ribs in the interspaces are narrow and separated by broader furrows; the number of ribs varies as on the right valve. Concentric ornamentation like that of the right valve. The antero- and postero-dorsal areas are narrow and bent at an angle with the rest of the valve; they bear small ribs. Ears nearly equal, with radial ribs. Form a (from the Lower Chalk, figs. 6—10). The examples found in the Lower Chalk present some slight general differences from Form 8. Thus (1) the margins between the main ribs are less concave, (11) the growth-ridges are also less concave, (ii) the hinge-line is rather longer, and consequently the areas do not slope inwards, but, as a rule, shehtly outwards, (iv) the convexity of the right valve seems, on the average, to be rather greater. Measurements : Q@ @ @ ® 6 © (%) © @ £@0) @) = (2) (3) irre 5 5 ly “UE TRS le IG) a TG I issn 5 6 I) ye ae RR IARC (14) (15) (16) (17) (18) (19) (20) (21) (22) (28) (24) (25) iar on BY TK) SIR EY TIRE ep TTT sete. Height. . 17 18 195 17 7 15 4 14 OF oe 1S Saaploees (1—15) Form sp. (16—25) Form a. (1—3) B. mucronata zone, Norwich. (4) as A Clarendon, Salisbury. (5 (16—22) Chalk Marl, Folkestone. (23—25) Totternhoe Stone, Burwell. 15) A. quadratus zone, Kast Harnham, Salisbury. Affinities —This species is distinguished from P. (Neithea) quinquecostatus (see p. 202) by the following characters:—(1) the average size is much less; (2) on the right valve the main ribs are more prominent and the interspaces are more concave ; (3) the ribs in the interspaces are less uniform in size; (4) the height of the shell is relatively greater; (5) generally the right valve is more convex and the umbo more sharply incurved; (6) the hinge-line is relatively shorter (especially in Form f) ; (7) the concentric ridges in the grooves are more PECTEN. 217 widely separated—in P. quinquecostatus these ridges are continued from the ribs across the grooves without change. See also 1. striato-costutus (below). The figure of Pecten sexcostatus given by Woodward is not suffi- Remarks. ciently good for exact determination, but specimens which have been obtained from the same locality as the type leave no doubt as to the identity of P. sexcos- tutus with Jamra Dutemplei, D’Orbigny. The examples from the Lower Chalk are regarded by Peron as specifically inseparable from those found in the Upper Chalk, and with this view I agree, but since some slight differences are generally noticeable, I think it may be well to look on the examples from the Lower and Upper Chalk respectively as two forms or varieties of the same species, which may be referred to as Form a and Form B.A careful comparison of good series of specimens can scarcely leave any doubt on the mind as to the later forms having descended directly from the earlier. The examples found in the Gault probably also belong to Form a; they have, however, usually been referred to P. (Neithea) quinquecostatus. The strength of the main ribs and the convexity of the right valve vary considerably in different specimens. ‘There are also variations in the number of intermediate ribs, in their relative sizes, and in the depth of the incisions of the margin between the main ribs. In some examples from East Harnham the main ribs are unusually strong. In some of the larger specimens from Norwich the number of ribs near the margin of the valve is greater than usual owing to the introduction of small ribs in the grooves. T'ypes.—W oodward’s type appears to have been lost. D’Orbigny’s type of Janiva Dutemplei came from the Senonian of Chavot (Marne). Distribution —Form a.—Chalk Marl of Dover, Folkestone, and Ventnor. Totternhoe Stone of Burwell. H. subglobosus zone of Cherry Hinton. Form B.—A. quadratus zone of Kast Harnham (Salisbury) and Winchester. B. mucronata zone of Ballard Head (Dorset), Clarendon (Salisbury), and Norwich. Upper Chalk (? zone) of Brighton. Recorded by Rowe from the M. cortestu- dinarium and M. cor-anguinum zones of Thanet. Proven (Nerruea) striavrocostatus, Goldfuss,' 1833. Plate XLI, figs. 9, 10. A portion of a right valve and a nearly perfect left valve, which were found by 1 «Petref. Germ.,’ vol. ii (1833), p. 55, pl. xeili, figs. 2 ¢, d, e (not 2 a, b, f, g) ; Favre, ‘ Moll. Foss. Craic de Lemberg’ (1869), p. 156, pl. xiii, figs. 12, 13 ; Holzapfel, ‘ Moll. Aachen. Kreide’ (1889), p. 239, pl. xxvi, fig. 19; Vogel, ‘Holliindisch. Kreide’ (1895), p. 26; Miiller, ‘Mollusk. Untersen. v. Braunschweig u. Ilsede’ (1898), p. 37; Ravn, ‘Mollusk. i Danmarks Kridtaflej.’ (1902), p. 95, pl. ii, figs. 8, 9; Wolle- mann, ‘ Mauna der Lineburg. Kreide’ (1902), p. 63. 218 CRETACEOUS LAMELLIBRANCHIA. Mr. Clement Reid in the Chalk of Trimingham, probably belong to P. (Netthea) striatocostatus, Goldfuss. The six main ribs of the right valve are less prominent than in P. (N.) sevcostatus, and both these and the ribs in the interspaces bear two or three small, almost linear ribs, so that the total number of ribs on the valve becomes considerable; fine concentric ridges, similar to those of P. (N.) sea- costutus, are found in the grooves and sometimes pass on to the ribs. On the left valve the ribs are im pairs. P. striatocostatus is found in the Senonian of Denmark, Aachen, Lemberg, ete. Genus—-VELOPECTEN, Philippi, 1898. (‘ Zeitschr. d. deutsch. geol. Gesellsch., vol. 1, p. 597.) VeELorectEN Stuperi (Pictet and Rouw), 1853. Plate XLI, fig. 11; Plate XLII, fies. _—4. 1853. Huinnires Srupert, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Gentve, p. 504, pl. xlv, fig. 1. 1866. — Saurert, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. xvii, p. 178. 1870. — Scuvert, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Mat¢ér. Pal. Suisse, ser. 5), pp. 232, 234, pl. clxxix. 1875. -- = A. J. Jukes-Browne. Quart. Journ. Geol. Soc., vol. xxxi, p. 296. Description.—Shell large, oval or nearly circular, somewhat inequilateral and irregular; height a little greater than length. Hinge-line long, sometimes almost equal to the length of the shell. Ears very unequal; the anterior left ear not dis- tinctly separated from the rest of the valve. Right valve flat, sometimes shehtly concave, with more or less undulating surface. Radial ribs much more numerous, smaller, and closer together than on the left valve, alternately larger and smaller. Numerous growth-ridges cross the ribs, and produce a serrate appearance. Byssal sinus very deep; anterior ear very large. Left valve convex, with a more or less undulating surface, ornamented with about fifteen primary ribs, which are narrow, strong, and slightly wavy, and are separated by broad, shallow interspaces; these ribs are prominent on the dorsal part of the valve, but become smaller on the ventral part, especially in large speci- mens. A secondary rib is usually introduced in the middle of each interspace, at varying distances from the umbo; and between this and the primary ribs on each VELOPECTEN. 219 side other ribs (sometimes four or five) are introduced; these are usually smaller, and may be quite close together, but in old specimens they become widely separated ventrally. Both ribs and furrows are crossed by numerous fine, close- set, regular, concentric ridges. Anterior ear with about seven primary and seven secondary ribs. Posterior ear smaller and more distinctly limited. Affinities.—Hinnites Salteri, Seeley, from the Red Limestone of Hunstanton, is founded on a portion of the left valve; it appears to me to be only a large example of V. Studeri, in which the main ribs are less prominent than usual owing to the abrasion of the shell. See also V. trilinearis (below). Remarks.—The state of preservation of the examples of this species varies con- siderably, but is usually rather unsatisfactory. In the specimens from Warminster, where the species appears to be rare, the shell is preserved, and the ornamentation is very well shown, but in those from Folkestone the shell has usually disappeared. The examples from the Cambridge Greensand are internal casts in phosphate, in which there is no trace of the ears, and whilst some of the principal ribs are shown the details of the ornamentation are wanting. ‘The specimens from the Red Lime- stone of Hunstanton are usually considerably larger than those from the Cambridge Greensand, and have the shell preserved in part at any rate; in some cases the fine ornamentation is clearly shown, but often it is indistinct owing to the outer layers of the shell having disappeared ; in these large forms the main ribs become much less strong near the ventral margin, or, in some cases, almost in- distinguishable. T'ypes.—F rom the Gault of the Perte du Rhéne. The type of Hinnites Saltert, Seeley, from the Red Limestone of Hunstanton, is in the Woodwardian Museum, Cambridge. Distribution—Upper Gault (zone x) of Folkestone. Cambridge Greensand (derived from the Upper Gault). Red Limestone of Hunstanton. Upper Greensand of Warminster. VELOPECTEN TRILINHARIS (Seeley), 1861. Plate XLII, fig. 5. 1861. Hiynires rrininearis, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii, p. 119, pl. vi, fig. 2. 1866. — — var., Seeley. Ibid., vol. xvii, p. 178. Remarks.—The form named Hiniites trilinearis by Seeley was founded on a few imperfect specimens from the Cambridge Greensand. They seem to differ from the English examples of V’. Studeri in having the primary ribs on the left valve stronger and more widely separated, but they approach very closely some of the specimens of that species figured by Pictet and Campiche, especially in having 5 220 CRETACEOUS LAMELLIBRANCHIA. small secondary ribs at the summits of the primary ribs. I have not sufficient material to enable me to decide whether or not J’. trilinearis should be regarded as distinet from V. Studeri. Type.—In the Woodwardian Museum. Distribution.—Cambridge Greensand (derived from the Gault). VerLoprectEen prctinatus (Seeley), 1861. Plate XLII, fig. 6. 1861. Hinnrres pectrnatus, H. G. Seeley. Ann. Mag. Nat. Hist., ser. 3, vol. vii, Pp ALLS), Remarks.—This form agrees with V. trilinearis m having very strong primary ribs, but seems to differ in that those ribs are more numerous and consequently closer together ; the secondary ribs at the summits of the primaries also appear to be better marked, and are crossed by distinct concentric ridges. T'ype.—In the Woodwardian Museum. Distribution.—Cambridge Greensand (derived from the Gault). VuLOPECTEN, sp. Plate XLII, figs. 7, 8. A few specimens from one of the nodule beds of the Gault of Folkestone agree with V. trilinearis (Seeley) in having relatively few main ribs on the left valve, and in the presence of secondary ribs at their summits, but the shell appears to be proportionately higher and shorter. Genus—Hunnites, Defrance, 1821. (‘ Dict. Sci. nat.,’ vol. xxi, p. 169.) Hiynires Favrinus, Pictet and Rouw, 1853. Text-fies. 6, 7. 1845. Hinnires Leymert, 2. Forbes (non Deshayes). Quart. Journ. Geol. Soc., vol. 1, p. 250. 1853. — Favrinus, F. J. Pictet and W. Roux. Moll. Foss. Grés verts de Gentve, pp. 503, 547, pl. xliii, fig. 2, pl. xliv. 1854. == Leymertt, J. Morris. Cat. Brit. Foss., ed. 2, p. 169. 1858. ~- Favrines, FJ. Pictet and HE. Renevier. Foss. Terr. Aptien (Matér. Pal. Suisse, ser. 1), p. 135. 1865. — —_ H. Coquand. Mon. Aptien de Espagne, p. 155. HINNITES. 221 1870. Hrnnrres Favrinvs, F. J. Pictet and G. Campiche. Foss. Terr. Crét. Ste. Croix (Matér. Pal. Suisse, ser. 5 p. 231, pl. clxxviii. 1871. — : I’. Stoliczka. Paleont. Indica, Cret. Fauna S. India, vol. ili, p. 450. 1887. — L. Mallada. Sinops. Espec. Féss. Espana, vol. iii, Cret. infer. (Bolet. Mapa geol. Espana, vol. xiv), p. 131. Description.—Shell very large and thick, irregularly oval or subcireular, with rounded margins ; height sometimes equal to, but usually rather greater than the length. Hinge-line rather long; ears nearly equal. Right valve convex, attached by a more or less large portion in the region of Fic. 6.—Hinnites Favrinus, Pict. and Roux. Perna-bed, Atherfield. Museum of the Geological Society, No. 2022. Right valve. x }. the umbo; the unattached part has numerous broad, rounded, radial ribs of unequal size and sometimes bifurcated. Ribs with scale-like projections, and some- times showing fine radial grooves. A few concentric lamellz or depressions, and also numerous fine growth-lines, cross both ribs and grooves. Left valve nearly flat—sometimes slightly concave, sometimes slightly convex, with radial ribs and scales similar to those of the right valve, but the ribs rather 9G 222 CRETACEOUS LAMELLIBRANCHIA. narrower and the intervening grooves broader. The scale-like projections are sometimes greatly developed. Measurements : (1) (2) (3) (4) (5) (6) lengthy 139% . 130 50 eS eee eSeminar Height. 152 pay 5 Jl , wes . Ie . Wo ,. (1—6) Perna-bed, Atherfield. Afinities.—This species is related to Hinnites Renevieri (Coquand),’ but is dis- tinguished by the ribs being less frequently bifurcated and more nearly straight. H. Leymerii, Deshayes,’ differs from H. Favrinus by the great mequality of the ribs—a few being large with smaller ribs in the interspaces. Philippi* has discussed the affinities of the group to which the above-mentioned Fic. 7.—Hinnites Favrinus, Pict. and Roux. Museum of Practical Geology, No. 8444, Lower Greensand (Perna-bed), Atherfield. Left valve. x 2 3 species belong, and is inclined to regard it as genetically independent of the Tertiary species of Hinnites. This view seems to be based chiefly on negative evidence, viz. the absence, so far as at present known, of Hinnites from the Upper Pictet and Campiche, ‘ Foss. Terr. Crcét. Ste. Croix’ (1870), p. 227, pl. elxxvi. * Pictet and Campiche, ibid., p. 224, pls. clxxiv, clxyxv. Deshayes, ‘Mém. Soc. géol. France,’ vol. v (1842), p. 27, pl. xiv, fie. 1. > *Zeitschr. d. deutsch. Geol. Gesellsch.,’ vol. 1 (1898), p. 601. HINNITES. 992 Cretaceous and early Tertiary deposits. But until definite evidence of the inde- pendent origin of the Tertiary species can be given it seems to me better to refer the Lower Cretaceous species to Hinnites, since they agree so closely with the typical species of that genus. T'ypes.—The specimen referred to Hinnites Leymerii by Forbes is in the Museum of the Geological Society (No. 2022). Pictet and Roux’s types came from the 4 ‘ian of the Perte du Rhone. Distribution —Perna-bed and Fitton’s Bed 13 of Atherfield. Hythe Beds of Court-at-Street, Hythe. 224. CRETACEOUS LAMELLIBRANCHIA. ADDITIONS AND CORRECTIONS. Page 51. Placunopsis undulata (Miller). Two specimens closely resembling this species have been obtained by Mr. R. M. Brydone from the Trimingham Chalk. Figures are given by Holzapfel (1889) and Ravn (1902). Page 35. Barbatia aptiensis (Pict. and Camp.). This species has been found by the Rev. W. R. Andrews at the base of the Gault at Dinton, in the Vale of Wardour, and recorded as Arca Raulini by Mr. Jukes-Browne. Page 41. Barbatia Galliennei (A Orb.). A specimen has been obtained from the Chloritic Marl of Maiden Bradley. Page 70. Add Pecruncutus VauGHanl, sp. nov. Plate XLII, fig. 11. Description.—Shell stout, convex, nearly equilateral, but shehtly longer anteriorly than posteriorly, with a rounded subquadrate outline; length a little greater than height. Umbones small. Hinge-area very small. Ornamentation consists of numerous flattened radial ribs, separated by linear grooves; the ribs are more numerous on the left valve than on the right, and more numerous on the anterior than on the middle parts of the valves. A few faintly marked growth- lines are seen at intervals. Interior of valves not seen. Measurements : Length : : : 5 . 315 mm. Height : ‘ , : 5 OHO) ap Affinities. —This form presents some resemblance to I. subconcentricus, Lamarck,' but is more nearly equilateral, has a much smaller hinge-area, and the concentric ridges are absent. Remarks.—I have seen only one specimen of this species. The two valves are united, and consequently the interior cannot be seen. The specimen was collected by Mr. Arthur Vaughan, B.A., B.Sc., and presented by him to the Woodwardian Musewn. Distribution.—Greensand of Blackdown. Page 71, line 20 from the top. For “ Bed ii” read “ Bed 11.” ‘ ] Page 80. Trigonia spectabilis. Reference to Lycett—for pl. xxxvi read pl. xx. 1 D'Orbigny, ‘ Pal. Frane. Terr. Crét.,’ vol. iii (1844), p. 189, pl. ecevi, figs. 12—19. ADDITIONS AND CORRECTIONS. 225 Page 96. Modiola ligeriensis (VOrb.). The following should be added to the synonymy :—Modiola striata, Drouet, ‘Mém. Soc. Linn. de Paris,’ vol. iii (1824), p. 192, pl. vii, fig. 5. Non Modiolus striatus (Mont.), Maton and Rackett, 1807. Non Modiola striata, Defrance, 1824. Page 106. Septifer lineatus (Sow.). A specimen from the Beleivnitella mucronata zone, near Fareham (Hants), has been found by Mr. C. Griffith, of Winchester. Page 106. “Family Dreissensiide, Gray,” should be transferred to the middle of Page 110. Page 111. Line 11 should follow line 5. Page 112. Footnote 1. For vol. li vead vol. xlin. Page 135, line 3. For Kreide vead Neocoms. Page 143. For Pricaruna siginnina read Dimyopon Nitsson1 (Hagenow), 1842. Additional synonymy. 1842. Ostrea Ntiussont, Fv. Hagenow Neues Jahrb. fiir Min., ete., p. 546. 1891. Dimyopon Niussont, J. Bohm. Die Kreidebildungen des Fiirbergs, ete (Paleontographica, vol. xxxviii), p. 89, pl. iv, fig. 7. 1892. — - E. Stolley. Die Kreide Schleswig-Holsteins (Mit- theil. a. d. Min. Instit. Universit. Kiel, vol. i), p. 242. 1895. Cycnostreon Niussont, F. Vogel. Hollind. Kreide, p. 14, pl. i, figs. 4—7. 1900. Dimyopon Niussont, K. A. Griinwall. Meddel. Dansk. geol. Foren., No. 6, p. 75. 1902. - J.P. J. Ravn. Mollusk. i Danmarks Kridtaflej. I, Lamellibr. (K. Danske Vidensk. Selsk. Skrift. 6. Raekke, nat. math. Afd., vol. xi), p. 109. After the publication of Part III of this Monograph I received a copy of a paper by K. A. Grénwall on Dimyodon in the Danish Chalk. From the figures there given, and also from the one given by Bohm, I think that there can be no doubt as to the identity of Plicatula sigillina with the form described (but not figured) by von Hagenow as Ostrea Nilssoni. This identity has been confirmed by Mr. J. P. J. Ravn, of Copenhagen, to whom I have sent specimens of Plicatula sigillina from Norwich. 30 226 CRETACEOUS LAMELLIBRANCHIA. Ostrea Nilssoni has been referred by Bohm, Stolley, Grénwall, and Ravn to the genus Dimyodon, Munier-Chalmas.'| When describing Plicatula sigillina I remarked that although it belonged to a type distinct from the other Cretaceous species, yet it resembled the recent form Plicatula phillipinarum, Hantz. I have not seen the adductor impressions in any specimens of Plicatula sigillina, but nevertheless [ think that it is quite possible that the authors mentioned may be correct in referring this species to the genus Diinyodon, Munier-Chalmas. Dimyodon costatus, Gronwall, seems to be very closely related to D. Nilssoni. Page 152. Pecten Nilssoni, Goldf., Plate XLII, figs. 9, 10. Through the kindness of Mr. J. P. J. Ravn I have received specimens of P. Nilssoni from the Chalk of Faxe, and I am now able to state that I consider that the specimens from Trimingham, mentioned on page 152, and also another from the Act. quad- ratus zone of Hampshire (coll. R. M. Brydone), are referable to that species. 1 In Fischer’s ‘ Manuel de Conchyliol.’ (1886), p. 957. Synonyms are printed in ifalies. Acila AKquipecten Anomia - convexa — levigata — papyracea — pseudoradiata — radiata — ¥f transversa aptiensis — Austeni ... — carinata — Carteroni — Cornueliana cymodoce — Dupiniana evaltata ... — fibrosa — Fittoni — Forbesi — formosa ... — Gabrielis — Galliennei — Geinitzi ... —= glabra — Guerangeri EN Din xX. which the species are figured. PAGE 19 186—197 27—31 29, v, 10 29, v, 6—9 31, v, 18—16 burwellensis ae! 97-130..¥,.1—3 ale YE 30, v, 12 32S) 36 37 we = 45 35; Vly 40D 50 35 32, vi, 1—3 49 Arca ligeriensis Mailleana marullenis nana obesa Passyana pholadiformis radiata Raulini ... Robinaldina rotundata rotundita Sancte-Crucis ... securis subformosa vendinensis Barbatia — aptiensis — Austeni — Galliennei Geinitzi — Hugardiana — marullensis ... — rotundata — vendinensis ... Brachydontes ... — Hugardiana isocardizeformis... - Guerangeri Byssoarca marullensis The Roman numerals refer to the plates on PAGE 40 . 40 34, vi, 6, 7 Ad 56 41 35—37 35, 224, vi, 8, 9 37, vii, 1—3 41, 224, vii, 9 42, vii, 10, 11 = 40 38, vii, 4—7 40, vii, 8 ot aed 101—103 101, xvii, 4,5 38 INDEX. 228 PAGE Camptonectes .. 152—163 Cardium (Homicardeme ?) Vusient 37 | — umbonatum ... 69 | Ceromya crassicornis ... san LOL) Chlamys 163—186 — ternata 190 Crenella a ee ee O4 == |oxky 104, xvii, 12, 18 Cucullea 49—64 carinata : 47, iE — Commuehaha — (Idonearca) GPenieiiaen Hs — costellata e Bae Fy 45 | — (Dieranodonta) donningtonensis 54, x, 11—14; xi, 1, 2 — errans 52 — fibrosa a 57 —_ Fittoni 2,x, 4-7 a Forbesi 49, ix = formosa 56 oo Gabrielis eer 49) — glabra 57, xs gle, xii, 1—65 — Mailleana ... > 63, x1, 4.5 — nana 62, xiii, 1—3 — obesa ... 61, xu, 6—8 | (Dicranodonta ?) obliqua... 55, xi, 3, 4 — Paasyana 47 — securis 44 — striatella 45 — subnana 50 — vagans , x, 8—10 = venusta 56, x1, 5—7 Cyclostreon Nilssoni .. 225 Cypricardia undulata 100 Dianchora lata 121 | — obliqua 121 — spinosa 125 — striata 119 Dicranodonta ... 53 Dimyodon Nilssoni 225 Dreissensia_ ... oe oe ae sos JUD) lanceolata 110, xviii, 18—15; xix, 1—11 Grammatodon 44.— 4.7 PAGE Grammatodon carinatus 45, viii, 3—8 = securis... 44, vii, 1415; viii, 1, 2 Hinnites : 220—223 — Favrinus 220, Text-figs 6, 7 — Leymerir 220 — pectinatus 220 — Salteri 218 — Studeri 218 — trilinearis 219 Idonearca fibrosa 57 — glabra 57 Inoceranius siliqua ; 99 Isoarca 65, 66 | = Agassizi 65, xi, 7 | saree ntabrigiensis sop (88) | — obesa .. 65, xiii, 8 | Tsocardia crassicornis 65 — Orbignyana 65 Janira xequicostata 208, 209 — atava 197, 198 | — cometa ... 200 — Dutemplet 207, 215, 217 — Faucignyana ... 210 — Fontanieri 203 | — Geimitzii 210 — Morrisi son AIL one neocomiensis ... LO AAG SS | ee quadricostata ee 211, 212 _ — quinquecostata 201—203, 205 | Leda angulata 8 | — lineata ... 7 — Marie 6 — phaseolina 9 es scapha 3,7 | — WSeeleyi ... 5 — siliqua ett | — solea 5 | = spathulata 1,4 — subrecurva 2,9 — Vibrayeana 10 Lima brightoniensis 128 — spinosa ... 128 Limopsis ‘71-73 Limopsis albiensis Lithodomus — rugosus ? Lucina orbicularis Lyriodon crenulatus ... — excentricus ... — sinuatus Lyrodon excentricum ... INDEX. PAGE 71, xv, 1; 2—4 105 105, xvii, 14 71 83 76 76, 77 7 6 Modiola 92—104. aequalis 92, xv, 8—14 angusta 106 —— WGI ons 104. Cornueliana ... 104 — Cottx 106 — flagellifera . 99, xvii, 1, 2 — granulosa sa 106 — (Brachydontes) Guerangeri, 101, xvii, 4,5 — levigata re . O4 — ligeriensis 96, 225, xvi, 4—6 — lineata 106 — obesa... 93 — pedernalis 104 — quadrata ... 343 i 107 - reversa ... 94, xv, 15—18; xvi, 1—3 — rugosa 97 — simplex 97 — striata 225 — (Brachydontes) striato-costata, — subfaleata — subsimplex — typica — undulata Myoconcha — cretacea Mytilus — abruptus — exqualis — asper ... — bellus ... — ciplyanus — Cornuelianus... — Cotte ... — Cuvieri — edentulus 103, xvii, 9—1] 111 | 97, xvi, 7—10 Ate: 96 100, xvii, 3 (Brachydontes) vectiensis, 102, xvii, 6—8 | 14 114, xx, 3 91, 92 110 | 92 106 | 104 107 | 104. 106 | 106 | 110 | Mytilus falcatus flagelliferus Galliennei ~ Guerangeri gurgitis hainoensis ineequivalvis ... lanceolatus —~ ligeriensis lineatus Orbignyanue ... peregrinus - prelongus reversus rugosus semiradiatus ... simplex spathulatus striato-costatus subangustus ... — subfalcatus — sublineatus - subrugosus — subsimplex — tornacensis — tridens undulatus Neithea (see Pecten) Nucula albensis antiquata apiculata (Acila) bivirgata capseformis ... -~ Cornueliana ... Derancei gaultina impressa impressa Lamplughi lineata Marie Meyeri obesa ej obtusa equilateralis ... ee Abe ... 24, iv, I—17 DIDO PAGE 110 99 111 101 97 91 91, xv, 7 110 96 106 107 107 110 94. 97 wwe «= 4 97, 114 107 103 106 110 106 97 97 91 110 101 =< 26, iv, 22—26 23 ... 19, iti, —12 21 15 21 sek terete I) - 7 ae 6 15, ii, 21 65 . 22, iv, 2—4 230 Nucula obtusa... ornatissima ovata, Mant. ... ovata, Phil. pectinata phaseolina planata rhomboidea rhotomagensis seapha siliqua simplea solea spathulata subelliptica subrecurva Vibrayeana Nuculana angulata lineata Mari phaseolina ... (? Yoldia) seapha Seeleyi siliqua solea spathulata... speetonensis subrecurva... Vibrayeana Ostrea muricata Nilssoni Pachytos spinosus striatus Pecten... INDEX. PAGE | 12 19 21, iii, 16—21; iv, 1 12 16, ii, 22—27; in, 18 var. crete ... — (Neithea) equicostatus (Chlamys) aptiensis ... eequicostatus arachnoides (Camptonectes) arcuatus (Chlamys) arcuatus ... (Aiquipecten) arlesiensis, 194, xxxvii, 9—11 (Camptonectes) arzierensis 18, iii, 14, 15 2 | Pecten (Alquipecten) asellus 12, ii, 1115 | 10 10 2,9 , ly 1—11 . Ssh, Rss | .. 7,1, 28—32 . 6,1, 25—27 9, u, 1—83 . 3,1,8—14 . 5,1, 1L5—17 ae 11,1, 10 . 5,1, 18—24 T= 34 Syl On a 2,1, 4, 5 10, u, 4—9 Do — bo © oD 127 127 145—218 | . 208, xl; 8, 9 203, 215 var. longicollis 208 181, 182 174, 177, 178 159, 160, 161 175 158 PAGE 119 asper 186, xxxv, 12; xxxvi, 1—4 (Neithea) atavus 197, xxxix, 1—5 (Chlamys) Barretti 182, 185 (Aiquipecten) Beaveri . 188, xxxvill 167, xxxi, 1, 2 169 (Chlamys) britannicus “= Brongniarti (Aiquipecten) campaniensis 192, xxxviui, 4-8 (Camptonectes) cinctus 152, xxviii (Syncyclonema) cireularis, Gein. 146 (Camptonectes) circularis 154, 156 (Chlamys) comans 171, 172 (Neithea) cometa 200, xxxix, 6—10 ee OS ORS (Camptonectes) Cottaldinus, 156, xxix, 1—3 ra LAY, 153, 154 (Chlamys) cretosus, 174, xxxii, 4—6 ; xxii (Chlamys) concentricus (Syncyclonema) Cottaldinus ... (Camptonectes) crassitesta — cretosus, Golde. 7a = — var. nitida 176 — var. Zeisneri 176 — crispus 171, 176 (Camptonectes) curvatus 159, xxix, 7; xxxvii, 16 (Myuipecten) depressus 188, 189 (Camptonectes) divaricatus ... 160 — dubrisiensis ... 162, xxix, 8 (Aquipecten) Dujardini 190, 191 (Chlamys) Dutemplet 182 — elongatus 170, xxxi, 1O—13; xxxn, 1—3 Faujasi 171,173 — fissicosta ... 163, xxx, 3—8 = Galliennei . 182, 184. (Camptonectes ?) gaultinus 163, xxx, 1, 2 (Syncyclonema) germanicus ... 147, 148 (Chlamys) hispidus 183 (foot-note) (Camptonectes) imperialis . 153 (Chlamys) interstriatus 181, 182 (Aquipecten) jugosus 189, 190 (Syncyclonema) laminosus 145, 146, 149 (Camptonectes) lens, var. Morini 158 (Aquipecten) lineatus 194, 195 (Chlamys) Mantelli 180 Mantellianus 179, xxxiv, 1—6 Pecten (Chlamys) Marrotianus INDEX. PAGE 171,173 - Milleri 168, xxx1, 3—6 (Camptonectes) Morini 159 (Neithea) Morrisi . 201, xxxix, 11—13 Morrisi 204, 206 Nilssoni 149, 152, 226, xii, 9, 10 (Chlamys) nitidus 174, 178 obliquus 170, 171, 181 (Syncyclonema) opercularis . . 146 orbicularis ... 145, xxvii var. Loh- manne : ise 147 (Syncyclonema) orbicularis, var. magnus ae 147, 148 (Neithea) ornithopus ... 197, 199 (Chlamys) Passyi 182, 184. (#quipecten) pexatus 190, xxxvi, 5—7 pulchellus 194, xxxvii, 12—15 165, xxx, 9—12 210, x15.6;.7 (Chlamys) Puzosianus (Neithea) quadricostatus quinquecostatus 202, xxxix, 1l4—17; xl, 1—5 201, 214 171,173 - quinquecostatus (Chlamys) Raulinianus Robinaldinus 181, xxxiv, 7—12; xxxv, 1—10 (Camptonectes) Remeri 153 (Aiquipecten) sarumensis 192, xxxvui, 1—3 (Neithea) sexcostatus 214, xl, 1O—15; xli, 1—10 194, 195 195 217, xli, 9,10 (Camptonectes) striato-punctatus 157, xxix, 4—6 (Afyuipecten) spurius -- Staszyet (Neithea) striato-costatus ? striato-punctatus 160 (Chlamys) Stutchburianus 185, xxxv, 11 Stutchburiensis 185 169, xxxi, 7—9 175, 182, 184. 146, 149 subacutus subinterstriatus (Syncyclonema) sublaminosus (Aiquipecten) subpulchellus 195 ternatus one 191 (Neithea) triplicata ... 214 (Chlamys) undulatus... 175 Pecten (Neithea) versicostatus — (Camptonectes) virgatus — (Chlamys) Zeisneri Pectinites aculeatus = asper Pectunculus euglyphus marullensis = obliquus .. subleevis... umbonatus Vaughani Perissonota Pinnites ungulatus Placunopsis undulata Plagiostoma brightoniensis spinosa ... — spinosum — sulcata Phicatula — _ equicostata... — Barrois1 Carteroniana — _ gurgitis inflata minuta nodosa pectinoides ... — placunata — placunea = radiola — sigillina — spinosa Podopsis striata Portlandia pectinata ... Scaphula Septifer lineatus Spondylus -- eequalis — zequicostatus - Brunneri ... — capillatus ... — dichotomus duplicatus... bo oi) — PAGE 201, 202, 206, 210 160 175 127 ... 186 66—70, 224. VL, xave 3) 66, xiii, 9, 10 55 ... 67, xiv, 1—7 69, xiv, 8—12 . 224, xiii, 11 141, ll 136 xxvi, 12—18 135, xxv, 5—12 137, xxv, 13—21 139, xxvi, 1—11 138, xxv, 22—25 ey 137, 141 134 134, xxv, 1—4 143, 225, 106, 225, 137, 139 xxvi, 19—22 139 120 16 37 .. 106 xviii, 1—12 116—134 128 122, 123 Uy, 119 143 128, 131 Spondylus Dutempleanus INDEX. PAGE Trigonia eacentrica 125, xxii, 11—14; xxiii, 1—5 | — Fittoni — Dutemplet... es we 125 | — hunstantonensis — gibbosus ... 117, xx, 5—11 — ingens — latus 121, xxii, 1—10 | — Keepingi —- latus, Desh. 116 — leviuscula ... = lineatus 121 | — Mejyeri _ obliquus 121 | — nodosa — padopsideus 127 — ornata = radiatus lle — pennata — Reemeri 116, xx, 4 | — — pseudospinosa = serratus .. 124, xxi, 6, 7 | — Robimaldina ? = spinosus 127, xxiii, 6—11; xxiv, 1—7 rudis = striatus 119, xxi, 1—5 — seabricola -- strigilis 134 | — scapha — subspinosus sag) Ash | — sinuata — superbus 198) 139; = spectabilis ... Syncyclonema.... 145—152 Pees spinosa = orbicularis 147 — spinosa — sublaminosa 147 | — suleataria — tealbyensis ... Trigonia 73—90 | — _upwarensis ... — affinis 77 — Vectiana — aleformis 83, 84 | = Vicaryana — aliformis 83 Trigonoarea = Archiaciana 86 | = Passyana — carinata 90 Ts CRC e | Velopecten - _ hie , e | = pectinatus 7 pose ae = Studeri — costigera sao tote) ca ‘ gS } | = trilinearis = erenulata ... PA, aby WCE I} Task ; = Vola eequicostata — crenulifera ... 82 Cc pene 90 atava — 10 © 5 eat — Dutemplei — dedalea 80 a — Morrisi ... — dedalea 7s ; a — quadricostata — debilis 78 | j ; ety, | — quinquecostata ... — dunscombensis (8, xix, 12 eccentrica 76, 77 | ; — Etheridgei ... g1 | Yoldia... — exaltata 74, — scapha PRINTED BY ADLARD AND SON, LONDON AND DORKING. 8d, xix 78 oe [By 285 lls 76, 77 80, 224. 86 87 89 79 86 84 55 ey 47,48 47, viii, 9, 10 218—220 # 220, xlii, 6 218, xli, 11; xlii, 1—4 219, xli, 5 208 198 215 .. 202 211, 212 203, 204, 205 The figures are of natural size unless the amount of enlargement is stated. PLATE I. Genus Nucutana, Link. FIGS. 1—3. N. spathulata (Forbes). (P. 1.) 1. The Type. Atherfield Clay, Atherfield. Mus. Geol. Soc., No. 2112. 2. Crackers, Atherfield. Wiltshire Collection, Woodwardian Museum. a, right valve; b, anterior of same; ¢, same valve x 2. 3. Same horizon, locality, &c. Left valve. 4, 5. N. subrecurva (Phil.). Speeton Clay, Speeton. Leckenby Collection, Woodwardian Museum. (P. 2.) 4. a, left valve; 6, anterior view; ¢, dorsal. Figured by Gardner. 5. a, right valve; 0b, dorsal view. 6, 7. N. speetonensis, Woods. Speeton Clay, Speeton. Museum of Practical Geology, No. 6412. (P. 3.) 6. a, left valve; 6, ornament x 2. 7. a, left valve; 6, dorsal view. 8—14. N. [? Yoldia| scapha (dOrb.). 8—13, Atherfield Clay, Sevenoaks. (Be 3:) 8. Collection of C. J. A. Meyer. a, right valve; 0, dorsal view; ec, ornament x 2. Figured by Gardner. 9. British Museum, No. L 9280. Left valve. 10, 11. = Right valves. 12. Collection of C. J. A. Meyer. Left valve. 13. — — Right valve. 14. Speeton Clay, Speeton. Woodwardian Museum. Left valve. 15—17. N. Seeleyi (Gardn.). Speeton Clay, Speeton. (P. 5.) 15. The Type. Leckenby Collection, Woodwardian Museum. a, left valve; 3, dorsal view. 16. Woodwardian Museum. a, left valve; 6, dorsal. 17. Bed C3. Collection of G. W. Lamplugh. a, left valve; 6, dorsal outline. 18—24. N. solea (d’Orb.). Gault, Folkestone. (P. 5.) 18,19. Wiltshire Collection, Woodwardian Museum. Right valves. 20. Montagu Smith Collection, Woodwardian Museum. Interior of left valve x 2. 21—24. British Museum, No. L 4974. 21, 28, and 24, right valves; 22, left valve. 95—27. N. Marie (d’Orb.). Gault, Folkestone. (P. 6.) 25. British Museum, No. L 4973. a, right valve; 6, dorsal outline; ¢, same x 2. 26. British Museum, No. L 4973. a, right valve; b, same x 3. 27. Woodwardian Museum. Right vaive. 28—-32. N. lineata (Sow.). 28—31, Greensand, Blackdown. (P. 7.) 28. The Type, Bristol Museum. a, right valve; 0, dorsal view. 29. Collection of C. J. A. Meyer. Lett valve. 30. Wiltshire Collection, Woodwardian Museum. Left valve. 81. _- _- a, outline of left valve; 6, same x 2; ¢, same, dorsal, x 2; d, interior of another specimen, right valve, x 3. 32. Lower Greensand, Atherfield. Gardner Collection, British Museum, No. L 5109. a, outline of right valve; 6, same x 2; c, dorsal view xX 2. 3—35. N. angulata (Sow.). Greensand, Blackdown. (P. 8.) 33. Collection of C. J. A. Meyer. a, outline of right valve; 6, same X 4; ¢, another specimen, dorsal view, x 4. 34. a, outline of right valve; 6, same x 4. 35. The Types, British Museum, No. 43213. a, outline of right valve; 6, same x 3; ce, dorsal view of another specimen x 3; d, interior of another specimen, right valve, x 3. PLATE I E Wilson, del WT Crowther hth Weat, Newman ump CRETACEOUS LAMBELLIBRANCHIA. — 1 7 f ae ‘ + Py. Sa : on *. _ = 1 . _ =) = = one i oi - 7 i 7 - r 2 7 » - ’ P . . . § ry | & 7 a “ » = 7 a a - : ae : - 2 e P| - a pt . in a. . ; = - -_ z » Wye 7 ) ! : Re . _ 7 - 7 7 - 1 Te. » at - + Me Pon _ _ oa OG ' : > a - = - * - i a , as . - eo PLATE II. Nucutana (continued). FIGS. 1—3. N. phaseolina (Mich.). Gault, Folkestone. (P. 9.) 1. British Museum, No. L 5106. a, left valve; 6, dorsal view; ¢, posterior; d, left valve x 2. 2,3. British Museum, No. L 4969. 24a, right valve; 26, same x 3; 3, left valve. 4—9, N. Vibrayeana (@’Orb.). 4—8, Gault, Folkestone. British Museum, No. L 4971. (P. 10.) 4. a, right valve; b, same X 2; e@, dorsal view X 2. 5. a, right valve; 6, dorsal view. 6—S8. Left valves. 9. Cambridge Greensand (derived from Gault). The Type of WV. subelliptica, Seeley, Carter Collection, Woodwardian Museum. Right valve; natural internal mould. 10. N. sp., ef. siliqua (Goldf.). Chalk Rock (zone of Het. Reussianum), Cuck- hamsley. Montagu Smith Collection, Woodwardian Museum. a, internal mould of left valve; 6, mould of teeth x 3. (P. 11.) Genus Nucuta, Lamarck. 11—15. N. planata, Desh. 11—13, Speeton Clay, Speeton. Leckenby Collec- tion, Woodwardian Museum. (P. 12.) 11. a, right valve; 0, dorsal view. Figured by Gardner, Quart. Journ. Geol. Soe., xl (1884), pl. v, f. 3. 12. a, right valve; 6, dorsal view. 13. Right valve, somewhat crushed. Figured by Gardner, zbid., pl. v, f. 2. 14 Crackers, Atherfield. Woodwardian Museum. 4a, left valve; 6, dorsal view. Figured by Gardner, ibid., pl. v, f. 1. 15. Crackers, Atherfield. Leekenby Collection, Woodwardian Museum. Right valve. 16, 17. N. sp. Claxby Ironstone (zone of Belemnites lateralis), Benniworth Haven. Woodwardian Museum. (P. 13.) 16. a, left valve; 6, same, interior filled with oolitic ironstone; c, same, posterior ; d, same, dorsal. Figured by Gardner (as WV. Cornueliana, d’Orb.), Quart. Journ. Geol. Soc., xl (1884), pl. v, f. 5, 6. 17. Right valve. 18, 19. WN. Lamplughi, Woods. Speeton Clay (D 4), Speeton. Collection of G. W. Lamplueh. (P. 14.) 18. a, right valve; }, dorsal view. 19. Left vaive. 20. N.sp. Lower Greensand, Atherfield. British Museum. (P. 14.) a, left valve, outline; 6, same x 2; e, same, dorsal view of both valves x 2; d, same, posterior view X 2. 21. N. Meyeri, Gardn. Lower Greensand, Atherfield. British Museum. The AMagayey. (les 1k3)5)) a, left valve, outline; 6, same x 2; e, same, dorsal view of both valves x 2. 22—27. N. pectinata, Sow. Gault, Folkestone (except f. 24). (P. 16.) 22. Montagu Smith Collection, Woodwardian Museum. Right valve. 23. Woodwardian Museum. a, right valve; 6, same, posterior view; c¢, same, dorsal. 24, Gault, Aylesford. Woodwardian Museum. Right valve. 25. Woodwardian Museum. Left valve. 26. Wiltshire Collection, Woodwardian Museum. Left valve. 27. Woodwardian Museum. a, left valve; 6, posterior view; ¢, portion of ornamen- tation of left valve enlarged. } ZN UT MN) E. Wilson del.,W.H.Growther lith. Wet, Newman unp CRETACEOUS LAMELLIBRANCHIA PATE int: Nucuta (continued). FIGS. 1—12. N. (Acila) hivirgata, Sow. Gault, Folkestone (except f. 12). (P. 19.) 1. Woodwardian Museum. Right valve x 13. 2. British Museum, No. L 5907. a, outline of left valve; b, same x 14; ¢, dorsal outline. Figured by Gardner. 3. Wiltshire Collection, Woodwardian Museum. Right valve x 13. 4. British Museum, No. L 5907. Left valve x 13. Figured by Gardner. 5. — No. L 4972. a, right valve; 6, posterior end; ¢, dorsal x 13. 6. = a Left valve x 13. ile — — Median portion of left valve x 14. 8. — — Median portion of right valve x 1}. 9. — — Left valve x 14. 10. — No. L 5102. Hinge of right valve x 2. 11. Collection of C. J. A. Meyer. Antero-ventral portion of left valve x 6. 12. Cambridge Greensand. Woodwardian Museum. Internal mould, right valve. 13. N. pectinata, Sow. Cambridge Greensand (derived). _Woodwardian Museum. Internal mould. a, right valve; 6, dorsal view. (P. 16.) 14,15. N. pectinata, var. crete, Gardner. Greensand, Blackdown. Museum of Practical Geology. The Types of var. cretz. (P. 18.) 14. a, right valve; 6, dorsal (No. 6449). 15. Left valve (No. 6450). 16—21. N. ovata, Mant. Gault, Folkestone. (P. 21.) 16. British Museum, No. L 4968. Right valve. 17. Wiltshire Collection, Woodwardian Museum. Right valve. 18—20. British Museum, No. L 4968. 18, right valve. 19. a, left valve; 6, dorsal view ; 20, right valve. 21. Woodwardian Museum. a, right valve; 6, dorsal. PLATE I TA Brock del..WH. Crowther lith Weat, Newman imp CRETACEOUS LAMELLIBRANCHIA. PLATE IV. Nucuta (continued). FIGS. 1. N. ovata, Mant. Gault, Folkestone. British Museum, No. L 4968. a, right valve; b, dorsal. (P. 21.) 2—4, N. obtusa, Sow. Greensand, Blackdown. (P. 22.) 2. The Type, Bristol Museum. a, right valve ; 6, posterior view of same. 3. Museum of Practical Geology, No. 6351. Right valve. 4. — == = Left valve. Figured by Gardner. a, left valve ; 2, posterior of same; ¢, dorsal of same; d, hinge x 2. 5—8. N. impressa, Sow. Greensand, Blackdown. (P. 23.) 5. Wiltshire Collection, Woodwardian Museum. Right valve. 6. _— — — — a, left valve ; 6, dorsal ; ec, posterior. 7. Wiltshire Collection, Woodwardian Museum. Interior of right valve x 2. . Probably the type of \. apiculata, Sowerby. Museum of the Geological Society, No. 1564. a, right valve; 4, dorsal view. 9—16. N. albensis, V’Orb. Gault, Folkestone. (P. 24.) 9. Museum of Practical Geology, No. 1638. a, right valve; 6, dorsal view. 10. Wiltshire Collection, Woodwardian Museum. Left valve, 11. Woodwardian Museum. Right valve. 12. British Museum, No. 4963. a, left valve; 6, dorsal view. 13. -- — _— — os 14. Woodwardian Museum. a, left valve; 6, dorsal view. 15. Collection of C. J. A. Meyer. a, left valve; 6, dorsal view. 16. Wiltshire Collection, Woodwardian Museum. Left valve. 17. N. albensis? dOrb. Greensand, Blackdown. Wiltshire Collection, Woodwardian Museum. Right valve. (P. 25.) 18—21. N. gaultina, Gardn. Gault, Folkestone. British Museum, No. 4970. (P. 25.) 18. a, right valve ; 6, posterior ; ¢, dorsal. 19. Left valve. 20. Right valve. 21. a, left valve, outline; 6, same x 13; ¢, dorsal x 13. 22—26. N. antiquata, Sow. Greensand, Blackdown. Wiltshire Collection, Woodwardian Museum. (P. 26.) 22. a, left valve; b, dorsal view ; ¢, posterior. 23. a, right valve; 6, dorsal view. 24. a, dorsal view ; 8, left valve. oa) 25. Interior of right valve x 2. 26. Right valve. 27, 28. N. sp. Chalk Rock (zone of Het. Reussianum), Cuckhamsley. Montagu Smith Collection, Woodwardian Museum. Internal moulds of right valves. (P. 27.) 3 del. WH. her LO West, Newman im T.M.Brock del. WH. Crowther ith Pp CRETACBOUS LAMELLIBRANCHIA. FIGS. I—3. A 4,5. A 69, A PLATE V. Genus ANOMIA, Linneus. A. pseudoradiata, V’Orb. Lower Greensand. (P. 27.) 1. Crackers, Atherfield. Woodwardian Museum. a, outline of left valve; 6, same x 14; ¢, ornament of same x 6. 2. Atherfield Beds, Redhill. British Museum, No. L. 9288. Left valve. 3. Atherfield. Museum of the Geological Society. Left valve (young specimen) x 13. . sp. Crackers, Atherfield. (P. 28.) 4. Woodwardian Museum. Left valve. 5. Wiltshire Collection, Woodwardiau Museum. a, left valve, outline ; 6,same xX 2. 4. levigata, Sow. Lower Greensand. (P. 29.) 6. Museum of Practical Geology, No. 6414. Hythe Beds, Lympne. ? Interior of left valve. One of the Types. 7. Museum of Practical Geology, No. 6415. Atherfield Beds, Peasmarsh. a, left valve; 8, dorsal view of same. 8. Museum of Practical Geology, No. 6417. Punfield. a, left valve; 0, dorsal. 9. Collection of C, J. A. Meyer. Ferruginous Sands, Shanklin. Left valve. 10. A. convewa, Sow. Lower Greensand, Shanklin. Museum of the Geological Society, No. 2032. a, left valve; b, dorsal view. (P. 29.) 11. A. ef. pseudoradiata, VOrb. Gault, Black Ven. Museum of Practical Geology, No. 6440. a, left valve; b, portion x 3. (P. 30.) 12. A. ? transversa, Seel. Cambridge Greensand. Woodwardian Museum. a, left valve; 5, dorsal view of same. (P. 30.) 13—16. A. papyracea, V’Orb. Lower Chalk—Totternhoe Stone (zone of Holaster subglobosus). (P. 31.) 13. Woodwardian Museum. Burwell. Left valve. Figured by Etheridge. The dorsal part of the shell is crushed, giving the umbo the appearance of being at the margin. 14. York Museum. Reach. Left valve. Dorsal part of shell is crushed. 15. Woodwardian Museum. Burwell. Left valve. Figured by Etheridge. 16. Woodwardian Museum. Right vaive. TMBrock del WH Crowther hth. We CRETACEOUS LAMELLIBRANCHIA PLATE VI. Genus Arca, Lamarck. FIGS. 1—3. A. Dupiniana, d’Orb. (P. 32.) 1, 2. Perna-bed, Atherfield. Leckenby Collection. Woodwardian Museum. 1a, right valve; 1, dorsal view of same specimen ; 2, hinge of left valve x 15. 3. Ferruginous Sands, Shanklin. Collection of C. J. A. Meyer. Ornamentation on the right valve near the ventral margin below the umbones x 3. 4,5. A. Carteroni, VOrb. (P. 33.) 4. Lower Greensand, Upware. Woodwardian Museum. a, left valve; 4, anterior view ; ¢, dorsal of same specimen. Figured by Keeping. 5. Atherfield Beds, East Shalford. Collection of C. J. A. Meyer. a, left valve; b, hinge and area of same x 1}; ¢, ornamentation, from the anterior part of the valve, x 3. 6, 7. A. Sancte-Crucis, Pict. and Camp. Lower Greensand, Upware. Woodwardian Museum. (P. 34.) 6. a, left valve; b, outline of anterior end; c, dorsal view of same specimen. (The right umbo and the anterior part of the area are partly obscured by adhering rock.) 7. a, vight valve; 0, dorsal view of same specimen; c, ornamentation x 2. Genus BarBAtIA, Gray. 8, 9. B. aptiensis (d’Orb.). Crackers, Atherfield. Leckenby Collection, Woodwardian Museum. (P. 35.) 8. a, left valve; b, dorsal; c, right valve; d, anterior; e¢, part of left valve near the mid-ventral margin xX 3. 9. a, left valve; b, right valve. PLATE VII. Barsatia (continued). FIGS. 1—3. B. (Scaphula?) Austeni (Forbes). (P. 37.) 1,2. Crackers, Atherfield, Leckenby Collection, Woodwardian Museum. 14, right valve; 14, ornamentation near postero-ventral angle x 8. 2. Dorsal view of another specimen x 2. 3. Left valve. Perna-bed, Redcliff. Collection of C. J. A. Meyer. 4—7, B. marullensis (VOrb.). (P. 38.) 4. Left valve. Lower Greensand, Upware. Woodwardian Museum. 5. Gault (zone iii), Folkestone. Museum of Practical Geology, No. 1630. a, right valve; 4, dorsal view of same specimen; c, ornamentation on postero-dorsal area x 4; d, ornamentation from near the middle of the valve x 4. 6. Gault, Folkestone. Wiltshire Collection, Woodwardian Museum. a, right valve; , dorsal view of same specimen. 7. Gault, Folkestone. Museum of Practical Geology, No. 6559. Right valve. 8. B.rotundata (Sow.). Greensand, Blackdown. The Type, Bristol Museum. a, right valve; b, dorsal view ; c, same x 2. (P. 40.) 9. B. Galliennei (dV’Orb.). Chalk Marl, near Lyme Regis. Wiltshire Collec- tion, Woodwardian Museum. Internal mould. a, right valve ; b, dorsal view of same specimen. (P. 41.) 10, 11. B. sp., ef. Geinitzi (Reuss). Chalk Rock (zone of Het. Reussianum), Cuckhamsley. “Montagu Smith Collection, Woodwardian Museum. (P. 42.) 10. a, portion of wax mould of right valve; 6, ornamentation x 5. 11. Natural internal mould of right valve. 12. B. sp. Same locality and Collection. «a, internal cast of left valve; b, dorsal view of same. (P. 42.) 13. B.? sp, Same locality and Collection. a, left valve, outline natural size ; b, same X 2. (P. 43.) Genus GRAMMAtTODON, Meek and Hayden. 14, 15. G. seewris (Leymerie). Speeton Clay (zone of Bel. brunsvicensis), Speeton. Collection of G. W. Lamplugh. (P. 44.) 14. a, 6, right and left valves of same specimen. 15. a, left valve; b, ornamentation x 3. PLATE, VIL. TA Brock del. Weet, Newman imp W.H.Orow ther lith CRETACEOUS LAMELLIBRANCHIA. PLATE VIII. GRaMMATODON (continued). FIGS. 1,2. G. secwris (Leym.), Speeton Clay (zone of Bel. brunsvicensis), Speeton. (P. 44.) 1. Collection of G. W. Lamplugh. Dorsal view x 2. 2. York Museum. Left valve, with part of shell preserved. 3—8. G. carinatus (Sow.). (P. 45.) 3. Greensand, Blackdown. Wiltshire Collection, Woodwardian Museum. a, outline of left valve; b, same x 14; ce, dorsal view of same X 13; d, hinge and area of same X 2. . Same locality and Collection. a, left valve; b, dorsal; c, anterior view. . Same locality and Collection. Right valve. - Gault, Lyme Regis. Woodwardian Museum. Left valve. . Gault (zone ii), Folkestone. Museum of Practical Geology, No. 1632. a, right valve; 4, dorsal. 8. Gault, Folkestone. Wiltshire Collection, Woodwardian Museum. Left valve. The ventral part is crushed in, so that the shell appears too long pro- portionately. IQA Genus Triconoarca, Conrad. 9,10. TT. Passyana (d’Orb.). (P. 47.) 9. Greensand, Kingskerswell. British Museum, No. L 1853. a, right valve; 4, cast of hinge; c, ornamentation x 3. 10. Chloritic Marl, Maiden Bradley. Woodwardian Museum. Internal cast. a, right valve ; b, dorsal. yenus CucuLttma, Lamarck. 11—13. C. Cornueliana (d’Orb.). Lower Greensand, Atherfield. (P. 50.) 11. Right valve. Woodwardian Museum. Above the Crackers, 12. Right valve. Woodwardian Museum. Crackers. 13. Left valve. Woodwardian Museum. Above the Crackers. CRETACEOUS LAMELLIBRANCHIA. 4 rs PLATE IX. FIGS. 1—3. Cucullea Forbesi (Pict. and Camp.). Perna-bed, Atherfield. (P. 49.) 1. Wiltshire Collection, Woodwardian Museum. Left valve. a, dorsal ; 6, anterior of right valve; c, part of b x 3. 2. Woodwardian Museum. 3 a, hinge and area of left valve; & fo} 5) ’ 3. Wiltshire Collection, Woodwardian Museum. exterior of left valve. en ogenantiaae TA.Brock del. W. 1 Crowthe: ith. LIBRAN C AMELI C/T OU RETACE n S) - 7 7 7 , Ay ' - ry 7 i / oa a s — aa _ ed ¥ 7 -— i = - i _ - u - i bo ; 7 a Te 7 7 : ‘ _ . 7 A 7 _— 7 J re _ 7 = a > 7 - fi -_ > 7 > - =) - * —- 7 4 = >> a . 7 : 4 ; an — 7 : - 7 8 , 7 7 a” . ; _ @ 7 7 i : = A ; va 7 a - - es i A - 7 Y 4 7 - : - “ PLATE X. CucuLLaa (continued). FIGS. 1—3. C. Cornueliana (VOrb.). Crackers, Atherfield. (P. 50.) 1. Leckenby Collection, Woodwardian Museum. a, right valve; }, dorsal outline ; c, ornamentation X 4. 2. Leckenby Collection, Woodwardian Museum. a, right valve ; 0, dorsal. 3. Woodwardian Museum. Hinge x 2. 4—7. C. Fittoni (Pict.and Camp.). Crackers, Atherfield. (P. 52.) 4, Leckenby Collection, Woodwardian Museum. a, outline of left valve; 6, same x 1}; ¢, posterior of same x 13; d, dorsal of same x 13. 5. Woodwardian Museum. Hinge and area x 2. 6. Leckenby Collection. Left valve. 7. Wiltshire Collection. Right valve. 8—10. C. vagans, Keeping. Lower Greensand (Black-grit nodule), Upware. Woodwardian Museum. (P. 52.) 8, Drawn from a wax mould of an external cast. Right valve. 9, Natural internal mould. Right valve. Figured by Keeping. 10. Ornamentation x 38. 11—14. ©. (Dicranodonta) donningtonensis, Keeping. Claxby Ironstone (zone of Belemnites lateralis), Benniworth Haven. Woodwardian Museum. (P. 54.) 11. a, left valve ; 6, dorsal; ¢, interior. 12, Hinge of left valve. 13. Ornamentation xX 3. 14. Right valve. Newman imp West TA Brock de} A.T. Hollick hth. — ~o i 7 a > - > 5 . st } a 0 7 O 2 4 7 - - a —_— 7 = = cat’ = wee FIGS. 1S Pe sw) a 8—12. 0. C. Led bys) 2G CucuLnaa (continued). (Dieranodonta) donningtonensis, Keeping. Claxby Ironstone (zone of Belemnites lateralis), Benniworth Haven. Woodwardian Museum. (P. 54.) 1. a, left valve; 6, interior. 2. Right valve. (Dicranodonta ?) obliqua (Keeping). Lower Greensand, Upware. Woodwardian Museum. (P. 55.) 3. a, right valve, outline; 4, same x 13; ¢, dorsal. 4. Left valve, interior. . venusta, Nyst. Greensand, Blackdown. (P. 56.) 5. The Type, Bristol Museum. Left valve. a, dorsal outline; 6, outline; c, same x 2. G. The Type, Bristol Museum. Left valve. a, outline; 0, same x 2. 7. Collection of C. J. A, Meyer. a, right valve x 3 (the outer layers of the shell are absent, so that the apparent ornamentation differs from that in figs. 5 and 6) ; 6, dorsal view of same X 3. glabra, Parkinson. Greensand, Blackdown. (P. 57.) 8. British Museum, No. 26926. a, left valve; 0, dorsal of same specimen; c¢, orna- mentation x 6. 9. Wiltshire Collection, Woodwardian Museum. 4, left valve; 6, dorsal view. 10. Woodwardian Museum. Hinge of the left valve of a young form x 4. 11. Wiltshire Collection, Woodwardian Museum. Hinge of right valve—later stage than fig. 1O— x 2. 12. Woodwardian Museum. Hinge of right valve x 13. LATE XI. — Nui (Ny T.A. Brock del. West, Newman imp A..T. Hollick lith. CRETACEOUS LAMELLIBRANCHIA PLATE XII. Cucutnma (continued). FIGs. 1—5, C. glabra, Parkimson. Greensand, Blackdown. (P. 57.) la, 6, 2. Wiltshire Collection, Woodwardian Museum. Left valves. 3. Woodwardian Museum. a, right valve; 4, dorsal view of same specimen. 4, _ — Left valve. 5. Elongate variety. Wiltshire Collection, Woodwardian Museum. Left valve. 6—8. (C. obesa, Pict. and Camp. Gault. (P. 61.) 6. Folkestone. Wiltshire Collection, Woodwardian Museum. Young form. Right valve. 7. Same locality and Collection. a, left valve; 6, dorsal view of same. 8. Cambridge Greensand (derived from the Gault). Woodwardian Museum. Internal cast. a, left valve ; 6, posterior view. T.A Brock del West, Newman imp W.H. Crowther ith ATT AMELLIBRAN CH Q 3.0] 23] ie) > Q 3) O o tr PLATE XIII. Cucuttma (continued). FIGS, 1—3. (. nana, Leym. Gault, Folkestone. British Museum, No. L 4946. (P. 62.) 1. a, left valve; b, dorsal of same; c, same x 2; d, left x 2; e, anterior view x 1}. (The umbo is slightly pressed in, and consequently in 1a, d, appears less sharp than usual.) 2. Right valve x 2. 3. Left valve ; the posterior margin is slightly imperfect. » 13. A, 5. C. Mailleana (d’Orb.). (P. 63.) 4. Chalk Marl, Pinhay Cliffs. Collection of C. J. A. Meyer. a, left valve; 0, same, x 14; c, same, dorsal, x 14. 5. Chloritic Marl, Maiden Bradley. Woodwardian Museum. With the shell partly removed. a, right valve; 6, dorsal of same specimen. 6. C.,sp. Chalk Marl (Bed 10), Dunscombe. Collection of C. J. A. Meyer. a, right valve ; b, dorsal outline; ¢, ornamentation x 4. (P. 64.) Genus Isoarca, Minster. 7. I. Agassizi, Pict. and Roux. Cambridge Greensand (derived). Internal mould. Figured by Jukes-Browne. Woodwardian Museum. a, left valve; b, dorsal. (P. 65.) 8. I. obesa (VOrb.). Chloritic Marl, Ball Wood. Museum of Practical Geology, No. 6349. a, left valve; b, dorsal; c, ornamentation >< Da (lem (8)9))) Genus PEcruncuuus, Lamarck. 9, 10. Pectunculus marullensis, Leym. Ferruginous Sands, Shanklin. Collec- tion of C. J. A. Meyer. (P. 66.) 9. Left valve. a, x 2; 6, interior; ec, dorsal outline. 10. Left valve x 3 (another specimen). ernst 8c yy, SRO ricg TAN ATTEN A CRIT A TACKOUS LAME LLIBRAN GHIA 3 PLATE XIV. PrcruncuLus (continued). FIGS, 1—7. P. sublevis, Sow. Greensand, Blackdown. (P. 67.) 1 a—e, Wiltshire Collection, Woodwardian Museum. Right valve. 2 a,b. Walton Collection, Woodwardian Museum. Right valve. 3. Wiltshire Collection, Woodwardian Museum. Right valve. a, interior; 4, dorsal ; c, exterior xX 2; d, ornament of same x 5. 4, Same Collection. Young form. a, left valve; 6, same X 2; ce, dorsal outline. 5. Same Collection. a, 6, right valve; ce, dorsal outline. 6, 7. Museum of Practical Geology, No. 6573. Left valves. 8—12. P. wmbonatus (Sow.). Greensand, Blackdown. (P. 69.) 8. Wiltshire Collection, Woodwardian Museum. a, right valve; 4, outline of interior of same; ¢, dorsal outline. 9. Walton Collection, Woodwardian Museum. aa, left valve x 1}; 6, dorsal x 13; c, ornamentation x 5. 10. Same Collection. a, left valve; 6, interior; ¢, dorsal. 11. Wiltshire Collection, Woodwardian Museum. Right valve. 12. Museum of Practical Geology, No. 6572. Right valve. 13. P. euglyphus, Woods. Chalk Marl (Bed ii), Dunscombe. Collection of OC. J. A. Meyer. (P. 71.) 13. a, right valve, outline; 6, dorsal outline of same; ¢, ornamentation on anterior part of shell x 4; d, ornamentation on posterior part ofshell x 4; e, same valve » 2, b 5 a 5 Si & H. Crowther lth Ww Ww 4 SL LIBRANC LAME PLATE XV. yvenus—Limopsis, Sasso. Fias. 1—4. LL. albiensis, Woods. Gault, Folkestone. (P. 71.) 1. Zone in. Lett valve. Museum of Practical Geology. a, outline; b, dorsal out- line ; c, exterior x 3; d, interior x 4. 2. Zone vii. Right valve x 4. Same museum. 3. Right valve x 3. Same museum. 4. Zone ii. Part near umbo x 8. Same museum, 5,6. L.,sp. Chalk Rock (Reussianwm zone), Cuckhamsley. Montagu Smith Collection, Woodwardian Museum. (P. 72.) 5. Cast of interior of right valve, a, outline; b, dorsal outline; c, same x 2 6. Cast of interior of left valve. a, outline; 6b, dorsal outline; c, same x 2. Genus—Myrtitus, Linneus. 7. M. inequivalvis, Sow. Greensand, Blackdown. The Type. Bristol Museum. a, right valve; 5, left; c, antero-ventral; d, interior of right valve near the umbo x 2. (P. 91.) Genus—MoptoLa, Lamarck. 8—14. M. xqualis, Sow. Crackers, Atherfield. (P. 92.) 8. Leckenby Collection, Woodwardian Museum. a, right valve, outline; b, same x 14; ¢, dorsal of both valves. 9. Wiltshire Collection, Woodwardian Museum. Right valve. 10. Same Collection. Dorsal. 11—13. Same Collection. 11, left valve; 12, right valve (slightly crushed dorso- ventrally) ; 13, left valve 14. Woodwardian Museum. Right valve. 15—18. M. reversa, Sow. Greensand, Blackdown. (P. 94.) 15. Wiltshire Collection. Right valve, young form. 16. Wiltshire Collection. Left valve, young form. 17. Wiltshire Collection. a, right valve; b, dorsal outline of same. 18. Woodwardian Museum. a, left valve; b, dorsal of same; c, portion just posterior to middle of the sulcus, showing radial ribs x 3. TA.Brock del A.T.Hollich kth H1A TT IBRAN L LAMEL PLATE XVI. Mopto1a (continued). Figs. 1—3. MM. reversa, Sow. Greensand, Blackdown. Wiltshire Collection, Wood- wardian Museum. (P. 94.) 1. Right valve. 2. a, right valve; 6, dorsal of both valves. 3. Ornamentation, a little posterior to the centre of the valve x 4. 4—6. M. ligeriensis (dV’Orb.). Perna-bed, Atherfield. (P. 96.) 4. Wiltshire Collection. a, left valve; b, dorsal of both valves. 5. Leckenby Collection. a, left valve; b, dorsal of both valves. 6. Leckenby Collection. Part adjoining middle of ventral edge x 2. 7—10. M. subsimplea (d@’Orb.). Crackers, Atherfield. (P. 97.) 7. Leckenby Collection, Woodwardian Museum. Right valve. 8. Wiltshire Collection, Woodwardian Museum. Left valve. 9. Wiltshire Collection, Woodwardian Museum. a, right valve; b, dorsal of both valves. 10. Museum of the Geological Society of London (No. 2078). a, left valve; b, dorsal of both valves. Weet OcK dei AT Hallick lith Newman ime oo oT os _ eo : 77 7 , Oe: > a ad @& , - a -_ - - °) ra) 7 - a (= at Fias. Oo 6—8. 9—11. WO ey PLATE XVII. Moptora (continued). M. flagellifera, Forbes. (P. 99.) 1. Upper Greensand, Devizes. British Museum, No. 88,845. Right valve, slightly compressed dorso-ventrally. 2. Upper Greensand, Black Ven. Museum of Practical Geology, No. 6658. Dorsal view of both valves, somewhat compressed dorso-ventrally. M. undulata (Forbes). Atherfield Clay, Atherfield. The Type. Museum of the Geological Society, No. 2088. Left valve. (P. 100.) M. (Brachydontes) Guerangeri ? (VOrb.). (P. 101.) 4. Greensand, Haldon. Mr. W. Vicary’s Collection. Left valve. 5. Cenomanian (Bed 10), Dunscombe. Mr. Meyer's Collection. a, left valve; }, ven- tral of same; c, part of a X 2, M. (Brachydontes) vectiensis, Woods. (P. 102.) 6. Crackers, Atherfield. Woodwardian Museum. a, outline of left valve; b, same ae 7. Atherfield Beds, Peasmarsh. Museum of the Geological Society, No. 2092. Right valve. a, outline; b, x 2; c, dorsal x 2. 8. Atherfield Beds, Littleton Pit, Guildford. Museum of Practical Geology. Right valve x 14. Drawn from a wax cast of an external mould. M. (Brachydontes) striato-costata (d’Orb.). Greensand, Blackdown. (Po 1033) 9. Mr. Meyer’s Collection. Left valve. a, outline; b, x 2. 10. Wiltshire Collection. Right valve. a, outline; b, x 3. 11. Mr. Meyer’s Collection. Left valve. a, outline; b, x 2; c, dorsal x 2. Genus—CRENELLA, Brown. Crenella bella (Sow.). Crackers, Atherfield. Wiltshire Collection. (P. 104: .) 12. Right valve. a, outline; b, x 2. 13. Left valve. a, outline; b, x 2; ce, dorsal x 2; d, ornamentation from the dorsal surface x 6. Genus—LitHopomus, Cuvier. 14. Lithodomus rugosus (7), @Orb. Cenomanian (Bed 10), Dunscombe. Mr, Meyer’s Collection. a, left valve; b, dorsal. (P. 105.) rf CRETACEOUS LAMELLIBRANCH LA Figs. PATH ex Vaile Genus—SertiFer, Pécluz. 1— 12. S. lineatus (Sow.). (P. 106.) a 10. 11. . Hythe Beds, Lympne. Museum of Practical Geology, No. 6595. a, left valve ; b, dorsal. . Same locality, &e., No. 6595. a, right; b, antero-ventral. . Hythe Beds, Hythe. Museum of the Geological Society. Right valve. . Hythe Beds, Lympne. Museum of Practical Geology, No. 6595. a, left valve: b, antero-ventral. . Chalk Marl, Chardstock. Museum of Practical Geology, No. 6596. a, left valve; b, antero-ventral outline. . Cenomanian (Bed 12), Kempstone Rocks (Sidmouth). Museum of Practical Geology, No. 6773. a, antero-ventral outline; 6, right valve x 14; ¢, orna- mentation near the centre of the valve x 12; d, ornamentation near the posterior margin x 12. . Cenomanian (Bed 12), Axmouth. Mr. Meyer’s Collection. Antero-ventral of left valve. . Cenomanian (Bed 12), Dunscombe. Mr. Meyer's Collection. Left valve. . Chalk Rock (Reussianwm zone), Cuckhamsley. Montagu Smith Collection, Wood- wardian Museum. Right valve. For figures of a larger example from this zone see ‘Quart. Journ. Geol. Soc.,’ vol. li, 1897, pl. xxvii, figs. 11, 12. Chalk Rock, Dullingham. Woodwardian Museum. Internal mould. a, right valve; b, antero-ventral. Chalk Rock, Winchester. Mr. R. M. Brydone’s Collection. a, left valve; b, ante1o- ventral. (Figured ‘Quart. Journ. Geol. Soc.,’ vol. liii, 1897, pl. xxvii, figs. 9, 10.) Flint gravel (derived from Upper Chalk), near Ventnor. Left valve, somewhat flattened by crushing. Genus—DREISSENSIA, van Beneden. 13—15. D. lanceolata (Sow.). Crackers, Atherfield. (P. 110.) 13. 14. 15. Left valve. Wiltshire Collection. Left valve. Woodwardian Museum. Right valve. Woodwardian Museum. T.A.Brock del A.T Hollick lith CRETACEOUS LA} JE LI ABRANCHI PATH XX DREISSENSIA (continued), Fies. 1—1l1. WD. lanceolata (Sow.). (P. 110.) 1—3. Crackers, Atherfield. 1. Leckenby Collection, Woodwardian Museum. a, left valve; b, ventral— showing opening for byssus. 2. Wiltshire Collection, Woodwardian Museum. a, right valve; b, ventral. 3. Leckenby Collection. Right valve. 4, Perna-bed, Atherfield. Wiltshire Collection, Woodwardian Museum. a, left valve ; b, interior of same. 5. Upper Greensand, Shaftesbury. British Museum, No. 88,894. Left valve. 6—11. Greensand, Blackdown. 6. Wiltshire Collection, Woodwardian Museum. a, left valve; b, part near the umbo x 2; ¢, dorsal of both valves. 7. Wiltshire Collection. a, right valve; b, ventral; c, interior of same. . Bristol Museum. The type of Mytilus prelongus, Sowerby. , 10. Wiltshire Collection. Left valves. 11. Bristol Museum. One of the types of Mytilus tridens, Sowerby. a, right valve; b, antero-ventral. co 0 Genus—Triconta, Bruguiere. 12. T. dunscombensis, Lye. Cenomanian (Bed 11), Humble Point, Lyme Regis. Museum of Practical Geology (No. 6774). a, right valve ; b, dorsal + (227782) 13. T. ornata, @Orb. Hythe Beds, Lympne. Museum of Practical Geology (No. 6771). Left valve. (P. 85.) 14. J. crenulata, Lam. Cenomanian (Bed 10), Dunscombe. Mr. Meyer’s Collection. Left valve. (P. 82.) TABrock del A THollick lith West, Newman imp CRETACEOUS LAMELLIB RANCHIA Figs. les A, PAR Xexe Triconta (continued). T. scapha, Agassiz. (P. 73.) 1. Lower Greensand (probably Snettisham ironstone nodules), West Norfolk. The type of T. hunstantonensis, Seeley. Woodwardian Museum. Right valve. 2. Snettisham Clay, one third of a mile south-west of Snettisham Church. Museum of Practical Geology. Portion of left valve. Drawn from a wax cast of an external mould. Genus—Myoconcua, Sowerby. M. cretacea, VOrb. Chloritic Marl, Maiden Bradley. Woodwardian Museum. a, right valve ; b, ornamentation of same xX 3. (P. 114.) Genus—Sponvyits, Linnzus. S. Roemeri, Desh. Perna-bed, Atherfield. Woodwardian Museum. a, left valve (umbo slightly restored); b, outline from the posterior end; ¢, right valve ; d, ornamentation of left valve x 3. (P. 116.) 5—11. S.gibbosus, ’Orb. Cambridge Greensand (derived from the Upper Gault), Cambridge. Woodwardian Museum. (P. 117.) 5, 6a. Left valves; 65, anterior outline; 6c, ornament of left valve x 2. 7a. Left valve; b, posterior of both valves ; ¢, right valve. 8a. Left valve; 6, part of same x 2. 9a. Left valve; b, anterior outline. 10. Left valve. 11. Posterior outline of a specimen with talon-like right valve. PLATE XXI. SPoNDYLUS (continued). Figs. 1—5. SN. striatus (Sow.). Rye Hill Sand, Warminster. (P. 119.) 1. Museum of Practical Geology, No. 6836. a, left valve; b, anterior view. . Woodwardian Museum. Left valve. bo 3. British Museum. a, left valve and projecting umbo of right ; b, posterior view. 4. Wiltshire Collection, Woodwardian Museum. Right valve with only a small surface of attachment. 5. York Museum. Left valve. 6, 7. WS. serratus, Woods. (P. 124.) 6. Dr. Blackmore’s Collection. Uintacrinus-band of Marsupites zone, Devizes Road, Salisbury. Left valve. a, outline, natural size; b, x 14; c¢, ornament x 6. 7. British Museum. Upper Chalk. Left valve. a, outline, natural size; b, x 14; c, ornament x 4. PLATE XXII. SponDYLUS (continued). Fies. 1—10. S. latus (Sowerby). (P. 121.) 1. Woodwardian Museum. The type of S, equicostatus, Eth. Zone of Holaster subglobosus, Cherry Hinton. 1a, left valve; 1 }, posterior view of the same. 2. Same collection, horizon, and locality. a, left valve; }, portion of same just ventral to centre of valve, x 4. 3. Woodwardian Museum. Lower Chalk, Fulbourn. Left valve. 4—9, Dr. Blackmore’s Collection. Zone of A. quadratus. 4—8, Hast Harnham ; 9, West Harnham, near Salisbury. 4. a, left valve, with part of right projecting; b, posterior view of both valves. 5. Right valve. 6. Left valve. Part near the umbo x 2. 7. Left valve x 13. 8. Left valve. a, x 13; b, posterior outline; c, ornamentation x 5. 9. Left valve, with umbo and marginal parts of right valve x 1). 10. Woodwardian Museum (Coll. Mr. W. Hill). Zone of H. subglobosus, cutting east of South Cave Station, Yorkshire. a, left valve; b, ornamentation x 4. 11—14. 8S. Dutempleanus, d’Orb. Zone of A. quadratus. Dr. Blackmore’s Collection. 11—13, East Harnham. 14, Whaddon cutting. (P. 125.) 11. a, left valve x 14; b, ornamentation x 4. 12. a, left valve; 6, ornamentation x 3. 13. Posterior view of both valves. 14. Right valve. CRETACEOUS LAMELLIBRANCHI/ 5 —_ 7 7 4) 7 : ote — - : 7 : ; ’ | : - - ul | m : 7 . 2 : a | : 7 : on 7 | ; : : 7 : ; i “> : ->% : . sire - 7 ~ : ° 7 : —. 7 iin > - 7 «+ - > ws =) 7 - ; i - ~ . a 7 a : - : 4 ~ a - a : 7 7 ; =~ a 7 a ’ - = a > = - | | 7 i fi > a its » - : ) -“— = _ 7 "a PLATE XXIII. Sponpyius (continued). Fras. 1—5. 8S. Dutempleanus, Orb. (P. 125.) 1. A. quadratus zone, Whaddon cutting. Dr. Blackmore’s Collection. Left valve and umbo of right x 14. 2. A. quadratus zone, East Harnham, Salisbury. Dr. Blackmore’s Collection. Anterior outline showing spines on left valve. 3. B. mucronata zone, Norwich. Norwich Museum. Right valve. 4, Chalk of Trimingham. Museum of Practical Geology (Coll. Mr. C. Reid). Left valve. 5. B. mucronata zone, Norwich. Norwich Museum. Part of left valve. 6—11. SS. spinosus (Sow.). (P. 127.) 6. T. gracilis zone, Luton. Woodwardian Museum (Coll. Mr. W. Hill). a, left valve; b, anterior outline; c, section of ribs of left valve near the mid- ventral border x 2. 7. T. gracilis zone, East Knoyle. Woodwardian Museum (Coll. Mr. Jukes-Browne ). 8. H. planus zone, Cheveley. Woodwardian Museum. Left valve, with spines projecting from the right valve. 9, Same zone, etc. a, left valve; b, dorsal view; ¢, section of ribs of left valve near the mid-ventral border x 2. 10. Same zone, ete. a, right valve (umbo slightly imperfect) ; 6, section of ribs of right valve near the mid-ventral border x 2. 11. M. cor-testudinarium zone, Chatham. Woodwardian Museum (Coll. Mr. Jukes- Browne). a, left valve; b, anterior outline; ¢, ribs of left valve near the mid- ventral border x 2. —— faa ~\ \ eo Soe AAG os ewman im ee Vest Ni TABrock del AT Hollick ith ] CRETACEOUS LAMELLIBRANCHIA Fras. 6. al PLATE XXIV. Spondylus spinosus (Sow.) (continued). (P. 127.) Upper part of M. cor-anguinum zone, Mitcheldever. Dr. Blackmore’s Col- lection. a, left valve; b, posterior view. M. cor-anguinum zone, Fletcher’s pit, Gravesend. Woodwardian Museum. Small portion of left valve near the middle of the ventral border x 3. M. cor-anguinum zone, Hungry Down, Blandford. Woodwardian Museum (Coll. Mr. Jukes-Browne). Left valve, umbo slightly imperfect. Lower part of Marsupites zone, Witherington. Dr. Blackmore’s Collection. a, left valve; b, section of ribs of the same near the mid-ventral border se Same horizon, locality, and collection. a, left valve; b, section of ribs of left valve near the mid-ventral border x 2; c¢, posterior outline. Marsupites zone, Margate. Dr. Rowe’s Collection. a, right valve; 6, section of ribs of right valve near the mid-ventral border x 2; c, posterior outline; d, umbo of left valve x 5. A. quadratus zone, West Harnham, Salisbury. Dr. Blackmore’s Collection. Left valve. LAA NCHIA RA IS LAMELLIB a i Ni PLATE XXV. Genus—Pricatuta, Lamarck. Fis. 1—4. P. placunea, Lam. Hythe Beds, Lympne. Museum of Practical Geology, No. 6781. 1, 2, 4, right valves; 1 6, anterior outline; 3, left valve. (P. 134.) 5—12. P.Carteroniana, d’Orb. Lower Greensand, Upware. Right valves, except fig. 7 (left valve); 5), 6b, anterior outlines. Figs. 6—9, Woodwardian Museum. Figs. 5, 10—12 in Mr. J. F. Walker’s Collection. (P. 135.) 13—21. P. gurgitis, Pict. and Roux. Gault, Folkestone, except figs. 18, 21. (P. 137.) 13—15. Wiltshire Collection. Right valves; 13 8, left valve. 16, 17. York Museum. Rightjvalves. 18. Woodwardian Museum. Gault, Cambridge. Right valve. 19. York Museum. Right valve. 20. Part of left valve of 19. 21. Woodwardian Museum. Cambridge Greensand (derived from the Gault). 22—25. P. niiuta, Seel. (P. 138.) 22, 24. Woodwardian Museum. Cambridge Greensand. 23. Wiltshire Collection. Red Limestone, Speeton. Qos ns “ Red Limestone, Hunstanton. a, outline, natural size; b, x 3. A.T.Hollick ith labohn NDOTTC Wi PT ToD AROS CRETACEOUS LAMELLIBRANCHIA ie “A cca PLATE XXVI. PLIcATULA (continued). Fes, 1—11. P. inflata, Sow. Woodwardian Museum, Cambridge. Right valves (except fig. 7). (P. 139.) 1—3, 5. Totternhoe Stone, Burwell. 4. Lower Chalk, Burwell. 6. Totternhoe Stone, Arlesey. the a a Reach. Left valve. 8. 3 ss Burwell. 9. Lower Chalk, Burwell. 10. Chalk Marl, Haslingfield. 11. H. subglobosus zone, Cherry Hinton. 12—18. P. Barroisi, Peron. Right valves, except figs. 13, 14. (P. 141.) 12. H. planus zone, Dover. Dr. Rowe’s Collection. a, natural size; b, x 4. 13. H. planus zone, Twyford. Woodwardian Museum. Left valve, a, natural size; b, xX 4. 14. Top of I. cor-anguinum zone, North Foreland. Dr. Rowe’s Collection. Left valve, a, natural size; b,x 4. 15. H. planus zone, Dover. Dr. Rowe’s Collection, a, natural size; b, x 4. 16. Uintacrinus-band, Kingsgate, Margate. Dr. Rowe’s Collection. a, natural size; 6, x 4. 17. H. planus zone, Twyford. Woodwardian Museum. a, natural size; b, x 4. 18. Chalk Rock, near Winchester. Mr. R. M. Brydone’s Collection. a, natural size; b, x 4. 19—22. P. sigillina, Woodw. (P. 143.) 19. B. mucronata zone, Hartford Bridge, Norwich. Woodwardian Museum. a, interior of right valve; b, central part of same x 2. 20, Top of M. cor-testudinarium zone, Chatham. Dr. Rowe’s Collection. Left valve. 1. Same horizon, etc. Left valve x 2. bo po 2. M. cor-testudinarium zone, Chatham. Museum of Practical Geology, No. 179. eft valve. a, natural size; b, x 2. PLATE XXVII. Genus—Prcren, Miller. Pecten (Syneyclonema) orbicularis, Sow. (P. 145.) (All in the Woodwardian Museum, except fig. 4.) Fias. 1,2. Tealby Limestone, North Willingham. Right valves. 3. Gault, Folkestone, Wiltshire Collection. Right valve. 4. Var. haldonensis, Woods. Upper Greensand, Kinegskerswell. Museum of Practical Geology, No. 991. Right valve. 5. Chloritic Marl, Maiden Bradley. Right valve. 6—9. Upper Greensand, Ventnor. 6, right valve (ears partly drawn from another specimen); 6, antero-ventral portion of the same X 3. ¢a, right valve (margins of ears slightly restored) ; 7, posterior portion of the same X 3; 7c, left valve of the same specimen. 8, right valve. 9a, right valve; 9b, postero-ventral portion of the same x 5. 6, 7, Leckenby Collection. 8, 9, Wiltshire Collection. 10—15. Chalk Marl, Burwell. 10a, left valve; 10%, portion of the same near the ventral margin X 10 (on other parts of the valve the fine concentric ridges are closer together). 11—13, right valves. 14. Totternhoe Stone, Burwell. Part of interior of right valve x 2. PLATE XXVIII. Pecren (continued). P. (Camptonectes) cinctus, Sow. Claxby Ironstone (zone of B. lateralis) of Claxby. Woodwardian Museum. (P. 152.) Fies. la. Right valve x 4. 14, portion of the same, natural size. 2a. Left valve of another specimen X 2. 2, portion of the same, natural size. 3. Portion of left valve with the concentric laminz well preserved X 2 (The ears in figs. 1a, 2a, have been partly completed from other specimens.) aN) i — - 7 7 - , ot 7 . ° : - 7 eo) = 7 7 its ~ -~ ' : ogi 7 7 o ae ss -_ , 7 og 7 : . ws : = - - 7 7 . 7 _ -_ - PLATE XXIX. PECTEN (continued). Fias. 1—3. P. (Camptonectes) Cottaldinus, VOrb. Leckenby Collection, Woodwardian Museum. (P. 156.) 1. Lower Greensand, Whale Chine. Right valve. 2. Perna-bed, Atherfield. a, left valve; b, part of the same above the middle of the valve x 3. 3. Perna-bed, Atherfield. Left valve. a, part near the middle of the dorsal third x 3; b, part of the anterior ear x 4. 4—6. P. (Camptonectes) striato-punctatus, Rom. (P. 157.) 4. Speeton Clay (D1). Mr. Lamplugh’s Collection. a, part of left valve; b, part of same X 3. 5, Same horizon, etc. Anterior left ear x 3. 6. Claxby Ironstone, Benniworth Haven. Woodwardian Museum. Part of left valve. 7. P. (Camptonectes) curvatus, Gem. Greensand, Great Haldon. Museum of Practical Geology, No. R4780. Left valve. «a, natural size; b, same Seay (esl) 8. P. (Camptonectes) dubrisiensis, Woods. Chalk Marl, Dover. British Museum, No. 38243. a, right valve; b, left valve; c, anterior ear of bx 2. (P. 162.) X rx Sis LATE XD P TABrock del AT Hollick lith op lu CRETACEO PLATE XXX. Prcren (continued). Figs. 1,2. P. (Camptonectes ?) gaultinus, Woods. Gault. Woodwardian Museum. la, right valve, Folkestone, x 14; 16, portion of the same near the postero-dorsal margin x 6. 2, left valve, Black Ven, x 2. (P. 163.) 3—8. P. (Chlamys) fissicosta, Eth. Woodwardian Museum. (P. 163. o » Arlesey. 3—6. Totternhoe Stone, Burwell. Ue 5 3 » Cherry Hinton. 3, right valve (type). 4, left valve (type). 5a, right valve; 5b, part of the same specimen X 2. 6a, left valve x 14; 66, part of the same near the antero-ventral border x 3; 6c, another part near the middle of the valve x 3. 7, right valve of a variety with few ribs. 8, left valve, crushed near the umbo. 9—12. P. (Chlamys) Puzosianus, Math. Woodwardian Museum. (P. 165.) 9. Cenomanian, north of Beer Head. a, left valve; 6, postero-ventral part of the same X 2. 10. Cenomanian, Wilmington. a, left valve ; b, part of the same near the centre x 2. 11. Same locality. Right valve. 12. Top of Chloritic Marl, Melbury, North Dorset. Anterior part of right valve with the ornamentation well preserved x 2. eS te ie Yi , Lt SY, Wy fi ? / | [ABrock ~ TABrock del AT-Hollick lith CRETACEOUS LAMELLIBRANCHIA 7 7 foi) mie i a aie PLATE XXXI. Prcren (continued). Fias. 1,2. P. (Chlamys) britannicus, Woods. (P. 167.) 1. Dr. Blackmore's Collection. Upper part of M. cor-anguinum zone, Stratford, near Salisbury. a, part of valve; 6b, same x 4. 2. Mr. G. E. Dibley’s Collection. MM. cor-anguinum zone, Haling Pit, South Croydon. a, left valve; b, part of the same x 3. 6. P. (Chlamys) Milleri, Sow. Greensand, Blackdown. Woodwardian Museum. (Pe 168%) ray o Meyer Collection. a, left valve; b, part of the same near the umbo x 6. 4. Wiltshire Collection. a, right valve x 2. The anterior ear is drawn from oo another specimen in the same collection. 5. Wiltshire Collection. Right valve. Ornamentation just above the middle of the valve x 6. 6. Meyer Collection. a, left valve; 6b, postero-ventral part of the same x 3. 7—9. P. (Chlamys) subacutus, Lam. (P. 169.) 7, 9. Meyer Collection. Bed 11 (Cenomanian), Dunscombe. 7a, right valve; 7b, part of same x 3. 9, ribs of another right valve near the middle of the valve x 3. 8. Museum of Practical Geology, No. 6683. Greensand, Haldon. a, right valve; b, part of same in the middle of the dorsal third x 4; c, part near middle of ventral border x 4. 10—13. P. (Chlamys) elongatus, Lam. Woodwardian Museum. (P. 170.) 10, 11. Wiltshire Collection. Gault, Folkestone. 10, left valve. lla, left valve; 11}, part of same X 3. 12. Wiltshire Collection, Chalk Marl, Ventnor. a, left valve; b, postero-ventral part of same x 2. 13. Totternhoe Stone, Arlesey. Right valve. Ribs near the middle of the ventral border x 4. TABrock del AT-Hollick lith CRETACHOUS LAMELLIBRANCHIA a” a a ie PLATE XXXII. Prcren (continued). Fies. 1—3. P. (Chlamys) clongatus, Lam. (P. 170.) 1. Grey Chalk, Dover. York Museum. a, right valve; 6, portion of the same near the middle of the valve x 3. . Lower Chalk, Burwell. Woodwardian Museum. a, left valve; 6, part of the same near the middle of the valve x 3. 3. Same horizon, ete. a, right valve; b, part of same below the middle of the valve xX 3. (The anterior ear is displaced.) bo 4—6. P. (Chlamys) cretosus, Defr. A. quadratus zone, East Harnham. Dr. Blackmore’s Collection. (P. 174.) 4a, left valve x li. 4b, mid-ventral ribs of 4a x 3. 4c, right valve of the same specimen x 13. 4d, mid-ventral ribs of 4¢ x 3. 5a, left valve. 5b, part of 5a posterior to the middle of the ventral border x 4. 6a, left valve. 6b, umbo of 6a x 3. 6c, part of 6a near the mid-ventral border x 4. del ATHollick lith fey = fla Oe . ” o tas = - : - on Fias. Oo “JI FAL ASI ET pox Nexen Ae PECTEN (continued). Pecten (Chlamys) eretosus, Defr. Upper Chalk. (P. 174.) A. quadratus zone, East Harnham. Dr. Blackmore’s Collection. a, right valve x 13; /, part at antero-ventral edge xX 4; ¢, antero-ventral part of left valve of the same specimen x 4. Same horizon, ete. wo, left valve; b, part just behind the mid-ventral edge <3: Same horizon, ete. a, left valve x 14; /, part at postero-ventral margin x 4. Fine concentric ridges cover almost the entire shell, but are not shown in the figure. Near the umbo the radial ribs are spiny. M. cor-anguinumn zone, Porton. Dr. Blackmore’s Collection. a, left valve; }, part just behind the mid-ventral margin x 3. Marsupites zone, Witherington. Dr. Blackmore’s Collection. Left valve. M. cor-anguinum zone, Gravesend. Mr. G. E. Dibley’s Collection. «, right valve, with interior of anterior /eff ear; ), part of mid-ventral third x 4 Upper Chalk, Bromley. Wiltshire Collection. Right valve of specimen with coarse ribs. «, antero-yentral part; }, portion of same part X 3. Same horizon, ete. Part of mid-ventral third of left valve x 6. B. mucronata zone, Norwich. Norwich Museum, No. 2056. Part of left valve near the middle of the ventral edge Xx 4. A. quadiatus zone, Kast Harnham. Dr. Blackmore’s Collection. Part at the mid-ventral edge Xx 4. Upper Chalk, Charlton. Wiltshire Collection. Right valve of a specimen with the scaly spines large and well-preserved. Part near the ventral edge X 6. Upper Chalk, Trimingham. Mr. R. M. Brydone’s Collection. Right valve. Form with numerous slender ribs. Portion at the dorsal third x 6. PLATE XXXIII « STITT enon ns more in STP T ET! ian tartan he ada Sa aR Yom Yemen Baa Ms ie Ba a ct TABrock del. AT. Hol lick lith West. Newman imp CRETACEOUS LAMELLIBRANCHIA . Fias. PLATE XXXIV. PECTEN (continued). 1—6. P. (Chlamys) Mantellianus, VOrb. Upper Chalk (6. mucronata zone), Norwich. Norwich Museum (except fig. 3). (P. 179.) Doe No. 2093. a, left valve; b, part near mid-ventral edge x 6. No. 2058. Left valve. Woodwardian Museum. Right valve. a, natural size; b, middle part x 2; c, portion near the centre x 5. 4. No. 2055. Right valve. Part near the umbo x 2. No. 2055 (another specimen). Right valve. . No. 2053. Left valve x 2. 7—12. P. (Chlamys) Robinaldinus, VOrb. Perna-bed. Atherfield. | Wood- wardian Museum. (P. 181.) y ( 8 9 10. 1 12 . Leckenby Collection. a, left valve; 6, part near the margin just in front of the mid-ventral part x 4. . Leckenby Collection. a, left valve; b, part of the middle of the valve between the two strong growth-lines x 3. . Leckenby Collection. a, left valve; b, part near the mid-ventral edge x 3. a, right valve; b, part near the antero-ventral margin x 4. . Left valve; middle of ventral third » 4. . Wiltshire Collection. a, left valve; 6, part near the mid-ventral margin x 4; > c, anterior ear x 3. PLATE XXXIV. TABrock del AT Hollick Jith West,.Newman imp CRETACEOUS LAMELLIBRANCHIA ; a aes PLATE XXXV. PECTEN (continued). Fias. 1—10. P. (Chlamys) Robinaldinus, @Orb. Upper Greensand (except figs. 5, 6, 8). elise) 1. Warminster. British Museum, No. 67734. a, left valve ; 6, antero-ventral part of the same x 4. bo Warminster. Woodwardian Museum. a, left valve; 6, antero-ventral part x 4; c, part near the umbo x 4. 3. Ventnor. Wiltshire Collection. a, left valve; 6, posterior part x 4. 4. Warminster. Museum of Practical Geology, No. 7418. a, right valve; 6, part just in front of the mid-ventral edge x 4; c, anterior part of left valve of same specimen x 4. 5. Chloritic Marl, Maiden Bradley. Mr. J. Scanes’ Collection. ? Left valve ; antero-ventral part x 4. Same horizon, ete. Left valve; part at the antero-ventral margin x 4. Ventnor. Wiitshire Collection. Left valve; mid-ventral part x 4. Cenomanian (Bed 11), Beer Head. Meyer Collection. ? Left valve; antero- ventral part x 4. 9. Warminster. Bristol Museum. Right valve; postero-ventral part x 4. 10. Warminster. Museum of Practical Geology, No. 7407. Middle part of left valve x 4. COND 11. P. (Chlamys) Stutehburianus, Sow. Greensand, Blackdown. The Type. Bristol Museum. Ventral part x 14. (P. 185.) 12. P. (Aiquipecten) asper, Lam. Upper Greensand (Chert Beds), Baycliffe Quarry, Wiltshire. Mr. J. Scanes’ Collection. Left valve; part just in front of mid-ventral margin x 4. (P. 186.) AMELLIBRAN CHIA L c nm CRETACEOUS ® iw 7 ; y i i R » % ' - i if Wigs we a ; z pi : bee ys J ' ' , = ' ‘i - br; . 1 w 4 1 - we a 1 if 7 PLATE XXXVI. PEcren (continued). Fias. 1—4. P. (Aquipecten) asper, Lam. Upper Greensand, Warminster. (P. 186.) | . Woodwardian Museum. a, left valve (the anterior ear is drawn from another specimen) ; b, ventral part x 3. York Museum. Right valve. ho . Woodwardian Museum. « - = _ i .— ‘ v - a . - a . = - 7 . i 2 —_ = 7 7 a - _ ~— tf —_ = oy > - u = a >= 4 * - : 7 7 . u - a - 7 : : @ : a) 1 =i. A - an) 7 Es - a 7 - a = =e 7 _ . -— a - as - @ Ce — - -_ 7 . 7 . = ee 2 : : : 1 Pi} a PLATE XXXVIII. PECTEN (continued). P. (Aiquipecten) Beaveri, Sow. (P. 188.) Fias. 1. Chalk Marl, Dover. York Museum. a, left valve; , posterior portion x 3. 2. H. subglobosus zone, Shelford Lime-kiln, Gog-ma-gog Hill. Woodwardian Museum. a, right valve (the ears are drawn from another specimen) ; 6, antero-ventral portion of left valve of the same specimen. 3. HH. subglobosus zone, Cherry Hinton. Woodwardian Museum. Interior of part of right valve, showing byssal sinus. PLATE XXXVITI West,Newman amp A THollick delet lith CRETACEOUS LAMELLIBRANCHIA. ' i : i ' ' i - a il § ‘ : 7 i i a : . A ' _ 4 t ” i b be i a5 i 7 A ' F ‘ i ' i f : : 1 1 i i : ' j ‘ wv “Ss. =f; “eer bP ie 7 = — F > = - = 7 = _ : 7 a — 7 | e- Ww 7, oie 7 = 7 . _ S _—_ 7 > 7 > a * 7 : 9s 7 " — = - "a? oa a 7 . *. : D a ro 7 _— = _ = - s- ’ - - 7 7 = , _ os co - se @= = = a - = a - - = a _ a - - , = _ . = 7 _ - - @ at) 7 = - 7 — ‘* , a ~ - J z - a : ; . . had we 1s - = = : _ - 7 a a i) = on a = = ay mn 7 7 o . 7 a. oe - o . 7 - + = =. f - - = = a + -_ PLATE XXXIX. Prcten (continued). Fias. 1—5._ P. (Neithea) atavus, Rom. Lower Greensand, Upware. 1,5, Mr. J. F. Walker’s Collection. 2, 3, 4, Woodwardian Museum. (P. 197.) 1, right valve. 2, left valve. 3a, right valve; 3b, posterior view of both valves. 4a, right valve; 4 6, portion between the two middle ribs of left valve x 3; 4c, portion between the two middle ribs of right valve x 3. 5, portion between the two middle ribs of right valve x 4. 6—10. P. (Neithea) cometa (d’Orb.). Upper Greensand, Warminster. (P. 200.) 6. British Museum, No. 38267. Right valve. Woodwardian Museum. a, right valve ; 6, posterior view of the same ; c, anterior view of same. 8. British Museum, No. 88871. Left valve. 9. Museum of Practical Geology, No. 8278. Right valve. 10. Same museum, No. 8445. Portion of right valve x 4. 11—13. P. (Neithea) Morrisi (Pict. and Renev.). (P. 201.) 11. Hythe Beds, Lympne. Museum of Practical Geology, No. 8364. a, right valve; b, posterior view of the same; c, portion between two main ribs x 3. 12. Same locality, etc., No. 8446. a, left valve; 6, posterior view of the same. 13. Perna-bed, Atherfield. Woodwardian Museum. Left valve—posterior margin restored. 14—17. P. (Neithea) quinquecostatus, Sow. (P. 202.) 14. Upper Greensand, Ventnor. York Museum. a, right valve; b, anterior view of the same. 15. Upper Greensand (zone of Pecten asper), Shaftesbury. Bristol Museum. a, right valve; b, left valve; c, anterior view. 16. Same horizon, Warminster. Museum of Practica] Geology, No. 8419. a, right valve; b, anterior view of the same. 7. Upper Chalk (? M. cor-anguinum zone), Gravesend. Museum of Practical Geolozy, No. 8362. a, right valve; 6, left valve; c, posterior view of the same specimen. —_ ~ Lowman umn TABrock del ATHollick hth HIA = Ot LAMEDLLIBRAN a) 5 BOUS ’ J CREVTAC PLATE XL. Proren (continued). 5. P. (Neithea) quinquecostatus, Sow. (P. 202.) 1. Cenomanian (Meyer's Bed 12), Dunscombe. Woodwardian Museum. Portion between two main ribs of right valve x 6. 2. Upper Chalk (A. quadratus zone), West Harnham, Salisbury. Dr. Blackmore’s 5 —) Collection. a, right valve; b, anterior view; ¢, portion of right valve x 4. 3. Upper Chalk, probably Sussex. British Museum, No. 74979. Right valve. 4, Upper Chalk (? M. cor-anguinum zone), Gravesend. Bristol Museum. a, right valve; b, portion of the same between two main ribs x 4. . Upper Chalk, Sussex. British Museum (Dixon Collection), No. L. 14742. Right valve. Ox 6,7. P. (Neithea) quadricostatus, Sow. (P. 210.) 6. Upper Greensand (Chert Beds), Sutton Veny, Warminster. Woodwardian Museum. Posterior half of left valve. 7. Upper Greensand, Warminster. Woodwardian Museum. Portion of right valve x 4. (The line near the middle of each furrow is accidental.) 8,9. P. (Neithea) equicostatus, Lam. (P. 208.) 8. Upper Greensand, Worbarrow. Museum of the Geological Society, No. 1530. a, right valve x 2; b, posterior view of the same x 2. 9. Upper Greensand (Chert Beds, zone of P. asper), Haldon. Bristol Museum. a, right valve; b, anterior view of the same x 2; ¢, part of anterior ear of the same x 4. 10—15. P. (Neithea) seacostatus, Woodw. Upper Chalk (A. quadratus zone), Kast Harnham, Salisbury. Dr. Blackmore’s Collection. Right valves, except fig. 12. (P. 214.) 10a, x 14; 106, portion of same x 4; lla, x 13; 11 }, posterior view of the same xX 12; 12, left valve x 11; 13 a, natural size; 13 b, part of posterior view of the same x 2; 14a, x 13; 145, outline of the same, posterior aspect, natural size; 15, natural size. PLATE. XL. Nest,Newman tmp T:ABrock del. AT. Hollick ith CRETACEOUS LAMELLIBRANCHIA. ui 7 shall = 7 i ” ; a A ie rat ie inl ye ; , 7 th — PLATE XLI. Pecren (continued). Figs. 1—8. P. (Neithea) sexcostatus, Woodw. 1—5, Form B, Upper Chalk. 6—8, Form a, Lower Chalk. (P. 214.) 1. A. quadratus zone, East Harnham, Salisbury. Dr. Blackmore’s Collection. a, right valve; b, portion of the two middle main ribs and part between x 4. 2. Same horizon, etc. a, right valve; b, posterior view of the same. 3. B. mucronata zone, Hartford Bridge, Norwich. Woodwardian Museum. a, right valve x 13; b, portion of the same near the ventral margin x 4; c, portion dorsal to middle of valve x 4. nN . B. mucronata zone, Norwich. Norwich Museum. Right valve x 2. Oo . A. quadratus zone, East Harnham. Dr. Blackmore’s Collection. Right valve. Portion of the two middle main ribs and part between x 4. 6—8. Chalk Marl, Dover. Woodwardian Museum. Right valves. 6a, x 13; 6), posterior view of the same x 2; 6c, part between two main ribs x 4 7a, x 13; 76, posterior view of the same x 1}; 7c, part between two main ribs x 4. 8a, x 15; 8b, part between two main ribs x 4. 9,10. P. (Neithea) striatocostatus 2? Goldf. Chalk, Trimingham. Museum of Practical Geology (Coll. Mr. Clement Reid). (P. 217.) 9a, portion of right valve; 9b, part of the same x 6. 10a, left valve x 2; 106, part of the same x 5. Genus—V ELoPECctEn, Philipp. ll. V. Studeri (Pict. and Roux). Upper Greensand, Warminster. York Museum. (P. 218.) lla, left valve; 116, part of the same x 2; I1c, right valve of the same specimen. CRETACEOUS LAMELLIBRANCHIA PLATE XLI PLATE XLII. VELOPECTEN (continued). Fies. 1—4. V. Studeri (Pict. and Roux). (P. 218.) 1. Gault, Folkestone. Wiltshire Collection, Woodwardian Museum. Left valve. 2. Gault (Bed xi), Folkestone. Museum of Practical Geology, No. 1612. Left valve. 3. Cambridge Greensand (derived). Internal cast in phosphate. Woodwardian Museum. Imperfect left valve. 4. Red Limestone, Hunstanton. Woodwardian Museum. a, antero-ventral por- tion of left valve of a large specimen ; 6, portion of the same x 4. Or V. trilineavis (Seel.). Cambridge Greensand (derived). Woodwardian Museum. The type. a, left valve; >, part of the same near the ventral margin X 3. (P. 219.) or) V. pectinatus (Seel.). Cambridge Greensand. Woodwardian Museum. The type. a, part of left valve ; b, portion of the same xX 3. (P. 220.) 7,8. V.sp. Gault, Folkestone. Wiltshire Collection, Woodwardian Museum. 7, left valve. 8, portion of another left valve x 4. (P. 220.) 9,10. Pecten Nilssoni, Goldf. Upper Chalk. Mr. R. M. Brydone’s Collection. (Pp. 152, 226.) 9. Trimingham. Portion of left valve. 10. A. quadratus zone, Hampshire. Right valve. 11. Pectuneulus Vaughani, Woods. Greensand, Blackdown. Woodwardian Museum (Coll. Mr. A. Vaughan). Left valve. (P. 224.) PLATE XLIL. TABrock del. West,Newman imp AT Hollicklith CRETACKOUS LAMELLIBRANCHIA. ¥, » : a : vee a” a ? ° Up * a | | » # jig? a out *e vss es ® . * a ~ ~ ‘ VN \ eS a7 : “ IJ) SS ; » rp Da? PB D> py» eS %) oe. Dp MD? Dp >» >> 2D. y $65 y, as 4 yp >> oP 2 > Hp D> i >, y > I> )» I 3)) wy Ra QP ae? 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