Transactions of the Royal Society of Edinburgh http://journals.cambridge.org/TRE Additional services for Transactions of the Royal Society of Edinburgh: Email alerts: Click here Subscriptions: Click here Commercial reprints: Click here Terms of use : Click here VI.—On Cretaceous Ammonoidea from Angola, collected J. W. Gregory, L. F. Spath and J. W. Gregory Transactions of the Royal Society of Edinburgh / Volume 53 / Issue 01 / March 1922, pp 91 - 160 DOI: 10.1017/S0080456800004579, Published online: 06 July 2012 Link to this article: http://journals.cambridge.org/abstract_S0080456800004579 How to cite this article: J. W. Gregory, L. F. Spath and J. W. Gregory (1922). VI.—On Cretaceous Ammonoidea from Angola, collected. Transactions of the Royal Society of Edinburgh, 53, pp 91-160 doi:10.1017/S0080456800004579 Request Permissions : Click here Downloaded from http://journals.cambridge.org/TRE, IP address: 128.83.63.180 on 01 May 2015 91 ) VI.—On Cretaceous Ammonoidea from Angola, collected by Professor J. W. Gregory, D.Sc, F.R.S. By L. F. Spath, D.Sc, F.G.S. Communicated by Professor J. W. GREGORY, D.Sc, F.R.S. (With Four Plates and Four Text-Figures.) (Read December 6, 1920. MS. received January 21, 1921. Issued separately January 17, 1922.) CONTENTS. PAGE INTRODUCTION . 92 SEDIS 131 LIST OF LOCALITIES 94 Genus Elobiceras, Spath 132 30. Elobiceras szajnochai, n.n. 132 CLASSIFICATION OF CERTAIN ALBIAN AMMONITES 95 31. n.n. 132 DESCRIPTION OP SPECIES 113 32. flexicostaturn, sp. nov. 133 Family Dipoloceratidx, Spath . 113 33. angustum, sp. nov. 134 Genus Subsehloenbachia, Spath* 113 34. intermedium, sp. nov. 134 A. Group of S. 'perinflata : 35. sp. ind. (juv.) . 135 1. Subsehloenbachia cf. perinflata, n.n. 113 36. densieostatum (Crick MS.) . 135 2. „ sp. n. aff. perinflata, n.n. 113 37. lobitoense (Crick MS.) 136 3. „ depressa, sp. nov. 114 38. arietiforme, n.n. 137 4. „ cf. quadrata, n.n. 115 39. cf. arietiforme, n.n. 138 5. „ sp. ind. 116 40. sp. ind. 139 6. „ subrotunda., sp. nov. 116 Genus Neokentroceras, Spath 139 7. „ sp. nov. ?ind. 117 41. Neokentroceras curvicornu, sp. nov. 139 8. „ sp. juv. 118 42. sp. ind. 140 B. Group of S. rostrata : 43. subtuberculatum, sp. nov. 141 9. Subsehloenbachia sp. nov. ?atf. rostrata, J. 44. pseudovaricosum, sp. nov. 142 Sowerby sp. .118 45. „ v. compressa, n. 142 10. „ stoliczkai, Spath . .119 46. aff. fseudovaricosum, sp. nov. 143 11. „ sp. nov. ?ind. 120 47. ? 143 12. „ aff. orientalis, Kossmat sp. 120 Genus Prohysteroceras, Spath 143 13. „ sequatorialis, „ „ 121 48. Prohysteroceras wordiei, Spath . 143 14. „ aff. sequatorialis, „ „ 122 49. „ „ var. compressa, nov. 144 15. „ sp. cf. sequatorialis, „ „ 122 50. „ decipiens, sp. nov. 145 16. ? ,, cf. angolaensis, Boule, Lem., 51. ,, dubium, sp. nov. 146 and Thev. sp. 123 52. „ sp. ind 146 17. ? „ sp. nov. ? . .123 53. „ sp. juv 147 147 C. Group of S. bispinosa : Family Hamitidse, Hyatt emend 148 18. Subsehloenbachia cycloceratoides, sp. nov. 123 Genus Torneutoceras, Hyatt 54. Torneutoceras cf. attenuatum (Sowerby), D. Group of S. evoluta : 148 19. Subsehloenbachia evoluta n.n. 124 d'Orbigny sp. 20. „ sp. ind 125 55. „ virgulatum, Brongniart sp. 148 21. „ irregularis, sp. nov. 125 Genus Helicoceras, d'Orbigny 149 22.? „ ambigua, sp. nov. .126 56. Helicoceras cf. annulatum, d'Orbigny 150 150 E. Group of S. simplex : Genus Ptyehoeeras, d'Orbigny 23. Subsehloenbachia gregoryi, sp. nov . 127 57. ? Ptyehoeeras gaultinum, Pictet . 150 24. „ sp.nov. ?aff. gregoryi,sp. n. 127 Family Anisoceratidx, Hyatt emend 151 151 F. Group of S. neuparthi: Genus Anisoceras, Pictet 151 25. Subsehloenbachia aff. neuparthi, Choffat sp. 128 58. Anisoceras cf. oldhamianum, Stoliczka 152 26. „ robusta, sp. nov. .129 Family Desmoceratidx, Zittel 152 27. „ striata, sp. nov. .129 Genus Desmoeeras, Zittel emend. Grossouvre 152 G. Group of S. inflatiformis: 59. Desmoeeras cf. latidorsatum, Michelin sp. 28. Subsehloenbachia sp. ind. cf. inflatiformis, 153 Genus Puzosia, Bayle Szajnocha ap. 130 153 29. „ sp. ind 131 60. Puzosia cf. mayoriana, d'Orbigny sp. 154 CONCLUSIONS * Subsehloenbachia is to be replaced by Inflaticeras, Stieler emend., throughout this memoir, completed before the publication of STIELER'S paper (" Ub. d. sogen. Mortoniceraten d. Gault," Centralbl.f. Min., etc., 1920, pp. 345-52,392-400) ; and Pseudophacoceras, Spath is invalidated by Oxytropidoceras, Stieler. Also, if STIELER'S reading of Brancoceras be adopted, HYATT'S generic term Hyiteroceras must be used for the lineage here called Brancoceras. TRANS. ROY SOC. EDIN., VOL. LIII, PART I (NO. 6). 14 92 DR L. F. SPATH ON I. INTRODUCTION. The Ammonoids described in the present paper were placed first of all, for study, in the hands of Mr J. M. WORDIE, whose departure, however, as geologist with Sir E. SHACKLETON'S Antarctic Expedition prevented the completion of the work. A preliminary list of identifica- tions by Mr WORDIE included a number of forms of "Schloenbachia" especially " S." inflata, J. Sowerby sp., this form alone being quoted from ten localities. Professor GREGORY, in his " Contributions to the Geology of Benguella," * referred to these identifications, and in his correlation-table classed the beds with " Schloenbachia injlata " as " Vraconnian," following the prevailing custom. It may be well, however, to remark here already that A. injlatus, J. Sowerby, will be shown to be an exclusively Albian, and not even uppermost Albian, form, and that there is no evidence of any Cenomanian admixture in the typically Albian fauna of the so-called " zone of A. injlatus" in Angola, so that the term Vraconnian is here rejected. Moreover, EENEVIER'S " Vraconnian" was meant for ^ost-inflata beds, and, in the writer's opinion, SOWERBY'S species is not represented at all in the Angola collection. - In March 1915 the collection was offered to the late G. 0. CRICK for examination and description. At about the same time Mr R. B. NEWTON studied the brachiopoda, pelecypoda, and gastropoda of Professor GREGORY'S collection, and his results, together with other palse- ontological and petrographical papers, were published in vol. li of the Transactions of the Royal Society of Edinburgh. + Mr NEWTON also briefly referred to the Ammonites, and followed CHOFFAT in considering the beds from which Professor GREGORY'S collection was obtained as of Vraconnian age, i.e. as " intermediate between the Albian and Cenomanian." I Mr CRICK had intended to publish his results at the same time, but owing to failing health he could not continue the work. The supervision of the fragmentary MS. was entrusted to the writer early in 1920, together with the task of naming the collection of Ammonoidea, which now are in the British Museum (Natural History), having been presented by Professor GREGORY in September 1916. The writer's thanks are due to Dr A. SMITH WOODWARD and to Dr F. A. BATHER, of the British Museum, for the opportunity of dealing with the collection ; also to Professor J. W. GREGORY for his ever-ready advice and help with the preparation of this paper, which now is offered as a belated contribution to the series of palaeontological papers that appeared in 1916. Especial acknowledgments are due to the Carnegie Trust for a very generous grant towards the cost of the illustrations. The writer soon discovered that he would have to study the collection quite independently of the work done by Messrs CRICK and WORDIE. Of 117 specimens in the collection, Mr CRICK'S notes only deal with fifteen ; and of these only the descriptions, but not the inter- pretations, of two new species have been accepted. Of the remaining specimens, a number bore provisional identifications by Mr WORDIE, acknowledged in each case under the specific descriptions, but these also had to be revised and largely altered. One specimen was described by Mr CRICK as " Mortoniceras delaruei, d'Orbigny sp.,"a form of the Middle Gault. Apart from this poorly preserved fragment, the identification of which, however, must be questioned, as will be seen under the specific descriptions, and, possibly, a second doubtful fragment, there is no evidence that a horizon below that of sub- zone VI6 of JACOB § or of Bed XI at Folkestone || is represented in this collection. Mr CRICK * Trans. Roy. Soc. Edin., vol. li, pt. iii, No. 13, 1916, pp. 498 et seq., 521. t Ib., Memoirs Nos. 14-17, 1916. I lb., No. 15, p. 562. § "Etudes Pal. et Strat. s. la partie moy. d. Ter. Cret., etc.," Trav. Lab. Ge'ol. Fac. Sc. Univ. Grenoble, vol. viii, 1908, p. 296. || " On the Gault of Folkestone," by F. G. H. PRICE, Q.J.G.S., vol. xxx, 1874, p. 353. CRETACEOUS AMMONOIDEA PROM ANGOLA. 93 himself, in his introductory remarks, stated that a preliminary examination of the specimens showed that they were chiefly referable to the genus " Mortoniceras," and that only one horizon appeared to be represented, viz. the Vraconnian, or zone of Mortoniceras rostratum, usually referred to in the literature dealing with West Africa as the zone of Schloenbachia injlata. Now, obviously, it was undesirable to continue to use in the customary indefinite manner the names of two such important Ammonites as SOWERBY'S A. rostratus and A. inflatus ; and a study of the English types of this group was essential. Since PICTET,* in 1861, erroneously stated that A. milletianus and A. inflatus could occur together (if very rarely), and on the other hand made A. inflatus range up, with A. curvatus and A. falcatus, beyond A. varians, into the Rhotomagian, the term A. inflatus has stood for one of the most heterogeneous assemblages of Ammonites ever known. What forms the records of A. inflatus, without figures, from many foreign, e.g. American, localities may include, it is impossible to say. On the other hand, SCHLUTER t stated already in 1876, what is practically confirmed at the present day, namely, that " no species of Cephalopoda occurs in the lowest Cenomanian [his zone of Pecten asper and Catopygus carinatus], that is found already in the beds below ; and that A.