8o R. BULLEN NEWTON on 



forms have been described by Dr. Oppenheim, 1 but those also differ in their 

 nearly circular contour and less acutely angled costae. The genus Divaricella 

 of E. von Martens, 2 under which the new Luciniform shell is included, has 

 existed from older Tertiary times to the present day, although its origin may 

 apparently be traced from Stoliczka's, 3 Lucina (Cyclas) taenio/ata, an extremely 

 rare form, found in the later Cretaceous deposits (Ariyalur Group) of India, 

 known as the Ninnyoor limestones of the Trichinopoly District, which chiefly on 

 account of the absence of Ammonites are regarded as of transitional age between 

 the Cretaceous and Tertiary epochs. The living species are chiefly Atlantic. 

 The specific name is in honour of Dr. Paul Oppenheim, a well known authority 

 on African Tertiary Mollusca, especially in connection with faunas from Egypt, 

 Togoland, and the Cameroons. 



OCCURRENCE. Cutting No. 6. 

 COLLECTOR. Mr. Kitson. 



Family CARDITID^:. 



Cardita cf. planicosta (Lamarck). 

 Venericardia planicosta. 



Lamarck : Ann. Mus. Hist. Nat. (Paris), 1806, Vol. 7, p. 55 ; ibid., 1807, Vol. 9, pi. 19 (31), fig- 10 ; 

 J. Sowerby : Mineral Conchology, 1814, Vol. i, pi. 50, p. 107 ; Deshayes : Desc. Coq. Foss. Paris, 1825, 

 Vol. I, pi. 24, figs. 1-3, p. 149 ; Conrad : Journ. Acad. Nat. Sci. Philadelphia, 1830, Vol. 6, pp. 213-215. 



Cardita planicosta. 



J. cle C. Sowerby : Dixon's " Sussex," 1850, pi. 2, figs. 14, 18, p. 169 ; Deshayes : Suppl. Dcsc. Coq. 

 Foss. Paris, 1860, Vol. i, p. 756; S. V. Wood : Mon. Pal. Soc., 1871, pi. 21, fig. 5, p. 150. 



Venericardia planicosta. 



Cossmann : Ann. Soc. R. Mai. Belgique, 1887, Vol. 22, p. 86. 



Cardita planicosta. 



R. B. Newton : Syst. List, British Eocene Mollusca, c, 1891, p. 39. 



Venericardia planicosta. 



C. J. Maury : Paleontology of Trinidad-Journ. Acad. Nat. Sci. Philadelphia, 1912, Vol. 15, 2nd Ser., 

 pi. 8, figs 15, 1 6, p. 51. 



REMARKS. A single specimen of small size representing a right valve, 

 appears to show relationship to this species. The radial costae, numbering 

 about 25, are of similar squarish design, and with depressed summits, their width 



1 Palaeontographica, 1903, Vol. 30, part 3, pi. 15., figs. 10-13, pp. 146, 147. 



2 Beitr. Meerest. Mauritius Seychellen-Mollusken (Mobius & Richter), 1880, pi. 22, fig. 14, p. 321. 



3 The Pelecypocla : Mem. Geol. Surv. India, Palaeontologia ftidica, 1871, pi. 13, fig. 9, p. 257. 



