74 R. BULLEN NEWTON on 



Family CARDIID^. 

 Cardium of. obliquum, Lamarck. 



PLATE 7, figs. 6-9. 

 Cardium obliquum. 



Lamarck : Ann. Mus. Nat. Hist. (Paris), 1805, Vol. 6, p. 344, and 1807, Vol. 9, pi. 18 (20), fig. i ; 

 Deshayes : Desc. Coq. Foss. Paris, 1829, Vol. i, pi. 30, figs. 7, 8, 11, 12, p. 171 ; ibid., Suppl. 1858, 

 Vol. i, p. 568. 



Cardium (Loxocardium} obliquum. 



Cossmann : Ann. Soc. R. Mai. Belgique, 1886, Vol. 21, p. 173. 



Cardium obliquum. 



R. B. Newton : Syst. List, British Eocene Mollusca (Edward's Coll.), &c., 1891, p. 52. 



Cardium (Loxocardiuni) obliquum. 



Oppenheim : Palaeontographica, 1903, Vol. 30, part 3, p. 156. 



REMARKS. In general appearance, a number of small valves show a 

 relationship to this species having a well rounded anterior margin and a steep 

 posterior declivity. Some differences may be noted in the sculpture, such as 

 the fewer and consequently rather more distant costae, which moreover do not 

 possess the minute, triangular scale-like tubercles so often possessed by well 

 preserved examples of the European species and which was the chief 

 character of M. Cossmann's 1 section, Loxocardium, In the present specimens, 

 however, this scaly feature is absent, only some small granulations being 

 observable on the anterior costae, otherwise they are smooth, with the exception 

 of bearing closely-set transverse striations which are also, but more strongly, 

 developed in the furrows where they would be less subjected to erosive 

 agencies. Like the European species, the Nigerian valves are furnished with 

 costae having flattened summits, while both forms are similarly striated as 

 described. The larger sized valves have a height and length respectively of 

 13 x 15 millimetres, whereas those from Europe measure 26 x 28, as 

 stated by Deshayes. The species has been recognised by Dr. Oppenheim, 

 from the Mokattam Beds of Egypt, while M. Cossmann regards it as extend- 

 ing throughout the Eocene Series of Europe (Anglo-Parisian Basin) ; it may 

 therefore be restricted to Eocene times, although it is worthy of comment 

 that specimens are in the Edwards Collection of the British Museum from 

 the Roydon Beds of Hampshire, which belong to the Headon Hill Series, 



1 Ann. Soc. R. Mai. Belgique, 1886, Vol. 21, p. 172. 



