SOME TERTIARY FOSSILS FROM THE MIIKE COAL-FIELD. 9 



The shell is oval, oblique, strongly inequilateral, thick, 

 flatly convex, with about 23 strong, flattened, broad, rugose ribs 

 which are separated by furrows much narrower than the ribs 

 themselves. The hinge in none of the specimens is exposed to 

 view, but the general characters of the shell-surface leaves no 

 doubt of its being a Venericardia resembling in its compressed 

 shape V. j^ectunciilaris Lam, (Anim. sans Vert., vol. v, p. 610 

 no. 2 and Deshayes, Coq. Foss. Envir. Paris, p. 150. pi. XXIV, 

 fig. 1, 2) and in its oblique oval outline V. multicostata Lam. 

 (Desh. Coq. Foss. Env. Paris, p. 151, pi. XXVI, fig. 1, 2), 

 both from the Paris Basin and occurring in the '* Sables de 

 Bracheux " which is now considered by many geologists to be 

 Middle Paheocene. 



Our specimens were obtained at depths of 280 ft., 300 ft., 

 358 ft., 405 ft., and 842 ft. 



7. Cardita mandaica n. sp. 

 PI. II. Figs. 8-11. 



The shell is transverse, elongate, oblong or subquadrate, 

 very inequilateral and inflated. The surface is ornamented w^ith 

 about 20 radiating, flattened, somewhat rugose ribs separated by 

 intervals narrower than the ribs themselves. The beaks are 

 prominent and incurved. 



A small specimen with both valves complete (fig. 9ab) 

 measures 15 millim. in length, 13 millim. in height and 11 

 millim. in thickness. The right valve represented in fig. 10 is 

 about 27 millim. in length and 25 millim. in height. 



This species bears a marked resemblance to Cardita obovata 



