230 CRETACEOUS LAMELLIBRANCHIA. 
margin rounded. Ventral margin straight or slightly convex. Posterior margin 
truncated, shehtly convex. Postero-dorsal margin shghtly concave, nearly parallel 
to the ventral margin. Umbones broad, curved inwards and backwards. The 
part of the shell in front of the umbones is shehtly depressed ; the part behind the 
wmbones is more deeply depressed. Surface with well-marked growth-rings. 
Length 87 mm.; height 59 mm. 
Afjinities.—In this species the sides of the shell are more flattened, the antero- 
dorsal margin is more convex, and the part of the shell in front of the umbones is 
less depressed than in P. ovalis. he hinge has not been seen, but the form of the 
shell agrees closely with that of typical species of Panopea. 
Fie. 28.—Panopea, sp. Lower Greensand (“ Scaphites” Beds), Whale Chine, Atherfield. Sedgewick 
Museum. Internal cast of right valve. Natural size. 
Remarks.—In addition to the specimen figured, which was collected by 
C. J. A. Meyer, an internal cast and the posterior part of a left valve only have 
been seen. 
Distribution.—Upper Greensand (zone of Scehlwnbachia varians) of Blackdown. 
Panopra, sp. Text-fig. 28. 
Internal casts resembling P. Meyert, but with the posterior border obliquely 
truncated, occur in the Lower Greensand (‘“Scaphites”’ Beds) of Whale Chine, 
Atherfield. 
Yd 
