Vol. 60.] KH.ETK OF THE SOUTH-WALES DIRECT LIKE. 



207 



line, the east of a specimen of either genus shows a sharply-pointed 

 beak. 



On the other hand, Pleurophorvs had a large hinge-plate, bearing 

 strong cardinal teeth, so that the cast should be broad and blunt 

 beneath the beak (as in casts of Cardinia, so common in the Lower 

 Lias). There seems, then, to be little doubt that Moore correctly 

 diagnosed the genus. Quenstedt (' Der Jura ' pi. i, fig. 32) figures 

 a somewhat similar form, but the upper and lower borders con- 

 verge backward : it can, therefore, scarcely be considered as identical 

 with our specimen. Brauns (5) unhesitatingly refers Quenstedt's 

 figure to Anoplophora postera, and only doubtfully includes Moore's 

 species as a synonym. It seems, therefore, very uncertain whether 

 we have found the species that is so common in the bottom beds 

 in Germany. 



Our specimen was derived from the main Aiicirfa-he&s. 



Carditjm cloacixum, Qu. (Text-fig. 6.) 



Average dimensions : horizontal, 14| millimetres; vertical, 13 mm. 

 The largest specimen that we found measured 221 mm., vertically. 



Fig. 6. — Cardium cloacinum, Qu. ( mcujaijied S\ diameters). 



Hinge (restored) 



In the fact that the curvature of the ribs is concave towards the 

 front, and that they increase in breadth towards the posterior margin, 

 the shell has a somewhat Cardit a -like aspect. But the beaks are 

 scarcely, if at all, turned towards the front, and the teeth are of the 

 typical Card'm //^-pattern. There is considerable variability in the 

 number and breadth of the ribs, as well as in the transversitv and 

 convexity of the valves. 



The ribs are broad and, apparently, flat-tcpped, separated only 

 by linear grooves (exactly after the pattern of the radial ribs seen 



