146 



VENERICARDIA scalaiis. 



TAB. CCCCXC—fg. S. 



Spec. Char, Orbicular^ subtriangular^ depressed ; 

 longitudinal sulci about 20^ linear ; concentri- 

 cally striatedj hinge teeth long and thin. 



1 HE ribs (if they can be so called) are very flat and 

 close together, they are so regularly crenated by the 

 concentric striae as strongly to resemble a rope ladder ; 

 the rather triangular form and general flatness at once 

 distinguish this from both the preceding, in whatever 

 state of preservation it may be met with. They all have 

 toothed edges, but the number of teeth in this is greater 

 than in either of the others. 



We are indebted to the Rev. G. R. Leathes for the 

 use of a series of specimens, consisting of above 100, by 

 which these three shells were proved to be distinct spe- 

 cies ; they are all of them liable to lose their external 

 surfaces by decay ; but even when thus rendered imper- 

 fect, the characters above given will be found to distin- 

 guish them. They are equally abundant in the Suffolk 

 and Norfolk Crag. 



