CONCHYLIA— DITHYi?^. 36. 139 



The outline of this shell appears to resemble that of the Cytherea 

 Tigerina ; but from the description of Montagu the teeth are differ- 

 ent, and the reticulations are coarser. 



36. VENUS— LliVA^E. 



Testa transversa vel suborbicularis, oequivalvis, ineequilateralis, clausa. 

 Cardo dentibus tribus, exterioribus infernS approxvmatis superne di- 

 ver gentibus : lateralibus nullis. Ligamentum externum. 



Shell transverse or somewhat orbicular, equivalve, inequilateral, 

 closed. Hinge with three teeth, the outer ones close together at 

 the base and divergent at their tips : lateral teeth none. Liga- 

 ment external. 



The Venus tribe, pre-eminent for the elegance of their figure 

 and splendor of colors, formerly so numerous and difficult of dis- 

 crimination, are now very properly confined to the simple characters 

 which are exhibited above: with three strong teeth in each valve, 

 one or two of which are generally cloven, all close together at their 

 insertion, and the outer ones spreading obliquely in opposite direc- 

 tions, with the middle one straight. 



In this respect they difier from the Venerupis, which has all 

 the teeth parallel and erect. The beaks are prominent and 



T ^ 



