VENUS. 



GENERIC CHARACTER. 



Shell equivalved, inequilateral, regular, closed, trans- 

 verse or suborbicular ; cardinal teeth three on each valve, 

 approximate, anterior and posterior ones diverging from 

 the summit ; ligament exterior ; muscular impressions 

 tvro, not elongated, remote, connected by the submarginal 

 impression, which is deeply sinuous before. 



OBSERVATIONS. 



In this extensive genus are included some of the most 

 beautiful of bivalve shells. Linne referred to it species of 

 the following genera : Petrlcola, Venerupis, Sanguinolaria, 

 Corbis, Lucina, Donax, Astarte, Cyrena, Cyprina, IVIcga- 

 desma, Cytherea, Venus and Venericardia. Although 

 those species have been since eliminated and more natural- 

 ly distributed, yet in consequence of the great access^ions 

 from the zeal of modern observers, and owing to the con- 

 siderable variation, both in sculpture and colouring, that 

 many of them undergo, great difliculty and uncertainty of- 

 ten meet the conchologist in his endeavours to ascertain 

 species, and more than usual caution is requisite in deter- 

 mining any one to be new. 



In general form and exterior appearance these shells arc 

 undistinguishable from Cytherea, but the hinge of the lat- 

 ter has the posterior cardinal tooth situated immediately 

 under, and parallel to, the edge of the lunule in the right 



