BIVALVES VENUS. 41 



VENUS Venus. 



DESCRIPTION OF PLATE X. 



Div. L— Fig. 1. V. dione. Dnr. 11. —Fig. 8. V. pectunculus. 



Drvr. II.—Fig. 2. V. oraata. Div. Ill — Fig. 7. V. scripta. 



Fig. 5. V. ovata. Div. V.— Fam. 1. Fig. 4. V. literata. 



Fig. 6. V. flexuosa. Fam. 1. Fig. 3. V. palustris. 



Shell bivalve, the frontal margin flattened, with incumbent lips: 

 hinge with three approximate teeth, the lateral ones divergent at 

 the tip. 



IT has already been observed, that this g-enus, with re- 

 gard to beauty, surpasses the other genera of Bivalves. 

 It contains no less than one hundred and fifteen 

 species. 



The divisions of the Venus are also very numerous, 

 and are distinguished by a much greater variety of form, 

 (as the elongated, compressed, angular, and orbicular,) 

 than is to be observed in any other genus of this order. 



Notwithstanding this great diversity of formation, 

 there is one leading feature which is observable in 

 most of the species, viz. the flatness of the frontal mar- 

 gins, and the lips being often incumbent; but the 

 surest g-uide in the classification of these shells is the 

 hinge, which, with scarce any exception, contains three 

 teeth, all approximate; in addition to these, there is 

 a lateral tooth, not unfrequently divergent at the tip. 

 The interior margin of the shell is sometimes crenu- 

 lated; and a few of the species, though rarely, gape. 



In many specimens the exterior surface is covered 



