164 BIVALVES. 



DONAX Dentictdata.* 

 TOOTHED DONAX. 



Specific character. Shell strong, thick, ovate, 

 wedge-shaped, with longitudinal striae, the inter- 

 stices punctured;| anterior slope rough, with 

 transverse striae, and elevated in the middle in a 

 kind of keel ; white or lead colour, usually with 

 a few purple rays proceeding from the umbones, 

 inside purple ; very concave under the umbones ; 

 margin denticulated; about half an inch long and 

 nearly an inch broad. 



This is described as a British 1 species, but it 

 is rarely found on our coasts. It inhabits the 

 West Indies, Africa, and the Mediterranean. 



GENUS. VENUS.J 



VENUS. 



Generic character. Shell bivalve, equivalve, 

 inequilateral, closed ; shape ovate, suborbicular, 

 or subcordate ; both the area and areola are well 

 defined, the area is generally flattened, and the 



* Plate VIII. figure 6. 



t Punctured, pricked or marked with small dots, from tha 

 Latin punct um> a point or dot. 

 \ Plate VIII. figures 7, 8. 



