66 GENUS X. VENUS. 



difficulty in knowing where to draw the line of distinction 



between them. 



The animal is a Cockle, and differs but little from the ani- 

 mal of the Tellina, if we except perhaps Venus lapicidn and 



litJwphaga. 



liinnaeus describes 38 species, Gmelin has added 107, and 



Dr.Turton 9. Total, 154. 



Lamarck has placed Venus Uthophaga, &c. in his genus 



Petricola, and Venus islandica and some others in Cyclas, and 



Venus pensylvanica, &c. in Ldicina ; and has divided the rest 



into five genera, as follows : 



Paphia. Shell sub-transverse, inequilateral, the valves shutting 

 close ; the cartilage internal ; the hollow for its insertion 

 is under the beaks, and between or beside the teeth of the 

 hinge (^Venus divaricata. See pi. 2. f. 24). 



Venus. Shell nearly orbicular or transverse, with three hinge 

 teeth approaching, of which the side ones are more or 

 less diverging (^Venus verrucosa Linn. See pi. 2.f. 25). 



Meretrix. Shell with tw o or three approximate hinge teeth 

 converging at the base, with a distant one under the 

 heart-shaped depression in one valve, and a hollow for its 

 reception in the other (Venus Meretrix. See pi. 3.f. 26). 



Venericardia. Shell nearly orbicular, inequilateral, with lon- 

 gitudinal ribs on the outer surface; two thick oblique hinge 

 teeth, not diverging (Venus imbricata. See pi. 3. /. 27). 



Capsa. Shell transverse, with two hinge teeth in one valve, 

 and one bifid tooth intruded in the other (Venus de- 

 fiorata Linn. See pi. 3. /. 28). 



