DONAX. 157 



Cuneus foliatus. Da Costa Brit. Conch, p. 204. t. 15. 



left hand fig. 6. 

 Venus lithophaga. Retzius in Act. Taurin. 1786. p. 11. 



f. 1 and 2. Gmelin, p. 3295. Olivi Zool. Adriatica. 



p. 108. 

 Petricola sulcata. Lamarck Sj/st. des Anim. p. 121. 

 Gualter, t. 95. f. A. Borlase Cornwall, t. 38. f. 23. Enc. 



Method, t. 262. f. 4. 

 Inhabits the Sea burrowed in Rocks and Stones. Mediterra- 

 nean. Linneeus. Coasts of America. Gronovius. Adria- 

 tic. Olivi. Britain. Borlase, fyc. 

 Shell about a quarter or half an inch long, and varying much 

 in breadth, which in some specimens scarcely exceeds the 

 length, and others are twice as broad ; the shape also varies 

 considerably, some shells being convex, and others nearly 

 flat, so that it is difficult to find two alike ; but the species 

 may, notwithstanding these variations, be readily known by 

 its elevated, remote, reflected, concentrical, membranaceous 

 ridges, which have their interstices longitudinally striated ; the 

 colour is brownish white, and the inside stained with purple 

 towards the hinge ; the hinge has two primary teeth in one 

 valve, and a bifid one in the other. Venus sub-rhomboidea 

 of Montagu is most probably nothing more than a variety of 

 this species. 



