418 



VENERIS. 



are world-wide in their geographical distribution ; the 

 British Islands and Northern Ocean, the Mediterranean 

 and Eed Seas, Australia, and the Cape of Good Hope, all 

 affording us examples. They are usually found buried in 

 the sand at low-water, though some species range as deep 

 as one hundred fathoms. Although not generally em- 

 ployed as food, they are all edible. Extinct examples are 

 numerous in the Oolites of India, the United States, and 

 Patagonia. 



Species of Venus. 



affinis, Sow. 

 antiqua, King. 

 casina, Linn. 

 Chemnitzii, Desh. 

 cingulata, Lam. 

 clathrata, Desh. 

 consobrina, Desh. 

 crebrisulca, Lam. 

 crenulata, Chem. 

 crispata, Desh. 

 declivis, Sow. 

 Dombei, Lam. 

 effossa, Phil. 

 foveolata, Sow. 

 Isabelleana, D'Orb. 

 Jukesii, Desh. 

 lacerata, Hartley. 

 lamellaris, Solium. 



laqueata, Sow. 

 Listeri, Gray. 

 lyra, Hanley. 

 magnifica, Hani. 

 monilifera, Sow. 

 multicostata, Sow. 

 nodulosa, Sow. 

 oblonga, Hanley. 

 puerpera, Linn. 

 pulicaria, Brocl. 

 resticulata, Soiv. 

 reticulata, Linn. 

 rosalina, Rang. 

 rugosa, Chem. 

 sculpta, Desh. 

 Sowerbyi, Desh. 

 tuberosa, Desh. 

 verrucosa, Linn. 



Genus MERCENARIA, Schumacher. 



Shell ventricose, sub-globose, triangularly heart-shaped ; 

 valves with the margins finely crenulated. Hinge with 

 three erect, compressed, diverging teeth in each valve, the 



