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CONCHOLOGY. 



2. Ostrea. The Oyster. Forty-eight species. 



As given by Lamarck, is a natural and well-defined family. 

 It is too well known to require description. It fixes itself to 

 other bodies by the laminae of the whole surface of one valve, 

 and generally remains immoveable, exhibiting no other signs 

 of life than that of opening its valves to receive nutriment. 



Shell irregular, inequivalve, inequilateral, exterior roughly 

 foliaceous, interior somewhat pearly ; the left or inferior 

 valve larger, deeper, and adhesive, its summit prolonging with 

 age in a sort of heel ; the right or superior valve smaller, 

 more or less in the form of a lid ; hinge without teeth ; liga- 

 ment short, sub-interior, inserted in an oblong cardinal cavity, 

 increasing with the summit ; muscular impression single and 

 sub-central. 



Ostrea edulis. 

 O. hippopus. 

 0. borealis. 

 0. Adriatica. 

 O. cochlear. 

 O. cristata. 

 0. gallina. 

 0. numisma. 

 0. lingua. 

 O. tulipa. 

 0. Brasihana. 

 O. scabra. 

 0. rostralis. 

 0. parasitica. 

 O. denticulata. 

 O. spathulata. 

 O. cornucopise. 

 0. cucullata. 

 0. doridella. 

 O. rubella. 

 O. limacella. 



Ostrea ruscuriana. 

 O. Virginica. 

 O Canadensis. 

 O. excavata. 

 O. mytiloides. 

 O. sinuata. 

 O. trapezina. 

 0. tuberculata. 

 O. rufa. 



O. margaritacea. 

 0. gibbosa. 

 O. Australis. 

 O. elhptica. 

 0. haliotidsea. 

 O. deformis. 

 0. fucorum. 

 0. plicatula. 

 O. glaucina. 

 O. fusca. 

 0. turbinata. 

 O. cristagalli. 



