OSTREA caiinata. 

 TAB. CCCLXV. 



Iyn, O. carinata, Lamarck Hist. Nat. VI. 216. 



(PEC. Char. Elongated, pointed at both ends, 

 arched, plaited ; sides fattened ; middle 

 longitudinally cariniformed ; plaits numer- 

 ous, ano-ular, and regtdar ; ears two, variable. 



The pointed ends, the depth of the valves, and regu- 

 larity of the plaits, are characters by wliick this Oyster 

 may generally be known: the curvature and ears are 

 variable, the anterior or exterior ear being often obsolete 

 in old shells. 



A series of specimeias of various ages have been selected 

 for the illustration of this species : it will be seen that the 

 curvature varies considerably. Fig. 1 is the most elon- 

 *s°ated variety ; it is from the grey Marl below the Chalk 

 at Folkstone in Kent : the remainder are silicious : tliey 

 are from the green Sand of Chute Farm near Longleat 

 Park. An extremely elegant French specimen, nearly 

 double the size of any here figured, was some time ago 

 ffiven to me by Mr. de Gerville, with intentions that 

 render his friendship more dear to me than even his nu- 

 merous presents do : it is from the Chalk Marl, and 

 Is so much curved as to form three-quarters of a ring : 

 the outer ear is obscure, but the inner is very large. A 

 figure of this specimen is given in Mr. G. B. Sowerby's 

 work upon the Genera of Shells. Tlie Rev. Mr. White 

 in his Natural History of Selburnt', has figured a similar 

 specimen : and the same species probably is given by 



