ARTEMIS. 427 



ARTEMIS, Poll 



Shell suborblcular, more or less strong, equivalve, closed ; 

 surface concentrically striated ; inner margins entire. Mus- 

 cular impressions oblong, nearly equal ; pallial sinus lan- 

 ceolate, acute, deep, oblique. Hinge strong, composed of 

 three diverging teeth in one valve, and four in the other. 

 Ligament external, sunken, rather long; lunule strongly 

 defined. 



Animal suborbicular, its mantle freely open, the margins 

 entire, or only partially serrated. Siphonal tubes long, 

 united to their extremities, margins of their orifices fim- 

 briated. Foot semilunar. 



This well-marked group was constituted by Poli ; the 

 habit and characters of both shell and animal evince its 

 very natural constitution. Common as the two species 

 which inhabit our seas are, our knowledge of their con- 

 struction, however, is almost entirely derived from the ob- 

 servations of the distinguished Neapolitan naturalist who 

 founded the genus. It too often happens that whilst the 

 animals of the rarer shells are carefully observed, noted, 

 and drawn, we are apt to neglect those most abundant, 

 fancying they are always at hand. Guilty of this crime, 

 and confessing our guilt as a warning to others, we are 

 obliged to content ourselves for the present with a very im- 

 perfect notice of these mollusks, but, before the completion 

 of our work, hope to present our readers with a full and 

 original account of them. 



