151 



consistence of the shell ; but it is eminently distinguished by having 

 two muscular impressions. Lamarck, who first characterized the 

 genus placed it next to Corlnila, chiefly, perhaps, in consequence 

 of the inequality of its valves. 



Two species only are described by Lamarck, the ineequivalvis, 

 Linn., and the ohtusa, a newly described species. Sowerby has 

 added another, imder the name of flexuosa. According to Blain- 

 ville, two fossil species have been discovered by Defrance. The 

 animal is so similar to that of Solcn, that Poll has referred it to 

 the same genus, which he calls Hyipogea. 



Pandora trilineata. — Specific character. Hinge margin 

 bilineate from the beak to the tip; valves not very inaequal. 

 PL 2. 



Pandora trilineata, nobis. Journ. Acad. Nat. Set., vol. ii. 

 p. 26L 



Oliva. — Shell subcylindric, oblong, smooth, more or less polish- 

 ed ; epidermis none ; spire short ; suture canaliculated, the edge 

 of each volution extending a little upward, canal bounded above 

 by a revolving, carinate callus ; body whorl near its base with a 

 slightly elevated band, beginning below the middle of the aperture 

 and revolving to the base of the labrum ; aperture elongated ', 

 labrum and columella with calcareous deposite, much striated, striae 

 on the latter more elongated ; base deeply emargiuate ; operculum 

 none. 



Ohs. The smoothness and polish of these beautiful shells are 

 no doubt owing to the extension of the smooth surface of the 

 mantle of the inhabitant, over their whole exterior. The animal 

 is not yet well known, but Lamarck supposes it to be carnivorus. It 

 is marine. 



Of all the species figured in the books, and existing in the col- 

 lections, Linne formed but about two species, which he referred to 

 his genus Valuta under the names of olioa and porpltyra. Bru- 

 guiere applied to them the present generic name, which was adopt- 

 ed by Lamarck, who, with his usual acute perception of natural 

 differences, described more than sixty species, among which are a 

 few that exist only in the fossil state, and according to Blainville^ 

 thirty-two new species have been added by M. Duclos, from the 

 coast of New Guinea. 



This genus is closely allied to AnciUa, which, however, is des- 



