151 
consistence of the shell ; but it is eminently distinguished by haying 
two muscular impressions. Lamarck, who first characterized the 
genus placed it next to Corhula, chiefly, perhaps, in consequence 
of the inequality of its yalyes. 
Two species only are described by Lamarck, the insequivalvisj 
Linn., and the ohtusa, a newly described species. Sowerby has 
added another, under the name of flexuosa. According to Blain- 
yille, two fossil species haye been discovered by Defrance. The 
animal is so similar to that of Solen, that Poll has referred it to 
the same genus, which he calls Hypogea. 
Pandora triline at a. — Specific character. Hinge margin 
bilineate from the beak to the tip ; valves not very inmqual. 
PI. 2. 
Pandora trilineata^ nobis. Journ. Acad. Nat. Sci.y vol. ii. 
p. 261. 
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 emarginate ; 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 Voluta under the names of oUva and porphyra. 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 AncilJaj which, however, is des- 
