the Family Osteodesmacea. 149 
does not belong to the same genus, but to our genus 
Cocutopesma: His reference to Amru. phaseolina 
Lam., is doubtless correct, as he had access to the col- 
lection of that eminent naturalist, in which the species 
described by him were labelled by his own hand. 
Notwithstanding the great similarity in Mr. Kiener's 
description of this shell and that by M. Deshayes of the 
preceding species, they are essentially different. Hav- 
ing been enabled to compare perfect specimens of both, 
I would point out some of the differences às follows: 
T. plicdta is more broadly truncated, thinner, its 
height greater in proportion, and the valves, which in 
T. phaseolina are only feebly striated. by the lines of 
increment, are covered with numerous elevated, undu- 
lating, transverse, rounded ridges, giving the exterior 
an ap e somewhat like that of Lurrara Cam- 
peachénsis, Wood’s Ind., of our southern coast. Its white- 
ness is also peculiar to itself, being a sort of polished 
chalk-white, without the yellow tinge prevailing in the 
generality of shells. The specimen of T. phaseolina in 
my collection was received from the Mediterranean. lt 
is moderately convex, somewhat attenuated posteriorly, 
and very abruptly truncated, with the carination strongly 
marked. The summits are a little pearly. The inte- 
rior of the valves is not shining, except near the mar- 
gins. That portion of the description i in italics denotes 
additions to Kiener’s description, from the shell before 
me. * 
