424 Deep-sea Trawling off the S.W. Coast of Ireland : 
just in front of the central part stronger than those down 
the anterior side and the few upon the rostrum, which is 
truncate at the end and well marked off from the rest of 
the shell by a conspicuous contraction in the lower margin. 
Length 7, height 33 millim. 
From 1000 fath. 
Only a single specimen of this species was obtained. It is 
peculiar for the straightness of the hinge-line. In this 
respect, to some extent, it resembles the figure of Cardiomya 
perrostrata, Dall (Bull. Mus. Comp. Zool. Harvard, vol. xii. 
pl. i. figs. 3a, 36). That species, however, is distinguished 
by a somewhat longer rostrum, and the main portion of its 
valves is more globular. 
Nuculana pusio (Philippi) ? 
From 1000 fath. 
Several specimens from this locality I cannot distinguish 
from others obtained by the ‘ Porcupine’ expedition, which 
were named Leda pusio of Philippi by Jeffreys. With this 
determination, however, I am not at all satisfied, for both the 
description and figure of Philippi indicate a shell of a con- 
siderably different form. I have not had an opportunity of 
seeing fossil examples, upon which the species was founded, 
and therefore hesitate to separate the recent specimens as a 
distinct species. 
I feel compelled to adopt the generic term Nuculana not- 
withstanding the observations of Mr. Dall *. 
Mérch + in his paper “On the genera of Mollusca 
established by H. F. Link,” arrived at a similar conclusion. 
Dall has translated ‘ Die Schalen gleich, schliessen 
tiberall” (part of Link’s diagnosis) thus: “shell smooth, 
closed all round,” and states that this “ will not apply to the 
group separated by Schumacher, afterwards, under the name 
of Leda.” ‘The correct rendering of the above sentence I 
believe should be the valves equal (or alike) closed all round t, 
terms which do apply to the only species quoted by the 
author, namely, N. rostrata, which is synonymous with 
N. pernula of Miller, under which name this species is now 
usually known. 
As Nuculana has some years precedence over Leda, in 
Mr. Dall’s words, it “‘must necessarily be adopted. ‘The 
longer an untenable name is retained, the more inconvenience 
* Bull. Mus. Comp. Zool. 1886, vol. xii. p. 245. 
+ Proc. Zool. Soc. Lond. 1862, p. 228. 
{ It is not probable that notice was taken of the very slight chink at 
. the end of the rostrum. 
