576 MR. S. HANLEY ON THE GENUS LEPTOMYA. [June 20, 
5. On the Genus Leptomya (A. Adams). 
By Sytvanus Hantey. 
[Received June 13, 1882.] 
The little genus Leptomya (which, despite my aversion to the multi- 
plicity of names induced by the unnecessary division of established 
genera, I regard as a natural and a useful one, because its members 
cannot be placed elsewhere) was briefly characterized, in English, by 
Arthur Adams in 1864. Reference was made to only two species, 
both so cursorily described that it was almost impossible to determine 
them, as neither had been figured. Of the first, regarded as an 
abnormal Newra by Hinds (N. cochlearis, Hinds), only a single 
valve had been previously taken. It is not absolutely positive that 
the second (Scrobicularia adunca of Gould) may not prove identical, 
although the description by Hinds is more applicable to another | 
species than to his own type. The genus was also limited to these 
two by Tryon, in his useful catalogue of Bivalves, in 1869. In the 
Linnean ‘ Proceedings’ I have published the characters of a third 
species, L. gravida ; and now I know at least two others, which I here 
characterize. 
LEPTOMYA PSITTACUS, Sp. NOV. 
T. subeequilateralis, nivea, fragilis (sed opaca), acuminato-obovata 
(vel rotundato-ovata), antice late rotundata, postice acute angu- 
lata et breviter sed conspicue rostrata, ad umbones ventricosa, 
rostrum versus concava et compressa, sublevigata, margines 
versus autem rugis tenuibus confertisque concentrice lamellata. 
Margo dorsalis utrinque subrectus, antice paulum, postice modice 
declivis ; margo ventralis in medio valde arcuatus, postice sinu- 
atus, et rapide acclivis. Area lunularis impressa ; area dorsalis 
postica perangusta. 
Long. 1:2, lat. 1 poll. 
Hab. ign. (Mus. Hanley). 
The outline of this very rare shell reminds one of the head of a 
parrot. The beak is placed high up, as in LZ. gravida. 
LEPTOMYA SPECTABILIS, Sp. Nov. 
T. precedenti similis, sed ovato-acuminata, haud rostrata, sed 
postice subcuneiformis ; margo ventralis simplex et antice sub- 
arcuatus ; extremitas postica infra medium posita. 
Long. 1°25, lat. 0°95 poll. 
Hab. Japan? (Mus. Hanley)... 
I believe this was the shell. supposed by A. Adams to be the 
L. cochlearis of Hinds, with whose description it fairly accords; 1 
found it thus marked in Taylor’s' collection, which had been largely 
recruited from Adams’s types. 
The name spectabilis' was attached to a fine example, classed as 
a Scrobicularia (it is not that of Philippi) in the British Museum, 
