370 Dr. H. A. Nicholson on the Genus Climacograpsus. 
It is evident that the two must be distinguished ; and if I am 
wrong in considering Acmella a subgenus of Acicula, I should 
be equally in error in proposing to ‘subordinate it to Trieu 
The latte: has, by Stimpson (Researches on the Hydrobiine, 
&c.) and Stoliczka (Paleontologia Indica, v. p. 271), been re- 
ferred to the Rissoide ; but Stoliczka places it in a different 
subfamily from Assiminea. I have very little doubt that this 
position 1s correct ; and the conclusion at which I have arrived 
is that  Cyclostoma tersum, Bens., belongs to the Rissoide, 
that it is allied to Z'ricula and also, probably, to Acicula, but 
that it must be considered the type of a distinct genus, thus 
characterized :— 
ACMELLA, gen. nov. 
(Subgen. nov., Ann. & Mag. TN Hist. 1869, ser. 4. 
vol. iii. p. 178.) 
Testa ovata, cornea ; apertura ovata; peristomate obtu 
doin corneum, beau, a TETES E excentrico, 
sinistrali. 
Animal Assimineæ simile; proboscide brevi; tentaculis brevibus, 
obtusis, oculos insuper haug procul ab extremitatibus gerentibus ; 
pede mediocri, ovato. 
Species unica typusque :— 
Acmella tersa (Bens.). 
Cyclostoma tersum, Bens. Ann. & Mag. Nat. Hist. 1853, ser. 2. vol. xi. 
85 
Sons tersa, Pfr. Mon. Pneum. ii. 158, iii. 172. 
Since last year, Major Godwin-Austen has obtained a second 
pena of Cyathopoma from the ranges sou uth of Assam, which 
much better with Mr. Benson’s description of Cyclo- 
es milium than that first found; it, however, has spiral 
sculpture, It Roue appears more ws ever probable that C. 
milium is a Cyathopoma, and possibly a worn specimen of the" 
shell last found, in v which the dignes had been abraded. 
XXXVI.—On the Genus poner. Has. with Notes on the 
British Te ni the Genus. By He - ALLEYNE 
NICHOLSO 
THE genus Climacograpsus was originally founded by Hall, 
the eminent American spaliscartologist (Grapt. Quebec Group, 
p. 111) to include certain species of PEA R which had 
JERSE, 
on Nod History | in the ved: Acide] "School of . 
Edinburgh. 
