CRUSTACEA. 
287 
Mysidopsis, g. n. 
This genus is founded upon Mysis didelphys (Norman), which differs from 
M. vulgarism being a little more robust in form, in having the antennal scale 
somewhat less produced, with the second joint shorter, and in having fewer 
cilia to the telson ; so that we do not quite see the convenience of grouping it 
(as Hr. G. 0. Sars has done) with two other species to form a new genus as 
follows : — 
1. 3£ysid(ypsi8 didelphys (Norman). — 2. M. gihbosa, sp. n. — 3. M, angusta^ 
sp. n. 
Nematopus, g. n. 
1. Nematopus elegam{(j. 0 . Sars, Zoologisk Reise i Christiania ogThrond- 
hjems Stifter, p. 42), — 2. N. serratus (G. 0. Sars, 1. c. p. 43). — 3. N, mict'ops, 
sp. n. — 4. N. obesus, sp. n. 
Diastyltd^. 
Hr. Boeck describes (Forh. Kelensk. Selslc. Christ. 1864, p. 189) a Crus- 
tacean of this family under the name of Cuma cornuta, which has a peculiarly 
characteristic spinous appearance, and is furnished with two large teeth near 
the anterior portion of the carapace. 
This description seems to correspond so closely with the species given by 
Mr. Spence Bate under the name of Diastylis bicornis (Ann. & Mag. Nat. Hist. 
Feb. 1865, vol. xv. p. 84), that we have little doubt they are synonymous, 
and consequently must bear the name of Diastylis cornuta (Boeck). 
AMPHIPODA. 
OhCHEST1DA5. 
Prof. Grube has given the description of several amphipod Crustacea (Archiv 
fiir Naturg. Bandi. p. 201) which he found on the Istrian shores of the Medi- 
terranean Sea. Among these is Nicea istrica, which the author says resembles 
Allorchestes except in the following points : — Antennae breves, subaequales. 
Gnathopoda subchelati. Telson profunde divisum. 
"VVe have little doubt that this species is identical with Nicea prevostii* 
of Milne-Edwards, which was found at Naples. 
Gammaridas. 
Anonyx Jiliger, sp. n., Stimpson, Proc. Acad. Nat. Sc. Philad. 1864, p. 167, 
from Puget Sound j closely allied to Lysianassa longicornis (Lucas) 
Ampelisca pugetica, sp. n., Stipipson, 1. c. p. 168, from Puget Sound. 
Amp>hitonotus septemdentatus and A. occidentalism sp. n., Stimpson, 1. c., from 
Puget Sound. 
Dexamine brevitarsus, according to Prof. Grube’s description {1. c. p. 196), 
bears a general resemblance to Atylus gibbosus as figured in the ^British 
Sessile-eyed Crustacea ’ (Spence Bate and Westwood); but the absence of 
the appendage to the mandible, and the close assimilation of the third joint 
* Nicea prevostii, Cat. Brit. Mus. Amph. Crust, p. 53. A^nphithoe prevostii, 
Edwards, Ann. des Sci. Nat. t. xx. p. 378, and 2 ser. t. xiv. pi. 14. f. 11; 
Hist, des Crust, t. iii. p. 36. 
t L. lovigicornis (Lucas, Expl. Sc. Al^«^r. Crust, p. 63), or L. chausica 
(Spence Bate), not AUbrotus chausicus (Milne-Edwards). 
