Report on the Crustacea Schizopoda of Ireland. 245 
Genus Neomysis, Czerniaysky. 
Neomysis vulgaris (J. V. Thompson). 
Not in the Survey Collection. 
Irish Records.—River Lee, up to Cork and Cove (J. V. Thompson): Belfast 
Lough (W. Thompson). 
Distribution.“ All round our coast in brackish water” (A. M. N.*). 
European Atlantic coasts (except Spain and Portugal); Baltic; White and 
Murman Seas; Black Sea(?) (A. M. N.*): Bouches du Rhone (A. F. Marion én Wit.) 
Dasymysis, gen. nov. 
Synon. Acanthomysis, Czerniavsky.—Monogr. Mysid. imprimis Imperii Rossiet, 
1882, Fase. I., p. 184. 
Skin hispid. Antennal scale lanceolate, setiferous on both margins. Tarsus 
with about three articulations and a slender nail. TZedson linguiform, entire ; 
proximal part of lateral margins naked, or with a few spines near the base ; 
distal parts of margin densely armed with numerous unequal lanceolate spines. 
In the male, the first, second, and fifth pleopods are like those of the female; the 
third is hardly at all modified; the fourth with a peduncle and two branches, 
the inner as usual in Mysine; the outer narrowly cylindrical, somewhat flexuous, 
bi-articulate, the proximal joint elongate, the distal very short and beset with 
two short subequal setiform flagella. 
Type. Mysis longicornis, Milne-Edwards.—‘‘ Hist. Nat. Crust.,” 1837, i1, 
p. 459, pl. xxvi., figs. 7-9. G. O. Sars—‘‘ Middelhay. Mysider,” 1877, p. 22, 
pls. 9, 10, = Acanthomysis platydens, Czerniavsky, op. cit. p. 137. 
The genus Acanthomysis, instituted by Czerniavsky, with I. longicornis (G. O. 
Sars) as the type, cannot be retained, since it is stated that the pleopods are as 
in Mysis, the type being thus excluded. The genus Mysis, as restricted by 
Czerniaysky himself, contains the species WM. relicta, M. oculata, M. mixta, and 
several others of more doubtful value. The three which we have named have 
the pleopods very different from those of I. longicornis. The third pleopod of 
the male has a well-developed basal joint, and two distinct, if short, branches. 
The fourth pleopod of the male has the outer branch multi-articulate, and much 
stouter than in UM. longicornis (cf. G. O. Sars, ‘‘ Monog. over Mysider,” pp. 69, 
2M 
TRANS, ROY. DUB. SOC., N.S. VOL. VII., PART VII. 
