tteport on the Crustacea Sc/iiso/ioda of Ireland. 245 



Genus Neomysis, Czerniavsky. 

 Neomysis vulgaris (J. V. Thompson). 



JVoi 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 in Hit.) 



Dasymysis, gen. no v. 



Synon. Acanthomysis, Czerniavsky. — Monogr. Mysid. imprimis Imperii Eossici, 



1882, Fuse. I., p. 134. 



Skin hispid. Antennal scale lanceolate, setiferous on both margins. Tarsus 

 with about three articulations and a slender nail. Telson linguiforui, 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 Mysinaj; 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, ii., 

 p. 459, pi. xxvL, figs. 7-9. G. 0. Sars— " Middelhav. Mysider," 1877, p. 22, 

 pis. 9, 10, = Acanthomysis platy^ens, Czerniavsky, op. cit. p. 137. 



The genus Acanthomysis, instituted by Czerniavsky, with M. longicornis (G. 0. 

 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 

 Czerniavsky himself, contains the species 31. relicta, M. ocidata, M. mixta, and 

 several others of more doubtful value. The three which we have named have 

 the pleopods very different from those of M. 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 M. longicornis (cf. G. 0. Sars, " Monog. over Mysider," pp. 69, 



TRANS. EOT. DUB. SOC, N.S. VOL. VII., PAUI Vil. . 2 M 



