246 Horr & Beaumontr—Survey of Fishing-grounds, W. Coast of Ireland, 1890-91. 
73, 76, pls. xxx1.—xxxiil.). In so far as the pleopods are concerned M. longicornis 
might be included in the genus Neomysis, from which, however, it is dis- 
tinguished by other characters. 
Dasymysis longicornis (M.-Edw.). 
Mysis longicornis, Milne-Edwards, loc. cit. 
? Mysts longicornis, Heller, ‘‘ Crust. pod. Siidl. Europ.,” 1863, p. 302. 
Mysis longicornis, G. O. Sars, loc. ett. 
Acanthomysis platydens, Czerniavsky, loc. cit. 
Acanthomysis longicornis, Czerniavsky, op. cit., ‘* Fase. III.,” p. 75. 
Acanthomysis spinosissima, Czerniaysky, op. cit., ‘Fase. I.,” p. 185, pls. xxxi., 
SXEXEXI 
Form narrow and slender, abdomen nearly straight. Sz hispid in all parts. 
Rostrum obtusely angular. yes large, pyriform, widely separate, extending well 
beyond the lateral margin of carapace. Peduncle of antennule rather elongate, 
the second joint dorsally produced into a forwardly-directed process; the last 
joint rather tumid and nearly equal in length to the first. Antennal scale 
but slightly extending beyond peduncle of antennule, narrowly lanceolate in 
form, its extremity divided from the rest by an oblique suture. Tarsus about 
three-articulate, the proximal articulation the longer, nail slender but distinct. 
Telson elongate, entire; widely dilate at the base, thence suddenly constricted ; 
the posterior part narrowly linguiform, and densely armed at the margin 
with numerous, unequal, lanceolate, straight or slightly curved spines, their 
extremities with a distinct axial marking.t Inner uropod hardly longer than 
telson, narrowly lancolate, base swollen; otocyst oval, large; inner margin 
in region of otocyst beset with a row of spines of gradually increasing size. 
Outer wropod one-fourth longer than inner, very narrow, with a slight outward 
curve, apex obliquely truncate. Male, with the fourth pleopod not reaching the 
posterior extremity of the sixth segment. Length of female scarcely 9 mm. 
Pigment blackish-brown, not abundant. 
Survey.—Station 118, Ballinskelligs Bay, 32 to 28 fathoms, soft mud. 21st 
August, 1890. | 
Previous Irish Record.—None. 
+ The external chitinous sheath of the spine is suddenly thickened towards the distal end, the lumen 
being thus reduced in such a way as to present the appearance of an axial line. This character (also 
present in L. apiops(?)) appears to have suggested to Mr. Walker that the extremity of the spine is 
trigonal. 
