248 IIoLT & Beaumont— ^SHJvr^ of Fishing -grounds, W. Coast of Ireland, 1890-91. 



truncate edge set with numerous unguiforin spines ; the inner in the form of a 

 setose tubercle. Second maxilla small and feeble. First maxilliped strong ; basal 

 joint without an incisive lamina, second joint very short, third rather swollen; 

 penultimate without setjB, but strongly spined at the external apex ; last joint very 

 small and armed with a long, narrow apical spine. Legs small and feeble, sparsely 

 setose ; tarsus with few articulations, nail inconspicuous. Incubatory pouch of 

 female of three lobes on each side, the anterior pair rudimentary. Genital 

 appendages of male very long, anteriorly directed, witliout setse. Pleopods rudi- 

 mentary, simple, alike in both sexes. Telson short, anterior part of lateral margin 

 naked, posterior part closely spined, a small apical cleft. Uropods short, subequal ; 

 otocyst well developed. (Abbreviated from G. 0. Sars.) 



Mysidella typica, G. 0. Sars. 

 (PI. XVI., figs. 6, 7.) 



Mysidella tijpica, G. 0. Sars, Carcinolog. Bidrag til Norges Fauna, I. Moiiogr. ATysider, Hefte III., 

 1879, p. 86, pis. XXXV., xxxvi. 



Body rather abbreviate ; cephalo-thorax short, sub-gibbous ; abdomen much more 

 slender, cylindrical, slightly tapering, last segment short ; last two segments of 

 cephalo-thorax exposed dorsally. Eostrum distinctly angular. Fi/es well developed, 

 but not large, rather remote from each other, bi-ight fulvous. Peduncle of antenmde 

 scarcely one-fourth as long as the cephalo-thorax, its basal joint short, nearly as 

 wide as long. Antennal scale three times as long as wide, reaching by scarcely a 

 third of its length beyond peduncle of antennule, outer margin nearly straight, 

 inner distinctly arcuate, apex bluntly acuminate. First maxilliped with the pen- 

 ultimate larger than the preceding joint, and armed with three teeth. Legs, first 

 hardly longer than second maxillipeds; tarsus shorter than preceding joint, 

 2-articulate ; nail slender, setiform ; second to fifth legs sub-equal in length ; tarsus 

 longer than preceding joint, 3-articulate ; posterior leg much longer than the rest, 

 very narrow ; tarsus elongate, 3-articulate. Telson hardly one-fourth as long as 

 abdomen, about twice as long as wide, linguiform, tapering distinctly towards the 

 apex ; anterior half of lateral margin naked, posterior half with about eighteen 

 closely set spines of gradually increasing length, apex obtusely rounded, with a 

 short, narrow rectilinear cleft; each side of cleft with (about) two to four minute 

 spines. Inner uropod a little longer than telson, about seven-eighths as long as 

 the outer, its inner margin spined throughout (from the level of the centre of the 

 otocyst). Colour, body pellucid with a little red pigment here and there. Length 



