MYSIDEA. 647 



there is a narrow oblong palpus. The stomach has the form repre- 

 sented in figure Z, the natural size of which is given below the figure. 

 The interior of the stomach was without teeth, but was provided with 

 longitudinal cartilaginous ridges or plates, and had a villous surface. 



GENUS CYKTOPIA, Dana. 



Carapax plus minusve rostrcdus. Oculi paulo dblongi, dbliqutl gibbosi 

 lenticuli-s totis in gibbositate versis. Pedes abdaminales bene natatorii. 

 tSegmentum abdominw posticum apice obtusum vel truncatum et minute 

 spinulosum, prope apicem barbd nudd utrinque armatum. 



Carapax more or less beaked. Eyes somewhat oblong, obliquely gib- 

 bous, the lenses being directed in a cluster obliquely outward into 

 the gibbosity. Abdominal feet natatory. Last abdominal seg- 

 ment obtuse or truncate at apex, and minutely spinulous, armed on 

 either side near apex with a naked oblong barb. 



This genus, like Euphausia, has branchiae attached to the bases of 

 the thoracic legs, and the last abdominal segment has the same kind 

 of naked setae either side of apex. But this caudal segment is trun- 

 cate at apex, and, what is of more importance, the eyes, instead of 

 being orbicular and covered with facets, have all the facets directed 

 in a cluster obliquely outward. The pedicels of the eyes extend 

 straight forward parallel with the medial line, and at the same time 

 the eye looks laterally and only so. 



Two species were obtained, but the specimens of neither were adult. 

 The inner antennae have a long basal portion, and two flagella [the 

 flagella were broken off near the base]. The outer were apparently 

 rudimentary, and consisted of a rather short, three-jointed base, and 

 two short branches. 



The mandibles terminate in a dentate apex. The legs are fur- 

 nished with small branchiae ; in the specimens they were more or less 

 rudimentary or imperfect ; the two posterior pairs of legs were wholly 

 wanting excepting the branchiae, as in Euphausia. 



