HANSEN: THE ISOPODA. 117 



The body is considerably depressed and relatively broad, scarcely 2| times 

 longer than broad. 



Read. Its dorsal surface almost flat, with irregular rugosities. The eyes 

 are very small and dark. The frontal part bends feebly downwards ; the ante- 

 rior margin is considerably curved. The antennulse (Plate IV. Fig. 2 d) are 

 rather loug, 3-jointed ; the basal joint thick, the second longer than the first 

 and comparatively thick, the third rather short and slender. The antennae 

 of medium length, 3-jointed ; the basal joint of medium length and almost 

 twice as broad as long, with the outer margin concave ; the second joint is at- 

 tached to the anterior half of the outer margin of the first joint; it is stout and 

 twice as long as the basal one ; the third joint is rather short and slender. The 

 labrum of medium size, Avith the anterior margin very convex; its median 

 part is covered by the hypopharynx, which extends forward to the middle of 

 the basal joint of the antennulse. The hypopharv'nx is long, not broad, and 

 tapers somewhat towards the rounded apex. The mandibles and the maxillulse 

 are easily seen in the figure ; a rounded protuberance behind each maxillula 

 most probably represents the maxilla ; maxillipeds I have not been able to 

 discover. 



Thorax. The fifth segment is the broadest, and from that the thorax de- 

 creases a little in breadth towards both ends. The segments, when seen from 

 above, with the lateral outline much rounded, but the incisions between them 

 are short. On the ventral side a median, very conspicuous cone on each seg- 

 ment. The legs subequal in structure ; aU are relatively short and very thick, 

 but the fourth and fifth pairs are somewhat larger and still more clumsy than 

 the first pair ; Figure 2 e (on Plate IV.) represents the left leg of the first pair, 

 and a description is scarcely needed. 



Abdomen. It does not occupy one third of the length of the body, and an- 

 teriorly it is somewhat narrower than the last thoracic segment ; it is triangular 

 with rounded angles, a Mttle longer than broad, and the lateral outline is some- 

 what sinuous, which shape indicates the segmentation. All segments are com- 

 pletely fused ; vestiges of transverse sutures are scarcely discernible on the 

 dorsal, but rather distinct on the ventral side. 



Size. The specimen is 3.3 mm. long. 



The misshaped male is exhibited in Figure 2 c (on Plate IV.). The outline 

 of the thorax is somewhat irregular ; the abdomen is very wry, with all the 

 segments well separated on the dorsal surface, and the last segment having 

 about the shape of an oblique square. The result of this deformity is, in 

 my opinion, very interesting. 



Habitat. The label states that the two females (with their male.s) were 

 found in the branchial ca\aty of Munida nfulgens Fax., from Station 3378 

 (Lat. 3° 58' 20" N., Long. 81° 36' W.), 112 fathoms. 



