HANSEN: THE ISOPODA. 117 
The body is considerably depressed and relatively broad, scarcely 23 times 
longer than broad. 
Head. 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 antennule (Plate IV. Fig. 2d) are 
rather long, 3-jointed ; the basal joint thick, the second longer than the first 
and comparatively thick, the third rather short and slender. The antenne 
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, with 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 antennule. The hypopharynx is long, not broad, and 
tapers somewhat towards the rounded apex. The mandibles and the maxillule 
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 ; all 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¢ (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 little longer than broad, and the lateral outline is some- 
what sinuous, which shape indicates the segmentation. Allsegments 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¢ (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 males) were 
found in the branchial cavity of Munida refulgens Fax., from Station 3378 
(Lat. 3° 58’ 20” N., Long. 81° 36° W.), 112 fathoms. 
