HANSEN: THE ISOPODA. 103 
Thorax (Fig. 2a). The posterior angle of the first segment rectangular, 
scarcely produced. For practical reasons, the “epimera” of the six following 
segments, though in reality constituting the first joint of the legs, are here 
treated as belonging to the thorax ; the epimera of the second thoracic segment 
with the posterior free angle nearly rectangular, those of the third segment 
‘omewhat obtuse-angular. The epimera of the four posterior segments poste- 
riorly considerably produced ; those of the fourth and fifth segments poste- 
riorly obliquely rounded ; the last two pairs with the triangular apex a little 
rounded, 
Thoracic Legs. All clumsy. In the three anterior pairs the fourth joint (the 
epimeron considered as the first joint) is shorter than the third, considerably 
incrassated, in the first pair with only one spine, in the second with six or seven 
(Fig. 2b), in the third with nine short spines at the interior margin ; the fifth 
joint only in the third pair with a spine at the antero-interior angle; the sixth 
joint short, without keel on the inner side; the claw (consisting of the seventh 
joint fused with the real claw) short and robust. The four posterior pairs (Fig. 
2c) with numerous, comparatively short spines. 
Abdomen. The first segment partly free, a little broader than the fourth. 
The sixth segment about 13 times broader than long; the dorsal surface feebly 
convex, very slightly keeled in the median line, and between this keel and the 
base of the uropod is seen a large, but shallow depression; as the posterior 
apex unfortunately is broken off, nothing can be said about its shape, but most 
likely it was acute, and the posterior margin probably with about five spines 
on each side, 
Uropods. They reach a little beyond the end of the abdomen ; both rami are 
proportionally narrow, of the same breadth and the same length, the inner ra- 
mus therefore posteriorly surpassing the outer one. The inner ramus more than 
three times longer than broad; the interior margin from a point a little behind 
the apex of the very long and narrow process from the peduncle turning ob- 
liquely outward, thus forming a posterior margin, with five or six small spines ; 
the exterior margin somewhat convex, but at a short distance from the rounded 
tip of the branch it changes its direction, bending somewhat outward, thus 
forming a low incision. The outer ramus with the tip rounded; the distal part 
of both margins faintly serrated with a smaller number of spines. 
Color. The whole dorsal surface yellowish white, the eyes grayish. 
Size. The single specimen measures 55 mm. in length and 26 mm. in 
breadth. 
Habitat. Station 3362 (Lat. 5° 56’ N., Long. 85° 10’ 30” W.), 1175 fathoms, 
1 specimen. 
Remarks. The species is closely allied to Æ. psora (L.), but is easily distin- 
guished by its enormous size, and the following characters : a different shape of 
the frontal plate; the eyes smaller and more distant from each other; the 
dorsal surface of the last abdominal segment slightly convex, with two large 
depressions. 
