EEPOET ON THE ISOPODA. 57 



traversed by numerous shallow lines dividing them into a number of slightly separated 

 convexities. 



The posterior margin of the sixth segment is not regularly concave as in other 

 species (e.g., Eurycope sarsii), but the line of division between it and the seventh 

 segment runs straight and transverse to the longitudinal axis of the body throughout 

 the dorsal region of the segments ; this brings about the equality in size between the 

 last two segments of the thorax. 



The abdominal shield was, unfortunately, considerably damaged, so that its shape 

 cannot be described with great accuracy ; it appears to be more or less oval in form and 

 truncated at its free extremity ; laterally and just in front of the articulation of the 

 long styliform uropoda is a spiny process directed backwards, nearly in the same straight 

 line with the longitudinal axis of the abdominal shield. 



The antennae are of great length, measuring 87 mm., six times the length of the 

 body of the animal ; the last two joints are the longest, measuring respectively 38 and 

 42 mm.; they have a few stout spines scattered over the surface; the nagellum is a 

 straight rod not divided at all into joints, it measures only 5 to 6 mm. 



The first pair of thoracic appendages (fig. 3) form a very distinct prehensile hand ; 

 the two basal joints are long and subequal, the third joint is very short, the fourth 

 and fifth are moderately short, the former somewhat swollen, the fifth is bent upon 

 the fourth joint, and there is a small claw-like sixth joint ; the inner edge of the 

 third and fourth joint is furnished with numerous spines. 



The next three pairs of thoracic appendages were lost. 



The three last pairs are natatory and similar to each other. Each of these limbs is 

 of considerable length, about as long as the body ; there appears to be, as in Munnopsis 

 typica, no terminal claw. 



The abdominal operculum covers over the abdomen below. 



The uropoda (fig. 4) are long and styliform, almost as long as the caudal shield itself ; 

 each is composed of two joints, which are furnished with long simple hairs. 



I include this species for the present within the genus Munnopsis, though I am quite 

 aware that exception might be taken to this view of its affinities ; the general form of 

 the body appears to be more that of Munnopsis than of any other genus except Desmo- . 

 soma ; on the other hand, the posterior segments of the thorax are by no means so 

 narrow relatively to the anterior section of the body as they are in the other species of 

 Munnopsis. The form of the uropoda is typical of Munnopsis, but also of Desmosoma. 

 The very " prehensile" character of the first pair of thoracic appendages appears to be 

 peculiar to the species ; it certainly is not found in Eurycope and Munnopsis, and 

 apparently not in the other genera belonging to this family. 



Station 232, off Ino Sima Island, Japan, May 12, 1875; lat. 35° 11' N., long. 

 139° 28' E. ; depth, 345 fathoms; bottom temperature, 41°-1 F. ; green mud. 



(ZOOL. CHALL. EXP. PART XLVIII. — 1886.) Ebb 8 



