ISOPODA. 55 



In general appearance this species greatly resembles the last, but it is instantly 

 recognised by the fact that the first segment of the mesosome has its epimera produced 

 into a single narrow blade only. 



The cephalosome is rounded, narrower than in the Coulman Island species, which is 

 figured on Plate IX., and the ocular peduncles are shorter and stouter. They do not 

 reach to anything like the distance of the epimera of the first segment of the mesosome. 



The mesosome is more distinctly setose than in the last species. The dorsal 

 ridges, with their median spines, are more strongly developed. The urosome is, in its 

 distal portion, prolonged into a definite terminal spine, and is densely setose. Both 

 pair of antennae appear to be very similar to those of the preceding species. 



The pereiopoda are .similar. The first pair are short and stout, prehensile in 

 function, the basis is rather long, the ischium not half the length, and the merus 

 shorter than that. This joint is expanded dorsal ly over the base of the carpus, and 

 carries several stout setae. The carpus is a stout joint, swollen ventrally and armed 

 with setse and two or three spines. The propodus is scarcely as long, stout and 

 setose ventrally. The dactylus has a stout base, a comparatively slender claw, with 

 an accessory spine and two curved setae. 



The remaining pereiopoda are distinctly ambulatory in function and have the 

 normal cylindrical joints, excepting only the merus, which preserves its peculiar 

 character and carries a spine dorsally. The carpus is stout and slightly swollen 

 dorsally, with one or two spines and a few setse ventrally, and the propodus 

 is longer, more slender and slightly curved, with a few setae ventrally. The dactylus 

 retains its accessory spine and two curved setae throughout. 



There is but a single specimen of this species, taken at Winter Quarters in 125 

 fathoms. 



NOTOXENUS. 



Body much vaulted anteriorly, widening conspicuously to the third segment of the 

 mesosome. 



Cephalosome rounded, smooth, with long and slender ocular peduncles. Eyes 

 very small. 



Antennae. Second pair with a peduncle of six joints, no accessory appendage. 



Mesosome. First four segments straight or very nearly so, three posterior segments 

 recurved. No special interval between any of them. A mid-dorsal spine on each. 



Metasome. One very small segment and a Targe urosome with diminutive pre- 

 terminal uropoda. 



Pereiopoda. The first prehensile, the remainder ambulatory, not unduly long. 



This genus is closely allied to Coulinannia of this Report, in fact I have long 

 hesitated about separating them, but the bodily form which should be of greater 

 importance than variation among the appendages, I think, quite justifies the course 

 adopted. 



