NO. 5.] ACCOUNT OF THE SPECIES. 51 



outermost being rather small, not extending beyond the middle of the adjacent 

 lappet. 



The anterior maxillipeds (fig. 6) are short and thick, with the 5 digiti- 

 form lobes of the anterior edge densely crowded together, and clothed with 

 strong, coarsely ciliated setae. On each of the 2 outermost lobes one of 

 these setae assumes the character of a claw-like spine. The outermost spine 

 in particular, is very strong and coarsely denticulate laterally. The apical 

 sensory appendages are 8 in number, and comparatively small. According to 

 Dr. Giesbrecht, they terminate, in the species of this genus, in extremely 

 dehcate brushes, which I, however, have failed to detect in the form here 

 in question. 



The posterior maxillipeds (fig. 7) are rather slender, being almost 3 times 

 as long as the anterior. The terminal part, however, is comparatively short, 

 scarcely more than half as long as the 2nd basal joint, and is not reflexed. 

 The setae clothing this part are also rather shorter than in the 2 preceding 

 forms, and are coarsely ciliated in their proximal part. 



The natatory legs (figs. 8 — 11) are built upon the very same type as in the 

 2 preceding forms. In the 1st pair (fig. 8), however, outside the 1st joint of 

 the outer ramus, there is a well-marked spine that is wanting in these forms. 



The last pair of legs (figs. 12, 13) exhibit a rather characteristic appear- 

 ance. They are each composed of only 2 joints, the 1st of which is rather 

 short and coarsely hairy inside. The distal joint is about twice as large, 

 oblong in form, and exhibits in the middle a conspicuous constriction. It is 

 likewise clothed with dehcate hairs both inside and outside, and carries at 

 the end 3 strong, denticulated spines of nearly equal length, the middle one 

 being attached to a projecting knob of the joint. 



Occurrence. The above-described specimen was found in a sample 

 taken on the 13th October, 1893, north of the New Siberian Islands, the tow- 

 net having been lowered to a depth of 50 metres. 



Distribution. Coast of Norway, rather abundant in the greater depths 

 of the fjords, below 150 fathoms. 



Gen. Undinella, n. 

 Generic Characters. Cephahc segment not coalesced with the 1st pedi- 

 gerous one, front produced below to a well-marked rostral prominence 



