1550 THE VOYAGE OF H.M.S. CHALLENGER. 



long. 123° 18' E. ; surface, at night ; surface temperature, 81°'7. The specimen female 

 or young. 



Remarks. — -Dana's Dairilia insequipes, two lines long, was taken " off south end of 

 Mincloro." The specific name probably refers to the inequality in length between the 

 third and fourth perseopods. In the third peraeopods the second joint reaches below the 

 first, and the first is not nearly as long as the following five joints ; in the fourth pair 

 the second joint does not reach below the first, and the first joint is scarcely if at all 

 longer than the following five ; it is however somewhat longer than the first joint of the 

 preceding pair. 



Brachyscelus latipes, <j>, n. sp. (PL CXCVII., B.). 



Head large, deep and rounded, the triangular cavity which contains the antennae 

 and mouth-organs being entirely below, not at all in front, the hind margin sinuous 

 laterally; the perseon narrowing a little backwards, the first two segments very short; 

 the third segment of the pleon the longest. The integument both of head and body 

 very firm, with conspicuous scale markings. 



Upper Antennae. — The first joint the thickest ; the second about half the length 

 of the first, the two together forming a curve ; the third joint as long as the first or a 

 little longer, carrying groups of filaments on the upper margin; the fourth and fifth 

 joints together not so long as the third, the fifth very slender. 



Lower Antennse represented in the female only by the prominent gland-cone. 



Epistome domed; the Upper Lip small, transversely oval. 



Mandibles. — The trunk broad, especially near the front; the cutting edge broad, 

 with a prominent tooth at the top, the border slightly convex, finely striated, without 

 any tooth at the lower corner, on the right mandible there is a little upturned spine- 

 like process, adjacent to the hind margin of the principal plate near the centre. 



Maxillipeds. — The distal border of the inner plate flat, wider than the base, having 

 two little central embedded spinules; the outer plates with their inner margins little 

 dehiscent, minutely pectinate, the surfaces carrying some small spinules. 



First Gnathopods. — The first joint scarcely at all bent, the lower part channelled 

 in front; the second joint with a strong brush of spines along the hind margin; the 

 third joint not longer than broad, also with several spines about the hind margin, but 

 not closely grouped as in the second joint ; the wrist very much wider than the third 

 joint, wider than long, the front margin convex, smooth, the hind margin pectinate 

 and divided into five teeth, to which succeeds the apical tooth, the broad distal margin 

 on the other side of it being also pectinate and divided into four teeth ; the hand 

 shorter than either the length or breadth of the wrist, with front margin smoothly 



