1590 THE VOYAGE OF H.M.S. CHALLENGER. 



of flao-elluni longer than the peduncle, tapering, carrying some groups of filaments, the 

 two following joints slender, small. 



Lower Antennse not fully developed. 



Mandibles. — The palp small, almost straight, the jointing not fully developed. 



First Gnaihopods. — The side-plates with the lower front corner produced, rounded. 

 The first joint reaching considerably below the side-plate; the third joint broader than 

 long, with a slender spine at the apex of the convex hind margin ; the wrist broad, with 

 numerous spines on the inner surface, the hind margin very finely pectinate, the distal 

 process broad, not very long, with three graduated teeth on each side of the long central 

 one which is the longest and most produced ; the hand in close agreement with that 

 described for Oxycephalies porcellus, Claus, from the Pacific. 



Second Gnaihopods showing only such points of difference from those of the 

 specimen just mentioned as might be expected in a younger specimen, the wrist having 

 fewer spines, being less broad, with fewer teeth on the inner or front margin of the 

 wrist's process ; the denticulation of the almost straight hind margin of the hand is very 

 similar without being absolutely alike in the two specimens. 



First Perseopods. — Third joint shorter than fourth ; fourth shorter but much wider 

 than fifth. The perasopods in general as in the other specimen, but with fewer spinules, 

 the finger in the third pair more than a third the length of the preceding joint, and in 

 the fourth pah" more than half. 



Pleopods. — Cleft spine having an unsymmetrical subapieal dilatation to the longer 

 arm ; eight joints to each ramus. 



Uropods. — Peduncles of the first pah' scarcely as long as the rami, which are sub- 

 equal, with serrate margins, the inner slightly the longer, reaching as far back as the 

 outer ramus of the third pair ; peduncles of the second pair much shorter than those of 

 the first, shorter than the rami ; the rami rather shorter than those of the first pair, 

 the outer narrower and a little shorter than the inner, the edges for the most part 

 pectinate ; peduncles of the third pair longer than broad, shorter than the rami ; the 

 outer ramus a little shorter and much narrower than the inner. 



Telson more than twice as long as broad, the greatest breadth some distance below 

 the base, the sides being convex at first, finally converging to a very acute apex that 

 reaches beyond the uropods. 



Length, at full stretch, about three-tenths of an inch. 



Locality. — Station 106, August 25, 1873 ; Equatorial Atlantic ; lat. 1° 47' N., long. 

 24° 26' W.; surface to 40 fathoms ; surface temperature, 78° - 8. One specimen, young 

 male. 



Remarks. — The narrower base of the telson and the narrower wrist of the second 

 gnathopods as well as the smaller number of teeth in the wrist process of the first 



