1292 THE VOYAGE OF H.M.S. CHALLENGES. 



small spine where it meets the rounded, channelled, distal margin, which as usual in this 

 genus is faintly pectinate and armed with a spinule ; the finger is short, tapering from the 

 base to an angle of the hinder margin, and then again tapering to the apex, in which a 

 spine-like nail is inserted ; the hand and wrist are both scabrous on and near the hind 

 margin. 



Second Gnathopods. — The branchial vesicles oval, small. The first and second joints 

 of the limb similar to those of the first pair but longer ; the third joint longer than the 

 second, with a small and a large feathered spine on the hind margin, and at the almost 

 acute apex a large spine with a small one close beside it ; the proximal part of the wrist 

 as long as the hand, the narrowly triangular hinder process nearly as long as the hand, 

 scabrous, faintly serrate on its inner or front margin ; the hand narrower than in the first 

 pair, more strongly scabrous, and having two little spines at the apex of the hind margin ; 

 the finger shorter than that of the first gnathopods. 



First Perseopods. — Branchial vesicles larger than the preceding pair, not so long as 

 the first joint of the limb. The first joint broader than in the gnathopods, not sinuous ; 

 second joint longer than broad; third joint broader but shorter than the fourth, with one 

 slender spine standing out from the hind margin ; fourth joint slightly curved, having like 

 the third a minute spinule a little above the apex of the convex front margin ; fifth joint 

 a little longer than the fourth, with a spinule a little above the apex of the hind margin, 

 and another at the apex of the front; the finger not half the length of the fifth joint, 

 tapering from the base nearly to the bent tip, the hind margin a little pectinate. 



Second Perseopods like the first. 



Third Perseopods like the two preceding pairs/the first joint scarcely more dilated, 

 the fourth and fifth joints and the finger longer,, the fourth joint having a little spine at 

 the apex of the front margin, and its distal margin pectinate, the front margin of the 

 fifth joint being faintly scabrous, and having two spinules ; as in the other pairs, the 

 termination of the finger is not sharp and strong, though the new growth seems to 

 indicate that it is normally acute. 



Fourth Perasopods like the third, but with all the joints except the finger rather longer. 



Fifth Peneop>ods equal in length to the two first joints of the fourth pair, the first 

 joint not broad, fully as long as the following five together, the third a little longer than 

 the second, the fourth than the third, the fifth than the fourth, the fifth having a slender 

 spine at the apex of the front margin ; the finger is oval, about as long as the third joint, 

 scarcely scabrous. 



Pleop>ods. — Peduncles scarcely so long as the rami, coupling spines short, with long- 

 apical retroverted teeth ; the cleft spine represented by a minute rudimentary acute 

 spine near the top of the inner margin of the long first joint of the inner ramus ; inter- 

 locking process of the outer ramus very short ; joints of the inner ramus numbering from 

 six to seven, of the outer from seven to eight. 



