1142 THE VOYAGE OF H.M.S. CHALLENGER. 



Lower Lip. — The inner margins of the principal lobes not strongly sinuous ; the 

 mandibular processes rather long and divergent. 



First Maxillse. — The inner plate very small ; the outer plate apparently carrying 

 nine spines, of which the denticulation could not be clearly made out ; the first joint of 

 the palp very short, the second long, with four serrate spines on the apical margin, and 

 three slender submarginal spines. 



Second Maxillse. — The inner plate shorter and narrower than the outer ; the spines- 

 tolerably numerous on the apical border in each, not descending the outer margin in 

 either. 



Maxillipeds. — The inner plates not reaching quite to the distal end of the first joint 

 of the palp, with a few setse on the inner margin and several feathered spines on the 

 broad distal margin, which probably also carries the usual three spine-teeth ; in the 

 figure the inner margin of this plate faces outward ; when the maxillipeds are divided 

 into two halves, the inner plate as a rule becomes reversed ; the outer plates not nearly 

 reaching the end of the second joint of the palp, with five spine-teeth on the serrate inner 

 margin, and three or four more spines, partly spine-teeth, partly setiform, on the serrate 

 apical margin ; the first joint of the palp short, with a spine at the outer apex ; the 

 second more than twice as long as the first, with a spine at the outer apex, and many 

 spines along the inner margin ; the third joint narrower than the first, scarcely longer, 

 with spines at the upper part of the inner margin and all round the apical margin ; the 

 trunk of the finger very little longer than broad, the slender apical spines longer than 

 the trunk, the two together longer than the third joint. 



First Gnathopods. — The side-plates broader than deep, the hind margin deejter than 

 the front. The first joint reaching beyond the side-plates, narrow', widening distally, 

 not longer than the wrist, almost entirely unarmed ; the second joint short, with slender 

 spines at the apex behind ; the third joint with front and hind margins convex, each with 

 a group of spines, the distal scarcely distinct from the hind margin, with seven feathered 

 spines at the junction ; the wrist much longer than broad, the front margin smooth, with 

 an apical spine, the hind margin more convex than the front, fringed with numerous 

 feathered geniculate spines ; the surface carries five spines in three groups at a little 

 distance from the hind margin ; the hand tending to oblong, subequal in length to the 

 wrist, with five groups of spines near the almost straight front margin, four single spines 

 along the centre of the surface, and near the almost straight hind margin three or four 

 groups ; on this margin there are two stout spines, one at the centre, one nearer the apex, 

 which may be considered as palmar spines, though remote from the palm, which is short, 

 nearly straight, finely pectinate, joining the finely pectinate distal part of the hind margin 

 by a rounded angle ; the finger is broad, with a finely pectinate nearly straight inner 

 margin ending in a tooth at the base of the strongly curved nail, and having three or four 

 submarginal setules along its course, and a little spine-tooth near the centre ; the finger 



