846 THE VOYAGE OF H.M.S. CHALLENGEE. 



First MaxillsB. — Inner plate broader than the outer, its length scarcely greater than 

 its breadth, carrying eight plumose setae, which commence not at, but close to, the apex, 

 pass along the straight, slightly oblique distal margin, and along the curve which joins 

 it to the convex inner margin ; the outer margin is nearly straight ; the outer plate 

 narrows distally, and carries on the truncate distal edge nine spines, most of them 

 furcate, in the sense of having only one lateral tooth ; the innermost has three lateral 

 denticles, the one next to it is truly furcate, the lateral tooth being nearly as long as the 

 main branch and parallel to it ; the first joint of the palp has some setae at points of its 

 outer margin, the second joint, which is widest about the centre and overtops the outer 

 plate, has setae at three points of the somewhat serrate outer margin, and round the apex 

 and part of the inner margin has two rows of bristles, twenty-one in all, most of them 

 looking like slender setae, three at the apex being definitely spiniform, two of them 

 delicately pectinate on two edges, the third with a tendency to be so. 



Second Maxillse. — Both plates broad, especially the inner, which is broader and very 

 little shorter than the outer ; both are densely ciliated, the spines of the inner com- 

 mencing near the inner end of the broad distal margin, and passing far down the inner 

 margin, accompanied on this by plumose setae, some of which fringe it almost to the base ; 

 on the outer plate some short spines are placed on the distal border a little way from its 

 outer corner, and followed by a fringe of long, though slender, spines, which pass about 

 halfway down the inner margin. 



Maxillipeds. — The inner plates small, broad in proportion to their length, not 

 reaching nearly so far as the distal end of the first joint of the palp, the distal margin 

 set with several short, distally serrate spines; the outer plates crescent-like, reaching about 

 to the middle of the second joint of the palp, set along the inner margin with numerous 

 seta-like spines, which increase in length towards the apex, passing round the apex and 

 part of the outer margin as long plumose setae ; the first joint of the palp short, with 

 some setae on the apex, the second joint long and large, bordered on the inner margin 

 with long seta-like spines, longest at the broadest part of the plate which precedes the 

 apex, with a row also on the inner surface ; the third joint longer than the first, widening 

 distally, set on the inner surface with some six rows of spines, several of which are longer 

 than the finger, plumose at the centre, distally pectinate ; the finger curved, shorter than 

 the third joint, much thicker at the base than at the origin of the little crooked naU ; 

 the small dorsal cilium at not quite a third of the distance between the base of the finger 

 and the base of the naU. 



First Gnathopods. — The side-plates projected forwards below the head with a straight 

 front margin, the lower half carrying setae, the lower margin bent abruptly upwards to 

 meet the hind margin, which also carries setae at intervals. The first joint scarcely 

 reaching beyond the side-plate, with some long setae on the margins and inner surface, 

 and groups of spines on the distal part of the inner surface, most of these spines, and 



