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



are more uumerous than shown in either of the figures m.m., numbering about eighteen 

 on each mandible. 



Loiver Lip. — Triangular, the forward lobes being distally narrowed ; the mandibular 

 processes straight and narrow. 



First Maxillas. — The inner plate short, apically tipped with three strongly plumose 

 setae, of which the outermost is a little the longest ; the outer plate long ; of its eleven 

 spines three stand at intervals on the inner margin, the lowest with five, the next with 

 six, the following with seven lateral teeth ; the next spine is subapical, with six lateral 

 teeth ; in the six apical spines the number of lateral teeth varies from six to three, the 

 subapical tooth on the outer side has four ; the long and narrow second joint of the palp 

 has four slightly curved spine-teeth and a cilium or short seta. On the left maxilla some 

 of the spines of the outer plate had one more lateral denticle than the number counted 

 above from the right maxilla. 



Second Maxillie. — Inner \AdXe considerably shorter than the outer, a double row of 

 spines and plumose setae from the apex about half-way down the inner margin, ending as 

 usual with a plumose seta longer than the rest ; the outer plate with the usual pectinate 

 spines on the apical part. 



Maxillipeds. — Inner plates not reaching as far as the apex of the first joint of the palp, 

 the apical margin sloping outwards, with three little pointed teeth, the two innermost close 

 together, the third standing a little apart, followed by seven or eight feathered setae 

 which occupy the remainder of the margin ; besides the usual long setae which pass from 

 the inner margin to the outer apex, the plates have on their outer surface two marginal 

 spines below the apex and a cross-row of three small seta3 ; outer plates large, but not 

 reaching so far as the apex of the long second joint of the palp, teeth of the inner margin 

 minute and numerous, separated by more than their own width ; far back on the apical 

 margin are three spine-teeth, the largest and most-curved outermost, followed by plumose 

 setae down part of the outer margin ; low down on the outer surface of the plate are four 

 groups of setiform spines near the inner margin, and parallel with the marginal teeth 

 a row of fifteen spinules, with one long spine beneath ; the second joint of the palp 

 much longer than the first, the third a little longer than the first ; the finger small, 

 its surface striated with cilia, the dorsal cilium small, centrally placed ; the nail small, 

 spiniform, with short cilia at the base.^ 



First Gnathopods. — Side-plates very small, almost concealed by those of the next 

 segment, front margin convex ; first joint subequal in length to the elongate hand; second 

 joint much longer than either the third or fourth ; the third and fourth subtriangular, so 

 placed that the third is almost without free front, the fourth almost without free hind 



1 Besides the slender spines with which many parts of the palp are furnished, the tliird joint has at its apex one 

 spine stouter than the rest, pectinate on both edges, and such a spine is, I le'.ieve, by no means unfrequent in this 

 position. 



