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



Mandibles. — Cutting plate of the left mandible witli the edge forming an obtuse 

 angle, cut into eleven denticles, the six uppermost being the smallest, the three 

 following the largest ; the secondary plate nearly, if not quite, as broad as the 

 principal, its edge gently convex, cut into about eighteen minute equal denticles ; the 

 principal plate on the right mandil^le scarcely differing from that on the left, the 

 secondary plate with a straight edge and smaller denticles ; spine-row of three short 

 serrate spines and a group of five, that seem to be smooth and not in line with the 

 others ; the first joint of the palp shorter than the short third joint ; the second joint 

 broad, with a small spine near the middle of the inner margin, and a longer one near its 

 apex, the distal margin flat, slightly oblique ; the third joint abruptly narrower, rather 

 more than a third of the length of the second joint, with two long apical spines. 



Lower Lip very broad, principal lobes with the distal margin well cihated ; 

 mandibular processes apically rounded. 



First Maxillae. — Inner plate with one seta on the narrowly rounded apex ; outer 

 plate with the usual spines a little elongate ; the two-jointed palp as in other species. 



Second Maxillse with the plates rather broad, the longer outer one having many 

 spines on the distal margin. 



Maxillipeds. — The inner plates broad, reaching more than halfway along the inner 

 margin of the second joint, carrying a short spine and one somewhat longer on the 

 slightly curved distal margin ; the broad second joint has some six spines on the inner 

 margin, the longest being on the rounded apex of the rudimentary plate ; the joints of 

 the palp are about equal in length, the first two broader than the third, with some 

 rather strong spines ; the third joint has many adpressed cilia on the outer distal part, 

 and four spines at and near the inner apex, of w^hich one is long, with the distal half 

 pectinate ; the finger is of the usual type. 



First Gnathojiods. — Side-plates small, nearly concealed by the following pair, the 

 front margin considerably shorter than the hinder, the oblique lower margin having two 

 or three small spines. The first joint attached as usual, about equal in length to wrist 

 and hand united, broad, fringed on both margins with long setfe, those behind being 

 spine-like ; the short second joint with a group of long and short spines ; third joint 

 shorter than the wrist, the front margin convex, the hind margin straight, furred below, 

 the distal margin set with a row of seven or eight strong spines, which have the distal 

 half pectinate ; the wrist as long as the hand, with about a dozen strong pectinate spines 

 round the hinder and part of the distal margin, and some long slender spines on the 

 surface ; the hand widest at the commencement of the palm, the hind margin unarmed, 

 the palm convex, rather oblique, finely pectinate and denticulate, fringed with setules, 

 and having a long seta at the centre and another at the commencement, where there are 

 a row of palmar spines, three pairs and a single one ; the front margin has a spinule near 

 the middle and at a little distance from the apex three strong spines on the surface, this 



