1288 THE VOYAGE OF H.M.S. CHALLENGER. 



with three distant serrations on the lower and seven or eight not distant on the upper 

 side, all, as well as the tip, armed with setules. 



Upper Li}?. — The epistome a little arched above ; the outer plate of the upper lip 

 of a squared shape, with the distal margin unequally bilobed ; the inner plate shorter, 

 with the distal margin rounded. 



Mandibles. — The cutting edge small, oblique, with eight teeth ; the secondary plate 

 narrower than the principal at both proximal and distal ends, but especially at the 

 proximal ; on the right mandible its teeth are extremely fine, and the plate is more 

 widened distally than in some other species of this genus ; the spine-row containing a few 

 small but stout spines amidst others that are hair-like ; the molar tubercle with the 

 dentate crown moderately prominent ; the palp three-jeinted, longer than the trunk of 

 the mandible, set a little behind the molar tubercle ; the first joint short, the second 

 more slender, more than twice as long ; the third slender, tapering, longer than the other 

 two together, with a series of small spinules or setules all along it, except quite at the 

 base. 



Lower Lip compact ; the inner lobes small ; the mandibular processes having an 

 attachment close to the rounded distal end, which makes it difficult to separate the lip 

 from its surroundings. 



First Maxillse. — The outer plate has several strong unequal spines at the distal end, 

 amidst numerous hair-like setae ; the single joint of the palp is short, with the convex 

 outer and nearly straight inner margins meeting in a narrow apex, and distally fringed 

 with many hair-like setae or spines. 



The Second Maxillae not made out with sufficient certainty for description. 



Maxillipeds.— Inner plate or tongue short, the distal margin having the corners 

 rounded and in the centre two little embedded spines ; the outer plates not meeting at 

 the base, the inner margin at first straight, serrate with six teeth, at each of which there 

 is a little spine, the distal part oblique and finely denticulate ; the outer margin very 

 convex, with two or three little spines on the distal part ; there is also a row of six or 

 eight spinules on the outer surface, near the inner margin. 



First Gnathopods. — Side-plates shallow, much broader than deep. First joint as 

 long as the next four together, the breadth greatest just above the centre, the front 

 margin being convex above and concave below ; the second joint about as long as its 

 breadth, with a spine at the apex of the hind margin, and a smaller one just above ; the 

 third joint not larger than the second, with a spine at the apex of the hind margin, the 

 distal margin angled ; the wrist nearly as long as the two preceding joints together, the 

 lower half of the hind margin armed with about ten little teeth ; the hand oval, a little 

 longer than the wrist, abruptly narrower but not much, the front apex a little produced 

 and finely pectinate, the hind margin less convex than the front, armed with many little 

 teeth, the surface near the hind margin being also microscopically scabrous ; the finger 



