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



are ventrally flexed ; the sixth segment outdrawn on either side as far as the apex of 

 the telson. 



Eyes small, oval. 



Antennse broken. 



Upper Lip. — ^The two distal lobes very nnsymmetrical. 



Mandibles. — The cutting plate is a rather narrow plate attached as it were by a neck 

 to the trunk of the mandible, having the distal border cut into about ten small teeth ; 

 the secondary plate on the left mandible is similar to the principal, but on a smaller scale ; 

 the spine-row consists of ten curved denticulate spines, graduated in size, the larger being 

 near to the cutting plate ; the molar tubercle (not shown in the figures m.m.) is conical, 

 scarcely if at all dentate ; the palp is set far back, its first joint short, the second straight 

 and moderately long, but the two together not equalling the length of the thin, curved 

 third joint, which is a little ciliated at the acute apex. 



Loiver Lip. — The front lobes distally narrow^, armed with strong but short cilia, 

 widely dehiscent ; the inner lobes narrow ; the mandibular processes short, distallv 

 pointed. 



First Maxillse. — Inner plate small, oval, with a single short seta at the apex ; outer 

 plate with, I think, seven spines, some of them denticulate, on the oblique apical 

 margin, together with some spine-like cilia at the inner corner ; the palp rather broad, 

 the second joint having four short spines on the truncate distal margin, which is produced 

 into a small tooth at one corner. 



Second Maxillie.. — The plates about equal in wddth, the inner with a few setules or 

 spines at the apex and passing a little way down the inner margin ; outer plates damaged 

 in dissection. 



MaxiJlipeds. — Inner plates long and narrow, not reaching the distal end of the first 

 joint of the palp, the inner margin ending apically in a little tooth, besides which the 

 distal margin seems to have two scarcely visible spine-teeth ; there are long fine cilia to 

 be made out with difficulty on various parts of the plate ; the outer plates are very broad, 

 not reaching the end of the second joint of the palp, with a very few spinules on the 

 surface within the straight, smooth, inner margin ; the broad, rounded, distal margin is 

 finely pectinate on the inner part ; about the centre it carries a single conspicuous serrate 

 spine, and the outer part is strongly ciliated ; the first joint of the palp, which is the 

 longest, has some apical spines on both sides ; the second joint has more ; the third joint 

 is longer than the second, but narrower, with spines at two points on the outer margin, 

 and many round the serrate distal margin ; the finger is short, tapering to a very fine 

 point, its inner margin pectinately fringed with cilia as far as the nail. 



First Gnathopods. — Side-plates small, almost concealed by the following pair, the 

 hind margin straight, the front almost semicircular. The first joint equal in length to 

 the hand, with an apical spine on the hind margin, and one or two spinules along the 



