1174 THE VOYAGE OF H.M.S. CHALLENGER. 



apically narrowed, having numerous long spines on both surfaces but especially on the 

 outer surface, with apparently only one spine that could be properly designated a spine- 

 tooth, and even that a slender one, just below the apex; the distally serrate outer margin 

 carrying four very long spines; the spines on the outer surface of the bases of both the 

 inner and outer plates form long and striking series in this species; in the figure it is 

 as usual the inner surface that is shown ; the first joint of the palp about half the length 

 of the second, with a long spine on the apex of the short inner margin ; the second joint 

 long, not broad, the inner margin crowded with feathered spines ; the third joint longer 

 than the first, a little apically produced, with several groups of feathered spines over the 

 surface except near the base, and a long row of pectinate spines only visible when 

 the joint is turned at a particular angle ; the finger narrow, rather more than half 

 the length of the third joint, with a dorsal cilium some little way from the hinge, 

 the inner margin distally serrate, with four slender spines and a fifth much longer 

 than the other four; at the apex a still longer and stronger spine, longer than the 

 base of the finger, the equivalent of a nail, not however in a continuous line with the 

 base but at right angles to it. 



First Gnathopods. — The side-plates broader below than above, the lower front corner 

 rounded, produced forwards, the convex lower margin carrying a few spinules. The first 

 joint reaching little beyond the side-plates, having four long setae about the middle of 

 the convex hind margin ; the second joint short, with a group of very long spines on the 

 hinder apex ; the third joint a little longer than the second, the front and hind margins 

 convex, with long spines at six points of the hind margin, and two groups crossing the 

 inner surface above the oblique distal margin and its acute front apex ; the wrist shorter 

 but broader than the hand, twice as long as broad, more than half the length of the 

 hand, with spines at three points of the distal part of the convex front margin, the 

 whole of the slightly convex hind margin densely crowded with feathered spines, an 

 oblique row, in which fourteen spines may be counted, traversing the inner surface ; the 

 hand almost as long as the first joint, gently tapering, a small tract at the base of 

 the slightly convex front margin free, the rest, till near the apex, and the apex crowded 

 with long feathered spines, the front margin still more densely set with spines, some here 

 being shorter and stiffer than the prevailing setiform type ; at the apex is a palmar spine 

 with an incurved tip, but there is no palm worth speaking of; the finger is about half 

 the length of the hand, with a long dorsal cilium not far from the hinge, the inner 

 margin a little bulging at the base, then pectinate, slightly curved, running out into a 

 tooth, with three unequal setules near its base, the nail beyond this being long, sharp, 

 smooth-edged, more curved than the rest of the finger. 



Second Gnatliopods. — The side-plates longer than in the preceding pair, the lower 

 part less widened, fringed with slender spines and spinules. The branchial vesicles a 

 long smooth oval, nearly as long as the first joint. The first joint rather larger than in 



