REPORT ON THE AMPIIIPODA. 1089 



two longer ones on the broad distal margin, followed by four successively more and more 

 setdform ; the first joint of the palp short, the second much longer, fringed with long 

 slender spines on the inner margin; the third joint little longer than the first, dilated 

 distally, the convex outer margin longer than the inner, but not produced over the 

 base of the finger, the inner margin without spines, except near the apex ; the finger, 

 including the spine-like nail, is as long as the third joint, it has a couple of setules 

 on the inner margin near the base of the nail, and a small dorsal cilium so close to the 

 base that it might almost be supposed to belong to the third joint. 



First Gnathopods larger than the second. The side-plates small, directed forwards 

 at the front lower corner. The first joint almost entirely free from the side-plate, the 

 front margin straight, unarmed, the hind margin convex, with a solitary seta high up ; 

 the second joint short, with a group of slender spines on the hinder apex ; the third joint 

 a little longer than the second, its two convex margins meeting at an acute apex, with 

 groups of spines on the hind margin and on the inner surface above the apex ; the wrist 

 stout, much shorter than the hand, the hind margin closely fringed with spines in 

 groups ; the hand broader than the wrist, widening a little from the base, the front 

 margin very convex, with a few spines on the apex, and groups on the surface at a little 

 distance ; the hind margin straight, carrying two or three groups of spines at intervals, 

 and apically produced into a long tooth, with a spine on the outer side ; there is a deep 

 cavity on the inner side, of which the further margin is sinuous, apically forming a small 

 tooth, beyond which the remainder of the palm is sinuously denticulate ; the finger is 

 short, curved, with seven or eight minute spine-teeth at intervals along the inner margin ; 

 it closes tightly against the denticulate part of the palm, but leaves open part of the 

 cavity above-mentioned before the nail reaches the tooth-process of the hind margin ; 

 about the palm and on the surface of the hand near the hind margin there are various 

 spines, slender and not numerous. 



Second Gnathopods. — Side-plates small, rather wider above than below, the front 

 margin a little concave. Branchial vesicles small, narrowly oval. The first joint almost 

 entirely free from the side-plate, dilated after the manner usual with the last three pairs 

 of perasopods, and as found also on the second gnathopods of Gammaropsis exsertipes ; 

 narrow at the base, and to a less extent distally, the margins having a few spinules, and 

 the hind margin a setiform spine above the centre ; the second and third joints nearly 

 as in the first pair, but the third having its lower margin much more distinct from the 

 hinder ; the wrist little shorter and broader than the hand, with seven groups of spines 

 on the convex hind margin, and some groups on the surface near it ; the convex front 

 margin armed along the lower two-thirds with many long curved spines ; the hand, which 

 is somewhat curved, of nearly even width throughout, has the long convex front margin 

 armed with numerous long spines in many groups ; the serrate and nearly straight hind 

 margin carries four groups of slender spines, and has one or two stout palmar spines at 



(ZOOL. CHALL. EXP. — PART LXVII. — 1S88.) XxX 137 



