REPORT ON THE AMPHIPODA. 009 



the front lobes narrow, strongly dehiscent, suddenly widening and therefore coming 

 nearer together about half-way down the long cleft that separates them. 



First Maxillie. — Inner plate small, oval, with two plumose setae on the apex, the 

 outer the larger ; outer plate with the very oblique apical margin densely ciliated, 

 especially on the lower part ; its eleven spines strikingly different from one another in 

 their dentation ; of the two which stand apart from the rest at the lower end one is 

 slender with many small teeth, the other stout with three large ones ; of those set round 

 the upper end some are peculiar by their distal widenings. The large second joint of the 

 palp widens distally, the distal border being cut into six teeth, the tip of each except 

 the minute inner one having a small spine-tooth inserted in it ; between the outermost 

 marginal tooth and the next is an additional small prominence, and again between the 

 second and third teeth is a small cilium. 



Second Maxillie. — The plates are similar to one another in general shape, the convex 

 margins meeting in a pointed apex, the outer plate considerably longer than the inner. 

 From the apex down half the inner margin the inner plate has plumose setae ending in 

 one larger than the rest, and along the same part it has spines shorter than the setse, the 

 spines being armed midway with straight spine-like cilia. The spines which in like 

 manner arm the outer plate have these cilia, seemingly limited to four in number, except 

 on the lowest spines, which become more seta-like. 



Maxillipeds. — Inner plates small, not reaching nearly so far as the distal end of the 

 first joint of the palp, apical margin with three tiny teeth inserted on little prominences, 

 the plumose setae of the inner margin very long, passing over to quite small ones at the 

 outer angle of the apex ; the outer plates large and long, still not reaching the apex of 

 the second joint of the palp, the inner border showing some six and twenty minute 

 prominences as if for teeth, but with no appearance of teeth upon or within them, the 

 same description applying to two on the rounded apical border ; the second joint of the 

 palp more slender and somewhat longer than the first ; the third joint widening from a 

 narrow neck, with setae on both borders, distally furred ; finger long, with adpressed cilia 

 on the surface, a dorsal cilium nearer to the acute point than to the base. 



First Gnathoj)ods. — Side-plates a little excavate in front, much wider below than 

 above, with the usual little cilium-bearing indent at the lower end of the hinder margin. 

 First joint broad, about as long as the third, fourth, and fifth together, with setae on both 

 margins ; third joint with no free front margin, its hinder margin furred, apically 

 carrying geniculate spines and setae ; wrist equal in length to the hand, dilated below, 

 furred on the free part of the hinder margin, with spines round the distal part both 

 before and behind ; hand less wide than the wrist, widest at the base, but preserving 

 most of its width all along to the by no means oblique ])alm, which is bordered with 

 minute cilia, and defined by two spines, between which the finger closes down, the nail 

 overlapping the palm. There are various spines and setse, singly, in rows, and in groups, 



(ZOOL. CHALL. EXP. — PART LXVII. 1887.) XxX 77 



