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



First Maxillse. — The inner plates narrow, with seven or eight plumose setae on the apex 

 and distal part of the inner margin ; the outer plates long, with a brush of cilia along the 

 distal part of the inner margin ; of the eleven spines on the oblique apical margin, the 

 innermost four have many lateral denticles, the next four or five fewer, and the outermost 

 two have none ; the first joint of the palp is long, more than half the length of the 

 second ; the second reaches scarcely beyond the outer plate and has several pectinate 

 spines on the distal end. 



Second Maxillse. — The inner plates rather broader and a little shorter than the outer, 

 with numerous strongly pectinate spines passing from the apex of the outer margin in a 

 curve so oblique that it may be reckoned as well part of the inner as of the apical margin ; 

 the outer plates have longer spines round the apical margin and descending the inner 

 margin to a very short distance ; its sides are nearly parallel. 



Maxillipeds. —The inner plates long and narrow, their inner margins fringed with 

 setae, and the somewhat conical apices also fringed with long plumose setae; the outer 

 plates are large, with long spines or setae on the distal part of the inner and outer 

 margins and shorter spines set very closely round the narrowed apical part of the plates. 

 The first joint of the palp is longer than the second or third, with a few setae along the 

 inner margin and a group at the outer apex ; the second joint has also some long setae 

 at the apex of the straight outer margin, on the inner side it is apically produced, the 

 process being set round with long spines ; the third joint is short, with one or two spines 

 on the outer margin, and many long ones from the apex round the distal part of the 

 inner margin ; there seems to be no trace of a finger. 



First Gnathopods. — The side-plates triangular, the front margin convex, with one or 

 two dentations below, the apex very sharp, the slightly concave hind margin forming a 

 little tooth just before reaching the apex. The limb slight and feeble, much twisted, 

 probably being so when the creature is alive to secure the protection its feebleness requires. 

 The first joint narrowest at the two extremities, the front margin very sinuous, 

 with a few setae, the hind margin very convex ; the second joint as long as the third, 

 apically produced to a point ; the third joint with convex margins converging to an apical 

 point ; the wrist narrow, a little longer than the hand, which is also very narrow, some- 

 what curved, the hind margin concave, produced into a small thumb, against which lies 

 a short finger, the. two together forming a minute chela, about which four or five seta? 

 of different lengths are arranged ; the finger, which is beset with setae, has a hooked tip, 

 and two retroverted teeth on its inner margin. 



Second Gnathopods. — Side-plates not unlike the preceding pair, but longer, more 

 slender towards the apex and more curved, with five teeth or serrations on the lower part 

 of the front, and two at the lower end of the hind margin. The branchial vesicles long and 

 very narrow. The first joint of the limb longer than in the first gnathopods, narrow, not 

 much bent; the second joint shorter than the third; the third widening towards the distal 



