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



joint is equal in length to the second, its surface covered with adpressed cilia, its 

 apex armed with three small, lightly feathered spines. 



Lower Lip. — Principal lobes broad, with a small group of spine-like cilia, some seven 

 in number, with furcate tips, at the inner part of the distal margin ; mandibular processes 

 short, squared at the ends. 



First Maxillse. — Inner plate small, oval, with one plumose seta near the apex ; outer 

 plate with nine spines on the oblique truncate distal margin, the outermost the strongest, 

 curved, smooth ; of the others three are short, stout, smooth, the rest long, and very 

 slightly denticulate ; the second joint of the palp expanded a little distally, reaching 

 beyond the outer plate, its distal border toothed, carrying seven or eight slender spine- 

 teeth, accompanied by four or five submarginal spines. The comparative smoothness of 

 the spines on the outer plate may be noticed as a rather unusual feature. 



Second Mobilise. — Inner plate a good deal shorter and narrower than the outer ; near 

 the middle of the inner margin is a long plumose seta, followed by a second on the 

 surface, and then a third near the apex, at which there are two pairs of spines, succeeding 

 three small spines at the top of the inner margin ; the outer plate has seven or eight 

 long spines at the narrowed apex, succeeding a row of five on each margin, the spine- 

 bearing part of the outer margin being oblique. 



Maxillipeds narrow. The inner plates scarcely reaching beyond the base of the first 

 joint of the palp, with two long spiniform plumose setae on the inner margin, two long 

 spines much like them, but slightly curved, at the oblique outer end of the distal margin, 

 at the inner truncate portion of which there are two spine-teeth and a slender sub- 

 marginal spine ; the narrow outer plates do not reach the distal end of the second joint 

 of the palp ; the serrate inner margin fringed with sixteen long spine-teeth, followed by 

 six still longer on the oblique toothed distal margin ; the first joint of the palp short, 

 with a spine at the outer apex ; the second broad, not nearly twice as long as the first, 

 with nine or ten long spines spaced along the inner margin, and four or five about the 

 distal border ; the third broad, as long as the first, with a group of spines on the outer 

 margin, several round the distal border, and several on the surface of different sizes, some 

 very short but plumose like some of the long ones ; the finger slender, about as long as 

 the third joint, with a couple of cilia at the base of the nail. 



First Gnathopods. — Side-plates large, much broader below than above, somewhat 

 outdrawn in front, with the anterior angle rounded. The first joint reaching a little 

 below the side-plate, its front margin sinuous, fringed with some seta?, and carrying two 

 huge spines near the distal end, the hinder margin slightly convex, with some long setae 

 near the centre and a spine at the apex ; the second joint short ; the third rhomboidal, 

 with a few spines on the hinder and distal margins ; the wrist short, triangular, distally 

 cup-like, equal in length to the preceding joint, with an apical spine in front, the short 

 free hind margin fringed with spines ; the hand curved, shorter than the first joint, 



