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



First Maxillie. — luuer plate slender, distal portion ciliated; outer plate carrpng 

 distally seven thick dentate spines, the innermost having eight (and sometimes more) 

 teeth on its edge besides the apical one ; four other spines, much more slender, of 

 varying length, and but little dentate, are ranged on the side of the plate ; the surface of 

 the plate is ciliated near the spines ; the enlarged figure shows the growth of the new 

 spines within the plate, in which it will be observed that the innermost spine above 

 mentioned faces in the opposite direction to that which it has when set free. The palp 

 is a thin broad plate set upon a very short first joint ; the basal is much broader than the 

 distal half, which is bluntly pointed, and has slight serrations round the apex. 



Second Maxillse. — Inner plate a little shorter than the outer, ciliated on the inner 

 border, a row of seven or eight serrate spines at and near the apex. Outer plate ciliated, 

 apically armed with setse and spines ; the spines more or less serrate distally with curved 

 tips, one conspicuously longer than the rest, not serrate, a little clubbed at the end. 



Maxillipeds. — Inner plates reaching as far as the distal end of the second joint of 

 palp, tapering almost to a point, with one little spine-tooth on the inner side of the 

 apex, and one or two similar teeth and some small setse on the distally serrate outer 

 margin. Outer plate large, reaching far along the third joint of the palp or beyond it, 

 the apex obtusely pointed, the inner margin with a solitary seta. There is an appearance 

 of canals within the substance of the plate radiating towards the outer margin and distal 

 part of the inner margin, the margin itself being microscopically indented in corre- 

 spondence with the ends of these canals. First joint of palp with a seta at the distal end 

 of its very short inner margin ; second joint with its inner border twice as long as .the 

 outer border of the first joint, having three long and one or two short setse at and near 

 the distal end ; third joint longer than first, longer and less dilated than shown in the 

 foreshortened figure, borders naked except distally ; fourth joint small, tapering, second 

 half narrowed somewhat suddenly, ending in a short sharp nail with a cilium on each 

 side of it. 



First Gnathopods. — Side-plates broad, with a few cilia on the surface near the front 

 and lower margins, and a small notch near the distal end of the hind margin. First 

 joint a little curved, widened distally, having five setse on the front border ; second joint 

 with five on the hind margin, two of them very short ; third joint triangular, hinder part 

 a little furred, with a group of setse distally ; wrist (not furred as it is in Lysianassa 

 kidderi, S. I. Smith), subequal in length to the hand, but stouter, with distally a small 

 group of setse in front and a large one behind ; hand tapering, having in front some slight 

 setse, and a row of six behind along the inner side of the margin, with three longer and 

 two short ones on the outer side of it. Most of these setse narrow a little abruptly near 

 the middle as if two-jointed. The finger short, with a curved nail, set on the extremity 

 of the hand so as to leave no palm. 



Second Gnathopods. — Side-plates narrower than those of first segment, cihated and 



