1588 THE VOYAGE OF H.M.S. CHALLENGER. 



the wrist very broad, the greatest breadth a little less than the length ; the produced part 

 much broader than long, distally denticulate with eleven teeth, of which the central one 

 is the longest, forming a kind of apex ; the hinder margin is very faintly serrate and 

 pectinate, and there are numerous spines of various sizes upon the inner surface, chiefly 

 on or near the produced part, some of them being shown in the figure gn. 1 as seen 

 through the partially transparent joint ; the hand not nearly half as broad as the wrist, 

 the length not equalling the wrist's greatest breadth ; there are three spines on the lower 

 part of the very convex front margin ; the hind margin slightly concave or nearly 

 straight, having a low serration alternating with sharp and distinct but little teeth, the 

 adjacent inner surface set with numerous spines, and the apex produced nearly halfway 

 along the finger ; the finger slender, curved, more than half the length of the hand. 



Second Gnathopods. — The side-plates convex in front. The wrist much larger than 

 in the first pair, the hind margin much longer than the front, forming an acute apex, 

 the distal margin oblique, very long, finely and regularly denticulate, the hind margin 

 and inner surface carrying several slender spines ; the hand longer than in the first 

 gnathopods, scarcely so broad, its length not equalling the breadth of the wrist, having 

 numerous spines on the inner surface ; it is bent at the neck, below this the hind margin 

 being slightly convex, denticulate, the apex not projecting much behind the finger ; the 

 finger slender, curved, acute, considerably more than half the length of the hand, having 

 a little tooth on the inner margin. 



First Perseopods. — First joint with narrow neck, the front margin concave ; the 

 second joint longer than broad ; the third about as long as the fourth but broader, with 

 a few small spines on the hind margin, which except near the base is straight ; the fourth 

 shorter but much broader than the slender fifth ; the finger more than half the length 

 of the preceding j oint. 



Second Perseopods like the first, but the fifth and perhaps one or two other joints 

 longer ; the finger not half the length of the preceding joint. 



Third Perseopods. — The side-plates having a very narrow backward-directed process on 

 the inner side. First joint about twice as long as the greatest width, which is a little 

 above the centre, the front margin nearly straight, the hinder very convex ; the second 

 joint bent ; the third rather longer than the fourth, each with slender spines along 

 the front margin ; the fifth joint slender, slightly curved, much longer than the third 

 joint, the concave front margin fringed with a few spinules and minutely furred ; the 

 finger slender, rather more than a fourth of the length of the fifth joint. 



Fourth Perseopods. — First joint not longer but much broader than in the preceding 

 pair, with very convex hind margin ; the third joint longer than the fourth, strongly 

 pectinate along the front margin, which is produced into a little apical lobe also pectinate 

 and carrying a little spine ; the fourth joint longer than the fifth, pectinate along the 

 front margin, having a little spine not far from the apex which with the under surface of 



