1144 THE VOYAGE OF H.M.S. CHALLENGER. 



the finger curved, almost as long as the fifth joint, with a small dorsal cilium near the 

 base, and an opening in the apex. 



Second Perseopods scarcely differing from the first, except that the first joint is more 

 dilated, oval, with two spinules on the very convex front margin, and some long spines 

 on the surface near the hind margin and at its apex. 



Third Perseopods. — Side-plates with the front lobe as deep as the preceding side- 

 plates, the hind lobe small. The limb missing. The side-plate and branchial vesicle are 

 figured in position together with prp.2. $ . 



Fourth Perseopods missing. 



Fifth Perseopods. — The first joint little but evenly dilated, shorter than the fifth joint, 

 with four or five spinules on each margin ; the second joint longer than broad, with a 

 spinule on the apex in front; the third joint longer than the fourth, shorter than the first 

 or fifth, with slender spines at each apex, and a spine or spinule on each margin higher 

 up ; the fourth joint similarly armed ; the fifth with a group of slender spines at the apex 

 of the hind margin and a spinule at its centre, slender spines at three points of the straight 

 front margin, and two little stiff spines close to the finger ; the finger is short, curved, 

 with two or three very small setules along the otherwise smooth inner margin. 



Pleopods. — Coupling spines minute, narrow, bent, with two pairs of hooks ; there 

 appeared to be only one cleft spine on the inner ramus ; the joints of the rami five in 

 number ; the outer ramus rather the shorter, with its first joint more dilated than the first 

 of the inner ramus. 



Urojiods. — Peduncles of the first pair longer than the rami, with four spines on each 

 of the upper margins, the inner of which has an acute apex ; the apical spine below is 

 broad but not very long ; the rami are nearly equal, each with three marginal spines and 

 an apical group ; the peduncles of the second pair longer than the rami, with three spines 

 on one margin ; the outer ramus the shorter, with two spines on the outer margin, one at 

 the blunt apex, and a little one above it, the inner ramus with a spine on the inner 

 margin, and three at or near the apex ; the peduncles of the third pair very broad, longer 

 than the rami, reaching beyond the other peduncles, with two setse on the outer margin, 

 the apical border having two stout spines with two thinner ones on one side and one on 

 the other ; of the short rami the outer is a good deal shorter than the inner, with two 

 minute spines at its slightly bent tip, the inner ramus with one such spine a little larger 

 than those of the outer ramus. 



The Telson as broad as long, forming a pointed arch, not reaching the end of the 

 peduncles of the third uropods, with a raised point near the margin on each side, some 

 way above the apex, and a cilium adjacent to this tubercle. 



Length. — The female specimen, in the position figured, with the pleon folded and the 

 antennas outstretched, was a tenth of an inch ; the male was rather larger. 



