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



Second Perwopods. —These, with the side-plates, branchial vesicles, and marsupial 

 plates, closely resemble the preceding pair. 



Third Perwopods. — Side-plates broader than deep, the lobes nearly equal. The 

 branchial vesicles and marsupial plates nearly as in the two preceding segments. The 

 first joint of the limb oval, with spines at five points of the flattened front margin, and 

 three or four slight serratures on the hinder one ; the second joint short, with two 

 little spines on the front margin ; the third joint with spines at three points on the front 

 maro-in, and three on the very decurrent hind margin, the third being just behind the 

 rather blunt apex ; the fourth joint shorter than the fifth, with spines at three points in 

 front ; the fifth joint a little shorter than the third, with spines at four points of the 

 straight front margin, and two setules or cilia on the slightly convex hind margin ; the 

 finger as in the preceding pair of limbs. 



Fourth Perseopods. — These difi'er very slightly indeed from the third ; they are rather 

 larger, and the fourth joint has spines at four points of the front margin. 



Fifth Perwopods. — These are very similar to the two preceding pairs, but the first 

 joint is considerably larger, the front margin nearly straight, the hind margin very convex ; 

 the remaining joints are not longer than those that correspond in the fourth pair ; the 

 fourth joint has spines at three points in front. 



Pleopods. — The coupling spines, so far as could be made out, are filiform, witb back- 

 ward serratures at the upper part ; there is but one cleft spine ; the joints of the inner 

 ramus are four, of the outer five, in number. 



Uropods. — The peduncles of the first pair are shorter than those of the second, 

 shorter than the rami, with one or two spinules on the outer, and an apical -spinule on 

 the inner, margin ; the rami are slender, tapering, without spines, the inner longer than 

 the outer, tipped with a minute nail ; the peduncles of the second pair longer than those 

 of the first or third, a little shorter than the rami, which are subequal, curved at the tips, 

 with a small spine at about the centre, the inner ramus a little longer than the outer ; 

 the peduncles of the third pair are shorter than the broad, lanceolate, single ramus, which 

 reaches back not quite so far as the rami of the second pair, has strongly pectinate edges, 

 one or two setules on the surface, and a broad apical nail accompanied by a cilium. 



The Telson triangular, much longer than broad, the sides slightly convex, the smooth- 

 ness of each a little interrupted at the point where a submargiual cilium is inserted not 

 far from the rounded point of the apex, the margin here being almost imperceptibly 

 serrate. 



Length. — The specimen, in the position figured, measured, in a straight line from the 

 front of the head to the apex of the second uropods, three-twentieths of an inch. 



Locality. — Station 313, off Cape Virgins, Patagonia, January 20, 1876; lat. 52° 20' 

 S., long. 67° 39' W.; depth, 55 fathoms; bottom, sand; bottom temperature, 47°"8. 

 One specimen, female. 



