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



cliial vesicles a little smaller than in the preceding pair. The first joint larger than in 

 the third perseopods, but similar in shape ; the second and third also similar, the third 

 rather larger ; the rest of the limb missing. 



Fifth Perseopods. — Side-plates broader than deep. Branchial vesicles smaller than 

 the side-plates. First joint larger than in the preceding pair, much broader above than 

 below ; the third joint similar in shape and armature, but larger than there ; the fourth 

 joint like that of the third perseopods, but longer, with four groups of spines in front 

 and three behind ; the fifth joint in like manner with six groups in front and four 

 behind, in addition to the apical group of cilia ; the finger rather more than half the 

 length of the fifth joint. 



Pleopods. — There is a group of four spines near the distal end of the peduncles (at 

 any rate in the third pair), one of which is very long and strong ; there are others less 

 conspicuous in other parts ; the coupling spines are very small, their teeth small and 

 seemingly not much retroverted ; the cleft spines are three in number ; the joints of the 

 rami numbering from eleven to thirteen. 



Vropods. — Peduncles of the first pair long, with many small spines on the edges ; 

 the rami broken, their basal portions narrow, suggesting that they would be in total 

 length shorter than the peduncles ; peduncles of the second pair longer than the outer 

 ramus, with two large spines on one margin, and one spine at the apex of the other 

 margin ; the outer ramus with pectinate edges, four spines along one margin, and an 

 apical group of three spines, the inner ramus broader and longer, the end broken ; 

 peduncles of the third pair shorter than the one remaining ramus, which is lanceolate, 

 with pectinate edges, and has three spines along one margin, and four along the 

 other. 



Telson not longer than the peduncles of the third uropods, longer than the breadth 

 at the base, narrowing a little distally, cleft for about two-thirds of its length, a little 

 dehiscent between the two acute apices, from which the distal margin slopes upward, 

 having on each side two serrations in each of which there is a small cilium. 



Length.- — The specimen, in the position figured, from the front of the head to the 

 back of the third pleon-segment, measured one-fifth of an inch. 



Locality. — Station 313, off Cape Virgins, Patagonia, January 20, 1876 ; depth, 55 

 fathoms ; bottom, sand ; bottom temperature, 47 0, 8. Two specimens. Trawled. 



Remarks. — The specimen examined and described was a female. The specific name 

 refers to the place of capture. From Lphimedia capensis, Dana, renamed Atylus 

 capensis by Spence Bate, which was taken at the Cape of Good Hope, the present 

 species differs in having longer wrists, and the distal margin of the telson with fewer 

 serrations. There are many points in which the imperfect state of the Challenger speci- 

 mens on the one hand, and the brevity of Dana's description on the other, prevents 



