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



Second Perwopods. — Side-plates broad, front and hind margins straight, almost 

 jDarallel, the excavation behind not carried far down ; the joints of the limb as in the 

 preceding pair. 



Third Perwopods. — Side-plates broader than the first joint, the hinder lobe produced 

 below the front one ; first joint irregularly rounded, the front margin being almost 

 straio-ht, with one spine at the lower apex, the rounded lower margin overlapping the 

 second joint, which also has a spine at the apex in front; the third joint broad, decurrent, 

 with spines at two points on each margin ; the fourth joint shorter than third or fifth, 

 with sjjines at the apex ; fifth joint longer than third, with spines at tw^o points in front, 

 cilia behind ; finger curved, more than half the length of the fifth joint. 



Fourth Peraeopods. — Side-plates not bilobed. First joint broader than side-plate, 

 uith two spines in front, a little serration on the hind margin ; the limb resembles in 

 general character that of the preceding segment, but with the various joints rather larger. 



Fifth Perwopods. — Side-plate consisting of a single lobe, rounded behind and below, 

 narrowed in front ; first joint broader and longer than in the preceding pair, the rest 

 of the limb similar but smaller, the third joint being smaller than the third in the third 

 perseopods, while the remaining joints are rather longer than in that pair. 



Pleopods. — In all the pairs two coupling spines with two retroverted hooks, a single 

 cleft spine on the long first joint of the inner ramus, the inner ramus three-jointed, the 

 outer five-jointed. 



Uropods. — Peduncles of the first pair but little longer than the rami ; lower ramus a 

 little longer than the upper, each with a spine at some distance from the acute, little- 

 curved apex ; peduncles of the second pair shorter than the rami ; lower ramus with a 

 nail, longer than the upper, each with a spine at some distance from the apex, that on 

 the longer ramus marking the point at which the ramus is abruptly narrowed, a feature 

 belonging, I think, to all the species of this genus ; peduncles of the third pair shorter 

 than the rami, lower ramus longer than the upper, with a nail, both finely pectinate on 

 the edges. 



Telson projecting beyond the peduncles of the third uropods, cleft a little beyond the 

 centre, carrying a couple of cilia inserted a little aliove each apex, and a couple also on 

 each side below the level of the top of the cleft. 



Length of the specimen, from the front of the head to the end of the third pleon- 

 segment, in the position figured, about one-fifth 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. One specimen. Trawled. 



Remarks. — Between this specimen and the much lai-ger adult female from Australia, 

 for which I am indebted to the kindness of Mr. Haswell, the chief differences are in the 

 eyes and antennte. The eyes in the Australian specimen accord with Mr. Haswell's 



