1568 THE VOYAGE OF H.M.S. CHALLENGER. 



Paralycsea gracilis, Claus. 



1879. Paralycsea gracilis, Claus, Die Gattungen und Arten der Platysceliden, p. 40. 



1887. ,, „ (?) Bovallius, Systematical List of Amph. Hyper., Bihang. till K. 



Svensk. Vetensk.-Akad. Haudl., Bd. 11, No. 16, p. 33. 

 1887. „ „ Claus, Die Platysceliden, p. 64, Taf. xx. fig. 1-11. 



Head obliquely oval, mouth-organs much produced below it ; peraeon much shorter 

 than pleon, each of the first three segments much shorter than any one of the last four ; 

 first three segments of the pleon together much longer than the remainder of the pleon ; 

 scale-markings of the integument conspicuous. 



Eyes covering most of the head, showing no external trace of the division of each 

 eye into two groups of ocelli. 



Upper Antennas in the female very small ; the peduncle seemingly short, one-jointed, 

 the flagellum two-jointed, its first joint much longer than the peduncle, bent at the base, 

 and having a group of three or four broad filaments almost at the apex, the second joint 

 quite small, but longer than broad, tipped with long filaments. 



Lower Antennas not present in the female. 



First Gnathopods. — Side-plates with convex front margin. The first joint much 

 bent, concave in front, with a little hair or setule here and there ; second joint longer 

 than broad, the hind margin convex ; the third joint longer than the second, broader 

 than the fourth, the hind margin convex ; the fourth joint perhaps slightly longer than 

 the third, the distal margin projecting a little obliquely beyond the fifth joint or hand ; 

 the hand narrower than the wrist and a very little longer, the front margin convex, the 

 hinder straight, with a minute setule below the centre ; the finger curved, slender, rather 

 more than half the length of the hand, squarely widened at the base, the hind margin 

 then regularly concave except for a small interruption where a minute setule emerges 

 high up on the margin. 



Second Gnathopods like the first, but all the joints rather larger, except the finger. 

 Branchial vesicles oval, simple, broader than the first joint, not longer. The concave 

 front margin of the first joint seems to be without setules, the third and fourth joints 

 are equal in length, and each of them little longer than the second, and little shorter 

 than the fifth. 



First Perasopods not very different in appearance to the gnathopods, but considerably 

 larger. The side-plates convex in front, the lower hind corner produced a little back- 

 wards. The first joint wider than in the gnathopods and less concave in front ; the third 

 joint much larger than the second, widened distally, with convex front margin ; the 

 fourth joint longer than the third, wider than the fifth and nearly as long, with a slight 

 narrowing near the apex ; the fifth joint slender, slightly curved, with a few little setules 

 along the hind margin and one at the apex of the convex front ; the finger not half the 



