12 CRUSTACEA MALACOSTRACA. II. 



lateral margins of the four posterior segments show considerable difference from A.spinosus, as in 

 A. mcinus the anterior lateral process of each of these segments is much broader at the base, and this 

 proximal part has a short, triangular protuberance both in front of and behind the main part of the 

 process; furthermore the angle in front of the basal joint of each leg is produced into a small, acute 

 protuberance. The ventral surface of the segments with acute processes as in A. spinosus. Second 

 pair of legs (fig. i c) with a strong spine both from the anterior (upper) and the lower (posterior) angle 

 of fourth joint, with a spine from the upper angle and two spines on the lower margin of fifth joint, 

 while the sixth joint has two spines on the upper and five on the lower margin; fifth joint as long 

 as the sixth and a little shorter than the fourth, while in A. spinosus the fifth joint is considerably 

 shorter in proportion to the fourth. 



Abdomen scarcely as long as the sum of the three posterior thoracic segments plus half of 

 the fourth. The lateral processes of the five anterior segments somewhat long but distinctly shorter 

 than in A. spinosus, the short terminal part of each process is suddenly slender. Sixth segment as 

 long as the three preceding segments and half of the second segment combined, a little more than 

 two and a half times as long as broad at the middle; the major anterior part of each lateral margin 

 with six very feeble protuberances, each bearing a conspicuous seta. (Uropods lost excepting their 

 basal joint.) 



Length of the single immature female 6.3 mm. 



Remarks. Among the characters enumerated in the description the shape of the eye-lobes, 

 the processes on the lateral margins of the four posterior thoracic segments and the relative length 

 of some of the joints in the chelipeds and second pair of legs are most easily observed. 



Occurrence. Only taken by the "Thor" at the following locality. 



South of Iceland: Lat. 62 57' N., Long. 19 58' W., 505 fm.; i spec. 



3. Apseudes tenuis n. sp. 

 (PI. I, figs. 2 a 2e). 



Subadxilt Female. The eye-lobes are strongly produced and acute (fig. 2a), almost as much 

 as in A. mcitms. The lateral process of the head shaped nearly as the eye-lobe; the lateral margin 

 behind the last-named process considerably convex. The upper surface of the carapace with the trans- 

 verse furrow very distinct, long. 



The antennulse more slender than in the preceding species; first peduncular joint more than 

 four times as long as the second and with the proximal half of the inner margin distinctly serrate; 

 the inner flagellum lo-jointed, more than two-thirds as long as the outer which is i3-jointed. - An- 

 tennae (fig. 2 a) with the flagellum g-jointed and the squama not reaching the end of the penultimate 

 joint of the flagellar peduncle. 



Chelipeds (fig. 2c) considerably more slender than in A. vicinus but conspicuously stronger than 

 in the two following species. Basal joint on the posterior margin with some minute spiniform setae 

 on the proximal part and somewhat before its end a very protruding angle bearing a strong spine, 

 while the anterior margin is furnished with some setfle; the ischium has two spines near the end of 

 the lower margin; the carpus slender with the lower margin unarmed and more than half as long 



