352 Rhachotropis 



Body rather slender, peraeon segments 1 — 3 dorsally a little raised 

 bebiüd, segmeut 7 produced to a very small dorsal tooth, pleon segments 1 — 3 

 tricarinate, carinae ending in teeth, the central ou segment 3 much sraaller 

 and more obtuse than the preceding. segment 4 with dorsal tooth, lateral 

 ridges not produced. Head, rosti'ura short, lateral corners narrow üiangular. 

 Side-plate 1 linguiform. lower margiu sti'aight, corners not acute, 4*^ slightly 

 emargiuate, 5*^ and 6*^ without lateral ridge. Pleon segment 3, postero- 

 lateral margius firmly serrate. Eyes rather large, rounded oval, light brown. 

 Autenna 1 in 9 not very long, 1^* Joint not as long as 2^ and 3'^ combined, 

 3^ about balf as long as 2*^, both calceoliferous, flagellum subequal to peduncle, 

 12^1o-jointed, calceoliferous; accessory flagellum 2-jointed. Antenna 2 in Q a 

 little longer, ultimate and penultimate joints of peduncle subequal, fringed above 

 with calceoli, together as long as flagellum of about 14 joints. Antenna 1 

 in ö more than twice as long as in , flagellum at base carrying fascicles 

 of sensory filaments. Antenna 2 in d rather longer, flagellum nearly twice as 

 long as peduncle. Gnathopod 1 rather strong, somewhat smaller than other- 

 wise similar gnathopod 2, 6*^ Joint oblong oval, about twice as long as 

 broad, elongate palm defined by very slight spiniferous angle. Peraeopods 1 — 5 

 more slender and with more elongate fingers than in R. aculeata (p. 348); 

 peraeopods 3 — 5 rapidly encreasing in length. 2"^ Joint simple, oblong oval, a 

 little narrowed below, 6^'^ Joint very long in peraeopod 0, wliich is about 

 '^/^ as long as the body. üropods 1 — 3, outer ramus not much shorter than 

 inner, in uropod 3 both rami subfoliaceous, abruptly tapering to the apex, 

 marginal spinules few. Telson unarmed, not sti'ougly tapering tili near the 

 acute contiguous apices, cleft nearly to the middle. Colour semipellucid, 

 whitish, blotched with light red. L. o 12, d 10 mm. 



Arctic Ocean, North-Atlantic, Noith-Sea and Skagerrak (South- and West-Norway). 

 Depth 94—188 m. Other localities doubtful. 



8. B. macropus U. Sars ?1874 Aniphithonotus aculeatus (pari.), Buchholz in: 

 Zweite D. Nordpolarf., v.2 p. 31(5 | 1882 Tritropis hdleri (err., non A. Boeck 1871!), 

 Hoek in: Niederl. Arch. Zool., suppl. 1 nr. 7 p. 58 j 1894 Rhachotropis h., T. Stebbing 

 in: Bijdr. Dierk.. v. 17 p. 37 j 1893 R. macropus, G. O. Sars, tl/'rust. Norwav, v. L p. 428 

 t. 151 f. 1. 



Very like K. helleri (p. 351), but peraeon segments not dorsally raised; 

 segment 7 produced to very small tooth, pleon segments 1 — 3 tricarinate, carinae 

 ending in teeth, central of segment 3 like the preceding, segment 4 with 

 dorsal tooth, lateral ridges not produced. Pleon segment 3, postero-lateral 

 margins strongly serrate, serratiou turning the corner. Eyes large, rounded, 

 dark brown with whitish coating. Antenna 1 in 9 moderately long, 1^* Joint 

 as long as 2^, S^ more than half as long as 2^, both densely calceoliferous, 

 flagellum scarcely as long as peduncle; accessory flagellum 2-jointed. Antenna 2 

 subequal, ultimate Joint of peduncle longer than penultimate, flagellum not 

 nearly equal the 2 joints combined. Peraeopods 1 — 5 much more elongated and 

 slender, peraeopod 5 longer than the whole body. üropods 1 — 3 and telson 

 not notably differing from those of R. helleri, but telson large, extending 

 beyond uropod 3, cleft to the centre, apices only subacute. Colour whitish, 

 blotched with reddish orange, patches generally less confluent than in E. helleri. 

 L. 9 16 mm. 



Arctic Ocean, North- Atlantic, North-Sea and Skagerrak (Norway, depth 188 — 752 m ; 

 Barents Sea; Kara Sea; Spitzbergen.) 



