Onisimus 27 



Body unusiially turaid. Head, lateral angles acute. Side-plate 1 little 

 expanded below, 4*^^ fonaing an almost rectangular corner below the hinder 

 eraargination. Pleon segraent 3, postero-lateral angles acutely uncinate. 

 Eyes oval, the broad eud below, rieh vermilion in life. Antenna 1, peduucle 

 tumid, flagelliim with lOjoints, 1^* very large, accessory flagellum with 4joints, 

 1^* large. Antenna 2. flagellum 7-jointed. Gnathopod 1 ratherstout, 6^^' Joint very 

 little louger than 5*^, palra rather oblique. Gnathopod 2, 6*^^ Joint (as figured) 

 much more than half as long as 5*^ with a very small excavate palm. 

 Peraeopods 3—5, 2^ Joint large, bind raargin distinctly serrate, 4*^ Joint 

 only moderately broad. üropod 3 without spiuules. Telson short and broad, 

 incised ^5 of the length, apices broad. Colour whitish, faintly tinged with 

 red. L. reaching 15 mm. 



Arctic Ocean (midway between Jan Mayen and Finmark). Depth 3220 — 3310 m. 



5. O. brevicaudatus H. J. Hansen 1886 0. b., H. J. Hansen in: Dijmphna 

 Udb., p.216 t.21 f.7 -7e ! 1894 0. b. (part.), T. Stebbing in: Bijdr. Dierk., u 17 j). 12 j 

 1893 Pseudaiibrotus littoralis (err., non Anonyxl. Kreyer 1845!) (part."), A. Della Valle 

 in : F. Fl. Neapel, v. 20 p. 799. 



Head, lateral angles narrowly rounded. Side-plate 1 somewhat expanded 

 below, 4'^'' with a rather small expansion. Pleon segment 3, postero-lateral 

 angles acutely upturned. Eyes on the projecting lobes of the head, narrowed 

 above, almost triangulär, not approaching summit of head. Antenna 1. flagellum 

 in 9 with 11 joints, in d with 17, 1^* large, accessory flagellum with 5 joints, 

 l^*long. Antenna 2. flagellum in Q 15-, in d 24-jointed. Both autennae have 

 calceoli in d. Gnathopod 1, 6^'* Joint longer than 5*^ palm oblique, fiuger pro- 

 jecting a little beyond it. Gnathopod 2, 6"' Joint in d with margins subparallel, 

 hinder longer than front, finger fixed in middle of apical margin and closing 

 down on oblique palm; in Q with margins diverging distally, hinder shorter 

 than front, finger fixed near front angle and when closed leaving a gap between 

 its concave raargin and the excavate palra. Peraeopods 3—5, 4*^ Joint 

 moderately broad. üropod 3 with spinules on the rami. Telson with breadth 

 and length subequal, distal margin straight or faintly rounded or faintly 

 emarginate, L. Q 16"5, d 15-5 mm. 



Kara Sea (lat. 71» 13'N.). Depth llOui. 



6. O. caricus H. J. Hansen 1886 0. c, H. J. Hansen in: Dijmphna Hdb., 

 p. 214 t. 21 f. 6 1 1894 O.e., T. Stebbing in: Bijdr. Dierk., r 17 p. 11 | 1893 Amnyx 

 edwardsü (part.), A. Della Valle in: F. Fl. Neapel, ».20 p. 828. 



Head, lateral angles slightly projecting, broadly rounded. Side-plate 1 

 considerably expanded below, 4*^^ with hinder expansion rather short, obtusely 

 truncated. Pleon segment 3, postero-lateral angles produced upwards into a 

 Short blunt point. Eyes on the projecting lobes of the head, narrowed above, 

 almosi triangulär, not approaching summit of head." Antenna 1, flagellum 

 in Q with 16 joints, 1^* equal to 2 or 3 next combined, accessory flagellum 

 4-jointed; flagellum in d with 30 joints, 1^* Joint equal to 4 or 5 next combined, 

 accessory flagellum with 5 joints, 1^* elongate. Antenna 2, flagellum in o 20-, in 

 d 37-jointed. Maxillipeds with 3 spines on apical margin of outer plates, where 

 other species appear to have only one. Gnathopod 1, 6*^ Joint longer than 

 5^\ palm oblique, spinules fringing it and part of the bind margin. Gnatho- 

 pod 2, 6*'i Joint in both sexes rather more than half as long as 6^\ sub- 

 triangular, expanding distally, front margin rather the longer, finger stout, 

 leaving an interval between its concave margin and the excavate palm. 



