Aceroides. ßathymedon 255 



Head with small but distinct rostrum. Side-plates not deep, 1^* not 

 expanded. Eyes absent. Antenna 1 in 9 longer than antenna 2, peduncle rather 

 Short, flagellum much longer. Upper lip broad, with margin scarcely insinuate. 

 Lower lip with inner lobes separate. Mandible less sti-ong than in Arrhis (p. 248), 

 palp sti-aight. Maxillae 1 and 2, maxillipeds and gnathopods 1 and 2 as in that 

 genus. Peraeopods 1 and 2 (Fig. 63) large, 4*^^ to T^'i joints much expanded. 

 Peraeopods 3 and 4 much smaller, 2*^ Joint little expanded, finger slender. 

 Peraeopod 5 characteristic of the family. Uropods 1 — 3 and telson normal. 



1 species. 



1. A. latipes (0. Sars) 1866 Oediceros obtusus var., Goes in: Öfv. Ak. Eörh., 

 V. 22 p. 527, 536 t. 40 f. 24, 24' 1 1882 Halicreion latipes, G. O. Sars in : Forh. Selsk. 

 Christian., nr. 18 p. 97 t. 4 f. 10 j 1883 HJl, J.S.Schneider in: Tromse Mus. Aarsh., 

 V.6 p. 43 I 1892 & 93 Aceropsis l, Aceroides l, G. 0. Sars, Crust. Norway, v.l 1. 120 

 f. 2; p.341 1 1887 Aceros distinguendus, H. ,1. Hansen in: Vid. JVIeddel., ser.4 v.9 p.ll8 

 t.4 f. 8 I 1893 Halimedond., A. DellaValle in: F, Fl. Xeapel, t;.20 p. 916. 



Neither very slender uor in front very tumid. Kostrum very small, 

 acute. Side-plate 1 obliquely quadrate, 3*^ slightly emarginate below, subequal 

 to 4*^ öth—yth broad. Antenna 1 in 9 , 1«* Joint 

 as long as 2*^ and 3'^ combined, flagellum nearly twice 

 as long as peduncle, with 12 joints, each with 2 long 

 setae. Antenna 2 in 9 much shorter, ultimate Joint 

 of peduncle shorter than penultimate, flagellum as 

 long as the 2 combined. Gnathopod 1, 5^^ Joint 

 shorter than 6*^, process rather large, pointed obli- 

 quely forward, 6^^ Joint oblong oval widening to 

 oblique palm, which is longer than bind margin. 



Gnathopod 2, o^^ Joint with very narrow process, :^^^^^~^ *"' ^^^^^ 



6*'^ elongate, palm shorter than bind margin. Peraeo- 

 pods 1 and 2 (Fig. 63) very large and powerful, 



4*^ Joint much expanded distally, a curved ridge ^^^ 



on the outside fringed with long setae, 5^^ Joint "''^MumSS^ ~ ''''' ioi"*^ 



Short, heart shaped, setose, 6**^ expanded distally, 



finger large, foliaceous. Peraeopods 3 and 4 much Fig. es. a. latipes. 



more feebly constructed, subequal to one another, [After^G°o! sais.] 



2^ Joint not oval, finger slender. Peraeopod 5, 



2^ Joint large, oval, 5*'' much shorter than 4*^ or 6*^. üropod 3, rami 



with a few spinules, narrowly lanceolate, longer than peduncle. Telson 



nearly Square. L. 9 (young?) 5 mm. 



Arctic Ocean (Spitzbergen; Kara Sea; Greenland; Varangerfjord [Norwav], 

 depth 144—188 ui). 



15. Gen. Bathymedon 0. Sars 



1871 Halimedon (part.), A. Boeck in: Forh. Selsk, Christian., 1870 p. 169 | 1892 

 Bathymedon, G. 0. Sars, Crust. Norway, v. 1 p. 332. 



Near to Westwoodilla (p. 249). Front of head produced to a short 

 rostrum, lateral angles deep, quadrate. Side-plates not very large, sparingly 

 setose. Eyes poorly developed or wantiug. Mandible powerful, 2^ Joint 

 of palp only a little or not arcuate. Maxillipeds, outer plates rather large, 

 though sometimes not reaching apex of 2*^ Joint of palp. Gnathopods 1 and 2, 

 5*^ Joint usually long, with or without distal process, 6*^1 Joint usually oval, 

 not very large, palm oblique. Gnathopod 2 longer and more slender than 

 gnathopod 1. Other characters nearly as in Westwoodilla (p. 249). 



4 species. 



