287 



lamellae simple and rather large; incubatory laraellte well developed, and 

 fringed with slender setae. Uropoda subequal in structure, rami lanceolate. 

 Telson small, squamiform, entire. 



BeniayJiS. — This is a well defined and rather extensive family, 

 comprising, as it does, several genera, some of which, as the genus Monn- 

 ctdodes, is very rich in species. In some points the forms under question 

 somewhat remind one of tlie Pontoporeiidm and Phoxocephalidce, having a simi- 

 lar ability for concealing themselves in the loose bottom material, and the 

 pereiopoda, with the exception of the last pair, are constructed in accordance 

 therewith, being generally ratlier stout, with the joints more or less 

 expanded and densely setous. From both these families, however, as also 

 from most other Amphipoda, the forms here treated of may be easily recog- 

 nized by several well-marked characteri.stics. Thus the eyes, when distinctly 

 developed, exhibit a very peculiar appearance, both as to place and structure, 

 being, as a rule, put so close together as to appear as a single organ, which 

 is situated quite dorsally at the end of the more or less projecting frontal 

 part of the cephalon. Another easily reognizable characteristic is the great 

 length of the last pair of pereiopoda, which, moreover, are very unlike the 

 preceding pairs, and are constructed much upon the same type as the penultimate 

 pair in the Phoxocephcdido'. In an admirable memoir inserted in the «Troms0 

 Museums Aarshefter» VI, Mr. Schneider has treated of tlie northern forms 

 belonging to this family, giving good descriptions of most of them, as also 

 some characteristic detail figures, chiefly referring to the form of the cephalon. 

 He enumerates in all 27 species, and has subsequently added another new 

 species {Monoeulodes tessellatus). The species were referred, according to the 

 arrangement of Boeck, to 7 different genera. In the following pages will be 

 described no less than 12 genera represented in the fauna of Norway. Of 

 these 6 ax'e now for the first time established. In addition an exclusively ai'ctic 

 genus, Acanthosteplicia, has been instituted b}^ Boeck, and another genus was 

 mox'e recently described by the Rev. Mr. Stebbing from the Challenger Expe- 

 dition under the name of Ocdiceroides. 



Gen. 1. CEdicerOS, Kroyer, 1842. 



Body rather robixst, with broadly vaulted back, and the segments 

 sharply defined. Cephalon produced in front to a sharp rostrum curving 

 downwards. Coxal plates comparatively broad and rounded at the edges, 4tli 

 pair rather large, bilobed, nearly as deep as the 3rd. Eyes distinct, contig- 



