185 



Tail with the genital segment in female scarcely subdivided. Caudal rami 

 sub-lamellar, with 2 successive setae on the outer edge and 3 on the tip. An- 

 terior antennae composed in female of 7 joints, the first 2 of which are much 

 larger than the others and clothed with numerous strong setae; outer joints in 

 male coalesced. Posterior antennae much elongated and distinctly prehensile, 

 being armed at the tip with a short uncinate claw. Anterior lip deeply incised 

 in the middle. Maxillae with a slender appendicular masticatory lappet inside 

 the principal one; the latter securiform in shape and rather expanded at the 

 base, its outer edge coarsely serrated and divided proximally into 2 unequal 

 lobules, one of which is distinctly denticulaled; palp unusually large and in- 

 curved, resembling in structure that in the Clausidiidce. Anterior maxillipeds 

 with the basal part very large and massive, terminal part produced into a 

 straight digitiform process denticulated at the tip, and having inside a densely 

 spinulose seta. Posterior maxillipeds, as usual, very different in the 2 sexes, 

 in female conically tapered, with the dactylar joint small and tipped by a short 

 uncinate claw, in male very large and distinctly prehensile, dactylus long and 

 slender. Natatory legs strongly built, with both rami 3-articulate in all the 

 pairs. Last pair of legs biarticulate, proximal joint small and less perfectly 

 separated from the segment, distal joint comparatively large, foliaceous, and 

 extending laterally, being armed in a similar manner to that in the preceding 

 genus. 



Remarks. This is a very distinct genus, exhibiting several aberrant 

 characters, some of which seem to point to the Clausidiidce. According to 

 the prehensile nature of the posterior antennae and the structure of the masti- 

 catory part of the maxillae, it ought however unquestionably to be included 

 in the present family. One of the most perplexing peculiarities is perhaps the 

 remarkable mobile rostral lamella, from which indeed the generic name here 

 proposed has been derived. The genus comprises as yet only a single species, 

 to be described below. 



101. Rhinomolgus anomalus, G. O. Sars, n. sp. 

 (PI. CV & CVI). 



Specific Characters. -Female. Body not particularly slender, with the 

 anterior division oval fusiform in outline, greatest width about equalling 2 /s of 

 the length and occurring a little in front of the middle. Cephalic segment 

 large, and exhibiting behind a rather slight transverse suture defining the 

 cephalon from the 1st pedigerous segment; front narrowly rounded, Rostral. 



