27 



and extending beyond the genital segment; appendicular bristle attached close 

 to the base of the joint and accompanied by a transverse row of smal spinules. 



Colour of preserved specimens dark corneous. 



Length of adult female 0.78 mm. 



Remarks. This is a well defined and easily recognisable species, being 

 especially distinguished by the comparatively robust, sub-clavate form of the 

 body, as also by the structure of the caudal rami and of the last pair of legs. 



Occurrence. Some few specimens of this form, all of the female sex, 

 were picked up from samples taken at Ris0r from a depth of about 30 fathoms, 

 muddy sand. A solitary specimen was also obtained at Korshavn from about 

 the same depth. 



18. Ectinosoma compressum, G. O. Sars, n. sp. 

 (PI. XVII, lig. 1). 



Specific Characters. Female. Body rather slender and conspicuously 

 compressed, exhibiting in the dorsal aspect of the animal a very narrow, almost 

 linear form. Cephalic segment scarcely exceeding in length the exposed part 

 of the trunk, and conspicuously contracted in front; rostral plate somewhat 

 prominent and, seen from above, narrowly truncated at the end. Urosome 

 scarcely exceeding in length the exposed part of the trunk and somewhat 

 tapered behind, being covered on the ventral face with small spikes; genital 

 segment fully as long as the 2 succeeding segments combined; anal segment 

 small and deeply incised behind in the middle. Caudal rami quite short, 

 being scarcely longer than they are broad, and somewhat divergent; apical 

 seta? rather elongated. Anterior antennae comparatively slender and attenuated, 

 being composed of 6 well-defined joints. Anterior maxillipeds rather power- 

 fully developed, though somewhat less so than in E. tenerum. Natatory legs 

 with the rami comparatively slender, the outer one in 1st pair extending a 

 little beyond the middle joint of the inner. Last pair of legs closely contiguous 

 in the middle, with the proximal joint rather large and lamellar; distal joint 

 broadly rounded in form, with the 2 outer marginal setae very long and slender, 

 the innermost one much shorter; appendicular bristle attached to a small digiti- 

 form process issuing from the edge between the 2 outermost setae; inner 

 expansion of proximal joint rather narrow, and extending considerably beyond 

 the middle of the distal joint, its apical setae very unequal, the inner one much 

 elongated, the outer scarcely Vs as long. 



Colour of the living animal not yet ascertained. 



