297 



with the hand oblong in form, dactylus slender and finely ciliated inside. 1st 

 pair of legs with the terminal joint of outer ramus about as large as the middle 

 one, and armed with 2 spines and 2 somewhat unequal setse; inner ramus scarcely 

 longer than the 1st joint of the outer, and consisting of only a single joint car- 

 rying 3 comparatively short apical setse and a minute lateral bristle. Inner ramus 

 of 2nd pair of a structure similar to that of 1st pair; that of the 2 succeeding 

 pairs extremely small and rudimentary, knob-like, with a very long ciliated seta 

 accompanied by a small bristle. Last pair of legs with the distal joint long and 

 narrow, linear in form, and carrying 4 moderately long setse, 2 apical and 2 

 lateral ; inner expansion of proximal joint somewhat produced, though not extending 

 to the middle of the distal joint, and provided at the narrowly truncated end 

 with 2 subequal ciliated setse. 



Colour dark grey. 



Length of adult female 0.95 mm. 



Remarks. This form is of considerably larger size than any of the other 

 species, and is moreover easily recognised by its more slender, almost linear body 

 and the short caudal rami. It also differs rather conspicuously in some of the 

 structural details, especially as regards the imperfect development of the inner 

 ranii of the natatory legs. 



Occurrence. I have only met with this form in a single locality, viz., at 

 Hval0r, outside the Christiania Fjord. It occurred here not unfrequently in a 

 depth of about 6 fathoms, on a muddy bottom covered with decaying algae. 



Gen. 62. EnhydrOSOma, Boeck, 1872 (not Brady). 



Generic Characters. Body somewhat resembling in shape that in the 

 species of Cletodes, being more or less slender and attenuated behind, with the 

 segments sharply marked off from each other, and connected in such a manner 

 that the body is capable of rolling up into an almost perfect ball by a strong 

 ventral flexure. Integuments very coarse. Cephalic segment comparatively large, 

 with a short somewhat deflexed rostral projection. Caudal rami of different 

 shape in the different species. Eye distinct, though of small size. Anterior an- 

 tennae (in female) composed of only 5 joints clothed with partly ciliated setae, 2 

 of the joints belonging to the terminal part; those of male very strongly hinged. 

 Posterior antennae well developed, with a small, but distinctly defined outer ramus 



