171 



Occurrence. Only 2 specimens, male and female, of this form have hitherto 

 come under my notice. They were taken at the same time in the upper part of 

 the Christiania Fjord from a depth of 30 40 fathoms, muddy bottom. 1 ) 



ill. Amphiascus attenuates, G. 0. Sars, n. sp. 



(PL CXII). 



Specific Characters. Female. Body moderately robust and very conspi- 

 cuously attenuated behind, exhibiting in the dorsal view of the animal a somewhat 

 clavate form. Cephalic segment very large and broad, evenly rounded in front; 

 rostrum rather broad, triangular. Urosome much narrower than^the anterior 

 division and evenly tapering behind, last segment about the length of the pre- 

 ceding one. Caudal rami quadrangular in form, being a little broader than they 

 are long, the 2 middle apical setse, but especially the inner one peculiarly ex- 

 panded near the base. Anterior antennse rather slender and composed of 9 well- 

 defined joints, the first 4, composing the proximal part, being nearly equal in 

 length, terminal part comparatively short, scarcely exceeding 1 / 3 of the proximal 

 one. Posterior antennse likewise of rather slender form, outer ramus very small 

 and composed of only 2, not very distinctly defined joints. Oral parts, on the 

 whole, normal. 1st pair of legs differing somewhat in structure from those in the 

 other species, outer ramus much shorter than the 1st joint of the inner, its 

 largest joint being the middle one, with a comparatively short seta at the end 

 inside, last joint rather small and armed with 3 spines and 2 geniculated setse; 

 1st joint of inner ramus very slender, linear, being about 3 times as long as the 

 other 2 combined, last joint not much longer than the 2nd and slightly expanded 

 distally, carrying on the tip 2 strong claws and a small hair-like bristle inside 

 them. Natatory legs rather strongly developed, with the full number of setse. 

 Last pair of legs with the distal joint oval in form, and carrying 6 comparatively 

 short marginal setse; inner expansion of proximal joint rather broad, extending 

 to about the middle of the distal joint, marginal setaB 5 in number, spiniform, 

 the outermost one very small. Ovisacs of moderate size. 



Colour whitish, with rosy ovaries, and the ovisacs generally of a dark 

 purple hue. 



Length of adult female 0.87 mm. 



Remarks. This form differs in some respects rather conspicuously from 

 the other species, especially as regards the structure of the two pairs of antenna) 



l ) Found occasionally this summer at Farsund, soiith coast of Norway. 



