388 



of proximal joint extending beyond the distal joint, and carrying only 4 com- 

 paratively short spiniform setae. 



Colour not yet ascertained. 



Length of adult female 0.44 mm. 



Remarks. This is a very small form and in some respects differs con- 

 siderably from the other known species. It may at once be recognised from 

 any of them by the anomalous structure of the caudal setse, especially that of 

 the outer medial one. The structure of the anterior antennae also is rather 

 peculiar, and the 1st and last pair of legs likewise differ somewhat in shape 

 from that usually met with. 



Occurrence. 2 female specimens of this peculiar form were found in a 

 sample taken last summer at Korshavn from a depth of 20 30 fathoms, sandy 

 bottom. 



Amphiaseus spinulosus, G. 0. Sars, n. sp. 



(Suppl. PI. 22). 



Specific Characters. Female. Body comparatively shorter and stouter 

 than in the preceding species and somewhat tapering behind. Rostrum of usual 

 shape, conically produced. Urosome considerably shorter than the anterior division, 

 and having the segments well marked off from each other, the anterior ones exhibit- 

 ing each laterally 2 oblique rows of spinules somewhat remote from the hind edge, 

 last segment shorter than the preceding one. Caudal rami comparatively small, 

 apical setae of moderate length and normal structure. Anterior antennae not 

 much elongated, but rather slender, 8-articulate, the first 2 joints of about equal 

 size, 4th joint considerably longer than 3rd, terminal part about the length of 

 those joints combined. Posterior antenna? with the outer ramus normally developed. 

 1st pair of legs with the outer ramus shorter than the 1st joint of the inner, 

 middle joint without any seta inside, last joint of about same size and, as in 

 the 2 preceding species, armed with 2 spines and 2 geniculate setae; inner ramus 

 with the 1st joint long and slender carrying near the end inside the usual seta, 

 last joint scarcely twice as long as the middle one and armed on the tip with 

 a claw-like spine, a thickish seta and a small bristle; both joints combined not 

 attaining half the length of the 1st. Natatory legs with the rami less narrow 

 than in the preceding species; number of setae somewhat reduced. Last pair of 

 legs with the distal joint oblong in form, slightly bilobular at the end, marginal setae 

 6 in number, the 2 apical ones longer and thinner than the others; inner expansion 

 of proximal joint broadly triangular and narrowly truncated at the end, scarcely 

 extending beyond the middle of the distal joint, marginal setae 5 in number. 



