335 



antennae short and stout, with the proximal joint scarcely longer than the distal 

 one, and carrying in front a strong ciliated seta; outer ramus about the length 

 of the distal joint, and provided with 4 setse, 2 apical and 2 lateral. Posterior 

 maxillipeds of moderate size, with a long seta issuing from the basal joint in 

 front, hand finely ciliated inside, dactylus scarcely longer, and clothed inside with 

 slender spinules. 1st pair of legs with the inner ramus projecting a little beyond 

 the outer, both coarsely spinulose outside. The 3 succeeding pairs rather strongly 

 built, with the inner ramus a little shorter than the outer. Last pair of legs 

 with the distal joint comparatively small, cordiform in shape, with 5 marginal 

 setse ; inner expansion of proximal joint well developed, broadly triangular in form, 

 and extending considerably beyond the distal joint, marginal seta? 5 in number, 

 and rather strong, spiniform, the outermost the smallest. 



Male with the anterior antennae moderately strong and composed of 7 

 well defined joints, the 4th being somewhat dilated. 1st pair of legs with a highly 

 chitinized plug-like prominence inside the 2nd basal joint. Inner ramus of 2nd 

 pair of legs transformed in much the same manner as in the Tlialestridce, middle 

 joint carrying at the end outside 2 closely juxtaposed spiniform appendages, the 

 outer of which is very coarse. Last pair of legs smaller than in female, with 

 the inner expansion of the proximal joint much reduced in size, and provided with 

 only 2 spiniform setae. 



Colour more or less reddish. 



Length of adult female 0.80 mm. 



Remark*. In its outward appearance the present form somewhat recalls 

 certain species of the genus Amphiascus. The structure of the 1st pair of legs, 

 however, is very different, and the female is only provided with a single ovisac. 

 Also the other structural details prove it to be much more nearly allied to the 

 genus Tachidnis. as was also suggested by Prof. Brady. 



Occurrence. I have taken this form rather abundantly in one place, near 

 Farsund, on a muddy bottom at a depth of about 20 fathoms. It also occurs 

 occasionally in some other localities of the south coast of Norway (Lillesand, Risor), 

 as also in the upper part of the Christiania Fjord. 



Distribution. British Isles (Brady), Arctic Ocean, off Spitsbergen and 

 Franz Josef Land (Scott). 



