140 



antennae not quite twice as long as the body, flagellum nearly attaining the length 

 of the peduncle. 1st pair of legs comparatively short, with the 2 outer joints of 

 about equal length; 2nd pair densely spinous, with the propodal joint longer than 

 the carpal one. The 2 succeeding pairs of legs scarcely as long as the body. 

 Natatory legs less strongly developed than in Ilyarachna, carpal joint of the 2 

 anterior pairs narrow cordiform, and scarcely longer than the propodal joint, dac- 

 tylus rather elongated. Uropoda with the basal part oblong oval, slightly narrowed 

 distally, and carrying about 12 plumose seta?, outer ramus much smaller than the 

 inner, but well defined. Colour greyish white. Length of adult female 5 mm. 



Remarks. This species may be easily recognized from the allied forms 

 by its short and compact body, and by the very conspicuous spinous whorls 

 encircling the anterior segments of the mesosome. 



Occurrence. Besides off the Lofoten Islands, where the species was first 

 discovered, I have met with it occasionally at VadsO, as also in several localities 

 on the west coast of Norway (Espevser, Floro, Aalesund, Trondhjem Fjord), the 

 depth ranging from 100 to 300 fathoms. Out of Norway, it has not yet been 

 recorded. 



Gen. 4. Aspidaraehna, G. o. Sars, n. 



Syn: Ilyarachna, G. O. Sars (part). 



Generic Characters. Body short and compact, with the 2 divisions of mesosome 

 very sharply defined, the posterior one being very large, clypeiform, partly projecting 

 in front over the anterior. Cephalon broad, transverse, evenly convex above, 

 frontal margin slightly emarginated. Caudal segment triangular, rather broad at 

 the base. Superior antenme much more fully developed in male than in female. 

 Inferior antennae of moderate size. Mandibles very strong, cutting edge undivided, 

 molar expansion very small, conic, tipped with slender bristles, palp distinct, though 

 rather feeble. The 4 anterior pairs of legs constructed, on the whole, in a similar 

 manner to that in the 2 preceding genera, though the 3rd and 4th pairs are not 

 particularly elongated. Natatory legs very fully developed. Uropoda with 2 dis- 

 tinct rami, as in the genus Echinozonc. 



Remarks. This genus also is founded upon a species previously referred 

 by the present author to the genus Ilyarachna. A closer anatomical examination 

 has also in this instance revealed some peculiar features of apparently generic 

 value. Thus, the uropoda, as in the genus Echinozone, are distinctly biramous; 



