66 



extending to the end of the stem of the uropoda, proximal half thick and cylindrical, 

 distal half abruptly attenuated, and armed on each side with about 4 slender, 

 almost setiform spinules, apical spinules likewise slender and about the length of 

 the lateral. Colour greyish, with a more or less distinct yellowish brown tinge. 

 Length about 5 mm. 



Adult male much more slender than the female, with the carapace less 

 deep and quite unarmed, pseudorostral projection of a rather different appearance 

 from that of the female, being nearly horizontal, with the apical setae very small, 

 subrostral corners rectangular, unarmed. Exposed segments of trunk of altogether 

 normal appearance, epimeral parts of last segment acutely produced behind. 

 Each of the 3 anterior caudal segments with a median denticle ventrally. The 

 several appendages transformed in a manner similar to that in Diastylis. 

 Length 6 mm. 



Remarks. This peculiar form was first described in the year 1846 by 

 Kr0yer from Greenland specimens, and was subsequently found by the present 

 author also off the Norwegian coast. From the upturned, nose-like pseudorostral 

 projection with its long, radiating, apical sette, the peculiar form of the exposed 

 segments of the trunk, and the generally much bent, narrow tail, the female 

 acquires a rather extraordinary appearance, well represented by Kroyer in PI. 3 

 of the great work, Gaimard's "Voyage en Scandinavie'', Zoology. The hitherto 

 unknown adult male, on the other hand, exhibits a much more normal aspect, 

 resembling on the whole the males of other Diastylidse. 



Occurrence. I have found this form in great abundance in the Varanger 

 Fjord at Vads0. as also in another place on the Finmark coast, viz, Hammerfest. 

 More recently I have also met with it in certain localities on both the west and 

 south coasts of Norway, for instance in the Trondhjem Fjord, at Christiansund, 

 and at Ma?rd0, off Arendal. From this occurrence it would seem, that the 

 present species is distributed along the whole coast of Norway, though it must 

 evidently be regarded as originally a true arctic form. It is generally found in 

 moderate depths, ranging from 6 to 20 fathoms, on a bottom consisting of muddy 

 clay, with which the body is generally thickly covered. As indicated by the very 

 strongly built posterior pairs of legs, it possesses very great dexterity in rapidly 

 burying itself deeply in the mud, so that often only the tip of the upturned 

 pseudorostral projection with its circle of apical setse is visible above the surface. 

 When taken up, it generally curves its tail abruptly upon the dorsal face of the 

 anterior division. The adult males, as is generally the case, are much more 

 agile than the females, and are often found swimming about with great speed, 

 whereas it is rather unusual to see the females ever leave the bottom. 



