406 



Specific Characters. Female. Rather like S. longicaudata, but of somewhat 

 smaller size and, when viewed dorsally, at once distinguished by the epimeral 

 plates of the 4 anterior segments being expanded laterally, forming together a 

 broad hyaline rim surrounding the anterior part of the body, edges of the plates 

 very finely spinulose. Urosome with the segments very sharply marked off from 

 each other, the lateral parts forming in all of them, except the last, lamellar 

 expansions densely spinulose at the edges. Posterior edges of all the segments 

 of the body somewhat raised dorsally, and clothed with very coarse spinules. 

 Caudal rami, as in the type species, narrow linear in form and exceeding half 

 the length of the urosome, apical setae long and slender. Anterior antennae 

 resembling in structure those in 8. longicaudata, though differing somewhat in the 

 mutual relation of the joints in the proximal part, the 1st joint being only slightly 

 longer than the 2nd, which is fully as long as the 2 succeeding joints combined. 

 Posterior antennae with the outer ramus comparatively smaller than in that species, 

 though of a very similar structure. 1st pair of legs with the outer ramus much 

 shorter than the 1st joint of the inner, the latter very narrow and somewhat 

 sigmoid in shape. The 3 succeeding pairs of legs comparatively smaller than in 

 the type species, and having the basal part bent in an elbow-like manner, as 

 in 8. setosa; both rami very narrow. Last pair of legs comparatively small, 

 with the distal joint narrowly exserted at the tip; inner expansion of proximal 

 joint considerably smaller than in S. longicaudata and defined outside 

 an angular sinus. 



Colour whitish grey. 



Length of adult female 0.80 mm. 



Remarks. This form is closely allied to S. longicaudata, and was indeed 

 considered by Th. Scott to be only a variety of that species. Having, however, 

 on a closer comparison of both forms, found several perfectly constant differences, 

 both as regards the external appearance and some of the structural details, I am 

 led to the conclusion that the present form should more properly be separated 

 as a distinct though closely-allied species. 



Occurrence. This form was found last summer rather abundantly at Kors- 

 havn in a depth of 30 50 fathoms, coarse sandy bottom. In the same locality 

 S. longicaudata also occurred ; but it was fairly easy to pick out the present form, 

 on account of its coarsely spinulose body and the laterally expanded epimeral 

 plates of the anterior segments, which, in the dorsal aspect of the animal, give 

 it a rather peculiar appearance. 



Distribution. Scottish coast (Scott). 



:imal 



