42 AXEL OHLIN, AROTIC CRUSTACEA. 



nasicoides Lilljeborg. After consulting tlie recently published 

 parts III & IV of Särs' Cumacea, 1 find now some differences 

 not allowing the identification of both forms. Tlius, the dor- 

 sal crest of the carapace is not continuing up to the poste- 

 rior margin, but is interrupted a little behind the middle of 

 the carapace. Generally two or three spines are to be found 

 before the posterior margin. There are in all 13 — 15 median 

 spines. Between them there is a fine hair. The antero-lateral 

 margin is serrated by 8—10 spines on each side and the end 

 of the rostrum by six. Instead of the three spines on each 

 side of the middle line of the lascinia which are so charac- 

 teristic for Leucon nasicoides, there is, in this species, gener- 

 ally only one, or, in some specimens, none. 



The rostrum is longer and more pointed than in L. nasi- 

 coides or L. fidvus, and, in this respect, it resembles more 

 L. pallidus or L. acutirostris, from which L. Natliorsti is easily 

 to be distinguished by the uropoda. 



The inner ramus of these is about of the same length as 

 the basal part and a little longer than the outer, its distal 

 joint being half as long as the proximal one, and provided 

 at the apex with a few (4—5) spines. Outer ramus with 

 about seven setse at the apex and the inner side. Especially 

 in old specimens, a faint ciliation on these setee is to be ob- 

 served. 



The body is more robust than in L. nasicus, although a 

 little more oblong than in L. nasicoides. 



Antennje, oral parts and legs not deviating from those 

 found in the type species. 



Length of ovigerous female 7 mm. 



breadth » » » 0,8 » 



Male of a smaller size. 



Old males are very seldom to be met with. In my col- 

 lections, consisting of about oO specimens, there is only a 

 single fullgrown male, which, as is usually the case in this 

 genus, is destitute of the median dorsal crest. 



Localities: 



Stat. 32. King Charles Island, Bremor Sound, dcpth 100—110 iii., 

 bottom terap. — l,i5 C, sött clay with stones, H/VIII, 

 many spec. 



