385 



and nut nearly so thick, last joint of tlie peduncle longer than the penulti- 

 mate one, flagellum somewhat exceeding the peduncle in length, and composed 

 of 8 articulations. Anterior gnathopoda very feeble and nearly naked, being 

 generally strongly folded, propodos narrowly oblong in form, and exceeding 

 in length the carpus, dactylus rather elongated, but of very feeble consis- 

 tency, nearly membranous. Posterior gnathopoda scarcely longer than the 

 anterior, but considerably stronger, propodos about same size as the carpus, 

 and nearly quadrangular in form, inferior edge terminating in an angular 

 projection, dactylus rather broad and somewhat curved, being provided 

 anteriorly by several small bristles, its tip bidentate. All the pereiopoda 

 extremely strong, with the propodal joint much swollen, and, in the 2 anterior 

 pairs, equalling in length the 3 preceding joints combined, dactylus strongly 

 curved, and terminating in a sharj) point, basal joint of the 3 posterior pairs 

 oval quadrangular in form, that of last pair somewhat broader than in the 2 

 preceding pairs, and having the infero-posteal corner angularly produced. Last 

 pair of uropoda with both rami quite naked, sublinear in form, and termina- 

 ting in an obtirse point, inner ramus considerably larger than the outer. 

 Telson rounded oval in form, edge evenly curved throughout. Colour, accor- 

 ding to the statement of Kroyer, whitish. Length of adult female 7 mm. 



JRemarJcs. — The present remarkable form was first described by 

 Kroyer under the above name, and subsequently recorded by Sp. Bate under 

 another name, viz., Barivinia compressa. On the identity of both there cannot 

 exist any doubt whatever. Among the 4 species of the genus Ichthyomysocus 

 of Hesse, that named I. morrhiice. is in all probability identical with the 

 present species. Judging from the figures given by that author of the several 

 species, the present form is prominently distinguished from the other 3 by 

 its much shorter and stouter form of body. 



Occurrence. — ■ I have myself only met with a single, quite young 

 specimen of this form, which was taken in the Trondhjemsfjord from the skin 

 of a living Jiaja bails. Boeck records it from the south coast of Norway and 

 states its occurrence on diiferent kinds of fish, such as the sturgeon, sharks and 

 codfish. There are, however, no specimens to be found either in his collec- 

 tions or in our University Museum, and I have thus been obliged to draw 

 the accompanying figures from specimens collected on the Danish coast and 

 kindly sent me by Dr. Hansen. 



Distribution. — British Isles (Sp. Bate), Kattegat (Kroyer), Bohusliin 

 (Bruzelius), coast of France (Chevreux). 



