21 



tally; anal opercle somewhat projecting, but perfectly smooth. Caudal rami narrow 

 linear, about equalling in length the last 2 segments combined, and everywhere 

 minutely hairy, the 2 middle apical setae slightly unequal and much stronger than 

 the others, having the outer part minutely annulated and thickly covered with 

 delicate cilia. Anterior antennae almost attaining the length of the cephalosome, 

 and slightly attenuated, carrying strong curved setse along the anterior edge and 

 on the tip, the outer 4 articulations somewhat narrower than the 3 proximal ones. 

 Posterior antennse with remarkably strong and densely ciliated spines at the tip, 

 outer ranius not even attaining 1 / 3 of the length of the inner, and much narrower. 

 Inner ramus of the 3 posterior pairs of natatory legs (in the adult animal) con- 

 sisting of only 2 joints, the proximal of which, especially in the 2nd pair, is greatly 

 expanded, and produced at the inner corner to a strong deflexed spiniform process, 

 in front of which a similarly strong curved spine is attached; distal joint in this 

 pair produced at the tip, between the 2 innermost spines, to a similar, but smaller 

 process. Last pair of legs extremely small, with the distal joint scarcely longer 

 than the proximal one, and provided with one apical seta and 2 small lateral spines. 



Body semipellucid, with a pale yellowish tinge. 



Length of adult female 1.45 mm. 



Remarks. I have been in some doubt about the correctness of my identifi- 

 cation of the above- described form with Norman's species, because the inner ramus 

 of the 3 posterior pairs of natatory legs in that species is described by Brady 

 as 3-articulate, whereas in the Norwegian form it consists of only 2 joints; but 

 in all other respects it so closely agrees with Brady's description, that I have 

 not felt justified in establishing a new species on account of this apparent difference, 

 which may perhaps be due to the circumstance that the specimen dissected by 

 Brady had not attained its full development. On the other hand, I am of opinion 

 that the solitary male specimen described by Dr. Giesbrecht from the Gulf of 

 Naples may more properly be referable to a distinct species, differing, as it does, 

 very conspicuously in the large size of the rostral plate. 



Occurrence. Only a very limited number of specimens of this form, all 

 of the female sex, have hitherto come under my notice. They were taken at 

 different times, some off the west coast of Norway, some off the Lofoten Islands, 

 from considerable depths amounting to 100 fathoms. 



Distribution. English and Scottish coasts (Brady, Scott). 



