72 



setiforra. Telson not attaining half the length of the stem of the uropocla, and 

 exhibiting the usual shape and armature. Colour light fuscous. Length 4 mm. 



Remarks. This form is nearly allied to L. ampullacea, though easily 

 distinguishable by its less strongly built body, the almost globose and densely hairy 

 anterior division, and the extremely slender tail. It is also much inferior in size. 



Occurrence. I first found this form in the Christiania Fjord, at Holme- 

 strand, where it occurred rather abundantly, and have subsequently met with it 

 also in several other places on the Norwegian coast, as far north as Vads0. It 

 is a pronounced deep-water form, only occurring in depths below 60 fathoms, on 

 a muddy bottom. I have not hitherto succeeded in finding adult male specimens 

 of this species either. Out of Norway, this form has not yet been recorded. 



Fam. 6. Pseudocumidae. 



Characters. Body of various forms, sometimes very slender, sometimes 

 comparatively short and clumsy. Anterior division generally well marked off from 

 the posterior, and having 5 segments exposed behind the carapace; the latter of 

 moderate size and without any spiniform protuberances, pseudorostral projection 

 of varying form, subrostral corners generally well marked, lower edges unarmed. 

 Tail slender, smooth. Eye generally well developed. Superior antennae only 

 slightly different in the two sexes, inner flagellum rudimentary. Inferior antennae 

 in female very small, in male well developed, resembling those in the male 

 DiastylidoB. Oral parts on the whole normal. The 2 anterior pairs of legs in 

 female, and all but the last pair in male, provided with well-developed exopodites; 

 3rd and 4th pairs in female with a small appendage (rudimentary exopodite) 

 outside the basal joint. Two pairs of pleopoda present in the male, the posterior 

 pair, however, very small and rudimentary. Uropocla with the inner ramus uni- 

 articulale, the outer biarticulate. Telson well defined from the last caudal seg- 

 ment, but very small, flap-shaped. 



Remarks. This family in some characters apparently approaches the 

 Diastylidce, in others the Lampropidce, but evidently ought to be kept apart from 

 all of them. With the Diastylidce it agrees among other things in the structure 

 ot the inferior antenna in the male, as also in the presence of only 2 pairs of 



