28 



diminishing in length, propodal joint in all of them unusually produced and 

 carrying at the tip, outside the dactylus, a single spiniform seta. Uropoda fully 

 as long as the last 3 segments combined, inner ramus somewhat shorter than 

 the basal part, but projecting considerably beyond the outer, its 1st joint with 2 

 spinules, each of the other 2 joints with one; outer ramus with the proximal 

 joint quite short. Telson about twice the length of the last segment, and much 

 shorter than the basal part of the uropoda, gradually tapering distally to an 

 obtuse point carrying 3 subequal spines. Colour light yellow, with a whitish band 

 across the carapace. Length of adult female about 6 mm., of male 5'/ 2 mm. 



Remarks. This is an easily recognizable form, being at once distinguished 

 from all our other Cumacea by the peculiar development of the carapace, the 

 fornicate character of which, indeed, makes it rather difficult to obtain an exact 

 lateral view of the animal. 



Occurrence. I first found this remarkable form off the Lofoten Islands, 

 and have subsequently met with it occasionally also in some other localities of 

 the Norwegian coast, for instance, in the outer part of the Hardanger Fjord, at 

 Aalesund, and in the Trondhjem Fjord. It is a pronounced deep-water species, 

 only occurring in greater depths ranging from 120 to 400 fathoms. Out of Nor- 

 way, this form has not as yet been recorded. 



Fam. 4. Leuconidae. 



Characters. Body more or less slender, with no sharp demarcation be- 

 tween the anterior and posterior divisions. Integuments rather thin. Carapace 

 generally small, with the antero-lateral corners more or less produced, pseudoro- 

 stral projection in some cases distinctly prominent, in other cases obsolete. 1st 

 pedigerous segment well defined. Tail with the last segment obtusely produced 

 behind. Eye, in all the known forms, absent. Superior antennae with the outer 

 flagellum 3-articulate, the inner uniarticulate. Inferior antennae in female very 

 small, in male well developed, attaining the length of the body. Mandibles com- 

 paratively short, with the body triangular in form, or forming outside an angular 

 expansion, masticatory part strongly incurved, with only 2 small setse behind the 

 cutting edge, molar expansion short and massive. Anterior maxillae with the 



