45 
author as Cuma angulata, is, according to my opinion, in which I am supported by 
Dr. Hansen, the adult male of this species. It is one of our largest and finest 
species, and in the polar sea it attains a still larger size. I have examined 
some specimens kindly sent to me by Dr. Stuxherg from the Siberian polar sea, and 
which had a length of no less than 26 mm. It is, moreover, easily recognized 
from our other species by its comparatively slender form and by the large spini- 
form processes formed by the lateral parts of the last pedigerous segment. The 
species which most closely resembles it is D. Bradyi Norman (not yet found off 
the Norwegian coast), and indeed some forms of D. BathJcei exhibit by their more 
spiny carapace, as it were, a transition to this species. 
Occurrence.- I have met with this form along the whole coast of Norway, 
from the Christiania Fjord to Yadso, and in some places in great abundance. 
It is generally found in moderate depths varying from 10 to 30 fathoms, especi¬ 
ally where the bottom consists of very loose mud, in which it buries itself with 
great dexterity. Sometimes I have found it rather abundantly on a bottom covered 
with a thick layer of putrid dark mire avoided by most other Crustacea. Although 
young males are nearly as frequent as females, I have not yet met with any 
sexually mature male specimen (= Cuma angulata Kr.), probably owing to the 
circumstance that the existence of such specimens is limited to certain short 
periods of the year. 
Distribution. —Kattegat (Meinert), Bay of Kiel (Moebius), Pommerian 
coast (Zaddach), the Baltic (Lindstrom), Heligoland (Ehrenbaum), Dutch coast 
(Hoek), British Isles (Sp. Bate), Atlantic coast of North America (Verrill), Green¬ 
land (Hansen), Spitsbergen (Norw. North Atl. Exp.), Franz Joseph Land (Heller), 
the Barents Sea (Hoek), the Kara Sea (Hansen), the Siberian Polar Sea (Stuxberg). 
2. Diastylis cornuta (Boeck). 
(PI. xxxv & XXXVI). 
Cuma cornuta, Boeck, Christiania Vid. Seisk. Forh. 1863, p. 190. 
Syn: Diastylis bispinosa, G. O. Sars (not Stimpson). 
„ „ bicornis, Sp. Bate. 
Specific Characters. — Female: Body less slender than in the preceding 
species, with the anterior division rather tumid and oval in form. Carapace 
comparatively large, about twice as long as the exposed part of the trunk, and 
somewhat vaulted above, surface rather uneven, owing to numerous unequal spiniform 
projections, some of which are very conspicuous, 2 of them especially, issuing one 
on each side of the frontal lobe, being distinguished by their size, looking like a 
