62 



legs exhibiting the usual transformation. Pleopoda of the structure characteristic 

 of the genus. Uropoda very slender, with the inner ramus somewhat longer 

 than the outer, and armed inside with about 20 ciliated spinules. Telson consi- 

 derably more produced than in the female, and exhibiting above at the flexure 

 a very distinct angular projection, distal part narrow, linear. Length amounting 

 to 7 mm. 



Remarks. The present species, first described in the year 1864 by the 

 present author, may be easily recognized in both sexes by the evenly vaulted 

 carapace, the very prominent pseudorostral projection, and the coarse serration 

 of the lower edges of the carapace, which latter character has given rise to the 

 specific name serrata. 



Occurrence. Of the south and west coasts of Norway, Ibis form is by 

 no means unfrequent, occurring in some places, for instance in the Christiania 

 Fjord, rather abundantly in depths ranging from 30 to 100 fathoms, muddy 

 bottom. Its northern distribution extends to Hasvig in west Finmark, and I 

 have found it there, as also in some other places, down to a depth of 300 

 fathoms. Male specimens (in the adult state) are found at some periods of the 

 year not infrequently. They are extremely agile and in almost constant motion. 



Distribution. Off the Skagen Lighthouse (Meinert). 



12. Diastyloides biplieata, G. 0. Sars. 



(PI. XLVI). 

 Diastylis biplieata, G. 0. Sars, Om den aberrante Krebsdyrgruppe Cumacea, p. 46. 



Syn : Diastylis lamellata, Norman. 

 Diastylis Calveri, Norman (adult male). 



Specific Characters. Female. General form of body resembling that of 

 the preceding species, anterior division, however, still more tumefied, approaching 

 the globular shape. Carapace large and broad, the width considerably exceeding 

 the height, dorsal face somewhat gibbously vaulted behind, lateral faces sculptured 

 with 2 very distinct oblique plicae extending from the most prominent part of the 

 branchial region, and joining at the anterior part of the lower edge, hind edge 

 of carapace elevated to a similar plica; pseudorostral projection rather large and 

 slightly upturned, being somewhat hollowed at the base, subrostral corners in- 

 conspicuous, anterior half only of the lower edges coarsely serrate. Exposed seg- 

 ments of trunk with the anterior edge more or less distinctly elevated, lateral 

 parts of last segment scarcely produced behind, though terminating in an acute 

 corner. Caudal segments simple, unarmed. Superior antennae with the peduncle 



