342 DE. H. J. HAKSEN ON THE 



Group A. 

 Prontal plate elongate, at least nearly three times longer than 

 broad. Three posterior pairs and especially seventh pair of 

 thoracic legs with a great number of long plumose natatory setae, 



1. CiEOLAiVA BOEEALis, LUljelorg (1852). 



1890. Cirolana borealis, H. J. Hansen, Cirolanidse, &c., p. 321, pi. i. 



figs. 1-1 V (with synonymy). 

 1897. Cirolana borealis, G. 0. Sars, Crust, of Norway, vol. ii. p. 70, pi. 29. 

 Eyes blackish, seen from the side somewhat longer than deep, 

 with the major portion of the upper margin straight. 



Erontal plate about three times longer than broad ; its front 

 end not visible from above. Clypeus without anterior process ; 

 its surface feebly convex, with a deep furrow along each lateral 

 margin. 



Antennulse considerably shorter than the peduncle of the an- 

 tennae ; flagellum consists of numerous very short joints. 



Antennae reach almost or about to the middle of thorax; 

 flagellum with numerous (about thirty) joints. 



Epimera of second and third thoracic segments with a short 

 rudiment of an impressed line besides the submarginal furrow ; 

 epimera of fourth to seventh segments without any furrow or 

 ridge besides the submarginal one ; epimera of seventh segment 

 somewhat smaller than those of the sixth. 



SeA^enth thoracic legs have second joint strongly flattened and 

 expanded, somewhat less than twice as long as broad, with both 

 lateral margins and the longitudinal ridge along the middle of 

 the lower side very closely set along their whole length with 

 long plumose setae. Eourth joint scarcely longer than fifth and 

 somewhat shorter than sixth. 



Last abdominal segment with the lateral margins convex, not 

 angular at the beginning of the terminal third; this distal part 

 with about four pairs of marginal spines ; the tip moderately 

 angular, scarcely acute. 



Uropoda slender. The endopod, which, when directed parallel 

 with the axis of the animal, reaches somewhat beyond the end of 

 abdomen, is somewhat more than two and a half but not fully 

 three times longer than broad, without notch at the end of the 

 outer margin. Exopod at least four times longer than broad and 

 considerably shorter than the endopod, with about four spines 

 along the outer margin. 

 Length 27-33 mm. 



