13 



differing in the fact that the terminal joint is narrower and generally incurved; 

 inner ramus of same leg reaching beyond the middle of this joint. Body in both 

 sexes highly pellucid, with the oral area slightly tinged with red. Length of 

 adult female reaching to 9 mm., of male to 6y 2 mm. 



Remarks. This species was established in the year 1838 by Kr0yer, but was 

 very imperfectly characterised, for which reason it was not accepted by subsequent 

 authors as a distinct species, but only as a large variety of C. finmarchicus. 

 Dr. Giesbrecht has, however, recently vindicated its claim to be regarded as di- 

 stinct, having pointed out some distinctive characters of the female. The structure 

 of the hitherto unknown male also confirms the correctness of Dr. Giesbrecht's 

 opinion about the distinctness of this form. It may be easily recognized from 

 the 2 preceding species, not only by its large size (it is indeed one of the largest 

 Calanoids known), but also by the angularly produced lateral corners of the last 

 pedigerous segment, and the comparatively short urosome. The male, too, is fairly 

 well marked by the less prominent frontal part, but especially by the structure 

 of the last pair of legs. 



Occurrence. This form is occasionally found off the Finmark coast and 

 the Lofoten Islands, together with Calanus finmarchicus; but farther south it seems 

 to be wholly restricted to the great depths of the fjords, occurring under such 

 circumstances as far south as in the Christiania Fjord. It must evidently be 

 regarded here as a relict form, representing a remnant of the glacial fauna which 

 prevailed around our coasts in ancient times (the glacial period). 



Distribution. About the arctic character of this species no doubt can 

 arise, it being met with throughout the Polar Sea from Greenland to the Behring 

 Strait, and often in great abundance at the very surface of the water. In the 

 Polar basin explored by Nansen it was very common, occurring in the greater 

 number of the plankton-proofs examined. 



Fam. 2. Eucalanidae. 



Characters. Body, as a rule, very slender, with the cephalosome and 

 the 1st pedigerous segment generally coalesced, frontal part more or less pro- 

 duced, with 2 soft tentacular filaments below. Last pedigerous segment imperfectly 

 developed. Urosome comparatively short, consisting in female, as a rule, of only 

 3 segments, caudal rami partly confluent with the anal segment and somewhat 



