16 G. O. SARS. [SEC. ARC. EXP. FRAM 



Order Copepoda,. 



Suborder Calanoida. 

 Fam. Calcinidse. 



66. Calanus finmarchicus (GUNNER.). 



This common species occurred abundantly in plankton-samples from 

 many different places. 



67. Calanus hyperboreus, KROYER. 

 Found occasionally together with the preceding species. 



Fam. Euchsetidse. 



68. Euchasta norvegica, BOECK. 



Some immature specimens of this form occurred in one of the 

 plankton-samples taken on July 10, 1898. 



Fam. Stephidse. 



69. Stephos arcticus, G. 0. SARS, n. sp. 



(Pi. I.) 



Specific Characters. -- Female. Body somewhat more slender 

 than in the other known species, with the anterior division oblong oval 

 in form, greatest width not attaining half the length. Last pedigerous 

 segment not wholly confluent with the preceding one, a slight notch on 

 each side indicating the limit between the two; lateral lobes rounded 

 off and slightly unequal, the right one somewhat more prominent than 

 the left. Urosome slender and narrow, attaining almost half the length 

 of the anterior division, genital segment slightly asymmetrical, bulging 

 somewhat on left side. Caudal rami about the length of the last seg- 

 ment, apical seta3 rather slender, the innermost but one much the 

 longest, and attaining about half the length of the body. Anterior an- 

 tennae shorter than the anterior division of the body, and, as in the 

 other species, composed of 24 articulations. Posterior antennae, oral 

 parts, and natatory legs of the structure characteristic of the genus. 

 Last pair of legs extremely small, with the distal joint conical in form 

 and scarcely denticulated. 



Male somewhat smaller than female and of more slender form, 

 with the urosome narrower and 5-articulate, 2nd segment the largest 



