i4 



COPEPODA 



about the biology and distribution, collected in the last years, is in danger of losing considerably in 

 value. All questions regarding development, propagation and distribution should in most regions be 

 extremely difficult to investigate, if we instead of a single well defined species had two very 

 badly limited. 



Description J 1 — ?• Size: f$. 2"8 — 5-5 ram. fj 1 . 3 — 4-4 mm. (Smallest specimens Faeroe Iceland 

 Channel ; largest Davis Strait). 



The number of secretory pores scarcely differed in the males and females, or in specimens 

 from different localities. In the first pair of legs no secretory pores were found; on the anterior sur- 

 face of Ri I, at the base of Se, sometimes a minute pore (?) was seen. In pes II — V a minute pore 

 was found on the anterior surface at the base of a minute Se of third basipodite; in the Re I — II a 

 more or less distinct pore was found at the base of Se in the four last pair of legs, and a distinct one 

 was found at the base of the Se 2 — 3 Re III, but in addition to these in the pes III — IV a pore was 

 found corresponding to the missing Se 1 Re III, in pes II this pore was most often wanting. The 

 shape of the labrum etc. (cf. textfig. 6) is somewhat different from Sars' fig. (pi. I). Between the 

 insertion of the antennulae a small elevation is found, which by a transverse groove, less prominent 

 than shown in the figure, is divided into a shorter anterior portion (a) and a longer posterior one (b). 

 Separated from this by a narrow groove and between the insertion of the antennae a low elevation 

 (c), slightly convex from before backwards and from side to side is seen. In front limited by a trans- 

 verse groove, behind by the free posterior margin and laterally gradually continued into the transverse 

 chitinous bar, situated between the articular cavity of the antennae and mandibulae respectively, the 

 labrum proper is found. The mentioned chitinous bar is medially to the articular cavity of the 

 mandibulae connected with the area labialis, thus forming the chitinous bed, in which the manduca- 

 tory portion is situated (cf. Sars' fig. pi. II). The labrum proper has in front, in the middle, a prominent 

 tumulus, beset with a number of long bristles directed backwards. On each side of the process an 

 oblique series, directed outwards and backwards, sometimes fused with the lateral marginal row, is found ; 

 it consists of short spinelike hairs. In front of hinder margin on each side a group of fairly long setae, 

 beginning in the middle and directed backwards and outwards, is observed and laterally a marginal 

 row of rather short spinelike hairs is found. 



The oral surface of the labrum shows an arrangement alike that of Cal. hyperboreus (pi. I fig. 

 1 b), but the enlarged group in front is less developed (differing on the two sides in the two examined 

 specimens), the first group is converging anteriorly, the second group is medioconvex, well separated 

 from the first group, but only indistinctly from the third one; the third to the fourth groups are partly 

 fused and consist of several rows of hairs. Transversely between the last series only a few teeth 

 are found. 



The lamina labialis (textfig. 1), which seems to form a part of a transverse chitinous system, 

 has posteriorly a median tooth, and on each side two or three teeth (often assymmetrical). In front 

 of the lamina labialis a delicate granulation is found in the middle between a median series of shorter 

 and a lateral of longer hairs. Behind the lamina and between the serrulae 6dentatae an outer group 

 of fairly delicate hairs and a median one of thick granules, fused with a group between the labial lobes 



