Systematical notes. 



Copepoda. 



Acrocalanus pediger Cl. n. sp. 



(PI. I, fig. 1—20). 



Diagnosis. The female. Antennas of the 1st pair 25- (or 23-)jointed. Dorsal 

 mar<iin regularly convex. Abdomen 4-jointed. Distal part of Re 3 of the 4th pair of 

 natatory legs '.vith coarsely denticulate exteriör margin. Of the öth pair of legs the left 

 only developed and 4-jointed — L. 1,3 mm. 



The male. Antennae of the 1st pair similar, 19-jointed, the proximal 6 joints uniting 

 into a thicker proximal part, less than Vs of the distal. Abdomen 5-jointed. Distal part 

 of Re 3 of the 2 — 4 pairs of natatory legs much shorter than the proximal and with 

 entire (not saw-like) exteriör margin. Fifth pair of legs asymmetrical, the left longer 

 than the right — L. 1,2 mm. 



Description of the female. Body. Length (anterior part 1, posterior part 0,3) 

 1,3 mm. Anterior part 4-jointed. Ce and Th 1 more or less indistinctly separate, twice 

 as long as the three other joints together. Th 4 and 5 indistinctly sepai"ate. The dorsal 

 outline (laterally) nearly as in A. gracilis. Abdomen 4-jointed; longitudinal proportion of 

 the joints: 3:1:1:2. Furca as long as broad, shorter than the anal-segment. St 2 

 slightly longer than the abdomen and soraewhat longer than St I and St S, which are a 

 little longer than St 4. Si very short and tine, geniculate. Interiör margin of the furca hairy. 



First pair of antennce reach with 2 or 3 joints beyond the furca, 25-jointed {Aa 

 1 ~ 2 and 8 ~ 9 sometimes indistinctly articulate). Joints 3 to 1 1 short, scarcely longer 

 than broad, 11~15 one and a half times longer than broad, the following about twice 

 as long as broad. *S 2 to 4 times longer than the joints, those of Aa 28 and 24 longer 

 than the other. S of the ultimate short, the longest scarcely more than twice as long 

 as the joint. . • ■ 



Second j^aii' of antennce. B 1 broader than long, with 1 Si reaching to the distal 

 margin of B 2, coarsely plumose. 5 2 as long as broad with 2 distal, pluraose Si. Re 

 slightly shorter than Ri Re 1 broader than long. Re 2 as long as broad, as Re 3 — 6 

 together and as Rel. Si of the joints 2, 2, 1, 1, 1, 1, 3. There is besides, soraewhat 

 below the eud of Rel, a Sp, somewhat shorter than Re, while the other are at least 

 1 ^'2 times longer than Re. Ri 1 twice as long as broad, distally with 2 Si, one longer 

 and one shorter. Ri 2 half as long as Ri 1. Li with 8 Si increasing in length towards Le; 



K. Sv. Vet. Akad. Haudl. Band 35. N:o .'). 5 



