P. T. CLEVE, PLANKTON COLLECTED BY MR. THORILD WULFF. 377 



margin of the joint, whicli ends in a triangel tooth, behind 

 wliich is anotlier, but smaller, tooth. 



Maxilliped of the 2nd pair. Exteriör margin of B2 dis- 

 tally notched. 



Natatory legs. Longitudinal proportion of the three joints 

 of Re and St. 



Relative length of the four pairs as 10 : 13 : 11 : 6. 



Se of the 1st— 3d p. 1, 1, 3, of the 4th. p. 1, 0, 1, 

 those of the 1st to 3d p. triangulär with serrate margins. 

 The Se of Re 3 divide the joint in equal parts. St of the 

 lst — 3d p. knife-like, straight, with finely serrate margins 

 (teeth about 5 in 0,01 millim.). The S of the 4th p. bristles. 

 — Si of the lst p. 0, 1, 4, of the 2nd and 3d p. 0, 2, 5, of 

 the 4th p. 0, 1, 5. 



Longitudinal proportion of the joints of Ri 



Ri of the 4th p. rudimentary. 



Proportional length of Ri of the lst — 3d p. 10 : 12, 5 : 8, 5. 

 Ri of the lst and 2nd p. somewhat more than half as 

 long as Re, of the 3d p. shorter. — Si of the lst p. 1, 1, 5, 

 of the 2nd p. 1, 2, 5 of the 3d p. 1, 1, 2. 



Description of the male. Body, anterior part 0,43 to 0,45 

 millim.; posterior part 0,35 to 0,41 millim. Thorax 3 not 

 reaching to the middle of the genital segment, Th 4 short, 

 acute. — Abdomen 2-jointed; genital segment in front with 

 a ventrally cnrved spine. .Furca with parallel branches, of 

 equal breadth throughout and at least 10 times longer than 

 broad. Of the two St the interiör is rather longer than 

 the furca and more than twice as long as the exteriör, which 

 is somewhat shorter than the Si. Longitudinal proportion 

 of the abdominal segment and the furca as 10 : 8 : 12. 



Arkiv för zoologi. Band 1. 28 



