374 ARKIV FÖR ZOOLOGI. BAND 1. 



dinal axis of tlie body. First thoracic segment dorsally with 

 a backwards directed spine, somewhat in front of the posterior 

 margin. Genital end 2nd abdominal segments with a row 

 of stiff small bristles on the ventral side. Ri of the 1 — 5 

 pairs of legs with 3-joints. Furca symmetrical, as long as 

 the anal segment. — Length 1.3 millim. 



Description. Body, anterior part length 1 millim, posterior 

 part length 0,3 millim. Greatest breadth behind the head, 

 about 0,43 millim. Cephalon highly woulted. Rostral fila- 

 ments short, with broad, triangulär bases. Two dorsal eyes. 

 Frontal organs distinct. On the place of the ventral eye is 

 a conical process. — Anterior part of the body 6-jointed, 

 proportional length of the joints as 10:2,4:2:2:1,5:2,5. 

 The first segment carries dorsally a backwards directed spine. 

 Last segment symmetrical, ending in two backwards directed 

 spines. — Abdomen 3-jointed. Proportional length of the 

 joints and the furca as 10:5:6:8. Genital segment and 

 the following ventrally with a set of small stiff bristles. — 

 Furca 2 1 2 times longer than broad. Se inserted at 2 k of the 

 lenght of the furca. 



AnteancB of the lst pair reach to the end of the furca, 



forming regular bows, 21-jointed, Aa 1 to 4 and Aa 24 to 



25 uniting. The exteriör margin of the first joint (Aa 1 — 4) 



with two spines, the 2nd joint (Aa 5) with one spine, the 



7th and 8th (Aa 10 and 11) each with one spine. Length of 



the joints in 0,01 millim. 



Aa 1-4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 



4,5 5 (i 6 8 9 9 9 10 12 10 



Antennce of the 2nd pair. Bl with a plumose Si reaching 

 beyond the distal margin of B2. B2 with 2 Si, one shorter, 

 as long as the joint, plumose, the other twice as long. Re 

 and Ri of equal length. Proportional length of Re l + 2, ( Re 

 3 — 6 and Re 7 as 19: 7,5: 12,5. Sp of Re 7 inserted somewhat 

 nearer the distal than the proximal part. Terminal S 3, long, 

 plumose. — Proportional length of B2, Ri 1 and Ri 2 as 10 : 

 14 : 10. Ri 1 with 2 Si inserted somewhat in front of the centre. 

 Ri 2 twice as long as broad. Le with 6 long S and 3 small 

 bristles on the outside. Li with 3 longer, 4 shorter and one 

 very small Se. 



