the ventral surface of the abdomen is almost flat and whitish. Dorsal side 

 of segments 1 — 7 with a large, sucker-shaped process; pleural region of 

 these segments with a whitish gill which consists of a long, conical, finger- 

 like process. The gills of segments 1, 7 and 8 are shorter and thinner 

 than the others. Anterior -angle seta strong and long; it is situated on the 

 dorsal process on segments 1—7; anal surface setae situated on the sides 

 of the segment, posterior to the base of the dorsal process; segment 8 

 smaller and narrower than segment 7; its dorsal tubercle is absent; the 

 anterior-angle seta and the surface setae of segment 8 are arranged in a 

 row, as on segment 9; the anterior -angle seta is markedly longer than the 

 others. Two small, lateral setae at the base of the gill, at the base of 

 the conical lateral process. 



Dorsal sclerite of segment 9 brownish and trapezoidal; its anterior 

 margin shorter than the posterior margin; 4 setae at the sides of the 

 posterior margin, a longer medioanal seta, a short, thin intermediate seta 

 and a short, thin lateral seta, and a larger anterior -angle seta. 



Laterodorsal sclerite "b" of anal legs (Figure 272) brown; the dark 

 brown basal margin, the oblique groove and the groove perpendicular to 

 this are well marked; the basoventral hook is absent; there is no distal 

 sword-shaped process; the small, distodorsal part of the sclerite has a 

 dark median stripe; the distal seta of this part is very long, longer than 

 the claw; the seta situated nearby, further basally, is much shorter, but 

 larger than the short dorsal seta of the basal part of the sclerite; ventral 

 seta situated on a small, round sclerite, short and strong. The seta of the 

 small ventral sclerite of section "c" is like the latter seta; the lateral 

 sclerite "c" is much larger than the ventral sclerite. 



Claw (Figures 272 and 273) (especially its basal part) long and narrow, 

 unlike in Rh. retract a; seta 1 (unlike that of the higher Rhyacophila) 

 much shorter than seta 2; dorsal seta 3 situated at the base of the distal 

 part of the claw, long, curved and longer than the outer seta 6; inner side 

 of the basal part with the large, strong seta 4, which is the longest seta of 

 the claw; the outer side also bears the long seta 5; ventral side with 

 setae 7 and 8; seta 7 is situated at the base and is short; seta 8 is situated 

 near the membranous transverse stripe; long, and curved; both setae are 

 light. 



Pupa. Length about 8—9 mm. Labrum with rounded anterior margin; 

 each side with 5 dark setae, as in species of Rhyacophila s. str. 

 Mandibles long, yellowish brown, slightly curved, serrated on the inner side; 

 base of the serrated part of the right and left mandible with 2 teeth. As in 

 other species of Rhy ac o phi la, the natatorial setae are situated on seg- 

 ments 1—4 of the mid-tarsi. According to Thienemann (1912:255), the 

 presegmental plates of the holding apparatus are present on segments 3—7, 

 postsegmental plates on segments 4 and 5; thus, compared with Rhy a - 

 cophila s. str., there is one additional pair of presegmental sclerites and 

 one pair less of postsegmental sclerites (segment 3). 



Mode of life and habitats. Small cool brooks in mountain and 

 spring regions; under stones; phytophagous. 



Distribution. Not recorded from the USSR; it probably occurs in 

 Transcarpathia. Mountains in Central and southern Europe. 



274 



