The dorsal sclerite of segment 9 is dark in the middle, chestnut brown, 

 lighter laterally, without dots (Figure 224); the black anterior margin is 

 broad laterally and narrower in the middle; posterior margin with black 

 narrow stripes at the base of the medioanal setae; the anterior and medio- 

 anal setae are thick, long and blackish brown; intermediate seta short, thin 

 and situated on a dark stripe; the lateral seta is smaller and situated 

 outside the stripe; both setae light. 



Basal part of sclerite "b" of anal legs with a broad black border at the 

 base, with a large reddish brown spot and indistinct dots; basoventral 

 hook is massive, slightly curved and reddish at the end (Figure 225); the 

 ventral plate at the base of the hook and the short seta on it are brownish; 

 the sword-shaped process on the lateral part is well developed, blunt at the 

 end; distal part of sclerite "b" with a wide black border in the middle which 

 bears a short thin dark seta; lateral seta of distal part is long, black; seta 

 of the basal part similar but shorter; the outer sclerite of part "c" of the 

 leg is yellowish, with a dark margin in the middle; ventral sclerite dark 

 brown, with a brownish seta (Figure 225). 



Claw slightly curved, its distal part much shorter than the basal part 

 and with two ventral spinules; the large dark setae 1, 3 and 5 of the claw 

 are blackish and stout; seta 6 shorter and lighter; seta 2 short and yellowish; 

 the basal median seta 4 is straight and light; setae 7 and 8 are transparent, 

 curved and long, reaching to the end of the claw (Figure 225). 



Mode of life and habitats. Mountain brooks and rivulets with 

 a stony bottom and a clean cool water. 



Distribution. Caucasus, Transcaucasia, Iran, the Balkans. 



3. Group Pararhyacophila Dohler 

 Dohler, 1950:272-274, 284-286. 



Full-grown larva. Length 19—25 mm. Head larger and broader than in 

 subgenus Rhyacophila s. str.; frontoclypeus with a characteristic 

 rhomboidal figure in the posterior part; the anterior part often slightly 

 or markedly dark. Dorsal and lateral stripes well marked, broad, with 

 numerous distinct dark dots. 



231 As in Rhyacophila s. str., anterior-angle depression of the pronotum 

 bears 2 long and a small seta. The thoracic gills consist of a short, thick, 

 sausage-shaped filament which is deeply constricted at the base. Abdominal 

 gills (Figure 22 7) situated on the sides of segments 1—8, consisting of four 

 short, fingerlike filaments divided by a constriction; the ventral filament 



is shorter and thinner than the other three; anal legs with a sword-shaped 

 process on the dorsolateral sclerite. 



Young larva. The number of filaments of the abdominal gills is smaller 

 in 2nd-, 3rd-, and 4th- stage larvae, and each tuft consists of only 2 or 3 filaments. 



232 Mode of life and habitats. Mountains; brooks and rivulets with 

 clean cool water, on stony bottom and with more or less rapid current. 



Distribution. Greater and Lesser Caucasus. Southern and Central 

 Europe. 



242 



