large dark spots are present laterally, near the posterior margin. Medio- 

 anal setae widely separated; they are long, dark brown and thick; inter- 

 mediate setae also long but lighter and thinner; lateral setae light, short 

 and thin; anterior -angle setae large and dark. The large lateroventral seta 

 is situated in the pleural region on a small dark brown sclerite; intermediate 

 255 ventral seta brown, thinner and shorter, medioventral seta small and 

 setuliform. 



Anal legs short (Figures 261—264). Dorsolateral sclerite "b" with a 

 broad dark brown basal margin; ventrobasal hook blunt and slightly curved, 

 reddish, with a broad, blackish brown base; ventral sclerite near it small 

 and yellow; the seta on this sclerite light and spinelike. The groove 

 extending from the basoventral to the dorsodistal angle of the basal part 

 of the sclerite is darker than the other part of the surface; the transverse 

 groove perpendicular to the basal groove is clearly marked; a sword-shaped 

 process absent; dorsal seta of the basal part of the sclerite long and strong. 

 Apical part of the sclerite irregularly rhomboidal, broadly black in the 

 middle and brownish in the other part; in Rhyacophila s. str.,the medio- 

 basal seta of this part is thin and little marked; in Rh. retracta this seta 

 is dark, strong and long; outer dorsodistal seta dark, thick, and the longest 

 seta of the anal legs. The medioventral sclerite of section "c" is yellow; its 

 seta is spinelike, light and slightly shorter than the ventral seta; the second 

 sclerite of section "c" is larger, extending to the side of the leg; it forms 

 an irregular triangle; a small dark brown, stump- shaped sclerite with a 

 small hook-shaped process (the homologue of the sword-shaped process of 

 the Rh. impar type) near the angle of the sclerite adjacent to the latero- 

 dorsal sclerite; this process is wedged between the above sclerite of 

 section "c" and sclerite "b." 



Claw strongly curved (Figures 264 and 265); unlike in many species, 

 seta 1 in the basal part of the claw is thinner than seta 2, which is light, 

 thick, strongly curved, resembling seta 2 of the claw of species of Him a - 

 lopsyche; however, it is longer than this; outer seta of the basal part 

 (seta 5) longer than the transparent, curved ventral setae 7 and 8; seta 8 

 situated on a tubercle; the mediobasal seta 4 is situated near seta 8; it is 

 the longest and thickest seta of the claw; setae 3 and 6 are situated on the 

 dorsal outer side of the apical part; two large massive spines on a 

 common base are present on the ventral side. 



Mode of life and habitats. Mountain brooks and rivulets with 

 cool water and a water temperature of 9—12° in summer; they live in rapid 

 current on the lower surface of stones. 



Distribution. USSR: Altai, Maritime Territory. Not recorded 

 outside the USSR. 



2. Rhyacophila laevis Pictet 



Thienemann, 1912:250-251, 255-256, Figures 1-5.- Lestage, 1921 :418. 

 Krawany, 1935:245, Figure 2.- Dohler, 1950:286. — Botosaneanu, 1952b: 

 895-907, Figures 1-5; 1956c:590-594, Figures 1-3. 



Full-grown larva. About 10—11 mm long (Figure 2 66). Head reddish 

 yellow, with a pale, punctate figure; occipital foramen with a narrow 

 blackish brown border. Frontoclypeus with a curved row of indistinct 



271 



