ventral seta situated subapically, as on tibia, in foi-m of a thin, pointed, 

 light spine; anterior ventral seta subventral, slightly more distal, thin, spine- 

 shaped, brownish; distoventral spinule blunt, thick, others small, thin, 

 situated ventrally in distal half, subventrally in basal part and in middle. 

 Claw longer and thinner than on forelegs, more curved; basal seta similar, 

 small, light. 



Hind coxa (Figui'e 652, C) shorter than mid-coxa; femui- thicker; tibia, 

 tarsus, and claw slightly longer; chaetotaxy the same. 



Abdomen green in live specimens, nearly cylindrical anteriorly; segment 1 

 shorter than following segments, without doi'sal oi' lateral processes; 

 segments 2—4 of equal size, segments 5—8 tapering; segment 9 much smaller; 

 anal legs thick, projecting laterally. Hairs of lateral line and gills absent. 



Tergite of segment 9 small, grayish brown, little differentiated; medio- 

 anal setae long, brown; anterior-angle setae the same; intermiediate and 

 397 lateral seta moderately long, latter seta darker, thicker, and longer than 

 former; one seta between medioanal setae. 



Sclerite "b" of anal legs chestnut brown, with indistinct outline; dorsal 

 median seta chestnut brown, very long, thick; neighboring seta also thick, 

 slightly shorter; lateral seta thinner, almost half as long, 6—7 thin, short to 

 moderately long setae lateral to it; a long dark seta apically at median 

 margin; 4 light, grayish, thin, short to moderately long setae basally; ventral 

 seta light, small, brownish. Sclerite "c" chestnut brown, with dark reddish 

 brown lateral margin and a small light seta. 



Claw brown basally, reddish brown distally, with 2 dorsal denticles; 

 seta 1 situated basally, short, brown; seta 2 very thin, light, moderately long, 

 situated dorsal to suture; seta 6 situated subdorsally and laterally at suture, 

 short, brown; seta 3 situated subdorsally on the median side, brownish, 

 moderately long; ventral setae 7 and 8 short, light; seta 5 small, light, 

 situated laterally; seta 4 similar, situated on inner side, both near seta 8. 



Case 4.5—5.5 mm long (Figure 653), much longer and wider than larva, 

 smooth, narrower posteriorly, with round cross section, made of fine, densely 

 arranged sand grains. 



Pupal case to 6 mm long, sometimes made entirely or in part of secretion, 

 with a sievelike membrane at each end with numerous, very small holes. 

 Case attached to substrate by thick, dark brown ligaments from margin at 

 anterior and posterior end. 



Mode of life and habitats. Mountain rivers and rivulets. 



Distribution. USSR: The Caucasus (Zanga River). 



2. Micrasema setiferum Pictet 



Siltala, 1905:26-28, Figure 7.- Ulmer, 1909:277,320.- Lestage, 1921: 

 880-886. 



Full-grown larva. Length 5—6 mm. Head yellowish brown; fronto- 

 clypeus darker anteriorly, posterior part with a wedge-shaped pattern of 

 dark and light dots. Mandibles short, massive, each with 3 blunt teeth and 

 a small, tooth-shaped process. 



Pronotum (Figure 654) wide, with a characteristic curved, transverse 

 ridge with 4 setae on each side; a row of setae near and at anterior margin. 



498 



