of short, brown filaments; dorsally, close to the point of attachment, 

 anterior end of case covered by a membrane with 8—10 holes; posterior 

 opening of case small, round, membrane with numerous holes (Figure 121 ). 



Mode of life and habitats. Lakes, clear brooks, mountain rivers 

 and rivulets, on stones, on solid bottom of sand and detritus, close to shore, 

 often in large numbers, a few specimens occur deeper, to 9 m. 



Distribution. Northeastern part of the European USSR, West and 

 East Siberia; Altai, Sayans, the Maritime Territory, Sakhalin, Shantar 

 Islands. In addition, Mongolia. 



2. Genus Ecclisomyia Banks (P r a e c o s m o e c u s Mart.) 



Full-grown larva. Medium-sized, at most 12— 13 mm long. Head and 

 thoracic sclerites dark, without pattern. Forelegs short. Gills single. 

 Case straight, of uniform width, made of small and large sand grains, 

 with rough surface. 



Pupa. Labrum with rounded anterior margin. Mandibles with serrate 

 median blade. Wing sheaths reaching segments 3—4. Holding apparatus 

 on segments 3—7. Anal appendages short, lobe -shaped, curved, pointed; 

 subapical setae thick, long. Case, as in the larva, with dome -shaped 

 anterior and posterior end; holes in membranous parts among sand grains 

 of cover. 



Distribution. USSR: Kamchatka, Kurile Islands, the Maritime 

 Territory and Amur Region, Sayans, Altai. In addition. North America, 

 including Alaska and California. 



1 . Ecclisomyia digitata Martynov (Praecosmoecus 

 digitatus Mart.) 



Lepneva, 1 949: 179-1 80, Figures 38-40. 



Full-grown larva. Length 11— 12m2Ti. Head (Figure 122) chestnut 

 brown, slightly lighter laterally near occipital fbramen; dots visible only 

 in preparations. Eyes on light area, far from anterior margin; antennae 

 situated between eye and base of mandible. Frontoclypeus with wide 

 anterior part; posterior part with triangular pattern of large reddish 

 brown dots; similar dots lateral to coronal suture on the dorsal and 

 lateral stripes and ventral side. Median and intermediate anterior -margin 

 setae brown, moderately long; lateral anterior-margin seta light, curved; 

 anterior frontal seta the same, intermediate frontal seta long, one of the 

 longest on the head; posterior frontal seta short, thin, dark. Seta 9 dark, 

 long; seta 11 situated further posteriorly, short; seta 7 short, situated 

 near anterior margin; small, light seta 10 situated laterally in front of 

 eye; seta 12 situated behind eye, moderately long; setae 13 and 14 situated 

 in the middle, 13 small, 14 thick, dark, longest on the head; seta 15 thin, 

 long; seta 17 slightly longer and thicker; seta 16 short, procumbent, light. 

 Ventral setae 8 and 18 small, thin. Gula in form of oblong triangle, 

 slightly narrower anteriorly; gular suture longer than gula (Figure 123). 



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