Abdominal segment 1 with large, saddle-shaped dorsal process or 

 with 2 small lateral processes. Holding apparatus on segments 3—7 or 

 3—8; postsegmental plates on segment 5 transverse. 



Anal appendages rodlike, narrow, slightly curved at the end, rarely 

 lobe-shaped as in Lepidostomatidae; anal rods reduced, small, and thin 

 or absent in pupae living outside water. 



Case as in the larva, attached to the substrate by varying methods, 

 or pupae lying free on the bottom. Anterior and posterior openings 

 of case closed by a membrane which may be sievelike or with only a 

 few holes; case covered with plant fragments, sand grains, rarely with 

 small stones. 



Mode of life and habitats. Running and stagnant water, on 

 stones, on sand -detritus bottom, or among vegetation; rarely on solid, 

 slightly silty bottom in the sublittoral. 



Distribution. Throughout the USSR. In addition, Europe, Asia, 

 North America, western zone of South America, Mediterranean coast 

 of Africa, some localities on the Pacific coast of Australia. 



Key to Subfamilies 



Full-grown larva 



1 (4). Anterior margin of pronotum rounded, projecting anteriorly, 



covering the head from above. 



2 (3). Only primary setae on head; metanotum with a pair of small, 



anterior, median sclerites 2. Neophylacinae Schm. (p. 95) 



3 (2). Small secondary setae present on head in some species; 



metanotum without median anterior sclerites 



3. Apataniinae Ulm. (p. 103) 



4 (1). Anterior margin of pronotum slightly projecting, straight or slightly 



concave. 



5 (6). Light lines on head in some species, as in Lepidostomatidae. 



Fore femur generally resembling mid- and hind femora but slightly 

 shorter and wider; tibia rodlike, slightly wider distally. Gills of 

 varying structure 1. Dicosmoecinae Schm. (p. 74) 



6 (5). Light lines on head absent. Fore femur short, massive; tibia 



wide, short, markedly wider distally. 



7 (8). Pronotum with sharp, transverse ridge ("hump"). Gills single. 



Length 8— 14 mm 5. Drusinae Banks (p. 388) 



8 (7). Pronotum without "hump." Gills with 1, 2, or 3 filaments. Larva 



medium-sized or large, 30— 32 mm ... 4. Limnophilinae Kol. (p. 177) 



Pupa 



1 (2). Anal appendages wide, lobe-shaped or rodlike, small and thin .... 



1. Dicosmoecinae Schm. (p. 74) 



2 (1). Anal appendages narrow, rodlike. 



3 (8). Apex of mandibles relatively slightly narrowed, medium blade 



angular, serrated. Gills single. 



73 



