longer than gula. Labrum with broadly membranous margin; dorsal 

 sclerite with a transverse r-ow of 12—22 strong, dark setae anteriorly. 

 Mandibles short, massive, with small blunt teeth distally, both mandibles 

 with dense brushes of light chaetoids in median indentation; lateral setae 

 short, situated near base. 



Pronotum varying in form, sometimes with curved, projecting anterior 

 angles. Mesonotum with large median sclerite and a small anterior-angle 

 sclerite; sclerites sometimes partly fused anteriorly. Metanotum with 

 small, round, anterior-angle sclerites and 2 small median sclerites which 

 are sometimes replaced by sclerotized dots. 



Forelegs shorter than other legs, hind legs much longer and thinner, 

 hind tibia sometimes divided. 



Abdominal segment 1 partly sclerotized; dorsal process not always 

 distinct; lateral processes displaced ventrally, with numerous black hooks 

 on a thin sclerite apically. Lateral line on segments 3—7, with dense light 

 hairs. Gills presegmental, with 2 — 3, rarely one filament on segments 2 — 7 

 or 7—8, in a dorsal, lateral, and venti-al row. 



Tergite of segment 9 relatively large, indistinct. Anal legs wide basally, 

 short. Sclerite "b" with blunt, beaklike distal process curved downward. 



Case made of fi-agments of leaves or detritus, sometimes of pieces of 

 grass stalks or loose, black pieces of wood. 



Mode of life and habitats.' Small, stagnant, or slowly running, 

 sunlit, overgrown water bodies; among vegetation or detritus on bottom. 



Distribution. USSR: the Far East and Transcaucasia. In addition, 

 Europe (Spain), Asia, Africa, America, Australia; mainly in tropical and 

 subtropical regions. 



Key to Genera 

 Full-grown larva 



1 (2). Length about 15 mm; pronotum with curved anterior-angle process; 



anterior-angle tergite of mesonotum relatively large, partly fused 

 with median tergite; hind tibia divided; larval case made of 2 large 



fi-agments of leaves, an upper and a lower 



1. Anisocentropus McL. (p. 500) 



2 (l). Length about 22 mm; pronotum with straight or slightly concave 



anterior mai-gin, without projecting anterior angles; mesonotum with 

 399 large median and small anterior- angle tergites; hind tibia not 



divided; case made of a stalk of grass or a soft black fragment of 

 wood with a tunnel inside 2. Ganonema McL. (p. 506) 



1. Genus Anisocentropus McLachlan 



Only one species, A.pallidus, occurs in the USSR. 

 Mode of life and habitats. Small, sunlit water bodies. 

 Distribution. USSR: Maritime Territory. In addition, Africa, Asia, 

 North and South America, Australia, Sunda Islands. 



500 



