posterior seta. Natatorial setae of midlegs are dense, well developed. 

 Claws of legs well developed, hook-shaped, a soft cylindrical process between 

 them. Sclerites of the raptatorial apparatus are brown and convex; pre- 

 segmental plates on segments 4—7; postsegmental plates on segments 3—5; 

 spinules small, straight and numerous. Gills absent in the larvae even in 

 species with gills. End of body of female pupa blunt; end of body of male 

 pupa with rudiments of the developing genitalia. 



Case 15— 30 mm long, consists of small stones or sand grains; its upper 

 surface not smooth; ventral surface of case open; margin of case attached 

 to the substrate by numerous disks which sometimes have short stems; 

 numerous openings through wall of case between the small stones or sand 

 grains. The pupa is situated in a semitransparent, dark brown cocoon. 



The subfamily Rhyacophilinae Ulm. was established by Ulmer (1903: 

 124-126; 1907:206-207) with the genus Rhyacophila Pict.; Banks (1940) 

 separated from Rhyacophila the Asian genus Himalopsyche Banks, 

 which contains large species; Lepneva (1956) described the new genus 

 Philocrena Lepn. from a larva from Transcaucasia; this genus is 

 represented in Transcaucasia by one rare, high- mountain, relict species. 



Mode of life and habitats. Living in rapidly running brooks and 

 rivulets with a usually stony bottom. 



Distribution. Throughout the USSR and also in Europe, Asia and 

 America. 



Key to Genera 

 Full-grown larva 



1 (2). Gular suture markedly longer than gula; second segment of maxillary 



palps markedly longer than the other segments. Pronotum relatively 

 smooth, without sculpture and without longitudinal row of setae 

 parallel to the median suture; gills, if present, of varying form; 

 anal legs normally developed; sclerite "b" sometimes with a lateral 



process. Widely distributed throughout the USSR 



1. Rhyacophila Pict. (p. 217) 



2 (l). Gular suture not so long; second segment of maxillary palps not 



longer than the other; pronotum of different structure; gills, if 

 present, in the form of a comb of filaments on a narrow, conical, 

 lateral process of the segment; anal legs of different structure. 

 Rare. 



3 (4). Body markedly flattened; pronotum with a longitudinal row consisting 



of one primary seta and several thinner secondary setae on both 

 sides of the median suture; tracheal gills in the form of a comb of 

 filaments on a long, narrow, conical process; anal legs relatively 

 short; sclerite "c" sometimes with a long process which is forked 

 at the end. Middle Asia 2. Himalopsyche Banks (p. 298) 



4 (3). Body nearly cylindrical; pronotum oblong, with a sculpture consisting 



of ridgelike and tuberculate processes; sides of meso-, metathorax 

 and first abdominal segment with rounded tubercles; tracheal gills 

 absent; anal legs very large, and the claws are unusually long. 

 Transcaucasia 3. Philocrena Lepn. (p. 308) 



217 



