7 (4). Larvae of a different form, large or medium sized; tracheal gills 



absent; abdominal segment 9 without dorsal sclerite; case absent. 



8 (9). Dorsal side of labrum membranous and movable in its greater 



part, with broad, straight, anterior margin and narrow, posterior 



margin; a small sclerite at the base of the labrum 



IV. Philopocamidae Steph. (p. 408) 



9 (8). Labrum sclerotized dorsally. 



10 (ll). Larvae larger, to 40 mm long; head and pronotum oblong; narrow 



labium has an ordinary structure, with small palps; sclerites have 



a distinct, dark punctate pattern 



V. Stenopsychidae Mart. (p. 423) 



11 (lO). Larvae medium sized; head almost as long as broad; labium 



prolonged in a narrow ligula; labial palps absent 



VI. Psychomyiidae Kol. (p. 440) 



12 (l). All segments of the legs or only the coxae with usually numerous, 



large secondary setae; sides of the abdomen with a longitudinal 

 row of thin, light setae; if this row is absent, abdominal segments 

 are densely covered with small, dark chetoids; meso- and meta- 

 notum sclerotized; if they are membranous, the anal legs are very 



long, with a large number of long, strong setae 



II. Superfamily Neochaetoidea Lepn. (p. 465) 



13 (14). Only pronotum sclerotized; anal legs very long 



VIII. Polycentropodidae Ulm. (p. 472) 



14 (13). Nota of all 3 thoracic segments sclerotized; anal legs shorter. 



15 (16). Secondary setae of legs present only on coxae; tracheal gills 



absent VII. Ecnomidae Ulm. (p. 465) 



16 (15). All leg segments with numerous secondary setae; tracheal gills 



numerous. 



17 (18). Frontoclypeus with distinct lateral notches; gula extending to 



occipital foramen; meso- and metanotum with a transverse suture 

 EX. Arctopsychidae Mart. (p. 528) 



18 (17). Frontoclypeus without lateral notches or lateral notches little 



marked; gula small, triangular; meso- and metanotum complete, 

 without suture X. Hydropsychidae Curt. (p. 543) 



Pupa 



1 (12). Tracheal gills absent; anal appendages absent or very small and 



narrow, with 2—7 setae; if there are more setae (29—30) the 

 appendages are short and cylindrical; pupae large (26— 30 mm), with 



long antennae curled around the posterior end of the body 



I. Superfamily Paleochaetoidea Lepn. (p. 214) 



2 (3). Pupae small (2.2— 5.0 mm); wing sheaths narrow, pointed, extending 



to body's end or slightly beyond it; cases sac -shaped, of various 

 form, usually more or less flattened laterally or dorsoventrally, 

 consisting of secretion with a covering of algae or fine sand grains 

 2 qo III. Hydroptilidae Steph. (p. 345) 



3 (2). Pupae large, medium sized or small; cases cavelike, rarely (Macrone- 



matinae) irregularly tubular. 



213 



