3. Genus Macronema Pictet 



Full-grown larva. Length 2 0—22 mm. Head flattened dorsally, with a 

 horseshoe-shaped ridge with a crown of numerous strong, long secondary 

 setae. Anteclypeus with transverse sclerites. Submentum trapezoidal. 

 Process of trochantin of prothorax conical. Tibia and tarsus with a dense 

 brush of thin, light, hairlike setae. Anal legs relatively long. 



Mode of life and habitats. Building capturing nets, living on 

 bottom of rivers. They feed on microplankton, according to Sattler (1963). 

 518 Distribution. Ob, Yenisei and Amur basins in the USSR. In 



addition, Asia, America (mainly South America), Africa and Australia. 



1. Macronema radiatum McLachlan 



Lepneva, 1947:142-147, Figures 1-16; 1960a:175-l 78 (Figures 1 and 2). 



Full-grown larva. Length 20—22 mm (Figure 729). Head broad, flattened 

 dorsally on frontoclypeus and adjacent parts of lateral sclerites bordered 

 by a ridge (Figure 730); frontal sutures (unlike in Hydropsyche) with 

 lateral curvatures in region of tentorial pits. Large spots near ridge near 

 posterior angle of frontoclypeus; these spots indistinct or slightly dark; 

 similar spots lateral to sclerite posteriorly between frontal sutures and 

 ridge, sometimes also posterior to ridge. All 3 anterior-margin setae 

 situated close together in angles; lateral seta long, brown; intermediate 

 setae short; median seta larger; both latter setae light and thin; a light 

 secondary seta near margin of sclerite. Anterior frontal seta thin and 

 small; a similar secondary seta further anteriorly in some specimens; 

 middle frontal seta small, situated near suture, posterior to tentorial pit; 

 posterior frontal seta slightly longer, situated near suture in region of 

 posterior-angle spots. Surface of sclerite posterior to ridge and lateral to 

 tentorial pits smooth and without chetae; other part of frontoclypeus and 

 lateral sclerites surrounded by the ridge punctate because of presence of 

 canal pores; these pores are funnel-shaped, with a curved, thin hair, 

 sometimes 2 hairs, situated in them (Figure 731). 



Seta 9 near the frontal suture, brown, longest seta of head; thin and short 

 seta 11 situated near it; seta 7 smaller than seta 9, situated near dorsal 

 articulation of mandibles; small light seta 10 situated anterior to eye; 

 seta 16 situated near frontal suture, strong, brown and long near the spots; 

 small, light seta 15 situated slightly anteriorly and laterally, near ridge. 

 A row of 12 — 16 strong, brown, long setae situated laterally along ridge, 

 among them several short and light setae and a ridge without setae 

 posteriorly. 



Ventral side of head with 2 rows of transverse dashes (Figure 734). Gula 

 absent, but gular suture anteriorly curved laterally in some specimens, 

 probably a trace of the margin of the gula. Seta 8 thin and short, situated 

 near ventral articulation of mandible; seta 18 very small, situated in the 

 posterior part. 



Two brownish, transverse sclerites near posterior margin of anteclypeus; 

 these sclerites divided by a narrow membranous stripe in the middle. 



592 



