Case made of mineral particles. 



Pupa. Length 15.0— 15.5 mm. Antennae long, coiled around posterior 

 abdominal segments. Labrum wide, with short setae. Mandibles as in 

 Psychomyiidae, long, with thin end. Gills as in larva. Anal rods thin, 

 with curved end. 



Case as in larva, attached at posterior end. 



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



Distribution. Western part of the European USSR and eastern part of 

 the Asiatic USSR. In addition, Europe, East Asia, North and South America. 



Key to Genera 

 Full-grown larva 



1 (2). Head and pronotum with pale pattern, without longitudinal stripes; 



median tergites of metanotum transverse, situated one behind the 



other; case made of mineral particles; the European USSR 



1. Odontocerum Leach (p. 512) 



2 (1). Head and pronotum with dark stripes on light background; tergites of 



metanotum arranged differently, and smaller; case made of plant 



particles; the Asiatic USSR 



2. Psilotreta Banks (p. 519) 



1. Genus Odontocerum Leach 



Only one species, O. albicorne, occurs in the USSR. 

 Mode of life and habitats. Brooks and small rivulets. 

 Distribution. Western part of the European USSR. In addition, 

 Europe. 



1. Odontocerum albicorne Scopoli 



Pictet, 1834: 164, Figure 2.— Klapalek, 1888:35, Figure 12.- Ulmer, 

 1903:99-100, Figures 7, 61, 100.- Thienemann, 1905b: 532-533, 545, Figures 

 60-67.- Siltala, 1907:483-485.- Ulmer, 1909:252, Figure 379.- Lestage, 

 1921: 592-597, Figure 202. - Nielsen, 1942:450—465, Figures 93-103.- 

 Hickin, 1942: 119-122, Figures 1—8. - Lepneva, 1940: 212. 



Full-grown larva. Length 16— 18 mm (Figure 667). Sclerites mainly 

 yellowish light brown; pattern reddish brown with dark brown dots. Head 

 short, broad, slightly wider posteriorly, width about 0.92 of its length; sides 

 straight (Figure 668); eyes at about ^U of length from anterior margin. 

 Antennae situated near anterior margin with small sensillae. Head with a 

 ridge in form of a sclerotized fold from dorsal articulation of mandibles 

 above antenna and eye; ridge becomes less distinct posteriorly, runs along 

 coronal suture, and meets with ridge of opposite side, resembling the crown 

 of Macronematidae. 



Frontoclypeus narrow, with shallow lateral indentations; surface with a 

 pale brownish pattern with triangular posterior part covering entire sclerite, 



512 



