Claw with 3 large, dorsal denticles in a row; middle denticle smaller; 

 seta 1 short, dark; seta 2 long, situated near dorsal margin of bar; seta 3 

 dark brown, long, the longest on the claw; seta 6 thick, situated on outer 

 side; ventral setae 7 and 8 relatively large, light, straight; seta 5 situated 

 near 8, small, light, in form of thin spine; seta 4 similar but slightly smaller. 



Case made of pieces of plants arranged in 7—8 turns of spiral (Figure 

 69). 



Pupa. Length 14 — 18mm. Frontal sclerite swollen at base, with 

 wide, brown stripe in old pupae. Antennae with short scape, filiform, 

 reaching abdominal segment 6 in male pupae. All 6 setae of labrum 

 situated near anterior margin, thick, black, of about the same length. 

 Apex of mandibles blunt, short; outer setae relatively large, thick, situated 

 near tubercle. Natatorial setae on mid-tarsi less dense than usual, 

 sparse on fore and hind tarsi. Dorsal process of abdominal segment 1 

 large, with slightly concave apex. Setae of lateral line dense, dark, 

 especially long on segment 8. Gills on segments 2—8; a dorsal and a 

 ventral gill near anterior margin of segment 8. Holding apparatus on 

 segments 3-7; number of spinules : 111:4-6; IV:4-5; V:4-5+6; Vl:5-7; 

 VIl:4-6. 



Anal appendages pointed posteriorly, with 4 long, black, thick setae. 

 Sheath of ventral appendages of male genitalia forming wide blunt processes; 

 penis sheath short. 



Pupal case to 24 mm long, among littoral vegetation. 



Mode of life and habitats. Stagnant and slowly running water, 

 usually swampy, with brown peaty water; often in peat deposits and draining 

 ditches. 



Distribution. Northern, central, and western territories of the 

 European USSR. In addition. Northern and Central Europe. 



2. Oligotricha lapponica Hagen (N e u r o n i a lapponica Hag.) 



Siltala, 1905:5-9, Figure 1.- Lestage, 1921 :572-579, Figure 192c. 



FIGURES 70— 73. Oligotricha lapponica Hagen (after 

 Siltala): 



70 — frontoclypeus; 71 — pronotum; 72 — left mandible of 

 pupa, ventral; 73 — anal lobes of female pupa, ventral. 



54 



