dorsoventral filaments; only the ventral filament of these gills sometimes 

 present; gill of segment 6 with only a ventral filament, or gill absent; 

 segment 7 without gills. 



Lateral lobes at end of body relatively narrow, with strong, dark setae; 

 penis sheath broad and rounded at the end. 



Pupal case to 12 mm long; walls loose, with a covering of sand grains 

 and detritus. 



Mode of life and habitats. Predacious, building capturing nets; 

 living in lakes and slow rivulets and brooks. 



Distribution. The western and central regions and south of the 

 European USSR, the Caucasus. In addition, Europe, Iran. 



3. Cyrnus insolutus McLachlan 



Siltala, 1903c:10-ll, Figure 3; 1905:131-132, Figure 35. - Ulmer, 

 1909:230,296.- Lestage, 1921 :504-510, Figures 168-169. 



Full-grown larva. Length 11 mm. Sclerites yellowish; punctate 

 pattern distinct; membranous parts darker than in C. flavidus, with a 

 pinkish tone. Frontoclypeus mainly slightly dark; its middle light; dots 

 distinct on dark background; curved row of large dots posterior to the 

 sclerite sharply marked. Dorsal surface of head mainly brownish lateral 

 to the frontal sutures or brown only near the sutures; dorsal stripes 

 indistinct; large dots present in their place, along the coronal suture and 

 along the sides. Light spots at the base of setae; sclerites dark ventrally 

 at the sides near the occipital foramen, with large groups of distinct dark 

 dots; gular suture with a narrow, dark margin. 



Propleuron with distinct dots; hornlike process dark; pleural sclerites 

 of meso- and metathorax brown. Coxae, femora and tibiae with dark dots. 



Sclerite of section "b" of anal legs yellow, with large dots; claw dorsally 

 with 1 or 2 small spines in the region of the subapical band. 



Pupa. Length 6.0— 6.5 mm. Antennae almost reaching end of body. 

 Labrum and mandibles as in C. flavidus. Wing sheaths reaching end of 

 segment 5 or middle of segment 6; natatorial setae present on the tarsi of 

 fore and midlegs. Gills present on segments 2—7; gill of second segment 

 sometimes with a dorsal and a ventral filament; this gill has only a dorsal 

 filament in most specimens; segment 2 without gills in some specimens; 

 segments 3—6 with 2 gill filaments; segment 7 with only a ventral filament 

 or also with a short, dorsal filament. Plates of holding apparatus present 

 on segments 3—8; number of spinules as follows: 111:6—12; IV:6— 9; 

 V-.6-9+ 11-16; VI:8-13; VII:6-8; VIII:5-7. 



Anal lobes of male pupae with rounded indentations on the inner side; 

 they are narrower at the end and widely separated in female pupae. 



Pupal case 9— 13 mm long. Walls of case loose; case covered mainly 

 with fine plant detritus, sometimes also with silt and larger fragments of 

 plants; pupa lying in a gray, thin cocoon. 

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



Distribution. West of the European USSR. In addition, Europe 



(rare). 



518 



