thin gills, if present. Anal i^ods straight, tapering, with sparse spinules; 

 setae relatively large, situated basally, in middle, subapically and apically. 

 Ventral appendages of male genitalia wide, short, rounded, not longer than 

 bifid penis sheath. 



Case 14— 2 mm long, made, as in larva, usually of sand only or together 

 with detritus, or of detritus only; small stones sometimes present at ends; 

 both openings with sievelike membranes; case attached to stones or tree 

 remains. 



Mode of life and habitats. Usually in running water, but also in 

 lakes, on a bottom of stone or sand and stone; late-hatching species, pupae 

 appear in September; adults, in late October. 



Distribution. Northern, western, and central parts of European 

 USSR. In addition, Europe, except the South. 



2. Genus Annitella Klapalek 



Mode of life and habitats. Running water, open shore of lakes 

 with a moderate surf. 



Distribution. Northern and western parts of the European USSR, 

 Altai, Sayans. In addition, Europe. 



305 1. Annitella obscurata McLachlan (C ha e t opt er y x 

 obscurata McLachlan)* 



Lepneva, 1949:174, 176. 



Full-grown larva. Length 14— 17 mm. Head (Figure 534, A) slightly 

 oblong. Frontoclypeus slightly narrower than in C h a e t o pt e r y x. Dorsal 

 side of head brownish, frontoclypeus slightly darker anteriorly; tentorial 

 pits reddish brown. Rows of 2 or 3 dots on area of dorsal stripes lateral 

 to frontal sutures; 3 large dots near fork; rows and groups of smaller dots 

 lateral to coronal suture. Sides of head with large dots from eye to occipital 

 foramen. Ventral side of head mainly smoky brown, lighter anteriorly, with 

 a large, distinct, light median spot in middle of posterior part; dots near 

 occipital foramen large, on less light background. Gula brown. Setae as 

 in Chaetopteryx (Figure 534, B). 



Labrum reddish brown, as in Chaetopteryx, darker than head; setae 

 the same; a dark spot behind median pit. Mandibles black; sub ventral 

 tooth largest on left mandible, 2 distal teeth and a small tooth-shaped process 

 on dorsal blade dorsal to it, ventral blade of left mandible with a large, distal 

 tooth; right mandible distally with 2 almost equal teeth, one tooth on ventral 

 blade, 2 small teeth on dorsal blade; brush as in Chaetopteryx; lateral 

 dorsal seta short, light brown; ventral seta light, half as large. Sclerites 

 of cardo yellowish brown, black, lateral stripe at anterior margin relatively 

 narrow, spot at median margin small, black. Median sclerites of submentum 

 small, fused with lateral sclerites; seta thin, moderately long, pinkish brown, 

 situated near anterior margin of median sclerites. 



Synonymy, see Schraid, 1955:211. 



383 



