Number and arrangment of gills of Ch. ma cla ch la ni 



Segment 



Dorsal 





Pie 



ural 



Ventral 



2 





1 



1 





3 





1 



1 





4 











5 



1(0) 









6 









1 (0) 



Pupa. Length 12 — 15 mm. Antennae filiform, i-eaching end of abdominal 

 segment 7, scape slightly larger than following segments. Anterior 2 of 

 5 large, hooked setae of labrum shorter than posterior 3. Wing sheaths 

 reaching end of abdominal segment 3. Mid-tarsi natatorial, with dense 

 setae; hind tarsi with sparse setae. 



Presegmental plates of holding apparatus with 3—4 hooks, postsegmental 

 plates of segment 5 with 10—12 hooks. Presegmental gills on segment 2 

 absent. 



Anal rods thin, slightly curved at end; basal seta longer than others, 

 2nd seta situated at beginning of apical third of rod, other 2 setae subapically 

 and apically. 



Case as in larva. 



Mode of life and habitats. Mountain and spring-fed brooks, on 

 stones among moss. 



Distribution. Northern part of the European USSR, northern Urals. 

 In addition. Central Europe mountains. 



5. Subfamily DRUSINAE Banks (Ecclisopteryginae 

 Nielsen, Drusinae Schmid) 



309 



Full-grown larva. Length 10—14 mm. Sclerites of head and pronotum 

 and some other parts of body rugose, shagreened with stripes of small 

 tubercles in reticulation; membranous parts of integument also rugose, 

 with dark tubercles or minute spinules. Head short, wide in middle, 

 narrower anteriorly; dorsal surface flat anteriorly. Eyes situated in 

 broad middle of head, antennae between eye and anterior margin. Anterior 

 margin of labrum membranous, trilobed, with median and lateral processes. 

 Mandibles scraping, with chisel-like distal part; teeth snaall or absent. 



Pronotum flat or concave anteriorly, convex in other parts; stripe 

 between concave and convex parts forming a hump or blunt angle, best 

 visible in lateral view. Mesonotum wider than pronotum, with distinct, 

 black margin posteriorly and laterally. Antei-ior tergites of metathorax 



388 



