Ratio of length of legs 65:100:96; punctation distinct in some 

 places. 



Dorsal process of abdominal segnient 1 small, low. Lateral line 

 beginning at end of abdominal segment 2 with several dark hairs. 

 Gills on segments 2 — 7; segment 2 without presegmental gills. 



Numberand arrangement of gills of H . i n f u ma t us (after Si Itala) 



Segment 



Dorsal 



Pleural 



Ventral 



2 



1 





1 



1 



3 ^ 



1 



1 



1 



1 

 1 



4 



1 

 1 



1 



1 



1 

 1 



5 



1 



1(0) 



1(0) 



1 

 1 



6 



1(0) 

 1(0) 







1 



1 



7 









1(0) 

 1(0) 



Tergite of abdominal segment 9 yellowish; 3 thin, secondary setae 

 between long, dark, medioanal setae. A short, thin, secondary seta 

 near lateral seta. 



Sclerite "b" of anal legs with 6 — 7 small thin setae. 



Case (Figure 493, D) bulky, 30 — 50 min long, covered with coarse 

 fragments of wood usually including a long fragment which projects 

 posteriorly, so that case is 60 — 65 mm long; fragments arranged 

 longitudinally or obliquely; posterior opening with a membrane with 

 a large round hole. 



Pupa. Length 16—21 mm. Antennae reaching to abdominal seg- 

 ments 6 — 7, wing sheaths to segments 3—4. Dorsal process of ab- 

 dominal segment 1 wide, with sm.all spinules at posterior margin. 

 Holding apparatus on segments 3 — 7; number of hooks: III: 3 — 6; 

 IV: 3-7: V: 4-7 +21-23; VI: 4-9; VII: 3-8. Anal rods 1.0-1.1 mm 

 long, with slightly curved end; basal seta larger than others. Lateral 

 lobes of male genitalia (Figure 494) very long, with almost straight 

 posterior margin, much longer than small, bifid penis sheath. 



Pupal case short, attached at anterior end; anterior and posterior 

 opening with thin sievelike membranes with numerous holes. 



Mode of life and habitats. Clear brooks, in parts with slow 

 current; pupae occur from mid-July in Karelia. 



Distribution. Northwestern part of the European USSR. In addi- 

 tion. Central Europe. 



349 



