black, situated at end of stripe, 3 of them long and thick, middle seta larger 

 than others, 4th seta thin, strong, situated medially. Claw pinkish brown, 

 with 2 dorsal denticles. 



Number and arrangement of gills of A . senilis (after Siltala) 



Segment 



Dorsal 



Pleural 



Ventral 



1 



1 





1 



1-2 



2 



10 



1 



8 



3 



6 





7 



4 



2 

 2 





1 

 2 



5 



2 

 2 





1 

 2 



6 



2 

 2 





1 

 2 



7 



1 



1 





1 

 2 



8 



1 





1 



Case made of secretion, as in A. fulvus ; posterior membrane with 

 wide, curved slit dorsally. 



Pupa. Length 8— 10 mm. Antennae of male pupae coiled 4.5 times around 

 posterior end of body. Labrum rounded anteriorly and laterally, without 

 anterior median process; setae thin, reddish brown. Mandibles dorsally 

 with whitish basal part; apical part dark brown, blade straight, coarsely 

 serrated, with slightly curved, pointed end; lateral setae light, of equal 

 length. 



Wing sheaths of male pupae reaching end of segment 8. Mid-tarsi 

 natatorial, with dense, golden brown setae. 



Dorsal, posterior-angle processes of abdominal segment 1 narrow, reddish 

 brown. Holding apparatus on segments 3—7 (Figure 743, A, B); number of 

 spinules: 111:3; IV:3; V:2— 3 + 13(22); Vl:4; VII:3. Gills on segments 2— 8. 



Dorsal processes of abdominal segment 9 with 4 black setae, 3 of them 

 thick, of different length, 4th seta short, thin, situated behind others. Anal 

 rods (Figure 744, A) narrow; anterior part uniformly wide; posterior part 

 much longer, tapering, curved upward, with hooked ends; 2 small, light, 

 median processes situated one behind the other between wide and narrow 

 part on left rod, a larger process on right rod; one seta situated between 

 wide and narrow part, one in middle of posterior part, 2 small setae 

 subapically. Sheath of genitalia lobe- shaped, curved inward, penis sheath 

 short. 



Case attached at both ends by disks; anterior disk wide, flat, free part 

 of the membrane with a wide, elliptical or semicircular opening directed 

 anteriorly or obliquely downward (Figure 744, B,C). Posterior end narrower 

 attached by a stalked disk which raises case slightly above substrate; 



577 



