TABLE 11 









Ventral 





Segment 



Plonrol 











lateral 



median 



Mesothorax 







21-25 





Metathorax 



- 



- 



18-20 



19-20 



1 



- 



- 



16-18 



18-20 



2 



- 



9-14 



14-15+17-20 



15-16 



3 



8-10 



9-12 



11-15+13-14 



12-14 



4 



8-11 



10-12 



10-15+12-15 



12-13 



5 



7-8 



9-13 



11-12+12-13 



12-13 



6 



8-9 



10-11 



10-12+12-14 



8-9 



7 



- 



8-12 



6-8+8-9 



- 



8 



— 



— 



5-8+5-6 



- 



(4 73) 



FIGURES 672 and 673. Arctopsyche ladogensis Kol.: 



672 - gills of middle segment, ventral; 673 — claw of left anal leg, outer view (A), 

 inner view (B). 



Segment 9 with 2 weakly sclerotized yellowish sclerites with minute 

 covering setae dorsally, in the anterior half; a small band of such setae 

 situated posteriorly between the sclerites. Posterior half of sclerite light, 

 without setae; this part of the sclerite covered by the fold between 

 segment 9 and the anal legs in the normal position; transverse anal slit 

 situated near the posterior margin. Five anal gills. Primary dorsal setae 

 situated at the posterior margin of the sclerites, displaced to the anterior 

 half of the segment; medioanal seta longer and thicker than the others, 

 light brown; anterior- angle seta similar, slightly smaller; a light, smaller 



538 



