with 3 short setae, a similar seta in middle; primary anterior seta situated 

 almost ventrally, short, strong, reddish brown; primary, apical ventral 

 seta long; basal seta much shorter; the 3 anterior of the 5 secondary, 

 ventral setae short, the 2 posterior setae moderately long. 



Number of gill tufts in A. excisus (after Siltala) 



Segment 



Dorsal 



Ventral 





1 







2 



1 









1 



1 



1 





1 





1(0) 



3 











1 



1 



1 



4 



1(0) 







1 



1 



1(0) 



5 



1 



1 



6 



1 



1 



7 





1 



451 



Tibia straight, narrow, longer than femur, with a longitudinal row of 

 8 moderately long setae dorsally; 3 distal setae light, very thin; 4th and 

 5th seta slightly thicker and darker than others; 3 basal setae also long, 

 accompanied by 2 — 3 small, light setae; anterior surface distally with a 

 long reddish brown seta projecting laterally (primary? ); posterior surface 

 with a long, brown, but thinner seta in middle; subdorsal and subventral 

 areas with a short seta; ventral setae in form of a row of short, light 

 spines. 



Tarsus long, narrower, and slightly shorter than tibia, with 8 thin, 

 moderately long setae dorsally, 3rd and 4th seta, and 5th and 6th seta, 

 forming pairs anteriorly and posteriorly; posterior surface distally with 

 a long, reddish brown (primary? ) seta; 4 (sometimes 3) light spinules 

 ventrally. 



Abdominal segment 1 and metathorax are widest part of body; abdomen 

 tapering posteriorly; dorsal process large, medioanal seta reddish brown, 

 moderately long, situated on process; brownish black sclerite lateral to 

 lateral processes slightly curved, in contrast to the aterrimus group; 

 a thin, moderately long, brown seta near distal margin; a small brownish, 

 weakly sclerotized area with light spinules nearby, slightly basally. 



Gills on segments 2 — 7 in one dorsal and 2 ventral rows; segment 2 

 ventrally with a gill with 3 short, thick filaments in median row, with one 

 filament in lateral row. 



Tergite of segment 9 absent, in contrast to the aterrimus group; 

 surface setae situated posteriorly on a membranous area, as on preceding 

 segments; medioanal seta reddish brown, long; intermediate and lateral 

 setae small, thin, yellowish; anterior-angle seta short, brown. 



Sclerite "b" of anal legs brown; the intermediate of the 3 large, 

 distodorsal setae black, long, thick, other 2 smaller, blackish brown; 



564 



