Tergite of abdominal segment 9 brown, with indistinct punctation at 

 anterior margin; setae dark brown; medioanal setae long, thick, more than 

 twice as long as width of tergite; anterior-angle setae slightly shorter, 

 thinner; intermediate seta large, strong, only slightly smaller than anterior- 

 angle seta; lateral seta short, thin; surface with 6 setae near posterior 

 margin. 



Sclerites "b" and "c" brown; distodorsal setae of sclerite "b" dark brown; 

 medioanal seta thick, long, markedly longer than neighboring seta; lateral 

 seta much smaller, strong, moderately long; median subapical seta the 

 same; distoventral seta moderately long, strong, brown; surface with 

 2 brown, moderately long setae, 3 short, and 2—3 small, thin setae.- 

 301 Sclerite "c" with blackish brown, wide, lateral margin; seta small, dark, 

 strong. 



FIGURE 528. Chaetopteryx sahlbergi McL. Larval case 

 made of detritus (A), detritus and sand (B),and mainly sand (C) 



Claw mainly pale brown, dark reddish brown apically, pointed with a 

 large, dorsal denticle; seta 1 short, brown, thick, situated subdorsally in 

 basal part on median side; seta 3 situated in the apical part, strong, dark 

 brown, longest, thickest, and darkest seta of the claw; seta 2 thin, moderately 

 long, situated in lateral part of dorsal side near end of suture; seta 6 

 situated slightly more distally and closer to end of suture, short, thin; 

 setae 2 and 6 brown; ventral setae 7 and 8 situated ventrally, one behind 

 the other, close together, short, light, some distance from suture and nearer 

 basal margin of claw; seta 5. situated near 8, small, transparent; median 

 seta 4 small, light, situated subventrally near suture. 



Case 14— 18 mm long, made mainly of detritus or detritus and sand grains 

 (Figure 528, A), rarely of sand only (Figure 528, C), almost straight or 



378 



