Dorsal sclerite of segment 9 trapezoidal (Figure 400); anterior- 

 margin seta clearly marked, situated in the middle of the sclerite, curved 

 posteriorly and inward; other setae of dorsum situated near the posterior 

 margin; medioanal seta strong (as on the preceding segments), longer than 

 the others; anterior-angle seta thinner and also long, posterolateral seta 

 slightly thicker (like the anterior -margin seta) and curved posteriorly and 

 inward; short lateroventral seta situated on a small sclerite at the sides 

 of the segment; the other two ventral setae also situated on a small sclerite 

 in the middle; anterior seta short and posterior seta long. 



Anus situated between two deep folds. Anal legs situated lateral to the 

 folds, short (Figure 400); sclerite "b" covering the anal leg dorsally and 

 laterally; distodorsal seta of the 4 setae of this sclerite, thick, long, the 

 longest seta of the anal legs; subapical seta and seta on the bridge much 

 shorter; lateral seta situated near the ventral margin, small and thin. 

 Sclerite "c" curved, large, with a short seta. Claw (Figure 401 ) with 

 relatively large basal part and apical part bent at a right angle. All 8 setae 

 of the claw present: seta 2 in the basal part situated on the outer side near 

 the transverse stripe; seta 1 situated dorsally in the middle; both setae 

 relatively long; seta 3 is the longest seta of the claw, situated dorsally in 

 the middle in the distal part, near the bend; the much shorter seta 6 

 situated on the outer side medially, the long seta 4 is situated in the basal 

 part near the dorsal margin; short seta 5 situated subventrally, on the outer 

 side; setae 7 and 8 form short spines. 



The larva begins to build the case only after molting into the 5th stage; 

 the cases of full-grown larvae may therefore be at different stages of 

 construction (Figure 402); filamentous algae are used much more in the 

 early stages of construction than in complete cases; the algae are not 

 well visible in complete cases, because of the thicker walls and the 

 decomposition of the algae. 



Young larva. The most prominent characters of the young larva of 

 A. mu It ipu n c t at a are its generic characters: the rounded head with the 

 extremely long setae 9, 12 and 17, the abdominal setae, which are almost as 

 long as the above setae, and the long, characteristic setae of the anal legs 

 (Figures 403,404"). 



The freshly hatched larva is 0.75 mm long; width of head of 1st stage 

 0.13 mm, of 2nd stage 1.16 mm, of 3rd stage 0.21 mm, of 4th stage 0.2 6 mm. 

 Membranous areas of the body greenish; coloration of the sclerites changes 

 during development; the sclerites are light in the 1st stage; only head and 

 pronotum are brownish yellow; the margin of the occipital foramen, the 

 posterior margin of the pronotum, the pleural suture and the margin of the 

 coxae become dark in the 2nd and 3rd stage; some characters of the 

 coloration, which are characteristic for the full-grown larva appear already 

 in the 4th stage. 



The setae of the head of the young larvae are relatively longer than in 

 full-grown larvae; some of them (e. g., setae 13 and 16) are thinner; the 

 setae are still little differentiated, e. g., the lateral anterior-margin seta 

 and the anterior frontal seta of the frontoclypeus are straight in the 1st, 

 2nd and 3rd stage and become curved inward only in the 4th stage. 



The projecting blades of the left mandible of the young larva (Figure 405) 

 have with well-marked teeth in the 1st and 2nd stage; upper blade with 

 5 teeth, lower blade with 4; the teeth are still present in the 3rd stage but 



359 



