417 



Gills only presegmental, dorsal on segments 2 — 7, ventral on segments 

 2 — 8; a lateral row of gills could not be found in the only specimen in the 

 collection of the Zoological Institute. 



Tergite of abdominal segment 9 small, anterior margin brown, with small 

 light dots; posterior margin with shallow median indentation; medioanal 

 seta dark brown, moderately long; anterior-angle seta similar; 

 intermediate and lateral seta small, thin; lateral ventral seta short, brown. 



Anal legs wide, short, strongly convex laterally. Sclerite "b" chestnut 

 brown dorsally and laterally, yellow in lateral ventral part; all 3 distodorsal 

 setae of sclerite equally thick, dark brown, long; a short brown seta nearby 

 subapically, a dark, strong, i-noderately long seta in light area. Sclerite "c" 

 large, yellowish brown, with a strong, moderately long, brownish seta. 



Claw (Figure 680) moderately long, with a narrow membranous stripe; 

 setae as in O d o nt o c e r um : dorsal seta 1 moderately long, strong; seta 2 

 situated nearby, short; seta 3 long; seta 6 dark, situated laterally in apical 

 part; seta 5 large, light, situated laterally in basal part near stripe; seta 

 4 dark, large situated medially; ventral setae 7 and 8 light, seta 8 shorter 

 than usual. 



Case made of densely arranged, fine, sand grains, slightly wider anteriorly, 

 curved, with wide anterior and posterior openings (Figure 681). 



Mode of life and habitats. Running water bodies. 



Distribution. USSR: Maritime Territory, Vladivostok area. In 

 addition, Japan, Korea. 



VIII. Family MOLANNIDAE Wallengren 



Full-grown larva. Length 12 — 18 mm. Body flattened dorsally. Head 

 slightly oblong; gula extending from anterior to posterior margin, wedged 

 between large lateral sclerites. Eyes situated some distance from anterior 

 margin; antennae with long sensillae with a light apical seta. 



Pronotum entirely sclerotized. Mesonotum with more or less marked 

 transverse suture in some species. Metanotum with 2 snnall, median, 

 anterior-margin tergites. 



Fore tibia with characteristic distoventral process; this process little 

 marked on mid-tibia; hind legs long^ narrow, femur with a transverse stripe, 

 claw modified; all legs with numerous setae. 



Dorsal and lateral processes of abdominal segment 1 large, long. Lateral 

 line on segments 3 — 7 forming a dense row of small light hairs; segment 8 

 with a row of small, reddish, sclerotized dots. Gills presegmental, with 

 1—4 filaments on segments 1—7. Tergite of segment 9 indistinct, thin; anal 

 legs short, massive. 



Case made of sand grains, sand grains and detritus, or detritus only, 

 shield- shaped, consisting of a tube with an anterior hood and lateral winglike 

 extensions. 



Pupa. Length 10 — 15 mm. Antennae of male pupae almost as long as body, 

 those of female shorter. Clypeus with 3 setae. Labrum moderately long, 

 narrow, with small median process at anterior margin; setae short, 6 on 

 each side. 



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