and strong, and is the longest seta of the leg; the basodorsal seta of the 

 femur is curved and shorter than the apical seta; both ventral setae situated 

 basally, on a process, and spinelike; ventral setae of tibia spinelike, short, 

 standing close together on a process in the distal part of the tibia; posterior 

 seta almost twice as long as anterior seta; both dorsal setae of tibia 

 situated subapically; one straight and long, the second short and curved; 

 dorsal setae of tarsus similar, the ventral setae spinelike and light yellow; 

 claw of forelegs longer than the tarsus, with a spinelike basal seta. Mid- 

 legs and hind legs with long tarsi and strong massive claws; tarsi of hind 

 legs longer than the femora; mid-tarsi almost as long as the femora. The 

 setae of midlegs and hind legs are shown in Figure 467. The posterior 

 distoventral seta of the tarsi forms a leaf-shaped, long spine. Claws 

 massive, strong, almost as long as the tarsus on the midlegs, slightly shorter 

 on the hind legs; a small short spinule near the base of the basal seta of the 

 claw. 



Abdomen broadest in the region of segment 4; segment 1 very short, 

 narrow, as broad as the metathorax; segment 2 with very broad lateral 

 processes; the first abdominal segment dorsally with a narrow rudimentary 

 tergite lateral to which is situated the long median seta and a short inter - 



356 mediate anal seta; anterior -angle seta of segment 2 (as in segment l) is 

 a third as long as the width of the head; both setae situated on small, 

 slightly convex sclerites; similar sclerites are situated in the middle of the 

 dorsum of segments 2—8 near the base of the medioanal setae. 



Dorsal sclerites of abdominal segment 9 (Figure 4 68) overhanging the 

 anal legs like a roof; the medioanal seta is the longest seta of the body; 

 intermediate seta very short and thin; lateral seta forming a light thick, 

 spine curved posteriorly and inward; angle seta of the sclerite straight and 

 strong, as is the anterior-margin seta, which is displaced toward the 

 posterior setae; the short lateroventral seta is situated on the side of the 

 sclerite, on a small sclerite. 



357 Sclerite "b" of the anal legs broad, with a thin lateral seta and 3 strong 

 distal setae; one of them situated on the bridge; intermediate distal seta 

 longer and thicker than the others; sclerite "c" oblong, its seta thin. Claw 

 short and massive; the transverse membranous stripe is situated in the 

 basal third (Figure 469); distal part with two short, pointed, spinelike 

 processes at the base; claw with only 5 setae; seta 2 is situated on the 

 outside near the transverse membranous stripe and is moderately long; 

 seta 3 shorter and thinner, situated in the middle; a small groove near it 

 and more dorsally; seta 8 thick and short; setae 5 and 7 shorter and thinner; 

 setae 1,4 and 6 absent. 



The larvae retains the tracheal gills of the young larva at the beginning 

 of the stage; they become rapidly atrophied later. 



Case (Figure 475) dark gray, slightly dorsovenL'ally compressed, 

 3.4— 4.0 mm long; dorsal side of case convex, with five longitudinal ribs, one 

 median and two lateral. The middle of the dorsum of the case of old cases 

 is convex and ribbed, darker than the ventral surface and the ends and forms 

 a hump on the dorsum. 



Young larva. Length of lst-stage larva 0.55 mm; width of head in 

 1st stage 0.11 mm, in 2nd stage 0.13 mm, in 3rd stage 0.16 mm, in 4th stage 

 0.19 mm, in 5th stage 0.21 — 0.24 mm; ratio between length of head, thorax 



396 



