part; anterior angle with 4 dots in pairs near white stripe; posterior margin 

 with a narrow, black line laterally. 



FIGURE 753. M y s ta c i d e s sp., larva nova, 

 ventral (B) 



Head, dorsal (A) and 



Mesonotum mainly whitish yellow, with a smoke brown band at lateral 

 and posterior margin; stripe at median suture indistinct posteriorly, grayish, 

 brown, with small dots anteriorly, reaching small, dark, median part of 

 anterior margin; an oblique row of 3 large dots on surface, as in M . a z u r e a; 

 2 dots laterally and 3 less distinct dots in posterior part; anterior margin 

 470 brownish, with 2 dark dots in middle; posterior margin brownish, with 2 

 large, and several, small dots in raiddle. Chaetotaxy as in M. azurea; 

 setae whitish yellow. 



Meso- and metapleuron with a large, indistinct, brownish dot on episternum. 



Articulation between coxa and trochanter, and between femur and tibia, 

 slightly dark; large distal spots on tibiae and tarsi of hind legs brown, 

 indistinct, slightly darker than ground color. 



Gills absent. Darker part of segment 9, pinkish brown; anterior margin 

 straight, as in M. azurea; setae the same. Sclerite "b" of anal legs pale 

 with large, dark dots; the intermediate of the 5 distal setae thick, dark 

 reddish brown; middle of sclerite rugose. Claw reddish brown, with 2 large, 

 dorsal denticles laterally and 3 small denticles in middle. 



Case straight, slightly tapering posteriorly, made of small, densely 

 arranged sand grains and fragments of detritus. 



Mode of life and habitats. Lakes. 



Distribution. USSR: Transbaikalia. Not recorded outside the USSR. 



3. Mystacides dentata Martynov 

 Lepneva, 1949:168—169. 



Full-grown larva. Length 8 — 9 mm. Main color of head (Figure 754, A) 

 light yellow; dots distinct, pinkish brown; stripes and spots absent or 



588 



