257 



addition to projecting, middle tooth; ventral blade with one tooth and a 

 process; right mandible, in addition to middle tooth, with 2 distinct teeth 

 and one less distinct tooth dorsally, and one tooth ventrally; lateral setae 

 situated basally, large, dorsal seta thicker and longer than ventral; chae- 

 toids of dorsal brush forming 3—4 rows, those near basal margin longer 

 than apical chaetoids. 



Base of maxillolabium (Figure 449) with brown pregula, divided by 

 dark groove from gula. Sclerites of cardo with a median stripe and broad, 

 black, transverse stripes; both setae small, thin. Middle of submentum 

 with yellowish brown, transverse sclerites with a dark, moderately long 

 seta at anterior margin. Sclerite of stipes large, extending laterally 

 partly to dorsal side; lateral seta large, thick; median seta thin. Palpifer 

 large, about as long as palp; distal seta sm^l, thin, dark; median basal 

 seta light, small. Palp short, tapering apically; sclerite of segment 1 

 semicircular, of segment 2 open on median side. Galea short, conical, 

 partly sclerotized. Mentum dark brown, in form of a narrow curved plate 

 with concave anterior margin; ventral sclerites rodlike, with a small, thin, 

 light seta. Labial palpiger horseshoe-shaped; palps markedly longer than 

 distal process of labium. 



Pronotum (Figure 450) yellowish brown; groove in anterior third dark 

 brown in middle; posterior margin light brown dorsally, yellowish laterally, 

 wide black stripes sometimes fused; dots small, not always distinct. 

 Anterior, submarginal area with 4 large, dark setae; primary anterior- 

 angle seta larger; secondary anterior-margin setae arranged in 2 rows: 

 short, strong, black setae directed upward, and thin yellow setae directed 

 anteriorly; secondary surface setae numerous (120 — 140), in contrast to 

 other species of P o t a m o p hy 1 ax , and of different size; these setae 

 include short, strong, black setae characteristic for the species. 



Mesonotum (Figure 451) light brown, slightly darker than pronotum 

 „co anteriorly and in mid-posterior; anterior margin with a narrow, dark brown 

 stripe laterally; posterior margin dark brown; posterior angle broadly 

 black; punctation fine; setae numerous (65 — 85). 



Anterior medi-an tergite of metathorax transverse, grayish brown; 

 posterior median tergite smaller, of similar color, rhomboidal, with rough 

 margin; lateral tergite oblong, yellow, with a black spot at articulation with 

 pleuron, also with a transverse band of dark streaks and several dots, and 

 with rows of dots at median margin in posterior part (Figure 451). Anterior 

 median tergite with a primary anterior- margin seta; posterior median 

 „ „ tergite with 3 surface setae, including a larger medioanal seta; primary 

 anterior- angle seta situated near anterior margin of lateral tergite; 

 secondary setae numerous, in 3 groups: anterior surface setae (10 — 17), 

 posterior surface setae (13 — 15), and anterior -angle setae (15 — 20), the 

 latter situated in anterior part of lateral sclerite. 



Propleuron (Figure 450) yellowish brown, with broad, black, pleural 

 suture; greater part of episternum also dark, trochantin rounded apically, 

 black basally and anteriorly, apical seta relatively large, situated near a 

 small setule, second setule situated more basally; primary seta of epimeron 

 situated near suture; 2 — 3 secondary setae small, strong. 



Pleural sclerites of meso- and metathorax (Figure 451) with black, 

 pleural suture; epimeron surrounding coxa, slightly produced ventrally on 

 mesothorax, more so on metathorax; secondary setae: 25 — 31 on mesepi- 

 sternum, 23 — 26 onmesepimeron, 29 — 33 onmetepisternum, 23 — 29 on 

 metepimeron. 



323 



