Maxillolabium (Figure 242),labrum and mandibles resemble those of 

 species of Rhyacophila s. str.; gula, pregula, submentum and cardo 

 brown and of the same form as in species of Rhyacophila s. str.; seta 

 of submentum light, situated near the anterior angles of the sclerite; seta 

 of cardo small and thin; stipes yellow, broad in the middle; the setae are 

 thin, brownish; basal seta slightly longer than distal seta. Palpiger, 

 maxillary palps and galea as in Rhyacophila s. str.; distal seta of 

 palpiger situated on a membrane, brown, thin, reaching the middle of the 

 galea; basomedian seta small, light and thin. Mentum brown; the median 

 suture distinct only in the basal part; anterior margin with a small median 

 notch; ventral sclerites in form of dots; their setae are light and thin; 

 sclerites of labial palpiger broadly sickle -shaped, yellow; palps short. 



Pronotum (Figure 243) of characteristic form; it is short in the middle 

 so that the posterior margin of each half is situated obliquely to the anterior 

 margin. Anterior margin brown; the deep membranous notch near the 

 anterior angle, which is characteristic for Rhyacophila, is absent; it is 

 replaced by a small curve of the anterior margin; anterior angle of the 

 sclerite dark brown; lateral margin reddish brown in the anterior third; 

 the other part has a black border which is broad in the posterior third; 

 posterior angles black; posterior margin broadly black in the middle and 

 on the sides, brown in the middle of each half, with broad processes; these 

 processes do not project posteriorly as much as in Rhyacophila s. str. 

 The greater part of the sclerite is yellow; it is brownish posteriorly and 

 on the sides, dots present along the median suture and on the sides of the 

 posterior part; several indistinct dots near the anterior margin of the 

 sclerite. Small convex sclerotized dots in the depression of the curve of 

 the anterior margin bear 2 long black anterior-angle setae, a primary seta 

 and a secondary seta; third seta short, brownish, situated lateral to the 

 curve, on the dark margin of the anterior angle; short inward-curved 

 yellow setae at the anterior margin, beginning from the angle; the setae 

 are small and denser lateral to this curve. All surface setae are situated 

 in the anterior part of the sclerite; there is a dark long seta in the middle; 

 and a short light seta slightly more laterally; lateral to the anterior-margin 

 dots is a thin, inward-directed long yellow seta, and nearby a similar short 

 seta; anterior -angle region with several sparse, light, small setae; lateral 

 margin and the adjacent area without setae. 



Mesothorax is heart-shaped, larger than metathorax, similar in form to 

 the following abdominal segments; the anterior-margin seta of the meso- 

 notum is, as usual, longer than that of the metanotum and dark; anterior - 

 angle seta situated on a small process; near it, a thin secondary anterior- 

 angle seta which is slightly shorter than the primary seta; medioanal seta 

 as long as the primary anterior -angle seta; intermediate and lateral setae 

 small and thin, well marked. Anterior -margin seta of metanotum small; 

 other setae as on the mesonotum. 



The episternum of the prothorax (Figures 244, 246) is brown, dark brown 

 at the base area of the pleural suture dark, partly black; trochantin broad 

 at the base; seta on the membranous apex of the horn-shaped process 

 strong, reddish black; setules situated behind each other and light. 



The rodlike sclerites of the pleuronof meso- and metathorax are 

 narrow (Figure 245); the transverse sclerite is short and broader than the 

 oblong longitudinal plate which is slightly oblique, at an acute angle to the 



258 



