Full-grown larva. Length 20.0— 20.5 mm (Figure 209). Dorsal surface 

 of head (Figure 210, A) yellowish brown with a distinct dark pattern; fronto- 

 clypeus posteriorly with a blackish brown heart-shaped figure with a trans- 

 verse row of dots leaving the posterior angle of the sclerite light. Dorsal 

 stripes short, dark and fused with the lateral stripes; white round spots at 

 the base of setae 15 and 16; dots on the stripes distinct; a broad, light 

 space posteriorly, at the sides of the coronal suture. Ventral surface of 

 the head (Figure 210, B) without spots. 



(223) 



FIGURES 211-213. Rhyacophila nubilaZett.: 



211 - mandibles, dorsal; 212 —dorsal sclerite of segment 9; 213 - left anal leg (external; 

 slightly dorsal view) and base of claw. 



Dorsal sclerite of labrum light yellow, with indistinct margin. Setae 2 

 and 5 brown and thick; all other setae thin, light and almost transparent; 

 seta 3 is curved to the sclerite and is hardly noticeable. Mandibles dark 

 223 (Figure 21 1); lower blade of the left mandible serrated; basal denticle of 

 the blade larger than the others; blade of right mandible indistinctly 

 serrated; dorsodistal outer seta of mandibles light, short and curved; baso- 

 ventral seta straight, dark brown and much longer. Sclerites of maxillo- 

 labium light yellow; submentum slightly larger than in Rh. septentrionis, 

 with almost straight anterior margin; setae small and light, situated at a 

 distance from the anterior margin. 



Pronotum yellowish brown, its posterior margin broadly black, with a 

 brown transverse stripe in the middle of each half; posterior angles 

 prolonged and black; lateral margin of the posterior part with a black 

 border; lateral margin of anterior part with a narrow blackish brown stripe; 

 anterior angles black; anterior margin with narrow dashes laterally. A 



232 



