trapezoidal and large; one seta of the mandibles light, curved, second seta 

 straight and dark brown. Pregula fused with the gula and dark brown like 

 the cardo; seta of cardo short; submentum (Figure 255) with an almost 

 straight anterior margin; lateral margins slightly concave; posterior 

 angles rounded; seta short, situated at the side of the sclerite near the 

 anterior angle; sclerite of stipes yellow; basal seta thin, light yellow and 

 long; apical seta shorter and thinner. 



Pronotum (Figure 256) reddish yellow; posteriorly, near the median 

 punctate figure and the dots it is darker laterally; a narrow brown stripe 

 near the anterior margin; the broad posterior margin is uniformly black, 

 without light intervals, with a deep notch in the middle and wide, black, 

 posterior processes; posterior angles long and black; lateral margin 

 broadly black; in its greater part it has a dark brown border in the anterior 

 quarter. Anterior angle with a large black spot (Figure 257) and with 4 light 

 small setae; the light notch nearby is visible as a small white spot; it bears a dark, 

 relatively long primary anterior-angle seta and 2 secondary setae; one of them 

 is dark, moderately long and situated near the primary seta; the second is 

 situated anterior to it; it is short and light; there are small, sparse, yellow, 

 curved setae at the anterior margin. Pronotum with a row of 4 setae in about mid- 

 length of the sclerite; the median seta is long and dark, the next is short, light, 

 situated near the median seta, the other 2 are also thin and light and situated at a 

 251 distance from each other and from the former 2 setae; the black lateral margin of 

 the sclerite bears a strong, brown relatively long seta; there is a similar 

 dark, short seta a short distance from the margin. 



[253) 



FIGURES 260 and 261. Rhyacophila retracta Mart.: 



260 —abdominal segments 1—7, dorsal; 161 — abdominal segments 8 and 9 and 

 part of the anal legs, dorsal. 



268 



