dark dots in the posterior part. Median anterior-margin seta larger than 

 the others; it is curved inward and recumbent; intermediate seta small 

 and light; lateral seta larger, situated lateral to the frontal suture. Anterior 

 frontal seta large and recumbent as in Rh. retract a; middle seta small, 

 the posterior seta slightly longer. Large dots on the sides lateral to the 

 frontal sutures and the coronal suture; the group of anteocular setae is 

 formed by setae 9, 7 and the small and thin seta 11; setae 12 and 14 in the 

 middle and posterior part of the head are situated close together and of 

 almost the same length; setae 15 and 16 are situated behind each other; 

 the small seta 13 is situated lateral to them; seta 17 small, situated near 

 the bifurcation of the frontal suture. 



(256) 



FIGURES 266-273. Rhyacophila laevis Pict.: 



266 —full-grown larva, dorsal; 267 — labrum; 268 —mandibles: left mandible, ventral (A); 

 right mandible, dorsal (B); 269 — gula and base of maxillolabium; 270 — part of pronotum, 

 propleuron and base of coxa of foreleg; 271 — abdominal segments 1—3, dorsal; 272 — right 

 anal leg, outer view; 273 — distal end and claw of left anal leg, inner view (271 - after 

 Thienemann; 266-270, 272-273 - after Botosaneanu). 



272 



