long. Seta 9 situated anterior to the eye, as long as the posterior frontal 

 seta; seta 11 transparent, thin, situated posterior to seta 9; seta 7 situated 

 at the anterior margin, long but shorter and slightly lighter than seta 9; 

 setae 12 and 14 situated nearby, posterior to the light field around the eyes; 

 seta 14 much longer than seta 12; seta 15 short but thicker than seta 12; 

 small seta 16 situated in the posterior part of the head; ventral seta 8 

 situated near the anterior margin of the head, spinelike and transparent; 

 small seta 18 situated posterior to the gula. 



(267] 



FIGURES 288-291. Rhyacophila lata Mart.: 



288 - head, dorsal; 289 - labrum; 290 - mandibles, dorsal: left mandible (A), 

 right mandible (B); 291 —gula and maxillolabium. 



Labrum (Figure 289) of the same form as in Rh. sibirica, but slightly 

 narrower; dorsal sclerite golden brown, with indistinct margin; membranous 

 border broad anteriorly and laterally; lateral white stripes short. All 

 setae light. 



286 



