laterally; there are small light setae at the anterior margin, 2 or 3 of them 

 are larger; posterior part of sclerite with a long medioanal seta; a pit 

 posterior to this seta; a small seta laterally near the base; 2 short setae 

 in the middle of each half; 2 strong black setae near the lateral margin, one 

 near the margin and the second slightly away from the margin; 2 small 

 thin setae close to the anterior angle. 



(273; 



FIGURES 298 and 299. Rhyacophila obscura Mart.: 



298 - anterior part of head, dorsal and labrum; 299 - mandibles, dorsal: left 

 mandible (A) and right mandible (B). 



Meson otum slightly larger than metanotum. Anterior -margin seta of 

 mesonotum well developed and large, that of the metanotum small but well 

 marked; anterior -angle seta of both segments long, dark, with a small 

 secondary seta at the base; medioanal seta also long, longer than the setae 

 of head and pronotum; a small intermediate seta and a small lateral seta 

 at the sides. 



293 



