of the eye; seta 10 thick at base, curved anteriorly; setae 12, 14, 15 and 17 

 longer than the others (1.5 times as long as the width of the head); seta 18 

 very small, shorter than the setules in the occipital region. 



(332; 



FIGURES 411-415. Hydroptila fe mora li s Eat. (after Nielsen): 



411 - full-grown larva, lateral; 412 - head, dorsal; 413 - right antenna; 414 - labrum; 

 415 — mandibles: left mandible, dorsal (A) and right mandible, ventral (B). 



Sides of labrum (Figure 414) parallel; membranous part of anterior 

 margin broader laterally than in the middle; larger in the right half than 

 in the left half; hairlike spinules long, straight, forming a median group at 

 both sides; 4 setae are situated in a median depression at the margin of 

 the sclerite; they form short, strong pines which are thicker in the middle; 

 setae 5 and 6 equally long; a fringe of dense, thin, short, hairlike spinules 

 334 near the anterior margin and on the surface of the sclerite. 



Mandibles (Figure 415) shining, light brown; process of upper blade of 

 left mandible with deep, basal notch; a small, blunt tooth distally, like on 

 the right mandible; the brush in the medial depression consists of chetoids 

 forming a row; dorsal seta of mandibles almost straight, brown; ventral 

 seta strongly curved, yellow; there are similar thin hairs at its base as on 

 the labrum. Setae of submentum strong, as long as the lateral setae of the 

 stripes. 



Prothorax and mesothorax slightly narrower posteriorly, lateral margins 

 of metathorax almost parallel. Thoracic segments slightly laterally 

 compressed; pronotum covering the segment anteriorly and laterally more 



366 



