Labrum slightly broader and shorter than in H. angustipennis 

 (Figure 700, A); lateral tufts and covering chetae of posterior part darker 

 than in H. angustipennis; some of them are shox^t, dark, ordinary setae; 

 primary, light setae of anterior part among secondary setae; seta 5 yellowish. 



FIGURE 700. Hydropsyche pell uc id ula Curt. 

 Labrum (A), left mandible, dorsal (B), right mandible, 

 dorsal (C) 



Mandibles (Figure 700, B, C) slightly longer and narrower than in 

 H. angustipennis. Each mandible with 2 teeth, which are apical teeth 

 of the upper and lower blade; the only tooth of the upper, very short blade of 

 the right mandible curved slightly upward; lower blade with 3 teeth, the 

 middle tooth shorter than the other 2; basal tooth in the form of a low tubercle; 

 an apical and a small basal tooth on upper blade of left mandible; lower 

 blade with 3 teeth of different size, middle tooth smallest; basal tooth blunt, 

 larger than on right mandible, but markedly lower than in H. angusti- 

 pennis and of different form; hairs of brush golden yellow; outer setae 

 of mandibles light; both primary setae situated close together, longer than 

 others. 



Maxillolabium darker than in H. angustipennis, brown or dark brown, 

 of the same form. Inner margins of lobes of submentum parallel with a 

 narrow, light indentation; oblique row of setae of basal part (unlike in 

 H. angustipennis) mainly situated in posterior half; 2 setae longer and 

 thicker than others; primary seta situated slightly medial to the lateral 

 depression, between basal part and lobes; a similar, relatively long seta 

 slightly anteriorly; 2 setae situated more medially, near base of the lobe, 

 one of them very small; 4 short and several very small setae on the surface 



569 



