dark background: 3 spots anteriorly and 1 posteriorly, posterior spot and 

 medioanterior spot usually indistinct; dark background laterally with a row 

 of 4 small dots near the anterior margin; posterior part in the posterior 

 angle and laterally with light dots which are more distinct in dark speci- 

 mens. Lateroanterior margin seta transparent, curved inward, short, 

 situated in the angle; intermediate seta relatively long, straight, dark brown, 

 situated near lateral seta; median seta small, dark, situated at a distance 

 from the other 2. Frontal setae small; anterior frontal seta situated in 

 the anterior angle, among the secondary setae; median frontal seta situated 

 medial to the tentorial pit. Covering setae yellowish brown or yellow, 

 setuliform, situated on the dark lateral stripes; covering setae on the light 

 spots less numerous, absent in some places; anterior-angle group with 

 several thicker, blunt setae. Clypangulus small, with a narrow, lateral, dark 

 stripe with several small ordinary covering setae. Dorsal stripes chestnut 

 brown, broader behind the eyes, converging near the coronal suture; a more 

 or less distinct dark stripe along the suture; groups of light brown dots on 

 the dark stripes along the frontal sutures and posterior to the eye; ventral 

 surface and sides of head mainly light; a wide, dark brown area with large, 

 more or less light dots lateral to the gular suture; one of these spots bears 

 the short, spine like, light, seta 18. Dorsal surface with seta 9, which is dark 

 brown and longer than the other setae of the head; seta 11 situated nearby 

 on the outer side thin, small and light brown; seta 7 situated near the 

 anterior margin, shorter and thinner than seta 9; ventral seta 8 similar to 

 seta 7, slightly smaller; seta 10 light, small, situated anterior to the eye; 

 the large, brown seta 14 and the smaller seta 12 situated behind the eye; 

 seta 15 thin, light brown and short; seta 16 longer, situated near the suture. 

 Dorsal stripes with covering setae similar to those on the frontoclypeus; 

 similar, sparser and thinner setae on the light sides of the head; sausage- 

 shaped, blunt setae among them in some places. 



490, 



FIGURE 689. Hydropsyche angu s ti penn is Curt. Larva (young prepupa) 

 lateral (after Haller) 



Labrum (Figure 691) shorter and broader than in H.ornatula McL.; 

 dorsal surface darker, reddish brown, covered with fine chetae; spots near 

 the posterior angles shining dark reddish brown; posterior-angle sclerites 

 thin and brown; distinct grayish brown spots on the dark background 

 laterally near the posterior margin, a similar spot near the median pit. 



560 



