of the lobe, slightly anterior to its middle. Setae at base of cardo and in 

 tufts of stipes darker and shorter than in H. angustipennis. 



Pronotum reddish brown; primary anterior-angle seta shorter but thicker 

 than in H. angustipennis; large, pale dots distinct; margin of sclerite 

 similar. Meso- and metanotum slightly lighter, yellowish brown with an 

 oblique stripe and large spots laterally; pattern sometimes indistinct; black 

 median spot at posterior margin of mesonotum resembling that in H. an - 

 gustipennis, but anterior margin is not always uniformly curved; its 

 sides usually form an obtuse angle and its middle is straight; dots anterior 

 and lateral to the spot pale but more distinct than in H. angustipennis 

 (Figure 701, B). Setae similar. Black median spot at posterior margin 

 larger than in H. a ngu s t ip e nn i s, with 1 or 3 serrations posteriorly 

 (Figure 701, C); median serration always deeper than lateral serrations.* 



499 



FIGURE 701. Hydropsyche p ellucid u la Curt. Prothoracic sternite (A), mesonotum (B), 

 median spot of posterior margin of metanotum (C) 



Primary seta of prothoracic trochantin blackish brown, longer than in 

 H. angustipennis, almost reaching end of horn; 3 secondary dark chetae 

 near it. Brownish sclerites posterior to large sclerite of prothoracic 

 sternite (Figure 701, A) irregularly rectangular. 



Legs dark brown, lighter in some places; their form and chaetotaxy 

 closely resembling those of H. angustipennis; posterior surface of fore 

 coxa with similar feathered setae as in H. angustipennis; anterodorsal 

 margin of mid-coxa and hind coxa less convex than in H. angustipennis. 



Ventral gills present on abdominal segment 7. Claw of anal legs thicker 

 than in H. angustipennis. 



Pupa. Length 11 — 13 mm. Labrum as in H. angustipennis; setae 

 black. Mandibles reddish brown; right mandible with apical tooth and 

 3 teeth; left mandible with 4 teeth, the 2 apical teeth smaller than the other 2; 

 blades and teeth finely serrated; primary outer setae of same length. 



Mid -tarsi with dense natatorial setae. 



Presegmental plates present on abdominal segments 3—8; number of 

 spinules as follows: 111:11-12; IV:9-10; V:12-14; VI:9-10; VII:6; VIII:4-6; 

 postsegmental plates present on segments 3—4, as in H. angustipennis. 

 Anal rods and sheaths of genitalia of male pupae as in H. angustipennis. 



Pupal case 14 mm long, covered with small stones. 



" This character is not decisive, as stated by Ulmer (1909:236). 



570 



