PLECOPTERA OF NORTH AMERICA 143 



covers most of the clypeus before the yellow M-line across 

 the frons. Ocelli minute, sub-equal and equidistant. An- 

 tennae brown, paler on base of flagellum ; palpi darker 

 brown. 



Prothorax yellow, with a wide smooth middle tract and 

 rather narrow borders all around set off by deep grooves. 

 Embossed markings on the sides of the disc, brown, rath- 

 er coarse, fewer toward the side margins. Two dots at 

 the front of the mesothorax mark the angles of a wide 

 yellow triangle, and the wing roots are yellow. Legs pale 

 brown. Wings subhyaline with pale brown veins. All 

 of the portion before the cord suffused with an amber- 

 brown tint that deepens to strong brown over the anal 

 area of the hind wing. 



Abdomen brown. Tails yellowish, tapering, covered 

 with short hairs ; subanal lobes elongate triangular. 



Female. Hind margin of the 8th sternite scarcely pro- 

 duced into a subgenital plate, broadly and evenly truncate. 



Holotype female, Nevada, Cornell University Collection. 



Clioperla sobria Hagen. 



(Plate 25, fig. 9.) 

 1875. Perla sobria Hagen, Bull. G'eol. Surv. Terr., p. 577. 

 1907. Perla sobria Banks, Cat. Neurop., p. 12. 



Length to tip of wings, female, 15 mm.; expanse, 26 

 mm. 



General color fuscous varied with yellow on head and 

 prothorax. 



Head a little wider than prothorax ; with a yellow spot 

 in the ocellar triangle, yellow beside the eyes, a yellow 

 spot at the base of the antennae and one in front of the 

 anterior ocellus ; occiput mottled yellowish ; rest of head 

 dark brown to blackish ; ocelli small, forming a triangle 

 almost twice as wide as long, the hind ocelli closer to the 

 eyes than to each other. Antennae dark brown. 



Prothorax wider than long; sides nearly straight, not 

 narrowed behind; light yellow with coarse chocolate 

 brown rugosities; angles quite sharp. Legs brown. Wings 

 subhyaline with brown veins ; hind wings without inter- 

 cubital crossveins. 



Abdomen brown, tails pale yellow. 



Male, unknown. 



Female. Subgenital plate produced almost half way 

 across the ninth sternite, rounded, with a narrow deep 

 median notch. 



Type, female, No. 247, Colorado Mts., Pacific Slope, 

 August, 1873 (Hagen Collection, Mus. Comp. Zool., Cam- 

 bridge). 



