98 THOMAS SAY FOUNDATION 



General color orange and black with yellowish wings. 



Head a little wider than prothorax ; orange yellow with 

 a large black area over the entire ocellar triangle and ex- 

 tending forward upon the clypeus ; frontal ridges dark 

 brown; area just behind the eyes brownish; lateral tu- 

 bercles indistinct; antennae yellowish at base, darker to- 

 wards the tip. 



Prothorax orange yellow with a wide dark blackish 

 strip on each side or rather with a wide orange median 

 stripe and a narrow yellowish stripe on each lateral mar- 

 gin ; pronotum nearly twice as wide as long, narrowed 

 behind ; front angles subacute, hind angles narrowly 

 rounded ; surface not very rugose. Legs yellowish ; ends 

 of femora with a narrow transverse blackish band ; wings 

 slightly tinted with greenish yellow; venation as in Plate 

 12, fig. 8. 



Abdomen dark brown, somewhat lighter toward the tip ; 

 tails yellowish, darker towards the tip. 



Male. Abdominal segments normal to the 8th which 

 bears a low wide ventral triangular apical lobe, ciliate 

 margined, and set off at the sides by shallow excisions of 

 the border. Segment 9 is prolonged beneath to twice its 

 dorsal length. Rearward this ventral portion is smoothly 

 contoured, rounded and up curving with inrolled edges 

 above. Dorsally segment 9 is strongly chitinized, squarely 

 truncated with a minute black denticle at the middle and 

 another at sides of the flat truncate dorsum. At the sides 

 it is frailer, membranous and emarginate to rearward. 

 Segment 10 is wholly included in 9 beneath and partly 

 above; on the dorsal side it is divided by a deep median 

 cleft and the rear angles beside this cleft rise in a pair of 

 genital hooks that are slender, recurved above, and trun- 

 cate. The subanal lobes rise between these hooks in a 

 pair of slender pale delicate upturned processes; supra- 

 anal process short and upcurved. 



Female. Subgenital plate somewhat produced and me- 

 dially with a deep rounded notch which is about as wide 

 as it is deep. 



Distribution. — San Francisco, Cal., 2 females; Mary's 

 Peak, Ore., "596," July 16, 1911. 



Perla ramosa, new species. 



(Plate ]9, fig. 17; plate 13, fig. 1.) 



Length to wing tips, female, 28 mm. ; expanse, 52 mm. 



General color yellowish varied with brown. Head yel- 

 lowish above except for a brownish inverted V-mark be- 

 tween the ocelli and joining them, and a wash of the same 



