52 THOMAS SAY FOUNDATION 



5. Costal crossveins before the cord 7 to 8 



irregula ris 



Costal crossveins before the cord 2 to 6 signata 



Costal crossveins before the cord to 1 (brachyp- 

 terous) yosemite 



6. Tip of subcosta runs out into costa vagans 



Tip of subcosta downcurved to join vein Rl 6 



7. Apex of fore wing obtuse, semicircular in out- 



line aitrca 



Apex of fore wing more pointed 7 



8. Vein Sc2 joins vein Rl generally much before the 



cord americana 



Vein Sc2 joins vein Rl at or beyond the cord 8 



9. Western species ignotus 



Eastern species 9 



10. Prothorax hardly longer than wide 1 'meat a 



Prothorax twice as long as wide slossonae 



Perlodes dolobrata Smith. 



(Plate 9, figs. 1, 6.) 

 1917. Protarcys dolabrata Smith, Trans. Amer. Ent. Soc, 43:469 

 (female). 



Expanse of wing, male 33 mm. ; female 44 mm. 



Coloration brownish, darker on the thorax than on the 

 top of the head. The pale M-line across the front is 

 bordered before and behind with brown. The pale spot 

 on the crown is small, occupying half the space between 

 the ocelli. The round frontal tubercles are set in pale 

 areas, but their summits are capped with fine brown mar- 

 morate embossed markings. Similar fine markings cover 

 the pale post-ocular areas at either side of the vertex. 

 There is a narrow line of yellow behind the brown across 

 the occiput and the hind angles of the head are brown. 



The mid-dorsal pale line of the prothorax is obscure in 

 the middle, hardly more than the middle groove being 

 there yellow ; but the yellow is extended laterally on front 

 and hind borders. The brown rugosities of the sides of 

 the disc of the prothorax are coarse and rather conspic- 

 uous. The width of the prothorax is one-half greater 

 than its length, and its sides are convergent to rearward. 

 Front angles rather acute ; collar rather wide. Middle 

 pale line on meso- and metathorax very obscure. Femora 

 brown dorsally, except for a narrow pale line capping the 

 knee. Basal seventh of tibiae brown externally, the re- 

 mainder pale. Wings smoky hyaline, with veins some- 

 what infuscated, especially at the stigma. 



