158 THOMAS SAY FOUNDATION 



Perlesta placida Hagen. 



(Plate 15, fig. 7; plate 24, figs. 15, 16.) 



1861. Perla placida TIagen, Svn. Neurop. X. A., p. 28. 

 1892. Perla placida Banks, Cat. p. 342. 



1904. Perla placida Banks, Proc. Ent. Soe. Wash., 6:205. 



1906. Perlesta placida Banks, Can. Ent., 38:222. 



1907. Perlesta placida Banks, Cat. Neurop., p. 12. 



1907. Perlesta placida Tucker, Kans. Univ. Sci. Bull., 4:78. 



1908. Perlesta placida Banks, Proc. Ent. Soe. Wash.. 9:150. 



1862. Perla decipiens Walsh, Proc. Acad. Nat. Sci. Phil., p. 364. 

 1892. Perla decipiens Banks, Cat., p. 341. 



1907. Perla decipiens Banks, Cat. Neurop., p. 11. 



1862. Perla brunneipennis Walsh, Pine. Acad. Nat. Sci. Phil., p. 3(>7. 



1892. Perla brunneipennis Banks, Cat. p. 342. 



1907. Isoperla brunneipennis Banks, Cat. Neurop., p. 13. 



1898. Chloroperla virginiea Banks, Trans. Anier. Ent. Soe., 25:199. 



1907. Perlesta virginiea Banks, Cat. Neurop., p. 12. 



1905. Perlinella cinctipes Banks. Psyche, 12:56. 

 1907. Perlesta cinctipes Banks, Cat. Neurop., p. 12. 



1914. Isoperla texana Banks, Proc. Acad. Nat. Sci. Phil., p. 611. 



1921. Perlesta costal is Klapalek, Annales, Soe. Ent. Belg., p. 5 of re- 

 print. 



1921. Perlesta virginiea var. immaculata Klapalek, Ann. Soe. Ent. 

 Belg., p. 5 of reprint. 



Length to tip of wings, male, 9-11 mm. ; female, 10-14 

 mm. Expanse, male, 16-20 mm. ; female, 17-25 mm. 



General color brown to blackish with yellow on head 

 and with the costal margin of the wings yellow. 



Head a little wider than prothorax; usually with a 

 blackish quadrangular spot over the ocellar triangle, ex- 

 tending in front towards the base of the antennae ; frontal 

 ridge yellow ; clypeus mostly dark brown ; rest of head 

 mostly yellow. There is a great deal of variation in the 

 amount and shape of dark coloring on the head ; in some 

 specimens the ocelli are connected by a dark V-shaped 

 mark ; in others each ocellus is surrounded by a black 

 ring while in still others the head is almost uniformly 

 light brown. Hind ocelli closer to the eyes than to each 

 other. Antennae yellowish at the base, except the first 

 segment which is fuscous, blackish towards the tip. 



Prothorax light to dark brown, sometimes with a yel- 

 lowish, median longitudinal stripe ; wider than long ; nar- 

 rowed behind ; sides nearly straight ; front angles sub- 

 acute, hind angles somewhat rounded ; surface rugulose. 

 Legs brown ; femora often darker on the outside ; tarsi 

 darker, first and second segments very short, third at 

 least twice as long as one and two combined. Wings sub- 

 hyaline to heavily infuscated with a yellow costal mar- 

 gin ; veins brown except costa, subcosta and costal cross- 

 veins which are lemon yellow (the yellow costal margin 

 is very pronounced in the darker specimens) ; subcosta 



