292 THOMAS SAY FOUNDATION 



PLATE 1. 



Head and Prothorax of Plecoptera. 

 Acroneuria pacifica Bks. 

 Acroneuria ruralis Hag. 

 Acroneuria abvormis Newm. 

 Isogenus frontalis Newm. 

 Acroneuria lycorias Newm. 

 Isoperla montana Bks. 

 Pcrlodes tibialis Bks. 

 Acroneuria carolinensis Bks. 

 Perla immarginata Say 

 Perlinella dry mo Newm. 

 Kathroperla perdita Bks. 

 Perla luetuosa Bks. 



