OF WASHINGTON. 207 



Caenis hilaris Say . 



Abundant throughout the summer along the Potomac and at 

 Falls Church, Va. 

 Caenis arnica Hagen. 



Falls Church, Va., Sth August. This is a smaller species than 

 C. hilaris. 

 Heptagenia vicaria Walker. 



A pair from Falls Church, Va., collected in May. 

 Heptagenia verticis Say. 



A subimago from Washington, taken at light. 

 Heptagenia terminata Walsh. 



Not as common as the preceding species. 

 Heptagenia pulchella Walsh. 



Quite abundant ; High Island and Plummer's Island, Potomac 

 river. 

 Heptagenia canadensis Walker. 



H. maculipennis Walsh. 



Falls Church, Va., nth June; Plummer's Island, Md., July 

 and August. 

 Heptagenia flaveola Pictet. 



This is our common species of the genus. It is close to H. 

 interpunctata Say, but is smaller and lacks the dark dorsal ab 

 dominal stripe. 

 Heptagenia simplex Walsh. 



Three specimens from Plummer's Island, Md., 29th August. 



Order NEUROPTERA. 



Suborder MEGALOPTERA. 

 Family SIALID^. 

 Sialis infumata Newman. 



From the loth of May on through June, near small streams. 

 Chauliodes fasciatus Walker. 



Along the Potomac in August. 

 Chauliodes serricornis Say. 



Upper part of the Potomac river; High Island and Plummer's 

 Island, Md. , July; Glencarlyn, Va., iSth June. 

 Chauliodes pectinicornis Linne. 



One from Washington, at light. 

 Chauliodes rastricornis Rambur. 



Washington, at light, July. 



