INSECUTOR INSCITI^ MENSTRUUS 103 



the under side, which shows only in strongly appressed mounts. 

 The genitalia, therefore, are as in hirsuteron, idaho'ensis, 

 spencerii, and aldrichi, these species having genitalia of the 

 same type. Indeed, the adults are similar, all having the same 

 coloration of the legs and mesonotal marking, which is subject 

 to variation. In idaho'ensis and spencerii the wing scales are 

 parti-colored as befits a prairie life ; in the other three they are 

 black, as suits the forest. Not improbably these species are re- 

 cently evolved and not fully separated where their localities 

 adjoin. Their general regions are well marked; aestivalis in 

 the forests of the Rocky Mountains ; hirsuteron in the southern 

 Atlantic region ; spencerii in the prairies of Canada ; idaho'ensis 

 in the river prairies of Nevada, Idaho, and Montana ; aldrichi 

 in the river bottoms with idaho'ensis. 



Aedes idahoensis Theobald. 

 One female. 



Aedes cinereus Meigen {fuscus Osten Sacken). 

 One male and three females. ' 



Aedes canadensis Theobald. 

 Three females. 



Aedes vexans Meigen {sylvestris Theobald). 

 Nine males and four females. 



Aedes sansoni Dyar & Knab. 



One male and sixteen females. The male is sansoni, 

 as determined by the genitalia; but abfitchii Felt & 

 Young^ may also occur. At Kaslo, British Columbia, 

 on Kootenai Lake, of essentially the same fauna as this, 

 abfitchii} was determined. I think both will be found, as lake 

 pools should develop sansoni, while abfitchii^ comes from 

 marshes, for which there is opportunity at Sandpoint. 



In comparison with the Kaslo list (Proc. Ent. Soc. Wash., 

 vi, 37, 1904), the following A'edes were there noted: 

 Aedes pullatus Coquillett (as impiger Walker). 

 A'edes abfitchii Felt & Young" (as cantons Meigen). 



*This should be called A. mimesis Dyar. See my remarks under this heading 

 in a paper on the Aedes of Montana, which follows. 



