24 INSECUTOR INSCITI^ MCNSTRUUS 



One thousand seven hundred and nineteen specimens were 

 obtained, as follows: White River, Ontario, June 12-25, 1918; 

 Nipigon, Ontario, June 26, 1918 ; Dryden, Ontario, June 39-30, 

 1918 ; Winnipeg Beach, Manitoba, July 5, 1918 ; Lake Minne- 

 wanka. Alberta, July 22, 1918; Banff, Alberta, July 7-25, 1918; 

 Laggan, Alberta, July 11, 1918. 



Eastern records are found in the monograph under impiger 

 (page 757). They are correct, except that "Ottawa, Ontario 

 (J. Fletcher)'' should be transferred to lasarensis. 



The species with broad white rings at the bases of the tarsal 

 joints may be separated as below, improving my genitalic table 

 (Ins. Ins. Menstr., vi, 78-79, dichotomies 27-34), omitting 

 bimaculatus, which does not concern us here. 



An unfortunate difficulty arises under sansoni, described 

 from females from Banff. I identified this as a supposed 

 Rocky Mountain species, specimens having been cited from 

 Drummond and Missoula, Montana, Juliaetta and Sand Point, 

 Idaho, Modern, Colorado (Cockerell). and Salt Lake County, 

 Utah, April 12, 1911 (C. T. Vorhies). The form is sufficiently 

 distinct from excrucians ; though close in the genitalia, the 

 larva is very different, resembling stimulans. But it turns out 

 that it does not occur at Banff! Males which I collected there 

 last season belong to excrucians and Htchii, so it is clear that 

 the name sansoni must be referred to the synonymy of one of 

 these. I select excrucians as the larger and commoner species, 

 not being able to tell these apart with females only. 



This leaves the Rocky Mountain form again without a 

 name. I therefore propose the name mutatus, specifying as 

 types of Aedes mutatus, new species, males from Missoula, 

 Montana. Type No. 21918, U. S. Nat. Mus. 



All the American species whose genitalia are known are 

 given in the table, though only four of them concern us in the 

 Canadian fauna. A. stimulans Walk, seems not to occur in 

 the fauna proper, although taken in its southern limits (Platts- 

 burg, New York). A. excrucians and fitchii are characteristic 

 members of the Canadian fauna, though distributed somewhat 



