114 INSECUTOR INSCITI^ MENSTRUUS 



countered by me at Whitehall, unless it frequents high timber, 

 of which there was none at that place. 



Aedes sansoni Dyar & Knab. 



The types of sansoni are five specimens, numbered, respec- 

 tively, 10, 13, 14, 17, and 20 by the collector. Nos. 10, 13, and 

 34 are females, 17 and 30 are males. No. 20 is Aedes curriei, 

 as shown by the genitalia. No. 17 has lost the abdomen, but 

 has the sides of the mesonotum very white, as is also the case 

 in the females, Nos. 13 and 14. No. 10 has the usual mixture 

 of brown and white, the brown predominating, and may be 

 selected as the type. The wings show a sprinkling of white 

 scales along costa and subcostal vein. 



A. sansoni was described from Banff, Alberta, a locality 

 on a river flowing from the Rocky Mountains. In 

 the monograph, we added certain other specimens, namely : 

 Larvae from Kaslo, British Columbia; a male from Juliaetta, 

 Idaho; male and females from Eureka, California, and 

 females from Fieldbrook, California. I have lately removed 

 the California specimens to increpitus Dyar (Ins. Insc. Mens., 

 v, 15, 1917). I now propose to remove the Kaslo larvae. The 

 larvae agree with abfitchii essentially, and will be found re- 

 ferred to under the heading mimesis below. This will define 

 sansoni as the river-pool species of the Rocky Mountain 

 streams, and definitely associate the Banff female with the 

 male from Juliaetta, Idaho. Males from Missoula, Montana, 

 agree. Larvae from Missoula are of the typical river-pool 

 form (see Plate II), indistinguishable from stimulans Walker 

 of the east or increpitus Dyar of California. The three species 

 separate on male genitalia: 



Basal lobe of sidepiece weak, tuberculate, sparsely setose, accompanied 



by a very strong spine stimulans Walker 



Basal lobe of sidepiece tuberculate and diffused, without a strong spine. 

 Filament of harpago slenderly sickle-shaped, expanded at basal 



third (see Plate II) sansoni Dyar & Knab 



Filament of harpago with angular expansion beyond middle. 



increpitus Dyar 



A. sansoni was common in all the wooded river bottoms. 



