INSECUTOR INSCITI^ MENSTRUUS 119 



harpago. The coloration of the mesonotum makes an asso- 

 ciation with lazarensis impossible. 



Aedes aestivalis Dyar. 



Two rubbed females from Evaro (1) are tentatively referred 

 here. The species is abundant in northern Idaho and has 

 been discussed on a previous page. Several specimens from 

 Drummond, listed under aldrichi, come very close to aestivalis, 

 and, taken alone, would easily be so determined. I think, 

 considering the circumstances, that they are aberrations of 

 aldrichi. 



Aedes spencerii Theobald. ' 



Only three specimens were captured among numerous idaho- 

 ensis. A. spencerii is dominant on the prairies of Saskatche- 

 wan, as shown by Knab, and is represented in southern Mon- 

 tana by idaho'ensis. Quite possibly the species intergrade on 

 middle ground. The occurrence of so few spencerii in this 

 region suggests that it may be here an aberrational form of 

 idaho'ensis, becoming dominant in the north. 



A. spencerii, as found in Saskatchewan, is a medium-sized 

 species, the wing-veins bicolored, the abdomen with a dorsal 

 whitish stripe, often much suffused with white, occasionally 

 the dorsal stripe more or less completely absent; mesonotum 

 gray or yellowish gray, anterior angles brown, dorsal brown 

 stripes usually completely conjoined into a band and touching 

 the short posterior stripes ; occasionally the dorsum is suf- 

 fused with a brown shade. Legs with white scales, often 

 numerous, the tibiae largely white-scaled above. 



The three specimens referable here, from Drummond (July 

 10), are all of the gray form, old and worn. Two fresh 

 specimens of the yellow form were bred from pupae in irriga- 

 tion pools at Laurel, July 17-18. No adults were seen flying 

 at this place. The larva was not obtained, nor has a larva 

 corresponding to that of spencerii been taken in Montana. 

 Mr. Parker sent two larvse on slides, Laurel, August 25, 1914 

 (R. W. Wells), and Harlem, May 28, 1915 (R. A. Cooley), 

 which do not coincide with any known species (see Plate II). 



