INSECUTOR INSCITI^ MBJNSTRUUS 13 



very deceptive resemblance to trichurus Dyar, which species 

 occurs in the Kootenai region, by having the rnesonotum very 

 dark with a white lateral spot. However, in trichurus, there are 

 three impressed dorsal dark bands and the lateral white spot 

 is entirely in front of the lateral groove ;^ in tohoensis there are 

 but two dorsal impressed lines and the white spot is on both 

 sides of the lateral groove. 



Aedes hexodontus Dyar. 



Comparison of specimens shows that this species is identical 

 in mesonotal coloration with lazarensis Felt & Young and im- 

 piger Walker. The ornamentation is very variable, being gold- 

 en yellow with two narrow lines of dark brown scales, or 

 wholly golden yellow, or wholly brown. The form with the 

 distinct brown lines resembles lazarensis, the form wholly yel- 

 low, impiger. The larvae, however, are distinct from both of 

 these species. 



The breeding places of hexodontus are marshy pools, filled 

 by snow-water, often very shallow, never deep; often small 

 like the hoofprints of cattle. I found hexodontus plentiful in 

 some cattle tracks in the edge of a marsh near Tallac on Lake 

 Tahoe. The cattle tracks were filled by spring water; there 

 were no hexodontus in the marsh itself, though other mosquito 

 larvae were there. At the end of Fallen Leaf Lake, hexodontus 

 was breeding in seepage pools in a hollow under poplar trees. 

 The water here was a small stream of drainage from melting 

 snow. At Summit, Placer County, a few hexodontus pupse 

 were taken in a shallow pool in an open marsh with willow 

 bushes. The water in these marshes is comparatively poor in 

 organic matter as the pools are not enclosed and often have 

 considerable current of water through them; but the ground 

 over which they are formed must give a certain richness. 



No form representing hexodontus was recognized in the col- 

 lections made in the Kootenai region of British Columbia. 

 This material was taken in 1903 and worked over by Mr. Co- 

 quillett at a time when the specific characters of Aedes were 



'Suture between the mesonotal prescutum and scutum. 



