no Transactions of the Royal Canadian Institute 



Distribution : Northern forests from the Atlantic to the Rocky Moun- 

 tains, the moist Pacific strip (from palustris) ; Yukon Valley, Alaska, 

 (from mimesis). 



Canadian Records. 



White River, Ontario, June 25, 1907 (F. Knab). 



Dryden, Ontario, June 27, 19 18 (H. G. Dyar). 



Winnipeg, Manitoba, June 22, 1907 (F. Knab). 



Aweme, Manitoba, June 5, 1904 (N. Criddle). 



Elkhorn, Manitoba, June 10, 1907 (T. N. Willing). 



Saskatoon, Saskatchewan, June 7, 1918 (A. E. Cameron). 



Prince Albert, Saskatchewan, June 10, 19 18 (A. E. Cameron). 



Oxbow, Saskatchewan, June — , 1907 (F. Knab). 



Regina, Saskatchewan, June 10, 1904 (T. N. Willing). 



Banff, Alberta, July 7, 19 18 (H. G. Dyar). 



Edmonton, Alberta, June i, 1919 (H. G. Dyar). 



Royal Oak, British Columbia, April, 1917 (R. C. Trehearne). 



Dawson, Yukon Territory, July 20, 19 19 (H. G. Dyar). 



Group Trichurus. 

 Aedes (Heteronycha) trichurus Dyar. 



Culex trichurus Dyar, Journ. N.Y. Ent. Soc, xii, 170, 1904. 

 Culex cinereoborealis Felt & Young, Science, n.s., xx, 312, 1904. 

 Aedes poliochros Dyar, Ins. Ins. Mens., vii, 35, 19 19. 



A large dark gray mosquito. Mesonotum gray on the sides, brown 

 centrally and with brown posterior lateral stripes, but these markings 

 not contrasted. Generally a small whitish space in front of the lateral 

 stripes. Abdomen black, with broad basal segmental white bands, even ; 

 venter whitish-scaled. Legs black, the femora white towards base and 

 nearly to tip below. Wing-scales black. 



The winter is passed in the egg state, the larvae developing in early 

 ground pools, leafy woods-pools and old road-side ditches. The mating 

 habits of the males have not been observed. The adults fly in woods, 

 but disappear early in the season. The name trichurus applies to the 

 western form, cinereoborealis to the eastern, and poliochros to that in the 

 wooded prairies. The eastern and western forms have larval differences 

 the larvae of the prairie form are unknown. 



Distribution: Southern fringe of the northern forests, Massachusetts 

 to British Columbia. 



