INSE;CUT0R INSClTIiE MENSTRUUS 79 



enormously. Kootenai Lake rose 24 feet in 1903, in spite 

 of its great length (some 80 miles), producing flood condi- 

 tions in low land. The three positive records for aestivalis 

 (Kaslo and Sicamous in British Columbia, and Sand Point, 

 Idaho) are all at large lakes. The specimens from Nanoose 

 Bay, on Vancouver Island, recorded in the monograph, are evi- 

 dently aldrichi which had flown across from the high water in 

 the lower Fraser River. The worn specimens found by me at 

 Prince George, British Columbia, are probably also aldrichi. 

 It is impossible to be certain as between these two species with 

 worn material. 



Species 12 



Aedes (Ochlerotatus) aldrichi Dyar & Knab. 



Grabhamia speucerii idahoensis Aldrich (not Theobald), Theob., 



Mon. Culic, iii, 250, 1903. 

 Acdes aldrichi Dyar & Knab, Proc. U. S. Nat. Mus., xxxv, 57, 



1908. 

 Aedes aldrichi Theobald, Mon. Culic, v, 620, 1910. 

 Acdes aldrichi Howard, Dyar & Knab, Mosq. No. & Cent. Am. 



& W. I., iv, 735, 1917. 

 Aedes aldrichi Dyar, Ins. Ins. Mens., v, 121, 1917. 

 Aedes aldrichi Dyar, Ins. Ins. Mens., vi, 78, 1918. 

 Acdes aldrichi Cockerell, Journ. Econ. Ent., xi, 198, 1918. 

 Aedes vinnipe genesis Dyar, Ins. Ins. Mens., vii, 34, 1919. 

 Aedes aldrichi Hearle, Can. Ent., Hi, 115, 1920. 

 Aedes aldrichi Dyar, Ins. Ins. Mens., viii, 198, 1920. 



This is closely allied to hirsuteron, seeming distinct by the 

 smaller size and usually divided mesonotal brown stripe. This 

 is the species breeding in pools filled by high water from rivers 

 in the region from the plains to the Pacific coast. It occurs 

 all along the Yellowstone Valley in Montana, the lower Fraser 

 River in British Columbia, and the lower Columbia River be- 

 tween Oregon and Washington. The adults fly considerable 

 distances from the flood-waters, although not so far as the 

 larger vexans Meigen which accompanies them. As shown by 

 Mr. Eric Hearle, the larvae occur in shaded alder bottoms, and 

 not in the open pools infested by vexans. 



A. vinnepegensis was described from the valleys of the Red 

 and Assiniboine Rivers in Manitoba, Canada. The mesonotal 



