INSECUTOR INSCITI^ MENSTRUUS 106 



The writer passed through Montana by the Northern Pacific 

 Railroad, and made a few stops for collecting. The course of 

 the railroad is as follows : Entering Montana on the west 

 from the northern spur of Idaho, it follows up Clark's Fork 

 of the Columbia River, passing beyond the entry of the Flat- 

 head River, and crosses the divide of the Mission Range at 

 (1) Evaro, (3,971 feet) ; proceeding downward by a sharp 

 grade into the valley of the Hell Gate River, (3) Missoula 

 (3,323 feet) is reached; the road then follows up the valley of 

 that stream to (3) Drummond (3,967 feet) ; a tributary of 

 this same stream is followed practically to its source, whence 

 the road rises sharply and crosses the Continental Divide at 

 (4) Homestake (6,356 feet) ; it then descends into the valley 

 of the Missouri River, passing (5) Whitehall (4,371 feet) ; 

 thence it ascends a tributary of the Missouri, the Gallatin 

 River, nearly to its source, passing (6) Bozeman (4,773 feet), 

 well up in the narrower part of the Gallatin Valley; a low 

 divide is crossed through the Gallatin Range and the road 

 descends into the valley of the Yellowstone River, passing (7) 

 Big Timber (4,094 feet) and (8) Laurel (3,311 feet). No 

 stops were made after Laurel, the road following the same 

 valley as it widens into the plains, almost to the eastern border 

 of Montana. 



Unfortunately, no stop was feasible at Homestake (4), so 

 nearly all the collections are from river valleys. The wooded 

 mountains should yield other species, such as A'edes pullatus 

 and trichurus as at Kaslo, British Columbia, and A'edes aesti- 

 valis, as at Sandpoint, Idaho. This forested mountain region 

 connects along the Coeur d'Alene-Bitterroot chain with the 

 main Rocky Mountains, and the mosquitoes mentioned not 

 improbably follow into western Montana. Indeed, Parker 

 lists two of them, namely, pullatus and hirsuteron (=aesti- 

 valis). 



Disregarding the high forested regions and the sparsely 

 wooded mesas and hills, and referring only to the river valleys, 

 the following conditions appear: Mosquitoes are naturally 

 abundant and certain species have been evidently much in- 

 creased in numbers by artificial conditions. Five species were 



