80 INSECUTOR INSCITI^ MENSTRUUS 



dorsal pleural appendage small ; ventral pleural appendage 

 large, the rostriform lobes bearing a single acute spine. 



Habitat. — Formosa. 



Holotype, $ , Urai, altitude about 1,500 feet, October 2, 

 1931 (T. Esaki). 



THE MOSQUITOES OF THE GLACIER NATIONAL 

 PARK, MONTANA 



(Diptera, Culicida) 



By HARRISON G. DYAR 



The Glacier National Park occupies the crest of the Rocky 

 Mountain Range, including the Continental Divide. The altitude 

 of the range is not great ; but the mountain masses, traversing 

 an otherwise arid region, carry the Canadian fauna southward, 

 almost in its entirety. On the west, the approach is gradual, 

 the forested area reaching to the region about Whitefish Lake; 

 but in the east, owing to the abrupt faulting of the geological 

 formation known as the Lewis Overthrust, the transition to 

 the bare prairie is sudden. The railroad follows the middle 

 fork of the Flathead River and tributary creeks, and approach- 

 ing from the west the change at the summit is abrupt and 

 startling. The forest carpet is suddenly broken. Wide reaches 

 of prairie appear, and when one arrives at the Glacier Park 

 station, the mountains are behind, and the open prairie is about. 

 The forest is seen in little patches hanging precariously to the 

 higher slopes and huddled in narrow strips in the river valleys 

 as these reach out into the plains. 



In a former paper (Ins. Ins. Mens., v, 104-121, 1917), I 

 listed the mosquitoes to be found on the plains of Montana. 

 The present forms a supplement to that, and adds the species 

 of the mountains of the State. On reaching the prairie, the 

 appropriate mosquitoes do not at once appear. There is a 

 mosquito-less area of perhaps some fifty miles before the accus- 

 tomed forms appear in their habitual abundance. No doubt 

 there is an occasional migration. In fact a specimen of Acdes 



