1892.] ENTOMOLOGICAL NEWS. 203. 



so easy to observe, but throughout the mountains they are to be 

 seen more or less clearly. In the fall, when the Spruce is green, 

 the Quaking Asp yellow, and the Oak Scrub red, very beautiful 

 effects are produced. In Custer County, I have found it conve- 

 nient to divide the fauna as follows : 



(1) High-Alpine fauna, living from 10,000 feet upwards. 



(2) Mid- Alpine " clown to 6500. 



(3) Sub-Alpine 6,500 " the foothills. 



These three faunae, as will be explained in detail in a paper now 

 preparing, are very different from one another. The terms may 

 be used also when referring to other counties, but it must always 

 be remembered that even between north and south Colorado there 

 is a difference in the faunae of a given altitude. Therefore, the 

 tree-zones are in some ways more useful than a statement of the 

 altitude. For detailed work, I divided Colorado into 78 counties 

 and vice-counties, included in nine river basins, of which four are 

 on the Atlantic, and five on the Pacific slope. Grand R. basin, 

 on the Pacific slope, includes seventeen of these divisions, viz. : 

 Saguache, N. W. ; Hinsdale, N. ; San Juan, N. ; Ouray; Mont- 

 rose, E. ; Gunnison, S. (S. of Gunnison R., Taylor R., Willow 

 Creek); Gunnison, N. ; Mesa, N. E. ; Delta; Pitkin; Eagle, S. 

 (S. of Eagle R.); Eagle, N. ; Summit, N. (N. of Little Snake R., 

 Dillon, Canon Creek); Summit, S. ; Garfield, S. ; Routt, S. E. ; 



Grand, S. 



SAGUACHE, N. W. 



This is a triangular piece of country N. W. of the Cochetopa 

 Hills, upper mid-alpine in character. In the Summit Park region, 

 by the head of a tributary of Los Pinos Creek, Populus tremu- 

 loides and Achillea miUefolium were noted. This was on October 

 1 3th, and the only insect recorded was a red Chironomus larva, 

 similar to those found in England. The next day there was a 



snow-storm. 



MONTROSE, E. 



Contains low sub-alpine and mid-alpine districts, with great 

 differences of climate. In 1887 I traveled from the Gunnison 

 River via Montrose to Cimarron. The Uncompaghre Valley, 

 north of Montrose, is a great barren plain, consisting of dried 

 mud, baked and cracked in the sun; with scattered and solitary 

 Chenopodiaceae and such plants, and stunted cacti. On October 

 6th a strong breeze was blowing, and the scanty vegetation \\.i- 



