236 DAVENPORT ACADEMY OF NATURAL SCIENCES. 



found the same species at the edge of a snow bank, altitude 10,000 

 feet, and along a deep cafion in which the Engelmann Spruce occurred 

 and mosses characteristic of those swamps, at an altitude of 9,000 feet. 

 Here the water comes from the melting snow of the mountains, but 

 the water held in these mossy swamps is ice cold. So, too, the water 

 in the Engelmann Spruce swamp in Rapid Creek Park, though not 

 coming from snow banks in the mountains, was cold. This Poa is a 

 sub-arctic plant which has found a congenial home in these sub-arctic 

 canons that radiate from the mountains. The Poa Whceleri may be 

 placed in the same category. The P. Suksdorfii has apparently a 

 narrower altitudinal distribution. It is quite important to take into 

 consideration altitudinal distribution as well as the nature of the soil. 

 In comparing notes for the season of 1896 and 1897 it is interesting 

 to observe that some of the species occur at nearly the same alti- 

 tude. A few cases are here appended, including Fort Collins, Color- 

 ado, and Sheridan, Wyoming. 



sspprips Medicine Bow Range, Bk; Horn Range, 



AND FooT-HiLLS, N. Colo; and Foot-Hills, Wyoiviing. 



Beckmannia erucaeformis . . . . 4,q8o — 3.7 '5 — 4,000 



Boiiteloiia oligostachya 2i,g8o — 7,800 3,7 15 — 4,000 



Calamagrostis Purpurascens. 10,000 — t r, 000 10,000— 



Deschainpsia cacspitosa 7>775 — ' 1,000 7,500-- 9,500 



Festuca Kingii 8,700 — 9,500 5,500— 7,800 



Koeleria crhtata 5,000— 7,775 3>730 — 7,500 



Phleiim alpiniim 8,300 — 10,000 7,500 — 9,500 



Phleu7n pratense 4,950 — 10,500 3,7i5 — 6,600 



Poa arctica 9,500 — 10,000 7,500 — 



Poa Buckleyana 9,100 — 7,5oo — 9,200 



Poa Fendleriana 8,500 — 10,500 10,000 — 



Poa nemoralis 7.500 — 9,500 5,500—10,000 



Poa rupestris g.ooo — 10,000 9,500 — 10,500 



Poa Wheeleri 9,1 00 — 



Savastana odoraia 8,500— 7, 500 — 9,200 



Stipa viridiila 4,978— 5,000 3,7' 5 — 



Trisetiim subspicatiini 10,500 — 1 1,200 6,500 — 9,200 



This table seems to indicate that the same species occur at a much 

 lower altitude in Wyoming than in Northern Colorado, a fact borne 

 out by other plants found in this region. Some exceptions occur as 

 Koeleria cristata and Boiiteloua oligostachya. The plain surrounding 

 Sheridan is much lower than Fort Collins. The descent towards the 

 Medicine Bow Range is much more gradual than in the Big Horn. 

 From the base of the Big Horn foot-hills in Sheridan County, in the 



