404 PROCEEDINGS OF THE ACADEMY OF [J^^lj, 



While it is well known that an absolute delimitation of zonal areas in 

 mountain regions is impossible, whether plants or animals are chosen as 

 characteristics, still the zones as outlined above are fairly well defined 

 by their plant inhabitants. 



Of the mountain mammals of northern Colorado many range widely 

 from timber line to the plains, and, with a few exceptions, there are 

 none whose range is closely coincident with any one of the zones men- 

 tioned above. These exceptions are the following: Sciurus dberti 

 concolor, Citellus variegatus grammurus, Citellus elegans, Cynomys 

 leucurus, Peromyscus truei nasutus, Neotoma jallax, and Spilogale tenuis 

 in the Transition zone ; and Lepiis americanus bairdi, OcJiotona saxatilis 

 and Phenacomys preblei in the Hudsonian zone. 



The Canadian zone possesses no characteristic mammals. Species 

 ranging through both Hudsonian and Canadian zones, but mainly 

 restricted to them, are the following: Evotomys gapperi galei, Microtus 

 nanus, Gulo luscus, Mustela americana, Putorius streatori leptus and 

 Putorius arizonensis. 



Boreal species which include the Transition zone within their range ' 

 are as follows: Cervus canadensis, vis canadensis, Sciurus fremonti, 

 Eutamias am.oenus operarius, Eutamias minimus consohrinus^ Callo- 

 spermophilus lateralis, Marmota flaviventer, Neotoma orolestes, Microtus 

 mordax, Thomomys fossor, Thomomys clusius fuscus, Zapv^ princeps, 

 Erethizon epixanthus, Sylvilagus pinetis,^ Felis hippolestes. Lynx uinta, 

 Ursus americanus, Sorex ohscurus, Sorex personatus, and Neosorex 

 palustris navigator. Vidpes macrourus should probably be included in 

 this list, but as to its altitudinal limits I haA^e no definite information. 

 Sonoran species extending into the Transition zone are the following : 

 Odocoileus macrourus, Antilocapra americana. Mephitis mesomelas 

 varians and Putorius longicauda. 



Of general distribution through both Sonoran and Boreal regions may 

 be mentioned the following species : Odocoileus hemionus. Bison hison,^ 

 Eutamias quadrivittatus , Citellus tridecemlineatus pallidus. Castor cana- 

 densis jondator, Peromyscus nebracensis, Peromyscus rufinus, Microtus 

 pennsylvanicus modestus, Lepus campestris, Lepus townsendi, Canis sp.,^^ 

 Taxidea taxus, Lutreola, lutreocephala energumenos and Putorius nigripes. 

 Both the wild cat and timber wolf ought probably to be included under 



' Extends into the Sonoran. 



^ Also Sonoran to some extent. I have taken it 12 km. east of Boulder on the 

 hot barren plains. 



" Now practically extinct. 



'" The distribution of the different forms of coyotes through the mountains is 

 not 3^et kno-\vn. 



