228 UNIVERSITY OF COLORADO STUDIES 



Boulder County contains the type-localities of the following 

 vertebrates : 



Mammals : Eptesicus pallidus Young, Etitamias operarius Merriam, 

 Evotomys gap peri galei Merriam, Neotoma fallax Merriam, Phena- 

 cotnys preblei Merriam. 



Birds: Dryohates villosus monticola Anthony, Megascops asio 

 maxwellicB Ridgway (in part). 



Fishes: Notropis universitatis Evermann & Cockerell, Richard- 

 sonius evermanni {Leuciscus evermanni Juday) . 



The type-localities of very many invertebrates are in Boulder 

 County, and will be indicated in the treatment of the different groups. 

 There are indications, especially noticeable in the flora, that during 

 Pleistocene or early post-Pleistocene time the climate of the county 

 was less arid, and the biota of the eastern states spread westward 

 through Nebraska, invading the foothill region of Colorado. This 

 invasion appears to be quite distinct from the northern element 

 spreading down the Rocky Mountain chain. Its members now 

 suffer from the more arid conditions, and survive only in more or 

 less isolated spots, as may be observed in various places in north- 

 eastern Colorado. In several cases, at least, the specific types have 

 been altered, so that we have endemic forms, sometimes of extreme 

 rarity. Such are the birch Betiila andrewsii A. Nelson, the fern 

 Asplenium andrewsii A. Nelson, and certain species of CratcBgus in 

 our county. The discovery and study of these forms is of extreme 

 interest to the student of evolution. 



Species which have been found on the University campus are 

 marked with an asterisk. 



Phylum PROTOZOA 



For a modern classification see Calkins, Protozoology (1909). For our species, see 

 these Studies, Vol. IV, p. 261, and Vol. VI, p. 305. 



SuBPHYLUM Mastigophora 



Protozoa in which the kinoplasm is concentrated in the form of one or more vibratile 

 or undulating motile processes, called flagella, or in a kinetonucleus which may lie 

 inside or outside of the trophonucleus. Simplest forms closely related to bacteria 

 (Calkins). 



