298 University of California Publications in Zoology t v L - 16 



Ferry on the Snake River, and three weeks were spent in the Blue 

 Mountains in very intensive study. Notes published by others bearing 

 on the distribution of the vertebrates of the region have been used 

 whenever possible. Mr. S. H. Lyman of Dayton has kindly allowed 

 the use of his unpublished notes on the birds of the region. It is hoped 

 that the full accounts of the distribution of each species of vertebrates 

 in the region, which were prepared in working up the present paper, 

 may soon be published. 



Great care has been taken to obtain accuracy in the specific identifi- 

 cations. Specimens have been secured when possible, except of easily 

 recognized forms. In a few cases the subspecific identification is based 

 on the geographical distribution as given by recognized authorities. 

 Dr. Joseph Grinnell has checked a large number of identifications of 

 mammals and birds. The identification of the reptiles and amphibians 

 is due to Mr. Charles L. Camp. 



The botanical names used have been taken from Piper (1906) ex- 

 cept in a few cases where other names seemed more desirable. Speci- 

 mens of many of the more important species of plants were collected. 

 Dr. H. M. Hall identified a number of specimens and Dr. H. S. Yates 

 determined several grasses. 



FAUNAS AND ASSOCIATIONS OF THE REGION 



In southeastern Washington three prevailing types of vegetation 

 may be recognized. Along the Columbia River there is an area where 

 sagebrush is the dominant plant ; further east is a region where bunch- 

 grass forms the most prominent part of the natural vegetation; and 

 the Blue Mountains are largely covered by conifer forests. Correlated 

 with these differences in vegetation there are important differences in 

 the species of vertebrates found in each of these districts. The as- 

 semblage of species found in each such region delimited by climatic 

 features may be called a fauna, and the region itself may be called a 

 faunal area, or, more simply, an area. The term * * area ' ' as here used 

 refers to the whole of any geographical district where a particular 

 type of vegetation is dominant and includes all of the habitats in such 

 a district. 



Each faunal area is made up of several different kinds of habitats 

 and each habitat shelters a different association of vertebrates. Some 

 habitats and associations in the different faunal areas are very similar, 



