Fig. 76.—Thirteen-lined Spermophile (Spermophilus tredecimlineatus).—By permission of the N.Y. Zoölog. Soc.
The grey foxes (Urocyon), Coyote (Canis latrans), large Timber Wolf (Canis occidentalis), the Caxomistle (Bassariscus), the Coati (Nasua), Raccoon (Procyon), Badger (Taxidea), three genera of skunks, pumas, several species of lynx and some bears (Ursus) represent the Carnivora, though one species each of raccoon, skunk, badger, puma and lynx range into the Boreal. The American types of shrews (Blarina) and moles (Scalops and Scapanus) are characteristic of the Sonoran, though partially shared with the Boreal. A great many peculiar rodents inhabit the Sonoran; cotton-rats (Sigmodon), pocket-gophers (Geomys, etc.), several genera of the beautiful little kangaroo-rats (Dipodomys, etc.); while the prairie-dogs (Cynomys), the white-footed mice (Sitomys), wood-rats (Neotoma) and one genus of pocket-gophers (Thomomys) are chiefly Sonoran, but have Boreal representatives. The flying squirrels (Sciuropterus), true squirrels (Sciurus), ground-squirrels (Spermophilus), rabbits (Lepus), wolves (Canis) and otters (Lutra) have a very wide range through both the Boreal and Sonoran, but have many more species in the latter region.
Fig. 77.—Grey Squirrel (Sciurus carolinensis).—By permission of the N.Y. Zoölog. Soc.
The Sonoran region may be divided into the upper and lower Sonoran zones, which are demarcated by temperature and are of transcontinental extent. Each of these zones may, in turn, be subdivided into arid and humid provinces, but our purpose does not necessitate entering into such refinements.
Fig. 78.—Grey Fox (Urocyon virginianus).—By permission of the N.Y. Zoölog. Soc.
