322 VERTEBRATE ANIMALS OF THE UNITED STATES 



E. occidentalis Merr. Color dark chestnut above; sides gray; under 

 parts salmon buff; length 145 mm.; tail 45 mm.; hind foot 18 mm.: 

 Puget Sound and coast region of Washington. 



E. nivarius Bailey. Color light chestnut above; sides gray; length 

 150 mm.; tail 50 mm.; hind foot 18 mm.: high peaks of the Olympic 

 Mountains, Washington. 



8. Fiber Cuvier {Ondatra Link) . Muskrats. Body large and stout; 

 legs short; feet large, the feet and toes being fringed with short, stiff 

 hairs; hind toes partly webbed; tail flattened laterally, with few hairs; 

 fur thick, with longer hairs projecting from it; anal musk glands present: 

 3 species, with many subspecies, all in North America; the most impor- 

 tant fur-bearing animals in the country. 



F. zibethicus (L.). Common muskrat. Color brown, variable, 

 darker dorsally, whitish beneath; length 560 mm.; tail 250 mm.; hind 

 foot 81 mm.: North America, from the Arctic barrens and Hudson Bay 

 to the Mexican boundary; very common. The animals live in swamps 

 and ponds and streams, in the banks of which they may burrow to form 

 the nest where the young are born. They also form large dome-shaped 

 houses two or three feet high and five or six feet in diameter by heaping 

 up sticks and reeds, the upper portion of which contains a chamber 

 above the level of the water where they spend much of the winter. 

 Their food consists of roots and water-plants, and also shell-fish and 

 other small animals; they raise severaUitters annually of from 3 to 13 

 each, and do not hibernate. 



Subspecies of F. zibethicus 



F. z. zibethicus (L.). Northeastern and central States; westward to 

 Minnesota and the Great Plains; southward to Georgia and Arkansas, 

 except along the Atlantic seaboard south of Delaware Bay. 



F. z. macrodon Merriam. Colors rich and bright; black phase often 

 common; in size the largest of the genus; length 620 mm.; tail 274 mm.; 

 hind foot 88: Atlantic coast region from Delaware Bay to Pamlico 

 Sound. 



F. z. osoyoosensis Lord. Color glossy brown to black: Puget 

 Sound region and Rocky Mountains. 



F. z. occipitalis Elliot. Paler and more reddish than F . z. osoyoosen- 

 sis: northern Willamette Valley and coast of Oregon. 



F. z. mergens Hollister. Color pale; size large: northern part of 

 Great Basin. 



F. z. pallidus Mearns. Color uniform rusty red; size small: 

 Colorado River Valley; eastward to Rio Grande. 



