226 Firtp Museum or Natura History — Zoéxoecy, Vot. XI. 
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Osporn, Proc. Iowa Acad. Sci., I, 1887-89 (1890), p. 43 (Iowa). Brayton, 
Geol. Surv. Ohio., IV, Pt. 1, 1882, p. 153 (Illinois, etc.). Strone, Geol. Wis., 
Surv. 1873-79, I, 1883, p. 439 (Wisconsin). Merriam, Mamm. Adirondack 
Reg., 1886, p. 275. EVERMANN & Butter, Proc. Ind. Acad. Sci., 1893 (1894), 
p. 126 (Indiana). GarMAN, Bull. Essex Inst., XXVI, 1894, p. 6 (Kentucky). 
Ruoaps, Proc. Acad. Nat. Sci. Phila., 1896 (1897), p. 186 (Tennessee). MILLER, 
Proc. Bost. Soc. Nat. Hist., XXVIII, 1897, p. 11 (North Shore, Lake Superior). 
SnypER, Bull. Wis. Nat. Hist. Soc., II, 1902, p. 121 (Wisconsin). Apams, 
Rept. State Board Geol. Surv. Mich., 1905 (1906), p. 129 (Michigan). Jackson, 
Proc. Biol. Soc. Wash., XX, 1907, p. 73 (S. W. Missouri). McATEE, Proc. Biol. 
Soc. Wash., XX, 1907, p. 5 (Munroe Co., Indiana). Haun, Ann. Rept. Dept. 
Geol. & Nat. Resources Ind., 1908 (1909), p. 517 (Indiana). HoweE.t, Proc. 
Biol. Soc. Wash., XXII, 1909, p. 62 (Tennessee, Mississippi. etc.). Jb., XXIII, 
1910, p. 29 (Illinois, Missouri, Kentucky). 
Type locality — Eastern Canada. 
Distribution — Eastern United States and southeastern Canada, south 
to northern North Carolina and northern Georgia and west to 
eastern Nebraska and Kansas. Replaced farther west and in the 
South by allied forms. 
Description — General color dark chestnut brown above; under parts 
brownish white; fur of back and rump mixed with long, blackish 
brown hairs; throat whitish; chin with brown spot; feet brown, the 
claws horn color; tail black, nearly bare and flattened, vertically 
being considerably higher than wide. Freaks of color often occur; 
black specimens are not uncommon and partly white or entirely 
white individuals are occasionally taken. 
Measurements — Size somewhat variable, generally 19 to 23 inches 
long. The following measurements probably represent an average 
specimen: Total length, 21.50 in. (546 mm.); tail vertebre, 10.50 
in. (266 mm.); hind foot, 3.30 in. (86 mm.). 
Remarks — Cases of albinism, either complete or in part, are not un- 
common. About three years ago Mr. W. S. McCrea of Chicago, 
called my attention to a series of seven Muskrat skins from Hayfield, 
Iowa, all of which were uniformly marked, having a white ring 
around the neck and the entire under parts, feet and terminal portion 
of tail white. Such uniform coloration in a series of specimens was 
perplexing and suggestive, especially as they all came from the 
same locality; but later two specimens were received from Indiana, 
which were similarly marked, but with the dark parts much paler. 
The Field Museum collection contains a pure white example of this 
species. 
The Muskrat or “‘Musquash,” as it is sometimes called, is common 
in the ponds, streams and overflowed marshes throughout Illinois and 
