Feb., 1912. Mammals of Illinois and Wisconsin — Cory. 203 



Measurements — (Average of 8 specimens from various localities.) 

 Total length, 8.88 in. (225 mm.); tail vertebras, 4.38 in. (11 1 mm.); 

 hind foot, 1.15 in. (29.6 mm.). 



The Rice Field Mouse occurs within our limits in southern Illinois, 

 where Mr. Howell secured four specimens taken at Olive Branch, Alex- 

 ander Co. In Louisiana and northwestern Florida, where I have taken 

 it, it inhabits swampy places, hummocks, and old fields, but apparently 

 never far from water, in which it is quite at home, being an expert 

 swimmer. In such localities the nest is in a burrow in the ground, 

 but Audubon and Bachman state that in extensive salt marshes they 



Oryzomys palustris 



'Area of Intergradatlon 



Map illustrating the approximate distribution of Rice Field Mice or Rice Rats of the genus 

 Oryzomys which occur in eastern United States. 



Oryzomys palustris (Harlan). Type locality — Fast Land, near Salem, Salem Co., 



New Jersey. Description as previously given. 

 Oryzomys p. natator Chapman. (Bull. Amer. Mus. Nat. Hist., V, 1893, p. 44.) Type 



locality — Gainesville, Alachua County, Florida. Larger than palustris and 



tail longer; color more fulvous brown. 

 Oryzomys p. coloratus Bangs. (Proc. Bost. Soc. Nat. Hist., XXVIII, 1898, p. 189.) 



Type locality — Cape Sable, Monroe Co., Florida. Larger than natator; 



color more reddish brown. 



