ORYZOMYS. 233 
eastern and southeastern portions; but in Mexico some are met with 
at 10,000 feet elevation, and these forms are provided with a woolly 
covering to protect them from the cold of such high altitudes. 
48. Oryzomys. Rice Rats. 
=; eS 
of : =a Ol 
C. H. Merriam. Synopsis of the Rice Rats (Genus Oryzomys) of the 
United States and Mexico, Proc. Wash. Acad. Scien., 111, 1901, p. 273. 
Oryzomys Baird, N. Am. Mamm., 1857, p. 458. Type Mus palus- 
tris Harlan. 
Oligoryzomys Bangs, Proc. N. Eng. Zodl. Club, 1, 1900, p. 94, pl. 
Rar t OM 
‘Form rat-like; ears nearly buried in the fur; hairs of body 
coarse; tail longer than head and body; the hairs longest on the 
FiG. 39. ORYZOMYS COSTARICENSIS. 
Nos 7963 Am Mus, Nat. Hist. Coll. Twice nat. size. 
UPPER TOOTH ROW. LOWER TOOTH ROW. 
Enlarged io times. Enlarged to times. 
