MILLER AND REHN: NORTH AMERICAN MAMMALS. 95 
Genus ZYGODONTOMYS Allen. 
1897. Zygodontomys Allen, Bull. Amer. mus. nat. hist., ix, p. 
38. March 11, 1897. Type.— Oryzomys cherriei Allen. 
Zygodontomys cherriei (Allen). 
1895. Oryzomys cherriei Allen, Bull. Amer. mus. nat. hist., 
VII, p. 329. hTovember 8, 1895. 
1897. Zygodontomys cherriei Allen, Bull. Amer. mus. nat. 
hist., IX, p. 38. March 11, 1897. 
Type locality.— Boruca, Costa Rica. 
Genus SIGMODONTOMYS Allen. 
1897. Sigmodontomys Allen, Bull. Amer. mus. nat. hist., ix, 
p. 38. March 11, 1897. Type.— iSigmodontomys alfari Allen. 
Sigmodontomys alfari Allen. 
1897. Sigmodontomys alfnri Allen, Bull. Amer. mus. nat. 
hist., IX, p. 39. March 11, 1897. 
Type locality. — Jimenez, Costa Rica. Altitude, 700 feet. 
Genus REITHRODONTOMYS Gi^lioli.^ 
o 
1873. Heithrodontomys Giglioli, Richerche intorno alia distrib. 
geog. gener., p. 60. Type.— Reithrodon from North America 
zr Mus lecontii Audubon and Bachman. 
1 A synopsis was published by Allen in 1895 (Bull. Amer. mus. nat. hist., vii, pp. 
107-143, May 21, 1895), but the subsequent increase of nearly 100 per cent in the number 
of known forms makes it necessary to treat the genus as not revised. 
