Oryzomys ratticeps (Hensel, 1873) . Abh. Preuss. Akad. Wiss., (1872), p. 36.

TYPE LOCALITY: Brazil, Rio Grande do Sul .

DISTRIBUTION: S. Brazil; Paraguay.

COMMENT: Included in buccinatus by Hershkovitz, 1959, J. Mammal., 40:347, but considered a distinct species in subgenus Oryzomys by Avila-Pires, 1960, Acta Trab. Prim. Cong. Sudam. Zool., sec. 5, Vertebrados, 4:3-8, Avila-Pires, 1959, Atas Soc. Biol. Rio de J., 3(4):3, Cabrera, 1961: 395, Corbet and Hill, 1980:144, Voss and Linzey, 1981, Misc. Publ. Mus. Zool. Univ. Mich., 159:13, and Myers and Carleton, 1981, Misc. Publ. Mus. Zool. Univ. Mich., 161: 19.

ISIS NUMBER: 5301410008035054001.