Thomasomys Coues, 1884 . Am. Nat., 18:1275.

TYPE SPECIES: Hesperomys cinereus Thomas, 1882 .

SYNONYMS: Erioryzomys, Inomys .

COMMENTS: Thomasomyine. A complex genus whose nomenclatural history is intertwined with Aepeomys, Delomys, and Wilfredomys, taxa which have been used as subgenera (e.g., Ellerman, 1941; Cabrera, 1961) or as genera (see their accounts). Comparative anatomical studies involving some Thomasomys include Carleton (1973), Hooper and Musser (1964a), and Voss and Linzey (1981); chromosomal numbers of several species published by Gardner and Patton (1976). Revisionary studies required to critically overhaul species taxonomy and to place ranking of various genus-group taxa in a phylogenetic context. Species recognized here basically follow Cabrera (1961).