Petromyscus Thomas, 1926 . Ann. Mag. Nat. Hist., ser. 9,17:179.

TYPE SPECIES: Praomys collinus Thomas and Hinton, 1925 .

COMMENTS: Most faunal lists, either without question or with reservations, recognized only two species (Ellerman et al., 1953; Meester et al., 1986), but our study of museum specimens and original descriptions of taxa revealed the presence of four distinctive species, a conclusion also recorded by Skinner and Smithers (1990).