Akodon aerosus Thomas, 1913 . Ann. Mag. Nat. Hist., ser. 8, 11:406.

TYPE LOCALITY: Ecuador, Tungurahua Prov., upper Rio Pastaza, Mirador, 1500 m .

DISTRIBUTION: SE Ecuador, E Peru, and NW Bolivia.

SYNONYMS: baliolus.

COMMENTS: Type species of Chalcomys, usually placed as a synonym of the subgenus Akodon (Cabrera, 1961; Reig, 1987). Formerly included as a subspecies of A. urichi by Cabrera (1961), but Gardner and Patton (1976), noting the pronounced difference in diploid number, listed the two as separate species. Probably more than one species yet masquerades under the name of A. aerosus (see Patton et al., 1990).