Phyllotis definitus Osgood, 1915 . Field Mus. Nat. Hist. Pubi., Zool. Ser., 10:189.

TYPE LOCALITY: Peru, Ancash Dept., Macate, 9000 ft .

DISTRIBUTION: Andes of Ancash, Peru.

COMMENTS: Included in P. magister by Pearson (1958) and in P. darwini by Hershkovitz (1962) but distinctive karyotype is unlike either of those species (see Pearson, 1972).