Phyllotis osilae J. A. Allen, 1901 . Bull. Am. Mus. Nat. Hist., 14:44.

TYPE LOCALITY: Peru, Puno Dept., Osila (Pearson, 1958:426, considered the place-name equivalent to Asillo, 17 mi ENE Ayaviri, 13,000 ft) .

DISTRIBUTION: Upper Andean slopes on Atlantic drainage, from SC Peru (Cuzco), through WC Bolivia, to N Argentina (Catamarca).

SYNONYMS: lutescens, nogalaris, phaeus, tucumanus .

COMMENTS: All-acrocentric karyotype (2n=68) interpreted as ancestral state of the genus (Pearson and Patton, 1976).