Ctenomys knighti Thomas, 1919 . Ann. Mag. Nat. Hist., ser. 9, 3:498.

TYPE LOCALITY: Argentina, Catamarca Prov., Otro Cerro .

DISTRIBUTION: Mountains between Tucumân and La Rioja (W Argentina), north to Salta.

SYNONYMS: viperinus.

COMMENTS: Cabrera (1961:550) believed viperinus synonymous with knighti . The chromosome no. is 2n=36.