Mesomys stimulax Thomas, 1911 . Ann. Mag. Nat. Hist., ser. 8, 7:607.

TYPE LOCALITY: N. Brazil, Amazon estuary, "Cameta, Lower Tocantins.”

DISTRIBUTION: N. Brazil, Surinam.

COMMENT: Formerly included in hispidus by Cabrera, 1961:536; considered a distinct species by Husson, 1978:438.