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

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

DISTRIBUTION: N Brazil, Suriname.

COMMENTS: Formerly included in hispidus by Cabrera (1961:536); considered a distinct species by Husson (1978:438). Emmons and Feer (1990:223) gave its range as south of Amazon and east of Rfo Tapajós in Brazil. May be a subspecies of hispidus .