Microsciurus flaviventer (Gray, 1867) . Ann. Mag. Nat. Hist., ser. 3, 20:432.

TYPE LOCALITY: Brazil. Cabrera (1961) suggested the type locality could be restricted to Pebas, based on Thomas (1928b) .

DISTRIBUTION: Amazon basin of Colombia, Ecuador, Peru, and Brazil west of the Rios Negro and Jurua.

SYNONYMS: avunculus Thomas, 1914; brevirostris; florenciae J. A. Allen, 1914; manarius Thomas, 1920; napi (Thomas, 1900); otinus (Thomas, 1901); peruanus (J. A. Allen, 1897); rubicollis Thomas, 1914 (lapsus for rubrirostris); rubrirostris J. A. Allen, 1914; sabanillae Anthony, 1922; similis (Nelson, 1899); simonsi (Thomas, 1900); vivatus Goldman, 1912.