A check list of the Araneae type specimens deposited in the Museu Nacional, Universidade Federal do Rio de Janeiro, is given, including also all the type specimens of species described by Mello-Leitão without a clear repository. From a total of 923 type lots (which comprises 813 valid species names) cited in the list, 667 are available, 239 were not located (76 of them with uncertain repositories) and 17 are lost. The spelling of Olios hieroglyphicus Mello-Leitão, 1919 is fixed by action of first reviser. Based on the comparison of these type specimens, the following taxonomic changes are proposed on this paper: Actinopodidae: Actinopus ceciliae Mello-Leitão, 1931c = A. crassipes (Keyserling, 1891) n. syn.; Theraphosidae: Cyclosternum melloleitaoi Bücherl, Timotheo da Costa & Lucas, 1971 = Hapalopus nondescriptus Mello-Leitão, 1926b n. syn.; Anyphaenidae: Aysha garruchos Brescovit, 1992 = Aysha caxambuensis (Mello-Leitão, 1926a) (originally described as Teudis c.) n. syn., n. comb.; Sillus spinifrons Mello-Leitão, 1926a = Patrera longipes (Keyserling, 1891) n. syn.; Araneidae: Wagneriana janeiro Levi, 1991 = Wagneriana dimastophora (Mello-Leitão, 1940g) (originally described as Verrucosa d.) n. syn., n. comb.; Pholcidae: Pholcophora juruensis Mello-Leitão, 1922c = Physocyclus globosus (Taczanowski, 1874) n. syn.