Melissodes pygmæa Cresson, 1872:279, ♀. 2 ♀♀, Texas (leg. Belfrage). - Cresson, 1879Cresson, E.T. 1879. Catalogue of North American Apidae. Transactions of the American Entomological Society and Proceedings of the Entomological Section of the Academy of Natural Sciences 7:215-232. (distribution); Cockerell, 1906Cockerell, T.D.A. 1906. The North American bees of the family Anthophoridae. Transactions of the American Entomological Society 32 (1):63-116. (distribution); Cockerell, 1913Cockerell, T.D.A. 1913. Names applied to the Eucerine bees of North America. Proceedings of the United States National Museum 43:261-273. (distribution). - As Eucera pygmaea: - Dalla Torre, 1896Dalla Torre, C.G. 1896. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus, X. Apidae (Anthophila). Sumptibus Guilelmi Engelmann, 1-643. (distribution), 244 (comb. nov.). - As Exomalopsis pygmaea: - Lutz & Cockerell, 1920Lutz, F.E. & T.D.A. Cockerell 1920. Notes on the distribution and bibliography of North American bees of the families, Apidae, Meliponidae, Bombidae, Euglossidae, and Anthophoridae. Bull. Amer. Mus. Nat. Hist 42 (15):491-641. (distribution); Timberlake, 1947Timberlake, P.H. 1947. A revision of the species of Exomalopsis inhabiting the United States (Hymenoptera, Apoidea). Journal of the New York Entomological Society 55 (2):85-106. (distribution); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209. (distribution); Timberlake, 1980Timberlake, P.H. 1980. Review of North American Exomalopsis (Hymenoptera, Anthophoridae). University of California press, LTD, London, England. 158 pp. (distribution).
Exomalopsis bruneri Crawford, 1902:238, ♂♀.Lincoln, Nebr.. Synonymized with Exomalopsis pygmaea (Cresson, 1872) by Timberlake, 1947Timberlake, P.H. 1947. A revision of the species of Exomalopsis inhabiting the United States (Hymenoptera, Apoidea). Journal of the New York Entomological Society 55 (2):85-106.:105. - Lutz & Cockerell, 1920Lutz, F.E. & T.D.A. Cockerell 1920. Notes on the distribution and bibliography of North American bees of the families, Apidae, Meliponidae, Bombidae, Euglossidae, and Anthophoridae. Bull. Amer. Mus. Nat. Hist 42 (15):491-641. (distribution); Timberlake, 1980Timberlake, P.H. 1980. Review of North American Exomalopsis (Hymenoptera, Anthophoridae). University of California press, LTD, London, England. 158 pp.:62 ( listed as synonym of Exomalopsis pygmaea (Cresson, 1872)). - As Anthophorula bruneri: - Cockerell, 1914Cockerell, T.D.A. 1914. New and little known bees. The Entomologist 47 (611):115-119. (distribution); Cockerell, 1914Cockerell, T.D.A. 1914. Bees visiting Helianthus. The Canadian Entomologist 46 (12):409-415. (distribution).