riddlei, Hemigrammus Meek [S. E.] in Eigenmann & Ogle 1907:13 [Proceedings of the United States National Museum v. 33 (no. 1556); ref. 1266] Los Castillas, Orinoco River, Venezuela. Syntypes: FMNH missing. Appeared in key but not in text or in list of new taxa on p. 2; footnote says, "Based on specimens collected by Dr. O. Riddle at Los Castillas, on the Orinoco, and now in the collections of the Field Museum of Natural History." On p. 12 it is stated that Hemigrammus contains 19 species, but the key contains 20. Apparently left in proofing. Types missing -- (Ibarra & Stewart 1987:45 [ref. 12367]). •Valid as Hyphessobrycon riddlei (Meek 1907) -- (Eigenmann 1912:340 [ref. 1227], Eigenmann 1918:189 [ref. 1240]). •Possibly a species of Microschemobrycon -- (F. Lima pers. comm. 03/21). •Species inquirenda -- (Lima & Marinho 2024:181 [ref. 40817]). Characidae: Stethaprioninae. Habitat: freshwater.