nigrum, Petromyzon Rafinesque [C. S.] 1820:251 [Western Review and Miscellaneous Magazine: a monthly publ., devoted to literature and science, Lexington, KY v. 3 (no. 4); ref. 5088] Ohio River, U.S.A. Also in Rafinesque 1820:84 [ref. 3592]. Objectively invalid; preoccupied by Petromyzon niger Lacepède 1802. 1°Homonym. Petromyzontidae.