concolor, Ammocoetes Kirtland [J. P.] 1840:473, Pl. 27 (fig. 1) [Boston Journal of Natural History v. 3 (nos 3-4) (art. 10, 17); ref. 18404] Mahoning and Scioto rivers, Ohio, U.S.A. No types known. Apparently Petromyzon concolor of Wright 1892:439 [ref. 22767] is an identification and not a new species description. •Synonym of Ichthyomyzon unicuspis Hubbs & Trautman 1937 -- (Scott & Crossman 1998:54 [ref. 24570]). Current status: Synonym of Ichthyomyzon unicuspis Hubbs & Trautman 1937. Petromyzontidae. Habitat: freshwater.