2519 Ichthyomyzon unicuspis Hubbs & Trautman, 1937 Petromyzontidae Northern lampreys Petromyzontinae Petromyzontiformes Petromyzonti Silver lamprey North America: St. Lawrence-Great Lakes basin from Quebec to southwest Ontario and south through upper Mississippi and Ohio river basins to Tennessee; Hudson Bay basin in Manitoba; Missouri River in Nebraska and Mississippi River in Mississippi. Readily distinguishable from the sea lamprey by its single dorsal fin. AMNH 7607 Ichthyomyzon unicuspis AMNH 65176 1941 Ichthyomyzon unicuspis AMNH 37205 1974 Ichthyomyzon unicuspis AMNH 37206 1974 Ichthyomyzon unicuspis AMNH 39529 1977 Ichthyomyzon unicuspis