Say, Thomas, 1787–1843, American naturalist, b. Philadelphia. He went on collecting expeditions to Georgia and Florida and, with Stephen H. Long, to the Rocky Mts. and up the Mississippi and Minnesota rivers. He was professor of natural history at the Univ. of Pennsylvania from 1822 to 1828 and spent the rest of his life at Robert Owen's colony in New Harmony, Ind. Called the father of American descriptive entomology, he wrote on paleontology and conchology as well. His complete entomological papers were collected by J. L. Le Conte (2 vol., 1859), and his complete writings on conchology were edited by W. G. Binney (1858).