identified as coming from an amphibian known as Palaeosauropus primaevus from the Mississippian Age over 330 million years ago. He was a member and vice-president of the American Philosophical Society (elected in 1828) and also served as president of the Academy of Natural Sciences of Philadelphia (1858–1863), both based in Philadelphia. Lea served as president of the American Association for the Advancement of Science in 1860. Family His two sons, Henry Charles Lea and Matthew Carey Lea achieved distinction in scholarly fields and the family publishing business. The brothers married the Jaudon sisters and their children also joined the family business, which ultimately became Lea & Febiger. Henry Charles Lea (September 19, 1825 – October 24, 1909) was an American historian, civic reformer, and political activist in Philadelphia. Mathew Carey Lea (1823–1897) was a lawyer as well as founder of mechanochemistry and early photographer. Death and legacy He died on December 8, 1886, in Philadelphia and was interred in Laurel Hill Cemetery. In 1829 Edgar Allan Poe wrote a poem dedicated to Lea titled "To Isaac Lea". Three mollusks were named in his honor, Crenella leana Dall, Lymnea leai and Periploma leanum. The National Museum at Washington now has his immense collection of freshwater mussels from the family Unionidae, as well as other collections. The Historical Society of Pennsylvania has the records of Lea & Febiger, as well as predecessor companies. Two slabs of rock containing the fossilized footprints and plaster casts of the footprints discovered by Lea are in the collections of the Smithsonian Institute. Publications Lea, I. 1818. An account of the minerals at present known to exist within the vicinity of Philadelphia. Journal of the Academy of Natural Sciences of Philadelphia 1, 462–482. (BHL link) (1823) Complete, Historical, Chronological, and Geographical American Atlas (1827–1874). Observations on the Genus Unio. 13 volumes. Contributions to Geology, Carey, Lea & Blanchard, Philadelphia, 1833 (1837). "Observations on the Naiades". Transactions of the American Philosophical Society 5 (1838). Synopsis of the Family of Naiades Lea I. (1838). "Description of New Freshwater and Land Shells". Transactions of the American Philosophical Society 6: 1–154. A Synopsis of the Family of Naiades, Blanchard and Lea, Philadelphia, 1852 On the Fossil Foot-marks in the Red Sandstone of Pottsville, Pennsylvania, self-published, Philadelphia, 1852 Observations on the Genus Unio, Together with Descriptions of New Genera and Species in the Family Unionidae, Volumes 6-7, J. Kay, Philadelphia, 1857Check Lists