Scope and Contents From the Collection: The collection consists of 704 letters addressed to Haldeman, Constantine Rafinesque and Thomas Say, with a letterbook of 22 letters written by Haldeman. In subject, the letters refer to paleontology, conchology, entomology, ichthyology, to Indian relics and to spelling reform. A letter from Leidy is illustrated and several of those written by Haldeman bear pencil sketches. In his letterbook is information about a proposed U. S. Naval Expedition to South America with J. G. Strain, and...

Overview Helen Elizabeth Lawson, the second daughter of Alexander and Elizabeth De Scaife Lawson, was born in Philadelphia sometime in or about the year 1808. An accomplished scientific illustrator, her contemporaries described her work to be "so perfect as certainly leave nothing to be desired", and H.A. Pilsbry stated that he considered her illustrations for Amos Binney's The Terrestrial Air-breathing Mollusks of the United States, to be the finest shell illustrations ever made. This collection...

Overview Joseph Mellick Leidy (1823-1891), one of the great American scientists of the 19th century, possessed a vast knowledge of the natural world. Best known as the Father of American vertebrate paleontology, he also pioneered the fields of parasitology and protozoology, and was the preeminent anatomist of his time. He was also an influential teacher of natural history and an expert in areas as diverse as entomology, geology and pathology. The Joseph Leidy Correspondence collection contains...