LESQUEREUX, Leo, paleontologist, born in Fleurier, Switzerland, 18 November, 1806. He was destined for the church by his mother, but, on entering the academy of Neuchatel, met Arnold Guyot, and together they became devoted to natural science. After completing his course at the academy in 1827, he went to Eisenach for the purpose of perfecting himself in the German language preparatory to entering the University of Berlin, and supported himself by teaching French. From 1829 till 1834 he was principal of the college at Chaux de Fonds, but, becoming deaf, he was obliged to give up this place. He then worked at engraving, and also made watch springs until 1848. Meanwhile he had begun the study of mosses and of fossil botany, becoming interested also in the subject of peat, its production, and possible reproduction. His knowledge of this subject led to his engagement by the government of Neuchatel to examine the peat-bogs of that canton, and later, under the patronage of the king of Prussia, he explored the peat bogs of northern Europe. His researches gained for him in 1844 a gold medal, which was awarded by the government of Neuchatel for the best popular treatise on the formation of peat. In 1848 he came to the United States, and at first made his home in Cambridge, where he assisted Louis Agassiz for a time, but soon removed to Columbus, Ohio, where he has since lived. There he became first associated with William S. Sullivant in the study of American bryology. Together they published "Musci Americani Exsiccati" (1856; 2d ed. 1865), and subsequently he assisted Mr. Sullivant in the examination of the mosses that had been collected by Captain Charles Wilkes on the South Pacific exploring expedition and by Lieutenant Amiel W. Whippie on the Pacific railroad exploration, and finally in his "Icones Muscorum" (Cambridge, 1864). His own most valuable researches, beginning in 1850, were studies of the coal formations of Ohio, Pennsylvania, Illinois, Kentucky, and Arkansas, on which he contributed memoirs to the reports of the state surveys. His investigations on the coal flora of Pennsylvania are of special value. He prepared a "Catalogue of the Fossil Plants which have been named or described from the Coal Measures of North America" for the reports of Henry D. Rogers in 1858, and in 1884 furnished "The Coal Flora" (3 vols. of text, with an atlas) for the second geological survey of Pennsylvania, which is regarded as the most important work on carboniferous plants that has thus far appeared in the United States. Since 1868 parts of the materia in fossil botany have been referred to him by the various national surveys in the field, and he has contributed to their reports the results of his investigations. He is a member of more than twenty scientific societies in the United States and Europe, and in 1864 was the first member that was elected to the National academy of sciences. The titles of his publications are more than fifty in number, and include twelve important volumes on the, natural history of the United States, besides which he has published "Letters written on Germany" (Neuchatel, 1846) and "Letters written on America" (1847-'55). He has also published, with Thomas P. James, "Manual of the Mosses of North America" (Boston, 1884).