Ferdinand Vandeveer Hayden , an American geologist, born in Westfield, Mass., Sept. 7,1829. He emigrated to Ohio at an early age, and graduated at Oberlin college in 1850. He afterward studied medicine at the Albany medical college, taking his degree in 1853. In the spring of that year he visited the "Bad Lands" of Dakota on White river in the interest of Prof. James Hall, explored one of the remarkable ancient deposits of extinct animals, and returned with a large and valuable collection of fossil vertebrates. He again ascended the Missouri river for the American fur company in the spring of 1854, and spent two years in exploring the upper Missouri, entirely at his own expense, returning in 1856 with another large collection of fossils, a part of which was deposited in the academy of sciences of St. Louis, and a part in that at Philadelphia. These collections attracted the attention of the officers of the Smithsonian institution, and he was appointed geologist on the staff of Lieut. G. K. Warren of the topographical engineers, who was then making a reconnoissance of the northwest, and continued on this duty till 18(51, when he entered the army as a medical officer.

In 1864 he was assistant medical inspector of the department of Washington, and in the autumn of the same year chief medical officer of the army in the Shenandoah valley. In 1865 he was elected professor of geology and mineralogy in the university of Pennsylvania, and held that post till 1872, when he resigned on account of the increased labor in managing the survey. In the summer of 1866 he made another expedition to the upper Missouri in behalf of the academy of sciences of Philadelphia, bringing back another valuable collection of vertebrate fossils. The United States geological survey of the territories, under charge of Prof. Hayden, was commenced in the spring of 1867 with an appropriation of $5,000; continued in 1868 with $5,000, in 1869 with $10,000, in 1870 with $25,000, in 1871 with $40,000, in 1872 with $75,000 and $10,-000 for engraving, and in 1873 with $75,000 and $20,000 for engraving. Seven annual reports of the survey have been published, and a final report on Nebraska, in octavo, besides 3 vols. 4to, with illustrations. Besides his reports, Dr. Hayden has written about 40 scientific papers, published in the "American Journal of Science," in the proceedings of the academy of sciences of Philadelphia, and in the reports of the Smithsonian institution.

He is a member of the national academy of sciences, and of many other American and European societies. Dr. Hayden has occupied about 20 years in exploring the west, and has extended his investigations over much of Kansas, Nebraska, Colorado, Dakota, Montana, Idaho, Utah, and New Mexico.