CONRAD, Timothy Abbott, naturalist, born in New Jersey, in August, 1803; died in Trenton, New Jersey, 9 August, 1877. He was from early life an investigator of American paleontology and natural history, devoting himself to the study of the shells of the tertiary and cretaceous formations, and to existing species of mollusks. In 1831 he began the issue of a work on "American Marine Conchology," and the year following published the first number of his "Fossil Shells of the Tertiary Formation." which was never completed. A "Monography of the Family Unionidae" was issued between 1835 and 1847. The lithographed plates in his publications were in part his own work. He contributed many articles to the "American Journal of Science" and the "Journal of the Philadelphia Academy of Science." As one of the New York state geologists he prepared the geological report for 1837. He was paleontologist of the New York geological survey from 1838 till 1841, and wrote the annual reports in that department. He also made the reports of paleontological discoveries in the Pacific railroad survey and the Mexican boundary survey. He defended the theory of periodical refrigeration, and suggested that the Mississippi depression was the consequence of the upheaval of the Appalachians and the later elevation of the Rocky mountain area. A list of his scientific papers is given in the catalogue of the Royal society of England.