William Heyden Easton, 80, a USC paleontologist and world authority on fossil corals. A native of Bedford, Ind., Easton studied at Bard College in New York and the Corcoran Art Institute in Washington, D.C.. He earned two degrees from George Washington University and a doctorate from the University of Chicago. He worked for the Illinois Geological Survey and, during a sabbatical year from USC, for the U.S. Geological Survey. After serving as a Navy officer toward the end of World War II, Easton joined the USC faculty in 1946. He chaired the geological sciences department from 1964 through 1967. Highly knowledgeable about French language, literature and culture, he also served two nonconsecutive years as acting chairman of the French and Italian department. Easton was a past president of the national Paleontological Society and a fellow of the Geological Society of America. He was the author of the widely used textbook “Invertebrate Paleontology,” published in 1960, and of more than 100 journal articles. On July 7 in Westlake Village of cancer.