Austin B. Williams, 80, a zoologist and leading authority on the classification of eastern American decapod crustaceans, died of cancer Oct. 27 at his home in Falls Church.

Since 1971, Dr. Williams had been a research scientist with the systematics laboratory of the National Oceanographic and Atmospheric Administration's National Marine Fisheries Service, with offices at the Smithsonian Institution's National Museum of Natural History.

He was the author of more than 115 scientific publications, including a 1984 monograph, "Shrimps, Lobsters and Crabs of the Atlantic Coast of the Eastern United States," which was published by the Smithsonian Institution in 1984.

A 1965 study of the decapods of the Carolinas received a Science Citation Classic honor in 1983. He also was co-author of a book, "Lobsters of the World -- an Illustrated Guide."

Dr. Williams was born in Plattsburg, Mo. He graduated from McPherson College. He received a doctorate in zoology from the University of Kansas, where he studied Ozark crayfish.

From 1951 to 1955, he was on the staff of the University of North Carolina's Institute of Fisheries Research, studying the history and ecology of penaeid shrimps. From 1956 to 1963, he was at the University of Illinois, then returned to the University of North Carolina, where he continued his study of marine and estuarine decapods.

In 1997, Dr. Williams received the Excellence in Research Award of the Crustacean Society. He was the society's associate editor from 1986 to 1991. He was co-founder and president of the Estuarine Research Federation and president of the Atlantic Estuarine Research Society, the Biological Society of Washington and the American Association for Zoological Nomenclature.

His wife, Jean McNicol Williams, died 1982.

Survivors include a son, David McNicol Williams of Beaufort, N.C., and two grandchildren.