Snakes of the United States and Canada
Carl H. Ernstis a Distinguished Professor of Biology at George Mason University in Fairfax, Virginia. He has written six books, including the award-winningTurtles of the World(Smithsonian Institution Press, 1989) and is coauthor ofSnakes in Question(Smithsonian Institution Press, 1996).Evelyn M. Ernstis director of information for the  National Science Resource Center in Washington, D.C.