The authors thank Bryan A. Jowers, Glendale, California, for the
excellent winter silhouettes. For help in obtaining specimens or
photographs of species not easily accessible to us, we thank the
following: Roger W. Barbour, University of Kentucky; William Harlow,
College of Environmental Science and Forestry, State University of New
York; Richard Johnson, Caroline Dormon Nature Preserve; Betty E. Lemon,
University of Southwestern Louisiana; R. Dale Thomas, Northeast
Louisiana University; and Lino Della-Bianca and Edwin R. Lawson of the
U.S. Forest Service.