Peterson Field Guide To Eastern Butterflies

Guide to Eastern Butterflies
by Paul A. Opler and Vichai Malikul. 486 pages.
Peterson Field Guides
The Peterson Field Guides employ a unique identification system, which has been called "the greatest invention since binoculars." Each guide pinpoints key field marks for quick recognition and easy comparison of species. All guides are illustrated with drawings and photographs in color and black and white, and all provide up-to-date range information and the most useful descriptions you'll find anywhere. 4-1/2" x 7-1/4" standard format.