A field guide to eastern butterflies
Paul A. Opler ; illustrated by Vichai Malikul
(The Peterson field guide series, 4)
Houghton Mifflin, c1992
Eastern butterflies
"Sponsored by the National Audubon Society, the National Wildlife Federation, and the Roger Tory Peterson Institute."
Includes 48 leaves of col. plates
Includes bibliographical references (p. 359-362) and indexes
Houghton Mifflin