How to know the butterflies
Subtitle: illustrated key for determining to species all butterflies found in North America, north of Mexico, with notes on their distribution, habits, and larval food, and suggestions for collecting and studying them
By: by Paul R. Ehrlich and Anne H. Ehrlich. With sections contributed by D. L. Bauer [and others].
Edition: 1st edition.
Series: Pictured key nature series
Publisher: W. C. Brown
Published: 1961
Place of publication: Dubuque, Iowa
Number of pages: 262
Subjects: Butterflies -- North America