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Psyche 
[March 
for larval food, it also may function, and have evolved, as a repro- 
ductive isolating mechanism. Greater knowledge of mating behavior 
in this group (Shapiro and Carde, 1970), as well as more informa- 
tion on the southeastern New York populations, may be able to dis- 
tinguish the correct hypothesis. 
Our current state of knowledge does not allow us to choose 
between independent evolution and character displacement in ac- 
counting for the differences between the American eurydice and 
portlandia groups. But character displacement is an attractive 
hypothesis for the eurydice - appalachia habitat selection difference. 
Acknowledgments 
We wish to thank William D. Field of the U.S. National Museum 
and Dr. Alexander B. Klots of the American Museum of Natural 
History for their advice and cooperation; Dr. Michael Emsley for 
the loan of specimens of Lethe eurydice fumosa from the Philadelphia 
Academy of Natural Sciences; N. D. Riley of the British Museum 
(Natural History) and Dr. T. Nyholm of the Naturhistoriska 
Riksmuseum (Stockholm) for aiding in the search for the early 
types; Dr. Lee D. Miller for information on Euptychia spp. ; Lucien 
Harris, Jr. and Frank Rutkowski for field notes and unpublished 
locality data; Edward L. Rittershausen for specimens from south- 
eastern New York; Dr. Takashi Shirozu, Kyushu University, Japan, 
for data on Asiatic Lethe ; and Dr. Peter A. Hyypio for deter- 
mining species of sedges. Dr. John G. Franclemont of Cornell 
University provided invaluable assistance in the taxonomic research. 
Mrs. Adrienne R. Shapiro assisted in color determinations and in 
the preparation of the manuscript. Dr. John Burns made several 
helpful suggestions. 
This research received partial support from National Science 
Foundation Grant GB 7757 (Environmental Biology) and from 
the Grace Griswold Memorial Illustrations Fund, Department of 
Entomology and Limnology, Cornell University. To both we extend 
our thanks. 
References 
Boisduval, J. B. A. and J. Le Conte 
1829. Histoire generate et iconographie des lepidopteres et des chenilles 
de PAmerique Septentrionale. Paris: Librairie Roret. 228 pp., 
78 pis. 
Brown, W. L., Jr. 
1957. Centrifugal speciation. Quart. Rev. Biol. 32: 247-277. 
