4 U.S. NATIONAL MUSEUM BULLETIN 2 80 



flattened. In practice this was achieved by carefully separating the 

 right valve from the vinculum and tearing the diaphi-agma so that 

 the juxta remams adjacent to the right valve. The method was highly 

 satisfactory as all the genitalic structures then lay flat in one plane. 

 The genitalia were held flat, run through the alcohol, clove oil, xylene 

 series, and mounted as explained above. Illustrations of the peoriine 

 species and several other species were made with the male genitalia 

 prepared in this manner. 



Terms. — The Comstock-Needham system has been used in naming 

 the wing veins (fig. 50). I have followed Kornerup and Wanscher 

 (1962) for color terminology, viewing both the color plates and the 

 specimen by incandescent illumination. Physiographic distribution 

 terminology follows Lobeck (1948). Unless otherwise indicated, the 

 phrase "North America" is taken to mean America north of Mexico. 



Acknowledgments 



The investigation was carried out under the dhection of Prof. 

 John G. Franclemont, to whom I wish to express my gratitude for 

 his kind advice during the course of the project and for his helpful 

 criticisms of the manuscript. A special note of appreciation is due 

 Mr. Paul E. S. Whalley, who checked several type specimens in the 

 British Museum (Natural Histor37^) against my descriptions and photo- 

 graphs; to Dr. Pien-e E. L. Viette, who made available many of the 

 Ragonot types in the Paris Museum; to Dr. Alexander B. Klots for 

 his numerous helpful suggestions; to Dr. J. F. Gates Clarke, who sug- 

 gested and encouraged my work on this interesting problem, and to 

 Dr. H. E. Moore, Jr. and Dr. W. D. Duckworth, who offered useful 

 comments on the manuscript. 



I wish to thank the Allied Chemical Corporation for a contribution 

 toward the cost of preparing the manuscript and for a grant which 

 enabled me to spend one month collecting specimens at the Archbold 

 Biological Station, Lake Placid, Fla. I am also indebted to the pub- 

 lisher of the Goode Base Map Series, Department of Geography, 

 The University of Chicago, for granting permission to reproduce 

 copyrighted material used in several of the plates. Maps 1 through 6 

 and Map 12 are based on Goode Base Map No. 202, copyi'ight by 

 the University of Chicago. 



Finally, the investigation would not have been possible without the 

 kind cooperation of numerous individuals and institutions who loaned 

 specimens for my studies. I extend my appreciation to Dr. George W. 

 Byers, University of Kansas; Mr. Harry K. Clench, Carnegie Museum; 

 Mr. Hugh B. Cunningham, Illinois Natural History Survey; Dr. 

 Donald R. Davis, U.S. National Museum; Dr. Howard E. Evans, 



