342 PROCEEDINGS OF THE NATIONAL MUSEUM vol. hi 



More than 12,000 specimens have been made available for study 

 from numerous institutional and private collections, as follows: 

 American Museum of Natural History by Dr. M. Cazier, Dr. H. 

 Ruckes, and Mrs. P. Vaurie; British Museum (Natural History) 

 by Dr. W. E. China; California Academy of Sciences by Drs. E. S. 

 Ross, H. B. Leech and J. W. Green; Carnegie Museum by Dr. G. 

 Wallace; Museo Nacional de Historia Natural, Santiago, Chile, by 

 Dr. D. S. Bullock; Direcci6n General de Agricultura, Mexico City, 

 by Dr. F. Bonet; Eastern Illinois State College, Charleston, 111., by 

 Dr. G. Riegel; Illinois Natural History Survey, Urbana, 111., by Dr. 

 H. H. Ross; Instituto de Ecologia e Experimentagao Agricolas, Rio 

 de Janeu'o, by Dr. D. Mcndes; Iowa State College, Ames, Iowa, 

 by Drs. H. M. Harris and J. L. Laffoon; Los Angeles County Museum, 

 Los Angeles, Calif., b}^ Dr. F. Truxal ; University of Michigan Museum 

 of Zoology, Ann Arbor, Mich., by Drs. T. Hubbell and R. F. Hussey; 

 Universidad Nacional de La Plata, Buenos Aires, by Dr. B. A. Torres; 

 Museum of Comparative Zoology, Cambridge, Mass., by Dr. J. 

 Bequaert; Naturhistorisches Museum, Vienna, by Dr. M. Beier; 

 Oregon State College, Corvallis, Greg., by Dr. V. D. Roth; San 

 Diego Museum, San Diego, Cahf., by Mr. J. D. Lattin; Universidad 

 Nacional de Tucumdn, Tucuman, Ai-gentina, by Dr. K. J. Hay ward; 

 University of Cahfornia, Berkeley, Calif., by Dr. P. D. Hurd, Jr., 

 and Mr. J. D. Lattin, and from the Division of Entomology and 

 Parasitology of the same institution, Davis, Calif., by Dr. A. T. 

 McClay; University of Kansas, Lawrence, Kans., by Dr. R. H. 

 Beamer; University of Massachusetts, Amherst, Mass., by Dr. M. E. 

 Smith; U.S. National Museum, by Drs. R. I. Sailer and H. G. Barber; 

 and Washington State College, Pullman, Wash., by Dr. M. T. James. 

 The following individuals lent their private collections for study: 

 Dr. F. Bonet, Mexico City; Dr. D. S. Bullock, Angola, Chile; Dr. 

 J. M. Capriles, Mayaguez, Puerto Rico; Dr. J. C. M. Carvalho, Rio 

 de Janeiro; Dr. H. M. Harris, Ames, Iowa; Dr. R. F. Hussey, Gaines- 

 ville, Fla.; Mr. J. D. Lattin, Berkeley, Calif., Mr. J. C. Lutz, Phila- 

 delphia, Pa.; Dr. D. Pelaez, Mexico City; Dr. J. A. Slater, Storrs, 

 Conn. ; and Dr. R. L. Usinger, Berkeley, Calif. To all these individuals 

 and the institutions mentioned, the author expresses sincere appre- 

 ciation. 



Real help in the pursuit of this project also came in other forms 

 from certain colleagues on the staff at Iowa State College, the scene 

 of this research. Dr. H. H. Knight has been especially generous of 

 his time in discussing many of the problems that have arisen and in 

 giving valued opinions on them; in addition, he has opened his 

 unusually complete and valuable library of older volumes for unre- 

 stricted use. I also appreciate the help received from Drs. H. M. 



