SECTION VI 

 ACKNOWLEDGMENTS 



The cooperation of various publishers who kindly permitted the repro- 

 duction of figures from their in part copyrighted publication is 

 gratefully acknowledged: American Microscopical Society; the pub- 

 lishers of American Midland Naturalist; American Museum of Natural 

 History; University of Michigan; and Washington Academy of Sciences. 



Mr Jack R. Schroeder and Mrs Carol>'n B, Cast, Scientific Illustrators, 

 and Mr Victor E. Krantz of the Smithsonian photographic laboratories 

 provided valuable assistance in the preparation and copying of the 

 illustrations. 



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