SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOLUME SI. NUMBER 8 



PARASITES AND THE AID THEY GIVE IN 

 PROBLEMS OE TAXONOMY, GEO- 

 GRAPHICAL DISTRIBUTION, 

 AND PALEOGEOGRAPHY 



BY 



MAYNARD M. METGALF 



The Johns Hopkins University 



(Publication 3010) 



CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 



FEBRUARY 28, 1929 



