A Revision 



of the 



Genus Eucerceris Cresson 



(Hymenoptera: Sphecidae) 



Introduction 



The wasp genus Eucerceris was erected by E. T. Cresson in 1865. 

 In 1939 the Avriter published his first extensive paper on this genus 

 (ScuUen, 1939). A second paper with a revised key to the known 

 species (ScuUen, 1948) was published later describing additional 

 species. Since the above publications appeared, the writer, through 

 the assistance of grants from the National Science Foundation and 

 the Graduate School of Oregon State University, has been able to 

 study types in this country and in the museums of Europe. Further- 

 more, in more recent years a vast amount of additional material 

 and information has been secured through the field work of the 

 writer and numerous other workers. Many new species have been 

 discovered in Mexico. The distribution data and information relative 

 to known species have been greatly extended by recent workers. 



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