A REVIEW OF THE AMERICAN SPECIES OF XYLOCELIA. 

 (Hymenoptera; Psenidae.) 



By Clarence E. Mickel, Lincoln, Nebraska. 



The genus Xylocelia has received comparatively Httle atten- 

 tion from systematists so far as the American species are con- 

 cerned. Dr. A. S. Packard recognized the genus as represented 

 in our fauna in 1867 under the name Diodonhis of authors (nee 

 Curtis), and placed in it the new species americanns. In 1892 

 Mr. W. J. Fox described five new species and gave a synoptic 

 key for the six species then known. Since 1892 a number of 

 new species have been described by Messrs. Cockerell and Fox, 

 Mr. H. L. Viereck, Mr. S. A. Rohwer and Dr. E. G. Titus. 

 While working over the material in the collection of the Uni- 

 versity of Nebraska recently, seven new forms were noted by the 

 writer. With this addition the list of known American forms 

 of Xylocelia totals twenty-five and it seems desirable to present 

 at this time a synoptic key for separating the species. In 

 cases where examples of a species have not been at hand, the 

 characters used in the table are based on the original descriptions. 

 No doubt more careful collecting of our smaller wasps will bring 

 other new forms to light, and it is hoped that this review may be 

 of service in determining the described American species. 

 The types of the seven new species here described are in the 

 entomological collection of the University of Nebraska. The 

 writer wishes to acknowledge his indebtedness to Dr. E. G. 

 Titus for the loan of the type of Xylocelia adamsi, and to Prof. 

 Myron H. Swenk for going over the manuscript. 



Genus Xylocelia Rohwer. 

 1837. Diodontus, Shuckard, Essay indig. Fossor. Hymen., p. 186, (nee Curtis). 

 1867. Diodontus, Packard, Proc. Ent. Soc. Phila., vi, p. 392. 

 1892. Diodontus. Fox, Trans. Amer. Ent. Soc., xix, p. 314. 

 1915. Xylocelia, Rohwer, Proc. U. S. Nat. Mus., xxxxix, p. 243. 



344 



