246 ENTOMOLOGICAL NEWS. [J une > '09 



In running the specimen over the table prepared by Mr. 

 Davis in reference quoted above, it readily traces as far as E. 

 canadensis Cress. In the description of canadensis there are 

 many characters in common to vierecki. But the differences 

 pointed out in the comparative description are decidedly too 

 marked to pass under the same species. The table or key in 

 this paper is practically in substance that of Mr. G. C. Davis, 

 but the first group has been entirely rearranged and partly 

 changed so as to show the relation more clearly as well as to 

 simplify the arrangement and incorporate the new species. 



One male was caught while it was flying about some weeds 



Euceros vierecki Hertzog. 



mostly Ambrosia trifida L. A number of Braconids and 

 Ichneumon-flies were in its company. This seems to indicate 

 that the species no doubt is a beneficial parasitic insect. Of 

 European species it may be noted that E. crassiconiis Grav., 

 is parasitic on Cidaria barberaria and Thecla quercus and E. 

 superbus Kriechb., is parasitic on Calliniorpha dominula. 



It gives me great pleasure to dedicate the species to Mr. 

 H. L. Viereck of the Bureau of Entomology, Washington, 

 D. C., who has given me much encouragement in the study 

 cf Hymenopterous insects. The illustration is due to the 

 kindness of Mr. W. R. Walton, Harrisburg, Pa. 



