i. AMERICAN HYMENOPTERA. 



rectly from them, modified or added to by comparing with 

 other specimens and the original descriptions. During the 

 time that I have carried on this work material has been 

 loaned, through Dr. H. T. Fernald, and assistance given by 

 many persons. I am greatly indebted to Dr. L. O. Howard 

 of the U. S. Department of Agriculture and Dr. Henry 

 Skinner of the American Entomological Society for the 

 loan of material; to Messrs. J. C. Crawford and E. T. Cres- 

 son, Jr., for aid at the museums with which they are con- 

 nected ; to the Committee of Nomenclature of the Entomo- 

 mological Society of America, for rulings on numerous 

 problems ; to Mrs. A. K. Dimmock, for information as to 

 the habits of Thyreodon morio, with specimens of its cocoons 

 and of Encyrtus thyreodontis, its parasite ; to Messrs. C. W. 

 Johnson, E. D. Sanderson, William Beutenmiiller, W. D. 

 Hunter and others for the loan of material ; to Messrs. C, O. 

 Waterhouse, Geoffrey Meade-Waldo and A. G. B. Bouquet 

 for information in regard to types in the British Museum ; 

 and to Mr. W- T. Home with regard to types in Havana, 

 Cuba. 



This division of the subfamily was first proposed by 

 Forster in 1868 as the Family Ophionoidae and first given 

 tribal rank by Ashmead in 1894. Most of the work on this 

 group has been done on European species by Brulle, Graven- 

 liorst, Forster, Vollenhoven, Thomson, Taschenberg and 

 Szepligeti, but Brulle, Taschenberg and Szepligeti have also 

 described many American species. Among American work- 

 ers, Cresson, Norton and Ashmead have described numerous 

 species, but none of these have treated the tribe as a whole. 

 Felt's paper is the best for the North American species, but 

 only covers the more common species of Ophion, Eremotylus 

 and Enicospilus. The largest American collections in this 

 tribe are probably at the United States National Museum 

 and the American Entomological Society in Philadelphia, 

 but the Massachusetts Agricultural College has a good repre- 

 sentation, and the British Museum has considerable unworked 

 material. The largest number of types was found in the col- 

 lection of the American Entomological Society. 



