246 PROCEEDINGS OF THE NATIOX.VL MUSEUM vol.84 



American literature; but that the group must be of considerable 

 economic importance is indicated by the abundance of certain 

 of the species such as matricus Provancher, rufofemoratus Provancher, 

 suaveolens Walsh, obscurus Cresson, and others. Such host records of 

 North American species as are known are given in the discussion of 

 the species. 



MATERIAL STUDIED 



Through the kindness of the Academy of Natural Sciences of 

 Philadelphia, I have had access to the types of all Cresson's and 

 Davis' species and to other material in the Academy. The types of 

 Provancher's species, with the exception of clavatus, have been 

 examined by my associates A. B. Gahan and C. F. W. Muesebeck, 

 and specimens compared by them with these types are in the National 

 Museum. The types of Say's two species and Walsh's two are no 

 longer in existence, but specimens of Say's species identified by Gahan 

 and myself and of Walsh's easily recognized species are also in the 

 United States National Museum. 



In addition to nearly 400 specimens in the National Museum I have 

 had for study about 300 specimens lent to me by the following institu- 

 tions and individuals: California Academy of Sciences, University of 

 Arizona, Texas Agricultural Experiment Station, Kansas University, 

 Colorado Agricultural College, Canadian National Collection, Cornell 

 University, American Museum of Natural History (New York); 

 Connecticut State Experiment Station (New Haven) ; Boston Society 

 of Natural History ; P. W. Fattig, of Emory University, Atlanta, Ga. ; 

 Frank D. DeGant, of Cleveland, Ohio; Andrew R. Park, of Springfield, 

 111. ; and Henry K. Townes, of Cornell University. 



To all these institutions and individuals I wish to extend my 



thanks. 



Genus EXETASTES Gravenhorst 



Exetastes Gravenhorst, Ichneumonologia Europaea, vol. 3, p. 395, 1829. (Geno- 

 type, Ichneumon fornicator Fabricius.) 



Leptobatus Gravenhorst, Ichneumonologia Europaea, vol. 3, p. 432, 1829. 

 (Genotype, Leptobatus ziegleri Gravenhorst.) 



Rhimphalea Davis, not Foerster, Trans. Amor. Eut. Soc, vol. 24, p. 274, 1897, 

 (Genotj'pe, Rhimphalea hrcvicorpa Davis.) 



Mostly rather large insects (7-15 mm), conforming to the following 

 description: 



Head from above transverse; never strongly swollen, though with 

 the temples sometimes strongly convex; face flat or convex, usually 

 with a median elevation ; clypeus divided uito basal and apical portions 

 by elevation of basal portion, by impression of apical portion, or by 

 marked dift'erence in sculpture and frequently also by difference in 

 color, arcuate or truncate at apex and frequently with a median 

 apical groove or narrow emargination; mandibles distinctly bidentate, 



