THEODORE II. PRISON 3 



The prol)lem as to the exact numl^cr of genera within the 

 sul)family under discussion is a difficult one. Bradley, in 1908,'' 

 considers ten genera, whereas Kieffer, in 1912, recognizes only 

 nine. The difference in number is not so marked, but the 

 different criteria as to the validity of the genera are noticeable 

 in many places. For instance the Evania of Kieffer comprises 

 the genera Evania, SzepligeteUa, Acanthinevania and Evaniella 

 recognized by Bradley. The generic classification of Bradley 

 takes into consideration the structure of the mouth-parts in 

 conjunction with certain other characters. Kieffer, well aware 

 of Bradley's work, bases his generic classification solely on wing 

 venation. Only an intensive study, supplemented by dis- 

 section, of a large series of specimens and species, particularly 

 type material, can be productive of a workable, natural or 

 phylogenetic classification in this group. 



Practically all the types of the species of this group from 

 Brazil and Peru are in Europe, and hence it has been necessary 

 to rely solely upon the published descriptions. In many cases 

 the descriptions are so general that several closely allied species 

 may be easily included under a single description. Likewise, 

 it happens, that species easily sepai'able if closely compared 

 run to the same place in the published keys. Thus, whenever 

 the author has dealt with a species which did not thoroughly 

 agree with a previous description, he has described it as a new 

 species. In the opinion of the author it is far better to create 

 a synonym where a description is unrecognizal)le or characters 

 of importance are not considered, than to list what is probably 

 a new species under an old name. The former course usually 

 brings about a better understanding of the type or species, where- 

 as the latter can only cause confusion, wrong conceptions of 

 g(^ogra])hic distribution, (>tc. 



At this place I wish to acknowledge the many courtc^sies and 

 suggestions of Dr. AU^xander D. MacGillivi-ay, under whose 

 h('l])ful and constant guidance this study was conducted; to 

 Dr. 8. A. Forbes, IMr. J. \\. Malloch and Dr. C. P. Alexander, 

 for access to the collections of the Illinois State Natural History 

 Survey and for numerous favors; to Dr. F. C. Baker, for the 



^ The Evaniidac, Ensign-Flics, an Archaic Family of Ilyinenoptcra. J, C. 

 Bradley. Trans. Amer. Ent. So-.., xxxiv, 1908, pp. 101-194. 



TRANS AM. ENT. SOC, XLVHI. 



