No. 2315. TRIBES OF ICENEUMONINAE—CUSHMAN AND ROHWER. 381 



In 1859 ^ he published his first synopsis of his family Pimplariae. 

 This he divided into two main sections which he called Pimplariae 

 and Xorides, the latter corresponding to the tribe Xoridini of Ashmead, 

 and the former including genera since divided into the tribes Acoeni- 

 tini, Lissonotini, and Pimplini. His main divisions are based on 

 practically the same characters as those used by Gravenhorst, while 

 those of the smaller divisions were new and still largely persist in 

 the more recent keys. The generic descriptions are full and detailed, 

 and the Swedish species are listed under each genus. In the follow- 

 ing year he published a larger work ^ in which the generic key is 

 largely reprinted from the earlier paper, but each Swedish species is 

 discussed in considerable detail. His two main sections are here 

 called subfamilies. 



Cresson. — The fii*st American writer to take more than a general 

 interest in the Hymenoptera was Cresson, who in 1887 published 

 his Synopsis.^ For this work Cresson claims little originality, con- 

 fessing to having compiled his keys from the writings of previous 

 authors. He did, however, a valuable work in marshaling the 

 known North American species and added much to the knowledge 

 of the group in America, 



Cresson's key to the Pimplinae is much easier to use than most 

 others. He, however, made no attempt to divide the subfamily 

 into tribes nor to express by his key the relationship of the genera 

 to each other. His specific keys, based largely on color, are useful, 

 although too much reliance must not be placed on characters of this 

 sort. 



Foerster. — A few years after Holmgren had published his synopsis 

 Foerster* produced his system of classification of the Ichneu- 

 monidae. In tliis work he divided the group into 34 coordinate 

 families, 4 of which, the Pimploidae, Lissonotoidae, Acoenitoidae and 

 Xoridoidae, together with Ashmead's tribe Labenini, constitute the 

 five tribes into which Ashmead divided the subfamily Pimplinae. 

 The Xoridoidae represent Plolmgren's section II; the Acoenitoidae, 

 section I, division 1 ; the Pimploidae, section I, division 2, phalanges 

 1 and 2; and the Lissonitoidae, section I, division 2, phalanx 3. 



• A. E. Holmgren, Conspectus Generum Pimplarlarum Suecia, Ofversigt af Konigliga Svenska Veten- 

 skaps-Akadeniiens Forhandlingar, vol. 6, 1859. pp. 121-132. 



2 A. E. Holmgren, Forsok till Uppstallning och Beskrifning af Sverlgos Ichneumonider, Monographia 

 Pimplarlarum Sueciae, Konigliga Svenska Vetenskaps-Akademiens Handlingar, vol. 3, No. 10, 1860, pp. 

 1-76. 



3 E . T. Cresson, Synopsis of the Families and Genera of the Hymenoptera of America North of Mexico, 

 1887, supplementary volume of Trans. Amer. Ent. Soc, pp. i-vi, 1-350. 



< Arnold Foerster, Synopsis der Familien und GattungenderIchneumonen,Verh.nat.hist. Ver.preuss. 

 Rheinl., vol. 25, 1868, pp. 142, 162-170. 



