380 PROCEEDINGS OF THJE NATIONAL MUSEUM. vol. 57. 



had done little more than describe genera and species they contributed 

 only slightly to the taxonomy of the group and it is not necessary to 

 discuss their work in detail. 



From the beginning the classification of the Ichneumoninae has 

 been rendered unsatisfactory and difficult by the exclusive employ- 

 ment of characters of such nature that they apply to but one sex, 

 or are conspicuous only in more or less extreme types, while absent 

 or inconspicuous in other genera obviously closely allied. In addi- 

 tion all recent classifications have followed very closely that of 

 Foerster which was based almost entirely on Holarctic genera, and 

 the attempt to adapt this arrangement to the genera of the world has 

 added much to the confusion. 



Gravenhorst. — In 1829 Gravenhorst^ published the first real 

 attempt at the classification of the Ichneumonidae. He divided the 

 family into thirteen genera. Most of these he subdivided into a 

 number of families or subgenera to which he gave names, and some 

 few of these he further divided into unnamed groups which he called 

 sections. AU of Gravenhorst's subgenera and many of his sections 

 have since been raised to generic rank. 



Of the genera treated by Gravenhorst as subgenera that are here 

 placed in the subfamily Ichneumoninae, seven, Glypta, Lissonota, 

 PolysiyTiinda, Clistopyga, Pimpla, EpJiialtes, and Khyssa, he consid- 

 ered as subgenera of Pimpla. As subgenera of Pimpla Gravenhorst 

 also included ScTiizopyga and (TracJiyderma) = Tylocomnus, both now 

 placed in the subfamily Tryphoninae. Xorides, Xylonomus, Odon- 

 tomerus, and the Cryptine genus EcMhrus constituted his genus 

 Xorides. Coleocentrus and Arotes were the unnamed subgenera IV 

 and VI respectively of his genus Banchus. Pliytodietus he placed 

 as subgenus VIII of Cryptus. Acoenites formed a genus by itself 

 without subdivisions. 



Gravenhorst's key is in the form of a chart classifying the insects 

 down to subgenera, which are bracketed into their genera. The 

 characters employed are mostly superficial, indefinite, or unisexual 

 and have largely persisted up to the present for the major divisions 

 within the group. 



Holmgren. — Holmgren^ separated the Ichneumonidae into five 

 families corresponding to the usual five subfamilies. He made no 

 key to these families, but gave a rather long description of each, 

 mentioning nearly all parts. 



1 J. L. C. Gravenhorst, Ichneumonologia Europaea, Vratislaviae, Sumtibus Auctoris, 1829, vol. 1, pp. 

 i-xxxiii, 1-827; vol. 2, pp. 1-939; vol. 3, pp. 1-1097. 



' A. E. Holmgren, Forsok till Uppstallning oeh Beskrlfning af de i Sverige Funne Tryphonider, Konigliga 

 Svenska Vetenskaps-Akademiens Handlingar, 1855, pp. 93-394, 2 pis. 



