INTRODUCTION. 



This was the position of matters when Prof. C. G. Thomson 

 began to issue his great ' Opuscula Entomologica,' a work of the 

 most amazing erudition aud minutest observation ; new genera 

 were erected upon constant and beautifully natural characters, 

 the affinities of groups and genera were exposed with the utmost 

 acumen and the previous artificial, rule-of-thumb method of 

 naming was swept away. His short papers in the ' Annales ' of the 

 French Entomological Society and the ' Deutsche Entomologische 

 Zeitschrift ' are of equally high merit. During the twenty-eight 

 years that the ' Opuscula ' occupied in production many workers 

 had given their attention to the subject : in Germany, Brischke 

 brought out an account of the Prussian species, Kriechbaumer had 

 contributed many papers both upon Palaearctic and exotic groups, 

 and Dr. Schmiedeknecht had monographed the CUYPTINJE in the 

 -combined light of Thomson's and Carl Tschek's discoveries ; 

 in Holland, Van Vollenhoven had beautifully illustrated a great 

 many species : in Britain, the Eev. T. A. Marshall had issued his 

 1872 Catalogue of the indigenous ICHNEUMONIDJE, which enabled 

 Bridgman and Fitch to contribute their Introductory Papers on 

 the subject to the ' Entomologist ' ; while in 1896, Dr. Tosquinet 

 presented his ' Ichneumonides d'Afrique' to the Entomological 

 Society of Belgium, and the Abbe Berthoumieu brought forward 

 his general account of the ICHNEUMONIN^E of Europe and the 

 adjacent countries in the French ' Annales.' During the same 

 period Fred. Smith and Francis Walker, Motschulsky and Van 

 Vollenhoven had described new kinds from Asia and Australia, 

 and Cresson, Davis, and Ashmead had begun the task of elucidating 

 this branch of the American fauna. 



The present century was begun under the satisfactory con- 

 ditions of a complete synopsis of the genera of ICHNEUMONID^E 

 by W. H. Ashmead, which, though often faulty and not less 

 frequently obscure, has proved invaluable to the general student ; 

 and Dalla Torre completed his synonymic Catalogue of the world's 

 species, a work of even higher intrinsic worth, and one which 

 gives a good idea of the extent to which the study of the ICHNEU- 

 MONIDJE has now grown, as may be gathered from the fact that 

 the mere names of the species there occupy over a thousand 

 closely printed pages. 



As regards India, Linnaeus, De Geer, Fabricius, and several 

 more of the old authors described a certain number of Ichneumons 

 from there, though rarely in an exact manner ; and we are often 

 quite at a loss to recognise those brought forward by Brulle in his 

 general account of 1846 ; additions to the Indian species were also 

 made by Smith and Walker, but the latter frequently assigned 

 his species to incorrect genera. But the great majority of the 

 published species have been described by Peter Cameron, who 

 has been most assiduous in this respect, and had his know- 

 ledge of the Palsearctic forms been commensurate with his zeal in 

 bringing forward the Oriental, he would have already laid a very 

 substantial foundation for future research. Unfortunately for 



