INTRODUCTION. xH 



models of minute observation and judicious deduction of facts there- 

 from. These were supplemented, by Roesel, in 1749. Three years later, 

 De Geer's Memoires began to appear, and, not being completed until 

 1778, form a connecting link between pre- and postLinnean time, which 

 is reckoned from the publication of the tenth edition of Linne's Systema 

 Naturae, in 1758; consequently it was not always easy, until the recent 

 publication of Mr. Sherburn's work, to tell to which the descriptions of 

 the former belong. 



POST-LINNEAN TIMES. 



In 1735, Linne brought out the first editon of his epoch-marking 

 Systema Naturae, followed by Fauna Suecica, in 1746. But it is from his 

 1758 work that priority, that bone of contention, is usually accepted to 

 date. In it he removes all the fossorial Hymenoptera from among the 

 parasites into a new genus, called Sphex. The Parasitica he divides into 

 seven families, the first of which has the abdomen sessile and mucronate. 

 The next five are distinguished nearly entirely by the colour of the 

 scutellum and abdomen, and the last has the body small and sessile. 

 After him wrote Poda, several of whose Ichneumoninae have recently 

 taken precedence to the for-long-accepted names of later authors. The 

 remainder of the eighteenth century authors of note will be found in the 

 " Works Consulted " and need no especial notice here. The first work 

 entirely devoted to the Hymenoptera, as we now understand that Order, 

 is Fabricius' Systema Piezatorum, of 1804. Eighty-three genera are here 

 delineated, distinguished primarily by the structure of the mouth and, 

 secondly, by the antennal conformation. Here the Ichneumonidae are 

 again intermingled with Fossors, Sawfiies, Evaniidae, &c. ; and, taken 

 as a whole, this work of one of the most celebrated entomologists is 

 in strong contrast to the Ichneumonologia Europaea, of Professor J. L. C. 

 Gravenhorst, which appeared in 1829, and embodied the observations of 

 Latreille, Schrank, Panzer and Jurine. This monumental work constituted 

 for the Ichneumonidae what Rev. William Kirby's Monographia Apum 

 had been for the Anthophila — a sound and, at the time of its publication, 

 exhaustive basis for all subsequent research. In it is summed up and 

 concreted such knowledge as then existed respecting these insects, and it 

 is only within comparatively recent years that we have dared to depart in 

 any essential detail from the classification there adopted, which had pre- 

 viously, in 18 18, been mapped out in the same author's Conspectus 

 Ichneumonidum. 



Since the time of Gravenhorst, the subject has attained such proportions 

 that no one has treated of it in its entirety. The first subsequent author of 

 note is Wesmael, who, in the Nouv. Mem. Ac. Brux., of 1844, published his 

 Tentamen Dispositionis Ichncumonum, which treated of those groups con- 

 tained in the present volume This was supplemented by its author in his 

 Mantissa, which appeared in 1848 ; in his Adnotationes, of 1S49 > his 

 Ichneumones Platyuri Europaei, of 1853, and Amblypygi, of 1854 ; in his 

 Miscellanea, of 1855, and Otia, of 1857, all of which were published in 

 the Bui. Ac. Brux. His final Remarques Critiques sur la Collection de 

 Gravenhorst appeared in the Mem. Couron. Ac. Belg., in 1859, and is of 

 the greatest utility in studying the latter's great work. Where Wesmael 

 left the Ichneumoninae, they were taken up by Holmgren, who not only 

 collected the former's treatises into systematic form, but considerably 



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