ROEBUCK : ON YORKSHIRE ICHNEUMONID^. 35 



Dispositio methodica Exochorum Scandinaviae, 1874; Dispositio 

 methodica Mesoleiorum Scandinavise, 1873; and Monographia 

 Pimplariarum Sueci^, i860. A monograph of the genus 

 Pezomachus was pubHshed by Forster in 1851, and one of 

 Campoplex in 1868 by the same author. The Rev. T. A. 

 Marshall published a very useful article in the Ent. Ann. for 

 1874, pp. 114 to 146, in which at p. 123 he gave a table of 

 Ichneumonidse and Braconidae and the lepidopterous and other 

 insects on which they were parasitic. Snellen van Vollenhoven is 

 at present publishing ' Pinakographia, Illustrations of more than 

 one thousand North-West-European Ichneumonidse sensu Lin- 

 nseano,' in Dutch and English, with very excellent coloured plates, 

 being a continuation of his ' Esquisses hymenopterologiques, 

 1868-73. These works include also Braconidce, Oxyiira, and 

 ChalcididcR. This work of Vollenhoven's ought to be in the library 

 of every society in the Union, containing, as it will eventually do, 

 admirable figures of a large proportion of the British species. 



This is the place for reminding the lepidopterists how very 

 greatly they can assist in the study and collection of this and 

 other parasitic groups by the simple process of preserving and 

 boxing the species they unwillingly breed, making notes upon 

 their habits, and afterwards placing them for study and determina- 

 tion in the hands of entomologists who make the group their 

 speciality. But it will be well to remember the importance of 

 setting the insects so as to facilitate their examination. Marshall 

 says (Ent. Ann, 1874, p. 128) that unless small Ichneumonidse 

 •' receive the best attention in the way of setting, they are useless 

 ' as specimens. Any small winged Hymenopteron, if left to itself, 

 ■'is sure to dry with the wings doubled up, or concealing the 

 ' characters of the abdomen, &c.^ in some way that renders its 

 ' identification or description -impossible. Much has been said 

 'against carding specimens intended for examination, but the 

 ' objections apply less to parasitic Hymenoptera than to most 

 'other kinds of insects. The parts of the mouth are of only 

 ' secondary value, and the leading characters are nearly always 

 ' taken from the upper surface. Without knowing what others 

 ' may be able to do, I can say for myself that I rarely succeed in 



