Fabricius having drawn his best character for the division of 

 Pimpla and Cryptus from a sexual distinction (the form of 

 the antennae), it becomes necessary to have recourse to other 

 parts to estabhsh them as genera. The only difference we 

 shall now point out is the nearly sessile abdomen of Pimpla, 

 and the peduncled one of Cryptus, a mark which will be 

 found sufficient to separate them. 



By this arrangement the genus Pimpla will be very much 

 circumscribed ; nevertheless it will be sufficiently extensive to 

 admit of the following sections : 



I. Ovipositor longer than the body. 



* Abdomen slender. 



1. P. persuasorius Linn. — Don. 15. 522. — Beginning of 

 July ; about Pine-trees near Manchester, and in a garden in 

 Norfolk. Mr. Bracy Clark informs me that he took the females 

 upon Pine-trees in Switzerland, and that they were not able 

 to extricate their oviduct from the crevices in the bark where 

 they were inserted. 



2. P. manifestator Linn. — Panz. 19. 21. — Sain. 8. 4. — 

 Lijinean Transactio7is v. 3. tab. 4. 



June ; upon posts, Norfolk, Kensington Gardens, &c. 



3. P. mediator Fab. Scurra Panz. 92. 6. 



4. P. extensor? Fab.— Panz. 109. 11. 



* * Abdomen robust. 



5. P. Cossivora Nob. — Bred from the pupa of Cossus lig- 

 niperda. Brit. Ent. pi. 60. 



II. Ovipositor shorter than the body. 



6. P. pennator? Fab. 



7. P. instigator Fab. 



8. P. spectrum (Sirex) Don. v. I.pl. 225. not o^ Linn, nor 

 Fab. — June, amongst leaves of Horse-radish. 



9. P. iEthiops Nob. — Bred from the pupae of Arctia 

 caenosa. Brit. E?it. j)l. 68. 



10. P. examinator Fab. 



11. P. accusator i^«6. — Pa7iz. 109. 12. 



The above are the only species that appear to be described. 

 It is well known that they all deposit their eggs in different 

 larvae ; those with long oviducts in internal feeders, and the 

 others in caterpillars of moths : many, if not all the Pimplae 

 when taken, emit a very foetid odour. The ovipositor is ge- 

 rally considered to consist of 3 parts, but my friend Mr. Tho- 

 mas Carpenter has discovered that the central part or oviduct 

 is composed of a sheath inclosing 2 filaments ; which gives 

 strength, prevents the entrance from being closed when the 

 oviduct is placed at a right angle with the body, and enables 

 the insect to regulate the passage to the size of the egg : the 

 same structure obtains in the Cynipsidae also. 



One of the plants upon which Arctia cccnosa feeds, Butomus 

 timbellatiis (Flowering Rush), is given with the Pimpla, which 

 is a female. 



