9462 Entomological Society. 



been enabled to make, these creatures retain in their grasp even after they have passed 

 into the pupa state. They scarcely appear to cease eating, except now and then for a 

 miuute or so, from the time they first begin to feed till they have become full grown. 

 The larva is a singular-looking one. The head is bent forward under the body. 

 Between the segments it is more deeply furrowed than any larva with which I am 

 acquainted. A lougitudinal furrow extends down the back from the head to the anal 

 extremity, cutting each segmeut across. The skin, during life, throughout the whole 

 course of this furrow, is perfectly transparent, so that the workings of the internal 

 organs may be plainly seen. The body of the larva while alive has the appearance of 

 a thin transpareul skiu filled with minute particles of curd. These appearances vanish 

 after deaih, when the body becomes dense, and has an appearance of solidity about it 

 which it Lad not before. Several pupae of the parasite were found in the nest, as well 

 as examples of the perfect insect. It also contained a number of cocoons spun 

 by the larvae of Anomalon Vesparura, with the larvae still unchanged inside the 

 cocoons. 



" Between the above date and the 3rd of September I took out thirteen more nests 

 of V. vulgaris, which contained examples of Ripiphorus either in the larva, pupa or 

 perfect slate. In one which had been destroyed by means of gas tar a few days before 

 I took it out, I was fortunate in discovering a small larva of Ripiphorus firmly attached 

 to its victim. Both were dead and had become partially dried, so that when im- 

 mersed in spirits they did not separate, but remained attached just as they were 

 before death. These are interesting, because in them may be seen the exact way ia 

 which the parasitic larva fastens on its prey. In another, which I took out on the 

 2nd of September, I found, on opening some closed-up cells appropriated to queens, 

 one larva and one pupa, which differed in nothing that I could discover from those of 

 Ripiphorus found in the cells of workers, except that they were something like double 

 the size; in fact, about as much larger as the larvae and pupje of queen wasps are 

 larger than those of workers (ante, pp. 49, 58). 



"Until the present summer I had not met with a specimen of Ripiphorus since 

 the year 1859, although I had made diligent search for it every succeeding summer. 

 What had become of it all that time, and how it was that all at once it made its 

 appearance in such numbers, are questions more easily asked than answered. Where 

 it occurs it appears to be very local, for I have never met with it except in one 

 particular part of Cokethorpe Park, within a space of ground about four furlongs in 

 length by two in width. I have searched yearly for it in nests obtained from other 

 parts of the park and the surrounding neighbourhood, but always in vain. 



" In one nest of V. vulgaris, which I look out on the 24th of August, I found, in 

 addition to exan)ples of Ripiphorus in the larva, pupa and perfect state, a number of 

 cocoons spun by the larvae of Anomalon Vesparum, intermixed with which were those 

 of a much smaller species of ichneumon, which made its appearance in the perfect 

 state a few days afterwards. Of what genus this may be I have yet to learn. I am 

 not aware that an ichnuemon of this size has been described as an inhabitant of wasps' 

 nests ; it may, therefore, possibly prove to be new. 



" Upon the crown of almost every nest I examined, after the season had become 

 somewhat advanced, I found eggs of Volucella ; and my attention was in several 

 instances drawn to a nest by seeing a specimen of Volucella pellucens or of V. bom- 

 bylaus hang about or alight near the entrance to it. 



