Predaccous Insects and their Prey. 327 



proofs. Mr. R. Shelford, M.A., and Mr. A. H. Hanim have 

 not only read proofs, but they have also greatly helped me 

 in comparing them with the data on the specimens. It is 

 impossible to hope that mistakes have been entirely 

 avoided, but at any rate exceptional labour has been ex- 

 pended upon their reduction to the lowest possible number. 



The present memoir was undertaken in order to deter- 

 mine, as far as possible, the enemies of those groups of 

 insects which are believed on good grounds (see especially 

 Mr. G. A. K. Marshall's experiments recorded in Trans. 

 Ent. Soc. Lond. 1902, pp. 292—405) to be specially de- 

 fended against entomophagous Vertebrates. So far from 

 following Haase in the belief that such groups enjoy abso- 

 lute immunity from all attacks, including those of parasites, 

 it seemed probable that the lessened exposure to Vertebrate 

 enemies would be largely compensated by a relatively in- 

 creased exposure to predaceous Invertebrata, and especially 

 insects. And this conviction has been confirmed even 

 more fully than would have been anticipated from the 

 limited extent of the recorded material. Thus it will be 

 found from African records alone that the widely mimicked 

 Limnas clirysippus has been seen to be devoured by an 

 Asilid fly, a large Dragonfly, and a Locustid ; while 

 another species of Locustid and a large wasp have been 

 found eating the larva. Attacks by predaceous insects upon 

 the specially defended groups of Coleoptera, and upon the 

 stinging Hymenoptera are also proportionately numerous. 



It was originally intended to conclude the present paper 

 with a large number of records of predaceous Hymenoptera 

 and their prey, chiefly due to the energy and power of 

 observation of Mr. A. H. Hamm, who is especially devoted 

 to the study of the Fossorial group. It was not at first 

 contemplated that any attempt would be made to search 

 through the vast literature of this subject, extending through 

 two centuries and a half. This widening of the field of 

 work was brought about through a misunderstanding. I 

 wrote to my kind friend Mr. Edward Saunders for records 

 of attacks by Fossors, meaning such records as are con- 

 tained in his note-books or on the specimens in his 

 collection. In reply he sent me a most valuable abstract 

 of recent literature on the subject, and expressed the 

 opinion that a list of the published records was greatly 

 needed. Under these circumstances Mr. A. H. Hamm 

 began to search systematically and was soon aided by 

 Mr. R. Shelford and Commander Walker. A little later 



