Predaceous Insects and their Prey. 327 
proofs. Mr. R. Shelford, M.A., and Mr. A. H. Hamm 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 chrysippus 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 
