Prcclaccous Insects and their Prey. 329 



the predaceous species frequently or even normally attack 

 insects which are themselves predaceous or parasitic, in 

 such instances tending towards the preservation rather 

 than the destruction of insect life. It is unnecessary to 

 quote instances when they will be found in numbers 

 scattered through the following tabulated records ; but I 

 may allude to the amusing reciprocity exhibited by 

 examples 268 and 293. In the former an Empid fly was 

 devouring the Anthomyid fly, Cctricca tigrina : in the latter 

 Caricecc tigrinci was devouring an Empid ! 



In order to facilitate reference, all records in Part I of 

 this memoir have been conspicuously numbered. In Part 

 II, dealing with the predaceous Hymenoptera, the reference 

 numbers will be confined to original records, published 

 for the first time. The difference in method is due to 

 the small proportion in Part I of examples previously 

 published, as contrasted with their immense preponderance 

 in Part II. 



The study of the original records here brought forward and 

 their comparison with the results obtained in the future, 

 will be aided by a statement, made whenever possible, of 

 the collection in which each example is to be found. The 

 words, " In Hope Dep.," " In Brit. Mus.," etc., appearing 

 beneath the name of the predaceous species implies that 

 the prey as well as the captor exists in the collection indi- 

 cated. A modified statement will make it clear when the 

 captor alone or the prey alone is known to be in existence. 



References to previous publication will in Part I be found 

 under the name of the observer. For the sake of brevity 

 the publications of the Entomological Society of London 

 are indicated by no more than the abbreviation " Trans." or 

 " Proc," together with the year of publication and page. 



In Part I the Orders to which the predaceous insects 

 belong are treated merely in the order of the number of 

 records. It will at once be recognized that evidence of 

 importance has only been obtained in the Diptera of Part 

 I and the Hymenoptera Aculeata of Part II. 



I. DIPTERA. 



The records in the first part of this memoir are set forth 

 in a tabular form, beginning with the family which stands 

 foremost among predaceous Diptera, — the Asilidm. 



A. ASILID.E AND THEIR PrEY. 



