PREFACE. 



THE present work by Prof. Mario Bezzi, which gives an 

 account of the African Diptera of the family Syrphidge, and 

 which greatly advances our knowledge of those insects, has 

 only been made possible by the richness and completeness 

 of the collections submitted to him for examination, by the 

 Imperial Bureau of Entomology. These collections are now 

 in the British Museum (Natural History), to which they 

 have been presented by the Imperial Bureau, and have added 

 very considerably to the importance and value of the 

 collection of Syrphida? already there. 



The thanks of the Trustees are due to Mr. Gray A. K. 

 Marshall. Director of the Imperial Bureau, for the care with 

 which he had revised the greater part of the MS. for the 

 press. Mr. E. E. Austen and Mr. F. W. Edwards have also 

 rendered assistance in correcting proofs and in other ways in 

 which their special knowledge of the Diptora has been of 

 great advantage. 



CHARLES J. GAHAN. 



BRITISH MUSEUM (\ATURAL HISTORY;. 

 March 1915. 



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