iv. Preface. 



in a work issued in 1903. The present volume deals with the 

 Diptera, other than Mosquitoes and Tsetse-flies, which inhabit the 

 parts of Africa indicated in the Author's Introduction. It is hoped 

 that it will be followed in due course by other volumes of the 

 same nature, and that these will collectively form material which 

 will be of service in the compilation of a larger Monograph. 



The cordial thanks of the Museum are due to successive 

 Secretaries of State for the Colonies for the encouragement that has 

 been officially given to the Colonial Medical officers to make 

 collections, and to send information to the Museum, as well as 

 to those whose practical efforts in the field have proved so 

 essential to the accomplishment of the present undertaking. 



SIDNEY F. HARMER, 



Keeper of Zoology. 



BRITISH MUSEUM (Natural History), 



LONDON, S.W. 

 July, 1909. 



