INTRODUCTION. 



The principal object of the present Nomenclature has been 

 to give a complete list of the species of the Dipterous 

 Insects that have been recorded as found in the British 

 Islands, with their principal Synonyms. 



It is intended for the following purposes : — 



As a Complete List of the species at present known as 

 inhabiting the British Islands. 



As Labels for the Cabinet, for which purpose it has been 

 printed in a peculiar type and only on one side of the paper. 



The Collection contains most of the species in the 

 list, and it consists of the type specimens described by 

 Dr. Leach, Mr. James Francis Stephens, Mr. Curtis, 

 and Mr. Francis Walker. 



The Nomenclature has beeiS prepared by Mr. Adam White 

 from Mr. Walker's two volumes on the British Diptera in 

 the " Insecta Britannica." 



The remainder of the Diptera, containing the Nemocera, 

 will soon be published. 



JOHN EDWARD GRAY. 



December, 1853. 



