148 



CATALOGUE OF DIPTF.RA 



numbers five or six, all rich in individuals, and exercising no 

 unimportant functions in the economy of nature. Tacliype^a 

 arenaria, which sometimes swarms upon our coasts, has many- 

 analogies of structure with its companions, the swift-footed but 

 heavy-winged Onjgmce and Coilopce, and like them is pro- 

 bably confined to a northern range. Not to detain you further 

 with remarks that may appear obvious or trivial, I will only 

 add my best wishes for the success of your undertaking ; and 

 am, Your very obedient, &c. 



Alex. Henry Haliday. 



Crifden,7iear Holywood, Oct. \Oth, 1832. 



