H. Eltringham 457 



somewhat less readily than M. fh>iiie.slic(i, though after Fannia canicidaris 

 it is perhaps our next most frequent uninvited guest. In autumn it is 

 given to entering houses, especially attics and disused apartments, in 

 enormous numbers, and so-called hibernating house-flies are almost 

 invariably of this species. Professor Poulton has recorded them^, in 

 his house in the Isle of Wight, in such numbers as to contaminate the 

 secondary water supjjly. It is not remarkable that the species has 

 received such slight mention in current works on the house-fly since 

 it is only with some practice that it can be distinguished therefrom. 

 The early stages of the species have not so far as I am aware been 

 observed in this country. 



I succeeded in breeding the fly from bullock dung. A sample of 

 this material sent to the laboratory for experimental purposes contained 

 numerous bright yellow larvae, some of which I preserved, others being 

 kept till they matured. Having found that M. auiumnalis De 6. 

 resulted from these larvae I inspected bullock dung in the fields and 

 had little difficulty in finding the larvae again. It is probable that this 

 is by no means the only material in which the species may be found 

 though it is evident that it is one of the substances in w'hich it regularly 

 breeds. I hope shortly to collect existing records of this fly and to 

 pubHsh fuller details of my own observations on its life-history. 



' Proc. Eiit. Soc. Land. p. xxi-xxii, 1915. 



(Received October lilh, 1915. 



