352 
C. GORDON HEWITT. 
— Liunaeiis never selected a more truly specific title ; 
nevertheless^ other species of closely allied Hies are found in 
houses. These may be either co-inhabitants, that is, living in 
houses, as in the case of H. canicular is and one or two 
others to be mentioned subsequently, or they may be 
visitants. The visitants normally lead an open-air life, but 
sometimes, as in the case of Stomoxys calcitraus, they 
spend a portion of their time in houses, when climatic condi- 
tions are less favourable for out-door life. Such flies as the 
blow-fly, or “blue-bottle,” Calli ph ora ery throcephala, 
and its allies, enter houses only in search of suitable sub- 
stances upon which to deposit their eggs. The appearance in 
houses of certain flies, as, for example, Pollenia rudis, can 
only be regarded as accidental, and the cause may be often 
traced to the occurrence of climbing plants such as ivy or other 
creepers on the walls of the house. 
In India two species of flies closely allied toM. domestica 
are found — M uscadomestica sub-sp. d e t e r m i n a t a Walker 
and M. enteniata, both of which, on account of their close 
resemblance to M. domestica and the similarity of their 
breeding habits, are frequently mistaken for it. 
(1) M. domestica sub-sp. deter mi nata Walker. 
Th is Indian variety of the house-fly was described by 
Walker (1856) from the East Indies. His description is as 
follows : “ Black, with a hoary covering ; head with a white 
covering; frontalia broad, black, narrower towards the 
feelers ; eyes bare ; palpi and feelers black ; chest with four 
black stripes ; abdomen cinereous, with a large tawny spot on 
each side at the base ; legs black ; wings slightly grey, with 
a tawny tinge at the base ; prtebrachial vein forming a very 
obtuse angle at its flexure, very slightly bent inward from 
thence to the tip; lower cross-vein almost straight; alulae 
whitish, with pale yellow borders ; halteres tawny.” 
In appearance and size it is very similar to M . domestica. 
Its breeding habits are also similar. Aldridge (1904) states 
