DIPTERA. 83 
cularly on fungi in a state of decomposition, on dung-heaps, cow 
dung, &e. They are essentially parasites, settling on both man 
and beast, to suck up the fluid substances which are diffused over 
the surface of their bodies. In our dwellings they eat anything 
that will serve to nourish them. Generation succeeds generation 
with the greatest rapidity. 
The House Fly (Musca domestica, Fig. 62) is about three lines 
in length, ash coloured, with the face black, the sides of the head 
yellow, and the forehead yellow with black 
stripes ; the thorax is marked with black lines ; 
the abdomen is pale underneath, and a trans- 
parent yellow at the sides, in the males; and is 
speckled with black. The feet are black; the 
wings transparent, and yellowish at the base. ie ee ce aa 
This species is extremely plentiful through- 
out the whole of Kurope. Every one knows how annoying it is 
towards the end of the summer, and especially so in the South of, 
France during the hot season. 
The Ox Fly (Musca bovina), a near relation of the house fly, is 
also very common. It settles on the nostrils, the eyes, and the 
wounds of animals. 
The Executioner Fly (Musca carnifex), which is not rare in 
France, also attacks oxen. It is of a dark metallic green colour, 
with a slight ash-coloured down. Its forehead is silvery at the 
front and sides, the abdomen is edged with black, the wings hyaline 
and yellow at the base. 
Section of the Anthomyides.—The section of Anthomyides com- 
prises insects which appear to be Creophili whose organisation has 
become weakened by almost insensible degrees. Their colours vary 
very much—black, grey, and iron-colour are everlastingly shaded 
and blended together. To that may be added reflections which 
are above the ground colour, and which change the hues of the 
little animal according to the incidence of the rays of ight. The 
Anthomyides resemble the genus Musca very closely in their habits 
as well as in their organisation. 
In this group of Diptera we will first say a few words about the 
Anthomyie. These flies are to be found in all places and on all 
flowers, particularly on the heads of Composite and Umbellifere. 
Gee 

