354 
C. CiOUDON HP^WITT. 
domestica and M. corvina. It will be seen, therefore, 
that its breeding habits are very similar to those of M. 
domestica and the sub-species determinata. It is in- 
teresting and important to note tlie rather exceptional choice 
of cow-dung as a breeding-place. 
(3) Homalomyia canicularis. L. 
This species of fly (see ‘Quart. Journ. Micr. Sci.,’ vol. 51, 
PI. 22, fig'. 3) is often mistaken by the uninitiated for M. 
domestica which are not full grown. Although it may be 
called the small or lesser house-fly its differences from M. 
domestica are great, as it belongs to a different group of 
calypterate Muscidae, namely, the Anthomyidas. One of the 
chief distinguishing features of this group is that the fourth 
longitudinal vein of the wing (M. 1 -t- 2) goes straight to the 
margin of the wing and does not bend upwards at an angle 
as in M. domestica. 
The male of H. canicularis differs from the female in 
some respects. In the male the eyes are close together, and 
the frontal region is consequently very narrow ; the sides of 
this, these are the inner orbital regions, are silvery white, 
separated by a narrow black frontal stripe. In the female 
the space between the inner margins of the eyes is about one 
third of the width of the head ; the frons is brownish black, 
and the inner orbital regions are dark ashy grey. The bristle 
of the antenna of H. canicularis is bare; in M. domes- 
tica, it will be remembered, the bristle bears a row of setae 
on its upper and lower sides. The dorsal side of the thorax 
of the male is blackish grey with three rather indistinct longi- 
tudinal black lines. In the female it is of a lighter gi'cy, and 
the three longitudinal stripes are consequently more distinct. 
The abdomen of the male H. canicularis is narrow and 
tapering compared with that of M. domestica. It is bronze 
black in colour, and each of the three abdominal segments 
has a lateral translucent area, so that when it is seen against 
the light, as on a window-pane, three, and sometimes four, 
pairs of yellow ti'anslucent areas can be seen by the trans- 
