IDENTIFICATION OF HOUSE-FLIES 13 



fly"; thus it will be easy for the reader to identify the 

 common house-fly by the close resemblance of its 

 wing pattern to that of the blue-bottle, with which it 

 is classified in the family of the Muscida. 



In the pattern of the next figure the vein 4 runs 

 comparatively straight throughout and meets the 

 margin at a spot intermediate between the third and 

 fifth veins ; here all the main nerve-lines diverge more 

 evenly and terminate more equi-distantly apart ; this 

 latter plan is the wing pattern which will suffice to 

 identify the lesser house-fly, but it is shared with all 

 the Anthomyidcs, and more or less with some others, 

 which are very common outdoor flies. 



The pattern of the lowest figure illustrates the wing 

 of the common blood-sucking stable-fly, Stomoxys 

 calcitrans, which only occasionally invades the house. 

 Here the vein 4 is deflected upwards towards the 

 margin ending near the termination of the vein 3, but 

 the bend is a smoothly rounded curve and not a 

 curiously abrupt angle, as in the first and second figures. 



If the reader will study the house-fly in captured 

 specimens, he will be able to observe that they slightly 

 differ in their inconspicuous colouration and markings. 



The male of the lesser house-fly is sometimes more 

 observable than the male of the commoner house-fly, 

 by reason of his being a most indefatigable dancer 

 with companions in mid air around any central 

 ornament, and also by reason of his possessing pale 

 patches, more or less yellowish grey, on the sides of the 

 abdomen ; but such markings are also in some degree 

 observable in other male flies, being very conspicuously 

 of a brighter yellow in the common small outdoor 



