FLIES THAT FREQUENT HOUSES 37 



mon in barns. It breeds in vegetable refuse, manure, 

 and excrement. Hcematobia serrata, the horn fly, is 

 similar, but much smaller. It is occasionally found in 

 houses ; common on cattle. 

 cc. With blunt mouth-parts (Fig. 6). 



d. Last section of vein M of the wing with abrupt angle. 

 e. Thorax with four longitudinal lines and without 



golden hairs. House-fly, Musca domestica. 

 ee. A larger fly with no lines on thorax but with golden 



Fig. 14. — Wing of stable-fly (M . stabulans). (x 8.) 



hairs. Cluster-fly, Pollenia rudis. 

 dd. Last section of vein M of the wing with a broad gentle 

 curve (Fig. 14). 

 /. Eyes microscopically hairy; each abdominal seg- 

 ment with 2 spots. Larvae are found in dung 

 and excrement. Myiospila meditabunda. 

 ff. Eyes bare; abdomen gray and brown marbled. 

 Muscina assimilis with black legs and feelers, 

 and Muscina stabulans with legs more or less 

 yellowish, and which breeds in decaying vege- 

 table substances, dung, and excrement, are fre- 

 quently found in houses. 



