KEY TO MUSCID/E 



First posterior cell scarcely contracted at the margin; 

 black, not shining; tip of scutellum reddish 9. 



9. Legs and palpi wholly black Muscina assimilis. 



Legs and palpi partly or wholly yellow 



Muscina stabulans. 



10. Abdomen non-metallic n. 



Abdomen metallic 12. 



11. Thorax without distinct stripes and usually covered 

 with a yellowish "dust"; more than two pairs of acrostical 

 bristles; two anterior and three posterior dorso-centrals. 



Pollenia rudis. 



Thorax with distinct stripes only in front, if at all; 

 not more than two pairs of acrostical bristles; two anterior 

 and four posterior dorso-centrals . . . Myospila meditabunda. 



Thorax with four stripes; not more than two pairs of 

 acrostical bristles; three anterior and four posterior dorso- 

 centrals Musca domestica. 



12. Metallic between the eyes; a prominent bristle on 

 inner surface of each middle tibia . . Pseudopyrellia c&sarion. 



Not so 13. 



13. Abdomen grayish Pollenia rudis. 



Abdomen greenish or bluish 14. 



14. Thorax not metallic; no spines on the 3rd longitudinal 

 vein except at its junction with the 2nd 15. 



Thorax and abdomen bright metallic blue or green; 

 spines on the first section of the 3rd longitudinal vein. . .17. 



15. Distal third of arista naked; bucca ("cheeks") red 

 in front, black behind Cynomyia cadaverina. 



Distal third of arista bearing some hairs; bucca 

 unicolorous. Calliphora 16. 



1 6. Bucca black, beard red C. vomitoria. 



Bucca brownish or reddish, beard black 



C. erythrocephala. 

 Bucca black, beard black C. viridescens. 



17. Two stout bristles on dorsal posterior margin of the 

 2nd abdominal segment Lucilia sylvarum. 



Not so 18. 



1 8. Acrostical bristles in front of the transverse suture 

 wanting or feebly developed 19. 



Acrostical bristles in front of the transverse suture 



well developed 20. 



267 



