XV] MUSCIDiE 241 



J" Antennal arista bare or somewhat pubescent . . = Tachinides. 



3 \ Antennal arista plumose or distinctly pubescent .. .. .. =4 



f Antennal arista bare on the distal half ; bristles rarely present on the 



4 •{ dorsal surface of the anterior segments of ?Lhdomen= Sarcophagides . 



L Antennal arista plumose or pubescent to the tip . . . . . . =5 



f Dorsum of abdomen usually bristly on anterior part ; legs usually long 

 J =Dexiidcs. 



I Abdominal segments without bristles, except more or less near the tip ; 

 I legs not markedly elongated . . . . . . =MusciDiE. 



r First posterior cell narrowed or closed ; arista plumose to the tip 

 I =MusciD^. 



" '1 First posterior cell very slightly or not at all narrowed in the margin ; 

 l^ arista plumose, pubescent or bare . . . . =AnthomyidcB. 



Family Muscid^. 



The various individuals of this family are distinguished by 

 the absence of bristles on the abdomen, except at the tip, and 

 by the narrowed first posterior cell. The antennal arista is 

 usually plumose to the tip, sometimes only on the upper 

 side, and rarely bare. The eyes of the male are approximated 

 or contiguous, and the front of the female broad. The eyes 

 may be either bare or hairy. With the exception of Glossina, 

 the abdomen is composed of four visible segments. The 

 members of this family are generally of moderate size, and are 

 never elongate, very hairy, or bare flies. 



For the sake of convenience, we have followed Alcock in 

 dividing the Muscidae into two artificial groups according to 

 whether the adults suck blood or not. The importance of the 

 latter group (including house-flies, blowflies, etc.) as carriers 

 of disease, has been described by Graham-Smith [loc. cit.) and 

 it is unnecessary to give any further description of them in 

 the present account. On the other hand, the blood-sucking 

 Muscidae include some of the most formidable biting-flies that 

 carry disease. 



Blood-sucking Muscidae ^ 



In the majority of blood-sucking Muscidae the proboscis is 

 strongly chitinized and rigid, is slightly or not at all retractile, 

 and is more or less slender and tapering, and the labella are 

 small, rigid and strongly chitinized, and serrated or spinose, so 



^ After Alcock, loc. cit. 



H. B. F. 16 



