BRITISH FLIES 



21 



15 (16) Small cross-vein alj.seut; posterior cells four or three; cubital 

 fork often wide open. Proboscis often long, thin, and porrect, 

 with very small sucker-flaps. Abdomen usually short and 

 rounded. Thorax, scutellum, and legs rarely with detinite 

 cha3totactic Ijristles. VII. Bombylid^. 



%j'|i# \ 



Fiu. i'3.^Boiiihi/lius major <5 . x 3. 



The abdomen is very long and thin in the exotic genus Systropus, 

 and that genus has no pubescence or bristles except some short spicules 

 on the tibiae. The Toxophorinrp, bear some remarkable curved bristles 

 on the thorax and especially on the enlarged shielddike prothorax, but 

 those bristles appear to be of some distinct nature and scarcely lend 

 themselves to cha^totactic arrangement. In the Anthracince the pro- 

 boscis is short and the eyes of the male are scarcely more approximated 

 than those of the female, while the abdomen is rather oblong in 

 shajte. 



The Bombi/lidw are large or rather large or even rather small 

 {Phthiria) Hies which are usually covered with a dense soft furry 

 ]iubescence which may oljscure all the ground colour and hide any 

 cbietotactic bristles. The true Loiubylinw have short rounded bodies, 

 and a remarkably long, thin, porrect proboscis. The species are sun- 

 lovers and are never predaceous in the perfect state, but are parasitic 

 in the larval stage on Hymenopterous and Lepidopterous larvae. The 

 imagines are most perfect hoverers, and almost live in the air during 

 hot sunshine. 



16 (15) Small cross-vein present; posterior cells Ave; cubital fork long 

 and only moderately wide open ; subcostal vein reaching little 

 more than half the wing. Proboscis short and fleshy, with 

 large sucker - flaps. Abdomen rather elongate, tapering. 

 Thorax, scutellum, and legs with distinct chsetotactic bristles. 



