228 DIPTERA. 



Family XXIII. — Bomhyliidce. . 



Head rounded, closely appressed to the thorax ; abdomen 

 clothed with woolly hairs ; antennae with the third joint not 

 annulated, and generally provided with a bristle or tuft at the 

 extremity ; ocelli present ; proboscis generally very prominent • 

 legs rather long and slender. 



The Bee-Flies are small or middle-sized, densely hairy, and 

 veiy active insects, with long tongues, with which they suck 

 honey from flowers ; but the larvae, like many other Diptera, are 

 parasitic on the earlier stages of other insects, like Ichneumons. 

 Many are known to attack the larvae and pupae of Lepidojytera and 

 Hymenojjtera, while several species which inhabit Cyprus and 

 North America make themselves very useful by diminishing the 

 numbers of the locusts, in the egg-capsules of which their 

 larvae feed. 



Family XXIV. — Therevidce. 



Head semicircular, nearly as broad as the thorax; antennae 

 with a very short terminal bristle ; eyes contiguous in the male 

 and separated in the female ; abdomen generally long and pointed; 

 larvae in fungi and rotten wood. 



The species of the typical genus Thereva, Latr., are rather 

 numerous. They are slender middle-sized black species, with the 

 incisions of the abdomen white or yellow, and are often densely 

 clothed with black, yellow, or white hair; they are generally 

 found about trees or bushes. 



Family XXV. — Scempinidce. 



Head semicircular ; antennae with the third joint rather long, 

 with no terminal bristle ; eyes generally contiguous in the male, 

 and separated in the female ; ocelli present ; thorax somewhat 

 convex ; abdomen flattened ; legs short, unarmed ; larvae in fungi 

 or trees. 



This family includes a few small black flies, not exceeding a 

 quarter of an inch in length. They are not very common, but 

 are sometimes found on windows. 



Family XXVI. — Acroceridce. 



Head small and round ; antennae two- or three- jointed, with a 

 bristle at the extremity, and placed on different parts of the head 



