218 Descriptions of British Diptera. 



Rather a scarcp species, but occurring at times in the vicinity of 

 London, and in some other parts of England. " I took it in Da- 

 renth wood in 1826, in the beginning of August." J. C. Dale, Esq. 



Family MYOPID^. 



Antennae with the second joint longer than the third ; the style 

 dorsal, and consisting of tAVo joints : proboscis long and slender, ge- 

 nerally geniculated at the base, and near the middle : ocelli three ; 

 face usually very much dilated ; the eyes rather small : winglets 

 minute ; wings lying along the body ; the first posterior cell usually 

 somewhat open, the anal one generally elongated. 



As above defined, this family comprehends only two British ge- 

 nera, viz. Myopa and Zodion, which are readily distinguished from 

 each other by the former having the proboscis geniculated at the 

 base and middle, and the latter by having it bent at the base only. 

 The presence of ocelli, and other prominent characters separate 

 them decidedly from the Conopidse, to which, however, they bear 

 some resemblance in the shape of the body. 



Genus MYOPA. 



Antennae with the first joint short and cylindrical ; second rather 

 long, somewhat thickened at the tip, and compressed at the base ; 

 third rounded-ovate, with a short two-jointed style on the back : 

 proboscis geniculated at the base and middle ; labrum, tongue, and 

 palpi variable, the latter generally somewhat elongate and fringed 

 with hairs : inferior part of the face inflated ; the forehead wide in 

 both sexes ; eyes rather small : ocelli three : thorax robust ; abdo- 

 men consisting of six segments, somewhat narrowed at the base, the 

 extremity obtuse and curved inwards ; the fourth segment dilated 

 beneath: legs rather strong, thighs somewhat thickened, the claws 

 and pulvilli much developed : wings lying along the back when at 

 rest ; the anal cell straight. 



About twenty species belong to this genus, but scarcely more 

 than a third of these have hitherto been found in Britain. The re- 

 markable dilatation of the lower part of the face, in connection with 

 the incurved abdomen, and rather short strong legs, give them a 

 very peculiar aspect. The prevailing colours are rust-red and 

 brown. Although much similarity pervades the species in respect 

 to colour and marking, the structure of the oral organs undergoes 

 considerable modifications, as is occasionally pointed out in the sub- 

 sequent descriptions of the difi'erent species. We are still unac- 

 quainted with the larvae, but from the analogy which exists between 



