FLIES. 233 



FAMILY XXXV. Muscidce. 



Antennae with the third joint more or less oval, always com- 

 pressed and provided with a terminal bristle ; proboscis ending in 

 a double fleshy lobe ; abdomen nearly always soft, very rarely 

 horny. 



The Muscidce form the most typical and by far the largest 

 family of the Diptera, and nearly half the known species will fall 

 under this heading. It may be divided into numerous subordinate 

 groups, which some authors regard as distinct families, while 

 others treat them only as sub-families, dividing the Muscidce into 

 two main sections, called Muscidce Caly pierce, and Muscidce Acalypterce. 

 In the former, the alulae are more or less well developed, and in 

 the latter they are rudimentary or absent. We will now proceed 

 to consider some of the most important sub-families, genera, and 

 species of the Muscidce. 



MUSCID.E CALYPTER^. 

 SUB-FAMILY LTachinince. 



Antennal bristle almost naked, or clothed with very short and 

 fine hairs; forehead generally broad; eyes straight, naked, or 

 hairy. Abdomen more or less oval, and set with long bristles, 

 especially on the hinder segments. 



The larvas of this sub-family, like those of most of the Calypterce, 

 are parasitic on the larvae and pupae of Lepidoptera, in the same 

 manner as the larvae of the Ichneumonidce. The largest of the 

 Muscidce found in Central Europe is Echinomyria Grossa, Linn., a 

 black and very bristly fly, with a very broad abdomen. It 

 measures about three-quarters of an inch in length. It is some- 

 times found resting on dandelions in clearings in woods, and has 

 been bred from Lasiocampa Trifolii. 



SUB-FAMILY II. Dexince. 



Antennal bristle pectinated ; forehead broad in both sexes ; 

 eyes straight, naked ; abdomen with long bristles on at least the 

 two last segments. 



Our European species are not specially remarkable, but this 

 sub-family includes the Australian genus Rutilia, Desv., the species 

 of which are half an inch in length, and of the most splendid 

 metallic green or blue, the most brilliant of all the Muscidce. 



