364 INSECTS. 



The thick, short tongue of the Housefly (Musca 

 domestica, PL XVI., fig. 3), with its large two-lobed 

 extremity, and capability, of being drawn entirely into 

 the mouth when not in use is well known. The an- 

 tennae somewhat resemble those of the Syrphidae, and 

 the wings are sparsely veined, and sometimes nearly or 

 quite without the little alulae or winglets. 



This last peculiarity is used to subdivide the family 

 into the Calypterce, in which the alulae are large, and the 

 Acalypterae, in which they are wanting, or very minute. 



In the habits of both larva and fly in the several 

 groups of genera in this one family, there is nearly as 

 much variety as in all the other families of Brachycera 

 together. Thus, while among the Flies are found flower- 

 lovers feeding on honey, blood-suckers, Flies preying on 

 others, Flies oviparous, and Flies ovoviviparous ; among 

 the larvae are found some terrestrial and some aquatic, 

 carrion -feeders, vegetarians, and wine-bibbers ; parasites 

 in the nests, and parasites in the bodies of other 

 insects; gall-makers, and leaf-miners. Of the Flies with 

 parasitic larvae there is a very large group, of which one 

 genus alone, Tachines, contains more than one hundred 

 and sixty species, varying in length from one-eighth 

 to two-thirds of an inch. They are powerful Flies, and 

 some are of brilliant and metallic colours, while others 

 are dull-coloured, hairy, and unattractive. Nearly all 

 the species are rare. The commonest Fly in the group 

 is Ententes geniculatus (PL XVI., fig. 1), a blood- 

 sucking, dowdy-looking Fly, frequently found in the 

 house, and which is remarkable as having the proboscis 

 doubled under, about the middle, as in the Syrphidae. 



Another insect with the same propensity to " bite " 

 men and beasts, is Stomoxys calcitrans (PL XVI., fig. 2), 



