344 DIVISION III. ARTICULATED ANIMALS.—CLASS IV. INSECTA. 
C. Iufipes. — This species experiences its transformations in the bodies 
of living bumble bees, escaping between the segments. 
CO. Calcitrans resembles the Domestic Fly: it is often seen on windows, 
and is very troublesome, before a rain, by its pricking bite, generally upon 
one’s legs. 
Musca. — The Flies. These insects have the antennxw inserted near the 
forehead, the palpi placed upon the proboscis, and transverse nerves to the 
wings. 
M. Grossa.— This is the largest species known, being nearly, if not 
quite, the size of the bumble bee. The body is very bristly and black; the 
head is buff; the eyes brown; and the base of the wings reddish. It makes 
a loud, buzzing noise, and settles upon flowers in the woods. 
M. Vomitoria is the Common Meat Fly, with a fulvous forehead, black 
thorax, and blue abdomen, with black marks. Its sense of smelling is very 
keen, and it soon finds meats which are exposed to its attacks, and covers 
them with its eggs. 
M. Carnaria. —The Executioner Fly is rather larger than the Meat 
Fly. It is of a dark, metallic, green color, with a slight ash-colored down. 
It attacks oxen, and deposits its eggs on meat, and often in the wounds of 
animals. “ 
M. Domesticu. —The House Fly. This insect has an ash-colored body ; 
the face black, and also the feet; the sides of the head yellow; and the 
forehead likewise yellow, with black stripes. This fly is common to all 
countries, invades all houses, and soils, with its dark-colored exudations, 
walls, ceilings, windows, mirrors, and all light-colored objects. It feeds on 
sweet substances and the fluids that are diffused by perspiration over the 
bodies of man and beast. In the early part of the season it does not bite 
or sting; but towards the end of summer, it becomes nearly as annoying as 
the mosquito. 
After the JJuscides, the remaining Diptera, composing the sixth family 
of the order, are all parasites 
a kind of lice, living on the bodies of vari- 
ous animals, birds, and other insects. They are sometimes called Spider 
Flies; they run swiftly, and fly sidewise. They constitute the genus L/ip- 
pobosca. Il. equina (the Forest Fly). This insect, in some places, is 
very troublesome to horses, attaching itself in great numbers beneath the 
tail. J. avicularia lives on various species of birds. ZZ. ovdna infests 
sheep. Other species live on bats; one is the torment of the stag, and 
another makes its home on the honey-bee. 
The Dipterous insects, for the most part, are a very ferocious class of 
creatures. They delight in blood, and live by robbery and murder ; other 
insects, all kinds of beasts, and even man, suffer from their attacks. Yet 
in the great economy of Nature they are not without their use. 
