2S 
Family 
SIMULID^E. 
Although undistinguished in the British Islands by any English 
name, the members of this family, of which it is probable that our 
fauna includes at least a dozen species, are only too well-known to 
all those who have had occasion to enter their haunts. The family 
consists of the single genus Simitlium, which is universally dis- 
tributed, and of which some sixty-six species, difficult to distinguish 
from one another, have been described up to the present time. The 
females of some of these flies, which are among the most dreaded 
of all blood-sucking Diptera, sometimes occur in enormous swarms, 
and by their attacks upon horses, mules, and cattle, especially in 
certain parts of the United States, occasion great losses among these 
animals, besides molesting human beings. In the district of South 
Hungary called the Banat the Columbacz Midge (Simulium colum- 
baczense, Schdnb.) has been notorious for more than a hundred years 
owing to the destruction caused by it among cattle. 
In appearance Simulida; are small black or greyish flies, not 
exceeding 4 mm. in length, with a conspicuously humped thorax, 
short straight antennae, broad and delicate iridescent wings, stout 
legs, and a short proboscis which is not visible from above. The 
males, which are incapable of sucking blood, are fond of dancing in 
the air in the sun ; as a rule they are much darker in coloration than 
the females, and are often velvety black, with silvery markings on 
the front of the thorax. 
The preliminary stages are passed in running water. The eggs 
are deposited in a compact layer or gelatinous mass on stones or 
plants close to the water's edge. The larval stage lasts for about 
four weeks in the summer, though longer in cold weather, and the 
winter is passed in this stage. In shape the larva is somewhat like 
a tiny leech, broadening out posteriorly, where it is attached by 
means of a sucker to a stone, the stem of a water-plant, a dead leaf, 
or other object. The larva is able to shift its position by crawling in 
a looping fashion, but usually remains in a more or less erect position. 
