192 ZOOLOGY. 
Divis. 2. Bracuocera, Macq. Antenne short, not having apparently 
more than three distinct joints; palpi one- or two-jointed. 
(Stirps 2.) Noracanrna, Latr. Antenne apparently composed of only 
three joints, the last, however, being articulated ; proboscis exserted, seldom 
inclosing more than two lancets. The structure of the mouth is very 
incomplete, and the number of sete variable. Pupa coarctate, the skin of 
the larva, however, nearly retaining its previous form. Fam. 3, Strati- 
omyde ; 4, Beride; 5, Cenomyide. 
(Stirps 3.) Tanystoma, Latr. Antenne with only three joints, ordi- 
narily terminated by a seta (Yabanus and Midas excepted) ; proboscis 
exserted, generally with four sete (six in female Tabanide ; mouth obsolete 
in Acroceride) ; larva with a scaly head; pupa incomplete. Fam. 6, 
Tabanide ; 7, Bombyliide ; 8, Anthracide ; 9, Acroceride ; 10, Empide ; 
11, Tachydromtiide ; 12, Hybotide; 18, Asilide; 14, Mydaside; 15 
Therevide ; 16, Leptide ; 17, Dolichopide ; 18, Scenopinide. 
(Stirps 4.) Aruericera, Latr. Antenne with only two or three joints, 
terminated by a seta; proboscis generally withdrawn into the oral cavity, 
with two sete (four in the Syrphide; mouth obsolete in the Gistrida@) ; 
pupa coarctate, the skin of the larva forming an oval case. Fam. 19, 
Syrphide ; 20, Conopide ; 21, Muscide ; 22, Gistride. 
Section 2. Tuoracocernata. (Stirps 5.) Puprpara, Latr. (Order 
Homaloptera, Leach). Head immersed in the thorax; claws denticulated ; 
larva nourished in the abdomen of the mother, and not deposited until 
after it has passed to the pupa state. Kam. 23, Hippoboscide ; 24, 
Nycteribuide. 
2 
The first section includes a great majority of the Diptera (including 
those to which the term fly is popularly assigned), in which the head and 
antenne are free. The mouth is a soft rostrum, containing several bristle- 
shaped organs in a groove along its upper surface, which also forms a 
channel oe the liquid food. 
The Culicide is a family of which Culex (including the mosquitoes) is 
the best known genus, and notwithstanding their small size, their organiza- 
tion is very perfect. The rostrum is very long and slender, apparently 
simple, but composed of seven organs. The male, which does not sting, 
can be readily distinguished by the feathery antenne. These tormenting 
insects do not move about much during the day; but where they abound, as 
soon as the sun sets, they fill the air in myriads, and become a serious evil. 
They abound in warm climates ; and in the low regions of the lower Missis- 
sippi, they fill the houses and the cabins of the steamboats as evening 
advances. In many parts of the United States it is necessary to exclude 
them from beds by a netting of gauze called a mosquito bar. In districts 
where they are rare, a house may be infected with them from a vessel used 
to catch rain water, and in which a passing female may deposit her eggs. 
These are laid upon the surface of stagnant water one at a time, but in 
contact with each other, and to the number of two or three hundred. In 
two days the larva make their appearance, in fifteen days they become 
396 
