HEMIPTERA, 159 
than the wings, semi-membranous, like the elytra of the Orthoptera, 
and sometimes opaque and coloured, sometimes transparent and 
veined. There are a few longitudinal plicz in the wings. 
The composition of the trunk begins to experience modifications 
which approximate it to that of the Insects of the following orders. Its 
first segment, hitherto designated by the name of thorax, has, in se- 
veral, much less extent, and is incorporated with the second, which is 
equally exposed. 
Several have simple eyes, of when: however, there are frequently 
but two. 
The Hemiptera exhibit the same forms and habits in their three 
states. The only change they experience consists in the development 
and growth of the volume of the body. They usually have a stomach 
with firm and muscular parictes, a small intestine, followed by a large 
one divided into several inflations, and biliary vessels, few in number, 
and inserted at a distance from the pylorus. I divide this order into 
two sections *. 
In the first, that of the Herrroprera, Lat., the rostrum arises 
from the front; the elytra are membranous at the extremity, and the 
first segment of the trunk, much larger than the others, alone forms 
the thorax. 
The elytra and wings are always horizontal or slightly inclined. 
This section is composed of two families. 
FAMILY I. 
GEOCORIS &. 
In this family the antennz are exposed, longer than the head, and 
inserted between the eyes, near their internal margin. There are 
three joints in the tarsi, the first of which is sometimes very short. 
It forms the genus 
Cimex, Lin. 
In some, or the Longzlabra, the sheath of the sucker consists of four 
exposed and distinct joints, the labrum is much prolonged beyond the 
head, subulate, and striated superiorly. 
The tarsi always consist of three distinct joints, the first of which 
is almost as long as the second, or longer. These species always dif- 
fuse a disagreeable odour, and suck the juices of various Insects. 
Sometimes their antennz, always filiform, are composed of five 
joints; the body is generally short, oval, or rounded. 
* In the systems of Messrs. Kirby and Leach, they form two orders. Our 
Heteroptera ave there termed Hemiptera, and our section of the Homoptera forms the 
second under the same name. 
