274 - INSECTA, 
The antenne vary and are always multiarticulated. Two ocelli 
are observable in several species, but concealed between the scales *. 
The three segments of which the trunk of the hexapoda is composed, 
are united in one single body; the first is very short, and the two 
others are confounded together. The scutellum is triangular, but 
the apex is directed towards the head. The wings are simply veined, 
and vary in size, figure, and position; in several, the inferior ones 
are plaited longitudinally near their inner margin. At the base of 
each of the superior wings is a kind of epualette, prolonged poste- 
riorly, that corresponds to the piece called teguéa in the Hymenop- 
tera. As it is more developed here, I will call it pterygoda. The 
abdomen, composed of from six to seven annuli, is attached to the 
thorax by a very small portion of its diameter, and presents neither 
sting nor ovipositor analogous to that of the Hymenoptera. In se- 
veral females, however, as in Cossus, the last rings become nar- 
rowed, and extended to form an oviduct resembling a pointed and 
retractile tail. The tarsi always have five joints. There are never 
more than two kinds of individuals, males and females. The abdo- 
men of the former is terminated by a kind of flat forceps which con- 
tains the penis. 
The females usually deposit their ova, frequently very numerous, 
on the vegetable surfaces which are to nourish their larve, and soon 
after perish. 
The larve of Lepidopterous Insects are well known by the name 
of caterpillars. ‘They have six squamous or hooked feet, which cor- 
respond to the legs of the perfect Insect, and from four to ten addi- 
tional membranous ones, the two last of which are situated at the 
posterior extremity of the body, near the anus; those which have 
but ten or twelve in all, have been called, from their mode of pro- 
gression, geomeitre. They cling to the plane of position with their 
squamons feet, and then, elevating the intermediate segments of the 
body in the form of a ring or buckle, approximate the two hind feet 
to the preceding ones, disengage the latter, hold on with the last feet, 
and move their body forwards to recommence the same operation. 
Several of these geometre, when at rest, remain fixed to the 
branches of plants by the hind feet alone, where,in the form, colour and 
direction of their body they resemble a twig ; they can support them- 
selves in this position for a long time, without exhibiting the 
slightest symptom of life. So fatiguing an attitude must require 
prodigious muscular force, and in fact Lyonet counted four thousand 
and forty-one muscles in the caterpillar of the Cossus ligniperda. 
* According to an observation mace by Dalman, they do not exist in the Diurne. 
