466 INSECTA. 



superior margin of the front of the head, near the eyes, seem to be 

 vestiges of mandibles. Finally, we observe, and in equally exiguous 

 proportions, the labrum or upper lip. 



The antennse 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 epaulette, prolonged 

 posteriorly, that corresponds to the piece called tegula in the Hy- 

 menoptera. 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 nei- 

 ther sting nor ovipositor analogous to that of the Hymenoptera. In 

 several 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 females usually deposit their ova, frequently very numerous, 

 on the vegetable surfaces which are to nourish their larvas, and soon 

 after perish. 



The larvse of Lepidopterous Insects are well known by the name 

 of caterpillars. They have six squamous or hooked feet, which 

 correspond to the legs of the perfect Insect, and from four to ten 

 additional membranous ones, the two last of which are situated at 

 the posterior extremity of the body; those which have but ten or 

 twelve in all, have been called, from their mode of progression, geo- 

 vietrse. Several of these geometrse, 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 themselves in this position for a long time, without exhibit- 

 ing the slightest symptom of life. So fatiguing an attitude must re- 

 quire prodigious muscular force, and in fact Lyonet counted four 

 thousand and forty-one muscles in the caterpillar of the Cossus lig- 

 niperda. 



The body of these larvss is generally elongated, almost cylindri- 



