38 INSECTA. 
side, a character also observed in the Cercopis spumaria, 
while in the Cicadzx there are four, two on each side. In the 
Membracis cornutus the duodenal ear-like sac is replaced by 
a large pouch, but also attached to the esophagus by a sus- 
pensory filament, a character exclusively peculiar to these 
Insects. : 
Some—Cantatrices—have antenne composed of six joints, 
and three simple eyes(1). They embrace the division of the 
Mannifere of Linneus, the genus Tet¢tigonia of Fabricius, and 
form that of our Cicade proper. 
Cicapa, Oliv.— Tettigonia, Fab. 
These Insects, of which the elytra are almost always transparent 
and veined, differ from the following ones, not onlyin the compo- 
sition of their antenne and the number of the ocelli, but in the 
absence of the faculty of leaping, and in the music of the males; 
which, in the heat of summer, the epoch of their appearance, pro- 
duce that loud and monotonous sound which has induced authors to 
designate them by the name of Cantatrices or Singers. 
The organs by which it is effected are situated on each side of the 
base of the abdomen; they are internal and each one is covered by a 
cartilaginous plate, which closes like ashutter(2). The cavity which 
(1) The mesothorax, viewed from above, is much more spacious than the pro- 
thorax, and is narrowed towards the extremity, which forms a sort of scutellum, 
We observe nearly the same disposition of parts in Fulgora, and other genera 
which are derived from it. The mesothorax has frequently the form of a reversed 
triangle, and the prothorax is generally very short and transversal. In the fol- 
lowing Cicadariz, such as the Membraces, Cicadellz, &c., it is, on the contrary, 
longer than the other thoracic segments, greatly developed in one direction or 
another, and the mesothorax is only visible in the form of an ordinary and trian- 
gular scutellum. In all this family, the metathorax is yery short and concealed. 
Considered in its relation to other Insects, the head of the Cicadariz, viewed an- 
teriorly, presents a triangular space immediately above the labrum, corresponding 
to the epistoma or clypeus; then, still higher up, another space, frequently inflated 
and striated, termed by Fabricius the frons, but which is analogous to the face 
or interval between the eyes; above this comes the frons, and then the vertex. 
(2) This piece is merely an inferior appendage of the metathorax. The tymbal 
occupying a particular cavity, sometimes exposed above, sometimes covered and 
only visible beneath, isa lateral prolongation of a skin which forms the anterior 
diaphragm of the two inferior cavities of the first segment of the abdomen. The 
opposite diaphragm, or the posterior of these cavities, constitutes the piece called 
the mirror, or miroir. It appears, that, like the other diaphragm, it is formed at 
the expense of the tracheal membranes. 
