HEMIPTER A. 178 
three simple eyes*. They embrace the division of the Mannifere of 
Linneus, the genus Tettgonta of Fabricius, and form that of our 
Cicadz proper. 
Cicapa, Oliv.—Terticonia, Fab. 
These Insects, of which the elytra are almost always transparent 
and veined, differ from the following ones, not only in the compo- 
sition of their antennz and the number of the ocelli, but in the ab- 
sence of the faculty of leaping, and in the music of the males; which, 
in the heat of summer, the epcch of their appearance, produce 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 a shutter +. The cavity which 
encloses this apparatus is divided into two cells by a squamous and 
triangular septum. When viewed from the side of the abdomen, 
each cell presents anteriorly a white and plaited membrane, and 
lower down, in the bottom, a tight, thin, transparent membrane, 
which Reaumur terms /e mirotwr. If this part of the body be opened 
above, another plaited membrane is seen on each side, which is 
moved by an extremely powerful muscle composed of numerous 
straight and parallel fibres, and arising from the squamous septum. 
This membrane is the tymbal. The muscles, by rapidly contracting 
and relaxing, act on the tymbals, alternately tightening and restoring 
them to their original state. Such is the origin of these sounds, 
which can even be produced after the death of the Insect, by jerking 
the muscle. . 
The Cicade live on trees or shrubs, of which they suck the 
juices. The female, by means of an ovipositor enclosed in a bilami- 
nated semitubular sheath, and composed of three narrow, elongated, 
squamous pieces, two of which terminate in the form of a file, pierces 
* The mesothorax, viewed from above, is much more spacious than the pro- 
thorax, andis 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 following Cicadariz, 
such as the Membraces, Cicadelle, &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 triangular scutellum. In all this family 
the metathorax is very short and concealed. Considered in its relation to other 
Insecis, the head of the Cicadavize, viewed anteriorly, presents a triangular space im- 
mediately 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 analcgous to the face or interval between the eyes; above this 
comes the frons, and then the vertex. 
+ This piece is merely an inferior appendage of the metathorax. The tymbal oc- 
cupying a particular cavity, sometimes exposed above, sometimes covered and only 
visible beneath, is a 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, 
