HEMIPTEKA. 173 



three simple eyes*. Xfe6y embrace the division of the Manniferae of 

 Linneeus, the genufr^eltigonia of Fabricius, and form that of our 

 Cicadae propej;. q 



^' Cicada, Oliv. — Tettigonia, 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 antenn?e and the number of the ocelli, but in the ab- 

 sence of the faculty of leaping, and in the mvisic of the males ; which, 

 in the lieat of summer, the epoch 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 ])y 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, v/hich closes like a shutter f . 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 tiglit, thin, transparent membrane, 

 which Reaumur terms /e miroir. If this part of the body be opened 

 above, another plaited membrane is seen on each side, whicli 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 Cicadas 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 raesotliorax, 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 following Cicadaria;, 

 such as the Merabraces, Cieadellfe, &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 

 Insects, the head of the Cicadaviw, viewed anteriorly, presents a triangular space im- 

 mediately above the labrum, corresponding to the epistonia or clypeus; then, still 

 higher up, another space, frequently inflated and striat'jd, 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. 



t 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. 



