HEMIPTERA, 177 
om Memeracis, Fab. 
Where the prothorax is elevated, compressed and foliaceous along 
the middle of the back *. 
Tracopa, Lat. 
Where that part of the body presents, on each side, a horn or 
pointed projection without any intermediate elevation, and is pro- 
longed postericrly into an arched point of the length of the abdomen, 
and replacing the scutellum f. 
There, the tibie are of the ordinary form, or non-foliaceous. 
Darnis, Fab. 
Where the posterior prolongation of the prothorax covers the top 
of the abdomen almost wholly or for the greater part, and the elytra 
form an elongated and arched triangle f. 
Bocypium, Lat. 
Where the elytra are wholly or mostly exposed, the posterior and 
scutellar prolongation of the prothorax being narrow and more or less 
lanceolate or spiniform §. 
In the others, the scutellum is at least partially exposed, although 
the prothorax may be prolonged ; the posterior extremity of the pro- 
thorax presents a transvere suture, which distinguishes it from the 
scutellum. 
Centrotus, Fab. 
Such are the 
C. cornutus ; Cicada cornuta, L; Panz., Faun. Insect. Germ., 
L, 19. Length four lines; thorax furnished with a horn on 
each side, and prolonged posteriorly into a point as long as the 
abdomen.—In the woods on Filices and other plants. 
C. geniste, Fab.; Panz., Ib., 20. But half the size of the 
cornutus, with its thorax simply prolonged posteriorly—On the 
Genistee |]. 
We will now pass to those species in which the head is scarcely 
lower than the prothorax, or is level with it, and horizontal or but 
slightly inclined when seen from above; where the prothorax is nei- 
ther raised in the middle nor prolonged posteriorly, and at most only 
presents lateral dilitations; and where the mesothorax has the form 
of an ordinary sized and triangular scutellum. ‘The elytra are al- 
ways entirely exposed, and the posterior tibize at least, always spinous. 
In several, such as the following, the thorax has the figure of an ir- 
regular hexagon ; it is prolonged and narrowed posteriorly, and ter- 
* The Membracis foliaceus, Fab. 
+ Membraces from the Brazils, which appear to me to be analogous to the fol- 
lowing species of Germar, glabra, albimacula and wanthocephala. 
t See Fab., Syst. Ryngot. 
§ The Centrotus horridus, trifidus, globularis, clavatus, claviger, Fab. 
\| The C. cornutus, scutellaris, &c., Fab. 
