10 
MEMBRA CIDJE. 
The front is triangular in shape, its surface may be smooth, punctured, or pilose. 
At the cleft base a short proboscis is articulated. The compound eyes are large, 
usually hemispherical, and studded with minute facets. 
The two ocelli are almost always visible as bright spots placed between, or a little 
below, the line joining the eyes, not on the guise or cheeks, as is commonly seen in the 
Fulgoridae. When these Membracidse are viewed as it were in profile, the lower part 
of the front of the head, being flattened, appears as if the insect was beaked like a bird. 
The vertex is rarely visible, as it is more or less covered by the pronotum, or at 
least it is only separated by a suture, without any neck to connect it with the thorax. 
The prone, or the more or less perpendicular aspect of the head, with reference to the 
anterior part of the pronotum, is a good character to consider. 
The Antenna .—These organs are remarkably small and inconspicuous. Whatever 
function they fulfil in other insects, the sense they develop must be very obtuse in the 
Membracidee. The fact that they cannot be found on many specimens in our cabinets 
does not however prove that in the living insects they may not exist. 
The large Cicadidae show them only as fine bristles, and in the family at present 
under consideration they are still further degenerated, or are obsolete. 
In the species which best show them, they consist of two larger basal joints, articu¬ 
lated to the lower part of the front, and terminated by a long and fine bristle. Plate I, 
Fig. 6r/, represents these organs behind the clypeus of Xerophyllum servillei, and Plate I, 
Fig. 7a, indicates their position under the ocelli of Membracis jtaveola and Umbonia 
spinosa. 
The Rostrum .—The form of this organ does not essentially differ from that of the 
Fulgoridse. It is short, and when at rest, folded between the first and second pairs 
of legs. 
The two joints enclose three setae or bristles, which are often seen protruded. 
These piercing organs are shown on Plate A, Fig. 8, which represents the mouth-parts 
of TJmbonia orozimbo. The labrum in its position may be seen in Plate I, Fig. 3. 
M. fasciata. 
The Eyes and Ocelli .—The compound eyes are large, and usually protuberant. 
The facets are small, and the hemispherical mass is sometimes sunk in a sort of cup 
with a rim or edge. The two ocelli are almost always present, and are visible as 
bright spots between the eyes, at varying distances. Some authors have used their 
position for the diagnosis of species, but as there is much uncertainty in judging 
their distances, the character is not used in this memoir of the family. Occasionally 
the eyes are lenticular or bean-like, or in form somewhat hooked. See Aconophora, 
Plate A, Fig. 2. 
The Thorax .—As is usual in the Homoptera and other insects, this segment is 
