14 
MEMBRA Cl DTE. 
appears to belong more to the pronotum than to the scutellum proper, and ought 
therefore to be included in it. 
Although the scutellum is said to be exposed in all Centrotid®, the tegmina in 
almost all cases so cover it that it only comes into view when the alar organs are 
expanded for flight. 
The Sternum and its Parts .—The thoracic-parts of Membracid® show no particular 
diversity of form, each portion being indicated by the seats of articulation for the legs. 
No voice organs similar to those of the true Cicadid® are present, and the insects 
appear to be mute as to producing sounds except by a faint buzzing.* 
The Tegmina or Elytra .—Difficulties in homologising the wings of the Hemiptera 
have been long recognised. The neuration of the upper and lower wings is 
always different. 
The tegmina of the Hemiptera Heteroptera are usually quite simple in their 
venation, but the tegmina of the Homoptera are often very complex, as may be seen in 
the tine network of Fulgorid® (lantern flies), which is almost as delicate as that of the 
Neuroptera. 
The tegmina of the Membracid® follow the general rule in insects, that the 
upper wing is the largest. Exceptions to this rule however are to be found in the 
Orthoptera, where there are many specific cases of an entire absence of elytra, in 
which event the lower wings become very large and efficient. 
Wing neuration presents great difficulties where we find variation not only in 
the species of the same genus but also in the different sexes. There are peculiar 
obstacles to the study of the wings of Membracid®. The pronotum is so large 
that in some cases it quite encloses them, and they can only be unfolded, in 
dead specimens, by the removal of this part of the thorax. The pronotum, moreover, 
is not cleft as we see in most Coleoptera, but consists of one hard piece, soldered 
to the shoulders, and it is only then possible for the insect to open its wings 
after a depression of the abdomen. Characteristic notches are then provided in the 
shoulder edges for the insertion of the wings, and so as to allow them to have 
free play. 
Dr. Leon Fairmaire, Dr. Goding, and Canon Fowler have given detailed notes and 
outlines of neuration in many species of Membracid®, and I have gladly availed myself 
of their help. 
A review of the outlines I give to represent the neuration of the wings and 
tegmina will show their very diverse characters. Scudder and others have laid much 
* The Cicadidse in Surinam are called Scbaarslijpers or shear-grinders, doubtless from the noise of 
their chirping. No noise, however, has yet been detected from the Membracidte, though these insects 
are allied to the Fulgoridse and Cicadidae. 
