6 
MEMBRA CIDJE. 
governed by the character of the vegetation, the substance of which they puncture 
for the juices required for food. 
At present the early life-history of the family is obscure, and we are ignorant 
even of the metamorphosis of the onty three or four European species which 
represent it. 
The natural position amongst insects is that between the trimerous Cicadidse, and 
the Circopidse, or Frog-hoppers. 
The Membracidae have been supposed to supply the place of Aphidae in semi- 
tropical countries, but this is hardly true, for communities of both families can be 
found spread over the same areas of country. 
Their geographical range is wide, for the species affect not only countries which 
are subject to great cold, as is found in Canada and the North of the United States, 
but they are numerous under the tropical heats of Brazil, the Amazons, and Ecuador. 
The more temperate regions on the slopes of the Himalaya, and the high grounds of 
Central Africa, are also rich in examples. 
The extraordinary and striking forms of Sphongophorus clacatus, Bocydium 
glohularis and L mbonia spinosa were known to Linnaeus, to Stoll, and Coquebert. 
William Kirby and William Spence perhaps first suggested the theory of protective 
disguise, as an explanation of the lichen-like, fungoid, and thorny exteriors of these 
species, and ot many of the examples contained in these genera.* 
The works of Carolus Stal are numerous and scattered, but they lose much of 
their value as they are without figures. His tables are often obscure in their defini¬ 
tions. Thus such terms of qualification as saepissime, levissime, and raro paullo, 
should be as far as possible rejected, as bewildering to the searcher. His work 
on the African Membracidae in Vol. IV. of the “ Hemiptera Africana,” 1SG4, 
however, appears to be our best guide at present to these insects of that Continent. 
These species in great measure belong to the Centrotidae and their allies, which are 
the last to be treated, in this monograph. 
A number of species are named by Mr. Francis Walker, and are preserved in the 
cabinets of our National Museum. Some are type specimens, single and unique. 
In great part they are more or less sufficiently described in “Walker’s List of 
Homoptera in the British Museum,” but some of these I have not been able to 
figure here. Mr. Walker added several new and good genera to the family of 
Membracidae. 
Canon W. W. Fowler’s monograph, above alluded to, is the most important 
memoir that has occurred up to present date. It is profusely illustrated by coloured 
plates. Had it not been confined to the insects of one portion of the world only, 
* Kirby and Spence, Intro, to Ent., vol. ii. p. 182, fifth edition, 1843. 
