472 MODERN CLASSIFICATION OF INSECTS. 
tibiz, in some species, are terminated on the inside by an oblique, 
hollow, fleshy lobe or pulvillus (fig. 120. 17.), serving, apparently, to 
assist the raptorial habits of the species, which are more pre-emi- 
nently insectivorous than any of the other terrestrial species; the 
membranous part of the fore-wings often extends nearly to the base 
of the wings, and the veins are few and large. * 
These insects vary greatly in size as well as in general appearance, 
colouring, &c. In many the sides of the abdomen are greatly dilated 
and thin, not being covered by the wings: in others, the body is short 
and thick ; whilst in some, Zelus, &c., it is very slender: this is much 
more especially the case in the genera Ploiaria | and Emesa, which 
last consists of species resembling the thinnest bits of stick fastened 
together; these two genera are further distinguished by the perfectly 
raptorial structure of the very small fore-legs, with the coxe greatly 
elongated, like those of the Mantide. In their motions they resemble 
the Tipule, balancing themselves on their long legs. 
The species are chiefly exotic, very few being natives of our 
climate: they generally want the power of emitting a strong scent ; 
but the wounds they are able to make with their proboscis are very 
acute: this is more especially the case with the large exotic species, 
one of which, “ of the size of our cockchaffer,” greatly annoys the 
inhabitants of Chili by night. It is called Benchuca. Another large 
species, Arilus (Prionotus Zaér.) serratus, or the wheel bug (so 
named in the West Indies, from the singular protherax circularly 
elevated, and toothed like a cog-wheel), is stated by Kirby and 
Spence (Jnér. i. 110.) on the authority of Major General Davies, to 
be able to communicate a sharp electric shock. Many are found 
upon flowers and trees, and some inhabit our houses; amongst the 
latter may especially be mentioned Reduvius personatus (fig. 120. 
15.), a black insect, which is asserted to feed upon the bed-bug, the 
larva (fig. 120. 18.) and pupa of which have the instinct to envelope 
themselves in a thick coating of particles of dust (De Geer, Mém. 
iii. pl. 15., and Geoffroy, i. pl. 9. f.3h), and so completely do they 
* Dufour, Rech. Anat. Hemip!. g. 12. sp. 2. states, that in Red. marginatus the 
structure of the Hemelytra has been overlooked, and that the membrane is entirely 
wanting; but this is not the case: it is the corium that is nearly obsolete: this is 
proved by other species in the family, as Opistoplatys Australasiee (Westwood in 
Z Jl.), Holoptilus Lemur Westwood, &e. 
+ In the 6th vol. of the Turin Transactions is contained a memoir on the circu- 
lation observed in this insect. 
