166 ~ ZOOLOGY. 
The body is flattened and robust. The antenne are short, the posterior 
feet saltatorial, the tarsi trimerous, the abdomen has two very short 
appendages, and that of the female is without a prominent ovipositor. 
These insects produce a stridulation by rubbing their hinder thighs against 
the wing-covers, and the large common species of the United States 
(Zdipoda carolina), which is found in dry places, such as dusty roads, may 
be seen hovering a yard or two above the ground over a single spot, the 
wings then producing a fluttering sound which is not heard in its ordinary 
fight. This species is brown, with the wings black, margined with yellow. 
Acridium eristatum (fig. 81), Edipoda stridula (jig. 78), O. caerulescens 
(fig. 79), O. migratoria (fig. 80). The last is two inches long, and inhabits 
central, southern, and eastern Europe, where it occasionally commits great 
ravages upon the vegetation. Various species are abundantly distributed 
over various parts of the world. 
Orper 6. Nevroprtera (pl. 79, figs. 54-76). This is a somewhat irregular 
mandibulate order, the characters presented by it being varied, and on this 
account various modifications have been proposed for it. In the Lzbellulida, 
the trophi make an approximation to those of the Orthoptera, to which the 
order has been united by Erichson, whilst Kirby separates the Trichoptera 
as a distinct order. The antenne are generally setaceous and short. The 
four wings have usually reticulate nervures ; they are generally of equal size 
and eonsistence, and the posterior pair is not generally folded. The pupa 
is sometimes active and sometimes quiescent. The larvee are hexapod, 
mostly predaceous, and they are either terrestrial or aquatic. 
Blanehard divides the order into nine tribes, named after the genera 
Termes, Embia, Psocus, Perla, Ephemera, ibellula, Myrmeleon, Raphidia, 
and Phryganea, the last belonging to one section, and all the rest to 
_ another. Westwood (who considers the Z7ichoptera to be a distinct order) 
adopts the following arrangement: 1, Zermitidw; 2, Psocide; 3, Periide ; 
4, Ephemeride ; 5, Libellulide; 6, Myrmeleonide ; 7, Hemerobude ; 8, 
Sialide ; 9, Panorpide; 10, Raphidude; 11, Mantispidee. 
The Thripside (pl. 80, fig. 51) form a group of small extent, which 
Burmeister includes in his great order Gymnognatha. The species 
are minute and linear, with four narrow and equal wings, deprived of 
- ervures, strongly fringed with long hairs, and not folded. The mouth is 
mandibulate, the tarsi dimerous and ending in a vesicle, as in some of the 
lower Arachnida. They are considered hurtful to plants, and it is probable 
that an American species attacks the human skin, causing an itching like 
that of Simulium. The pupe are active, and their affinities are with the 
WNeuroptera. There are various species in Europe and America. They 
form Haliday’s order Thysanoptera, and include a number of genera. 
The Termitide include the genus Termes (pl. 79, fig. 56, a, b, ¢, d) or 
white ant, which presents many curious features in its economy. The body 
is white and oblong, the antennez short and moniliform, the eyes lateral, 
the stemmata two in number, and the mouth mandibulate, resembling 
that of the Orthoptera in having a galea; and the tarsi are four-articulate. 
They live together in societies composed of various kinds of individuals. 
370 
