120 



NATURAL HISTORY. 



The geographical distribution of the Orthoptera is very wide, no family being strictly 

 confined to the warmer regions of the earth, but all extending their range at least as far as the 

 south of Europe, and most of them having representatives in much higher latitudes. Neverthe- 

 less, even of those groups which are best represented in cold 

 and temperate climates, the species are usually far larger 

 and more numerous in warm and tropical countries, to 

 which, indeed, some of the families are chiefly confined. 

 The total number of known species may be estimated at 

 about 6,000. 



We have already seen that in certain structural 

 characters the Orthoptera remarkably approach what may 

 be imagined to be the original type of " the Insect," and 

 it is therefore not surprising to find that Orthoptera are 

 the very earliest types of insects that have been discovered 

 in the fossil state. In Davonian rocks in America remains 

 of various forms belonging to this order, and especially to 

 its most generalised and central type that of the Cock- 

 roacheshave been met with, together with others which 

 certainly seem most nearly related to the forms with 

 veined membranous wings, constituting our second sub- 

 ordinate group; similar types occur in the Carboniferous 

 and Permian formations on both sides of the Atlantic ; 

 and others gradually make their appearance, showing 

 characters which enable them to be referred to existing 

 families, such as the beautifully preserved Dragon Flies of 

 Solenhofen, and numerous other forms which are met with 

 in a more or less imperfect state in Secondary rocks. In 

 the Tertiaries they become still more numerous, and still 

 more closely allied to the living forms. 



It is somewhat difficult to hit upon a satisfactory classi- 

 fication of these insects, but the following will serve our 

 purpose of indicating the alliances of the different types. 

 We divide the Orthoptera as here understood into four 

 sub-orders, of which the first (ORTHOPTERA GENUINA) in- 

 cludes the forms upon which the order Orthoptera was 

 originally founded by Latreille. A second group, PSEUDO- 

 NEUROPTERA, is formed by the membranous-winged types 

 formerly referred to the order Neuroptera. The order is 

 completed by two groups of small insects, namely, the PHV- 

 SOPODA (including the various species of Thrips, the true 



position of which is somewhat doubtful) and the MALLOPHAGA, which may be described as man- 

 dibulate lice. The comprehension of the sub-orders and tribes into which we propose to divide 

 the Orthoptera will be facilitated by the following tabular arrangement : 



ALIMENTARY CANAL OF COCKKOACH. 



g, oesophagus; r, crop; gi, gizzard; mp, malpigliian 

 glands; sg, salivary glands; sr, salivary recepta- 

 cles. 



T. With Wings (except in a few forms). 

 A. Mouth of ordinary construction : 



1. Fore wings horny or leathery (tegmina) 



a. Hind wings with veins radiating from the base, 



fan -like : 



* Hind legs formed for leaping 

 f Hind legs formed for walking 



5. Hind wings with veins radiating from the apex of 

 a homy piece occupying the base of the anterior 

 margin . 



Sub-order 1. ORTHOPTERA GENUINA. 



Tribe 1. SALTATORIA. 

 , 2. CURSORIA. 



3. EUJ'LJJXOPTERA. 



