1G6 ZOOLOGY. 



The Ijodj is flattened and robust. The antenna? 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 hirge common species of the United States 

 {(Edipoda Carolina), whicli is found in dry j^laces, such as dusty roads, may 

 be seen liovering 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 

 flight. This species is brown, with the wings black, margined with yellow. 



Acrid'mm eristatum [fig. 81), CEdlpoda stridula {fig. 78), 0. cmrulescens 

 {fig. 79), 0. migratoria {fig. 80). The last is two inclies 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. 



Oedek 0. Neueopteea (_/;/. IS)., figs. 5-i-7G). This is a somewhat irregular 

 inandibulate order, the characters prepented by it being varied, and on this 

 account ^'arious modiflcations have been proposed for it. In the LihelluUdw., 

 the tropin make an a])proximation to those of the Orthoptera, to which the 

 order has been united by Erichson, whilst Kirby separates the TricJiojytera 

 as a distinct order. The antennte are generally setaceous and short. The 

 four wings have usually reticulate nervures ; they are generally of equal size 

 and consistence, and the posterior pair is not generally folded. The jjupa 

 is sometimes active and sometimes cpiiescent. The larvie are hexapod, 

 mostly predaceous, and they are either terrestrial or aquatic. 



Blanchard divides the order into nine tribes, named after the genera 

 Termes., EmMa., Psocus., Perla., Ephemera., Libellula., Myrmeleon., Jiaphidia., 

 and PJiryganea., the last belonging to one section, and all the rest to 

 another. Westwood (who considers the Triclioptera to be a distinct order) 

 adopts the following arrangement : 1, TennitidiB', '2i., Psocidm ; Z., PerlidcG ^ 

 4, Epliemeridm j 5, JJheilul'uhB ; 6, Myrmeleo7iid(B ^ 7, IleinerobiidcB ; 8, 

 Sialidm; 9, Panrnpidm ; 10, RapTiidiidai ; 11, Mantlspidai. 



The Thripsidte {pi. 80, fig. 51) form a group of small extent, which 

 Burmeister includes in his great order Gym7iognatha. The sj^ecies 

 are minute and linear, with four narrow and equal wings, deprived of 

 nervures, strongly fringed with long hairs, and not folded. The mouth is 

 uiandibulate, 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 Shmdium. The pupa3 are active, and their affinities are with the 

 NeuToptera. There are various species in Europe and America. They 

 form Ilaliday's order Thysanojjtera., and include a number of genera. 



The Termitidce include the genus Termes {pi. 79, fig. 56, a, 5, <?, d) or 

 white ant, whicli })resents many curious features in its economy. The body 

 is white and oblong, the antenna? short and moniliform, the eyes lateral, 

 the stemmata two in number, and the mouth mandibulate, resembling 

 that of the OrtliopUra in having a galea ; and the tarsi are four-articulate. 

 They live together in societies composed of various kinds of individuals. 

 370 



