98 PARTIAL ORISMOLOGY. 



but it will equally apply to the posterior ones, when they are of the same 

 size and quality as the former (see the table, 79). Where the poste- 

 rior wings differ in form from the anterior, they are in general smaller 

 often, however, broader, if not longer. It is chiefly in the Orthoptera 

 that we observe this more significant size of the posterior wings ; in 

 these they are sometimes even longer than the anterior, and extend 

 beyond them ( Gryllotalpa) ; it is the same in some beetles with short 

 elytra (Necydalis, Atractocerus) . In general, however, the true wings 

 of an Order are perfectly uniform in structure, although their veins 

 ramify differently, and, this also applies more generally to the pos- 

 terior wings, which less distinctly show the above-described separation 

 into three principal areolets, although, upon a careful inspection, these 

 would not be found deficient in them. 



The following are the most important orismological definitions of the 



wings :- 



The ANTERIOR WINGS (alee anteriores) are those attached to the 

 second thoracic segment; they are also called SUPERIOR (al. supe- 

 r lores) from their covering the posterior ones in repose ; or, the FIRST 

 (primaries) from their preceding the others in flight. The posterior 

 wings have had, from opposite reasons.- opposite names applied to them, 

 as al. posteriores, al. inferiores, and al. secundarice. In each wing we 

 distinguish, as the ANTERIOR MARGIN (margo anterior], or EXTERIOR 

 MARGIN (margo externus), that margin which, in flight, lies in the 

 direction of the head; that opposed to it as the INNER MARGIN (m. 

 internus) ; the third, generally taking the direction of an obtuse angle, 

 with regard to its situation as to the others, is called the POSTERIOR 

 MARGIN (m. posterior}. The angles formed by these margins at their 

 point of contact, receive the following names : the ANTERIOR ANGLE 

 (angulus anterior} is that at the apex of the wing, formed by the ante- 

 rior and posterior margins ; the POSTERIOR ANGLE is that formed by 

 the contact of the posterior and interior margins. We have already 

 made mention of the humeral and scutellar angles. 



The general outline of the wings is distinguished according to its 

 form; the following terms are used to express them: FALCATE 

 (falcatcB, PL XV. f. 12) are wings whose anterior margin forms a circle 

 bending outwards, and their posterior margin is also directed forwards 

 (many Lepidopterd). 



TAILED (eaudatce, PI. XV.' f. 13) are those which have a long and 



