OF Lr.riDOrTEROUS l.\SECTS. 29 



In the Macroglossa with vitreous wings, the scales in the centre of the 

 wing are so little adhesive, that they disappear almost as soon as the in- 

 sect has used them in flj'ing. 



The nervures are listular, filiform organs, more or less ramified, 

 which seem intended to support the two membranous laminae indicated 

 above, and which constitute, properly speaking, the framework of the 

 wing; they extend themselves in their ramifications from the base to 

 the exterior edge of the wing. Their number, counting them from the 

 exterior edge, varies from eight to twelve, and it is not always the same 

 in the anterior and in the posterior wings. * It is the nervures that give 

 to the wings their more or less diversified form whicii has been called 

 the section of the wlng^ (coupe d' aile.) 



The spaces comprised between the nervures are designated by the 

 name of cellules. '\ These vary ac^-ovding to the arrangement of the 

 former. The two most remarkable are the discoidal cellules, wiiich we 

 sometimes use to characterize tribes or genera. 



The inferior wings, wliilst they present an anatomical structure anal- 

 ogous to that of the superior wings, have always a form somewhat dif- 

 ferent. They are generally rounded, or ovally elongated, sometimes a 

 little sloped and hollowed upon their internal or abdominal side, hi 

 the species of Rhopalocerata, where this side is not sloped, it is thin, 

 downy, and membranaceous, and frequently forms, with that of the op- 

 posite side, a canal or gutter which envelopes the anterior part of the 

 abdomen. The superior wings, on the contrary, approach more or less 

 to a triangular form. 



Besides their two faces, the wings present for our consideration va- 

 rious parts which have received the following names : the middle of the 

 wing is generally called the disc ; the part near tlie thorax, the hasc ; 

 and that which is opposite to it, where the nervures meet, the posterior 

 or exterior edge. The two other edges take diflerent names according 

 as the reference is to the superior or to the inferior wings, hi the for- 

 mer, the edge which is in front is called the anterior edge, costal edge, 

 or simply the side; that which is opposite to this, which ought for tliat 

 reason to be called the posterior edge, is called the internal edge, be- 

 cause in the Noctuma with roofed wings it is in contact with the body, 

 fn the second, the edge which we have called the costal or superior is 

 generally designated by the name of the external or anterior edge. Fi- 

 nally, that which is in contact with the abdomen is called the abdominal 



* Dr. Boisduval making considerable use of these nnrviiros in his system of 

 classification here gives a minute account of them which we may, at some future 

 time, furnish for the readers of the Journal. — Tr. 



t Kirb}- and Spence call them arcotcl^. — Tk. 



