228 



The Orders of Insects 



elongate and grooved on their inner surfaces, so as 

 to form, when in apposition, a sucking-tube. The 

 palps of the first maxillae are sometimes present; those 

 of the second, nearly always. The segments of the 

 fore-body are firmly united together, the pronotum 

 is small and bears a pair of erectile plates, the patagia; 

 the meso- and meta-scuta form the greater part of the 



.-r 



Fig. 125. — Wing-neuration in a Cossid Moth. II. Sub-costal ; III. radial; IV. 

 median; V. cubital; VI. VII. VIII. anal nervures. From Quail, Natural 

 Science, vol. 13. 



thoracic skeleton dorsally. A pair of small scales — 

 the tegula; — overlapping the bases of the forewings 

 are borne on the mesothorax. The forewings are 

 larger than the hindwings, but the latter have in 

 most cases a better developed anal area than the 

 former. The neuration is predominantly longitudinal. 

 In a typical lepidopterous wing there are (fig. 125, H) 

 a simple, unbranched sub-costal nervure ; (III) a five- 

 branched radial nervure j (IV) a three-branched median 



