Table of Contents xv 



PAGE 



The formation of the bridge 230 



The intercalary veins 232 



The supplements 234 



The antenodal cross-veins 235 



The postnodal cross-veins 236 



The arculus 236 



The triangle of the Anisoptcra 236 



The supertriangle 237 



The anal veins 237 



The anal crossing 237 



The secondary anal veins 239 



The basal anal area > 239 



The cubital area 239 



The anal triangle 239 



The membranule 239 



The chief cubito-anal cross- vein 239 



The subtriangle 239 



The anal loop 239 



The supplemental anal loop 240 



The cubito-anal or foot-shaped loop 240 



The cubital supplement 240 



The quadrangle of the Zygoptera 240 



The subquadrangle of the Zygoptera 241 



(c) The methods of specialization of the wings of the Odonata 241 



{d) Comparison of terminologies of the wing-veins of the Odonata 242 



CHAPTER XII 

 The Wings of the Plecoptera 



(a) The more general features of the wings of the Plecoptera 243 



{b) The tracheation of the wings of the Plecoptera 243 



(c) The classification of the Plecoptera 244 



(d) The special features of the wings of the Plecoptera 245 



The anastomosis or the transverse cord 247 



The pterostigma 247 



The basal anal cell 247 



(e) The primitive plecopterous type of wings 248 



(/) The methods of specialization of the wings of the Plecoptera 254 



Specialization by reduction 254 



Specialization by addition 255 



CHAPTER XIII 



The Wings of the Corrodentia 258 



CHAPTER XIV 



The Wings of the Embiidina 262 



CHAPTER XV 



The Wings of the Thvsanopteka 267 ■ 



