SEXUAL SELECTION 



377 



to the same family, we meet with a new and remarkable 

 modification; in the males a small notched ridge projects 

 obliquely from each side of the abdomen, against which the 

 hind femora are rubbed." As the male is furnished with 

 wings (the female being wingless), it is remarkable that the 

 thighs are not rubbed in the usual manner against the wing- 



Fio. 15. — Pneumora (from specimens in tlie British Museum). Upper figure, male; 



lower fi^rure, female. 



covers; but this may perhaps be accounted for by the 

 unusually small size of the hind-legs. I have not been able 

 to examine the inner surface of the thighs, which, judging 

 from analogy, would be finely serrated. The species of 

 Pneumora have been more profoundly modified for the sake 

 of stridulation than any other orthopterous insect; for in the 

 *^ Westwood, "Modern Classification," vol. i. p. 46!. 



