Plate 33. 



CRICKETS AND MAY-FLIES. 

 I and 2 afford illustrations of the excessive development of " ornament " ; 

 fig. 3 of devices for seizing the female ; figs. 4 and 5 of unaccountable 

 differences in the development of wings. 



1. The Pneumatic Cricket (Pneumora scutellaris), showing the strange 

 markings on the female. 



2. The Cleft-footed Burrowing Cricket (Schizodactylus monstrosus). 



3. The Giant Alder-fly {Corydalis crassicornis), with its huge jaws for 

 grasping the female. 



4. The Stone-fly (Perla maxima), the large-winged Continental form. 



5. Loch Tanna Stone-fly {Isogenus nubecula), male, with vistigial wings. 



[Face page 220, 



