iv CONTENTS. 



CHAPTER X. 



Page. 



The Diodonti ........ 99 



CHAPTER XI. 

 Some Grave Diggers [Cerceris and Pfiilanthus) . . 108 



CHAPTER XII. 

 The Spider Ravishers {Pomjnlns and Agenia) . . 125 



CHAPTER XIII. 

 The Enemies of the Orthoptera . . . .167 



CHAPTER XIV. 

 The Mud- Daubers (Pelopaeus) . . . . .176 



CHAPTER XV. 



Extracts From Marchal's Monograph on Cerceris or- 



NATA 200 



CHAPTER XVI. 

 On the Sense of Direction in Wasps . . . .211 



CHAPTER XVII. 

 The Stinging Habit in Wasps 220 



CHAPTER XVIII. 

 Conclusions ..... . . 228 



