PREFACE. 



In submiting the following pages to the 

 scientific world, although I do so knowing their 

 many shortcomings, I trust there is sufficient 

 that is new to make amends for any slight 

 inaccuracies, which could, perhaps, hardly have 

 been avoided, since so little has been done to 

 pave the way for the present investigation. 



The Plates, which form no inconsiderable 

 feature in this Work, have been carefully executed 

 on copper, by myself; andj have spared no 

 trouble to make them as perfect as possible. 



I have endeavored to give prior authorities 

 for my statements as often as possible, except 

 when the facts are well known, but much 

 work upon the anatomy of insects is so scattered 

 that it has often not been in my power to discern 

 whether I am entitled to priority of discovery. 



