IV PREFACE. 



In conclusion, I wish to say that as every one is liable 

 to mistakes, I hope that my readers will look leniently 

 upon them, should they find any. I can only hope that 

 they may prove- to be "exceeding few." I would add 

 that I have followed the classification given by Dr. Elliott 

 Coues in his " Key." 



c. B. c. 



