PREFACE. 



In undertaking the present work I was not fully aware of the many difficulties 

 attending it — indeed they could hardly have been anticipated. With an immense 

 mass of materials, without libraries to refer to, and only defective museums for 

 comparison, I have constantly been in fear of describing animals as new that 

 have long been known to European Naturalists. In no department of American 

 Zoology is there so much confusion as in Herpetology. This is to be traced 

 partly to the earlier Naturalists, partly to the practice of describing from 

 specimens preserved in alcohol, or from prepared skins. I have endeavoured to 

 avoid error in this respect, by describing in almost every instance from the living 

 animal, and often after a comparison of many individuals. 



I consider myself fortunate in having secured the assistance of so good an 



artist as Mr. J. Sera, an Italian by birth, but long resident in the United States, 



who has caught the character and attitude of the animals with singular felicity. 



The colouring of the plates may be fully relied on, as almost every one was done 



from fife; and when coloured from dead animals, it is always mentioned in the 



description, so that no one may be deceived. 

 Vol. I.— 2 



