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 every instance from the living animal, and often 

 after a comparison of many individuals. 



t consider myself fortunate in having secured the assistance of 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. His figures are the 

 more valuable, from being all taken from life. 



In presenting the first volume of North American Herpetology, I have to return 

 my thanks to those gentlemen who have aided me in the undertaking — and 



