INTRODUCTION. 



I HAVE, in offering a third volume of the North American Herpetology to the 

 pubUc, to acknowledge many services rendered me by the following gentlemen. 



To Dr. Harlan I am indebted for the free use of his private collection of 

 reptiles, his library, &c. 



Drs. S. J. Morton and E. Hallowell, of Philadelphia, have also materially 

 assisted me in some interesting anatomical investigations, which will appear in 

 the last volume. 



To Dr. W. Blanding, formerly of Camden, S. C, but now of Philadelphia, I 

 am also greatly obliged for sevex'al undescribed reptiles, from the south as well 

 as the west; especially for a new and beautiful specimen of Cistuda. 



To Professor Green, also of Philadelphia, I am indebted, not only for much 

 information on the reptiles generally, but for the use of his library, museum, and 

 many valuable unpublished notes on the Salamanders. 



I have to offer my thanks also to Drs. Binney and Storer, of Boston, for 

 having furnished me with several new Salamanders, together with some curious 

 remarks on their habits; and to Dr. Dekay, of New York, who has communicated 



