INTRODUCTION 



A CHECK LIST of North American Amphibians and 

 Reptiles has long been wished for by all students of 

 American Herpetology. This list has been prepared gen- 

 erally upon the lines of the American Ornithologists' Union 

 Check List of Birds, and following that example, it has in- 

 cluded the species and subspecies which the authors deem 

 valid ^ and of certain occurrence in North America, north of 

 the Rio Grande, and in Lower California, Mexico. Miller's 

 List of North American Land Mammals (Bull. U. S. Nat. 

 Mus., No. 79, 1912) has also been a valued guide. 



This volume is the result of lists begun some years ago 

 independently by both authors. The arrangement is on 

 the following system: The higher groups and genera are 

 in systematic sequence, the species are in alphabetic order. 

 No attempt is made to give synonyms. Species not listed 

 are believed to be invalid. The citation of original appear- 

 ance of names is given for all except such (e. g., family 

 names) as are formed automatically. Following the citation 

 of the original description of each species comes the place of 

 first appearance of the name in its present combination — 

 accurate in so far as we have been able to determine. Refer- 

 ences are added to Cope's North American Batrachia and 

 to his Crocodilians, Lizards, and Snakes of North America. 

 Both are frequently erratic and inaccurate, but large and 

 excellent portions of both works are to a great extent from 

 the pen of S. F. Baird, as painstaking an investigator 

 as this country has produced. These monographs are in 



> By this statement it is not meant that the authors in all cases have verified the status of a number 

 of more recently established forms by critical study. The judgment of reliable workers has been 

 accepted where no special reason appeared to contraindicate the validity of the form. As for the ad- 

 mission of subspecies — or rather tri nominal designation — for certain forms no special attempt has 

 been made at con.sistency, the authors on principle leaning towards binominals in all cases where the 

 need of trinominals has not been clearly established. 



