AN ANNOTATED CHECKLIST AND KEY 

 TO THE AMPHIBIA OF MEXICO 



By Hob ART M. Smith and Edward H. Taylor 



INTRODUCTION 



A NEW era in the study of Mexican herpetology was initiated in 1932, 

 a year marked first by the appearance of Dr. Remington Kellogg's 

 "Mexican Tailless Amphibians in the United States National Mu- 

 seum," ' a work of fundamental importance; and second, by the renais- 

 sance of intensive field exploration in Mexico. 



Since 1932 the number of amphibians in collections from Mexico has 

 increased about a thousand percent, and the number of recognizable 

 forms more than a hundred percent. For example, Kellogg recog- 

 nized 65 species of anurans, basmg his study upon some 2,200 speci- 

 mens. We recognize 161, represented by collections totaling about 

 25,000 specimens. 



The salamanders of Mexico have never been treated fully, although 

 Dr. E. R. Dunn's "The Salamanders of the Family Plethodontidae," 

 which appeared in 1926, summarized over half the salamander fauna, 

 67 percent of which (by number of forms) is comprised by members of 

 the family Plethodontidae (as of today). Dunn recognized 15 forms 

 in 291 Mexican specimens; we list 43 forms, represented by some 9,000 

 specimens, and of all salamander groups combined 64 forms and 15,000 

 specimens. We are acutely aware that much revisionary work is still 

 to be done in Mexico and in adjacent areas. Several genera and species 

 obviously are polyphyletic assemblages; the study of some, like Rana 

 pipiens, is beset with the difiiculties of tremendous variability, wide 

 range, and larger quantities of material than can easily be handled. 

 Satisfactory solutions to many problems await collections from critical 

 areas, and no doubt numerous species and subspecies remain to be 

 discovered and defined. Probably many of the forms we regard as 

 species will ultimately be regarded justifiably as subspecies. How- 

 ever, assumption of subspecific status for geographically separated 

 species (as we consider them) should be undertaken with temerity, as 

 witness the implications of Moore's recent work by which some widely 



> U. 8. Nat. Mus. BiiU. 160, 1932. 



