CHECKLIST OF THE AMPHIBIA OF MEXICO 3 



will be subjected to individual attention at leisure. The present list 

 takes a step toward such general review by providing a brief survey 

 of the present status of Mexican forms and a concise analysis of recent 

 advances, to which additions and emendations may be made readily. 



In preparing this summary we have followed, with some exceptions, 

 the style of our "Annotated Checklist and Key to the Snakes of 

 Mexico." ^ The present account differs chiefly in the natural arrange- 

 ment of the species and in the distribution of the keys, which instead 

 of being united are scattered through the list in appropriate places. 

 The keys are to transformed specimens, except where otherwise 

 indicated, since the larvae are too incompletely known to permit the 

 construction of useful keys. Lilvewise the eggs of relatively few 

 forms are known. Juvenile transformed specimens will not be 

 identifiable in all cases, since important characters may nob be evident 

 in them. 



For the sake of brevity we have indicated the E. H. Taylor-H. M. 

 Smith collection by the abbreviation EHT-HMS. 



Class AMPHIBIA Linnaeus 



Amphibia Linnaeus, Systema naturae, ed. 10, vol. 1, 1758, p. 194. 



KEY TO MEXICAN ORDERS OF AMPHIBIA » 



1. One or two pairs of limbs present; no scales 2 



No limbs present; animals with slender, elongate, annulated, wormlike 

 bodies; scales hidden in skin Gyranophiona (p. 3) 



2. Animals with elongate bodies; hind legs not or slightly larger than fore; 



a tail present in larvae and adults; neotenic forms sometimes occur- 

 ring; 2 or 4 limbs Caudata (p. 5) 



Animals with greatly shortened bodies; hind legs much stouter than fore- 

 legs; tail absent in adult; no neotenic forms; always 4 limbs. Salientia(p. 33) 



Order GYMNOPHIONA Muller 



Gymnophiona Mtjller, Zeitschr. Phj^siol., vol. 4, 1832, p. 24. 



Family CAECILIIDAE Gray * 



Caeciliadae « Gray, Ann. Philos., ser. 2, vol. 10, 1825, p. 217. 



2 U. S. Nat. Mus. Bull. 187, 1945. 



» Characters used in all cases apply to Mexican forms. These may not apply universally. 



* Despite rather remarkable skull differences, all living forms of the order Gymnophiona have been 

 recognized under a single family. 



» Cited as Coeciliidae by Gray in 1850, Catalogue of the Batrachia Qradientia of the British Museum, 

 p. 56; first use of present orthography, Caeciliidae, by Cope, Amer. Nat., vol. 23, 1889, p. 862. 



