THE AMPHIBIANS AND REPTILE'S OF THE SIERRA NEVADA 

 DE SANTA MARTA, COLOMBIA 



Bv Alexander G. Ruth vein 

 ( With a description of the region by ^f. A. Carriker, Jr.) 



Introduction 



The explorations of the University of Michigan in the Santa Marta 

 region have had as the principal object the study of the distribution of 

 several groups of animals abundant in the tropics. It is believed that 

 geography should be emphasized by museums, that the most reliable results 

 at the present time are to be obtained by the study of the distribution of 

 particular groups by persons acquainted with these groups systematically, 

 and that certain problems can best be studied in particular regions. 



The groups which have received principal attention in the study of 

 the Santa Marta region are the Formicidae, Amphibia, and Reptilia. Con- 

 siderable work has been done on the Crustacea, and rather extensive col- 

 lections have been made in other groups, but the ants, amphibians, and 

 reptiles are the groups studied in sufficient detail to permit of the drawing 

 of general conclusions upon the distribution. This paper contains descrip- 

 tions of the field work and the region studied and a discussion of the 

 distribution of the amphibians and reptiles. 



The Field Work 



The specific problems in the distribution of the reptile-amphibian fauna 

 of the Santa Marta Mountains region which were to be investigated were 

 two: to determine more exactly the nature and place of the changes in the 

 fauna which evidently take place in western Venezuela or eastern Colombia, 

 and to obtain more data on the responses of these groups to changes in 

 altitude. It is probably well known to herpetologists that a number of 

 reptiles and amphibians found in northern Venezuela do not occur in west- 

 ern Colombia and that a number of northern Colombian species do not 

 occur in Venezuela, but there has been no evidence of the nature and 

 extent of the changes in the faunas nor data by which the place could be 

 more accurately fixed. Besides being in the general region of the above- 

 mentioned faunal change, the Santa Marta Mountains seemed to offer 

 exceptional opportunities for studies in the altitudinal distribution of rep- 

 tiles and amphibians. The abrupt rise from sea level to heights perennially 

 covered with snow and the tropical location of the region promised a 

 considerable faima and sharply delineated distributions. 



The first expedition was sent to the region in 1913. The party, con- 

 sisting of A. S. Pearse, F. M. Gaige, and the writer, spent eight weeks, 



