Ampbibians aiul Reptiles of Mexico. 297 



largely volcanic in nature. In tlie heart of tlie ränge lies the 

 Lagima de Catemaco, one of the few large lakes in the Republic. 

 The lake is several miles in diameter and lies in a deep basin and 

 is siirroimded by sharp conical elevations of several hundred feet. 

 The bottom consists of volcanic debris in the form of small and 

 large fragnients, and there are several large rock Islands. It has 

 the appearance of being a very large crater lake, and the surrounding 

 elevations are apparently snbsidary cones of the extinct volcano. 



C 1 i m a t e. 



The region lies within the tierra caliente of Hann and Calveet's ^) 

 Zone III — the zone characterized by a mean annual temperature 

 of 68—77" F. As said before, the elevation of the piain is about 

 15 raeters. 



The nearest stations where meterological observations have been 

 made are San Juan Evangelista (88 m) and Acayucan (158 m). 

 According to the table given by Calvert '^), the mean annual 

 temperature for a period of five years is for the former 74,3** and 

 for the latter 76,1'-. It is safe to conclude that the mean annual 

 temperature of Cuatotolapam is very close to 75'\ This places the 

 region climatologically (cf. Calveet's map) very near to ('alvert's 

 Zone II, and it might be considered to be intermediate in respect 

 to climate. According to Mr. La Rue, the hottest months are April 

 and May, and the coldest January and February. 



We recorded the temperatures for forty days at Cuatotolapam 

 (July 10 to August 18) and these may be summarized as follows: 



Maximum and Minimum Temperatures for 

 July and August, 1910. 



1) in: Proc. Acad. nat. Sc. Philadelphia, 1908, p. 474. 



2) in: U. S. VVeather Review, 1908, p. 93—97. 



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