1228 REPORT OF NATIONAL MUSEUM, 1898. 



VI. THE TOLTECAN SUBREGION. 



This subregion includes three districts which possess characteristic 

 species and whicli differ iu climate. The Austr oriental is a humid 

 region, with abundant rains and fogs, and includes the eastern face and 

 slope of the central plateau, with the mountain elevations, including 

 parts of the States of Puebla, Vera Ornz, Hidalgo, and San Luis 

 Potosi. It is cut off to the north from the Austroriparian subregion by 

 an interval in the States of ISTuevo Leon and Tamaulipas. The middle 

 or Anstrocentral district includes the valleys of Mexico and Toluca, 

 and the region northward to the edge of the Sonoran subregion, includ- 

 ing the State of Guanajuato, and perhaps farther north. The climate 

 of this district is much less humid than that of tlie Austroriental dis- 

 trict. The Anstroccidental district includes the high lauds of Oaxaca, 

 Guerrero, Michoacan, and Jalisco. It is the most arid of the three 

 divisions and extends farthest to the south and west. 



The northern boundary of the Toltecan subregion is not yet determina- 

 ble; hence it is not possible to state whether species from the States 

 of Durango and Zacatecas, such as Eutwnia angustirostris, should be 

 referred to it or not. A small collection made by Wilkinson in south- 

 ern Chihuahua at Batopilas^ has the character of the Chihuahuan 

 fauna, with the following species not otherwise found in it: 

 Anolis nehnlosus Wiegmann. 

 Uta hicarinata Dumeril. 

 Scolecophis (vmnlus Co])e. 



The humid and dry districts of the Toltecan subregion repeat in petto 

 the differences between the Austroriparian and Sonoran subregions. 

 The Austroriental district is distinguished by the larger number of 

 batrachian genera and species and of certain genera of Crotalidte. It 

 also includes some genera which may be regarded as immigrants from 

 the Central American region of the Neotropical realm. 



The characteristic species of the Austroceatral district are:^ 



URODELA. 



Sired on mexicanum Shaw. 

 Amblystoma tigrinum Green. 



SALIENTJ.A. 



Bufo compactilis Wiegmann. 

 Bufo intermedins Giinther. 

 Spea multipUcata Cope. 

 Spea hammondii Baird. 

 Hyla exiniia Baird. 

 Hyla arenicolor Cope. 

 Rana montezuniae Baird. 



1 Cope, Proc. Amer. Phil. Soc, 1879, p. 261. 



2 For the exact liabitat of several of these I am indebted to the important papers 

 of Dr. A. Duges, iu La Naturaleza, 1888, p. 97, and 1896, p. 3. 



