DISTRIBUTION OF THE FRESH-WATER FISHES 

 OF MEXICO. 



SETH EUGENE MEEK. 



Mexico consists of a high plateau bordered on each side by a 

 narrow coastal plain. It lies between the United States and 

 Central America, but is not separated from either by natural 

 boundary lines. The southern half of this country lies in the 

 torrid zone, the rest in the North Temperate. Its geographical 

 position, its elevation and diversity of climate make it, from a 

 biological standpoint, a most interesting country. The Rocky 

 Mountains extend into the northern United States as a single 

 range to the Yellowstone Park. Here is given off to the west 

 the Wasatch range, which extends south into Mexico as the 

 western range of the Sierra Madre. The Rocky Mountains 

 proper become in Mexico the eastern range of the Sierra Madre. 

 These two mountain ranges include a plateau, the elevation of 

 which varies from three to eiirht thousand feet above the sea- 



is built the City of Mexico, while the two m« 

 minate in the famous peaks of [xtaccihuatl 

 The valley of Mexico though at one time it 

 into the Lerma now comprises a drainage > 

 The great central plateau comprises the largi 

 On the east and the west is a low narrow pk 

 ascent to the plateau is steep. South of tht 

 the mountains extend as one range through C < 

 become the Andes in South America. The R 

 general is a treeless plain, covered with only a 

 The ^ Yucca, the Mesquite, various speck? 



growth of various species of grasses, comprise 

 the vegetation of this region. During the ra 



