Fig. 1 in Observations on Garter Snakes of the Thamnophis eques Complex in the Lakes of Mexico's Transvolcanic Belt, with Descriptions of New Taxa

Fig. 1. Areas of lakes and interior drainage of the transvolcanic belt (axis) of Mexico as they existed before the coming of the conquistadors circa A.D. 1500. Adapted from the excellent map serving as figure 4 (p. 108) in the first volume of the Handbook of Middle American Indians, Robert Wauchope, general editor, in a section on hydrography by Jorge L. Tamayo in collaboration with Robert C. West, and published by the University of Texas Press in 1964. The eight lakes from which samples of Thamnophis eques are available for this study are shown in boldface type. Other lakes and two ancient capitals are indicated by circles containing numerals as follows: 1 Sayula, 2 Zapatlán, 3 Guadalupe, 4 Magdalena, 5 Tacumbo, 6 Jaripeo, 7 Zirahuén, 8 Tzintzuntzan the Tarascan capital, 9 Zumpango, 10 Tenochtitlán the Aztec capital, 11 Xochimilco, 12 Xaltocan, 13 Texcoco, 14 Chalco, 15 Apam, and 16 Tepeyahualco.