xxx FIELD COLUMBIAN MUSEUM ZOOLOGY, VOL. V 



Rio Verde, San Luis Potosi; Rio Verde, collection made by W. L. Tower, 



August. 



Lerma, Mexico; Rio Lerma, March 17 and 18. 

 City of Mexico, Mexico; Viga canal, March 20. 

 Chalco, Mexico; Canals, April 19. 

 Cuautla, Morelos; Rio Cuautla, March 25. 

 Yautepec, Morelos; Rio Yautepec, March 27. 

 Jojutla, Morelos; Rio Apatlaco, March 28. 

 Puebla, Puebla; Rio Atoyac; April 4 and 18. 

 Atlixco, Puebla; tributary of the Rio Atoyac, April i. 

 Matamoras, Puebla; Rio Atila, April 2. 

 Chietla, Puebla; Rio Coetzala, April 3. 

 Jalapa, Vera Cruz; Rio Sordo, March 13. 

 Xico, Vera Cruz; Rio Texcolo, March 12. 

 San Francisco, Vera Cruz; Rio San Francisco, March 10. 

 Vera Cruz, Vera Cruz; small creek north of the city, March 9. 

 Boca del Rio, Vera Cruz; Boca del Rio, March 7. 

 Cordoba, Vera Cruz; Rio Blanco, April 6. 

 Rio Blanco, Vera Cruz; Rio Blanco, March 5. 

 Otopa, Vera Cruz ; Rio Otopa, March 4. 

 Motzorongo, Vera Cruz; Rio Motzorongo, April 9. 

 Refugio, Vera Cruz; Rio Tonto, April 10. 

 El Hule, Oaxaca; Rio Papaloapam, April 22. 

 Obispo, Oaxaca; Rio Obispo, April 24. 



Perez, Vera Cruz; Rio Tesechocan, March i and 2, and April 23. 

 San Juan Evangelista, Vera Cruz; Rio San Juan Evangelista, Feb. 27. 

 Sanborn, Vera Cruz; tributary of Rio Coatzacoalcos, February 22. 

 San Geronimo, Oaxaca; Rio San Geronimo, February 26. 

 Tehuantepec, Oaxaca; Rio Tehuan tepee, February 25. 



THE RIVER SYSTEMS OF MEXICO AND A LIST OF FISHES 

 KNOWN FROM EACH. 



RIO GRANDE SYSTEM. 



From El Paso, Texas, east to the Gulf of Mexico the Rio Grande 

 forms the boundary between Mexico and the United States, therefore 

 only this portion of the river and its southern tributaries are con- 

 cerned in the drainage of Mexico. In the Rio Grande system 

 is included the numerous small independent streams and lakes east of 

 the Sierra Madre Mountains in Chihuahua and Durango, for these 

 were, no doubt, at some former period tributaries to the Rio Grande. 

 This portion of the Mexican plateau in general is a treeless plain with 

 a scant vegetation. The yucca, the mesquite, various species of 

 cacti, sage brush, a few stunted cedars and the like, together with a 

 sparse growth of various species of grasses, comprise the larger part 

 of the vegetation of this region. During the rainy season, and a 

 short time after it, there is promise of a luxuriant growth of plant 



