vi Field Columbian Museum — Zoology, Vol. V. 



and for his many courtesies which resulted in considerable substantial 

 aid. I would also mention Mr. D. W. Hedrick, who was superin- 

 tending the construction of the bridges along the Vera Cruz & 

 Pacific R. R. Mr. Hedrick gave me the freedom of the bridge 

 camps, which proved to be excellent stopping places in that country. 

 The superintendents of these camps were very helpful to me in my 

 work while there. At Perez I met Mr. Julius Freisser, formerly a 

 taxidermist in Chicago, who assisted me in making collections of 

 fishes at Perez, Obispo, and El Hule. In general the railroad and 

 other employees of the organizations mentioned above were very 

 courteous and helpful to me in my work. 



Dr. Barton W. Evermann and Mr. Barton A. Bean have assisted 

 me in examining material in the U. S. National Museum. Dr. G. A. 

 Boulenger and Mr. C. T. Regan have done the same in the British 

 Museum, Dr. D. S. Jordan in Stanford University, and Mr. Henry 

 W. Fowler in the Academy of Natural Sciences, Philadelphia. Dr. 

 Theo. Gill, Washington, D. C, has kindly called my attention to 

 a few important references which I would have otherwise omitted. 

 Hon. Geo. M. Bowers, United States Commissioner of Fish and Fish- 

 eries, kindly loaned the Museum thirty-one original drawings of fishes 

 for use in illustrating this work. Four other drawings were kindly 

 loaned by Dr. Richard Rathbun. To Dr. Evermann I am under 

 obligations for superintending the making of blocks from these draw- 

 ings, and also for reading the proof sheets while this work was 

 going through the press. Dr. Wm, Owen, of the University of Chi- 

 cago, and Prof. H. N. Hoffman, of Indiana University, also rendered 

 me valuable service in correcting the misspelled names of Rafinesque 

 and others. Dr. Frederick Starr, of the University of Chicago, has 

 also kindly revised the proof sheets of this paper with regard to the 

 spelling of geographical names. I also desire to acknowledge the 

 many courtesies I received from Hon. Powell Clayton, U. S. Minister 

 to Mexico, while doing field work in Mexico in 1901 and 1903. In 

 making these acknowledgments I wish to assume responsibility for 

 whatever errors this volume may contain. 



In the present paper it has been my purpose to give a descriptive 

 list of the fresh -water fishes of Mexico, and keys to assist in identifying 

 the same. It is impossible to draw an arbitrary line separating the 

 fresh-water fishes from those of the salt water. A few of the species 

 of Pomadasys, Achirus, Gobius, and the like, included in this work, 

 are properly salt-water fishes. I have listed them here rather as fishes 

 found in fresh water. 



In the preparation of this publication I have examined every 

 paper to which I have had reference and access that throws light on 



