VI IXTKODCCTION. 



1. Principal Faunal Woeks on the Feesh-water Fishes of Mexico and 



Central America. 



The fresh-Avater fishes of Mexico and Central America are included in Jordan and 

 Evermann's great work on the fishes of North and Middle America (Bull. U.S. Nat. 

 Mus. xlvii. 1896-1900), which is, however, so far as the Central- American fresh-water 

 fish-fauna is concerned, rather a compilation than a critical revision ; and necessarily so, 

 seeing that the majority of the types are preserved in the British Museum and a large 

 proportion of the remainder at Vienna. Dr. S. E. Meek has recently made extensive 

 collections in Mexico, and has published an account of the fresh-water fishes of Mexico 

 north of the Isthmus of Tehuantepec (Publ. Columbian Mus., Zool. v. 1904) based on 

 his own material. Of other works dealing with Mexican fresh-water fishes we may 

 mention Girard's valuable report on the fishes collected during the United States and 

 Mexico boundary survey, published in 1859, Steindachner's report on a collection 

 from the Lerma Basin and the Valley of Mexico (Denkschr. Ak. Wien, Ixii. 1895), and 

 a paper by Jordan and Snyder dealing with fishes irom the same region (Bull. 

 U.S. Fish. Comm. xix. 1900). 



Dr. Giinther's memoir on the Fishes of Central America (Trans. Zool. Soc. Lond. 

 v\. 1868) is still the best account of the fresh-water fishes of this region, and it is 

 remarkable how little our knowledge of them has been increased since its publication. 

 It was preceded by Kner and Steindachner's account of a collection from Panama 

 (Abhandl. Bayer. Ak. x. 1864), and the only important contributions since are by Gill 

 and Bransford on the fishes of Lake Nicaragua (Proc. Ac. Philad. 1877), Steindachner 

 rai those of the Eio Mamoni, Panama (Denkschr. Ak. Wien, xli. 1879), and two recent 

 papers by Meek, one on the fishes of Lakes Managua and Nicaragua, the other describing 

 collections from Guatemala and Costa Rica (Publ. Columbian Mus., Zool. vii. 1907). 



2. Principal Collections described in this Work. 



The present account is based on the specimens preserved in the British Museum, 

 including the actual types of a large proportion of the species and co-types or 

 authenticated examples of many others. 



First in importance are the large collections made in Central America by Messrs. F. 

 D. Godman and O. Salvin and Capt. J. M. Dow during the years 1859-1865, which 

 formed the basis of Dr. Gunther's report. 



Next to these must be placed a fine series of Mexican fishes received from the Field 

 Museum of Natural History, Chicago, in 1905, including examples of many of the 

 species recently described by Dr. Meek. 



