6 BULLETIN 189, UNITED STATES NATIONAL MUSEUM 



The extensive collections from Panama Bay and from Baja Cali- 

 fornia in the U. S. National Museum have been used freely and have 

 proved very valuable in the study of the variation and relationship of 

 many species discussed in this catalog. 



ACKNOWLEDGMENTS 



Most excellent cooperation, often direct help, and innumerable 

 courtesies were extended to me by my fellow workers in ichthyology, 

 and by many other friends. My sincere appreciation and deep grati- 

 tude are hereby expressed to everyone who has contributed to the 

 prosecution of this work, which I can only hope will prove worthy of 

 the efforts expended on it. To the secretary of the Smithsonian Institu- 

 tion, Dr. Alexander Wetmore; to the head curator of biology in the U. S. 

 National Museum, Dr. W. L. Schmitt; and to the curator of fishes in 

 the same institution, Dr. L. P. Schultz, in whose division the catalog 

 was prepared, I am deeply indebted. Without constant use of the 

 national collections the work of necessity would have been less com- 

 plete. To M. J. Lobell, who as biologist of the Mission to Peru col- 

 lected most of the specimens furnished by the Mission and whose field 

 notes concerning the specimens were placed at my disposal, a word of 

 commendation is due. Miss Jane W. Roller prepared the drawings of 

 the new species described and assisted the author in many other ways, 

 and Luis Revas kindly checked the local names. 



EXPLANATIONS 



In the sequence of the families the British Museum (Natural His- 

 tory) classification (see Regan, in Encyclopaedia Britannica, ed. 14, 

 vol. 9, 1929, pp. 305-328), except for minor changes, has been followed. 



Synonymies and references. — No attempt has been made to provide 

 complete synonymies. However, a reference to the original descrip- 

 tion of each species, together with the type localities, is included. All 

 publications containing records of Peruvian fishes that have come to 

 my attention have been cited. Furthermore, a work of a general 

 nature containing fairly complete synonymies generally also has been 

 cited for each species. 



Under the synonymies, as well as in the text, references have been 

 cited by giving the last name of the author or authors, the year of 

 publication, and generally the page number. The complete refer- 

 ences are given in the Bibliography. With each reference the localities 

 furnishing the basis for the record are listed, followed by a few words 

 in parentheses, which in a general way show what is contained in the 

 account cited. If only a name is given in the publication cited, without 

 comments of importance, parenthetical remarks are omitted. 



The local names used either were fm-nished by the Mission or were 

 taken from publications on Peruvian fishes. 



Sequence of characters used in the descriptions. — The sequence of 



