INTRODUCTION. 



The collection of fishes in alcohol includes about 450 species and is 

 composed of the following elements: Fishes of Alaska, species found in 

 the Gulf of Mexico and East Florida, the genera of fresh- water fishes 

 of the United States and Alaska, and the salmonoids of North America, 

 exclusive of Greenland. 



It was originally intended to add to the above the fishes of the Pacific 

 coast of the United States and those of New England; but, as the 

 amount of labor involved in the preparation of an exhibit so extensive 

 would have been too great for the time allowed, it was thought best to 

 limit the work as indicated above, especially as the New England spe- 

 cies and those of our west coast have already been extensively dis- 

 tributed to museums in Europe. 



The species exhibited at this time constitute nearly one-third of the 

 whole number known to exist in North America north of Mexico. They 

 are almost exclusively littoral species or those occurring in moderate 

 depths. 



In selecting the representatives of the fresh-water genera, I have en- 

 deavored, whenever possible, to obtain the type species of the genus 

 and one of the types of the species. When this could not be spared, I 

 have taken individuals identified by Professor Jordan and afterward 

 verified by myself by means of the original descriptions and those pub- 

 lished by Jordan and Gilbert in Bulletin No. 16, U. S. National Museum, 

 and elsewhere. It is hoped, therefore, that the names employed to des- 

 ignate species may be relied upon as properly belonging to them. In 

 some cases 1 have treated as distinct species certain forms which are 

 now included under one name by other writers ; this course seemed to 

 me to be justified by the material examined, and will, doubtless, stand 

 or fall upon its merits. 



As to the specific names used, they are supposed to be the oldest legiti- 

 mate ones. In the interpretation of generic characters I cannot always 

 agree with some of my contemporaries, and these differences of opinion 

 are reflected in the names employed. 



The principal common names of the species are given in some detail; 

 it is impracticable to fix upon any one appellation which is everywhere 

 applied to a species ; indeed, names of widely different signification are 

 attached to fishes in the various portions of their habitat. 



It is attempted to state the geographical distribution of species as 

 fully and clearly as our knowledge of the literature and the fishes will 

 permit. In many instances the limits of a species are not definitely 



[3] . 389 



