INTRODUCTORY NOTE. 
The accompanying plates of fresh-water fishes were drawn by Mr. Sonrel 
under the direction of Professor Agassiz and Professor Baird as early as 1849, 
and were intended for use in a Monograph of the fresh-water Fishes of North 
America projected by the Swiss naturalist and the young Assistant Secretary 
of the Smithsonian Institution, to be prepared under their joint authorship. 
The work was never completed, the attention of each of the partners having 
been diverted to other subjects. An edition of 1,000 copies of these plates 
was printed, and, after the lapse of nearly forty years, it seems desirable to 
distribute them to the libraries. Their interest is mainly of a historical char- 
acter, and the accompanying text, prepared by President Jordan, is limited 
to a brief explanation of the figures. 
G. BROWN GOODE. 
SmrirHsoNIAN InsTITUTION, 
March 22, 1889. 
