THE AMERICAN CHAEACIDAF, 1 



INTRODUCTION. 



The revision of the American Characidae, based on the collections of the 

 Nathaniel Thayer Brazilian Expedition in the Museum of Comparative Zoology 

 was commenced by Mrs. Rosa Smith Eigenmann and myself in 1888. A little 

 more than a year later the work was temporarily suspended. The published 

 results, so far as obtained, are enumerated on p. 8-10. Work was resumed 

 in 1903 with the collections of Indiana University and of the United States "* 

 '■ National Museum, and a monograph completed in 1906. 



Types in several museums in London, Paris, and Vienna were examined in 

 1906 and 1907. In 1907 the study of the collections made by the Thayer Expe- 

 dition was renewed. This material made it necessary to rewrite the entire 

 monograph, for, forty years after it was gathered, it was still the most impor- 

 tant collection of South American fresh-water fishes, and contained a large number 

 of undescribed species and genera. 



The revised monograph, through the Tetragonopterinae, was finished in the 

 spring of 1908. During the preparation of this revision it became apparent that 

 the material at my command, from several regions of South America, was 

 deficient. To obtain material from one of these regions, I spent the autumn of 

 1908 in British Guiana. Volume 5 of the Memoirs of the Carnegie Museum 

 contains a detailed account of this Guiana Expedition. 



In May, 1909, my position of Curator of Ichthyology in the Carnegie Mu- 

 seum placed me in charge of another large series of South American fresh-water 

 fishes. This collection was made under my general direction, between November 

 6, 1907 and January 10, 1910, by Mr. John D. Haseman, one of my former 

 students. For the most part it came from areas not covered by the Thayer 

 Expedition. The Director of the Carnegie Museum, Dr. W. J. Holland, has 

 kindly allowed me to incorporate in the present monograph the results obtained 

 from a study of the Carnegie collections. 



1 Contribution from the Zoological Laboratory of Indiana University, No. 98. 



