PREFACE 



An important object aimed at in these historical notes is to give the 

 student of American animals a background for his knowledge of zoological 

 names. In order to attain this object still more fully, brief biographical 

 notices of the authors of these names, in so far as they appear in this work, 

 have been introduced at the end of the book. 



In the choice of the scientific names of the animals described the author 

 has endeavored to follow the best usage. He has usually conformed to 

 the laws of priority established by the International Commission of Nomen- 

 clature, and has adopted the rulings of the Commission where such have 

 been made. In a few cases, however, these laws have been disregarded, as, 

 for instance, in the case of Amceba, Holoihuria, and Physalia, and for the 

 reason that it seems probable that in such cases the scientific names of the 

 animals which are now in common use will by common consent be retained. 

 The author has no desire to be an innovator in this book in the use of 

 zoological names, but wishes only to use those which will probably in the 

 future be the names of the animals described. 



The name of the author of each species and genus follows the first 

 mention of it in the descriptions, as is customary, and in those cases in 

 which the author originally placed his species in some other genus than 

 the one here employed, his name is in parentheses. Wherever an author's 

 name appears more than once in the same genus it is usually abbreviated 

 after the first occurrence. No other abbreviations occur in the text except 

 in the case of LinnaBus. In all cases where his name appears as the author 

 of a generic or specific name it is abbreviated to l ' L. " 



The illustrations which have been introduced have been copied mostly 

 from textbooks, special treatises, and monographs, for the use of which 

 hearty thanks are here extended to their authors, whose names appear in 

 parentheses after the titles of the figures. Thanks are also due to the 

 following publishers for permission to make these copies: Doubleday, 

 Page & Company, Gustav Fischer, Ginn & Company, Henry Holt & Com- 

 pany, The Macmillan Company, and The Whitaker & Ray-Wiggin Company. 



In compiling this book the author has utilized every source of informa- 

 tion within his reach and is consequently under obligations to very many 

 people and their published works. His personal obligation to all those 

 friends who have given valuable advice and assistance, often at the expendi- 

 ture of much time and labor, is very great indeed. The following are those 

 to whom he feels a special indebtedness: Mr. Nathan Banks, Dr. H. L. 

 Clark, Prof. W. R. Coe, Dr. C. B. Davenport, Prof. J. H. Gerould, Prof. 

 L. von Graff, Prof. C. W. Hargitt, Prof. G. T. Hargitt, Prof. J. S. Kingsley, 

 Prof. R. von Lendenfeld (deceased), Prof. A. Looss, Dr. M. M. Metcalf, 

 Prof. E. L. Mark, Prof. S. 0. Mast, Prof. J. P. Moore, Dr. T. Odhner, 

 Dr. A. E. Ortmann, Prof. R. C. Osburn, Dr. H. A. Pilsbry, Prof. A. A. 



