A MONOGRAPH ON THE ISOPODS OF NORTH AMERICA. 



By Harriet Kichardson, 



Collaborator, Division of Marine Invertebrates. 



\ 



INTRODUCTION. 



In the preparation of the present monograph my purpose has been 

 to give descriptions and tigures of all the species of isopodous Crus- 

 tacea, marine, terrestrial, and fresh-water, known to North America, 

 with synopses, so as to assist the student in the identification of each 

 species. The descriptions are made as concise and as nearly uniform 

 as possible. The original descriptions have been prepared primarily 

 from specimens in the collection of the U. S. National Museum, but 

 have been supplemented by specimens from other museums. The 

 collection from the Museum of Comparative Zoology at Harvard Uni- 

 versity, for the examination of which I am indebted to Prof. Walter 

 Faxon; the collection in the Peabody Museum of Yale LTniversity, 

 which I obtained through the courtes}^ of Prof. A. E. Verrill; the col- 

 lection from the American Museum of Natural History, kindly loaned 

 me by Prof. W. M. Wheeler; the collection from the University of 

 Pennsylvania, which I obtained through the kindness of Dr. Philip P. 

 Calvert and Dr. J. Percy Moore; the collection from the Academy of 

 Natural Sciences of Philadelphia, including Sa3''s valuable t5"pes, 

 loaned to me by Doctor Pilsbr}'; the collection from the University of 

 California, kindly sent by Dr. William E. Ritter, and specimens from 

 the University of Cincinnati, obtained through the kindness of Prof. 

 Joshua Lindahl, have been of great assistance in the preparation of 

 this work. In addition to these valua))le sources, specimens have also 

 been sent me by Dr. Carl Eigenmann, of the Universit}^ of Indiana, by 

 the U. S. Bureau of Fisheries, the U. S. Department of Agriculture, 

 and various others. 



A large number of the North American species described are not 

 represented in the museums of this country. The descriptions of 

 these forms are quoted from various sources, the original description 

 being given in some cases — in other cases a later description b}' another 

 author, where the description seemed better. Where the descriptions 

 are (^[uoted, I have not seen or examined any specimens. 



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