PREFATORY NOTE. 



UNITED STATES GEOLOGICAL AND 

 GEOGRAPHICAL SURVEY OF THE TERRITORIES, 



Washington, D. (7., July 1, 1880. 



The present series of monographs of the 'North American 

 Pinnipedia, by Mr. J. A. Allen, may be considered as a second 

 installment of the systematic History of North American Mam- 

 mals, of which the Fur-Bearing- Animals by Dr. Elliott Cones, 

 U. S. A., forming No. 8 of the Miscellaneous Publications of 

 the Survey, was published as a specimen fasciculus. The first 

 monograph of this series, treating of the Walruses, was prepared 

 nearly three years since for publication in the Bulletin of the 

 Survey, but before it was quite ready for the press, Dr. Coues, 

 owing to his pressing engagements in other directions, invited 

 Mr. Allen to extend his treatise to embrace the entire suborder 

 of the Pinnipeds, to which he had already given special atten- 

 tion, with a view to its incorporation as a part of the proposed 

 general History of North American Mammals. Since, how- 

 ever, considerable time must elapse before the whole work can 

 be completed, it has been thought best not to delay the publi- 

 cation of the part already prepared relating to the Pennipeds. 



As nearly all of the species belonging to this group found in 

 the northern hemisphere are members of the North American 

 fauna, the present treatise is virtually a monograph of all the 

 species occurring north of the equator, and includes incideutally 

 a revision of those of other seas. The literature of the whole 

 group is not only reviewed at length, but the economic pha.se 

 of the subject is treated in detail, embracing, in fact, a general 

 history of the Sealing industries of the world. The technical 

 treatment of the subject is based rnainjy on the rich material 

 of the National Museum, supplemented at many important 

 points by that of the Museum of Comparative Zoology of Cam- 

 bridge, which, through the kindness of the directors of these 

 institutions, was generously placed at the author's disposal. 

 That contained in the other principal museums of the country 



in 



