vi 



INTRODUCTION. 



for the first time published. Much of the most valuable portion of 

 the present volume has been thus contributed by this gentleman. 



From the notes and observations of Mr. Titian R. Peale, another of 

 the naturalists of the Expedition, much also has been derived; and 

 in fact every facility has been most promptly afforded by all parties 

 attached to the Expedition, or in charge of the collections. To the 

 gentlemen of the Academy of Natural Sciences of Philadelphia, and 

 especially to Dr. Thomas B. Wilson, and to Professors Joseph Henry 

 and Spencer F. Baird, of the Smithsonian Institution, I avail myself 

 of the present opportunity of tendering my deep sense of obligation 

 for indispensable privileges and facilities in the libraries and museums 

 of the Institutions mentioned, and personally for much valuable advice 

 and assistance. 



The Plates of the Atlas to the present volume were colored at the 

 establishment of Mrs. Lavinia Bowen, Philadelphia, and I deem it but 

 justice to say that they are, in the particular of representing the colors 

 of species accurately, highly creditable. I most cheerfully bear testi- 

 mony to her exceeding carefulness and ability in this important feature 

 in zoological illustrations. Many of the drawings were made by 

 Mr. Peale. 



JOHN CASSIN. 



Academy of Natural Sciences, 

 Philadelphia, May 10th, 1858. 



