PREFACE. XV 



sent to me by the Rev. Thomas S. Savage of Pass Christian, the Rev. FAw. Fontaine of 

 Austin, Mr. W. Sargent of Natchez, and ]\Ir. .lenks of IMidcileboro', are among tlie most 

 valuable of the kind I have received ; iuul to l\Ir. Jenks I am indebted for most of the 

 eggs tiie development of which I have been able to trace. For a number of years he 

 has provided me annually with many hundreds of eggs, of all our common species. 1 

 have also received many valuable invoices of eggs from Mr. T. W. P. Lewis, of Key 

 West ; from the Hon. J. 'I'ownsend, of Edisto, in South Carolina ; from Dr. John Ranch, of 

 Burlington, Iowa ; from Franklin C. Hill, of Logansport, Indiana ; from Dr. Michener, of 

 Arondale, in Pennsylvania ; from Mr. Winthrop Sargent, of Natchez ; from Mr. Eppes, of 

 Tallahassee ; from Dr. Nott, of Mobile ; from Prof. Baird, of the Smithsonian Institution : 

 from the late Rev. Z. Thompson, of Burlington, Vermont ; from Dr. A. Sager, of Ann- 

 Arbor; from Major and Dr. LeConte, of Pliiladelpliia ; from Dr. Hoy, of Racine; from the 

 late Dr. Burnett, of Boston; from Mr. Sanborn Tenney, of Auburndale ; and from a number 

 of intelligent boys of the vicinity of Cambridge. I have myself obtained many rare eggs 

 from species kept alive in my garden, and raised a large number of young Turtles. 



It may not be superfluous to state, that most of these specimens were sent alive to 

 Cambridge, so that I had the amplest opportunity of studying their natural attitudes, their 

 modes of moving and of eating, and sometimes the manner in which they lay their eggs. 

 I have of course availed myself of these favorable circumstances to examine and compare 

 the largest possible numbers of specimens of the same species, in order to determine the 

 range of variations of each of them. There are many species, of which I have exam- 

 ined many hundreds of specimens. I have also caused innumerable drawings of these 

 specimens to be made by my tried friend, J. Burkhardt, representing their varieties of color 

 and form, and their different attitudes. These drawings and sketches would fill <npr one 

 hundred plates, and are too numerous to be published in this series ; but I shall avail 

 myself of every opportunity to publish them, in the style of Plates 26 and 27. Minor 

 contributions are mentioned, in their proper places, in the text. 



There is another kind of assistance, which I take gi-eat satisfaction in recording, as it 

 comes from young friends and former pupils. Among them there is one, a lineal descend- 

 ant of one of the great patriots of the American Revolution, whose modesty forbids 

 that I sluHikl mention him by name. On hearing of my intention to )iublish a work on 

 the Natural History of the United States, he immediately came forward with a most lib- 

 eral pecnniary eontributidn to my undertaking. From otlier pupils I have derived assistance 

 in the prosecution of the work itself. Mr. James E. Mills, of Bangor, (Maine,) has worked 

 out for nie the special characters of the families of the Testuiliiiata : and Dr. Weiiilaiid lias 

 helped me in revising the anatomical characters of the (nxler, in accordance with the prin- 

 ciples laid down in the First Part of the work; while Mr. II. James Clark has assisted me , 

 from the beginning of my investigation of the embryology of these animals, and drawn, with 



