PREFACE. V 



Whenever possible, figures of American animals were 

 selected in preference to those from foreign sources. 



When an object is magnified, the amount of enlarge- 

 ment is stated to be so many diameters, e. g. 250 diam. 

 i. e. 250 times the diameter of the natural size. 



HENRY JAMES CLARK. 



CAMBRIDGE, Mass., September, 1865. 



