1 



QL 



1^1 



CONTRIBUTIONS 



TO 



THE NATURAL HISTORY 



UNITED STATES OF AMERICA. 



BT 



LOUIS AGASSI Z, 



FIRST MONOGRAPH. 



IN THREE PARTS. — I. ESSAY ON CLASSIFICATION. — H. NORTH AMERICAN TESTUDINATA. 

 III. EMBRYOLOGY OF THE TURTLE: WITH THIRTY-FOUR PLATES. 



VOL. I. 



BOSTON: 



LITTLE, BROWN AND COMPANY. 



LONDON: TRLFBNER & CO. 

 1857. 



