viii PREFACE. 
necessary, and a carefully selected bibliography 
will be found following each principal group of ani- 
mals. In the matter of illustration, representations 
of about five hundred animals and their parts have 
been given. Many of the cuts are original, and 
were designed especially to illustrate the habits of 
the animals, their economic value, etc. Others are 
from Buckley, Huxley, and various accurate sources 
already acknowledged. 
The valuable assistance of S. U. Holder is cor- 
dially acknowledged, and thanks are returned to 
Mr. Ralph N. Monroe for photographs of the Flor- 
ida crocodile and for the loan of valuable specimens ; 
also to Professor E. L. Youmans and Professor A. 
‘S. Bickmore for pertinent suggestions and advice. 
Acknowledgments are also made to Dr. E. P. 
Wright, of the University of Dublin, for the meas- 
-urements of the gigantic shark Rhinodon ; and to W. 
Morey, Esq., of Colombo, Ceylon, for the original 
outline drawing. 
C. F. H. 
New York, November 1, 1884. 
