PREFACE vii 



York Zoological Society have contributed several illus- 

 trations, for the use of which I am much indebted. 



Photographs not otherwise credited were taken by the 

 author, most of the subjects being included among the 

 exhibits at the New York Zoological Park. The goldfishes 

 are the property of Mr. Joseph Taubles, while the tropical 

 fishes are from the author's private collection. 



Several chapters included have already appeared in vari- 

 ous publications, and for their use my thanks are due to the 

 New York Zoological Society, Messrs. Doubleday, Page & 

 Co., and the Advanced Agricultural Publishing Co. 



L. S. C. 



New York Zoological Park, 

 January, 1917. 



