PREFACE 



A KNOWLEDGE of Fishes, living and fossil, is not to be 

 included readily within the limits of an introductory study. 

 In preparing the present volume it has nevertheless been 

 my object to enable the reader to obtain a convenient 

 review of the most important forms of fishes, and of their 

 structural and developmental characters. I have also en- 

 deavoured to keep constantly in view the problems of their 

 evolution. 



At the end of the book a series of tables affords more 

 definite contrasts of the anatomy and embryology of the 

 different groups of fishes. And as an aid to further study 

 has been added a summarized bibliography, including 

 especially the works of the more recent investigators. 



My sincere thanks are due to my friend and colleague, 

 Professor Henry Fairfield Osborn, for many suggestions 

 during the early preparation of the book, and for the care 

 with which he has later revised the proof. I must also 

 express my indebtedness to Mr. Arthur Smith Woodward 

 of the British Museum for his personal kindnesses in 

 aiding my studies. My thanks are also due to my father, 

 William Dean, for the preparation of the index. 



The figures, unless otherwise stated, are from my 

 original pen drawings. 



B. D. 



BIOLOGICAL LABORATORY OF COLUMBIA COLLEGE, 

 May, 1895- 



