PREFACE 
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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. 
