PREFACE 



This work treats of the fish from all the varied points of 

 view of the different branches of the study of Ichthyology. In 

 general all traits of the fish are discussed, those which the fish 

 shares with other animals most briefly, those which relate to 

 the evolution of the group and the divergence of^ its various 

 classes and orders most fully. The extinct forms are restored 

 to their place in the series and discussed along with those still 

 extant. 



In general, the writer has drawn on his own experience as an 

 ichthyologist, and with this on all the literature of the science. 

 Special obligations are recognized in the text. To Dr. Charles 

 H. Gilbert, he is indebted for a critical reading of most of his 

 proof-sheets ; to Dr. Bashford Dean, for criticism of the proof- 

 sheets of the chapters on the lower fishes ; to Dr. William Emer- 

 son Ritter, for assistance in the chapters on Protochordata; to 

 Dr. George Clinton Price, for revision of the chapters on lancelets 

 and lampreys, and to Mr. George Clark, Secretary of Stanford 

 University, for assistance of various kinds, notably in the prep- 

 aration of the index. To Dr. Theodore Gill, he has been for 

 many years constantly indebted for illuminating suggestions, and 

 to Dr. Barton Warren Evermann, for a variety of favors. To 

 Dr. Richard Rathbun, the writer owes the privilege of using 

 illustrations from the "Fishes of Xorti: and Middle America" 

 by Jordan and Evermann. The remaining plates were drawn 

 for this work by Mary H. Wellman, Kako Morita, and Sekko 

 Shimada. Many of the plates are original. Those copied from 

 other authors are so indicated in the text. 



No bibliography has been included in this work. A list of 

 writers so complete as to have value to the student woulcl make 



