PREFACE xi 



greatest detail. There have been described probably twenty thousand 

 kinds of fishes and to each of these are many references, in certain 

 cases hundreds and even thousands. To attempt, therefore, to include 

 them in the present work was hardly practicable; for one thing, it 

 would entail years of added labor and extra volumes. Moreover, such 

 a labor seemed to the editors the less necessary since it is the particular 

 branch of the subject which has already been given the greatest atten- 

 tion. Hence the student of the systematique is here referred only to 

 general works. In a word, the present volume leads the investigator 

 through the literature of the fishes only so far as families and genera : it 

 records species rarely. 



Only in instances of rare and unusual fishes have we cited the literature 

 in extenso, e. g. deep-sea fishes of especial interest in morphology or 

 physiology, or fishes of restricted localities. For new species the reader 

 must still consult his Zoological Record. For genera he has now the 

 splendid work of Jordan (1917.1). None the less, he will here find 

 references to extensive papers which cite new species in considerable 

 number, together with many useful taxonomic revisions and synopses. 

 His further systematic details he must continue to "run down" in 

 Jordan and Evermann's "Fishes of North and Middle America," Boul- 

 enger's "Fishes of Africa," Day's "Fishes of India," etc., Gunther's 

 " Catalogue [1859-70] of the British Museum," for living fishes, and 

 Smith Woodward's for fossil [1889-1901], the latter forming the 

 " Bible " of all students of this theme. In the last regard it will be found 

 that the detailed indexing of fossil teeth has been largely omitted, though 

 fossil spines, ichthyodorulites, have been included. In a word, the 

 compilers have tried, so far as possible, not to reprint needlessly the 

 classical work of systematists, or to re-index such pubhcations as 

 the Zoological Record or the cards of the Concilium Bibhographicum. 



(b) In matters of Synonymy we have not attempted to decide 

 questions of priority in nomenclature: we have accepted a name as 

 an author has given it, save in case its synonymy was obvious. In 

 general we have been content to follow technical names which are well 

 known. 



In the case of Group-names, e. g. Ganoidei, we have sometimes for 

 convenience followed older and popularly accepted terms and for the 

 same reason we have adopted the groups for classification given in 

 Cambridge Natural History (1904). These at least are clear and 

 accessible; and although we do not personally subscribe to them toto 

 ccelo, we feel that our present function is rather to place in the reader's 

 hand sources of information than to decide for him which kind of 

 classification he should ultimately adopt. 



