PREFACE xiii 



Especial acknowledgment should be made to the President of the 

 American Museum, Professor Henry Fairfield Osborn, who, firm 

 in the faith of the ultimate value of our labors, stood our sponsor 

 in obtaining the funds necessary to ensure the stipends of the editorial 

 staff and to cover the large outlay for publication. Also to the Director 

 of the Museum, Dr. Frederick A. Lucas, to its Librarian, Dr. R. W. 

 Tower, and to our colleagues Mr. John Treadwell Nichols, and 

 Professor W. K. Gregory, we are indebted for constant counsel and 

 for help in many directions. Nor should we fail to mention the favors 

 shown us by authorities of numerous libraries and universities, notably 

 Dr. H. M. Lydenberg of the New York Public Library. 



The author finally and gratefully records the constant inspiration 

 received from his editorial colleagues with whom since 1919 he had 

 weekly conferences. Entangled in other studies, he could only give 

 the necessary time to mark his share of the copy for the Subject 

 Index, to revise proof, and to review and decide discussions which 

 concerned the conduct of the work. 



The present volume terminates a task, infinitely painstaking, thank- 

 less, insistent, withal necessary, which has been upon our table for over 

 thirty years. It seemed never to end, and we grew old with it; Quousque 

 tandem! Our hope is only that the references we now provide will be 

 of constant service to workers everywhere, for when all is said and 

 done, an elaborate bibliography is the strongest scaffolding upon which 



any research can be built. 



Bashford Dean. 



American Museum of Natural History. 

 January 15, 1923. 



