PREFACE. 



This classification of the families and genera of bats, primarily 

 based on skeletal and dental characters, is chiefly the result of my 

 studies of the collections in the United States National Museum. 

 During two visits to Europe I have, however, been permitted with 

 the utmost liberality to examine the material in the museums of Lon- 

 don, Paris, Leiden, and Berlin, with the result that members of prac- 

 tically all the known genera of Chiroptera have passed through my 

 hands. To the authorities of these institutions I take pleasure in 

 acknowledging my indebtedness. I am also under special obligations 

 to Mr. Oldfield Thomas for the unique facilities that I have enjoyed 

 for working in the British Museum, and to Mr. Knud Andersen for 

 his unfailing kindness in verifying special characters in the specimens 

 in London. Finally, to my assistant, Dr. Marcus W. Lyon, jr., 

 acknowledgment is due for his care in superintending the drawing 

 of some of the illustrations and assistance in reading proof during 

 my absence from Washington. 



The pen drawings in the text are mostly by Miss Mary Mason 

 Mitchell and the late Dr. J. C. McConnell; those in Plates XI to 

 XIV are also by Doctor McConnell. The wash drawings of the 

 teeth, forming Plates I to X, were made under my supervision by the 

 late Mr. F. van Iterson. They should be regarded as semidiagram- 

 matic. 



Owing to the fragmentary condition of the remains by which they 

 are known, it has not seemed expedient to attempt to introduce the 

 extinct genera in a system based on characters which the fossils have 

 for the most part lost. It has also seemed inexpedient to deal with 

 subgenera at a time when the species of bats are still very imperfectly 

 known. 



All questions of nomenclature have been decided in accordance 

 with the Code of Nomenclature of the American Ornithologists' 

 Union, pending the final adoption of an international code. 



Gerrit S. Miller, Jr. 



<• Cormura, Stenoderma. and Amurphochihts are the only genera among the 173 

 here recognized that I have not seen. 



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