68 INDEX GENERUM MAMMALIUM. 
The completeness of the index has been greatly enhanced by work- 
ing naturalists, who have sent separates of their papers containing new 
names, have revised lists of their gehera submitted to them for that 
purpose, or furnished information which has made it possible to 
include full lists of the names published by them. In some cases, 
notably that of Dr. Florentino Ameghino, director of the Museo 
Nacional, Duenos Aires (who has named over four hundred genera of 
extinct mammals), the revision of such lists involved considerable 
labor. Among others who have furnished lists of their genera are 
Dr. J. A. Allen, curator of mammals in the American Museum of 
Natural History, New York; Dr. Ch. Depéret, of Lyons, France; 
Mr. €. W. De Vis, curator of the Queensland Museum, Brisbane; 
Prof. Dr. Alfred Nehring, of Berlin; Prof. Henry F. Osborn, of 
Columbia University, New York; Prof. William B. Scott, of Princeton 
University: Mr. Oldfield Thomas, curator of mammals in the Natural 
History Museum, London; Dr. E. L. Trouessart, of Paris, and Dr. 
F. W. True, of the U. S. National Museum. 
For important aid in looking up or verifying references to books 
inaccessible in Washington, acknowledgments are due Mr. C. Davies 
Sherborn and Mr. Oldfield Thomas, of the British Museum; Dr. J. A. 
Allen, of the American Museum; Mr. 8. N. Rhoads, and Mr. Witmer 
Stone, of Philadelphia. 
I am also under obligations to several persons for special assistance 
rendered in various ways. To Mr. W. E. De Winton, of the British 
Museum, for dates and etymology of ;Zwurus; to Dr. Paul Matschie, 
of the Berlin Museum, for publications; to Dr. Santiago Roth, of La 
Plata, Argentina, for copies of papers and for information concerning 
several generic names; to Mr. W. L. Sclater, Director of the South 
African Museum, for information respecting several South African 
rodents; to Mr. F. A. Lucas, of the U. S. National Museum, and 
Dr. E. L. Trouessart, of Paris, for referenees and assistance in 
other ways; to Dr. William H. Dall and Dr. Leonhard Stejneger, 
for advice regarding questions of nomenclature; to Prof. O. P. Hay, 
of the American Museum of Natural History, for references, numerous 
suggestions during the progress of the work, and for the opportunity 
of examining the proof of his *Catalogue of Extinct Vertebrates of 
North America; to Dr. W. D. Matthew, of the American Museum, 
New York, for notes on several doubtful groups of extinct mammals; 
to Mr. Gerrit S. Miller, jr., for several names, for verifying refer- 
ences, and for information regarding the genera of Vespertilionide 
and Microtine; to Dr. Charles W. Richmond, for references and data 
concerning dates of publication of names; and to Miss Mary J. Rath- 
bun, for the privilege of consulting her manuscript catalogue of genera 
of Crustacea in the search for names which might preoccupy names of 
mammals, and also for calling my attention to the generic names con- 
tained in Brewster's Encyclopedia, 
