MEXICAN TAILLESS AMPHIBIANS 15 



ACKNOWLEDGMENTS 



Dr. Leonhard Stejneger and Miss Doris M. Cochran, of the National 

 Museum, have facilitated the preparation of this report in many ways, 

 and to them the writer is greatly indebted for criticisms and sug- 

 gestions. Grateful acknowledgment for the privilege of including 

 specimens under their care in this report is hereby extended to Dr. 

 G. K. Noble, of the American Museum of Natural History in New 

 York; Dr. Thomas Barbour, director of the Museum of Comparative 

 Zoology in Cambridge, Mass.; Dr. Alexander G. Ruthven, director 

 of the University Museums of the University of Michigan in Ann 

 Arbor; Alfred C. Weed and K. P. Schmidt, of the Field Museum of 

 Natural History in Chicago; Joseph R. Slevin, of the California 

 Academy of Sciences in San Francisco; Dr. Ernst Ahl, of the Museum 

 fiir Naturkunde in Berlin; Dr. Otto Wettstein, of the Naturhistori- 

 sche Museum in Vienna; Dr. Laura Gambetta, of the Istituto 

 Zoologico R. Universita in Turin; Dr. Louis Roule, director, and 

 F. Angel, of the Museum National d'Histoire Naturelle in Paris; 

 and W. H. Parker, of the British Museum of Natural History in 

 London. To Dr. E. R. Dunn, of Haverford College, Haverford, Pa., 

 the writer is indebted for comments and notes on specimens that he 

 had examined in American and European museums. The drawings 

 for the figures of toads of the genus Bufo, prepared under the author's 

 supervision, were loaned by the Bureau of Biological Survey. 



ABBREVIATIONS 



The following abbreviations are used in the lists of specimens 

 examined during the preparation of this report and in the text where 

 catalogue numbers are given: 



A.M.N.H American Museum of Natural Historj^ New York, 



N. Y. 

 A.N.S.P Academy of Natural Sciences of Philadelphia, 



Philadelphia, Pa. 

 B.M British Museum of Natural Histor}-, London, 



England. 

 C.A.S California Academy of Sciences, San Francisco, 



Calif. 

 C.G.E.M Coraision Geografica Exploradora de Mexico, 



Mexico City, Mexico. 



F.M.N.H Field Museum of Natural Iliitory, Chicago, 111. 



M.C.Z Museum of Comparative Zoology, Cambridge, 



Mass. 

 M.H.N.P Museum National d'Histoire Naturelle, Paris, 



France. 



M.N.B Museum fiir Naturkunde, Berlin, Germany. 



N.M.W Naturhistorische Museum, Vienna, Austria. 



U.M.U.M University Museums, University of Michigan, Ann 



Arbor, Mich. 

 U.S.N. M United States National Museum, Washington, D. C. 



