AUTHOR'S PREFACE xi 



F. Loewinson-Lessing, Institut Polytechnique de St. Petersbourg, 



Laboratoire de Mineralogie et de Geologie, 

 Dr. G. O. Clerc, President of the Uralian Society, Ekaterinburg, 



Russia, 

 Prof. W. F. Hume, Director of the Geological Survey of Egypt, 



Cairo, Egypt, 

 Capt. Gilbert Clayton, Sudan Agent, War OflSce, Cairo, Egypt, 

 Dr. K. Inouye, Director of the Imperial Geological Survey of 



Japan, Tokyo, Japan, 

 Yashuhisa Mogi, ivory carver, son of Mitsutoshi Otoni, wood 



carver, formerly of Tokyo, 

 M. A. Lamme, Director of the Instituto de Geologia y Perforaciones, 



Montevideo, Uruguay, S. A, 

 Dr. E. T. Mellor, Director of the Geological Survey of South 



Africa, Pretoria, Africa, 

 Eusier R. Morey, former U. S. Consul, Colombo, Ceylon, 

 P. E. PiERis, Colombo, Ceylon, 

 W. J. Yerby, U. S. Consul, Dakar, Senegal, 

 Dr. E. Venadsky, Imperial Academy of Sciences, Petrograd, 



Russia, 



Special acknowledgment is due Dr. Edward H. Barbour, 

 Prof. Richard S. Lull, and Dr. William D. Matthew for 

 their valuable assistance in the preparation of the chapter 

 on elephant evolution, and to Thomas F. Ryan, Esq., for 

 much important material regarding the ivory commerce of 

 the Congo and the carving of ivory in Belgium. 



