Contributors- 



George A. Bartholomew, Department of Zoology, University of 

 California, Los Angeles 



W. Frank Blair, Department of Zoology, University of Texas, 

 Austin 



William H. Burt, Museum of Zoology, University of Michigan, 

 Ann Arbor 



E. Raymond Hall, Museum of Natural History, University of 

 Kansas, Lawrence 



William Hovanitz, Department of Biology, California Institute of 

 Technology, Pasadena 



Carl L. Hubbs, Scripps Institution of Oceanography, University 

 of California, La Jolla 



Philip B. King, General Geology Branch, United States Geological 

 Survey, Menlo Park, California 



E. Gorton Linsley, Department of Entomology and Parasitology, 

 University of California, Berkeley 



H. D. MacGinitie, Department of Biology, Humboldt State Col- 

 lege, Areata, California 



Paul S. Martin, Geochronology Laboratories, L^niversity of 

 Arizona, Tucson 



Alden H. Miller, Museum of Vertebrate Zoology, University of 

 California, Berkeley 



Robert Rush Miller, Museum of Zoology, University of Michi- 

 gan, Ann Arbor 



Kenneth C. Parkes, Carnegie Museum, Pittsburgh, Pennsylvania 



Frank E. Peabody, Department of Zoology, University of Cali- 

 fornia, Los Angeles 



Robert W. Pennak, Department of Zoology, University of 

 Colorado, Boulder 



James A. G. Rehn, Academy of Natural Sciences of Philadelphia, 

 Pennsylvania 



VI 1 



