668 REVIEWS 



Iowa Geological Survey, Vol. XX. Annual Report, 1909, with 

 Accompanying Papers. By Samuel Calvin, State Geologist, 

 and Others. Pp. 542; Plates 42, Maps 10, Figs. 42. 



The report contains the following papers: "Geology of Butler 

 County," by Melvin F. Arey, pp. 1-60; "Geology of Grundy County," 

 by Melvin F. Arey, pp. 60-96; "Geology of Hamilton and Wright 

 Counties," by Thomas H. MacBride, pp. 97-150; "Geology of Iowa 

 County," by S. W. Stookey, pp. 151-98; "Geology of Wayne County," 

 by Melvin F. Arey, pp. 199-236; "Geology of Poweshiek County," 

 by S. W. Stookey, pp. 236-70; "Geology of Harrison and Monona 

 Counties," by B. Shimek, pp. 271-486; "Geology of Davis County," 

 by Melvin F. Arey, pp. 487-524. 



Shimek's report on the geology of Harrison and Monona counties 

 contains a detailed description of the mammalian fauna recently dis- 

 covered in the Aftonian interglacial deposits. These are especially 

 important, since in only one other instance in North America has it been 

 possible to determine definitely the age of a Pleistocene mammalian 

 fauna. Preliminary reports and descriptions of this fauna have been 

 published by Shimek and by Calvin in Science and in the Bulletins of 



the Geological Society of America. 



E. R. L. 



Practical Mineralogy Simplified. For Mining Students, Miners, 



and Prospectors. By Jesse Perry Rowe. New York: John 



Wiley & Sons, 191 1. Pp. 162. 



This textbook is arranged to give a few special or characteristic 



properties or tests for the common minerals, that will enable persons 



unskilled in chemistry or mineralogy to identify them by simple methods. 



It is readable and well arranged. It will doubtless serve a useful purpose. 



W. H. E. 



