REVIEWS 137 



geographic changes which the state underwent in the course of its 

 history. It is illustrated by numerous paleogeographic maps and some 

 excellent diagrams and sections. This brief summary of the geological 

 history of the state is very welcome to those who live beyond the con- 

 fines of Missouri, as it doubtless is to many residents of the state. 



One chapter deals with the life of the various geologic periods. 

 Others deal with the minerals and rocks of the state and with its eco- 

 nomic geology. The later chapters outline the range of industries 

 dependent upon geologic materials, and give a summary of the value 

 of the mineral products. The range of mineral resources is perhaps 

 larger than most of those unfamiliar with the geology of the state have 

 known. 



R. D. S. 



