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tion, are represented in the English Wealden, and only one is found in 

 the Potomac flora of Eastern United States. 



The third paper deals with the Miocene flora in southern Chile, and 

 with deposits which are of particular interest, because they represent the 

 Tertiary coal fields of Chile. The genus Araucaria is very prominent 

 in this flora, and Berry discusses at considerable length the Mesozoic and 

 Tertiary distribution of Araucarias throughout the world, with reference 

 also to the recent occurrence of this type. The floral elements of the 

 Tertiary in Chile are compared with other fossil floras and present-day 

 distribution of plants in South America. 



The next paper deals with the PHocene fossil plants from eastern 

 BoHvia. The flora and its environmental conditions are discussed. 

 Berry draws some conclusions as to the changes of level, in consequence 

 of the uplift of the Andes Mountains, which has taken place since this 

 flora existed. His conclusion is that the rise must have been not less 

 than 6,500 nor more than 9,000 feet. The author includes a list of these 

 plants which he caUs the Pisllypampa flora. 



The last paper deals with the late Tertiary plants from Jancocata, 

 Bolivia. This flora, according to his determination, is of Plio-Pleistocene 

 age. 



The foregoing articles contain much valuable information on the 

 climatological and ecological conditions under which these floras grew 

 up. They are a valuable addition to our knowledge of South American 

 fossil plants. But there is still a great deal to be done along these lines, 

 although the departments of mines of the South American states seem 

 to have been not unmindful of the interesting plant deposits in their 

 respective countries. 



A. C. N. 



Rocks and Their Origins: By Grenville A. J. Cole. Cambridge 

 University Press, 1922. Pp. 175, figs. 20. 



This little book, the first edition of which came out in 191 2, is inscribed 

 by the author as "intended for those who are not specialists in geology." 

 A comparatively slight knowledge of geologic technology is presupposed 

 on the part of the reader; and the style of the book is simple and clear, 

 but the simple treatment does not entail any loss of accuracy of statement. 



A brief introductory chapter brings out the distinction between rocks 

 and minerals, and lists the more common minerals with their chemical 

 compositions. A chapter each on limestones, clay rocks, sandstones, 

 igneous rocks, and metamorphic rocks constitutes the remainder of the 



