Geology. 91 



10. Geologie der Steinkohlenlager ; by Dannenberg. Erster 

 Teil. Pp. 197, 25 figs. (Gebriider Borntraeger.) Berlin, 1908.— 

 This publication is evidently one of importance, and will be 

 reviewed after the appearance of the second part, which the 

 publishers announce will be issued sometime within the coming 

 year. h. e. g. 



11. The Geology of Coal and Coal-mining ; by Walcot 

 Gibson. Pp. x, 328, 8 plates. London, 1908 (Edward Arnold.) — 

 Geologists and engineers will be interested in the series of works 

 on economic geology, dealing with mining, quarrying, water 

 supply, etc., to be issued under the general editorship of Pro- 

 fessor Marr. The above volume is the first of the series and dis- 

 cusses varieties of coal, their formation, origin, distribution, value 

 of fossils in coal exploration, and methods for a study of exposed 

 and concealed coal fields. Somewhat over half of the book is 

 devoted to a critical discussion of the coal fields of the world, — 

 those of Great Britain being treated with the greatest detail. 

 Eighteen pages are devoted to the North American coal fields, 

 and little use is made of the valuable investigations of the United 

 States Geological Survey and the various state surveys. Mining- 

 engineers, prospectors, and students of economic geology will 

 find Dr. Gibson's book helpful reading. h. e. g. 



12. Physical History of the Earth in Outline ; by James B. 

 Babbitt. Pp. 212, 6 illustrations. Boston, 1908 ( E. E. Sherman 

 & Co.) — The object of this book is to explain the changes of cli- 

 mate through geological time, on the assumption that the earth 

 has a " proper rotary motion transverse to or across the diurnal 

 rotation." An idea of the author's views in relation to orthodox 

 science may be gained from the fact that he accepts Agassiz's 

 account of glaciation in Brazil and believes the irregular coast 

 lines of Maine, Norway, and the world in general, as well as the 

 river system of North America, to be due to glaciation. h. e. g. 



13. Triassic Ichthyosaitria, toith special reference to American 

 Forms ; by John C. Merriam. Memoirs of the University of 

 California, Vol. i, No. 1. Pp. 155, text-figures 154, plates 1-18. 

 Berkeley, 1908 (University Press). — The inaugural number of 

 this new series of memoirs contains the results of twelve or more 

 years of thorough work upon one of the most important groups 

 of fossil vertebrates. Ten field-expeditions, sent out by the 

 University of California and generously aided by a patron of that 

 institution, have brought together a magnificent collection of 

 ichthyosaurs from the marine Triassic of California and Nevada. 

 While this collection forms the chief subject of the memoir, the 

 European genera are also reviewed. Admirers of the author, 

 and they are many, will be glad to learn that the present work, 

 with all its breadth of treatment and refinement of detail, 

 " can be considered as no more than a report of progress, as 

 new material and additional information regarding the structure 

 and affinities of the Triassic forms are constantly being obtained." 

 In this case one of the great difficulties met with in paleonto- 



