Notices respecting New Boohs. 511 



Fallacies regarding Precious-metal Ore-deposits " (pages 257-271). 

 This controverts some of the many prejudices held by " the 

 practical miner," such as " against certain formations and in 

 favour of others," arising from unfavourable results in some local 

 workings, or vice versa, unchecked by subsequent experience. 

 Also against mines having unusually rich ores, in some instances, — 

 for or against veins with certain strikes, and other circumstances, 

 particularly as to the " appearance of ores." A hopeful view of 

 advance in mining knowledge with both miners and geologists is 

 held in this Eeport. 



The next memoir is "a Eeview of the Fossil OstreidaD of 

 North America; and a Comparison of the fossil with the living 

 forms; by C; A. "White, M.D., with Appendices by Prof. A. 

 Heilprin and Mr. J. A. Ryder " (pages 273-430, including 39 plates 

 of the fossil and 10 of the recent Oysters of North America). Dr. 

 White treats of the group generally, and of the successional forms 

 of Ostrea and its immediate allies, from the Carboniferous to the 

 Cretaceous, inclusive. Prof. Heilprin notices the Tertiary species ; 

 and Mr. Ryder supplies an account of the life-history of the 

 Oyster as known in the living state in North America. " A 

 Geological Reconnaissance in Southern Oregon," by Mr. I. C. 

 Russell (pp. 431-464, with 3 plates and 10 woodcuts of maps, 

 sections, &c), is more particularly interesting as showing the 

 extent and changes of the great lake-system of that country, and 

 the immediate relationship of the faults and displacements of strata 

 to the water-areas of the several valleys at successive periods, and 

 of the climatic oscillations during their history. 



A good Index enhances the value of this useful volume. 



" Photo-relief" Maps, published by the Society for Promoting 

 Christian Knowledge : London. 



We have received specimens of a series of the Relief-maps to be 

 issued as " photo-lithograph." This hew adaptation of relief-maps, 

 photographed from models, to education, as an aid in realizing 

 the surface-configuration of a country, will, we think, be largely 

 appreciated by both teachers and students, especially as the maps 

 are published at a low cost. Looking at the specimens before us, — 

 those of a map of Scotland, which has the slight defect of too even 

 a shore-line for the West Coast, — we are forcibly impressed by the 

 valley- systems as a leading feature, and are reminded of the 

 immense denudation which, during terrestrial history, has carved out 

 the surface, and left us the hills as vestiges of the old land. The 

 relative positions of watersheds, and of the tracks of roads and 

 canals, and the sites of battles, as well as of early occupation, are 

 hereby readily recognized and their reasons understood. These 

 maps are to be issued in three forms :■ — (1) Plain, with the physical 

 configuration only, besides parellels of latitude and longitude and 

 sites of some chief towns. (2) In addition, the names of the chief 

 mountains, rivers, towns, &c, and the divisions of counties. (3) In 



