Geology and Natural History. 



477 



Birds, ocean-currents, drifting logs and ice, and winds prove to 

 be ineffective in carrying to Newfoundland the plants from the 

 southwest, so that an ancient land-bridge is suggested. This is 

 the more demanded from the presence in Newfoundland of a vole 

 and a muskrat, mammals closely related to species of our coastal 

 region. The amount of water withdrawn from the ocean to form 

 the Pleistocene glaciers was apparently sufficient to leave exposed 

 nearly, if not all, the old coastal plain which now forms the sub- 

 merged bench off our coast, and in addition there is unquestioned 

 evidence that since the Glacial Period this coastal bench has been 

 much higher than it is now ; so that upon this now submerged 

 plain, as the ice-front receded northward, the southwestern plants, 

 most of which still occur on Cape Cod, Long Island, or in the 

 Pine Barrens of New Jersey, must have spread to Newfoundland, 

 where they form now an isolated flora." 



The author states that he will be glad to supply a copy of the 

 paper here reviewed to those geologists who wish to have it. 



c. s. 



3. Topographic and Geologic Survey of Pennsylvania. 

 Richard R. Hice, State Geologist. 1908-1910. Pp. 103 ; 6 

 plates, 4 figures. Harrisburg, 1911. — The present Survey of 

 Pennsylvania was established in April, 1899, when an appropria- 

 tion for joint work with the U. S. Geological Survey was made. 

 The chief work contemplated was the preparation of a contour 

 topographic map on a scale of 1:62,500 with 20-foot contours; 

 for this an annual appropriation of $20,000 for two years was 

 made. The present volume, besides showing what progress has 

 been made thus far, emphasizes the fact that as the mineral pro- 

 duction of the state is so large, amounting in 1907 to $658,000,000, 

 or more than $100,000,000 in excess of all the states west of the 

 Mississippi River, the present appropriation is entirely inadequate. 

 It is urged that a sum not less than $40,000 be authorized for 

 each of the next two years to do the work planned. This volume 

 also contains two papers, one on the natural gas development in 

 Pennsylvania by Frederick G. Clapp, and another by Percy E. 

 Raymond, giving a preliminary list of the fauna of the Allegheny 

 and Conemaugh Series in Western Pennsylvania. In regard to 

 the former subject, the conclusion is reached that the disappear- 

 ance of natural gas production from the state is certainly many 

 years distant. 



4. Virginia Geological Survey. Bidletin No. VI. Report on 

 the Mineral Production of Virginia during the Calendar Years 

 1909 and 1910; by Thomas Leonard Watson. Pp. v, 123; 

 one figure. Charlottesville, 1911 (University of Virginia). — The 

 general facts in regard to the mining industries of Virginia dur- 

 ing the years 1909 and 1910 are given in this bulletin. The total 

 mineral production in 1910 amounted to nearly $22,800,000, 

 having increased from about $18,000,000 in 1908. The products 

 are varied, but those of greatest importance are coal, iron, and 

 clay. The bulletin also discusses the distribution, occurrence, 

 and development of the mineral products, some forty in all, now 



