Geology and Natural History. 187 



that there is nothing to show that the fossiliferous beds con- 

 cerned were deposited at a time of maximum glaciation, and this 

 possibility must be held in mind in view of the recent tendency 

 to enlarge the estimates of Pleistocene time and to consider it a 

 period of great climatic variability. Such a question has greater 

 force since Collier Cobb has recently made note of finding 

 rounded, subangular and even striated cobbles' on the Atlantic 

 side of Currituck Banks off the North Carolina coast, which he 

 regards as having been transported by icebergs from the New 

 England coast during a period of maximum glaciation.* j. b. 



3. The Geography and Geology of Alaska. A summary of 

 existing knowledge, by Alfred H. Brooks, with a section on 

 climate, by Cleveland Abbe, Jr., and a topographic map and 

 description thereof by R. U. Goode. Professional Paper No. 

 45, IT. S. Geological Survey, 1906; 327 pp., xxxiv pis., 6 figs. — 

 For all except those who have made a specialty of Alaskan geo- 

 logical exploration, this will be the most valuable volume pub- 

 lished by the government on the geography and geology of 

 Alaska, giving a general view of the physiographic provinces and 

 of the present knowledge of the country. 



It shows what results may be accomplished in the course of a 

 few years by government support for the scientific exploration 

 of a previously unknown land. Apart from the scientific results, 

 it is doubtless true that from an economic standpoint these 

 explorations have increased the value of Alaska to the United 

 States many times the sum of money spent in the explorations. 



J. B. 



4. Geology and Mineral Resources of part of the Cumberland 

 Gap Goal Field, Kentucky ; by George Hall Ashley and 

 Leojvidas Chalmers Glenn, in cooperation with the State Geo- 

 logical Department of Kentucky, C. J. Norwood Curator. 

 Professional Paper No. 49, IT. S. Geological Survey, 1906 ; 239 

 pp., xl pis., 13 figs. — This well written and illustrated report 

 contains 40 pages on the general geography, physiography and 

 geology of the region, followed by 1 70 pages on the geography 

 and stratigraphy of the coals. The volume contains much of 

 scientific interest and is of great economic value. j. b. 



5. The Pleistocene Deposits of Sankoty head, JVantucket, and 

 their Fossils ; by J. A. Cushman. Pub. Nantucket Maria Mit- 

 chell Assoc, I, 1906, 21 pp., 3 pis. — This paper brings together 

 all that is known regarding the Sankoty Head section, the occur- 

 rence of the fossils, horizons, a list of the fauna (86 species, of 

 which 66 are Mollusca), and another of the literature of these 

 deposits. This paper should be studied in connection with an 

 article recently published on the same deposits, in the Journal of 

 Geology, December, 1905, pp. 713-734, by J. Howard Wilson, 

 where about 15 additional species are listed. c. s. 



* Notes on the Geology of Currituck Banks, Journal of the Mitchell 

 Society, vol. xxii, No. 1, pp. 17-19. 



