68 Scientific Intelligence. 



■which Martha's Vineyard and later Cape Cod formed the most 

 southwesterly limits. This hypothesis, well supported by the 

 facts, assists in the solution of a problem, pointed out by Shaler, 

 that the drift of Cape Cod and Nantucket contains igneous and 

 sedimentary materials not known to occur in place in southern 

 New England. Some knowledge is thus obtained of geological 

 formations now submerged on the eastern portion of the conti- 

 nental shelf. Cambrian fossils have in the past fifteen years been 

 determined from some of these erratics. Evidence of a glacial 

 lake has been determined, formerly existing over Cape Cod and 

 Cape Cod Bay and confined between two lobes of the glacier. 

 This body of glacial water has been named Lake Sbaler. j. b. 



5. Les Variations Periodiques des Glaciers. Onzieme rap- 

 port, 1905 r6dige par Dr. Harry Fielding Reid et E. Muret, 

 President et Secretaire de la Commission Internationale des gla- 

 ciers. Extrait des Annales de Glaciologie, t. I, Sept. 1906, pp. 

 161-181. Berlin (Freres Borntraeger, Editeurs). — Reports are 

 published concerning glaciers of all the continents, showing the 

 amount of advance or retreat or the stationary attitude. The 

 report contains a valuable series of data which in the course of 

 time must throw a great deal of light upon the question of the 

 smaller and larger variations of climate. j. b. 



6. The Roman Comagmatic Region, by H. S. Washington. 

 Carnegie Institution, Publication No. 57, 8vo, 199 pp. Washington, 

 D. C, 1906. — This volume contains the results of a great amount 

 of careful, accurate and laborious work, in the field and in the 

 laboratory, upon the volcanic rocks of central Italy. The work 

 is essentially petrographic and not geologic in character, though 

 enough descriptive matter of a geologic nature has been added 

 by the author to enable the reader with the aid of the map to 

 understand the relation of the places and mode of occurrence of 

 the different rocks investigated. These comprise the various 

 types which occur in the main line of volcanoes extending from 

 Lake Bolsena southeast to Vesuvius and the Phlegrean Fields. 

 They have been thoroughly studied and compared and of forty- 

 four of them complete and elaborate chemical analyses have 

 been made, thus adding very greatl} 7 to our knowledge of the 

 chemical nature of the magmas composing this interesting and 

 important series of eruptive centers. 



As one result of this exhaustive study of a large number of 

 leucitic rocks the author is able to present certain interesting 

 generalizations regarding the origin and conditions of formation 

 of leucite. 



In the final portion of the work the author treats the district 

 as a whole and presents its general aspects as a " petrographic 

 province" or as he suggests in the place of this term a comag- 

 matic region. In other comagmatic regions which have thus far 

 been studied, the only one which, in the high potash content of 

 its rocks approaches it, is that of Central Montana. 



The new quantitative classification has been employed through- 



