��THE POPULAR SCIENCE MONTHLY.
��and archaeology. Among thern are those of Prof. Hyatt on the "Evolution of the Fauna of the Lower Lias " ; of Mr. S. H. Scudder on a Palaeozoic " Cockroach Fauna " at Richmond, Ohio; of Prof. Marcou on " Canadian Geological Classification for the Province of Quebec " ; of Mr. Alfred C. Lane on the " Geology of Nahant " ; of Mr. War- ren Upham on " Marine Shells and Frag- ments of Shells in the Till near Boston " ; of Mr. Samuel Garman on the " Evolution of the Rattlesnake " ; and of Prof. Goodall on the " Life and Work of Dr. Asa Gray."
Several archaeological papers, which ap- pear in this volume of the " Proceedings," are also published separately by the Peabody Museum of American Archaeology and Eth- nology, under the title of Palceolilhic Man in Eastern and Central America. They are "Early Man in the Delaware Valley," in- cluding an account of the lately discovered " Rock Shelter " at Naaman's Creek, and descriptions of Palaeolithic implements ; and an account of an implement from the In- diana gravel, by Hilborne T. Cresson ; Prof. G. F. Wright's paper on the " Age of the Philadelphia Red Gravel " ; " Water-worn Implements from the Delaware River," by Dr. C. C. Abbott ; and remarks on the whole subject by President F. W. Putnam. Prof. Wright's paper bears upon the age of the rock shelter and of the implements in the Delaware Valley described by Mr. Cresson, which the author decides are older (perhaps by a thousand years) than the deposits at Trenton, N. J., Loveland and Madisonville, Ohio, Little Falls, Minn., and Medora, Ind. (Cresson).
An Obsidian Implement from Pleistocene Deposits in Nevada, by WJ Mc Gee, discusses the age of a handsome neolithic work found on Walker River, to which the author has already made reference in the " Monthly " (November, 1888, p. 25). The solution of the question is partly dependent upon the char- acter of the occurrence of the implement whether it be adventitious or normally in situ. The deposit being unconsolidated, this can not be determined certainly without the help of other human relics found in the same place to keep it company ; and such have not been found. But, since the implement was ob- served, the discovery of other extremely an- cient relics in various parts of the country
��has given color to the hypothesis that this was an original deposit ; and the author now inclines to that view.
The Aborigines of the District of Colum- bia and the Lower Potomac a symposium in the Anthropological Society of Washing- ton besides an address by Otis T. Mason, introducing the subject, contains papers on " The Geological Antecedents of Man in the Potomac Valley," by W J McGee ; " The Palaeolithic Period in the District, of Colum- bia," by Thomas Wilson ; " Ancient Village Sites and Aboriginal Workshops," by S. V. Proudfitt ; " The Pottery and Textiles of the Tide- Water Region," by W. H. Holmes; "The Shell Mounds of the Potomac and Micomico," by Elmer R. Reynolds ; " Indian Tribes of the District," by James Mooney ; and a discussion by Prof. F. W. Putnam.
Of six additional " Bulletins " of the United States Geological Survey, No. 48 is On the Form and Position of the Sea-Level, with special reference to its dependence on superficial masses symmetrically disposed about a normal to the earth's surface, by Robert Simpson Woodward. The treatise is mathematical, and relates to a problem of peculiar difficulty, the solution of which has been as yet only approached. The same author's Latitudes and Longitudes of Certain Points in Missouri, Kansas, and Neiv Mex- ico, constituting " Bulletin No. 49," relates to the processes of determination at Oswego, Elk Falls, and Fort Scott, Kan. ; Springfield and Bolivar, Mo. ; and Albuquerque, N. M. The author has endeavored to collect, arrange, and discuss the observations in such a man- ner as to render their results most useful for the purposes of geography and geodesy. Bulletin No. 50, also by Mr. Woodward, con- sists of Formulas and Tables to facilitate the Construction of Maps. The tables were pre- pared for the Division of Geography in 1885-86. Constant use since then has demonstrated their utility. They have been revised and extended, and are accompanied by an explanatory text. Dr. Charles A. Wldte gives, in Bulletin No. 51, descriptions of some Invertebrate Fossils from the Pacific Coast. They fall under five headings : " New Mollusca from the Chico-Tejon Series of Cali- fornia," representing nineteen new species and one new genus ; " The Occurrence of Equiv- alents of the Chico-Tejon Series in Oregon