622 



SCIENCE 



[N. S. Vol. XXVII. No. 694 



This exhibit is shortly to be transferred to 

 Brooklyn. 



The Bulletin of the Boston Society of Nat- 

 ural History for March gives notice of the 

 coming meeting of the geologists and mineral- 

 ogists of the northeastern section of the 

 United States, to be held in New York, April 

 6. It also gives a description of the botanical 

 collection of the society and the work in its 

 development. 



Leaflets Listing and Describing Birds of 

 Oregon may be added to the ever-increasing 

 number of publications whose intent is to 

 furnish inforniation as to the habits and value 

 of birds and the desirability of protecting 

 them. These just mentioned are intended 

 largely for use in the public schools. No. 1, 

 by William L. Finley, treats of the " Study 

 of Birds and Their Economic Value " ; No. 2, 

 by the same writer, tells of " Some Common 

 Birds of Oregon with Notes on their Eco- 

 nomic Value." 



SOCIETIES AND ACADEMIES 



THE SECTION OP GEOLOGY AND MINERALOGY OP 

 THE NEW YORK ACADEMY OP SCIENCES 



The regular monthly meeting of the Sec- 

 tion of Geology and Mineralogy of the New 

 York Academy of Sciences was held on Mon- 

 day evening, January 6, 1908, at the academy 

 rooms in the American Museum of Natural 

 History, New York City. 



The section authorized the officers to 

 arrange for a joint meeting of sections and 

 departments of geology and mineralogy from 

 neighboring academies, museums, surveys and 

 colleges to be held in April. Invitations are 

 being prepared and will be distributed through 

 New England and the Middle Atlantic States. 

 Two papers were presented, the titles and 

 abstracts of which follow. 

 A Revised Classification of the North Ameri- 

 can Siluric System: Amadeus W. Geabau. 

 A review of the successive modifications of 

 the classification of the Siluric system in 

 North America brings out the fact that the 

 process of refining has been largely by sepa- 

 ration off from this system of those divisions 

 not properly belonging to it. Thus Dana in 

 1863 (first edition of the "Manual") in- 



cluded the Ordovicic and Cambric as Lower 

 Silurian, dividing it into Potsdam, Trenton 

 and Hudson, and dividing the Upper Silurian 

 into Niagara, Salina and Lower Helderberg. 

 In the fourth edition of the " Manual " (1895) 

 the Cambric, Ordovicic and Siluric systems 

 are recognized as distinct, though the name 

 Lower Silurian is still preferred for the 

 Ordovicic. The three-fold division of the 

 Siluric is into (1) Niagara, (2) Onondaga 

 (Salina), and (3) Lower Helderberg. In 1899 

 Clarke and Schuchert published their revised 

 classification of the New York series, which 

 has been pretty generally adopted. In this 

 the Helderbergian exclusive of the Manlius 

 was separated as Lower Devonic, while the 

 remainder of the Siluric (Niagara and Onon- 

 daga (Salina), of Dana, 1895) was divided 

 into the Oswegan (Oneida Conglomerate-Sha- 

 wanguhk grit and Medina sandstone), Ni- 

 agaran (Clinton, Rochester, Lockport and 

 Guelph), and Cayugan (Salina, Eondout and 

 Manlius). Since then Grabau and Hart- 

 nagel have independently demonstrated that 

 the Oneida is the equivalent of late Medina, 

 and the Shawangunk, Salina. In 1905 Gra- 

 bau suggested the Richmond age of the lower 

 1,100 feet of the Medina of Western New 

 York,' uniting the upper with the Clinton. 

 These relations were more fully discussed in 

 1906"^ and again in 1907 before the Geological 

 Society of America, New York meeting, after 

 a prolonged investigation of the Appalachian 

 deposits. This relationship is now fully estab- 

 lished and the dividing line between Ordovicic 

 and Siluric is drawn at the base of the Upper 

 Medina or the Medina proper. For the red 

 Medina shales now recognized as of Ordovicic 

 age the name Queenston beds is proposed, 

 from the town of that name on the Niagara 

 River opposite Lewiston, where these beds 

 are partly exposed. 



Recent studies by Grabau and Sherzer in 

 southern Michigan and adjoining regions in 

 Canada and Ohio have demonstrated the exist- 

 ence of about 900 feet of fossiliferous strata 

 above the Salina, to which it is proposed to 

 restrict the name Monroe. These will be fully 



1 Science, XXII., p. 529, October 27, 1905. 



' Bull. 92 N. Y. State Museum. 



