168 Scientific Intelligence. 



J. W. Powell. So that this special committee of the American 

 Association " on the International Congress of Geologists," now 

 consists of James Hall, J. S. Newberry, T. Sterry Hunt, C. H. 

 Hitchcock, Raphael Pumpelly, J. P. Lesley and the names added 

 as above. Its officers are James Hall, chairman ; Persifor Frazer, 

 secretary ; and C. H. Hitchcock, treasurer. 



The third committee is the Committee of the International 

 Congress, appointed by the council of the London meeting of the 

 Geological Congress to organize an American Session of the 

 Congress, and is technically known as the American " Comite 

 d'Organisation," or Committee of Organization. And it is the 

 only American Committee of the Congress. It is composed of the 

 following gentlemen : 



Messrs. Branner, Chamberlin, Cope, Dana, Davis, Dutton, 

 Frazer, Gilbert, Hague, Hall, Heilprin, Hitchcock, Hunt, Le 

 Conte, Leidy, Lesley, Marsh, Newberry, Powell, Procter, Shaler, 

 Stevenson, Walcott, Whitfield, Winchell and Williams. 



Its officers are J. S. Newbei-ry, chairman ; G. K. Gilbert, vice- 

 chairman ; and H. S. Williams, secretary. h. s. w. 



2. Professor Wm. M. Fontaine on the Potomac or Younger 

 3Iesozoic Flora. — This new volume of the U. S. Geological Survey 

 has been mentioned with high commendation by Mr. Lester F. 

 Ward, in the last volume of this Journal. Professor Fontaine 

 closes the volume of 377 pages, with an extended and thorough 

 comparison of the genera and species of the Potomac flora with 

 those elsewhere of the Jura-Trias and Cretaceous periods, and 

 ends with thirty pages of tables, twenty of which are a further 

 exhibition of these relations. We cite the last page preceding 

 the tables, presenting Professor Fontaine's conclusions from the 

 plants as to the age of the Potomac deposits. 



" Taken as a whole, then, and compared with the Cenomanian 

 flora of the Dakota and New Jersey Cretaceous strata, the angi- 

 osperms of the Potomac decidedly point to the Neocomian as the 

 age of the Potomac beds. 



" From this brief review of the flora, we see that there is in it a 

 very large and important element that belongs to the Jurassic or 

 typical Mesozoic flora ; a less important but still large element, 

 that has near relations in Cenomanian and even living forms; 

 while the largest, most fully developed and characteristic element 

 is most nearly allied to forms distinguishing the Neocomian. All 

 the important species common to the Potomac and the floras of 

 known formations are found in the Neocomian, including under 

 this name both the Wealden and Urgonian. If any additional 

 evidence were needed of the Neocomian age of the Potomac, it 

 may be found in the peculiar union of old and new types, whose 

 evidence, if we consider them by themselves, is conti'adictory. 

 Schenk, in Die Foss. Pflanz. der Werns. Schichten, page 29, in 

 speaking of the character of the Neocomian flora of the Werns- 

 dorf beds, well says that the flora of the older Cretaceous occupies 

 in the development of the plant kingdom a position similar to that 



