78 PROCEEDINGS OF THE NATIONAL MUSEUM vol.76 



New York are too well established to require further comment here. 

 But the case of the succeeding Galena dolomite is quite different. 

 The more I study this formation the less I am satisfied with the 

 rej)uted Trenton age of its typical parts. Provisionally, and mainly 

 to emphasize my doubts regarding its precise age, I have moved it 

 up in the scale opposite the Cincinnatian. At present it seems that 

 the dolomite in the vicinity of Dubuque, Iowa, is certainly a younger 

 formation than the Kimmswick limestone of Missouri, with which 

 it has been correlated by other geologists ; and some of the beds that 

 have been assigned to the Galena in Wisconsin are older than Tren- 

 ton, whereas others are younger than the Maysville of Ohio. A 

 special paper needs to be written about the Galena. 



Ohio Valley. — No deposits of the Buffalo River series occur in 

 Tennessee, but in Kentucky a calcareous phase of one of its sand- 

 stones is found in deep wells as far south, at least, as Lexington. 

 Over it are at least three of the limestone formations that make up 

 the Stones River group in central Tennessee. This group attains 

 greater thickness in the western third of the Appalachian Valley, 

 but pinches out completely and rapidly to the west of the Cincinnati 

 anticline. The absence of the southern Appalachian Mosheim lime- 

 stone in both Kentucky and central Tennessee is a notable feature 

 of this column. Formerly the Mosheim was believed to be included 

 in, or to underlie, the horizon of the Murfreesboro limestone. How- 

 ever, in August of 1928 Doctor Butts and I studied a completely 

 exposed section in the eastern part of Lee County, Va., in 

 which both formations occur in typical development and in which 

 the Mosheim overlies the Murfreesboro. In the next Orclovician 

 belt to the southeast the Murfreesboro is absent and the Mosheim 

 as usual in contact with the eroded top of the Canadian system. 



In Kentucky and Middle Tennessee the Lowville limestone of the 

 Black River group is in contact with the tdp of the Stones River, 

 the great Blount group and also the succeeding Little Oak limestone 

 of east Tennessee and Alabama being absent. The Black River also 

 lacks some hundreds of feet of limestone beds that are present in 

 the section of Mulberry Valley north of Sneedville, Tenn. The 

 Trenton, however, is more fully represented, though its beds and 

 fossils are very different from the beds and fossils of similar age in 

 New York and Pennsylvania. The Prosser of Minnesota, being 

 closely akin to the New York Trenton, differs in like manner from 

 the Trenton of Kentucky and Tennessee. Evidently the New York- 

 Minnesota Trenton faunas invaded the continent from a different 

 source than that which supplied the life of Trenton formations in 

 Kentucky and Tennessee. As these northern and southern facies of 

 the Trenton have not yet been found interfingering or mingling 



