274 S. L. POWELL 



Medina to the base of the Cambrian, with each in practically 

 normal development. The section embraces the following mem- 

 bers: 



Medina sandstone, gray sandstone, quartzitic 400-500 feet 



Sevier shales, calcareous shales and sandstones, and bluish-gray 



impure limestone. All very fossiliferous 1,200 feet 



Utica shale, fossiliferous blue to black shales, and limestones with 



shale partings 300 feet 



TeUico sandstone, red and gray sandstones 400 feet 



Trenton, dark gray-blue, and black limestones with shale partings 500 feet 

 Athens shale, black carbonaceous shales, carrying graptolites, 



trilobites lingulas 560 feet 



Black River, coarse dark coralline limestone with bands of smoky 



marble in upper part 250 feet 



Birdseye (Lowville), pure dove limestone, with Tetradium 50 feet 



Chazy, cherty magnesian limestone, with Maclurea magna 500 feet 



Beekmantown, pure and impure, cherty and magnesian limestone 1,700 feet 



As the Ordovician is now known to extend as far south as 

 Alabama, evidenced by the finding of Ordovician graptolites by 

 Professor E. A, Smith, and as the writer has found Ordovician 

 fossils in the black slates in eastern Virginia, and as the Ordovician 

 is known to occur far to the north and west of this point, it is but 

 fair to presume that the sediments represented in the rocks of this 

 section were laid down far within the confines of that ancient sea 

 and that the section is therefore in normal development. Further- 

 more, as will presently be shown, the fossils — graptolites and 

 others — occurring here are the same as those found in equivalent 

 strata in New York and Canada, and Dr. Ruedemann makes the 

 statement that the essential identity of the Alabama fauna with 

 the Normanskill graptolite fauna cannot be gainsaid. It therefore 

 seems most probable that the sea was open and continuous from 

 Alabama to Canada, and that sedimentation was virtually the same 

 throughout. The section here should, therefore, be practically the 

 same as in New York. A notable difference occurs in the Tellico 

 sandstone, which, however, may be but an expansion of the Dolge- 

 ville shale, a name proposed by Cushing in 1909 for the shaly phase 

 of the upper Trenton which he previously described as "Trenton 

 Utica passage beds." It may therefore be stated with greater 



