The Age of the Galena. Livieslone. — Winchell. 33 
Wequetonsing and Peloskey 080 
Traverse Citj' probably a little less than (KiO 
XtPissiXG Reach. 
Above lake Huron.* 
Sault Ste. Marie 70 
Mackinac. St. Ignace, Gros Cap. and McGulpin'.s jioiiit.. \7^ 
Wequetonsing and Petoskey 2.") 
Besides these, there are isolated ridges and terraces at in- 
termediate levels, but as yet no certain correlation of these at 
different places has been made out. 
These notes make the record of observations so far made by 
me in the basin of the upper Great lakes substantially com- 
plete ; and this is the sixth of a series of papers in which they 
have been published. On each of the principal excursions 
from twenty to sixty photographs were taken of the features 
observed. The plates used were 6| by 8^ inches. Many of 
the pictures are good, .although few views of the best sort 
could be obtained on account of the rough and tineultivated 
condition of the countr3^ 
THE AGE OF THE GALENA LIMESTONE. 
By N. H. WiN'CHELL, Minneapolis, Minn. 
[Read at the Brooklyn meeting of the American Association for tlie Advancement of 
Science, August, 1894.] 
From the time of Schoolcraft, who, in 1820, assigned the 
lead-bearing beds of the upper Mississii)pi to the Subcarbon- 
iferous, until now, the Galena formation has been a subject of 
much difference of opinion. W. H. Keating thought all the 
magnesian limestones of the upper Mississippi valley belonged 
above the Coal Measures, and made them the parallel of the 
Lias of Europe. Owen showed that they pass below the Coal 
Measures, and at first (1839) classified the lead-bearing beds 
with the Cliff' limestone of Ohio, which was admitted to be of 
the same age as rocks which in New York state were of the 
Upper Silurian. Locke went further, and made out a fair 
case by placing the underlying beds, which now are generally 
admitted to be of Trenton age, as the equivalent of the Blue 
limestone of Ohio, which was then also supposed to be of the 
*Add581 feet, the mean hight of lake Huron, for hights above the 
sea. 
