DESCRIPTION OF PLATES, 
PLATE I. 
Fossils of the Medina sandstone. 
Fig. 1. Dictuolites Beckii. 
— 2. Fucoides auriformis. 
— 3. Fucoides heterophyllus. 
PLATE II. 
Surface of the Medina sandstone, showing the clouded appearance from different kinds of sand, the 
stranded fragments of rock and shells of Lingula. This is a common appearance upon the surface 
of the thin strata over many yards in extent, and throughout a thickness of many feet. 
PLATE III. 
Fin and scales of the Sauripteris Taylori, from the Old Red Sandstone. The fin is a little less than the 
natural size, and the scales are of the natural size. The sauroid character of this fin is well repre¬ 
sented in the arrangement of the bones, as seen in the engraving. 
PLATE IV.* 
Natural section of the bank of the Niagara river, from the falls to Lewiston. The successive strata and 
their disappearance beneath the water are explained upon an inspection of the section. The water 
level is carried on from Lewiston southward, showing a depth of one hundred and four feet at the 
falls, being the actual descent in the surface between the two points. 
* Plates IY, Y, VI, VI a, and VI b, represent almost a continuous natural section from Lake Ontario to the Pcr.n 
sylvania line. The low uninteresting banks occupied by the Onondaga salt group, from near Niagara falls to Black-Roik, 
and some other portions of little interest, are omitted, as being unimportant. 
[Geol. 4th Dist.] 87 
