414 Concerning Foot-Prints. [July, 
After a time the skeletons of some of the Carboniferous reptiles 
were brought to light. One of the earliest and most interesting 
of these discoveries was made by Lyell and Dawson, while ex- 
amining the stump of a Sigillaria, one of the most common trees 
of the coal swamps, which had been buried in the sand that now 
forms the thick beds of sandstone at the South Joggins, Nova 
Scotia. The stump in question seems to have rotted away in the 
interior during the time when it was partially buried in the sand, 
so as to form a convenient retreat for the reptiles that made it 
their home, and in which they died as they were entrapped by 
the sand, which at length filled the stump and preserved the re- 
mains. Other skeletons of Carboniferous reptiles have since been 
discovered in considerable abundance at Linton, Ohio. A care- 
ful study of these remains has shown that there was no lack of 
diversity or of ornamentation and beauty among the reptiles 
that recorded their existence on the sands of the Carboniferous 
sea-shore, the authenticity | of which has been so abundantly 
verified. 
In the Triassic period, which 
next succeeds the Carboniferous 
age in geological history, another 
great advance was made in the 
progress of life on the earth by 
the appearance of birds, which, 
as a class, stand next above the 
reptiles in the zodlogical scale. 
The existence of the feathered 
tribes during the Triassic period 
was first made known by the 
covery of their foot-prints in the 
red sandstone of the Connecticut 
(Fic. 79.) SLAB OF TRIASSIC SANDSTONE valley. 
WITH TRACKS OF BIRDS AND REPTILES. The Triassic formation in which 
these i impressions were found fills the greater part of the Connect- 
icut valley, and is again largely developed in New Jersey, afford- 
ing in that State the red shales and sandstones so well known to 
travelers over the various railroads that radiate from Jersey City. 
It is this formation that furnishes the “ brown stone ” so largely 
used for architectural purposes in New York and the neighboring 
cities. The same formation stretches southward as far as Vir- 
ote - North Carolina, where it contains highly valuable beds 
of coa 
. 
