GENERAL OBSERVATIONS. 299 



geologists as Devonian, though suspected to be Triassic. The animal appears 

 to have been more Lacertian than Batrachian; and this superiority to other 



Fig. 520. 



Telerpeton Elgiuense. 



species of the next period is partly the occasion of the doubt as to its being true 

 Devonian. In the same quarry there have been observed thirty-four consecutive 

 footprints of a four-footed animal which was probably amphibian. The tracks 

 of the fore-feet are one inch broad, and those of the hind-feet three-fourths of 

 an inch, while the stride was four inches. 



GENERAL OBSERVATIONS ON THE DEVONIAN AGE. 



American Geography. — 1. General features. — The facts gathered 

 from the Silurian strata lead us to conceive of the age — far the 

 longest of all the ages, excepting the Azoic — as one of small, barren 

 lands in the midst of great waters. We may suspect the existence 

 of land-plants ; yet the suspicion is not sustained by observation. 

 But before the Devonian age had half passed, the land had become 

 covered with vegetation, preparatory for a freer and nobler life 

 than that of the waters. Still, the dry land of the continents had 

 increased but little in extent. The Azoic area, which had been 

 enlarged on the north by successive additions from emergence 

 during the Silurian, had expanded farther in the same direction, 

 until, at the close of the Devonian, the State of New York formed 

 a part of the land that bore the new vegetation. For, as seen on 

 the map, p. 170, the rocks which succeed one another reach less 

 and less far northward, proving that there was this progress south- 

 ward with each period. 



The general map on page 133 shows the area over which the 

 Silurian and Devonian formations are now uncovered in other parts 



