FOSSIL VERTEBRATES — AMPHIBIA 507 
Amphibamus and Pelion are from the Carboniferous beds of 
Ohio. In the first genus the body was rather long; the legs 
were short with the posterior pair somewhat the largest; the 
head was rather large and rounded; the teeth were numerous 
and set close together. Pelion had a rather shorter and broader 
head, the legs were longer and better developed. 
Mrcrosaurta.—These were in many ways the most highly 
developed of the Ladbyrinthodontia; the vertebre, as already 
explained, approached more nearly the modern type of reptilian 
vertebre than any of the group. Their advanced position is 
evidenced by other parts of the body as well as the vertebre ; 
all the bones of the body are more perfectly ossified; the bones 
of the skull are set more firmly together, and the lmbs are 
longer and stronger so that the animal was able to raise the 
body from the ground, and must have possessed a considerable 
degree of agility. The carpus and tarsus were ossified, and 
there were well-developed claws on the feet. Many remains 
have been found in the trunks and stumps of fossil trees in the 
working of the quarries in the South Joggins coal region of 
Nova Scotia, showing that the animals were to some extent at 
least arboreal in their habits, and that they had reached a free- 
dom of motion and a range of habitat far in advance of that 
of the other amphibians of the time. It is to this group that 
we must look, in all probability, for the direct ancestors of the 
reptiles. The name Sawromorpha has been given to the group 
in recognition of the close relation between it and the Reptilia. 
Hylonomus and Hylerpeton are forms from the South Joggins 
quarries of Nova Scotia. They were rather elongate in form, 
with a lizard-like appearance. The vertebra were well devel- 
oped, and the whole body was covered with bony scutes instead 
of the ventral surface only as in most of the forms. The teeth 
were smooth at the base, but near the top the dentine was some- 
what plicated. These were among the best developed of the 
amphibian forms. It is interesting to note the occurrence of 
the same genus, //ylonomus, in Nova Scotia and in Bohemia. 
From the Carboniferous rocks of Ohio, near Linton, have 
