EXTINCT AMPHIBIA OF NORTH AMERICA 39 
America and Europe. The lizards find their counterpart in the 
Hylonomidae and the Tuditanidae. The turtles are represented by 
Dissoro phus and its allies from the Texas Permian and the crocodilian 
aspect of the fauna is found in the large labyrinthodonts of the 
Permian, but more especially of the Triassic. 
The Amphibia whose remains are found preserved in the Carboni- 
ferous rocks of North America all belong to the order Stegocephala, 
characterized by the completely roofed-over cranium and the great 
development of the parasphenoid. Five suborders of the Stegoce- 
phala may be recognized. ‘These are: The Branchiosauria, The 
Microsauria, The Aistopoda, The Temnospondyli, and The Stereo- 
spondyli. All five of these suborders are represented in the Carboni- 
ferous of North America but it is our purpose here to examine only 
forms belonging to the first two suborders, i.e., the Branchiosauria 
and the Microsauria. 
The Branchiosauria were salamander-like in form and were, for 
the most part, devoid of the heavy dermal armor of many of their 
contemporaries. ‘They were naked, with the exception of small ovoid 
scales on the back and the chevron-shaped armature of the ventral sur- 
face which was almost universally present among the Carboniferous 
Stegocephala and may have been present in the Amphibia as late 
as the Laramie Cretaceous. ‘The tail was rather long and flattened 
from side to side and the creatures were adapted for life in the water 
for at least the early part of their existence, as is shown by the posses- 
sion of gills in many of the Permian and late Carboniferous 
forms of Europe. The group of the Branchiosauria are without 
doubt the direct ancestors of the modern salamanders and perhaps of 
the other groups as well. No branchiosaurian has ever been described 
from so low in the geological series as the one here given and it is the 
first evidence of the occurrence in North America of a group which 
was so abundant in Europe during the Permian. 
MICRERPETON CAUDATUM gen. et sp. nov. 
(Figs. 1-7) 
The genus Muicrerpeton, of which the single species is described 
below, is the only evidence of the occurrence of the Branchiosauria 
in North America, and as such is of unusual interest. There have 
