EXTINCT AMPHIBIA OF NORTH AMERICA 47 
lines which represent them are, however, distinct. A portion of the 
scutes are missing and part of them are obscured by lying over the 
vertebral column. They are all somewhat shifted to the left. The 
lines are very small and close together. I count sixteen of them in a 
distance of two millimeters. In 
length the longest line preserved is 
a little more than four millimeters, 
measuring from the point of the 
chevron. ‘The lines representing the 
scutes came to a point in a median 
ridge which is now represented by a 
line. The dermal scutes on the abdo- 
men were probably the forerunners of 
the abdominal ribs of the reptiles. 
The impression of the tail contains 
some of the most interesting features 
in the entire specimen. Scattered over 
it and in places laid in a mosaic are 
impressions of small dermal scales 
which may have covered the entire 
body. In form the scales are ovoid, 
being half as wide as long (Fig. 6). 
The markings on the scales partake 
of the nature of radiating lines much 
after the pattern of the sculpturing 
of the cranial bones in many of the 
Fic. 4.—The banded color- 
foe markings on the tail of Micrer- 
scales are less than one-half a milli- — peton. xs. 
Microsaurial and later forms. The 
meter in diameter and their character 
can only be ascertained under high magnification. Near the middle 
part of the tail there are preserved distinct transverse bands of 
a dark color (Fig. 4). These markings are more or less evident 
throughout the entire tail impression but they are elsewhere not 
so distinct as in the central region. The lines are evidently due to 
rows of pigmented scales and in all probability the animal’s entire 
body was transversely striped. 
The most interesting and important single structure discovered on 
