EXTINCT AMPHIBIA OF NORTH AMERICA 4I 
he stated that the Mazon Creek beds are possibly to be placed some- 
what lower than the Lower Kitanning, so that the deposits are in the 
lower part of the Allegheny series as they are now understood. The 
specimen was collected many years ago by Mr. W. F. E. Gurley at 
Mazon Creek but it has never been studied, although Dr. Newberry 
examined it and pronounced it to be amphibian and said in a note 
that Professor Cope should see it. Unfortunately Cope did not see it 
and it has lain unknown in the collection as unnoticed by students 
as if it were still in its old bed. I am indebted to Dr. Stuart Weller 
for calling my attention to the specimen and to him is due the interest 
which I have taken in the form. 
The specimen (Fig. 1) is exceptionally perfect. Not only are 
nearly all of the skeletal elements present but the general contour of 
the body, the character of the dermal covering, the color-markings, 
the lateral line system, and many other features of interest have been 
detected. Such completeness of preservation is very uncommon even 
among the remains obtained from this locality. In this case the 
entire form was preserved but the collector in cracking the nodule 
lost the chips containing the hands and feet so that portions only of the 
limbs remain. It is thus impossible to determine the phalangeal 
formula, but the feet were probably like those of Branchiosaurus 
amblystomus Cred., as given by Credner, to which the present form is 
closely allied and indeed must be placed in the same family with 
Branchiosaurus, Pelosaurus, and Melaner peton. 
The remains here described represent a small salamander-like form, 
and they are the earliest geological evidence of the group, which with- 
out doubt gave rise to the modern salamanders. ‘The parts preserved 
in the specimen are: the complete outline of the head with the cranial 
elements easily distinguishable and the black pigment of the iris; the 
entire vertebral column including pits in the tail region where the 
vertebrae were without doubt entirely cartilaginous; parts of the 
pectoral girdle; parts of the pelvic girdle; the humerus of the left 
side; the ventral scutellation; the ribs of one side of the body; and 
indications of ribs on the other; portions of both hind limbs and a 
complete impression of the fleshy tail. On this impression of the tail 
are preserved small horny scales, transverse color-markings, and dis- 
tinct impressions of the lateral line system. 
