118 HAY—VERTEBRATES OF CARBONIFEROUS AGE. [March 16, 
I have been in much doubt what disposition to make of this 
material. All the specimens show some important differences from 
the descriptions and figures of Dr. Newberry, and they may rep- 
resent a distinct and undescribed species, but of this I cannot be 
sure. On the other hand, if it is identical with Newberry’s spe- 
cies, the latter requires redescription, and an attempt to furnish 
this may result in basing a description on a species distinct from 
that described by Dr. Newberry. 
The striking peculiarity of the type of Dr. Newberry’s Z. pelti- 
gerus and the one which suggested the specific name was the pos- 
session of a series of enlarged scales along the midline of the 
back, both in front of the dorsal fin and behind it. Those in 
front of the fin are said to be four times as large as the ordinary 
scales, and are so figured. Those behind the fin are said to be- 
come modified posteriorly into the strong fulcra of the tail, but 
Dr. Newberry’s figures do not represent any fulcra present. I find 
such enlarged scales in only one of the specimens in my hands, 
that of one of the halves of nodule No. 3, which bears the im- 
pression of a little fish 50 mm. long. In all the other specimens 
they are missing, even when the preservation is such that they 
might be expected. Evidently the opportunity of seeing them 
depends, to a great extent, on the way in which the nodule splits. 
These scales, as shown in the specimen referred to, begin close 
behind the head and continue backward nearly to the fin, but 
there is a brief interruption, probably accidental, about three- 
fourths of the way back. Just in front of the fin they again ap- 
pear and, as shown especially in the Columbia University speci- 
men, they change gradually into fin fulcra. This row of scales 
extends further forward than that described by Dr. Newberry, are 
in greater number and of different form; but all these differences 
may not be important. Immediately behind the dorsal fin I find 
no enlarged scales in any of the specimens. ‘The fulcra begin as 
small, pointed scales and gradually enlarge. 
Excepting the enlarged scales mentioned above, Dr. Newberry 
neither described nor figured any others peculiar in any way. Those 
immediately behind the shoulder girdle and on the flanks are all 
represented as being about as high as long. But in all of the speci- 
mens in my hands which are well enough preserved I find that the 
scales in several perpendicular rows just behind the shoulder girdle 
are twice as high as long. In case Dr. Newberry’s type specimen 
