OCT. 1906. FOSSIL FISH-SPINE, PHLYCTAEN ACANTHUS TELLERI. 165 
be found, as those portions secured are generally in a very good 
state of preservation, the large quantity of high explosives used 
in getting out the limestones, which, while fine grained and rather 
uniformly stratified, break up very irregularly and almost in- 
variably furnish the collector with a quantity of fragments almost 
impossible to assemble, and in most cases furnish even a poor 
conception as to what portion of the specimen they should be 
assigned. 
The figure shown on plate I is that of the type specimen. As 
found the spines are uniformly almost flat on both their right and 
left faces and of a nearly uniform thickness from the anterior to 
the posterior margins. The writer, who has been familiar with 
all of the specimens collected in the past twenty-five years, has 
never observed but one specimen in any other form, and that one, 
while showing a strong tendency to be triangular in its section, 
preserved no indications whatever of a posterior margin. The 
anterior margin is slightly rounded, and has an irregular arrange- 
ment of tubercles down its face to the angle of the spine (Plate 2), 
below which none have been observed. As noted by Dr. Eastman, 
the tubercles on the lateral faces are without any regular arrange- 
ment, unless in a few cases where the lines of growth are promi- 
nent there seems to be a tendency to parallel those lines ; the 
double row of tubercles noted by him on the posterior angle we 
find to occur only on a small portion of the upper part of the 
spine, below which we find the angular sulcus as described, but 
without tubercles, the greatest width of the spine being at the 
angle on the anterior face which is at or about the bottom line 
of the type specimen. Plate 2 is that of another specimen in 
which the angle of the anterior face, the curvature of the upper 
portion of the spine and that portion below the angle is most 
beautifully shown. Plate 3 is that of left face of another speci- 
men of the spine from slightly above the angle of the anterior 
face downwards toward the inserted portion, showing a length 
very nearly equal to the length of spine above the angle. At the 
base of this specimen, at about the middle of the left face, we find 
a line running diagonally towards the posterior face. This we 
at first supposed to be a fracture of the spine, or, if possible, the 
line of a vascular canal, and which later proves to be the portion 
of another spine. 
