168 
The American Geologist. 
M arch, 1896 
The antero-clorso-lateral plate is in an excellent condition 
to show the tenon in its almost vertical position with perfect 
distinctness. The socket for the reception of the tenon is also 
preserved in the left exoccipital, the only one visible. The 
outline of the posterior part of this plate, the supra-scapula, 
is somewhat restored and may not be quite true to nature. 
In the second specimen the parietal on the left side is well 
shown in connection with the supra-occipital and the margi¬ 
nal plates on both. The outer border of the post-orbital oan 
be traced, outlining the cavity for the eye. 
The point of the head is distinct and its heavily pyritized 
condition suggests the probability that it was largely carti¬ 
laginous, a supposition which is borne out by the similar state 
of the crania of some of the other species of Titanichthys. 
The fore part of the cranium was apparently very narrow 
so far as its osseous portion was involved, but it may have 
been extended below or outside of the orbits with cartilage. 
The sub-orbital or maxillary plates are both preserved and 
are reproduced in plate X, both inside and outside. The 
strong shoulder for the support of the great shear-tooth is vis¬ 
ible and in the outside view the shear-tooth itself may be seen. 
It still lies in its place in the bone of the right side. The in¬ 
side figure in the plate is for convenience taken from the left 
sub-orbital reversed. 
One other point deserves a passing word, though more as a 
curious fact than for any valuable deduction that it can fur¬ 
nish. In the hollow of the left sub-orbital plate and exactly 
in the spot where the eye was situated lies a roundish mass 
which, it is scarcely doubtful, represents the eye itself. No 
details can be made out. It is simply a mass of crystallized 
pyrites resembling that which has replaced the snout of the 
fish, but its position and form render the origin here suggested 
the only probable view. 
So small a species of Titanichthys as the one represented by 
the plates here figured cannot have been a very formidable in¬ 
habitant of the waters of the Appalachian sea. Whatever its 
dentition may have been, it must have been quite defenseless 
beside its greater congeners, omitting all mention of the di- 
nichthyids. No evidence regarding the food of these species of 
fishes has yet come to light. Their plates are always found 
