349 [Cope. 
1872.] 
STRATODUS. Cope. 
This genus is well characterized by its dentition, which is remarkable 
for the small size and large number of the teeth, and their peculiar form. 
I possess one premaxillary, a considerable part of the maxillary, and 
nearly the whole of both palatines, besides other bones of one species. 
These were found not very far from the remains of the Cimolicthys 
semianceps m. and it required some investigation to determine the rela- : 
tionship between them. Ihave, however, portions of the maxillary and 
premaxillary of Cimolichthys, and both of these elements are so very un- 
like those in Stratodus, that there can be no doubt of its independence. 
T have, unfortunately, no dentary bone of Stratodus, and the outer row 
of palatines resembles in some measure those figured in Odmolichthys 
levesiensis, Leidy, by Agassiz. 
The premavitlary teeth are in two series. They are stout at the base 
and oval in section, and are contracted and flattened rapidly upwards. 
On this basis is set an oval sharp edged flat, or spade-shaped crown, the 
long axis of compression being placed at right angles to that of the com- 
pression of the apex of the base. This gives a barbed appearance. The 
muxillary teeth are similar in form, but are in but few rows. The pala- 
tine teeth are constructed on the same plan, but they are longer, and the 
bases are subcylindric and slightly curved. All the teeth possess a large 
pulp cavity. 
The premazillary bone displays some of the density of composition seen 
in Lnchodus. Its upper anterior surface meets the inferior of an acute 
angle. It is a broad oval, and is slightly concave. The inner face forms 
a truncate rim round the bases of the inner teeth, and terminates in a 
vertical crest of dense bone. ‘The external face is, on the other hand, 
perpendicular, and extends obliquely upwards and backwards. An acute 
anterior angle of the maxillary under-runs it below, so far as to exclude 
all but one or two of the premaxillary teeth from the outer row. The 
external lamina of the premaxillary forms an extensive squamosal suture 
with this part of the maxillary by overlapping it from above. 
This arrangement shows a certain similarity to Hsox, especially in the 
large number of palatine and small number of maxillary teeth. It dif- 
fers materially in the lack of articular surfaces between the maxillary, 
palatine, etc., in the upward prolongation of the premaxillary, and the 
peculiar forms of the teeth. 
STRATODUS APICALIS. Cope. sp. nov. 
Established on one incomplete individual, as above mentioned. 
The maxillary teeth are mostly smaller than the premavxillaries, and 
diminish in size posteriorly ; there are four or five series of them an- 
teriorly, Seven to nine rows on the palatine bones ; they are slender and 
curved downwards from oblique bases, and cylindrie in section ; they 
contract to a neck and then expand into the ovate spade-shaped cutting 
apex. They are in every respect the largest of the teeth, some making 
