DAVIS : FOSSIL FISH EEMAINS. 
51 
group of teeth is distinguished by the prevaiHng prominence of 
the buttressed condition of the anterior coronal borders, and the 
relative uniformity or evenness of the posterior face, besides the 
relatively fewer rows of acuminate teeth, as inferred from this 
feature being so prevalent in all collections of Orodi, while the 
linear forms are least commonly met with. The authors also state 
that in addition to the teeth and pieces of cartilaginous matter 
which appear to have formed the supports of the jaws, 
there were a number of exceedingly small bodies " irregularly 
circular in outline, with a depressed convex coronal portion, which 
rises into an eccentric acumination or transverse ridge along one 
side, and delicately sculptured with irregular carina radiating from 
the apex towards the marginal borders." Below they are concave. 
No two specimens appear to be exactly alike, though they have a 
general resemblance, especially in the dark horny luster of the 
enameled crown, by which they are readily distinguished from 
the teeth with which they are associated. It seems not improbable 
that these minute bodies constituted part of the dermal covering 
or shagreen of the fish. 
The description of the fossil Agassizodus from the Kansas 
coal measures bears a close resemblance to the description given 
by Prof. Owen of the dentition of the modern Cestracion, and as 
the subject forms one of the few rare instances in which one of 
the earlier plagiostomous fossil fishes can be reliably compared 
with an existing form, I venture to give Prof. Owen's description 
as follows, " The teeth at the anterior part of the jaws are the 
smallest ; they present a transverse, sub-compressed, conical 
figure, with the apex produced into a sharp point ; these points 
are worn away from the used teeth at the anterior and outer parts 
of the jaw, but are strongly marked in those which still lie below 
the margin. There are six subvertical rows of these small cuspi- 
date teeth on each side of the jaw, together with a median row 
close to the symphyseal line ; and from twelve to fourteen teeth 
to a row. Behind the cuspidate teeth, the five consecutive rows of 
