Sept. 1847.] 267 



given ; the structure of the dentine is not as compact as in C. megalodon. 

 A partial description of this fine species was given in a previous paper 

 published in the Proceedings of the Academy, when I named it after the 

 distinguished pioneer of Tertiary Geology in the United States, Dr. Samuel 

 Geo. Morton. 



2. Carcharodon acntidens. This beautiful species resembles C. agus- 

 tidens, Agassiz, but is very acutely pointed. Of four specimens which 

 are in my cabinet, the largest cone measures three inches, and it is more 

 than three times the depth of the root, which is concave, very thick and 

 prominent on the inner face. The body of the tooth, or enamelled portion 

 is conical, the lower third swollen, widest next the lateral denticles which 

 are distinct from it. The inner face is arched, while the outer is nearly flat, 

 though undulated by depression next the edges, and having a deep furrow 

 longitudinally in the middle near the base of the enamel, which extends to 

 the root. This does not extend as low on the inner face, and is sloped, 

 leaving an interspace next the root. The cutting edges are sharp and finely 

 indented, the serratures very close. Most of the specimens are straight, but 

 I have two which are oblique. There are examples of this species in the 

 Cabinet of the Academy. 



3. Carcharodon lanciformis. Very flat, acutely pointed, triangular, nearly 

 equilateral, the posterior edge slightly sloped, while the anterior is straight. 

 The root is not much thicker than the base of the cone, very concave, the 

 rami not symmetrical, one being much longer than the other ; in the small 

 lateral teeth this, however, is scarcely perceptible. The edges are sharp and 

 finely indented ; the inner face elevated ; the outer plane, in some specimens 

 concave. Viewed laterally, some are much bowed or arched forward. In 

 the middle of the outer face near the base of the enamel, is a longitudinal 

 depression, the sides of which are elevated and unite above the horizontal 

 middle line, and form a ridge to the apex. It has lateral appendages, which 

 are not distinct from the principal cone. The enamel extends lower on the 

 outer face than on the inner. 



I have a series of specimens from the Eocene beds of Ashley and Cooper 

 rivers, S. C. 



4. Oxyrhina Desorii. Prof. Agassiz described under this name specimens 

 which subsequent experience induces him to consider identical with Lamina 

 cuspidata, with which he had noticed a resemblance. 



I take pleasure in restoring the name of the distinguished M. Desor, the 

 friend and co-laborer of M. Agassiz, in this department of science, to a fine 

 species in my cabinet. 



It is very massive thicker than any other of this genus in this respect 

 resembling Oxyr. crassa, but not so broad. Viewed en profit, the form is 

 similar to Lamna Hopei, much curved inwardly, except near the apex, which 

 is flat. The edges are cutting in their whole extent, the base of the enamel 

 arched, and nearly equal on both faces, the root very thick, compact and 



