200 DR. GIBBES' MONOGRAPH OF THE 



" Otodus levis. — This has very much the form of Lamna cuspidata, but the position, 

 form and size of the lateral winglets, mark it as a true Otodus. It is more slender 

 than any other of this genus, lanciform, equilateral, straight, convex on the inner 

 face, and undulated on the outer from a triangular depression near the base, extending 

 longitudinally nearly to the apex. The lateral cones are broad and thick, and 

 detached from the base of the enamel, which extends lower on the outer face than on 

 the inner, I have a single specimen (Fig. 141) from the Eocene of South Carolina." 

 I have since seen one in the cabinet of the Academy from New Jersey. 



4. O. CRA.SSUS, Agassiz. Fig. 142. — This species is distinguished by a 

 considerable thickness, but not as thick as 0. ohliquus. Contrary to other species, 

 the root has not a marked preponderance. Instead of the outer face being swollen, 

 or strongly prominent, in this it is flat, even at the base of the enamel. The height 

 of the cone does not equal the length of the root. The surface of the enamel is 

 finely striated on both faces. The lateral cones are absent in the only specimen I 

 have seen, but of the identity of the species I have no doubt. 



It is from the Cretaceous of Alabama. 



5. O. MACROTUS, Agassiz. Figs. 143, 144. — This is flat in proportion to its size, 

 and is characterized by large compressed, rounded, lateral denticles, detached from 

 the principal cone. The outer face is a plane, the inner full, moderately rounded' 

 with faint striae visible. The base of the enamel is nearly horizontal, and equal on 

 both faces. The larger specimen figured (Fig. 144) is from the Eocene of South 

 Carolina, the smaller (Fig. 143) from the mouth of Potomac Creek, Virginia, given 

 me by J. G. Bruff, Esq. 



6. O. TRIGONATUS, Agassiz. Figs. 145, 146. — These are small teeth on an 

 elongated base. The cone is straight, pointed, and narrow, with sharp edges. The 

 thickness is not great, the outer face is flat, the inner convex. The lateral denticles 

 are rounded. From San tee, {Eoce?ie) South Carolina. 



7. O. APicuLATUs, Agassiz. Fig. 147. — This species is on the confines of Otodus, 

 lesembles Oxyrhina hastalis, but may be distinguished by a very minute lateral 

 denticle on each side of the cone. It is sharp pointed, the apex a little turned back. 

 The anterior edge is straight or slightly arched, the posterior curved. The outer 

 face is plane, the inner swollen, though less so than in other species of Otodus, which 

 makes it so flat. 



I have figured the only specimen I have seen of this species, from the Eocene of 

 South Carolina. 



