FROM THE PHOSPHATE BEDS OF SOUTH CAROLINA. 251 



XENODOLAMIA.* 



Xenodolamia pravus. 



Shark teeth of an unusual form, from the Ashley phosphate beds, are repre- 

 sented in figures 33-36, Plate xxxiv. I have supposed that these may be sym- 

 physial teeth of Car char odon megalodon, or perhaps of C. angustidens, but I have 

 not been able to determine the question. Nor is it positive that all these teeth 

 pertain to the same species or genus. 



In all the specimens the root exceeds the crown in bulk, and in comparison 

 with the usual condition of the root in the teeth of Sharks has the appearance of 

 being deformed. 



In the largest tooth, figure 33, the crown is demi-conical, somewhat tapering 

 and nearly straight, and its lateral acute borders are denticulate. The length and 

 breadth of the root are nearly equal, and both are much greater than the length 

 of the crown. It forms a prominence at the base of the crown to one side of the 

 middle nearly as thick as the length of the crown on its inner face. The processes 

 of the crown form two cones projecting in the same direction obliquely. Length 

 of the tooth from the bottom of the root notch, 10 lines; length of crown medially 

 and posteriorly, 5| lines; breadth at base, 8 lines; greatest length of root, 8 lines; 

 breadth, 8,f lines; thickness, 4| lines. 



The tooth represented in figure 34 is about half the size of the preceding. 

 The crown is oblique and more expanded laterally at the base, and the borders 

 are more distinctly denticulated. The inner process of the root is proportionately 

 less prominent and the outer one is undeveloped. 



Length of the tooth from the point to the notch of the root, b\ lines; length 

 of crown on the posterior face, 3 lines ; breadth at base, 5f lines. 



Xenodolamia simplex. 



The remaining pair of teeth perhaps belong to a different species and genus. 

 The crown is very much smaller in proportion to the root than in the former, and 

 its lateral borders are not denticulated. 



The tooth represented in figure 35 has a small oblique, demiconoidal crown 

 with a rather wide and slightly recurved summit. The root is of comparatively 

 enormous proportion, and resembles in shape that of the large tooth first described. 



Length of the tooth from the root notch, 5 lines; length of crown, 1| lines; 

 breadth at base, 2f lines; length of root, 6f lines; breadth, 7 lines. 



* Contracted from Xenodontolamia. 



