FROM THE PHOSPHATE BEDS OF SOUTH CAROLINA. 241 



The breadth of the tooth is nearly 21 inches; its median height 8f lines, and 

 at the sides 4 lines. The width of the crown fore and aft is about 5 lines, and its 

 thickness at the middle about the same, while at the sides it is but 1| lines. 



Myliobates gigas. 

 Cope: Proceedings Academy Natural Sciences, 1861, 140. 



This species was first described and named by Prof. Cope from remains found 

 in the miocene formation of Charles Co., Maryland. Of the specimens, presented 

 to the Academy, the best is represented in figure 4, Plate xxxiii. It consists of a 

 dental pavement, indicating by its strongly arched condition antero-posteriorly 

 that it pertained to the roof of the mouth. It retains portions of thirteen median 

 teeth, together with part of two rows of lateral teeth on one side, and of one row on 

 the other side. In its present state it measures four inches in its extreme length. 

 The fore part of the pavement including six median teeth is more than half broken 

 away, while the remaining portion of the same teeth is much abraded from the 

 attrition of food. The pavement is comparatively thin in proportion with its 

 breadth. The triturating surface is convex transversely, and is more curved at the 

 sides than across the middle. It is nearly even and smooth, and exhibits but 

 feeble striation fore and aft. The median teeth and their intervening sutures are 

 straight along the middle, but curve backward at the extremities. The posterior 

 median teeth are wider fore and aft than the more anterior ones. 



Two lateral rows of teeth appear to have completed the dental pavement at the 

 sides. In the specimen the teeth of the inner lateral row are not symmetrical on 

 the two sides, three on the right being longer than broad, while three of the left 

 are nearly equal in the same directions. Their front and back sutures are the 

 shortest, and slant outward and backward; the antero-internal and postero-external 

 sutures are intermediate in length to the former and those opposite to them. The 

 teeth of the outer row are convex along the external border, but more abruptly 

 rounded posteriorly. 



The upper or attached surface of the dental plate is feebly elevated at the 



lateral borders and middle. 



The posterior seven median teeth, except the last one, occupy an extent of two 

 and a half inches. The breadth of the median teeth is 3 in. 2i- lines. The width 

 fore and aft of the seventh median tooth is 4 lines ; of the twelfth tooth, 5 lines. 

 The thickness of the dental plate at the middle is 61- lines. 



A fragment of a second specimen presents nearly identical characters, but is 

 less even on the triturating surface due to the slight prominence of the anterior 



