246 DESCRIPTION OF VERTEBRATE REMAINS, CHIEFLY 



been in the other tooth. The width of the crown fore and aft at the middle is 4| 

 lines; the length of the root is half an inch. 



Figure 16 represents an inferior tooth with the extremity of the left side lost. 

 The median portion is unsymmetrical, on the right appearing to be more abruptly 

 produced forward than on the left. The side of the tooth narrows rapidly from 

 the median line outwardly. The breadth of one side of the crown is about 1| 

 inches; the width at the middle is 4| lines, and at the outer end 2| lines. The 

 length of the root is half an inch. The breadth of the dental plate, estimated 

 from this specimen, would be about two inches and a third. 



Figure 17 represents the right portion of a superior tooth. The triturating 

 surface is flat at the middle, but slightly convex laterally. The front and back 

 borders are less oblique than in the lower teeth, forming an angle of nearly 10° 

 less. At the middle the same borders are less angularly curved; and the front 

 border at its outer end is more deflected forward. The breadth of one side of the 

 crown is about 16 lines; the width of the triturating surface at the middle is 3| 

 lines; near the outer end where narrowest, 2| lines. The length of the root is 

 about five lines. 



Figure 18 represents a fragment from the left side apparently of an upper tooth. 

 The triturating surface has a greater width than in the preceding specimen, espe- 

 cially towards the middle. The lateral borders appear more oblique and more 

 abruptly deflected inwardly to the middle than in the former. Width of the 

 triturating surface fore and aft at the middle, 5| lines; at the side, 2| lines. 

 Length of the root, 9 lines. 



Perhaps this specimen may pertain to a diff"erent species from the preceding. 



^TOBATIS PROFUNDUS. 



Cope: Proceedings Academ}^ Natural Sciences, 1861, 139. 



Isolated specimens of teeth, mingled with those above described, Professor Cope 

 has referred to a distinct species with the name of A. profundus. They appear to 

 me to be only the most anterior and worn teeth of the same species as those referred 

 to A. arcuatus, as similar difl"erences are observed between the corresponding teeth 

 of the recent A. narinari. 



Figure 19, Plate xxxi., represents an anterior tooth of the lower dental series. 

 The two sides of the crown meet at an obtuse rounded angle forward, and the 

 triturating surface is worn off in a convex manner anteriorly. The ends of the 

 crown also appear to be worn off. The breadth of the crown is 17 lines; the 

 width fore and aft at the middle is 2| lines. The length of the root is about five 

 lines. 



