68 ODONTOGRAPHY. 



Fifth The fifth tooth has also three ridges and six points : the inner points 



Tooth. 



are notched. As in the last tooth, the two posterior roots are consolidated, 

 and support the two posterior ridges, while the anterior ridge is supported 

 by the anterior fang ; in every instance, each ridge has a corresponding fang, 

 although in many cases two or more of these become consolidated. The 

 specimen from which this description is taken, is petrified. It measures 

 four inches and a half antero-posteriorly ; three inches transversely ; • cir- 

 cumference of the neck, eleven inches and a half. A drawing of this tooth 

 is given in Plate IX. Fig. 3, and its situation shown in Plates V. VI. 

 and VII, 

 sixth The sixth and last tooth is much larger than either of the others : it is 



Tooth. 



seen in place, but not well displayed, in Plate VII., and is figured separately 

 in Plate X. Both of these specimens are large and splendid teeth, the 

 latter weighing 3 lb. 6 oz. ; being ten ounces less than another specimen. 

 The crown of this tooth is divided into four ridges, with a complex talon ; 

 and sometimes, as in the specimen before me, into five ridges, of which the 

 last, or posterior, is smaller than the other four. The furrows are more 

 deeply cleft than in the other teeth, and the ridges, of course, are larger ; 

 each of them is divided into mastoid eminences, rather flattened than 

 rounded. The inner eminences are notched, and more projecting than the 

 outer. The complex talon, or fifth ridge, is of small size, having only about 

 half the elevation or breadth of the preceding ridges ; like them it is divided 

 into two mastoid eminences. There is a posterior tubercle. The two anterior 

 ridges are worn at their extremities, the three posterior almost perfect ; the 

 basal cingulum or eminence, which encircles the base of the crown, is more 

 prominent on its outer than on its inner face. The anterior ridge of the 

 crown is supported by a single fang, bearing some resemblance to the foliated 



