141 



589. The inferior molar of the right side of the lower jaw of a Mammoth. It 

 exhibits the most complete state in which the actions of mastication 

 permit so large a grinder to be seen ; the anterior division of the crown 

 not being quite worn down to the fang, and the last or hindmost plate 

 being just on the point of coming into use. The whole length of the 

 tooth is thirteen inches : the total number of lamellar divisions of the 

 crown seventeen, of which the summits of fourteen are abraded in a 

 grinding surface of nine inches extent. The greatest breadth of this sur- 

 face is two inches and a half. The first three fangs supporting the com- 

 mon dentinal base of the anterior lamellae are well developed. 



This tooth would have been succeeded by one of the size of No. 567, 

 which it resembles in the proportion of breadth to length, in the thick- 

 ness and relative number of coronal lamellae, and in the festooning of the 

 enamel. It approaches much nearer the character of the molars of the 

 Indian Elephant than it does those of the thin-plated variety of the 

 grinders of the Mammoth, as Nos. 614 and 617. From these it differs 

 not only in the less numerous and thicker plates, but likewise in the 

 thicker coat of external cement which hides the lateral interspaces of 

 the coronal plates ; and in having the fangs developed from the whole 

 base of the tooth, even from the posterior plate, the summit of the middle 

 mammillary process of which has just begun to be abraded. The inner 

 border of the grinding surface of No. 57 1 is convex, while in the present 

 molar it is concave ; this difference depends, however, upon the amount 

 of attrition, for it is obvious that the inner border of the present specimen 

 would become convex if it were worn down one inch lower than it is. 

 From the lower molar of the Indian Elephant the present tooth of the 

 Mammoth differs in the more equable length of the coronal plates, which, 

 in the Elephant, by their more progressive elongation, give a triangular 

 figure to the side view of the crown : it differs also in the greater length 

 of the grinding surface, which includes two more plates, although these 

 are not thinner, and are of less breadth, contrary to the usual character 

 assigned to the Mammoth. 



From British drift or pleistocene beds. Mus. Parkinson. 



590. An upper molar of a Mammoth, much worn by mastication. The 



