DENTITION. 221 



A notable peculiarity in the Mexican tooth is, that the 

 body of the molar is very much bowed sidewise, i.e. concave 

 on the outer side, and convex on the inner. The amount of 

 arcuation is much greater than I remember to have seen in 

 any other species of Elephant, fossil or recent, in molars of 

 corresponding age, viz., adolescent. Something of the same 

 kind is seen in Mr. Bollaert's specimen, as figured in the 

 ' Geologist ; ' but in this case, in a minor degree, in conse- 

 quence of the anterior third of the crown having been worn 

 away. I believe that this peculiarity in the lower molars of 

 E. Golumbi is a constant character of the species, and that it 

 bears a relation to the converging form of the rami of the 

 jaw, to be noticed in the sequel. 



The dimensions of the Mexican molar are : — 



Length of crown, 7-4 in. Width of ditto in front, 23 in. Greatest ditto, 2-5 in. 

 Height of ditto at eighth ridge, 4-3 in. Space occupied by the eight anterior discs, 

 4'3 in. 



It is hardly necessary to remark that the characters of the 

 molar above described differ entirely from those of the 

 common form of the Mammoth of North America. 



Von Meyer, in the ' JSTeues Jahrbuch' for 1840, 1 briefly 

 notices some fossil remains of Mastodon and Elephant, con- 

 tained in the Mexican collection of Herr Uhde. Among 

 these are an upper and lower molar of a fossil Elephant, in 

 which the enamel-plates were wider apart than in E. primi- 

 genius, in this respect having a closer resemblance to those 

 of E. proboletes of Fischer de Waldheim, which Lartet con- 

 jecturally refers to E. meridionalis. The description would 

 agree with that of E. Columbi, from the same region. 



Sir Charles LyelPs Georgian specimen, from the Brunswick 

 Canal, upon which my first knowledge of E. Golumbi was 

 founded, consists of the middle portion of the penultimate or 

 last true molar, probably the latter (m. 3), lower jaw, right 

 side, broken off both at the anterior and posterior ends. The 

 fragment comprises ten complete ridges, with part of two 

 others, of which the anterior seven are more or less worn. 

 All the fangs are broken off, together with the basal mass of 

 ivory. The summit of the crown is concave from back to 

 front, and the tooth is also concave with a little torsion on ■ 

 the outside, and convex inwards, showing that it was con- 

 siderably arcuated laterally, like the specimen last described. 

 The discs of wear are of moderate width, as in the Indian 

 Elephant, with a tendency in some of them to expansion in 

 the middle. This is most pronounced in the second, where 

 the expansion nearly attains half an inch. The plates of 



1 Leonhard and Bronn's 'Jahrbuch,' 1840, p. 581. 



