220 ELEPHAS COLUMBI. 



ridge tlieir separation can be traced to a depth of nearly an 

 inch, a condition which ordinarily involves a high degree 

 of crimping of the enamel-plates. The crown is narrow in 

 front, and widens so abruptly behind as to have suggested 

 to De Blainville the term ' subdidyme' to characterize it; he 

 describes it as resembling most the analogous tooth of the 

 existing African Elephant. This peculiarity is best expressed 

 by the dimensions, viz., length of crown 2" 7 inches, width in 

 front at the second ridge 1*1 inch, width behind 1*7; the 

 length being to the extreme width in the ratio of about 3:2. 

 The empty alveolus of the last milk molar (m.m. 4) is dis- 

 tinctly visible in M. Le Clerc's specimen. The penultimate 

 milk molar thus yields, for its term in the ridge-formula, 8 

 colliculi besides talons. The specimen, so far as mineral 

 condition is concerned, is well fossilized, like those from the 

 Sewalik hills and the ' Forest-bed' of the Norfolk coast, 

 being hard, heavy, and weathered, and not adherent to the 

 tongue. 



The specimen next to be noticed is a detached and very 

 finely preserved antepenultimate true molar (m. 1) of tbe 

 lower jaw left side, No. 741 a of the additions to the Cat. of 

 Toss. Mainm. of the Royal College of Surgeons. It is a 

 comparatively late acquisition (since 1855), and was brought 

 from Mexico by Mr. Taylor. The crown and body of the 

 tooth are quite perfect from end to end ; the fangs are mostly 

 broken off, but a portion of them still remains. The crown 

 is composed of twelve colliculi, with front and hind talons. 

 Of these the eight anterior divisions are worn, the rest being 

 intact. The discs of wear are wide and open, wider than in 

 the ordinary varieties of the existing Indian Elephant, and 

 nearly approaching the width commonly presented by E. 

 antiquus. But they differ from those of the latter species in 

 showing no angular expansion in the middle of the discs, 

 and no outlying loop at the angles. In this respect they 

 correspond more with the discs of the existing Indian Ele- 

 phant. The edges (maehcerides) of the enamel-plates are 

 highly crimped with numerous close set flexures ; in this 

 respect also maintaining a resemblance to the Indian Ele- 

 phant, and differing from E. antiquus. Notwithstanding the 

 distinctions here indicated, the aspect of the crown in the 

 Mexican molar bears a striking general resemblance to that 

 of typical specimens of the same age of E. antiquus, the most 

 obvious difference being, that the crown in the former is 

 much wider in proportion to the length than in the latter, 

 in which the molars have narrow crowns like those of the 

 African Elephant. The specimen is represented by fig. 2 of 

 Plate X. 



