ELEPHAS MERIDIONALIS.— DENTITION. 185 



iris et abies, Taxus baccata, and aquatic plants referable to Pot amor/ den, Nitphar 

 luteum, Nymphaa alba, Menyanthes trifoliata, Ceratophyllum demersum, and Osmunda 

 reyalis, &c. 



IV. DENTITION. 



The general affinities and distinctions between incisors and molars of E. meridionalis, 

 as compared with teeth of E. antiquus and E. primigenius, have been already noticed, 1 as 

 well as the variations to which they are subject. These comparisons may be summarised as 

 follows : 



1. The tusks, in general, present a simple curve, as in the recent species, in both 

 E. meridionalis and E. antiquus, whilst they are spiral in E. primigenius, and generally 

 more slender in proportion. 



2. The incisive alveoli are more or less divergent in all, and are variable as to length, 

 breadth, and depth. 



3. The molars are very broad in E. meridionalis and E. primigenius, and are narrow 

 generally in E. antiquus, excepting in the broad-crowned variety. 



4. The height of the molar has its minimum in E. meridionalis ; it is higher in 

 E. primigenius, and attains to the maximum height in E. antiquus. 



5. The enamel is thick in E. meridionalis and in varieties of E. antiquus, whilst it 

 is thin in E. primigenius. 



6. The enamel borders are rarely crimped in E. meridionalis ; and, when at all, the 

 plaiting is more often confined to only portions of the margins of odd plates, or presents 

 -a slight roughening of the external border and surface, as seen in Plates XXIV and 

 XXV. The main feature is the deep channelling and general unevenness of the enamel. 

 In E. antiquus the crimping is generally pronounced, and affects the entire thickness of 

 the enamel with a central angular notch. In E. primigenius all these characters are 

 generally absent, the borders of the enamel being usually undulating, without plaiting of 

 any sort, or it is confined to parts of the enamel of a disc. 



7. The contour of the worn disc in E. meridionalis is generally more uniform in 

 breadth throughout, excepting a tendency in odd discs to central expansion and 

 angulation. In E. antiquus there are marked central expansions and angulations. The 

 disc is narrow in E. primigenius, and rarely shows any tendency to mesial expansion, and 

 no disposition to form the central notch so prominent in many of the teeth of the latter. 2 



8. The cement-wedges are largest in E. meridionalis, less so in E. antiquus, and mucli 

 thinner in E. primigenius. In consequence the plates are wide apart in the first, more 

 approximated in the second, and crowded in E. primigenius. 



9. The terms " thick- and thin-plated molars " I have applied to teeth of E. antiquus 



1 Pages 7 aud 77 . 



2 Plates III and V, E. antiquus. 



