388 SOLIPEDIA. 



of one of these teeth (fig. 145) from the cavernous fissure, 

 A, at Oreston (fig. 50, p. 132) ; and it is illustrated by 

 contrast with the same view of the corresponding lower 

 molar of a common Horse of about fourteen hands high 

 (fig. 144). Some of the numerous fossil equine teeth of 

 large size, from the cave at Kent's Hole, do not manifest 

 this character ; but the large-sized molar teeth of the 

 Horse, from the newer pliocene blue-clay at Cromer,* are 

 as much narrower transversely, compared with the teeth 

 Fi 9- 146 - of the large varieties of the 



existing Horse, as are the 

 somewhat smaller molars 

 from Kent's Hole, Kirk- 

 dale, and Oreston. One of 

 the Cromer fossil teeth, from 

 the lower jaw, with a 

 grinding surface measuring 

 one inch five lines in long 

 (antero posterior) diameter, 

 and eight lines in short 

 (transverse) diameter, pre- 

 sented a swelling of one 

 lobe, near the base of the 

 implanted part of the tooth 

 (fig. 146).*f- To ascertain 

 the nature and cause of 



Diseased lower molar, Eguus fossilis, , . , T T i i 



Cromer. this enlargement, 1 divided 



it transversely, and exposed a nearly spherical cavity, 

 large enough to contain a pistol-ball, with a smooth 



* Lyell ' On the Boulder Formation and Fresh-water Deposits of Eastern 

 Norfolk,' Philosophical Magazine, 1840, p. 361. 



f I am induced to cite one of the curious examples of disease in an extinct 

 animal from the rarity of its occurrence in the tissue which is the subject of it. 



