above the Coal Fotmation^ in Berwickshire. 39 



glass, and which retains extreme density in the pldest fossil spe- 

 cimens ; the tooth in the I'ock is as soft as bone, and indeed you 

 may cut it like a piece of gypsum with the softest knife. The 

 tooth of the wolf and of other carnivorous quadrupeds, is never 

 fluted around the base of the crown (the comparison is of course 

 here made with the canine teeth) ; the fossil tooth is distinctly 

 grooved around the outer margin of its base, and the rock is 

 easily perceived to fill up these inequalities of its surface. At 

 the ba.*;e of the concave side of the fossil tooth, it expands more 

 suddenly than that of a wolf, or similar carnivorous quadruped, 

 but not more than teeth with which I shall presently compare it 

 Of all the teeth of carnivorous quadrupeds, the canine are the 

 most variable, in the same species, in their form and develop- 

 ment, the most similar in different species (and even in different 

 oiders of quadrupeds), and in the determination of fossil or 

 existing animals, they afford the least satisfactory indications; 

 next to them are the false molares ; then the incisors ; then the 

 carnivorous tooth ; and the most important and influential are 

 the tuberculated molares, which are the most constant 'in their 

 forms, present the greatest number of points for comparison, 

 and are the most intimately related to the kind of food and the 

 whole organization and habits of the animal. I am therefore 

 far from placing any reliance on the determination of a species 

 of these animals, founded on the inspection of a small part of the 

 outer surface of the crown of a canine tooth imbedded in a hard 

 sandstone lock, and this was all that was exhibited of the tooth, 

 when Mr Cliff was in possession of the specimen, and gave his 

 opinion about it. 



I have removed the rock fi*om the broadest part of the tooth 

 and from its cavity, so as to obtain a full view of the transverse 

 section of its base, the form of its cavity, and the structure and 

 thickness of its parietes, so that I have had more points of com- 

 parison exposed, and more data on which to found my opinion. 

 In all the teeth of quadrupeds approaching in form to this fossil 

 tooth, there is a thick layer of enamel covering the crown, 

 which is distinguished by its vitreous lustre, its translucency, its 

 uniform compact texture, and its resistance to the point of the 

 knife; and by these characters we can easily perceive the extent 

 to which the enamelled coating passes down over the osseous 



