98 MESSES. HANCOCK AND ATTHEY ON 



It is this outer row of comparatively small teeth that appears 

 to have been seen and described by M. Agassiz, the inner row 

 of laniary teeth having escaped his observation. Nor is it any 

 wonder that such a matter of detail should have been overlooked 

 by this naturalist ; and, indeed, many such omissions are found 

 in the great work alluded to. But when we consider the no- 

 velty and vastness of the matter before him, and especially that 

 the bent of his mind was directed mainly to the larger problems 

 of his subject, the only marvel is that such blunders are not 

 more numerous. The laniary teeth are very frequently con- 

 cealed in the matrix ; and when the jaw is in its natural posi- 

 tion, they are liable to be obscured by the external row, which 

 stands up on an elevated ridge of the alveolar margin. 



The laniary teeth vary in number in the different species, and 

 probably, in a limited degree, even in the same species ; but this 

 is difficult to determine, for it rarely happens that the row is 

 complete, these large teeth being frequently broken off. Never- 

 theless in several of our specimens they can be observed arranged 

 at pretty regular intervals, evincing that the series, as far as it 

 extends, is complete. In one mandible, in which the row is 

 nearly entire, there are eighteen or nineteen teeth ; and in the 

 mandible of another species fourteen or fifteen can be counted. 

 The teeth in the maxillte appear to be equally numerous. 



The teeth themselves (Plate III., figs. 1, 2) are, as we have 

 already said, sharp pointed and conical ; they are a little re- 

 curved, the bend being usually greatest a short way above the 

 base. Fine large specimens are upwards of |^th of an inch long ; 

 but they are generally much less ; they vary considerably in this 

 respect in the different species. They are most frequently wide 

 at the base, and contract rather suddenly immediately above ; 

 thence the attenuation is very gradual, until within a short dis- 

 tance of the apex, a little below which the crown is slightly 

 swelled ; from this point the sides of the tip incline more rapidly 

 towards each other, and unite to form an extremely sharp apex. 

 In some species the apex is much produced and attenuated, in 

 others it is comparatively short ; but in all it is characterized 

 by its sharpness. The sharp pointed tip or apex is formed of a 



