ARMADILLOS. 321 



The teeth are more numerous in the Priodon, the largest of 

 existing Armadillos, than in any other land Mammal, but they 

 are of very small size and simple form, and are all referable to 

 the molar series(l). They vary in number from twenty-four to 

 twenty-six in each upper jaw, and from twenty-two to twenty-four 

 on each side of the lower jaw, amounting to from ninety- four to 

 one hundred in total number. They are compressed laterally, most 

 so where they are smallest at the anterior part of the series, in- 

 creasing in size, and especially in breadth, as they recede back- 

 wards, with oblique or horizontal flat grinding surfaces, and con- 

 tinued of the same size and form to their implanted extremity, 

 which is excavated by a large conical pulp-cavity. This absence of 

 roots and the undivided hollow base, indicative of the constant 

 growth of the tooth, are common, as has been before stated in the 

 general observations on Mammalian dentition, not only to the teeth 

 of the Armadillos, but to those of all the known species of the order 

 Bruta. In the Priodont the teeth, though so unusually numerous, are 

 separated by slight intervals ; those of the lower jaw oppose their 

 outer sides to the inner sides of the upper teeth when the mouth 

 is shut. 



In the subgenus Tatusla of F. Cuvier, which includes the 

 7~banded, 8-banded, and 9-banded Armadillos, the upper teeth are 

 also confined to the maxillary bones, but are much fewer in number 

 and larger than in the Priodon. In the species whose dentition 

 is figured and described by M. F. Cuvier(2), there are eight molars 

 on each side of the upper jaw, and nine on each side of the lower 

 jaw (PL 85, fig. 2). It agrees, therefore, with the Dasypus octocinctus 

 of Linnseus {Das. uroceras, Lund.), a species with a tail somewhat 

 shorter than the body, and a native of Central Brazil and Paraguay, 

 where it is called " Tatu-verdadeiro." In both jaws the teeth pro- 

 gressively increase in size from the first to the penultimate, the 

 last suddenly decreasing in size : those of the lower jaw alternate 

 in position with the upper teeth, and it results from this reciprocal 

 position that the grinding surface is worn down into two sloping 

 facets. The Dasypus novem-cinctus L., (D. longicaudus, Max.) has 



(I) PI. 85. fig. 1, a—d. (2) Loc. cit. PI. Ixxx. 



Y 



