ARMADILLOS. 323 



In the Chlamydotheiium, Lund, there are eight teeth on each 

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

 these the two anterior ones in the upper jaw, and the three anterior 

 ones in the lower jaw% are incisors by position. The latter are 

 shaped like small cylinders, with a more or less reniform transverse 

 section, while the molars are very large and compressed, so that 

 their section resembles an elongated kidney : their sides are marked 

 with several canaliculate impressions, and their grinding surface 

 presents two projections, the effect of the action of the teeth of 

 the opposite jaw ; elsewhere the surface is flat, and a little hollowed 

 in the middle. The size of the species {Chlam. Humboldtii), of which 

 the dentition is here described, was six feet, or double that of the 

 Priodon, which is the largest of existing Armadillos ; but the Chlam. 

 giganteum equalled in bulk the Rhinoceros. 



The extinct Glyptodon{\) seems to have surpassed the Rhinoceros 

 in size : and its dentition(2) w^as more complicated, more adapted to 

 a vegetable diet, than that of the Chlamydothere. The total num- 

 ber of teeth in the Glyptodon has not yet been determined. A 

 fragment of the anterior part of the lower jaw shows that the teeth 

 extended close to the symphysis, and, therefore, indicates their 

 presence in the intermaxillary bones above. The single tooth, on 

 which the generic character of the Glyptodon was founded, is long, 

 rootless, as in the existing Armadillos, but compressed laterally, 

 and divided by two deep, angular, longitudinal, and opposite grooves 

 on each side, into three plates, which give the grinding surface 

 the form of as many rhomboidal lobes. The alveoli on the frag- 

 ment of jaw^ above mentioned, indicate the anterior teeth there to 

 have had the same form, and, from the allusion wdiich Dr. Lund(3) 

 makes to the teeth in the Hoplophorus (Glyptodon) of the Brazihan 

 Caverns, it would seem that the comphcated form just described, 

 pervaded the whole dental series. 



The teeth of the Armadillo-tribe are harder than those of 



(1) SirW. Parish's Buenos Ayres, 8vo. 1839, Geol. Trans. 2nd series, vol. vi. p. 81 — 85. 



(2) PI. 86. fig. 1 and 2. 



(3) " Its teeth are shaped like the molars of the Capihara, but have a different stnicture, 

 inasmuch as they are simple, and not composed of laminae." Loc. cit. p. 10. 



Y 2 



