318 [Dec. 18, 



than above. The vomer is very thick and strong, and the turbinal 

 bones are well developed. The premaxillse, though small slender 

 bones, enter largely into the lateral boundary of the nasal aperture. 

 Inferiorly they are separated in the middle line by a narrow fissure, 

 which runs back into the crescentic anterior palatine foramen. 



The maxillary bones are extremely elongated ; while the palatine 

 bones are small in proportion to them, and, like the premaxillse, are 

 separated by a very narrow median fissure. The extreme length of 

 the roof of the palate, formed by these three pair of bones, is 10 

 inches ; while its width (between the inner edges of the teeth), 

 though rather greater in front than behind, nowhere exceeds If inch. 

 From before backwards the palate has a double curvature, being 

 concave downwards from the anterior end of the premaxilla to the 

 level of the third tooth, and convex thence to the end of the palate- 

 bones ; so that the posterior part of the palate has a very marked 

 inclination upwards and backwards. 



There were eight teeth in each maxilla, all trilobed, the longitu- 

 dinal grooves separating the lobes being less marked in the anterior 

 teeth. 



The mandible is represented by the two horizontal rami, with the 

 symphysis, the greater part of the right coronoid process, and the 

 entire right condyle, together with many of the sixteen teeth. It 

 very closely resembles the mandibles of Schistopleuron gemmatum, de- 

 scribed by Nodot, but is wholly unlike the restored jaw of Glyptodon 

 clavipes given (on the authority of a drawing) by Professor Owen*. 



The articular surface is situated almost wholly upon the anterior 

 surface of the condyle of the mandible, looking but very slightly 

 upwards ; it is transversely elongated, slightly concave from side to 

 side, and convex from above downwards. In all these respects it 

 furnishes a counterpart to the glenoid articular surface of the tem- 

 poral bone of Glyptodon clavipes, already described by Professor 

 Owen. 



The length of the head of the present specimen, when entire, was 

 probably not less than 13 inches. The greatest depth of the 

 cranium, from the centre of the frontal bone to the middle of the 



* The mandible of the Turin Glyptodon, mentioned at the end of this paper, 

 is quite similar to that of the new specimen, and to that of M. Nodot's Schisto- 

 pleuron. 



