4 PLAC0D0NT1A. 



teeth of the type specimen of P. hypsiceps figured by Meyer 

 in the ' Palseontographica/ vol. xi. pi. xxiv., and suggest 

 that the latter merely belongs to a young individual of 

 P. gigas. This is confirmed by the distinctness of the 

 sutures in the latter specimen. Purchased,~1860. 



R. 1642. Part of a right maxilla probably belonging to an immature 



(Fig.) individual of this species; from Baireuth. Figured by 



Owen in the ' Phil. Trans.' for 1858, pi. x. figs. 2-5. The 



last three maxillary teeth are preserved, beneath the first 



of which is seen the germ of a replacing tooth. 



Purchased. 



32781. Portion of a maxilla, showing sections of two teeth, with 

 their replacing germs ; from Baireuth. Purchased, 1854. 



19677. The posterior portion of the left ramus of the mandible, in 

 (Fig.) a flattened and imperfect condition ; from Baireuth. The 

 type of P. bathygnathus ; figured by Owen in the ' Phil. 

 Trans.' for 1858, pi. xi. figs. 1-3. The two hinder molari- 

 form teeth are in use, while beneath the anterior one 

 there is the crown of a successional tooth in its alveolus. 

 As remarked by Meyer in the ' Palseontographica,' vol. xi. 

 p. 208, this specimen presents no characters by which it 

 can be specifically distinguished from the mandible 

 figured in plate xxxii. figs. 1, 2 of that volume, although 

 the last tooth is somewhat smaller. The absence of a 

 ledge on the outer side is due partly to a chipping away 

 of this portion of the jaw and partly to its compression. 



Purchased, 1845. 



33070. The imperfect posterior portion of a similar left mandibular 

 ramus, containing the last two teeth ; from Baireuth. 

 Here the external ledge is well-preserved. 



Purchased, 1858. 



R. 1641. An imperfect mandible of similar type ; from Baireuth. 



(Fig.) Figured by Owen in the < Phil. Trans.' for 1858, as the 

 type of P. pachygnathus. On the left side the first and 

 third molariform teeth, and on the right the first and 

 second are shown. The crown of the second tooth is 

 more nearly square than in the preceding specimens, and 

 thereby resembles the corresponding tooth on the right 

 side of the mandible figured by Meyer. The last tooth' 

 precisely resembles that of No. 19677. Purchased. 



