PLACODONTID^I. 3 



One of the undermentioned specimens suggests that P. hypsic&ps 

 is founded on a young cranium of this species. It will also he 

 shown below that the mandibular rami described as P. pachygnathus 

 and P. bathygnathus present no characters by which they can be 

 distinguished from this form. 



Hab. Europe (Germany). 



41139. Cast of the imperfect cranium, showing the occipital region 

 and the greater portion of the palate. The original is 

 the type, and was obtained from the Muschelkalk of 

 Baireuth, Bavaria. It is figured by Agassiz in his 

 'Recherches sur les Poissons Fossiles,' vol. ii. pi. lxx. 

 fig. 14 ; and also by Meyer in the ' Palseontographica,' 

 vol. xi. pi. xxv. fig. 1. Purchased, 1868. 



41096. The crushed cranium ; from the Muschelkalk of Baireuth. 



{Fig.) Noticed by Meyer in the ' Neues Jahrb.' 1868, pp. 48-52 ; 

 and described, and the occipital region figured, by Seeley 

 in the ' Phil. Trans.' for 1889, p. 281, pi. xxiv. figs. 5, 6. 

 This specimen closely accords with the more imperfect 

 one figured in the ' Palaeontographica,' vol. xi. pi. xxviii. 

 With the exception of the second of the right maxillary 

 series, all the teeth of the palate are preserved, but three 

 of the premaxillary teeth are wanting : there is a minute 

 palatal tooth in each maxilla. Seeley considers that this 

 specimen indicates the absence of a basioccipital condyle ; 

 but it seems doubtful whether this is not due to its im- 

 perfection, since such a condyle is shown in the ' Palaeon- 

 tographica,' vol. xi. pi. xxvii. fig. 3. When entire this 

 skull evidently bad the vaulted contour characteristic of 

 P. hypsiceps. Purchased, 1868. 



33071. Fragment of the left side of the posterior half of a palate 

 probably referable to a small individual of this species ; 

 from Baireuth. Some of the teeth have been reset, and 

 the second maxillary one appears to be placed at right 

 angles to its true position. Purchased, 1858. 



35868. Part of the left side of the hinder portion of the palate of 

 an immature individual ; from Baireuth. This specimen 

 shows the three palatine teeth in use, beneath the hind- 

 most of which is seen the germ of a much larger replacing 

 permanent tooth in its alveolus. The germ-tooth ' agrees 

 in size with the hinder palatine teeth of the type specimen, 

 but the teeth in use agree precisely with the palatine 



