TAPINOCEPHALID.ZE. 



83 



faces become flattened and form distinct angles at their junction 

 with one another. The rib-facets on the anterior dorsals are 

 sessile. 



The series of bones of the limb-girdles and limbs, upon certain of 

 which the genus Phocosaurus was based, are provisionally included 

 under the present generic heading, since there is no evidence to 

 show that they are generically distinct. In this series the coracoid 

 and precoracoid remain distinct ; the humerus has the head placed 

 high up, the distal extremity moderately expanded, the radial 

 condyle of normal size, and no ectepicondylar foramen ; the pelvis 

 (fig. 17) is characterized by the large acetabulum and the compara- 

 tive lowness of the ilium, which has distinct pre- and postacetabular 

 processes. 



Tapinocephalus atherstonei, Owen 1 . 



Including Phocosaurus megischion, Seeley 2 . 



The type species. Of huge dimensions, perhaps somewhat ex- 

 ceeding those of Titanosuchus. It is quite probable that the under- 

 mentioned specimens may indicate two distinct species. 



Hah. South Africa. 



R. 1705. The imperfect anterior extremity of the cranium ; from 

 (Fig.) the Karoo system near Jan Willem's Fontein, Prince 

 Albert district. The type ; figured by Owen in his ' Cata- 

 logue of the Fossil Reptilia of S. Africa,' pi. i. The 

 broken posterior surface and part of the alveolar surface 

 have been cut and polished. The bones forming the free 

 surfaces of the facial aspect are in great part or entirely 

 wanting, and no trace of the position of the nares remains. 

 The determination of the bones exhibited in the transverse 

 section by Owen appears to be correct. In the section 

 of the alveolar border of the maxilla an outer series of 

 fully developed teeth and an inner one of replacing germs 

 are distinctly visible. The hindmost tooth, of which a 

 section is shown, has a large pulp-cavity, like the teeth of 

 Titanosuchus. In advance of this tooth there are several 

 empty dental alveoli, but none of them appear large 

 enough to have held a tusk answering to the lower tusk 

 of Titanosuchus. This specimen apparently indicates the 

 absence of secondary posterior nares ; and it evidently 



1 Cat. Foss. Eept. S. Africa, p. 1 (1876). 



2 Phil. Trans, for 1888, p. 91. 



g2 



