102 Annals of the South African Museum. 



somewhat expanded lower end. Its upper end is fixed between the 

 squamosal and the opisthotic. The external surface shows a 

 well-marked longitudinal depression at the lower end of the upper 

 half. The front edge of the bone is thin, the posterior border well 

 rounded. 



The squamosal is a strong bone, articulating with the postorbital, 

 quadrate, parietal, opisthotic, paroccipital, and exoccipital. It forms 

 the outer posterior corner of the skull, i.e. half the outer and posterior 

 borders of the supraternporal fossa. It passes over on to the 

 occipital plate, and takes part in the border of the lateral occipital 

 foramen. The articulation between the squamosal and the opis- 

 thotic is pierced by a large oval foramen. 



The parietal has a strong median crest which divides posteriorly 

 and forms there the upper border of the occipital plate. The bone 

 passes over this lateral crest and forms part of the occipital plate, 

 articulating with the supraoccipital and squamosal, and taking part 

 in the border of the lateral foramen. Anteriorly the bone articulates 

 with the frontal, laterally with the squamosal, and below with the 

 opisthotic and alisphenoid. As in Ornithosnclius there is no inter- 

 parietal. 



The occipital plate is fairly small, and consists of the supra-, ex-, 

 and basi-occipitals, parietal, and squamosals. The supraoccipital 

 forms the upper median portion of the plate and enters into the 

 upper edge of the foramen magnum. The paroccipital forms no 

 part of the border of the foramen magnum. Its outer corner is bent 

 almost horizontally and rests on the posterior prolongation of the 

 squamosal, with which bone it has a long curved articulation. The 

 basioccipital is small, but it seems to form most of the incomplete 

 condyle. The opening for the 12th nerve is in the exoccipital about 

 2 mm. from the lateral border of the foramen magnum. 



The palate is incomplete. The anterior prolongations of the 

 pterygoids are long, and there is a well-defined median groove. 

 The internal nares are not seen ; but they must have been con- 

 siderably in advance of the postpalatal vacuities. In both these 

 features this form agrees with the features displayed by Erpetosuchus 

 and Proterosiichus two forms which von Huene groups together as 

 the Pwtcrosuchia, and differs from Ornithosuchus and the Phytosaurs. 

 The palatine has a long articulation with the pterygoid and forms 

 the inner and anterior borders of the post-palatal vacuity, while its 

 outer border, and probably the posterior, is formed by the trans- 

 palatine. The transpalatine has a suture with the jugal on its 

 outer side, 



