Species of Tylosaurus from Upper Cretaceous Beds of Pondoland. 333 



present. From the anterior end to the outer corner of the bone the 

 margin of the bone is almost in a straight line. The line of the 

 suture with the postorbital is not unlike that of Tylosaurus 

 proriger. The fronto-parietal suture is more like that of Mosasaurus 

 horridus. The under surface of the bone has the sides for the 

 articulation of the postorbitals behind, of the prefrontals in 

 front. Down the middle of the bone in the centre region is a 

 well-marked groove. 



The postorbital only has its frontal portion preserved. As 

 preserved it agrees pretty closely with that of Tylosaurus proriger, 

 but is more slender. 



The parietal has a broad upper surface exactly as in Tylosaurus 

 proriger, and in this differing markedly from Mosasaurus. The 

 present species differs from T. proriger in that the pineal foramen 

 is well behind the plane which passes through the front of the 

 temporal fossa. 



The illustrations given show the contour of the bones, and that it 

 is pretty safe in concluding that the South African form belongs to 

 the genus Tylosaurus. It is manifestly not Tylosaurus proriger, 

 Cope. If v. Huene has rightly referred the species recently 

 described by him to Tylosaurus dyspelor, Cope, then the South 

 African species is a very near ally. But as it differs in that the 

 frontal is relatively shorter, and in a number of other points, I 

 propose to call the Pondoland form Tylosaurus capcnsis. 



PLATE XXII. 



FIG. 



28. Upper view of frontal and parietal regions of skull of Tylofaurus capensis. 



29. Under view of ditto. 



Both | nat. size. 



