(332) 



16. On a Species of Tylosaurus from the, Upper Cretaceous Beds of 

 Pondoland.'Bj E. BKOOM, M.D., D.Sc. 



(Plate XXII., Figs. 28-29.) 



ABOUT ten years ago a collection of bones was made from the 

 Cretaceous beds of Pondoland by Dr. Eogers and Professor Schwarz. 

 The bones were for the most part fragmentary and water-worn, and, 

 except in one or two instances, detached. As was recognised at the 

 time, all the bones found represent portions of the skeletons of 

 Chelonians and Pythonomorphs. In the Annual Report of the 

 Geological Commission for 1901, p. 41, the bones are referred to as 

 jaw-bones of a reptile related to Mosasaurns and Chelonian bones. 

 Eecently the collection was placed in my hands to see if I could 

 make anything further of the remains. Most of the bones are frag- 

 ments of the carapace of Chelonians with other bones of the 

 skeleton. The fragments, however, are too imperfect to justify one 

 in deciding on the species. There are pretty certainly two species 

 and probably three represented. One is of large size possibly with 

 a carapace 6 ft. in length : one is a quite small turtle less than a foot 

 in length. 



The Pythonomorph remains are more satisfactory, as not only 

 are there some jaw fragments with teeth, but a satisfactory portion 

 of the frontal region of the skull. 



The skull fragment consists of the nearly perfect frontal bone 

 with about the anterior half of the parietal and portions of both 

 postorbitals. 



The frontal is a large triangular bone, measuring 304 mm. in 

 greatest length and 234 mrn. in greatest width. The upper surface is 

 moderately flat and smooth. Near the parietal suture in the middle 

 line the bone is slightly depressed, and also in front where it meets 

 the prefontals. The anterior end of the bone is more rounded than 

 in any frontal I have seen figured, as if the nostrils were wider apart 

 than usual, and as if there might have been distinct nasal bones 



