South African Fossil Reptiles and Amphibia. 49 



species, however, it must have been considerably further in advance 

 of the orbits than in the species under consideration. 



The lachrymal is a long bone forming the inferior anterior quad- 

 rant of the orbital border, and passing forward to within 33 mm. 

 of the nostril. Anteriorly it lies between the nasal and the maxilla, 

 and posteriorly meets the jugal below the orbit. Superiorly it has a 

 long articulation with the prefrontal. 



The prefrontal is a broader and stouter bone forming the superior 

 anterior quadrant of the orbital border. It meets the lachrymal, 

 nasal, frontal, and postfrontal. 



The frontal is a comparatively narrow, elongate bone, 160 mm. in 

 its greatest length, completely shut out from the orbit by the 

 junction of the prefrontal and postfrontal. Together the f rentals 

 form one-half of the interorbital width. Posteriorly they meet the 

 parietal, being separated from each other for the last 35 mm. by 

 that bone. 



The postfrontal is larger than the prefrontal. It forms at the 

 most but 12 mm. of the orbital border. It articulates with the 

 prefrontal, frontal, parietal, suprasquamosal, and poster bital. 



The postorbital is considerably larger than the postfrontal, forming 

 15 mm. of the orbital border, and extending back for 130 mm., being 

 40 mm. broad in its widest part. It articulates with the jugal for 

 most of its length, with the squamosal, suprasquamosal, and post- 

 frontal. It differs from the corresponding bone in T. kanncmcyeri 

 in that there is no constriction behind the orbit. Indeed, from the 

 orbital border the bone rapidly widens. 



The jugal is a large bone, forming part of the posterior border of 

 the orbit and extending from the lachrymal backwards for a length 

 of about 200 mm. It has a short vertical articulation with the 

 lachrymal, a long junction with the maxilla, and posteriorly lies 

 between the quadrato-jugal and the squamosal. On its upper 

 border it meets the postfrontal. 



The parietal is smaller than the frontal, and lies in a marked 

 depression of the cranial surface. Its greatest length is 115 mm., 

 and the circular pineal foramen lies between the bones 82 mm. 

 behind the anterior point of the elements. 



The suprasquamosal is a large bone 100 mm. long and 55 mm. 

 broad, practically rectangular in shape. It articulates with the 

 parietal, postfrontal, postorbital, squamosal, tabulare, and post- 

 parietal. 



The postparietal is placed behind the parietal, forming part of the 

 upper cranial surface and being bent at right angles to form the. 



