668 ' DU. R. BROOM ON THU STEUCTUIIE OF TUE SKULL 



In both specimens tlie nasal region is lost, but in both the 

 frontal and parietal i-egions are preserved — in specimen A in 

 perfect condition ; in specimen B considerably weathered. 



The shape of the frontal and parietal bones will be best under- 

 stood from the figures. The frontal is moderately flat in front, 

 but bends upwards behind to articulate with the elevated 

 parietal. The interorbital width is 117 mm. There is a fairly 

 large prsefrontal which forms much of the supraorbital margin. 



The postfrontal is a small bone wedged in between the frontal 

 and the postorbital. The postorbital is large. It forms appa- 

 rently the Avhole of the postorbital arch, and passing upwards 

 forms about half of the upper wall of the temporal fossa. 



The parietal is narrow, but very massive. The pineal foramen 



Text-figure 6. 



Palatiil view of skull of Binophoneus incjena, gen. et sp. nov. 

 . Entirely drawn from Spec. B. 



About ^ uat size. 



is large and round. Some distance behind the foramen the fossae 

 are only 5-3 mm. apart. 



The jugal is not well preserved, but specimen B has a large 

 isolated fragment of it. In this fragment is also much of the 

 anterior part of the squamosal. 



The squamosal is a very large bone. It forms most of the 

 posterior wall of the temporal fossa. It has a large anterior 

 process which forms much of the subtemporal arch, and a still 

 larger portion of the bone passes downwards and foi'wards to 

 support the quadrate. The squamosal also forms a lai-ge part of 

 the back of the skull, as is shown in text-fig. 7. The quadrato- 

 jugal is a small bone which lies inside the squamosal for the most 

 part and also supports the quadrate. 



