Annals of the Transvaal Museum 
127 
The postfrontals separate the frontalsfrom the orbits. They are very 
narrow in front where they are in touch with the prefrontals and they 
gradually broaden posteriorly. They terminate at about the middle of the 
hinder rim of the orbit against the postorbitals and their posterior end 
nearest to the parietals is in touch w T ith the supratemporals. 
The prefrontals are very large and broad. They form the whole front 
rim of the orbit. The position of the lacrymal could not be ascertained, 
but I take the lacrymal to be at the front and outer end of the prefrontal. 
The combined bones reach further forward than the frontals. At their 
anterior end they are separated from the anterior end of the frontals by a 
posterior process of the nasals. 
The jugal is a large bone, which is very broad at the orbit. It forms 
the greater part of the outer side of the orbital rim. Its boundary with 
the maxillary could not be found. Posteriorily it is bordered by the 
postorbital and the quadrato-jugal ; possibly also by the squamosum. 
The postorbital is a relatively small bone, which forms the hinder 
and outer part of the orbital rim. Its transverse dimension is slightly 
greater than its longi tudinal. 
No sutures could be found between the squamosum and the quadrato- 
jugal. The tabular is a small triangular bone, which does not reach up to 
the anterior end of the otic notch. The dermosupraoccipitals are very 
broad bones. 
The ossification centrum of the supratemporal lies at the inside of the 
anterior end of the otic notch. The sutures of this bone with the squa- 
mosum and the dermosupraoccipital could not be made out. 
Excepting the prevomer portion and the hinder process of the 
pterygoids, the bones of the skull base are well preserved (PI. XVIII, 
XXIV, fig. 8). 
The basioccipital is not visible from below, its whole lower surface 
being covered by the basisphenoid. While trying to develop the occipital 
condyles of skull No. 1, the hinder right end of the basisphenoid broke 
away, thus showing another bone, separated from the basisphenoid by a 
sutural surface. This other bone is the basioccipital and can be followed 
to the left side of the basisphenoid all along its hinder end, beyond which 
it projects slightly. This specimen shows the basioccipital is very broad. 
In skull No. 2 the basioccipital and the basisphenoid have been broken 
longitudinally along their middle. The sutural surface between the two 
bones is clearly visible and the basioccipital is found to be a short and 
very thick bone. Its upper part terminates abruptly in front, but its 
lower part continues a short distance as a very thin, broad and flat process. 
The breadth of the bone in skull No. 1 is about 38 mm. and in skull No. 2 
it is 28 mm. (here it has suffered from side compression). Its length in 
skull No. 2 is 31 mm. 
The basisphenoid is a broad, flat bone. Its lower surface is slightly 
hollow. In skull No. 2, where the right side of the bone is well preserved, 
the surface is seen to be slightly raised at the inner end of the lateral 
posterior process (PI. XXIV, fig. 3). The lower surface of the portion of 
the bone between these convexities, i.e. the middle part of the hinder end 
of the basisphenoid, is concave from side to side and convex longitudinally. 
In the middle behind, the bone forms a slight process, which reaches to 
the hinder end of the basioccipital. On either side behind, the basi- 
sphenoid forms a flat and broad horizontal process, which is directed 
towards the corresponding condyle. Between this process and a higher 
portion of the bone there is a transversely elongated cavity. Similar 
