Annals of the Transvaal Museum. 
129 
and slightly convex from the inner side outwards. It is surrounded by a 
narrow ridge on the upper, outer, and lower sides. The whole surface 
looks slightly inwards. This condyle is separated from the basioccipital 
and the central hinder process of the basisplienoid by a deep notch, which 
terminates on the lower surface below the middle of the hinder lateral 
process ; on the upper surface (in the brain cavity) it reaches nearly as far 
forward as the basioccipital. A portion of the left condyle is present, but 
very much distorted and pressed on to the left side of the upper surface of 
the basioccipital. The matrix between the condyle and that bone, however, 
shows that an identical notch existed also on this side. The medullary 
surfaces of the exoccipitals, or rather the upper surfaces of the condyles, 
show on each side two foramina, one behind the other. 
There is a suture between the exoccipital and the basisphenoid j us ^ 
below the outer edge of the hinder lateral process of the last-mention e d 
bone. The exoccipital processes extend towards the tabularia, which th e y 
join at the under side. In the middle of this process there are markings, 
which convey the impression of once having belonged to a suture. The 
outer half of this process would then be the opisthoticum. 
The occurrence of two foramina on the upper surface of the condyles 
is very remarkable. They occur just there, where one expects to find the 
passage for the vagus nerves. One of them must indeed have served this 
purpose. If the other is taken to be the exit of the hypoglossus the 
results of a recent study of V. IlUENE’S are contradicted (4, p. 103). The 
same difficulty was encountered by SCHROEDER in his description of 
Capitosaurus helgolandiae. Schroeder draws the attention to some 
foramina on the outside of the condyle. One of these foramina, a small 
one, is situated above the rounded, hinder edge of the exoccipital ; another, 
much larger one, just below this edge. In Myriodon there are two fora- 
mina in the same relative position as those just mentioned in Capitosaurus. 
The lower one is slightly larger than the upper one and is situated there, 
where one would look for the exit of the vagus group (PI. XXIV, fig. 3). 
Schroeder assumes that the upper one might be the exit of the hypo- 
glossus. The upper foramen in Myriodon is double, i.e. the foramen is 
really a depression, at the bottom of which there are two foramina. On 
the lower surface of the condyle in Myriodon there are two other foramina. 
The one is very small and situated at the lower end of the base of the 
exoccipital process, in front and slightly to the inside of the foramen for 
the vagus group. This foramen apparently corresponds with the small one 
which Schroeder found in the same position in Capitosaurus ( 6 , p. 254). 
The other is larger and situated near the lower inner border of the condyle. 
What the relation of all these outer foramina is to the two inner ones 
could not be established with certainty. Our material is too scanty (there 
is only one perfect condyle and just a fragment of another present) to go 
further into the question. The notches which separate the condyles from 
the basioccipital and basisphenoid seem to correspond to the opening in 
the floor of the foramen magnum in Capitosaurus helgolandiae , and must 
as this have been filled with cartilage. 
In both skulls a large epipterygoid is seen to be present. It is a 
broad flat bone behind, resting against the outer front end of the upward 
process of the pterygoid. It nearly reaches the skull roof in this region. 
The lower border of this bone is in touch with the pterygoid up to about 
half its length forward. The upper border is strongly concave, thus 
leaving a large opening between the skull roof and this bone. The front 
