Annals of the Transvaal Museum 
ii5 
this cavity passes forwards and outwards and over the anterior lateral 
border. 
The other piece is.a fragment of the distal end of the right bone (PL XIII, 
fig. 8). The globose part of the articulation 
surface has a thickness of 2-7 cm. The lateral 
collateral pit has a tremendous size. It has a 
length of 2 cm. and a breadth of 1-2 cm. Its 
upper anterior and lower posterior ends are 
open. The cavity has a more or less cylindrical 
shape. That this piece must belong to the right 
bone is shown by the fact that its latero- 
posterior surface is concave close to the medial 
fracture, which concavity is a portion of the 
large concavity on the latero-posterior surface, 
well-known from other first phalanges. The 
antero-medial surface of the bone is separated 
by a ridge from the articulation surface. 
Metatarsale II is only represented by the 
proximal end of the right bone (text-fig. 20). 
The proximal articulation surface has the shape of a quadrangle. All 
four sides of this quadrangle are concave. The medial side is deepest in 
the middle, while the deepest place of the lateral side lies nearer to the hinder 
border. The lengths of the different borders of the proximal surface are: 
medial 5-7 cm., lateral approximately 6 cm., posterior 4-1 cm. and anterior 
approximately 3 cm. Ridges run from the corners of the proximal surface 
downwards on to the shaft. The upper end of the antero-lateral ridge is 
weathered away, but very probably it was sharp. The antero-medial ridge 
is rounded. The base of the postero-medial ridge is broader than that of the 
postero-lateral one. The proximal surface of this last ridge is slightly lower 
than that of the former one. The postero-lateral ridge stands further out from 
the bone than the postero-medial one. The anterior border of the proximal 
surface overhangs the anterior surface of the bone. The length of the piece 
is 4 cm. 
Metatarsale III. There is one piece which, I take it, belongs here, viz. 
the distal end of the right bone. Its medial side is missing (PI. XIV, fig. 4). 
The lateral side has a thickness of 2-4 cm. The lateral collateral pit is very 
deep. Its hinder edge has a small process behind the middle of the pit and 
its anterior edge has two knob-like processes with a groove in between. The 
upper knob-like process is separated from the process on the hinder edge by 
a deep groove. A rounded ridge passes on the anterior surface inwards and 
slightly upwards from the upper knob-like process. The anterior surface is 
slightly concave between this ridge and the articulation surface. I am not 
quite certain of the identification of this bone. 
The last bone of this collection is also difficult to identify. It is probably 
the proximal end of the left ulna and although there is no certainty on this 
point I will here describe it as such. The length of the piece (PI. XIV, fig. 5) 
is nearly 8 cm. Its antero-medial side is weathered. As preserved, the length 
of the lateral border of the proximal surface (text-fig. 21) is 3-6 cm. The 
length of its posterior border is 5 cm. The length of its antero-medial border 
was greater than 5-6 cm. The proximal surface is divided into two portions 
by a high ridge, which passes over the surface from the middle of the posterior 
to the middle of the antero-medial side. The portion of the proximal surface 
which lies medial and posterior to this ridge is convex and slopes down towards 
Text-fig. 20. Dr omicosaurus gra- 
cilis. Metatarsale I and II 
of the right side. Outline of 
proximal end of the bones, 
seen from the proximal side. 
x i- 
