124 
Annals of the Transvaal Museum 
attachment of ligaments. At its narrowest place the shaft has a breadth of 
2*3 cm. and a thickness of i-2 cm. The distal end (text-fig. 24) has a breadth 
of 37 cm. and a thickness of 1-9 cm. Its anterior end is turned to the lateral 
side and its posterior end to the medial side. Its long axis makes an angle of 
about 25 0 with the long diameter of the proximal end. The distal articulation 
surface has two facets. The postero-lateral part of the articulation surface 
passes somewhat upwards on to the shaft. The antero-medial edge of the 
distal end of the bone has two longitudinal ridges, separated by a groove. 
The postero-lateral ridge is high, the antero-medial one forms the slightly 
prominent border of the antero-medial surface. 
Radius. The radius (PI. XVIII, figs. 1 and 3) has a greatest length of 13-3 cm. 
The antero-lateral edge of the bone has a length of 12-3 cm. The proximal 
end of the radius is broad and thin (text- 
fig. 25). Its breadth is 3-6 cm. This was 
originally a few millimetres more, for the 
postero-medial corner of the proximal end 
is broken off. Its thickness is 17 cm. The 
proximal articulation surface is concave 
from the high posterior end of the antero- 
medial border to the slightly lower anterior 
end of the postero-lateral border. The 
breadth of the shaft at its narrowest place 
is i-8 cm. and its thickness 1*3 cm. The 
distal articulation surface has a length of 
3-5 cm. (text-fig. 25) and a breadth of Text-fig. 25. Massospondylus Browni. 
i*9 cm. The fairly flat surface slopes from 
the postero-medial corner downwards to 
the antero-lateral end. Both the antero- 
lateral and the postero-medial edges are 
concave, but the antero-lateral one is convex at the distal end. This gives 
the impression that the distal end is bent slightly backwards and to the 
medial side. The distal end of the antero-lateral edge bears a sharp ridge, 
which runs from the articulation surface upwards for a short distance, and 
which leans forwards. The postero-medial edge of the distal end is fairly sharp. 
Left radius. Outline of proximal 
and distal end seen from above 
and below respectively. Anterior 
border above. Nat. size. 
Carpus. 
Two carpalia are preserved in both hands. Those of the right hand, how- 
ever, are fragmentary. A large flat bone was situated behind the first meta- 
carpale and is apparently the first carpale. A small bone was situated lateral 
to this one and was evidently displaced. It is most probably the second 
carpale. Both bones have been completely covered by cartilage. 
First carpale (PL XVII, fig. 5). The breadth of the bone is 4 cm. This may 
have been slightly greater, for the extreme upper medial corner is broken off. 
Its height is 2-5 cm., its medial thickness i-i cm. and its lateral thickness 
o-8 cm. The medial portion of the anterior surface is convex in its lower half, 
while its upper half is concave. The lateral portion of the anterior surface is 
also concave. The two concave surfaces are separated by a rounded ridge. 
The lateral concave surface occupies about one-third of the anterior surface. 
The posterior surface is convex. The upper edge of the bone is slightly da- 
maged. The medial edge is thick, and convex forwards, inwards and down- 
wards. The lower edge is broad and in its middle lies a pit, probably for the 
attachment of a ligament. The lateral edge is thin and projects towards the 
lateral side in its middle. The upper edge was thin. This bone can be fitted 
