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Annals of the Transvaal Museum 
end. of the bone. The original breadth was, therefore, 5-5 cm. The surface is 
covered with numerous small knobs and pits. The outer border of this portion 
is formed by a long posterior and a short anterior sharp edge, which stand 
nearly at right angles to each other. The vertex of this angle is high and 
projects to the lateral side. The medial border of this surface passes upwards 
and forwards and, after reaching a point opposite the angle on the lateral 
border, downwards and forwards. There is a high boss on the proximal surface 
at the angle between these two medial borders. The medial and lateral angles 
of the border lie exactly opposite each other. The surface posterior to these 
two angles serves for articulation with the processus postacetabularis ilei. In 
gracilis. Left ischium. 
Outline of thearticulatio 
ischio-pubica seen from 
in front. Nat. size. 
Text-fig. 14. Dromicosaurus gra- 
cilis. Right ischium. Outline 
of distal surface seen from the 
distal end . The medial border 
to the left. Nat. size. 
1 
I 
front of the medial boss is a small triangular surface, which is bordered in 
front by a ridge ; this ridge is a continuation of the anterior part of the lateral 
border and runs obliquely across the proximal surface, meeting the medial 
border further downwards than its starting point. Distally to this ridge is 
the processus subacetabularis ischii. The medial border of this processus is 
extremely thin and slightly concave upwards. The upper surface of the pro- 
cessus is concave. The edge with the lateral surface is rounded. The lateral 
surface of the processus is convex from above downwards. The medial surface 
of the whole proximal end is strongly concave from above downwards. The 
distal end of the upper surface of the processus makes an acute angle with 
the articulation surface for the pubis. The articulatio ischio-pubica has a 
triangular shape (text-fig. 13) and the surface is covered with small knobs 
