Annals of the Transvaal Museum 
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surface to the lower end of the fossa intercondyloidea, is 3-5 cm. Its thickness 
over the condylus medialis is 8-i cm. and over the condylus lateralis 9 cm. 
The upper end of the fossa intercondyloidea is damaged. It starts at least 
12 cm. above the distal end. The condylus medialis is damaged; its breadth 
as preserved is 5 cm. Its height is about 6*5 cm. The condylus lateralis is 
much narrower; its breadth is 3*3 cm. The breadth of the distal end (text- 
fig. 15) is about 11*5 cm. The distal articulation surface is full of cracks and 
could not be well cleaned of matrix. The lateral side of the distal end is hollow 
and the hinder end of the condylus lateralis stands, out slightly to the lateral 
side. The anterior surface of the distal end is hollow along its middle. Seen 
from the front it seems as if the lateral side of the bone runs slightly further 
downwards than the medial side. The diaphysis is hollow. The bone only 
forms a thin shell round a very large cavity. 
Tibia. 
Only the right tibia is preserved and that in perfect condition. It has a 
large proximal articulation surface and a straight shaft (PI. XIV, figs. 1 — 3, and 
text-figs. 16 and 17). During its 
excavation, the bone of the diaphysis 
parted in small fragments from the 
filling of its cavity; however, all the 
pieces were fitted and glued together 
on the spot. The total length of the 
bone is 3 7 • 5 cm . The head of the tibia 
(text-fig. 16) has a length of 13 cm., 
measured from the hinder end of the 
medial condylus to the edge of the 
anterior crest. Its greatest breadth, 
transverse to this greatest length, is 
8-5 cm. The length of the lateral side 
of the head is 9 cm. Anteriorly the 
head of the tibia has a laterally 
directed process, the tuberositas Text-fig. 16. Dromicosaurus gracilis. Right 
tibiae. The lateral border of the tibia. Outline of proximal surface seen 
proximal articulation surface is di- above - Lateral side to the right, 
rected straight backwards from the 
tuberositas tibiae, but before reaching the lateral condylus it becomes slightly 
concave; the remainder of this border is convex. The medial border runs from 
the tuberositas tibiae inwards and curves slightly backwards until at about 
3-5 cm. from the anterior end the convexity becomes greater. It diminishes 
again at about 5 cm. from the anterior end; from this point further backwards 
the medial border is only slightly curved, but the convexity is greater around 
the condylus medialis. The posterior border is slightly convex behind each 
condylus and notched in the middle. The proximal articulation surface shows 
a large shallow concavity above the medial condylus ; another large concavity 
is situated on the anterior end, while the upper surface of the lateral condylus 
is convex. The lateral posterior side of the surface is slightly lower than the 
medial posterior side. From the hinder border the articulation surface goes 
steeply upwards and forwards. The hinder border is overhanging; it rounds 
off abruptly into the lateral border; its medial end is slightly damaged. The 
shaft narrows down quickly immediately below the head. 
The distal end is transversely broad. The medial one-third of the distal 
articulation surface is flat and slopes slightly from its anterior edge backwards 
8—2 
