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Annals of the Transvaal Museum 
much further backwards on the lower than on the upper surface. Their lateral 
collateral pit is deeper than their medial one. 
The second phalanx of the third finger has a divided proximal articulation 
surface. There is no pit behind the distal articulation surface on the upper 
surface of the bone, and contrary to the condition in the penultimate phalanges 
of the second and third fingers, where one side of the distal end does practically 
not project beyond the other, the lateral side of the distal end of this phalanx 
projects beyond its medial side. The lateral collateral pit is deeper than the 
medial one. The lateral portion of the distal articulation surface of II, i, III, i 
and III, 2 is broader than the medial portion. 
The fourth and fifth fingers are remarkable. The fourth has only three 
phalanges and the fifth only two. The phalanges of both fingers can be re- 
cognised by their plainness. None of them has a superior-posterior process. 
The first phalanx of the fourth finger has an evenly concave proximal articu- 
lation surface. The distal articulation surface is evenly convex; there is no 
pit behind it on the upper surface. The second phalanx has an evenly concave 
proximal and an evenly convex distal articulation surface. There is no pit on 
the upper surface. The collateral pits are represented by very slight con- 
cavities, bordered below by a knob-like process. The endphalanx of this 
finger is a remarkable, small, three-edged body. Two of the edges border the 
very slightly concave articulation surface. The third edge forms the sides and 
the anterior end of the bone. The first phalanx of the fifth finger has an 
oval-shaped evenly concave, proximal articulation surface. It stands some- 
what obliquely on the axis of the bone, the superior border lying further 
forwards. The distal articulation surface is evenly convex and its lower 
lateral side sends a small process backwards below the collateral pit. The 
endphalanx of the fifth finger has the same general shape as the endphalanx 
of the fifth digit of the foot. Its proximal articulation surface is oval-shaped 
and very slightly concave. It stands obliquely on the axis of the bone for its 
superior edge lies much further forwards than its inferior one. The inner edge 
of the bone is straight and the outer-anterior one evenly convex from the 
inner-anterior end to the outer-posterior end. The anterior portion and part 
of the outer portion of this edge has been covered with cartilage. 
The clawphalanx of the first finger is high and strongly curved (PI. XVII, 
fig. 4). The groove for the claw lies slightly deeper on the medial than on the 
lateral side. There is a broad ridge on each side below this groove. The highest 
part of this ridge on the medial side lies below its middle line, while the 
highest part of the lateral ridge follows the middle line of the ridge. The 
proximal ends of both ridges terminate some distance in front of the articula- 
tion surface by a low, sharp, curved ridge. The medial ridge passes further 
backwards than the lateral one. The distal end of the medial ridge lies slightly 
higher than that of the lateral one. There is a broad thick "boss on both sides 
in front of the middle of the articulation surface. The boss on the lateral side 
is thicker and is situated higher up the side of the bone than the medial one. 
The bosses are separated from the just mentioned ridges on their respective 
sides by a broad groove. These grooves pass downwards and backwards above 
the boss for the flexor tendon, where they become deep and narrow, and con- 
tinuing come very near to each other behind it. Upwards they are continuous, 
with the grooves for the claw. The tuberositas for the flexor tendon is divided 
into two portions by a longitudinal groove, which lies to the lateral side of 
the middle line on the lower surface. The lateral portion of the tuberositas, 
which lies higher on the lateral side than the inner portion on the medial one, 
is high and narrow, while the inner portion is low and broad. As in all these 
