AND CLASSIFICATION OF THE FOSSIL REPTILIA. 
2G7 
The antero-external lateral area is much shorter, since it is limited proximally by 
the tranverse articulation. It is about 10 centims. wide, and deeply concave 
proximally, forming an excavation for the head of the radius ; but distally its width 
is reduced to one-half, and the bone, which is flattened transversely in the middle of 
the shaft, becomes convex transversely above the distal articulation. This surface 
meets the internal border of tlie bone in a shai'p ridge. 
The distal articulation (Plate 22, fig. 3) has a pear-shaped contour, narrow behind, 
and wide in front. It is oblique, extending distally several centimetres further on the 
inferior than on the superior border. Its extreme width is 13 centims., and extreme 
thickness 9 centims. It is convex from back to front, the convexity increasing 
anteriorly and interiorly ; but the outer part of the bone is somewhat concave in the 
transverse direction. 
The proximal extremity of the olecranon ((Plate 22, fig. 2) is sub-quadrate, being 
11 centims. wide by 9 centims. thick at the articulation, and 6 centims. thick at the 
posterior border. It is defined by four straight borders, is convex superiorly in both 
dimensions, and its rugose surface gives every appearance of being cartilaginous. 
The proximal articulation is imperfectly freed from the matrix, but it consists of an 
internal part 14 centims. long, and an external part about 10 centims. long, so that 
internally the bone extends forward as an angular process G centims. wide, where it 
merges in the mass of the articulation. The inner part of the articulation extends 
further proximally than its external part, and on the middle of the posterior half of 
this surface is a strong sharp-roinided ridge, which was received into a corresponding 
groove on the distal end of the humerus. 
There is something very Mammalian in the character of this proximal articular 
surface ; but it is perhaps the character of all others in which the Anomodont type 
approximates to a Dinosaur. 
Small Bones of the Extremities of Titanosuchus ferox. (Plate 24, figs. 1, 2.) 
Two small bones, 'numbered 49,367, were collected with the other remains of 
Titanosuchus ferox (Owen). Their forms are such that they may be phalanges, or 
carpal or tarsal bones, for in contour they resemble carpal bones of some Plesio- 
saurians, but are much thinner than might have been expected from the massive 
character of the larger limb bones. I regard the larger of the two bones as probably 
an external phalange, and the smaller as a middle phalange. 
The larger bone is compressed, sub-quadrate, but broader than long, w^itli concave 
lateral margins, long and narrow proximal and distal articular surfaces, which somewdiat 
approximate towards one side of the bone. The external or superior surface is concave 
transversely, and gently concave in the vertical direction ; the inferior surface is flat. 
What I suppose to be the proximal surface is G’5 centims. long, transverse to the 
axis of the bone, and inclined obliquely in the transverse dmection, so that the length 
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