IG 
FOSSIL REPTILIA OF THE 
inches 10 lines ; the fore-and-aft breadth of the outer condyle is 3 inches 3 lines, that 
of the inner condyle 3 inches 8 lines ; the depth of the posterior inter-condyloid 
notch is 1 inch 3 lines. 
The proximal ends of the tibia and fibula are crushed below their articular 
surfaces ; most so in the right leg, with fracture of both bones. The medullary 
cavity of the right tibia has been obliterated by this violence, and the strong, compact 
wall broken and crushed in upon it. The fibula, with a smaller cavity and 
thicker, compact walls, has better resisted the pressure, especially in the left limb. 
The length of the tibia (Tab. X, 66) is 12 inches 10 lines, that of the fibula (ib. 67) 
is about an inch shorter. The expanded upper end of the tibia passes over the outer 
and part of the front surface of the head of the fibula ;* the expanded lower end of 
the tibia passes behind that of the fibula, showing a kind of twisted, terminally 
overlapping relation between the two bones. There is a distinct interosseous space (o) 
between the upper three fourths of their shafts. The breadth of the proximal end 
of the tibia, which may be a little increased by compression, is 5 inches 6 lines. 
The breadth of the distal end is 4 inches 6 lines. The tibia, which, on the left 
side, has suffered least compression at its upper end, and has been partially dislo- 
cated from the femur, shows a coadapted surface of very similar shape to that of 
the femur, convex from before backward, slightly concave transversely at the back 
part of the joint. In both bones the articular surfaces are rough, as if they had 
been connected together ligamentously. The tibial articular surface divides 
posteriorly, as before noted, into two condyloid processes, with an inter-condyloid 
space of about 2 inches breadth ; one condyle is for the inner condyle of the femur, 
the other is adapted to the posterior prominence of the outer femoral condyle. 
The back part of the proximal end of the fibula next the outer condyle of the 
tibia is similarly produced into a convex protuberance. The fore and outer part 
of the tibia is produced into a strong procnemial tuberosity or process. 
The shaft of the fibula contracts to a diameter of 1 inch 10 lines, and then 
expands transversely, but without corresponding fore-and-aft enlargement, to the 
distal breadth above recorded. 
To the major part of the distal end of the tibia, at least to two thirds of its inner 
or tibial side, is articulated the tarsal bone {a), including the coalesced homologues 
of the astragalus, naviculare, with the ento- and meso-cuneiform bones, of the mam- 
malian tarsus. This bone (Tab. X, fig. 1, a) presents an anterior surface of an 
elongated, irregular, triangular form, with the apex tibiad or toward the inner side 
of the tarsus. It becomes narrower as it proceeds backward beneath the tibia (ib., 
fig. 3, a), its articular surface with which is concave from before backward, 
* In their natural relative positions, the fibula has been slightly dislocated outward in the left leg. 
(Tab. X.) 
