114 BRITISH FOSSIL REPTILES. 



than the opposite one. This femur, being broken across about 6 inches from its 

 upper end, shows a medullary cavity of about 1^ inch in diameter, with a compact 

 and finally cancellous wall, which is nearly an inch in thickness next the base of 

 the inner process, and is about 3 lines in thickness on the opposite side of the 

 shaft (PI. 57, fig. 2). The transverse breadth of the shaft here is 2 inches 7 lines, 

 the fore-and-aft breadth is 2 inches. The transverse breadth of the distal end is 4 

 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 (PI. 57, 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, in part, 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 dislocated 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 sm'face 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 fibiUa 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. 



1 In their natural relative positions, the fibula has been slightly dislocated outward in the left leg. 

 (PI. 57.) 



