90 BRITISH FOSSIL REPTILES. 



proximal end of the bone was relatively deeper. This end, divided by the cleft 

 from the great trochanter, was subcompressed from side to side below the swelling 

 out of the head, which had been broken or abraded away, showing a fine cancellous 

 structure at that part. The antero-posterior diameter of this part is 6 inches ; 

 the transverse diameter, opposite the base of the outer trochanter, is 3 inches 

 8 hnes. 



The fore part of the shaft showed at its upper half a flattened, oblong, rather 

 rough surface for muscular implantation. Below, and on the outer side of this 

 surface, was a rough, roundish, slightly prominent tuberosity (s), continued at its 

 inner side into a ridge, which descends with a slight curve outwards on the fore 

 part of the middle of the shaft of the femur, where it terminates in a point at v. 

 These risings indicated the force of the large muscles acting upon the limb, and 

 by their insertions raising and drawing forward the femur. Behind the base of 

 the process was a large, oblong, rough ridge indicating the extension of the 

 surface of attachment, behind and beyond the process itself, for a powerful 

 muscle depressing and drawing back the femur. From the great trochanter a 

 narrow, rough surface, not projecting as a ridge, extended nearly straight 

 down the outer and back part of the shaft. Exterior to this surface was an 

 oval foramen, most probably for the passage of the blood-vessels and nerve to 

 the medullary cavity. 



The transverse section of the middle of the shaft is nearly circular ; the 

 thickness of the compact wall of the medullary cavity is here about one sixth 

 of the transverse diameter of the bone. I have not seen a bone of any other 

 Dinosaur indicative of more vigorous action of the hind limbs than the present 

 femoral shaft. 



The foregoing instructive fossil was accompanied by the shaft of a til:)ia of 

 corresponding size, crushed and broken at both ends ; it measured 18 inches 

 in length and 2 inches 8 Unes in diameter at its middle, the circumference of 

 the shaft there being 10 inches. 



These proportions indicated a hind leg, longer and more slender, relatively 

 to the trunk, than in the Megalosaur, Iguanodon, or other Dinosaur with which 

 such comparison may be made. The bone being fractured across the middle 

 of the shaft, shows a large medullary cavity ; the compact, bony wall does not 

 exceed 3 lines in thickness, the cavity itself being 1 inch 3 lines in diameter. 



At the proximal end the antero-posterior expansion and its ridges have been 

 broken away. The bone gradually contracts, as it descends, to a subtriedral 

 shaft, with a triangular transverse section, two of the angles being rounded off, 

 and the third remaining, which was opposite the fibula. The distal expansion 

 has been, in like manner, broken away ; but its commencement shows the rise 

 of an anterior ridge in addition to the fibular one. I shortly after received from 



