Professor S. G. 8eeley — Dinosaurs from BJicbUc Beds. 3 



femur (PI. I, Fig. 1) is about 38 inches long. It is a moderately 

 strong bone, compressed from front to back, with the proximal and 

 distal ends in the same plane. There is no trace of a sigmoid curve 

 such as is seen in Palceosauriis, and to some extent in Megalosanriis 

 and Dimodosaurus. The least transverse width of the proximal end 

 is 9^ inches and the greatest width 10| inches. Of this width, at 

 least 2| inches is due to the inward direction of the convex articular 

 surface, which measures 6 inches from front to back in the middle of 

 the articulation, is flattened above, and is round from above downward 

 as it extends inward. Below the proximal articulation towards the 

 outer border, the front of the bone is impressed for a width of about 



3 inches. This condition somewhat approximates to that seen in the 

 corresponding part of the femur oi Euskelesaurus Browni ; only in that 

 type the transverse expansion of the head of the bone is much less, 

 and the shaft of the bone is nearly cylindrical, shorter, and relatively 

 stouter. The lower border of this impression is an oblique ridge, 

 which passes downward and outward, but is not appreciably 

 elevated ; it is 4 or 5 inches long, and is the only representative 

 of the proximal trochanter of Megalosaurns, which is scarcely 

 developed in Euskelesanrns and Palceosaurus, is almost lost in 

 Massospondyhis and Dimodosaurus, and passes away in some Zan- 

 clodonts. This is one of the most distinctive characters of the bone. 

 Below the termination of the ridge the external lateral contour of 

 the bone is concave in length, and this causes the shaft to narrow 

 from a width of 7 inches to 5^ inches in its middle length, below 

 which it widens again to 11|^ inches towards the distal end. The 

 middle length of the inner lateral border is occupied by a trochanter, 

 which is now br-oken away but had the backward direction seen in 

 carnivorous genera of Saurischia. Its broken base is a foot long, 

 is perfectly straight, and occupies the middle thii'd of the length 

 of the bone. Above the trochanter the concave inner border 

 is approximately parallel to the convex external border. The 

 widening of the distal end of the bone is similarly due to an inward 

 extension of the bone below the trochanter in a concave contour. 

 This inner side is flattened and inclines slightly forward, being 

 supported by the large inner distal condyle. The length and 

 position of the lateral trochanter are distinctive ; in EusJcelesaunis 

 it occupies the middle of the bone, and in Massospondyhis it is 

 towards the middle, but in both the African genera it is relatively 

 shorter, while in Palceosaurus and Megalosaurus the proximal 

 position of the trochanter is as pronounced as in Zandodon; so that 

 this also is a distinctive feature of the bone. 



The distal end is about 11^ inches wide. In front there is a slight 

 concave longitudinal channel, slightly external to the middle width. 

 The distal extremity is truncated. The larger inner condyle seen 

 behind is 7 inches from front to back, and separated from the outer 

 condyle by a moderately deep concave channel about 2 inches wide. 

 The back-to-front measurement between the two channels exceeds 



4 inches. The outer posterior surface external to the lesser condyle 

 is oblique, and has the usual compressed aspect. 



