Stegosaurus priscus, sp. nov. 



147 



end, and showing a well-developed articular surface suggestive of 

 that in the femur of a chicken in which the epiphyses are not yet 

 fused with the bone or have been artificially removed by roasting and 

 boiling afterwards. The articular surfaces on the femur of St. prisons 

 are not flat but rugose, and show irregular grooves and furrows 

 resembling those of the bone-surface to which the epiphysis is 

 attached in birds and mammals. The manner in which these surfaces 

 pass into the rest of the bone is likewise the same as in the strongly 

 macerated chicken just mentioned. The lack of a pit for the attach- 

 ment of the ligamentum teres is another noteworthy feature of 

 St. prisons and all Stegosauridse, and the whole character of the 

 articular surface is entirely different from that of the Ornithopodous 

 femur where a pit for the ligamentum teres is indicated. To show 

 the differences here referred to, a strongly macerated femur of Gallus 



Fig-. 6. Femora of various animals, a. Strongly macerated femur of Gallus. 

 b. Non-macerated femur of the same. c. Femur of St. priscus. d. Femur 

 of Hypsilophodon Foxii. 



(Fig. 6a) and another which has not been macerated (Fig. 61), 

 besides a well-ossified femur of Ilypsilophodon (Fig. 6d), showing the 

 pit for the ligamentum teres, and the femur of St. prisons, have been 

 drawn together of equal size in Fig. 6, and it is thus easy to see 

 between which bones there is the greater resemblance. I do not wish 

 to imply by pointing to these similitudes that Stegosaurus had separate 

 epiphysial bones, but I wish to emphasize the fact that in this genus 

 the amount of cartilage on both ends of the femur was decidedly much 

 greater than in the Ornithopodidse, and that the shape of the proximal 

 and distal end of the bone must have been originally somewhat 

 different from the present shape. The lack of a trochlea on the 

 distal end of the femur of Stegosaurus can give us a clue to the 

 amount of cartilage missing, for Stegosaurus, being a terrestrial animal, 

 cannot have walked, and especially sat dowm. without bending its 



