[STERNBERG] PANOPLOSAURUS M I RUS 99 



the inner side slightly in advance of the coraco-scapular union. It is 

 situated considerably below the centre and is completely within the 

 coracoid. 



Length of coracoid at midheight 255 mm. 



Height at coraco-scapular union 150 " 



Humerus. — The humerus (Plate II, Figure 2), as in Stegosaurus, 

 is short and massive with the extremities greatly expanded and without 

 medullary cavity. The shaft is greatly constricted below the mid- 

 line, the greatest constriction being at about three-fifths the distance 

 down. The radial crest (Plate II, Figure 2) is well-developed though 

 not so long, relatively, as in Stegosaurus}^ 



The radial crest is more clearly defined than in the last-named 

 genus, there being a decided depression between its superior border 

 and the head. 



The round, well-defined head is somewhat internal to the centre 

 of the proximal end and is produced backward so as to overhang the 

 posterior border of the shaft. It is large and round to conform to the 

 glenoid cavity. When the bone is erect the articular face of the head 

 looks obliquely downward and the faces of distal condyles obliquely 

 upward. The position of the head and condyles, together with the 

 strong radial crest, implies that in the articulated skeleton the limb 

 would be strongly flexed as in Stegosaurus and the Ceratopsia. Just 

 below the head, on the anterior internal border of the bone, is a rugose 

 area for the attachment of muscles. 



The distal condyles are well differentiated, the external one being 

 the more pronounced. 



Greatest length of humerus 430 mm. 



Greatest breadth (including radial crest) 240 " 



Least diameter of shaft 71 " 



Greatest breadth at distal end 186 " 



Forefoot. —The left forefoot (Plate VIII, Vol. XIII, R.S.C., 1919) 

 is represented by Metacarpals I, II and III, and their complete digits. 

 They are articulated and in their relativ^e positions though it is not 

 possible to say that these bones represent the complete foot. The 

 drawing shows the foot as it was found in the rock. Metacarpals I 

 and III — ^the distal and proximal ends are so rotated relatively to one 

 another as to throw the toes well apart, though the proximal ends of 

 the metacarpals are closely applied to each other. Pressure has been 

 exerted on the end of digit III so as to push the ungual over the second 

 phalanx and squeeze that bone back hiding it from the front view. 



'^ U.S. Nat. Mus. Bull. No. 89, 1914, by C. W. Gilmore, PI. 20, Fig. 2. 

 —38 



