New Species o/Propappus, and Pose of Parciasaurian Limbs. 325 



condition in Pareiasaurus, where the former is much smaller. The 

 acromion process is large and differs from that of Pareiasaurus in 

 being directed more upwai'ds than forwards. Above the acromion 

 the scapula is comparatively narrow, but stout. 



The coracoid is perfectly preserved. The subglenoid portion is 

 roughly about the size of the glenoid cavity. The lower and 

 posterior corner is truncated, and doubtless articulated with a 

 cartilaginous sternum. The whole lower border of the coracoid and 

 precoracoid has a flattened and thickened edge, probably for a short 

 articular cartilage which met the similar cartilage of the other side. 

 The inner side of the lower part of the precoracoid and of part of the 

 coracoid is very markedly concave. 



The following are some of the principal measurements : 



Posterior end of coracoid to top of acromion 275 mm. 



Greatest width of glenoid 130 ,, 



Width of scapula immediately above acromion ... 60 ,, 

 Thickness of scapula immediately above acromion 40 ,, 



Humerus, 



The right humerus is in perfect condition, and while re- 

 sembling that of Pareiasaurus scrridens it differs rather strikingly in 

 one or two points. As I pointed out some years ago, the British 

 Museum specimen of Pareiasaurus baini gives a most misleading 

 idea of the animal from the fact that in restoring the humerus the 

 upper half was fixed on to the lower at a wrong angle. The articular 

 head of the bone is placed nearly in the same plane as the lower 

 portion of the bone. In Pareiasaurus serridcus the head makes 

 with the distal portion an angle of about 70. In Propappus rogersi 

 the head makes with the distal end of the bone an angle of only 

 about 30. But to make up for the very small rotation of the shaft, 

 the delto-pectoral crest is twisted very abruptly forwards and 

 developed into a prominent knob, which stands out at right angles 

 to the plane of the distal part of the humerus. The head of the 

 bone is very similar to that of Pareiasaurus, being similarly arranged 

 to fit the peculiarly shaped glenoid cavity. Most probably it had a 

 thick pad of cartilage. The greatest width of the head of the bone is 

 178 mm. The middle of the shaft is very narrow, measuring only 

 4cS mm. in diameter. The lower half of the bone agrees closely with 

 that of Pareiasaums. There is a well-developed entepicondylar 

 foramen, but no ectepicondylar. The articular surface for the radius 

 and ulna is large with a rounded part for the head of the radius and 



