174 TEETTAET VEETEBEATA OF THE EATtM. 



it has four roots. M. 2 is bilophodont ; it is somewhat longer than broad. M. 3 

 (PL XVII. fig. 6) is also bilophodont, with a talon ; the anterior crest is slightly 

 concave forwards, the shorter posterior one nearly straight. There seems to have 

 been a small accessory cusp in the valley between the main crests, and another on 

 the anterior border of the tooth ; in wear these become united with the inner ends 

 of the posterior and anterior crests respectively. There are only four roots to this 

 tooth, the postero-internal one being enlarged to support the talon^ 



Fore Lmib. — The scapula (PI. XVII. figs. 9, 9 a) is not completely known, the best 

 specimen wanting the upper portion. The prescapular fossa is very small, the post- 

 scapular large and regularly concave from side to side. The spine (s.) commences 

 some distance above the glenoid surface and rises Very rapidly ; its greatest height, so 

 far as preserved in the specimen here described and figured, is about 7'5 cm. The 

 coracoid border [c.h.) is thin and sharp above, but thickens rapidly below, where it 

 passes into the great tuberous coracoid process [cor.). This seems to be larger than 

 in any other mammal, forming a massive hook-like process overhanging the glenoid 

 cavity, the articular surface of which appears to have been continued for a short 

 distance on its posterior face. On its inner side it is raised into a prominent ridge, 

 separated f]:om the border of the glenoid cavity by a groove. The glenoid border 

 is marked off from the actual edge of the glenoid cavity by a slight notch, above 

 which it is thickened and rounded, thinning, however, very rapidly upwards. The 

 large glenoid cavity proper [g.c.) is nearly circular in outline, but, as already mentioned, 

 the articular surface is continued fcjrwards on the coracoid process ; the articular 

 surface (fig. 9 a) is nearly flat from side to side and concave from before backwards. 

 The dimensions of this scapula are given below. 



Two specimens of the humerus are known, one, though otherwise imperfect, exhi- 

 biting the whole length, while the other (PL XVII. figs. 7, 7 a) includes the distal 

 three-quarters of the bone in almost perfect condition with exception of the 

 articular surface. The chief peculiarity of this humerus is the enormously massive 

 distal extremity, the condyles especially being greatly developed. The trochlear 

 surface is divided into two nearly equal portions by a comparatively shallow groove 

 Avhich runs obliquely outwards and forwards, so that the articulation appears some- 

 what oblique. There is a very large and deep coronoid fossa {c.f.) and a deep though 

 much smaller and more sharply defined olecranon fossa (ol.f.), but the two do not 

 appear to have communicated with each other. The outer condyle [o.c.) is a great 

 mass of bone, of which the posterior flattened surface forms the outer wall of 

 the olecranon fossa. The outer face is also flattened and looks outwards and 

 downwards. From its upper end the supinator ridge (s.r.), forming a prominent crest, 

 runs upwards and backwards. The inner condyle (i.e.) is also very prominent ; below 

 it seems to be separated from the trochlea by a deep notch ; anteriorly it is hollowed 

 into a pocket-like fossa which is sharply defined by a prominent ridge below, but above 

 passes gradually into the antero-internal face of the shaft. The deltoid crest {d.) 



