166 



DR. C. W. ANDREWS ON LOWER MIOCENE [June 1914, 



while the third occupies the whole width of the posterior side of 

 the tooth, and extends a little along the outer border. 



The dimensions (in centimetres) of this specimen are : — 



Length 4"9 



Width 5-4 



Numerous fragments of the lower tusk of Dinotlierium were col- 



lected : these show no traces of the 



Fig. 



1. 



A = Tibia of a Tetrabelodont seen from the front. 

 B = Distal end of a tibia of a large Anthracothere 



seen from the front. 

 C = The same, distal articular surface. 



c.7\ = cnemial crest. 

 [All the figures are a fifth of the natural size.] 



engine-turning ' characteristic 

 • of the ivory of the upper 

 tusks of Eleplias, but 

 indicate that the dentine 

 was composed of con- 

 centric lamellae, which 

 tend to split apart as dis- 

 integration takes place. 

 No trace of enamel has 

 been observed on any 

 of the fragments. One 

 specimen of the tip of 

 the tusk shows that it 

 was strongly compressed 

 at the end, which forms 

 a sharp point. 



The above - described 

 specimens are from Bed 

 31. 



In Bed 22, a Probo- 

 scidean tibia (fig. 1, A) 

 was collected, the bone 

 being well preserved and , 

 complete, except that 

 the distal epiphysis 

 is missing. It is verv 

 similar in structure to 

 the tibia of an African 

 elephant, with which it 

 was compared, differing 

 only in some minor fea- 

 tures. Thus the pit for 

 the insertion of the ex- 

 tensor muscles on the 

 upper face of the cne- 

 mial crest is much less 

 stronolv marked on the 

 fossil ; while, on the 

 other hand, the rugose 

 surface below and at the 

 side of it is more pro- 

 minent. There is a deep 



