MAMMALIA. 



65 



preceded again in the Middle Eocene of Egypt by Moeri- "Wall-case 

 theriwm (Fig. 62), which comprises still smaller species 43 - 

 whose relation to Mephas would hardly be suspected if all 

 the intermediate gradations were unknown. Here the cross- 



Fig. 61. — Skull and lower jaw of Palssomastodon beadnelli, showing 

 elongated chin with pair of terminal cutting teeth (l.i.), from the 

 Upper Eocene of the Payum, Egypt ; one-twelfth nat. size. nor. 

 position of nostrils; u.i. upper incisor or tusk. (After 0. W. 

 Andrews.) 



Pig. 62. — Skull and lower jaw of Moeritherium lyonsi, from the Middle 

 Eocene of the Payum, Egypt; one-seventh nat. size, ant orb., 

 antorhital foramen; c, canine; ex. oc., exoccipital ; fr., frontal; i. 1-3, 

 incisors ; ju., jugal ; m. 1-3, molars ; mx., maxilla ; to., nasal ; p.a., 

 parietal; par. oc, paroccipital ; p.m. 2-4, premolars; p. mx., pre- 

 maxilla ; pt., post-tympanic process of squamosal ; s.oc, supra- 

 occipital : sq., squamosal. (After G. W. Andrews.) 



ridged molars are first becoming recognisable; one pair of 

 incisors above and below is growing at the expense of its 

 fellows to become real tusks ; and the arrangement of the 

 bones of the skull is beginning to show features which are 

 known only in the order Proboscidea. Several instructive 



