The President's Address. By Dr. H. Woodward. 159 



elevation seen in the modern Elephants, but resembled that of an 

 ordinary form of mammal such as the Pig or Tapir. With the 

 increased length of the proboscis the length of the jaws diminished, 

 the teeth were reduced in number, and became deeper and larger, 

 and the jaws also correspondingly deeper, also the facial angle 

 became more vertical, and the jaw shorter. In the modern Ele- 

 phant we may observe that the brain actually is just above the 

 palate and over the grinding-surface of the teeth, which no longer 

 occupy a position anterior to the brain, as in ordinary mammals. 



In Dinotherium the incisors so characteristic of modern Ele- 

 phants are wanting in the upper jaws, but two exist in the lower 

 jaw curved downwards, quite unlike that in any other of the Pro- 

 boscidea known ; molars and premolars seem to have been present 

 in the jaw at the same time. 



The Ancylopoda represent another primitive sub-order of 

 ungulates, with a very wide range in Miocene and Pliocene times. 

 They resemble the great extinct ground sloths of America, and the 

 existing ant-eaters of the old world, and when the limbs alone were 

 known they were referred to the Edentates. Homalodontothcrium, 

 Macrothcriitm, and Chalicotherium belong to this sub-order, and are 

 met with in Patagonia, North America, Europe and Asia. 



Tyfotheria. — These form a group of extinct ungulates from 

 South America, found in the Pampas formation, some of them of 

 considerable size, comprising Typothcrium, Pyrotherium, and Pachy- 

 rucus. The teeth are more or less rodent-like. They appear to be 

 little-modified descendants of very primitive mammalia. 



Toxodontia. — Named from the typical genus Toxodon. The 

 complete skeleton of Toxodon is known. The animal was shorter- 

 limbed, but more bulky than a horse, having rodent-like incisors in 

 its jaws. The teeth are deepened, and more or less curved, often 

 growing persistently throughout life. The dental series is nearly 

 complete, only the canines being reduced or absent. The name 

 Toxodon is derived from the bow-like form of these teeth. 



Lytopterna. — This is a South American group of animals 

 which in their foot and tooth structure resemble the uneven-toed 

 ungulates (the Perissodactyla), though they are not related to them. 

 Protcrotherium and Thoatherium belong to this sub-order. A better 

 known genus is that of Macraachcnia patagoniea, an animal with 

 a long neck and three complete digits. The original fossil remains 

 of this animal were obtained by Darwin during the voyage of the 

 ' Beagle.' 



Perissodactyla (Uneven-toed Ungulates). — Many early forms 

 are included in this division, the Perissodactyla, or uneven-toed 

 Herbivora. Nearly all the ancestors of these animals had penta- 

 <lactyle (five-toed) feet. One of the earliest of these families are the 

 Tapirs, the living representatives of which being found as far apart 

 from one another as South America and the Malay Peninsula. 



