338 AQUATIC PACHYDEEMATA ; DINOTHERIUM, TOXODON. 



of that appendage, having only a large upper lip. The upper 

 jaw seems to have been destitute of either incisors or canines ; 

 but the lower is armed with two enormous tusks, which, instead 

 of projecting upwards or forwards, sweep downwards and curve 

 gently backwards, having their roots imbedded in enormous 

 sockets. The general conformation of the skull bears so much 

 resemblance to that of the Dugong, as to indicate that the Dino- 

 therium must have been exclusively aquatic in its habits ; pro- 

 bably having either the hind-feet formed as paddles, like the Seal; 

 or being entirely destitute of these members. Its diet was un- 

 doubtedly vegetable ; and we may conceive it to have used its 

 tusks for tearing up strong-fibred plants, by a rake-like action, 

 from the bed of the river, or for anchors by which it might moor 

 itself to the banks, or for hooks by which it might assist itself in 

 dragging its unwieldy body (the length of which was probably 

 not less than eighteen feet) out of the water. Its remains have 

 been found in fresh- water deposits, with those of the Rhinoceros, 

 Tapir, &c. Another genus, which has been established from the 

 skull only, is the Toxodon^ of which the only remains at present 

 known are contained in the Museum of the College of Surgeons, 

 London. This was a large South American animal, which 

 seems to have been allied both to the Pachydermata and 

 Rodentia, and to have had the dimensions of the Hippopotamus, 

 though perhaps still more adapted for aquatic habits. 



304. Some remains of gigantic Pachyderms, that seem to 

 have been intermediate between the Mastodon and the Dinothe- 

 rium, have been recently brought from Australia, in some parts of 

 which they are said to abound. " They tell us plainly," says 

 Professor Owen, " that the time was, when Australia's arid 

 plains were trodden by the hoofs of heavy Pachyderms ; but 

 could the land have then been, as now, parched by long-continued 

 droughts, with dry river-courses, containing here and there a 

 pond of water ? All the facts and analogies which throw light 

 on the habits of the extinct Mastodons and Dinotheres, indicate 

 these creatures to have been frequenters of marshes, swamps, or 

 lakes. Other relations of land and sea than now characterise the 

 southern hemisphere, a different condition of the surface of the 



