198 



Lophiodon bathygnathus , or the Deep-jawed Lophiodon, from the charac- 

 teristic proportions of the jaw just cited. 



This fossil has been described and figured by Dr. Harlan in Silli man's 

 American Journal of Science, vol. xliii. 1842, pi. 3. fig. 1, under the 

 name of Sus Americana, conceiving that from " its general appearance 

 and number of the teeth this fragment bore a close analogy with the 

 same part in the Sus babirussa, Buff." acknowledging, however, that " the 

 Babyroussa" was a much smaller animal. Besides the difference of size, 

 the last molar in the fossil has the anterior transverse ridge proportionally 

 larger and the posterior lobe proportionally smaller than in the Baby- 

 roussa, resembling the Lophiodon in the points in which it thus differs from 

 the Sus cited. The form of the fossil jaw differs at the part supporting 

 the last molar from that in the Babyroussa, where the socket of the last 

 molar overhangs the inner surface of the ramus, whilst in the fossil the 

 inner surface of the ramus beneath the last molar describes a gentle con- 

 vexity from the tooth to the lower margin of the ramus. The outer part of 

 the ramus of the jaw of the Babyroussa begins to expand below the fourth 

 and fifth molars, counting forwards from the last, to form the socket of the 

 large tusk ; but the fossil jaw does not offer the least indication of an en- 

 largement for that purpose, and the fractured anterior end, as displayed in 

 the cast, is very different in shape from the corresponding part of the jaw 

 in the Babyroussa, and shows merely the dental canal and no socket for 

 the tusk which would be here situated in the Babvroussa or Wild Boar. 



The nearest approximation which the fossil in question allows to be 

 made to any known existing or extinct animal is to the great tapiroid 

 Pachyderms. Ulterior discoveries, may, indeed, show that the Lophiodont 

 dentition was combined with other characters in the American fossil, 

 necessitating a generic distinction, and it is well to remember that the 

 dentition of the Macrauchenia of South America, a three-toed Pachy- 

 derm with an astragalus almost identical with that of the Lophiodon, and 

 of a size which agrees with the jaw of the fossil Sus Americana of 

 Harlan, has yet to be discovered. 



The original of the cast here described was brought to light during 

 the excavation of the Brunswick canal, Georgia. North America ; it is 



