70 



The species are thus characterized : 



Mastodon latidens. — Mastodon dentibus molaribus latissimis,, den- 

 ticulis rotundatis, elevatis. Palato valde angusto. 



The dentition very much resembles that of the elephant. The 

 molar tooth is gradually pushed forward, and rises as the fangs are 

 added, according to the demand occasioned by the abrasion of the ex- 

 posed crown, and the consequent absorption of the anterior fang ; the 

 posterior part of the tooth not having yet cut the gum, while the an- 

 terior portion is completely worn away. Before it are seen the relics 

 of the preceding tooth, the place of which the tooth in use was pro- 

 gressively supplying. 



The lower jaw in this species is less square and deeper than it is in 

 M. giganteum. 



The tusks, judging from the alveoli, must have been of equal vo- 

 lume with those of the largest living elephant. 



The following is the measurement of some of the remains of M. 

 latidens. 



Extreme breadth of fragment of cranium (upper jaw 



with the greatest part of both grinders) 1 Ft. 3 In. 



Length of ditto 1 8 



Extreme length of right anterior grinder (6 denticuli 



and the spur) 8| 



Extreme breadth at third denticulus 4 



Circumference of lower jaw, measured over the grind- 

 ing surface of the tooth 2 4 



Extreme length of tooth 1 If 



Extreme breadth 4| 



Circumference of the lower extremity of right femur 2 2 



Same, round the condyles 2 4 



Mastodon elephantoides. — M. dentibus latis ; denticulis numeroas, 

 compressis. 



This species must have been smaller than the last. There is a fine 

 example of the lower jaw, showing the tooth in the highest degre* 

 of perfection. The tooth is 1 1 inches long and 3^ inches broad 

 has no less than ten denticules, and each of these denticules is ma 

 millated with small points ; five being the smallest, and eight ths 

 greatest number on any one denticule. In front of this tooth s 

 seen the remnant of the preceding one, worn down and disappear 

 ing ; and behind it is the cavity wherein the young tooth, intendd 

 as a successor to that in existence, was in the course of formatio:. 

 The denticules are much more compressed than those in the specis 

 last described ; they are closer together, and the whole tooth a- 

 proaches still more nearly to that of the elephant, while the jaw is n 

 unison with the appearance of the tooth. 



Pachydermata ordinaria. — In this group we have the remains )f 

 the genera Sus, Hippopotamus, and Rhinoceros. Of the first thee 

 is only a single specimen, consisting of a small portion of the lowr 

 jaw, containing one molar tooth and the fragment of another. *f 

 the second there are but few fragments, nor are they sufficiently ch- 

 vacteristic to warrant a definition of the species, which must have ben 



