TRANSACTIONS OF WAGNER 

 3 



MASTODON 



Fore and aft diameter of the crown . . . . . 97 mm. 

 Transverse diameter of the crown at fore part . . . 60 " 

 Transverse diameter of the crown at back part . . . 67 " 



The tooth of the left side, also preserved entire, essentially accords with 

 that just described. The jaw fragment retains the alveoli of the premolar in 

 advance, which thence would appear to have been a two-fanged tooth. It also 

 retains the fore part of the alveoli of the succeeding true molar, which co-ordi- 

 nates with the isolated tooth above described. 



In the collection from Mixon's plantation of 1890 are five isolated speci- 

 mens, the crowns of molar teeth, which appear to have belonged to the same 

 animal, a young one, from the jaws of which the teeth had not yet protruded. 

 They are entirely unabraded from wear, and are nearly destitute of cementum. 

 They consist of the fourth upper molar of both sides, the corresponding lower 

 left molar incomplete, and both lower third molars, of which the right one is 

 imperfect. 



The upper first true molar, that of the left side being represented in plate 

 ii. fig. I, nearly accords in form and construction with that of plate ii. fig. 6, 

 previously described. It is smaller, and the lobes of each transverse pair are 

 less deeply separated by angular notches from the greater proportionate de- 

 velopment of their medial offsets. 



The first lower molar, of the same side, represented in plate ii. fig. 3, 

 resembles the former, narrowed transversely and with its homologous lobes 

 reversed in position, and with its posterior talon proportionately more de- 

 veloped and appearing as a conspicuous pair of unequal conical eminences. 



The fourth lower molar, incomplete in its anterior two outer lobes, is an 

 enlarged representative of the tooth preceding it, just described. 



The measurements of the teeth are as follows : 



Fore and aft length of the crown of the upper fourth molar. 106 mm. 



Transverse breadth at base of the anterior lobes . . 65 " 



Transverse breadth at base of the posterior lobes . . 68 " 



Height of middle external lobe 53 " 



Fore and aft length of the crown of the lower third molar . 97 " 



Transverse breadth at base of the anterior lobes . . 46 " 



Transverse breadth at base of the posterior lobes . . 56 " 



Height of middle internal lobe . . . . . 44 " 



Among the characteristic specimens of the Florida Mastodon under 

 examination from Mixon's plantation are five isolated molar teeth, which, 



