ODONTOGRAPHY. 71 



A partial description of this tooth has been given by Professor De 

 Blainville from an imperfect specimen belonging to the Ecole de Mines, in 

 Paris. 



The fifth tooth has been described by Professor De Blainville as being Fifth 



Tooth. 



quadri-lobate, or having four ridges and a small talon; and he suggests 

 that there should be also an enlargement of the inner side by the addition 

 of two tubercles to the internal mammilla. I have never met with any 

 instance of the existence of four lobes, or ridges, in the fifth upper molar 

 of the Mastodon Giganteus, nor in any other tooth of that species, except 

 the ultimate molar, and to this the description has not a resemblance ; 



i 



neither this nor the fifth having any intermediate papillae in the Mastodon 

 Giganteus. But his description agrees well with the fifth molar of Mas- 

 todon Longirostris, and makes it probable that the tooth alluded to as the 

 fifth of the Mastodon Giganteus should be referred to Mastodon Longirostris. 

 Such a mistake of the great palaeontologist would not be wonderful in the 

 midst of the vast number of facts he was called by his researches to inves- 

 tigate. 



The particular description of the sixth tooth may be left till after a Fourth 



Tooth of 



consideration of the fourth and fifth teeth, as they exist in the Shawangunk shawangunk 



Head. 



head. In this head (Plate XVI.), the fourth tooth is in place, and measures 

 three inches in length by three and a quarter in breadth. It has three 

 ridges, all very much worn, especially on the inner edge. In the first ridge, 

 the internal cusp is nearly worn away, the second and third cusps are less 

 worn ; but the three are confluent at the inner edge, distinct at the outer. 

 The internal cingulum is worn away ; the external, not strongly developed. 

 There is no talon, nor papillary eminence. The fangs, at their origin, are 

 three in number ; but the two posterior unite to form one. The correspond- 



