72 ODONTOGRAPHY. 



ing tooth in the lower jaw has the same dimensions, and is like this, 

 excepting that the outer edge is worn away. 

 Fifth Theffth tooth in the same head is larger than the last, being four inches 



Tooth of 



shawangunk long and three broad. It has three ridges or lobes, each bearing two pairs 



Head. 



of cusps : the anterior are worn into one, the middle are more distinct, and 

 the third pair are but little worn. There is no additional or papillary 

 eminence between the ridges, as supposed by De Blainville. Both of these 

 ridges are remarkably flattened on the anterior and posterior surfaces. 

 There is a slight eminence at the posterior extremity, but no distinct talon : 

 the cingulum is more developed on the outer edge than on the inner. The 

 roots rise from three distinct origins corresponding with the ridges, and are 

 then lost in their sockets. The tooth on the left side of the upper jaw 

 corresponds with this on the right. 

 suth The sixth tooth in the same head from which the two last have been 



Tooth of 



shawangunk described, though not of the largest size, is a fully developed, perfect 



Head. 



specimen of the ultimate molar. It has four ridges, and a small talon at its 

 posterior extremity. The points or summits of these ridges are in a number 

 of instances bifurcated, particularly in the outer mammillae. At their bases, 

 the cusps run together, and are flattened on the anterior and posterior part. 

 They incline forwards, as is most common in all the teeth. The valleys 

 between the ridges are deep, and without papillary eminences. The basal 

 cingulum is more marked on the inner than on the outer edge. This tooth 

 measures six inches and a quarter in length, three inches in width over 

 the cusps. 



The roots are concealed in their sockets ; but we have preferred 

 describing the crown' in this specimen, because it is in place, and there 

 can be no doubt as to its true denomination. Having many teeth of this 



