136 Fossil Reptiles of New-Jersey. 



To supply the brevity of these notices we shall here add 

 a few observations which we trust will be found to confirm the 

 sound and accurate views respecting this fossil long since en- 

 tertained by our respected associate. 



The upper part of the tooth is irregularly fractured — see Pl.III. 

 fig. 1, — but enough remains to enable us to describe its general 

 form, which is pyramidal, slightly curved backwards, and divided 

 into two distinct surfaces by an anterior and posterior edge, 

 destitute of serratures. The outer surface represents at the 

 base the segment of a large circle, while the inner surface de- 

 scribes the segment of a smaller one, giving a section of the 

 base of the enamelled part of the tooth the appearance repre- 

 sented at figure 2. The tooth is covered with a smooth, 

 brownish black shining enamel, without striae, which des- 

 cends somewhat lower on the external than the internal side. 

 The osseous support is of a dingy white color, entirely resem- 

 bling in structure that of the Maestricht animal. The cavity 

 which held the vicarious tooth (dent de remplacement) is 

 smoother towards the apex, where it was in contact with the 

 enamel of that tooth, than elsewhere. The fragment of jaw 

 exhibits none of the external surfaces of that bone except be- 

 neath, and even there its existence is somewhat problematical. 

 The following are the principal dimensions in Enghsh inches 

 and tenths. 



Height of tooth, - - - - 1'06 



Diameter at base, from outside to outside, - 1*02 



Do. in the direction of the length of the jaw, 1'33 



Height of osseous support from upper side of jaw, 1 '00 

 Length of cavity which contained the vicarious tooth, 2-05 

 Depth of jaw, ----- 2-04 



We will now examine what differences exist between the 

 Maestricht animal and that which has been described. The 

 external surface of the former is described as being " plane/' 

 If by this word it is meant that the surface is flat, which is the 



