106 .R. S. Lull — New Tertiary Artio dactyls. 



served teeth, however, apparently Dp 3 , is very distinctive, 

 having* two external crescents which are quite molar-like, 

 while the single internal crescent, if such it may be called, 

 is complicated by a median fold which in turn bears crenu- 

 lations and abuts against the space between the two outer 

 crescents. The horns of the inner crescent are extended 

 fore and aft and the posterior one bears an internal 

 crenulatiom Anteriorly a fold extends inward from the 

 antero-external crescent to embrace the forward horn of 

 the inner crescent. It forms the anterior border of the 

 roughly triangular tooth. 



Lower milk dentition. — Four teeth are preserved. 

 Here the most peculiar feature lies again in the com- 

 plexity of a single tooth, this time Dp 4 , which is not unlike 

 a molar except that it is three-lobed like M 3 reversed, 

 in that the anterior lobe is the smallest. This lobe con- 

 sists of an external and internal portion connected to- 

 gether broadly by their anterior ends and diverging 

 posteriorly, otherwise they resemble somewhat a minia- 

 ture replica of the inner and outer crescents of a normal 

 lobe. An external pillar arises from the cingulum in 

 each reentrant angle between the lobes, making two 

 instead of the normal one. 



The measurements of the milk dentition, all maximum, 

 are as follows : 



Upper series. m. 



Total length of the three teeth -0300 



Dp 3 , length -0106 



Dp 3 , breadth -0073 



Dm 1 , length -0115 



Dm 1 , breadth -0093 



M 2 , length -0122 



M 2 , breadth -0102 



M 2 , height of crown -0098 



Lower series. 



Total length of the four teeth -0340 



Dp.,, length -0055 



Dp" , breadth -0022 



Dp 3 , length -0070 



Dp 3 , breadth -0034 



Dp 4 , length -0115 



Dp 4 , breadth -0055 



M 1; length -0113 



Mi, breadth -0063 



