162 IN CONFIRMATION OP THE GENUS OWENIA SO-CALLED, 



The large incisors are separated at the base by a space of 15 mm. 

 They are in shape compressed twisted cones, diverging strongly 

 outwards with a double curve which brings their trenchant apices 

 nearly parallel with the axial line of the jaw. The surface of wear 

 describes a convoluted curve from the middle of the outer upper 

 edge to the inner face of the extreme tip and thence downwards 

 upon the anterior surface of the tooth j the surface of wear is 

 much larger on the right tooth than on the left. The apex of the 

 tooth is unguiform, a shape conferred upon it by the coat of 

 enamel investing the outer surface of the tooth. 



The general shape of the premolar is triangular with the trans- 

 verse and longitudinal diameters in the ratio 1 : 1*4. Wear has 

 exposed an irregular field of dentine on the lobe and a larger one of 

 crescentic shape on the talon ; these are separated by their respec- 

 tive margins of enamel and these again by the remains of the 

 depression which in the younger tooth separates the talon from the 

 lobe. From the middle of the outer surface of the crown a pro- 

 jecting fold or cingulum runs along the posterior half to the end 

 of the talon ; the fore end of the crown is not reached by the 

 worn surface above, showing that in the unworn tooth the lobe 

 had a backward curve. 



Of the molars there is little to be said ; they present nothing 

 which would compel us to distinguish the mandible from that of 

 a Nototherium. The premolar and first molar of the right side 

 are, like the incisors, much more reduced by attrition than those of 

 the opposite side, and the greatest amount of reduction has taken 

 place on the inner side of their crowns, a circumstance which 

 reminds us of a somewhat similar condition of things in E. grata. 

 In a large number of mandibles of Nototherium and Diprotodon 

 a similar detrition of the inner sides of the anterior cheek-teeth 

 does not once occur. 



Dimensions. 

 Total length from tip of incisor to base of condylar 



process 450mm. 



Height atm 4 90 



Transverse diameter at ra 4 67 



