.389 



by the socket in the specimen No. 1460 : the crown of this tooth may, 

 possibly, have presented a modification of form different from the rest, 

 and a further affinity of the Diprotodon to the Kangaroo may prove to 

 be manifested by a more compressed and trenchant character of the 

 anterior molar. 



Fig. 2. Side view, Jig 3', grinding surface, of the second molar tooth. (See 

 Nos. 1491 and 1493.) 



Fig. 3. Side view, Jig. 3', grinding surface, of the third molar tooth. (See 

 Nos. 1492 and 1494.) 



Fig. 4. Side view, Jig. 4', grinding surface, of the fourth molar tooth. (See 

 No. 1495.) 



Fig. 5. Side view, Jig. 5', grinding surface, of the crown of the fifth and 

 last molar tooth. The fractured surface of the anterior eminence shows 

 the thickness of the enamel. (See Nos. 1496 and 149J.) Fig. 5" shows 

 the posterior surface of the second transverse eminence and the wrinkled 

 and punctate surface of the enamel. 



Fig. 6. Side view, Jig. 6', grinding surface, of the last lower molar tooth of 

 the Tapirus americanus, showing the close similarity of the modifications 

 of the crown of this and the extinct Australian Diprotodon. 



Fig. 7 '• The grinding surface of the last lower molar tooth of a large extinct 

 Kangaroo (Macropus Titan). 



In the genus Macropus the crowns of the molar teeth support two principal 

 transverse eminences, as in the Tapir and Diprotodon, but they are connected 

 together bv an oblique longitudinal ridge which crosses the valley, and a similar 

 ridge connects the anterior transverse eminences with the anterior basal talon, 

 which in the present species is unusually developed. 



PLATE VII. 



Views of the anterior end of the right ramus of the lower jaw of the Dipro- 

 todon australis (see No. 1460.) : half the natural size. 



Fig. 1. Outside view : i, fractured base of the incisive tusk ; ml, the socket 

 of the first molar tooth ; m 2, the second molar tooth ; m 3, the third 

 molar tooth. 



