94 STUDIES IN TASMANIAN MAMMALS, LIVING AND EXTINCT, 



EOCENE. 



From Eocene times; the Nototheria retain — 



B. Bilophodont molars (still manifested among the 

 modern Tapirs, to some extent) as found in many 

 Eocene ungulates. 



B. Flattened femora and humeri of generalised 

 Eocene mammals. 



The absence from the head of the femur in the Noto- 

 theria of a ligamentum teres brings the animals into line 

 with the Eocene Dinoceras, as well as the following living 

 and extinct forms: — Elephant, Sea Otter, Sea Elephant, 

 Orang, both forms of Monotremata, and the gigantic 

 pleistocene Ground Sloths of South America. 



MIOCENE. 



From Miocene times, the Nototheria retain but little 

 that is essentially characteristic, unless the nasals of such 

 forms as have advanced the least upon the fighting trend 

 really do manifest bony cores, which is at present uncer- 

 tain. The facts point to a higher stage in N . tasmanicum, 

 making an approach to the pliocene dermal horn stage. 



PLIOCENE. 



From Pliocene times the Nototheria retain — 



A. The central nasal horn, or horns. 



B. N. tasmanicum, and its allies, show about the same 



amount of development in this connection that 

 pliocene ungulates did. 



C. Nototherium mitchelli appears to have advanced 



to early pleistocene in this matter, but still re- 

 tains the pliocene characters of short and wide 

 nasals, as in Pachygnathus. 



D. A character here also reaches towards the Tapir 



stirp, as much as towards the Rhinocerotidce, 

 namely, in JY. mitchelli, the nasal septum extends 

 beyond the nasal bones, as in Elasmognathus, 

 while in the other Nototherian group {N. tas- 

 manicum and its allies), the nasals extend to the 

 nasal septum, as in T . indicus, T . americanus, and 

 T. roulini. Always, of course, with special, 

 marsupial variations. 



