EOPROTEROTHERIUM . 



The following table will give what is known in comparing 

 the two series. 



Proterotherium 



PERIOD 

 Santa Cruz 



UPPER MOLARS NASALS PES 



metaconule present normal tridactyl 



protoconule and protocone separate 



metaconule present 



protoconule and protocone separate 



metaconule present normal tridactyl 



metaconule present short tridactyl 



protoconule and protocone fused 



Deuterotherium Deseado 



metaconule lacking 



protoconule and protocone separate 



metaconule lacking 



protoconule and protocone separate 



tridactyl 

 normal monodactyl 



Eoproterotherium Ameghino 



Eoproterotherium Amegh., 1904, Anal. Mus. Nac. B. A., ser. 3, t. 3, p. 441. 



The genus is founded on single teeth of the upper molar 

 series, which, except for size, are 

 very like those of Proterotherium. 

 Limbs, etc., are unknown, so that 

 this genus is simply a carrying back 

 of the Proterotherium line into 

 the Deseado. We found no teeth of 

 this form, but one species has been 

 described, E. inaequifacies, of which 



Ii /* | , c after Ameghino. 



reproduce Ameghino s figure com- 

 pared with Proterotherium, which shows this species to 

 have the metaconule better developed. 



Notodiaphorus gen. nov. 



The basis of this genus is particularly a hind limb found 

 associated which is much less developed than the Santa 

 Cruz genus Diadiaphorus to which it is most nearly related. 

 These two genera are unique in having the ectal facet on 



