SUBORDER A 



TYPOTHERIA 



233 



Tyjjotherium Bravard (Figs. 311, 316). Attaining nearly the size of a pig. 

 Lower Pleistocene of Argentina. 



Trachytypothermm Ameghino. Pliocene. 



Typotherium cristatum Serres. Pampas Formation, Buenos Aires, Argentina. A, Skull, upper aspect. 

 i3, Upper jaw, palatal aspect. C, Right fore foot. I), Left hind foot. 1/4. (After Gervais.) 



3.1.4.3. 

 2.1.4.3.' 

 therium beds of Patagonia. Systematic position somewhat doubtful. 



Eutrachytherus and Proedrium Ameghino. Dentition 



Pyro- 



Family 5. Archaeopithecidae (Henricosborniidae, Pantostylopidae) Ameghino. 



Premolars simpler than molars. Upper premolars and lower third molars are 

 triangidar, lower first and second molars are oblong, much broader than long. Ecto- 

 loph with parastyle, often also with mesostyle and metastyle. Protoloph oblique and 

 longer than metaloph. Both ridges often joined on the inner side. Crista and crochet 

 sometimes also present. The posterior crescent of the lower p'emolars is smaller than 

 the anterior, in the molars the posterior crescent is the larger of the two. Premolars 

 with only one central cusp, situated at the junction of the two crescents ; molars with 

 a second central cusp, which is near the posterior end of the second crescent. All teeth 

 are brachyodont. Lower jaw (Icnown in Selenoconus) rather low. About the size of 

 a rabbit. 



Possibly the forerunners of the Archaeohyracidae, but not related to 

 the Primates or to the Hyracidae. Restricted to the Eocene, Notostylops 

 beds of Patagonia. Henrico sbornia, Othnielmarshia, Archaeopithecus, Pantostylops, 

 etc., Ameghino. 



