I goo.] O shorn, Phylogeny of the Rhinoceroses of Europe. 235 



(Fig. 3) given by M. Henri Filhol ; as above stated the incom- 

 plete condition of the jaw leaves it uncertain whether this animal 



Fig. 3. Ronzotherium velatinuin. Type : Puv. External view of left ramus. X i, after 

 Filhoi; 



from the Lower Oligocene of Ronzon is a primitive member of 

 the Diceratheriinge, Aceratheriinse, or Amynodontidae. 



Characters . — Premolars 2, 3, 

 4, with incomplete crests ; pre- 

 molar I missing in the type 

 specimen ; coronoid and condyle 

 greatly elevated (as in Amy no- 

 don) ; tetradactyl, fifth digit of 

 manus believed to be present (as 

 vciAmytiodon and Acerathei-iuni). 



It should be noted that 

 the American Diceratheres 

 of the Lower Oligocene 

 are tridactyl ; the Ameri- 

 can Amjnodohts (Cadur- 

 cotheriidai or Amynodontidae) are tetradactyl, but with a much 

 larger fifth digit than that associated by Filhol with R. velaiiiuim. 



Fig. 4. Superior grinding teeth. ^, Third and 

 fourth premolars, Cadibo7ia^ Munich. B^ First 

 and fourth premolars, first molar, Phosphorites^ 

 Munich. C, First and second molars, /'/joi'/^or/Z^j, 

 Paris. All figures X g. 



