1900.] Oshorn, Phylogeny of the Rhinoceroses of Europe. 24 1 



molar ; third and fourth lower premolars with depressed and incomplete 

 posterior crests. Measurements : pm^-m^ = 224. 



This new species is well represented by teeth in the Paris, 

 Munich, and British Museum collections from the Phosphorites of 

 Quercy and Cazark, mistakenly catalogued as the Upper Oligo- 

 cene A. lemane?ise, from which it differs widely. No true A. 

 lemanense remains are found in the Phosphorites, which is believed 

 by the writer not to extend into the Upper Oligocene. None 

 the less A. filholi is probably ancestral to A. lemanense and repre- 

 sents the first known member of the tetradactyl, dolichocephalic 

 phylum which directly or through collaterals leads up to Ace- 

 ratheriuni incisivum of the Lower Pliocene. 



Th6 distinctness of this species was independently recognized 

 by M. Boule, who in recent lectures has compared it with A. 

 platycephalum. M. Filhol and M. Deperet also both concur with 

 the writer that it is distinct from A. lemanense^ and M. Filhol as- 

 sures me that it is equally distinct from R. velaunutn, which is a 

 much smaller animal. The name Aceratherium may be retained 

 for all members of this phylum, although technically the names 

 Badactheriujn Croizet or Aphelops Cope might be applied to the 

 ancestral truly hornless Aceratheres. 



The entire absence of a crochet and the non-molariform pre- 

 molars distinguish this species sharply from A. lemanense ; the 

 internal cingulum is partly a sexual character ; it varies in differ- 

 ent specimens, although strongly marked in the type. 



Besides the admirably preserved and highly characteristic 

 Paris types, in Munich we find two large molar teeth, m^ and m^ 

 from the Phosphorites (Escamps, Lalbenque, Dep. Lot) ; also a 

 single well worn molar, m^, and two isolated upper molars, m^ 

 (Phosphorites, Cazark, Dep. Lot), of exactly the same size as the 

 A. platycephalum from our Lower Oligocene ; also from Cazark 

 two upper premolars, p^, p*, which exhibit imperfectly formed 

 crests and a crista. In London (British Museum) are lower pre- 

 molars and molars (Phosphorites, Caylux, Nos. M. 1457, 1458, 

 1459, also upper molars M. 1455, m^-m") all catalogued R. leman- 

 ensis. There can be no question that all these teeth belong to 

 the same species, A. filholi, which is far more primitive than the 

 Upper Oligocene A. lemanense to which they have been referred ; 

 not only the premolars but the molars are simpler. The premolar 



November , igoo.'\ 16 



