260 Bulletin American Museum of Natural History. [Vol. XIII, 



pm^ is quite simple ; pm^ shows a crista and small antecrochet ; 

 pm 3 shows a prominent crochet ; pms ^"* differ from molars in 

 the absence of antecrochet fold ; the molars show a crista, re- 

 duced antecrochet, and very prominent crochet. (2) Another 

 maxilla (No. 4230) shows a larger size, pm'^ — m^ = 200. 

 Lyons : similar teeth are found from Grive-St.-Alban. It is 

 probable that this stage represents a distinct species, in which case 

 it should be termed R. steinheimetisis Jager ; at present, however, 

 we know no means of distinguishing it from R. sif/iorrensis. Mu- 

 nich : A fine example of maxillary series from Georgensgemiind 

 (catalogued A. i?icisivutn) exhibits premolars and molars without in- 

 ternal cingulum ; the premolars have complete internal crests. 



Conclusions. — There is a gradual advance in size (molars from 

 190 to 200) and in the evolution of the premolars, as we pass 

 from the Middle to the Upper Miocene Ceratorhinae. 



3. Lower Pliocene Stage. Last of Smaller Race. 



Eppelsheim. 



R. steinheimensis. — Kaup referred the smaller teeth of 



Eppelsheim to A. mimitum Cuvier ; this was an error. One of 



these Eppelsheim teeth, a third superior molar, is 



in London (British Museum, No. 1257) ; it agrees 



closely in every particular with those of R. simor-. 



rensis both in size and character ; it is a much 



worn tooth and shows a large antecrochet. Casts 



„. of the Eppelsheim molars (M. 2739, 2740, 2742) are 



steinheimensis. also identical with those of R. simorrensis. Darm- 



Last supenor 



molar. Stein- sTADT : An examination of Kaup's originals in this 



heim, Munich. ^ ° 



Museum confirms the above determination (see 

 Kaup, '62, Taf. II, figs. 6, 10, 11, 13). There is little doubt, there- 

 fore, that this smaller race of Ceratorhinse persisted in the Lower 

 Pliocene ; the specific characters of this stage are undetermined. 



B. Larger Race. 



4. Lower Pliocene Stage. 



Eppelsheim.^ Pikermi. 



We can imagine that the smaller race arrived in Europe (either 

 from Asia or Africa), was arrested in size development and 



