1900.] Osboni, Phylogeny of the Rhinoceroses of Europe. 26 1 



terminated in the smaller Eppelsheim species ; then from the 

 same original stock, by subsequent migration, a collateral larger 

 race arrived, which in general had developed along the same 

 lines, but had retained certain primitive characters. 



Such a collateral species is Kaup's R. schleierinacheri oi Eppels- 

 heim (Fig. 13, C). It exhibits molar-premolar teeth measuring 

 260 ; it is thus nearly one-third larger than R. steinheimensis ; it 

 resembles the R. sansaniensis series in the following points : 

 superior molars : antecrochets reduced ; a crista (progressively 

 bifid); a prominent crochet; skeleton: metapodials of medium 

 length ; tridactyl manus. It differs as follows : premolars with 

 crests internally confluent upon wear (primitive); first lower pre- 

 molar persistent (primitive); a sagittal crest (primitive); small 

 cutting teeth (progressive); very large nasal and frontal horns 

 (progressive); no postfossettes in the molars ; wide distance be- 

 tween orbit and naso-maxillary notch (this space is somewhat 

 shorter in R. sansaniensis., indicating a progressive lengthening of 

 the skull in R. schleiermacheri). 



Therefore, as placed together in the Paris Museum the Middle 

 Miocene R. sansa?uensis and the Lower Pliocene (Pikermi) R. 

 schleiermacheri exhibit first a striking racial similarity in form ; 

 second, a difference in size exactly such as one would expect in 

 the progression from a Middle Miocene to a Lower Pliocene type; 

 third, certain primitive and progressive differences which render 

 the theory of direct descent of one from the other impossible. If 

 one compares the skulls closely one sees the striking racial like- 

 ness in the form, and especially in the proportions and positions 

 of the horns upon the nasals ; the occiput of R. schleiermacheri is 

 relatively lower and is somewhat broader below. In both speci- 

 mens the infraorbital foramen is very close to the naso-maxillary 

 notch ; thus it is evident that these species, although not geneti- 

 cally related, represent collateral branches of a similar race. The 

 growth of the skull between the orbit and anterior nares points 

 to progressive dolichocephaly and to correlated elongation of the 

 limbs and feet. 



The successors and relatives of this Ceratorhine phylum are, 

 apparently, R. leptorhinus Cuvier, Middle Pliocene, represented 

 by a fine skull (Paris Museum, Montpellier, Herault); the long- 

 limbed R. etruscus from the Upper Pliocene of Italy, France, and 



