92 UNGULATA. 



crests, and an outer wall with open valleys ; they may or may not 

 have a " combing-plate " and a buttress at the antero-external angle ; 

 their crowns vary in height, but are never very tall. The hinder 

 premolars are as complex as the true molars ; the lower cheek-teeth 

 are distinctly crescentoid, and there is no third lobe to m73. 



A. Atelodine group. 



Two fronto-nasal horns are present ; all the cutting-teeth, with 

 the occasional exception of the lower incisor, are absent in the 

 adult, and the upper true molars not unfrequently lack a buttress. 

 The man us has three digits. The group is more specialized than 

 any of the others. 



Rhinoceros antiquitatis, Blumenbach 1 . 



Syn. Rhinoceros tichorhinus, Fischer 2 . 

 Rhinoceros pallasi, Desmarest 3 . 

 Rhinoceros jourdani, Lortet and Chantre 4 . 



The nasal septum is fully ossified and of great stoutness; the 

 upper true molars have no buttress, but all the upper cheek-teeth 

 have a large " combing-plate " and three fossettes on the worn 

 crowns, of which the plane of wear is nearly horizontal ; there is 

 usually no distinct cingulum on their anterior surfaces, and the 

 enamel is very rugose. The crowns of the lower cheek-teeth are 

 worn nearly horizontally. 



Hob. Europe and Northern Asia (Pleistocene). 



49661. Cast of the skull of an immature individual. The original 

 is from Kronberg, Bavaria. Purchased, 1878. 



M. 2763. Cranium, wanting the palate ; from the Pleistocene of 

 Siberia. No history. 



M. 2764. Cranium, wanting the palate ; from the Pleistocene of 



(Fig.) Siberia. This specimen is figured in Owen's ' British 



Fossil Mammals and Birds,' p. 325, fig. 120. 



No history. 



1 Handbuch der Naturgeschichte, 1st French ed. vol. ii. p. 408 (1803), 



2 Zoog. Syst. 1813, teste Flower. 



3 Mammalogie, p. 402 (1822). 



* Arch. Mus. Lyon. vol. i. p. 80 (1872). 



