NO. I 



THE WHITE RHINOCEROS HELLER 



59 



PLATE 13 



(About natural size) 



Illustrating generic characters 



Fig. i. Coelodonta antiquitatis, adult; from the Pleistocene of the Tunguska 

 River, Siberia. No. 6053, U. S. National Museum. 



Tips of premaxillse and nasals broadly united into a solid bridge ; 

 teeth with central fossettes of enamel filled by cement; vomer 

 thickened. 



Fig. 2. Ceratotherium simum cottoni, female, old ; from Rhino Camp, Lado 

 Enclave; weathered skull. No. 164597, U. S. National Museum. 



Teeth with central fossettes of enamel and cement ; three upper 

 premolars ; vomer thin and knife like ; occipital crest produced 

 beyond condyles. 



Fig. 3. Diceros bicornis, male, old ; Loita Plains, Southern Guaso Nyiro 

 District, British East Africa; shot by Col. Theodore Roosevelt, 

 June 18, 1909. No. 162930, U. S. National Museum. 



Teeth without fossettes, the folds remaining open ; four upper 

 premolars ; sphenoidal process of basi-occipital large. 



Fig. 4. Rhinoceros unicornis, immature; the milk molars in use; only the first 

 molar erupted; permanent incisors just erupting; from the 

 menagerie of Barnum and Bailey; sex and origin unknown;. No. 

 16251, U. S. National Museum. 



Teeth with one or two central fossettes, but without the cement 

 layer present; functional incisors present. 



