68 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



PLATE 22 

 (About Ys natural size) 



Illustrating sexual differences in skulls 

 Nasal boss much larger and zygomatic breadth much greater in males. 

 Fig. i. Ceratotherium simum cottoni, male, old; from Rhino Camp, Lado 

 Enclave; weathered skull. No. 164598, U. S. National Museum. 

 Fig. 2. Ceratotherium simum cottoni, male, adult; from Rhino Camp, Lado 

 Enclave ; weathered skull. No. 164596, U. S. National Museum. 

 Fig. 3. Ceratotherium simum cottoni, female, old; from Rhino Camp, Lado 

 Enclave ; shot by Col. Theodore Roosevelt, January 29, 1910. 

 No. 164595, U. S. National Museum. 

 Fig. 4. Ceratotherium simum simum, female, old; from South Africa; exact 

 locality not known; specimen in the department of paleontology 

 of the American Museum of Natural History. 



This specimen shows much larger teeth than any of the female 

 skulls of cottoni. 



