68 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 6l 



PLATE 22 

 (About % 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 simian 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. 



