EAST AFKICAN MAMMALS IN NATIONAL MUSEUM. 



161 



The mastoid breadth m a wild-killed adult male Hon from Nairobi 

 (No. 155443) is 135 millimeters; in a McMillan lion of the same age 

 (No. 199707) it is 152. 



The lambdoidal ridge and occipital bones are broader in the Mc- 

 Millan skulls than in any skulls of wild lions. Here again the splonius 

 and complexus muscles, through nondevelopment, have failed to 

 influence the bone as in a normal wild lion whose life is one of tearing 

 and shaking of strong prey. 



Capacity of the hraincase. — As stated above, external measurements 

 of the braincase in wild lions are less than in park-reared animals 

 of equal age. The capacity of the braincase, however, is consid- 

 erabl}^ greater. Young adults of each, as usual among carnivores, 

 have greater braincase capacity than old or aged adults. The bones 

 forming the cranium of the zoo lion are thicker, and the actual size 

 of the brain is less than in wild-killed examples. In the case of the 

 McMillan lions the capacity is about 50 cubic centimeters less in 

 males and about 40 less in females, than in wild-kiUed examples of 

 equal age from the same locaUty. 



The "Kichardson Hon," front the New York Zoological Park, 

 celebrated as the record skuU for greatest breadth, and the MeneUk 

 lion, the type-specimen of Felis leo roosevelti, are both park-reared ani- 

 mals of uncertain history but they show the skuU characters of cap- 

 tive lions to a marked degree. Even the skuUs of these enormous 

 lions have less braincase capacity than any wild-killed examples 

 of the East African lion. 



Following are some measurements of the capacity of the brain- 

 case in fully adult lions : 



MALES. 



FEMALES. 



Wild-killed. 



Do 



Do 



Park-reared . 



Do 



182309 



182326 



182421 



1 197137 



1 19952-1 



Felis leo massaid. 



do 



do 



do 



do 



Ulu 



Kapiti . . 



do.. 



Nairobi . 

 do.. 



245 

 255 

 245 

 190 

 215 



1 McMillan lions. These are the only park-reared skulls strictly comparable with wild-killed F. I. 

 TTMSsaica. 



100468°— 18— Bull. 99 11 



