120 Bulletin American Museum of Natural History [Vol. LXXII 



series and one cannot admit the cases at one extreme or the other as 

 dwarfism or gigantism. 



Cranial Individuality in Adult Males of Dendrohyrax d. emini 







Old VIII 



Early 



VIII 



American Museum Number 





53836 



53837 



53823 



53822 



Greatest length 





122.8 



110.0 



114.5 



106.5 



Condylobasal length 





120.7 



110.0 



114.0 



106.5 



Zygomatic breadth 





67.5 



65.2 



63.2 



62.3 



Anterior edge of orbit to gnathion 



43.7 



38.5 



40.3 



34.0 



Frontal suture, length 





34.2 



32.9 



36.7 



35.0 



Bregma to occiput 





49.5 



40.0 



40.0 



40.0 



Palatal length 





63.5 



58.2 



60.0 



59.0 



Basisphenoid plus basioccipital, 



length 



41.2 



34.3 



35.9 



32.1 



Premolars plus molars, length 





42.3 



39.5 



37.7 



41.0 



In the instance of the older skulls the two specimens contrasted 

 differ chiefly in the measurements of length, the discrepancies between 

 the two being greatest in the post orbital region, but also pronounced in 

 the preorbital. The two younger skulls, on the other hand, show a 

 striking difference in the length of muzzle but little difference other than 

 this. 



Similar broad divergence is observed in the Congo Expedition series 

 of Procavia j. lopesi where the skulls of three female specimens all in 

 Stage VIII and with nearly the same degree of tooth wear (see " height 

 of crown") are of three types, one (No. 53776) long and slender, another 

 (No. 53777) long and broad, a third (No. 53796) short and slender. 

 The degree of difference is perhaps best shown by the following table of 

 measurements. 



Cranial Divergence of Stage VIII Females of Procavia j. lopesi 



American Museum Number 



53776 



53777 



53796 



Greatest length 



103.0 



98.8 



92.0 



Condylobasal length 



102.5 



95.7 



89.8 



Zygomatic breadth 



57.2 



57.8 



51.8 



Width at postorbital processes 



35.6 



40.5 



34.0 



Length of nasal suture 



27.0 



24.4 



24.5 



Frontal suture, length 



39.5 



38.4 



34.0 



Bregma to occiput 



33.2 



32.7 



31.7 



Diastema, length 



15.0 



11.6 



10.7 



Premolars plus molars, length 



42.3 



41.8 



39.3 



Height of crown, M 3 



4.5 



4.1 



4.1 



