146 Bulletin American Museum of Natural History. [Vol. XVI, 



cipital process and m a , which in kenaiensis is 84 mm. and in dalli 94 

 mm., while the basal length of the skull is the same in both forms. 

 Correlated with this is a marked difference in the angle made by the 

 basioccipital axis with the palatal axis. These differences are 

 strongly pronounced, as shown in the accompanying illustrations 

 (Figs, i and 2). The teeth are also broader and heavier in the 

 Kenai form, the tooth-row is more convex outwardly, and the palate 

 is broader. 



Fig. i. Ovis dalli kenaiensis, $ ad., No. 17609, Kenai Peninsula. nat. size. 



Considering the great distance separating these two forms 

 of the White Sheep, it is perhaps surprising that the external 

 differences are not more marked. The fact that they are 



