172 Merriam Four New Arctic Foxes. 



Characters. Size large, nearly equalling pribilof ens-is; rostrum broad 

 and massive; frontals high anteriorly and swollen on each side of median 

 sulcus; premolars large and swollen. Compared with lagopus the skull 

 is decidely larger; the rostrum and nasals broader; frontals more elevated 

 anteriorly; molars and premolars larger. Compared with pribilofensis, 

 with which it nearly agrees in size, the rostrum is shorter and broader; 

 rostral constriction or 'step' much more pronounced; frontals anteriorly 

 more elevated; base of cranium shorter; molars and premolars decidedly 

 larger and more swollen. 



Cranial measurements. Skull of type specimen [ 9 yg- ad.] : basal 

 length 123; zygomatic breadth 71; palatal length 66; postpalatal length 

 56; breadth of rostrum opposite second premolar 27. An old 9 f rom 

 type locality: basal length 128; zygomatic breadth 77; palatal length 68; 

 postpalatal length 60; breadth of rostrum at second premolar 26. Upper 

 carnassial (on cingulum) in young $ 13.5; first upper molar (transverse 

 diameter from notch on outer side) 11. 



