136 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



83617, (^ ad., U. S. National Museum. Collected on the beach on west 

 side of Guadalupe, May 22, 1892, by C. H. Townsend. 



''Cranial Characters. — Contrasted with skulls of Arctocephalus [aus- 

 tralis or philUpi \= pJiilippii\) from the Galapagos Islands, skulls of A. 

 townseudi differ in somewhat smaller size ; much shorter rostrum ; shorter 

 nasals ; larger and more freely open incisive foramina ; heavier and shorter 

 ascending branches of premaxillae, which do not push backward along the 

 nasals as in australis \=pliilippii\ ; smaller, flatter and smoother audital 

 bullae ; much narrower and more deeply excavated palate ; narrower post- 

 palatal notch ; broader and heavier jugals ; broader zygomatic processes 

 of maxillae, which are expanded to form a broad floor under the anterior 

 half of the orbit ; larger, broader, and more rounded anterior nares in the 

 male, and absence of sagittal crest between frontals. 



"The most important characters are the exceedingly narrow and exca- 

 vated palate, flat audital bullae, short and thick ascending arm of pre- 

 maxilla, and broadly expanded zygomatic root of maxilla, forming a floor 

 under the anterior half of the orbit. There are also tooth characters : the 

 first upper molar (5th molariform tooth) is mainly posterior to plane of 

 anterior root of zygoma ; both upper true molars are double rooted, and 

 the last upper premolar is incompletely double rooted. 



"In the female of townsendi the narrow and deeply excavated form of 

 the palate is even more emphasized than in the male, and the postorbital 

 constriction is very much narrower than in the female of australis 

 [= philippii]r 



" Measurements of Male Skull of Arctocephalus townsendi (the type). 



" Greatest basal length (gnathion to occipital condyles) 256 



Basal length (gnathion to basion) 243 



Basilar length of Hensel (basion to incisors) 233 



Palatine length (gnathion to postpalatal notch) 1 20 



Postpalatal length (postpalatal notch to basion) 125 



Zygomatic breadth 151 



Lateral series of teeth (canine to last molar inclusive) 88 



Distance between canines 22.5 



Distance between 3d pair of molariform teeth 22.5 



Breadth (anteroposterior) of zygomatic root of maxilla between in- 

 ferior lip of antorbital foramen and orbit 21 " 



The Guadalupe Island Fur Seal, though now commercially extinct, 

 being reduced to a few individuals, was formerly so abundant as to have 



