1912] Townsend: Northern Elephant Seal 171 



followed a period of comparative immunity during which its 

 numbers slowly increased. Again subjected to persistent slaugh- 

 ter from 1880 to 1884, it disappeared for a time and was not 

 seen until rediscovered at Guadalupe Island in 1892. Since then 

 thirty-five elephant seals have been killed at Guadalupe for 

 museum purposes. Had that island been visited by seal oil 

 hunters, the elephant seal would probably not be in existence 

 to-day. 



Present Number. 



When the Albatross left Guadalupe on March 4, 1911, there 

 were not less than 125 elephant seals on the rookery. The breed- 

 ing season having just commenced and the number of adult 

 females present being considerably less than the number of adult 

 males, and less than half the number of yearlings, there is rea- 

 son to believe that the adult female portion of the herd would 

 be better represented before the end of the month. The present 

 size of the herd may therefore be estimated at 150 animals of all 

 classes. 



Eleven days later when the Albatross reached San Cristobal 

 Bay on the Peninsula, I examined the site of the old rookery at 

 that locality without finding any indication of its being occupied. 

 We found no signs of elephant seals at either San Benita or 

 Cedros Islands where the ship called on the voyage southward. 

 I examined the shores of San Benita very thoroughly. Both of 

 these islands were formerly breeding resorts of the species. 



Distinctness of the Northern Species. 



The specific distinctness of the northern elephant seal is well 

 shown in the accompanying photographs of skulls of M. angus- 

 tirostris and M. leoninus in the American Museum of Natural 

 History. The skulls are those of adult males and both exceed 

 twenty-two inches in extreme length, angustirostris being longer, 

 while leoninus has the greater zygomatic width. 



In the northern species the zygomatic arch is heavier 

 throughout than in the southern species. In the former the 

 jugal at its narrowest point has nearly twice the height of that 

 of the latter, while its extreme length is considerably less. Its 



