9 



becomes almost impossible to nicely discern the relative position of 

 individuals, even under favourable circumstances, and the difficulty is 

 greatly enhanced by the imperfect data afforded by the examination of 

 a few specimens only. 



The exceptional form of the cranium of the Northern Fur-Seal, as 

 quoted above, appears to display no characters more strongly defined 

 than those commonly seen in the skulls of many species of the same 

 genus among the undomesticated mammalia ; consequently, a specific 

 distinction applied to this animal would probably have been quite 

 sufficient to meet every requirement for scientific classification. 



To the foregoing doubts as to the propriety of generic separation 

 from the Southern Fur-Seal, I may further add, that little dependence, 

 for the purpose of distinguishing kinds, can be placed on the 

 appearance of the skin, or on the limit of the range of habitat ; for 

 the colouring of the external hair, and the length, abundance, and 

 quality of the under-fur, are greatly diversified by sex, by age, by 

 seasonal condition, and by climate. And the geographic range is not 

 confined within small bounds, but on the contrary it is extensive, as 

 clearly established by the habitat of this Fur-Seal, which extends from 

 the shores of Kamtschatka to those of California, 1 an extent of ocean 

 greater than that from California to the Island of Juan Fernandez, or 

 than those intervening spaces between the numerous localities in the 

 Southern Seas, the recognised strongholds of the Southern Fur-Seals. 

 The barrier, therefore, if any, which forbids the intercourse between 

 these antipodean relatives exists, not in the distance, but in the passage 

 across the warm temperature of the torrid zone. 



Taking such a view, I can scarcely accede to so broad a separation as 

 that proposed by Dr. Grray >} but I am willing to consider the Northern 

 animal as a distinct species, suggesting, however, the probability of 

 its ultimately proving to be only a member of the one great Fur-Seal 

 tribe of both hemispheres. 



The colour of the external coating of the male, when adult, varies 

 from black-grey to brown-grey, occasionally pure black; while the 

 adult female is usually grey, or ash-coloured, but during the shedding 

 of the coat, many are seen partly ash-coloured and partly brown. The 

 young of both sexes, previous to the first moult, are uniformly glossy 

 black, silvered more or less by short white tips ; mostly so about the 

 nape of the neck and hinder parts of the body ; or, as Dr. Gray 

 himself observes, " the skin is so like that of the Arctocephalus 

 nigrescens, 2 that we were induced to regard it as a second specimen of 

 that species." 



The under-fur of both sexes and of the young is of a rich reddish 

 colour, more or less tinted with deeper or lighter shades. 



x The Northern Sea Lion (Otaria Stelleri) and the Zalophus OKllespii, also 

 occupy precisely the same extensive range. 



2 Arctocephalus Falklandicus of Peters, Allen, Sclater, &c. 



