218 THE ZOOLOGIST. 



Beginning with the Otariidce or Eared Seals, commonly known 

 as Sea-lions and Sea-bears, we find the greater number of the 

 species confined to the South Polar Ocean, where they pass most 

 of their time at sea, but, as is well known, resort to the land at 

 certain seasons for breeding purposes. In the Atlantic Ocean, 

 so far as I know, the Eared Seals have never been ascertained to 

 occur further north than the estuary of the La Plata on the 

 American coast, and the vicinity of the Cape on the African 

 coast. But in the Pacific, on the contrary, three distinct species 

 of Otaria are found all over the arctic portion of that ocean, and 

 there are well-founded traditions of Eared Seals having been 

 formerly met with in the Galapagos, while they still occur on the 

 coasts of Peru and Chili. I think therefore we may assume that 

 Otaria was originally an Antarctic form, but has travelled north- 

 wards along the West American coast and is now firmly estab- 

 lished in the North Pacific. In a parallel way in the class 

 of birds, the Albatrosses, Diomedea, which are essentially a 

 group of the Antarctic Seas, are represented by three distinct 

 species in the North Pacific. 



The second family of the marine Carnivora, on the other 

 hand, the Walruses, Trichechidce, are entirely Arctic in their 

 distribution ; one species, Trichechus rosmarus, being peculiar to 

 the North Atlantic, while a second nearly allied species, T. 

 obesus, takes its place in the Northern Pacific. 



The third family of Pinnipeds is more numerous and varied, 

 both in genera and species, than the two preceding, and has a 

 more extended range. The Seals, Phocidce, embracing about 

 nine different generic forms, are most numerous in the Arctic 

 and Antarctic seas, but are also feebly represented in some inter- 

 mediate localities. Beginning with the North Atlantic, we find 

 several species of Phoca inhabiting various parts of this area, and 

 the Grey Seal, Halichcerus, and the Bladder Seal, Cystophora, 

 exclusively confined to it. In the North Pacific all the four true 

 Seals belong to the genus Phoca, and three of them are identical 

 with the North Atlantic species, but when we descend as far 

 south as the Gulf of California on the American coast we meet 

 with a species of Sea-elephant, Macrorhinus, which, like Otaria, 

 has no doubt penetrated up here thus far from its ancestral 

 abode in the' Antarctic Ocean. 



Returning to the Central Atlantic, we find two species of Seals 



