FOSSIL REMAINS. 469 



that if originally derived from the marine species to which they 

 are allied, it may well be supposed that the peculiar conditions 

 of environment to which they have been for so long a time sub- 

 jected have not been powerless in effecting slight changes of 

 structure, as they have certainly led to well-marked changes in 

 habits. 



As already noted, Macrorhinus is the only genus having rep- 

 resentatives on both sides of the equator, the two species of 

 which are nevertheless separated by wide areas, the one occur- 

 ring on the Pacific coast of North America between the parallels 

 of 23 and 35 north latitude, while the other is restricted to the 

 shores and islands of the southern extremity of the South Amer- 

 ican continent, New Zealand, and a few groups of pelagic islands 

 in the southern parts of the Indian Ocean. 



Of the Stenorhynchince only four species are recognized, all of 

 large size, and all confined to the cold-temperate or subfrigid 

 southern waters. 



FOSSIL REMAINS. 



NORTH AMERICA. In North America teeth or other remains 

 attributed to Seals have been reported as occurring at various 

 localities, in Tertiary and Quaternary deposits, from Maine and 

 Canada southward to Virginia and South Carolina. In several 

 instances, merely the finding of such remains has been recorded, 

 the specimens themselves having never been described, or even 

 specifically determined, so that it is impossible to assign them 

 to any particular species, or even to say whether they were 

 correctly identified as the remains of Seals. In other cases, 

 remains described as Phocine are unquestionably referable to 

 Squalodont Cetaceans. In only two or three instances are the 

 supposed remains of Seals obviously Phocine, and in each of 

 these cases they were found in deposits of Post-pliocene age, 

 and referred (usually with some doubt) to existing species. 

 The subject may, therefore, be conveniently treated under the 

 following heads, namely : 1. Remains supposed to be Phocine, 

 but which are not specifically determinable. 2. Squalodont 

 remains described as Phocine. 3. Remains doubtfully referred 

 to existing species. 4. Extinct species. 



I. Remains supposed to be Phocine, but not specifically determin- 

 ate. 1. Newberu, North Carolina. Under this head must be 

 placed the incidental reference by Dr. Harlan * to the remains 



* Am Journ. Sci., vol. xliii, 1842, p. 143. 



