1897.] JDlSTRIBUTiON OF ilAKINE MAMMALS. 351 



extended range. The Seals, Fhocidce, embracing about nine 

 different generic forms, are most numerous in the Arctic and 

 Antarctic seas, but are also feebl}' represented in some iutei'- 

 mediate localities. Beginning with the Xorth Atlantic, we find 

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

 the G-rev Seal (HaKchcerus) and the Bladder-Seal {Gystopliora) 

 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 Nortli 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 {Macrorhiaus) which, like Otaria, has no 

 doubt penetrated thus far from its ancestral abode in the Antarctic 

 Ocean. 



Eeturning to the Central Atlantic we find two species of Seals 

 inhabiting these waters, both belonging to the same genus 

 Monachus. One of these {M. alhiventer) inhabits the Mediter- 

 ranean and the adjoining coasts of the Atlantic, while the other 

 {M. tropicalis) is in these days restricted to some of the smaller 

 and less known islands of the West Indies. 



The Fhocidce of the Antarctic Ocean ail belong to genera 

 distinct from the Arctic forms and more nearly allied to Monachus, 

 the Seal of the Mid-Atlantic. They are of four species 

 belonging to as many genera : Ogniorhimis, Lohoclon, Lej^tonychotes, 

 and Ommatophoca. Besides these the Sea-elephant of the whalers 

 (Macrorhiaus) is essentially an Antarctic form, though now nearly 

 extinct there, after long persecution by man. But, as already 

 noted, it extends, or has in former days extended, far up the west 

 coast of America, and is still occasionally found on Santa Barbara 

 Island on the coast of California. 



III. Distribution of Sii-eniann. 



Only two forms of Sirenians are at the present time existing on 

 the earth's surface— the Manatee {Manatus) and Dugong {Halicore) 



each representing a distinct family of the Order. The Manatee 



is an inhabitant of the coasts and estuaries of both sides of the 

 middle Atlantic Ocean— one species {Manatus seneijalensis) occur- 

 ring on the African shores, and another {21. americanus) on the 

 S. American coast and in the Antilles. A third species (M. inunguis), 

 so far as we know at present, is found only in fresh water high up 

 the Amazons. 



The Dugong (HaUcore) is distributed from East Africa, along 

 the shores of the Indian Ocean and its islands, to North Australia. 

 Three species of this genus have been established — Halicore 

 tabernaculi from the Eed Sea, II. dugong from the Indian Ocean, 

 and II. auMralis from Australia ; but it is doubtful how far these 

 forms are actually distinguishable. 



Besides Mancitus and Hcdicore, a third quite distinct form of 

 Sirenian was formerly an inhabitant of the North Pacific. This 

 was Steller's Sea-cow {Bhytina stelleri), by far the largest animal of 



