3. Phocarctos. Grinders large, lobed, the six upper with two notches on the hinder edge. Under-fur sparse. South America.
4. Arctocephalus. Grinders thick; crown conical. Under-fur abundant.
Tribe 4. Zalophina. Grinders 5/5·5/5, large, thick, in a close continuous series; the fifth upper in front of the back edge of the zygomatic arch.
5. Zalophus. Grinders large and thick, in a close uniform series. Under-fur sparse. North Pacific.
6. Neophoca. Grinders large, thick, all equal, in a continuous uniform series. Under-fur sparse. Flap of toes very short. Australia.
Tribe 5. Eumetopiina. Grinders 5/5·5/5, more or less far apart; the hinder upper behind the hinder edge of the zygomatic arch, and separated from the other grinders by a concave space.
7. Eumetopias. Under-fur sparse. Flap of toes very short. West coast of North America.
8. Arctophoca. Under-fur abundant. Flap of toes long. West coast of South America.
Sect. I. The palate produced behind to a line even with the condyles. The palatine surface of the maxillaries extending behind the teeth and with its posterior processes very long. It is deeply concave behind, and becomes deeper as the animal increases in age. The hinder nostril is short, with a truncated front edge. Flap of toes rather long. Sea-lions.