Thalassarctos, the polar bear (1 species) inhabiting the Arctic regions; Ursus, the true bears (12 species), which range over all the Nearctic and Palæarctic regions as far as the Atlas Mountains, the Indo-Chinese sub-region in the mountains, and to Hainan and Formosa; Helarctos, the Malay or sun-bear (1 species) confined to the Indo-Malayan sub-region; Melursus or Prochilus, the honey-bear (1 species), confined to the first and second Oriental sub-regions, over which it ranges from the Ganges to Ceylon; and Tremarctos, the spectacled bear—commonly known as Ursus ornatus—which is isolated in the Andes of Peru and Chili, and forms a distinct group.
Fossil Ursidæ.—Two bears (Ursus spelæus and U. priscus) closely allied to living species, abound in the Post-tertiary deposits of Europe; and others of the same age are found in North America, as well as an extinct genus, Arctodus.
Ursus arvernensis is found in the Pliocene formation of France, and the extinct genus Leptarchus in that of North America.
Several species of Amphicyon, which appears to be an ancestral form of this family, are found in the Miocene deposits of Europe and N. India; while Ursus also occurs in the Siwalik Hills and Nerbudda deposits.
Family 33.—OTARIIDÆ (4 Genera, 8 Species.)
| General Distribution. | |||||
 | |||||
| Neotropical Sub-regions. | Nearctic Sub-regions. | Palæarctic Sub-regions. | Ethiopian Sub-regions. | Oriental Sub-regions. | Australian Sub-regions. |
| 1 — — — | 1 — — 4 | — — — — | — — 3 — | — — — — | — 2. 3 — |
The Otariidæ, or Eared Seals, comprehending the sea-bears and sea-lions, are confined to the temperate and cold shores of the North Pacific, and to similar climates in the Southern Hemisphere, where the larger proportion of the species are found. They are entirely absent from the North Atlantic shores. Mr. J. A. Allen, in his recent discussion of this family (Bull. Harvard Museum) divides them into the following genera:—
Otaria (1 species), Temperate South America, from Chili to La Plata; Callorhinus (1 species), Behring's Straits and Kamschatka; Arctocephalus (3 species), temperate regions of the Southern Hemisphere; Zalophus (2 species), North Pacific, from California to Japan, and the shores of Australia and New Zealand; Eumetopias (1 species), Behring's Straits and California.
Fossil Otariidæ.—Remains supposed to belong to this family have been found in the Miocene of France.
Family 34.—TRICHECHIDÆ. (1 Genus, 1 Species.)