[176] These are united in one family, the _Canidæ_ or Dog family; but this name is unfortunate, as there are no original wild dogs, only those which have run wild from man. Dogs are now almost certainly shown to be descended from wolves and jackals. [177] Thalassarctos (ursus) maritimus. [178] Trichechus rosmarus. [179] Plantigrade. [180] Enhydra marina. [181] Pinnipedia. [182] Otariidæ (_ous_, _otos_, an ear), eared Seals. [183] Callorhinus (Otaria) ursinus. [184] Phoca vitulina. [185] Hence their name _Sirenia_, a curious name for voiceless animals. [186] Cetacea--_cete_, a whale. [187] Megaptera. [188] Phocæna communis. [189] Orca gladiator. [190] Picture heading, Chap. II. [191] Picture heading, Chap. IV. [192] Picture heading, Chap. VIII. [193] Picture heading, Chap. VI. [194] _Ibid._ Chap. VII. [195] Sauropsida. [196] Picture heading, Chap. III. [197] Picture heading, Chap. V. [198] Picture heading, Chap. IX. [199] Picture Heading, Chap. X. [200] Chapter XI., Europe in the Age of Ice. [201] From “A Legend of a Stone Axe,” a clever and suggestive poem in the _New Quarterly_, April 1879. The text is slightly altered. [202] _Animal Intelligence_, Romanes, p. 261. INDEX. _References printed in Italics are to Figures in the Text._ _Aard-vark, or Cape ant-eater_, 202; habits of, 203. Adjutant bird killing the cobra, 121; _with its feet flat_, 128. Æpyornis of Madagascar, 140. Affection in animals, 348–352. Africa, _aard-vark and pangolin of_, 202; darting birds of, 168; isolation of, in ancient times, 340; wild animals of, 275. Air-bladder, uses and hindrances of an, 53; of fish, use of, 26; of minnow, 25; of mud-fish, 55. _Air-breathers, home of the early_, 70. Air-breathing fish, 34. Air-sacs in bones of birds, 135. Alaska, sea-otters of, 301. Albatross, habits of the, 146; _home of the_, 147. Aldabra, tortoises of, 101. Aleutian Isles, sea-lions of the, 306, 310. Alligators acting as scavengers, 109. Alytes, a frog-father carrying strings of eggs, 87. Amazons, manatees in the, 316; monkeys of the, 246; mud-fish of the, 33. Amblystoma, air-breathing form of axolotl, 81. America, absence of wild hogs in North, 263; beaver communities of, 229; earliest forms of horse come from, 265; jaguar and puma of, 292; passenger pigeons of, 162; _ant-bear of_, 200; characters of monkeys of, 245; sturgeon in rivers of, 32; songless perching-birds of, 169; stags with single antlers in, 273. American and Australian colonists, argument drawn from, 131. Ammocœtes, history of, 18; _larva of lamprey_, 16. Amphibia, ancestors of the mammalia, 191; large ancient, 82–84; wonderful metamorphosis of, 335. Amphibian, true meaning of the term, 77, 81. _Amphioxus lanceolatus_, 11. Ancestors of the higher milk-givers, 213. _Angling-fish_, _Lophius piscatorius_, 59.