Family =Delphinidae=. Monodon--narwhal. Phocaena--porpoise. Orca--killer. Globicephalus--Ca'ing whale. Grampus. Lagenorhynchus. Delphinus--dolphin. Tursiops. Prodelphinus. Order 4. UNGULATA. Division A. UNGULATA VERA. Suborder (1). ARTIODACTYLA. Section (_a_). SUINA. Family =Hippopotamidae=. Hippopotamus. Family =Suidae=. Sus--pig. Babirussa. Phacochaerus--wart hog. _Hyotherium._ Family =Cotylopidae=. _Cotylops (Oreodon)._ _Cyclopidius._ Family =Agriochoeridae=. _Agriochoerus._ Family =Anoplotheriidae=. _Anoplotherium._ Section (_b_). TYLOPODA. Family =Camelidae=. Camelus--camel. Auchenia--llama. Section (_c_). TRAGULINA. Family =Tragulidae=. Dorcatherium (Hyomoschus)--chevrotain. Section (_d_). RUMINANTIA or PECORA. Family =Cervidae=. Moschus--musk deer. Cervus--deer. Cervulus--muntjac. Hydropotes--Chinese water deer. Family =Giraffidae=. Giraffa--giraffe. _Sivatherium._ Family =Antilocapridae=. Antilocapra--prongbuck. Family =Bovidae=. Tetraceros--four-horned antelope. Gazella--gazelle. Bos--ox. Bison. Bubalus--buffalo. Suborder (2). PERISSODACTYLA. Family =Tapiridae=. Tapirus--tapir. Family =Lophiodontidae=. _Lophiodon._ _Hyracotherium._ Family =Palaeotheriidae=. _Palaeotherium._ Family =Equidae=. _Hipparion._ Equus--horse. Family =Rhinocerotidae=. Rhinoceros. _Elasmotherium._ Family =Titanotheriidae=. _Titanotherium (Brontops)._ _Palaeosyops._ Family =Chalicotheriidae=. _Chalicotherium._ Family =Macraucheniidae=. _Macrauchenia._ Division B. SUBUNGULATA. Suborder (1). TOXODONTIA. Family =Astrapotheriidae=. _Astrapotherium._ Family =Nesodontidae=. _Nesodon._ Family =Toxodontidae=. _Toxodon._ Family =Typotheriidae=. _Typotherium._ Suborder (2). CONDYLARTHRA. Family =Phenacodontidae=. _Phenacodus._ Suborder (3). HYRACOIDEA. Family =Hyracidae=. Procavia (Hyrax). Suborder (4). AMBLYPODA. Family =Coryphodontidae=. _Coryphodon._ Family =Uintatheriidae=. _Uintatherium_ (_Dinoceras_). Suborder (5). PROBOSCIDEA. Family =Dinotheriidae=. _Dinotherium._