FAM. ANTHRACOTHERIIDAE.--This well-known and ancient family consists of creatures of for the most part a Pig-like form, with teeth approaching the selenodont shape, and a complete dentition. The carpals, tarsals, metacarpals, and metatarsals are all free. The toes are four (or five) to each foot, with the outermost beginning to be reduced. These of course are all generalised and primitive characters, pointing nowhere in particular, except, of course, to an Artiodactyle stock, on account of the teeth and the two predominating toes. The type genus of the family, _Anthracotherium_, is not, as its name might seem to denote, a relic of the Carboniferous period; its remains were found in lignite, which may also show that it was at least semi-aquatic in habit. Its form, however, must have been Pig-like, so at least one would presume from the elongated skull and shortish legs. There were species as great as a Rhinoceros, and smaller forms. The genus began in the Oligocene and continued down to the Pliocene. It is known from Europe, Asia, and America. The skull is long with a prominent sagittal crest. The facial part is also very long, and the orbits are not closed by a bony ring. The premolars are simple teeth; the molars distinctly bunodont with a tendency in one or two to the selenodont condition. The canines are powerful, as are also the incisors. The scapula has been specially compared with that of the Camel. It has no acromion, which is usually though not always absent in Ungulates. An ally of the present animal, for instance, the Hippopotamus, has the acromion developed. The radius and ulna, the tibia and fibula, are all fully developed. {329} _Ancodus_ (or _Hyopotamus_, as it has been called) is also Oligocene in range, and its remains have been found in the same countries as have those of _Anthracotherium_. Both genera are indeed closely allied. _Ancodus_ seems to be a more slightly-built creature. The skull looks weaker, but presents much the same features of organisation. In _A. velaunus_, a species found in French rocks, a metacarpal of digit I. was present in the manus, while _A. brachyrhynchus_ had a completely five-fingered manus. The Miocene genus _Merycopotamus_ (from the lower layers of the Siwalik formation in India) is more distinctly selenodont than the forms already discussed. On this ground it has been placed in a separate sub-family. As, however, in other respects it does not depart from the Anthracotherian type of structure, this proceeding seems to be hardly necessary. There are two species known, of which one, _M. nanus_, is, as its name denotes, a dwarf form.