Of the smaller Felidae, the best known are the Lynxes and the Cats, properly so called. Of these the Lynxes are distinguished by their short tails, and by the fact that the ears are furnished with a pencil of hairs. They differ so much from the other Felidae as to be often placed in a separate genus (Lyncus). The best-known species are the European Lynx (Felis lyncus), the Caracal (F. caracal) of southern Asia and Africa, and the Canadian Lynx (F. Canadensis) of North America. In the true Cats (Felis catus) the tail is long, and the ears are not tufted. The Wild Cat formerly abounded in Britain, but is now almost extinct, though it still occurs in Europe, especially in the Hartz and Carpathian Mountains. It is a large and fierce animal, and appears to be quite a match for any man not possessing firearms. It seems tolerably certain that the Wild Cat is not the original stock of the Domestic Cat, the exact origin of which is uncertain. The Felis chaus is the common "Jungle-cat" of India and Africa.

As regards the distribution of the Carnivora in time, the order does not appear to be represented earlier than the Eocene period, though our knowledge on this subject is certainly defective, as shown by the fact that the oldest forms at present known are referable to highly specialised groups.

The aquatic Carnivores (Pinnipedia) appear to commence in the Miocene Tertiary, but they are principally known as Post-tertiary fossils.

The great family of the Ursidae. is represented in Miocene times by the genus Hyaenarctos. True Bears first appear during the Pliocene, and in the Post-pliocene period Europe posssessed several Bears, of which the well-known "Cave-bear (Ursus spelaeus) is the best known.

The Procyonidae are doubtfully known in deposits anterior to the Post-pliocene.

The Mustelidae date back to the Miocene, but present no points of special interest.

The Viverridae. are an ancient group, and are represented by a number of extinct types. Two Viverrine forms (Tylodon and Palaeonyctis) occur in the Eocene Tertiary of Europe; and in the Miocene are found several interesting examples of the group, of which the most remarkable is the genus Ictitherium, which is in some respects nearly allied to the Hyaenas.

The Hyaenidae are not known from deposits older than the Upper Miocene, but the best known fossil member of this family is the Cave-hyaena (H. spelaea) of the Post-pliocene, which is probably but a variety of the living Hyaena crocuta.

The family of the Canidae seems to be one of the oldest of the families of the Carnivora, and is represented in the Eocene period by several genera (Cynodictis, Galethylax, etc.) In the later Tertiary and Post-tertiary, various extinct forms of this family are likewise known to occur.

The family of the Hyaenodontidae comprises certain extinct Eocene Carnivores (Hyaenodon, Pterodon, &c), in which there is the anomalous feature that all the praemolars and molars have cutting edges.

Lastly, the family of the Felidae appears to commence in the Eocene period, the best-known extinct type of this family being the genus Machairodus including the so-called "sabre-toothed Tigers." In this wonderful genus we are presented with the most highly carnivorous type of all known beasts of prey. Not only are the jaws shorter in proportion than those of the most rapacious of existing Felidae, but the canine teeth are of enormous size, compressed and sabre-shaped, and having their margins finely serrated. Species of Machairodus must have been as large as the living Lion; and the genus has an extraordinary range both in time and space, occurring in North and South America, in India, and in Europe, and extending from the Miocene to the Human period.