The lion belongs to the genus Fells of Linnaeus (for the characters and position of which see Carnivora), and differs from the tiger and leopard in its uniform colouring, and from all the other Felidae in the hair of the top of the head, chin and neck, as far back as the shoulder, being not only much longer, but also differently disposed from the hair elsewhere, being erect or directed forwards, and so constituting the characteristic ornament called the mane.
Among the existing land Carnivora (of which no representatives except the introduced dingo are found in Australasia) the cat-tribe (Felidae) has now an almost cosmopolitan range, although it only reached South America at a comparatively recent date.
In size the lion is only equalled or exceeded by the tiger among existing Felidae; and though both species present great variations, the largest specimens of the latter appear to surpass the largest lions.
The variations in external characters which lions present, especially in the colour and the amount of mane, as well as in the general colour of the fur, indicate local races, to which After a Drawing by Woll in Elliot's Monograph of the Felidae.
The internal structure of the lion, except in slight details, resembles that of other Felidae, the whole organization being that of an animal adapted for an active, predaceous existence.