Third, the "Congo dauw" (_Equus hippotigris_), closely resembling the dauw.

Fourth, the "quagga" (_Equus quagga_); and fifth, the undetermined species known as the "white zebra" (_Equus Isabellinus_), so-called from its pale yellow, or Isabella colour.
These five species evidently have a close affinity with each other--all of them being more or less marked with the peculiar transversal bands or "stripes," which are the well-known characteristics of the zebra.

Even the quagga is so banded upon the head and upper parts of its body.
The zebra proper is "striped" from the tip of the nose to its very hoofs, and the bands are of a uniform black, while the ground colour is nearly white, or white tinged with a pale yellow.

The "dauws," on the other hand, are not banded upon the legs; the rays are not so dark or well defined, and the ground colour is not so pure or clean-looking.
For the rest, all these three species are much alike; and it is more than probable that either "Burchell's" or the "congo dauw", was the species to which the name of "zebra" was first applied; for that which is now called the "true zebra" inhabits those parts of Africa where it was less likely to have been the first observed of that genus.

At all events, the "congo dauw" is the "hippotigris," or tiger-horse, of the Romans; and this we infer from its inhabiting a more northerly part of Africa than the others, all of which belong to the southern half of that continent.