These were very large--some of them more than twelve feet high--and differing from the dome-shaped kind so common everywhere.
They were of the shape of large cones, or rounded pyramids, with a number of smaller cones rising around their bases, and clustering like turrets along their sides.

I knew they were the hills of a species of white ant called by entomologists _Termes bellicosus_.
"There were other hills, of cylinder shape and rounded tops, that stood only about a yard high; looking like rolls of unbleached linen set upright--each with an inverted basin upon its end.

These were the homes of a very different species, the _Termes mordax_ of the entomologists; though still another species of _Termes_ (_Termes atrox_) build their nests in the same form.
"I did not stop then to examine these curious structures.

I only speak of them now, to give you an idea of the sort of place it was, so that you may understand what followed.
"What with the cone-shaped hills and the cylinders, the plain was pretty well covered.

One or the other was met with every two hundred yards; and I fancied with these for a shelter I should have but little difficulty in getting within shot of the gnoos.
"I made a circuit to head them, and crept up behind a large cone-shaped hill, near which the thick of the drove was feeding.