Among the animals belonging to these regions, the following are especially noticeable:—­The tiger, the elephant, the hippopotamus, the crocodile, the monitor, the two-humped camel, the Angora goat, the elk, the monkey, and the spotted hysena, or Felis chaus.  The tiger, which is entirely absent from Mesopotamia, and unknown upon the plateau of Iran, abounds in the low tract between the Elburz and the Caspian, in the flat region about the Sea of Aral, and in the Indus valley.  The elephant was, perhaps, anciently an inhabitant of Upper Egypt, where the island of Elephantine remained an evidence of the fact.  It was also in Persian times a denizen of the Indus valley, though perhaps only in a domesticated state.  The hippopotamus, unknown in India, was confined to the single province of Egypt, where it was included among the animals which were the objects of popular worship.  The crocodile—­likewise a sacred animal to the Egyptians—­frequented both the Nile and the Indus.  Monitors, which are a sort of diminutive crocodiles, were of two kinds:  one, the Lacerta Nilotica, was a water animal, and was probably found only in Egypt; the other, Lacerta scincus, frequented dry and sandy spots, and abounded in North Africa and Syria, as well as in the Nile valley.  The two-humped camel belonged to Bactria, where he was probably indigenous, but was widely spread over the Empire, on account of his great strength and powers of endurance.

The Angora goat is, perhaps, scarcely a distinct species.  If not identical with the ordinary wild goat of Persia and Mesopotamia (Capra cegagrus), he is at any rate closely allied to it; and it is possible that all his peculiar characteristics may be the effect of climate.  He has a soft, white, silky fleece, very long, divided down the back by a strong line of separation, and falling on either side in beautiful spiral ringlets; his fleece weighs from two to four pounds.  It is of nearly uniform, length, and averages from five to five and a half inches.

The elk is said to inhabit Armenia, Affghanistan, and the lower part of the valley of the Indus; but it is perhaps not certain that he is really to be found in the two latter regions.  Monkeys abound in Eastern Oabul and the adjoining parts of India.  They may have also existed formerly in Upper Egypt.  The spotted hyena, Felis chaus (Canis crocuta of Linnaeus), is an Egyptian animal, inhabiting principally the hills on the western side of the Nile.  In appearance it is like a large cat, with a tuft of long black hair at the extremities of its ears—­a feature which it has in common with the lynx.

Among the rarer birds of the Empire may be mentioned the ostrich, which occurred in Mesopotamia; parrots, which were found in Cabul and the Punjab; ibises, which abounded in Egypt, and in the Delta of the Indus, the great vulture (Vultur cinereus), which inhabited the Taurus, the Indian owl (Athena Indica), the spoonbill (Platalea nudifrons); the benno (Ardea bubulcus), and the sicsac (Charadrius melanocephalus).