_Hab._ Sandy tracts of the interior of Algeria, Tunisia, and Western Egypt, south to Nubia and Sennaar. The great folio work of Geoffrey St.-Hilaire and Frédéric Cuvier entitled ‘Histoire Naturelle des Mammifères,’ which was issued in livraisons from 1824 to 1842, contains a long series of coloured figures of mammals, mostly taken from examples living in the well-known Menagerie attached to the Jardin des Plantes. Amongst these in the seventy-second livraison, published in 1842, were the first descriptions and figures given of both sexes of the present Gazelle, from examples stated to have been brought from Sennaar by Burton. They had lived in the Menagerie, we are told, two years, and had bred a young one, which resembled its parents in most particulars. The appropriate scientific name “_leptoceros_,” from the long thin horns, had been given to this species, we are informed, by Georges Cuvier, and was adopted by the authors of the work referred to, who, however, called it at the head of their article, after their usual fashion, only by the French name “_Antilope à longues cornes_.” Very little more information was acquired concerning this Gazelle for many years. Most of the systematists were entirely unacquainted with it, and could only quote the original descriptions. Sundevall and Gray considered it to be merely a variety of _Gazella dorcas_. Rüppell, during his extensive travels in East Africa, seems never to have come across it, and does not mention it in any of his publications. The first author after its describers to recognize its existence was Heuglin, who in 1877, in the second volume of his ‘Reise in Nordost-Afrika,’ writes of this species, the name of which he had previously misapplied to another Gazelle, and gives a coloured figure of its head and figures of two pairs of its horns. Heuglin met with _G. leptoceros_ in the Libyan desert of Egypt, near the Natron Lakes and the Fayoum, where he states its Arabic name is “Abu el haráb.” Sir Victor Brooke had never seen specimens of this Gazelle, and in his ‘Monograph’ relies mainly upon Heuglin’s description. So matters remained until recent years, when examples of this Gazelle, or of a very closely allied form, turned up unexpectedly from a new quarter. Loche, Lataste, and other authorities on the zoology of Algeria had mentioned the existence far in the interior of that country of an Antelope called “El Rim,” and examples of the horns of a problematical Gazelle called “El Reem” had been brought to England from the shops at Biskra. In 1894 an enthusiastic sportsman and naturalist, Sir Edmund Loder, F.Z.S., resolved to make a serious attempt to discover this mysterious animal, and proceeded to Algeria for that purpose. We cannot do better than transcribe for our readers Sir Edmund’s own account of the results of this successful expedition, which was read before the Zoological Society of London on June 5th, 1894:--