The first notice of the existence of a species of this form in North-eastern Africa appears to have been given by Lichtenstein, who read a paper on the Antelopes of Northern Africa before the Academy of Sciences of Berlin on March 11th, 1824. Amongst the four Antelopes discussed in this learned treatise, which was mainly based upon the specimens sent to the Royal Collections by the well-known travellers Hemprich and Ehrenberg from Dongola and Sennaar, were several representatives of the present species which Lichtenstein not unnaturally referred to the _Antilope dama_ of Pallas. The same course was pursued by Hemprich and Ehrenberg themselves, who shortly afterwards published full descriptions and figures of it in their ‘Symbolæ Physicæ.’ They inform us that they met with specimens of this Antelope in Southern Dongola in the month of July 1822, and hunted it along with the Addax and Leucoryx, which occurred in the same district. They found it plentiful in herds and easy of access, even without the use of horses. Like the other species mentioned, it feeds principally on the acacias. They did not meet with this Antelope until they arrived at 20° N. lat. going south, after which they found it abundant. The Arabs, who much esteem the flesh and sell it when dried, call it “_Addra_.” It did not appear to approach the banks of the Nile, but kept entirely to the desert and to the valleys which traverse it, especially to the Chor-el-Lebben. Not far from the same date another distinguished German traveller and naturalist, Rüppell, whose name we have already had frequent occasion to mention, also met with this Antelope. Rüppell sent his specimens to Frankfort-on-the-Main, where they were described and figured by Cretzschmar on the part of the Senckenbergian Society of Naturalists in 1826. Cretzschmar also referred these specimens to _Antilope dama_; but Hamilton Smith, after examining them in the Senckenbergian Museum, came to the correct conclusion that they belonged to a different species, on which he proposed to bestow the name _Antilope ruficollis_. We must therefore use _Gazella ruficollis_ as the correct scientific designation of this animal. A third German naturalist, Heuglin, who has recorded his experiences of this species, tells us that he met with it, generally in pairs or small families, and often mixed up with herds of other Gazelles, in the desert districts of Dongola and Kordofan, where it is known to the Arabs as the “Adra” or “Ledra.” From this native name, Bennett, in his memoir on _Gazella mhorr_, to which we shall presently refer, proposed to call the present species _Antilope addra_, but, as has been already stated, Hamilton Smith’s name has precedence.