_Oryx Leucoryx Pallasi_, =Fitz.= SB. Wien, lix. p. 178 (1869). Vernacular Names:—_El Walrush_ and _El Bukrus_ of Bahrein Arabs (_Pennant_). Height at withers about 35 inches. Prevailing colour of body, neck, and head a dirty white, slightly darker on the haunches. On the face the frontal and nasal patches are brown in colour and sometimes separated from each other; the brown stripe that passes from the eye unites with the stripe that arises near the base of the ear to form on the cheek a large patch which extends below the jaw and joins across the inter-ramal area with the corresponding patch of the opposite side; from this patch a narrow brown stripe runs along the throat, and is traceable as far as the chest, which is also brown. Ears whitish; the tip and edges not black or brown. Mane on neck whitish like the rest of the body, and there is no median dorsal black stripe. Tail white; the tuft black at the end. Fore leg from the shoulder, and hind leg from the thigh, deep brown, both on the outer and inner side down to the fetlocks; pasterns white. A faint brown longitudinal stripe is traceable on each side between the belly and the flanks. Hair along spine reversed from rump. Horns long, straight, attaining a length of about 25 inches; ribbed for about two-thirds of their length; the ribs small and close-set. _Female._ Similar to the male, and horns equally long or longer. _Hab._ Southern Arabia, to the shores of Persian Gulf. As we have already pointed out, it is highly probable, if not certain, that the _Antilope leucoryx_ of Pallas and his immediate successors was the present species and not the preceding, which, however, is now universally known as “The Leucoryx.” In the description of his _Antilope leucoryx_ (which forms the sixteenth species in his second memoir on the genus _Antilope_ published in 1777) Pallas affords us so little information that not much can be made of it. He gives “Arabia, and perhaps Libya,” as its locality, and adds references to the passage in the ‘Cynegetica’ of Oppian which we have already quoted, and to “_Gazellæ Indicæ cornu singulare_”—a “curious horn of an Indian Gazelle” which he had described in a former memoir on some fossil bones from Siberia. On referring to this memoir, and to the figure by which it is accompanied, we cannot say that we are by any means satisfied that the “curious horn” in question, which is remarkable for its length and slenderness (33 inches long, as given by Pallas) and for its numerous annulations, belonged to the present species. We will, however, go so far as to allow that it may possibly have done so. At any rate we must admit that it could hardly have been a horn of the Antelope which we now call the Leucoryx.