The animal having been thus exterminated towards the end of the last century, its very existence became a matter of doubt to some naturalists, who were inclined to consider the specimens of it left in our museums as small or immature individuals of the nearly allied Roan Antelope (_H. equinus_). This view was taken by Andrew Smith[3], de Blainville, Gray, and even Harris, who, one would think, might have learned better from the traditions on the subject prevalent among the Boers. But the accurate Sundevall was strongly against this opinion, and, after examining the specimens at Upsala, Stockholm, and Paris, said decidedly “_Minimè animal fictum, ut credidit A. Smith_.” Sundevall, however, failed to convert Gray on this subject, and Gray, although, as he tells us, he had examined the specimen at Paris, chose to unite this species to the Roan Antelope, and to call them both _Hippotragus leucophæus_. The most recent authority to vindicate the claims of the Blue-buck to specific distinctness is Herr F. F. Kohl, of Vienna, who, in an article upon new and rare Antelopes in the Imperial Natural History Museum, published in 1866, after accurately describing the specimen in that collection and pointing out its distinctive characters from _H. equinus_, gave a full list of the various synonyms to be allocated to these two species. There can be little doubt, therefore, that _Hippotragus leucophæus_ must be regarded as an extinct animal, of which at the present time five mounted specimens only are known to exist. All these we have already alluded to, but we may repeat that they are to be found in the Museums of Paris, Leyden, Vienna, Stockholm, and Upsala. Finally, however, we are glad to be able to add that, although our National Collection does not contain a complete example of this species, yet it possesses a frontlet and horns which, after careful comparison, we have no hesitation in referring to _H. leucophæus_. The horns (fig. 88, p. 11) are just 20 inches in length and 6·1 in basal circumference; they have the characteristic ridging and curvature of the horns of the male, and are obviously adult, but their size is less than the horns of the female Roan Antelope. The frontlet on which they are borne measures 3·85 inches between the orbits. The exact origin of this frontlet is not known, but it has been long in the Museum. [Illustration: Fig. 88. Frontlet of the Blue-buck. (From the specimen in the British Museum.) ]