We now conclude the long series of Gazelles with three abnormal forms, each constituting a genus of itself, which, curiously enough, are all restricted to N.E. Africa. As regards the first two of them there can be no question, we believe, of their close alliance to the Gazelles, _Ammodorcas_ being, in several respects, intermediate between _Gazellla_ and _Lithocranius_, and leading on to that most specialized form of the group. About the correct position of the Beira, however, there is considerable doubt, and it is quite possible that a more natural place for it in the Antelopine series may be hereafter discovered. The Dibatag, or Clarke’s Gazelle, was first met with by the sportsman and naturalist whose name it bears in 1890, during his exploring trip into the Dolbahanta and Marehán country south-east of Berbera. Writing to Thomas about his discovery, Mr. T. W. H. Clarke (of Secheron, Battery Point, Hobart, Tasmania) says (see P. Z. S. 1891, p. 209):-- “I saw this Gazelle for the first time on December 17th, 1890, about three hours from ‘Bairwell,’ or about one day from ‘Buroa Well, Habergerhagi’s country,’ and afterwards on the road all the way into the Marehan district, 8° N., 47° E. I killed a male, and found one of the horns broken off close to the skull, which had apparently been done a year or so ago. “They are very graceful animals, with a long neck and well-proportioned head and horns; the body is rather slender, but considerably larger than in _Gazella spekei_, about the size of a female _G. walleri_. The legs are long and slender; the hoofs are not so triangular as those of _G. spekei_, and small for the size of the animal. They have small ears and a long upper lip, just like those of _G. walleri_ or a Giraffe. The horns are of the shape of a sickle, and less than 12 inches in length, the longest, out of the eleven males killed, measuring 11 inches. The tail, from what I remember, is about 12 or 13 inches in length, very thin, and thinly covered with black hair about 1 inch long. “The colour of the body in this Antelope is like that of the neck, of a kind of pink-fawn, but the belly is whitish and the tail black. The face resembles that of _G. walleri_, only _G. walleri_ has no white in front of the eye. “When running, or rather jumping, these Gazelles look very peculiar; their long neck and head being thrown back and the tail thrown forward, so that there appears to be only a foot between head and tail. The country they are mostly found in is of low thorn-bush and sandy; they do not seem to like the big bushes, though at times they are found there. In this respect they differ from _G. walleri_, this species liking many bushes to go and rest in.