OCR Text |
Show 1878.] SIR V. BROOKE ON A NEW GAZELLE. 929 2. On a new Species of Gazelle from Western Africa. By Sir VICTOR BROOKE, Bart., F.Z.S. [Received November 19, 1878.] (Plate LVI.) I have the pleasure of bringing before the notice of the Society a new and exceedingly interesting form of Gazelle. As is well known, the different species into which the genus Gazella is divisible (vide P. Z. S. 1873, p. 535) resemble each other so closely that it is often very difficult to define them. The differences exist in nature, let their taxonomic value be what it m a y ; but in many cases they absolutely baffle verbal description. In the form at present under consideration there is no such difficulty. Although the materials at m y command consist only of the skulls of three males, with a small portion of the skin of the head attached to one of them, characters are apparent which separate the form from all known Gazelles. Indeed m y only doubt is as to whether the species should not constitute the type of a new subgenus. The specimens belong to M r . Gerald Waller, and it is through his courtesy that I have the opportunity of exhibiting them this evening. Mr. Waller tells m e that the skulls were procured on the mainland of Africa, north of the island of Zanzibar, about lat. 3° S. and long. 38° E. He is unfortunately unable at present to give any further particulars respecting the species. The new Gazelle differs from all hitherto described species in the verv great backward prolongation of the occiput. This extension is is principally gained by the great size of the supraoccipital bone and the prominence of the occipital crest. The skull is much more depressed, the facial axis forms a more obtuse angle with the cranial axis, and the rami of the lower jaw are more slender than in any known Gazelle. The ascending rami of the praemaxillae are remarkably thick, and do not nearly reach the nasals. In all other Gazelles the molars and premolars are decidedly hypsodont; in the new species they are as decidedly brachyodont, and, in comparison with the skull, remarkably small. The horns do not differ greatly from those of Gazella dor'cas; they are, however, more massive and more laterally compressed. The skin of the head is of a uniform foxy red, with white marks under the eye. Mr. Waller has expressed a desire that the species should be named after his brother, who lost his life in Africa. I have therefore much pleasure in proposing the name Gazella walleri for the new form. The followino* table of the comparative dimensions of Gazella walleri and Gazella dorcas, and the Plate (LVI.), will render further description unnecessary. |