484 sir victor brooke on [May 16, 



maxillae bearing a much larger relative proportion to the general 

 width of the skull in this than in the two other species. 



The horns of these Antelopes, though bearing a strong family 

 likeness, are, if looked at carefully, very easily distinguishable from, 

 each other. 



The strength, decision, and spiral twist of the keels, standing as 

 they do in inverse ratio to the size of the three species, give a widely 

 different character to the horns at all ages, especially when we com- 

 pare the massive and rather short horns of T. euryeeros with the 

 long, graceful, slender horns of T. spekii. 



In colour and external surface the horns of T. angasii and T. 

 spekii differ considerably, those of the latter, in all the specimens I 

 have examined, being of greenish-brown colour, the annulations 

 wide apart, smooth, and polished, with the posterior of the two 

 keels which encircle the horns very strongly raised during its entire 

 course, running strongly outwards as it nears the points of the horns, 

 where it dies away. In T. angasii the horns are black, the annulations 

 rough and closely set, and the posterior keel, though well marked at 

 all ages, is much more indistinct and undecided than in T. spekii. 



Between the horns of T. euryeeros and T. angasii there exists so 

 wide a difference that, if once their respective characters are ob- 

 served, they cannot be mistaken for each other. 



Besides the very great massiveness of the former, the anterior 

 keel is almost, in some cases quite, obsolete, the surface of the horns, 

 as in those of T. spekii, being greenish brown and very smooth, con- 

 trasting strongly with the black, crisp annulations of T. angasii. 



My chief object in entering so particularly into the differences 

 observable in the skulls and horns of these Antelopes is, in some 

 degree, to substantiate the following interesting conclusion, relative 

 to the distribution of Trageluphus spekii, at which I have arrived 

 after my observations on the subject. In the ' Proceedings' of this 

 Societv for 1848 (p. 88), there is a notice of an Antelope obtained 

 by Capt. Allen during the Niger expedition at Kokki, on a small 

 tributary (the Abo) of the Cameroons river, in the Bight of Biafra. 

 In the Appendix to the ' Narrative of the Expedition to the Niger,' 

 in 1841, vol. ii. p. 488, I find a reference to the same Antelope, 

 with the statement that " Mr. Ogilby believed the horns to have 

 been taken from A. euryeeros ; but Mr. Mitchell, the Secretary of 

 the Zoological Society, and Mr. Waterhouse, thought they might 

 have belonged to an entirely new and undescribed species." The 

 skull and horns of this individual are now, and have been for many 

 years, in the British Museum. The specimen is mentioned in Dr. 

 Gray's Catalogue of the Mammalia of the British Museum (p. 137) 

 as var. 1 of Tragelaphus euryeeros. I have most carefully exa- 

 mined it, and have compared it with the type of Tragelaphus spekii, 

 with the specimen of that Antelope in my own collection (fig. 1, 

 p. 486), with a specimen in the British Museum, composed of the 

 skin, horns, and feet, which specimen Mr. Layard recognizes as one 

 sent by him from South Africa to M. Verreaux, and which passed 

 from M. Verreaux into the British Museum, and with a frontal bone 



