128 Field- Columbian Museum — Zoology, Vol. i. 



Certain individuals of both sexes of this species have on either 

 side of the face a whitish stripe between the eye and end of nose, 

 resembling very much the markings of Clarke's gazelle, Anunodor- 

 cas clarkei. This was particularly the case with individuals shot 

 to the south of Toyo Plain, where it was rare to obtain one with- 

 out this conspicuous mark. The animals also were larger than 

 their brethren in other parts of the country to the north and west. 

 I was impressed with this peculiarity, and should have considered 

 it of some value if it had been confined to individuals from one 

 section of the country, but on careful examination of the speci- 

 mens obtained on my return to the north of Toyo, I occasionally 

 found one with this stripe indicated along the nose, but not so 

 clearly defined as is generally the rule in the individuals from the 

 south of the plain. WHen clearly marked it gives the head of 

 Waller's gazelle a very close resemblance to that of Clarke's 

 gazelle, as both have similarly shaped faces, very narrow and 

 pointed. Taking the extremes of the two styles, the strongly 

 marked white stripe, and its almost total absence, one would 

 be likely to imagine that there were two well defined races 

 of Waller's gazelle. This species has in front of the eye, filling 

 up the antorbital vacuity, a black secretion which forms a large 

 conspicuous prominence on each side of the face. The only other 

 animals in which 1 have seen this carried to an equal degree, 

 allowing for their comparative size, are the Dik-Diks. There is 

 a small opening in the center of this sac-like prominence, from 

 which the secretion exudes and stains everything it comes in 

 contact with, the same as ink would. Neither the skin, when 

 removed from the animal, nor the skull, give any indication of 

 this prominence, and so the creature when mounted, or in a 

 drawing given of it, presents no resemblance, so far as the face 

 is concerned, to the living animal; those specimens I have seen 

 in the museums have this part laid flat to the skull and painted 

 white, being more of a caricature of the live Gerenuk than any- 

 thing else. In life this gazelle is a fine creature, graceful in form 

 if not in movement, and having an extraordinary structure of face 

 and peculiar expression, which cause it to be a rather unique 

 species among its allies in the family. 



The skull of this singular gazelle is remarkable among those 

 of its relatives for the large proportion that is exhibited behind 

 the horns, caused by an elongation of the occipital region. The 

 interparietal is very long, the length being almost equal to the 

 greatest width, and pointed posteriorly. Between the orbits- 



