of Gazella isabella to Gazella dorcas. 293 



dorcas. But tlie maferial on which to base tills supposition 

 is rather scanty and imperfect. . 



Before describing the gazelles from the lied Sea and 

 adjacent regions I will endeavour to j)oint out the characters 

 that distinguish them from the dorcas group. 



The ditieicnce lies principally in their skulls. 



In placing the skull of a Ked Sea gazelle in profile beside 

 that of a dorcas, the former appears relatively lower and 

 flatter, with the parietal region less domed, while the latter 

 Las its frontal outline rising more abruptly, and the parietal 

 region more prominently domed, and descending in a steei)er 

 curve posteriorly. The preinaxillarics of the former are 

 straighter and more obliquely directed forwards, while those 

 of the latter have a more vertical downward direction at first, 

 forming an angle of about 70° with the obliquely directed 

 anterior part. Their outliiie is suggestive of a boomerang. 



The giiatliion of t)ie lied Sea gazelle is finer and more 

 contracted than that o( dorcas. 



Turning the skulls over to examine their under surfaces 

 it will be seen that the angle formed by the basisphenoid 

 with the palatal plane is more acute in dorcas, but in the 

 lied Sea gazelle it is more obtuse, or, in other wordr^, the 

 posterior half of the lower surface is more nearly in line with 

 the anterior half. 



In dorcas the palate is wider and forms a simple arch, 

 while in the Red Sea gazelle it is narrower, WMth the palatal 

 surfaces of the maxillaries convex and merging into a central 

 groove anteriorly *. Tiie alveolar margin is also longer with 

 the molars narrower. The buUie are smaller. 



The horns of dorcas are longer and turn upwards and 

 forwards at the tips, but are much more variable in form than 

 those of the other species, which are shorter, but always 

 hooked strongly inwards at the tips at a right angle or less 

 than a right angle. 



In colour the Ked Sea gazelles are of a bright reddish 

 fawn, the light lateral stripes being distinct and the dark 

 lateral stripe rufous or dusky rufeus. The nose-spot is present 

 in most specimens. In dorcas the colour is sandy fawn, with 

 an indistinct light lateral stripe, and the dark lateral stripe 

 only slightly deeper in tone than the colour of the back. The 

 nose-spot is rarely present. 



Having examined nearly forty skulls, both male and female, 

 of these gazelles and measured many of them, I have chosen 



* This character is also noticeable in G. d. isabella, though less 

 pronounced. 



