1934] Hatt, American Museu?n Congo Expedition Pangolins and Aard-Varks 665 



length was 1780 were: length of mouth from tip of lower jaw to corner 

 of mouth, 52; from middle of eye to end of snout, 185. 



This aard-vark differs externally from 0. e. erikssoni in its slightly 

 smaller size, longer ears, and shorter front claws. The skull differs from 

 erikssoni, as represented by the two specimens from Niapu and the type 

 description, in the following features : The inflation of the region of the 

 frontonasal suture is more pronounced, and, in consequence, the upward 

 curve of the posterior part of the nasals is greater. The nasal region is 

 also broader, to the extent that the greatest width of the combined nasalia 

 is more than one half the length of the nasal suture. The lacrimal bone 

 of faradjius is comparatively long, and the length of its suture shared 

 with the frontal anterior to the orbit is about 70 per cent of the total 

 length of the lower frontal border between the orbit and the posterior 

 external angle of the nasal. In erikssoni the lacrimal-frontal suture is 

 60 per cent or less of the length of the lower frontal border. The zygo- 

 matic arch at the level of the end of the zygomatic process of the maxil- 

 lary is very broad (over 20 mm.), while in erikssoni, the arch is very 

 narrow, its depth measuring less than 20 mm. 



The mandible of faradjius is more massive and broader, and the 

 angular and coronoid processes are higher than in erikssoni. Thus the 

 greatest height of the mandible equals about 45 per cent of its greatest 

 length in the race from Faradje, whereas in erikssoni this height is only 

 39 per cent of the length. The greatest breadth of the mandible in the 

 former race is contained in the mandibular length 4.8 times, whereas in 

 the latter race the length is near 5.5 times the breadth. The tip of the 

 angular process lies midway between the alveolar plane and the articular 

 process, whereas in the larger forest form it is much lower, the height 

 above the alveolar level being only about one half the distance from the 

 tip of the angular process to the tip of the articular. 



Sexual Differences. — Sexual dichromatism, which seems not to 

 have been noted in the literature, is well marked in adult specimens. In 

 the males the hair of the entire head is dark brown, but in the females 

 that below the orbits, except for a dark gular stripe, is light-colored. On 

 the outer surface of the thigh the hairs are slightly blacker in males than 

 in females, in which sex the hairs retain more of the reddish wash of 

 youth. 



Age change of color in both sexes involves an intensification and 

 extension of the pigmented areas of the head (particularly in the males) , 

 a progressive blackening of the dark area of the limbs and shoulders 

 that all but obliterates the deep red color found on immature specimens, 



