292 DR. 0. F. SONNTAG ON THE ANATOMY 



between them is more smooth and polished than that of the rest 

 of the inferior surface of the tongue. 



The median ventral sulcus contains a median crest, which, 

 however, is narrow. 



The Nisnas Oercopitheque (C. pyrrhonotus). 

 Habitat : Sudan. 

 Mr. Pocock's sketch shows an oval lamella with two apical points 

 (text-fig. 20 G). It is very similar to that of C. patas. 



THE ^THIOPS GROUP. 



Species examined : C. cethiops ; C. sabceus ; C. tantalus ; 

 C. rufoviridis. 



The only pigmented specimen observed is my young one of 

 C. tantalus. 



The Abyssinian Oercopitheque (C. cethiops). 

 Habitat : Sudan. 



Measurements. — Total length 4'3 cm. ; length of the oral part 

 3 - 5 cm.; length of the pharyngeal part -8 cm.; greatest width 

 1-8 cm. These figures refer to the largest of five examples. 



The apex has no mesial notch, no dorsal sulcus is present, 

 and the structures mentioned on page 278 are absent. The whole 

 dorsum is very rough. 



The Circumvallate Papillw. 

 Three small plane or umbilicated papillae are arranged in the 

 form of an isosceles triangle with an acute vertical angle. They 

 are surrounded by prominent conical papilla? which may conceal 

 the fossae and Valiums, or be a little distance from them. The 

 two-pair type of vallate papilla? is rare (1 in 5). 



The Fungiform Papilla. 

 These stretch right across the dorsum and have the usual 

 arrangement, but many are concealed by the long conical papilla? 

 (text-fig. 22 C). All are hemispherical, smooth and polished, and 

 some have a small central pit. 



The Conical Papilla. 

 The arrangement cannot be made out easily as their long and 

 numerous points conceal the papillary bodies and interpapillary 

 dorsum. Their distribution according to size is typical, however. 

 All are filiform and have one or more points. 



Lymphoid Nodules. 

 There are many large nodules, and several large duct orifices 

 are visible in some specimens. 



