278 DR. C. F. S0NNTAG ON THE ANATOMY 



are more numerous than in the Simiidae, and the lateral organs 

 possess very different characters. In the Simiidse, as was shown 

 in my last paper (18), the lateral organs consist either of convex 

 bodies on the sides of the tongue, or of fissures and laminae on 

 the dorsum ; in the Cercopitheciclae they consist of rows of fissures 

 and laminae on the lateral borders. 



In all the Cercopithecidae the following structures are absent : — 



1. Foramen caecum. 



2. Apical gland of Nuhn or Blandin. 



3. Lytta. 



4. Plicae fimbriates. 



The plicae may, however, be present in the very young animal 

 (see page 291), and disappear as age advances. 



The species of different genera have been arranged in groups, 

 according to their external characters, by Pocock and others, but 

 they cannot be so arranged according to the characters of their 

 tongues. I have arranged my species of Gercopithecus according 

 to Pocock's grouping, and it will be seen how the lingual 

 structures vary, sometimes considerably, in each of the groups. 

 As regards classification, I will not go farther than state that 

 the members of the ^Ethiops-group are the only species of 

 Gercopithecus in which the vallate papillae exhibit the double 

 pair type in a pure or unmodified foian. 



In most tongues the conical and fungiform papilla 1 exhibit the 

 usual arrangement in clusters and rows of varying degrees of 

 obliquity, and the conical pnpillse have the usual distribution 

 according to size ; their points, as a rule, have the usual 

 direction. The fungiform papillae stretch across the entire dor- 

 sum or are absent from the centre, thereby forming a dorsal 

 bounding zone. 



Genus Presbytes (= Semnopithecus). 



The Purple-faced Langur (P. cephalopterus). 

 Habitat : Ceylon. 



Measurements. — Total length 3*7 cm. ; length of the oral part 

 3 cm. ; length of the pharyngeal part "7 cm. ; width between the 

 lingual attachments of the palato-glossal folds 1'4 cm. ; width of 

 the anterior part P5 cm. ; thickness in the vallate area IT cm. ; 

 thickness of the apex '2 cm. 



The spatulate tongue has a flat apex ; the latter is devoid of a 

 notch, and is covered by small conical and fungiform papillae, but 

 the latter are not numerous. The lateral borders are rounded, 

 and have papillae disposed in the usual manner. The fungiform 

 papillae thereon are neither numerous nor prominent. They also 

 lodge the lateral organs, which are well-developed, thus agreeing 

 with the description of Boulart and Pilliet (1). The structures 

 mentioned above are absent. 



