OF THE TONGUES OF THE MAMMALIA. 295 



The Fungiform Papilla} (text-fig. 23 G). 

 Fungiform papillae are absent from the centre of the dorsum, 

 and do not form a cluster in front of the vallate papillae. In this 

 respect the tongue resembles those of G. preussi, C. burnetti, and 

 G. mona, and differs from that of G. celhiojjs. They form, there- 

 fore, a papillary zone on which they have the usual arrangement. 

 Some are smooth and glistening, others are granular, and all are 

 hemispherical or cylindrical in shape. 



The Conical Papilla} (text-fig. 23 H). 



Conical papillae make the entire dorsum rough, but not to such 

 a, degree as in G. patas and G. cethiops. They have the usual 

 arrangement in clusters and rows, and the direction in which 

 their points run is typical. Between the rows there are strips of 

 interpapillary dorsum. 



None of them overlap the fungiform or vallate papilla?. 



When they are examined through a lens it is seen how the 

 papillae vary greatly in shape and appear flattened out. The 

 surface may be plane or excavated (text-fig. 23 H), and one or 

 more processes are present. 



The Lateral Organs (text-fig. 23 D). 

 The lateral organs consist of a series of short laminae and sulci 

 convex forwards. Each ridge is bisected by a longitudinal 

 sulcus. The measurements, laminae, and sulci are shown as 

 follows : — 



Organ. Length. Lamina}. Sulci. 



Right 1-6 cm. 8 9 



Left 1-5 5 6 



The ridges decrease in size from before backwards, and the 

 lateral vallate papillae are level with the posterior lamina?. 



Lymphoid Nodules and Glands (text-fig. 23 A, a). 

 Prominent lymphoid nodules are present on the base of the 

 tongue, and a number of orifices are visible. 



The Frenal Lamella (text-figs. 23 B a & C a). 

 The frenal lamella is triangular and entire or bifid, being divided 

 in the latter (text-fig. 23 B, a) into large left and small right 

 parts. The edges ai'e devoid of processes and tubercles and 

 extend almosb to the posterior fissures and laminae of the lateral 

 organs. 



The Frenum. 



The frenum occupies the xvhole of the median ventral sulcus 

 as a ridge, and the part stretching from the sulcus to the upper 

 surface of the frenal lamella is very short, as in all Cercopithecida?. 



Plicce fimbriatce are absent, even in the young specimen. The 

 animal was older, however, than my young G. patas in which 

 plica? are present. 



