OF THE TONGUES OF THE JMAMMALIA. 519 



The BLAOK-:eARED Marmoset {H. jMnicillata). 



The conical tongue, whicli is green in colour, has tlie following 

 measurements: — total length 2'y5 cm.; length of the oval part 

 2"1 cm. ; length of the pharyngeal part -25 cm.; width between 

 the lingual attachments of the palato-glossal folds "9 cm. 



The apex is pointed and tuberculated ; running backwards 

 from I' 4c cm. is a median lidge. whence transverse ridges, which 

 are convex forwards, run out to the lateral borders. 



The Circumvcdlate Papilke. — -Three papilhe form an isosceles 

 triangle. The apical papilla is close to the epiglottis, and the 

 lateral papillse are close to the edges of the tongue. The lateral 

 papillae are small, and their fossae and Valiums axe concealed by 

 conical papillas (text-fig. 51 A, b). The posterior papilla, which 

 is ©val and excavated, has a nodulated vallum composed of two 

 rows of lobules (text-fig. 51 A, c). 



2Vie Fungiform Papillce form a wide dorsal bounding zone, and 

 the area of the centre without papillse is small. They have the 

 usual arrangement, but the posterior rows form thick clusters in 

 front of the vallate papillae. They are hemispherical or flat, and 

 the surfaces are smooth and glistening. As in H. jacchus^ there 

 are none on the inferior surface of the tongue. 



The Goniccd Pcqnllce have the usual arrangement, but their size 

 remains the same from apex to base. They ai'e scale-like and 

 imbricating, as in H. jacciius. They form a nari-ow zone on the 

 inferior surface of the tongue (text-fig. 51 A, a). 



Lymphoid Tissue and Glands. — The area occupied by the 

 lymphoid nodules is small, and no duct orifices are visible. 



The lateral organs consist of a few very fine laminae and sulci. 

 It is difticult to detect these, even on high magnification, by a 

 hand lens, so mici'oscopical examination is necessary in order to 

 settle their characters. 



The Inferior Sitrface (text -fig. 51 A, a). — A narrow ventral 

 pap)illary border is present ; the narrow, deep ventral mesial sulcus 

 opens posteriorly into a triangular fossa; and the f renal lamella is 

 triangular, with an entire apex and notched sides. 



The Pygmy Marmoset {E. 2)ygviaia). 

 The tongue has the following characters : — 



1. It is conical with a rounded apex. 



2. The vallate papilke form an isosceles triangle. 



3. The fungiform papillae resemble those of II. jjenicillata. 



4. The conical papillae form imbricating scales. 



5. The lateral organs are well-marked. 



6. The ventral papillary zone is well-marked. 



7. The ventral mesial sulcus is long and deep. 



8. The triangular frenal lamella has a bifid apex. 



