OF THE TONGUES OF THE MAMMALIA. 



64» 



into the basal limiting sulcus. In 0. brevirostris thex^e are no 

 glands on the inferior surface, but the whole dorsum has patulous 

 orifices. Those on the base of the tongue are very large. 



Genus Platanista : — The glands are numerous, but nob as long 

 as those in Orcella. Some open into sacs. 



Genus Mesoplodon (text-fig. 28) : — Numerous large and small 

 glandular orifices are present, and there are five large sacs with 

 linear orifices. 



Genus Lagenorhynchus (text-fig. 26 B) : — The orifices cover 

 the posterior two-thirds of the tongue, and increase in size from 

 before backwards. The central ones lie on elevations. No sac& 

 are present, and there are no glands on the inferior surface. 



Genus Tim'siops (text-fig. 27 C) : — Many small orifices surround 

 the edges of the anterior part of the tongue, and there are large 

 clusters beneath the tip. 



Text-figure 27. 



c. 



Tongues of the Cetacea. A: Flioccena communis ; B: Del])Mnapterus leucas \ 

 C : Tursiops tursio. 



Genus Phoccena (text-fig. 27 A) : — No sacs are present, and 

 many minute orifices crowd the posterior part of the dorsum. 



Genus Delphinus (text-fig. 26 0) : — Many small orifices, lying 

 in the centre of small areas crowd the posterior part of the 

 dorsum. And there are clusters of pores on each side of a 

 median ventral elevation. Two sacs (s) are present on the base 

 of the tongue. 



Genus Delphinaptems (text-fig. 27 B) : — No sacs are present, 

 and the glands are restricted to the posterior part of the dorsum. 



Genus Cephalorhynchus (text-fig. 25 B) : — Innumerable small 

 elevations with minute, but patulous, orifices cover the posterior 

 part of the tongue and pharynx. No orifices are present on the 

 inferior surface, and no sacs are present. 



Genus Physeter (text-fig. 25 A) : — The surface of the foetal 

 tongue is pitted all over. But the nature of the specimen at 



Proc. Zool. See— 1922, No. XLIV. 44 



