OF THE TONGUES OF THE MAMMALIA. 647 



backwards, but there is a distinct intermolar eminence. In 

 Halicore, on the other hand, the posterior two-thirds are greatly 

 elevated as in some Ungulata. 



The apex is rounded and entire in both genera, and the lettered 

 horders are entire and devoid of lobules which characterise the 

 Cetacean tongue. Neither notches nor sulci are present. 



The mucosa on the oral part is plain, but that on the 

 pharyngeal part has many folds. The base has glandular openings 

 arranged singly or in pairs. There are no glands on the inferior 

 surface, and no apical gland of Nuhn is present. The glands are 

 less developed than in the Cetacea. 



Feipillce : — In both genera there is, behind the apex, a cluster 

 of retroverted cuticular spines. And as the tongue is not very 

 mobile they are of great assistance in cropping the vegetation on 

 Avhich the animals live. Behind that cluster the dorsum is plain 

 in Mecnatus, but covered with a velvety pile of small papilla in 

 Halicore. Owen (27) figures a plain dorsum behind the spines 

 in the latter. 



In Manatus, according to Owen (27), there are many vallate 

 papillae. In ffcdicore they are represented by clusters of pits. 



Latered Organs : — In Memectus (4) these are well-developed 

 and appear as large cushions with numerous fissures. In Hedicore 

 these are absent. 



The Inferior Surfeice has many large orifices in Manatus, and 

 many embedded cylindrical bodies in Hedicore, but I was unable 

 to examine the latter microscopically. 



The Frenum is slight, and there is no frenal lamella, foi'amen 

 ceecum, lytta, sublingua, or plicae fimbriatae. No comb-like 

 structures are found on the infero-lateral aspect. 



Order UNGULATA. 

 Suboi-ders Peeissodactyla and Artiodactyla. 



In most species the tongue is long, comparatively narrow, and 

 very mobile. But it is broad and flat in Rhinoceros. It has the 

 greatest mechanical power in Gireiffa. 



The eipex is truncated, pointed or rounded, and may or may 

 not have a notch. In many species it has clusters of hard 

 mechanical papillae, as in the Sirenia. It is free in all forms, 

 and this gives it considerable mobility. 



The lettered horclers are full and rounded. They may be com- 

 paratively smooth, or covered with prominent conical and 

 fungiform pa,pillae. But Su,s is the only genus with lateral 

 lobules similar to those in the Cetacea. 



The anterior part of the tongue is flat and very mobile. 

 Posterior to that is an intermolar eminence which raises the food 

 up to the molar teeth. Most posteriorly is a flat, thin, more or 

 less glandular part. 



The intermoleir eleveotion is present in all families. It is entire 



