38 



MR. R. I. POCOCK ON THE EXTERNAL 



The sublingua is also present, as Milne-Edwards and Grandidier 

 have shown, in the Indrisidse. It has a single median inferior 

 crest and three apical denticles. In Propithecus it hardly differs 

 in form from that of the Lemuridse, being broad at the base 

 posteriorly, nearly parallel-sided, and attenuated at the apex. 

 In Indris its lateral edges are rather strongly convex, the base 

 being narrowed like the apex. In Lichanotus it is very short, 

 its free lateral edge being apparently only about half as long 

 relatively as in Propithecus and Indris. 



In Galago, Nycticebus, and Perodicticus the sublingua is broader 

 than in the Lemuridse, especially at the apex, which is almost 

 truncated and armed with many denticles— i. e. 9 in a Galago 

 monteiri — and its attachment to the tongue in the middle line is 

 set farther back so that a greater extent of its apex is free. I 

 also noticed 9 denticles at the tip in a specimen of Perodicticus 

 ibeanus. But in both Perodicticus and Galago these denticles 

 form a continuous series, whereas in an example of Nycticebus, 

 with 7 denticles, the outer on each side was larger than the rest 

 and separated from them (text-fig. 10, E, F, H). 



In Chiromys the sublingua is of a different type. It has a 

 free lateral margin, but towards its abruptly attenuated tip it is 

 closely adherent to the tongue. It is not denticulated, but ends 

 in front in a firm, deflected hook which is the anterior termi- 

 nation of a thick median keel or ridge, itself carrying two or 

 three teeth, and traversing the whole of the underside of the 

 sublingua back to the upper end of the lingual frenum. Just in 

 front of the point there is on each side of the sublingua a small, 

 probably glandular pouch, like a watch-pocket, with its orifice 

 looking forwards. The frenal lamella? are present and narrow; but 

 I could not be sure of their exact form. In the example of this 

 genus I examined the sublingua is less cordate and the tongue 

 less rounded than depicted by Owen, who, moreover, did not 

 mention the small teeth on the carina or the pocket-like glands 

 near the base of the sublingua (text-fig. 11, A, B). 



The sublingua of Tarsius, described and figured by Burmeister, 

 is different from that of Lemurs. It is not so well developed, is 

 softer in consistency, and is defined from the tongue laterally by 

 a groove. In the middle it is provided with a rod-like thickening 

 which has a knob-like expansion at the apex. This rod, corre- 

 sponding to the median carina of the sublingua seen in Chiromys 

 and other Lemurs, was compared to the lytta of the tongue of 

 Canis by Burmeister. But the bifurcation of this rod and some 

 other structures at> the tip of the sublingua described by that 

 author I was unable to detect in the single example of the tongue 

 of Tarsius I examined. In this specimen the frenal lamellae 

 consist of a pair of longish slender processes, each tipped with a 

 few small projections. At the proximal end of these processes 

 on the outer side the edge expands abruptly to form a flap with 

 a lobulate margin which extends far backwards along the sides 

 of the tongue. Burmeister described the frenal lamellae as the 



