xvn NESOPITHECUS, AN INTERMEDIATE FORM 553 



which have been considered ; for it has the typical Eutherian 

 dentition of four premolars and three molars. These teeth, 

 especially the superior molars, are particularly compared to the 

 corresponding teeth of Lemur and Galago. Of this and the 

 allied genus, Protochriacus, several species are known. 



Adapis, a representative of another family, is one of the best 

 known of ancient Lemuroids. It has the typical mammalian 

 dentition of forty-four teeth in a close series without diastemata. 

 The orbits are completely separated from the temporal cavity, 

 the eyes looking forwards. The canines are large and caniniform. 

 The skull is deeply ridged behind with the usual sagittal crest. 

 This genus is European, and corresponds to the already mentioned 

 American Eocene Tomitherium, perhaps belonging to the same 

 family. 



Nesopithecus is an extinct genus from Madagascar, lately de- 

 scribed by Dr. Forsyth Major. 1 There are two species, N. roberti 

 and N. australis. The dental formula is I 2, C 1, Pm 3,.M 3, for 

 the upper jaw, the lower jaw having but a single pair of incisors. 

 The lachrymal foramen is just inside, or on the edge, of the orbit, 

 so that one distinctive Lemurine character is lost. The genus is 

 also Ape-like in the form of the canines and incisors, these 

 having been especially compared by Dr. Forsyth Major with 

 those of the Cercopithecidae. The molars, too, agree with those 

 of the same family. There is, however, one important feature in 

 which Nesopithecus resembles not only the Lemurs as opposed to 

 the Apes, but the Malagasy Lemurs. As already mentioned (p. 544), 

 Dr. Major has shown that in the Malagasy Lemurs, even including 

 the aberrant Chiromys, and in the Tertiary and European Adapis, 

 the bulla tympani is not produced by an ossified extension of the 

 annulus tympanicus, but from the adjacent periotic bone, the 

 annulus remaining separate and lying within the fully-formed 

 bulla. This feature shows conclusively that Adapis is a Lemur, 

 and that Nesopithecus, originally supposed to be a Monkey, cannot 

 be removed from the Lemuroidea, many though its likenesses to 

 the higher Primates undoubtedly are. However, this feature, 

 combined with the fact that the orbital and temporal cavities are 

 in communication, shows the Lemuroid position of Nesopithecus, 

 though it is quite conceivable that it is on the way to become 

 an Ape. 



1 Proc. Zool. Soc. 1899, p. 987. 



