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 described 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.
- ↑ Proc. Zool. Soc. 1899, p. 987.
