MESOPITHECUS 351 



and departs proportionally from the human type. The poste- 

 rior lobe or talon of the second premolar is more developed, 

 and the fore-and-aft extent of the tooth greater, than in the 

 chimpanzee, thereby more resembling the second premolar of 

 the siamang, and less resembling that of the human subject. 

 The last (third) molar is undeveloped in the fossil jaw of the 

 DryapitTiecus, and its amount of departure from the human 

 type, and approach to that of Innus, cannot be determined. 

 The canine is more vertical in position than in Troglodytes or 

 Pithecus, but this character is offered by some of the small 

 South American apes, and cannot be cited as a mark of real 

 affinity. From the portion of humerus associated with the 

 jaw of Dryopithecus, the arm would seem to have been pro- 

 portionally longer and more slender than in the chimpanzee and 

 gorilla, with a cylindrical shaft, more like that in the long-armed 

 apes (Hylohatcs), and less like the arm of the human subject. 



The characters of the nasal bones, orbits, mastoid processes, 

 relative length of upper limb to trunk, relative length of arm 

 to fore arm, relative length and size of thumb, relative length 

 of lower limb ; and, above all, the size of the hallux and shape 

 of the astragalus and calcaneum, must be known before any 

 opinion can be trusted as to the proximity of Dryojnthecus to 

 the human subject. 



Genus Mesopithecus, Wagn. — In tertiary formations of 

 Greece, at the base of Pentelicon, remains of a Quadrumane 

 have been found, which Professor Wagner* regards as transi- 

 tional between Hylohates and Semnopithccus : the third lobe 

 of the last molar is, however, as well developed as in the 

 latter genus. 



In the pliocene deposits of Montpellier remains of a 

 monkey occur, referred by Christol to a Ccrcojnthecus ; and in 

 pliocene brick-earth in Essex the writer has determined part 

 of the fossil jaw and teeth of a Macacus. 



* Abhanglungen der k. bayer Akademie, bd. ii., 1854, Munchen. 



