Abstract: A fragment of mandible with right P3--M3 was collected from the Jiangchuan, Yunnan asa new species, Macaca jiangchuanensis sp. nov.. Macaca arctoides, and Presbytis cf.phayrei from the Baoshan, Yunnan, early Holocene, are also described in this paper.
The diagnosis of the new species is tentatively given as following: An early Pleistocene macaque, smaller than that of Procynocephalus wimani. The mandibular corpus is high and thick.The distance between the anterior and posterior cusps are compressed in the lower molars. The M2 and M3 are relatively larger than the M1 when compared with Rhinopithecus (M·) lantian-ensis and Macaca robusta. The wear condition is intermediate between Macaca and Rhinopi-thecus. The talonid fovea of the P4 is lower. The mandibular ramus is more vertical.
The upper part of the mandible is robust and thick, its lower part becomes slender. On the lingual side, the sublingualis and mylohyoid lines below the Ms run obliquely to the spina mentalis and the fossa digastrica, respectively. There is a mental foramen below the P4. The buccal walls of the thick enamels are inflated. The buccal cusps are heavily worn, whilethe lingualcusps are just worn, different from the wear pattern of Macaca robusta or Rhinopithecus (M.)lantianensis.
The Jiangchuan mandible can be distinguished from Procynocephalus wimani in that theformer is smaller in size and shows more characters of Macaca. The mandiblular ramus is morevert?cally oriented the Pч is less molariform. The contact facet between the crown is buccally situated.
By comparison with Rhinopithecus (M.) lantianensis, the Jiangchuan mandible is low(26.0<42.0 in R. (M.) lantianensis. The buccal surface of which inflated in the middle. The lowerpart of the mandibular corpus is thin; the Pa is more oblique to the post part; the distance bet-ween the anterior and posterior cusps is compressed. The sublingualis and mylohyoid lines aresimilar to that of M. thibetana. It is unlike R. (M.) lantianensis in that the dentition is small relative to the size of the mandibular corpus.
Otherwise, it is worth mentioning that Rhinopithecus (M.) lantianensis is a special colo-bine. The buccal surface of the mandible already shows the characters of Rhinopithecus in thatthere is a thick inflation of the lower part of canine extending to the lower ridge. The P3 possesses two cusps (the protoconid and mnetaconid), like P, without its sectorial shape.
The Jiangchuan specimen is different from M. robustus in its larger size(P.- -Ms, 50mm>40- -45mm in M. robustus). The anterior part of the jaw is more vertical and robust except the diagnostic features of the new species. So the Jiangchuan specimen links the early Macaca forms between south Asia and north China.
Macaca arctoides and Presbytis cf. phayrei from Baoshan, Yunnan, early Holocene. Anage of 7000 B.P. was determined by radiocarbon dating.Presbytis cf.phayrei is different from the modern forms in that the distance between the anterior and posterior cusps is morecom pressed and the mandible is thinner and flat. It is significant in its geographical distribution, which seems to indicate that the leaf monkeys did not arrive in China until later Pleisto-cene-early Holocene.
We are grateful to Dr. Nina G. Jablonski, University of Western Australia and other members of the Primate research group of the Kunming Zoology Institute for their sincere help and to the field team of the Yunnan Provincial Museum and Yuxi region,Jiangchuancounty Museum for their collection. The paper was supported by a grant from the Program ofthe National Academy of Sciences.

Key words: Macaca jiangchuanensis sp. nov.; M. arctoides; Presbyzis cf.; Phayrei; Jiangchuan; Baoshan; Yunnan