In some districts the demarcation is not quite distinct, as in the Tana basin, where some of the Galla and Somali Hamites from the north have encroached on the territory of the Wa-Pokomo Bantus on the south side of the river. But on the central plateau M. Dybowski passed abruptly from the territory of the Bonjos, northernmost of the Bantu tribes, to that of the Sudanese Bandziri, a branch of the widespread Zandeh people. In this region, about the crest of the Congo-Chad water-parting, the contrasts appear to be all in favour of the Sudanese and against the Bantus, probably because here the former are Negroids, the latter full-blood Negroes. Thus Dybowski[226] found the Bonjos to be a distinctly Negro tribe with pronounced prognathism, and altogether a rude, savage people, trading chiefly in slaves, who are fattened for the meat market, and when in good condition will fetch about twelve shillings. On the other hand the Bandziri, despite their Niam-Niam connection, are not cannibals, but a peaceful, agricultural people, friendly to travellers, and of a coppery-brown complexion, with regular features, hence perhaps akin to the light-coloured people met by Barth in the Mosgu country. Possibly the Bonjos may be a degraded branch of the _Bayas_ or _Nderes_, a large nation, with many subdivisions widely diffused throughout the Sangha basin, where they occupy the whole space between the Kadei and the Mambere affluents of the main stream (3 deg. to 7 deg. 30' N.; 14 deg. to 17 deg. E.). They are described by M. F. J. Clozel[227] as of tall stature, muscular, well-proportioned, with flat nose, slightly tumid lips, and of black colour, but with a dash of copper-red in the upper classes. Although cannibals, like the Bonjos, they are in other respects an intelligent, friendly people, who, under the influence of the Muhammadan Fulahs, have developed a complete political administration, with a Royal Court, a Chancellor, Speaker, Interpreter, and other officials, bearing sonorous titles taken chiefly from the Hausa language. Their own Bantu tongue is widespread and spoken with slight dialectic differences as far as the Nana affluents.