So far as initiation is concerned these northern tribes may be divided into three main groups that are clearly marked off from one another by the presence or absence of certain characteristic ceremonies. In all tribes hitherto described by us, in Central and Northern Central Australia, the two ceremonies of circumcision and subincision are carried out, but as the northern coast is approached we meet with tribes which first of all drop, if they have ever practised, the rite of subincision, and, lastly, in the very north and on the Islands, we meet tribes that perform neither of these ceremonies. In no case is the knocking out of a tooth in any way connected with initiation. The three groups are as follows:—(1) Those in which neither circumcision nor subincision is practised. This includes a number of tribes inhabiting Bathurst and Melville Islands, the Coburg Peninsula and the country drained by the East, South and West Alligator Rivers and, probably, also a large extent of country to the east of this along the coast line. Amongst these tribes are included the following:—Melville and Bathurst Island Tribes, Iwaidji, Kakadu, Koarnbut, Norweilemil, Punuurlu, Kumertuo, Geimbio, Noalanji and Larakia.

(2) Those in which circumcision only is practised. This includes a smaller number inhabiting, mainly, country to the south of that of the first group of tribes, though, in the case of the Worgait, they extend to the north-west coast. They are the Worgait, Warrai, Djauan and Nullakun.