In considering in detail the population of the delta (see map 6, area 13), it is convenient to segregate groups according to tribal distinctions rather than strictly according to geographical points. The reason lies primarily in the fact that the early writers and the mission records were relatively explicit with respect to names of villages and groups but were badly confused with respect to localities. In the densely populated but physiographically homogeneous delta region, with its scores of small streams, sloughs, and islands, explorers found it very difficult to establish clear landmarks by which the inhabitants might be oriented. A state of confusion has arisen of a kind to generate many controversies among ethnographers, controversies which are not pertinent in the present connection and which it is desirable to avoid as far as possible. In order to adopt a more or less uniform system with respect to tribal nomenclature and arrangement it is proposed to follow here the practice of Schenck (1926), who has made an exhaustive study of the area. _Bolbones (syn. Cholbones, Chilamne, Chulame)._--This large group occupied the sloughs of the lower San Joaquin west of Stockton. Schenck, on his map (1926, p. 133) shows their territory as being bounded by the main stream of the San Joaquin River on the east and by the channel now known as the "Old River" on the west. This delineation of their habitat is supported by the diaries of Abella and Viader. Schenck classifies the subtribes or divisions of the main group as follows: Cholbones a group Pescadero a village Jusmites or Cosmistas a village plus Fugites or Tugites a village plus Tomchom, under Fugites a village Nototemnes a village