Schenck places them along the south shore of Suisun Bay from the east entrance of Carquinez Strait and through the slough region between the Sacramento and San Joaquin rivers as far upstream as Isleton on the Sacramento. However, he points out that there is great uncertainty with respect to their exact location, an uncertainty which is emphasized by the wide divergence between his views and those of Merriam. Even the Spanish accounts present numerous discrepancies. In view of this state of our knowledge Schenck makes the very reasonable suggestion that the lower delta tribes may have been so greatly disturbed and shifted around during the period from 1775 to 1810 that the aboriginal locations were forgotten. It is worth while to examine in some detail some of the evidence on this problem. We may begin with examination of the area at and just east of Carquinez Strait on the south shore of Suisun Bay. This consideration entails a preliminary discussion of two small groups, the Aguastos and the Huchium (syn. Habastos, Quivastos, Juchium, Huchimes, Tuchimes, etc.). This tribe or group of tribes, which must have been of some importance, is not mentioned by name by Kroeber or Schenck, but there is a brief set of typed notes in the Merriam collection in which the location is discussed (MS entitled: "On the East Side San Francisco Peninsula"). The multiplicity of synonyms, however, as well as the large number of neophytes involved, indicates that these tribes were very familiar to the missionaries. The Merriam notes (pp. 5 and 6) point out the following considerations. 1. "Abella's diary (1811) speaks of present Point San Pablo as the Point of the Huchunes and says their territory extended on the mainland from this point to Pt. San Andres (Pt. Pinole)." 2. Several rancherias belonging to this tribe are mentioned as being on the east side of the bay. 3. "The mission books locate the Habasto tribe 'on the other side of the Bay from the Mission of San Francisco toward the estero which goes to the rivers (Suisun Bay).' Abella's diary calls Point San Pedro the Point of the Abastos." Merriam therefore was strongly of the opinion that these tribes inhabited the south shore of San Pablo Bay and did not extend farther than Carquinez Strait. On the other hand, the item in the mission books quoted by Merriam (par. 3, above) indicates Suisun Bay rather than San Pablo Bay. Moreover, there is another statement in the baptism books alongside the designation "Aguastos ó Huchum" to the effect that this tribe was 16 to 18 leagues by water from San Francisco. This distance would place them close to the site of the modern town of Pittsburg, that is, on the southern shore of Suisun Bay. But this area is assigned by Schenck to the Tarquines and perhaps the Julpunes, tribes which are also clearly mentioned by name in the mission records.