The possibility that this "abnormal" quantity of the core tools characterizing the early phase of Topanga can be related to a functional part of a seed-gathering economy relieves some difficulties in making cultural comparisons, and provides a more realistic approach. Why Topanga should have more core tools than other reported sites may also have an answer. Some early archaeologists failed to recognize core tools and naturally did not collect them. Sites immediate to the coast generally have a split marine-land economy, and though the metate and mano are present, the core tools used for purposes of pitting such artifacts are distributed more widely in a mound mass charged with shell refuse. Often, along the coast, beach cobbles and cobbles from marine conglomerate provide the only lithic source close at hand, and a resulting tool made from a cobble resembles more a chopper or a "teshoa" flake. This is particularly true of metate-producing sites around Santa Barbara. The Tank Site is adjacent to a massive basalt outcrop from which angular core tools were manufactured. Thus, quarry refuse, and immediate lithic supply, and an economy demanding a great many pecking tools, plus erosional factors that might have concentrated artifacts in the course of time, can in part help explain the great quantity of core tools found at Topanga. [Illustration: Table 8 Suggested Chronology of Early Milling and Hunting Cultures of Southern California] Since Carbon-14 dates are lacking, Topanga can receive only a relative position in a not too well understood southern California cultural sequence. Cultural placement therefore rests upon the recovered types of artifacts, the physical and chemical alterations of both mound mass and artifacts, and the physiographic location of the Topanga sites in terms of a paleogeographic environment. That two phases of the Topanga Culture exist is shown by stratigraphic evidence in the Tank Site with supporting evidence in the adjacent LAn-2 characterizing a Phase II period. Recently a cultural chronology has been suggested for southern California coastal archaeology (Wallace, 1955, p. 227, table 3). Earlier a similar chronology was constructed (Treganza, 1950, table 8) which lacked recent data but was more comprehensive and included possible cross-cultural ties with the desert cultures of the southwestern part of the Great Basin.