THE INHABITANTS OF THE OIL RIVERS OR RIVERS SECTION OF SOUTHERN NIGERIA ARE DIVIDED BY HISTORY, GEOGRAPHY, AND LANGUAGE INTO TWO GROUPS--THE COASTAL PEOPLES AND THE HINTERLAND PEOPLES. COASTAL DIALECTS BELONG TO THE IJO GROUP OF LANGUAGES WHILE THE HINTERLAND DIALECTS ARE OF ANOTHER LANGUAGE FAMILY. DURING THE 19TH CENTURY THE HINTERLAND PEOPLES WERE POLITICALLY AND ECONOMICALLY DOMINATED BY THE COASTAL PEOPLE AND THE LANGUAGES SPOKEN BY THE VARIOUS GROUPS DEMONSTRATED (1) A HIGH INCIDENCE OF BILINGUALISM IN THE HINTERLAND NOT PARALLELED BY SIMILAR BILINGUALISM ON THE COAST, (2) A HIGH INCIDENCE OF COASTAL PERSONAL AND PLACE NAMES IN THE HINTERLAND, AND (3) THE FREQUENT USE OF COASTAL LANGUAGES IN EVERYDAY AFFAIRS IN HINTERLAND COMMUNITIES. THE CESSATION OF THE OIL RIVERS TRADE, THE COLONIAL REGIME, AND NIGERIAN NATIONALISM AND INDEPENDENCE HAVE CAUSED NOT ONLY SOCIAL-ECONOMIC CHANGES BUT LINGUISTIC CHANGES AS WELL. A GROWING SENSE OF ETHNIC IDENTITY AMONG THE MINORITY HINTERLAND GROUPS IS SEEN IN A SHIFT AWAY FROM USE OF COASTAL DIALECTS AS SECOND LANGUAGES AND A CONSCIOUS DESIRE TO REPLACE "FOREIGN" USAGE WITH THE VERNACULAR. THE CHANGE IN THE LANGUAGE SITUATION, THEN, ILLUSTRATES THE SOCIAL-ECONOMIC TREND AWAY FROM NATIONAL AND REGIONAL UNITY TOWARD DIVERSITY AND PARTICULARISM. THIS ARTICLE APPEARED IN "ANTHROPOLOGICAL LINGUISTICS," VOL. 9, NO. 1, JAN. 1967. (JD)