from the Benguela plateau. During this period, the Benguela 'nation' was in the majority, accounting for a third of Africans. As of 1830, the Kongo 'nation' rose to dominance, along with other groups that spoke the Kikongo language, such as the Cabinda and Loango (Symanski, 2006). Although these populations maintained disparate ethnicities in Africa, they recognized a common ancestry (Hall, 2005, p. 153). From 1850 to 1870, the Kongo population came to represent 28 per cent of Africans; this figure rose to 39 per cent when the other 'nations' who also spoke Kikongo were taken into account. In terms of the ceramic sets dating to the period, wavy, arched motifs organized into sets of three and four cuts became common, as did sets of triple and quadruple short diagonal lines forming sequences. Such motifs were identical to the decorative patterns etched into ceramic vessels by populations from coastal, lower and central Zaire at the end of the nineteenth and beginning of the twentieth centuries. These ceramic sets also featured vessels with a circular design containing an incision in the shape of a cross, which, in some cases, was also etched into the material. As previously discussed, this symbol has been interpreted as the Bakongo cosmogram in North American contexts. In the case of Chapada dos Guimarães, the correlation suggests that groups from this cultural subset were mainly responsible for the introduction of this symbol to the region.