336 BUREAU OF AMERICAN ETHNOLOGY [Bull. 177 
The Mabaruma Phase presents a contrast to the other pottery mak- 
ing groups identified in British Guiana in the elaborateness of its 
ceramics. Surfaces are well finished and frequently polished, vessel 
shapes incorporate annular bases and broad flangelike rims, and deco- 
ration by incision and modeling occurs on 13.8 percent of the total 
sherds. Although there is variation in the size of habitation sites, 
the upper end of the range is much larger than in any of the other 
phases.?° These features suggest that population concentrations may 
have been larger and that sociopolitical organization may have been 
slightly more advanced than ina typical Tropical Forest culture. Un- 
fortunately there is no evidence of burial practices or ceremonialism, 
either of which might provide a clue to the existence of occupational 
division of labor or differences in social status. In view of this infer- 
ence of higher cultural development, it is of interest to note the influ- 
ence that the Mabaruma Phase exerted on two contemporary Tropical 
Forest groups with which it came into contact. Decorated sherds of 
Mabaruma Phase types exceed those of the lecal style in sites of the 
Abary Phase and the Koriabo Phase, but evidence of reciprocation 
is very slight. 
A considerable amount of change can be detected in Mabaruma 
Phase pottery during the time covered by the seriated sequence. Some 
decorative motifs died out and others were introduced (fig. 48), and 
several modifications occurred in vessel shape, not to mention the 
alterations in paste characteristics, especially evident in the plain 
wares (fig. 49). These changes appear to represent a gradual evolu- 
tionary simplification in vessel shape and decoration, but the possibil- 
ity of some external influence cannot be ruled out, especially with 
reference to the change in adorno style (cf. fig. 49). During the 
latter part of its existence, the Mabaruma Phase expanded along the 
coast toward the southeast, and also reinvaded its Orinoco homeland. 
Its termination was probably brought about by increasing European 
settlement, but there is no direct evidence of this in the form of his- 
torical documentation or trade materials in British Guiana. 
The third intruder into British Guiana was the Abary Phase, whose 
arrival is estimated to date at around A.D. 1100 (fig. 126). From a 
postulated origin in Trinidad, the group moved into the Northwest 
District where it came in contact with the Mabaruma Phase (fig. 127). 
A friendly relationship between the two peoples is suggested by the 
strength of the influence exerted on Abary Phase potters and the 
evidence of continuing trade after the newcomers settled on the Abary 
River. The small habitation sites and simple ceramics of the Abary 
Phase imply that it represents a typical culture of the Tropical Forest 
1 Site R-386 of the Rupununi Phase is an exception, but dates from the 19th century 
and probably reflects influences not present in the aboriginal situation. 
