E d 
pao ARCHEOLOGY IN BRITISH GUIANA 145 
nubbins, and small faces. Koriabo Scraped consists of wide, shallow, 
incised grooves usually made with a slightly serrated, flat-edged stick, 
which scraped away the clay particles when the design was made. 
These scraped grooves are combined with low applique nubbins, eyes, 
and faces, usually placed on the edge of wide rims with the grooves 
spaced in between. Both these types are found only in the middle 
of the Koriabo Phase sequence and are most abundant at Site N-2. 
Distinctive Koriabo Phase rim forms are everted and slightly thick- 
ened on the interior, with a broad channel on the upper surface or an 
angular faceted upper edge. Griddle sherds suggest the use of 
manioc. The only common pottery artifacts are pot rests. Stone 
tools are few. They include polished celts and chisels, but the forms 
are not distinctive. 
All the Koriabo Phase sites produced trade sherds of Mabaruma 
Phase plain and decorated types. These comprise 13.4 percent of the 
total sherd sample, indicating that the commerce was rather extensive 
and demonstrating the contemporaneity of the Koriabo Phase with 
part of the Mabaruma Phase occupation of the Northwest District. 
COMPARATIVE DATA, CONCLUSIONS, AND INTERPRETATIONS 
The archeological sequence in the Northwest District is the longest 
in British Guiana, and also the most varied. This region is part of 
the area of most intensive European settlement, with the result that 
collections have been made from some of the sites for over 100 years. 
The general sequence, from a preceramic shellfish gathering horizon 
to pottery making and presumably agricultural groups, has been 
known for a long time and our main contribution has been to suggest 
a more detailed chronology and to expand the distribution of the 
cultures involved. 
Barring the possible existence of a paleo-Indian horizon, the earliest 
occupation of the Northwest District is represented by the remains 
of the Alaka Phase. Sites consist of small shell midden deposits 
surrounded by, or at the edge of, the mangrove swamp. Scattered 
in the refuse, along with shells, bones, crab carapaces and ash, were 
crude stone choppers, picks, scrapers, and similar unshaped, rudi- 
mentary, percussion-flaked tools. Objects of other materials were 
very rare. Distribution of shell middens extends beyond the North- 
west District into the Pomeroon District and possibly as far east as 
the mouth of the Essequibo River (fig. 58). Further work may make 
it possible to distinguish at least one other shellfish gathering Phase, 
since large middens existing in the Pomeroon District appear to have 
a slightly different artifact complex than that associated with the 
Alaka Phase. However, since there is an equally good possibility 
that the cruder implements have not been recognized as artifacts and 
