130 BUREAU OF AMERICAN ETHNOLOGY [Bull. 177 
well abraded and one face shows striation lines produced by a for- 
ward and backward movement. The fragment measures 7 cm. long, 
4.0 cm. wide at one end and 3.2 cm. wide at the other, with the thick- 
ness varying from 1.0-1.8 cm. 
Mortar—A mortar was roughly shaped from a piece of syenite by 
pecking to create a circular, bowl-shaped object with a depression 
4.0 cm. deep and decreasing from 12 cm. in diameter at the mouth to 
2 cm. in diameter at the bottom. The largest exterior diameter is 
15.0 cm. and the height 8.5 cm. The base is irregularly flattened over 
an area 8-9 cm. in diameter. ‘The bottom of the depression has been 
worn smooth by pounding and grinding. 
Polishing stones——The three rocks showing abrasion scratches are 
all fragments of hematite concretions, which have been broken and 
then used for polishing or painting so that one or more surfaces is well 
smoothed. One fragment is rectanguloid, measuring 2.0 by 2.2 by 
3.5 cm. with the widest face the polished one; another measures 3.0 
by 2.0 by 1.5 cm. 
Flakes and natural rocks.——The most commonly used rock material 
for artifacts in the Koriabo Phase is quartzite, a situation which is 
reflected in the abundance of flakes. In the Appendix, table 15, listing 
the rock materials, it should be noted that hematite or limonite iron 
concretions are tabulated only when they showed some use. It is of 
no interest to record the number of these concretions occurring nat- 
urally in the lateritic soil. All the flakes show distinct bulbs of per- 
cussion; they range in size from 2.0 by 1.5 by 0.8 cm. to 6 by 4 by 2 cm. 
PorTrtERY TYPE DESCRIPTIONS 
The ceramic study of the Koriabo Phase is based upon the analysis 
of 4,378 sherds of Koriabo Phase types, of which 217 or 4.9 percent are 
decorated. These were classified into three plain and two decorated 
types. The occurrence of each type by level is tabulated in the Ap- 
pendix, table 16. The binomial system was used in naming and the 
types are described in alphabetical order. 
BARIMA PLAIN 
PASTE: 
Method of manufacture: Coiling; clean breaks along the coil lines common. 
Coil width 1.0-1.5 cm. : 
Temper: Cariapé. Particles range from large hunks, 2-3 mm. long, visible 
to the naked eye (pl. 32, d-g), to small fragments so fine they are difficult 
to detect except with a magnification of at least 20X. All the sherds 
with cariapé temper are considerably lighter in weight than sherds of 
other pottery types. 
Texture: Porous, soft and fine; like pumice in both feel and appearance. 
Color: Majority the same tan orange in cross section as on the surface, but 
some sherds have a light-gray core with a thin orange-tan surface layer. 
Firing: Oxidized, usually complete but a few incompletely oxidized. 
