98 BUREAU OF AMERICAN ETHNOLOGY [Bull. 177 
2. Unzoned, curvilinear incisions, commonly in paired units or parallel 
lines (pls. 21, cf, 22). 
8. Zoned incisions, consisting most commonly of rectilinear elements, 
parallel lines, or gashes typically in a triangular zone set off by 
incisions (pl. 21, g-i). 
4. Band of incised lines on the sloping interior of everted rims. Hither 
rectilinear or curvilinear, usually parallel lines broken into sections 
around the rim by diagonal or vertical gashes or short parallel 
incisions, so that the diameter is partitioned into 2, 3 or 4 sections 
(pl. 21, jl). 
5. Lines on the exterior of rims. Usually this consists of a single or 
double line running around the rim of the vessel about 1.0—2.5 em. 
below the lip. Variations of this motif consist of vertical or 
diagonal parallel lines spaced at varying intervals around the rim 
exterior (pl. 21, m-o). 
TEMPORAL DIFFERENCES WITHIN THE TYPE: Rim forms 3, 4, and 5 appear to be 
restricted to the middle and upper part of the seriated sequence (Appendix, 
table 6), but this may be the result of the poor rim sample from the earlier 
levels. Design motifs 8 (zoned) and 4 (lines on the interior of everted rims) 
are restricted to the middle and upper part of the sequence (Appendix, table 7). 
CHRONOLOGICAL POSITION OF THE TYPE: Aruka Incised is found throughout the 
Mabaruma Phase, but shows a steady increase in popularity from the lower 
(earlier) part to the upper (late) part of the sequence (fig. 48). 
HOSORORO PLAIN 
PASTE: 
Method of manufacture: Coiling. Breaks along coil lines often distinct. 
Temper: The clay has extremely fine sand particles as natural inclusions 
and does not appear to have any added temper. 
Texture: Extremely compact; not friable, but weak and breaks easily. 
Color: Ranges from orange tan to gray tan to gray through cross section. 
Some sherds have a black core with paper-thin to 3 mm. thick bands of 
orange along the interior and exterior. 
Firing: Incompletely oxidized. 
SURFACES: 
Color: Majority light to dark tan, some orange tan. Interior and exterior 
usually the same color, but on a few the interior is gray. 
Treatment: Both interior and exterior are scraped smooth and fairly regular 
and even. Faint crackle lines and a light film of clay on the surfaces sug- 
gest the clay was handled when fairly wet. Fine pits on both surfaces 
result from unevenness that was not erased in the smoothing. 
Hardness: 3.5-4. 
FORM : 
Rim: Direct with a rounded or slightly tapered lip; exteriorly thickened 
with a flat top; sharply everted with a flat insloping flange, rounded lip. 
Body wall thickness: 4-10 mm. ; majority 5-6 mm. 
Body diameters: Range 20-34 em. 
Base: Three forms are of equal popularity; in the absence of complete ves- 
sels it is impossible to associate these with a particular rim shape. 
A. Flat, unthickened or thickened to as much as 1.5 cm., joining the 
sidewall at an angle of 40 to 50 degrees; diameter 8-12 cm. (fig. 
39, A). 
