Mortars
Newly acquired mortars are represented but by three fragmentary pieces. Only one is of sufficient size to suggest an outer diameter of approximately 12 inches, and all three appear to be of the cobble type similar to the complete specimen collected in 1947 (Treganza and Malamud 1950, pl. 24, a). Considering the area excavated and the very small number of both mortars and pestles that were recovered, it would be safe to assume this complex was of little significance in the history of the Tank Site. Their function was probably concerned primarily with something other than the food economy, such as grinding pigments or functioning in some specific capacity. Wooden mortars and pestles can not be totally excluded, but the great preponderance of manos and metates would probably preclude any serious assumption that mortars and pestles ever played any important roll at the Tank Site.
Included in feature 18 was a spherical cobble 8 inches in diameter, marked by a well-defined, shallow, circular depression. Its surface bears the marks of shaping by pecking and some rubbing; the depression is well-smoothed, as if worn down by constant use. We can not say whether the piece is completed, as such; or whether, possibly, it represents a small mortar in an arrested state of manufacture.
Pestles
Five complete pestles were recovered, providing a total of nine for the two seasons. The specimens this year differ from those already known in being more stylized, i.e., four are almost perfectly cylindrical and show wear at both ends. All are made of sandstone and have gently rounded pounding surfaces. Specimens 1, 2, and 4, as listed below, were found in a single cache.
1. Shaped over-all by pecking, forming a slightly tapered cylinder, somewhat bulbed at either extremity. Both ends evidence use. This example, by far the largest recovered from the Tank Site, compares in many respects to pestles associated with later cultures of the coast and interior. Length, 31.5 cm.; average diameter, 6.9 cm. (pl. 24, a).
2. Entirely shaped by pecking and grinding. Two opposite sides somewhat flattened by abrasion as if used as a mano on a slab metate, and resulting in a somewhat flattened cylinder form. Both ends used. Length, 13.5 cm.; average diameter, 6.8 cm. (pl. 24, c).
3. Similar to specimen 2, though more nearly circular in cross section and surface shows no grinding. Length 16.5 cm.; average diameter, 7 cm.
4. Completely worked by pecking and grinding. Cylindrical form distorted by slight tapering and dorsoventral flattening. Used at both ends. Length, 15.2 cm.; average diameter, 6.5 cm.
5. This specimen is composed of a highly weathered sandstone so that the surface treatment is no longer discernable. Shaped to a truncated conoid and apparently used only on the larger end. Length, 18.5 cm.; greatest diameter, 8.5 cm.