Since the Tank Site showed promise of being an unusual and important deposit, considerable care was observed during both seasons of excavation to isolate and expose any concentration of lithic remains which appeared to be in any way atypical of the average mound matrix. As a result, numerous associations of stones, such as mano caches, highly weathered inverted metates, and massive piles of rejected cores, broken manos and metates, and plain cobbles, were set apart from the rest of the site and given the term “feature.” In some instances these features possess obvious meaning, as was true of the mano caches and the inverted metates, but in other instances the purpose remains unknown. If nothing else, this technique of isolating features as excavation progressed provided an adequate view of the internal structure of a village, a type of information largely lacking in southern California archaeology.

The features described below represent a continuation of the series reported for 1947.

Feature 14 (pl. 19, b).—Cache of 4 manos. The placement of these specimens precludes a chance affinity; they were closely grouped and each was standing more or less on end. No other artifacts were found in association.

Feature 15 (pl. 19, d).—Owing to its areal extent, feature 15 is somewhat difficult to define. The complex of stone by which it is characterized has been arbitrarily broken down for descriptive convenience. There is no way of knowing whether the entire complex exemplifies a single unit or if in the course of time it merely developed from a single point of departure.

Feature 15a.—This was 10 by 10 feet with an average depth of 4 to 8 inches. Four inverted metates, additional metate fragments, manos, core tools, and a single fragment of a slate pendant. In the southeast portion were 12 symmetrical stream cobbles of different sizes. This latter aggregation is of interest. The almost perfect symmetry of the stones suggests selection, and the physiographic location of the Tank Site implies such stones must have been transported to it. None shows any evidence of utilitarian use, and in the light of present knowledge the existence and function of such objects cannot be explained.

Feature 15b.—Badly weathered, fragmentary metates; altered “lumps” of sandstone; manos; and core tools. Three small pestles were found near association.

Feature 15c.—Inverted, killed, sandstone metate; sandstone slab; and core tools. Burial 11 was in close proximity, but owing to its badly disturbed condition, no positive association could be made with the feature.

Feature 15d.—Metates; altered sandstone blocks; core tools; manos; and fragments of human leg bones.

Feature 16.—Disintegrated, pitted metate and fragments of 2 other metates; mano fragments; core tools; unworked stone; and unidentifiable fragments of human bone.

Feature 17.—Characterized by a number of symmetrically water-worn cobbles. Contrasts with other features wherein metates, manos, cores, and irregular, unutilized stones predominate. Fragmentary metates, manos, and core tools were also present, as were 2 segments of human femora.

Feature 18.—Badly weathered, inverted, deep-basin metate in near association to symmetrical sandstone cobble containing a ground depression. The latter may represent the initial stage of mortar manufacture, though the smoothness and regularity of the depression surface somewhat invalidates the idea.

Feature 19.—Metates (deep basin, shallow basin, and slab); mano fragments; scraper planes; core hammerstones; and fragments of human femora and tibiae. The deep-basin metate was right side up, in contrast to the usual inversion.

Feature 20.—Deep-basin metate with associated metate fragments; carbon-smudged blocks of disintegrated sandstone core tools; and sections of human femora.

Feature 21 (pl. 18, b).—Large, shallow-basin metate and fragments of 2 others; 2 large, reworked, granite boulders; 3 blocks of highly decomposed sandstone; core tools; mano; and fragments of human femur.

Feature 22 (pl. 20, b).—Deep-basin metate; 2 slab metates and 3 metate fragments; chunks of altered sandstone; core tools; and a large, chert blade.

Feature 23 (pl. 20, d).—This feature constituted by far the largest single concentration of stone, being about 8 feet in diameter. In addition to quantities of unworked pieces of granite and sandstone, the following artifacts were noted: 53 metate fragments (31 deep basin, 13 shallow basin, and 9 slab), 15 manos, 11 scraper planes, 4 side scrapers, 5 bifaced chopper, and 2 abrading stones.

Feature 24 (pl. 18, d).—Large, decomposed fragments of fired sandstone (18 × 12 × 11 inches); 2 metate fragments; core tools; and fragments of human long bones.

Feature 25 (pl. 19, a).—Cache of 6 manos.

Feature 26 (pl. 20, a).—One slab metate; metate fragments; manos; core tools; and limonite pigment.

Feature 27.—Killed, inverted, deep-basin metate; slab metate; 2 scraper planes; 1 mano; 6 core hammerstones; 1 cobble hammerstone; 1 bifaced chopper; fossil mammal bone; and fragments of human bones.

Feature 28 (pl. 20, c).—Killed, inverted, shallow-basin metate; fragments of 2 slab metates; 1 shallow-basin type; 4 mano fragments; and 2 core hammerstones. This feature is of interest due to its very shallow depth (4 inches to top of metate). No disturbance could be detected, indicating either that when Mr. Trujillo plowed the site (1920) his plow was drawing less than 4 inches or the deposit has undergone some degradation since the time of his activity.

Feature 29.—Inverted, deep-basin metate; hammerstone; granules of red ocher; and fragments of human long bones.

Feature 30.—Single, inverted, shallow-basin metate.

Feature 31.—Inverted, deep-basin metate; 9 complete manos and 3 fragments; 2 scraper planes; 6 core hammerstones; 7 chunks of altered sandstone; and fragments of human leg bones.

Feature 32.—Fragments of highly altered metates and 3 chunks of burned sandstone. Unknowingly, a section of this feature was moved during our 1947 operations.