The southwest quadrant of the mound was excavated in 0.5-foot levels; all other portions were taken down in 1.0-foot levels. Horizontal plans were recorded at all levels and photographs were taken. Vertical walls 1.5 feet thick were preserved across the mound along the W100 and N100 lines (Fig. 9), and trenches three feet wide were extended north, south, and west of the mound in order to obtain complete vertical profiles. Excavation and recording methods were generally the same as previously described for the other mounds. [Illustration: Fig. 9 HARROUN SITE: 41 UR 10 MOUND D AREA CYPRESS CREEK] STRUCTURE OF MOUND D The structure of Mound D was clearly indicated by the vertical cross sections (Fig. 7). An old humus-stained surface underlying the marginal portions of the mound was sharply defined at an average elevation of 98.0 feet. No artifacts or cultural refuse were found in the floodplain below this surface. Prior to construction of the mound a shallow, circular pit had been excavated in the surface of the floodplain to an average depth of 1.5 feet. The sides of the pit sloped sharply downward, and the floor was approximately level. An embankment of yellow-brown sand, possibly composed of back-dirt from the pit, was mounded up about 1.5 feet high and four to six feet wide around the perimeter of the pit. This light sand zone contained a few artifacts but little or no charcoal. A hard-packed house floor about 0.2 feet thick lay on the bottom of the pit. This floor zone was composed of compact sandy clay which contrasted sharply with the overlying mound fill. Charcoal, ash, and burned clay daub were found in quantity in the floor zone, but only a few artifacts were recovered. Just above the house floor was a 1-foot thick layer of dark gray-brown sand containing several charred poles and a large amount of charcoal, ash, and burned clay daub. Above that was the sandy fill making up the bulk of the mound. A mantle of surface humus from 0.2 to 0.8 feet thick covered the mound. A ring of post molds was discovered around the edge of the floor, and other molds on the west side of the house marked the position of an extended entranceway (Fig. 10). No interior post molds were discovered. The pothole, which extended downward through the center of the floor, had apparently removed a centrally located hearth, only slight evidence of burning at the edge of the pothole remaining to show that the hearth had been there. The entire mound fill, including the embankment around the house, was composed of various shades and textures of sand. All of this material was probably derived from the sandy floodplain surrounding the mound. Small quantities of clay around the hearth and on the house floor could have been acquired at nearby outcrops in the stream channel.