Excavation of Mound C revealed that a circular house (House No. 1) was built on the south bank of the Harroun Site lake, was occupied for an unknown period of time, then was burned—perhaps intentionally. After a thin layer of sand had been strewn over the burned ruins, a second, smaller house (House No. 2) was erected on the remains of the earlier house. House No. 2 was likewise destroyed by fire, after which the remains of both houses were buried under a mound of sand. Both houses probably had centrally located hearths, and one or both of them had an entranceway opening to the west. As at Mound B, a low pile of sandy soil may have been banked around the outside of one or both houses before they were destroyed. Architecturally the houses at Mound C were quite similar to the one at Mound B. The sparse occurrence of artifacts and other cultural refuse suggests that neither House No. 1 nor House No. 2 was an ordinary domicile. It appears likely, rather, that both were ceremonial structures of some sort. This hypothesis is supported by the fact that the houses were considered important enough to be afforded burial beneath a mound, probably after having been ceremonially “cremated.” Mound D This low circular mound was located on the south bank of Cypress Creek about 150 feet east of Mound A (Fig. 1). It was perched at the very edge of the floodplain overlooking the creek channel. In recent years the channel had been migrating laterally and had begun to encroach on the north edge of the mound. The average diameter of Mound D at the base was about 60 feet, and its highest point was at a relative elevation of 100.6 feet, or about 2.5 feet above the surface of the surrounding floodplain (Fig. 9). A shallow depression about 12 feet across in the top of the mound marked the location of the usual pothole. This pothole had originally been only 5 to 6 feet in diameter, but had been considerably enlarged at the surface of the mound by recent erosion. Excavation of Mound D was begun shortly before the end of the 1958 field season. It was dug, like the other mounds, by the quadrant method; but, because there was not enough time for thorough excavation, only the southwest quadrant was carried down to the sub-mound level in 1958. The other three quadrants were taken down to the 98-foot level, however, where a circular zone of dark, organically stained soil, 19.8 feet in diameter, clearly outlined the location of a house structure (House No. 4) similar to those at Mounds B and C. During the final work at Harroun in February, 1959, the entire northwest quadrant was exposed, excavated, and recorded. Only the peripheral ring of post molds was exposed in the other two quadrants.