Changes in pottery styles, and especially in decoration, are very marked during this period. Although plain gray ware was still made, pottery with black designs on a white background shows up in great quantities. In the western part of the San Juan area, painted pottery with a pinkish-orange background and red designs makes its first appearance; examples of this type show up as trade pieces in eastern San Juan sites. The differences between culinary and nonculinary wares become more marked. The former are usually corrugated vessels, formed by pinching or indenting the clay coils while they were still plastic and before the pot was fired. Later in the period, this type of corrugation became quite decorative in itself and some of the better cooking ware aesthetically rivals the painted wares. [Illustration: Corrugated cooking pot. Diameter at mouth, 11½″; Maximum diameter, 16⅓″; Height, 16″.] There was a greater variety of vessel forms and painted designs. For example, designs were no longer confined to the interiors of the bowls, but were also painted on the exteriors and upon a great variety of vessel forms. Many of these designs still seem to be derived from those inherent in basketry, others may have been taken from textile designs, and still others originated especially for use on pottery vessels. Principal design elements seem to have been parallel lines—sometimes straight, sometimes stepped or wavy—zigzags, triangles, checkerboards, and interlocking frets. In the latter part of the period, these elements became broader and heavier and were rendered with greater assurance. A slip or wash of very fine clay was now smeared on the vessel before firing to give it a smooth finish. Burials were generally in refuse heaps, abandoned storage pits and rooms, or beneath the floors of houses. Infants and small children were frequently buried beneath the floors of houses, as though the parents either desired to keep them around as long as possible, or believed that the soul of the dead child would return with the birth of the next one if the body were close by. Grave offerings consist mainly of pottery, but we may be sure that various perishable objects also accompanied the dead; however, conditions for preservation are so poor in these open sites that most traces of perishable materials have long since disappeared.