Although, as a rule, the paste of which the ware is made is comparatively free from foreign matter, yet many pieces, especially of the decorated ware, when broken, show little whitish or ash-colored specks. These, when found in aboriginal pottery east of the Mississippi, have, I believe, been without question considered as fragments or particles of shell broken up and mixed with the paste. This may be correct in reference to the pottery found east of and in the Mississippi Valley, but this whitish and grayish matter in the pottery of the Indians of New Mexico and Arizona is in most cases pulverized pottery, which is crushed and mixed with the paste. Black lava is sometimes crushed and used in the same manner. The principal material used is a clay, apparently in its natural state, varying in color according to locality. Although comparatively free from pebbles or lumps of foreign matter, we detect in some of the coarser specimens small particles of mica and grains of other materials, and in one broken specimen the elytron of a small coleopterous insect. But as a general rule, the paste appears to have been free from foreign matter. A slight glance at this large collection is sufficient to show that the potters worked by no specific rule, and that they did not use patterns. While it is apparent that only a few general forms were adopted, and that, with few exceptions, the entire collection may be grouped by these, yet no two specimens are exactly alike; they differ in size, or vary more or less in form. The same thing is also true in reference to the ornamentation: while there is a striking similarity in general characteristics, there is an endless variety in details. No two similar pieces can be found bearing precisely the same ornamental pattern. Much the larger portion of the collection consists of vessels of various kinds, such as bowls, cooking utensils, canteens, bottles, jars, pitchers, cups, ladles, jugs, water vases, ornamental vessels, paint-pots, &c. These vary in size from the large vase, capable of holding ten gallons, to the little cup and canteen, which will contain less than half a pint. The other and much smaller portion includes all those articles which cannot be classed as vessels, such as images, toys, toilet articles, representations of animals, &c. The collection can perhaps be most satisfactorily classified by reference to the coloring, ornamentation, and quality, thus: 1. _The red or uncolored pottery_, which is without ornamentation of any kind. Some of this is coarse and rough, and in this case always more than ordinarily thick; but the larger portion has the surface smooth and often polished. The color varies from the natural dull leaden hue of the clay, to a bright brick red, the latter largely predominating.