Iowa and western Missouri present implements of white flint which when seen cannot be confused with those of other sections of the country, for the form is peculiar (see Figs. 118 and 122). On the Plains, from the Black Hills to the Arkansas River, large rough implements abound (see Figs. 153 and 174) on certain sites, but generally the projectile points are small and slender. The notched objects of flint, probably used as axes, are common in certain sections. Scrapers are to be found everywhere in this region. The implements of the Rocky Mountains themselves might be separated into three or four localities. There are so few collections from the Rocky Mountains, south of the headwaters of the Columbia and the Missouri, that I have not sufficient data on which to base accurate observations. This will be secured, however, at some future time. Typical Mandan spears and arrows are shown in Fig. 138. Colorado types and those from elsewhere in the mountains are seen in Figs. 123, 134, and 153. It appears that many of the scrapers, knives, and projectile points of the Great Plains were made of material brought down from the mountains. Naturally, the natives went to the nearest quarry sites, obsidian ledges, or where chert and agatized wood and other flakable materials were to be found. [Illustration: FIG. 215. (S. 7–8.) Egyptian points from near Cairo, Egypt. Presented for comparison. Note how unlike any American forms. Of these 22, only 6 are similar to the United States types. Material: finely chipped, true brown flint. Age unknown. Collection of L. V. Case, Tarrytown, New York. ] Central and western Texas furnish slender points of yellow chert and scrapers of the same material. But there are also projectile points of white and red flint quite different from those of Kansas and Nebraska. (See Figs. 119 and 189.) Arizona and New Mexico types are chiefly of obsidian, yet there is chalcedony and agatized wood. (See Fig. 128.) While Arizona and New Mexico chipped objects are of the same general character as those from the Columbia River and its tributaries, yet, usually, they can be distinguished. (See Figs. 97, 104, 110.) But there are obsidian points in both regions identical in character. The Pacific Coast furnishes more large implements than are to be found between California and Tennessee. Illustrations of California types are in Figs. 78, 136, and 151. There are also California forms which are rare in the Columbia Valley. Obsidian was used almost exclusively in California.