A few localities have furnished bone, stone, and clay pins similar to these in shape. Specimens of the latter may be found both in the National and Peabody museums. They were probably intended as stoppers for bottle-shaped earthen vessels. Bone pins are generally headless, and have in most cases been intended as implements for perforating and for sewing. Mr. Schumacher found a pin-like object of bone on the island of San Clemente, Cal. It resembles the shell pins pretty closely, having a somewhat spherical head. It is figured by Professor Putnam in a recent work.[57] As already stated, the exact uses to which these pins were applied by the mound-building tribes are unknown; various uses have been suggested by archæologists. The favorite idea seems to be that they were hair-pins, used by the savages to dress and ornament the hair. It would seem that many of them are too clumsy for such use, although when new they must have been very pretty objects. The shorter and headless varieties would certainly be quite useless. Similar objects of bone or ivory, often tastefully carved, are used by the natives of Alaska for scratching the head, although it seems improbable that this should have been their most important function. Professor Dall suggests that some of the shell pins may have been used as were the "blood-pins" of the Indians of the northwest coast. When game is killed by an arrow or bullet, the pin is inserted in the wound, and the skin drawn and stitched over the flat head, so that the much valued blood may be prevented from escaping. A small, very tastefully carved specimen of these pins is given in Plate XXXI, Fig. 4. It was obtained from the Indians of Oregon. A similar specimen comes from San Miguel Island, Cal. It is possible that they may have served some purpose in the arts or games of the ancient peoples; yet when we come to consider the very great importance given to ornaments by all barbarians, we return naturally to the view that they were probably designed for personal decoration. From the Pacific coast we have shell pins of a very different type. They also are made from the columellæ of large marine univalves, and were probably used as ornaments, doubtless to a great extent as pendants. These objects have been obtained in great numbers from the ancient graves of the California coast, at Santa Barbara, at Dos Pueblos, and on the neighboring islands of Santa Clara, Santa Catalina, San Clemente, and Santa Rosa. Professor Dall is of the opinion that the shell mostly used is the _Purpura crispata_, the smaller specimens probably being derived from the _Mitra maura_.