From the elementary stages exhibited in these specimens a gradual advance is made by the addition of details and the elaboration of all the features. A corona encircles the head, the ears are outlined (Fig. 5, Plate LXX), the eyes are elaborated by adding one or more concentric circles or ovals, brows are placed above, and groups of notched and zigzag lines extend downward upon the cheeks. The node at the mouth is perforated or cut in intaglio in circular or oblong figures, and the chin is embellished by a variety of incised designs. Illustrations of the various forms are given in Plates LXIX and LXX. These objects are especially numerous in the mounds of Tennessee, but their range is quite wide, examples having been reported from Kentucky, Virginia, Illinois, Missouri, and Arkansas, and smaller ones of a somewhat different type from New York. In size they range from two to ten inches in length, the width being considerably less. They are generally found associated with human remains in such a way as to suggest their use as ornaments for the head or neck. There are, however, no holes for suspension except those made to represent the eyes, and these, so far as I have observed, show no abrasion by a cord of suspension. Their shape suggests the idea that they may have been used as masks, and as such may have been placed upon the faces of the dead in the same manner that metal masks were used by some oriental nations. Among the large number of interesting objects of shell obtained from the McMahan Mound at Sevierville, Tenn., were a number of these shell masks. In the notes of the collector they are mentioned as having been found on the breast or about the heads of skeletons. The example shown in Fig. 1, Plate LXVII, is a medium-sized, rather plain specimen from the above-named locality. It is seven and one-fourth inches long and nearly six inches wide, and has been made from a _Busycon perversum_. The margins are much decayed, and the convex surface is pitted and discolored. The inside is smooth, and has a slight design rudely engraved upon it. Of a very different type is the specimen shown in Fig. 2. It is new looking, and well preserved. The slightly translucent surface is highly polished, and the engraved lines are quite fresh looking. It was collected by J. D. Lucas, and is labeled Aquia Creek, Va. It is five and one-half inches in length by five in width, and is apparently made from some dextral-whorled shell. The outline is somewhat rectangular, the upper surface being pretty well rounded and ornamented with a corona of incised lines, which are arranged in six groups of four each. Inside of these a single incised line runs parallel with the edge, from temple to temple. The eyes are represented by small circles with small central pits, and the lids are indicated by long, pointed ellipses. From each of the eyes a group of three zigzag lines extends downward across the cheek, terminating near the edge of the plate, opposite the mouth.