Cardium corbis.
Standella, sp.
Tapes staminea.
Of these last species, the cockle, Cardium corbis, and the clam, Tapes staminea, occur quite frequently.[[26]] All of these were used as food by the occupants of the mound. The various species of Helix were probably also used, as they were in more recent times eaten by the California Indians.[[27]] It may be, however, that this species lived on the mound.
The state of preservation of the shells is proportional to their natural hardness. Hence the shells of the Macomas are the most conspicuous, those of the mussels, as the most perishable, are the least noticeable ones in the mound. The relative frequency of occurrence in the case of the three most important species depends on different circumstances.
The lower and the upper strata of this mound are composed of the same varieties of shells, in which point it is different from many shellmounds in other regions. It is, however, true that oyster shells predominate in the lower strata, while Macoma shells are more numerous in the upper ones.[[28]]
Visiting the different shellmounds in the vicinity of the Bay, one finds a general similarity in the kinds of shells composing them. Rarely one or another variety of shell, the Macoma or the cockle, or some other, is found to predominate. This general homogeneity of composition in the shellmounds around the Bay, and the small differences in the amount of any particular species, indicates as a whole the general similarity of the shell fauna at many points about the Bay during the period of occupation of the mounds.
The Indian camping grounds in the interior, although quite similar in form and origin to the shellmounds on the coast, when opened generally present a great difference in appearance. Traces of shells are almost unnoticed from the outside, yet large quantities supplied as food by the rivers of the interior are doubtless to be found in them. These shells have been found during excavations, or their use has been confirmed by persons who observed the mode of living of the Indians of these regions. The Indians also obtained salt-water mussels by trade, even in quite recent times. From the fact that shells are not in evidence on the surface of the camp grounds, one must conclude that their use diminished.
Bones.—Bones of vertebrates are also found in most of the shellmounds. These together with the shells represent the debris of their kitchens. No other shellmound has been seen where so large a quantity of bones was observed as in that at Emeryville. Bones of land and sea mammals, of birds, and of fishes were found in abundance throughout the mound, and fairly evenly distributed in the strata. This fact is the more remarkable since the shellmound at West Berkeley, scarcely two miles distant, does not yield nearly such quantities of bone as this one. The occupants of the mound at Emeryville at all periods were huntsmen to a great degree, besides being fishermen; those of the mound at West Berkeley seem to have depended largely upon fishing; hence the stone sinkers were far more numerous in that mound than at Emeryville.
So far the fauna of only the lowest strata up to 3 feet above the base have been studied. The following species obtained in this horizon were determined by Dr. W. J. Sinclair.