The Edible Mussel (_Mytilus edulis_) on the few rocks, and washed up in curious bunches of forty or fifty, held together by its rope-like _byssus_. The Scollop Shell (_Pecten concentricus_), used for card-racks and pin-cushions. Cockles, or Cuckoos (_Natica heros_), and their remarkable _nidus_, called “sand-circle,” looking like the top of a stone jug without the stopple, and broken on one side, or like a flaring dickey made of sand-paper. Also, _Cancellaria Couthouyi_ (?), and Periwinkles (?) (_Fusus decemcostatus_). We afterward saw some other kinds on the Bay-side. Gould states that this Cape “has hitherto proved a barrier to the migrations of many species of Mollusca.”—“Of the one hundred and ninety-seven species [which he described in 1840 as belonging to Massachusetts], eighty-three do not pass to the South shore, and fifty are not found on the North shore of the Cape.” Among Crustacea, there were the shells of Crabs and Lobsters, often bleached quite white high up the beach; Sea or Beach Fleas (_Amphipoda_); and the cases of the Horse-shoe Crab, or Saucepan Fish (_Limulus Polyphemus_), of which we saw many alive on the Bay side, where they feed pigs on them. Their tails were used as arrow-heads by the Indians. Of Radiata, there were the Sea Chestnut or Egg (_Echinus granulatus_), commonly divested of its spines; flat circular shells (_Scutella parma?_) covered with chocolate-colored spines, but becoming smooth and white, with five petal-like figures; a few Star-fishes or Five-fingers (_Asterias rubens_); and Sun-fishes or Sea-jellies (_Aureliæ_). There was also at least one species of Sponge. The plants which I noticed here and there on the pure sandy shelf, between the ordinary high-water mark and the foot of the bank, were Sea Rocket (_Cakile Americana_), Saltwort (_Salsola kali_), Sea Sandwort (_Honkenya peploides_), Sea Burdock (_Xanthium echinatum_), Sea-side Spurge (_Euphorbia poylgonifolia_); also, Beach Grass (_Arundo, Psamma_, or _Calamagrostis arenaria_), Sea-side Golden-rod (_Solidago sempervirens_), and the Beach Pea (_Lathyrus maritimus_).