Acorn barnacle

A species of barnacle. A'corned, a. ( Her.) Having acorns, as an oak-tree with acorns on it. A'corn-shell. ( Zool .) The popular name for the Bala nus and other cirripeds, which inhabit a tubular shell whose base is usually formed of calcareous lamine. Its shell is composed of many pieces, and thus capable of enlargement to the wants of the enclosed animal, which performs its nece ary functions by an aperture at the top. The tentacula from this animal being feathered, our credulous ancestors believed that it gave origin to a bird called the barnacle-goose. These curious but common shells are found in all seas. They are affixed to marine bodies, and their peduncle is sometimes found a foot long. Their growth must be exceedingly rapid. A ship going out with a perfectly clean bottom will often return, after a short voyage, covered with them.-"Go at low water to a rock on the beach, choose a few of the oldest and largest limpets, left uncovered by the receding tide, and incrusted with the acorn-shells; throw the limpet-shells into a gla of seawater, and in a minute or two the acorn-shells upon them will begin to open. Presently a beautiful feathered apparatus will be extended, then withdrawn. It will again be put forth, and again retracted; but with such grace, regularity, and precision, that the eye regards it with ever new delight; and when we consider that it thus ministers, at the same moment, both to respiration and nutrition, a train of ideas is excited, which rises from the humble shell to HIM by whom it has thus wondrously been Fig. 25.- ACORN-SHELL. fashioned."