in zoology, a genus of insects belonging to the order of vermes mollusca. The body is roundish, covered with a bony crust, and often beset with moveable prickle; and the mouth is below, and consists of five valves. 1. The specimen on Plate CI. is the esculentus, or eatable echinus. It is of a hemispherical form, covered with sharp strong spines, above half an inch long; commonly of a violet colour; moveable; adherent to small tubercles elegantly disposed in rows. These are their instruments of motion by which they change their place. This species is taken in dredging, and often lodges in cavities of rocks just within low water mark. They are eaten by the poor in many parts of England, and by the better sort abroad. In old times they were a favourite dish. They were drest with vinegar, honied wine or mead, parsley or mint; and thought to agree with the stomach. They were the first dish in the famous supper of Lentulus, when he was made flamen Martialis, or priest of Mars. By some of the concomitant dishes, they seem designed as a whet for the second course, to the holy personages, priests and vestals invited on that occasion. Many species of shell-fish made part of that entertainment. 2. The lacunatus, or oval echinus, is of an oval depressed form; on the top it is of a purple colour, marked with a quadrefoil, and the spaces between tuberculated in waved rows; the lower side studded, and divided by two smooth spaces. Length, four inches. When clothed, it is covered with short thickset bristles mixed with very long ones.—There are 15 other species, all natives of the sea.

in architecture, a member or ornament near the bottom of the Ionic, Corinthian, and Composite capitals.