AQUILA, the principal standard of a Roman legion. The standard of Romulus is said to have consisted of a handful of hay, straw, or fern, affixed to a pole or spear; whence the company of soldiers who served under it was called Manipulus. This primitive standard was soon superseded by the figures of animals, which, as Pliny tells us (H. N. x. 4), were the eagle, wolf, minotaur, horse, and boar: but in B.C. 104 the eagle was permanently adopted. It was made of silver or bronze, and was represented with expanded wings.