LUCANUS, the STAG-BEETLE, in zoology; a genus of insects of the order coleoptera. The antennæ end in a club or knob, which is compressed or flattened on one side, and divided into short laminae resembling the teeth of a comb; the jaws are porrected or advanced before the head, and are dentated. There are 20 species. The largest, as well as the most singular, is the cervus; which is easy to be known by two large moveable maxillæ, resembling in form the horns of a stag, which project from its head, and have in a special manner acquired the appellation of Stag-Beetle. Those maxillæ, broad and flat, equal to one third of the insect's length, have in the middle, towards their inner part, a small branch, and at their extremity are forked. Besides this, they have several small teeth throughout their whole length. The head that bears these maxillæ is very irregular, very broad and short. The thorax is something narrower than the head and body, and margined round. The elytra are very plain, without either streaks or lines. The whole animal is of a deep brown colour. It is commonly found upon the oak, but is scarce in the neighbourhood of London, and though the largest of coleopterous insects to be met with in this part of the world, it is much smaller than those of the same species that are found in woody countries. This creature is strong and vigorous, and its horns, with which it pinches severely, are carefully to be avoided.—The jaws are sometimes as red as coral, which gives this insect a very beautiful appearance; the female is distinguished by the shortness of the jaws, which are not half so long as those of the male.—These insects feed on the liquor that oozes from oaks, which they suck with their trunk or tongue. The females deposit their eggs in the trunks of decayed trees, such as the oak and the ash. The larvae or grubs lodge under the bark and in the hollow of old trees, which they eat into and reduce into fine powder, and there transform themselves into chrysalids. They are common in Kent and Sussex, and are sometimes met with in other parts of England. The porrected jaws are particularly useful to these animals, in stripping off the bark from trees, and affixing themselves thereby to the tree, while they suck with their trunk the juice that oozes from it.