LUCANIDÆ Latreille. This family is closely allied to the next, and is often united with it, as it differs chiefly from the outer lamellate joints of the antennæ not being so closely united into a compact club, as in the Scarabeidæ, and the mentum is usually large. The genus Lucanus, called the Stag-horn beetle, is of large size, with enormously developed jaws in the male, as in Lucanus dama Fabr. (Fig. 402, ). The larva of Lucanus dama (Fig. 403, and cocoon, natural size) is long, thick, nearly cylindrical, and the corneous rust-colored head is armed with two large jaws. Living in rotten wood, like the Cerambycidæ, it constructs a cocoon of the chips it makes. The larva of the European L. cervus is stated by Roesel to live six years. Harris states that they lay their eggs in crevices of the bark of trees, especially near the roots. The larvae resemble the grubs of the Scarabæans in color and form, but are smoother, being less wrinkled. Dorcas brevis, Say (Fig. 404) is an exceedingly rare insect whose habits are unknown.