mandible

The peculiarity of their beak consists in the lower mandible being considerably longer than the other into which it shuts.

The insertion is tendinous on the dorsal surface of the lower mandible in common with the dorsal aponeurosis of pars profundus.

The most dorsal aponeurosis inserts on a tubercle at the posterior tip of the dorsal edge of the mandible.

The stripe p. 160corresponding to the deep yellow stripe on the upper mandible is sky blue.

In Lethrus F. in the female, but not the male, the mandible is armed below with a long incurved horn.