INSECTA. 515 



leaves at the club of antennas, the female with six shorter ; thorax black 

 with a white felt ; stone-coloured or red-brown shield-covers. The larva 

 lives three years underground, and destroys the roots of plants ; in the 

 autumn of the fourth year it changes into a nymph, from which the beetle, 

 that lives on leaves of all kinds of trees, after some weeks makes its 

 appearance, but commonly continues under ground until May. This 

 insect in some years appears in large numbers, and causes dreadful damage, 

 as for instance, according to the newspapers, in 1836, around Quedlimburg, 

 where, in the middle of May, 132 Dutch mud (of four bushels) were col- 

 lected. Another species, somewhat smaller, with reddish-brown thorax, of 

 the same colour as the shield-covers, Melol. Hippocastani FABE. (PANZER 

 Deutschl. Ins. Heft 97, Tab. 6, RCESEL 1. 1. figs. 9, 10) is met with in this 

 country in some years as well as the former, and sometimes in no fewer 

 numbers. Compare on the cockchafer SUKOW Naturgesch. des Maikafers 

 (aus dem iiten Stuck dcr Verhandl. des Badischen Landivirtsch. Vereins) 

 Carlsruhe 1824, (with an anatomical description of the larva and beetle), 

 and STEAUS DUECKHEIM Cons. gen. &c. 



D. Xylophila (Xylophili LATE, in part, Dynastidce MAC L., 



VESTW.). Elytra shorter than abdomen, with pygidium free. 



.ntennse short, mostly with ten (more seldom eight or nine) joints, 



ith club lamellate, always with three joints. Mandibles princi- 



illy horny, produced at the apex beyond the clypeus, armed with 



tooth at the base, mostly supplied internally with a border mem- 



anous, ciliated, narrow. Ligula horny, connate with mentum. 



brum covered by clypeus. Claws mostly equal (except those of 



terior tarsi in males of some species). Scutellum distinct, moderate 



small, broad, triangular, with apex rotundate. 



These insects often present a great difference of form in the two 

 sexes, the head and thorax in the male being armed with horny 

 excrescences, which in the female are less developed or entirely 

 absent. They are usually brown or black in colour ; some exotic 

 species are amongst the largest of beetles. The larvae live in decay- 

 ing wood and in garden mould. 



t Clypeus broad, mostly rotundate or subsinuate. Head of both sexes 

 unarmed, or supplied with a small tubercle^ never horned. 



HexodonOLiv.,YAKR. Mandibles not crenate exteriorly. Body 

 3-orbicular. Elytra dilatato-marginate. Head small, with eyes 

 nute. 



Sp. Hexodon rcticulatum OLIV., GUERIN Iconogr., Ins. PI. 23, fig. 6; habitat 

 Madagascar. 



Pachylus DEJ., BUEM. 



332 



