INSECTA. 515 
leaves at the club of antennz, 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. Hippocastant FaBR. (PANZER 
Deutschl. Ins. Heft 97, Tab. 6, Rasru 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 Maikdfers 
(aus dem 12ten Stiick der Verhandl. des Badischen Landwirtsch. Vereins) 
Carlsruhe 1824, (with an anatomical description of the larva and beetle), 
and Straus DuRcKHEIM Cons. gén. &c. 
D. Xylophila (Xylophili Larr. in part, Dynastide Mac L., 
Westw.). Elytra shorter than abdomen, with pygidium free. 
Antenne short, mostly with ten (more seldom eight or nine) joints, 
with club lamellate, always with three joints. Mandibles princi- 
pally horny, produced at the apex beyond the clypeus, armed with 
a tooth at the base, mostly supplied internally with a border mem- 
branous, ciliated, narrow. Ligula horny, connate with mentum. 
Labrum covered by clypeus. Claws mostly equal (except those of 
anterior tarsi in males of some species). Scutellum distinct, moderate 
or 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 larvee live in decay- 
ing wood and in garden mould. 
+ Clypeus broad, mostly rotundate or subsinuate. Head of both sexes 
unarmed, or supplied with a small tubercle, never horned. 
Hexodon Outy., FABR. Mandibles not crenate exteriorly. Body 
sub-orbicular. Hlytra dilatato-marginate. Head small, with eyes 
minute. 
Sp. Hexodon reticulatum Oxiv., GUERIN Iconogr., Ins. Pl. 23, fig. 6; habitat 
Madagascar. 
Pachylus D¥s., Burm. 
