THE LUCANIDA. 281 
which resembles the shape of Adéeuchus sacer, but it has a bril- 
liant golden colour, which was supposed to have been an in- 
vention of the artists of the days of the Pyramids, but this is 
not the case; and the coloured <A¢euchus was found, in 1819, by 
M. Cailliaud, and it is not rare in Sennaar. 
There are some Scarabe@ide which live in Europe, and are 
smaller than the sacred beetles, but which have the same habits. 
One kind, which is very common in France, is named after the 
pill of dung it carries about, and is called Gymnopleurus pilularius. 
Another species, which has a thick body and long hind legs, 
is named after Sisyphus, and is sometimes found in the environs 
of Paris. 
The last tribe of the family of the Scarabeide we have to 
notice comprehends the genus Passa/us, and contains very large 
beetles, which have long flat bodies, the prothorax separated 
from the trunk by a waist, antenna bowed, and spined fore 
legs. All have a brilliant black colour, and inhabit the American 
continent, the East Indies, and Australia. They live in the 
trunks of old trees, and hide beneath the bark, and the flatten- 
ing of their bodies enables them to do this. The larva, which 
live upon decaying wood, whilst they resemble for the most 
part those of the Scarabeide, have a peculiar construction, which 
proves that their development is not far advanced. Their first 
and second pairs of legs are as long as usual, but those of the 
third pair only exist as little tubercles. 
The Lucanide, or the Stag Beetle family, were formerly in- 
cluded amongst the Scarabeide, but their longer antenne and 
peculiar form give them a different aspect. There are also 
some differences in the larve; and it is now proved that the 
nervous system, which is very centralised in the Scarabeide, is 
much less so in the Lucanide. The two families are therefore 
separated by structural differences. 
The Lucanide are usually very large insects, whose males are 
well known on account of,the enormous size of their mandibles, 
These structures,» which belong to the mouth, are differently 
curved and toothed, according to the species, and they look like 
large pincers, and give the beetles a very formidable appearance. 
It is impossible, from our present knowledge, to account for the 
