COLEOPTEROUS INSECTS. 
187 
iarva forms for its protection an oval cocoon, con- 
structed of earth and the gnawed fragments of other 
materials, agglutinated by a viscous secretion which 
exudes from its body. 
The lamellicorn insects may be regarded as con- 
stituting two great groups or tribes, corresponding 
to the two comprehensive genera of Linnaeus, Sca- 
rabasus and Lucanus. In the former the antennae 
terminate in a foliated mass, generally capable of 
being alternately closed or expanded ; but it is 
sometimes composed of joints that fit into each other, 
either in a globular form, or in the shape of a re- 
versed cone : the mandibles are nearly alike in both 
sexes, and the males are frequently distinguished 
by horns or prominences on the head and thorax. 
The first generic group among the Scarab^iid^;, 
which requires to be noticed, has been named 
ATEUCHUS. 
The term is probably derived from the Greek 
privative a, and riu%og, a weapon or implement of 
war, in allusion to the head -being without horns, 
contrary to what is observed in most of the allied 
genera. The antennae consist of nine joints, the 
three next the apex forming a foliaceous knob. The 
body is somewhat rounded, and usually rather de- 
pressed, and there is scarcely any appreciable mark 
of distinction in the external appearance of the two 
sexes. The maxillae terminate in a membranous 
