COLEOPTEROUS INSECTS. 99 
there are three obvious divisions, consisting of the 
head, thorax, and abdomen. 
The head appears as a single piece, without any 
obvious suture or division, and is generally of a 
harder substance than the rest of the body. Its 
form is most commonly triangular with the angles 
somewhat rounded, frequently it is orbicular, and 
in a numerous and important tribe ( Curculionidce) 
it is produced into an elongated rostrum or snout. 
The hinder part is occasionally constricted into a 
short neck, which inosculates in the anterior cavity 
of the thorax, and admits of a considerable degree 
of motion in almost every direction. The position 
of the head, or its inclination w'ith respect to the 
body, is generally somewhat slanting, forming an 
angle more or less obtuse ; but in some instances it 
is bent inwards and forms an acute angle. . The 
anterior part of the head is occupied by the mouth 
and its various appendages, near to which are placed 
the antennas and eyes. 
The mouth is greatly more complicated in its 
structure than among the higher animals, and its 
various parts undergo numerous modifications in 
different tribes. They will be found however to be 
essentially as follows : the labrum or upper lip, the 
mandibles , the maxillce or under jaws, the labium 
or under lip, and the mentum . 
The upper lip ( labrum ) is a small moveable piece 
placed on the upper side of the mouth, and closing 
it from above. It is variable in form, but is most 
