30 
elements or entomology.' 
only one pair, they are usually situated on the upper lip; when two 
or more, the posterior ones are generally on the lower lip; and hi 
some inseets furnished with a sucking trunk, they are oftentimes 
found inserted at each side of that organ. These feelers are com- 
posed of several joints, the number of which vary. I.ikc the antenna , 
to which they bear analogy, they are endowed with powers of motion, 
but still more extensively. They also serve, like the antenna - , as an 
essential character in the construction of genera ; and from their situ- 
ation, the number of joints, termination, and relative proportion and 
size, are exceedingly useful for that purpose. 
brio ns, tlic Front: the anterior or fore part of the head, the space 
between the eyes and the mouth. 
Ci.ypecr, Shield of the haul in coleopterous insects: the part cor- 
responding with the front of the head in the other orders. In the 
beetle kind it is advanced more or less upon or over the mouth, and 
in some forms a sort of cap, the rim of which extends so far over the 
head as to conceal the mouth beneath. The anterior edge of the cly- 
peus is sometimes mistaken for the upper lip. 
Vertex, the Crown or summit of the. Head. 
Gvla, that part which is opposed to the front of the head, usually 
called the Throat. 
TRUNCUS, the Trunk ; the second principal division of which an 
insect consists, comprehending that portion which is situated between 
the head and the abdomen. The trunk includes the Thorax, Collar, 
Sternum, and Seulcl, 
Thorax: a term indefinitely applied sometimes to the whole trunk, 
the scutcl excepted: in a stricter sense it implies only the dorsal part 
of the trunk, and may he considered as expressive of that portion of 
the superior surface which lies between the head and the base of the 
wings. The appropriation of suitable terms, by which a thorax con- 
sisting of one or of several pieces may ho discriminated from each 
other, is desirable, lii some the thorax is of r. single piece, as in the 
orders Coleoptera and litre ip ter a ; in that of Lejiidoplera it comprehends 
several segments, and a similar structure is still more conspicuous to 
view in the order Hi/rnenoptera. Tire first or anterior segment of the 
thorax, in those consisting of several pieces, lias been sometimes 
called the collar ; but in admitting this, the coleopte mis and hemipterous 
orders of insects can have no thorax, This will he rendered plain, 
when we consider that in the latter kinds of insects the first pair of 
legs arises from what is usually understood by the lower surface of 
the thorax ; the interior segment, in hvmenopterous insects, corre- 
sponds with the whole thorax in the former, for the first pair of legs 
arises from it in exactly the same manner. In the former, the thorax 
pf a single piece is immediately Succeeded behind by a scutcl, while in 
