COLEOPTEROUS INSECTS. 
131 
near the middle of the interior row, which is large, 
somewhat square, and very highly polished. The 
under side of the body and legs are bronzed green, 
except the base of the thighs and greater part of 
the tibia?, which are pale reddish yellow. 
This insect is of frequent occurrence in most 
parts of Britain. The genus derives its name from 
a Greek word, referring either to the nature of the 
place which the species frequent, or to the activity 
of their motions.* It is distinguished by the an- 
tennae gradually becoming a little thicker towards 
the extremity ; by the thorax being at least as long 
as broad, and nearly of the same width as the head ; 
by the large and very prominent eyes ; and by hav- 
ing the four first joints of the anterior tarsi slightly 
dilated in the males. It contains only a few species, 
some of which bear such a strong resemblance to 
each other, as to countenance the conjecture that 
they may be mere varieties. They frequent marshy 
places, and the margins of lakes and ponds, running 
about with remarkable celerity during the heat of 
the day. They are most prevalent in the northern 
parts of Europe, the more common kinds becoming 
scarce in the south, and two or three not extending 
further than the northern extremity of Germany. 
There is one species found in America. 
a marsh, or i Xaip^os, light, acli t«. 
