32 INSECTA. 
The two anterior legs, as well as in the following subgenus, act 
as pincers. 
Ve tia, Lat. 
Where the antennz are also filiform, but the sheath of the sucker 
has but two apparent joints, and the legs, much shorter, are inserted 
at nearly equal distances from each other(1). 
FAMILY II. 
HYDROCORIS&. 
In our second family of the Hemiptera, the antenn# are in- 
serted and concealed under the eyes; they are shorter than 
the head, or hardly as long. 
All these Insects are aquatic, carnivorous, and seize others 
with their anterior legs, which flex on themselves and act as 
pincers. ‘They sting severely. 
Their tarsi present but one or two joints. Their eyes are 
in general remarkably large. 
Some—Nepides—have the two anterior legs in the form of pincers, 
composed of a thigh, either very thick or very long, with a groove 
underneath for the reception of the inferior edge of the tibia and of © 
a very short tarsus; or one that is even confounded with the tibia, 
and forming with it a large hook. 
The body is oval and much depressed in some, and linear in others. 
They form the genus 
Nepa, Lin. 
Or that of the Aquatic Scorpions, as they are commonly called, 
which is thus divided: 
Gatcvutus, Lat. 
Where all the tarsi are similar, cylindrical, and composed of two 
(1) Lat., Gener. Crust. et Insect., Il, p. 151. 
