HEMIPTERA. 31 
In the others the rostrum is long and straight, the labrum pro- 
jects from its sheath, and the antenne are filiform or a little larger 
near the extremity. The simple eyes are situated on a tubercle. 
They are considered by Fabricius as Saldz. 
Latreille separates them into two divisions. His Acanrata—or 
part of the Satp#, Fab.(1)—have salient antenne, at least equal in 
length to half that of the body. Their form is oval. The simple 
eyes are closely approximated and sessile. In his PeLoconus(2) the 
antenne are much shorter and bent under the eyes. The body is 
shorter and more rounded, and there is a tolerably large scutellum. 
The simple eyes are remote. These Hemiptera approach the Nau- 
cores, and with the following appear to lead to them. 
Sometimes the four posterior legs, very slender and extremely 
long, are inserted on the sides of the pectus, and are very remote 
from each other at base; the tarsial hooks are very small, but little 
distinct, and situated in a fissure of the lateral extremity of the tar- 
sus(3). These legs are adapted for swimming or walking on water, 
and are peculiar to the genus 
a 
° 
HypromeTra, Fab.(4) 
Which Latreille divides into three subgenera. 
HyYypRomETRA, Lat. 
Or Hydrometra properly so called, where the antennz are setace- 
ous, and the head is prolonged into a long snout, receiving the ros- 
trum in a groove underneath(5). 
Gerrris, Lat. 
Where the antenne are filiform, the sheath of the sucker is triar- 
ticulated, and the second pair of legs are very remote from the first, 
and at least double the length of the body(6). 
(1) Fab.,Ib. The Saldz zosterz, striata, littoralis; Lat., Ib. 
(2) Lat., Consid. sur POrd. Nat. des Crust. et des Insect., III, p. 142; Germ. 
Faun. Insect. Europ., XI, 23. 
(3) The prothorax is extended above the mesothorax, in the form of an elon- 
gated plate, narrowed and terminated in a point, representing the scutellum, 
under which the elytra originate. The mesothorax is greatly elongated. 
(4) Fab., Syst. Ryngot. 
(5) Lat., Gener. Crust. et Insect., II, p. 131. 
(6) Lat. Ib. ’ 
