RIIYKCOTA. 
31 
are two other genera which belong to this family, viz. : 
Naucoris and Ranatra , both of which genera are 
represented by a single British species, the N. cimicoides , 
which has very thick pincer-like fore-legs, and is an 
excellent swimmer; and the R. linearis , a long stick¬ 
like cylindrical creature, 18 lines long exclusive of its 
spiracular tail filaments, which are alone 15 lines long; 
it has long nipper-like feet with habits similar to the 
Abater-Scorpion. 
The second section (Aurocorisa) contains several 
families, but I shall only take a short notice of the 
Ilydrometridce or Abater-Measurers, Cimicidoe , the Bed¬ 
bug family, the Reduviidas , and the Lygceidce . Every 
one who has wandered by a stream or river, or loitered 
on the bank of a pool, must be acquainted with the 
forms of certain long and lanky creatures of a dark 
colour with slender legs, with which they skim or skate 
along the surface of the w T ater. These are Abater- 
Measurers (. Hydrometrce ), a very appropriate term, for 
they take four or five quick steps and then stop, then 
on again and stop. There are four or five species, of 
which the commonest, perhaps, is Id. Gibbifera and 
II. lacustris ; they are generally about 4A to 5J lines in 
length; they feed on small insects that may happen to 
come in their way, which they catch with their pre¬ 
hensile fore-legs. In many, if not most individuals the 
wings are imperfectly developed, in fact, they are often 
altogether absent—but these apterous individuals are as 
capable of reproduction as the winged. The underside 
of the bodies of the Hydrometra are often clothed with 
a fine coating of plush, which serves to repel the action 
of the water and to facilitate locomotion. A smaller 
