28 Marvels of the Universe 
Photo by] [J. J. Ward, FES. 
FOOT OF HYDROMETRA. 
From one of the walking legs. 
Photo by) [J. J. Ward, FES. 
FORE-FOOT OF HYDROMETRA. 
Modified for holding prey. 
position of the first pair of legs, which are attached just 
below the prominent eyes. The entire insect reminds one 
very forcibly of the Stick Insects, much more so than 
Hydrometra does because of the superior size of Ranatra. 
The fore-part of the creature, again, suggests relationship 
with the Mantis, for the first pair of legs end in sickle- 
shaped joints which fold down like the blade of a pruning- 
knife into a slit in the next joint. At one side of this 
sheath is a strong, sharp spine, serving to hold more 
securely any unfortunate insect imprisoned by the closed 
sickle. The hinging of these leg-joints enables such prey 
to be brought against the point of the beak, where its 
juices may be sucked. 
The two long bristles that constitute Ranatra’s tail are 
hollowed along their inner faces so that when they are 
brought together they constitute a tube connecting with 
the respiratory system of the insect. Ranatra can skim 
along the surface like the Skaters, but it will usually be 
found clinging to the weeds in an almost inverted position 
with the tip of its tail tube just out of the water. In this 
position it can remain for an unlimited period, for the 
whole of its air-supply can be obtained through this tube. 
Ranatra has two pairs of long and serviceable wings, but 
from the very neat way in which they are folded and 
packed upon the back, they are not at all noticeable. In 
the ordinary way Ranatra is an inconspicuous, monotonously 
mud-coloured creature ; but if we have the rare fortune to 
see it with wings expanded for flight, we shall be astonished 
to find that under the wings the back proper is coloured 
bright red. 
The Water Scorpion is a sluggish creature closely allied 
to Ranatra, and though as dissimilar in general appearance 
as possible, the fore-legs are developed in much the same 
manner and with the same purpose in view. It has also 
the tail bristles ; but there all external resemblance ends. 
The mud-coloured body is broad, but exceedingly thin. 
Under the wings the broad back is coloured red. The 
name Water Scorpion is not a good one, for the fore-limbs 
of the scorpion are pincers like those of the crabs, whilst 
these are more akin to those of Mantis. 
One other of these Water Bugs must be mentioned. 
This is the Boatman—usually pleonastically styled Water 
Boatman. When seen at the surface he appears to be a 
rather lazy boatman, for his oars, though ready for action, 
are still. It will be noted that he is back downwards with 
the head below the surface and the tail just above. His 
great eyes enable him to see above and below at the same 
time, and if you make a movement he at once brings his 
oar-like hind legs into play and takes a rapid inclined 
