144 THE ENTOMOLOGIST. 
of the groove are set with small teeth something like those of a 
saw; the tibia and tarsus slants down into the canaliculated 
femur, the former being roughened. ‘The inner rim on the 
femur where the tarsus comes, when the claw is closed, is raised 
into a small triangular spike, and this would seem to be of 
service as a catch and support for any object which, from its size, 
prevents the tibia and tarsus from fitting down into the groove 
in the femur. I have been much struck with the firmness 
of the grasp on its prey obtained by this insect : on one occasion 
I placed some sticklebacks in the glass with a Ranatra, when one 
of them, about an inch long, was seized (the total length of the 
Ranatra, exclusive of its anal filament, being only eighteen lines), 
and notwithstanding the fish’s repeated and vigorous struggles it 
was held fast. I then took hold of the stickleback and_raised it. 
out of the water: the Ranatra, however, would not let go, and 
was drawn out of the water with the fish. I forcibly separated 
the two, replaced the insect, and, immediately afterwards, the fish ; 
but the latter was again seized in a very short time, and the 
insect continued its meal. The entire absence of fear displayed 
under unusual circumstances by the Ranatra (m common with 
most other water insects) is noteworthy, and on one occasion a 
Ranatra placed, soon after capture, in a vessel of water, within a 
short time commenced feeding. 
The Ranatra never seems to move in search of food; it waits 
patiently, with its fore legs extended, ready to seize any small 
insects coming within its reach ; it is not by any means voracious, 
and a specimen which I have kept for about six months, feeding 
it chiefly on blood-worms, often refuses its food altogether; and, 
even if a blood-worm is presented to-it, so that it is grasped by 
the Ranatra the latter will often release the larva; at other times 
it will readily take the proffered object and continue to suck its 
juices until nothing but the skin of the blood-worm appears ; 
this occupation occupies generally about two hours, and a blood- 
worm a day, or even less, seems to satisfy the requirements of the 
insect. These observations refer to November and December: 
its rapacity may be greater during the warmer months. I have 
seen a Ranatra seize and kill a diving spider (Argyroneta 
aquatica), and I have fed it on Notonecte. It has also seized 
small water-beetles, such as Hyphidrus ovatus and, in this case, it 
turns the beetle round and round, as though to find a weak part, 
