NOTE ON THE HABITS OF RANATRA LINEARIS. 148 
observations during November) I find that the intervals between 
each inspiration vary from a few minutes to as long a time as 
fifty-six or sixty minutes, the average time being something over 
half-an-hour. The usual position is with the head down- 
wards, the body being held in a slanting or almost vertical 
position. Occasionally the body is carried horizontally, but I do 
not remember ever to have seen a Ranatra resting with its head 
uppermost. 
The movements to the surface are usually effected by the 
insect crawling slowly backwards, directing its motion upwards 
by means of its long legs, with which it contrives to grasp the 
aquatic plants. It will, however, occasionally let go its support 
and float to the surface, by the lightness of its body, but this is 
commonly only done when the tail has become obstructed by the 
weeds with which it is surrounded. 
Notwithstanding its slight specific gravity and the form of the 
legs, which are ill adapted for such progress, the Ranatra can 
swim downwards through the water, but only slowly and with 
apparent difficulty, moving its second and third pair of legs in 
unison; when the second pair are moved forward the hind legs 
are projected backwards: but although the tibie of the middle 
and posterior legs are fringed with two rows of short hairs, these 
members seem to offer a good deal of resistance to the water. 
In swimming the fore legs are of little or no assistance, being 
only used occasionally to grasp objects within the reach of the 
long claw-lke tibiz and tarsi; indeed the purpose served by the 
fore legs seems to be to catch and hold prey, and the claws are 
sometimes employed as combs to remove any impurities about 
the head and neck; but as predatory organs they are most 
effective. Their action in seizing an insect is quick and decisive ; 
indeed it is only in this act and in warding off the approach of 
an object of alarm with these same members that anything like 
celerity of movement is to be observed in Ranatra linearis, 
except, perhaps, in flight, which I have not witnessed. When 
taken out of water and placed on any rough substance the 
Ranatra walks slowly and somewhat awkwardly, using the second 
and third pairs of legs in pairs as in swimming, carrying the body 
high from the surface over which the insect is progressing. The 
fore legs are admirably adapted for holding small insects. The 
flattened femur is grooved along one edge and the raised margins 
