Mr. A. Murray on the Habits of the Prisopi. 267 
swimming by means of its wings. At first I could hardly believe 
my eyes; but having found several specimens, and shown them 
to,some of my friends, there can be no doubt about the fact”’*. 
For an account of the structure and economy of this wonderful 
creature, as well as of another similar species found at the same 
time, which, although living under water, does not use its wings, 
but its legs, for swimming, I must refer the reader to Mr. Lub- 
bock’s paper. I shall only observe that, although the wings in 
both are largely ciliated or fringed with hair, they are not more 
so than the wings of their terrestrial allies. As Mr. Lubbock 
says, “There is nothing in their structure to suggest the idea 
that they are aquatic.” 
Not so with our species when it is fairly examined with 
reference to its supposed habits and means of carrying them 
out. 
The whole underside, even the head, is hollowed out like the 
half of a reed. The surface of that side is flexible, smooth, and 
finely polished. The margins are thinned off, and the segments 
of the abdomen, where not fitted to the posterior legs, are pro- 
vided with flaps or quasi claspers. All the legs fit most beauti- 
fully and closely: to the side of the abdomen. Their outer 
margin is dentate and provided with a thick fringe of hair, 
which, like the feathers of a duck, repels water. Moreover at 
the knee-joint, where there is unavoidably an opening or unpro- 
tected space, it is provided with a flap or side knee-pan—a 
provision which occurs in no other insect with which I am ac- 
quainted. This flap hangs down, filling up the opening, and is 
furnished, like the rest of the outer margins of the leg and body, 
with a supply of hair impervious to water. The posture of the 
animal in the water is, fastened to the upper surface of a stone, 
and with its head turned up stream in opposition to the current. 
It sits with its fore legs extended forwards in front of the head, 
and the inner side of the thighs is hollowed out exactly to fit 
the sides of the head, and the thigh itself is bent down so as to 
form the continuation of the sides of the long cup or saucer 
which the underside of the animal represents. The antenne fold 
back on the upperside of the head, where there is a depression 
to receive them. In the other Phasmide the tegmina or upper 
wing-cases are usually short, narrow, and coriaceous, and appa- 
rently not fitted for much use. - Here they are as long as the 
body, so as to cover the whole of the large under wings when 
folded up; they are broad enough to do so; and. the whole are 
only of a semicoriaceous texture, flexible and pergaminous, but 
most so at the base, thinning away at the termination into a 
* Trans. Linn. Soe. xxiv. p. 135. 
Ne is 
