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 imder 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 ofi", 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 antennae fold 

 back on the upperside of the head, where there is a depression 

 to receive them. In the other Phasmidae 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. Soc. xxiv. p. 135, 



19* 



