254 



NATURAL HISTORY OF ARTHROPODS. 



ures about two-thirds of an inch to the end of the abdomen, while the respiratory 

 tubes are a little more than one-fourth of an inch in length. It lives beneath stones 

 and rubbish in bayed-out places of our streams on the eastern side of the United 

 States. As no specimens have yet been reported from the region west of the Missis- 

 sippi basin, we are unable to record its distribution beyond the limits named ; but 

 within that region it extends from Albany, N. Y., to eastern Georgia. As far as its 

 habits have been observed, it seems to delight in very muddy spots, and buries or 

 covers itself by the leaves and dead twigs which lodge in the shallow cavities along 

 our inland streams. 



This genus is remarkable for the contracted condition in which the abdominal 

 stigmata are often found to be. Respiration would seem to be effected chiefly 

 through the apical tube, and there are large bladders for holding air, placed directly 

 within the mesothoracic cavity, communicating with the dorsal stigmata by means 

 of tracheal tubes. 



The oriental countries, including Japan and the Philippine Islands, are tenanted by 

 large, oblong species, not much wider behind than in front, which have a distinct tooth, 

 or tubercle, upon the inner angle of the anterior femora, and very long respiratory tubes. 

 Akin to these are the species composing the genus Ranatra. These latter are, how- 

 ever, in strong contrast with all the others in their extremely elongated form and the 

 simplicity of their integument. Here the fore-legs are raptorial, with the tibiae and 

 one-jointed tarsi slender, curved, opposable at tip to the erect tooth which projects 

 from the lower side of the femora. The other pairs of legs are exceedingly long and 



almost thread-like, with a pair of slender, long, curved nails 

 at the tip of the tarsi. They have a short head, with a corre- 

 spondingly short but very acute rostrum, and the antennae, 

 composed of three variously-shaped joints, are stowed away 

 on each side of the throat. The first joint is very short, the 

 second is longer and protracted transversely, the third is 

 longest, fusiform, curved. The prothorax is about one- 

 half as long as the wing-covers, somewhat cylindrical, but 

 widened at base and a little contracted in the middle. 



Two species inhabit the greater part of the United States, 

 R.fusca and R. quadridentata. The former is a fuscous 

 grayish insect, more slender and generally smaller than any 

 other American form now known, which inhabits ponds and 

 the quiet parts of streams in New England, the Atlantic 

 States, and the gulf region as far west as central Texas. It 

 delights to live among the muck and rubbish of shallow fresh 

 water, and may sometimes be seen lodged on the leaves and 

 stems of the pond-weed leaves in basins of cold spring 

 water. During the warm summer weather it may be seen at 

 times resting on the bottom, stilted on its long legs, with the 

 respiratory tube projecting upwards, just a little outside of 

 the surface of the water. At such times it rests motion- 

 less for intervals of an hour or more, but at other times it 

 searches for the eggs of pond fish, which it destroys by drawing out their contents, 

 and it occasionally attacks the young fish of other kinds, grasping them with its curved 

 fore-claws and sucking their blood. 



FIG. ZVl. Ranatra fusca. 



