HEMIPTERA. 1 93 



the mesothorax is scale-like, narrowed, rounded, and depressed 

 around the tip. Behind this, the abdomen tapers more or less to- 

 wards the last segment, which is usually armed each side with a 

 tooth-like process. The under side of the body is generally min- 

 utely pubescent and sericeous like satin, and this is sometimes con- 

 tinued along the sides of the thorax. There are commonly two 

 forms of the adult belonging to the same species, the winged and 

 un winged. These do not necessarily co-exist. During soni 

 only the winged forms appear ; while in others, and especially if the 

 spring and summer are cool, the individuals will all be unwinged. 

 Often in sunn}-, protected places, where the food is abundant, all 

 will be winged, while, in exposed localities, the same species will be 

 found unwinged, with, perchance, a single, more vigorous specimen 

 winged. In some parts of the Southern States three forms occur, 

 those before cited and another which has the wing-covers of 

 half length." (UhK 



The water-striders prefer quiet waters, upon which they rest, or 

 ; which they skim rapidly. They jump from the water to capture 

 flies or other insects for food. Fig. 164 represents a species of Hy- 

 grotrccJnts. " These insects stow 

 themselves away under the banks 

 of streams, in the mud beneath 

 es or rubbish, or at the bottom 

 of water under stones and roots of 

 trees when the autumn begins to 

 be cold ; and from thence they 

 .r upon the surface of the 



water as soon as the warm weather F, C . ^- Hye rotr,ck** c**f*rmi t . 

 of spring returns. Soon after this, 



the eggs are attached by a sort of glue to the leaves an 

 of aquatic plants. They are whitish translucent, long, cyliml, 

 more blunt at the end from which the young emerge than at the 

 somewhat tapering, but round, opposite extremity. If the 

 continues to grow \\.irnx i. th-M- eggs mature in about t 



occur in our fauna; these can be separated by the 

 following table : * 



A. Body oval, less than three times as long as broad ; pronotum not 1< 

 i broad. 



This table was prepared by Professor 1 1 ners. 



