400 1NSECTA. 



FAMILY II. 



HYDROCORISJE. 



IN our second family of the Hemiptera, the antennae are inserted and 

 concealed under the eyes ; they are shorter than the head, or hardly as long. 



All these insects are aquatic, carnivorous, and seize others with their 

 anterior legs, which flex on themselves and act as pincers. They sting 

 severely. 



Their tarsi present but one or two joints. Their eyes are in general 

 remarkably large. 



NEPA, Linneeus, 



Or the Aquatic Scorpions. This genus is now variously divided. In 



Nepa proper, the anterior tarsi have but one joint, and the four posterior 

 ones two, and where the antennae appear forked. The rostrum is curved 

 beneath ; the coxae of the two anterior legs are short, and their thighs much 

 wider than their other parts. 



Their body is narrow and elongated and almost elliptical. Their abdomen 

 is terminated by two setae which enable them to respire in the oozy and aquatic 

 localities at the bottom of which they live. Their eggs resemble the seed of a 

 plant of an oval figure, crowned with a tuft of hairs. 



The other subgenera of the Nepides are Galgvlus,Naucoris, Belostoma, &c. 



The others Notonectides have their two anterior legs simply curved 

 underneath, with thighs of an ordinary size, and the tarsi pointed and densely 

 ciliated, or similar to those of the posterior ones. Their body is almost cylin- 

 drical or ovoid, and tolerably thick or less depressed than in the preceding 

 insects. Their posterior legs are densely ciliated, resemble oars, and are 

 terminated by two very small and rather indistinct hooks. They swim or row 

 with great swiftness, and frequently while on their back. They compose the 

 genus 



NOTONECTA, Linnceus, 



Which has been divided into CORIXA and NOTONECTA PROPER. 



The second section of the Hemiptera; that of the HOMOPTERA, Lat., is 

 distinguished from the preceding one by the following characters : the rostrum 

 arises from the lowest portion of the head, near the pectus, or even from the 

 interval between the two anterior legs: the elytra almost always tectiform 

 are of the same consistence throughout and semimembranous, sometimes 

 almost similar to the wings. The three segments of the trunk are united en 

 masse, and the first is frequently shorter than the second. 



