3158 



THE JOINTED ANIMALS 



the water. The form of the body is in some {Nepa) broad and flat; in others 

 (Ranatra) elongated. The female of Nepa lays her eggs in chains on aquatic plants, 

 and each egg has seven short processes radiating from one end. The eggs of the 

 Ranatra are laid one by one in notches, which the female makes in the stems of 

 the plant. 



Certain exotic species of this family are remarkable for their great size, attain- 

 ing in the genus Belostoma a length of over four inches. The water boatmen 

 (Notonedidcz) may be recognized by the large broad head without ocelli, and the 



COMMON BRITISH WATER BUGS. 



i. The water boatman (Notonecta glauca); 2. The water scorpion (Nepa cinerea), with (3) its larva and (4) its eggs; 

 5. Naucoris cimicoides; 6. Corixa geoffroyi; 7. Ranatra linearis; 8. Limnobates stagnorum; 9. Pond skater (Gerris 

 paludum], with (10) its eggs and larvae; n. Larva of Velia currens (natural size). 



short thick rostrum. They have long hind-legs fringed with hairs on one side, 

 which they use like oars in swimming. When the insect comes to the surface to 

 breathe, it rests with these long legs, stretched out like a boatman leaning on his 

 sculls. Though the name Notonedidce has reference to their mode of swimming on 

 the back, this habit is not characteristic of all the species. All are predaceous 

 bugs, like all the rest of the same tribe, and are found abundantly in stagnant 

 waters. Two of the common species, Notonecta glauca and Corixa geoffroyi are 

 figured on p. 3158. 



