1911 Encyclopædia Britannica/Water-boatman

WATER-BOATMAN, an aquatic hemipterous insect of the family Notonectidae, of which the best known species (Notonecta glauca) is a prominent feature in the pond-life of Great Britain. The technical name, Notonecta, meaning “back-swimmer,” alludes to the habit of the insect of swimming upside down, the body being propelled through the water by powerful strokes of the hind legs, which are fringed with hair and, when at rest, are extended laterally like a pair of sculls in a boat. As is the case with other water-bugs, this insect is predaceous and feeds upon aquatic grubs or worms. The body is richly supplied with long hairs, which serve to entangle bubbles of air for purposes of respiration. The eggs are laid in the stems of water plants.