18 WATER-SCORPIONS. 
There are two distinct types in this family, both of which 
are illustrated. In one case (Nepa),-the body is long-oval, flat 
and thin; in the other (Ranatra), it is almost linear and cylin- 
drical. The color is pale brownish, so’ that the carnivorous in- 
sects, well hidden among plants and under flat stones, are not 
readily seen. They disguise themselves still more by being 
covered with mud, and by remaining motionless for a long time, 
Fic. 12.—Ranatra fusca P. B. Original. 
so that they do not look at all like animate beings, and thus are 
not detected by their unsuspecting victims, small insects and 
fish. | 
Prof. Uhler writes of the common Ranatra fusca, P. B., 
Fig. 12: “during the warm summer weather it may be seen 
at times resting at the bottom, stilted on its long legs, with the 
