124 THE FOOD OF ANIMALS 



is recognized by its extremely slender body and leisurely gait, 

 while the Common Skaters (Gerris paludum) are somewhat 

 broader, and very rapid in their movements, pouncing swiftly 

 upon flies and other insects, which they seize with their fore- 

 legs. The Water- Boatmen (Notonecta glauca and others) are 

 comparatively broad aquatic bugs of predaceous habit, which 

 swim on their backs, using the long hind-legs as sculls. More 

 sluggish and of forbidding appearance are the Water -Scorpions 

 and Long Water- Bugs. The common Water-Scorpion (Nepa 

 cinerea) (fig. 385) is a sombre-looking flattened creature with 

 large grasping front legs, the appearance of which suggests the 

 popular name. There is also a curious bristle-like tail, which has 

 to do with breathing, and will be described elsewhere. The Long 

 Water- Bug (Ranatra linearis\ to use the words of Staveley (in 

 British Insects), " resembles the Nepa in having a small head, two 

 long tails, and extended prehensile fore-legs, but here all family 



likeness ends, for this most curious-looking 

 creature is but a series of thickish lines (as 

 ts name imports). A long linear body 

 with two long thin tails, and four long thin 

 legs, are all we can see except a pair of 

 forceps \i.e. the fore-legs], which would be 

 long and thin too if they were not so 

 crooked. The creature looks cruel and 

 hungry, but where it stows all the prey for 

 which it is so greedy is a problem to be 

 solved. A less aldermanic figure can 

 scarcely be conceived. ..." 



A marine bug- (Halobates) (fig. 307) is 



Fig. 397--A Marine Bug (Halobates] . . & \ , r i 



particularly interesting as being one of the 



very few insects which inhabit the open sea. It has been found 

 skating on the surface, far out of sight of land. 



True Lice are wingless blood-sucking creatures, shown by the 

 nature of their mouth-parts to be degraded forms of the Hemip- 

 tera. The tips of their legs are hooked, so as to give a firm hold 

 on the exterior of their host. 



