WATER-STRIDERS. 27 
proach of some disturbing object, gliding away in all directions. 
To show at least the form of one of the most peculiar ones, the 
illustration, Fig. 19, of Rheumatobates Riley: Berg has been re- 
produced. 
Fic. 19c.—Rheumatobates rileyi Berg. Male larva, enlarged, with female antenna 
shown at right (Heidemann, del.). After Insect Life, Div. of Entomology, 
Dep. of Agriculture. 
FAMILY HYDROBATIDAE. 
(Water-striders). 
These are well known insects, familiar to all who observe 
things in the water. They are truly aquatic insects, although 
they do not dive, but live upon the surface of quiet waters, upon 
which they rest, or over which they skim very rapidly. Fre- 
quently they congregate in great numbers, but when disturbed 
they move away with amazing swiftness. 
“The family Hydrobatide includes insects built upon an 
elongated pattern, with prominent round eyes, the head inserted 
in the thorax up to the base of the eyes, and curving forward; 
from it the stout rostrum bends back to pass between the fore- 
limbs. Long antenne, of four joints, arise from the prom- 
inences, placed some distance in front of the eyes, and the back 
