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THE WHIRLIGIGS. 
In the Water Beetles, the spiracles are set rather high, so as to be covered by the hollowed 
elytra, and to be capable of breathing the air under those organs. When, therefore, the 
Beetle dives, it is in noways distressed for want of air, as it carries a tolerable supply beneath 
the elytra. When, however, that supply is exhausted, the beetle rises to the surface, just 
pushes the ends of the elytra out of the water, takes in a fresh supply of air and again seeks 
its subaquatic haunts. Any one may see in almost any ditch the Great Water Beetle ( Dyticus 
dimidiatus ), ever and anon rising to the surface, poking its tail out of the water, and then 
diving to the bed of the stream. 
Towards evening, this, in common with many other Water Beetles, is, accustomed to leave 
the streams, to spread its wide wings, and to soar into the air. In the early morning it again 
seeks its watery homo, and is accustomed to save time and exertion by closing its wings, and 
dropping like a stone as soon as it perceives the water below. The larva of the Dyticus is a 
(Larva.) (Male.) (Female with egg-sac.) 
GREAT WATER BEETLE. —Dyticus dimidiatus. 
terribly ferocious creature, both in aspect and character. It inhabits the waters, and is a very 
hyena in the terrible grasp and power of its jaws. The perfect insect is quite as voracious, 
and when a number are kept in a single vessel, they are sure to attack and kill each other. 
No one who cares for the animated inhabitants of his aquarium should permit a Dyticus to be 
placed among them, as a fox makes no more havoc in a chicken-roost than a Dyticus in an 
aquarium. 
A smaller species is called Ilybius ater. 
To this group belong the Whirl wig Beetles, or Gyrihldjs, so plentiful 
on the surface of many rivers and ponds, but always choosing a still spot, 
where they are overshadowed by the bank or an overhanging tree, for the 
locality wherein they perform their mazy dance. These insects are very hardy, 
and even on a winter’s day the Whirlwigs may be seen taking advantage of 
the last gleam of sunshine, and wheeling around their complicated maze as 
merrily as if the warm winds of summer were breathing on them. The reader 
will see a magnified specimen in the engraving ; its natural length is signified 
by the line aside. 
The Whirligigs of North America, the country boy will tell, “give milk.” For certain 
they emit a milky liquid when caught, which latter is not easily accomplished, as they dive 
with exceeding celerity, when they adhere for a time by their claws to the bottom. They 
WHIRL WIG BEE- 
TLE.— Gyrinus 
mergus. 
