I20 NATURE STUDY. 



the children to put the Whirligigs in box or row by them- 

 selves and label them Gyrinidae. 



There are two other kinds of beetles which one is sure 

 to find in the water of a pond, and not infrequently in 

 quiet pools in brooks. They are much alike in shape, be- 

 ing elongated, elliptical beetles, with two pairs of legs fit- 

 ted for swimming. They belong to two great families — the 

 Divers and the Scavengers. The Divers are rather more 

 flattened, and their wing-covers are often roughened or 

 furrowed, and sometimes marked with a yellow stripe or 

 band. The Scavengers are shiny black. 



Some of the Divers and Scavengers are the largest of 

 the Water-beetles, and are always looked upon as real 

 prizes by the children. Indeed, the}^ have much about 

 them to interest anyone. The easiest way to distinguish 

 the two families, so far as the larger kinds of Water-bee- 

 tles is concerned, is bj- a sharp spine which extends back 

 between the hind legs of the Scavengers. Their antennae, 

 or "feelers," also, are shaped like a club, with the big- 

 gest end outward, while those of the Divers are threadlike. 



The Divers live upon other insects and even upon small 

 fishes ; the Scavengers eat almost anything, from other in- 

 sects to decaying vegetable matter. The Divers are so- 

 called because they rise to the surface, raise their wing- 

 covers, and gather air beneath them which they can draw 

 upon for breathing while at the bottom of the pond. The 

 vScavengers have a covering of fine hairs beneath the body 

 which holds a quantity of air and gives them a silvery ap- 

 pearance when in the water. In the winter time, when 

 the pond is frozen over, they are much less active than in 

 summer, and need less air. Besides, I suppose there is 

 barely ever a time when there are not air-holes in the ice, 

 at least along the shore, where the rushes and bushes keep 

 the ice melted around them.. 



When the Divers and the Scavengers have been taken 

 home and separated, they should be pinned in different 

 rows or boxes, the Divers being labeled Dytiscidae, and 

 the Scavengers Hydrophilidse. 



