464 



THE WHIRLWIG BEETLES. 



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 marginalis), ever and anon rising 

 to the surface, poking its tail out of the water, and then diving to the bed of the scream. 

 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 home, 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. Sometimes, 

 however, it is diref ully disappointed, mistaking the glitter of glass, such as the sashes of 



cucumber frames, the tops of 

 green-houses, and similar ob- 

 jects, for the water into which 

 it is accustomed to plunge, and 

 in consequence receive no 

 small shock when it comes in 

 contact with the hard glass. 

 Even when kept in an aqua- 

 rium, the Water Beetles are 

 apt to act in this manner, and 

 to leave their residence after 

 dark. The larva of the Dyticus 

 is a 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 the chicken roost than a Dyticus in an 

 aquarium. 



The courage and ferocity of the creature are so great that it will attack insects much 

 larger than itself, and not even the fish can escape the jaws of this insatiable devourer. 

 Before the character of the Dyticus was as generally known as is now the case, a gentle- 

 man had put a pair of these Beetles into a vessel of water, thinking that they would be 

 sure to agree and permit him to watch their habits. Next morning, however, when he 

 came to inspect his protege's, he was shocked and startled to find that the male was dead 

 and already half eaten by his disconsolate widow. 



The male of the Great Water Beetle, in common with other species, is specially no- 

 table for the singular development of the fore-legs, the tarsi of which are developed into 

 a most extraordinary apparatus caused by the dilation of the three first joints, which are 

 flattened so as to form a nearly circular disc, covered on its under surface with a mul- 

 titude of wonderfully constructed suckers, one being very large, another about half its 

 size, and the others very small, and set on pear-shaped footstalks. This structure may 

 be seen on reference to the illustration. This forms a beautiful object for the micro- 

 scope, but requires some care in its preparation, as the air contained in the suckers re- 

 fuses to permit the Canada balsam to enter, and unless it be wholly expelled, a series 

 of unsightly black blots is the result. 



The larger specimen in the engraving is the Dyticus dimidiatus, and the smaller is the 

 Ilybius ater, both British species. 



To this group belong the WHIRLWIG BEETLES or GYRINID^, so plentiful on the surface 



WATER BEETLES. 

 Hyblus ater. Cytlcus dimidiatus. 



