462 THE WATER BEETLES. 



tive dimensions may be readily seen by comparing the Manticora with the Cicindela, 

 both being drawn of the natural size, and the Cicindela being rather a large species. 

 At the left-hand upper corner is shown a species belonging to the same family, which is 

 remarkable for its very great comparative length and the globular centre of its thorax. 



A VERY large and important family of Beetles, the Carabidse, now comes before us, which 

 is represented in England by very many species, the common Ground Beetles being familiar 

 examples. The celebrated BOMBARDIER BEETLE (Brachinus crepitans) belongs to this family. 

 This little beetle is plentifully found in many places, though it seems to be rather local, 

 the banks of the Thames being one of its favourite resorts. When this beetle is handled, 

 a sharpish explosion is heard, and on looking at the creature, a tiny wreath of bluish 

 vapour is seen to issue from the body. This vapour has a very pungent odour, and when 

 discharged against the skin, leaves a yellow mark like that produced by nitric acid. 

 Originally, it is a liquid, secreted by certain glands, but as soon as it come in contact with 

 the atmosphere it becomes suddenly volatilized, thereby producing the explosion and 

 causing the smoke-like vapour to arise. The insect can fire off its miniature artillery 

 seven or eight times in succession. Even after the death of the insect, the explosion can 

 be produced by pressure. 



One species of this genus, Lebia crux-minor, is given in the illustration. It is one of 

 the British beetles, and notable for the cross-like mark from which it derives its name. 

 The largest species belonging to this family are to be found in the exotic genus Anthia, 

 an example of which is given in the illustration. The males are remarkable for the 

 enormous size of the mandibles, and the thorax, or chest, seems to be divided into two 

 parts. Most of the species are found in Southern Africa, Anthia sulcata is a native of 

 Senegal. 



It may be here remarked that the very largest of the Carabidae is a Javanese beetle, 

 named Mo RMOLYCE, which is mostly found under the branches of trees. Mr. Westwood 

 mentions that one of these insects in his possession has attained the extraordinary length 

 of three inches and a half. It is a very odd-looking insect, hardly recognisable as a 

 beetle, and more resembling the mantis than the beetles, having a very long neck, a verj' 

 flat body, elytra wide and flattened like those of the leaf-insect, and a thorax also flat and 

 deeply toothed at the edges. 



Passing by the group of Carabidae known as the Scaritidse, a sub-family of beetles 

 which are mostly found under stones or in holes near the sea-shore, we come to the 

 Harpalides, of which the Harpalus caspicus is our present example. They are mostly 

 rather small, and seldom bright coloured, with the exception of a few species, such as the 

 well known SUN BEETLES, which are so familiar to us as they run actively over gravel 

 walks or roads as if enjoying the blazing sunbeams. It is worthy of notice that the dark 

 coloured species seldom voluntarily show themselves by day. The species of this sub- 

 family are extremely numerous, and it is no easy matter to distinguish with certainty 

 between them. One very remarkable insect, belonging to the genus Blemus, inhabits the 

 sea-shore, and resides under stones just above low-water mark, and in situations which are 

 only left bare at very low tides. How the creature contrives to exist under such 

 apparently adverse conditions is something of a mystery. 



WE now come to the large group of WATER BEETLES, which are divided into several 

 families. The fresh waters of our rivers, ponds, and lakes are very populous with the 

 Water Beetles, which may be seen by thousands on a summer day, swimming, diving, 

 rising to the surface, and evidently enjoying life to the utmost. 



In order to enable them to perform the various movements which are necessary for 

 their aquatic existence, their hind legs are developed into oars with flattened blades and 

 stiff hairy fringes, and the mode of respiration is slightly altered in order to accommodate 

 itself to the surrounding conditions. It has been already mentioned that in all insects 

 the respiration is conducted through a series of apertures set along the sides, and 

 technically called spiracles. 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 



