COLEOPTERA. 



131 



do not exhibit the slender curved form and sharp dentition met with in the tiger- 

 beetles. 



The number of species of Carabidai at present known can scarcely be less than 

 eleven thousand. This family seems better represented in temperate and colder 

 regions than within the tropics, though species, in more or less abundance, are to 

 be found in every country and island of the world. Whilst the species are almost 

 all predaceous in their habits, we find them under a variety of different forms and 

 with several distinct peculiarities of structure, many of which are to be regarded as 

 special adaptations to the various situations in which the insects hunt for their prey. 



The Carabidw like all other beetles have their enemies, but we never find in 

 this family any of those mimetic and protective disguises that are so commonly 

 met with in certain other groups ; and to escape from their enemies the ground- 

 beetles have mostly to rely upon their speed of foot, or the readiness with which 

 they can take to flight or disappear amongst the herbage. Many species are, how- 

 ever, provided with anal glands that secrete an acrid or stinking liquid which is 

 sometimes ejected with considerable force when the insect is handled. In the 

 " bombardier-beetle " (Brachinus crepitans) and others of the same group, the 

 secretion is volatilised on emission, and issues as a little cloud of smoke, which is 

 accompanied at each discharge by a slight sound ; and when the insect is irritated 

 it repeats the discharge several times in succession, but each time with diminished 

 force. The " bombardier " is a rusty-red species, with dull blue-black elytra, and a 

 narrow head and prothorax, and is pretty common, especially on chalk, in different 

 parts of the south and south-east coasts of England. Amongst those species of 

 the family that in habits and general appearance most closely resemble the 

 Cicindelidce, are the little beetles of the genus Elaphrus. These love to run about 

 in the rays of the sun, not so much in dry places, as on the muddy banks of 

 rivers, on the sands of the seashore, and in other damp situations. They have 

 large prominent eyes, a narrow prothorax, slender legs, and curiously marked 

 elytra. This genus is confined to the Northern Hemisphere. The species which 

 we figure, Elaphrus riparius, like some other beetles of 

 the family, is able to produce a stridulating noise by 

 rubbing the back of its abdomen against a projecting 

 nervure on the under side of the elytra. Those tiny 

 little beetles of a glistening bronzy-black appearance, 

 and with beautifully sculptured elytra, which are to be 

 seen on almost any bright day in the spring or summer, 



running quickly over garden beds or paths, belong to MaphrmHpaHus (enlarged), 

 the genus Notiophilus, and are some of the smallest 



species in the whole family. The genus Carabus, after which the family is 

 named, contains over three hundred species, and is somewhat remarkable in its 

 distribution ; for, with the exception of a small group of species found in Southern 

 Chili, it is restricted in its range to the North Temperate zone. Six or seven 

 species are found in Britain ; Carabus violaceus and C. nemoralis are perhaps the 

 two most frequently met with, being abundant in gardens and fields in almost 

 every part of the country. The first is nearly smooth, of a dull blue-black colour, 

 with purplish borders to the thorax and elytra, and is of about the same size 



