THE BEETLES 3095 



In external structure the carnivorous ground beetles {Carabidce) approach the 

 Cicindelidce, from which they may in most cases be distinguished by their general 

 shape, as well as by the fact that they never exhibit the coloration and markings 

 characteristic of that family. Other points of difference may be seen in their less 

 prominent eyes, in the absence of an articulation in the hook of the maxillae, and in 

 the shape of the mandibles, which, though occasionally long, do not exhibit the 

 slender curved form and sharp dentition met with in the tiger beetles. 



The number of species of Carabidcz 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. While 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 Carabidce 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 among 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 volatilized 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 southeast coasts of England. Among 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 con- 

 fined 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 an}' bright day in 

 the spring or summer, running quickly over garden 

 beds or paths, belong to the genus Notiophilus, and are Elaphrus riparius (enlarged.) 

 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 



