COLEOPTERA. 
I 3 I 
do not exhibit the slender curved form and sharp dentition met with in the tiger- 
beetles. 
The number of species of Carabidcc 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 Carabidcc 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 
Cicindelidcc, 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 
the genus Notiopliilus , 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; Cctrabus violciceus 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 
Wp 
Elaphrus riparius (enlarged). 
