358 ZOOLOGY 
found amongst grass, or under stones or bark, and as a rule 
roam about at night. Their larvae are found in the same situa- 
tions as the beetles; they are rather broad, and their terminal 
segment is usually provided with two processes. 
Family DyriscipAE.—Water-beetles, sometimes known as 
“ water-tigers.” Some are large oval beetles, others are quite 
minute, their hind limbs are flattened, covered with hairs, and 
adapted for swimming. Their antennae are devoid of any 
sensitive pubescence. ‘The first three joints of the tarsus are 
in the males of the larger forms modified to form a plate-like 
organ. The larvae are very voracious; the mouth is closed, 
but the large pincer-like mandibles are perforated, as in 
Myrmeleo, and the juices of the fish, tadpoles, or other 
aquatic animals which fall into their clutches are sucked up 
through these. The genus Dytiscus is furnished with nine 
pairs of dorsal stigmata, and the beetles breathe by coming to 
the surface of the stagnant water in which they live, expiring 
the used air through the last large pair of stigmata, and tak- 
ing in a new supply under their elytra. 
Family STaPHYLINIDAE.— This group includes the rove- 
beetles and devil’s coach-horses. They have long linear 
bodies, with very short elytra, which leave the five or six 
posterior abdominal segments exposed. They inhabit damp. 
places under stones, manure-heaps, etc., and are often found 
amongst moss or leaves, or amongst fungi. Many of them 
live in ants’ nests. Some tropical species of this family are 
viviparous. 
Family SCARABEIDAE or LAMELLICORNIA.— This family 
contains 700 genera and over 10,000 species of beetles. The 
antennae end in lamelliform plates, such as have been de- 
scribed in Melolontha vulgaris. The body is as a rule thick 
and squarish, the legs often short and fossorial. Many of them 
attain a gigantic size. The larvae are thick fleshy grubs with 
a horny head and the posterior segments swollen out, baggy, 
and incurved. 
Family ELATERIDAE.—Skip-jack beetles with serrated an- 
tennae, and an elongated body rather flatly arched. There is 
an articulation between the pro- and meso-thorax, and when 
the prosternal spine is suddenly brought down into the 
