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 Dytiscidae. — 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 amtogst fungi. Many of them 

 live in ants' nests. Some tropical species of this family are 

 viviparous. 



Family Scaeabeidae or Lamellicoenia. — 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 Elateeidae. — 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 



