COLEOPTERA. I35 



family ; two ocelli being present in Homalium arid its allies, and a single ocellus 

 in the genus Phloeobium. The mandibles vary in form according to the habits of 

 the species ; they are usually strong, often sharply curved and pointed at the end, 

 and of a distinctly carnivorous type. Attached to the base and running a little 

 way alongside the inner margin of each mandible, there is to be seen in many 

 species a narrow flexible plate fringed, or not, with hairs at the end. This piece, 

 first made known by Kirby, who called it the prostheca, is rarely met \vith 

 except in the Staphylinidce. The ligula is narrow, and bears distinct para- 

 glossse ; and the outer lobe of the maxilla is never palpiform. The rove-beetles are 

 for the most part carnivorous, and prey upon all kinds of larvae and other insects, 

 as well as upon slugs, snails, and \vorms, but they feed largely on carrion, and to 

 some degree on vegetable matter. Several species live in fungi, some in flowers, 

 others under bark and in rotten wood, while in the case of certain genera, such as 



BRITISH ROVE-BEETLES. 



1, The devil's coach-horse (Ocypus olens) ; 2, Staphylinus pubescens ; 3, Philonthus ceneus ; 4, Oxyperus rufus ; 

 5, Pccderus riparius ; 6, Staphylinus ccesareus. (Nos. 3, 4, and 5, slightly enlarged.) 



Lomechusa and Atemeles, the species are to be sought for in or about ants' nests. 

 Some of these latter species are w T elcome guests, since, like the Aphides, they 

 secrete a liquid which is eagerly swallowed by the ants ; others may possibly act as 

 scavengers. Amongst the species of the genera Spirachtha and Corotoca, which 

 live with the Termites in South America, some are very remarkable from the fact 

 that the females give birth to living young. 



Many of the British species of beetles belong to this family. Every one has 

 seen the devil's coach-horse, that long, black, ugly-looking but useful insect which 

 is to be found under stones and earth, or roving about in gardens, and which when 

 you attempt to stay its progress, by pointing with a stick or finger, stands with 

 threatening jaws and upturned tail as if ready to accept the challenge. This species 

 which, with a few others, is represented in the figure, is scientifically known as 

 Ocypus olens, and is one of the largest of the rove-beetles. Its habit of turning 

 up the tip of the abdomen is not peculiar to it, but is common to nearly all the 

 beetles of the family, which on that account are sometimes called cock-tail beetles. 



We come now to a series of small families, forming the group known as the 

 Clavicornia or Necrophaga. This group, however, rests on no true scientific basis. 



