104 THE HELOCERA. 



lected for a time^ it is sometimes found to consist 

 exclusively of pins. 



The Byrrhi evidently approach the Dermestideous 

 Necrophaga in their structure, and in some respects 

 in their habits ; indeed by some entomologists they 

 are arranged with these in a single group. The 

 remainder of the Helocera present more resemblance 

 to the true Carrion Beetles ; they are usually flattened 

 above, and of a square form and shining black colour ; 

 the head is quite free, and armed with mandibles of 

 considerable size; the antennae are geniculated, that 

 is to say, the first joint is much elongated, and the 

 second is inserted upon one side of its apex, so that 

 the organ forms as it were a knee at this point, and 

 the three last joints form a large solid club; the 

 elytra leave a considerable portion of the abdomen 

 uncovered, but the dorsal surface of this is nearly 

 perpendicular, so that the elytra really attain almost 

 to the hinder extremity of the body. Like the 

 Byrrhi, these insects draw all their limbs close up to 

 the body when threatened with danger, and lie in a 

 death-like state until they suppose the time of peril 

 to have passed away; from this circumstance they 

 have received the name of Mimic-Beetles, and the 

 name Hister applied to the principal genus is evidently 

 derived from the Latin word histrio, a mimic or actor. 

 All our British species are of small size, rarely 

 exceeding one-third of an inch in length. They feed 

 upon animal and vegetable substances in a state of 

 decomposition, and several of them may be met with 

 abundantly in dung, especially in spring. Although 

 they are generally of a deep black colour, some (espe- 

 cially the species of the genus Saprinus) exhibit fine 

 metallic tints. A few species {De?idrophihis and 



