HYDROPHILIDAE, SILPHIDAE, AND STAPHYLINIDAE 99 



in the cambium layer, which was full of sap, upon which it appeared to 

 be feeding. The tree was visited on the i_|.th and i5th, and portions of 

 the bark stripped off, but the insect was not observed in it before the 

 i6th. It had apparently been attracted to the tree by the presence of 

 the oozing sap. 



Family SILPHIDAE. 



Present investigation has not shown this family of beetles to be of 

 importance in the forest. It is chiefly of interest owing to the habit of 

 some members termed " burying " beetles. These insects bury the bodies 

 of small mammals by removing the soil below the bodies so as to cause them 

 to sink into the ground ; the beetles then feed and oviposit in the decom- 

 posing mass, in which their grubs are also reared. This habit has not yet 

 been observed in the case of the Indian forest species, whose life histories 

 are little known. 



The beetles of the family vary in shape and appearance, and 

 may be recognized by having the conical-shaped coxae of the front legs 

 placed close together, the antennae being usually clubbed. They are 

 supposed to be similar in habits to the Staphylinidae, and some may be 

 predaceous. 



A common Indian species is Silpha tetraspilota, a squarish, flat beetle, 

 with a broad prothorax, and broad elytra marked with a few prominent 

 longitudinal ridges. 



Family STAPHYLINIDAE. 



(Rove Beetles.} 



The beetles are easily recognized by the short truncate elytra which 

 only cover the base of the abdomen, and leave exposed this latter, which is 

 more or less long and flexible. The under-wings are folded up and tucked 

 away under these short elytra. The shape varies from elongate and narrow 

 to oval or elongate-oval forms, shining-black or brown or dull yellow-brown 

 in colour. The elongate forms have a superficial resemblance to earwigs 

 (Forficulidae), from which they must be distinguished. The legs ;uv short. 

 and have a tarsus with a variable number of joints. The beetles run 

 rapidly, and have the power of curling up tin- abdominal segments over the 

 back. The mouth is usually provided with stout mandibles, which are 

 often specially prominent in the larval forms which live under the bark ot 

 trees. In other respects the larvae often resemble in form the beetles, save 

 that the wings are absent. 



The beetles and larvae of the forest forms of this family are in many 

 cases predaceous, feeding upon bark- and wood-boring insects, or on species 



<; 2 



