566 PHILOSOPHY OF ZOOLOGY. 



is entire. In the Pcederidae, the maxillary palpi are nearly 

 the length of the head, as in Poederus, Evcesthetus, and 

 Stenus. In the Oxytelidse, the maxillary palpi are greatly 

 shorter than the head, and the antennae are inserted in front 

 of the eye, as in Oxy telus, Siagonium, Omalium, Piestes, 

 Proteinus and Lesteva. The Aleocharidae differ from the 

 preceding family in the antennae being inserted between 

 the eyes, as in Aleochara. 



2. Head sunk in the thorax as far as the eyes. In the 

 Lomechusidae, the tibiae are entire, as in Lomechusa. In 

 Tachinidae, the tibiae are spinous, as in Tachinus and Ta- 

 chyporus. 



III. PENTAMERA SERRICORNUA. The elytra cover the 

 abdomen; the antennae are usually filiform, or slightly 

 clavate ; and, in the males particularly, serrated, pectinat- 

 ed or plumose. In some of the genera, the thoracic ster- 

 num is advanced in front, under the head, and likewise 

 produced behind. This character is exhibited in those 

 which have the mandibles notched or bifid at their extre- 

 mity, as the Elateridae, a numerous family, in which the 

 natural genera have not yet been established ; and, in those 

 which have entire mandibles, as Buprestidae, having fili- 

 form palpi, and containing the genera Buprestis, Tracys, 

 and Aphanisticus : and the Melasidae, in which the palpi 

 have an"enlarged terminal joint, as Melasis and Cerophy- 

 tum. 



In those having the thoracic sternum destitute of the sin- 

 gular character exhibited by the preceding families, there 

 are several genera in which the mandibles are forked at the 

 apex, or furnished with a tooth beneath. In some, the 

 body and elytra are soft, and the head furnished with a 

 neck, as the Lymoxylonidae, in which the elytra do not 

 embrace the abdomen, as Lymoxylon, Hyleccetus, Atrac- 

 ?tqcerus, and Cupes ; and, in Mastigoidae, in which the ab- 



