378 INSECTA. 



of their mandibles against the wood they inhabit, and mutually answer the 

 signal. Such is the cause of that noise, resembling the accelerated tick of a 

 watch* which is so often heard, and which is super stitiously called the death- 

 watch. 



A. tesselatum, Fab. Three lines in length; a dead dusky brown, with 

 yellowish spots formed by hairs; thorax smooth? elytra not striated. 



JH. pertinax. Blackish ; thorax with a yellowish spot at each posterior 

 angle, and near the middle of its base a compressed eminence divided an- 

 teriorly by a depression; elytra with punctured stria. According to De 

 Geer, it will permit itself to be roasted to death by a slow fire, rather than 

 exhibit the least sign of life when it is seized. 



There are other species. 



The third and last section of the Serricornes, forming also a last 

 tribe, that of the XYLOTROGI, is distinguished from the two preced- 

 ing ones, as we have already stated, by the entire freedom of the 

 head; and consists of the genus 



LYMEXYLON, Fab. 

 Now consisting of Jlirudocerus, Hyleccetus, Lymexylon, Cupesm&Rhysodes, 



FAMILY IV. 

 CLAVICORNES(l). 



In the fourth family of the pentamerous Coleoptera, as in the third r 

 we find four palpi, and elytra covering the superior surface of the 

 abdomen y or its greater portion; but it differs in the antennae, which 

 are almost always thicker at the extremity, that even frequently 

 forms a perfoliaceous or solid club; they are longer than the maxil- 

 lary palpi, and their base is exposed, or barely covered. The legs 

 are not natatory, and the joints of the tarsi, at least those of the- 

 posterior ones, are usually entire. 



In their larva state, at least, they feed on animal matters- 

 We will divide this family into two sections: the common charac- 

 ters of the first of which are, antennae always composed of eleven- 

 joints, longer than the head, not forming from the third a fusiform 

 or nearly cylindrical club, and their second joint not dilated in the 



(1) Club-horned. 



