TRIMEROUS FUNGUS-BEETLES. 179 



these tribes, their separatioD, probably, would never have taken place, 

 since, as we have seen, the number of these joints is subject to much 

 variation in the smaller species of Clavicornes. But a much more im- 

 portant distinctive character is the structrre of the tarsal joints ; being 

 dilated, evenly cushioned beneath, and with the penultimate joint often 

 dee[)ly bilobed, thus allymg them to the Phytophaga, whilst it sepa- 

 rates them from the i>entamerous Clavicornes, which, though thej' usu- 

 ally have the tarsi more or less garnished with hairs, never, we believe, 

 exhibit the dense and even brush of hair-like papilhe which is so char- 

 acteristic of the genuine Tetramera; and in the few instances iu which 

 any dilatation of the tarsi occurs among the Clavicornes, it is small in 

 extent and limited to the anterior feet of the males, being a sexual dis- 

 tinction. It is also worthy of note that the important and rudimental 

 joints in the present tribe are uniformly the penultimate, as iu the tetra- 

 merous section, whilst in the imperfectly developed tarsi of the small 

 pentamera, it is usually the first, or first and second joints that are de 

 ficient. 



The characters of the few known larvae of this tribe do not afford any 

 clear indications of their systematic position ; for whilst the larva first 

 described by Fischer and co[)ied by Westwood, and supposed to be that 

 of Tritoma, strikingly resembles the larvie of the Chrysomelidiie in its 

 thick fleshy and spotted body, the larva of Triplax, figured by the last 

 namt'd author, bears, as he remarks, a strong resemblance to that of the 

 genus Culydiuni, which we have placed iu our aberrant groui) of Sub- 

 clavicornes ; and the larvae of Endomychus have been compared both 

 to th(\se of Sili)ha and Lampyris. Thus it appears that the position ot 

 these faiuilies, separate and remote from the pentamerous Clavicornes, 

 first assigned to them by Latreille, rests upon strong considerations j 

 and we may add that Lacordaire, one of the latest and highest author- 

 ities upon the classification of this order, has virtually given his sanc- 

 tion to this arrangement. For though his work had not reached the 

 trimerous section, at the time of his death, it is evident,' from his not 

 including them iu the pentamerous series, that he had reserved them 

 for this i)osition. 



It is worthy of remark that the dilated and cushioned tarsi of these 

 insects would seem to indicate a decided diversity of habit as compared 

 with other fungus beetles which have simple tarsi. The most obvious 

 explanation is that this structure of the feet enables them to adhere to 

 the smooth surface of the boleti upon which they deposit their eggs and 

 in which their larv£e reside, whilst those beetles which subsist mostly 

 upon the fungi which grow beneath the bark of decaying trees, require 

 no such provision. 



