THE ABERRANT FAMILIES. 241 



attempt has yet been made towards determining their 

 circular arrangement. The LUCANID^, or stag beetles, 

 evidently follow next in the series, from which they 

 are to be distinguished by several characters: the 

 tarsi are invariably five-jointed,, of that structure, 

 developed in a greater or less degree, which belongs 

 to the CetoniadcB: the antennae are of the lamelliform 

 structure, but are more developed than in the two 

 former families, that is, in regard to their length, 

 and the acute angle which distinguishes the typical 

 genera, of which the common stag beetle of Europe is a 

 familiar example : the tarsi are particularly lengthened 

 in the types, but very short in the aberrant genera. 

 The whole appear to be herbivorous or lignivorous 

 that is to say, feeding on vegetable substances either 

 in a living or decayed state. Several genera may be 

 safely included in this family, however, which depart 

 very considerably from most of these characters. Their 

 large exserted jaws, and general affinity to others of 

 a more decided character, fully justify us in bringing 

 them in here. The excessive developement of the 

 jaws, indeed, constitute the most typical, or, at least, 

 the most obvious, character of the Lucanidce ; and 

 yet, in the aberrant groups, these organs are not very 

 prominent. The greater part seem to be naturally ar- 

 ranged in the following sub-families : The Lucanince 

 and the Lamprlmince are obviously the two typical; 

 while the genera Hister, Ptinus, and probably that of 

 Byrrhus, seem to lay the foundation of the three aber- 

 rant sub-families : around each of these may be as- 

 sembled several other modern genera of minute ligni- 

 vorous insects, now scattered as small families, in our 

 systems, under different heads. However this may be, 

 it is perfectly clear that, in the Lucanince, we have that 

 point of junction between the typical pentamerous in- 

 sects of this family, and those which, by their frequently 

 dilated tarsi, become analogous, and pass into the Tetra- 

 mera. The Lucanince, also, are highly interesting in 

 another point of view : they form, beyond doubt, the 



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