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Annals Entomological Society of America [Vol. X, 



various branches is but very roughly indicative of a relative 

 time displacement. The lateral arrangement of the genera 

 is intended to indicate the superficial relationship of the present 

 day genera. The sub-families Pyrophorinae and Elaterinse 

 evidently branched off in the quite remote past. 



The paleontological record has recently been carefully 

 studied by Professor Wickham,* who has presented a most 

 excellent review of our knowledge of the fossils of these insects. 



Fig. 10. Schematic Phyletic Arrangement of the Elateridae. Solid lines indicate 

 known geologic time that genera were extent. Dotted lines are 

 hypothetical. 



Fossils having a decided Elaterid habitus are found at the base 

 of the Mesozoic era in the Triassic rocks, these specimens, 

 recorded by Handlirsch, bear no character, however, which 

 can definitely place them in this family. Similar fossils are 

 also found in the Liassic. The Jurassic chalks bear fossil 

 insects which are decidedly elateriform, but the placing of 



* Bull. Mus. Comp. Zool. LX, No. 12, p. 493-527, 1916. 



