246 ENTOMOLOGICAL NEWS. [June, '07 



like form, evidently with complex metamorphoses whose nearest 

 allies in the former period were undoubtedly the Perla-like in- 

 sects of that age. 



The Coleoptera also are represented in these strata by the 

 first undoubted fossils. The group has no allies among the 

 ancient insects. The older idea that the Staphylinidse were pos- 

 sibly derived from something- like the Forficulids is based upon 

 the most superficial observations and is now generally recog- 

 nized as untenable. Beetles probably arose as small insects 

 with the habits of the Corrodentia, but with the immense ad- 

 vantage of complex metamorphosis, making possible a better 

 adaptation to their environments. The resemblance between 

 beetle larva and those of the Sialidae is the only positive evi- 

 dence we have as to the phylogeny of this group and a rejection 

 of this would simply leave the group isolated. The three groups 

 which have been considered distinct orders are now uniformly 

 united to form one order. 



In the Jurassic the remaining large groups of insects make 

 their appearance, though none allied to Papilio or Apis appear 

 before the middle of this era. 



The Neuropterous groups are very commonly separated into 

 distinct orders, probably because of the very evident leading of 

 Panorpids and Phryganids toward the higher orders. The 

 Neuroptera are maintained as one order in the scheme here 

 presented, because of the author's conviction that the change 

 from a Perla to a Sialis has not involved anv such fundamental 



j 



changes in structure as marked the differentiation of the beetle, 

 and that in becoming a Panorpa or a Phryganea there was 

 nothing comparable to the formation of the groups of flies or 

 wasps or moths. If, however, other views are held, the result 

 would be simply the separation of this group into two, three, 

 four, five, or more orders, having the relationships indicated on 

 this diagram. 



The Diptera have often been made into two groups by the 

 separation of the fleas, and more rarely into three, and the Tly- 

 menoptera and Lepidoptera have always had the same value. 

 The derivation of the Diptera from a Panorpid-like ancestor 



