Introduction 23 



series above that which it would take frQm a comparison of external 

 characters alone. This is one of the considerations that lead me to place 

 it where I do. Special discussion of Palpicornia and some smaller 

 groups will be found below. 



An Alternative View of Phylogeny 



I have thus far presented the phylogeny as developed by conti- 

 nental authors with but little interpolation of individual opinion. To 

 complete the account of the bearing of their hypotheses upon the 

 classification it seems necessary to point out that they are only fairly 

 supported by part of the known facts and so contradicted by some 

 others that it would be extremely injudicious to subvert an established 

 classification on such theoretical grounds, though some modifications 

 based thereon may be acceptable. 



To my mind, the assumption implied in the phylogeny thus far 

 presented, that of all the families of the protocoleoptera of pretriassic 

 times, none have survived except those that were succeeded by Adephaga 

 and Polyphaga (as defined by phylogenetic authors), is unwarranted. 

 I can conceive of the great groups of flesh-eating Adephaga and plant- 

 eating Phytophaga arising under favorable environment; and of other 

 similar groups responding by increase in genera and species to various 

 environments produced by geological changes, but I must maintain that 

 the utter extinction of all the families of protocoleoptera that existed 

 prior to the origin of such groups is improbable and that it is far more 

 likely that some of the present small families, especially those of discon- 

 nected distribution, represent remnants of families that existed prior 

 to the origin of the Adephaga. 



The consequences of the false assumption may be seen in the failure 

 of the phylogenetic scheme to coincide with the results obtained from 

 study of genitalia, from study of larvae, especially the blattoid forms, 

 from study of digestive system, and other internal parts, all of which 

 have been mentioned above. The remedy may lie in separating from 

 the mass called Polyphaga all the small families with primitive char- 

 acters in the adult and larva, and treating them phylogenetically as 

 more primitive than Adephaga. It is not, however, my purpose to 

 propose a new system of phylogeny, but rather in this paragraph to point 

 out the defects of that already presented as a reason for not following 

 any phylogenetic theory in arranging the sequence of families beyond 



