254 ENTOMOLOGICAL NEWS. [June, 'l6 



scent is the most direct of the developmental lines leading 

 from the ancestors of the Lepismids to those of the winged 

 forms, and even in the adult stages, the Blattids have pre- 

 served many characters common to the ancestors of the Le- 

 pismids and Blattids of today. The Blattid line of development 

 is very closely paralleled by that of the Mantids, and ulti- 

 mately the lines of descent of the Blattids and Perlid.s con- 

 verge, if we trace them back far enough. Indeed, it would 

 appear that those features wherein the most ancient Blattoid 

 forms differ most from their modern representatives, are 

 those in which they approach the closest to the Perloid forms, 

 so that the two lines of descent in all probability sprang from 

 ancestors similar enough to be grouped in a single family, 

 although their modern representatives have followed rather 

 widely divergent lines of development. The Blattid line of 

 development is rather closely approached by that of the 

 Termites ; but the Termite line of descent appears to lead 

 back to that of the Perlids rather than to the Blattid group. 

 The Blattids are enough different from their nearest relatives 

 to be grouped in a distinct order, and were therefore desig- 

 nated as the Palacoptcra in a previous paper (Ent. News, Vol. 

 26, p. 349). 



The foregoing statements may be briefly summed up as fol- 

 lows : The Phylliidae are closely related to the Phasmidae 

 and also to the true Locustidae (usually termed "Acrididae"). 

 The true Locustidae ("Acrididae"), Tettigonidae ("Locusti- 

 dae"), and Gryllidae arose from forms intermediate between 

 the Grylloblattid and Phasmid lines of descent. The Phasmid, 

 Grylloblattid, Forficulid, Embiid and Termitid lines of descent 

 all converge upon that of the Perlidae, although the Forficulid 

 and Embiid groups are somewhat nearer to the Perlidae than 

 are the other groups. The Perlids, as a whole, are the most 

 primitive of the groups thus far mentioned, but are not more 

 primitive than the Blattidae. The Mantid line of development 

 closely parallels that of the Blattid group, and approaches the 

 Perlid line of development near the point at which the Blattid 

 and Perlid lines of descent converge. The ancestors of the 

 forms giving rise to the Blattid and Perlid lines of develop- 



