248 ENTOMOLOGICAL NEWS. [June, 'l6 



As is indicated in the diagram, the line of descent of the 

 Tettigonidae (which are usually incorrectly termed "Locus- 

 tidae") closely parallels that of the Gryllidae, the more primi- 

 tive members of the two groups being very closely related, 

 although the more highly modified members of the two lines, 

 are quite widely divergent. The Grylloid and Tettigonoid 

 forms comprise the order Orthoptera (in the restricted sense) 

 which occupies a position somewhat intermediate between the 

 Phasmid and the Grylloblattid lines of descent and is also 

 related to the Perlids. A study of the extremely interesting 

 insect Grylloblatta campodciformis Walk., led me to believe 

 that the Gryllids and Tettigonids approach more closely to the 

 Grylloblattid line of descent, while the true Locustids ("Acridi- 

 dae") approach rather more closely to the Phasmid line of 

 descent ; but an examination of an extremely primitive Gryl- 

 loid insect from Thayetmyo, Burmah (which bears a slight 

 resemblance to an Ephemerid!) would indicate that the Gryl- 

 lids also approach the Phasmid line of descent, and such primi- 

 tive Tettigonoid forms as Phasmodes (the Prophytoptera 

 Ent. News, Vol. 26, p. 348), are remarkably Phasmid-like, so 

 that it is doubtless more correct to consider the Grylloid-Tet- 

 tigonoid group as arising from forms intermediate between 

 the Phasmoid insects and the Grylloblattoid insects (which also 

 approach the Phasmid line of descent). 



Certain Phasmoid insects, such as Timema, have retained 

 many characters suggestive of the Perlid group, and many 

 other facts indicate that the Phasmid line ultimately leads 

 back to that of the Perloid insects. The Phasmid line of 

 descent also converges toward that of the Grylloblattids, and 

 at the same time approaches the Mantoid group in some re- 

 spects, although the Mantoid insects have followed a some- 

 what different course of development. In order to show in 

 the diagram, that the Phasmoid line not only leads back to the 

 Perloid line, but also approaches the Mantid line, and is like- 

 wise connected with the Grylloblattoid line by intermediate 

 forms, it was necessary to swing the Phasmoid line around 

 from its position near the Mantoid line, and over the other 



