272 Annals Entomological Society of America [Vol. XII^ 



4. The Dermaptera, Embiidina and Plecoptera are grouped 

 together more closely than is done by Handlirsch, who recog- 

 nized no near affinities among them. 



In other respects Crampton's diagram is not incompatible 

 with Handlirsch's views, so far as it goes, but in regard to the 

 relationship of other orders not included among the "Orthop- 

 teroid" groups, but believed by Handlirsch to be derived from 

 Orthopteroid ancestors (including Blattoid and Protoblattoid 

 derivatives) his views are very different. These, however,, 

 do not concern us here. 



In general Crampton believes that the Plecoptera rather 

 than the Blattoidea most nearly represent among living insects 

 the ancestral stock from which the Orthoptera and Phasmoidea 

 have developed, while Grylloblatta has its closest affinities 

 among the Mantids, Embiids and Dermaptera, and its line 

 of descent is therefore represented as coming from the ancestral 

 stock common to the Panisoptera and Panplecoptera. This 

 view differs somewhat from former views expressed by this same 

 author, in which he placed Grylloblatta in his super-order 

 " Panorthoptera, " with the Orthoptera and Phasmoidea. The 

 position of this important annectant form will be further 

 discussed at a later stage. 



THE TERMINAL ABDOMINAL STRUCTURES. 



Two papers by Crampton ('17 and '18)^ have recently 

 appeared, in which these structures in the more primitive 

 orders are discussed from the comparative standpoint. In 

 the earlier paper, which deals with the female, the author 

 states that "the neck and cervical structures furnish far more 

 definite characters for grouping these insects than the terminal 

 abdominal structures of the female do," and in another paper 

 already cited ('19, p. 64), he emphasizes the phylogenetic 

 importance of the former structures on account of their being 

 remarkably constant within an order or superorder and less 

 subject to such variations as depend upon changes of function. 

 While admitting the general truth of this statement, it should 

 be kept in mind that such characters as were present in the 

 common ancestors of all insects may be inherited by some 6i 



8 Crampton, G. C, Jour. N. Y. Ent. vSoc, Vol. XXV, No. 4, Pis. XVI, XVII 

 (1917); Bull. Brooklyn Ent. See, Vol. XIII, pp. 49-68, Pis. 2-7 (1918). 



