270 Annals Entomological Society of America [Vol. XII, 



No Orthopteroid insects are known from the Trias, the 

 insect record of which is very scanty, but true Orthoptera 

 appear in the Lias, belonging to several groups, some of which 

 were silent while others possessed stridulating organs. 



Among the former were the Locustopsidae, which had 

 antennae and an ovipositor of the Tettigoniid type, but wing 

 venation more like that of the Acridoidea, and, like the latter, 

 lacked the stridulatory apparatus in the male tegmina. True 

 Acridoidea are known from the lower Tertiary, so they were 

 probably derived from the Locustopsidae during Cretaceous 

 times. The stridulating forms were in part, at least, true 

 GrylHd^, and Handlirsch concludes that from primitive non- 

 stridulating saltatorial stock two branches arose, one leading 

 to the common ancestors of the Grylhdae and Locustidas 

 (Tettigoniidas) , the other giving rise to the Elcanidae and Locust- 

 opsidce, from which latter the Acridioidea were evolved. He 

 regards the TridactyHdee as probably derivatives of the 

 Elcanidae, some of which, like Tridactylus, possessed pecuHar 

 lobe-like swimming appendages on their hind tibiae. 



Other orders which Handlirsch assigns to the Orthopteran 

 stem are the Dermaptera, " Diploglossata" and Thysanoptera. 

 These groups are unknown below the Tertiary epoch, and this 

 fact has evidently influenced Handlirsch's judgment in his 

 attempt to find suitable ancestors for them in the Orthoptera 

 of the Cretaceous. 



The Ephemerida, Odonata and Plecoptera are considered to 

 have no direct relationship with each other or with other orders 

 except through their Palaeodictyopterous ancestors. 



Since the publication of "Die fossilen Insekten, " two new 

 orders of insects have been discovered which must be considered 

 in any discussion of the phylogeny of the orthopteroid groups. 

 These are the Zoraptera, represented by a single genus, Zoro- 

 typus Silvestri ('IS)^ containing five species, and the Gryllo- 

 blattoidea, likewise represented by one genus, Grylloblatta 

 Walker ('14)^ with a single species (G. campodeiformis) . The 

 former group is compared by its author with the Isoptera and 

 Blattidae and also with the Dermaptera {teste Caudell) and 



2 Silvestri, Fil., Ballet. Lab. Zool. Gen. Agric. Portici, Vol. VII, pp. 193-209, 

 Figs, i-xiii (1913). 



3 Walker, E. M., Can. Ent., Vol. XLVI, pp. 93-99, PL VI (1914). 



