292 Annals Entomological Society of America [Vol. XII, 



ten. Across its middle arise the dorsal and inner valves in the 

 same transverse plane. They are likewise of subcylindrical 

 form, the inner valvulae pointed like the ventral pair, while the 

 dorsal valvulae have well-developed styli upon their apices, 

 a primitive feature, unlike any of the Orthoptera at so late a 

 stage. Judging by the comparative lengths of the valvulae 

 the styli evidently go to form the apices of the dorsal valvulae. 

 There is no trace of the intervalvular membrane, this structure 

 being doubtless formed from the median part of the sternal 

 area, both before and behind the bases of the inner valvulae. 

 The remaining parts of the sternum go to form the valvifers 

 (antero-lateral region) and the broad bases of the dorsal valvulae 

 (postero-lateral region). 



It will be seen that at this stage the ovipositor of Gryllo- 

 blatta is distinctly more primitive in character than that of a 

 Tettigoniid nymph of corresponding stage. This is seen in the 

 form and position of the valvulee and in the presence of styli. 

 In these respects they approach the Blattidas and Mantidae, 

 but the valvulae of the ninth segment have not the terminal 

 position, nor have the dorsal valvulae the broad, flattened form 

 found in these groups. In these respects the Blattids and 

 Mantids are the more primitive and Grylloblatta occupies a 

 position between them and the Tettigoniidae. 



Phasmoidea. 



In this well circumscribed order the ovipositor is of a some- 

 what primitive type and is, at the same time, more or less degen- 

 erate and probably functionless in m.ost cases. It is generally 

 largely concealed by a hood-like subgenital plate, which as in 

 the Orthoptera, is the eighth sternum. The end-segments 

 (8 to 10) show no tendency to become abbreviated and the 

 sternal surface of segment nine retains its primitive horizontal 

 position in the same plane with that of segment ten. The 

 abdominal spiracles are all situated in the pleural m.embrane. 

 The cerci are always relatively short and unsegmented and the 

 anal valves (supra-anal plate and paraprocts), though promi- 

 nent, are not usually large nor densely chitinized. 

 . In the remarkable little Phasmid, Timema calijornica 

 Scudd. (Figs 39, 40), the genitalia appear to be of very primitive 

 form, but they may perhaps be more correctly described as of 



