1919] Walker: Structure of Orthopteroid Insects 279 



The superior apophyses are triangular processes of average 

 length. The inferior apophyses curve inwards to meet the 

 inferior intervalvula, which is a large, thin, sagittiform plate. 



The inner valvule are much shorter than the other two 

 pairs and are somewhat widely overlapped by the dorsal 

 valvulse. The rami .are connected across the well-developed 

 intervalvular membrane, a little beyond its middle, by the 

 broad pons valvularum, and are articulated at their bases 

 with the inferior intervalvula behind the inferior apophyses. 

 A portion of the proximal division of the rami is separated 

 from the remainder by a distinct joint. The inner valvulas 

 are apparently supported by a strong chitinous process pro- 

 jecting inwards from the inner surface of the dorsal valvules 

 at point about opposite the posterior limit of the intervalvular 

 membrane. 



The ninth and tenth segments are very short and the tenth 

 tergite, as in all the groups of true Orthoptera, does not form 

 a complete ring, there being a distinct though unchitinized 

 sternal area. The eighth spiracle occupies the pleural mem- 

 brane near the edge of the tergite. 



The cerci are long and taper from a stout base to a slender 

 apex. They are unsegmented, but it may be noted that in 

 males of some species of the closely allied genus Pristoceuth- 

 ophiliis (e. g. P. cercalis Caudell) a few small segments are 

 present at the apices of the cerci. Although this is very 

 probably a caenogenetic character, it is of interest in connection 

 with the other primitive characters met with in the subfamily 

 Rhaphidophorinae. 



As an example of the more specialized type of ovipositor 

 in the Tettigoniidae, we may take Conocephalus fasciatiis De 

 Geer (Figs. 5-8). The ovipositor of this species is straight and 

 sword-shaped, the valvulae being more strongly compressed 

 and closely coherent than in Ceiithophilus. Both dorsal and 

 inner valvulae engage the ventral valvulae by tongue-and-groove 

 joints, the groove in each case running along the edge of the 

 ventral valvulae. The basivalvula is not a distinct plate, 

 but there is a flattened ventral area, which is evidently its 

 equivalent. It is but little chitinized, except in its ventro- 

 lateral edge. The superior intervalvula is larger than in 

 Ceuthophilus and shows a distinct external pocket or invagina- 

 tion and a well-developed median apodeme, extending down- 



