1922] Walker: Structure of Orthopteroid Insects 27 



2. The non-introversible chitinized parameres, whose bases 

 are prolonged cephalad so as to reduce greatly, or even oblit- 

 erate, the roof of the penis, and to occupy a sac of their own, 

 the paramere sac, above the spermatophore sac. 



3. The median division of the ventral lobe into two folds, 

 which are membranous and not pubescent. 



This type may be illustrated by Nediiba carinata Walk., a 

 member of the Decticinas. Posterior, dorsal and lateral views 

 of this species are given in Figs. 29, 30 and 31. 



The pseudosternite is practically absent, only a slight, 

 membranous fold being found in its place. The parameres are 

 large cornua with slender, upcurved apices and stout bases, 

 arising from the walls of the paramere sac, the floor of which 

 is also somewhat chitinized. The paramere sac is comparatively 

 large, the spermatophore sac rather small, at least when con- 

 tracted, and the intervening fold is produced into a pair of 

 short processes which are chitinized ventrally. The ventral 

 lobes are, as usual in this type, wholly membranous. The 

 glandular pouches, opening into the ejaculatory duct at its 

 distal end, are of considerable size. 



Of the same general type are the genitalia of Conocephalus 

 (C. hrevipennis Scudd., Figs. 32, 33). They differ from those of 

 Neduba in the form of the parameres, which are represented by 

 a pair of thick, muscular ridges, arising from the floor and sides 

 of the paramere sac. Along the edge of each ridge is a chitinized 

 bar, which meets its fellow in front but diverges caudad, and 

 curving ecto-dorsad around the end of the ridge, terminates in 

 a short spine. These bars are covered with fine spinules. The 

 ventral lobes are of large size and folded inwards to allow con- 

 siderable expansion of the spermatophore sac. The septum 

 between the paramere sac and the spermatophore sac is simple 

 and unchitinized. The endapophyses are small and con- 

 cealed beneath the penis, but have distinct inward processes. 

 The glandular pouches opening into the ejaculatory duct are 

 of large size and are lined with chitin. 



In the last nymphal instar of Conocephalus (Fig. 34) the 

 penis has a simpler tubular form; the parameres, represented 

 merely by the slightly chitinized, dorso-terminal edges of the 

 orifice, being as yet not at all retracted, so that there is no 

 paramere sac at this stage. The ventral lobes are divided into 

 a larger outer and a smaller inner part. The former is dis- 



