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in Cryptocercus, the p4 are divided into several bundles: throughout their length in 

 Mantoida and Parcoblatta; only anteriorly in Lamproblatta, Anaplecta, and Blaberus. 

 The posterior insertions take rather different positions: on the lateral anterior margin of 

 tergite 10 TIO {Cryptocercus, fig.l43a,b), or on the anterior margin of the paratergites 10 

 TlOp (Sphodromantis, fig.l; Mantoida, fig. 36, 37; Parcoblatta, fig. 262, 263), or in the 

 membrane median to TlOp (Anaplecta, fig. 200); in this latter case they can be far 

 anteriorly (Lamproblatta, fig. 169, 170; Polyphaga, fig. 109; Blaberus, fig. 294) or 

 extremely far medially (left p4 of Eurycotis, fig. 58; Nahublattella, fig. 235). 

 In Cryptocercus the insertion on tergite 9 and that on tergite 10 take the same relative 

 position (compare fig. 143a and b), and p4 is clearly a dorsal muscle of segment 9. The 

 p4 of the other species are assumed to be the same dorsal muscles, and the posterior 

 insertion is assumed to have undergone a ventromediad and anteriad shift which is 

 variously pronounced in the different species. The homology of these p4 is suggested by 

 the constant position of the anterior insertion and by the following fact: In last-instar 

 nymphs of Eurycotis and Blaberus the posterior p4-insertion is by far more laterally than 

 in the adults; that means, it shifts mediad during late ontogeny. In the various species, the 

 final position of the posterior p4-insertion in the adult might depend on the extent to which 

 the adult character state prevails against the nymphal state. A dorsolateral position (like 

 in Cryptocercus, fig. 143b) is probably a neotenic trait. However, in some species this could 

 also be a primitive feature. 



In Periplaneta americana, whose posterior p4-insertions have a similar ventromedian 

 position as in Eurycotis (compare fig. 58), the innervation of p4 is known (Pipa 1988): It 

 is accomplished by a nerve-branch (the common base of 4Alc and 4Ald in Pipa) which 

 innervates, apart from p4 (359, 360 in Pipa), the various groups of dorsal muscles (M and 

 MDM9 in Pipa). This is consistent with the assumption that even those p4 having their 

 posterior insertions far medially are true, though modified, dorsal muscles. 

 The p5-muscles are dorso ventral muscles of segment 10. Dorsally they always insert on 

 the lateral anterior margin of tergite 10 TIO. Their ventral insertions are on or near the 

 Pv-sclerites {Eurycotis, fig. 58; Lamproblatta, fig. 169; Anaplecta, fig. 200; Nahublattella, 

 fig.235) or, if separate Pv-sclerites are missing, on the anterior margin of the paraprocts 

 Pp {Sphodromantis, fig.l; Polyphaga, fig. 109; Cryptocercus, fig. 143a; Parcoblatta, 

 fig. 262; Blaberus, fig. 293). Hence, the position of the p5-insertions (Pv-sclerites or 

 anterior margin of paraprocts Pp) differs in the same way as in the pl-muscles. The 

 insertions of pi and p5 suggest that in those species without separate Pv-sclerites the Pv- 

 sclerotisations have become incorporated into the anterior part of the paraprocts. (This 

 part of the paraprocts is then labelled Pv in the figures). Moreover, the insertions of pi 

 and p5 (ventral muscles of segment 9, dorsoventral muscles of segment 10) suggest that 

 the Pv-sclerites (or the Pv-parts of the paraprocts) are sternal sclerotisations of abdominal 

 segment 10. However, this question cannot be finally settled here. 



The p6-muscles are dorsoventral muscles of segment 9. The dorsal insertion is always far 

 laterally on tergite 9 T9. The ventral insertion is either close to the line of contact between 

 the lateral margin of the subgenital plate and the paratergite of segment 9 T9p {Eurycotis, 

 fig. 69; Cryptocercus, fig. 146; Lamproblatta, fig. 172; Anaplecta, fig. 203; left muscle of 



