266 



The lateral primary muscles of the left side (s5) are in Blaberus divided into three bundles 

 (s5a - 2 bundles - and s5b in fig.296, 298). s5a and s5b resemble s5a and s5b of 

 Nahublattella in their dorsal insertions: s5b near the anterior margin of L4U' (fig. 250, 

 304); s5a in the left ventral wall of the genital pouch (fig. 240, 298). The ventral insertions 

 are similar, too, but in Blaberus s5a has shifted posteriad (fig. 237, 296). The division of 

 s5 into s5a and s5b is assumedly homologous in Nahublattella and Blaberus. The smaller 

 median muscle of Blaberus, also named s5a, is regarded as a median subdivision of s5a. 

 In Parcoblatta s5 shows a similar and certainly homologous division: The ventral and 

 dorsal insertions of s5b are similar to Blaberus (fig. 265, 267, 296, 298), but the dorsal 

 one is somewhat more posteriorly. The ventral and dorsal insertions of s5a are, as 

 compared with Blaberus, by far more posteriorly. 



The lateral primary muscles of the right side (s6) are in Blaberus present as two bundles 

 (s6a and s6b in fig.296, 298), which are certainly homologous with s6a and s6b of 

 Nahublattella: The dorsal insertions of s6a and s6b take the same positions as in 

 Nahublattella (fig. 240, 298), but s6b has considerably expanded posteriad and now 

 occupies the whole right margin of R3'. As regards the ventral insertions, s6a has, as 

 compared with s6b, shifted far posteriad (like s5a on the left side!). s6 of Parcoblatta 

 shows the same division: The dorsal and ventral insertions of s6b are situated like in 

 Blaberus (fig. 265, 296), and the dorsal insertion likewise occupies the whole right margin 

 of R3. The dorsal and ventral insertions of s6a are, as compared with Blaberus, shifted 

 even farther posteriad (like those of s5a on the left side!). 



Only Parcoblatta and Blaberus have the secondary muscle sl4, which is divided into two 

 bundles in Parcoblatta (sl4a,b). The ventral insertion is closely behind s4 (fig. 265, 296, 

 333k,l). The dorsal insertion is immediately anterior to s6a in Blaberus, but, corresponding 

 to the posteriad shift of s6a, far anterior to s6a in Parcoblatta. 



6.10. The subgenital plate and associated structures 



The subgenital plate is poor in complex structures, and hardly any character is valuable 

 for the phylogenetic analysis in the frame of this study. 



In most species the subgenital plate is asymmetrical, but the degree of asymmetry varies, 

 and various parts are concerned: mainly the styli S9s and the dorsal sclerotisation S9d in 

 Anaplecta (fig. 204); the posterior edge of the plate in Polyphaga (fig. 113, 114); mainly 

 S9d in Sphodromantis (fig. 5), Lamproblatta (fig. 173), Parcoblatta (fig. 265), and Blaberus 

 (fig.296); S9d and the apophyses S9a in Nahublattella (fig.237, 238); the apophyses S9a 

 and the lateral and posterior edges in Mantoida (fig.40); the whole subgenital plate in 

 Metallyticus (fig. 22). Only in Chaeteessa (fig. 30), Eurycotis (fig. 62), Tryonicus (fig. 86), 

 and Cryptocercus (fig. 147) the subgenital plate is symmetrical or nearly so. 

 The apophyses S9a can be very different in their length and distinctness (compare 

 Chaeteessa, fig. 30, and Parcoblatta, fig. 265). Cryptocercus has no apophyses at all 

 (fig. 147). As explained in 3.1., the areas designated as apophyses S9d are not in all species 

 homologous in a strict sense, but short apophyses may be homologous with only the 

 anterior parts of long apophyses. Such relations are obvious if Parcoblatta (fig. 265) is 



