233 



Polyphaga and Ergaula 



The homology of hla with hia of Lamproblatta and Cryptocercus is suggested mainly by 

 the similar position of the hla-base posterior to the sl-insertion (fig. 127, 157, 185) and 

 by the similar relations between the hla-base and sclerite L4K (discussion in 6.3.4.). A 

 muscle inserting directly on hla or L3 (114) is missing; the very stout 14 has probably 

 taken over the function of 114 (discussion in 6.3.4.). 



Tryonicus 



The hla-base has the same relative position as in Eurycotis: right-ventral to the L41-region 

 and left-posterior to the nla-process (sclerites L4K and L4N in fig. 97). hla and L3 of the 

 two species are certainly homologous. Tryonicus, however, shows three special features 

 as compared with the species discussed so far: (1) The hla-base is distinctly more 

 posteriorly (compare fig. 87, 97 and 63, 67). However, this is also true of Cryptocercus. 

 (2) The introversible membranous basal part of hla (30 in fig.97) is by far more extensive, 

 and, consequently, hla can be retracted more deeply into the left complex. (3) The basal 

 margin of L3 is connected with L4 (L4K) by the sclerite ribbon L3a (fig.89,98). This last 

 feature is restricted to Tryonicus. 



Anaplecta, Nahublattella, Parcoblatta, and Blaberus 



The two first-mentioned peculiarities of Tryonicus are more pronounced: The hla-base is 

 at the posterior edge of the left complex, and the membranous basal part of hla (30 in 

 fig.210, 242, 269, 300) is so extensive that hla can be retracted into the left complex 

 except for its distalmost part only (fig. 2 10, 242, 269) or even completely (fig. 295a). (These 

 two features have also been investigated and found in all other Blattellidae and Blaberidae 

 hsted in 5.15.). Another feature common to these 4 species is the membranous infolding 

 fpe separating the left part of the left complex (with the hla-base) from the right part 

 (fig. 210, 243, 268, 299). These similarities clearly suggest the homology of hla and L3 

 in the 4 species. With Tryonicus as an intermediate, homology can also be assumed with 

 hla and L3 of the previous species. 



Additionally, the homology of hla and L3 in Anaplecta and Eurycotis is more directly 

 suggested by the anterior insertion of the hla-muscle 114 or 114c,d, which is, in both 

 species, on and near the nla-process (fig. 72, 73, 222). In Nahublattella, Parcoblatta, and 

 Blaberus, however, the anterior insertion of the main muscle of hla (114 or 114a,b in 

 fig. 249, 276, 303) is on L2D' or L2, on top of the Ive-apodeme (L2a-region). In Anaplecta, 

 interestingly enough, the top of the Ive-apodeme and the nla-process are firmly connected 

 with each other (fig. 222). This might suggest that all Blattellidae and Blaberidae have 

 gone through an evolutionary stage showing this connection, and that, at that time, muscle 

 114 has shifted from L4n to L2a. Homology is assumed for all hla-muscles 114. (The shift 

 of 114 will be disscussed in a functional context in 7.5.). 



Of these 4 species only Parcoblatta and Blaberus show the following features: (1) 114 is 

 divided into two bundles (114a and 114b in fig. 276, 303; the division in Eurycotis 

 mentioned above is clearly not homologous with this division). (2) There is a muscle 

 within the membranous basal part 30 of hla (136 in fig.276, 303). (3) The distal part of 



