247 



membranous ventral wall of cbe adjoins (fig. 75, 76). Therefore, in Archiblatta the 

 sclerotisation of cbe is assumed to have developed by an expansion of Rl (Rlt-region, 

 fig.330f). The situation in Eurycotis, with Rl occupying a large part of cbe (fig. 75; 

 compare e.g. fig.99, 160), can be regarded as a primitive stage of such a development. As 

 a result, homology is assumed for the cbe-sclerotisations of Polyphaga and Ergaula 

 (mainly part of R2, X in fig.3301,m), but the cbe-sclerotisation of Archiblatta (mainly part 

 of region Rlt, Y in fig.330f) is not homologous with these. In Archiblatta R2 and the 

 heavier sclerotised dorsal parts of Rl are still distinctly articulated (A6) in the left-dorsal 

 wall of the cbe-invagination (like in Eurycotis, A6 in fig. 75). In Polyphaga and Ergaula 

 this articulation is missing (A6* in fig. 135, 137). 



The shape of R2 is rather variable. Details are shown in the figures. Some peculiar features 

 are: In Parcoblatta (fig. 285) R2 is strongly curved. In Nahublattella R2 bears the 

 conspicuous elements 42 and 43 (fig. 254). Only in Tryonicus and Lamproblatta R2 has 

 an extension posterior to articulation A7 (R2m in fig. 102, 91 and 174, 193), which lies 

 in the rightmost part of the vla-lobe (left complex), and which has in Lamproblatta a close 

 contact with sclerite L7. 



Only Blaberus (fig.311, 312a), Byrsotria, and Nyctibora (fig. 3 19) have a pecuHar sclerite 

 R5 ventral to R2 and A7. The R5 of the three species take exactly the same relative 

 position and are certainly homologous. 



As regards the muscles, r9 is specific to Polyphaga (fig. 141; Ergaula not studied), and 

 r8 is specific to Cryptocercus (fig. 167). Since the posterior insertions take completely 

 different positions, a homology of r8 and r9 is most unlikely. 



6.7.5. Homology relations and character states of the elements in Blattaria II: The 

 tre-tendon 



A tre-tendon is present in Archiblatta (fig.330f), Eurycotis (fig. 74, 330g), Tryonicus 

 (fig.99, 330h), Ergaula (fig.330m), Polyphaga (fig. 134, 3301), and Cryptocercus (fig. 160, 

 330i). Homology is ascertained by the similar position of the tre-base in the anterior dorsal 

 wall of the right phallomere, by a muscle from the right half of the sugenital plate (s8), 

 and by two or three muscles from the dorsal part of the left complex (b4-group; fig. 79, 

 139, 165; muscles not studied in Tryonicus). A muscle from tre to R3 is specific to 

 Cryptocercus (r7 in fig. 165). In Lamproblatta as well as in Anaplecta, Nahublattella, 

 Parcoblatta, Blaberus, and all other Blattelhdae and Blaberidae studied (fig.330n-s) tre, 

 s8, and b4 are missing. 



6.7.6. Homology relations and character states of the elements in Blattaria III: The 

 posterodorsal elements 



The elements discussed here are those dorsal and posterior to the summit of the cbe- 

 invagination and posterior to articulation A3 (compare fig. 32 If, h). In Eurycotis (fig.74- 

 77), for example, this part of the right phallomere is composed of the dorsal wall of cbe, 

 the ridge pva, the dorsal lobe fda, and the ventral tooth pia, and it contains the 

 sclerotisations comprised in Rl: three sclerites RIF, RIG, and RIH. This part of the right 

 phallomere has undergone very complicated evolutionary changes. 



