306 



In subgroup 2.2.2. the anterior 114-insertion (114 present in Lamproblatta and Cryptocercus 

 only) is not stabilised by cuticular elements (no swe- or Ive-apodemes, L4n-region highly 

 reduced, no nla-process), and the force acting on the anterior 114-insertion seems to be 

 completely conducted to the subgenital plate by the sl-muscles, which insert immediately 

 anterior to 114 (fig. 157, 158, 184, 185). Also in subgroup 2.2.1. (Tryonicus) neither an 

 swe- nor an Ive-apodeme are present, and the stabihsation by cuticular elements does not 

 seem to be very effective. The mechanism cannot be assessed here since the muscles are 

 not known. 



(O) The shape and sclerotisation of the dca-processes 



dca-processes are restricted to Blattaria (6.1.1.) and are probably ground-plan elements of 

 this taxon (7.5. (F)). In 7.3. it has been stated that in the Blattarian ground-plan the dca 

 are two cushion-like processes posterior to LI; this statement has to be substantiated. Two 

 membranous cushion-like dca are present in representatives of both of the basic Blattarian 

 subgroups 2.1. {Archiblatta, fig. 54) and 2.2. {Tryonicus angustus, fig. 107, Cryptocercus, 

 fig. 153, Polyphaga, fig. 120). More or less completely sclerotised (by LI) dca are also 

 present in both the subgroups 2.1. (Eurycotis, fig. 67) and 2.2. (Tryonicus parvus, fig. 94, 

 Nahublattella, fig.243, 244), but since the Llm-region is a ribbon-like extension in the 

 common ground-plan of Blattaria and Mantodea, and since Llm is expanded posteriad in 

 the species with sclerotised dca-processes (to contribute to this sclerotisation), this is 

 assumed to be a derived state. 



In those species of subgroup 2.2. having two membranous dca, these dca are very similar 

 (fig. 107, 120, 153; these are the members of the subgroups 2.2.1. and 2.2.2. except 

 Ergaula, fig. 105, and Lamproblatta, fig. Ill , but no member of subgroup 2.2.3. is 

 concerned). This pecuUar shape of the dca is assumed to represent the plesiomorphic state 

 within subgroup 2.2. It is not regarded as a synapomorphy of the respective species since 

 this assumption would be inconsistent with the many assumed autapomorphies of the 

 subgroups 2.2.2. and 2.2.2.2. It also cannot be regarded as a synapomorphy of the 

 subgroups 2.2.1. and 2.2.2. (assuming a secondary change in Lamproblatta and, less 

 drastic, in Ergaula) since the shape of the dca in their primitive membranous condition 

 is not assessable in subgroup 2.2.3.: Here the dca are either completely sclerotised 

 {Nahublattella) or missing (remaining species), situations which are both derived. 

 A sclerotised peak 18 in between the dca-processes is present only in Tryonicus angustus 

 and Cryptocercus (fig. 107, 153). To regard this as a synapomorphy (assuming secondary 

 loss in Tryonicus parvus) would be inconsistent with the autapomorphies of subgroup 

 2.2.2. only, but in my view the latter are much more conclusive. The peaks 18 are possibly 

 non-homologous in the two species, or they are again an element of the ground-plan of 

 subgroup 2.2. 



The following discussions under (P) and (Q) + (R) will be concerned with the evolution 

 of three characters for which the polarity is essentially clear, but for which the distribution 

 of the character states within Blattaria is somewhat in conflict with the phylogenetic 

 hypothesis in 7.4.; reversals of apomorphic character states seem to have taken place. 



