225 



anterior extension to the right on L4K of Tryoniciis) are strongly reduced. Probably as 



a consequence, the nla-process is missing. 

 Thus, L4K of Cn'ptocerciis is composed of anterior parts of L41 (with the insertions of 

 12 and 14) and a highly reduced L4n (with part of the insertion area of 114). L4N of 

 Cryptocercus is made of the posterior part of the L41-region (with the reduced pda- 

 sclerotisation) and of L4d. The distribution of all elements present is the same as in L4K 

 and L4N of Anaplecta and Tiyonicus, and homology can be assumed for L4K, for L4N, 

 and for the dividing line between them (through L41). The reduction of the L4n-region 

 and the loss of the nla-process are derived features of Cryptocercus. The anteroventral 

 part of L41 has also been lost in Anaplecta. 



L4K of Lamproblatta (fig. 177, 178) resembles L4K of Cryptocercus (fig. 150, 151): 



- The sclerites take the same position dorsal to the base of the hla-hook. 



- A process nla on or near L4K is missing. 



Anterior to L4K in Lamproblatta or on and anterior to L4K in Cryptocercus there insert 

 some muscles having the same course, and the insertions on or near L4K show the same 

 positions relative to each other: 



- A muscle to the subgenital plate (si in fig. 185; left part of sl+3 in fig. 157). 



- A muscle to sclerite L3 on the hla-hook (114 in fig. 184, 157). The 114-insertion is partly 

 on L4K in Cryptocercus but completely on membrane in Lamproblatta. 



- A muscle to the pne-pouch (12 in fig. 184, 156). The 12-insertion is on L4K in 

 Cryptocercus but on the membrane anterior to L4K in Lamproblatta. 



Therefore, L4K of Lamproblatta and Cryptocercus are assumed to be homologous and to 

 have the same composition: anterior part of L41, vestiges of L4n. However, since in 

 Lamproblatta the insertions of 12, 114, and si are exclusively on membrane and muscle 

 14 has been lost (compare fig. 155), the muscles do not yield any direct evidence for the 

 presence of the regions L41 and L4n and for the distribution of L41 and L4n within sclerite 

 L4K. The distribution can only be deduced from a comparison with Ctyptocercus, as it 

 is done in fig.325h,i. That the 114-insertion is completely on membrane could be 

 interpreted as a further reduction of the L4n-region as compared with Cryptocercus. That 

 the 12-insertion is anterior to L4K (not on L4K as in Cryptocercus) is inteipreted as a 

 shift of this insertion to the anterior, not as a reduction of the respective L41-sclerotisation 

 (comparison with Polyphaga, see below). 



L4K of Polyphaga is situated not in the dorsal but in the posteroventral part of the hla- 

 base (fig. 122-124; compare fig. 151, 178). It is assumed to be homologous with L4K of 

 Lamproblatta and Cryptocercus and to have shifted and rotated (clockwise as seen from 

 the left) ventrad around the posterior part of the hla-base. This is suggested by the 

 following features: 



- In Polyphaga and Lamproblatta L4K is broadly horseshoe-shaped and curves into the 

 base of the hla-hook. (According to the assumed shift and rotation in Polyphaga - the 

 latter is almost 180° - the orientation of the sclerite is in Lamproblatta and Polyphaga 

 opposite). In Cryptocercus this curvature of L4K is missing. 



- In Polyphaga and Cryptocercus L4K bears the insertion of a muscle coming from the 

 left-anterior part of L2 (14 in fig. 132, 155). 14 is missing in Lamproblatta. 



