27 



regioning, will be performed with practicability as the main point of interest (the best 

 possible way to explain homology relations). It is in general arbitrary. (The definition of 

 the regions, however, will in some cases be done in correspondence \Vith a concrete 

 division of the respective main sclerite into smaller sclerites in a certain, arbitrarily selected 

 species). Only the more complicated main sclerites will be divided into regions. The small 

 letters are in most cases abbreviations of typical attitudes (e.g. position) of the regions. 

 These abbreviations and the definition of the various regions will be given in the homology 

 discussion of the respective main sclerites (chapter 6.). 



The meaning of a term designating a certain sclerite region, e.g. Rlc, is hence as follows: 

 R 1 c 



a sclerotisation of belonging to being the region c, which 



the Right side, main sclerite 1, takes a rather central position 



In Blattellidae Plectopterinae, some other Blattelhdae, and Blaberidae the phallomere 

 complex is side-reversed (Bohn 1987), being essentially a mirror-image of the phallomere 

 complex of the other Blattarian subgroups. In the terminology for the sclerites, this fact 

 will be taken into account by adding ' at the end of the term. This will be done in the 

 terms for individual sclerites as well as in the terms for sclerite regions. (For example, 

 L4U' is a L4U on a side-reversed phallomere complex, and it is on the right side). This 

 procedure is different from Bohn (1987), who adds ' after the first letter (L4U' would be 

 L'4U), but the meaning is the same. (Of course, since homology should be the basis of 

 the terminology, the left complex will still have this name, if it is, after a reversal of the 

 phallomere complex, on the right side of the body; the same practice will be applied to 

 the right phallomere.) 



4.2. Abbreviations for other sclerites of the postabdomen 



The terminology for the sclerites of the postabdomen is largely pre-set by the earlier 

 literature. Abbreviating is done according to the same principle as in the phallomere 

 sclerites. A capital letter in the first position designates the category (S = sternite; T = 

 tergite; E = sclerotisation of an appendage = extremity). A number in the second position 

 designates the abdominal segment the sclerite belongs to. A small letter in the third position 

 (not obligatory) serves to designate a special region. As discussed in 3.1., there are many 

 problems concerning the correct morphological assignment and designation of postab- 

 dominal sclerotisations. In such problematical cases neutral abbreviations will be used (e.g. 

 Pp = paraproct; Ep = epiproct; all elements of the subgenital plate are called S9 despite 

 the possibility of true appendages being involved). 



4.3. The terminology for the formative elements 



The phallomere complex contains many areas where the cuticular body wall forms 

 pouches, apodemes, tendons, hook-, spine-, tooth-, or lobe-like processes, or comparable 



