20 



complex. The ventromedial! ends of the paratergites TlOp are in most species distinctly 

 articulated with the lateral ends of the paraprocts Pp (articulations A99 in fig.321b,c). 

 Median to the paratergites TlOp and beneath the TlOv-sclerotisation there is on each side 

 a transverse (or oblique) bulge, the subanal lobe (sbl in fig.321b,c). The paraprocts Pp 

 are always present as one pair of sclerites (fig.321b,c). From their lateral ends at the 

 articulations A99 they extend mesad and sclerotise more or less extensive parts of the 

 subanal lobes sbl. Laterally the paraprocts are restricted to the ventral sbl-walls, medially 

 they curve more and more into their dorsal walls (fig.321b,c). Consequently, the posterior 

 parts of the paraprocts are curved upwards and back anteriad, and the paraprocts have a 

 ventral anterior margin and a dorsal anterior margin. (The latter will subsequently be 

 designated as the posterior margin, which is true in a strict morphological sense). The 

 median tips of the subanal lobes (Y in fig.321b,c) lie on both sides of the anus (Af in 

 fig.321c) and are either membranous or also sclerotised by the paraprocts. The median 

 walls of the subanal lobes continue anteriad into the lateral walls of the rectum (Re in 

 fig.321b,c). 



In front of the (ventral) anterior margins of the paraprocts there is often another pair of 

 ribbon-shaped sclerites (Pv in fig. 320, 321b,c). These Pv-sclerites are either completely 

 free (like in fig.321) or connected with the paraprocts laterally. In some species separate 

 Pv-sclerites are missing, and in these cases they seem to have fused to the anterior margins 

 of the paraprocts. 



The membrane anterior to the ventral sclerotisation of tergite 10 (TlOv in fig.321b) is 

 evaginated to form an unpaired supraanal lobe (spl in fig.320, 321b,c), whose ventral wall 

 continues anteriad into the dorsal wall of the rectum (Re in fig. 320, 321b,c). In Mantodea 

 the supraanal lobe bears a sclerotisation in its dorsal wall, the epiproct (Ep in fig.320, 

 321b,c). In many Blattaria the supraanal lobe is still distinct but never has a sclerotisation. 

 In other Blattaria the supraanal lobe is no longer distinct from other small membranous 

 foldings in the anal region, and its presence is questionable. 



Discussion of morphology 



Concerning all these elements, only the assignment of the anterior part of tergite 10 (TIO 

 including TlOp) to abdominal segment 10 and the consideration of the cerci as the 

 appendages of segment 1 1 is generally accepted. Regarding the other elements there are 

 various opinions. Snodgrass (1933, 1936, 1937) regards the cerci and the subanal and 

 supraanal lobes as elements of segment 11, the paraprocts being the medially divided 

 sternite and the epiproct being the tergite of segment 11. Sternite 10 is assumed to be 

 missing, tergite 10 is the true tergite 10, with no other elements incorporated, and the 

 telson is only a small membranous ring surrounding the anus. Chopard (1917), Walker 

 (1922), and Ford (1923) differ from Snodgrass only in assuming a participation of sternite 

 10 within the anterior margins of the paraprocts. This is said to be indicated by the 

 articulations between the paraprocts and the paratergites of segment 10 (A99 in fig.321b,c) 

 and by some muscle insertions. In complete contrast to these authors, Heymons (1895) 

 and Matsuda (1976) consider segment 11 as strongly reduced - the cerci being its only 

 persisting products - and regard the subanal lobes and the paraprocts as well as the 



