Dorsoventral discrepancies in millipedes (Myriapoda: Diplopoda). (A) Dorsal view of a female Glomeris marginata, anterior to the top. This species has twelve tergites. (B) Ventral view of a female Glomeris marginata. This view reveals the presence of 17 pairs of trunk legs. Also note the lateral pleurites, which are not fused to the tergites or sternites. This species does not form exoskeletal rings. (C) A generalized juliform diplopod, lateral aspect, anterior to the left. In this diplopod group sternites, pleurites and tergites are fused into rigid armour rings, which give the trunk its annulated ("segmented") appearance. Only the first tergite, the neck-shield or collum, is free, i.e. not fused to any other component. Note that the first three armour rings bear a single pair of legs, whereas all following rings have two leg-pairs each. A and B are drawn after specimens preserved in methanol. C has been modified and simplified from .