Kjærandsen (2009) characterized this more vaguely defined species group with some species resembling the species of the trisignata-group. The group is mainly characterized by having subsymmetric (not strongly asymmetric) and usually less prominent, lamellated dorsointernal branch of the male gonostylus, by having straight R4+5 vein (R4+5-bending index 0.86–1.28, 1.1, n = 25, Fig. 3B&D), and by usually having greatly reduced and vestigial median ocellus. Species in this group share the characteristically smooth rounded, whitish apex of the dorsal branch of the gonostylus with the trisignata group, but the hypandrial lobe is more variable, being conic, triangular or enlarged and apically diverging. The ventral branch of the gonostylus is variable, often boot-shaped, with or without characteristically fan-tipped setae ventrally, and the pseudocercus is of variable length. The female terminalia is also variable, with two-segmented cercus retained in two (supposedly primitive) species, and with slender, sclerotized postgenital plate. Kjærandsen & Chandler 2006 suggested a separate subgroup for P. parallela, P. monica and an undescribed species from Burma, based on their smaller size and dull coloration with lack of distinct thoracic stripes. However, when looking at their terminalia in relation to other species, these characters are likely to be a result of parallel evolution. Pending a phylogenetic analysis,P. parallela and P. monica are included in the wider canalicula-group. The canalicula-group is distributed in the Holarctic Region and the included species are: P. altaica, P. aurivernica, P. canalicula, P. monica, P. ovata, P. parallela, and P. ussuriensis (Fig. 1).