| Abstract: | Scoleces of two dilepidid genera, Kowalewskiella Baczynska, 1914 and Himantaurus Spasskaja et Spassky, 1971, were investigated. The rostellar hooks of both are of davaineoid type, which is quite uncommon for the family. The morphology of their rostellar apparatus, especially the form of proboscis, differs much. But when the rostellum is retracted, the crown of hooks is folded in the same manner: hooks tips assume anterior direction. The muscular system of rostellar apparatus and the transformation of scolex in the act of rostellum's retraction of Kowalewskiella finds close analogy in Aploparaksis (family Hymenolepididae s.l.), and of Himantaurus--in Paradilepis (family Dilepididae). But such morphological and functional resemblance between scoleces of Kowalewskiella and Aploparaksis from one side and of Himantaurus and Paradilepis from another is undoubtedly a result of convergence. The morphological types of rostellar hooks in these pairs of genera are very different. |
