As the 1 The four primitive interradial cathammata disappear in the fully formed ephyra and become replaced by sixteen subradial concrescence-areas without any ostia or ring-canal at the margin.
K, M, Mw, Ms, P, R2, ephyra grows in size it gradually takes on the form and structure of the young medusa.
E, Young ephyra just liberated, showing the eight bifurcate arms of the disk ' and the interradial single gastral filaments.
SISYPHUS, in Greek mythology, son of Aeolus and Enarete, and king of Ephyra (Corinth).
The comparison of the metagenetic type of development, such as that of Aurelia, with the more primitive genera of Scyphomedusae, indicates clearly that the scyphistoma and ephyra are recapitulative larval stages which are represented by the adult forms of primitive genera, making such allowances as are necessary when comparing adult and larval forms. The metagenesis has arisen through the scyphistoma-larva acquiring the power of larval proliferation by budding.
The ephyra has a flat, disk-shaped body, with eight marginal lobes (four perradial, four interradial); a tentaculocyst is lodged in a deep notch at the apex of each lobe.
The single ephyra carries the sixteen scyphistoma tentacles, which will atrophy and disappear.
F, Ephyra developing into a medusa by the growth of the adradial regions.