Tiny and degenerate, having several vestigial features, and
ephemeral; lacking mouth, manubrium and stomach [Orthopyxis
integra ]. Umbrella bell-shaped, higher than wide; jelly fairly
thick; velum broad, more than 1/2 bell radius. Four narrow
radial canals, either meeting at apex or each closing before
they meet; each with one irregularly-lobed sac-like outgrowth
midway along each side; ring canal narrow. Gonads on lobes of
radial canal outgrowths [O.integra-habitus ]. No marginal
tentacles or cirri; eight adradial marginal vesicles each with
one concretion. Sexually mature on release; swimming actively
but probably living for less than a week; assumed not to feed.
Limited evidence, from the two colonies studied, suggested that
medusae of either sex are sometimes retained on the colony and
not released, reportedly under environmental influence (Stefani,
1956; Stefani, 1959). Umbrella ca 1 mm high. Radial canal
outgrowths and marginal bulbs dark brown; with brown pigments in
radial and ring canals. (After Corn