FIG. 5. — Botrylloides crystallinus n. sp.: steps in aestivation: A-C, early phases: zooid regression moves from the base of the colony to its top; D, colony top where all zooids and buds were in regression; the disposition in systems is still visible; E, advanced phase: regressed zooids are reduced to little bodies; F, final phase: colonies appear as gelatinous masses with only tiny whitish ampullae at their surface. Scale bars: 0.5 cm.