English: Acrothoracica. A, B, examples of naupliar and cypris larval morphology of Acrothoracica. C, live corals, Leptatstrea, with the colour-valved Berndtia. D, most acrothoracican species live in gastropod shells, making slit-like burrows. Inserts show the burrows made by the barnacles (upper right) and a specimen in its burrow with extended cirri (lower left). E, Berndtia purpurea extending its cirri from the burrow inside the live tissue of the coral Leptastrea host. F Schematic diagram showing Trypetesa living in the columella of gastropod shells, showing the slit-like burrow opening. G, magnified view of columella of shell, showing the slit-like opening of the Trypetesa burrow. H, the dwarf male of Berndtia utinomii.