title: An ultrastructural study on spicule formation in the pennatulid colony Renilla reniformis.
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis; D003063:Cnidaria / Q000648:ultrastructure*; D003460:Crystallization; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D014961:X-Ray Diffraction
chemical_list: D002118:Calcium