 Spores are oblong to spindle @-@ shaped , and are flattened on one side ; they have dimensions of 54 – 68 µm by 10 – 13 µm . The spores each contain 3 – 5 oil drops . Although the spores have been described as smooth in older literature , when viewed with transmission electron microscopy , they are seen to have minute spots or punctures . The spores develop simultaneously ( synchronously ) within the ascus , a developmental feature shared with the Sarcoscyphaceae genera Cookeina and Microstoma . Like other members of the Pezizales order , the asci of C. geaster have an operculum — a " lid " — that opens when the spores are discharged . However , the operculum of C. geaster develops a two @-@ layered ring zone upon dehiscence , making it structurally distinct from members of both the Sarcosomataceae and the Sarcoscyphaceae families . 
